FACT - Status and experience from five years of operation of the first G-APD Cherenkov Telescope

Science.gov (United States)

Neise, D.; Adam, J.; Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Brügge, K. A.; Buss, J.; Dmytriiev, A.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Linhoff, L.; Mannheim, K.; Müller, S.; Neronov, A.; Nöthe, M.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Walter, R.

2017-12-01

The First G-APD Cherenkov Telescope (FACT) demonstrates the usability of novel Geiger-mode operated Avalanche Photo Diodes (G-APD, often called SiPM) for Imaging Atmospheric Cherenkov Telescopes (IACT). The camera consists of 1440 pixels with dedicated electronics operating at 2 Giga samples per second. It is installed on the refurbished HEGRA telescope with a mirror area of ≈ 9.5m2 on the Canary Island La Palma. FACT is taking data almost every night since the camera was installed in October 2011. It was possible to improve the data taking efficiency to very high values due to the very stable and reliable operation. This also allows to operate FACT remotely without any need for operators on site. Even remote human intervention became less and less frequent over the years, allowing operation to become mostly automatic. FACT is monitoring the long-term behavior of some very-high energy variable extra-galactic sources with unparalleled sampling density as well as testing the behavior of the sensors under severe weather conditions. Due to the long exposure of FACT's G-APDs under strong moonlight conditions it was possible to evaluate the aging effects of G-APDs due to collected charge. No indication of aging was found. No external calibration device is needed to operate FACT since the properties of the sensors themselves allow for a high precision self-calibration of the camera.

Conventional blood conservation techniques in 500 consecutive coronary artery bypass operations.

Science.gov (United States)

Ovrum, E; Holen, E A; Abdelnoor, M; Oystese, R

1991-09-01

With use of a nonpharmacological, simple, and inexpensive program for blood conservation, 500 consecutive patients underwent elective coronary artery bypass grafting without need of homologous red cell transfusions in 493 (98.6%). At least one internal mammary artery was grafted in all but 1 patient, with supplemental saphenous vein grafts. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of extracorporeal circulation. The volume remaining in the oxygenator and tubing set was returned without cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the heart-lung machine, autotransfusion of the shed mediastinal blood was continued hourly up to 18 hours after operation. The mean postoperative mediastinal blood loss was 643 +/- 354 mL, whereas 624 +/- 296 mL was autotransfused. Thirteen patients (2.6%) needed reexploration for bleeding, of whom 7 (7/500, 1.4%) received homologous blood. No other patients required red cell transfusions. In addition, 9 patients were given a mean of 2.6 units of fresh frozen plasma because of suspected coagulopathy. No platelets were transfused, and no cryoprecipitate therapy was undertaken. Thus, in total, 484 patients (96.8%) were not exposed to any homologous blood products during the hospital stay. At discharge, the mean hemoglobin concentration was 121 +/- 14 g/L (12.1 +/- 1.4 g/dL) and the hematocrit, 0.36 +/- 0.04. Postoperative complications were few. There was one in-hospital death (0.2%).

Heart bypass surgery

Science.gov (United States)

Off-pump coronary artery bypass; OPCAB; Beating heart surgery; Bypass surgery - heart; CABG; Coronary artery bypass graft; Coronary artery bypass surgery; Coronary bypass surgery; Coronary artery disease - CABG; CAD - CABG; Angina - ...

Gut hormones and gastric bypass

DEFF Research Database (Denmark)

Holst, Jens J.

2016-01-01

Gut hormone secretion in response to nutrient ingestion appears to depend on membrane proteins expressed by the enteroendocrine cells. These include transporters (glucose and amino acid transporters), and, in this case, hormone secretion depends on metabolic and electrophysiological events elicited...... that determines hormone responses. It follows that operations that change intestinal exposure to and absorption of nutrients, such as gastric bypass operations, also change hormone secretion. This results in exaggerated increases in the secretion of particularly the distal small intestinal hormones, GLP-1, GLP-2......, oxyntomodulin, neurotensin and peptide YY (PYY). However, some proximal hormones also show changes probably reflecting that the distribution of these hormones is not restricted to the bypassed segments of the gut. Thus, cholecystokinin responses are increased, whereas gastric inhibitory polypeptide responses...

Variations in dietary intake after bypass surgery for obesity. Possible relation to development of fatty liver after jejunoileal bypass

International Nuclear Information System (INIS)

Rogus, J.; Blumenthal, S.A.

1981-01-01

Consumption of nutrients and food energy was compared, with concomitant chemical and radiologic measurements of hepatic fat content, preoperatively and postoperatively in 25 patients who underwent gastric or jejunoileal bypass for obesity. Patients in the two operative groups ingested similar quantities of food before surgery. After surgery, caloric intake from all sources decreased in both groups but to a significantly greater extent in the gastric bypass patients. During the first six months postoperatively, the 13 gastric bypass patients showed no changes in hepatic fat content, whereas substantial increases in liver fat uniformly occurred in the 12 patients who had jejunoileal bypasses. It is suggested that dietary carbohydrate may have contributed to the accretion of liver fat in these 12 patients

Nutrient deficiency and obstetrical outcomes in pregnant women following Roux-en-Y gastric bypass

DEFF Research Database (Denmark)

Hammeken, Lianna Hede; Betsagoo, Ramsina; Jensen, Ann Nygaard

2017-01-01

OBJECTIVE: Roux-en-Y gastric bypass surgery and small-for-gestational-age births are known to be associated although the etiology is not fully understood. This study aimed to investigate pregnancy outcomes and maternal nutritional status among pregnant women with a history of Roux-en-Y gastric...... obstetric clinic at Aalborg University Hospital in Denmark and gave birth between 1 January 2010 and 31 December 2013 were included. Each Roux-en-Y-gastric-bypass-operated woman was closely matched with a non-Roux-en-Y-gastric-bypass-operated woman. Primary outcomes were small-for-gestational-age birth.......169) between women with a history of Roux-en-Y gastric bypass (11.51kg±8.97 standard deviation (SD)) and non- Roux-en-Y-gastric-bypass-operated women (12.18kg±6.28 SD). CONCLUSION: A history of Roux-en-Y gastric bypass surgery increases the risk of small-for-gestational-age birth and anemia, while a finding...

Economic consequences of extra by-passes in district heating networks. Investment-, running- and maintenance costs

International Nuclear Information System (INIS)

Herbert, P.

1995-02-01

For various reasons, extra by-passes are installed in district heating networks to ensure a high flow temperature when the water circulation is insufficient. By 'extra by-pass' we here mean a connection between the distribution pipe and the return pipe. This study mainly deals with extra by-passes to prevent freezing. The estimation of the extra by-pass costs is based on the district heating rates. Our assumption is that an extra by-pass can be regarded as a substation in the district heating network, with regard to the demand for the water flow, heat and power. The reason is the difficulty to obtain available facts to estimate the real costs concerning extra by-passes. Therefore, the method can not claim that the information about the costs is exact but gives an indication of the size of them. The valves in an extra by-pass can be set more or less open. We assume that manual valves in extra by-passes are wide open. Thermostatic valves are, however, assumed to be adjusted in order to cause a very small water flow. 2 refs, 16 figs, 9 tabs, 6 appendices

Target vessel detection by epicardial ultrasound in off-pump coronary bypass surgery.

Science.gov (United States)

Hayakawa, Masato; Asai, Tohru; Kinoshita, Takeshi; Suzuki, Tomoaki; Shiraishi, Shoichiro

2013-01-01

The detection of embedded coronary arteries is difficult especially in off-pump coronary bypass surgery. From June 2010, we introduced high-frequency epicardial ultrasound (ECUS) to assess and evaluate embedded arteries during off-pump coronary bypass surgery. Between June 2010 and June 2011, a total of 89 consecutive patients underwent isolated coronary bypass surgery at our institution. The patients consisted of 72 men and 17 women with a mean age of 67.9 years. We routinely use the VeriQC system (MediStim, Oslo, Norway) to detect the target vessels in the operation. The patients were assigned to one of two groups, depending on whether ECUS was used in the operation (n = 10, ECUS group) or not (n = 79, non-ECUS group). We analyzed the impact of introducing the ECUS in terms of operative outcome. All patients underwent revascularization using the off-pump technique without emergent conversion to cardiopulmonary bypass during surgery. The total number of distal anastomoses was 299, and 12 target vessels could not be identified either visually or on palpation. Thus, the frequency of the embedded coronary arteries was 4.01% (12/299 cases). The preoperative profiles of the two groups were not significantly different. Operation time was significantly longer in the ECUS group (P = 0.02). There were no significant differences in postoperative outcome between the two groups. In the present study, in which the target coronary arteries could not be detected either visually or on palpation in 12 (4.01%) of 299 cases, the use of high-frequency ECUS allowed all patients to undergo off-pump coronary bypass surgery without conversion to cardiopulmonary bypass during the operation. High-frequency ECUS is therefore useful in off-pump coronary bypass surgery.

Evaluation of waste temperatures in AWF tanks for bypass mode operation of the 702-AZ ventilation system (Project W-030)

International Nuclear Information System (INIS)

Sathyanarayana, K.

1997-01-01

This report describes the results of thermal hydraulic analysis performed to provide data in support of Project W-030 to startup new 702-AZ Primary Ventilation System. During the startup of W-030 system, the ventilation system will be operating in bypass mode. In bypass made of operation, the system is capable of supplying 1000 cfm total flow for all four AWF doubleshell tanks. The design of the W-030 system is based on the assumption that both the recirculation loop of the primary ventilation system and the secondary ventilation which provides cooling would be operating. However, during the startup neither the recirculation system nor the secondary ventilation system will be operating. A minimum flow of 100 cfm is required to prevent any flammable gas associated risk. The remaining 600 cfm flow can be divided among the four tanks as necessary to keep the peak sludge temperatures below the operating temperature limit. For the purpose of determining the minimum flow required for cooling each tank, the thermal hydraulic analysis is performed to predict the peak sludge temperatures in AY/AZ tanks under different ventilation flows. The heat load for AZ farm tanks is taken from characterization reports and for the AY farm tanks, the heat load was estimated by thermal analysis using the measured waste temperatures and the waste liquid evaporation rates. The tank 241-AZ-101 and the tank 241-AZ-102 have heat loads of 241,600 and 199,500 Btu/hr respectively. The tank 241-AY-101 and tank 241-AY-102 have heat loads of 41,000 and 33,000 Btu/hr respectively. Using the ambient meteorological conditions of temperature and relative humidity for the air and tank, some soil surface and the sludge levels reported in recent documents, the peak sludge and supernatant temperatures were predicted for various primary ventilation flows ranging from 100 to 400 cfm for AZ tanks and 100 and 150 cfm for AY tanks. The results of these thermal hydraulic analyses are presented. Based on the

Concomitant coronary artery revascularization and right pneumonectomy without cardiopulmonary bypass

NARCIS (Netherlands)

Hensens, AG; Zeebregts, C.J.A.M.; Liem, TH; Gehlmann, H; Lacquet, LK

Combined coronary artery bypass grafting (CABG) and pneumonectomy has a high morbidity and mortality rate, especially when the right lung has to be removed. A patient is described who underwent a CABG operation through a midline sternotomy without the use of cardiopulmonary bypass (CPB), and a right

It's Indisputable: Five Facts About Planning and Operating Modern Power Systems

Energy Technology Data Exchange (ETDEWEB)

Bloom, Aaron; Helman, Udi; Holttinen, Hannele; Summers, Kate; Bakke, Jordan; Brinkman, Gregory; Lopez, Anthony

2017-11-01

An indisputable fact cannot be rebutted. It is supported by theory and experience. Over the past 25 years, wind and solar generation has undergone dramatic growth, resulting in a variety of experiences that model the integration of wind and solar into the planning and operation of modern electric power systems. In this article, we bring together examples from Europe, North America, and Australia to identify five indisputable facts about planning and operating modern power systems. Taken together, we hope these experiences can help build consensus among the engineering and public policy communities about the current state of wind and solar integration and also facilitate conversations about evolving future challenges.

Effective void fraction for a BWR assembly with boiling in the bypass region

International Nuclear Information System (INIS)

Galperin, A.; Segev, M.; Knoglinger, E.

1991-09-01

Average BWR assembly cross-sections for nominal conditions, namely for zero bypass void, can be utilised in the analysis of transient conditions with boiling in the bypass. A model is developed to yield an effective channel void for such conditions. The use of this void in conjunction with the 'nominal conditions' cross section library approximately preserves the assembly K-infinity corresponding to the true channel and bypass voids. The effective void is an augmentation of the actual channel void. The augment is proportional to the bypass-to-channel volume ratio, to the bypass void, and to a weight W which is introduced to quantify the fact that a water molecule in the bypass has a different assembly criticality worth than one in the channel. The formula developed is superior to the practice of choosing W=1, namely a simple, non-weighted, transfer of water from channel to bypass. The use of this approximate effective channel void reproduces actual K-infinity values of assemblies to better than 5 mk, whereas the use of a simple model sometimes misspredicts the assembly K-infinity by 40 mK. The effective void model cannot handle cases in which both channel and bypass void value are high, simply because then the effective void α ch eff becomes meaningless. A method to treat the α eff >1 domain is developed by which corrections to cross sections are provided. Such corrections are synthesised as functions of the assembly parameters. (author) figs., tabs., refs

Splitting blood and blood product packaging reduces donor exposure for patients undergoing cardiopulmonary bypass.

Science.gov (United States)

Nuszkowski, M M; Jonas, R A; Zurakowski, D; Deutsch, N

2015-11-01

Cardiopulmonary bypass for congenital heart surgery requires packed red cells (PRBC) and fresh frozen plasma (FFP) to be available, both for priming of the circuit as well as to replace blood loss. This study examines the hypothesis that splitting one unit of packed red blood cells and one unit of fresh frozen plasma into two half units reduces blood product exposure and wastage in the Operating Room. Beginning August 2013, the blood bank at Children's National Medical Center began splitting one unit of packed red blood cells (PRBC) and one unit of fresh frozen plasma (FFP) for patients undergoing cardiopulmonary bypass (CPB). The 283 patients who utilized CPB during calendar year 2013 were divided into 2 study groups: before the split and after the split. The principal endpoints were blood product usage and donor exposure intra-operatively and within 72 hours post-operatively. There was a significant decrease in median total donor exposures for FFP and cryoprecipitate from 5 to 4 per case (p = 0.007, Mann-Whitney U-test). However, there was no difference in the volume of blood and blood products used; in fact, there was a significant increase in the amount of FFP that was wasted with the switch to splitting the unit of FFP. We found that modification of blood product packaging can decrease donor exposure. Future investigation is needed as to how to modify packaging to minimize wastage. © The Author(s) 2015.

Cerebroprotective effect of piracetam in patients undergoing coronary bypass burgery.

Science.gov (United States)

Holinski, Sebastian; Claus, Benjamin; Alaaraj, Nour; Dohmen, Pascal Maria; Kirilova, Kremena; Neumann, Konrad; Uebelhack, Ralf; Konertz, Wolfgang

2008-11-01

Reduction of cognitive function is a possible side effect after cardiac surgery using cardiopulmonary bypass. We investigated the cerebroprotective effect of piracetam on cognitive performance in patients undergoing coronary artery bypass surgery under cardiopulmonary bypass. Patients scheduled for elective, primary and isolated coronary bypass surgery were randomised either to piracetam or placebo group. The study was performed in a double blind fashion. Patients received either 12 g piracetam or placebo at the beginning of the operation. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on the third postoperative day. To assess the overall cognitive function and the degree of cognitive decline across all tests after surgery we combined the six test-scores by principal component analysis. A total number of 120 patients were enrolled into the study. Preoperative overall cognitive function were not significantly different between the groups. The postoperative combined score of the neuropsychological tests showed a deterioration of cognitive function in both groups (placebo-pre: -0.06+/-0.99 vs placebo-post: -1.38+/-1.11; ppiracetam-pre: 0.06+/-1.02 vs piracetam-post: -0.65+/-0.93; ppiracetam patients performed significantly better compared to the placebo patients after the operation and had a less decline of overall cognitive function (pPiracetam has a cerebroprotective effect in patients undergoing coronary artery bypass surgery with the use of cardiopulmonary bypass. It reduces an early postoperative substantial decline of neuropsychological abilities.

Complications of Laparoscopic Retroperitoneal Sutureless and Clampless Aortobifemoral Bypass

Directory of Open Access Journals (Sweden)

B. Segers

Full Text Available : Introduction: This report describes our experience with early complications that occurred in two patients who underwent sutureless aortobifemoral bypass using the EndoVascular REtroperitoneoScopic Technique (EVREST. Report: Two patients who underwent EVREST for aortoiliac TASC D lesions experienced a dislocation of the proximal assembly. The first dislocation occurred four hours post-operatively and led to the death of the patient, and the second occurred during surgery and led to open conversion. Conclusion: As a result of these serious complications, we recommend the use of anchorage stitches while using an endograft connector in a sutureless aortobifemoral bypass. Keywords: Early complications, Sutureless, Clampless, Retroperitoneoscopy, Aortobifemoral bypass

The impact of avoiding cardiopulmonary by-pass during coronary artery bypass surgery in elderly patients: the Danish On-pump Off-pump Randomisation Study (DOORS)

DEFF Research Database (Denmark)

Houlind, Kim; Kjeldsen, Bo Juul; Madsen, Susanne Nørgaard

2009-01-01

BACKGROUND: Coronary Artery Bypass Graft operation for ischemic heart disease provides improved quality of life and, in some patients, prolonged survival. Concern has, however, been raised about complications that may be related to the use of cardiopulmonary by-pass (CPB) and aortic cross......-clamping. It has been hypothesized that when coronary artery by-pass grafting is performed without the use of CPB, the rate of serious complications is reduced. METHODS/DESIGN: The trial is designed as an open, randomized, controlled, clinical trial with blinded assessment of end-points. Patients at or above 70...... years of age, referred for surgical myocardial revascularisation, are included and randomised to receive coronary artery by-pass grafting either with or without the use of CPB and aortic cross-clamping. Follow-up is performed by clinical, biochemical, electrocardiographic, and angiographic data...

Replisome-mediated Translesion Synthesis and Leading Strand Template Lesion Skipping Are Competing Bypass Mechanisms*

Science.gov (United States)

Gabbai, Carolina B.; Yeeles, Joseph T. P.; Marians, Kenneth J.

2014-01-01

A number of different enzymatic pathways have evolved to ensure that DNA replication can proceed past template base damage. These pathways include lesion skipping by the replisome, replication fork regression followed by either correction of the damage and origin-independent replication restart or homologous recombination-mediated restart of replication downstream of the lesion, and bypass of the damage by a translesion synthesis DNA polymerase. We report here that of two translesion synthesis polymerases tested, only DNA polymerase IV, not DNA polymerase II, could engage productively with the Escherichia coli replisome to bypass leading strand template damage, despite the fact that both enzymes are shown to be interacting with the replicase. Inactivation of the 3′ → 5′ proofreading exonuclease of DNA polymerase II did not enable bypass. Bypass by DNA polymerase IV required its ability to interact with the β clamp and act as a translesion polymerase but did not require its “little finger” domain, a secondary region of interaction with the β clamp. Bypass by DNA polymerase IV came at the expense of the inherent leading strand lesion skipping activity of the replisome, indicating that they are competing reactions. PMID:25301949

Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

Science.gov (United States)

Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

2011-01-01

NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

Investigation on the Core Bypass Flow in a Very High Temperature Reactor

Energy Technology Data Exchange (ETDEWEB)

Hassan, Yassin

2013-10-22

Uncertainties associated with the core bypass flow are some of the key issues that directly influence the coolant mass flow distribution and magnitude, and thus the operational core temperature profiles, in the very high-temperature reactor (VHTR). Designers will attempt to configure the core geometry so the core cooling flow rate magnitude and distribution conform to the design values. The objective of this project is to study the bypass flow both experimentally and computationally. Researchers will develop experimental data using state-of-the-art particle image velocimetry in a small test facility. The team will attempt to obtain full field temperature distribution using racks of thermocouples. The experimental data are intended to benchmark computational fluid dynamics (CFD) codes by providing detailed information. These experimental data are urgently needed for validation of the CFD codes. The following are the project tasks: • Construct a small-scale bench-top experiment to resemble the bypass flow between the graphite blocks, varying parameters to address their impact on bypass flow. Wall roughness of the graphite block walls, spacing between the blocks, and temperature of the blocks are some of the parameters to be tested. • Perform CFD to evaluate pre- and post-test calculations and turbulence models, including sensitivity studies to achieve high accuracy. • Develop the state-of-the art large eddy simulation (LES) using appropriate subgrid modeling. • Develop models to be used in systems thermal hydraulics codes to account and estimate the bypass flows. These computer programs include, among others, RELAP3D, MELCOR, GAMMA, and GAS-NET. Actual core bypass flow rate may vary considerably from the design value. Although the uncertainty of the bypass flow rate is not known, some sources have stated that the bypass flow rates in the Fort St. Vrain reactor were between 8 and 25 percent of the total reactor mass flow rate. If bypass flow rates are on the

Numerical simulation of an alternative to prevent hydrates formation in a bypass section

Energy Technology Data Exchange (ETDEWEB)

Almeida, Lucilla Coelho; Oliveira Junior, Joao Americo Aguirre; Fonte, Clarissa Bergman [Engineering Simulation and Scientific Software Ltda. (ESSS), Florianopolis, SC (Brazil); Silva, Fabricio Soares da; Moraes, Carlos Alberto Capela [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

2012-07-01

This work presents the use of Computational Fluid Dynamics to evaluate the feasibility of MEG (monoethylene glycol) injection as an alternative to prevent hydrate formation in a bypass section, present in an inlet module of a separation device of a subsea separation system. As the bypass section is open to the main pipeline, MEG will probably be dragged due to secondary flows generated by the main flow stream. The MEG removal rate is estimated, as well as the internal heat transfer between the currents and the heat loss to the external environment in order to estimate the temperature in the equipment. In a first step, the MEG removal was evaluated considering the heat transfer between the liquid phase (composed of water, oil and MEG) and the gas phase as well as the heat transfer by forced convection to the external environment. In a second step, the influence of a thermal insulation layer around the bypass line, reducing the heat loss to the external environment, was studied. Both simulations (with or without thermal insulation) showed the establishment of secondary flows in the open connection between the main line and bypass line, promoting the removal of MEG from the bypass section and enabling other components of the liquid phase and/or gas to enter in the bypass line. This MEG removal is faster when thermal isolation was considered, due to the fact that higher temperatures are established in the bypass, maintaining the liquid phase with lower densities and viscosities. With regard to temperature, the insulation was able to keep higher temperatures at the bypass line than those obtained without insulation, indicating that the combination of MEG injection and thermal insulation may be able to avoid the critical condition for hydrate formation. (author)

Oil Bypass Filter Technology Performance Evaluation - First Quarterly Report

Energy Technology Data Exchange (ETDEWEB)

Zirker, L.R.; Francfort, J.E.

2003-01-31

This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

NMOS-Based Integrated Modular Bypass for Use in Solar Systems (NIMBUS: Intelligent Bypass for Reducing Partial Shading Power Loss in Solar Panel Applications

Directory of Open Access Journals (Sweden)

Pieter Bauwens

2016-06-01

Full Text Available NMOS-based Integrated Modular Bypass for Use in Solar systems (NIMBUS is designed as a replacement for the traditional bypass diode, used in common solar panels. Because of the series connection between the individual solar cells, the power output of a photovoltaic (PV panel will drop disproportionally under partial shading. Currently, this is solved by dividing the PV panel into substrings, each with a diode bypass placed in parallel. This allows an alternative current path. However, the diodes still have a significant voltage drop (about 350 mV, and due to the fairly large currents in a panel, the diodes are dissipating power that we would rather see at the output of the panel. The NIMBUS chip, being a low-voltage-drop switch, aims to replace these diodes and, thus, reduce that power loss. NIMBUS is a smart bypass: a completely stand-alone system that detects the failing of one or more cells and activates when necessary. It is designed for a 100-mV voltage drop under a 5-A load current. When two or more NIMBUS chips are placed in parallel, an internal synchronization circuit ensures proper operation to provide for larger load currents. This paper will elaborate on the operation, design and implementation of the NIMBUS chip, as well as on the first measurements.

A variable current bypass shunt for electromagnets

International Nuclear Information System (INIS)

Berndt, M.M.; Lipari, J.J.

1992-11-01

An IGBT is used to control the current in bypass circuits that vary the relative strength of magnets connected in series. Each circuit consists of a water cooled assembly rated for continuous operation at 70 Volts and 0--50 Amperes DC, with 1 KV insulation between control/monitoring elements and magnets. The circuit operates as a 10KHz PWM switcher that includes filters and transient protection

Quality of intraoperative autologous blood withdrawal used for retransfusion after cardiopulmonary bypass.

Science.gov (United States)

Flom-Halvorsen, Hanne I; Øvrum, Eivind; Øystese, Rolf; Brosstad, Frank

2003-09-01

Intraoperative autologous blood withdrawal protects the pooled blood from the deleterious effects of cardiopulmonary bypass. Following reinfusion after cardiopulmonary bypass, the fresh autologous blood contributes to less coagulation abnormalities and reduces postoperative bleeding and the need for allogeneic blood products. However, few data have been available concerning the quality and potential activation of fresh blood stored at room temperature in the operating room. Forty coronary artery bypass grafting patients undergoing a consistent intraoperative and postoperative autotransfusion protocol had a median of 1,000 mL of autologous blood withdrawn before cardiopulmonary bypass. After heparinization the blood was drained from the venous catheter via venous cannula into standard blood bags and stored in the operating room until termination of cardiopulmonary bypass. Samples for hemostatic and inflammatory markers were taken from the pooled blood immediately before it was returned to the patient. There was some activation of platelets in the stored autologous blood, as measured by an increase of beta-thromboglobulin. Indications of thrombin formation, as assessed by plasma levels of thrombin-antithrombin complex and prothrombin fragment 1.2 were not seen, and there was no fibrinolytic activity. The red blood cells remained intact, indicated by the absence of plasma free hemoglobin. As for the inflammatory response, the levels of the terminal complement complex remained stable, and the cytokines tumor necrosis factor-alpha and interleukin 6 levels were not increased during storage. The complement activation products increased minimally, but remained within normal ranges. Except for slight activation of platelets, there was no indication of coagulation, hemolysis, fibrinolysis, or immunologic activity in the autologous blood after approximately 1 hour of operating room storage. The autologous blood was preserved in a condition of high quality, and retransfusion

Off-pump coronary artery bypass surgery in severe left ventricular dysfunction.

Science.gov (United States)

Azarfarin, Rasoul; Pourafkari, Leili; Parvizi, Rezayat; Alizadehasl, Azin; Mahmoodian, Roghaiyeh

2010-02-01

Our aim was to examine hospital outcomes of coronary artery bypass surgery in patients with and without left ventricular dysfunction, with regard to the surgical technique (off- or on-pump). Between March 2007 and March 2008, 689 consecutive patients underwent isolated first-time coronary artery bypass; 127 had ejection fractions fractions >30% (group 2). Data of preoperative risk profiles and hospital outcomes were collected prospectively. Off-pump operations were performed in 49 (38.6%) patients in group 1 and 196 (34.9%) in group 2. The incidences of infectious, neurologic, and cardiac complications postoperatively were significantly higher in group 1. In multivariate analysis, preoperative ejection fraction operations, but no significant difference in mortality was observed between those undergoing off-pump or conventional surgery in either group. Off-pump surgery helped to limit the increased morbidity rate after coronary bypass in patients with ventricular dysfunction.

MRI: A method to detect minor brain damage following coronary bypass surgery

Energy Technology Data Exchange (ETDEWEB)

Vik, A.; Brubakk, A.O. (Trondheim Univ. (Norway). Dept. of Biomedical Engineering); Rinck, P.A. (Trondheim Univ. (Norway). MR Center); Sande, E.; Levang, O.W. (Trondheim Univ. Hospital (Norway). Dept. of Surgery); Sellevold, O. (Trondheim Univ. Hospital (Norway). Dept. of Anaesthesiology)

1991-10-01

In order to assess the occurrence of minor focal brain lesions after coronary bypass surgery, magnetic resonance imaging (MRI) was used. Nine male patients (age 42-63) with angina pectoris were investigated at 0.5 Tesla. The investigation was performed one to seven weeks prior to the operation and one month after the operation. Before surgery, the images demonstrated more than five high intensity spots in the white matter of the brain in all but two patients. No additional spots were found after operation. This pilot study indicates that it might be difficult to use MRI to detect minor parenchymal lesions after cardiopulmonary bypass surgery. (orig.).

Oil Bypass Filter Technology Performance Evaluation - January 2003 Quarterly Report

Energy Technology Data Exchange (ETDEWEB)

Laurence R. Zirker; James E. Francfort

2003-01-01

This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

Pre-operative high sensitive C-reactive protein predicts cardiovascular events after coronary artery bypass grafting surgery: A prospective observational study

Directory of Open Access Journals (Sweden)

Balciunas Mindaugas

2009-01-01

Full Text Available C-reactive protein is a powerful independent predictor of cardiovascular events in patients with coronary artery disease. The relation between C-reactive protein (CRP concentration and in-hospital outcome, after coronary artery bypass grafting (CABG, has not yet been established. The study aims to evaluate the predictive value of pre-operative CRP for in-hospital cardiovascular events after CABG surgery. High-sensitivity CRP (hs-CRP levels were measured pre-operatively on the day of surgery in 66 patients scheduled for elective on pump CABG surgery. Post-operative cardiovascular events such as death from cardiovascular causes, ischemic stroke, myocardial damage, myocardial infarction and low output heart failure were recorded. During the first 30 days after surgery, 54 patients were free from observed events and 14 developed the following cardiovascular events: 10 (15% had myocardial damage, four (6% had low output heart failure and two (3% suffered stroke. No patients died during the follow-up period. Serum concentration of hs-CRP ≥ 3.3 mg/l (cut-off point obtained by ROC analysis was related to higher risk of post-operative cardiovascular events (36% vs 6%, P = 0.01, myocardial damage (24% vs 6%, P = 0.04 and low output heart failure (12% vs 0%, P = 0.04. Multivariate logistic regression analysis showed that hs-CRP ≥ 3.3 mg/l ( P = 0.002, O.R.: 19.3 (95% confidence interval (CI 2.9-128.0, intra-operative transfusion of red blood cells ( P = 0.04, O.R.: 9.9 (95% C.I. 1.1-85.5 and absence of diuretics in daily antihypertensive treatment ( P = 0.02, O.R.: 15.1 (95% C.I. 1.4-160.6 were independent predictors of combined cardiovascular event. Patients having hs-CRP value greater or equal to 3.3 mg/l pre-operatively have an increased risk of post-operative cardiovascular events after on pump coronary artery bypass grafting surgery.

Analysis of the force exercised in pipes by accumulation of water in the head stock of turbine bypass

International Nuclear Information System (INIS)

Cecenas F, M.; Ovando C, R.; Campos G, R. M.

2011-11-01

The head stock and valves of turbine bypass allow canalize the main vapor coming from the reactor toward the condenser, without carrying out work in the turbo-generator. In this work is assumed that is accumulates condensed in the head stock during a time period in which the bypass system does not operate. For operation maneuvers, the opening of the bypass is demanded, for what the accumulated water is suddenly dragged by the vapor to high pressure coming from the reactor toward the condenser, which operates to inferior pressures to the atmospheric. The generated flow produces a mechanical effort in the lines and its supports. By means of the RELAP5 code the bypass system is modeled, the discharge transitory to the condenser is simulated and the speeds of the mixture water/vapor are calculated. Processing the exit of RELAP5 the mechanical effort that is subjected the pipe is calculated, and the study is complemented with a sensibility analysis to the quantity of stored water in the volume of the bypass head stock. (Author)

Pancreatic and Intestinal Function Post Roux-en-Y Gastric Bypass Surgery for Obesity

DEFF Research Database (Denmark)

O'Keefe, Stephen J D; Rakitt, Tina; Ou, Junhai

2017-01-01

OBJECTIVES: Despite the fact that the most effective treatment for morbid obesity today is gastric bypass surgery, some patients develop life-threatening nutritional complications associated with their weight loss. METHODS: Here we examine the influence of the altered anatomy and digestive...... physiology on pancreatic secretion and fat absorption. Thirteen post Roux-en-Y gastric bypass (RYGB) patients who had lost >100 lbs in the first year following surgery and who gave variable histories of gastrointestinal (GI) dysfunction, were selected for study. Food-stimulated pancreatic enzyme secretion...... balance study when a normal diet was given containing ~100 g fat/d. RESULTS: Result showed that all patients had some fat malabsorption, but eight had coefficients of fat absorption associated with significantly lower feed-stimulated secretion rates of trypsin...

Cardiopulmonary bypass in pregnancy.

Science.gov (United States)

Kapoor, Mukul Chandra

2014-01-01

Cardiac surgery carried out on cardiopulmonary bypass (CPB) in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women. Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB. The CPB is associated with utero-placental hypoperfusion due to a number of factors, which may translate into low fetal cardiac output, hypoxia and even death. Better maternal and fetal outcomes may be achieved by early pre-operative optimization of maternal cardiovascular status, use of perioperative fetal monitoring, optimization of CPB, delivery of a viable fetus before the operation and scheduling cardiac surgery on an elective basis during the second trimester.

Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Zahra S Faritous

2011-01-01

Full Text Available Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG, 31 women needed prolonged mechanical ventilation (PMV, and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG.

Coronary Bypass Surgery in a 105-Year-Old Patient with Cardiopulmonary Bypass

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Temucin Noyan Ogus

2010-01-01

Full Text Available Coronary artery bypass grafting is one of the routine daily surgical procedures in the current era. Parallel to the increasing life expectancy, cardiac surgery is commonly performed in octogenarians. However, literature consists of only seldom reports of coronary artery bypass grafting in patients above 90 years of age. In this report, we present our management strategy in a 105-year-old patient who underwent coronary artery bypass grafting at our institution.

Your diet after gastric bypass surgery

Science.gov (United States)

Gastric bypass surgery - your diet; Obesity - diet after bypass; Weight loss - diet after bypass ... You had gastric bypass surgery. This surgery made your stomach smaller by closing off most of your stomach with staples. It changed the way your ...

Gastric bypass: why Roux-en-Y? A review of experimental data.

Science.gov (United States)

Collins, Brendan J; Miyashita, Tomoharu; Schweitzer, Michael; Magnuson, Thomas; Harmon, John W

2007-10-01

To highlight the clinical and experimental rationales that support why the Roux-en-Y limb is an important surgical principle for bariatric gastric bypass. We reviewed PubMed citations for open Roux-en-Y gastric bypass (RYGBP), laparoscopic RYGBP, loop gastric bypass, chronic alkaline reflux gastritis, and duodenoesophageal reflux. We reviewed clinical and experimental articles. Clinical articles included prospective, retrospective, and case series of patients undergoing RYGBP, laparoscopic RYGBP, or loop gastric bypass. Experimental articles that were reviewed included in vivo and in vitro models of chronic duodenoesophageal reflux and its effect on carcinogenesis. No formal data extraction was performed. We reviewed published operative times, lengths of stay, and anastomotic leak rates for laparoscopic RYGBP and loop gastric bypass. For in vivo and in vitro experimental models of duodenoesophageal reflux, we reviewed the kinetics and potential molecular mechanisms of carcinogenesis. Recent data suggest that laparoscopic loop gastric bypass, performed without the creation of a Roux-en-Y gastroenterostomy, is a faster surgical technique that confers similarly robust weight loss compared with RYGBP or laparoscopic RYGBP. In the absence of a Roux limb, the long-term effects of chronic alkaline reflux are unknown. Animal models and in vitro analyses of chronic alkaline reflux suggest a carcinogenic effect.

75 FR 71145 - San Joaquin River Restoration Program: Reach 4B, Eastside Bypass, and Mariposa Bypass Channel and...

Science.gov (United States)

2010-11-22

..., Eastside Bypass, and Mariposa Bypass Channel and Structural Improvements Project, Merced County, CA AGENCY... on the effects of the proposed Reach 4B, Eastside Bypass, and Mariposa Bypass Channel and Structural... Mariposa Bypass with the San Joaquin River (generally referred to as Reach 4B1). The improvements will...

[Coronary artery bypass surgery: methods of performance monitoring and quality control].

Science.gov (United States)

Albert, A; Sergeant, P; Ennker, J

2009-10-01

The strength of coronary bypass operations depends on the preservation of their benefits regarding freedom of symptoms, quality of life and survival, over decades. Significant variability of the results of an operative intervention according to the hospital or the operating surgeon is considered a weakness in the procedure. The external quality insurance tries to reach a transparent service providing market through hospital ranking comparability. Widely available information and competition will promote the improvement of the whole quality. The structured dialog acts as a control instrument for the BQS (Federal Quality Insurance). It is launched in case of deviations from the standard references or statistically significant differences between the results of the operations in any hospital and the average notational results. In comparison to the external control the hospital internal control has greater ability to reach a medically useful statement regarding the results of the treatment and to correct the mistakes in time. An online information portal based on a departmental databank (DataWarehouse, DataMart) is an attractive solution for the physician in order to get transparently and timely informed about the variability in the performance.The individual surgeon significantly influences the short- and long-term treatment results. Accordingly, selection, targeted training and performance measurements are necessary.Strict risk management and failure analysis of individual cases are included in the methods of internal quality control aiming to identify and correct the inadequacies in the system and the course of treatment. According to the international as well as our own experience, at least 30% of the mortalities after bypass operations are avoidable. A functioning quality control is especially important in minimally invasive interventions because they are often technically more demanding in comparison to the conventional procedures. In the field of OPCAB surgery

The Best Bypass Surgery Trial

DEFF Research Database (Denmark)

Møller, Christian H; Jensen, Birte Østergaard; Gluud, Christian

2007-01-01

Recent trials suggest that off-pump coronary artery bypass grafting (OPCAB) reduces the risk of mortality and morbidity compared with conventional coronary artery bypass grafting (CCAB) using cardiopulmonary bypass. Patients with a moderate- to high-risk of complications after CCAB may have...

A case report and brief review of the literature on bilateral retinal infarction following cardiopulmonary bypass for coronary artery bypass grafting

Directory of Open Access Journals (Sweden)

Trethowan Brian A

2011-11-01

Full Text Available Abstract Postoperative visual loss is a devastating perioperative complication. The commonest aetiologies are anterior ischaemic optic neuropathy (AION, posterior ischaemic optic neuropathy (PION, and central retinal artery occlusion (CRAO. These appear to be related to certain types of operation, most commonly spinal and cardiac bypass procedures; with the rest divided between: major trauma causing excessive blood loss; head/neck and nasal or sinus surgery; major vascular procedures (aortic aneurysm repair, aorto-bifemoral bypass; general surgery; urology; gynaecology; liposuction; liver transplantation and duration of surgery. The non-surgical risk factors are multifactorial: advanced age, prolonged postoperative anaemia, positioning (supine v prone, alteration of venous drainage of the retina, hypertension, smoking, atherosclerosis, hyperlipidaemia, diabetes, hypercoagulability, hypotension, blood loss and large volume resuscitation. Other important cardiac causes are septic emboli from bacterial endocarditis and emboli caused by atrial myxomata. The majority of AION cases occur during CPB followed by head/neck surgery and prone spine surgery. CPB is used to allow coronary artery bypass grafting on a motionless heart. It has many side-effects and complications associated with its use and we report here a case of bilateral retinal infarction during routine coronary artery bypass grafting in a young male patient with multiple risk factors for developing this complication despite steps to minimise its occurrence.

Optimal Bypass and Cream Skimming.

OpenAIRE

Laffont, Jean-Jacques; Tirole, Jean

1990-01-01

This paper develops a normative model of regulatory policy toward bypass and cream skimming. It analyzes the effects of bypass on second-degree price discrimination, on the rent of the regulated firm, and on the welfare of low-demand customers. It shows that pricing under marginal cost may be optimal for the regulated firm, excessive cream skimming occurs if access to the bypass technology is not regulated, and the prohibition of bypass may increase or decrease the regulated firm's rent. Copy...

Economic consequences of extra by-passes in district heating networks. Investment-, running- and maintenance costs; Rundgaangars ekonomiska betydelse foer fjaerrvaermenaeten. Investerings-, drift- och underhaallskostnader

Energy Technology Data Exchange (ETDEWEB)

Herbert, P. [AaF-Energikonsult Stockholm AB, (Sweden)

1995-02-01

For various reasons, extra by-passes are installed in district heating networks to ensure a high flow temperature when the water circulation is insufficient. By `extra by-pass` we here mean a connection between the distribution pipe and the return pipe. This study mainly deals with extra by-passes to prevent freezing. The estimation of the extra by-pass costs is based on the district heating rates. Our assumption is that an extra by-pass can be regarded as a substation in the district heating network, with regard to the demand for the water flow, heat and power. The reason is the difficulty to obtain available facts to estimate the real costs concerning extra by-passes. Therefore, the method can not claim that the information about the costs is exact but gives an indication of the size of them. The valves in an extra by-pass can be set more or less open. We assume that manual valves in extra by-passes are wide open. Thermostatic valves are, however, assumed to be adjusted in order to cause a very small water flow. 2 refs, 16 figs, 9 tabs, 6 appendices

Cardiopulmonary bypass in pregnancy

Directory of Open Access Journals (Sweden)

Mukul Chandra Kapoor

2014-01-01

Full Text Available Cardiac surgery carried out on cardiopulmonary bypass (CPB in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women. Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB. The CPB is associated with utero-placental hypoperfusion due to a number of factors, which may translate into low fetal cardiac output, hypoxia and even death. Better maternal and fetal outcomes may be achieved by early pre-operative optimization of maternal cardiovascular status, use of perioperative fetal monitoring, optimization of CPB, delivery of a viable fetus before the operation and scheduling cardiac surgery on an elective basis during the second trimester.

Evaluation of retrospectively ECG-gated 4-row multidetector CT in patients planned for minimal invasive coronary artery bypass grafting; Die EKG-getriggerte 4-Zeilen-Spiral-CT des Herzens in der praeoperativen Bildgebung vor minimalinvasiver koronarer Bypass-Operation

Energy Technology Data Exchange (ETDEWEB)

Begemann, P.G.C.; Ittrich, H.; Koops, A.; Adam, G.; Weber, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Radiologisches Zentrum, Universitaetsklinikum, Hamburg (Germany); Arnold, M.; Detter, C.; Boehm, D.H.; Reichenspurner, H. [Universitaetsklinikum Hamburg-Eppendorf, Herzzentrum, Herz und Gefaesschirurgie, Hamburg (Germany)

2005-08-01

Purpose: Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography. Material and methods: The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), coursek of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings. Results: All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and

Preoperative Scale to Determine All-Cause Readmission After Coronary Artery Bypass Operations.

Science.gov (United States)

Zywot, Aleksander; Lau, Christine S M; Glass, Nina; Bonne, Stephanie; Hwang, Franchesca; Goodman, Koren; Mosenthal, Anne; Paul, Subroto

2018-04-01

Coronary artery bypass graft (CABG) operations are associated with all-cause readmission rates of approximately 15%. In attempts to reduce readmission rates, the Hospital Readmission Reduction Program expanded to include CABG operations in 2015. The aim of this study was therefore to develop a predictive readmission scale that would identify patients at higher risk of readmission after CABG using commonly available administrative data. Data of 126,519 patients from California and New York (derivation cohort) and 94,318 patients from Florida and Washington (validation cohort) were abstracted from the State Inpatient Database (2006 to 2011). The readmission after CABG scale was developed to predict 30-day readmission risk and was validated against a separate cohort. Thirty-day CABG readmission rates were 23% in the derivation cohort and 21% in the validation cohort. Predictive factors included older age, female gender (odds ratio [OR], 1.34), African American ethnicity (OR, 1.13), Medicare or Medicaid insurance, and comorbidities, including renal failure (OR, 1.56) and congestive heart failure (OR, 2.82). These were independently predictive of increased readmission rates (p readmission scale was then created with these preoperative factors. When applied to the validation cohort, it explained 98% of the readmission variability. The readmission after CABG scale reliably predicts a patient's 30-day CABG readmission risk. By identifying patients at high-risk for readmission before their procedure, risk reduction strategies can be implemented to reduce readmissions and healthcare expenditures. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Mini-cardiopulmonary bypass impact on blood conservation strategy in coronary artery bypass grafting.

Science.gov (United States)

Abdel Aal, Mohamed; ElNahal, Nezar; Bakir, Bakir Moustafa; Fouda, Mohamed

2011-04-01

Cardiopulmonary bypass (CPB) using a closed circuit system with minimal priming volume can be a solution to ameliorate adverse effects of CPB. We hypothesize that the use of mini-bypass in routine coronary artery bypass grafting (CABG) reduces homologous blood product use and postoperative bleeding. The study is designed to determine the differences in blood loss and transfusion requirements associated with a minimized CPB circuit vs. a standard bypass circuit. From February 2009 to August 2009, 80 patients were prospectively randomized to undergo elective CABG. Group A included 40 patients who had the minimized bypass circuit (Medtronic Resting Heart Circuit). Group B had an equal number of patients who had the standard CPB circuit (Stockert III, SEC.BM). Laboratory parameters for hemoglobin, hematocrit and platelet count were measured at baseline after initiation of CPB and after bypass. Blood usage was controlled by study-specific protocol (transfusion for hemoglobin platelets (1.95±2.95 units vs. 3.23±2.85), and postoperative drainage in 24 hours (531.62±220.12 ml vs. 729±294.9 ml, P<0.05). The hematocrit was 33±5% in group A, and 27±1% in group B. There was statistical differences seen in the mean hemoglobin level which was 10.19±0.65 g/dl in group A, and 9.4±0.68 g/dl in group B. There was statistical difference in the duration of ventilation, length of ICU stay. The requirement of inotropic support was lower in group A. The adoption of mini-bypass significantly reduces morbidity including donor blood usage and postoperative bleeding in routine CABG patients.

An animal model for instructing and the study of in situ arterial bypass.

Science.gov (United States)

Saifi, J; Chang, B B; Paty, P S; Kaufman, J; Leather, R P; Shah, D M

1990-11-01

A canine model that used the cephalic vein to bypass from the brachial to the ulnar artery was designed for use in instructing and evaluating surgical technique needed for constructing an in situ arterial bypass. This model was used for instructing vascular residents in the in situ vein bypass technique. The use of this model enabled the resident to become more adept with the instruments for valve incision and construction of small vessel anastomosis. The improvement in the resident's operative technique was reflected by a decrease in the number of technical complications (missed valves, missed arteriovenous fistulas, poorly constructed anastomoses) and improved patency rate.

Distal anastomotic vein adjunct usage in infrainguinal prosthetic bypasses.

Science.gov (United States)

McPhee, James T; Goodney, Philip P; Schanzer, Andres; Shaykevich, Shimon; Belkin, Michael; Menard, Matthew T

2013-04-01

Single-segment saphenous vein remains the optimal conduit for infrainguinal revascularization. In its absence, prosthetic conduit may be used. Existing data regarding the significance of anastomotic distal vein adjunct (DVA) usage with prosthetic grafts are based on small series. This is a retrospective cohort analysis derived from the regional Vascular Study Group of New England as well as the Brigham and Women's hospital database. A total of 1018 infrainguinal prosthetic bypass grafts were captured in the dataset from 73 surgeons at 15 participating institutions. Propensity scoring and 3:1 matching was performed to create similar exposure groups for analysis. Outcome measures of interest included: primary patency, freedom from major adverse limb events (MALEs), and amputation free survival at 1 year as a function of vein patch utilization. Time to event data were compared with the log-rank test; multivariable Cox proportional hazard models were used to evaluate the adjusted association between vein cuff usage and the primary end points. DVA was defined as a vein patch, cuff, or boot in any configuration. Of the 1018 bypass operations, 94 (9.2%) had a DVA whereas 924 (90.8%) did not (no DVA). After propensity score matching, 88 DVAs (25%) and 264 no DVAs (75%) were analyzed. On univariate analysis of the matched cohort, the DVA and no DVA groups were similar in terms of mean age (70.0 vs 69.0; P = .55), male sex (58.0% vs 58.3%; P > .99), and preoperative characteristics such as living at home (93.2% vs 94.3%; P = .79) and independent ambulatory status (72.7% vs 75.7%; P = .64). The DVA and no DVA groups had similar rates of major comorbidities such as hypertension chronic obstructive pulmonary disease, diabetes mellitus, coronary artery disease, and dialysis dependence (P > .05 for all). Likewise, they had similar rates of distal origin grafts (13.6% vs 12.5%; P = .85), critical limb ischemia indications (P = .53), and prior arterial bypass (58% vs 47%; P = .08

The Fabulous Fact Fan.

Science.gov (United States)

Couch, Jene P.

1994-01-01

Discusses the use and construction of "fact fans," fun and easy-to-make manipulatives that provide elementary school students with the opportunity to explore mathematics operations being studied in the classroom and to practice addition, subtraction, multiplication, and division facts. (BB)

Analysis of operations and cyber security policies for a system of cooperating Flexible Alternating Current Transmission System (FACTS) devices.

Energy Technology Data Exchange (ETDEWEB)

Phillips, Laurence R.; Tejani, Bankim; Margulies, Jonathan; Hills, Jason L.; Richardson, Bryan T.; Baca, Micheal J.; Weiland, Laura

2005-12-01

Flexible Alternating Current Transmission Systems (FACTS) devices are installed on electric power transmission lines to stabilize and regulate power flow. Power lines protected by FACTS devices can increase power flow and better respond to contingencies. The University of Missouri Rolla (UMR) is currently working on a multi-year project to examine the potential use of multiple FACTS devices distributed over a large power system region in a cooperative arrangement in which the FACTS devices work together to optimize and stabilize the regional power system. The report describes operational and security challenges that need to be addressed to employ FACTS devices in this way and recommends references, processes, technologies, and policies to address these challenges.

The Application of Advanced Technique of Fan Frame Unit on High Bypass Ratio Aero Engine

Directory of Open Access Journals (Sweden)

Hou Peng

2017-01-01

Full Text Available High bypass ratio aero-engine was widely used on military and civil aviation domain, as the power of larger aircraft. Fan frame unit was the main bearing frame of high bypass ratio aero-engine, which composed of strut, HUB MID BOX and external bypass parts. Resin/composite was used on external bypass parts(acoustic liner, containment ring, fan outlet guide vane and fan case skin fillets, which not only reduced the weight and manufacturing cost, but also improved the noise absorption, containment and anti-fatigue ability of engine. The design of composite was becoming a key technique for high bypass ratio aero-engine. In special test of the core engine, nitrogen cooling system was designed to cool the cavity of spool. The nitrogen pipeline passed through the inner cavity of fan frame, then inserted into NO. 3 bearing seal, so nitrogen gas was sent into the cavity of core engine spool. On high bypass ratio aero-engine, the external bypass and fan frame inner cavity were the design platform for advanced technique, such as composite and pipeline system, and also provided guarantee for reliable operation of engine.

Mechanism for esophagus-jejunum stent bypass in the treatment of type 2 diabetes mellitus

Directory of Open Access Journals (Sweden)

Suo-lin FU

2012-09-01

Full Text Available Objective　To observe the effect of endoscopic esophagus-jejunum covered stent bypass on the treatment of type 2 diabetes mellitus (T2DM, and analyze the mechanism thereof. Methods　Five obese Beagle dog models of T2DM underwent endoscopic esophagus-jejunum covered stent bypass to serve as operation group, and five normal Beagle dogs as control group receive endoscopy and exploratory laparotomy. The T2DM indices of both groups, including fast plasma glucose (FPG level, fast insulin (FINS level, intravenous glucose tolerance test-2h plasma glucose (IVGTT-2h PG and IVGTT-2h FINS, were determined regularly before operation and 4, 8 and 12 weeks after operation. The insulin resistance index (HOMA-IR and the function of islet β-cell (HOMA-β were calculated with Homeostasis Model Assessment. The levels of gastric inhibitory polypeptide (GIP and glucagon-like peptide-1(GLP-1 were also determined. Results　Four weeks after operation, FPG, FINS, IVGTT-2h PG, and IVGTT-2h FINS all decreased significantly in operation group (P 0.05. The HOMA-IR index declined distinctly and HOMA-β index ascended obviously in operation group 4 weeks after operation (P 0.05. The level of GIP lowered significantly (P 0.05. Conclusion　T2DM may be treated with esophagus-jejunum covered stent bypass effectively and safely, and the mechanism thereof might be related to the changes in gastrointestinal hormones.

Fuel temperature prediction using a variable bypass gap size in the prismatic VHTR

International Nuclear Information System (INIS)

Lee, Sung Nam; Tak, Nam-il; Kim, Min Hwan

2016-01-01

Highlights: • The bypass flow of the prismatic very high temperature reactor is analyzed. • The bypass gap sizes are calculated considering the effect of the neutron fluences and thermal expansion. • The fuel hot spot temperature and temperature profiles are calculated using the variable gap size. • The BOC, MOC and EOC condition at the cycle 07 and 14 are applied. - Abstract: The temperature gradient and hot spot temperatures were calculated in the prismatic very high temperature reactor as a function of the variable bypass gap size. Many previous studies have predicted the temperature of the reactor core based on a fixed bypass gap size. The graphite matrix of the assemblies in the reactor core undergoes a dimensional change during the operation due to thermal expansion and neutron fluence. The expansion and shrinkage of the bypass gaps change the coolant flow fractions into the coolant channels, the control rod holes, and the bypass gaps. Therefore, the temperature of the assemblies may differ compared to those for the fixed bypass gap case. The temperature gradient and the hot spot temperatures are important for the design of reactor structures to ensure their safety and efficiency. In the present study, the temperature variation of the PMR200 is studied at the beginning (BOC), middle (MOC), and end (EOC) of cycles 07 and 14. CORONA code which has been developed in KAERI is applied to solve the thermal-hydraulics of the reactor core of the PMR200. CORONA solves a fluid region using a one-dimensional formulation and a solid region using a three-dimensional formulation to enhance the computational speed and still obtain a reasonable accuracy. The maximum temperatures in the fuel assemblies using the variable bypass gaps did not differ much from the corresponding temperatures using the fixed bypass gaps. However, the maximum temperatures in the reflector assemblies using the variable bypass gaps differ significantly from the corresponding temperatures

Results of The Comparative Study of 200 Cases: One Anastomosis Gastric Bypass vs Roux-en-Y Gastric Bypass.

Science.gov (United States)

Navarrete, Salvador; Leyba, José Luis; Ll, Salvador Navarrete; Borjas, Guillermo; Tapia, José León; Alcázar, Ruben

2018-05-01

Obesity has experienced worldwide increase and surgery has become the treatment that has achieved the best results. Several techniques have been described; the most popular are vertical gastrectomy (GV) and the Roux-en-Y gastric bypass (RYGB). However, mini-gastric bypass/one anastomosis gastric bypass (MGB/OAGB) has gained popularity due to its simplicity and good results. To comparatively evaluate the results of MGB/OAGB with those of RYGB with 1-year follow-up. The paper presents a comparative case and control study of 100 patients that underwent MGB/OAGB surgery and another 100 with RYGB surgery, operated between 2008 and 2016. Patients were not submitted to revision surgery and had the following pre-operative variables: age 40.46 ± 12.4 vs. 39.43 ± 10.33 years; sex 64 and 54 women, 36 and 46 men; BMI 44.8 ± 12.06 and 45.29 ± 8.82 kg/m 2 ; 50 and 54 cases with comorbidities, respectively, these being non-significant differences. The surgical time was 69.01 ± 4.62 (OAGB) vs. 88.98 ± 3.44 min; the time of hospitalization was 2 days, reaching a BMI of 27.7 ± 7.85 and 29 ± 4.52 kg/m 2 , with an excess weight loss 1 year after surgery of 89.4 vs. 85.9%, respectively. The morbidity rates are 9% for OAGB and 11% for the RYGB. There was a comorbidity resolution of 84.4 and 83.7% respectively, without mortality. The results show the benefits of both techniques, OAGB being the easiest to perform and with less surgical time.

Modulation method of scroll compressor based on suction gas bypass

International Nuclear Information System (INIS)

Wang Baolong; Han Linjun; Shi Wenxing; Li Xianting

2012-01-01

The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system. - Highlights: ► Suction gas bypass (SGB) is an effective regulating method of scroll compressor. ► SGB reduces the inner compression loss under over compression conditions. ► SGB largely decreases the heating/cooling capacity of the refrigeration system.

Simultaneous nephrectomy and coronary artery bypass grafting through extended sternotomy

Directory of Open Access Journals (Sweden)

Budrikis Algimantas

2012-08-01

Full Text Available Abstract Background The advances in surgical techniques, resuscitation and anesthesiology support over the last years have allowed simultaneous thoracic and abdominal operations to be made for cancer and concomitant severe heart vessel disease relieving the patient from several diseases simultaneously and achieving long lasting remission or cure. Clinical case A simultaneous nephrectomy and coronary artery bypass grafting procedure through extended sternotomy is reported. A 63-year-old man with severe coronary artery disease was found to have renal carcinoma. Diagnosis Postoperative pathological investigation of the tumor revealed the presence of renal cell carcinoma pT3a N0 M0, G2. Coronarography revealed advanced three-vessel coronary artery disease. Treatment We successfully performed a simultaneous curative surgery for renal carcinoma and coronary artery bypass graft surgery under cardiopulmonary bypass using a novel technique of extended sternotomy. Simultaneous surgery thus appears to be a beneficial and safe approach for the treatment of coronary artery disease and resectable renal cancer in carefully selected patients.

Extra-anatomic bypass for recurrent abdominal aortic and renal in-stent stenoses following radiotherapy for neuroblastoma.

Science.gov (United States)

Luehr, Maximilian; Siepe, Matthias; Beyersdorf, Friedhelm; Schlensak, Christian

2009-04-01

We describe the case of an 11-year-old girl with an abdominal neuroblastoma which was operated and intraoperatively irradiated nine years ago. After six years, she developed stenoses of the infrarenal abdominal aorta and both renal arteries. Initial treatment of the stenosed vessels comprised endovascular balloon dilatations and repeated stent-graft implantations, including drug eluting stents. However, severe in-stent stenoses occurred during follow-up and the girl developed acute renal failure. Open surgery was performed with two extra-anatomic bypasses, a thoracic-to-abdominal aortic bypass and a left iliac-to-renal bypass, on an urgent basis. The postoperative course was uneventful and the patient was discharged home two weeks after the operation with full recovery of renal function. We conclude that endovascular stent-graft placement in children can only be a palliative treatment due to outgrowing of the stent-graft and the potential risk of re-stenosis, especially after a history of irradiation. Vascular surgery with placement of extra-anatomic bypasses will provide a definite treatment.

Flash fluorescence with indocyanine green videoangiography to identify the recipient artery for bypass with distal middle cerebral artery aneurysms: operative technique.

Science.gov (United States)

Rodríguez-Hernández, Ana; Lawton, Michael T

2012-06-01

Distal middle cerebral artery (MCA) aneurysms frequently have nonsaccular morphology that necessitates trapping and bypass. Bypasses can be difficult because efferent arteries lie deep in the opercular cleft and may not be easily identifiable. We introduce the "flash fluorescence" technique, which uses videoangiography with indocyanine green (ICG) dye to identify an appropriate recipient artery on the cortical surface for the bypass, enabling a more superficial and easier anastomosis. Flash fluorescence requires 3 steps: (1) temporary clip occlusion of the involved afferent artery; (2) videoangiography demonstrating fluorescence in uninvolved arteries on the cortical surface; and (3) removal of the temporary clip with flash fluorescence in the involved efferent arteries on the cortical surface, thereby identifying a recipient. Alternatively, temporary clips can occlude uninvolved arteries, and videoangiography will demonstrate initial fluorescence in efferent arteries during temporary occlusion and flash fluorescence in uninvolved arteries during reperfusion. From a consecutive series of 604 MCA aneurysms treated microsurgically, 22 (3.6%) were distal aneurysms and 11 required a bypass. The flash fluorescence technique was used in 3 patients to select the recipient artery for 2 superficial temporal artery-to-MCA bypasses and 1 MCA-MCA bypass. The correct recipient was selected in all cases. The flash fluorescence technique provides quick, reliable localization of an appropriate recipient artery for bypass when revascularization is needed for a distal MCA aneurysm. This technique eliminates the need for extensive dissection of the efferent artery and enables a superficial recipient site that makes the anastomosis safer, faster, and less demanding.

Scintigraphic assessment of focal platelet accumulations following infrainguinal bypass surgery in humans

DEFF Research Database (Denmark)

Nielsen, Tina G; Hesse, B; Eiberg, J

1997-01-01

. In 28 patients undergoing in situ vein (n = 24), composite vein-polytetrafluoroethylene (PTFE) (n = 1) or PTFE (n = 3) bypass surgery, assumed vascular injuries were recorded intraoperatively. Autologous indium-111-labelled platelets were injected into the inflow artery immediately after restoration...... antiplatelet therapy or vein graft diameter. Only 2 of the 20 intragraft platelet depositions occurred in areas where intra-operative vascular injury was suspected. In the composite graft and the PTFE grafts, diffuse activity was observed throughout the entire bypass. In conclusion, focal activity...

Prospective randomized study comparing coronary artery bypass grafting with the new mini-extracorporeal circulation Jostra System or with a standard cardiopulmonary bypass.

Science.gov (United States)

Remadi, Jean Paul; Rakotoarivelo, Zava; Marticho, Paul; Benamar, Amar

2006-01-01

To assess the potential benefits of a new concept of cardiopulmonary bypass (CPB), the mini-extracorporeal circulation (MECC) Jostra System, we conducted a prospective randomized study among patients who underwent coronary artery bypass grafting (CABG) with a MECC Jostra System or with a standard CPB. In a prospective randomized study, 400 patients underwent elective CABG using a standard CPB (200 patients) or a Jostra MECC System (200 patients). The patients were randomly assigned to have preoperative data similar for both groups. The operative mortality rate (system is a new concept of CPB that seems to be reliable and safe. To perform CABG, the MECC provides an excellent surgical exposure like a standard CPB and a better biologic profile like CABG without CPB.

A nutritional and metabolic assessment of a cardiopulmonary bypass technique without donor blood

OpenAIRE

東,良平

1993-01-01

A nutritional and metabolic assessment of a cardiopulmonary bypass technique without donor blood was made in 23 patients undergoing open heart surgery (non-donor blood group). For comparison, 14 patients receiving cardiopulmonary bypass with donor blood prime (donor blood group) were also evaluated. 1)Serum transferrin level showed significantly more rapid recovery in the non-donor blood group compared to the donor blood group on the 7th post operative day. 2)Total protein, serum albumin, arm...

Evaluation of the patency of an extracranial-intracranial bypass using magnetic resonance angiography with selective presaturation of bypass vessels

Energy Technology Data Exchange (ETDEWEB)

Mabuchi, Shoji; Nakayama, Naoki; Isu, Toyohiko; Harata, Tatsuo; Nanbu, Toshikazu [Kushiro Rousai Hospital, Hokkaido (Japan)

1994-06-01

Three-dimensional time-of-flight magnetic resonance (MR) angiography using radiofrequency presaturation pulses was used to evaluate the patency of extracranial-intracranial (EC/IC) bypass in 11 patients. Presaturation causes signal loss in the vascular territory supplied by the presaturated EC/IC bypass graft. In all patients with a patent EC/IC bypass graft confirmed on conventional angiography, disappearance of the signal of the middle cerebral artery receiving blood flow from the bypass graft was clearly observed on MR angiograms with presaturation, indicating patency of the EC/IC bypass graft. MR angiography with presaturation pulses is a noninvasive and repeatable method for evaluation of the function of an EC/IC bypass graft. (author).

Sodium flow measurement in large pipelines of sodium cooled fast breeder reactors with bypass type flow meters

International Nuclear Information System (INIS)

Rajan, K.K.; Jayakumar, T.; Aggarwal, P.K.; Vinod, V.

2016-01-01

Highlights: • Bypass type permanent magnet flow meters are more suitable for sodium flow measurement. • A higher sodium velocity through the PMFM sensor will increase its sensitivity and resolution. • By modifying the geometry of bypass line, higher sodium velocity through sensor is achieved. • With optimized geometry the sensitivity of bypass flow meter system was increased by 70%. - Abstract: Liquid sodium flow through the pipelines of sodium cooled fast breeder reactor circuits are measured using electromagnetic flow meters. Bypass type flow meter with a permanent magnet flow meter as sensor in the bypass line is selected for the flow measurement in the 800 NB main secondary pipe line of 500 MWe Prototype Fast Breeder Reactor (PFBR), which is at the advanced stage of construction at Kalpakkam. For increasing the sensitivity of bypass flow meters in future SFRs, alternative bypass geometry was considered. The performance enhancement of the proposed geometry was evaluated by experimental and numerical methods using scaled down models. From the studies it is observed that the new configuration increases the sensitivity of bypass flow meter system by around 70%. Using experimentally validated numerical tools the volumetric flow ratio for the bypass configurations is established for the operating range of Reynolds numbers.

Effect of acetylcysteine on adaptation of intestinal smooth muscle after small bowel bypass

International Nuclear Information System (INIS)

Weisbrodt, N.W.; Belloso, R.M.; Biskin, L.C.; Dudrick, P.S.; Dudrick, S.J.

1986-01-01

The authors have postulated that the adaptive changes in function and structure of bypassed segments of small bowel are due in part to the change in intestinal contents following operation. The purpose of these experiments was to determine if a mucolytic agent could alter the adaptation. Rats were anesthetized and a 70% jejunoileal bypass was performed. The bypassed segments then were perfused with either saline or acetylcysteine for 3-12 days. Then, either intestinal transit was determined using Cr-51, or segments were taken for morphometric analysis. Transit, as assessed by the geometric center, was increased 32% by acetylcysteine treatment. Treatment also caused a decrease in hypertrophy of the muscularis. Muscle wet weight, muscle cross-sectional area, and muscle layer thickness all were significantly less in those animals infused with acetyl-cysteine. No decreases in hypertrophy were seen in the in-continuity segments. These data indicate that alterations in intestinal content can affect the course of adaptation of intestinal muscle in response to small bowel bypass

Utilising cardiopulmonary bypass for cancer surgery. Malignancy-induced protein C deficiency and thrombophilia.

LENUS (Irish Health Repository)

Marshall, C

2012-02-03

Cardiopulmonary bypass has evolved over the last 30 years. It is an important tool for the cardiac surgeon today and also has applications in non-cardiac operations such as surgery to extract tumours. Such patients undergoing surgery for cancer may be at an increased risk of a thromboembolic event post surgery, due to disturbances in the normal clotting pathway leading to hypercoagulability. One such disturbance is malignancy-induced Protein C deficiency. A deficiency of Protein C can cause hypercoagulabitity. Recent studies have examined cardiopulmonary bypass and inherited Protein C deficiency. However, surgery for cancer patients with a malignancy-induced Protein C deficiency involving cardiopulmonary bypass has not been reported. Surgery using CPB in these patients may result in increased morbidity and mortality. The objective of this article is to review the literature in order to discuss the occurrence, the aetiology and possible management of cancer patients with malignancy-induced Protein C deficiencies that require cardiopulmonary bypass for their surgery.

[Simplified laparoscopic gastric bypass. Initial experience].

Science.gov (United States)

Hernández-Miguelena, Luis; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Ríos-Cruz, Daniel; Marín-Domínguez, Raúl; Castillo-González, Armando

2014-01-01

Obesity surgery includes various gastrointestinal procedures. Roux-en-Y gastric bypass is the prototype of mixed procedures being the most practiced worldwide. A similar and novel technique has been adopted by Dr. Almino Cardoso Ramos and Dr. Manoel Galvao called "simplified bypass," which has been accepted due to the greater ease and very similar results to the conventional technique. The aim of this study is to describe the results of the simplified gastric bypass for treatment of morbid obesity in our institution. We performed a descriptive, retrospective study of all patients undergoing simplified gastric bypass from January 2008 to July 2012 in the obesity clinic of a private hospital in Mexico City. A total of 90 patients diagnosed with morbid obesity underwent simplified gastric bypass. Complications occurred in 10% of patients; these were more frequent bleeding and internal hernia. Mortality in the study period was 0%. The average weight loss at 12 months was 72.7%. Simplified gastric bypass surgery is safe with good mid-term results and a loss of adequate weight in 71% of cases.

The bypass solution as a capacity enhancing measure in connecting biogas plants to the grid; Die Bypass-Loesung als kapazitaetserhoehende Massnahme beim Netzanschluss von Biogasanlagen

Energy Technology Data Exchange (ETDEWEB)

Grassmann, Nils [PwC Legal AG, Frankfurt am Main (Germany). Bereich Energierecht in der Region Sued; Reinhardt, Anja [PwC Legal AG, Muenchen (Germany)

2012-07-01

In spite of repeated amendments to the laws governing the connection of biogas plants to the grid there still remain unresolved disputes in practice. A significant issue in this regard concerns what is referred to as the bypass solution, where a connection to the general supply grid of the receiving grid operator is created and at the same time technical equipment is installed which provides a connection to an upstream grid to which biogas can be backfed in times of low grid load. The Upper Regional Court of Duesseldorf classifies constellations of this kind as a combined grid connection to two different grids. It argues that since the legislature has provided no regulations on this constellation there can be no legitimate right to obtaining a connection of this configuration. However, this line of argumentation does not appear compelling. The meaning and purpose of Articles 31 ff. of the Gas Network Access Ordinance and the wording of the relevant norms both speak in favour of considering bypass solutions as capacity-enhancing measures. The receiving (downstream) grid operator would then be obliged, under the general requirements, to create a grid connection and to draw the bypass solution into consideration as a special means of backfeeding. This would provide legal certainty for all involved and allow technically meaningful solutions to be implemented.

Changes in adhesion molecule expression and oxidative burst activity of granulocytes and monocytes during open-heart surgery with cardiopulmonary bypass compared with abdominal surgery

DEFF Research Database (Denmark)

Toft, P; Nielsen, C H; Tønnesen, Else Kirstine

1998-01-01

Cardiac and major abdominal surgery are associated with granulocytosis in peripheral blood. The purpose of the present study was to describe the granulocyte and monocyte oxidative burst and the expression of adhesion molecules following cardiac surgery with cardiopulmonary bypass and abdominal...... during cardiopulmonary bypass was observed. The percentage of CD11a-positive granulocytes increased from 30% pre-operatively to 75% following cardiopulmonary bypass, while CD44-positive granulocytes increased from 5% to 13%. Despite the extent of the changes, these were not significant. The oxidative...... to an increased per-operative oxidative burst activity, and the induction of adhesion molecules on granulocytes associated with the cardiopulmonary bypass and surgery. In conclusion, open-heart surgery with cardiopulmonary bypass was associated with a rapid and pronounced activation of leukocytes which may play...

A comparison of high-dose and low-dose tranexamic acid antifibrinolytic protocols for primary coronary artery bypass surgery

Directory of Open Access Journals (Sweden)

Stephen M McHugh

2016-01-01

Full Text Available Background and Aims: Tranexamic acid (TA is used for prophylactic antifibrinolysis in coronary artery bypass surgeries to reduce bleeding. We evaluated the efficacy of two different doses of TA for prophylactic antifibrinolysis in patients undergoing primary coronary artery bypass grafting (CABG surgery in this retrospective cohort study at a tertiary care referral centre. Methods: One-hundred eighty-four patients who underwent primary CABG with cardiopulmonary bypass (CPB via sternotomy between January 2009 and June 2011 were evaluated. Pre-operative patient characteristics, intraoperative data, post-operative bleeding, transfusions, organ dysfunction and 30-day mortality were compared between high-dose TA (30 mg/kg loading dose followed by infusion of 15 mg/kg/h until the end of surgery along with 2 mg/kg priming dose in the bypass circuit and low-dose TA (15 mg/kg loading dose followed by infusion of 6 mg/kg/h until the end of surgery along with 1 mg/kg priming dose in the bypass circuit groups. Univariate comparative analysis of all categorical and continuous variables was performed between the two groups by appropriate statistical tests. Linear and logistic regression analyses were performed to control for the effect of confounding on the outcome variables. Results: Chest tube output, perioperative transfusion of blood products and incidence of re-exploration for bleeding did not differ significantly (P> 0.05 between groups. Post-operative complications and 30-day mortality were comparable between the groups. The presence of cardiogenic shock and increased pre-operative creatinine were found to be associated with increased chest tube output on the post-operative day 2 by multivariable linear regression model. Conclusions: Low-dose TA protocol is as effective as high-dose protocol for antifibrinolysis in patients undergoing primary CABG with CPB.

Bypass transition in compressible boundary layers

Science.gov (United States)

Vandervegt, J. J.

1992-01-01

Transition to turbulence in aerospace applications usually occurs in a strongly disturbed environment. For instance, the effects of free-stream turbulence, roughness and obstacles in the boundary layer strongly influence transition. Proper understanding of the mechanisms leading to transition is crucial in the design of aircraft wings and gas turbine blades, because lift, drag and heat transfer strongly depend on the state of the boundary layer, laminar or turbulent. Unfortunately, most of the transition research, both theoretical and experimental, has focused on natural transition. Many practical flows, however, defy any theoretical analysis and are extremely difficult to measure. Morkovin introduced in his review paper the concept of bypass transition as those forms of transition which bypass the known mechanisms of linear and non-linear transition theories and are currently not understood by experiments. In an effort to better understand the mechanisms leading to transition in a disturbed environment, experiments are conducted studying simpler cases, viz. the effects of free stream turbulence on transition on a flat plate. It turns out that these experiments are very difficult to conduct, because generation of free stream turbulence with sufficiently high fluctuation levels and reasonable homogeneity is non trivial. For a discussion see Morkovin. Serious problems also appear due to the fact that at high Reynolds numbers the boundary layers are very thin, especially in the nose region of the plate where the transition occurs, which makes the use of very small probes necessary. The effects of free-stream turbulence on transition are the subject of this research and are especially important in a gas turbine environment, where turbulence intensities are measured between 5 and 20 percent, Wang et al. Due to the fact that the Reynolds number for turbine blades is considerably lower than for aircraft wings, generally a larger portion of the blade will be in a laminar

Intraoperative echocardiographic imaging of coronary arteries and graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass.

Science.gov (United States)

Suematsu, Y; Takamoto, S; Ohtsuka, T

2001-12-01

No accepted approach exists for the intraoperative evaluation of the quality of coronary arteries and the technical adequacy of graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass. We assessed the accuracy of high-frequency epicardial echocardiography and power Doppler imaging in evaluating coronary arteries during coronary artery bypass grafting without cardiopulmonary bypass. To validate measurements of coronary arteries and graft anastomoses by high-frequency epicardial echocardiography and power Doppler imaging, we compared luminal diameters determined by these methods with diameters determined histologically in a study of off-pump coronary artery bypass grafting in 20 dogs. Technical errors were deliberately created in 10 grafts (stenosis group). The results of these animal validation studies showed that the maximum luminal diameters of coronary arteries and graft anastomoses measured by high-frequency epicardial echocardiography (HEE) and power Doppler imaging (PDI) correlated well with the histologic measurements: HEE = 1.027 x Histologic measurements + 0.005 (P anastomoses were examined intraoperatively by high-frequency epicardial echocardiography and power Doppler imaging, and luminal diameters determined by power Doppler imaging were compared with those determined by postoperative coronary angiography. The results demonstrated that graft anastomosis by power Doppler imaging correlated well with the angiographic measurements: PDI = 1.018 x Angiographic measurements - 0.106 (P anastomoses and can detect technical errors and inadequacies during coronary artery bypass grafting without cardiopulmonary bypass.

Gradual Hunterian ligation for infected prosthetic bypass.

Science.gov (United States)

Egun, A; Slade, D; McCollum, C N

2000-04-01

To review gradual snare occlusion for the management of complex or recurrent graft infection. Medical records of patients treated with gradual snare occlusion following graft infection were reviewed for indication for operation, type of bypass and graft material used. In addition, infecting organism, grade of infection (Szilágyi) and outcome were recorded. Four femoropopliteal, two extra-anatomic (axillofemoral) and aortobifemoral bypasses were included in this study. All had chronic infection (Szilágyi grade III) with onset of 4 to 24 months and two of which were recurrent. The causative organisms were coagulase-negative staphylococci, Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus in three patients, with no organism isolated in the remaining cases. There was no loss of limb following gradual snare occlusion but there was only one death due to aortic stump rupture 2 weeks later. Gradual snare occlusion is an alternative for the management of chronic or recurrent graft infection. Copyright 1999 Harcourt Publishers Ltd.

Nutrient deficiency and obstetrical outcomes in pregnant women following Roux-en-Y gastric bypass: A retrospective Danish cohort study with a matched comparison group.

Science.gov (United States)

Hammeken, Lianna Hede; Betsagoo, Ramsina; Jensen, Ann Nygaard; Sørensen, Anne Nødgaard; Overgaard, Charlotte

2017-09-01

Roux-en-Y gastric bypass surgery and small-for-gestational-age births are known to be associated although the etiology is not fully understood. This study aimed to investigate pregnancy outcomes and maternal nutritional status among pregnant women with a history of Roux-en-Y gastric bypass using maternal anemia and gestational weight gain as indicators of micronutrient and macronutrient deficiency in pregnancy. The study was designed as a retrospective matched cohort study. All Roux-en-Y-gastric-bypass-operated pregnant women (n=151) who were followed in the outpatient obstetric clinic at Aalborg University Hospital in Denmark and gave birth between 1 January 2010 and 31 December 2013 were included. Each Roux-en-Y-gastric-bypass-operated woman was closely matched with a non-Roux-en-Y-gastric-bypass-operated woman. Primary outcomes were small-for-gestational-age birth, maternal anemia and gestational weight gain. The two groups (matched 1:1) were compared by paired tests on all measures, conditional logistic regression for paired binary data and the paired t-test or Wilcoxon signed-rank test for paired continuous data. The risk of small-for-gestational-age birth (odds ratio (OR)=2.67, 95% confidence interval (CI); 1.04-6.82) and maternal anemia (OR=3.0, 95% CI; 1.09-8.25) were significantly increased for the Roux-en-Y gastric bypass group compared to the non-Roux-en-Y gastric bypass group. No significant difference was found in gestational weight gain (p=0.169) between women with a history of Roux-en-Y gastric bypass (11.51kg±8.97 standard deviation (SD)) and non- Roux-en-Y-gastric-bypass-operated women (12.18kg±6.28 SD). A history of Roux-en-Y gastric bypass surgery increases the risk of small-for-gestational-age birth and anemia, while a finding of differences in gestational weight gain is uncorroborated. Our findings suggest a role of micronutrient deficiency rather than reduced gestational weight gain in the etiology of small-for-gestational-age birth among

The incidence of ureteral obstruction secondary to aorto-femoral bypass surgery. A prospective study

DEFF Research Database (Denmark)

Henriksen, L O; Mejdahl, Steen; Petersen, F

1988-01-01

Hydronephrosis is reported to be an infrequent complication of aorto-femoral bypass operations. To define the true incidence of this complication, renography (131I-Hippuran) and renal scintigraphy (99 Technetium) were performed both pre- and postoperatively on 56 asymptomatic patients following...... successful aortic reconstruction. No patient developed signs of ureteral obstruction. It is concluded that hydronephrosis is a rare complication to aorto-femoral bypass surgery and postoperative control is only indicated in patients with symptoms from the urinary tract....

Double bypass for inoperable pancreatic malignancy at laparotomy: postoperative complications and long-term outcome

Science.gov (United States)

Ausania, F; Vallance, AE; Manas, DM; Prentis, JM; Snowden, CP; White, SA; Charnley, RM; French, JJ; Jaques, BC

2012-01-01

INTRODUCTION Between 4% and 13% of patients with operable pancreatic malignancy are found unresectable at the time of surgery. Double bypass is a good option for fit patients but it is associated with high risk of postoperative complications. The aim of this study was to identify pre-operatively which patients undergoing double bypass are at high risk of complications and to assess their long-term outcome. METHODS Of the 576 patients undergoing pancreatic resections between 2006 and 2011, 50 patients who underwent a laparotomy for a planned pancreaticoduodenectomy had a double bypass procedure for inoperable disease. Demographic data, risk factors for postoperative complications and pre-operative anaesthetic assessment data including the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) and cardiopulmonary exercise testing (CPET) were collected. RESULTS Fifty patients (33 men and 17 women) were included in the study. The median patient age was 64 years (range: 39–79 years). The complication rate was 50% and the in-hospital mortality rate was 4%. The P-POSSUM physiology subscore and low anaerobic threshold at CPET were significantly associated with postoperative complications (p=0.005 and p=0.016 respectively) but they were unable to predict them. Overall long-term survival was significantly shorter in patients with postoperative complications (9 vs 18 months). Postoperative complications were independently associated with poorer long-term survival (p=0.003, odds ratio: 3.261). CONCLUSIONS P-POSSUM and CPET are associated with postoperative complications but the possibility of using them for risk prediction requires further research. However, postoperative complications following double bypass have a significant impact on long-term survival and this type of surgery should therefore only be performed in specialised centres. PMID:23131226

Leptomeningeal contrast enhancement in moyamoya: its potential role in postoperative assessment of circulation through the bypass

International Nuclear Information System (INIS)

Komiyama, M.; Nakajima, H.; Nishikawa, M.; Yasui, T.; Kitano, S.; Sakamoto, H.

2001-01-01

Leptomeningeal contrast enhancement (LMCE) is one of the MRI features of moyamoya. Its clinical significance, however, is not elucidated. Our purpose was to characterise LMCE on MRI and to evaluate its role in the assessment of circulation through a surgically established bypass in moyamoya. We studied 16 patients with idiopathic moyamoya (seven males, nine females, includingt four children, aged 7 to 54 years, mean 24 years) who underwent T1-weighted MRI before and after intravenous contrast medium. The presence of LMCE, its intensity and anatomical distribution, catheter angiographic findings, and relation of LMCE to the bypass surgery were assessed. More LMCE was seen in the cerebrum in most patients with moyamoya than in normal controls. LMCE in the brain stem and cerebellum was minimal, similar to that seen in the controls. LMCE was less prominent following surgery than before operation or in patients who did not undergo surgery. In three patients examined both before and after operation LMCE became less prominent following bypass surgery. As LMCE becomes less prominent after ''effective'' bypass surgery, this may be used for evaluation of effectiveness of surgery in moyamoya. (orig.)

[Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

Science.gov (United States)

Bazylev, V V; Nemchenko, E V; Karnakhin, V A; Pavlov, A A; Mikulyak, A I

2016-01-01

Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ.

Coronary Artery Bypass in Octogenarians

Directory of Open Access Journals (Sweden)

Chen-Yen Chien

2012-09-01

Full Text Available Prevalence of coronary artery disease (CAD has increased with the expansion of life span among the elderly population in the world. Hence, the issue of the coronary artery bypass in octogenarians has attracted more attention. Recent literature about the topic revealed nearly the same excellent results as those in the younger population under the newly developed operative techniques and improving concept in perioperative management and postoperative care. In this article, we review the current status of the procedure that was thought to be dangerous in the earlier era, including its risk factors, result, and benefit.

FACTS device control strategy using PMU

Directory of Open Access Journals (Sweden)

Mohd Tauseef Khan

2016-09-01

Full Text Available The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

Outcomes of lower extremity bypass performed for acute limb ischemia.

Science.gov (United States)

Baril, Donald T; Patel, Virendra I; Judelson, Dejah R; Goodney, Philip P; McPhee, James T; Hevelone, Nathanael D; Cronenwett, Jack L; Schanzer, Andres

2013-10-01

, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year. Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Repletion of factor XIII following cardiopulmonary bypass using a recombinant A-subunit homodimer. A preliminary report

DEFF Research Database (Denmark)

Levy, Jerrold H; Gill, Ravi; Nussmeier, Nancy A

2009-01-01

Bleeding following cardiac surgery involving cardiopulmonary bypass (CPB) remains a major concern. Coagulation factor XIII (FXIII) functions as a clot-stabilising factor by cross-linking fibrin. Low post-operative levels of FXIII correlate with increased post-operative blood loss. To evaluate...... preliminary safety and pharmacokinetics of recombinant FXIII (rFXIII-A(2)) in cardiac surgery, patients scheduled for coronary artery bypass grafting were randomised to receive a single dose of either rFXIII-A(2) (11.9, 25, 35 or 50 IU/kg) or placebo in a 4:1 ratio. Study drug was given post-CPB within 10...

Obturator or "lateral" bypass in the management of infected vascular prostheses at the groin

Directory of Open Access Journals (Sweden)

Davidović Lazar B.

2002-01-01

above the knee popliteal artery in 4 subjects. After both types of reconstruction, extirpation of infected grafts from the groin was performed (Figure 2. The control examination was performed using physical and Doppler ultrasonographic examinations, one, 3, 6, 12 months, and then every year after the operation. In cases with suspected graft infection or thrombosis, control angography was also performed. One intraoperative perforation of the urinary bladder has been done accidentally during obturator bypass reconstruction. The mean follow-up period for patients with obturator bypasses was 2.3 years, while 2.1 years for patients with "lateral" bypasses. Comparing with "lateral" bypass, obturator bypass showed statistically significant lower (p < 0.05 30- day mortality and early graft infection rate, as well as statistically significant better early and total limb salvage rate. There were no statistically significant differences (p > 0.05 between obturator and "lateral" bypass procedures having in mind, late graft infection rate, as well as early and late graft patency (Figures 3 and 4. In cases with infected vascular prostheses in the groin, the authors recommend obturator bypass comparing with "lateral" bypass.

Pattern and predictors of dual antiplatelet use after coronary artery bypass graft surgery.

Science.gov (United States)

Mori, Makoto; Shioda, Kayoko; Yun, James J; Mangi, Abeel A; Darr, Umer; Geirsson, Arnar

2018-02-01

Resumption of dual antiplatelet therapy after coronary artery bypass grafting in patients presenting with acute coronary syndrome is recommended, but the current practice pattern in the United States remains unknown. We aimed to investigate the current pattern of dual antiplatelet therapy use after coronary artery bypass grafting at the Yale-New Haven Hospital. We conducted a single-center retrospective review of patients who presented with acute coronary syndrome and underwent coronary artery bypass grafting between 2014 and 2016. The primary outcome was hospital discharge with dual antiplatelet therapy. Mixed-effect multivariate logistic regression was used to evaluate predictors of dual antiplatelet therapy use or nonuse, accounting for surgeon-specific preference. The discriminatory ability of the model was evaluated with receiver operating characteristics analysis. Of 572 patients included, only 29% were discharged with dual antiplatelet therapy. In the mixed-effect multivariate model isolating surgeon preferences, increase in age (odds ratio, 0.95; 95% confidence interval, 0.92-0.98; P dual antiplatelet therapy use. Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting was associated with increased odds of dual antiplatelet therapy use (odds ratio, 31.5; 95% confidence interval, 12.8-77.2; P dual antiplatelet therapy use in patients with acute coronary syndrome who underwent coronary artery bypass grafting was low and variable among surgeons. The use or nonuse was guided by previously established risk factors of recurrent ischemia and bleeding, along with surgeon preference. Published by Elsevier Inc.

Spiritual Bypass: A Preliminary Investigation

Science.gov (United States)

Cashwell, Craig S.; Glosoff, Harriet L.; Hammond, Cheree

2010-01-01

The phenomenon of spiritual bypass has received limited attention in the transpersonal psychology and counseling literature and has not been subjected to empirical inquiry. This study examines the phenomenon of spiritual bypass by considering how spirituality, mindfulness, alexithymia (emotional restrictiveness), and narcissism work together to…

Off-pump coronary artery bypass surgery in selected patients is superior to the conventional approach for patients with severely depressed left ventricular function

Science.gov (United States)

Caputti, Guido Marco; Palma, José Honório; Gaia, Diego Felipe; Buffolo, Enio

2011-01-01

OBJECTIVES: Patients with coronary artery disease and left ventricular dysfunction have high mortality when kept in clinical treatment. Coronary artery bypass grafting can improve survival and the quality of life. Recently, revascularization without cardiopulmonary bypass has been presented as a viable alternative. The aim of this study is to compare patients with left ventricular ejection fractions of less than 20% who underwent coronary artery bypass graft with or without cardiopulmonary bypass. METHODS: From January 2001 to December 2005, 217 nonrandomized, consecutive, and nonselected patients with an ejection fraction less than or equal to 20% underwent coronary artery bypass graft surgery with (112) or without (off-pump) (105) the use of cardiopulmonary bypass. We studied demographic, operative, and postoperative data. RESULTS: There were no demographic differences between groups. The outcome variables showed similar graft numbers in both groups. Mortality was 12.5% in the cardiopulmonary bypass group and 3.8% in the off-pump group. Postoperative complications were statistically different (cardiopulmonary bypass versus off-pump): total length of hospital stay (days)—11.3 vs. 7.2, length of ICU stay (days)—3.7 vs. 2.1, pulmonary complications—10.7% vs. 2.8%, intubation time (hours)—22 vs. 10, postoperative bleeding (mL)—654 vs. 440, acute renal failure—8.9% vs. 1.9% and left-ventricle ejection fraction before discharge—22% vs. 29%. CONCLUSION: Coronary artery bypass grafting without cardiopulmonary bypass in selected patients with severe left ventricular dysfunction is valid and safe and promotes less mortality and morbidity compared with conventional operations. PMID:22189729

Off-pump coronary artery bypass surgery in selected patients is superior to the conventional approach for patients with severely depressed left ventricular function

Directory of Open Access Journals (Sweden)

Guido Marco Caputti

2011-01-01

Full Text Available OBJECTIVES: Patients with coronary artery disease and left ventricular dysfunction have high mortality when kept in clinical treatment. Coronary artery bypass grafting can improve survival and the quality of life. Recently, revascularization without cardiopulmonary bypass has been presented as a viable alternative. The aim of this study is to compare patients with left ventricular ejection fractions of less than 20% who underwent coronary artery bypass graft with or without cardiopulmonary bypass. METHODS: From January 2001 to December 2005, 217 nonrandomized, consecutive, and nonselected patients with an ejection fraction less than or equal to 20% underwent coronary artery bypass graft surgery with (112 or without (off-pump (105 the use of cardiopulmonary bypass. We studied demographic, operative, and postoperative data. RESULTS: There were no demographic differences between groups. The outcome variables showed similar graft numbers in both groups. Mortality was 12.5% in the cardiopulmonary bypass group and 3.8% in the off-pump group. Postoperative complications were statistically different (cardiopulmonary bypass versus off-pump: total length of hospital stay (days-11.3 vs. 7.2, length of ICU stay (days-3.7 vs. 2.1, pulmonary complications-10.7% vs. 2.8%, intubation time (hours-22 vs. 10, postoperative bleeding (mL-654 vs. 440, acute renal failure-8.9% vs. 1.9% and left-ventricle ejection fraction before discharge-22% vs. 29%. CONCLUSION: Coronary artery bypass grafting without cardiopulmonary bypass in selected patients with severe left ventricular dysfunction is valid and safe and promotes less mortality and morbidity compared with conventional operations.

The effects of intraoperative autologous whole blood sequestration on the need for transfusion of allogenic blood and blood products in coronary bypass operations.

Science.gov (United States)

Canver, C C; Kroncke, G M; Nichols, R D; Murray, E L; Mentzer, R M

1995-10-01

We investigated the effect of intraoperative autologous blood sequestration (IABS), an old blood conservation method, on transfusion requirements for homologous packed red blood cells (PRBC), platelets, and fresh frozen plasma (FFP) for patients undergoing coronary bypass surgery. This non-randomized retrospective study involved 204 patients who underwent isolated primary coronary artery bypass grafting (CABG). In 140 patients (IABS Group), autologous heparinized whole blood was removed intraoperatively via aortic cannula before bypass and retransfused at the conclusion of extracorporeal circulation. In 64 control patients, no IABS was performed. Demographic characteristics and operative and perioperative variables for both groups were similar (p > 0.05). In 140 patients, the mean sequestered blood volume was 1430 ml (range = 700-2100 ml). The banked PRBC requirement during hospitalization was 1.91 units in the No IABS Group and 2.25 units for the IABS Group (p = 0.2957). The need for platelet transfusion was 3.06 units in the No IABS Group and 1.09 units in the IABS Group (p = 0.0003). In the No IABS Group, 1.31 units of FFP was transfused and in the IABS Group, 0.49 units was transfused (p = 0.0004). To identify possible confounding factors, we performed a multivariate Poisson regression analysis for the 22 patient variables by a forward stepwise procedure. Regression analysis indicated that IABS did not alter the need for PRBC transfusion (p = 0.6194) but adjusted differences did confirm that IABS was associated with decreased need for transfusion of platelets and FFP (p = 0.0001 and p = 0.0002, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Variable volume combustor with an air bypass system

Science.gov (United States)

Johnson, Thomas Edward; Ziminsky, Willy Steve; Ostebee, Heath Michael; Keener, Christopher Paul

2017-02-07

The present application provides a combustor for use with flow of fuel and a flow of air in a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles positioned within a liner and an air bypass system position about the liner. The air bypass system variably allows a bypass portion of the flow of air to bypass the micro-mixer fuel nozzles.

Acute renal insufficiency and renal replacement therapy after pediatric cardiopulmonary bypass surgery

NARCIS (Netherlands)

Kist-van Holthe tot Echten, J. E.; Goedvolk, C. A.; Doornaar, M. B.; van der Vorst, M. M.; Bosman-Vermeeren, J. M.; Brand, R.; van der Heijden, A. J.; Schoof, P. H.; Hazekamp, M. G.

2001-01-01

The aim of the study was to investigate renal function and renal replacement therapy after cardiopulmonary bypass surgery in children. Patient characteristics (sex, age, diagnosis), operation type, and death were listed. The study was performed retrospectively using serum creatinine level before,

Collins' bypass for the main ring

International Nuclear Information System (INIS)

Ohnuma, S.

1982-01-01

Design of the bypass for the main ring at Fermilab is discussed. Specific design features discussed include space, path length, geometric closure, matching of betatron functions, and external dispersion. Bypass parameters are given

Brain microvascular function during cardiopulmonary bypass

International Nuclear Information System (INIS)

Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

1987-01-01

Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass

Heart bypass surgery - minimally invasive - discharge

Science.gov (United States)

... invasive direct coronary artery bypass - discharge; MIDCAB - discharge; Robot assisted coronary artery bypass - discharge; RACAB - discharge; Keyhole ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

Glucosa-Insulin-Potassium (GIK) solution used with diabetic patients provides better recovery after coronary bypass operations.

Science.gov (United States)

Straus, Slavenka; Gerc, Vjekoslav; Kacila, Mirsad; Faruk, Custovic

2013-01-01

Tight blood glucose control has become a therapeutical goal for anesthetic management for patients scheduled for cardiac surgery, especially if they are diabetic patients. This study was created to confirm the benefits of intraoperative GIK solution usage during coronary bypass operation of diabetic patients. Patients with type 1 and 2 diabetes mellitus (DM) referred for coronary artery bypass grafting (CABG) were randomized to receive GIK solution (GIK--study group) in the first 24 hours intraoperatively or to receive official Clinical protocol without GIK solution (non GIK - control group). The primary clinical outcome was the cardiac index (CI) since it represents the most sensitive measure of cardiac work in the immediate postoperative period, and the secondary clinical outcomes were the glycemic control, insulin consumption, duration of mechanical ventilation (MV), potassium level and atrial fibrillation (AF) appearance. One hundred diabetic patients, divided into two groups, were included in the study. The cardiac index did not show a significant difference, although the study group had CI with only minor variations than those of the controlled group, hence the reason we considered the study group as the more stable. The atrial fibrillation showed a difference between two groups, with 14 (28%) patients with postoperative AF in the control group compared with 3 (6%) patients with postoperative AF in the study group. As potassium values were stable in study group, we concluded that it can be one of the reasons for less postoperative AF in this group. The duration of MV showed a significant difference (0,003) between the two groups as well. In the study group the average MV time was 534,38 minutes, compared with the control group with 749,20 minutes. The average value of glucose was 11.1 mmol/l in the control group vs. 9.8 mmol/l in the study group. The study group had less insulin consumption in order to maintain target glycemia (p = 0.001). In the non GIK

Impact of gender on outcome after coronary artery bypass surgery.

Science.gov (United States)

Ennker, Ina C; Albert, Alexander; Pietrowski, Detlef; Bauer, Kerstin; Ennker, Juergen; Florath, Ines

2009-06-01

Following recent studies concerning the increased risk of coronary artery bypass surgery for women, the impact of sex is still a controversial issue. Between 1996 and 2006, 9,527 men and 3,079 women underwent isolated coronary artery bypass in our institute. To adjust for dissimilarities in preoperative risk profiles, propensity score-based matching was applied. Before adjustment, clinical outcomes in terms of operative mortality, arrhythmias, intensive care unit stay, and maximum creatine kinase-MB levels were significantly different for men and women. After balancing the preoperative characteristics, including height, no significant differences in clinical outcomes were observed. However, there was decreased use of internal mammary artery, less total arterial revascularization, and increasing creatine kinase-MB levels with decreasing height. This study supports the theory that female sex per se does not increase operative risk, but shorter height, which is more common in women, affects the outcome, probably due to technical difficulties in shorter patients with smaller internal mammary arteries and coronary vessels. Thus women may especially benefit from sequential arterial grafting.

Aorto-aortic intrathoracic bypass in surgical treatment of aortic

International Nuclear Information System (INIS)

Gutierrez Perez, F.; Duran Reyes, A.; Bigalli, D.; Filgueira Berobide, J.

1998-01-01

The prevalence of coarctation of the aorta is 6.5 percent of all congenital heart defects, according to national and international data. There is a restenosis rate of patients after surgery. Factors that influence this evolution depends on the age at which patients underwent surgery for the first time the anatomy of the aortic arch and type of surgical technique. Several procedures can be used to correct the coarctation, which include surgery and balloon catheter dilation. We present here a case of a patient of 22 years old, with a recurrent coarctation of the aorta studied by echocardiography and magnetic resonance imaging. The patient underwent surgery a third time. We used an anterior approach (median sternotomy) and performed an aortic bypass graft, intrathoracic, under cardiopulmonary bypass. Evolved favorably and was discharged on the sixth day of post operative day (Author) [es

Dual turbine power plant and a reheat steam bypass flow control system for use therein

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegtnes, K.O.

1977-01-01

An electric power plant having dual turbine-generators connected to a steam source that includes a high temperature gas cooled nuclear reactor is described. Each turbine comprises a high pressure portion operated by superheat steam and an intermediate-low pressure portion operated by reheat steam; a bypass line is connected across each turbine portion to permit a desired minimum flow of steam from the source at times when the combined flow of steam through the turbine is less than the minimum. Coolant gas is propelled through the reactor by a circulator which is driven by an auxiliary turbine which uses steam exhausted from the high pressure portions and their bypass lines. The pressure of the reheat steam is controlled by a single proportional-plus-integral controller which governs the steam flow through the bypass lines associated with the intermediate-low pressure portions. At times when the controller is not in use its output signal is limited to a value that permits an unbiased response when pressure control is resumed, as in event of a turbine trip. 25 claims, 2 figures

Efficiency and safety of leukocyte filtration during cardiopulmonary bypass for cardiac surgery

NARCIS (Netherlands)

Smit, JJJ; de Vries, AJ; Gu, YJ; van Oeveren, W

Background. Leukocyte filtration of systemic blood during cardiopulmonary bypass surgery to reduce post-operative morbidity has not yet been established because of the enormous leukocyte release from the third space. This study was designed to examine the efficiency and safety of leukocyte

Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass

DEFF Research Database (Denmark)

Christiansen, Claus Behrend; Berg, Ronan M G; Plovsing, Ronni R

2016-01-01

Background Cerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (d...

Perioperative outcomes in minimally invasive direct coronary artery bypass versus off-pump coronary artery bypass with sternotomy.

Science.gov (United States)

Tekin, Ali İhsan; Arslan, Ümit

2017-09-01

Surgical treatment of isolated left anterior descending coronary artery disease can be performed with either minimally invasive direct coronary artery bypass via a left anterior thoracotomy (MIDCAB) or off-pump coronary artery bypass via a median sternotomy (OPCAB). To compare the perioperative outcomes of patients undergoing MIDCAB or OPCAB surgery. Patients who underwent either MIDCAB or OPCAB for isolated left anterior descending (LAD) coronary artery disease between October 2013 and December 2015 were retrospectively evaluated. Operations were carried out by the same surgical team. Preoperative, intraoperative and postoperative data of the patients were recorded for analyses. Twenty-three patients (7 females, 16 males) underwent MIDCAB surgery, and 24 patients (4 female, 20 males) underwent OPCAB surgery. The two groups were comparable regarding preoperative patient characteristics. Duration of mechanical ventilation (5.1 ±0.7 h vs. 6.6 ±0.9 h), intensive care unit stay (19.4 ±2.5 h vs. 45.8 ±5.4 h) and hospital stay (4.3 ±0.4 days vs. 5.6 ±0.8 days) were significantly shorter in the MIDCAB group (p < 0.01). Patients in the OPCAB group required significantly more blood transfusions (1.83 ±0.38 units vs. 0.17 ±0.38 units) and fresh frozen plasma use (2.33 ±0.96 units vs. 0.69 ±0.76 units) (p < 0.01). Conversion to sternotomy was not required in the MIDCAB group. There was no mortality, conversion to cardiopulmonary bypass or serious complication in either group. We believe that the MIDCAB technique is more advantageous than the OPCAB technique in the treatment of patients with a critical LAD lesion.

Bypass Flow and Hot Spot Analysis for PMR200 Block-Core Design with Core Restraint Mechanism

International Nuclear Information System (INIS)

Lim, Hong Sik; Kim, Min Hwan

2009-01-01

The accurate prediction of local hot spot during normal operation is important to ensure core thermal margin in a very high temperature gas-cooled reactor because of production of its high temperature output. The active cooling of the reactor core determining local hot spot is strongly affected by core bypass flows through the inter-column gaps between graphite blocks and the cross gaps between two stacked fuel blocks. The bypass gap sizes vary during core life cycle by the thermal expansion at the elevated temperature and the shrinkage/swelling by fast neutron irradiation. This study is to investigate the impacts of the variation of bypass gaps during core life cycle as well as core restraint mechanism on the amount of bypass flow and thus maximum fuel temperature. The core thermo fluid analysis is performed using the GAMMA+ code for the PMR200 block-core design. For the analysis not only are some modeling features, developed for solid conduction and bypass flow, are implemented into the GAMMA+ code but also non-uniform bypass gap distribution taken from a tool calculating the thermal expansion and the shrinkage/swell of graphite during core life cycle under the design options with and without core restraint mechanism is used

Multi-slice CT angiography in evaluation of extracranial-intracranial bypass

Energy Technology Data Exchange (ETDEWEB)

Teksam, Mehmet E-mail: mehmetteksam@yahoo.com; McKinney, Alexander; Truwit, Charles L

2004-12-01

Multi-slice CT (MSCT) scanners provided significant improvement in vascular applications. In this study, our purpose was to determine the clinical utility of MSCTA in evaluation of extracranial-intracranial (EC-IC) bypass patency. Eleven (4 men and 7 women; mean age, 46 years; age range, 19-68 years) consecutive patients who underwent MSCTA and DSA after EC-IC bypass surgery were evaluated retrospectively. All patients underwent DSA within 3 weeks of MSCTA. The indications for EC-IC bypass were severe stenosis or occlusion of intracranial arteries in seven patients and therapeutic occlusion of intracranial artery for unclippable giant aneurysm in four patients. Ten patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and one patient underwent occipital artery-posterior cerebral artery (PCA) bypass. Eight STA-MCA bypasses in six patients were patent on MSCTA which were confirmed on DSA. Two MSCTA bypasses and one occipital artery-posterior cerebral artery (PCA) bypass were occluded in three patients on MSCTA and DSA. In one patient, minimal stenosis of the STA-MCA bypass was identified on MSCTA and DSA. In 1 patient, STA-MCA bypass was not well seen on MSCTA and suspected for occlusion. DSA identified the occlusion of bypass on this patient. MSCTA seems to be a very promising noninvasive technique in evaluation of EC-IC bypass.

Multi-slice CT angiography in evaluation of extracranial-intracranial bypass

International Nuclear Information System (INIS)

Teksam, Mehmet; McKinney, Alexander; Truwit, Charles L.

2004-01-01

Multi-slice CT (MSCT) scanners provided significant improvement in vascular applications. In this study, our purpose was to determine the clinical utility of MSCTA in evaluation of extracranial-intracranial (EC-IC) bypass patency. Eleven (4 men and 7 women; mean age, 46 years; age range, 19-68 years) consecutive patients who underwent MSCTA and DSA after EC-IC bypass surgery were evaluated retrospectively. All patients underwent DSA within 3 weeks of MSCTA. The indications for EC-IC bypass were severe stenosis or occlusion of intracranial arteries in seven patients and therapeutic occlusion of intracranial artery for unclippable giant aneurysm in four patients. Ten patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and one patient underwent occipital artery-posterior cerebral artery (PCA) bypass. Eight STA-MCA bypasses in six patients were patent on MSCTA which were confirmed on DSA. Two MSCTA bypasses and one occipital artery-posterior cerebral artery (PCA) bypass were occluded in three patients on MSCTA and DSA. In one patient, minimal stenosis of the STA-MCA bypass was identified on MSCTA and DSA. In 1 patient, STA-MCA bypass was not well seen on MSCTA and suspected for occlusion. DSA identified the occlusion of bypass on this patient. MSCTA seems to be a very promising noninvasive technique in evaluation of EC-IC bypass

Main facts 1995

International Nuclear Information System (INIS)

1996-01-01

This report presents the main facts of the studies carried out by the Direction des Etudes et Recherches (DER) of Electricite de France: new applications of electricity, classical and nuclear thermal power plants, electrical equipment, environment protection, monitoring and plants operations

[Coronary bypass in treatment of high-risk patients].

Science.gov (United States)

Avdagić, Harun; Mujanović, Emir; Mesanović, Nihad; Sijereić-Avdagić, Selma; Pirić, Melika

2009-01-01

Although it is possible to find a number of comparative studies in the world literature discussing the results of coronary artery bypass surgery (CABG) with and without cardiopulmonary bypass (CPB), until now such analysis has not been made in Bosnia and Herzegovina. The main aim of this scientific work was to compare morbidity and mortality, need for blood transfusions, length of stay in the intensive care unit, total length of hospitalisation and number of complication in two groups of patients operated with these methods. Patients with EuroScore > or =5 with CABG operated in Cardiovascular Clinic Tuzla, from May 2000 to May 2005 divided in two groups, were included in this study. There were 100 patients in the first group operated with CPB and 100 patients in the second group operated without CPB. The average time spent on respirators was shorter in patients operated without CPB (3.7 vs.9.74 hours, p = 0.023) and the time spent in Intensive care shorter too (19 vs. 23 days, p = 0.008). Volume of postoperative bleeding was less in patients operated without CPB (574.9 vs. 988.9 ml, p = 0.038), as volume after blood transfusion (168.8 vs. 350.3 mi, p = 0.001). Intraoperative inotrope support was less in patients operated without CPB (8.0 vs. 19.0%, p = 0.038) as postoperative inotrope support (6.0 vs. 17.0%, p = 0.027). The most usual postoperative complication was atrial fibrillation and there was no difference between patients operated with CPB and without CPB (24% vs. 17%, p = 0.293). Mortality was not different in patients operated with or without CPB (2.0% vs. 6.0%, p = 0.140). The average time of total hospitalisation was also shorter in patients operated without CPB (8.0 vs. 9.5 days, p = 0.039. In conclusion CABG without CPB has many advantages compared to the conventional method. Mortality and morbidity are reduced and there is less need for transfusion. The time spent on mechanical ventilation is reduced and less time is spent in intensive care. The total

21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is...

21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

Science.gov (United States)

2010-04-01

... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240...

Prognostic information in administrative co-morbidity data following coronary artery bypass grafting

DEFF Research Database (Denmark)

Abildstrøm, Steen Zabell; Hvelplund, Anders; Rasmussen, Søren

2010-01-01

The aim of this study was to evaluate the prognostic information obtainable from administrative data with respect to 30-day mortality following coronary artery bypass grafting (CABG) and to compare it with the European System for Cardiac Operative Risk Evaluation (EuroSCORE) recorded in a clinical...

Interventions in Infrainguinal Bypass Grafts

International Nuclear Information System (INIS)

Mueller-Huelsbeck, S.; Order, B.-M.; Jahnke, T.

2006-01-01

The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft

Augmented reality-assisted bypass surgery: embracing minimal invasiveness.

Science.gov (United States)

Cabrilo, Ivan; Schaller, Karl; Bijlenga, Philippe

2015-04-01

The overlay of virtual images on the surgical field, defined as augmented reality, has been used for image guidance during various neurosurgical procedures. Although this technology could conceivably address certain inherent problems of extracranial-to-intracranial bypass procedures, this potential has not been explored to date. We evaluate the usefulness of an augmented reality-based setup, which could help in harvesting donor vessels through their precise localization in real-time, in performing tailored craniotomies, and in identifying preoperatively selected recipient vessels for the purpose of anastomosis. Our method was applied to 3 patients with Moya-Moya disease who underwent superficial temporal artery-to-middle cerebral artery anastomoses and 1 patient who underwent an occipital artery-to-posteroinferior cerebellar artery bypass because of a dissecting aneurysm of the vertebral artery. Patients' heads, skulls, and extracranial and intracranial vessels were segmented preoperatively from 3-dimensional image data sets (3-dimensional digital subtraction angiography, angio-magnetic resonance imaging, angio-computed tomography), and injected intraoperatively into the operating microscope's eyepiece for image guidance. In each case, the described setup helped in precisely localizing donor and recipient vessels and in tailoring craniotomies to the injected images. The presented system based on augmented reality can optimize the workflow of extracranial-to-intracranial bypass procedures by providing essential anatomical information, entirely integrated to the surgical field, and help to perform minimally invasive procedures. Copyright © 2015 Elsevier Inc. All rights reserved.

Post-Bypass Extensive Ascites due to Splanchnic Bypass and the Effectiveness of Hyperalimentation Treatment

Directory of Open Access Journals (Sweden)

Veysel Temizkan

2013-04-01

Full Text Available Reperfusion edema may develop in the early periods of chronic ischemic tissue reperfusion. Reperfusion edema may be represented after the splanchnic bypass with ascites, abdominal distension, and liver and kidney function impairment. In this article, we are reporting the hyperalimentation treatment and its results for the common ascites and hepatorenal syndrome, after a coeliac and superior mesenteric artery bypass. [Arch Clin Exp Surg 2013; 2(2.000: 124-128

Bypass grafting to the anterior tibial artery.

Science.gov (United States)

Armour, R H

1976-01-01

Four patients with severe ischaemia of a leg due to atherosclerotic occlusion of the tibial and peroneal arteries had reversed long saphenous vein grafts to the patent lower part of the anterior tibial artery. Two of these grafts continue to function 19 and 24 months after operation respectively. One graft failed on the fifth postoperative day and another occluded 4 months after operation. The literature on femorotibial grafting has been reviewed. The early failure rate of distal grafting is higher than in the case of femoropopliteal bypass, but a number of otherwise doomed limbs can be salvaged. Contrary to widely held views, grafting to the anterior tibial artery appears to give results comparable to those obtained when the lower anastomosis is made to the posterior tibial artery.

[Rupture of venous bypass graft associated to infection of multiresistant bacteria].

Science.gov (United States)

Vidoedo, José C; Toledo, Timmy; Sampaio, Sérgio; Cerqueira, Alfredo; Vilaça, Isabel; Dias, Paulo; Carvalho, Joana; Meira, José; Mansilha, Armando; Paiva, José A; de Albuquerque, Roncon

2006-01-01

We report two cases of severe trauma of the upper limb requiring arterial revascularization. A brachio-brachial inverted saphenous bypass graft was done in both cases. Graft rupture attributed to local infection occurred at fourth post-operative week. Pseudomonas aeruginosa was isolated from the surgical wound in the first case and Acinetobacter baumanni in the second. The first case ended up with arm amputation mostly owing to extensive destruction of soft tissue, the patient being discharged home without any other sequel. In the second case the patient was successfully resuscitated after cardiopulmonary arrest, secondary to hemorrhagic shock. He underwent new brachio-brachial venous bypass graft avoiding the contaminated area. Irreversible ischemic signs plus growing overt infection led to arm amputation later on. This patient developed multi-organ failure and died by the fifth post-operative week. Acinetobacter baumannii and Pseudomonas aeruginosa are gram-negative bacilli widely present in hospital environment. Most of them are resistant to commonly used antibiotics. Their association with vascular conduit infections might have dreadful consequences as it happened in these cases.

Extra-intracranial standard bypass in the elderly

DEFF Research Database (Denmark)

Sandow, Nora; von Weitzel-Mudersbach, Paul; Rosenbaum, Sverre

2013-01-01

Patients with chronic atherosclerotic vessel occlusion and cerebrovascular hemodynamic insufficiency may benefit from extra-intracranial (EC-IC) bypass surgery. Due to demographic changes, an increasing number of elderly patients presents with cerebrovascular hemodynamic insufficiency. So far......, little data for EC-IC bypass surgery in elderly patients suffering occlusive cerebrovascular disease are available. We therefore designed a retrospective study to address the question whether EC-IC bypass is a safe and efficient treatment in a patient cohort ≥70 years....

Oxygen delivery and consumption during on-bypass cabg in htea and central analgesia

Directory of Open Access Journals (Sweden)

Віталій Олексійович Собокарь

2015-04-01

Full Text Available Objective. Despite some advantages, the use of high thoracic epidural anesthesia (HTEA during on-bypass cardiac surgery may be discouraged by fear of adverse hemodynamic effects and associated disturbances of oxygen delivery.Aim. To compare oxygen delivery and consumption during on-bypass coronary artery bypass grafting in settings of HTEA and central analgesia (CA.Methods. 132 patients were assigned into two groups – study group (n=85, where the surgery was performed under HTEA and control group (n=47 - where the surgery was carried out under CA. Using data of transesophageal cardiac ultrasound and blood oximetry blood oxygen delivery (DO2, oxygen consumption (VO2, oxygen extraction coefficient (CEO2 were calculated at four stages of the surgery: after induction, sternotomy, cardiopulmonary bypass and at the end of the surgery.Results. In the initial stages of the surgery DO2 and VO2 were reduced relative to reference values with a tendency to increase in the course of the operation and achievement of the normal or supernormal level (VO2, study group in the final stage. The decrease was due to moderate hypodynamic circulation and hemodilution. After sternotomy DO2 in the study group was higher than that of the control: 356 (279; 458 vs 317±89 ml·min-1·m-2, (р=0,021. After cardiopulmonary bypass oxygen saturation of venous blood (SatvO2, in the study group was 71 ± 9 % compared with 68 ± 10 % in the control group. At the end of the surgery SatvO2 in the study group was 71 (66; 75 vs 59 (53; 70 % in the control (р = 0,005 and oxygen tension of venous blood (РvО2 was correspondingly 39 ± 6 and 33 (30; 38 mm Hg (р = 0,027. Despite the decrease in DO2 and VO2, oxygen extraction indices - CEO2, pvO2, SatvO2, and remained within the reference range, except that of the control group at the end of the surgery. Furthermore, at no stage lactate rise or acid-base deviations was observed in the both groups.Conclusions. In patients operated

21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

Science.gov (United States)

2010-04-01

... bypass oxygenator. (a) Identification. A cardiopulmonary bypass oxygenator is a device used to exchange gases between blood and a gaseous environment to satisfy the gas exchange needs of a patient during open...

Dacron or PTFE for Above-knee Femoropopliteal Bypass. A Multicenter Randomised Study

DEFF Research Database (Denmark)

Jensen, L. P.; Lepäntalo, M.; Fossdal, J. E.

2007-01-01

more often than patients operated on for intermittent claudication, 10 and 3 respectively (p=0.003), and had higher mortality rates, 20% and 8% respectively (p=0.001). CONCLUSION: This trial confirms that Dacron is at least as durable as PTFE for above-knee bypass procedures, and might even be superior....

Study of transient turbine shot without bypass in a BWR; Estudio del transitorio disparo de turbina sin bypass en un BWR

Energy Technology Data Exchange (ETDEWEB)

Vallejo Q, J. A.; Martin del Campo M, C.; Fuentes M, L.; Francois L, J. L., E-mail: amhed_jvq@hotmail.com [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico)

2015-09-15

The study and analysis of operational transients are important for predicting the behavior of a system to short-terms events and the impact that would cause this transition. For the nuclear industry these studies are indispensable due to economic, environmental and social impacts that could result in an accident during the operation of a nuclear reactor. In this paper the preparation, simulation and analysis of results of a turbine shot transient, which is not taken into operation the bypass is presented. The study is realized for a BWR of 2027 MWt, to an intermediate cycle life and using the computer code Simulate-3K a depressurization stage of the vessel is created which shows the response of other security systems and gives a coherent prediction to the event presented type. (Author)

Gastric bypass surgery: Improving psoriasis through a GLP-1-dependent mechanism?

DEFF Research Database (Denmark)

Faurschou, Annesofie; Zachariae, Claus; Skov, Lone

2011-01-01

surgery. This most likely contributes importantly to the acute remission of type 2 diabetes, which is often induced by gastric bypass operations. The hormone is not hypersecreted after the purely restrictive bariatric procedure gastric banding and no case reports exist on improvement in psoriasis......, both a direct anti-inflammatory effect of GLP-1 as well as an indirect effect through weight loss could contribute to improvement in psoriasis. A potential involvement of GLP-1 in the remission of psoriasis observed after bariatric surgery offers exciting possibilities for research and eventually...... bypass surgery in patients with psoriasis may result in complete remission of the disease. A substantial weight loss is achieved in the months following surgery, which is likely to reduce psoriasis symptoms and risk of comorbidities. Interestingly, however, it has been described that improvement...

CT perfusion assessment of Moyamoya syndrome before and after direct revascularization (superficial temporal artery to middle cerebral artery bypass)

Energy Technology Data Exchange (ETDEWEB)

Chen, Yueqin [Hospital of Qingdao University, Department of Radiology, Qingdao (China); Hospital of Jining Medical College, CT Department, Jining (China); Xu, Wenjian [Hospital of Qingdao University, Department of Radiology, Qingdao (China); Guo, Xiang; Shi, Zhitao; Sun, Zhanguo; Wang, Jiehuan [Hospital of Jining Medical College, CT Department, Jining (China); Gao, Lingyun [Hospital of Jining Medical College, MR Department, Jining (China); Jin, Feng [Hospital of Jining Medical College, Department of Neurosurgery, Jining (China); Chen, Weijian; Yang, Yunjun [Hospital of Wenzhou Medical University, Department of Radiology, Wenzhou (China)

2016-01-15

To evaluate the utility of CT perfusion (CTP) for the assessment of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with Moyamoya syndrome (MMS). Twenty-four consecutive MMS patients, who underwent unilateral STA-MCA bypass surgery, received CTP before and after surgery. The relative perfusion parameter values of surgical hemispheres before treatment were compared with post-treatment values. All patients underwent CT angiography (CTA) before and after surgery in order to confirm the patency of bypass. The follow-up CTA after surgery clearly demonstrated 20 (20/24, 83.3 %) bypass arteries, whereas four (16.7 %) bypass arteries were occluded or very small. Postoperative rMTT and rTTP values (P < 0.05) of the surgical side were significantly lower than pre-operation. In patients (n = 20) with bypass patency, postoperative rCBF, rMTT and rTTP values (P < 0.05) of the surgical side were significantly improved. However, the differences of all parameters were not significant (P > 0.05) in the patients (n = 4) without bypass patency after revascularization. This study demonstrates that CTP can provide a crucial quantitative assessment of cerebral haemodynamic changes in MMS before and after STA-MCA anastomosis. (orig.)

On-pump versus off-pump coronary artery bypass surgery

DEFF Research Database (Denmark)

Houlind, Kim Christian

2013-01-01

Off pump coronary artery bypass surgery has been purported to be safer than conventional coronary artery bypass surgery performed using cardiopulmonary bypass. This theory was supported by a number of early series, but failed to be confirmed by a number of small, randomized controlled trials...

A new veno-venous bypass type for ex-vivo liver resection in dogs.

Science.gov (United States)

Lei, Peng; Liu, Shi-Qi; Cui, Xiao-Hai; Lv, Yi; Zhao, Ge; Li, Jian-Hui

2013-08-01

Ex-vivo liver resection is a procedure in which the liver is completely removed, perfused and after bench surgery, the liver is autotransplanted to the original site. Ex-vivo liver resection is an important treatment for unresectable liver tumors. This surgical procedure requires long operation time, during which blood flow must be carefully maintained to avoid venous congestion. An effective veno-venous bypass (VVB) may meet this requirement. The present study was to test our new designed VVB device which comprised one heparinized polyvinylchloride tube and three magnetic rings. The efficacy of this device was tested in five dogs. A VVB was established in 6-10 minutes. There was no leakage during the procedure. Hemodynamics was stable at anhepatic phase, which indicated that the bypass was successful. This newly-developed VVB device maintained circulation stability during ex-vivo liver resection in our dog model and thus, this VVB device significantly shortened the operation time.

Measurement of Blood Flow in an Intracranial Artery Bypass From the Internal Maxillary Artery by Intraoperative Duplex Sonography.

Science.gov (United States)

Yu, Zaitao; Shi, Xiang'en; Brohi, Shams Raza; Qian, Hai; Liu, Fangjun; Yang, Yang

2017-02-01

This study explored the hemodynamic characteristics of a subcranial-intracranial bypass from the internal maxillary artery by measuring blood flow on intraoperative duplex sonography. The hemodynamic parameters of the internal maxillary artery (n = 20), radial artery (n = 20), internal maxillary artery-middle cerebral artery bypass (n = 42), and internal maxillary artery-posterior cerebral artery bypass (n = 9) were measured by intraoperative duplex sonography. There was no significant difference in the internal diameters of the internal maxillary and radial arteries (mean ± SD, 2.51 ± 0.34 versus 2.56 ± 0.22 mm; P = .648). The mean radial artery graft length for subcranial-intracranial bypasses was 88.5 ± 12.78 mm (95% confidence interval [CI], 80.8-90.2 mm). Internal maxillary artery-middle cerebral artery bypasses required a shorter radial artery graft than internal maxillary artery-posterior cerebral artery bypasses (77.8 ± 2.47 versus 104.8 ± 4.77 mm; P = .001). The mean flow volumes were 85.3 ± 18.5 mL/min (95% CI, 76.6-93.9 mL/min) for the internal maxillary artery, 72.6 ± 26.4 mL/min (95% CI, 64.3-80.9 mL/min) for internal maxillary artery-middle cerebral artery bypasses, and 45.4 ± 6.7 mL/min (95% CI, 40.7-50.0 mL/min) for internal maxillary artery-posterior cerebral artery bypasses. All grafts were opened after the success of the salvage procedures had been established, and the early patency rates (1 month after the operation) were 95% for internal maxillary artery-middle cerebral artery bypasses and 100% the internal maxillary artery-posterior cerebral artery bypasses. Measurement of blood flow by intraoperative sonography can be helpful in decision making and predicting graft patency and success after neurosurgical bypass procedures. © 2016 by the American Institute of Ultrasound in Medicine.

Radionuclide angiographical assessment of the effects of aorto-coronary bypass grafting on ventricular function during rest and exercise

International Nuclear Information System (INIS)

Kito, Yoshitsugu; Fujita, Tsuyoshi; Ohara, Kuniyoshi

1983-01-01

Ventricular function was measured by radionuclide angiography during rest and exercise in 27 patients before and after aorto-coronary bypass grafting (AC bypass). The patients were divided in three groups: 6 patients in complete revascularisation (group A), 8 patients in surgical complete revascularisation (group B), and 13 patients in incomplete revascularisation (group C). Heart rate increased by exercise from 58 +- 5 bpm to 87 +- 5 bpm, from 60 +- 5 bpm to 90 +- 15 bpm, and from 61 +- 8 bpm to 84 +- 7 bpm before AC bypass, and increased from 81 +- 7 bpm to 116 +- 11 bpm, from 86 +- 13 bpm to 114 +- 12 bpm, and from 80 +- 11 bpm to 106 +- 13 bpm after AC bypass in group A, B and C, respecitively. EF decreased by exercise from 61 +- 7 % to 58 +- 12 %, from 53 +- 10 % to 49 +- 7 %, and from 54 +- 8 % to 52 +- 8 % before AC bypass, and increased by exercise from 66 +- 7 % to 77 +- 6 %, from 49 +- 11 % to 56 +- 13 %, and from 54 +- 8 % to 59 +- 10 % after AC bypass in group A,FB and C, respectively. dV/dt(Vmax/sec) increased by exercise from 4.0 +- 1.0 to 4.4 +- 1.0, from 2.5 +- 1.0 to 3.4 +- 1.5 and from 3.5 +- 0.5 to 3.4 +- 0.6 before AC bypass, and increased from 3.9 +- 0.5 to 6.2 +- 0.7, from 3.5 +- 0.9 to 5.0 +- 0.7, and from 3.6 +- 1.0 to 5.4 +- 1.5 after AC bypass in group A,B and C, respectively. In conclusion, left ventricular performance during exercise was significantly increased after AC bypass in all patients. However, the rate of increase in left ventricular performance during exercise after AC bypass was more significant in the group of complete revascularisation than in the group of others. Serial application of radionuclide angiography to patients after AC bypass appears promising in evaluating the long-term effects of operation on ventricular function. (author)

Prognostic information in administrative co-morbidity data following coronary artery bypass grafting

DEFF Research Database (Denmark)

Abildstrøm, Steen Zabell; Hvelplund, Anders; Rasmussen, Søren

2010-01-01

Objectives: The aim of this study was to evaluate the prognostic information obtainable from administrative data with respect to 30-day mortality following coronary artery bypass grafting (CABG) and to compare it with the European System for Cardiac Operative Risk Evaluation (EuroSCORE) recorded ...... was equal to that of the EuroSCORE (c-statistic 0.79). Conclusions: A standard co-morbidity index based on administrative data as well as on clinical data has proven equally useful for prediction of mortality amongst CABG patients.......Objectives: The aim of this study was to evaluate the prognostic information obtainable from administrative data with respect to 30-day mortality following coronary artery bypass grafting (CABG) and to compare it with the European System for Cardiac Operative Risk Evaluation (EuroSCORE) recorded...... in a clinical database. Methods: We used a co-morbidity index calculated from administrative data in the Danish National Patient Register by means of all admissions 1 year prior to CABG. In addition, each CABG was categorised as being isolated or not, and acute or not. The prognostic power of the co...

Assessing Patient bypass Behavior Using Taxi Trip Origin–Destination (OD Data

Directory of Open Access Journals (Sweden)

Gege Yang

2016-09-01

Full Text Available Many patients prefer to use the best hospitals even if there are one or more other hospitals closer to their homes; this behavior is called “hospital bypass behavior”. Because this behavior can be problematic in urban areas, it is important that it be reduced. In this paper, the taxi GPS data of Beijing and Suzhou were used to measure hospital bypass behavior. The “bypass behavior index” (BBI represents the bypass behavior for each hospital. The results indicated that the mean hospital bypass trip distance value ranges from 5.988 km to 9.754 km in Beijing and from 4.168 km to 10.283 km in Suzhou. In general, the bypass shares of both areas show a gradually increasing trend. The following hospitals exhibited significant patient bypass behavior: the 301 Hospital, Beijing Children’s Hospital, the Second Affiliated Hospital of Soochow University and the Suzhou Hospital of Traditional Chinese Medicine. The hospitals’ reputation, transport accessibility and spatial distribution were found to be the main factors affecting patient bypass behavior. Although the hospital bypass phenomena generally appeared to be more pronounced in Beijing, the bypass trip distances between hospitals were found to be more significant in Suzhou.

21 CFR 870.4300 - Cardiopulmonary bypass gas control unit.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass gas control unit. 870.4300... bypass gas control unit. (a) Identification. A cardiopulmonary bypass gas control unit is a device used to control and measure the flow of gas into the oxygenator. The device is calibrated for a specific...

SIMPLIFIED LAPAROSCOPIC GASTRIC BYPASS WITH GASTROJEJUNAL LINEAR MECHANICAL ANASTOMOSIS: TECHNICAL ASPECTS.

Science.gov (United States)

Palermo, Mariano; Serra, Edgardo

Gastric bypass is a restrictive and malabsorptive surgery. The restrictive part consists in the creation of a small gastric pouch. The gastrointestinal bypass serves as the malabsorptive element. To describe a simplified gastric bypass approach for morbid obese patients, showing our results, and also remarking the importance of this technique for reducing the learning curve. The patient is positioned in a split legs position and carefully strapped to the operating room table, with the surgeon between the patient's legs. Five trocars are inserted after pneumoperitoneum at the umbilicus. Dissection of the esophagogastric angle and lesser curvature is mandatory before the gastric pouch manufacturing. This pouch is done with two blue load staplers. Using a blue load linear stapler inserted only half way into the hole in the pouch is used to perform the gastrojejunal anastomosis and in order to create an anastomosis that is about 2 cm in length. A side-to-side jejunojejunostomy is done with a white load linear stapler. The last step of the gastric bypass consists in the cut of the jejunum between the two anastomosis with a white load linear stapler. Blue test is performed in order to detect leaks. From January 2012 to December 2015, 415 simplified RYGB were performed. Gender: 67% female and 33 % males. Average of BMI 44.7. Mean age was 42 years old. Mean operative time 79 min. 39 % of this sample had T2 diabetes. Regarding complications were observed, one fistula, one gastrojejunal stenosis and one obstruction due to a bezoar. The described technique is a simplified approach in which all the anastomosis are performed in the upper part of the abdomen, allowing the surgeons to be more systematized and avoiding them to make mistakes in the confection of the Roux-en-Y anastomosis. This simplified gastric bypass is a safe and reproducible technique. Bypass gástrico é cirurgia restritiva e malabsortiva. A parte restritiva consiste na criação de uma pequena bolsa g

The learning curve of robot-assisted laparoscopic aortofemoral bypass grafting for aortoiliac occlusive disease.

Science.gov (United States)

Novotný, Tomáš; Dvorák, Martin; Staffa, Robert

2011-02-01

Since the end of the 20th century, robot-assisted surgery has been finding its role among other minimally invasive methods. Vascular surgery seems to be another specialty in which the benefits of this technology can be expected. Our objective was to assess the learning curve of robot-assisted laparoscopic aortofemoral bypass grafting for aortoiliac occlusive disease in a group of 40 patients. Between May 2006 and January 2010, 40 patients (32 men, 8 women), who were a median age of 58 years (range, 48-75 years), underwent 40 robot-assisted laparoscopic aortofemoral reconstructions. Learning curve estimations were used for anastomosis, clamping, and operative time assessment. For conversion rate evaluation, the cumulative summation (CUSUM) technique was used. Statistical analysis comparing the first and second half of our group, and unilateral-to-bilateral reconstructions were performed. We created 21 aortofemoral and 19 aortobifemoral bypasses. The median proximal anastomosis time was 23 minutes (range, 18-50 minutes), median clamping time was 60 minutes (range, 40-95 minutes), and median operative time was 295 minutes (range, 180-475 minutes). The 30-day mortality rate was 0%, and no graft or wound infection or cardiopulmonary or hepatorenal complications were observed. During the median 18-month follow-up (range, 2-48 months), three early graft occlusions occurred (7%). After reoperations, the secondary patency of reconstructions was 100%. Data showed a typical short learning curve for robotic proximal anastomosis creation with anastomosis and clamping time reduction. The operative time learning curve was flat, confirming the procedure's complexity. There were two conversions to open surgery. CUSUM analysis confirmed that an acceptable conversion rate set at 5% was achieved. Comparing the first and second half of our group, all recorded times showed statistically significant improvements. Differences between unilateral and bilateral reconstructions were not

Fluid distribution kinetics during cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Mattias Törnudd

2014-08-01

Full Text Available OBJECTIVE: The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass. METHODS: Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166. RESULTS: The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02. The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml. CONCLUSIONS: The distribution half-time of Ringer's solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur.

Coronary artery bypass grafting without cardiopulmonary bypass and without interruption of native coronary flow using a novel anastomosis site restraining device ("Octopus").

Science.gov (United States)

Borst, C; Jansen, E W; Tulleken, C A; Gründeman, P F; Mansvelt Beck, H J; van Dongen, J W; Hodde, K C; Bredée, J J

1996-05-01

This study assessed the feasibility of coronary artery bypass grafting on the beating heart without interruption of native coronary blood flow using a novel anastomosis site restraining device. Recently, an end-to-side bypass technique was described that does not require interruption of flow in the recipient artery. By means of a suction device ("Octopus"), in 31 pigs the epicardium was grasped and immobilized through an arm contraption fixed to the operating table. In the first 15 consecutive pigs (study I), the two-dimensional motion of an epicardial beacon was monitored. In 16 subsequent pigs (study II), an internal mammary artery was grafted under the microscope in two steps to a proximal coronary artery segment, without cardiopulmonary bypass. First, the internal mammary artery was sutured end-to-side to the outside of the coronary artery. Secondly, an orifice was punched in the partitioning coronary wall by an excimer laser catheter introduced through a temporary side-branch of the internal mammary artery. Study II: During 43 suction periods in four anastomosis areas, immobilization was achieved for 15 to 169 min (>30 h in total) in 13 open- and 9 closed-chest procedures without hemodynamic deterioration. The area circumscribed by the edges of the beacon trajectory (area in which the anastomosis is to be tracked) was reduced from 73.0 +/- 43.0 mm(2) (mean +/- SD) to 1.3 +/- 0.5 mm(2) (p<0.001) in the open-chest and to 0.2 +/- 0.2 mm(2) in the closed-chest procedure. At 6 weeks, no myocardial or coronary suction lesions were found. Study II: Nonocclusive anastomosis surgery required 25 +/- 3 min. No leakage, serious arrhythmias, graft closure or hemodynamic deterioration occurred during the procedure or for 2 h after ligating the coronary artery proximally. At 6 weeks, all seven grafts were patent. Coronary bypass on the beating heart without interruption of coronary flow is feasible. In both open- and in closed-chest procedures, the "Octopus" reduced

The influence of core bypass flow during SBLOCA

International Nuclear Information System (INIS)

Maselj, A.; Jurkovic, M.

1996-01-01

Many parameters affect the behaviour of a NPP during a Small Break Loss of Coolant Accident (SBLOCA). The bypass flow between the core side and the downcomer is one of them. Different PWRs have different values of core bypass flow. In spite of the complexity of the real situation in the primary system during SBLOCA, some fundamental details of the phenomena can be explained with simplified mathematical models, which relate on basic parameters of the primary coolant. These models define the conditions for loop seal clearance and final results are confirmed with measured values. The analysis presented in the paper refers to Bethsy Test 9.1.b SB LOCA scenario, with variation of core bypass flow. Basic RELAP5 input model calculation results show very good agreement with the experimental data. The core liquid level depression before loop seal clearance is lower in case of smaller core bypass flow. This affects the fuel clad temperature because of different heat transfer mechanisms. Time of loop seal clearance is delayed with larger core bypass flow and consequently lower differential pressure between downcomer and core. (author)

Gastric bypass surgery

Science.gov (United States)

... your body will not get all of the calories from the food you eat. ... to a small hole in your pouch. The food you eat will now travel ... absorb fewer calories. Gastric bypass can be done in two ways. ...

A CFD method to evaluate the integrated influence of leakage and bypass flows on the PBMR Reactor Unit

International Nuclear Information System (INIS)

Janse van Rensburg, J.J.; Kleingeld, M.

2010-01-01

Research highlights: → Research and analysis to identify and rank different leakage flow paths in a HTR. → Development of integrated CFD methodology for the prediction of leakage flows. → Development of a methodology to simulate flow resistances in above CFD model. → Validation of predicted flow results against different numerical methodology. → Illustration of the significant improvement achieved through this methodology. - Abstract: An area that has been identified as significantly important in the development of a High Temperature Reactor (HTR) is the prediction of leakage and bypass flows through such a reactor. It is therefore essential to understand the causes of bypass flows and to determine the effect on the predicted fuel and component temperatures. This paper discusses the identification of leakage flows that are applicable to the Pebble Bed Modular Reactor (Pty) Ltd. (PBMR) design and the ranking of these leakage flows. The modeling methodology and results are also discussed. Similar to previous HTR's, it was found that leakage and bypass flows are important parameters to consider for safe and efficient operation of the PBMR. Through a focused approach, it is shown that PBMR is able to improve the understanding of this phenomenon and quantify the flows and subsequent influence on the operation of the system. This has resulted in a reduction of leakage and bypass from approximately 46% to 20%. The improved understanding of leakage and bypass flows allows PBMR to address this issue during the design phase of the project, which subsequently results in a vast improvement over historical HTR designs. This gives PBMR a distinct advantage over previous High Temperature Reactors.

Thallium-201 exercise myocardial imaging to evaluate myocardial perfusion after coronary artery bypass surgery

International Nuclear Information System (INIS)

Hirzel, H.O.; Nuesch, K.; Sialer, G.; Horst, W.; Krayenbuehl, H.P.

1980-01-01

To assess the usefulness of thallium-201 exercise scintigraphy in evaluating myocardial perfusion after coronary artery bypass surgery, imaging was performed after submaximal bicycle ergometry and at rest in 54 patients before and within 24 +- 10 (SD) weeks after operation. Scintigraphy identified 8 out of 20 patients who were symptom free after operation and showed normal exercise electrocardiograms as still having exercise-induced ischaemia and thus as having not truly benefited from the surgical intervention. In contrast, improvement in perfusion was documented in 17 out of 31 patients despite further complaints of chest pain and persistence of a pathological exercise electrocardiogram in 6 of them. Bypass graft patency rate paralleled the scintigraphic findings in the 35 patients who were restudied arteriographically. It was concluded that thallium-201 exercise scintigraphy is a useful technique to document changes in regional perfusion after surgery and is definitely superior to the clinical evaluation of patients including the exercise electrocardiogram. (author)

Passage of downstream migrant American eels through an airlift-assisted deep bypass

Science.gov (United States)

Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

2016-01-01

Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

Special Operations - Myths and facts

DEFF Research Database (Denmark)

Jensen, Lars H. Ehrensvärd

The brief addresses some of the myths, which have induced an institutional resistance at the political and military decision levels against understanding and considering special operations as a valuable strategic tool in contemporary and future conflict prevention, crisis management, and conflict...

No major differences in 30-day outcomes in high-risk patients randomized to off-pump versus on-pump coronary bypass surgery: the best bypass surgery trial

DEFF Research Database (Denmark)

Møller, Christian H; Perko, Mario J; Lund, Jens T

2010-01-01

Off-pump coronary artery bypass grafting compared with coronary revascularization with cardiopulmonary bypass seems safe and results in about the same outcome in low-risk patients. Observational studies indicate that off-pump surgery may provide more benefit in high-risk patients. Our objective...... was to compare 30-day outcomes in high-risk patients randomized to coronary artery bypass grafting without or with cardiopulmonary bypass....

[Therapy of low-output syndrome in patients following cardiopulmonary bypass with sodium nitroprusside and dopamine].

Science.gov (United States)

van Ackern, K; Franke, N; Peter, K

1978-01-01

In 12 patients with low output after open-heart surgery the therapeutic effect of vasodilatation with sodium nitroprusside (SNP) and dopamine was studied. All patients underwent aortocoronary bypass operations. After cardiopulmonary bypass, the cardiac index (CI) was 2.2 liters/min.m2. The pulmonary wedge pressure (PCWP) was about 20 mm Hg. Application of SNP lowered mean arterial pressure to 82 and PCWP to 13 mm Hg. Then PCWP was elevated to the control level by tranfusion of blood. This therapy increased CI by about 30% without positive inotropic intervention. Additional application of 5 micrograms dopamine/kg.min improved the CI to 3.8 liters/min.m2.

Aortic valve bypass

DEFF Research Database (Denmark)

Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik

2013-01-01

In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI). ...

An Installation of IPS Bypass Line at the Fuel Test Loop

Energy Technology Data Exchange (ETDEWEB)

Choi, Ho Young; Ahn, G. H.; Lee, M.; Kim, M. S.; Cho, S. H.; Han, J. S.; Hur, S. O. [KAERI, Daejeon (Korea, Republic of)

2010-12-15

The Fuel Test Loop(FTL) was installed for the national goal of self-supporting technology in the field of design and construction of nuclear power plant. The FTL with the fuel irradiation equipment is essential in developing, improving and inspecting the fuel of CANDU type or PWR type nuclear power plant. The FTL should be operated at the same conditions of commercial nuclear power plant such as temperature, pressure, flow rate, neutron flux and so on. Starting designing in December 2001, the FTL was installed from March 2007 to August 2008. Especially the In Pile Section(IPS) was installed at IR1 hole in August 2008. Until September 2009 after loading the test fuel, a series of power escalation tests (LSD, CSB1, CSB2, HSB, HOP) were conducted. And it was operated at the condition of CSB2 for the 8 cycles from October 2009 to July 2010. But it could not be normally operated in early 2010, because the high radiation released from irradiated materials due to the worn down bearing of main cooling pump. So, we removed the IPS and installed a newly designed IPS bypass line to prevent increasing high radiation. In this report we will present preliminary works, main works processes, devices of making work environments, a designing and manufacturing of IPS bypass line and a rack of IPS, installing know-hows, problems and solutions broke out during the work etc. We believe that our efforts to complete successful installing and operating of the FTL system will contribute for the efficient utilization of HANARO

Feasibility of arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke

International Nuclear Information System (INIS)

Wang Wei; Li Cheng; Liu Zhensheng; Zhang Xinjiang; Zhou Longjiang; Yin Haiyan

2010-01-01

Objective: To assess the feasibility of arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke. Methods: Six patients with acute cerebral infarction within 6 hours underwent intraarterial thrombolysis, in which arterial blood bypass was used. A 2.3 F microcatheter was advanced through the clot and two milliliters of contrast was injected beyond the clot that remained stagnant in the major branches. At this point, 20 ml of oxygenated blood from femoral artery was injected for 2 minutes through the microcatheter past the occluding clot. Then, conventional intraarterial thrombolysis, including fibrinolytic agents infusion and mechanical disruption, was performed. Intraarterial thrombolysis and oxygenated blood infusion alternated every 30 minutes. Results: Every patient received arterial blood bypass with average three times (from 1 to 5 times) in the process of the intraarterial thrombolysis, which cost (8.0 ± 3.2) min. Recanalization was achieved in all 6 patients, but minor subarachnoid hemorrhage developed in one patient. All the patients got favorable clinical outcome. The life conditions is excellent in 4 cases and good in 2 cases. Conclusions: Arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke might be feasible, which did not interfere with conventional intraarterial thrombolysis and prolong the operation time significantly but could protect ischemic penumbra. (authors)

Bypass flow rate control method

International Nuclear Information System (INIS)

Kiyama, Yoichi.

1997-01-01

In a PWR type reactor, bypass flow rate is controlled by exchanging existent jetting hole plugs of a plurality of nozzles disposed to the upper end of incore structures in order to flow a portion of primary coolants as a bypass flow to the upper portion of the pressure vessel. Two kinds of exchange plugs, namely, a first plug and a second plug each having a jetting out hole of different diameter are used as exchange plugs. The first plug has the diameter as that of an existent plug and the second plug has a jetting out hole having larger diameter than that of the existent plug. Remained extent plugs are exchanged to a combination of the first and the second plugs without exchanging existent plugs having seizing with the nozzles, in which the number and the diameter of the jetting out holes of the second plugs are previously determined based on predetermined total bypass flow rate to be jetted from the entire plugs after exchange of plugs. (N.H.)

21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter nonbiologic...

21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood through...

21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through the...

Cardiopulmonary bypass: development of John Gibbon's heart-lung machine

Directory of Open Access Journals (Sweden)

Andréia Cristina Passaroni

2015-04-01

Full Text Available AbstractObjective:To provide a brief review of the development of cardiopulmonary bypass.Methods:A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation.Results:The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from various degrees of tissue injury to multiple organ dysfunction syndrome. Investigators have long researched the ways in which cardiopulmonary bypass may insult the human body. Potential solutions arose and laid the groundwork for development of safer postoperative care strategies.Conclusion:Steady progress has been made in cardiopulmonary bypass in the decades since it was first conceived of by Gibbon. Despite the constant evolution of cardiopulmonary bypass techniques and attempts to minimize their complications, it is still essential that clinicians respect the particularities of each patient's physiological function.

Cell saver for on-pump coronary operations reduces systemic inflammatory markers: a randomized trial

DEFF Research Database (Denmark)

Damgaard, Sune; Nielsen, Claus Henrik; Andersen, Lars Willy

2010-01-01

This study investigated whether intraoperative use of a cell saver reduces the systemic inflammatory response after coronary operations using cardiopulmonary bypass (CPB).......This study investigated whether intraoperative use of a cell saver reduces the systemic inflammatory response after coronary operations using cardiopulmonary bypass (CPB)....

Characteristics of hemostasis system and hemorrhagic syndrome in infants with congenital heart disease in operations with cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Н. П. Леонов

2016-01-01

Full Text Available 97 neonates were included in this prospective observational study. While using the exclusion criteria, two groups without demographic differences were formed: the first group included 35 patients with blood loss greater than 10 ml/kg in the first 4 hours postoperatively, the second one consisted of 46 patients who did not have such blood loss. Hemostatic standard tests and thromboelastography were performed before surgery, immediately after surgery and 24 hours after it. As a result, a detailed description of the changes of hemostasis in the perioperative period in newborns with CHD was developed. It was found out that significant postoperative bleeding increases the incidence of coagulopathy, resuscitation after surgery, duration of mechanical ventilation, length of stay at ICU and 30-day mortality. It is confirmed that the main pathogenetic mechanisms of increased bleeding in the first hours after the operation are due to cardiopulmonary bypass coagulopathy, the dynamics and implications of which are documented in our study. Also established are prognostic clinical and laboratory predictors of coagulopathy associated with severe multiple organ failure.

The Role of Bile After Roux-en-Y Gastric Bypass in Promoting Weight Loss and Improving Glycaemic Control

Science.gov (United States)

Pournaras, Dimitri J.; Glicksman, Clare; Vincent, Royce P.; Kuganolipava, Shophia; Alaghband-Zadeh, Jamie; Mahon, David; Bekker, Jan H.R.; Ghatei, Mohammad A.; Bloom, Stephen R.; Walters, Julian R.F.; le Roux, Carel W.

2012-01-01

Gastric bypass leads to the remission of type 2 diabetes independently of weight loss. Our hypothesis is that changes in bile flow due to the altered anatomy may partly explain the metabolic outcomes of the operation. We prospectively studied 12 patients undergoing gastric bypass and six patients undergoing gastric banding over a 6-wk period. Plasma fibroblast growth factor (FGF)19, stimulated by bile acid absorption in the terminal ileum, and plasma bile acids were measured. In canine and rodent models, we investigated changes in the gut hormone response after altered bile flow. FGF19 and total plasma bile acids levels increased after gastric bypass compared with no change after gastric banding. In the canine model, both food and bile, on their own, stimulated satiety gut hormone responses. However, when combined, the response was doubled. In rats, drainage of endogenous bile into the terminal ileum was associated with an enhanced satiety gut hormone response, reduced food intake, and lower body weight. In conclusion, after gastric bypass, bile flow is altered, leading to increased plasma bile acids, FGF19, incretin. and satiety gut hormone concentrations. Elucidating the mechanism of action of gastric bypass surgery may lead to novel treatments for type 2 diabetes. PMID:22673227

Sen perforation af tyndtarm efter laparoskopisk gastrisk bypass

DEFF Research Database (Denmark)

Spanager, Lene; Sigild, Ulf Henrik; Neuenschwander, Anders Ulrich

2010-01-01

We present two cases in which the patients were admitted to a local hospital with acute abdominal pain four or five months after having undergone laparoscopic gastric bypass. In both cases, operation revealed a perforation of the small bowel close to the distal anastomosis. In the first case......, a massive constipation of the small bowel was most likely a contributing factor. In the second case, the cause was a kink of the entero-entero anastomosis leading to obstruction and finally perforation of the biliary limp. Late perforations are among the rarely reported complications associated with gastric...

Anterior ischemic optic neuropathy after conventional coronary artery bypass graft surgery.

Science.gov (United States)

Dorecka, Mariola; Miniewicz-Kurkowska, Joanna; Romaniuk, Dorota; Gajdzik-Gajdecka, Urszula; Wójcik-Niklewska, Bogumiła

2011-06-01

Perioperative optic neuropathy is a disease which can lead to serious, irreversible damage of vision. This complication could be the result of non-ocular surgery, for example, cardiac or spinal procedures. We present a case of anterior ischemic neuropathy (AION) which occurred following a conventional coronary artery bypass graft procedure. A 57-year-old man, 4 days after Conventional Coronary Artery Bypass Graft surgery as result of multi-vessel stabile coronary artery disease and history of anterolateral wall myocardial infarction, was admitted to the Eye Clinic due to significant loss of vision in his right eye. The patient had hypertension and was a heavy smoker. On admission, the slit lamp examination revealed a relative afferent pupillary defect in the right eye. The fundus examination showed optic disc edema with the presence of flame hemorrhages. Best corrected visual acuity (BCVA) was 0.02. The results of eye examination and fluorescein angiography confirmed the diagnosis of AION. Anti-aggregation and antithrombotic treatment was continued with steroids and vasodilators. After 7 days of this treatment we noticed the improvement of BCVA to 0.2. At 6-month follow-up, the vision was stable, and fundus examination revealed optic disc atrophy. After cardiac surgical operations, such as coronary artery bypass graft procedures, anterior ischemic optic neuropathy may occur. In those cases, close cooperation between the various specialists is necessary.

Small Intestinal Bypass Induces a Persistent Weight-Loss Effect and Improves Glucose Tolerance in Obese Rats.

Science.gov (United States)

Cao, Jiaqing; Ren, Quan; Tan, Cai; Duan, Jinyuan

2017-07-01

This study investigated the role of proximal small intestinal bypass (PSIB) and distal small intestinal bypass (DSIB) as well as their long-term effects on weight loss and glucose metabolism in high-sugar and high-fat diet-induced obese rats. Sprague-Dawley rats were divided into four groups: PSIB, bypassing 60% of the proximal small intestine length; DSIB, bypassing 60% of the distal small intestine length; sham-operated (Sham) animals; and control animals. All rats were fed a high-sugar and high-fat diet after surgery. The primary outcome measures were body weight, food intake, fasting blood glucose (FBG) levels, oral glucose tolerance test (OGTT), and the insulin tolerance test (ITT). Global body weight (BW) and food intake in the PSIB and DSIB groups were lower than those in the Sham group at postoperative week 2. BW and food intake in the PSIB group were lower than those in the DSIB group at postoperative week 24. The PSIB and DSIB groups exhibited improvement in glucose tolerance at postoperative weeks 4, 8, and 24. The PSIB and DSIB groups exhibited improvement in FBG at postoperative week 24, and only the DSIB group exhibited improvement in insulin sensitivity. This study provides experimental evidence that PSIB surgery induced a better and more persistent weight loss effect than DSIB surgery and that the two types of intestinal bypass surgeries yielded equivalent and stable long-term improvement in glucose tolerance in an obese rat model.

Predictions of the Bypass Flows in the HTR-PM Reactor Core

International Nuclear Information System (INIS)

Sun Jun; Chen Zhipeng; Zheng Yanhua; Shi Lei; Li Fu

2014-01-01

In the HTR-PM reactor core, the basic structure materials are large amount of graphite reflectors and carbon bricks. Small gaps among those graphite and carbon bricks are widespread in the reactor core so that the cold helium flow may be bypassed and not completely heated. The bypass flows in relative lower temperature would change the flow and temperature distributions in the reactor core, therefore, the accurate prediction of bypass flows need to be carried out carefully to evaluate the influence to the reactor safety. Based on the characteristics of the bypass flow problem, hybrid method of the flow network and the CFD tools was employed to represent the connections and calculate flow distributions of all the main flow and bypass flow paths. In this paper, the hybrid method was described and applied to specific bypass flow problem in the HTR-PM. Various bypass flow paths in the HTR-PM were reviewed, figured out, and modeled by the flow network and the CFD methods, including the axial vertical gaps in the side reflectors, control rod channels, absorber sphere channels and radial gap flow through keys around the hot helium plenum. The bypass flow distributions and its flow rate ratio to the total flow rate in the primary loop were also calculated, discussed and evaluated. (author)

STATISTICAL ANALYSIS OF DAMAGEABILITY OF THE BYPASS ENGINES COMPRESSOR BLADES

Directory of Open Access Journals (Sweden)

Boris A. Chichkov

2018-01-01

Full Text Available Aircraft gas turbine engines during the operation are exposed to damage of flowing parts. The elements of the engine design, appreciably determining operational characteristics are rotor blades. Character of typical damages for various types of engines depends on appointment and a geographical place of the aircraft operation on which one or another engine is installed. For example, the greatest problem for turboshaft engines operated in the dusty air conditions is erosive wear of a rotor blade airfoil. Among principal causes of flowing parts damages of bypass engine compressors are foreign object damages. Independently there are the damages caused by fatigue of a rotor blade material at dangerous blade mode. Pieces of the ice formed in the input unit, birds and the like can also be a source of danger. The foreign objects getting into the engine from runway are nuts, bolts, pieces of tire protectors, lock-wire, elements from earlier flying off aircraft, etc. The entry of foreign objects into the engine depends on both an operation mode (during the operation on the ground, on takeoff, on landing roll using the reverse and so on, and the aircraft engine position.Thus the foreign objects entered into the flowing path of bypass engine damage blade cascade of low and high pressure. Foreign objects entered into the flowing part of the engine with rotor blades result in dents on edges and blade shroud, deformations of edges, breakage, camber of peripheral parts and are distributed "nonlinear" on path length (steps. The article presents the results of the statistical analysis of three types engine compressors damageability over the period of more than three years. Damages are divided according to types of engines in whole and to their separate steps, depths and lengths, blades damage location. The results of the analysis make it possible to develop recommendations to carry out the optical-visual control procedures.

Cost Benefit Analysis: Bypass of Prešov city

Directory of Open Access Journals (Sweden)

Margorínová Martina

2017-01-01

Full Text Available The paper describes decision making process based on economic evaluation, i.e. Cost Benefit Analysis for motorway bypass of the Prešov city. Three variants were evaluated by means of the Highway Development and Management Tool (HDM-4. HDM-4 is a software system for evaluating options for investing in road transport infrastructure. Vehicle operating costs and travel time costs were monetized with the use of the software. The investment opportunities were evaluated in terms of Cost Benefit Analysis results, i.e. economic indicators.

Specialty Article: so You Think You Got a Bypass? A Case Series of Adventures in Bariatric Surgery.

Science.gov (United States)

Wang, Eugene Y; Shope, Timothy R

2018-05-01

To raise awareness for surgeons encountering bariatric patients with anatomy that deviates from the standard Roux-en-Y gastric bypass (RYGB). This is a single-institution retrospective case series over 12 years (2003-2014) involving patients who believed they received RYGBs, but actually did not. Data was obtained reviewing physician encounters, imaging, and operative reports. There were six cases with confusing clinical pictures, found to have aberrant RYGB anatomy: (1) gastric bypass with jejuno-jejunostomy only without gastrojejunostomy, (2) distal partial vertical gastrectomy without expected prosthetic band, (3) inverse vertical banded gastroplasty, (4) non-divided gastric bypass with no gastrojejunostomy, (5) 20-cm Roux limb, with gastro-gastric fistula, and (6) 200-cm bilio-pancreatic limb similar to the traditional Scopinaro procedure. There are cases of "Roux-en-Y gastric bypasses" that have no resemblance to the named procedure at all. Adjunctive upper gastrointestinal studies and upper endoscopies help surgeons make diagnoses that are incongruent with the surgical history. It is important to keep in mind that there could be anatomic or surgical variations which were born out of necessity or based on other surgeons' creativities.

CITY OF SANTA FE V. KOMIS REVISITED: AN ANALYSIS OF THE ACTUAL IMPACTS OF CONSTRUCTION AND OPERATION OF THE SANTA FE BYPASS ON THE VALUE OF NEARBY REAL ESTATE

International Nuclear Information System (INIS)

Bentz, E. J. Jr.; Bentz, C. B.; O'Hora, T. D.; Baepler, D.

2003-01-01

The Santa Fe Bypass for transport of transuranic waste (TRU) to the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico has been constructed and is operational (as of 2000). This paper presents a review of actual empirical data from the sales of real estate in the Santa Fe City/County area since the filing of the City of Santa Fe v. Komis lawsuit in 1988. The data analyzed covers the time period from 1989 through the last quarter of 2001

Study of transient turbine shot without bypass in a BWR

International Nuclear Information System (INIS)

Vallejo Q, J. A.; Martin del Campo M, C.; Fuentes M, L.; Francois L, J. L.

2015-09-01

The study and analysis of operational transients are important for predicting the behavior of a system to short-terms events and the impact that would cause this transition. For the nuclear industry these studies are indispensable due to economic, environmental and social impacts that could result in an accident during the operation of a nuclear reactor. In this paper the preparation, simulation and analysis of results of a turbine shot transient, which is not taken into operation the bypass is presented. The study is realized for a BWR of 2027 MWt, to an intermediate cycle life and using the computer code Simulate-3K a depressurization stage of the vessel is created which shows the response of other security systems and gives a coherent prediction to the event presented type. (Author)

Influence of Bypass on Thermo-Hydraulics of VVER 440 Fuel Assembly

Directory of Open Access Journals (Sweden)

Jakubec Jakub

2017-04-01

Full Text Available The paper deals with CFD modelling and simulation of coolant flow within the nuclear reactor VVER 440 fuel assembly. The influence of coolant flow in bypass on the temperature distribution at the outlet of the fuel assembly and pressure drop was investigated. Only steady-state analyses were performed. Boundary conditions are based on operating conditions. ANSYS CFX is chosen as the main CFD software tool, where all analyses are performed.

Reduction of cognitive performance by piracetam in patients undergoing coronary bypass surgery using heart-lung maschine

OpenAIRE

Alaaraj, Nour

2015-01-01

Introduction: The occurrence of cognitive dysfunction after coronary bypass surgery poses a relevant clinical problem. The precise pathophysiological mechanisms underlying post-operative cognitive dysfunction remain to be fully elucidated. However, it seems safe to assume that the etiology is multifactorial. Piracetam is approved for the treatment of chronic cognitive dysfunction in dementia. Emerging data suggests that piracetam may also be beneficial for post-operative cognitive outcomes. T...

Coronary Artery Bypass Grafting

Science.gov (United States)

... lung bypass machine is used during this procedure. Robot-assisted technique. This type of procedure allows for ... driving after 3 to 8 weeks. Returning to work after 6 weeks is common unless your job ...

21 CFR 870.4200 - Cardiopulmonary bypass accessory equipment.

Science.gov (United States)

2010-04-01

... Cardiopulmonary bypass accessory equipment. (a) Identification. Cardiopulmonary bypass accessory equipment is a... mounting bracket or system-priming equipment. (b) Classification. (1) Class I. The device is classified as class I if it does not involve an electrical connection to the patient. The device is exempt from the...

Prevalence and intensity of hyperglycemia in non-diabetic patients undergoing coronary artery bypass graft surgery with and without cardiopulmonary bypass

International Nuclear Information System (INIS)

Azarfarin, R.; Asl, Azin A.

2008-01-01

Objective was to study the prevalence and severity of hyperglycemia in nondiabetic patients undergoing cardiac operation. In an observational prospective study, 282 non-diabetic patients underwent elective off-pump (n=101) or non on-pump (n=181) coronary artery bypass grafting (CABG) surgery from March 2006 to July 2007 in Madani Heart Hospital, Tabriz, Iran. Blood glucose (BG) levels were measured during and 24 hours after operation. Frequencies of hyperglycemia (BG>-126 mg/dl) and severe hyperglycemia (BG>-180 mg/dl) and postoperative complications were compared in the 2 study groups. Prevalence of at least one episode of severe hyperglycemia was 54.6% (154/282) in our patients during and 24 hours after operation. Intra-operative hyperglycemia was slightly higher in on-pumping group. Frequency of post-operative hyperglycemia was higher, although not significantly different between the two groups. The 2 study groups were not significantly different in frequency of severe hyperglycemia during operation, although were different within 24 hours postoperative period. Prevalence of hyperglycemia especially severe hyperglycemia was high during, and after operation in both off-pump and on-pump CABG in non-diabetic patients. There was a borderline difference in blood glucose level between on-pump and off-pump CABG patients. It may be prudent to consider glycemic control protocols in these patients especially in early post-operative period. (author)

Obese patients with type 2 diabetes submitted to banded gastric bypass: greater incidence of dumping syndrome.

Science.gov (United States)

Padoin, Alexandre Vontobel; Galvão Neto, Manoel; Moretto, Myriam; Barancelli, Fabiano; Schroer, Caroline Eckerdt; Mottin, Cláudio Corá

2009-11-01

Dumping syndrome is one of ten most common complications in morbidly obese patients operated. Recent studies in relation to type 2 diabetes mellitus (DM2) in patients submitted to gastric bypass led us to examine the different outcomes in this group of patients. Our objective was to determine the difference in the prevalence of dumping syndrome in patients with DM2 submitted to gastric bypass. In this retrospective study, 49 diabetic and 54 non-diabetic morbidly obese patients were submitted to gastric bypass and followed up at 3, 6, and 12 months after surgery. The occurrence of dumping was determined by the patient's medical chart, where it was considered positive if recorded in at least one of three evaluations. The 103 patients evaluated had a mean BMI of 49.5 +/- 9.3 kg/m(2) and mean age of 38 +/- 9.7 years, with 75.7% being women. The prevalence of dumping syndrome in this population was 24.3%. The prevalence of dumping was greater in patients with DM2 (44.9%) when compared to the control group (5.6%; p DM2 as the only variable associated with dumping syndrome. Dumping syndrome is a common postoperative complication in gastric bypass. Patients with DM2 show a greater postoperative prevalence of dumping.

Anesthesia for off-pump coronary artery bypass surgery

Directory of Open Access Journals (Sweden)

Thomas M Hemmerling

2013-01-01

Full Text Available The evolution of techniques and knowledge of beating heart surgery has led anesthesia toward the development of new procedures and innovations to promote patient safety and ensure high standards of care. Off-pump coronary artery bypass (OPCAB surgery has shown to have some advantages compared to on-pump cardiac surgery, particularly the reduction of postoperative complications including systemic inflammation, myocardial injury, and cerebral injury. Minimally invasive surgery for single vessel OPCAB through a limited thoracotomy incision can offer the advantage of further reduction of complications. The anesthesiologist has to deal with different issues, including hemodynamic instability and myocardial ischemia during aorto-coronary bypass grafting. The anesthesiologist and surgeon should collaborate and plan the best perioperative strategy to provide optimal care and ensure a rapid and complete recovery. The use of high thoracic epidural analgesia and fast-track anesthesia offers particular benefits in beating heart surgery. The excellent analgesia, the ability to reduce myocardial oxygen consumption, and the good hemodynamic stability make high thoracic epidural analgesia an interesting technique. New scenarios are entering in cardiac anesthesia: ultra-fast-track anesthesia with extubation in the operating room and awake surgery tend to be less invasive, but can only be performed on selected patients.

Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

DEFF Research Database (Denmark)

Møller, Christian H; Steinbrüchel, Daniel A

2014-01-01

Coronary artery bypass grafting (CABG) remains the preferred treatment in patients with complex coronary artery disease. However, whether the procedure should be performed with or without the use of cardiopulmonary bypass, referred to as off-pump and on-pump CABG, is still up for debate....... Intuitively, avoidance of cardiopulmonary bypass seems beneficial as the systemic inflammatory response from extracorporeal circulation is omitted, but no single randomized trial has been able to prove off-pump CABG superior to on-pump CABG as regards the hard outcomes death, stroke or myocardial infarction....... In contrast, off-pump CABG is technically more challenging and may be associated with increased risk of incomplete revascularization. The purpose of the review is to summarize the current literature comparing outcomes of off-pump versus on-pump coronary artery bypass surgery....

Analysis of the force exercised in pipes by accumulation of water in the head stock of turbine bypass; Analisis de la fuerza ejercida en tuberias por acumulamiento de agua en el cabezal de baipas de turbina

Energy Technology Data Exchange (ETDEWEB)

Cecenas F, M.; Ovando C, R.; Campos G, R. M., E-mail: mcf@iie.org.mx [Instituto de Investigaciones Electricas, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)

2011-11-15

The head stock and valves of turbine bypass allow canalize the main vapor coming from the reactor toward the condenser, without carrying out work in the turbo-generator. In this work is assumed that is accumulates condensed in the head stock during a time period in which the bypass system does not operate. For operation maneuvers, the opening of the bypass is demanded, for what the accumulated water is suddenly dragged by the vapor to high pressure coming from the reactor toward the condenser, which operates to inferior pressures to the atmospheric. The generated flow produces a mechanical effort in the lines and its supports. By means of the RELAP5 code the bypass system is modeled, the discharge transitory to the condenser is simulated and the speeds of the mixture water/vapor are calculated. Processing the exit of RELAP5 the mechanical effort that is subjected the pipe is calculated, and the study is complemented with a sensibility analysis to the quantity of stored water in the volume of the bypass head stock. (Author)

Predictors of inotrope use in patients undergoing concomitant coronary artery bypass graft (CABG and aortic valve replacement (AVR surgeries at separation from cardiopulmonary bypass (CPB

Directory of Open Access Journals (Sweden)

Nelson William B

2009-06-01

Full Text Available Abstract Background Left ventricular dysfunction is common after coronary artery bypass graft and valve replacement surgeries and is often treated with inotropic drugs to maintain adequate hemodynamic status. In this study, we aimed to identify the demographic, clinical, laboratory, echocardiographic and hemodynamic factors that are associated with use of inotropic drugs in patients undergoing concomitant coronary artery bypass graft and aortic valve replacement surgery. Methods The study included 97 patients who had undergone concomitant coronary artery bypass graft and aortic valve replacement at Regions Hospital, University of Minnesota Medical School from January 2006 to December 2008. All data were collected retrospectively after reviewing electronic medical records. Inotropic support was defined as the use of dopamine [greater than or equal to] 5 ug/kg/min; any dose of epinephrine, norepinephrine, dobutamine, and milrinone at the separation from cardiopulmonary bypass. Results Inotropic support was used in a total of 50 patients (52% at the separation from cardiopulmonary bypass. Average age of the patients requiring inotropic support was 72.2 +/- 8.8 years. The study identified four significant, independent predictors of inotrope use: (1 Cardiac index [less than or equal to]2.5 L/min/m2, (2 LVEDP [greater than or equal to] 20 mm Hg, (3 LVEF [less than or equal to]40%, and (4 CKD stage 3 to 5. Conclusion We identified four independent risk factors for postoperative use of inotropic support in patients undergoing concomitant coronary artery bypass graft and arotic valve replacement surgery at the separation from cardiopulmonary bypass. The study results will be helpful to prospectively identify patients who will likely to require inotropic support at the separation from cardiopulmonary bypass.

Reconstruction Options for Pancreaticoduodenectomy in Patients with Prior Roux-en-Y Gastric Bypass.

Science.gov (United States)

Shah, Mihir M; Martin, Benjamin M; Stetler, Jamil L; Patel, Ankit D; Davis, S Scott; Sarmiento, Juan M; Lin, Edward

2017-11-01

Patients with prior Roux-en-Y gastric bypass (RYGB) operations for weight loss present reconstruction challenges during a pancreaticoduodenectomy (PD). With over 60,000 RYGB performed annually, the increasing odds of encountering such patients during a PD make it imperative to understand the RYGB anatomy and anticipate reconstruction options. This article describes the possible reconstruction options and their rationale. We reviewed our PD reconstruction options, compared them to what have been described in the literature, and derived a consensus from internal conferences comprising bariatric and hepatopancreatobiliary surgeons to describe known reconstruction options. In general, reconstruction options can include one of three options: (1) remnant gastrectomy, (2) preservation of gastric remnant, or (3) reversal of gastric bypass. This article describes individualized reconstruction options for RYGB patients undergoing PD. The reconstruction options can be tailored to the needs of the patient.

DER 86: main facts

International Nuclear Information System (INIS)

1987-01-01

This report presents the important facts among the studies carried out by the Direction des Etudes et Recherches (E.D.F.): new applications of electric power for customers, protection of environment, classical equipments for power plants and nuclear equipments, monitoring and control of power plants, electrical equipments, development and operation of electrical networks, informatics and office automation [fr

Monsanto may bypass NIH in microbe test.

Science.gov (United States)

Sun, Marjorie

1985-01-11

The Monsanto Company is planning to ask the Environmental Protection Agency for clearance to field test a genetically engineered microbial pesticide, bypassing the traditional approval process of the National Institutes of Health. Although only federally funded institutions are required to obtain NIH approval for genetic engineering tests, Monsanto is the first company to bypass the NIH regulatory process, which has become mired in a lawsuit brought by Jeremy Rifkin.

An Experimental Design of Bypass Magneto-Rheological (MR) damper

Science.gov (United States)

Rashid, MM; Aziz, Mohammad Abdul; Raisuddin Khan, Md.

2017-11-01

The magnetorheological (MR) fluid bypass damper fluid flow through a bypass by utilizing an external channel which allows the controllability of MR fluid in the channel. The Bypass MR damper (BMRD) contains a rectangular bypass flow channel, current controlled movable piston shaft arrangement and MR fluid. The static piston coil case is winding by a coil which is used inside the piston head arrangement. The current controlled coil case provides a magnetic flux through the BMRD cylinder for controllability. The high strength of alloy steel materials are used for making piston shaft which allows magnetic flux propagation throughout the BMRD cylinder. Using the above design materials, a Bypass MR damper is designed and tested. An excitation of current is applied during the experiment which characterizes the BMRD controllability. It is shown that the BMRD with external flow channel allows a high controllable damping force using an excitation current. The experimental result of damping force-displacement characteristics with current excitation and without current excitation are compared in this research. The BMRD model is validated by the experimental result at various frequencies and applied excitation current.

The use of technetium-99m hexamethylpropylene amine oxime labelled white blood cells to detect subclinical inflammation of the heart after cardiopulmonary bypass in children with congenital heart disease

International Nuclear Information System (INIS)

Kao Chiahung; Wang Yenliang; Wang Shyhjen; Hsieh Kaisheng

1992-01-01

Ten children (6 boys and 4 girls, aged 1-9 years old) underwent operations with a cardiopulmonary bypass, and the technetium-99m hexamehtylpropylene amine oxine ( 99m Tc-HMPAO) labelled white blood cell (WBC) heart scans were used to detect postoperative leukocyte infiltration in the hearts. The results showed that 80% (8/10) of the cases had subclinical inflammation in the hearts (grading of WBC scans ≥score 2), and a positive correlation (R=0.77) was noted between the severity of the inflammation (grading of the WBC scans) and the duration of the cardiopulmonary bypass in the operations. Another control group (9 boys and 2 girls, aged 2-13 years old) underwent operations without a cardiopulmonary bypass, and subclinical inflammation of hearts was demonstrated in only 1 case (9%) by the 99m Tc-HMPAO labelled WBC scans (grading of WBC scans 99m Tc-HMPAO labelled WBC heart scans may provide non-invasive and directly discernible evidence of subclinical inflammation in the heart due to a transient ischaemic state during a cardiopulmonary bypass, even if the clinical symptoms and signs of carditis are not apparent. (orig.)

21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class II...

Cardiopulmonary bypass and hemostasis

NARCIS (Netherlands)

Eijsman, Leon

1992-01-01

In chapter 1, we recalled that intracardiac defects can only be corrected when cardiopulmonary circulation is maintained by extracorporeal criculation and ventilation. To prevent clot formation in this artificial circuit, the socalled cardiopulmonary bypass (CPB), we completely depend on the

Reactor operation method

International Nuclear Information System (INIS)

Osumi, Katsumi; Miki, Minoru.

1979-01-01

Purpose: To prevent stress corrosion cracks by decreasing the dissolved oxygen and hydrogen peroxide concentrations in the coolants within a reactor container upon transient operation such as at the start-up or shutdown of bwr type reactors. Method: After a condensate has been evacuated, deaeration operation is conducted while opening a main steam drain line, as well as a main steam separation valve and a by-pass valve in a turbine by-pass line connecting the main steam line and the condenser without by way of a turbine, and the reactor is started-up by the extraction of control rods after the concentration of dissolved oxygen in the cooling water within a pressure vessel has been decreased below a predetermined value. Nuclear heating is started after the reactor water has been increased to about 150 0 C by pump heating after the end of the deaeration operation for preventing the concentration of hydrogen peroxide and oxygen in the reactor water from temporarily increasing immediately after the start-up. The corrosive atmosphere in the reactor vessel can thus be moderated. (Horiuchi, T.)

Outcome after VAC® therapy for infected bypass grafts in the lower limb.

Science.gov (United States)

Acosta, S; Monsen, C

2012-09-01

To assess the outcome of vacuum-assisted wound closure (VAC(®)) therapy for infected bypass grafts. A retrospective 7-year review of patient records from 2004 to 2011 of all patients receiving VAC(®) therapy for infected bypass grafts. Thirty-seven patients with 42 wounds and 45 infected bypass (28 synthetic) grafts received VAC(®) treatment. Two serious bleeding episodes from the suture lines occurred. The median VAC(®) therapy time was 20 days. The proportion of patent bypass grafts was 91% (41/45) at a median time of 3.5 months from the start of VAC(®) therapy. Five patients with seven bypasses had persistent infection or re-infection, and the total graft preservation rate was 76% (34/45). The median follow-up time was 15 months. The presence of two infected bypass grafts in one groin wound was associated with an increased major amputation rate (hazard ratio (HR) 7.4 [95% confidence interval (CI) 2.0-27.5]), and synthetic graft infection (HR 5.0 [95% CI 1.5-17.4]) and non-healed wound (HR 3.6 [95% CI 1.5-8.7]) were associated with mortality. VAC(®) therapy of infected bypass grafts was able to induce effective wound healing without compromising the early bypass function. Two infected synthetic bypasses in the wound were associated with the highest risk of adverse outcome. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Crohn’s disease after gastric bypass surgery

OpenAIRE

Janczewska, Izabella; Nekzada, Qayium; Kapraali, Marjo

2011-01-01

Bariatric surgery for the treatment of severe obesity has increased dramatically in recent years in the USA and parts of Western Europe. The most commonly used technique is the Roux-en Y gastric bypass (RYGBP). Several nutritional and gastrointestinal complications after bariatric surgery have been described during the last 10 years. The authors present two patients with diarrhoea and malnutrition; one after RYGBP and the other after jejunoileal bypass surgery. These patients were subsequentl...

THE RESPIRATORY SUBSTRATE RHODOQUINOL INDUCES Q-CYCLE BYPASS REACTIONS IN THE YEAST CYTOCHROME bc1 COMPLEX - MECHANISTIC AND PHYSIOLOGICAL IMPLICATIONS

International Nuclear Information System (INIS)

Cape, Jonathan L.; Strahan, Jeff R.; Lenaeus, Michael J.; Yuknis, Brook A.; Le, Trieu T.; Shepherd, Jennifer; Bowman, Michael K.; Kramer, David M.

2005-01-01

The mitochondrial cytochrome bc1 complex catalyzes the transfer of electrons from ubiquinol to cyt c, while generating a proton motive force for ATP synthesis, via the ''Qcycle'' mechanism. Under certain conditions, electron flow through the Q-cycle is blocked at the level of a reactive intermediate in the quinol oxidase site of the enzyme, resulting in ''bypass reactions'', some of which lead to superoxide production. Using analogs of the respiratory substrates, ubiquinol-3 and rhodoquinol-3, we show that the relative rates of Q-cycle bypass reactions in the Saccharomyces cerevisiae cyt bc1 complex are highly dependent, by a factor of up to one hundred-fold, on the properties of the substrate quinol. Our results suggest that the rate of Q-cycle bypass reactions is dependent on the steady state concentration of reactive intermediates produced at the quinol oxidase site of the enzyme. We conclude that normal operation of the Q-cycle requires a fairly narrow window of redox potentials, with respect to the quinol substrate, to allow normal turnover of the complex while preventing potentially damaging bypass reactions

Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease

DEFF Research Database (Denmark)

Møller, Christian H; Penninga, Luit; Wetterslev, Jørn

2012-01-01

Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.......Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear....

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A study on bypass flow gap distribution in a prismatic VHTR core

International Nuclear Information System (INIS)

Kim, M. H.; Jo, C. K.; Lim, H. S.

2010-01-01

Core bypass flow in VHTR is one of the key issues for core thermal margins and efficiency. The bypass flow in the prismatic core varies during core cycles due to the irradiation shrinkage and thermal expansion of the graphite blocks. A procedure to evaluate the local gap size variation between graphite blocks was developed and applied to a prismatic core VHTR. The influence of the core restraint mechanism on the bypass flow gap was evaluated. The predicted gap size is as much as 8 mm when the graphite block is exposed to its allowable limit of irradiation fluence. The analysis for the core bypass flow and hot spot was carried out based on the calculated gap distributions. The results indicate that the bypass flow and the location of core hot spots are closely related and a measure to reduce the bypass flow is necessary. (authors)

Thermal activation of dislocations in large scale obstacle bypass

Science.gov (United States)

Sobie, Cameron; Capolungo, Laurent; McDowell, David L.; Martinez, Enrique

2017-08-01

Dislocation dynamics simulations have been used extensively to predict hardening caused by dislocation-obstacle interactions, including irradiation defect hardening in the athermal case. Incorporating the role of thermal energy on these interactions is possible with a framework provided by harmonic transition state theory (HTST) enabling direct access to thermally activated reaction rates using the Arrhenius equation, including rates of dislocation-obstacle bypass processes. Moving beyond unit dislocation-defect reactions to a representative environment containing a large number of defects requires coarse-graining the activation energy barriers of a population of obstacles into an effective energy barrier that accurately represents the large scale collective process. The work presented here investigates the relationship between unit dislocation-defect bypass processes and the distribution of activation energy barriers calculated for ensemble bypass processes. A significant difference between these cases is observed, which is attributed to the inherent cooperative nature of dislocation bypass processes. In addition to the dislocation-defect interaction, the morphology of the dislocation segments pinned to the defects play an important role on the activation energies for bypass. A phenomenological model for activation energy stress dependence is shown to describe well the effect of a distribution of activation energies, and a probabilistic activation energy model incorporating the stress distribution in a material is presented.

Platelet hyperreactivity in response to on- and off-pump coronary artery bypass grafting

DEFF Research Database (Denmark)

Bochsen, Louise; Rosengaard, Lisbeth Bredahl; Nielsen, Allan Bybeck

2009-01-01

Hypercoagulability has been reported after off-pump coronary artery bypass grafting (OPCAB) compared with patients undergoing standard coronary artery bypass grafting (CABG) with cardiopulmonary bypass. The aim of this study was to evaluate the changes in platelet reactivity in response to cardiac...... and this study identified 23% of patients needing coronary bypass surgery to be at high risk for recurrent ischemic events at 1 month after surgery, based on the MA. These results suggest that a more aggressive antithrombotic treatment might be warranted for patients undergoing coronary artery bypass grafting...

Blood utilization in neonates and infants undergoing cardiac surgery requiring cardiopulmonary bypass.

Science.gov (United States)

Wesley, Mark C; Yuki, Koichi; Daaboul, Dima G; Dinardo, James A

2011-07-01

Neonates and infants undergoing cardiac surgery with cardiopulmonary bypass are exposed to multiple blood products from different donors. The volume of the bypass circuit is often as large as the patient's total blood volume and asanguineous bypass primes are unusual. As a result, blood products are required for the cardiopulmonary bypass prime and are often used to treat the postbypass dilutional coagulopathy. We review clot formation and strength, cardiopulmonary bypass prime considerations, assessment of postbypass coagulopathy, component therapy use, ultrafiltration techniques, and use of antifibrinolytic medications. A combined approach including techniques to minimize the prime volume, utilization of ultrafiltration, administration of antifibrinolytics during surgery, and the proper treatment of the dilutional coagulopathy can limit the transfusion requirements.

The use of technetium-99m hexamethylpropylene amine oxime labelled white blood cells to detect subclinical inflammation of the heart after cardiopulmonary bypass in children with congenital heart disease

Energy Technology Data Exchange (ETDEWEB)

Kao Chiahung; Wang Yenliang; Wang Shyhjen (Taichung Veterans General Hospital (Taiwan). Dept. of Nuclear Medicine); Hsieh Kaisheng (Taichung Veterans General Hospital (Taiwan). Dept. of Pediatrics)

1992-11-01

Ten children (6 boys and 4 girls, aged 1-9 years old) underwent operations with a cardiopulmonary bypass, and the technetium-99m hexamehtylpropylene amine oxine ({sup 99m}Tc-HMPAO) labelled white blood cell (WBC) heart scans were used to detect postoperative leukocyte infiltration in the hearts. The results showed that 80% (8/10) of the cases had subclinical inflammation in the hearts (grading of WBC scans {>=}score 2), and a positive correlation (R=0.77) was noted between the severity of the inflammation (grading of the WBC scans) and the duration of the cardiopulmonary bypass in the operations. Another control group (9 boys and 2 girls, aged 2-13 years old) underwent operations without a cardiopulmonary bypass, and subclinical inflammation of hearts was demonstrated in only 1 case (9%) by the {sup 99m}Tc-HMPAO labelled WBC scans (grading of WBC scans operations. There was a significant difference (P<0.001, by a Wilcoxon rank sum test) based upon the severity of the ischaemic heart damage in the two groups. In our preliminary conclusions, the {sup 99m}Tc-HMPAO labelled WBC heart scans may provide non-invasive and directly discernible evidence of subclinical inflammation in the heart due to a transient ischaemic state during a cardiopulmonary bypass, even if the clinical symptoms and signs of carditis are not apparent. (orig.).

High glycemic variability assessed by continuous glucose monitoring after surgical treatment of obesity by gastric bypass.

Science.gov (United States)

Hanaire, Helene; Bertrand, Monelle; Guerci, Bruno; Anduze, Yves; Guillaume, Eric; Ritz, Patrick

2011-06-01

Obesity surgery elicits complex changes in glucose metabolism that are difficult to observe with discontinuous glucose measurements. We aimed to evaluate glucose variability after gastric bypass by continuous glucose monitoring (CGM) in a real-life setting. CGM was performed for 4.2 ± 1.3 days in three groups of 10 subjects each: patients who had undergone gastric bypass and who were referred for postprandial symptoms compatible with mild hypoglycemia, nonoperated diabetes controls, and healthy controls. The maximum interstitial glucose (IG), SD of IG values, and mean amplitude of glucose excursions (MAGE) were significantly higher in operated patients and in diabetes controls than in healthy controls. The time to the postprandial peak IG was significantly shorter in operated patients (42.8 ± 6.0 min) than in diabetes controls (82.2 ± 11.1 min, P = 0.0002), as were the rates of glucose increase to the peak (2.4 ± 1.6 vs. 1.2 ± 0.3 mg/mL/min; P = 0.041). True hypoglycemia (glucose fasting state and 2 h postmeal. Glucose variability is exaggerated after gastric bypass, combining unusually high and early hyperglycemic peaks and rapid IG decreases. This might account for postprandial symptoms mimicking hypoglycemia but often seen without true hypoglycemia. Early postprandial hyperglycemia might be underestimated if glucose measurements are done 2 h postmeal.

Small-bowel volvulus in late pregnancy due to internal hernia after laparoscopic Roux-en-Y gastric bypass.

Science.gov (United States)

Naef, Markus; Mouton, Wolfgang G; Wagner, Hans E

2010-12-01

Internal hernias are a specific cause of acute abdominal pain and are a well-known complication after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Although internal hernias are a rare cause of intestinal obstruction, they may evolve towards serious complications, such as extensive bowel ischemia and gangrene, with the need for bowel resection and sometimes for a challenging reconstruction of intestinal continuity. The antecolic position of the Roux limb is associated with a decrease in the incidence of small-bowel obstruction and internal hernias. The best prevention of the formation of these hernias is probably by closure of potential mesenteric defects at the initial operation with a non-absorbable running suture. We present a patient in late pregnancy with a small-bowel volvulus following laparoscopic Roux-en-Y gastric bypass for morbid obesity and discuss the available literature. For a favorable obstetric and neonatal outcome, it is crucial not to delay surgical exploration and an emergency operation usually is mandatory.

Graft type for femoro-popliteal bypass surgery.

Science.gov (United States)

Ambler, Graeme K; Twine, Christopher P

2018-02-11

Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves grafts using autologous vein, polytetrafluoroethylene (PTFE) or Dacron as a bypass conduit. This is the second update of a Cochrane review first published in 1999 and last updated in 2010. To assess the effects of bypass graft type in the treatment of stenosis or occlusion of the femoro-popliteal arterial segment, for above- and below-knee femoro-popliteal bypass grafts. For this update, the Cochrane Vascular Information Specialist searched the Vascular Specialised Register (13 March 2017) and CENTRAL (2017, Issue 2). Trial registries were also searched. We included randomised trials comparing at least two different types of femoro-popliteal grafts for arterial reconstruction in patients with femoro-popliteal ischaemia. Randomised controlled trials comparing bypass grafting to angioplasty or to other interventions were not included. Both review authors (GKA and CPT) independently screened studies, extracted data, assessed trials for risk of bias and graded the quality of the evidence using GRADE criteria. We included nineteen randomised controlled trials, with a total of 3123 patients (2547 above-knee, 576 below-knee bypass surgery). In total, nine graft types were compared (autologous vein, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), polyurethane (PUR), Dacron and heparin bonded Dacron (HBD); FUSION BIOLINE and Dacron with external support). Studies differed in which graft types they compared and follow-up ranged from six months to 10 years.Above-knee bypassFor above-knee bypass, there was moderate-quality evidence that autologous vein grafts improve primary patency compared to prosthetic grafts by 60 months (Peto odds ratio (OR) 0.47, 95% confidence interval (CI

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards for bypass/bleeder stacks. 63.307 Section 63.307 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1) Except as otherwise...

Tidlige erfaringer med duplexovervågning af femoropopliteale og -krurale vene-bypass

DEFF Research Database (Denmark)

Nielsen, Tina G; von Jessen, Frants; Schroeder, T V

1993-01-01

Identification and correction of graft stenoses in femoropopliteal and -crural vein bypasses can prevent reconstruction failure. Sixty six consecutive vein bypasses entered a postoperative surveillance protocol, which implied clinical assessment, measurement of ankle blood pressure and duplex...... could not be reestablished. Of the 34 bypasses with normal duplex-scans only 2 (6%) thrombosed (p blood pressure measurement could reliably predict graft failure. This study indicates that duplex......-scanning effectively identifies grafts at risk and can be expected to improve long-term patency of infrainguinal vein bypasses....

Main facts 1995; Faits marquants 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

This report presents the main facts of the studies carried out by the Direction des Etudes et Recherches (DER) of Electricite de France: new applications of electricity, classical and nuclear thermal power plants, electrical equipment, environment protection, monitoring and plants operations.

Oral Triiodothyronine for Infants and Children Undergoing Cardiopulmonary Bypass.

Science.gov (United States)

Marwali, Eva M; Boom, Cindy E; Budiwardhana, Novik; Fakhri, Dicky; Roebiono, Poppy S; Santoso, Anwar; Sastroasmoro, Sudigdo; Slee, April; Portman, Michael A

2017-08-01

This study evaluated the efficacy and safety of oral triiodothyronine (T3; Tetronine, Dalim BioTech, Korea) for infants and children undergoing cardiopulmonary bypass in an Indonesian population. We performed a single-center, randomized, double-blind, and placebo-controlled trial in children aged 3 years and younger undergoing congenital heart disease operations with cardiopulmonary bypass. We administered oral T3 (1 μg/kg per body weight/dose) or placebo (saccharum lactis) by nasogastric tube every 6 hours for 60 hours after induction of anesthesia. The primary end point, time to extubation, was compared with Cox regression. The modified intention-to-treat group included 101 placebo and 104 treated patients. The stratified log-rank test did not show a significant treatment difference (p = 0.061) for time to extubation, but after adjustment for age, the nutritional Z score, and Aristotle surgical complexity, the hazard ratio was 1.33 (95% confidence interval, 1.00 to 1.76; p = 0.049). The effect of T3 was stronger in the strata aged 5 months and younger (hazard ratio, 1.86; 95% confidence interval 1.02 to 3.39; p = 0.043). Median intubation time was 47.3 hours for the placebo and 32.1 hours for the T3 group in aged 5 months and younger. Adverse events rates, including arrhythmia, were similar between groups, although sepsis was more frequent with placebo. Oral T3 supplementation may shorten time to extubation in children undergoing congenital heart disease operations, particularly infants aged 5 months or younger. Administration is relatively safe, simple and inexpensive. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Bypass of a nick by the replisome of bacteriophage T7.

Science.gov (United States)

Zhu, Bin; Lee, Seung-Joo; Richardson, Charles C

2011-08-12

DNA polymerase and DNA helicase are essential components of DNA replication. The helicase unwinds duplex DNA to provide single-stranded templates for DNA synthesis by the DNA polymerase. In bacteriophage T7, movement of either the DNA helicase or the DNA polymerase alone terminates upon encountering a nick in duplex DNA. Using a minicircular DNA, we show that the helicase · polymerase complex can bypass a nick, albeit at reduced efficiency of 7%, on the non-template strand to continue rolling circle DNA synthesis. A gap in the non-template strand cannot be bypassed. The efficiency of bypass synthesis depends on the DNA sequence downstream of the nick. A nick on the template strand cannot be bypassed. Addition of T7 single-stranded DNA-binding protein to the complex stimulates nick bypass 2-fold. We propose that the association of helicase with the polymerase prevents dissociation of the helicase upon encountering a nick, allowing the helicase to continue unwinding of the duplex downstream of the nick.

Reproduction of superior sagittal sinus animal model by bypass transplantation of biomaterial graft

Directory of Open Access Journals (Sweden)

Qing-yong LUO

2011-03-01

Full Text Available Objective To establish the beagles model of superior sagittal sinus bypass graft,and explore the feasibility of reconstruction of superior sagittal sinus with biomaterials using this model.Methods Eight adult male beagles(weight: 12.5-22.0kg were involved in the present study.The superior sagittal sinus was exposed and blocked via bone window,and then anastomosed side-to-end to the biomaterial graft under the dedicated microscope of neurosurgery surgery,expectant treatment such as anti-inflammatory was given for the animals.The digital subtraction venography(DSV and color Doppler flow imaging(CDFI of superior sagittal sinus were performed in 1,2,4 and 8 weeks after the operation.Eight weeks after the operation,all the animals were sacrificed and the material graft was examined histologically.Results The DSV and CDFI of superior sagittal sinus showed that the stomas of 2 beagles were with slight stenosis and high flow velocity,of 1 beagle with small leakage and low flow velocity,while of other 5 beagles were normal.The histological examination showed endothelial cells were growing on the graft and superior sagittal sinus,and crawling toward the lumen of graft 8 weeks after the operation.Conclusion The beagles model of superior sagittal sinus bypass graft was established successfully.The short-term effect of the model was satisfactory,while further work should be performed to determine the long-term effects.

Natural Product Screening Reveals Naphthoquinone Complex I Bypass Factors.

Directory of Open Access Journals (Sweden)

Scott B Vafai

Full Text Available Deficiency of mitochondrial complex I is encountered in both rare and common diseases, but we have limited therapeutic options to treat this lesion to the oxidative phosphorylation system (OXPHOS. Idebenone and menadione are redox-active molecules capable of rescuing OXPHOS activity by engaging complex I-independent pathways of entry, often referred to as "complex I bypass." In the present study, we created a cellular model of complex I deficiency by using CRISPR genome editing to knock out Ndufa9 in mouse myoblasts, and utilized this cell line to develop a high-throughput screening platform for novel complex I bypass factors. We screened a library of ~40,000 natural product extracts and performed bioassay-guided fractionation on a subset of the top scoring hits. We isolated four plant-derived 1,4-naphthoquinone complex I bypass factors with structural similarity to menadione: chimaphilin and 3-chloro-chimaphilin from Chimaphila umbellata and dehydro-α-lapachone and dehydroiso-α-lapachone from Stereospermum euphoroides. We also tested a small number of structurally related naphthoquinones from commercial sources and identified two additional compounds with complex I bypass activity: 2-methoxy-1,4-naphthoquinone and 2-methoxy-3-methyl-1,4,-naphthoquinone. The six novel complex I bypass factors reported here expand this class of molecules and will be useful as tool compounds for investigating complex I disease biology.

Hemodynamic effect of bypass geometry on intracranial aneurysm: A numerical investigation.

Science.gov (United States)

Kurşun, Burak; Uğur, Levent; Keskin, Gökhan

2018-05-01

Hemodynamic analyzes are used in the clinical investigation and treatment of cardiovascular diseases. In the present study, the effect of bypass geometry on intracranial aneurysm hemodynamics was investigated numerically. Pressure, wall shear stress (WSS) and velocity distribution causing the aneurysm to grow and rupture were investigated and the best conditions were tried to be determined in case of bypassing between basilar (BA) and left/right posterior arteries (LPCA/RPCA) for different values of parameters. The finite volume method was used for numerical solutions and calculations were performed with the ANSYS-Fluent software. The SIMPLE algorithm was used to solve the discretized conservation equations. Second Order Upwind method was preferred for finding intermediate point values in the computational domain. As the blood flow velocity changes with time, the blood viscosity value also changes. For this reason, the Carreu model was used in determining the viscosity depending on the velocity. Numerical study results showed that when bypassed, pressure and wall shear stresses reduced in the range of 40-70% in the aneurysm. Numerical results obtained are presented in graphs including the variation of pressure, wall shear stress and velocity streamlines in the aneurysm. Considering the numerical results for all parameter values, it is seen that the most important factors affecting the pressure and WSS values in bypassing are the bypass position on the basilar artery (L b ) and the diameter of the bypass vessel (d). Pressure and wall shear stress reduced in the range of 40-70% in the aneurysm in the case of bypass for all parameters. This demonstrates that pressure and WSS values can be greatly reduced in aneurysm treatment by bypassing in cases where clipping or coil embolization methods can not be applied. Copyright © 2018 Elsevier B.V. All rights reserved.

Posttraumatic growth in post-surgical coronary artery bypass graft patients

Directory of Open Access Journals (Sweden)

Catherine A Waight

2015-02-01

Full Text Available Recent research in posttraumatic growth has been applied to people with life-threatening illnesses to optimise recovery. There is a lack of research exploring posttraumatic growth in coronary artery bypass graft patients. This article describes the recovery experience of 14 coronary artery bypass graft patients (13 males and 1 female at their first outpatient review post-surgery. Grounded theory analysis was used to develop a model of distinct and shared pathways to growth depending on whether patients were symptomatic or asymptomatic pre-coronary artery bypass graft. Outcomes of posttraumatic growth in this sample included action-based healthy lifestyle growth and two forms of cognitive growth: appreciation of life and new possibilities. The model of posttraumatic growth developed in this study may be helpful in guiding future research into promoting posttraumatic growth and behaviour change in coronary artery bypass graft patients.

Vacuum-assisted drainage in cardiopulmonary bypass: advantages and disadvantages.

Science.gov (United States)

Carvalho Filho, Elio Barreto de; Marson, Fernando Augusto de Lima; Costa, Loredana Nilkenes Gomes da; Antunes, Nilson

2014-01-01

Systematic review of vacuum assisted drainage in cardiopulmonary bypass, demonstrating its advantages and disadvantages, by case reports and evidence about its effects on microcirculation. We conducted a systematic search on the period 1997-2012, in the databases PubMed, Medline, Lilacs and SciELO. Of the 70 selected articles, 26 were included in the review. Although the vacuum assisted drainage has significant potential for complications and requires appropriate technology and professionalism, prevailed in literature reviewed the concept that vacuum assisted drainage contributed in reducing the rate of transfusions, hemodilutions, better operative field, no significant increase in hemolysis, reduced complications surgical, use of lower prime and of smaller diameter cannulas.

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Does topical tranexamic acid reduce postcoronary artery bypass graft bleeding?

Directory of Open Access Journals (Sweden)

Amir Mirmohammadsadeghi

2018-01-01

Full Text Available Background: Postoperative bleeding is a common problem in cardiac surgery. We tried to evaluate the effect of topical tranexamic acid (TA on reducing postoperative bleeding of patients undergoing on-pump coronary artery bypass graft (CABG surgery. Materials and Methods: One hundred and twenty-six isolated primary CABG patients were included in this clinical trial. They were divided blindly into two groups; Group 1, patients receiving 1 g TA diluted in 100 ml normal saline poured into mediastinal cavity before closing the chest and Group 2, patients receiving 100 ml normal saline at the end of operation. First 24 and 48 h chest tube drainage, hemoglobin decrease and packed RBC transfusion needs were compared. Results: Both groups were the same in baseline characteristics including gender, age, body mass index, ejection fraction, clamp time, bypass time, and operation length. During the first 24 h postoperatively, mean chest tube drainage in intervention group was 567 ml compared to 564 ml in control group (P = 0.89. Mean total chest tube drainage was 780 ml in intervention group and 715 ml in control group (P = 0.27. There was no significant difference in both mean hemoglobin decrease (P = 0.26 and packed RBC transfusion (P = 0.7. Topical application of 1 g TA diluted in 100 ml normal saline does not reduce postoperative bleeding of isolated on-pump CABG surgery. Conclusion: We do not recommend topical usage of 1 g TA diluted in 100 ml normal saline for decreasing blood loss in on-pump CABG patients.

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Numerical investigation of a looped-tube travelling-wave thermoacoustic engine with a bypass pipe

International Nuclear Information System (INIS)

Al-Kayiem, Ali; Yu, Zhibin

2016-01-01

A new configuration (“a looped-tube with a bypass pipe”) was recently proposed for low temperature travelling wave thermoacoustic engines and a prototype using atmospheric air as the working gas achieved an onset temperature difference as low as 65 °C. However, no further research has been reported about this new configuration to reveal its advantages and disadvantages. This paper aims to analyse this type of engine through a comprehensive numerical research. An engine of this type having dimensions similar to the reported prototype was firstly modelled. The calculated results were then qualitatively compared with the reported experimental data, showing a good agreement. The working principle of the engine was demonstrated and analysed. The research results show that an engine with such a bypass configuration essentially operates on the same thermodynamic principle as other travelling wave thermoacoustic engines, differing only in the design of the acoustic resonator. Both extremely short regenerators and a near-travelling wave resonator minimise the engine's acoustic losses, and thus significantly reduce its onset temperature difference. However, such short regenerators likely cause severe heat conduction losses, especially if the engine is applied to heat sources with higher temperatures. Furthermore, the acoustic power flowing back to the engine core is relatively low, while a large stream of acoustic power has to propagate within its resonator to maintain an acoustic resonance, potentially leading to low power density. The model was then applied to design an engine with a much longer regenerator and higher mean pressure to increase its power density. A thermoacoustic cooler was also added to the engine to utilise its acoustic power, allowing the evaluation of thermal efficiency. The pros and cons of the engine configuration are then discussed. - Highlights: • Analysed the working principle of a bypass type thermoacoustic engine. • Analysed the pros and

HORMONE SUBSTITUTION AFTER GASTRIC BYPASS SURGERY IN PATIENTS WITH HYPOPITUITARISM SECONDARY TO CRANIOPHARYNGIOMA.

Science.gov (United States)

Wolf, Peter; Winhofer, Yvonne; Smajis, Sabina; Kruschitz, Renate; Schindler, Karin; Gessl, Alois; Riedl, Michaela; Vila, Greisa; Raber, Wolfgang; Langer, Felix; Prager, Gerhard; Ludvik, Bernhard; Luger, Anton; Krebs, Michael

2016-05-01

Craniopharyngiomas (CPs) are benign brain tumors presenting frequently in childhood and are treated by surgery with or without radiotherapy. About 50% of cured patients suffer from eating disorders and obesity due to hypothalamic damage, as well as hypopituitarism, necessitating subsequent hormone substitution therapy. Gastric bypass surgery has been reported to be an efficient treatment strategy for morbid hypothalamic obesity. However, so far it is unknown whether oral hormone substitution is affected by impaired intestinal drug absorption, potentially leading to severe hypopituitarism or pituitary crisis. Four morbidly obese CP patients with panhypopituitarism treated by gastric bypass surgery were included in this retrospective analysis. Dosages of hormone substitution therapy, blood concentrations of hormones, potential complications of impaired drug absorption, and anthropometric characteristics were investigated pre- and postoperatively after 6 to 14 months and 13 to 65 months. In all CP patients (3 female/1 male; baseline body mass index, 49 ± 7 kg/m(2)), gastric bypass resulted in distinct weight loss (-35 ± 27 kg). In follow-up examinations, mean daily dosage of thyroid hormone (levothyroxinebaseline 156 ± 44 μg/day versus levothyroxinefollow-up 150 ± 30 μg/day), hydrocortisone (hydrocortisonebaseline 29 ± 12 mg/day versus hydrocortisonefollow-up 26 ± 2 mg/day), growth-hormone (somatotropinbaseline 0.9 ± 0.5 mg/day versus somatotropinfollow-up 1.0 ± 0.4 mg/day), and desmopressin (desmopressinbaseline 222 ± 96 μg/day versus desmopressinfollow-up 222 ± 96 μg/day) substitution was unchanged. No patient developed adrenal insufficiency. Oral thyroid/hydrocortisone absorption testing performed in 1 patient indicated sufficient gastrointestinal drug absorption after bariatric surgery. Our preliminary results suggest that oral hormone substitution therapy is not impaired following gastric bypass operation in CP patients with morbid obesity

Esophageal bypass after failed chemoradiotherapy for unresectable esophageal cancer

International Nuclear Information System (INIS)

Matono, Satoru; Tanaka, Toshiaki; Mori, Naoki; Nagano, Takeshi; Fujita, Hiromasa; Shirouzu, Kazuo

2013-01-01

Esophageal stenosis and/or fistula often occur after chemoradiotherapy (CRT) for unresectable esophageal cancer. In such patients, an esophageal stent can help achieve oral intake. However an esophageal stent cannot be inserted where there is complete stenosis or where the tumor is located. In such cases, esophageal bypass surgery may be necessary. Here, we investigated the clinical characteristics and outcomes in patients who underwent esophageal bypass surgery in our institution. We reviewed 10 cases of esophageal bypass surgery (gastric tube in 8 cases, colon in 2 cases) after CRT for unresectable esophageal cancer, between 2001 and 2009. There were 5 of stenosis-only cases, 4 fistula-only cases, and 1 case of stenosis and fistula. There were postoperative complications in 5 cases (50%), and all these were treated conservatively and healed. The median survival from surgery to peroral intake was 20 days (range 9-90 days), and the median survival after starting peroral intake was 130 days (range 48-293 days). Esophageal bypass surgery can achieve good performance status and improve peroral intake. (author)

Emergency bypass post percutaneous atrial ablation: a case report.

LENUS (Irish Health Repository)

Hargrove, M

2010-11-01

A 34-year-old male undergoing percutaneous atrial ablation procedure for paroxysmal fibrillation required emergency sternotomy for cardiac tamponade. The patient had been anticoagulated and had received plavix and aspirin prior to and during the ablation procedure. Seven units of red cell concentrate had been transfused in the cardiac catherisation laboratory. On arrival in theatre, the patient was hypotensive, but was awake on induction of anaesthesia. No recordable blood pressure with non-invasive monitoring was observed. A sternotomy was immediately performed and, on evacuation of the pericardium, a bleeding site was not visible. The patient was commenced on cardiopulmonary bypass. Bleeding site was identified and the defect closed. The patient was weaned from cardiopulmonary bypass with minimal inotropic support and made an uneventful recovery. Bypass time was 38 minutes. A literature review showed a 1% incidence of post-ablation bleeding(1). The incidence of reverting to bypass for such an event has not been reported previously. During these procedures, it might be wise to have the cardiothoracic team notified while atrial ablation procedures are being performed in the cardiac catheterization laboratory.

Analgesic Treatment in Laparoscopic Gastric Bypass Surgery

DEFF Research Database (Denmark)

Andersen, Lars P H; Werner, Mads U; Rosenberg, Jacob

2014-01-01

This review aimed to present an overview of the randomized controlled trials investigating analgesic regimens used in laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Literature search was performed in PubMed and EMBASE databases in August 2013 in accordance to PRISMA guidelines. The litera......This review aimed to present an overview of the randomized controlled trials investigating analgesic regimens used in laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Literature search was performed in PubMed and EMBASE databases in August 2013 in accordance to PRISMA guidelines...

Gastric bypass surgery: Improving psoriasis through a GLP-1-dependent mechanism?

DEFF Research Database (Denmark)

Faurschou, Annesofie; Zachariae, Claus; Skov, Lone

2011-01-01

surgery. This most likely contributes importantly to the acute remission of type 2 diabetes, which is often induced by gastric bypass operations. The hormone is not hypersecreted after the purely restrictive bariatric procedure gastric banding and no case reports exist on improvement in psoriasis...... following gastric banding. Intriguingly, recent studies describe that GLP-1 may convey anti-inflammatory effects in addition to its effects on glucose homeostasis. Also, GLP-1 reduces appetite and gastrointestinal motility including gastric emptying, which reduces food intake and leads to weight loss. Thus...

Rankine cycle condenser pressure control using an energy conversion device bypass valve

Science.gov (United States)

Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

2014-04-01

The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

Active bypass flow control for a seal in a gas turbine engine

Science.gov (United States)

Ebert, Todd A.; Kimmel, Keith D.

2017-01-10

An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears. In at least one embodiment, the metering device may include a valve formed from one or more pins movable between open and closed positions in which the one pin at least partially bisects the bypass channel to regulate flow.

On-Pump Versus Off-Pump Coronary Artery Bypass Surgery in Elderly Patients

DEFF Research Database (Denmark)

Houlind, Kim; Kjeldsen, Bo Juul; Madsen, Susanne Nørgaard

2012-01-01

BACKGROUND: Conventional coronary artery bypass grafting performed with the use of cardiopulmonary bypass is a well-validated treatment for patients with ischemic heart disease. Off-pump coronary artery bypass grafting (OPCAB) has been suggested to reduce the number of perioperative complications......, especially in elderly patients. METHODS AND RESULTS: In a multicenter, randomized trial, we assigned 900 patients >70 years of age to conventional coronary artery bypass grafting or OPCAB surgery. After 30 days, a blinded end-point committee assessed whether a combined end point of death, stroke...... experiencing the combined end point within 30 days was 10.2% for conventional coronary artery bypass grafting and 10.7% for OPCAB. Implied risk difference of 0.4% (with a 95% confidence interval, -3.6 to 4.4) showed nonsignificance in a standard test for equality (P=0.83) and for noninferiority...

Assessing the FACTS at Kayenta

Energy Technology Data Exchange (ETDEWEB)

Pereira, M.; Renz, K.; Unterla, F. (Siemens AG Unternehmensbereich KWU, Erlangen (Germany))

1993-12-01

The world's first advanced series compensator with controllable series impedance as a flexible AC transmission (FACTS) device has been introduced at Western Area Power Administration's Kayenta substation in Arizona, USA. The system, which has been in operation for a year, allows existing transmission lines to carry up to 33 per cent more power. (author)

Advanced DVI for ECC direct bypass mitigation

International Nuclear Information System (INIS)

Kwon, Tae-Soon; Song, Chul-Hwa; Baek, Won-Pil

2009-01-01

An ECC direct bypass fraction during a late reflood phase of a LBLOCA is strongly dependent on the characteristics of the cross flow and the geometrical configuration of a DVI in the downcomer of a pressurized light water reactor. The important design parameters of a DVI are the elevation, the azimuthal angle, and the separator to prevent a steam-water interaction. An ECC sub-channel to separate or to isolate an ECC water from a high-speed cross flow is one of the important design features to mitigate the ECC bypass phenomena. A dual core barrel cylinder as an ECC flow separator is located between a reactor vessel and a core barrel outer wall in the downcomer annulus. A new narrow gap between the core barrel and the additional dual core barrel plays the role of a downward ECC flow channel or an ECC flow separator in a high-speed cross flow field of the downcomer annulus. The flow zone around a broken cold leg in the downcomer annulus has the role of a high ECC direct bypass due to a strong suction force while the wake zone of a hot leg has the role of an ECC penetration. Thus, the relative azimuthal angle of the DVI nozzle from the broken cold leg is an important design parameter. A large azimuthal angle from a cold leg to a hot leg needs to avoid a high suction flow zone when an ECC water is being injected. The other enhancing mechanism of an ECC penetration is a grooved core barrel which has small rectangular-shaped grooves vertically arranged on the core barrel wall of the reactor vessel downcomer annulus. These grooves have the role for a generation of a vortex induced by a high-speed cross flow. Since the stagnant flow in a lateral direction and rotational vortex provides the pulling force of an ECC drop or film to flow down into the lower downcomer annulus by gravity, the ECC direct bypass fraction is reduced when compared to the current design of a smoothed wall. An open channel of grooves generates a stagnant vortex, while a closed channel of grooves

Risk of iron overload is decreased in beating heart coronary artery surgery compared to conventional bypass.

Science.gov (United States)

Mumby, S; Koh, T W; Pepper, J R; Gutteridge, J M

2001-11-29

Conventional cardiopulmonary bypass surgery (CCPB) increases the iron loading of plasma transferrin often to a state of plasma iron overload, with the presence of low molecular mass iron. Such iron is a potential risk factor for oxidative stress and microbial virulence. Here we assess 'off-pump' coronary artery surgery on the beating heart for changes in plasma iron chemistry. Seventeen patients undergoing cardiac surgery using the 'Octopus' myocardial wall stabilisation device were monitored at five time points for changes in plasma iron chemistry. This group was further divided into those (n=9) who had one- or two- (n=8) vessel grafts, and compared with eight patients undergoing conventional coronary artery surgery. Patients undergoing beating heart surgery had significantly lower levels of total plasma non-haem iron, and a decreased percentage saturation of their transferrin at all time points compared to conventional bypass patients. Plasma iron overload occurred in only one patient undergoing CCPB. Beating heart surgery appears to decrease red blood cell haemolysis, and tissue damage during the operative procedures and thereby significantly decreases the risk of plasma iron overload associated with conventional bypass.

Outcome of gastroplasty and gastric bypass in a single centre in the UK

Directory of Open Access Journals (Sweden)

Sintler M

2009-09-01

Full Text Available Abstract Background Morbid obesity is defined as BMI>40 kg/m2. It affects 124,000 men and 412,000 women in England and Wales (NICE, July 2002. According to NICE guidelines, Bariatric surgery is indicated if the treatments for obesity such as exercise, diet and drugs fail. Procedures include laparoscopic gastric banding (LGB, vertical banded gastroplasty (VBG, and Gastric Bypass (GB. Aims The aim of this audit was to determine if NICE guidelines on the use of Bariatric surgery in the Manor Hospital, Walsall was being adhered to. Secondary aims were also to establish if Bariatric surgery is achieving its goal in the long-term and if weight reduction is being maintained in this group of patients. Methods A retrospective cohort study was carried out on patients who underwent Bariatric surgery between 1990 and 2004. Retrieved records were scrutinised and the following parameters were collated: pre-operative morbidities, intra and post-operative complication rates and weight reduction on follow-up. Results 129 patients were operated on in the 14 year period. For VBG, 40 out of 105 patients had weight gain by the 5th follow-up visit. This compared with 5 out of 18 patients after the same timescale for the GB group and 1 out of 6 in the LGB group. The most common post-operative complication was stenosis (28% of VBG group. Conclusion Bariatric surgery is relatively safe as an intervention for morbid obesity. Weight loss however is not maintained in the long term. VBG and LGB are short term interventions. Further research is required to look into the merits of gastric bypass surgery.

Coronary artery bypass grafting hemodynamics and anastomosis design: a biomedical engineering review.

Science.gov (United States)

Ghista, Dhanjoo N; Kabinejadian, Foad

2013-12-13

In this paper, coronary arterial bypass grafting hemodynamics and anastomosis designs are reviewed. The paper specifically addresses the biomechanical factors for enhancement of the patency of coronary artery bypass grafts (CABGs). Stenosis of distal anastomosis, caused by thrombosis and intimal hyperplasia (IH), is the major cause of failure of CABGs. Strong correlations have been established between the hemodynamics and vessel wall biomechanical factors and the initiation and development of IH and thrombus formation. Accordingly, several investigations have been conducted and numerous anastomotic geometries and devices have been designed to better regulate the blood flow fields and distribution of hemodynamic parameters and biomechanical factors at the distal anastomosis, in order to enhance the patency of CABGs. Enhancement of longevity and patency rate of CABGs can eliminate the need for re-operation and can significantly lower morbidity, and thereby reduces medical costs for patients suffering from coronary stenosis. This invited review focuses on various endeavors made thus far to design a patency-enhancing optimized anastomotic configuration for the distal junction of CABGs.

Protective effect of dexmedetomidine combined with ulinastatin on cardiopulmonary function injury caused by cardiopulmonary bypass surgery

Directory of Open Access Journals (Sweden)

Zhu Zhu

2016-11-01

Full Text Available Objective: To analyze the protective effect of dexmedetomidine combined with ulinastatin on cardiopulmonary function impairment caused by cardiopulmonary bypass surgery. Methods: A total of 78 patients who received valve replacement under cardiopulmonary bypass were divided into observation group and control group (n=39 according to random number table. Control group received intraoperative ulinastatin intervention and observation group received intraoperative dexmedetomidine combined with ulinastatin intervention. Differences in the levels of cardiac function indexes, myocardial injury markers, pulmonary function parameters, inflammatory indexes and so on were compared between two groups of patients 24 hours after operation. Results: Cardiac function parameters LSV, RSV and RVEF values of observation group 24 hours after operation were higher than those of control group while PAP value was lower than that of control group; serum myocardial injury markers H-FABP, cTn-T, CKMB, cTnⅠ and NT-proBNP levels were lower than those of control group; lung function parameters Cs and Cd values were higher than those of control group while RI, R5-R20, X5 and Fres values were lower than those of control group; serum pro-inflammatory factors IL-6 and TNF-α levels were lower than those of control group while anti-inflammatory factors sTNF-RI, IL-4 and IL-10 levels were higher than those of control group. Conclusions: Dexmedetomidine combined with ulinastatin can protect the cardiopulmonary function in patients with cardiopulmonary bypass, and help to reduce the occurrence of postoperative cardiopulmonary dysfunction and other severe complications.

Evaluation of Core Bypass Flow in the Prismatic VHTR with a Multi-block Experiment

International Nuclear Information System (INIS)

Lee, Jeong Hun; Yoon, Su Jong; Park, Goon Cherl; Kim, Min Hwan

2010-01-01

The core of Prismatic Modular Reactor (PMR) consists of assemblies of hexagonal graphite fuel and reflector elements. The core bypass flow of Very High Temperature Reactor (VHTR) is defined as the core flow that does not pass through the coolant channels but passes through the bypass gap between fuel elements. The increase in bypass flow makes the decrease in effective coolant flow. Since the core bypass flow has a negative impact on safety and efficiency of VHTR, core bypass phenomena have to be investigated to improve the core thermal margin of VHTR. For this purpose, the international project, I-NERI project, has been carried out since 2008. I-NERI project is collaborative project that KAERI and SNU of Korea side and INL, ANL and TAMU of U.S side are involved. In order to evaluate the core bypass flow, the multicolumn and multi-layer experimental facility is designed by SNU. In this experiment, the effect of cross-flow and local variation of bypass gap on the bypass flow distribution is investigated. Furthermore, the experimental data will be used for validation of CFD code or thermal hydraulic analysis codes such as GAMMA or GAS-NET

Analytical and computational investigations of a magnetohydrodynamics (MHD) energy-bypass system for supersonic gas turbine engines to enable hypersonic flight

Science.gov (United States)

Benyo, Theresa Louise

Historically, the National Aeronautics and Space Administration (NASA) has used rocket-powered vehicles as launch vehicles for access to space. A familiar example is the Space Shuttle launch system. These vehicles carry both fuel and oxidizer onboard. If an external oxidizer (such as the Earth's atmosphere) is utilized, the need to carry an onboard oxidizer is eliminated, and future launch vehicles could carry a larger payload into orbit at a fraction of the total fuel expenditure. For this reason, NASA is currently researching the use of air-breathing engines to power the first stage of two-stage-to-orbit hypersonic launch systems. Removing the need to carry an onboard oxidizer leads also to reductions in total vehicle weight at liftoff. This in turn reduces the total mass of propellant required, and thus decreases the cost of carrying a specific payload into orbit or beyond. However, achieving hypersonic flight with air-breathing jet engines has several technical challenges. These challenges, such as the mode transition from supersonic to hypersonic engine operation, are under study in NASA's Fundamental Aeronautics Program. One propulsion concept that is being explored is a magnetohydrodynamic (MHD) energy- bypass generator coupled with an off-the-shelf turbojet/turbofan. It is anticipated that this engine will be capable of operation from takeoff to Mach 7 in a single flowpath without mode transition. The MHD energy bypass consists of an MHD generator placed directly upstream of the engine, and converts a portion of the enthalpy of the inlet flow through the engine into electrical current. This reduction in flow enthalpy corresponds to a reduced Mach number at the turbojet inlet so that the engine stays within its design constraints. Furthermore, the generated electrical current may then be used to power aircraft systems or an MHD accelerator positioned downstream of the turbojet. The MHD accelerator operates in reverse of the MHD generator, re-accelerating the

FACT — LONGTERM MONITORING OF BRIGHT TeV BLAZARS

Directory of Open Access Journals (Sweden)

Katja Meier

2014-06-01

Full Text Available The First G-APD Cherenkov Telescope (FACT, located on the Canary Island of La Palma, has been taking data since October 2011. FACT has been optimized for longterm monitoring of bright TeV blazars, to study their variability time scales and flare probability. G-APD photo-sensors allow for observations even under strong moonlight conditions, and the telescope can be operated remotely. The monitoring strategy of FACT is discussed and preliminary results of the flare of Mrk501 in June 2012 are shown.

Bypass of a Nick by the Replisome of Bacteriophage T7*

Science.gov (United States)

Zhu, Bin; Lee, Seung-Joo; Richardson, Charles C.

2011-01-01

DNA polymerase and DNA helicase are essential components of DNA replication. The helicase unwinds duplex DNA to provide single-stranded templates for DNA synthesis by the DNA polymerase. In bacteriophage T7, movement of either the DNA helicase or the DNA polymerase alone terminates upon encountering a nick in duplex DNA. Using a minicircular DNA, we show that the helicase·polymerase complex can bypass a nick, albeit at reduced efficiency of 7%, on the non-template strand to continue rolling circle DNA synthesis. A gap in the non-template strand cannot be bypassed. The efficiency of bypass synthesis depends on the DNA sequence downstream of the nick. A nick on the template strand cannot be bypassed. Addition of T7 single-stranded DNA-binding protein to the complex stimulates nick bypass 2-fold. We propose that the association of helicase with the polymerase prevents dissociation of the helicase upon encountering a nick, allowing the helicase to continue unwinding of the duplex downstream of the nick. PMID:21701044

Rural health care bypass behavior: how community and spatial characteristics affect primary health care selection.

Science.gov (United States)

Sanders, Scott R; Erickson, Lance D; Call, Vaughn R A; McKnight, Matthew L; Hedges, Dawson W

2015-01-01

(1) To assess the prevalence of rural primary care physician (PCP) bypass, a behavior in which residents travel farther than necessary to obtain health care, (2) To examine the role of community and non-health-care-related characteristics on bypass behavior, and (3) To analyze spatial bypass patterns to determine which rural communities are most affected by bypass. Data came from the Montana Health Matters survey, which gathered self-reported information from Montana residents on their health care utilization, satisfaction with health care services, and community and demographic characteristics. Logistic regression and spatial analysis were used to examine the probability and spatial patterns of bypass. Overall, 39% of respondents bypass local health care. Similar to previous studies, dissatisfaction with local health care was found to increase the likelihood of bypass. Dissatisfaction with local shopping also increases the likelihood of bypass, while the number of friends in a community, and commonality with community reduce the likelihood of bypass. Other significant factors associated with bypass include age, income, health, and living in a highly rural community or one with high commuting flows. Our results suggest that outshopping theory, in which patients bundle services and shopping for added convenience, extends to primary health care selection. This implies that rural health care selection is multifaceted, and that in addition to perceived satisfaction with local health care, the quality of local shopping and levels of community attachment also influence bypass behavior. © 2014 National Rural Health Association.

Evaluation of aortocoronary bypass graft patency by reconstructed CT image

International Nuclear Information System (INIS)

Kawakita, Seizaburo; Koide, Takashi; Saito, Yoshio; Yamamoto, Tadao; Iwasaki, Tadaaki

1982-01-01

Ten patients were examined in the period of three months from January to March 1981. The patients were operated from 1 month to 7 years before CT. A bypass to the left anterior descending artery (LAD) was grafted in 10 cases, 2 to the right coronary artery (RCA), 4 to an obtuse marginal artery (OM), and 1 to a diagonal artery. Image reconstruction was performed in 10 cases by using an image analytical computer Evaluskop. Appropriate planes for reconstruction were selected by trial and error methods upon observation of CT images. When gained picture of a graft course coincided with surgical records or angiography, the work of building images was concluded. On cross section, grafts to LAD were visualized in all 10 cases: 9 in the entire course and 1 in a proximal part of the graft. Two to RCA, 4 to OM and 1 to a diagonal were also successfully visualized. Reconstruction of graft images succeeded in 9 grafts of 6 cases. The course of a graft could be pursued from the proximal to the distal end adjacent to the cardiac chamber. The picture of a bypass to LAD was visualized in 6 of 10 grafts. Two bypass to RCA could be depicted, and 1 to OM was also found. However 3 to OM and 1 to a diagonal failed to be visualized throughout their courses in reconstructed images. I think that the causes of faillure mainly depended upon the course of the graft. When a graft was running arc-like surrounding the heart chamber, it was very difficult to depict its entire length in reconstructed images, though the graft could be detected in cross sections. These preliminary studies indicated that reconstruction of CT images had some benefits for the pursuit of graft courses. (J.P.N.)

Preoperative Hba1c level in prediction of short-term morbidity and mortality outcomes following coronary artery bypass grafting surgery

Directory of Open Access Journals (Sweden)

Ümit Arslan

2015-05-01

Conclusion ― We concluded that in those diabetic patients that elective coronart artery bypass graft is applied, highly reactive HbA1c levels (HbA1c ≥7, may indicate morbitity in the early stages of post operation.

Increased post-operative cardiopulmonary fitness in gastric bypass patients is explained by weight loss

DEFF Research Database (Denmark)

Lund, M. T.; Hansen, M.; Wimmelmann, C. L.

2016-01-01

Roux-en-Y gastric bypass (RYGB) leads to a major weight loss in obese patients. However, given that most patients remain obese after the weight loss, regular exercise should be part of a healthier lifestyle. The primary aim of this study was to investigate the cardiopulmonary fitness in obese...... ± 2 kg during the study period. VO2max increased (A: 21 ± 1 vs D: 29 mL/min/kg, P exercise decreased and self......-perceived physical fitness increased after RYGB. Self-reported low- and high-intensity physical activity did not change. With weight loss, self-rated fitness level increased and the limitations to perform exercise decreased in RYGB patients. Nevertheless, as shown by the lower absolute VO2max, RYGB patients do...

Femoro-Supragenicular Popliteal Bypass with a Bridging Stent Graft in a Diffusely Diseased Distal Target Popliteal Artery: Alternative to Below-Knee Popliteal Polytetrafluoroethylene Bypass

Directory of Open Access Journals (Sweden)

Joung Hun Byun

2017-10-01

Full Text Available Background: Lesions in distal target arteries hinder surgical bypass procedures in patients with peripheral arterial occlusive disease. Methods: Between April 2012 and October 2015, 16 patients (18 limbs with lifestyle- limiting claudication (n=12 or chronic critical limb ischemia (n=6 underwent femoral–above-knee (AK polytetrafluoroethylene (PTFE bypass grafts with a bridging stent graft placement between the distal target popliteal artery and the PTFE graft. Ring-supported PTFE grafts were used in all patients with no available vein for graft material. Follow-up evaluations assessed clinical symptoms, the ankle-brachial index, ultrasonographic imaging and/or computed tomography angiography, the primary patency rate, and complications. Results: All procedures were successful. The mean follow-up was 12.6 months (range, 11 to 14 months, and there were no major complications. The median baseline ankle-brachial index of 0.4 (range, 0.2 to 0.55 significantly increased to 0.8 (range, 0.5 to 1.0 at 12 months (p＜0.01. The primary patency rate at 12 months was 83.3%. The presenting symptoms resolved within 2 weeks. Conclusion: In AK bypasses with a diffusely diseased distal target popliteal artery or when below-knee (BK bypass surgery is impossible, this procedure could be clinically effective and safe when used as an alternative to femoral-BK bypass surgery.

Severe scurvy after gastric bypass surgery and a poor postoperative diet

DEFF Research Database (Denmark)

Hansen, Esben P K; Metzsche, Carsten; Henningsen, Emil

2012-01-01

After bariatric gastric bypass surgery patients are at risk of developing micronutrient deficiencies. If gastric bypass surgery is followed by a vitamin deficient diet the patients have a risk of developing vitamin-C deficiency. When spontaneous ecchymosis is observed in the skin, in at......-risk patients, scurvy must be considered. When treated with large doses of vitamin-C the symptoms of scurvy rapidly improve even if the patient has developed multiple organ dysfunction syndrome. KEYWORDS: Scurvy; Gastric bypass surgery; Multiorgan dysfunction....

Effect of STA-MCA bypass based on the motor activation SPECT

International Nuclear Information System (INIS)

Kawaguchi, Shoichiro; Uranishi, Ryunosuke; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime

1999-01-01

The effect of STA-MCA bypass for ischemic cerebrovascular diseases (CVDs) on pure motor function using motor activation SPECT was evaluated and analyzed, and this effect with the resting cerebral blood flow and reserved capacity was compared. Motor activation SPECT were carried out on 22 cases with STA-MCA bypass for symptomatic ischemic CVDs. All motors activation SPECT using the finger opposition task on the affected side were performed before bypass, at 1 month, and 3 months after the bypass. Visual inspection was used to determine whether the result of the motor activation SPECT was as negative or positive. The activated region was detected anatomically precisely by superimposing the SPECT on the MRI. Before this study, the same examination was performed on normal controls. In controls, 91% showed the activated area on the sensorimotor cortex after the finger opposition tasks. Before bypass, the resting SPECT revealed reduction of cerebral blood flow (CBF) on the affected side in all cases. All cases also showed a disturbed response to acetazolamide (ACZ). Nine cases were positive in the motor activation SPECT. One month after bypass, the resting CBF increased in 11 cases. Seven showed preoperative positive motor activation. Fifteen cases were positive in the motor activation SPECT. Three months after bypass, 20 cases showed improvement in the resting CBF, and 19 cases were positive in the motor activation SPECT. Ten cases were negative in the preoperative motor activation SPECT. At one month after surgery, ACZ activation SPECT was performed in 12 cases. Five showed improvement of the response to ACZ. At 3 months after surgery, 8 of 12 cases treated with ACZ activation SPECT showed improved response to ACZ. In most of the cases, improved response to ACZ could be seen after response to motor activation improved. STA-MCA bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT. (K.H.)

Effect of STA-MCA bypass based on the motor activation SPECT

Energy Technology Data Exchange (ETDEWEB)

Kawaguchi, Shoichiro; Uranishi, Ryunosuke; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime [Nara Medical Univ., Kashihara (Japan)

1999-07-01

The effect of STA-MCA bypass for ischemic cerebrovascular diseases (CVDs) on pure motor function using motor activation SPECT was evaluated and analyzed, and this effect with the resting cerebral blood flow and reserved capacity was compared. Motor activation SPECT were carried out on 22 cases with STA-MCA bypass for symptomatic ischemic CVDs. All motors activation SPECT using the finger opposition task on the affected side were performed before bypass, at 1 month, and 3 months after the bypass. Visual inspection was used to determine whether the result of the motor activation SPECT was as negative or positive. The activated region was detected anatomically precisely by superimposing the SPECT on the MRI. Before this study, the same examination was performed on normal controls. In controls, 91% showed the activated area on the sensorimotor cortex after the finger opposition tasks. Before bypass, the resting SPECT revealed reduction of cerebral blood flow (CBF) on the affected side in all cases. All cases also showed a disturbed response to acetazolamide (ACZ). Nine cases were positive in the motor activation SPECT. One month after bypass, the resting CBF increased in 11 cases. Seven showed preoperative positive motor activation. Fifteen cases were positive in the motor activation SPECT. Three months after bypass, 20 cases showed improvement in the resting CBF, and 19 cases were positive in the motor activation SPECT. Ten cases were negative in the preoperative motor activation SPECT. At one month after surgery, ACZ activation SPECT was performed in 12 cases. Five showed improvement of the response to ACZ. At 3 months after surgery, 8 of 12 cases treated with ACZ activation SPECT showed improved response to ACZ. In most of the cases, improved response to ACZ could be seen after response to motor activation improved. STA-MCA bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT. (K.H.)

Transfusion requirements in elective cardiopulmonary bypass surgery patients

DEFF Research Database (Denmark)

Sivapalan, Praleene; Bäck, Anne Caroline; Ostrowski, Sisse Rye

2017-01-01

Managing haemostasis in patients undergoing cardiopulmonary bypass (CPB) surgery remains a challenge. There is no established laboratory test to predict transfusion requirements in cardiac surgery. We investigated whether preoperative Thromboelastography (TEG) with Platelet Mapping Assay (PMA......) or Multiple Electrode Aggrometry (MEA) could predict transfusion requirements in patients undergoing elective coronary artery bypass grafting (CABG) or combined CABG with aortic or mitral valve replacement. We prospectively investigated 199 patients undergoing elective CABG or combined procedures. PMA and MEA...

Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy

DEFF Research Database (Denmark)

Patti, M E; McMahon, G; Mun, E C

2005-01-01

AIMS/HYPOTHESIS: Postprandial hypoglycaemia following gastric bypass for obesity is considered a late manifestation of the dumping syndrome and can usually be managed with dietary modification. We investigated three patients with severe postprandial hypoglycaemia and hyperinsulinaemia unresponsive...... was assessed in all three patients. RESULTS: All three patients had evidence of severe postprandial hyperinsulinaemia and hypoglycaemia. In one patient, reversal of gastric bypass was ineffective in reversing hypoglycaemia. All three patients ultimately required partial pancreatectomy for control...

Mining legacy data: digitizing well logs leads to bypassed pay opportunities

Energy Technology Data Exchange (ETDEWEB)

Polczer, S.

1999-10-01

International Datashare Corporation's (iDc) computer software that filters graphic data through an algorithm programmed to recognize pre-set patterns, a process similar to optical character recognition, is described. The software is particularly well suited to large volumes of legacy data because it does not recognize numbers or calculations. Instead, it scans well log files as high-resolution raster files, strips them of all numeric data to isolate hydrocarbon signatures. This pattern recognition is expected to expose (to trained professionals) significant bypassed oil and gas pay that at the time of first development of the well were considered worthless due to lack of markets and transportation infrastructure. iDc plans to distribute the raster well log library of nearly one million records by making it available online. iDc also intends to rasterize and index other data sets such as drill stem data and fluids data , and combine the information into a complete solutions package to mark the company's 50 years in business. This new 'data mining' application is intended to enable operators to locate and develop hydrocarbon reserves that were originally bypassed. 1 photo, 1 fig.

Is phonology bypassed in normal or dyslexic development?

Science.gov (United States)

Pennington, B F; Lefly, D L; Van Orden, G C; Bookman, M O; Smith, S D

1987-01-01

A pervasive assumption in most accounts of normal reading and spelling development is that phonological coding is important early in development but is subsequently superseded by faster, orthographic coding which bypasses phonology. We call this assumption, which derives from dual process theory, the developmental bypass hypothesis. The present study tests four specific predictions of the developmental bypass hypothesis by comparing dyslexics and nondyslexics from the same families in a cross-sectional design. The four predictions are: 1) That phonological coding skill develops early in normal readers and soon reaches asymptote, whereas orthographic coding skill has a protracted course of development; 2) that the correlation of adult reading or spelling performance with phonological coding skill is considerably less than the correlation with orthographic coding skill; 3) that dyslexics who are mainly deficient in phonological coding skill should be able to bypass this deficit and eventually close the gap in reading and spelling performance; and 4) that the greatest differences between dyslexics and developmental controls on measures of phonological coding skill should be observed early rather than late in development.None of the four predictions of the developmental bypass hypothesis were upheld. Phonological coding skill continued to develop in nondyslexics until adulthood. It accounted for a substantial (32-53 percent) portion of the variance in reading and spelling performance in adult nondyslexics, whereas orthographic coding skill did not account for a statistically reliable portion of this variance. The dyslexics differed little across age in phonological coding skill, but made linear progress in orthographic coding skill, surpassing spelling-age (SA) controls by adulthood. Nonetheless, they didnot close the gap in reading and spelling performance. Finally, dyslexics were significantly worse than SA (and Reading Age [RA]) controls in phonological coding skill

Subarachnoid clonidine and trauma response in cardiac surgery with cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Claudia Gissi da Rocha Ferreira

2014-12-01

Full Text Available Background and objectives: The intense trauma response triggered by cardiopulmonary bypass can lead to increased morbidity and mortality. The present study evaluated whether clonidine, a drug of the class of α-2 agonists, administered by spinal route, without association with local anesthetics or opioids, reduces this response in cardiac surgery with cardiopulmonary bypass. Method: A total of 27 patients between 18 and 75 years old, divided by non-blinded fashion into a control group (15 and a clonidine group (12, were studied. All patients underwent identical technique of general anesthesia. Then, only the clonidine group received 1 μg kg−1 clonidine by spinal route. Levels of blood glucose, lactate and cortisol were measured at three consecutive times: T1, at the time of installation of invasive arterial pressure; T2, 10 min after the first dose for cardioplegia; and T3, at the time of skin suture; and troponin I values at T1 and T3. The variation of results between T2-T1, T3-T2, and T3-T1 was also evaluated. Results: There was a statistically significant difference only with respect to the variation in blood glucose in the clonidine group: T3-T2, p = 0.027 and T3-T1, p = 0.047. Conclusions: Spinal clonidine at a dose of 1 μg kg−1 did not decrease blood measurements of troponin, cortisol, or lactate. Blood glucose suffered a more moderate variation during the procedure in the clonidine group. This fact, already reported in the literature, requires further investigation to be clarified.

Facts controllers in power transmission and distribution

CERN Document Server

Padiyar, KR

2007-01-01

About the Book: The emerging technology of Flexible AC Transmission System (FACTS) enables planning and operation of power systems at minimum costs, without compromising security. This is based on modern high power electronic systems that provide fast controllability to ensure ''flexible'' operation under changing system conditions. This book presents a comprehensive treatment of the subject by discussing the operating principles, mathematical models, control design and issues that affect the applications. The concepts are explained often with illustrative examples and case studies. In partic

Renal tubular acidosis secondary to jejunoileal bypass for morbid obesity

DEFF Research Database (Denmark)

Schaffalitzky de Muckadell, O B; Ladefoged, Jens; Thorup, Jørgen Mogens

1985-01-01

Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...

Facts and interpretation on the subject of nuclear energy

International Nuclear Information System (INIS)

Kleinrath, H.

1977-01-01

This report analyses facts and their interpretations on nuclear-energy. Due to the fact that the discussion on nuclear energy was very controversial in the 1970s in Austria, there were various opinions. This report includes always two interpretations for each fact. Content overview: How high is the risk of the operation of nuclear-power-plants compared to other possibilities to produce electricity? How dangerous is the nuclear waste, which is produced during the operation of nuclear-power-plants? Which risks entail reprocessing-plants? How far is the question of final repository of nuclear waste solved? Is there any sense for Austria to do without nuclear-power-plants? Is electricity generated by nuclear power cheap? Are there alternatives in the generation of electricity to nuclear-power-plants? Does a waiver of nuclear-power-plants mean a social risk – hazard of our economic stability, hazard of jobs? Literature(kancsar)

Emergent cardiopulmonary bypass during pectus excavatum repair

Directory of Open Access Journals (Sweden)

Ryan Craner

2013-01-01

Full Text Available Pectus excavatum is a chest wall deformity that produces significant cardiopulmonary disability and is typically seen in younger patients. Minimally invasive repair of pectus excavatum or Nuss procedure has become a widely accepted technique for adult and pediatric patients. Although it is carried out through a thoracoscopic approach, the procedure is associated with a number of potential intraoperative and post-operative complications. We present a case of cardiac perforation requiring emergent cardiopulmonary bypass in a 29-year-old male with Marfan syndrome and previous mitral valve repair undergoing a Nuss procedure for pectus excavatum. This case illustrates the importance of vigilance and preparation by the surgeons, anesthesia providers as well as the institution to be prepared with resources to handle the possible complications. This includes available cardiac surgical backup, perfusionist support and adequate blood product availability.

Heart bypass surgery - minimally invasive

Science.gov (United States)

... MIDCAB; Robot-assisted coronary artery bypass; RACAB; Keyhole heart surgery; CAD - MIDCAB; Coronary artery disease - MIDCAB ... To perform this surgery: The heart surgeon will make a 3- to 5-inch (8 to 13 centimeters) surgical cut in the left part of your chest ...

Bypass during Liver Transplantation: Anachronism or Revival? Liver Transplantation Using a Combined Venovenous/Portal Venous Bypass—Experiences with 163 Liver Transplants in a Newly Established Liver Transplantation Program

Directory of Open Access Journals (Sweden)

Anne Mossdorf

2015-01-01

Full Text Available Introduction. The venovenous/portal venous (VVP bypass technique has generally become obsolete in liver transplantation (LT today. We evaluated our experience with 163 consecutive LTs that used a VVP bypass. Patients and Methods. The liver transplant program was started in our center in 2010. LTs were performed using an extracorporal bypass device. Results. Mean operative time was 269 minutes and warm ischemic time 43 minutes. The median number of transfusion of packed cells and plasma was 7 and 14. There was no intraoperative death, and the 30-day mortality was 3%. Severe bypass-induced complications did not occur. Discussion. The introduction of a new LT program requires maximum safety measures for all of the parties involved. Both surgical and anaesthesiological management (reperfusion can be controlled very reliably using a VVP bypass device. Particularly when using marginal grafts, this approach helps to minimise both surgical and anaesthesiological complications in terms of less volume overload, less use of vasopressive drugs, less myocardial injury, and better peripheral blood circulation. Conclusion. Based on our experiences while establishing a new liver transplantation program, we advocate the reappraisal of the extracorporeal VVP bypass.

Temporary diabetes insipidus in 2 men after on-pump coronary artery bypass grafting.

Science.gov (United States)

Uyar, Ihsan Sami; Sahin, Veysel; Akpinar, Besir; Yurtman, Volkan; Abacilar, Feyzi; Okur, Faik Fevzi; Ates, Mehmet

2013-01-01

Many complications have been reported after cardiopulmonary bypass. A common physiologic change during the early postoperative period after cardiopulmonary bypass is increased diuresis. In patients whose urine output is increased, postoperative diabetes insipidus can develop, although reports of this are rare. We present the cases of 2 patients who underwent on-pump coronary artery bypass grafting (with cardiopulmonary bypass). Each was diagnosed with diabetes insipidus postoperatively: a 54-year-old man on the 3rd day, and a 66-year-old man on the 4th day. Each patient recovered from the condition after 6 hours of intranasal therapy with synthetic vasopressin (antidiuretic hormone). The diagnosis of diabetes insipidus should be considered in patients who produce excessive urine early after cardiac surgery in which cardiopulmonary bypass has been used.

Cardiopulmonary bypass: development of John Gibbon's heart-lung machine

OpenAIRE

Passaroni, Andréia Cristina; Silva, Marcos Augusto de Moraes; Yoshida, Winston Bonetti

2015-01-01

AbstractObjective:To provide a brief review of the development of cardiopulmonary bypass.Methods:A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation.Results:The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from vari...

Dacron or PTFE for above-knee femoropopliteal bypass. a multicenter randomised study

DEFF Research Database (Denmark)

Jensen, L P; Lepäntalo, M; Fossdal, J E

2007-01-01

To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass.......To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass....

Long-term hypovitaminosis D and secondary hyperparathyroidism outcomes of the Roux-en-Y gastric bypass: a systematic review.

Science.gov (United States)

Switzer, N J; Marcil, G; Prasad, S; Debru, E; Church, N; Mitchell, P; Billington, E O; Gill, R S

2017-05-01

Pre-operative Vitamin D deficiency is markedly prevalent in prospective bariatric surgery patients. While bariatric surgery leads to significant weight loss, it can exacerbate or prolong Vitamin D deficiency. We systematically reviewed the literature to assess whether secondary hyperparathyroidism is maintained in the medium to long term in patients following the Roux-en-Y gastric bypass. A comprehensive literature search was conducted through Medline, Embase, Scopus, Web of Science, Dare, Cochrane library and HTA database. The search terms used were bariatric surgery, gastric bypass and hyperparathyroidism. Fourteen studies were included (n = 2688 subjects). Parathyroid hormone levels rose gradually from a mean pre-operative level of 5.69 ± 1.2 pmol/L to 6.36 ± 0.77 pmol/L, 7.59 ± 0.73 pmol/L and 8.29 ± 1.41 pmol/L at 2 years, between 2 and 5 years, and beyond 5 years, respectively. Vitamin D levels slowly fell to a mean of 20.50 ± 4.37 ng/mL and 20.76 ± 3.80 ng/mL between follow-up intervals 2-5 years and beyond 5, respectively. It appears that hyperparathyroidism persists at 5-year follow-up after gastric bypass, despite most patients being supplemented with calcium and Vitamin D. © 2017 World Obesity Federation.

A Novel Anti-Pollution Filter for Volatile Agents During Cardiopulmonary Bypass: Preliminary Tests.

Science.gov (United States)

Nigro Neto, Caetano; Landoni, Giovanni; Tardelli, Maria Angela

2017-08-01

Concerns regarding pollution of the operating room by volatile anesthetics and effects on atmospheric ozone depletion exist. Volatile agents commonly are used during cardiopulmonary bypass to provide anesthesia independent of any supposed myocardial protective effects. The authors' aim was to create and to assess the performance of a prototype filter for volatile agents to be connected to the cardiopulmonary bypass circuit to avoid the emission of volatile agents to the operating room, and also to the environment without causing damage to the membrane oxygenator. Observational trial. University hospital. Prototype filter for volatile agents. The prototype filter was tested in a single ex vivo experiment. The main data measured during the test were pressure drop to detect interference with the performance of the oxygenator, back pressure to detect overpressure to the outlet gas jacket of the oxygenator, analysis of exhaled sevoflurane after the membrane oxygenator, and after the filter to detect any presence of sevoflurane. The prototype filter adsorbed the sevoflurane eliminated through the outlet portion of the oxygenator. During the entire test, the back pressure remained constant (4 mmHg) and pressure drop varied from 243 mmHg to 247 mmHg. The prototype filter was considered suitable to absorb the sevoflurane, and it did not cause an overpressure to the membrane oxygenator during the test. Copyright © 2017 Elsevier Inc. All rights reserved.

Health and performance of calves with forestomach-bypass fed milk replacer.

Science.gov (United States)

McKinstry, D M; Cason, J L; Albert, T F; Sass, B

1976-02-01

Ten male Holstein calves were placed in groups of two calves each on similarity of age. On calf in each group was subjected to forestomach-bypass surgery at about 1 mo of age. Fortified commercial milk replacer with added minerals and vitamins was fed as the sole diet. The calves were housed indoors on slatted platforms. Weight gain was determined biweekly. Feed intake was determined daily. Necropsies were performed upon termination of the study. Recurrent ruminal bloat, fever, and anorexia of varying degrees and combinations occurred in four of the calves with forestomach bypass. Two of these calves showed slow weight gain. One of the four calves died following acute bloat while the other three calves were sacrificed following repeated episodes of bloat. The time of termination varied between 3 and 10 mo. One calf with forestomach bypass and all control calves appeared healthy throughout the experiment. Necropsies indicated that the ruminal bloat, seen in most of the forestomach-bypass calves, could be attributed to the back-flow of ingesta via the omasal-abomasal orifice. This ingesta appeared to produce gas which became trapped in the bypassed rumen.

Evolution of elderly patients who underwent cardiac surgery with cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Alain Moré Duarte

2016-01-01

Full Text Available Introduction: There is a steady increase in the number of elderly patients with severe cardiovascular diseases who require a surgical procedure to recover some quality of life that allows them a socially meaningful existence, despite the risks.Objectives: To analyze the behavior of elderly patients who underwent cardiac surgery with cardiopulmonary bypass.Method: A descriptive, retrospective, cross-sectional study was conducted with patients over 65 years of age who underwent surgery at the Cardiocentro Ernesto Che Guevara, in Santa Clara, from January 2013 to March 2014.Results: In the study, 73.1% of patients were men; and there was a predominance of subjects between 65 and 70 years of age, accounting for 67.3%. Coronary artery bypass graft was the most prevalent type of surgery and had the longest cardiopulmonary bypass times. Hypertension was present in 98.1% of patients. The most frequent postoperative complications were renal dysfunction and severe low cardiac output, with 44.2% and 34.6% respectively.Conclusions: There was a predominance of men, the age group of 65 to 70 years, hypertension, and patients who underwent coronary artery bypass graft with prolonged cardiopulmonary bypass. Renal dysfunction was the most frequent complication.

Drug Facts

Medline Plus

Full Text Available ... form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts ... addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain ...

Drug Facts

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Full Text Available ... Facts Search form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, ... Drugs? Effects of Drugs Drug Use and Other People Drug Use and Families Drug Use and Kids ...

Drug Facts

Medline Plus

Full Text Available ... Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts Heroin (Smack, Junk) ... treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice ( ...

A simple technique can reduce cardiopulmonary bypass use during lung transplantation

Directory of Open Access Journals (Sweden)

Marcos N. Samano

2016-04-01

Full Text Available Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure.

Diabetes-associated microbiota in fa/fa rats is modified by Roux-en-Y gastric bypass

DEFF Research Database (Denmark)

Arora, Tulika; Seyfried, Florian; Docherty, Neil G

2017-01-01

Roux-en-Y gastric bypass (RYGB) and duodenal jejunal bypass (DJB), two different forms of bariatric surgery, are associated with improved glucose tolerance, but it is not clear whether the gut microbiota contributes to this effect. Here we used fa/fa rats as a model of impaired glucose tolerance...... to investigate whether (i) the microbiota varies between fa/fa and nondiabetic fa/+ rats; (ii) the microbiota of fa/fa rats is affected by RYGB and/or DJB; and (iii) surgically induced microbiota alterations contribute to glucose metabolism. We observed a profound expansion of Firmicutes (specifically......, Lactobacillus animalis and Lactobacillus reuteri) in the small intestine of diabetic fa/fa compared with nondiabetic fa/+ rats. RYGB-, but not DJB-, treated fa/fa rats exhibited greater microbiota diversity in the ileum and lower L. animalis and L. reuteri abundance compared with sham-operated fa/fa rats in all...

Drug Facts

Medline Plus

Full Text Available ... Pain Medicine (Oxy, Vike) Facts Spice (K2) Facts Tobacco and Nicotine Facts Other Drugs of Abuse What ... Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800- ...

Drug Facts

Medline Plus

Full Text Available ... Oxy, Vike) Facts Spice (K2) Facts Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? ... Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800-662- ...

CH Packaging Operations Manual

International Nuclear Information System (INIS)

2008-01-01

This document provides the user with instructions for assembling a payload. All the steps in Subsections 1.2, Preparing 55-Gallon Drum Payload Assembly; 1.3, Preparing 'Short' 85-Gallon Drum Payload Assembly (TRUPACT-II and HalfPACT); 1.4, Preparing 'Tall' 85-gallon Drum Payload Assembly (HalfPACT only); 1.5, Preparing 100-Gallon Drum Payload Assembly; 1.6, Preparing SWB Payload Assembly; and 1.7, Preparing TDOP Payload Assembly, must be completed, but may be performed in any order as long as radiological control steps are not bypassed. Transport trailer operations, package loading and unloading from transport trailers, hoisting and rigging activities such as ACGLF operations, equipment checkout and shutdown, and component inspection activities must be performed, but may be performed in any order and in parallel with other activities as long as radiological control steps are not bypassed. Steps involving OCA/ICV lid removal/installation and payload removal/loading may be performed in parallel if there are multiple operators working on the same packaging. Steps involving removal/installation of OCV/ICV upper and lower main O-rings must be performed in sequence.

CH Packaging Operations Manual

International Nuclear Information System (INIS)

2009-01-01

This document provides the user with instructions for assembling a payload. All the steps in Subsections 1.2, Preparing 55-Gallon Drum Payload Assembly; 1.3, Preparing 'Short' 85-Gallon Drum Payload Assembly (TRUPACT-II and HalfPACT); 1.4, Preparing 'Tall' 85-Gallon Drum Payload Assembly (HalfPACT only); 1.5, Preparing 100-Gallon Drum Payload Assembly; 1.6, Preparing Shielded Container Payload Assembly; 1.7, Preparing SWB Payload Assembly; and 1.8, Preparing TDOP Payload Assembly, must be completed, but may be performed in any order as long as radiological control steps are not bypassed. Transport trailer operations, package loading and unloading from transport trailers, hoisting and rigging activities such as ACGLF operations, equipment checkout and shutdown, and component inspection activities must be performed, but may be performed in any order and in parallel with other activities as long as radiological control steps are not bypassed. Steps involving OCA/ICV lid removal/installation and payload removal/loading may be performed in parallel if there are multiple operators working on the same packaging. Steps involving removal/installation of OCV/ICV upper and lower main O-rings must be performed in sequence, except as noted.

CH Packaging Operations Manual

Energy Technology Data Exchange (ETDEWEB)

None, None

2009-05-27

This document provides the user with instructions for assembling a payload. All the steps in Subsections 1.2, Preparing 55-Gallon Drum Payload Assembly; 1.3, Preparing "Short" 85-Gallon Drum Payload Assembly (TRUPACT-II and HalfPACT); 1.4, Preparing "Tall" 85-Gallon Drum Payload Assembly (HalfPACT only); 1.5, Preparing 100-Gallon Drum Payload Assembly; 1.6, Preparing Shielded Container Payload Assembly; 1.7, Preparing SWB Payload Assembly; and 1.8, Preparing TDOP Payload Assembly, must be completed, but may be performed in any order as long as radiological control steps are not bypassed. Transport trailer operations, package loading and unloading from transport trailers, hoisting and rigging activities such as ACGLF operations, equipment checkout and shutdown, and component inspection activities must be performed, but may be performed in any order and in parallel with other activities as long as radiological control steps are not bypassed. Steps involving OCA/ICV lid removal/installation and payload removal/loading may be performed in parallel if there are multiple operators working on the same packaging. Steps involving removal/installation of OCV/ICV upper and lower main O-rings must be performed in sequence, except as noted.

Fishing Facts Unlimited. Enterprise: Man & Technology.

Science.gov (United States)

Southern Illinois Univ., Carbondale. Dept. of Technical and Industrial Education.

Fishing Facts Unlimited, a student conducted enterprise in Technical and Industrial Education at Southern Illinois University, Carbondale has been a very successful operation, both financially and in providing a community service. The service provided by the enterprise was the production and sales of a 48-page fishing guide to Southern Illinois.…

Effect of bypass on the motor activation SPECT compared to the acetazolamide SPECT

International Nuclear Information System (INIS)

Kawaguchi, Shoichiro; Iwahashi, Hideaki; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime

2002-01-01

The authors evaluated and analyzed motor activation single photon emission computed tomography (M-SPECT) in ischemic cerebrovascular disease compared to resting and acetazolamide (ACZ) activated SPECT studies. Seventeen cases with STA-MCA bypass performed for ischemic cerebrovascular disease were examined. The SPECT studies consisting of resting, ACZ activation, and motor activation stages were performed before bypass, at 1 month, and 3 months after bypass. The result of the M-SPECT was expressed as negative or positive. Before bypass: In all 17 cases, SPECT studies of the affected side showed reduction of resting cerebral blood flow (CBF) and reduction of cerebrovascular reserve capacity (CVRC). Eight cases were positive in the M-SPECT study. One week after bypass: The resting CBF increased in seven cases. Four showed preoperative positive M-SPECT. Eight cases showed improvement of the CVRC. Twelve cases were positive in M-SPECT, and two were negative in the preoperative M-SPECT. Three months after bypass: Thirteen cases showed improvement in the resting CBF, and fourteen cases showed improvement of the CVRC. Fourteen cases were positive in the M-SPECT, and among these, 6 were negative in the preoperative M-SPECT. There was a discrepancy between the improvement in CVRC and M-SPECT. M-SPECT study can provide information about the degree of hemodynamic compromise and effect of bypass surgery. (author)

Direct ECC bypass phenomena in the MIDAS test facility during LBLOCA reflood phase

International Nuclear Information System (INIS)

Yun, B. J.; Kweon, T. S.; Ah, D. J.; Ju, I. C.; Song, C. H.; Park, J. K.

2001-01-01

This paper describes the experimental results of ECC Direct Bypass Phenomena in the downcomer during the late reflood phase of LBLOCA of the reactor that adopts Direct Vessel Injection as a ECC system. The experiments have been performed in MIDAS test facility using superheated steam and water. The test condition was determined, based on the preliminary analysis of TRAC code, from modified linear scaling method of 1/4.93 length scale. To measure the direct bypass fraction according to the nozzle location, separate effect tests have been performed in case of DVI-4(farthest from broken cold leg) injection, DVI-2(closest to broken cold leg) injection, and DVI-2 and 4 injection, respectively. Also the test was carried out varying the steam flow rate greatly to investigate the effect of steam flow rate on the direct bypass fraction of ECC water. Test results show that the direct bypass fraction of ECC water depends significantly on the injected steam mass flow rate. DVI-4 tests show that the direct bypass fraction increases drastically as the steam flow rate increases. However, in DVI-2 test most of the injected ECC water penetrates into lower downcomer. The direct bypass characteristic in each of DVI-2 and DVI-4 tests is reflected into the direct bypass characteristic curve of DVI-2 and 4 test. The steam condensation reaches to the theoretically allowable maximum value

Effect of bypass on the motor activation SPECT compared to the acetazolamide SPECT

Energy Technology Data Exchange (ETDEWEB)

Kawaguchi, Shoichiro; Iwahashi, Hideaki; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime [Nara Medical Univ., Kashihara (Japan)

2002-03-01

The authors evaluated and analyzed motor activation single photon emission computed tomography (M-SPECT) in ischemic cerebrovascular disease compared to resting and acetazolamide (ACZ) activated SPECT studies. Seventeen cases with STA-MCA bypass performed for ischemic cerebrovascular disease were examined. The SPECT studies consisting of resting, ACZ activation, and motor activation stages were performed before bypass, at 1 month, and 3 months after bypass. The result of the M-SPECT was expressed as negative or positive. Before bypass: In all 17 cases, SPECT studies of the affected side showed reduction of resting cerebral blood flow (CBF) and reduction of cerebrovascular reserve capacity (CVRC). Eight cases were positive in the M-SPECT study. One week after bypass: The resting CBF increased in seven cases. Four showed preoperative positive M-SPECT. Eight cases showed improvement of the CVRC. Twelve cases were positive in M-SPECT, and two were negative in the preoperative M-SPECT. Three months after bypass: Thirteen cases showed improvement in the resting CBF, and fourteen cases showed improvement of the CVRC. Fourteen cases were positive in the M-SPECT, and among these, 6 were negative in the preoperative M-SPECT. There was a discrepancy between the improvement in CVRC and M-SPECT. M-SPECT study can provide information about the degree of hemodynamic compromise and effect of bypass surgery. (author)

Impact of smoking on early clinical outcomes in patients undergoing coronary artery bypass grafting surgery

OpenAIRE

Ji, Qiang; Zhao, Hang; Mei, YunQing; Shi, YunQing; Ma, RunHua; Ding, WenJun

2015-01-01

Background To evaluate the impact of persistent smoking versus smoking cessation over one month prior to surgery on early clinical outcomes in Chinese patients undergoing isolated coronary artery bypass grafting (CABG) surgery in a retrospective study. Methods The peri-operative data of consecutive well-documented patients undergoing isolated CABG surgery from January 2007 to December 2013 were investigated and retrospectively analyzed. All included patients were divided into either a non-smo...

Normothermic versus hypothermic cardiopulmonary bypass in children undergoing open heart surgery (thermic-2): study protocol for a randomized controlled trial.

Science.gov (United States)

Baos, Sarah; Sheehan, Karen; Culliford, Lucy; Pike, Katie; Ellis, Lucy; Parry, Andrew J; Stoica, Serban; Ghorbel, Mohamed T; Caputo, Massimo; Rogers, Chris A

2015-05-25

During open heart surgery, patients are connected to a heart-lung bypass machine that pumps blood around the body ("perfusion") while the heart is stopped. Typically the blood is cooled during this procedure ("hypothermia") and warmed to normal body temperature once the operation has been completed. The main rationale for "whole body cooling" is to protect organs such as the brain, kidneys, lungs, and heart from injury during bypass by reducing the body's metabolic rate and decreasing oxygen consumption. However, hypothermic perfusion also has disadvantages that can contribute toward an extended postoperative hospital stay. Research in adults and small randomized controlled trials in children suggest some benefits to keeping the blood at normal body temperature throughout surgery ("normothermia"). However, the two techniques have not been extensively compared in children. The Thermic-2 study will test the hypothesis that the whole body inflammatory response to the nonphysiological bypass and its detrimental effects on different organ functions may be attenuated by maintaining the body at 35°C-37°C (normothermic) rather than 28°C (hypothermic) during pediatric complex open heart surgery. This is a single-center, randomized controlled trial comparing the effectiveness and acceptability of normothermic versus hypothermic bypass in 141 children with congenital heart disease undergoing open heart surgery. Children having scheduled surgery to repair a heart defect not requiring deep hypothermic circulatory arrest represent the target study population. The co-primary clinical outcomes are duration of inotropic support, intubation time, and postoperative hospital stay. Secondary outcomes are in-hospital mortality and morbidity, blood loss and transfusion requirements, pre- and post-operative echocardiographic findings, routine blood gas and blood test results, renal function, cerebral function, regional oxygen saturation of blood in the cerebral cortex, assessment of

Indications and Outcomes of Prophylactic and Therapeutic Extracranial-to-intracranial Arterial Bypass for Cerebral Revascularization

Directory of Open Access Journals (Sweden)

Emre Gazyakan, MD, MSc

2015-04-01

Conclusions: The collaboration of neurosurgeons and plastic surgeons in performing EC-IC bypass can result in excellent outcomes with a high bypass patency rate and few complications, particularly for prophylactic EC-IC bypass.

Off-pump Coronary Artery Bypass Graft in a High Risk Patient ...

African Journals Online (AJOL)

On-pump coronary artery bypass graft (CABG) entails the use of cardiopulmonary bypass (CPB). The procedure is safe but it's not without complications like neurocognitive deficits, cerebrovascular accidents, myocardial ischemic injury and activation of inflammatory pathways that contribute to pulmonary, renal, hematologic ...

Long term results of polytetrafluoroethylene in above knee femoropopliteal bypass for critical ischaemia.

LENUS (Irish Health Repository)

Kavanagh, E G

2012-02-03

Ninety-six consecutive above-knee femoropopliteal bypasses, using polytetrafluoroethylene (PTFE) preferentially, were performed for limb-threatening ischaemia. Cumulative primary graft patency was 68 per cent, 49 per cent and 36 per cent and limb salvage 93 per cent, 85 per cent and 75 per cent at 1, 3 and 5 yr respectively. As a result of poor long term survival (51 per cent at 5 yr), and the healing of remedial lesions before graft occlusion, 68 patients (72 per cent) required no further intervention. Eighteen secondary bypasses were undertaken, 12 using ipsilateral saphenous vein. In this group of elderly patients with poor life expectancy, where a limited operation is desirable, the use of PTFE provided excellent limb salvage with low morbidity. Although we can no longer justify our continued use of PTFE in every case of critical ischaemia because of its inferior patency to autogenous vein, we continue to use it preferentially in patients whose lifespan is likely to be short and in cases where a remedial lesion is present.

Sodium/hydrogen-exchanger inhibition during cardioplegic arrest and cardiopulmonary bypass: an experimental study.

Science.gov (United States)

Cox, Charles S; Sauer, Henning; Allen, Steven J; Buja, L Maximilian; Laine, Glen A

2002-05-01

We sought to determine whether pretreatment with a sodium/hydrogen-exchange inhibitor (EMD 96 785) improves myocardial performance and reduces myocardial edema after cardioplegic arrest and cardiopulmonary bypass. Anesthetized dogs (n = 13) were instrumented with vascular catheters, myocardial ultrasonic crystals, and left ventricular micromanometers to measure preload recruitable stroke work, maximum rate of pressure rise (positive and negative), and left ventricular end-diastolic volume and pressure. Cardiac output was measured by means of thermodilution. Myocardial tissue water content was determined from sequential biopsy. After baseline measurements, hypothermic (28 degrees C) cardiopulmonary bypass was initiated. Cardioplegic arrest (4 degrees C Bretschneider crystalloid cardioplegic solution) was maintained for 2 hours, followed by reperfusion-rewarming and separation from cardiopulmonary bypass. Preload recruitable stroke work and myocardial tissue water content were measured at 30, 60, and 120 minutes after bypass. EMD 96 785 (3 mg/kg) was given 15 minutes before bypass, and 2 micromol was given in the cardioplegic solution. Control animals received the same volume of saline vehicle. Arterial-coronary sinus lactate difference was similar in both animals receiving EMD 96 785 and control animals, suggesting equivalent myocardial ischemia in each group. Myocardial tissue water content increased from baseline in both animals receiving EMD 96 785 and control animals with cardiopulmonary bypass and cardioplegic arrest but was statistically lower in animals receiving EMD 96 785 compared with control animals (range, 1.0%-1.5% lower in animals receiving EMD 96 785). Preload recruitable stroke work decreased from baseline (97 +/- 2 mm Hg) at 30 (59 +/- 6 mm Hg) and 60 (72 +/- 9 mm Hg) minutes after cardiopulmonary bypass and cardioplegic arrest in control animals; preload recruitable stroke work did not decrease from baseline (98 +/- 2 mm Hg) in animals receiving

21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

Science.gov (United States)

2010-04-01

..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery to...

Changes in adhesion molecule expression and oxidative burst activity of granulocytes and monocytes during open-heart surgery with cardiopulmonary bypass compared with abdominal surgery

DEFF Research Database (Denmark)

Toft, P; Nielsen, C H; Tønnesen, E

1998-01-01

surgery. The ability to respond with an oxidative burst was measured by means of flow cytometry using 123-dihydrorhodamine. The adhesion molecules CD11a/CD18, CD11c/CD18, CD44 were measured using monoclonal antibodies. Blood samples from eight patients undergoing open-heart surgery were taken before...... to an increased per-operative oxidative burst activity, and the induction of adhesion molecules on granulocytes associated with the cardiopulmonary bypass and surgery. In conclusion, open-heart surgery with cardiopulmonary bypass was associated with a rapid and pronounced activation of leukocytes which may play...

Assessment of long-term effects of aneurysms trapping and extracranial-intracranial bypass surgery in patients with complex cerebral aneurysms

Directory of Open Access Journals (Sweden)

MAO Zhi-qi

2012-02-01

Full Text Available Objective To study the long-term effects of extracranial-intracranial (EC-IC bypass and aneurysms trapping in patients with complex cerebral aneurysms. Methods Seventeen patients with complex aneurysms, who underwent EC-IC bypass and aneurysms trapping from 2008 to 2009, were followed up. Clinical records were reviewed, modified Rankin Scale (mRS was recorded at admission, discharging, and follow-up point, and activities of daily living (ADL scale (Barthel Index at admission and follow-up point. Results Seventeen patients (11 males and 6 females were followed up. At admission mRS scores were 1.06 ± 0.87, Barthel index 91.10 ± 10.30. Superficial temporal artery-middle cerebral artery (STA-MCA was performed in 8 cases, extracarotid artery-great saphenous vein-middle cerebral artery (ECA-GSV-MCA in 5 cases, extracarotid artery-radial artery-middle cerebral artery (ECA-RA-MCA in 3 cases, occipital artery-posterior inferior cerebellar artery (OA-PICA in 1 case. Patients were followed up for 19-39 months (mean 28.67 months. At follow-up point, 2 patients (11.76% died, operation-related mortality was 5.88% (1/17, operation-related morbidity 5.88% (1/17, mRS scores 1.07 ± 1.16, Barthel index 96.40 ± 10.30. Conclusion Patients with complex aneurysms who were impossible to be treated with surgical clipping or endovascular intervention could be cured with extracranial-intracranial bypass and aneurysms trapping, and good follow-up results were acquired.

Rural Bypass of Critical Access Hospitals in Iowa: Do Visiting Surgical Specialists Make a Difference?

Science.gov (United States)

Weigel, Paula A M; Ullrich, Fred; Ward, Marcia M

2018-02-01

Rural bypass for elective surgical procedures is a challenge for critical access hospitals, yet there are opportunities for rural hospitals to improve local retention of surgical candidates through alternative approaches to developing surgery lines of business. In this study we examine the effect of visiting surgical specialists on the odds of rural bypass. Discharge data from the 2011 State Inpatient Databases and State Ambulatory Surgery Databases for Iowa were linked to outreach data from the Office of Statewide Clinical Education Programs and Iowa Physician Information System to model the effect of surgeon specialist supply on rural patients' decision to bypass rural critical access hospitals. Patients in rural communities with a local general surgeon were more likely to be retained in a community than to bypass. Those in communities with visiting general surgeons were more likely to bypass, as were those in communities with visiting urologists and obstetricians. Patients in communities with visiting ophthalmologists and orthopedic surgeons were at higher odds of being retained for their elective surgeries. In addition to known patient and local hospital factors that have an influence on bypass behavior among rural patients seeking elective surgery, availability of surgeon specialists also plays an important role in whether patients bypass or not. Visiting ophthalmologists and orthopedic surgeons were associated with less bypass, as was having local general surgeons. Visiting general surgeons, urologists, and obstetricians were associated with greater odds of bypass. © 2016 National Rural Health Association.

West Valley Demonstration Project vitrification process equipment Functional and Checkout Testing of Systems (FACTS)

International Nuclear Information System (INIS)

Carl, D.E.; Paul, J.; Foran, J.M.; Brooks, R.

1990-01-01

The Vitrification Facility (VF) at the West Valley Demonstration Project was designed to convert stored radioactive waste into a stable glass for disposal in a federal repository. The Functional and Checkout Testing of Systems (FACTS) program was conducted from 1984 to 1989. During this time new equipment and processes were developed, installed, and implemented. Thirty-seven FACTS tests were conducted, and approximately 150,000 kg of glass were made by using nonradioactive materials to simulate the radioactive waste. By contrast, the planned radioactive operation is expected to produce approximately 500,000 kg of glass. The FACTS program demonstrated the effectiveness of equipment and procedures in the vitrification system, and the ability of the VF to produce quality glass on schedule. FACTS testing also provided data to validate the WVNS waste glass qualification method and verify that the product glass would meet federal repository acceptance requirements. The system was built and performed to standards which would have enabled it to be used in radioactive service. As a result, much of the VF tested, such as the civil construction, feed mixing and holding vessels, and the off-gas scrubber, will be converted for radioactive operation. The melter was still in good condition after being at temperature for fifty-eight of the sixty months of FACTS. However, the melter exceeded its recommended design life and will be replaced with a similar melter. Components that were not designed for remote operation and maintenance will be replaced with remote-use items. The FACTS testing was accomplished with no significant worker injury or environmental releases. During the last FACTS run, the VF processes approximated the remote-handling system that will be used in radioactive operations. Following this run the VF was disassembled for conversion to a radioactive process. Functional and checkout testing of new components will be performed prior to radioactive operation

Effects of graphite surface roughness on bypass flow computations for an HTGR

Energy Technology Data Exchange (ETDEWEB)

Tung, Yu-Hsin, E-mail: touushin@gmail.com [Idaho National Laboratory, P.O. Box 1625, M.S. 3855, Idaho Falls, ID (United States); Johnson, Richard W., E-mail: Rich.Johnson@inl.gov [Idaho National Laboratory, P.O. Box 1625, M.S. 3855, Idaho Falls, ID (United States); Sato, Hiroyuki, E-mail: sato.hiroyuki09@jaea.go.jp [Idaho National Laboratory, P.O. Box 1625, M.S. 3855, Idaho Falls, ID (United States)

2012-11-15

Highlights: Black-Right-Pointing-Pointer CFD calculations are made of bypass flow between graphite blocks in HTGR. Black-Right-Pointing-Pointer Several turbulence models are employed to compare to friction and heat transfer correlations. Black-Right-Pointing-Pointer Parameters varied include bypass gap width and surface roughness. Black-Right-Pointing-Pointer Surface roughness causes increases in max fuel and coolant temperatures. Black-Right-Pointing-Pointer Surface roughness does not cause increase in outlet coolant temperature variation. - Abstract: Bypass flow in a prismatic high temperature gas reactor (HTGR) occurs between graphite blocks as they sit side by side in the core. Bypass flow is not intentionally designed to occur in the reactor, but is present because of tolerances in manufacture, imperfect installation and expansion and shrinkage of the blocks from heating and irradiation. It is desired to increase the knowledge of the effects of such flow; it has been suggested that it may be as much as 20% of the total helium coolant flow [INL Report 2007, INL/EXT-07-13289]. Computational fluid dynamic (CFD) simulations can provide estimates of the scale and impacts of bypass flow. Previous CFD calculations have examined the effects of bypass gap width, level and distribution of heat generation and effects of shrinkage. The present contribution examines the effects of graphite surface roughness on the bypass flow for different relative roughness factors for three gap widths. Such calculations should be validated using specific bypass flow measurements. While such experiments are currently underway for the specific reference prismatic HTGR design for the next generation nuclear plant (NGNP) program of the U.S. Dept. of Energy, the data are not yet available. To enhance confidence in the present calculations, wall shear stress and heat transfer results for several turbulence models and their associated wall treatments are first compared for steady flow in a

Arterial pressure during cardiopulmonary bypass is not associated with acute kidney injury

DEFF Research Database (Denmark)

Kandler, K; Jensen, M E; Nilsson, J C

2015-01-01

BACKGROUND: Acute kidney injury (AKI) after cardiac surgery is common and is associated with increased mortality. We wanted to investigate if the arterial pressure or the use of norepinephrine during cardiopulmonary bypass were associated with AKI. METHODS: A retrospective analysis of patients who...... underwent coronary artery bypass grafting with or without concomitant procedures was conducted. AKI was defined using the RIFLE criteria. Data on arterial pressure and use of norepinephrine during cardiopulmonary bypass were entered in a binary logistic regression model to control for possible perioperative...... and in higher amounts, during cardiopulmonary bypass, in patients who developed AKI. These differences in arterial pressures and use of norepinephrine between the groups were not found to be significant when entered in the binary logistic regression model. CONCLUSION: No independent relationship between...

The problem of calcified ascending aorta during aortocoronary bypass

Directory of Open Access Journals (Sweden)

Nežić Duško G.

2004-01-01

Full Text Available Heavily calcified ascending aorta significantly increased morbidity and lethality during open-heart surgery. Cannulation and clamping (partial or total of severely atherosclerotic ascending aorta can easily cause damage and rupture of aortic wall, with consequential distal (often fatal embolization with atheromatous debris (brain, myocardium. From June 1998. until June 2000, 11 of 2 136 (0.5% patients who underwent coronary artery bypass grafting were with the severe atheromatous ascending aorta. The site of cannulation was in the aortic arch in three patients (aorta was occluded with Foley catheter in one case, and single clamp technique was used in the other two cases. The femoral artery was the cannulation site in other five cases. Profound hypothermia, ventricular fibrillation, and circulatory arrest, with no cross-clamping or cardioplegia, were used in three patients. Two patients were operated on with extracorporeal circulation, one in normothermia, on the beating heart, the other in moderate hypothermia, on fibrillating heart. In three patients myocardial revascularization was performed on the beating heart, in normothermia, without extracorporeal circulation. Postoperative course was uneventful in all 11 patients. Neither atheroembolism in the peripheral organs, nor atheroembolism of the extramities occurred. The proposed surgical approaches have the potential to reduce the prevalence of stroke and systemic embolization associated with coronary artery bypass grafting in patients with heavily calcified ascending aorta. This result was achieved due to the applied modifications of standard cardiosurgical technique.

D.E.R. 85: main facts

International Nuclear Information System (INIS)

1986-01-01

This report presents the important facts among the studies carried out by the ''Direction des Etudes et Recherches'' (E.D.F.): new applications of electric power for customers, protection of environment, classical equipments for power plants and nuclear equipments, monitoring and control of power plants, electrical equipments, development and operation of electrical networks, informatics and office automation [fr

Neurological bypass for sensory innervation of the penis in patients with spina bifida.

Science.gov (United States)

Overgoor, Max L E; Kon, Moshe; Cohen-Kettenis, Peggy T; Strijbos, Saskia A M; de Boer, Niels; de Jong, Tom P V M

2006-09-01

Most male patients with spina bifida have normal sexual desires. During puberty they begin to realize that they can achieve erection and sexual intercourse but without any sensation in the penis. We hypothesized that restored sensation in the penis would greatly contribute to their quality of life and sexual health. In this prospective study we investigated the outcome of a new operative neurological bypass procedure in patients with spina bifida. In 3 patients who were 17, 18 and 21 years old with a spinal lesion at L5, L4 and L3-L4, respectively, the sensory ilioinguinal nerve (L1) was cut distal in the groin and joined by microneurorrhaphy to the divided ipsilateral dorsal nerve of the penis (S2-4) at the base of the penis. All patients underwent preoperative and postoperative neurological and psychological evaluations. By 15 months postoperatively all patients had achieved excellent sensation on the operated side of the glans penis. They were unequivocally positive about the results and the penis had become more integrated into the body image. In 2 patients masturbation became more meaningful and 1 became more sexually active with and without his partner. The newly designed neurological bypass procedure in patients with spina bifida resulted in excellent sensibility in the glans penis. The new sensation appeared to contribute to the quality of the patient sexuality and sexual functioning as well as to the feeling of being a more normal and complete individual who is more conscious of the penis. This new operation might become standard treatment in patients with spina bifida in the future.

Red Blood Cell Transfusions Impact Pneumonia Rates After Coronary Artery Bypass Grafting Surgery

Science.gov (United States)

Likosky, Donald S.; Paone, Gaetano; Zhang, Min; Rogers, Mary A.M.; Harrington, Steven D.; Theurer, Patricia F.; DeLucia, Alphonse; Fishstrom, Astrid; Camaj, Anton; Prager, Richard L.

2016-01-01

Background Pneumonia, a known complication of coronary artery bypass (CABG) surgery, significantly increases a patient’s risk of morbidity and mortality. While not well characterized, red blood cell transfusions (RBC) may increase a patient’s risk of pneumonia. We describe the relationship between RBC transfusion and post-operative pneumonia after CABG surgery. Methods A total of 16,182 consecutive patients underwent isolated CABG surgery between 2011 and 2013 at one of 33 hospitals in the state of Michigan. We used multivariable logistic regression to estimate the odds of pneumonia associated with the use or number (0, 1, 2, 3, 4, 5, >6) of RBC units. We adjusted for predicted risk of mortality, pre-operative hematocrit, history of pneumonia, cardiopulmonary bypass duration and medical center. We confirmed the strength and direction of these relationships among selected clinical subgroups in a secondary analysis. Results 576 (3.6%) patients developed pneumonia and 6,451 (39.9%) received RBC transfusions. There was a significant association between any RBC transfusion and pneumonia (ORadj 3.4, p<0.001). There was a dose-response between number of units and odds of pneumonia, ptrend<0.001. Patients receiving only 2 units of RBCs had twofold (ORadj 2.1, p<0.001) increased odds of pneumonia. These findings were consistent across clinical subgroups. Conclusions We found a significant, volume-dependent association between an increasing number of RBCs and odds of pneumonia, which persisted after adjusting for pre-operative patient characteristics. Clinical teams should explore opportunities for preventing a patient’s risk of RBC transfusions, including reducing hemodilution or adopting a lower transfusion threshold in a stable patient. PMID:26209489

Rankine cycle load limiting through use of a recuperator bypass

Science.gov (United States)

Ernst, Timothy C.

2011-08-16

A system for converting heat from an engine into work includes a boiler coupled to a heat source for transferring heat to a working fluid, a turbine that transforms the heat into work, a condenser that transforms the working fluid into liquid, a recuperator with one flow path that routes working fluid from the turbine to the condenser, and another flow path that routes liquid working fluid from the condenser to the boiler, the recuperator being configured to transfer heat to the liquid working fluid, and a bypass valve in parallel with the second flow path. The bypass valve is movable between a closed position, permitting flow through the second flow path and an opened position, under high engine load conditions, bypassing the second flow path.

The Use of Tygon Tubing Sterilized by Gamma Radiation in Heart-Lung By-Pass Machines

Energy Technology Data Exchange (ETDEWEB)

Alladine, M. F.; Gibbons, J. R. P. [London Chest Hospital, London (United Kingdom)

1967-09-15

Tygon tubing is a co-polymer polyvinyl chloride. This tubing is used throughout the circuit of our heart-lung by-pass machines and had been sterilized by autoclaving or exposure to ethylene oxide gas. Tubing sterilized by autoclaving was noted to have a decrease in tensile strength and the transparency of the tubing was affected. Sterilization by ethylene oxide had the disadvantage that gas was often present in the lumen of the tube when connected to the machine. Lengths of Tygon tubing were sterilized by gamma radiation at varying radiation levels and temperatures. Bacteriological studies were done on the tubing and estimation of tensile strength carried out. We have found that a level of radiation of 2. 5 to 3. 0 Mrad at 20°C produces little or no change in tensile strength and the tubing remains bacteriologically sterile. Tygon tubing sterilized in this way has now been used in over sixty heart-lung by-pass machine operations. (author)

21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

Science.gov (United States)

2010-04-01

... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange (oxygenator...

78. Coronary bypass using bilateral internal mammary arteries in an achondroplast

Directory of Open Access Journals (Sweden)

Mohamed Abdulwahab Alassal

2015-10-01

Full Text Available Coronary bypass grafting for ischemic heart disease in achondroplastic dwarfs is very rare. Shortage of veins and sometimes, inadequate vein quality can cause difficulties during surgery. Only two achondroplastic cases were reported in literature that underwent coronary bypass surgery, in which the left internal mammary artery and vein grafts were used. To the best of our knowledge using bilateral internal mammary arteries in such patients was not reported. We report here a 55 years old male achondroplastic dwarf who had triple vessels coronary disease that underwent successful coronary bypass surgery using bilateral mammary arteries. Anatomic and surgical challenges in achondroplasia are highlighted

Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

Energy Technology Data Exchange (ETDEWEB)

Thines, Laurent [Lille University Hospital, Department of Neurosurgery, Lille (France); Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Agid, Ronit; Da Costa, Leodante; Terbrugge, Karel G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Dehdashti, Amir R.; Wallace, M.C.; Tymianski, Michael [Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada)

2009-08-15

Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

FACT. Energy spectrum of the Crab Nebula

Energy Technology Data Exchange (ETDEWEB)

Temme, Fabian; Einecke, Sabrina; Buss, Jens [TU Dortmund, Experimental Physics 5, Otto-Hahn-Str.4, 44221 Dortmund (Germany); Collaboration: FACT-Collaboration

2016-07-01

The First G-APD Cherenkov Telescope is the first Imaging Air Cherenkov Telescope which uses silicon photon detectors (G-APDs aka SiPM) as photo sensors. With more than four years of operation, FACT proved an application of SiPMs is suitable for the field of ground-based gamma-ray astronomy. Due to the stable flux at TeV energies, the Crab Nebula is handled as a ''standard candle'' in Cherenkov astronomy. The analysis of its energy spectrum and comparison with other experiments, allows to evaluate the performance of FACT. A modern analysis chain, based on data stream handling and multivariate analysis methods was developed in close cooperation with the department of computer science at the TU Dortmund. In this talk, this analysis chain and its application are presented. Further to this, results, including the energy spectrum of the Crab Nebula, measured with FACT, are shown.

Cost-utility analysis comparing laparoscopic vs open aortobifemoral bypass surgery

Directory of Open Access Journals (Sweden)

Krog AH

2017-06-01

Full Text Available Anne Helene Krog,1,2 Mehdi Sahba,3 Erik M Pettersen,4 Torbjørn Wisløff,5,6 Jon O Sundhagen,2 Syed SH Kazmi2 1Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 2Department of Vascular Surgery, Division of Cardiovascular and Pulmonary Diseases, Oslo University Hospital, Oslo, 3Department of Vascular Surgery, Østfold Central Hospital, Kalnes, 4Department of Vascular Surgery, Sørlandet Hospital HF, Kristiansand, 5Department of Health Management and Health Economics, University of Oslo, 6Norwegian Institute of Public Health, Oslo, Norway Objectives: Laparoscopic aortobifemoral bypass has become an established treatment option for symptomatic aortoiliac obstructive disease at dedicated centers. Minimally invasive surgical techniques like laparoscopic surgery have often been shown to reduce expenses and increase patients’ health-related quality of life. The main objective of our study was to measure quality-adjusted life years (QALYs and costs after totally laparoscopic and open aortobifemoral bypass. Patients and methods: This was a within trial analysis in a larger ongoing randomized controlled prospective multicenter trial, Norwegian Laparoscopic Aortic Surgery Trial. Fifty consecutive patients suffering from symptomatic aortoiliac occlusive disease suitable for aortobifemoral bypass surgery were randomized to either totally laparoscopic (n=25 or open surgical procedure (n=25. One patient dropped out of the study before surgery. We measured health-related quality of life using the EuroQol (EQ-5D-5L questionnaire at 4 different time points, before surgery and for 6 months during follow-up. We calculated the QALYs gained by using the area under the curve for both groups. Costs were calculated based on prices for surgical equipment, vascular prosthesis and hospital stay. Results: We found a significantly higher increase in QALYs after laparoscopic vs open aortobifemoral bypass surgery, with a difference of 0.07 QALYs, (p=0

Numerical and experimental investigation on labyrinth seal mechanism for bypass flow reduction in prismatic VHTR core

Energy Technology Data Exchange (ETDEWEB)

Yoon, Su-Jong, E-mail: paper80@snu.ac.r [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Jeong-Hun [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Sang-Moon [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Tak, Nam-il; Kim, Min-Hwan [Korea Atomic Energy Research Institute, 150-1 Deokjin-Dong, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Kwang-Yong [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of)

2013-09-15

Highlights: • Bypass flow reduction method was developed by applying labyrinth seal mechanism. • Grooves on side walls of replaceable reflector block were made. • Design of the grooved wall of the reflector block was optimized by the RSA method. • The flow resistance of the bypass gap rose from 18.04 to 26.24 by the optimization. • The bypass ratios at the inlet and outlet were reduced by 36.19% and 14.66%, respectively. -- Abstract: Core bypass flow in block type very high temperature reactor (VHTR) occurs due to the inevitable gaps between the hexagonal core blocks for the block installation and refueling. Since the core bypass flow affects the reactor safety and efficiency, it should be minimized to enhance the core thermal margin. In this regard, the core bypass flow reduction method applying the labyrinth seal mechanism was developed and optimized by using the single-objective shape optimization method. Response surface approximation (RSA) method was adopted as the optimization method. Side wall of the replaceable reflector block was redesigned and response surface approximate model was adopted to optimize the shape of the reflector wall. Computational fluid dynamics (CFD) analyses were carried out not only to assess the limitation of existing method of bypass flow reduction, but also to optimize the design of a newly developed reduction method. The experiment with Seoul National University (SNU) multi-block experimental facility was performed to demonstrate the performance of the reduction method. It was found that the effect of the existing bypass flow reduction method by sealing the bypass gap exit was restricted nearby the lower region of the core. However, the flow resistance factor of the bypass gap increased from 18.04 to 26.24 by the optimized reduction method. The results of the performance test showed that the bypass flow distribution was reduced throughout the entire core regions. The bypass flow ratios at the inlet and the outlet were

Coronary Artery Bypass Graft Surgery: The Past, Present, and Future of Myocardial Revascularisation

Directory of Open Access Journals (Sweden)

Michael Diodato

2014-01-01

Full Text Available The development of the heart-lung machine ushered in the era of modern cardiac surgery. Coronary artery bypass graft surgery (CABG remains the most common operation performed by cardiac surgeons today. From its infancy in the 1950s till today, CABG has undergone many developments both technically and clinically. Improvements in intraoperative technique and perioperative care have led to CABG being offered to a more broad patient profile with less complications and adverse events. Our review outlines the rich history and promising future of myocardial revascularization.

The treatment of malignant ventricular tachycardia by aorto-coronary saphenous vein bypass graft

Science.gov (United States)

Ikram, H.; Jeffery, R. M.; Parkins, R. A.; Makey, A. R.; Emery, E. R. J.; Stone, D. L.

1974-01-01

A 61-year-old man with a previous cardiac infarction had at least fifteen attacks of ventricular tachycardia which finally did not respond to either drug or electrical therapy. Angiography showed a blocked right coronary artery and a non-contractile portion of postero-inferior left ventricular wall. An aorto to right coronary saphenous vein bypass graft was inserted, and although attacks of tachycardia occurred following the operation these were of short duration and reverted spontaneously. He has been free of tachycardia for 5 weeks, with a greatly improved effort tolerance. ImagesFig. 2Fig. 3

Medical image of the week: Dobhoff tube placement with Roux-en-Y gastric bypass

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Ali H

2018-04-01

Full Text Available No abstract available. Article truncated after 150 words. Roux-en-Y gastric bypass is one of the most commonly performed bariatric operations in the United States. It involves partitioning a small gastric pouch off the proximal stomach and attaching that pouch directly to the intestine, thereby bypassing the large remainder of the stomach (1,2. Placing a Dobhoff tube (DHT and confirming its placement can be challenging due to the change in anatomy after the procedure. Here, we have a 65-year-old woman who presented to the hospital with acute encephalopathy and acute hypoxic respiratory failure due to multifocal pneumonia requiring intubation and prolonged ICU stay. A DHT was inserted after intubation for feeding purposes. An abdominal X-ray was obtained to confirm placement of the DHT (Figure 1. Normally the DHT tip should be placed in the 2nd to 3rd portion of the duodenum and would create a C-shaped tracing on the X-ray. However, in our patient who had history of Roux-en-Y …

Expression of adhesion and activation molecules on lymphocytes during open-heart surgery with cardiopulmonary bypass

DEFF Research Database (Denmark)

Toft, P; Tønnesen, Else Kirstine; Zülow, I

1997-01-01

Open-heart surgery with cardiopulmonary bypass (CPB) and abdominal surgery are associated with lymphocytopenia. We measured a panel of adhesion and activation molecules on lymphocytes to clarify possible association of CPB with increased expression of these molecules. Eight patients undergoing open-heart...... open-heart and abdominal surgery. The proportion of CD11a/CD18-positive lymphocytes rose from 67.6 +/- 8% to 86.4 +/- 3% after aortic declamping (p open-heart as well as abdominal operations. Thus CPB...

Autologous blood sequestration using a double venous reservoir bypass circuit and polymerized hemoglobin prime.

Science.gov (United States)

Neragi-Miandoab, Siyamek; Guerrero, J Luis; Vlahakes, Gus J

2002-01-01

Cardiac surgery often necessitates transfusion of homologous blood. Hemoglobin based oxygen carrying solutions (HBOCs) transport oxygen, suggesting use in cardiopulmonary bypass. HBOC was used in a novel oxygenator double-reservoir circuit that permits acute sequestration of a portion of the autologous blood volume during bypass. Two groups of seven mongrel dogs each were studied in an experimental bypass model using global myocardial ischemia and cardioplegia protection: HBOC group, initial venous return drained to a separate reservoir and hypothermic bypass was conducted with HBOC containing perfusate in a second bypass reservoir; Control group, crystalloid prime in a conventional circuit. Hemodynamics and metabolic and hematologic parameters were measured before and 60 min after aortic clamp removal and reinfusion of sequestered autologous blood. Blood gases, base excess, hematocrit, total hemoglobin, and platelet counts were measured. In the HBOC group, metabolic acidosis did not occur, and ventricular function was preserved. Net conservation of platelets was noted at study conclusion: control 33+/-13 x 10(3) per mm3 versus HBOC 48+/-13 x 10(3), p conservation of the platelet mass occurs, a portion of which is not exposed to the deleterious effects of hypothermia and cardiopulmonary bypass.

Coronary artery bypass grafting on the beating heart using the Octopus method

NARCIS (Netherlands)

Thijssens, K. M.; Rodrigus, I. E.; Amsel, B. J.; de Hert, S. G.; Moulijn, A. C.

2000-01-01

STUDY OBJECTIVE: To study the usefulness and effectiveness of off-pump coronary bypass grafting with the Octopus heart stabilizing device. METHOD: The files of thirty-one patients undergoing coronary artery bypass with the aid of the Octopus heart stabilizing device between April 1996 and October

Results of Infrageniculate Bypasses Using the Profunda Femoris Artery as Inflow Source.

Science.gov (United States)

Illuminati, Giulio; Calio', Francesco G; Pizzardi, Giulia; Pasqua, Rocco; Masci, Federica; Frezzotti, Francesca; Palumbo, Piergaspare; Vietri, Francesco

2018-02-01

When the common femoral artery is not accessible for infrainguinal bypass grafting, the profunda femoris artery (PFA) can be a valuable alternative inflow source for distal arterial revascularization. The purpose of this retrospective study was to evaluate the results of infrageniculate bypass grafting via the PFA as inflow source for critical limb ischemia. Between 1994 and 2016, 68 patients, 51 men of a mean age of 74 years, underwent an infrageniculate arterial bypass grafting for critical limb ischemia, using the PFA as inflow site. PFA was exposed at the Scarpa's triangle in 38 patients (56%) and at its medio-crural segment in 30 patients (44%). The distal anastomosis was performed on the infragenicular popliteal artery in 33 patients (48%), the peroneal artery in 14 patients (20%), the tibioperoneal trunk in 8 patients (12%), the posterior tibial artery in 8 patients (12%), and the dorsalis pedis artery in 5 patients (8%). The graft material consisted of a reversed great saphenous vein (GSV) in 62 patients (91%) and a 6-mm polytetrafluoroethylene graft in 6 patients (9%). The median duration of follow-up was 51 months (range, 6-72 months). As main results, postoperative mortality and morbidity, overall late patients' survival, primary grafts' patency, and limb salvage rate were considered. Operative mortality and morbidity were 3% and 4%, respectively. Overall patients' survival, primary patency and limb salvage rate, at 36 and 60 months were, respectively, 62% and 53%, 66% and 59%, and 92% and 77%. The PFA, both exposed at the Scarpa's triangle and at mid-thigh, is an excellent inflow source for infrageniculate revascularizations. It should remain an important part of the technical armamentarium of vascular surgeons, even in the endovascular era. Copyright © 2017 Elsevier Inc. All rights reserved.

EARLY POSTOPERATIVE COMPLICATIONS IN ROUX-EN-Y GASTRIC BYPASS.

Science.gov (United States)

Stoll, Aluisio; Rosin, Leandro; Dias, Mariana Fernandes; Marquiotti, Bruna; Gugelmin, Giovana; Stoll, Gabriela Fanezzi

Roux-en-Y gastric bypass is one of the most common bariatric surgery and leads to considerable weight loss in the first months. To quantify the main early postoperative complications in patients submitted to the gastric bypass. Observational retrospective cohort. Data of 1051 patients with class II obesity associated with comorbidities or class III obesity submitted to the gastric bypass with 30 days of follow-up starting from the date of the surgery. The age average was 36 years with a predominance of females (81.1%). The mean preoperative body mass index was 43 kg/m². The major complication was fistula (2.3%), followed by intestinal obstruction (0.5%) and pulmonary embolism (0.5%). Death occurred in 0.6% of the cases. In the period of 30 days after surgery the overall complication rate was 3.8%; reoperation was necessary in 2.6% and death occurred in 0.6%. Fistula was the main complication and the leading cause of hospitalization in intensive care unit, reoperation and death. Bypass gástrico em Y-de-Roux é uma das operações bariátricas mais comuns e leva a perdas consideráveis de peso já nos primeiros meses. Quantificar as principais complicações pós-operatórias precoces em pacientes submetidos ao bypass gástrico. Coorte retrospectiva observacional. Amostra de 1051 pacientes portadores de obesidade grau II associada à comorbidades ou grau III submetidos ao bypass gástrico com acompanhamento de 30 dias a partir da data da operação. A idade média dos pacientes foi de 36 anos com predominância de mulheres (81,1%). O índice de massa corporal pré-operatório médio foi de 43 kg/m². A principal complicação foi fístula (2,3%), seguida de obstrução intestinal (0,5%) e tromboembolismo pulmonar (0,5%). Óbito ocorreu em 0,6% dos casos. No período de 30 dias de pós-operatório a taxa geral de complicações foi de 3,8%; a de reoperação de 2,6% e óbito em 0,6%. A fístula foi a principal complicação e a principal causa de internamento em

The Brazilian Registry of Adult Patient Undergoing Cardiovascular Surgery, the BYPASS Project: Results of the First 1,722 Patients

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Walter J. Gomes

Full Text Available Abstract Objective: To report the early results of the BYPASS project - the Brazilian registrY of adult Patient undergoing cArdiovaScular Surgery - a national, observational, prospective, and longitudinal follow-up registry, aiming to chart a profile of patients undergoing cardiovascular surgery in Brazil, assessing the data harvested from the initial 1,722 patients. Methods: Data collection involved institutions throughout the whole country, comprising 17 centers in 4 regions: Southeast (8, Northeast (5, South (3, and Center-West (1. The study population consists of patients over 18 years of age, and the types of operations recorded were: coronary artery bypass graft (CABG, mitral valve, aortic valve (either conventional or transcatheter, surgical correction of atrial fibrillation, cardiac transplantation, mechanical circulatory support and congenital heart diseases in adults. Results: 83.1% of patients came from the public health system (SUS, 9.6% from the supplemental (private insurance healthcare systems; and 7.3% from private (out-of -pocket clinic. Male patients comprised 66%, 30% were diabetics, 46% had dyslipidemia, 28% previously sustained a myocardial infarction, and 9.4% underwent prior cardiovascular surgery. Patients underwent coronary artery bypass surgery were 54.1% and 31.5% to valve surgery, either isolated or combined. The overall postoperative mortality up to the 7th postoperative day was 4%; for CABG was 2.6%, and for valve operations, 4.4%. Conclusion: This first report outlines the consecution of the Brazilian surgical cardiac database, intended to serve primarily as a tool for providing information for clinical improvement and patient safety and constitute a basis for production of research protocols.

Biodistribution of technetium-99m pertechnetate after Roux-en-Y gastric bypass (Capella technique) in rats

International Nuclear Information System (INIS)

Rego, Amalia Cinthia Meneses do; Jacome, Daniel Torres; Ramalho, Rachel de Alcantara Oliveira; Araujo-Filho, Irami; Azevedo, Italo Medeiros; Medeiros, Aldo Cunha

2010-01-01

Purpose: The biodistribution of sodium pertechnetate, the most used radiopharmaceutical in nuclear medicine, has not been studied in details after bariatric surgery. The objective was to investigate the effect of Roux-en-Y gastric bypass (RYGB) on biodistribution of sodium pertechnetate (Na 99m Tc-) in organs and tissues of rats. Methods: Twelve rats were randomly divided into two groups of 6 animals each. The RYGB group rats were submitted to the Roux-en-Y gastric bypass and the control group rats were not operated. After 15 days, all rats were injected with 0.1mL of Na 99m Tc- via orbital plexus with average radioactivity of 0.66 MBq. After 30 minutes, liver, stomach, thyroid, heart, lung, kidney and femur samples were harvested, weighed and percentage of radioactivity per gram (%ATI/g) of each organ was determined by gamma counter Wizard Perkin-Elmer. We applied the Student t test for statistical analysis, considering p 99m Tc - . (author)

Endovascular Placement of an Extraluminal Femoropopliteal Bypass Graft in Human Cadavers

International Nuclear Information System (INIS)

Maynar, Manuel; Llorens, Rafael; Lopez-Sanchez, Carmen; Garcia-Martinez, Virginio; Qian Zhong; Lopera, Jorge; Castaneda, Wilfrido R.

2005-01-01

Purpose. A method to create an extraluminal femoropopliteal bypass graft using endovascular techniques was evaluated in situ on cadaver extremities in an attempt to develop a minimally invasive alternative technique for the management of infrainguinal occlusive arterial disease. Methods. The endovascular placement of an extraluminal femoropopliteal bypass graft was undertaken in 5 cadaver legs. Following percutaneous access to the popliteal artery (PA) or common femoral artery (CFA), a Rosch-Uchida needle was used to perforate the vascular wall, followed by the creation of an extraluminal tract using a looped wire and catheter. Once the desired level was reached the needle was again used to perforate the vascular wall of the proximal superficial femoral artery (SFA) or PA depending on the access used. Self-expanding expanded polytetrafluoroethylene (ePTFE) stent-grafts were then deployed to establish the extraluminal femoropopliteal bypass connecting the two arterial puncture sites. Following dilatation of the stent-graft, angiography was performed to assess the endoprostheses and to look for contrast leaks. Results. Technical success was achieved in all 5 legs. Procedure time varied from 15 to 30 min. The angiographic studies performed immediately after completion of the bypass procedure showed patency of the grafts with no evidence of kinking or leakage in any of the cases. Conclusion. This study has proved that the endovascular placement of an extraluminal femoropopliteal bypass graft in human cadaver legs using endovascular techniques under fluoroscopic control is technically feasible

Dynamic Performance of High Bypass Ratio Turbine Engines With Water Ingestion

Science.gov (United States)

Murthy, S. N. B.

1996-01-01

The research on dynamic performance of high bypass turbofan engines includes studies on inlets, turbomachinery and the total engine system operating with air-water mixture; the water may be in vapor, droplet, or film form, and their combinations. Prediction codes (WISGS, WINCOF, WINCOF-1, WINCLR, and Transient Engine Performance Code) for performance changes, as well as changes in blade-casing clearance, have been established and demonstrated in application to actual, generic engines. In view of the continuous changes in water distribution in turbomachinery, the performance of both components and the total engine system must be determined in a time-dependent mode; hence, the determination of clearance changes also requires a time-dependent approach. In general, the performance and clearances changes cannot be scaled either with respect to operating or ingestion conditions. Removal of water prior to phase change is the most effective means of avoiding ingestion effects. Sufficient background has been established to perform definitive, full scale tests on a set of components and a complete engine to establish engine control and operability with various air-water vapor-water mixtures.

Considering FACTS in Optimal Transmission Expansion Planning

Directory of Open Access Journals (Sweden)

K. Soleimani

2017-10-01

Full Text Available The expansion of power transmission systems is an important part of the expansion of power systems that requires enormous investment costs. Since the construction of new transmission lines is very expensive, it is necessary to choose the most efficient expansion plan that ensures system security with a minimal number of new lines. In this paper, the role of Flexible AC Transmission System (FACTS devices in the effective operation and expansion planning of transmission systems is examined. Effort was taken to implement a method based on sensitivity analysis to select the optimal number and location of FACTS devices, lines and other elements of the transmission system. Using this method, the transmission expansion plan for a 9 and a 39 bus power system was performed with and without the presence of FACTS with the use of DPL environment in Digsilent software 15.1. Results show that the use of these devices reduces the need for new transmission lines and minimizes the investment cost.

A simple method for estimating potential source term bypass fractions from confinement structures

International Nuclear Information System (INIS)

Kalinich, D.A.; Paddleford, D.F.

1997-01-01

Confinement structures house many of the operating processes at the Savannah River Site (SRS). Under normal operating conditions, a confinement structure in conjunction with its associated ventilation systems prevents the release of radiological material to the environment. However, under potential accident conditions, the performance of the ventilation systems and integrity of the structure may be challenged. In order to calculate the radiological consequences associated with a potential accident (e.g. fires, explosion, spills, etc.), it is necessary to determine the fraction of the source term initially generated by the accident that escapes from the confinement structure to the environment. While it would be desirable to estimate the potential bypass fraction using sophisticated control-volume/flow path computer codes (e.g. CONTAIN, MELCOR, etc.) in order to take as much credit as possible for the mitigative effects of the confinement structure, there are many instances where using such codes is not tractable due to limits on the level-of-effort allotted to perform the analysis. Moreover, the current review environment, with its emphasis on deterministic/bounding-versus probabilistic/best-estimate-analysis discourages using analytical techniques that require the consideration of a large number of parameters. Discussed herein is a simplified control-volume/flow path approach for calculating source term bypass fraction that is amenable to solution in a spreadsheet or with a commercial mathematical solver (e.g. MathCad or Mathematica). It considers the effects of wind and fire pressure gradients on the structure, ventilation system operation, and Halon discharges. Simple models are used to characterize the engineered and non-engineered flow paths. By making judicious choices for the limited set of problem parameters, the results from this approach can be defended as bounding and conservative

A rare case of small bowel volvulus after jenjunoileal bariatric bypass requiring emergency surgery: a case report

Directory of Open Access Journals (Sweden)

Patel Pranav H

2012-03-01

Full Text Available Abstract Introduction Bariatric surgery is on the increase throughout the world. Jejunoileal bypass bariatric procedures have fallen out of favor in western surgical centers due to the high rate of associated complications. They are, however, performed routinely in other centers and as a consequence of health tourism, management of complications related to these procedures may still be encountered. Case presentation We describe a rare case of small bowel obstruction in a 45-year-old British Caucasian woman, secondary to a volvulus of the jejunoileal anastomosis following bariatric bypass surgery. The pre-operative diagnosis was confirmed by radiology. We describe a successful surgical technique for this rare complication. Conclusions Bariatric surgery may be complicated by bowel obstruction. Early imaging is vital for diagnosis and effective management. The use of our surgical technique provides a simple and effective approach for the successful management of this bariatric complication.

Preliminary Calculations of Bypass Flow Distribution in a Multi-Block Air Test

International Nuclear Information System (INIS)

Kim, Min Hwan; Tak, Nam Il

2011-01-01

The development of a methodology for the bypass flow assessment in a prismatic VHTR (Very High Temperature Reactor) core has been conducted at KAERI. A preliminary estimation of variation of local bypass flow gap size between graphite blocks in the NHDD core were carried out. With the predicted gap sizes, their influence on the bypass flow distribution and the core hot spot was assessed. Due to the complexity of gap distributions, a system thermo-fluid analysis code is suggested as a tool for the core thermo-fluid analysis, the model and correlations of which should be validated. In order to generate data for validating the bypass flow analysis model, an experimental facility for a multi-block air test was constructed at Seoul National University (SNU). This study is focused on the preliminary evaluation of flow distribution in the test section to understand how the flow is distributed and to help the selection of experimental case. A commercial CFD code, ANSYS CFX is used for the analyses

Active bypass flow control for a seal in a gas turbine engine

Science.gov (United States)

Ebert, Todd A.; Kimmel, Keith D.

2017-03-14

An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears In at least one embodiment, the metering device may include an annular ring having at least one metering orifice extending therethrough, whereby alignment of the metering orifice with the outlet may be adjustable to change a cross-sectional area of an opening of aligned portions of the outlet and the metering orifice.

Exercise thallium-201 scintigraphy in evaluating aortocoronary bypass surgery

International Nuclear Information System (INIS)

Iskandrian, A.S.; Haaz, W.; Segal, B.L.; Kane, S.A.

1981-01-01

Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts

Construct exploit constraint in crash analysis by bypassing canary

Science.gov (United States)

Huang, Ning; Huang, Shuguang; Huang, Hui; Chang, Chao

2017-08-01

Selective symbolic execution is a common program testing technology. Developed on the basis of it, some crash analysis systems are often used to test the fragility of the program by constructing exploit constraints, such as CRAX. From the study of crash analysis based on symbolic execution, this paper find that this technology cannot bypass the canary stack protection mechanisms. This paper makes the improvement uses the API hook in Linux. Experimental results show that the use of API hook can effectively solve the problem that crash analysis cannot bypass the canary protection.

Perforated marginal ulcers after laparoscopic gastric bypass.

Science.gov (United States)

Felix, Edward L; Kettelle, John; Mobley, Elijah; Swartz, Daniel

2008-10-01

Perforated marginal ulcer (PMU) after laparoscopic Roux-en-Y gastric bypass (LRYGB) is a serious complication, but its incidence and etiology have rarely been investigated. Therefore, a retrospective review of all patients undergoing LRYGB at the authors' center was conducted to determine the incidence of PMU and whether any causative factors were present. A prospectively kept database of all patients at the authors' bariatric center was retrospectively reviewed. The complete records of patients with a PMU were examined individually for accuracy and analyzed for treatment, outcome, and possible underlying causes of the marginal perforation. Between April 1999 and August 2007, 1% of the patients (35/3,430) undergoing laparoscopic gastric bypass experienced one or more perforated marginal ulcers 3 to 70 months (median, 18 months) after LRYGB. The patients with and without perforation were not significantly different in terms of mean age (37 vs 41 years), weight (286 vs 287 lb), body mass index (BMI) (46 vs 47), or female gender (89% vs 83%). Of the patients with perforations, 2 (6%) were taking steroids, 10 (29%) were receiving nonsteroidal antiinflammatory drugs (NSAIDs) at the time of the perforation, 18 (51%) were actively smoking, and 6 of the smokers also were taking NSAIDs. Eleven of the patients (31%) who perforated did not have at least one of these possible risk factors, but 4 (36%) of the 11 patients in this group had been treated after bypass for a marginal ulcer. Only 7 (20%) of the 35 patients who had laparoscopic bypass, or 7 (0.2%) in the entire group of 3,430 patients, perforated without any warning. There were no deaths, but three patients reperforated. The incidence of a marginal ulcer perforating after LRYGB was significant (>1%) and appeared to be related to smoking or the use of NSAIDs or steroids. Because only 0.2% of all patients acutely perforated without some risk factor or warning, long-term ulcer prophylaxis or treatment may be necessary

Cardiopulmonary bypass in pregnancy

OpenAIRE

Mukul Chandra Kapoor

2014-01-01

Cardiac surgery carried out on cardiopulmonary bypass (CPB) in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women. Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB. The CPB is associated with utero-placental hypoperfusion due to a number of factors, which may translate into low fetal cardiac output, hypoxia and even death. Better maternal and f...

Basics of cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Manjula Sarkar

2017-01-01

Full Text Available Cardiopulmonary bypass (CPB provides a bloodless field for cardiac surgery. It incorporates an extracorporeal circuit to provide physiological support in which venous blood is drained to a reservoir, oxygenated and sent back to the body using a pump. Team effort between surgeon, perfusionist and anaesthesiologist is paramount for the successful use of CPB. However, it also has its share of complications and strategies to reduce these complications are the area of the current research.

Sequential Vein Bypass Grafting is Not Associated with an Increase of Either In-hospital or Mid-term Adverse Events in Off-pump Coronary Artery Bypass Grafting

Directory of Open Access Journals (Sweden)

Fucheng Xiao

2015-01-01

Full Text Available Background: The impact of sequential vein bypass grafting on clinical outcomes is less known in off-pump coronary artery bypass grafting (CABG. We aimed to evaluate the effects of sequential vein bypass grafting on clinical outcomes in off-pump CABG. Methods: From October 2009 to September 2013 at the Fuwai Hospital, 127 patients with at least one sequential venous graft were matched with 127 patients of individual venous grafts only, using propensity score matching method to obtain risk-adjusted outcome comparison. In-hospital measurement was composite outcome of in-hospital death, myocardial infarction (MI, stroke, requirement for intra-aortic ballon pump (IABP assistance and prolonged ventilation. Major adverse cardiac events (MACEs: Death, MI or repeat revascularization and angina recurrence were considered as mid-term endpoints. Results: No significant difference was observed among the groups in baseline characteristics. Intraoperative mean blood flow per vein graft was 40.4 ml in individual venous grafts groups versus 59.5 ml in sequential venous grafts groups (P < 0.001. There were no differences between individual and sequential venous grafts groups with regard to composite outcome of in-hospital mortality, MI, stroke, IABP assistance and prolonged ventilation (11.0% vs. 14.2%, P = 0.45. Individual in-hospital measurement also did not differ significantly between the two groups. At about four years follow-up, the survival estimates free from MACEs (92.5% vs. 97.3%, P = 0.36 and survival rates free of angina recurrence (80.9% vs. 85.5%, P = 0.48 were similar among individual and sequential venous grafts groups with a mean follow-up of 22.5 months. In the Cox regression analysis, sequential vein bypass grafting was not identified as an independent predictor of both MACEs and angina recurrence. Conclusions: Compared to individual vein bypass grafting, sequential vein bypass grafting was not associated with an increase of either in

DOES TRANEXAMIC ACID REDUCE BLOOD LOSS IN OFF-PUMP CORONARY ARTERY BYPASS?

Directory of Open Access Journals (Sweden)

A. Mehr-Aein

2006-09-01

Full Text Available Tranexamic acid is now used on a routine basis for on-pump coronary artery bypass grafting (CABG. We assessed the hemostatic effects of tranexamic acid to decrease bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery (OPCAB. A total of 66 patients were enrolled to elective OPCAB in a double-blind, prospective randomized study. Of these, 33 patients received tranexamic acid (15 mg/kg before the infusion of heparin and 15 mg/kg after protamin infusion, and 33 patients received only saline. Preoperative hematologic variables, postoperative bleeding and allogeneic transfusions were considered. D-dimer plasma levels were also evaluated to monitor the activation of fibrinolysis. Postoperative bleeding was significantly lower in the tranexamic acid group compared with the control group (320 ± 38 mL vs. 480 ± 75 mL at 12 hour, P < 0.001. The tranexamic acid group had significantly lesser need for allogeneic blood products (0.46 units/patients vs. 0.94 units/patients, P < 0.001. They had also lower post-operative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. The defective hemostasis occurs even in the OPCABG. Tranexamic acid effectively reduces postoperative blood loss and the need for allogeneic blood products after OPCAB is decreased.

Bypassing BDD Construction for Reliability Analysis

DEFF Research Database (Denmark)

Williams, Poul Frederick; Nikolskaia, Macha; Rauzy, Antoine

2000-01-01

In this note, we propose a Boolean Expression Diagram (BED)-based algorithm to compute the minimal p-cuts of boolean reliability models such as fault trees. BEDs make it possible to bypass the Binary Decision Diagram (BDD) construction, which is the main cost of fault tree assessment....

Progress in Management of Sediment Bypassing at Coastal Inlets: Natural Bypassing, Weir Jetties, Jetty Spurs, and Engineering Aids in Design

National Research Council Canada - National Science Library

Seabergh, William C; Kraus, Nicholas C

2003-01-01

.... Artificial bypassing mimics or preserves the pathways of sediment in the littoral zone and harmonizes the requirement for deepening navigation channels within the context of the natural sediment...

A Cardiopulmonary Bypass Based Blood Management Strategy in Adult Cardiac Surgery.

Science.gov (United States)

Budak, Ali Baran; McCusker, Kevin; Gunaydin, Serdar

2017-10-24

Despite the recent introduction of a number of technical and pharmacologic blood conservation measures, bleeding and allogeneic transfusion remain persistent problems in open-heart surgical procedures. Efforts should be made to decrease or completely avoid transfusions to avoid these negative reactions. Our coronary artery bypass grafting database was reviewed retrospectively and a total of 243 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) were studied in a 12-month period (January-December 2016) after the implementation of the new program, and compared with 275 patients of the previous 12-month period.All the staff involved in the care of the patients were educated about the risks and benefits of blood transfusions and the new transfusion guidelines in a 45-min training. We revised our guidelines for transfusions based on the STS. A transfusion log was created. Reduction in IV fluid volume was targeted. CPB circuitry was redesigned to achieve significantly less prime volume. Results: The proportion of patients transfused with red blood cells was 56% (n =154) in the control group and reduced by 26.8% in the study group (29.2%; 71 patients; P conservation group.  Conclusion: These findings, in addition to risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in adult cardiac operations.

Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting

DEFF Research Database (Denmark)

Jensen, Birte Ostergaard; Hughes, Pia; Rasmussen, Lars S

2006-01-01

It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). However, evidence for this statement is preliminary, and additional insight is needed.......It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). However, evidence for this statement is preliminary, and additional insight is needed....

Alterations in plasma soluble vascular endothelial growth factor receptor-1 (sFlt-1 concentrations during coronary artery bypass graft surgery: relationships with post-operative complications

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Orsel Isabelle

2008-04-01

Full Text Available Abstract Background Plasma concentrations of sFlt-1, the soluble form of the vascular endothelial growth factor receptor (VEGF, markedly increase during coronary artery bypass graft (CABG surgery with extracorporeal circulation (ECC. We investigated if plasma sFlt-1 values might be related to the occurrence of surgical complications after CABG. Methods Plasma samples were collected from the radial artery catheter before vascular cannulation and after opening the chest, at the end of ECC just before clamp release, after cross release, after weaning from ECC, at the 6th and 24th post-operative hour. Thirty one patients were investigated. The presence of cardiovascular, haematological and respiratory dysfunctions was prospectively assessed. Plasma sFlt-1 levels were measured with commercially ELISA kits. Results Among the 31 investigated patients, 15 had uneventful surgery. Patients with and without complications had similar pre-operative plasma sFlt-1 levels. Lowered plasma sFlt-1 levels were observed at the end of ECC in patients with haematological (p = 0.001, ANOVA or cardiovascular (p = 0.006 impairments, but not with respiratory ones (p = 0.053, as compared to patients with uneventful surgery. Conclusion These results identify an association between specific post-CABG complication and the lower release of sFlt-1 during ECC. sFlt-1-induced VEGF neutralisation might, thus, be beneficial to reduce the development of post-operative adverse effects after CABG.

Preliminary Estimation of Local Bypass Flow Gap Sizes for a Prismatic VHTR Core

International Nuclear Information System (INIS)

Kim, Min Hwan; Jo, Chang Keun; Lee, Won Jae

2009-01-01

The Very High Temperature Reactor (VHTR) has been selected for the Nuclear Hydrogen Development and Demonstration (NHDD) project. In the VHTR design, core bypass flow has been one of key issues for core thermal margins and target temperature of the core outlet. The core bypass flow in the prismatic VHTR varies with the core life due to the irradiation shrinkage/ swelling and thermal expansion of the graphite blocks, which could be a significant proportion of the total core flow. Thus, accurate prediction of the bypass flow is of major importance in assuring the core thermal margin. To predict the bypass flow, first of all, local gap sizes between graphite blocks in the core should be determined. The objectives of this work are to develop a methodology for determining the gap sizes and to perform a preliminary evaluation for a reference reactor

Renal Tubular Acidosis after Jejunoileal Bypass for Morbid Obesity: role of secondary hyperparathyroidism

DEFF Research Database (Denmark)

Andersen, NN; Ladefoged, NN

1991-01-01

The effect of calcium infusion was studied in patients with renal tubular acidosis (RTA) and secondary hyperparathyroidism. Both developed after jejunoileal bypass operation (JIB) for morbid obesity. In three of four cases the acidification defect was abolished, probably due to a decrease of serum...... parathyroid hormone. As we found RTA in 9% (95% confidence limits 2-21%) of our patients, screening for acidosis is recommended in obesity patients after malabsorptive operations. RTA can be verified through an ammonium loading test. Before deciding on re-establishing bowel continuity due to RTA, we suggest...... and vitamin D supplementation. If RTA can be abolished through correction of calcium homeostasis, reoperation may be avoided. Before deciding on re-establishing bowel continuity in JIB patients with RTA, we therefore suggest that patients be evaluated for secondary hyperparathyroidism and any calcium...

Noninvasive detection of coronary artery bypass graft patency by intravenous electron beam computed tomographic angiography.

Science.gov (United States)

Yamakami, Shoji; Toyama, Junji; Okamoto, Mitsuhiro; Matsushita, Toyoaki; Murakami, Yoshimasa; Ogata, Masaki; Ito, Shigenori; Fukutomi, Tatsuya; Okayama, Naotsuka; Itoh, Makoto

2003-11-01

This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion.

Redesign of emergency water supply system by-pass line from Cernavoda NPP Unit 1 and 2 using self regulating valves

International Nuclear Information System (INIS)

Tenescu, Mircea; Bigu, Melania; Nita, Iulian Pavel

2010-01-01

In this paper one considered improving the EWS (emergency water supply system) by-pass line in order to replace current manual operated valve with an self operated valve. This change is necessary in order to reduce the human error events in operation of the system in case of a DBE (design basis earthquake). The paper describes a theoretical and practical operation of a system using self regulating flow rate valves. Basically, the elimination of a possible human error in operating a system is important for nuclear safety in case of a DBE because it makes it avoidable in normal reactor cooling systems. The paper describes checking of the functioning of this equipment in operating conditions, investigating how it responds to various operating regimes. (authors)

A Case of Severe Accidental Hypothermia Successfully Treated with Cardiopulmonary Bypass

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Erfun M. Hatam

2017-01-01

Full Text Available After missing for seven days, a 34-year-old female was found with a rectal temperature of 19.8oC. Instead of attempting aggressive rewarming in the emergency department she was directly transferred to the operating room for extracorporeal rewarming. She received cardiopulmonary bypass (CPB for 66 minutes at an initial warming rate of 12oC/ hour and warmed to 36.2oC. Her postoperative course was complicated by sepsis, which eventually led to bilateral below-knee amputations after refusing antibiotics. She was discharged 22 days after admission, with full neurologic recovery. This remarkable case highlights the emerging role of CPB as the definitive therapy for severe accidental hypothermia.

Comparison of blood electrolytes and glucose during cardiopulmonary bypass in diabetic and non-diabetic patients

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Golamreza Maasoumi

2013-01-01

Full Text Available Background: Cardiopulmonary bypass (CPB during coronary artery bypass grafting is thought to contribute significantly to increased blood glucose level and altered blood electrolytes balance during the operation. In this (CABG study, blood electrolytes and glucose during CPB in insulin-dependent diabetic and non-diabetic patients were assessed with special emphasis on the trend of the changes. Materials and Methods: Blood glucose and electrolytes were assessed in 30 insulin-dependent diabetic and 30 non-diabetic patients, classified as class II and III American Society of Anesthesiologist, before, during, and after CPB. Repeated-measures analysis of variance (ANOVA was used to compare the trend of the changes during CPB for the two groups. Results: The trend in blood glucose level did not show any significant difference between two groups ( P = 0.59. For other blood factors, no significant between-group difference was detected except for PaCO 2 ( P = 0.002. Conclusion: The study suggested that the changes in blood electrolytes and the increase in blood glucose level do not differ between insulin dependent diabetic and non-diabetic patients.

Quantification of extracorporal platelet deposition in cardiopulmonary bypass: Effects of ZK 36374, a prostacyclin analogue

Energy Technology Data Exchange (ETDEWEB)

Martin, W.; Spyt, T.; Wheatley, D.J.; Thomas, I.; Davidson, J.F.

1989-03-01

The degree of extracorporal platelet sequestration in 32 patients undergoing cardiopulmonary bypass has been assessed using /sup 111/In labelled platelets and both a shadow shield whole body monitor and a standard gamma camera. The effects of ZK 36374, a prostacyclin analogue, on deposition of platelets in the oxygenator and atrial line filter were also investigated. Total platelet deposition in the placebo group ranged from 2.2% to 31.7%, mean 13.9+-7.8%; n=15, and was significantly higher than the deposition in the treatment group, range 0.7% to 9.4%, mean 3.9+-2.6%; n=16, P < 0.001. There was also a highly significant correlation between the gamma camera and whole body monitor measurements, r=0.99, P < 0.001, with no systematic difference between the techniques. This study demonstrates that accurate quantitative assessment of platelet deposition can be achieved with either the gamma camera or whole body monitor. In addition, significant reduction in platelet sequestration in the extracorporal circuit can be achieved by using ZK 36374 during the bypass operation.

Energy-efficient and cost-effective in-house substations bypass for improving thermal and DHW (domestic hot water) comfort in bathrooms in low-energy buildings supplied by low-temperature district heating

DEFF Research Database (Denmark)

Brand, Marek; Dalla Rosa, Alessandro; Svendsen, Svend

2014-01-01

temperature and additional cooling of bypass water by 3.9 °C, reducing the heat loss from the DH network by 13% and covering 40% of the heat used in the bathroom FH. The use of the bypass flow in bathroom FH is a cost-effective solution exploiting the heat that would otherwise be lost in the DH network......Using a bypass to redirect a small flow through the in-house DH (district heating) substation directly to the return pipe is a commonly used but energy-inefficient solution to keep the DH network “warm” during non-heating seasons. Instead, this water can be redirected to the bathroom FH (floor...... heating) to cool down further and thus reduce the heat lost from bypass operation while tempering the bathroom floor and guaranteeing fast provision of DHW (domestic hot water). We used the commercial software IDA-ICE to model a reference building where we implemented various solutions for controlling...

The impact of heparin-coated circuits on hemodynamics during and after cardiopulmonary bypass

NARCIS (Netherlands)

de Vroege, R; Huybregts, R; van Oeveren, W; van Klarenbosch, J; Linley, G; Mutlu, J; Jansen, E; Hack, E; Eijsman, L; Wildevuur, C

This study was performed to investigate if heparin-coated extracorporeal circuits can reduce the systemic inflammatory reaction with the subsequent release of vasoactive substances during and after cardiopulmonary bypass. Fifty-one patients scheduled for coronary artery bypass grafting were perfused

Overview of FACTS devices for wind power plants directly connected to the transmission network

DEFF Research Database (Denmark)

Adamczyk, Andrzej Grzegorz; Teodorescu, Remus; Rodriguez, Pedro

2010-01-01

Growing number of wind turbines is changing electricity generation profile all over the world. This brings challenges for power system operation, which was designed and developed around conventional power plants with directly coupled synchronous generators. In result, safety and stability...... of the electrical network with high wind energy penetration might be compromised. For this reason transmission system operators (TSO) impose more stringent connection requirements on the wind power plant (WPP) owners. On the other hand flexible AC transmission systems (FACTS) devices offer enhancement of grid...... research in FACTS applicability for WPPs is summarized. Examples of few existing FACTS applications for wind farms are given....

Experimental study of core bypass flow in a prismatic VHTR based on a two-layer block model

Energy Technology Data Exchange (ETDEWEB)

Wang, Huhu, E-mail: huhuwang@tamu.edu; Hassan, Yassin A., E-mail: y-hassan@tamu.edu; Dominguez-Ontiveros, Elvis, E-mail: elvisdom@tamu.edu

2016-09-15

Bypass flow in a prismatic very high temperature gas-cooled nuclear reactor (VHTR) plays an important role in determining the coolant distribution in the core region. Efficient removal of heat from the core relies on the majority of coolant passing through the coolant channels instead of the bypass gaps. Consequently, the bypass flow fraction and its flow characteristic are important in the design process of the prismatic VHTR. The objective of this study is to experimentally investigate the flow behavior including the turbulence characteristics inside the bypass gaps using laser Doppler velocimetry (LDV), bypass fraction and pressure drops in the system. The experiment facility constructed at Texas A&M University is a scaled model consisting of two layers of fuel blocks. The distributions of the mean streamwise velocity, turbulence intensity and turbulence kinetic energy within the bypass gap at two different elevations under different Reynolds number were investigated. Uncertainties in the bypass flow fraction estimation were evaluated. The velocity and turbulence study in this work is considered to be unique, and may serve as a benchmark for the related numerical calculations.

Effects of intestinal bypass surgery on appetite, food intake, and body weight in obese and lean rats.

Science.gov (United States)

Sclafani, A; Koopmans, H S; Vasselli, J R; Reichman, M

1978-04-01

Jejunoileal bypass surgery or sham surgery was performed in female rats made obese with ventromedial hypothalamic (VMH) knife cuts, and in lean control rats. After bypass surgery, the VMH rats underate and lost weight until they reached the body weight of the control sham rats, and they then maintained their weight at control levels. Bypass surgery in lean rats produced much smaller reductions in food intake and body weight. Both bypass groups initially consumed less of a sucrose solution and milk diet during 1 h/day tests, but their intakes returned to near normal levels during the second postoperative month. Reconnection of the intestinal tract in the VMH-bypass rats led to renewed hyperphagia and return to obese body weights. A second experiment revealed that bypass surgery reduces food intake and body weight in genetically obese (fatty) rats, but this effect is not as pronounced as that displayed by VMH rats. These results confirm recent clinical observations that reduced appetite and caloric intake are the major causes of the weight loss produced by intestinal bypass surgery.

The effect of laparoscopic Roux-en-Y gastric bypass on fibromyalgia.

Science.gov (United States)

Saber, Alan A; Boros, Michael J; Mancl, Tara; Elgamal, Mohamed H; Song, Susrap; Wisadrattanapong, Therawat

2008-06-01

Fibromyalgia is a chronic debilitating disorder affecting 3-5% of the US population. Treatment of this disorder is a challenge. The incidental finding of improvement of fibromyalgia following laparoscopic Roux-en-Y gastric bypass stimulated us to study this phenomenon. A retrospective chart review of patients with fibromyalgia who underwent laparoscopic Roux-en-Y gastric bypass. Postoperative decrease in median of BMI from 49.4 to 29.7 was significant (p value = 0.0010). This was associated with statistically significant improvement in median of pain score (p value = 0.0010) and median points of tenderness (p value = 0.0010). Significant weight loss following laparoscopic Roux-en-Y gastric bypass is associated with resolution or improvement of fibromyalgia. Consequently, the bariatric surgeon should be a member of the multidisciplinary team approach for treating fibromyalgia.

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Intra-arterial papaverine and leg vascular resistance during in situ bypass surgery with high or low epidural anaesthesia

DEFF Research Database (Denmark)

Rørdam, Peter; Jensen, Leif Panduro; Schroeder, T V

1993-01-01

In situ saphenous vein arterial bypass flow was studied in 16 patients with respect to level of epidural anaesthesia. Arterial pressure and electromagnetic flow were used to evaluate arterial tone by intra-arterial (i.a.) papaverine. Eight patients had a low epidural block (... patients were operated during high epidural anaesthesia (> Th. 10). Flow increased and arterial pressure decreased after i.a. papaverine in all patients. When compared with patients operated during high epidural anaesthesia, flow increase and decrease in vascular resistance took place in patients operated...... during low epidural anaesthesia (P i.a. papaverine was not significantly different in patients operated in low epidural and general anaesthesia (n = 8). In eight patients with insulin-dependent diabetes mellitus who had low epidural anaesthesia, the increase...

A multi-year analysis of spillway survival for juvenile salmonids as a function of spill bay operations at McNary Dam, Washington and Oregon, 2004-09

Science.gov (United States)

Adams, Noah S.; Hansel, Hal C.; Perry, Russell W.; Evans, Scott D.

2012-01-01

We analyzed 6 years (2004-09) of passage and survival data collected at McNary Dam to examine how spill bay operations affect survival of juvenile salmonids passing through the spillway at McNary Dam. We also examined the relations between spill bay operations and survival through the juvenile fish bypass in an attempt to determine if survival through the bypass is influenced by spill bay operations. We used a Cormack-Jolly-Seber release-recapture model (CJS model) to determine how the survival of juvenile salmonids passing through McNary Dam relates to spill bay operations. Results of these analyses, while not designed to yield predictive models, can be used to help develop dam-operation strategies that optimize juvenile salmonid survival. For example, increasing total discharge typically had a positive effect on both spillway and bypass survival for all species except sockeye salmon (Oncorhynchus nerka). Likewise, an increase in spill bay discharge improved spillway survival for yearling Chinook salmon (Oncorhynchus tshawytscha), and an increase in spillway discharge positively affected spillway survival for juvenile steelhead (Oncorhynchus mykiss). The strong linear relation between increased spill and increased survival indicates that increasing the amount of water through the spillway is one strategy that could be used to improve spillway survival for yearling Chinook salmon and juvenile steelhead. However, increased spill did not improve spillway survival for subyearling Chinook salmon and sockeye salmon. Our results indicate that a uniform spill pattern would provide the highest spillway survival and bypass survival for subyearling Chinook salmon. Conversely, a predominantly south spill pattern provided the highest spillway survival for yearling Chinook salmon and juvenile steelhead. Although spill pattern was not a factor for spillway survival of sockeye salmon, spill bay operations that optimize passage through the north and south spill bays maximized

A Left Atrial Myxoma Case with a History of Stroke on whom a Coronary Bypass Surgery was Performed

Directory of Open Access Journals (Sweden)

Cihangir Kaymaz

2009-12-01

Full Text Available Cardiac myxomas are the most frequently encountered benign cardiac tumors in adult groups. Patients with myxoma may suffer from variety of clinical features. A patient who had suffered from stroke a yearago came to our hospital with a chest pain complaint. In the echocardiography of the patient suffering from acute coronary syndrome, left ventricular disfunction and left atrial mass was determined. In the coronary angiography, LAD and Cx critical stenosis, and an abnormal feeding artery which roots from Cxperformed was observed. LIMA-AD, Ao-RCA bypass and mass exision withleft atriotomy was made. Cardiac tumor embolism which makes up a rare cause of cerebral embolies should be considered especiallyin patients with sinus rhythm. In the coronary angiography the feeding artery of the myxoma was shown. A patient who has underwent coronary bypass operation and left atrial myxoma exision has beenpresented as a case.

Headland sediment bypassing and beach rotation in a rocky coast: an example at the western Portuguese coast

Science.gov (United States)

Ribeiro, Mónica; Taborda, Rui; Lira, Cristina; Bizarro, Aurora; Oliveira, Anabela

2014-05-01

(less energetic) incident wave conditions. The persistence of these conditions induces an enlargement of the beach downdrift (southward) and eventually sediment bypassing. This process can result in a continuous inner bar along the headland coast, which migrates downdrift in the surf zone and weld to the downdrift beach. The counter-clockwise rotation observed in the winter is more variable being in agreement with the less persistent W and SW incident wave conditions, suggesting that sediment bypassing occurs only southwards. The work was funded by FEDER funds through the Operational Programme for Competitiveness Factors - COMPETE and FCT National Funds - Portuguese Foundation for Science and Technology under the project Beach to Canyon Head Sedimentary Processes (PTDC/MAR/114674/2009). First author benefits from a PhD grant funded by FCT (SFRH/BD/79126/2011).

Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial

DEFF Research Database (Denmark)

Eiberg, JP; Røder, Ole Christian; Stahl-Madsen, M

2006-01-01

To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery.......To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery....

Effects of preoperative aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in patients undergoing off-pump coronary artery bypass graft surgery.

Science.gov (United States)

Shim, Jae Kwang; Choi, Yong Seon; Oh, Young Jun; Bang, Sou Ouk; Yoo, Kyung Jong; Kwak, Young Lan

2007-07-01

Preoperative exposure to clopidogrel and aspirin significantly increases postoperative bleeding in patients undergoing on-pump coronary artery bypass graft surgery. Off-pump coronary bypass grafting has been proposed as an alternative technique to attenuate postoperative bleeding associated with clopidogrel. This study aimed to determine the effects of aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in off-pump coronary artery bypass grafting. One hundred six patients scheduled for off-pump coronary artery bypass grafting were divided into three groups: aspirin and clopidogrel discontinued more than 6 days before surgery (group 1, n = 35), aspirin and clopidogrel continued until 3 to 5 days before surgery (group 2, n = 51), and both medications continued within 2 days of surgery (group 3, n = 20). Thromboelastographic tracings were analyzed before induction of anesthesia. Routine coagulation profiles were measured before and after surgery. A cell salvage device was used during surgery and salvaged blood was reinfused. Chest tube drainage and blood transfusion requirement were recorded postoperatively. Patient characteristics, operative data, and thromboelastographic tracings were similar among the groups. There were significant decreases in hematocrit level and platelet count and prolongation in prothrombin time postoperatively in all groups without any intergroup differences. The amounts of perioperative blood loss and blood transfusion required were all similar among the groups. Preoperative clopidogrel and aspirin exposure even within 2 days of surgery does not increase perioperative blood loss and blood transfusion requirements in patients undergoing elective off-pump coronary artery bypass grafting.

The Metaphysical Instincts & Spiritual Bypassing in Integral Psychology

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Bahman A.K. Shirazi

2013-09-01

Full Text Available Instincts are innate, unconscious means by which Nature operates in all forms of life including animals and human beings. In humans however, with progressive evolution of consciousness, instincts become increasingly conscious and regulated by egoic functions. Biological instincts associated with the lower-unconscious such as survival, aggressive, and reproductive instincts are well known in general psychology. The higher-unconscious, which is unique to human beings, may be said to have its own instinctual processes referred to here as the ‘metaphysical instincts’. In traditional spiritual practices awakening the metaphysical instincts has often been done at the expense of suppressing the biological instincts—a process referred to as spiritual bypassing. This essay discusses how the metaphysical instincts initially expressed as the religious impulse with associated beliefs and behaviors may be transformed and made fully conscious, and integrated with the biological instincts in integral yoga and psychology in order to achieve wholeness of personality.

Fatal air embolism during cardiopulmonary bypass : analysis of an incident and prevention measures

NARCIS (Netherlands)

van der Zee, Michiel P.; Koene, Bart M.; Mariani, Massimo A.

Air embolism is a life-threatening complication during cardiopulmonary bypass. We present a case of a patient who suffered an air embolism during coronary bypass surgery, despite standard safety features and procedures. The patient died 3 days after surgery due to massive cerebral oedema. This case

DIET MICRONUTRIENT ADEQUACY OF WOMEN AFTER 1 YEAR OF GASTRIC BYPASS

Science.gov (United States)

LEIRO, Larissa Silveira; Melendez-ARAÚJO, Mariana Silva

2014-01-01

Background The more effective treatment for severe obesity is bariatric surgery. Gastric bypass is a surgical technique used worldwide; however, as well as other techniques; it has postoperative risks, including nutrient deficiency. Aim To determine the amounts of dietary iron, calcium, vitamin D and vitamin B12 ingested by patients of a public hospital one year after gastric bypass, and compare with the recommendations of the Recommended Dietary Allowances. Methods This was a transverse descriptive study and the sample consisted of 36 women, with at least one year of gastric bypass. Data collected included sociodemographic, anthropometric and diet variables. Dietetic information was collected through a validated food frequency questionnaire. Ingestion of iron, calcium, vitamin D and vitamina B12 was evaluated in comparison with the Recommended Dietary Allowances, as well as correlation of micronutrient ingestion with time of surgery. Results There was inadequate consumption of iron, calcium and vitamin D. The vitamin B12 intake was considered adequate. There was statistically significant positive correlation between the time of surgery and the ingestion of iron, vitamin B12 and vitamin D. Conclusion The intake of iron, calcium and vitamin D of women one year after gastric bypass was inadequate, emphasizing the importance of multiprofessional monitoring postoperatively to prevent nutrient deficiencies. PMID:25409960

Experimental investigations of the steady flow through an idealized model of a femoral artery bypass

Directory of Open Access Journals (Sweden)

Giurgea Corina

2014-03-01

Full Text Available The present paper presents the steps taken by the authors in the first stage of an experimental program within a larger national research project whose objective is to characterize the flow through a femoral artery bypass with a view to finding solutions for its optimization. The objective of the stage is to investigate by means of the PIV method the stationary flow through a bypass model with an idealized geometry. A bypass assembly which reunites the idealized geometry models of the proximal and distal anastomoses, and which respects the lengths of a femoral artery bypass was constructed on the basis of data for a real patient provided by medical investigations. With the aim of testing the model and the established experimental set-up with regard to their suitability for the assessment of the velocity field associated to the steady flow through the bypass, three zones that can restore the whole distal anastomosis were PIV investigated. The measurements were taken in the conditions of maintained inflow at the bypass entry of 0.9 l / min (Re = 600. The article presents comparatively the flow spectra and the velocity fields for each zone obtained in two situations: with the femoral artery completely occluded and completely open.

Microsurgical Bypass Training Rat Model: Part 2-Anastomosis Configurations.

Science.gov (United States)

Tayebi Meybodi, Ali; Lawton, Michael T; Yousef, Sonia; Mokhtari, Pooneh; Gandhi, Sirin; Benet, Arnau

2017-11-01

Mastery of microsurgical anastomosis is key to achieving good outcomes in cerebrovascular bypass procedures. Animal models (especially rodents) provide an optimal preclinical bypass training platform. However, the existing models for practicing different anastomosis configurations have several limitations. We sought to optimize the use of the rat's abdominal aorta and common iliac arteries (CIA) for practicing the 3 main anastomosis configurations commonly used in cerebrovascular surgery. Thirteen male Sprague-Dawley rats underwent inhalant anesthesia. The abdominal aorta and the CIAs were exposed. The distances between the major branches of the aorta were measured to find the optimal location for an end-to-end anastomosis. Also, the feasibility of performing side-to-side and end-to-side anastomoses between the CIAs was assessed. All bypass configurations could be performed between the left renal artery and the CIA bifurcation. The longest segments of the aorta without major branches were 1) between the left renal and left iliolumbar arteries (16.9 mm ± 4.6), and 2) between the right iliolumbar artery and the aortic bifurcation (9.7 mm ± 4.7). The CIAs could be juxtaposed for an average length of 7.6 mm ± 1.3, for a side-to-side anastomosis. The left CIA could be successfully reimplanted on to the right CIA at an average distance of 9.1 mm ± 1.6 from the aortic bifurcation. Our results show that rat's abdominal aorta and CIAs may be effectively used for all the anastomosis configurations used in cerebral revascularization procedures. We also provide technical nuances and anatomic descriptions to plan for practicing each bypass configuration. Copyright © 2017 Elsevier Inc. All rights reserved.

Does Off-Pump Coronary Artery Bypass Grafting Negatively Impact Long-Term Survival and Freedom from Reintervention?

Directory of Open Access Journals (Sweden)

Shahzad G. Raja

2013-01-01

Full Text Available Recently published evidence has raised concerns about worse late mortality and increasing need for reintervention after off-pump coronary artery bypass grafting. We undertook this study to assess the impact of off-pump coronary artery bypass grafting on survival and freedom from reintervention at 10 years. From January 2002 to December 2002, 307 consecutive patients who had isolated multivessel off-pump coronary artery bypass grafting at our institution were compared to a control group of 397 patients that underwent multivessel on-pump coronary artery bypass grafting during the same period. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years. Kaplan-Meier survival was similar for the two cohorts. After adjusting for clinical covariates, off-pump coronary artery bypass grafting did not emerge as a significant independent predictor of long-term mortality (Hazard Ratio 0.91; 95% Confidence Interval 0.70–1.12, readmission to hospital for cardiac cause (Hazard Ratio 0.96; 95% Confidence Interval 0.78–1.10, or the need for reintervention (Hazard Ratio 0.93; 95% Confidence Interval 0.87–1.05. Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting does not adversely impact survival or freedom from reintervention at a 10-year follow-up.

Application of a pharmacokinetics-pharmacodynamics approach to the free propofol plasma levels during coronary artery bypass grafting surgery with hypothermic cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Carlos R. Silva-Filho

2018-02-01

Full Text Available OBJECTIVES: The objective of this study was to apply a pharmacokinetics-pharmacodynamics approach to investigate the free propofol plasma levels in patients undergoing coronary artery bypass grafting under hypothermic conditions compared with the off-pump procedure. METHODS: Nineteen patients scheduled for on-pump coronary artery bypass grafting under hypothermic conditions (n=10 or the equivalent off-pump surgery (n=9 were anesthetized with sufentanil and propofol target-controlled infusion (2 μg/mL during surgery. The propofol concentration was then reduced to 1 μg/mL, and a pharmacokinetics-pharmacodynamics analysis using the maximum-effect-sigmoid model obtained by plotting the bispectral index values against the free propofol plasma levels was performed. RESULTS: Significant increases (two- to five-fold in the free propofol plasma levels were observed in the patients subjected to coronary artery bypass grafting under hypothermic conditions. The pharmacokinetics of propofol varied according to the free drug levels in the hypothermic on-pump group versus the off-pump group. After hypothermic coronary artery bypass was initiated, the distribution volume increased, and the distribution half-life was prolonged. Propofol target-controlled infusion was discontinued when orotracheal extubation was indicated, and the time to patient extubation was significantly higher in the hypothermic on-pump group than in the off-pump group (459 versus 273 min, p=0.0048. CONCLUSIONS: The orotracheal intubation time was significantly longer in the hypothermic on-pump group than in the off-pump group. Additionally, residual hypnosis was identified through the pharmacokinetics-pharmacodynamics approach based on decreases in drug plasma protein binding in the hypothermic on-pump group, which could explain the increased hypnosis observed with this drug in this group of patients.

Role of ternary fission in synthesis of bypassed nuclei

International Nuclear Information System (INIS)

Kramarovskij, Ya.M.; Chechev, V.P.

1983-01-01

A possible influence of ternary fission with escape of neutron-enriched light charged particles on the synthesis of bypassed nuclides is considered. It is shown that this concept cannot give explanation of bypassed isotope concentrations, but it can make some contribution, if the probability of ternary fission for superheavy nuclei grows sharply with Z 2 /A parameter. The account of β-delayed fission contributes to the shift of ternary fission fragments into the region of neutron-deficient isotopes. Consistent consideration of the ternary fission role in the nucleosynthesis is possible only with an important accumulation of experimental and theoretical data on this process, particularly for the nuclei with Z > 100

Extended fuel cycle operation for pressurized water reactor plants

International Nuclear Information System (INIS)

Silvestri, G.J. Jr.

1978-01-01

A nuclear steam turbine power plant system having an arrangement therein for extended fuel cycle operation is described. The power plant includes a turbine connected at its inlet to a source of motive fluid having a predetermined pressure associated therewith. The turbine has also connected thereto an extraction conduit which extracts steam from a predetermined location therein for use in an associated apparatus. A bypass conduit is provided between a point upstream of the inlet and the extraction conduit. A flow control device is provided within the bypass conduit and opens when the pressure of the motive steam supply drops beneath the predetermined pressure as a result of reactivity loss within the nuclear reactor. Opening of the bypass conduit provides flow to the associated apparatus and at the same time provides an increased flow orifice to maintain fluid flow rate at a predetermined level

Development of an economical and ecological optimized multi slot fish bypass

International Nuclear Information System (INIS)

Tauber, M.; Mader, H.

2009-01-01

The European Union's Water Framework Directive (WFD), which came into force in 2000, represents a new framework governing water policies. The ecological objectives of the directive are sometimes in conflict with the historical use of waterbodies for hydropower generation. This paper discussed the mitigation of negative economical effects caused by outfitting hydropower plants with fish migration facilities claimed by the WFD. In particular, it reviewed the new modified version of the Vertical Slot Fishpass which reduces water discharge while maintaining or even enhancing the biological migration of aquatic species. Reducing the flow rate in the fish bypass results in more available water for hydropower generation, which is economically advantageous for operators. The available water resource is simply used more efficiently. The bypass was modified by adding additional slot baffles and guide walls in order to induce intended losses at roughness obstacles and to obtain isolated roughness current in the multi slot area. A Froude similarity model was used to obtain the results of the first phase of this project. Different arrangements of the slot baffles and locations were measured. The results of all trials revealed that the newly developed multi slot variants have clear advantages over conventional vertical slot fish passages. Discharge was reduced by up to 34 per cent while still maintaining the same water levels in the pools. As such, the general flow velocities were also reduced by about 10 per cent, thereby achieving the primary objective of the project. 7 refs., 18 figs

Superfund fact sheet: The remedial program. Fact sheet

International Nuclear Information System (INIS)

1992-09-01

The fact sheet describes what various actions the EPA can take to clean up hazardous wastes sites. Explanations of how the criteria for environmental and public health risk assessment are determined and the role of state and local governments in site remediation are given. The fact sheet is one in a series providing reference information about Superfund issues and is intended for readers with no formal scientific training

Multivariate Analysis of Factors Influencing Length of Hospital Stay after Coronary Artery Bypass Surgery in Tehran, Iran

Directory of Open Access Journals (Sweden)

Amin Torabipour

2016-03-01

Full Text Available Length of hospital stay (LOS is a key indicator for hospital management. Reducing hospital stay is a priority for all health systems. We aimed to determine the length of hospital stay following Coronary Artery Bypass Surgery (CABG based on its clinical and non-clinical factors. A cross-sectional study of 649 consecutive patients who underwent coronary artery bypass graft surgery was conducted in Imam Khomeini and Shariati university hospitals, Tehran, Iran. Data was analyzed by using non-parametric univariate tests and multiple linier regression models. Thirty seven independent variables including pre-operative, intra-operative and post-operative variables were analyzed. Finally, an appropriate model was constructed based on the associated factors. The results showed that 70.3% of the patients were male, and the mean age of the patients was 59.3 ± 10.4 years. The Mean (±SD and median of the LOS were 11.7 ± 7.1 and 9 days, respectively. Of 37 investigated variables, 24 qualitative and quantitative variables were significantly associated with length of stay (p<0.05. Multiple linear regression analysis showed that independent variables including age, medical insurance type, body mass index, and prior myocardial infarction; admission day, admission season, Cross-clamp time, pump usage, admission type, the number of laboratory tests and the number of specialty consultation had more effect on the hospital stay. We concluded that some significant factors influencing hospital stay after CABG were predictable and modifiable by hospital managers and decision makers to manage hospital beds.

Sternal wound complications after primary isolated myocardial revascularization: the importance of the post-operative variables.

NARCIS (Netherlands)

Noyez, L.; Druten, J.A.M. van; Mulder, J.; Schroen, A.M.; Skotnicki, S.H.; Brouwer, R.

2001-01-01

OBJECTIVE: Select pre-, peri-, and post-operative variables, predictive for sternal wound complications (SWC), in a clinical setting. METHODS: We analyzed pre-, peri-, and post-operative data of 3815 patients who underwent a primary isolated bypass grafting. 100 patients (2.6%) had post-operative

The Effect of Bypass Nozzle Exit Area on Fan Aerodynamic Performance and Noise in a Model Turbofan Simulator

Science.gov (United States)

Hughes, Christopher E.; Podboy, Gary, G.; Woodward, Richard P.; Jeracki, Robert, J.

2013-01-01

The design of effective new technologies to reduce aircraft propulsion noise is dependent on identifying and understanding the noise sources and noise generation mechanisms in the modern turbofan engine, as well as determining their contribution to the overall aircraft noise signature. Therefore, a comprehensive aeroacoustic wind tunnel test program was conducted called the Fan Broadband Source Diagnostic Test as part of the NASA Quiet Aircraft Technology program. The test was performed in the anechoic NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel using a 1/5 scale model turbofan simulator which represented a current generation, medium pressure ratio, high bypass turbofan aircraft engine. The investigation focused on simulating in model scale only the bypass section of the turbofan engine. The test objectives were to: identify the noise sources within the model and determine their noise level; investigate several component design technologies by determining their impact on the aerodynamic and acoustic performance of the fan stage; and conduct detailed flow diagnostics within the fan flow field to characterize the physics of the noise generation mechanisms in a turbofan model. This report discusses results obtained for one aspect of the Source Diagnostic Test that investigated the effect of the bypass or fan nozzle exit area on the bypass stage aerodynamic performance, specifically the fan and outlet guide vanes or stators, as well as the farfield acoustic noise level. The aerodynamic performance, farfield acoustics, and Laser Doppler Velocimeter flow diagnostic results are presented for the fan and four different fixed-area bypass nozzle configurations. The nozzles simulated fixed engine operating lines and encompassed the fan stage operating envelope from near stall to cruise. One nozzle was selected as a baseline reference, representing the nozzle area which would achieve the design point operating conditions and fan stage performance. The total area change from

Local immobilization of the left anterior descending artery for minimally invasive coronary bypass grafting

NARCIS (Netherlands)

Boonstra, PW; Grandjean, JG; Mariani, MA

We describe a device for coronary artery stabilization during minimally invasive coronary artery bypass grafting performed without cardiopulmonary bypass via a small (8 to 10 cm) left anterolateral thoracotomy. This device facilitates the anastomosis of the left internal mammary artery to the left

The experience of totally endoscopic coronary bypass grafting with the robotic system «Da Vinci» in Russia

Science.gov (United States)

Efendiev, V. U.; Alsov, S. A.; Ruzmatov, T. M.; Mikheenko, I. L.; Chernyavsky, A. M.; Malakhov, E. S.

2015-11-01

A new technology - a thoracoscopic coronary bypass grafting with the use of Da Vinci robotic system in Russia is represented by the experience of NRICP. The technology was introduced in Russia in 2011. Overall, one hundred endoscopic coronary artery bypass procedures were performed. We have compared and analyzed results of coronary artery stenting vs minimally invasive coronary artery bypass grafting. According to the results, totally endoscopic coronary artery bypass grafting has several advantages over alternative treatment strategies.

Clinical significance of 201Tl reverse redistribution in patients with aorto-coronary bypass surgery

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Uehara, Tashiisa; Hayashida, Kohei; Kozuka, Takahira

1987-01-01

Detection of myocardial ischemia by the stress thallium scan has traditionally been performed using transient defect analysis on exercise, followed by redistribution studies. Worsening of the 201 Tl myocardial image from exercise to redistribution is referred to as reverse redistribution. In this study, we found reverse redistribution in 10 (21%) of 48 angina pectoris patients who had undergone aortocoronary bypass surgery. The clinical significance of this phenomenon in these patients was investigated in relation to angiographic and surgical findings. Reverse redistribution was found to occur in regions which were supplied by bypass grafts. These areas showed increased coronary blood flow and rapid thallium washout. Our results indicate that a perfusion defect in the bypass region of the redistribution image might be caused by relatively rapid washout in the bypass graft region compared to the adjacent normal myocardium. These results should be considered in the clinical interpretation of stress thallium scans. (orig.)

Re-birth after coronary bypass graft surgery: a hermeneutic-phenomenological study.

Science.gov (United States)

Abbasi, Mohammad; Mohammadi, Nooredin; Nasrabadi, Alireza Nikbakht; Fuh, Suh Boudouin; Sadeghi, Tahereh

2014-03-31

Although coronary artery bypass graft surgery has significant effects on reducing the symptoms of coronary artery disease, there is not enough knowledge and understanding of lived experience of patients after surgery. Understanding lived experience of this group of patients would be helpful for healthcare staff to provide better services to the patients. The aim of this study was to describe with a deeper understanding, the lived experiences of patients after Coronary Artery Bypass Graft Surgery. Using a hermeneutic phenomenological approach and a Van-Manen analysis method, in-depth semi-structured interviews were conducted with eleven participants who had lived experienced of at least six months post - coronary artery bypass graft surgery. Re-birth was the main theme that emerged in the process of data analysis. This theme was derived from four sub-themes including "feels younger", ''vigorous heart'', ''intrepid life'' and ''oriented to be healthy''. Life after a coronary artery bypass graft surgery is often appreciated as a re-birth by persons with these experiences as surgery did not only provide a feeling of wellness, but also added a sensation of youthfulness and improvement in the quality of life for these participants. In addition, they would actively participate in health promotional activities such as; adherence to medication and diet regimes, changes in lifestyle to maintain their health.

The effect of extracorporeal life support on the brain: cardiopulmonary bypass.

Science.gov (United States)

Jonas, Richard A

2005-02-01

This article reviews the mechanisms of brain injury associated with cardiopulmonary bypass. These include embolic injury of both a gaseous and particulate nature as well as global hypoxic ischemic injury. Ischemic injury can result from problems associated with venous drainage or with arterial inflow including a steal secondary to systemic to pulmonary collateral vessels. Modifications in the technique of cardiopulmonary bypass have reduced the risk of global hypoxic/ischemic injury. Laboratory and clinical studies have demonstrated that perfusion hematocrit should be maintained above 25% and preferably above 30%. Perfusion pH is also critically important, particularly when hypothermia is employed. An alkaline pH can limit cerebral oxygen delivery by inducing cerebral vasoconstriction as well as shifting oxyhemoglobin dissociation leftwards. If deep hypothermia is employed, it is critically important to add carbon dioxide using the so-called "pH stat" strategy. Oxygen management during cardiopulmonary bypass is also important. Although there is currently enthusiasm for using air rather than pure oxygen, ie, adding nitrogen, this does introduce a greater risk of gaseous nitrogen emboli since nitrogen is much less soluble than oxygen. The use of pure oxygen in conjunction with CO2 to apply the pH stat strategy is recommended. Many of the lessons learned from studies focusing on brain protection during cardiopulmonary bypass can be applied to the patient being supported with extracorporeal membrane oxygenation.

Computational fluid dynamic analysis of core bypass flow phenomena in a prismatic VHTR

International Nuclear Information System (INIS)

Sato, Hiroyuki; Johnson, Richard; Schultz, Richard

2010-01-01

The core bypass flow in a prismatic very high temperature reactor (VHTR) is an important design consideration and can have considerable impact on the condition of reactor core internals including fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) are affected by bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to better understand bypass flow phenomena and establish an evaluation method for the reactor core using the commercial CFD code FLUENT. Parametric calculations changing several factors in a one-twelfth sector of a fuel column are performed. The simulations show the impact of each factor on bypass flow and the resulting flow and temperature distributions in the prismatic core. Factors include inter-column gap-width, turbulence model, axial heat generation profile and geometry change from irradiation-induced shrinkage in the graphite block region. It is shown that bypass flow provides a significant cooling effect on the prismatic block and that the maximum fuel and coolant channel outlet temperatures increase with an increase in gap-width, especially when a peak radial factor is applied to the total heat generation rate. Also, the presence of bypass flow causes a large lateral temperature gradient in the block and also dramatically increases the variation in coolant channel outlet temperatures for a given block that may have repercussions on the structural integrity of the graphite, the neutronics and the potential for hot streaking and hot spots occurring in the lower plenum.

Endoscopic intestinal bypass creation by using self-assembling magnets in a porcine model.

Science.gov (United States)

Ryou, Marvin; Agoston, A Tony; Thompson, Christopher C

2016-04-01

A purely endoluminal method of GI bypass would be desirable for the treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets that create large-caliber anastomoses (Incisionless Anastomosis System [IAS]). The aim of this study was to evaluate procedural characteristics of IAS deployment and long-term anastomotic integrity and patency. We performed a 3-month survival study of Yorkshire pigs (5 interventions, 3 controls). Intervention pigs underwent simultaneous enteroscopy/colonoscopy performed with the animals under intravenous sedation. The IAS magnets were deployed and coupled with reciprocal magnets under fluoroscopy. Every 3 to 6 days pigs underwent endoscopy until jejunocolonic anastomosis (dual-path bypass) creation and magnet expulsion. Necropsies and histological evaluation were performed. The primary endpoints were technical success; secondary endpoints of anastomosis integrity, patency, and histological characteristics were weight trends. Under intravenous sedation, endoscopic bypass creation by using IAS magnets was successfully performed in 5 of 5 pigs (100%). Given porcine anatomy, the easiest dual-path bypass to create was between the proximal jejunum and colon. The mean procedure time was 14.7 minutes. Patent, leak-free anastomoses formed by day 4. All IAS magnets were expelled by day 12. All anastomoses were fully patent at 3 months with a mean diameter of 3.5 cm. The mean 3-month weight was 45 kg in bypass pigs and 78 kg in controls (P = .01). At necropsy, adhesions were absent. Histology showed full re-epithelialization across the anastomosis without fibrosis or inflammation. Large-caliber, leak-free, foreign body-free endoscopic intestinal bypass by using IAS magnets can be safely and rapidly performed in the porcine by model using only intravenous sedation. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Feasibility study on retinal vascular bypass surgery in isolated arterially perfused caprine eye model

Science.gov (United States)

Chen, Y; Wu, W; Zhang, X; Fan, W; Shen, L

2011-01-01

Purpose To investigate the feasibility of bypassing occluded segments of retinal venous main vessels in isolated, arterially perfused caprine eyes via the closed-sky vitrectomy approach using keratoprosthesis. Methods Isolated caprine eyes were used in this study. For each eye, the retinal vessel was perfused by Krebs solution via ophthalmic artery, and pars plana vitrectomy was performed using temporary keratoprosthesis. All retinal micro-vascular maneuvers were performed in a closed-sky eyeball. The main retinal vein was blocked by endodiathermy at the site of the vessel's first branching. Two openings, several millimeters apart, were created by vascular punctures in both the main vein and its branch vein wall straddling the induced occluded segment. Catheterization was achieved using a flexible polyimide tube, with each end inserted into the vessel wall opening. A sealed connection between the vessel and the tube was obtained by endodiathermy. Bypass of the occluded retinal vein segment was thus achieved, and the patency of this vascular bypass was confirmed by intravascular staining. Results Puncturing, catheterization, and endodiathermy were viable by closed-sky approach using keratoprosthesis. Bypassing of the occluded retinal main vein segment was accomplished with the combination of these maneuvers. Good results were obtained in 23 of 38 (60%) caprine eyes. Conclusions This study demonstrated that bypassing the occluded segment of retinal main vein can be successfully performed in a closed-sky eyeball model of isolated, arterially perfused caprine eye. This early work indicated that the more advanced retinal vascular bypass surgery in in vivo eye may be feasible in the future. PMID:21921946

Prospectively randomized clinical trial to compare in situ and reversed saphenous vein grafts for femoropopliteal bypass.

Science.gov (United States)

Harris, P L; How, T V; Jones, D R

1987-04-01

Two hundred and fifteen femoropopliteal bypass procedures using autologous saphenous vein grafts were randomly allocated to either the reversed or in situ technique. Eleven veins (5 per cent) were rejected at operation on the basis of their small size, nine in the reversed group and two in the in situ group, and there were two (2 per cent) perioperative deaths in each group, leaving 102 reversed and 98 in situ grafts for further study. The cumulative patency at 3 years of the reversed grafts was 77 per cent and that of the in situ grafts was 68 per cent (n.s.). The patency of all grafts was affected adversely by small veins (P less than 0.005), long grafts (P less than 0.05), low volume of blood flow in the grafts (P less than 0.001) and poor run-off (P less than 0.05). These factors influenced the outcome of the in situ and reversed operations to a similar degree and there was no statistically significant difference between them within any subgroup. The mean compliance of the in situ grafts measured 3 months or more after operation with an ultrasonic echo-tracking system was 0.024 +/- 0.01 per cent/mmHg (+/- s.d.) compared with 0.017 +/- 0.01 per cent/mmHg for the reversed grafts (t = 2.43, P less than 0.02). The incidence of fibrous stricture formation as shown by intravenous digital subtraction angiography was 29 per cent in both the reversed and the in situ grafts. The results of the study to date indicate that reversed and in situ vein grafts are equally effective for femoropopliteal bypass.

Coronary Artery Bypass Surgery: MedlinePlus Health Topic

Science.gov (United States)

... Living With Related Issues Specifics See, Play and Learn Images Videos and Tutorials Research Clinical Trials Journal Articles Resources ... bypass surgery - slideshow (Medical Encyclopedia) Also in ... is better to reduce postoperative stroke... Article: Blood transfusion and ...

Hybrid Repair of Complex Thoracic Aortic Arch Pathology: Long-Term Outcomes of Extra-anatomic Bypass Grafting of the Supra-aortic Trunk

Energy Technology Data Exchange (ETDEWEB)

Lotfi, S., E-mail: shamim.lotfi@kcl.ac.uk; Clough, R. E.; Ali, T. [Guy' s and St. Thomas' NHS Trust, Vascular Surgery (United Kingdom); Salter, R. [Guy' s and St. Thomas' NHS Trust, Interventional Radiology (United Kingdom); Young, C. P. [Guy' s and St. Thomas' NHS Trust, Cardiac Surgery (United Kingdom); Bell, R.; Modarai, B.; Taylor, P., E-mail: peter.taylor@gstt.nhs.uk [Guy' s and St. Thomas' NHS Trust, Vascular Surgery (United Kingdom)

2013-02-15

Hybrid repair constitutes supra-aortic debranching before thoracic endovascular aortic repair (TEVAR). It offers improved short-term outcome compared with open surgery; however, longer-term studies are required to assess patient outcomes and patency of the extra-anatomic bypass grafts. A prospectively maintained database of 380 elective and urgent patients who had undergone TEVAR (1997-2011) was analyzed retrospectively. Fifty-one patients (34 males; 17 females) underwent hybrid repair. Median age was 71 (range, 18-90) years with mean follow-up of 15 (range, 0-61) months. Perioperative complications included death: 10 % (5/51), stroke: 12 % (6/51), paraplegia: 6 % (3/51), endoleak: 16 % (8/51), rupture: 4 % (2/51), upper-limb ischemia: 2 % (1/51), bypass graft occlusion: 4 % (2/51), and cardiopulmonary complications in 14 % (7/51). Three patients (6 %) required emergency intervention for retrograde dissection: (2 aortic root repairs; 2 innominate stents). Early reintervention was performed for type 1 endoleak in two patients (2 proximal cuff extensions). One patient underwent innominate stenting and revision of their bypass for symptomatic restenosis. At 48 months, survival was 73 %. Endoleak was detected in three (6 %) patients (type 1 = 2; type 2 = 1) requiring debranching with proximal stent graft (n = 2) and proximal extension cuff (n = 1). One patient had a fatal rupture of a mycotic aneurysm and two arch aneurysms expanded. No bypass graft occluded after the perioperative period. Hybrid operations to treat aortic arch disease can be performed with results comparable to open surgery. The longer-term outcomes demonstrate low rates of reintervention and high rates of graft patency.

Hybrid Repair of Complex Thoracic Aortic Arch Pathology: Long-Term Outcomes of Extra-anatomic Bypass Grafting of the Supra-aortic Trunk

International Nuclear Information System (INIS)

Lotfi, S.; Clough, R. E.; Ali, T.; Salter, R.; Young, C. P.; Bell, R.; Modarai, B.; Taylor, P.

2013-01-01

Hybrid repair constitutes supra-aortic debranching before thoracic endovascular aortic repair (TEVAR). It offers improved short-term outcome compared with open surgery; however, longer-term studies are required to assess patient outcomes and patency of the extra-anatomic bypass grafts. A prospectively maintained database of 380 elective and urgent patients who had undergone TEVAR (1997–2011) was analyzed retrospectively. Fifty-one patients (34 males; 17 females) underwent hybrid repair. Median age was 71 (range, 18–90) years with mean follow-up of 15 (range, 0–61) months. Perioperative complications included death: 10 % (5/51), stroke: 12 % (6/51), paraplegia: 6 % (3/51), endoleak: 16 % (8/51), rupture: 4 % (2/51), upper-limb ischemia: 2 % (1/51), bypass graft occlusion: 4 % (2/51), and cardiopulmonary complications in 14 % (7/51). Three patients (6 %) required emergency intervention for retrograde dissection: (2 aortic root repairs; 2 innominate stents). Early reintervention was performed for type 1 endoleak in two patients (2 proximal cuff extensions). One patient underwent innominate stenting and revision of their bypass for symptomatic restenosis. At 48 months, survival was 73 %. Endoleak was detected in three (6 %) patients (type 1 = 2; type 2 = 1) requiring debranching with proximal stent graft (n = 2) and proximal extension cuff (n = 1). One patient had a fatal rupture of a mycotic aneurysm and two arch aneurysms expanded. No bypass graft occluded after the perioperative period. Hybrid operations to treat aortic arch disease can be performed with results comparable to open surgery. The longer-term outcomes demonstrate low rates of reintervention and high rates of graft patency.

Flow Simulation of Supersonic Inlet with Bypass Annular Duct

Science.gov (United States)

Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.

2011-01-01

A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.

Protection of semiconductor converters for controlled bypass reactors

International Nuclear Information System (INIS)

Dolgopolov, A. G.; Akhmetzhanov, N. G.; Karmanov, V. F.

2010-01-01

Possible ways of protecting thyristor converters in systems for magnetizing 110 - 500 kV controlled bypass reactors during switching and automatic reclosing are examined based on experience with the development of equipment, line tests, and mathematical modelling.

Correlation of femoral artery vs radial artery pressures with central pressure after cardiopulmonary bypass in children

International Nuclear Information System (INIS)

Yaseen, R.; Memon, H.

2008-01-01

To assess the effectiveness of femoral and radial arterial lines on the correlation of peripheral and central mean arterial blood pressure in children after discontinuation of cardiopulmonary bypass. Fifty children scheduled for cardiac surgery with cardiopulmonary bypass were included in the study. After approval from the hospital ethics committee and informed consent. 50 children undergoing cardiac surgical procedures with cardiopulmonary bypass were randomly assigned to two different groups. In Group- A (RAP, n-2) a radial arterial line and in Group-B (FAP, n-25) a femoral arterial line was used to monitor the blood pressure. Simultaneous mean peripheral arterial pressure and mean central aortic pressure were recorded before cardiopulmonary bypass and 5 mins after separation from the cardiopulmonary bypass. The correlation of mean peripheral arterial pressure (radial and femoral) versus mean aortic pressure were compared. The data was recorded as Mean +- SD and P-value. The ages of children ranged from 4-12 years and their weight from 14.1-28.5 kg. In all of them following cardiopulmonary bypass, aortic pressure correlates better with femoral arterial pressure (p<0.001). The radial arterial line readings under estimated central aortic pressure when compared to femoral arterial line readings. Aortic pressure readings correlate better with femoral arterial pressure than radial arterial pressure in children. (author)

Facts on Nirex

International Nuclear Information System (INIS)

1987-01-01

This folder contains twelve two-page leaflets (fact sheets) which answer questions posed about UK NIREX Ltd, its operations and radioactive waste. NIREX (the Nuclear Industry Radioactive Waste Executive) is the organisation responsible for implementing the British Government's policy for the disposal of most low- and intermediate-level radioactive waste produced in the United Kingdom. The questions posed are; what is NIREX. What is radioactivity. What is radioactive waste. Radioactive waste, what are the options. What is a radioactive waste repository. Some aspects of such a repository are then explained - how engineered barriers work, how geological barriers work, how long can concrete last, how is the radioactive waste transported, how are repository sites identified. The last two leaflets consider why do we need research, and look at radioactive waste management worldwide. The answers are in non-technical language and are short. (UK)

Massive sediment bypassing on the lower shoreface offshore of a wide tidal inlet: Cat Island Pass, Louisiana

Science.gov (United States)

Jaffe, B.E.; List, J.H.; Sallenger, A.H.

1997-01-01

Analysis of a series of historical bathymetric and shoreline surveys along the Louisiana coast west of the Mississippi River mouth detected a large area of deposition in water depths of 2.0–8.5 m offshore of a 9-km-wide tidal inlet, the Cat Island Pass/Wine Island Pass system. A 59.9 · 106 m3 sandy deposit formed from the 1930s–1980s, spanning 27 km in the alongshore direction, delineating the transport pathway for sediment bypassing offshore of the inlet on the shoreface. Bypassing connected the shorefaces of two barrier island systems, the Isles Dernieres and the Bayou Lafourche.The processes responsible for formation of this deposit are not well understood, but sediment-transport modeling suggests that sediment is transported primarily by wind-driven coastal currents during large storms and hurricanes. Deposition appears to be related to changes in shoreline orientation, closing of transport pathways into a large bay to the east and the presence of tidal inlets. This newly documented type of bypassing, an offshore bypassing of the inlet system, naturally nourished the immediate downdrift area, the eastern Isles Dernieres, where shoreface and shoreline erosion rates are about half of pre-bypassing rates. Erosion rates remained the same farther downdrift, where bypassing has not yet reached. As this offshore bypassing continues, the destruction of the Isles Dernieres will be slowed.

Operative Complications During Pregnancy After Gastric Bypass—a Register-Based Cohort Study

DEFF Research Database (Denmark)

Andreasen, Lisbeth A; Nilas, Lisbeth; Kjær, Mette M

2014-01-01

the puerperium. CONCLUSIONS: The incidence of internal herniation during pregnancy was 1 % in our study. Internal herniation may be a serious complication in pregnant women, and both the diagnosis and treatment requires handling by experienced obstetrical, radiological, and surgical staff....... during pregnancy in a national cohort of women with a history of gastric bypass surgery. METHODS: A national, register-based cohort study of all Danish women with a history of gastric bypass surgery who had given birth from 2004 to 2010 was conducted. Surgical codes registered during pregnancy and until...... 120 days postpartum were identified in national registers, and the individual charts were reviewed in relevant cases. RESULTS: Of 286 women giving birth, fourteen women underwent procedures that might be related to the earlier gastric bypass surgery. Three women were operated on suspicion of internal...

The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

NARCIS (Netherlands)

Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M. J.; de Geus, Hilde H. R.; Scholten, Evert W.; de Mol, Bas A. J. M.; Ince, Can

2012-01-01

OBJECTIVES: To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery

Functional abdominal pain syndrome in morbidly obese patients following laparoscopic gastric bypass surgery.

Science.gov (United States)

Eidy, Mohammad; Pazouki, Abdolreza; Raygan, Fahimeh; Ariyazand, Yazdan; Pishgahroudsari, Mohadeseh; Jesmi, Fatemeh

2014-03-01

Roux-en-Y gastric bypass surgery (RYGBP) is one of the most common bariatric surgeries, which is being performed using various techniques like gastrojejunostomy by hand swen, linear or circular stapler. Abdominal pain is a common complaint following laparoscopic gastric bypass procedure (LGBP), which has different aetiologies, such as overeating, adhesion, internal herniation, bile reflux and many more. In this study LGBP was performed in an ante-colic ante-gastric pattern in a double loop manner and the prevalence and distribution of pain in morbidly obese patients undergoing LGBP was assessed. The aim of this study was to analyze the distribution and frequency of post LGBP pain in morbidly obese patients. This study was performed on 190 morbidly obese patients referred to Hazrat Rasoul Hospital in Tehran. After LGBP, pain was measured in the following intervals: 24 hours, one week and one month after the operation. Before the operation onset, 2 mg Keflin and 5000 IU subcutaneous heparin were administered as prophylaxis. LGBP was performed using five ports including: one 11 mm port was placed 15-20 cm far from the xiphoid, one 12-mm port in mid-clavicular line at the level of camera port, one 5-mm port in subcostal area in ante-axillary region in the left, another 5-mm port in the right mid-clavicular area and a 5-mm port in sub-xyphoid. All operations were done by the same team. Staple was used for all anastomoses and hand sewn technique to close the staple insertion site. The mesenteric defect was left open and no effort was made to repair it. The results of this study showed that 99.94 % of the patients had complains of pain in the first 24 hours of post operation, about 60% after one week and 29.5 % still had pain after one month. In addition, left upper quadrant (LUQ) was found to be the most prevalent site for the pain in 53.7% of the patients in the first 24 hours, 59.6% after one week and 16.8% after one month (except for obscure pain) with a significance

Influence of median surgeon operative duration on adverse outcomes in bariatric surgery.

Science.gov (United States)

Reames, Bradley N; Bacal, Daniel; Krell, Robert W; Birkmeyer, John D; Birkmeyer, Nancy J O; Finks, Jonathan F

2015-01-01

Evidence suggests that prolonged operative time adversely affects surgical outcomes. However, whether faster surgeons have better outcomes is unclear, as a surgeon׳s speed could reflect skill and efficiency, but may alternatively reflect haste. This study evaluates whether median surgeon operative time is associated with adverse surgical outcomes after laparoscopic Roux-en-Y gastric bypass. We performed a retrospective cohort study using statewide clinical registry data from the years 2006 to 2012. Surgeons were ranked by their median operative time and grouped into terciles. Multivariable logistic regression with robust standard errors was used to evaluate the influence of median surgeon operative time on 30-day surgical outcomes, adjusting for patient and surgeon characteristics, trainee involvement, concurrent procedures, and the complex interaction between these variables. A total of 16,344 patients underwent surgery during the study period. Compared to surgeons in the fastest tercile, slow surgeons required 53 additional minutes to complete a gastric bypass procedure (median [interquartile range] 139 [133-150] versus 86 [69-91], Ppatient characteristic only, slow surgeons had significantly higher adjusted rates of any complication, prolonged length of stay, emergency department visits or readmissions, and venous thromboembolism (VTE). After further adjustment for surgeon characteristics, resident involvement, and the interaction between these variables, slow surgeons had higher rates of any complication (10.5% versus 7.1%, P=.039), prolonged length of stay (14.0% versus 4.4%, P=.002), and VTE (0.39% versus .22%, P<.001). Median surgeon operative duration is independently associated with adjusted rates of certain adverse outcomes after laparoscopic Roux-en-Y gastric bypass. Improving surgeon efficiency while operating may reduce operative time and improve the safety of bariatric surgery. Copyright © 2015 American Society for Bariatric Surgery. Published by

CFD Validation with a Multi-Block Experiment to Evaluate the Core Bypass Flow in VHTR

International Nuclear Information System (INIS)

Yoon, Su Jong; Lee, Jeong Hun; Park, Goon Cherl; Kim, Min Hwan

2010-01-01

Core bypass flow of Very High Temperature Reactor (VHTR) is defined as the ineffective coolant which passes through the bypass gaps between the block columns and the crossflow gaps between the stacked blocks. This flows lead to the variation of the flow distribution in the core and affect the core thermal margin and the safety of VHTR. Therefore, bypass flow should be investigated and quantified. However, it is not a simple question, because the flow path of VHTR core is very complex. In particular, since dimensions of the bypass gap and the crossflow gap are of the order of few millimeters, it is very difficult to measure and to analyze the flow field at those gaps. Seoul National University (SNU) multi-block experiment was carried out to evaluate the bypass flow distribution and the flow characteristics. The coolant flow rate through outlet of each block column was measured, but the local flow field was measured restrictively in the experiment. Instead, CFD analysis was carried out to investigate the local phenomena of the experiment. A commercial CFD code CFX-12 was validated by comparing the simulation results and the experimental data

Effects of a pre-operative home-based inspiratory muscle training programme on perceived health-related quality of life in patients undergoing coronary artery bypass graft surgery.

Science.gov (United States)

Valkenet, K; Trappenburg, J C A; Hulzebos, E H; van Meeteren, N L U; Backx, F J G

2017-09-01

Pre-operative inspiratory muscle training has been shown to decrease the incidence of postoperative pneumonia and length of hospital stay in patients undergoing coronary artery bypass graft surgery (CABG). This study investigated if this decrease acted as a mediator on the time course of quality of life. Complementary analyses of a published randomised controlled trial. The initial trial included patients awaiting CABG surgery at a Dutch university hospital. The secondary analyses used data from the initial trial for patients who had completed at least one quality-of-life questionnaire. Participants were allocated at random to the intervention group or the usual care group. The intervention group followed a home-based pre-operative inspiratory muscle training programme. Quality of life was measured at five time points. Between-group differences in quality-of-life scores were analysed using mixed linear modelling. The secondary analyses used data for 235 patients. In line with the initial trial, pneumonia and length of hospital stay were decreased significantly in the intervention group. The time courses for all patients showed significant improvements in quality of life after surgery compared with baseline. No significant differences in quality of life were observed over time between the two groups. Despite decreased incidence of pneumonia and length of hospital stay in the intervention group, this study did not find any improvements in quality of life due to the pre-operative home-based inspiratory muscle training programme. Clinical trial registration number ISRCTN17691887. Copyright © 2016 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Conventional hemofiltration during cardiopulmonary bypass increases the serum lactate level in adult cardiac surgery

Directory of Open Access Journals (Sweden)

Rabie Soliman

2016-01-01

Full Text Available Objective: To evaluate the effect of hemofiltration during cardiopulmonary bypass on lactate level in adult patients who underwent cardiac surgery. Design: An observational study. Setting: Prince Sultan cardiac center, Riyadh, Saudi Arabia. Participants: The study included 283 patients classified into two groups: Hemofiltration group (n=138, hemofiltration was done during CPB. Control group (n = 145, patients without hemofiltration. Interventions: Hemofiltration during cardiopulmonary bypass. Measurements and Main Results: Monitors included hematocrit, lactate levels, mixed venous oxygen saturation, amount of fluid removal during hemofiltration and urine output. The lactate elevated in group H than group C (P < 0.05, and the PH showed metabolic acidosis in group H (P < 0.05. The mixed venous oxygen saturation decreased in group H than group C (P < 0.05. The number of transfused packed red blood cells was lower in group H than group C (P < 0.05. The hematocrit was higher in group H than group C (P < 0.05. The urine output was lower in group H than group C (P < 0.05. Conclusions: Hemofiltration during cardiopulmonary bypass leads to hemoconcentration, elevated lactate level and increased inotropic support. There are some recommendations for hemofiltration: First; Hemofiltration should be limited for patients with impaired renal function, positive fluid balance, reduced response to diuretics or prolonged bypass time more than 2 hours. Second; Minimal amount of fluids should be administered to maintain adequate cardiac output and reduction of priming volumes is preferable to maintain controlled hemodilution. Third; it should be done before weaning of or after cardiopulmonary bypass and not during the whole time of cardiopulmonary bypass.

FACT — STATUS AND FIRST RESULTS

Directory of Open Access Journals (Sweden)

Daniela Dorner

2014-06-01

Full Text Available FACT is the first imaging Cherenkov telescope based on a camera using solid state photosensors (Geigermode Avalanche Photodiodes G-APD aka SiPM. Since October 2011, it has been taking data regularly. Apart from commissioning and calibration measurements, it has already started regular operation, where the main goal is to do long-term monitoring of bright TeV blazars. In June 2012, a flare of Mrk 501 was observed. Thanks to the robustness of the G-APDs, observations can be carried out during strong moon light without aging of the sensors. This improves the duty cycle of the instrument and provides better statistics for long-term light curves. The telescope, situated on the Canary Island of La Palma, is operated, already now, remotely from central Europe. For the future, robotic operation is planned. We report on our experiences during the commissioning, and we present first results from the first 1.5 years of observations.

Coronary artery bypass surgery in a patient with Kartagener syndrome: a case report and literature review

Directory of Open Access Journals (Sweden)

Bougioukas Ioannis

2010-08-01

Full Text Available Abstract Kartagener syndrome consists of congenital bronchiectasis, sinusitis, and total situs inversus in half of the patients. A patient diagnosed with Kartagener syndrome was reffered to our department due to 3-vessel coronary disease. An off-pump coronary artery bypass operation was performed using both internal thoracic arteries and a saphenous vein graft. We performed a literature review for cases with Kartagener syndrome, coronary surgery and dextrocardia. Although a few cases of dextrocardia were found in the literature, no case of Kartagener syndrome was mentioned.

Hypothenar hammer syndrome and basilic bypass.

Science.gov (United States)

Chander, R K; Phair, J; Oza, P; Patel, M; Balar, N

2014-12-01

We report a case of hypothenar hammer syndrome. The case presents necessary diagnostic measures and discusses the etiology of this syndrome. Additionally, the case reviews treatments, which culminated in the eventual use of ulnar artery bypass with autogenous basilica vein to treat and resolve the ischemic fingers of the patient. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Influence of Diabetes on Long-Term Coronary Artery Bypass Graft Patency.

Science.gov (United States)

Raza, Sajjad; Blackstone, Eugene H; Houghtaling, Penny L; Rajeswaran, Jeevanantham; Riaz, Haris; Bakaeen, Faisal G; Lincoff, A Michael; Sabik, Joseph F

2017-08-01

Nearly 50% of patients undergoing coronary artery bypass grafting have diabetes. However, little is known about the influence of diabetes on long-term patency of bypass grafts. Because patients with diabetes have more severe coronary artery stenosis, we hypothesized that graft patency is worse in patients with than without diabetes. This study sought to examine the influence of diabetes on long-term patency of bypass grafts. From 1972 to 2011, 57,961 patients underwent primary isolated coronary artery bypass grafting. Of these, 1,372 pharmacologically treated patients with diabetes and 10,147 patients without diabetes had 15,887 postoperative angiograms; stenosis was quantified for 7,903 internal thoracic artery (ITA) grafts and 20,066 saphenous vein grafts. Status of graft patency across time was analyzed by longitudinal nonlinear mixed-effects modeling. ITA graft patency was stable over time and similar in patients with and without diabetes: at 1, 5, 10, and 20 years, 97%, 97%, 96%, and 96% in patients with diabetes, and 96%, 96%, 95%, and 93% in patients without diabetes, respectively (early p = 0.20; late p = 0.30). In contrast, saphenous vein graft patency declined over time and similarly in patients with and without diabetes: at 1, 5, 10, and 20 years, 78%, 70%, 57%, and 42% in patients with diabetes, and 82%, 72%, 58%, and 41% in patients without diabetes, respectively (early p < 0.002; late p = 0.60). After adjusting for patient characteristics, diabetes was associated with higher early patency of ITA grafts (odds ratio: 0.63; 95% confidence limits: 0.43 to 0.91; p = 0.013), but late patency of ITA grafts was similar in patients with and without diabetes (p = 0.80). Early and late patency of saphenous vein grafts were similar in patients with and without diabetes (early p = 0.90; late p = 0.80). Contrary to our hypothesis, diabetes did not influence long-term patency of bypass grafts. Use of ITA grafts should be maximized in patients

Triiodothyronine supplementation and cytokines during cardiopulmonary bypass in infants and children.

Science.gov (United States)

Priest, James R; Slee, April; Olson, Aaron K; Ledee, Dolena; Morrish, Fionnuala; Portman, Michael A

2012-10-01

The Triiodothyronine Supplementation in Infants and Children Undergoing Cardiopulmonary Bypass (TRICC) study demonstrated a shortened time to extubation in children younger than 5 months old undergoing cardiopulmonary bypass for congenital heart surgery with triiodothyronine supplementation. Cardiopulmonary bypass precipitates a systemic inflammatory response that affects recovery, and triiodothyronine is related to cytokine mediators of inflammation. We sought to investigate the preoperative cytokine levels by age and relationship to the triiodothyronine levels and to examine the effect of the cytokine levels on the time to extubation. We measured 6 cytokines at preoperative time 0 and 6 and 24 hours after crossclamp removal in 76 subjects. The preoperative cytokine levels were related to both the triiodothyronine levels and the patient age. The postoperative cytokine levels were predictive of the triiodothyronine levels at 6, 12, 24, and 72 hours. Preoperative CCL4 was associated with an increased chance of early extubation. Inclusion of the cytokines did not change the relationship of triiodothyronine to the time to extubation, and the postoperative course of interleukin-6 was independently associated with a decreased chance of early extubation. The preoperative and postoperative cytokine levels, in particular, interleukin-1β, showed complex time-dependent relationships with triiodothyronine. The data suggest that cytokine-mediated suppression of triiodothyronine plays an important role in determining the clinical outcome after cardiopulmonary bypass. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Myocardial metabolism during anaesthesia with propofol--low dose fentanyl for coronary artery bypass surgery

NARCIS (Netherlands)

Vermeyen, K. M.; de Hert, S. G.; Erpels, F. A.; Adriaensen, H. F.

1991-01-01

We have studied the haemodynamic and myocardial effects of propofol-fentanyl anaesthesia in 12 patients undergoing coronary artery bypass surgery during the pre-bypass period. The induction dose of propofol was 1.5 mg kg-1 and mean infusion rate during maintenance was 4.48 mg kg-1 h-1 (range

40 CFR 63.1569 - What are my requirements for HAP emissions from bypass lines?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What are my requirements for HAP emissions from bypass lines? 63.1569 Section 63.1569 Protection of Environment ENVIRONMENTAL PROTECTION... HAP emissions from bypass lines? (a) What work practice standards must I meet? (1) You must meet each...

Ruptured peroneal aneurysm after infrapopliteal prosthetic bypass with Taylor patch

Directory of Open Access Journals (Sweden)

Florian Enzmann

Full Text Available Introduction: A 45-year-old mailman underwent an implantation of a femoro-peroneal polytetrafluoroethylene (PTFE bypass with a distal Taylor patch six years prior to admission after two failed autologous reconstructions and extensive fasciotomy. The initial pathology was an acute ischemia due to popliteal entrapment with subsequent popliteal thrombectomy. Report: The patient was examined because of pain, reduction of walking distance and development of a palpable mass at the medial fasciotomy site. A 6-cm pseudoaneurysm with complete disruption of the suture line of the vein patch was discovered and resected. Arterial continuity with a vein interposition graft was established using non-reversed cephalic vein. Conclusion: The etiology of the aneurysm is not entirely clear. One may argue that the fourth revascularization could have been performed with an arm vein instead of a prosthetic graft with the probability of a better long term patency in a young patient. 15 months after the procedure the bypass is patent and the patient is without any symptoms. This complication of a Taylor patch has not been reported before. Keywords: Taylor patch, Pseudoaneurysm, Infrapopliteal bypass

Skeletonization of Left Internal Mammary Artery in Coronary Artery Bypass Grafting

International Nuclear Information System (INIS)

Chaudhri, M.S.; Shah, M.U.A.; Asghar, M.I.; Janjua, A.M.; Iqbal, A.; Siddiqi, R.

2016-01-01

Objective: To compare mean per-operative flow capacity between skeletonized and pedicled left internal mammary artery (LIMA) in patients undergoing coronary artery bypass grafting (CABG) surgery. Study Design: Randomized control trial. Place and Duration of Study: Department of Cardiac Surgery, Armed Forces Institute of Cardiology and National Institute of Heart Diseases (AFIC-NIHD), Rawalpindi, Pakistan from February to August, 2013. Methodology: Patients undergoing CABG for coronary artery disease, under 80 years, excluded by the exclusion criteria; and fulfilling the inclusion criteria were randomly assigned to two groups of 70 each. One group underwent skeletonized and the other underwent pedicled technique of LIMA harvesting. Free flow was checked just before anastamosis of each LIMA to the LAD, manually in blood flow in ml per minute during cardiopulmonary bypass by allowing it to bleed into a 100 ml container over 20 seconds. A specialized proforma was used to record the age, gender, weight, disease, type of IMA used, and free flow of the IMA. Data was analyzed using SPSS 18. Result: The mean age of the patients was 57.16 years in 40 patients, ranging from 36 to 75 years. Disease pattern analysis showed 5 percent, 10.7 percent and 84.3 percent single, double and triple vessel coronary artery disease, respectively. There was significantly higher free flow in the skeletonized group than the pedicled group (p=0.04). Conclusion: Skeletonized IMA had superior flow to pedicled IMA in addition to its traditional proven advantages, which justifies its further use as a conduit for myocardial revascularization. (author)

Facts about Glaucoma

Science.gov (United States)

... Information » Glaucoma » Facts About Glaucoma Listen Facts About Glaucoma This information was developed by the National Eye ... is the best person to answer specific questions. Glaucoma Defined What is Glaucoma? Glaucoma is a group ...

Double bypasses soxhlet apparatus for extraction of piperine from Piper nigrum

OpenAIRE

Subramanian, R.; Subbramaniyan, P.; Noorul Ameen, J.; Raj, V.

2016-01-01

A simple modified soxhlet extractor, double bypasses sidearm soxhlet apparatus (DBSA) was designed and employed for extraction of piperine from Piper nigrum. Total extraction time, time taken for a cycle and yield observed in the double bypass sidearm soxhlet apparatus was compared with the soxhlet apparatus. Extraction time, time taken for an extraction cycle and yield of crude piperine obtained in DBSA were 12 ± 1 h, 8 ± 1.00 min, and 3.90 ± 0.10 g whereas the results obtained in the soxhle...

Long-term internal thoracic artery bypass graft patency and geometry assessed by multidetector computed tomography

DEFF Research Database (Denmark)

Zacho, Mette; Damgaard, Sune; Lilleoer, Nikolaj Thomas

2012-01-01

The left internal thoracic artery (LITA) undergoes vascular remodelling when used for coronary artery bypass grafting. In this study we tested the hypothesis that the extent of the LITA remodelling late after coronary artery bypass grafting assessed by multidetector computed tomography is related...

Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

NARCIS (Netherlands)

Piers, LH; Dorgelo, J; Tio, RA; Jessurun, GAJ; Oudkerk, M; Zijlstra, F

This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic

Peripheral tissue metabolism during off-pump versus on-pump coronary artery bypass graft surgery: the microdialysis study.

Science.gov (United States)

Pojar, Marek; Mand'ák, Jirí; Cibícek, Norbert; Lonský, Vladimír; Dominik, Jan; Palicka, Vladimír; Kubícek, Jaroslav

2008-05-01

The aim of this study was to monitor and compare metabolic changes in the skeletal muscle during coronary artery bypass grafting surgery with and without cardiopulmonary bypass (CPB) by means of interstitial microdialysis. Glucose, lactate, pyruvate and glycerol were assessed as markers of basic metabolism and tissue perfusion. Twenty patients undergoing surgical myocardial revascularization were enrolled in this pilot study. Ten patients were operated on without CPB (group A, off-pump) and 10 patients using normothermic CPB (group B, on-pump). Interstitial microdialysis was performed by a CMA 60 (CMA/Microdialysis AB, Sweden) probe, inserted into the patient's left deltoid muscle. Microdialysis measurements were performed at 30 min intervals. Glucose, lactate, pyruvate and glycerol were measured in samples using a CMA 600 Analyser (CMA/Microdialysis AB, Sweden). Results in both groups were statistically processed and the groups were compared. Both groups were similar with regards to preoperative characteristics. Dynamic changes of interstitial concentrations of the measured analytes were found in off-pump (group A) and on-pump (group B) patients during the operation. There were no significant differences in dialysate concentrations of glucose and lactate between the groups. Significant differences were detected in pyruvate concentrations, lactate-pyruvate ratio and glycerol concentrations between off-pump versus on-pump patients. Pyruvate concentrations were higher in the off-pump group (plactate-pyruvate ratios indicating the aerobic/anaerobic metabolism status were lower in the off-pump group (pglucose, glycerol, pyruvate and lactate were found in both groups of patients (off-pump and on-pump). The presented preliminary results suggest that extracorporeal circulation during cardiac operations could compromise skeletal muscle energy metabolism.

Can local application of Tranexamic acid reduce post-coronary bypass surgery blood loss? A randomized controlled trial

Directory of Open Access Journals (Sweden)

Latter David

2009-06-01

Full Text Available Abstract Background Diffuse microvascular bleeding remains a common problem after cardiac procedures. Systemic use of antifibrinolytic reduces the postoperative blood loss. The purpose of this study was to examine the effectiveness of local application of tranexamic acid to reduce blood loss after coronary artery bypass grafting (CABG. Methods Thirty eight patients scheduled for primary isolated coronary artery bypass grafting were included in this double blind, prospective, randomized, placebo controlled study. Tranexamic acid (TA group (19 patients received 1 gram of TA diluted in 100 ml normal saline. Placebo group (19 patients received 100 ml of normal saline only. The solution was purred in the pericardial and mediastinal cavities. Results Both groups were comparable in their baseline demographic and surgical characteristics. During the first 24 hours post-operatively, cumulative blood loss was significantly less in TA group (median of 626 ml compared to Placebo group (median of 1040 ml (P = 0.04. There was no significant difference in the post-op Packed RBCs transfusion between both groups (median of one unit in each (P = 0.82. Significant less platelets transfusion required in TA group (median zero unit than in placebo group (median 2 units (P = 0.03. Apart from re-exploration for excessive surgical bleeding in one patient in TA group, no difference was found in morbidity or mortality between both groups. Conclusion Topical application of tranexamic acid in patients undergoing primary coronary artery bypass grafting led to a significant reduction in postoperative blood loss without adding extra risk to the patient.

Myocardial injury and protection related to cardiopulmonary bypass

NARCIS (Netherlands)

de Hert, Stefan; Moerman, Anneliese

2015-01-01

During cardiac surgery with cardiopulmonary bypass, the heart is isolated from the circulation. This inevitably induces myocardial ischemia. In addition to this ischemic insult, an additional hit will occur upon reperfusion, which may worsen the extent of tissue damage and organ dysfunction. Over

Gastrointestinal motility during cardiopulmonary bypass : A sonomicrometric study

NARCIS (Netherlands)

Gu, YJ; de Kroon, TL; Elstrodt, JM; Rakhorst, G

Cardiopulmonary bypass (CPB) is known to impair the integrity of the gastrointestinal tract. However, little is known about the movement behavior of the gastrointestinal tract during CPB. This study was aimed to assess the gastrointestinal motility with sonomicrometry, a distance measurement using

Comparison of changes in lipid profile after bilio-intestinal bypass and gastric banding in patients with morbid obesity.

Science.gov (United States)

Corradini, Stefano Ginanni; Eramo, Annarita; Lubrano, Carla; Spera, Giovanni; Cornoldi, Alessandra; Grossi, Antonio; Liguori, Francesca; Siciliano, Maria; Pisanelli, Massimo Codacci; Salen, Gerald; Batta, Ashok Kumir; Attili, Adolfo Francesco; Badiali, Marco

2005-03-01

The presence of hypercholesterolemia is currently not considered a selection criteria for performing gastric restrictive or diversionary bariatric surgery. We prospectively investigated the effects of the bilio-intestinal bypass (BI-bypass) with a wide cholecysto-jejunal anastomosis and of adjustable gastric banding (AGB) on blood lipid concentrations in obese patients. To clarify the mechanism of the hypocholesterolemic effect of the BI-bypass, daily fecal sterol excretion was measured by gas-liquid chromatography (GLC). At 1 year after BI-bypass compared to baseline, the hypercholesterolemic (n=18) and the normocholesterolemic (n=19) patients significantly reduced total (-38% and -27%, respectively), LDL (-47% and -24%, respectively) and HDL (-11% and -13%, respectively) cholesterol and total / HDL cholesterol ratio (-25% and -13%, respectively). At 1 year after AGB, the total / HDL cholesterol ratio was significantly decreased (-11%) compared to baseline in hypercholesterolemic (n=12) but not in normocholesterolemic (n=6) patients, while total and LDL cholesterol were not affected in both groups. At 3 years after BI-bypass compared to baseline, the hypercholesterolemic (n=9) and the normocholesterolemic (n=11) patients significantly reduced total (-43% and -28%, respectively) and LDL (-53% and -29%, respectively) cholesterol and total / HDL cholesterol ratio (-38% and -21%, respectively). The BI-bypass induced a significant (P <0.005; n=7) 6-fold increase in mean fecal cholesterol output. The BI-bypass but not the AGB leads to a persistent and marked beneficial effect on blood LDL cholesterol associated with an increased cholesterol fecal output. BI-bypass but not AGB is indicated in morbidly obese patients with hypercholesterolemia.

Management of broken instrument by file bypass technique

Directory of Open Access Journals (Sweden)

Sultana Parveen

2017-02-01

Full Text Available Different devices and techniques have been developed to retrieve fractured instruments during the endodontic procedures. This case report describes the management of a broken instrument, which was accidentally broken during cleaning and shaping of the root canal in right 2nd molar tooth. A # 25 stainless steel K-file was separated in mesiobuccal canal of the treated tooth. At first, a radiograph was taken to confirm the level of separation of the instrument. The instrument was found to be separated at the apical 3rd of the mesial canal and then file bypass technique was performed. Calcium hydroxide dressing was given for 7 days followed by obturation with guttapercha cone and zinc oxide eugenol sealer in lateral condensation technique. It can be concluded that bypass technique can be considered as simple and effective technique for the management of broken instrument into the root canal.

[TRANSPORT OF OXYGEN DURING GEOMETRICAL RECONSTRUCTION OF THE LEFT VENTRICLE IN CONJUNCTION WITH CORONARY ARTERY BYPASS GRAFTING AND USING OF HIGH THORACIC EPIDURAL ANESTHESIA AS A MAJOR COMPONENT OF GENERAL ANAESTHESIA].

Science.gov (United States)

Zatevahina, M V; Farzutdinov, A F; Rahimov, A A; Makrushin, I M; Kvachantiradze, G Y

2015-01-01

The purpose of the study is to examine the perioperative dynamics of strategic blood oxygen transport indicators: delivery (DO2), consumption (VO2), the coefficient of oxygen uptake (CUO2) and their composition, as well as the dynamics of blood lactate indicators in patients with ischaemic heart disease (IHD) who underwent surgery under cardiopulmonary bypass with high thoracic epidural anaesthesia (HTEA) as the main component of anesthesia. Research was conducted in 30 patients with a critical degree of operational risk, during the correction of post-infarction heart aneurysmn using the V. Dor method in combination with coronary artery bypass grafting. The strategic blood oxygen transport indicators (delivery, consumption and the oxygen uptake coefficient) showed a statistically significant decrease compared to the physiological norm and to the initial data at two points of the research: the intubation of the trachea and during cardiopulmonary bypass. The system components of oxygen were influenced at problematic stages by the dynamics of SvO2 (increase), AVD (decrease), hemodilution withe fall of the HIb- in the process of JR in the persence of superficial hypothermia. The maintenance of optimal CA in the context of HTEA, combined with a balanced volemic load and a minimized cardiotonic support ensured the stabilisation of strategic blood oxygen transport indicators aithe postperfusion stage and during the immediate postoperative period The article is dedicated to the study of strategic blood oxygen transport indicators and their components during the operation of geometric reconstruc-tion of the left ventricle combined with coronary artery-bypass using cardiopulmonary bypass and with high thoracic epidural anesthesia as the main component of general anaesthesia. The analysis has covered the stagewise delivery dynamics, consumption and the oxygen uptake coefficient at II stages of the operation and of the immediate postoperative period. The study has ident (fled

Alzheimer's Disease Facts and Figures

Medline Plus

Full Text Available ... Share the facts: Quick Facts Prevalence Mortality Caregivers Cost Special Report Alzheimer's in each state Quick Facts Share the facts: Prevalence The number of Americans living with Alzheimer's is growing — and growing fast. An ...

The Need for District Support for School Reform: What the Researchers Say. Research Brief.

Science.gov (United States)

Appelbaum, Deborah

This article focuses on the school district's role in implementing Comprehensive School Reform (CSR). Research shows that effective district support for CSR varies from district to district. This is due, in part, to the fact that many prior models bypassed the district, operating under the belief that reform would be more effective if it targeted…

Intraarterial digital subtraction angiography after coronary bypass surgery - an alternative to coronary angiography

International Nuclear Information System (INIS)

Hauenstein, H.K.; Roeren, T.; Schlosser, V.; Urbani, B.

1985-01-01

Intraarterial digital subtraction angiography after coronary bypass surgery - an alternative to coronary angiography. Intraarterial DSA is a suitable method for early postoperative control of coronary artery bypass grafts. Small quantities of contrast media with low iodine content are injected into the aortic root. Investigations can be carried out with a routine fluoroscopic and digital equipment; additional cine-technique and analogue memory disc are not necessary. At an image rate of 3/s the bypass anastomoses can be exactly visualized in 75%, whereas diagnostic information was not sufficient in only 4% of all cases. The use of modern F-5-catheters and the nonselective injection make this method a less invasive alternative to coronary angiography. It is paticularly useful in evaluation of short- and long-term results. (orig.) [de

Coronary artery bypass grafting and concomitant excision of chest wall chondrosarcoma

Directory of Open Access Journals (Sweden)

Ganti Somsekhar

2009-02-01

Full Text Available Abstract Coexistence of coronary artery disease and cancer with both requiring surgical treatment at the same time is rare. A 52 year male undergoing elective coronary artery bypass grafting was incidentally discovered to have a large soft tissue mass of variable consistency with cartilaginous elements arising from the right costal margin and adjoining ribs by a broad attachment and protruding into right pleural cavity. Frozen section suggested it to be either a chondrosarcoma or a teratoma. A wide excision of the mass with the adjoining muscle and periosteum along with quadruple coronary artery bypass grafting was done. This report is unusual on account of a being the first reported case in world literature of concomitant excision of chondrosarcoma and coronary artery bypass grafting and b the conservative management of the incidentally discovered chondrosarcoma by wide excision rather than chest wall resection with no local recurrence to date. Pathology of chondrosarcoma, in particular, and various management strategies when coronary artery disease and cancer coexist, in general, is discussed.

Blood-conservation techniques for coronary-artery bypass surgery at a private hospital.

Science.gov (United States)

Davies, M J; Picken, J; Buxton, B F; Fuller, J A

1988-11-21

The utilization of homologous blood and blood products was recorded in 100 consecutive patients who underwent primary coronary-artery bypass surgery. Nine patients underwent saphenous-vein grafts only, 55 patients underwent a single internal-mammary-artery graft that was supplemented by vein grafts and 36 patients underwent bilateral internal-mammary-artery grafts and vein grafts. All patients underwent normovolaemic haemodilution, and autologous blood was collected before bypass surgery. Residual blood was collected from the cardiopulmonary bypass machine and was washed and concentrated in a cell processor, and blood also was scavenged postoperatively from the mediastinal drainage tubes as methods to conserve blood. The mean (+/- SD) utilization of homologous blood was 1.3 +/- 1.5 units with 0.2 +/- 0.7 units of fresh-frozen plasma being used, and 0.8 +/- 2.1 units of platelets being used. The utilization of homologous blood was not different among the three different methods of coronary-artery bypass surgery, but patients who underwent bilateral internal-mammary-artery grafts suffered a greater postoperative loss of blood than did those patients who underwent saphenous-vein grafts or single internal-mammary-artery grafts. A comparison of patients who were taking aspirin or a non-steroidal anti-inflammatory drug preoperatively with those patients who were not showed no difference in the utilization of homologous blood but a statistically-significant difference was found in the loss of blood postoperatively.

Engineered Photorespiratory Bypass Pathways Improve Photosynthetic Efficiency and Growth as Temperature Increases

Science.gov (United States)

Cavanagh, A. P.; South, P. F.; Ort, D. R.; Bernacchi, C.

2017-12-01

In C3 plants grown under ambient [CO2] at 25°C, 23% of the fixed carbon dioxide is lost to photorespiration, the energy expensive metabolic pathway that recycles toxic compounds produced by Rubisco oxygenation reactions. Furthermore, rates of photorespiration increase with rising temperature, as higher temperatures favor increased Rubisco oxygenation. Modelling suggests that the absence of photorespiration could improve gross photosynthesis by 12-55% under projected climate conditions; however, this is difficult to measure empirically, as photorespiration interacts with several metabolic pathways and is an essential process for all C3 plants grown at ambient [O2]. Introduced biochemical bypasses to the native photorespiration pathway hold promise as a strategy to mitigate the impact of temperature on photorespiratory losses. We grew tobacco containing engineered pathways to bypass photorespiration under ambient and elevated temperatures (+5°C) in the field to determine if bypassing photorespiration could mitigate high temperature induced losses in growth and physiology. Our preliminary results show that engineered plants have a higher quantum efficiency under heated conditions than do non-engineered plants, resulting in up to 20% lower yield losses under heated conditions compared to non-engineered plants. These results support the theoretical modelling of temperature impacts on photorespiratory losses, and suggest the bypassing photorespiration could be an important strategy to increase crop yields.

Duodenal-jejunal bypass liner implantation provokes rapid weight loss and improved glycemic control, accompanied by elevated fasting ghrelin levels

NARCIS (Netherlands)

Koehestanie, P.; Dogan, K.; Berends, F.; Janssen, I.; Wahab, P.J.; Groenen, M.; Müller, M.R.; Wit, de N.J.W.

2014-01-01

Background and study aims: Endoscopic implantation of a duodenal-jejunal bypass liner (DJBL) is a novel bariatric technique to induce weight loss and remission of type 2 diabetes mellitus. Placement of the DJBL mimics the bypass component of the Roux-en-Y gastric bypass (RYGB) procedure. In this

Development trend of low bypass ratio turbofan engines. Tei baipasu hi tabo fan engine no kaihatsu doko

Energy Technology Data Exchange (ETDEWEB)

Yashima, S [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

1994-03-10

As a turbojet engine gets a thrust by blowing out the exhaust of a gas generator, for decreasing the fuel consumption ratio is more advantageous when a bypass air quantity is made as much as possible. Therefore in the subsonic speed passenger aircrafts putting an economy in the first place, the high bypass ratio turbofan engines are used. Even in case of the subsonic speed aircrafts, in addition, for the trainer airplanes and fighters, a type to be built in the engines in the fuselages, the low bypass ratio engines with small front areas are used. When a turbofan engine with a low bypass ratio is picked up, therefore recently, it is general that a military engine with a bypass ratio under 1 (about 0.5 is frequent) is pointed, as for a development trend also from a viewpoint of the performance improvement as a military engine, an improvement of the thrust-weight ratio and specific thrust are attached importance to. In this paper, these performance parameters, a trend to make them lighter weight, and the elementary technologies peculiar to a low bypass ratio engine are described, and moreover the study and development state in Europe, America and Japan are put in order. 8 refs., 14 figs., 2 tabs.

Operation efficiency increasing of dual-purpose NPP's by means of improving turbine plants

International Nuclear Information System (INIS)

Ivanov, V.A.; Borovkov, V.M.; Levit, I.G.; Averbakh, Yu.A.; Titova, I.B.

1984-01-01

Ways of operation efficiency increasing power plants for combined electrisity prodUction and centralized heating with WWER-440 reactors and wet-steam heating-condensating turbines are considered. Two variants of floWsheets of by-pass steam distribution permitting to use energy of excess steam in a wide pressure range in the secondary circuit for keeping electric or thermal power of the power unit at a possibly higher level are analyzed. Optimum time of operating cycle prolongation of a heating WWER-440 poWer unit when using the suggested flowsheets with pipelines of by-pass distribution of excess steam covers 16-40 days for the range of change in expenditures at reconstruction for electric power and heat 13.5-17 rub/MWxh and 2-3 rub./MWxh. The maximum time of the reactor operating cycle prolongation for the considered situations makes up 30-80 days

Performance of a surface bypass structure to enhance juvenile steelhead passage and survival at Lower Granite Dam, Washington

Science.gov (United States)

Adams, Noah S.; Plumb, John M.; Perry, Russell W.; Rondorf, Dennis W.

2014-01-01

An integral part of efforts to recover stocks of Pacific salmon Oncorhynchus spp. and steelhead O. mykiss in Pacific Northwest rivers is to increase passage efficacy and survival of juveniles past hydroelectric dams. As part of this effort, we evaluated the efficacy of a prototype surface bypass structure, the removable spillway weir (RSW), installed in a spillbay at Lower Granite Dam, Washington, on the Snake River during 2002, 2003, 2005, and 2006. Radio-tagged juvenile steelhead were released upstream from the dam and their route of passage through the turbines, juvenile bypass, spillway, or RSW was recorded. The RSW was operated in an on-or-off condition and passed 3–13% of the total discharge at the dam when it was on. Poisson rate models were fit to the passage counts of hatchery- and natural-origin juvenile steelhead to predict the probability of fish passing the dam. Main-effect predictor variables were RSW operation, diel period, day of the year, proportion of flow passed by the spillway, and total discharge at the dam. The combined fish passage through the RSW and spillway was 55–85% during the day and 37–61% during the night. The proportion of steelhead passing through nonturbine routes was 95% when the RSW was on during the day. The ratio of the proportion of steelhead passed to the proportion of water passing the RSW was from 6.3:1 to 10.0:1 during the day and from 2.7:1 to 5.2:1 during the night. Steelhead passing through the RSW exited the tailrace about 15 min faster than fish passing through the spillway. Mark–recapture single-release survival estimates for steelhead passing the RSW ranged from 0.95 to 1.00. The RSW appeared to be an effective bypass structure compared with other routes of fish passage at the dam.

Preliminary Results of the Influence of Duodenojejunal Bypass in a Porcine Model of Streptozotocin-Induced Diabetes Mellitus.

Science.gov (United States)

Hiridis, S; Konstantinidis, K; Menenakos, E; Diamantis, Th; Papalois, A; Zografos, G

2016-04-01

Type 2 diabetic obese patients present with a normalization of plasma glucose levels shortly after most bariatric procedures, before any significant weight loss takes place. There is only scarce literature in the new field of metabolic surgery, with most experiments being performed on small animal models. Our aim is to develop a reliable large animal model for assessment of surgical correction of diabetes. Titrated doses of streptozotocin (STZ) were used for induction of diabetes mellitus. After standardization of the surgical technique to avoid any restrictive component, three groups were created, a duodenojejunal bypass (DJB; n = 4), a gastroileal conduit (GIC; n = 3) near the ileocecal valve, and a sham (control; n = 5) group. Preoperative and postoperative glycemic curves were recorded by means of intravenous glucose tolerance tests. Body weight fluctuations were recorded as well. Diabetes was successfully induced with the use of STZ in all cases. Animals in the sham group remained diabetic for 3 weeks after operation. There was normalization of blood glucose levels in the operative groups during the 3-week postoperative follow-up, without significant body weight changes. The duodenojejunal group resulted in stronger positive response of glycemia. STZ-induced diabetes in swine leads to a reliable large animal model for assessment of metabolic surgical procedures. STZ is an effective but highly toxic means for inducing stable diabetes in the sensitive porcine model. Duodenojejunal bypass, although less invasive, seems to exert better antidiabetic effects than gastroileal conduit.

Management of Post-Traumatic Phlegmasia Cerulea Dolens via Right-to-Left Femoral Vein to Femoral Vein Bypass (Palma Procedure).

Science.gov (United States)

Dua, Anahita; Heller, Jennifer; Lee, Cheong

2017-11-01

Phlegmasia cerulea dolens (PCD) is a rare condition resulting from venous occlusion that impairs arterial flow. We report a rare case of post-traumatic PCD after ligation of the iliac vein with successful treatment by right-to-left femoral vein to femoral vein bypass using left great saphenous vein (Palma procedure). The clinical presentation, diagnostic process, and approach to management along with a literature review on the operative management of PCD are presented in this case report.

Synthesis of a hybrid model of the VSC FACTS devices and HVDC technologies

Science.gov (United States)

Borovikov, Yu S.; Gusev, A. S.; Sulaymanov, A. O.; Ufa, R. A.

2014-10-01

The motivation of the presented research is based on the need for development of new methods and tools for adequate simulation of FACTS devices and HVDC systems as part of real electric power systems (EPS). The Research object: An alternative hybrid approach for synthesizing VSC-FACTS and -HVDC hybrid model is proposed. The results: the VSC- FACTS and -HVDC hybrid model is designed in accordance with the presented concepts of hybrid simulation. The developed model allows us to carry out adequate simulation in real time of all the processes in HVDC, FACTS devices and EPS as a whole without any decomposition and limitation on their duration, and also use the developed tool for effective solution of a design, operational and research tasks of EPS containing such devices.

Synthesis of a hybrid model of the VSC FACTS devices and HVDC technologies

International Nuclear Information System (INIS)

Borovikov, Yu S; Gusev, A S; Sulaymanov, A O; Ufa, R A

2014-01-01

The motivation of the presented research is based on the need for development of new methods and tools for adequate simulation of FACTS devices and HVDC systems as part of real electric power systems (EPS). The Research object: An alternative hybrid approach for synthesizing VSC-FACTS and -HVDC hybrid model is proposed. The results: the VSC- FACTS and -HVDC hybrid model is designed in accordance with the presented concepts of hybrid simulation. The developed model allows us to carry out adequate simulation in real time of all the processes in HVDC, FACTS devices and EPS as a whole without any decomposition and limitation on their duration, and also use the developed tool for effective solution of a design, operational and research tasks of EPS containing such devices

Distinctive striatal dopamine signaling after dieting and gastric bypass.

Science.gov (United States)

Hankir, Mohammed K; Ashrafian, Hutan; Hesse, Swen; Horstmann, Annette; Fenske, Wiebke K

2015-05-01

Highly palatable and/or calorically dense foods, such as those rich in fat, engage the striatum to govern and set complex behaviors. Striatal dopamine signaling has been implicated in hedonic feeding and the development of obesity. Dieting and bariatric surgery have markedly different outcomes on weight loss, yet how these interventions affect central homeostatic and food reward processing remains poorly understood. Here, we propose that dieting and gastric bypass produce distinct changes in peripheral factors with known roles in regulating energy homeostasis, resulting in differential modulation of nigrostriatal and mesolimbic dopaminergic reward circuits. Enhancement of intestinal fat metabolism after gastric bypass may also modify striatal dopamine signaling contributing to its unique long-term effects on feeding behavior and body weight in obese individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impaired alcohol metabolism after gastric bypass surgery: a case-crossover trial.

Science.gov (United States)

Woodard, Gavitt A; Downey, John; Hernandez-Boussard, Tina; Morton, John M

2011-02-01

Severe obesity remains the leading public health crisis of the industrialized world, with bariatric surgery the only effective and enduring treatment. Poor psychological adjustment has been occasionally reported postoperatively. In addition, evidence suggests that patients can metabolize alcohol differently after gastric bypass. Preoperatively and at 3 and 6 months postoperatively, 19 Roux-en-Y gastric bypass (RYGB) patients' breath alcohol content (BAC) was measured every 5 minutes after drinking 5 oz red wine to determine peak BAC and time until sober in a case-crossover design preoperatively and at 6 months postoperatively. Patients reported symptoms experienced when intoxicated and answered a questionnaire of drinking habits. The peak BAC in patients after RYGB was considerably higher at 3 months (0.059%) and 6 months (0.088%) postoperatively than matched preoperative levels (0.024%). Patients also took considerably more time to return to sober at 3 months (61 minutes) and 6 months (88 minutes) than preoperatively (49 minutes). Postoperative intoxication was associated with lower levels of diaphoresis, flushing, and hyperactivity and higher levels of dizziness, warmth, and double vision. Postoperative patients reported drinking considerably less alcohol, fewer preferred beer, and more preferred wine than before surgery. This is the first study to match preoperative and postoperative alcohol metabolism in gastric bypass patients. Post-RYGB patients have much higher peak BAC after ingesting alcohol and require more time to become sober. Patients who drink alcohol after gastric bypass surgery should exercise caution. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Management of a case of left tracheal sleeve pneumonectomy under cardiopulmonary bypass: Anesthesia perspectives

Directory of Open Access Journals (Sweden)

Aman Jyoti

2014-01-01

Full Text Available The lung tumors with carinal involvement are frequently managed with tracheal sleeve pneumonectomy and tracheobronchial anastomosis without use of cardiopulmonary bypass (CPB. Various modes of ventilation have been described during tracheal resection and anastomosis. Use of CPB during this period allows the procedure to be conducted in a more controlled way. We performed tracheal sleeve pneumonectomy for adenoid cystic carcinoma of left lung involving carina. The surgery was performed in two stages. In the first stage, left pneumonectomy was performed and in the second stage after 48 h, tracheobronchial resection and anastomosis was performed under CPB. Second stage was delayed to avoid excessive bleeding (due to heparinization from the extensive vascular raw area left after pneumonectomy. Meticulous peri-operative planning and optimal post-operative care helped in successful management of a complex case, which is associated with high morbidity and mortality.

Hybrid Endovascular Aortic Aneurysm Repair: Preservation of Pelvic Perfusion with External to Internal Iliac Artery Bypass.

Science.gov (United States)

Mansukhani, Neel A; Havelka, George E; Helenowski, Irene B; Rodriguez, Heron E; Hoel, Andrew W; Eskandari, Mark K

2017-07-01

Diminished pelvic arterial flow as a result of intentional coverage/embolization of internal iliac arteries (IIA) during isolated endovascular common iliac artery aneurysm (CIAA) repair or endovascular repair of abdominal aortic aneurysms (EVAR) may result in symptomatic pelvic ischemia. Although generally well tolerated, in severe cases, pelvic ischemia may manifest as recalcitrant buttock claudication, vasculogenic impotence, or perineal, vesicle, rectal, and/or spinal cord ischemia. Branched graft technology has recently become available; however, many patients are not candidates for endovascular repair with these devices. Therefore, techniques to preserve pelvic arterial flow are needed. We reviewed our outcomes of isolated endovascular CIAA repair or EVAR in conjunction with unilateral external-internal iliac artery bypass. Single-center, retrospective review of 10 consecutive patients who underwent hybrid endovascular abdominal aortic aneurysm (AAA) or CIAA repair with concomitant external-internal iliac artery bypass between 2006 and 2015. Demographics, index procedural details, postoperative symptoms, hospital length of stay (LOS), follow-up imaging, and bypass patency were recorded. The cohort of 10 patients was all men with a mean age of 71 years (range: 56-84). Hybrid repair consisted of contralateral IIA coil embolization followed by EVAR with external iliac artery-internal iliac artery (EIA-IIA) bypass. All EIA-IIA bypasses were performed via a standard lower quadrant retroperitoneal approach with a prosthetic bypass graft. Technical success was 100%, and there were no perioperative deaths. One patient developed transient paraplegia, 1 patient had buttock claudication on the side of his hypogastric embolization contralateral to his iliac bypass, and 1 developed postoperative impotence. 20% of patients sustained long-term complications (buttock claudication and postoperative impotence). Mean LOS was 2.8 days (range: 1-9 days). Postoperative imaging

Prolonged successful therapy for hyperinsulinaemic hypoglycaemia after gastric bypass

DEFF Research Database (Denmark)

Myint, K S; Greenfield, J R; Farooqi, I S

2012-01-01

Spontaneous hyperinsulinaemic hypoglycaemia following gastric bypass surgery (GBS) is increasingly recognised. However, its pathophysiology remains unclear. Some patients require pancreatectomy. Medical therapy with calcium channel blockers, acarbose and diazoxide has been reported to be beneficial...

Intratracheal Milrinone Bolus Administration During Acute Right Ventricular Dysfunction After Cardiopulmonary Bypass.

Science.gov (United States)

Gebhard, Caroline Eva; Desjardins, Georges; Gebhard, Cathérine; Gavra, Paul; Denault, André Y

2017-04-01

To evaluate intratracheal milrinone (tMil) administration for rapid treatment of right ventricular (RV) dysfunction as a novel route after cardiopulmonary bypass. Retrospective analysis. Single-center study. The study comprised 7 patients undergoing cardiac surgery who exhibited acute RV dysfunction after cardiopulmonary bypass. After difficult weaning caused by cardiopulmonary bypass-induced acute RV dysfunction, milrinone was administered as a 5-mg bolus inside the endotracheal tube. RV function improvement, as indicated by decreasing pulmonary artery pressure and changes of RV waveforms, was observed in all 7 patients. Adverse effects of tMil included dynamic RV outflow tract obstruction (2 patients) and a decrease in systemic mean arterial pressure (1 patient). tMil may be an effective, rapid, and easily applicable therapeutic alternative to inhaled milrinone for the treatment of acute RV failure during cardiac surgery. However, sufficiently powered clinical trials are needed to confirm these findings. Copyright © 2017 Elsevier Inc. All rights reserved.

Redox-mediated bypass of restriction point via skipping of G1pm

Directory of Open Access Journals (Sweden)

Greene James J

2006-07-01

Full Text Available Abstract Background It is well known that cancer cells bypass the restriction point, R, and undergo uncontrolled cell proliferation. Hypothesis and evidence We suggest here that fibrosarcoma cells enter G1ps directly from M, skipping G1pm, hence bypassing R, in response to redox modulation. Evidence is presented from the published literature that demonstrate a shortening of the cycle period of transformed fibroblasts (SV-3T3 compared to the nontransformed 3T3 fibroblasts, corresponding to the duration of G1pm in the 3T3 fibroblasts. Evidence is also presented that demonstrate that redox modulation can induce the CUA-4 fibroblasts to bypass R, resulting in a cycle period closely corresponding to the cycle period of fibrosarcoma cells (HT1080. Conclusion The evidence supports our hypothesis that a low internal redox potential can cause fibrosarcoma cells to skip the G1pm phase of the cell cycle.

Assessment of Cerebrovascular Reserve before and after STA-MCA Bypass Surgery by SPECT and SPM Analysis

International Nuclear Information System (INIS)

O, Joo-Hyun; Jang, Kyung-Sool; Yoo, Ie-Ryung

2007-01-01

The purpose of this study was to objectively assess the efficacy of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery using Technetium (Tc)-99m-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients who underwent STA-MCA bypass surgery. Brain perfusion SPECT images obtained at baseline and after the administration of acetazolamide were reconstructed using statistical parametric mapping in 23 patients, both before and after STA-MCA bypass surgery. The clinical outcomes of the surgery were also recorded and compared with the hemodynamic changes. A voxel with an uncorrected p-value of less than 0.001 was considered to be statistically significant. SPECT images of the territory supplied by the bypass graft showed an increase in both cerebrovascular flow and reserve at baseline, and the increase was significantly higher following the administration of acetazolamide. All patients showed improvement of clinical symptoms and increased blood flow to the left temporal, parietal, and frontal cortices as well as the thalamus. Brain SPECT effectively and objectively demonstrated the improved outcomes of STA-MCA bypass surgery, and thus may be used in postoperative analyses

75 FR 62919 - Notice of Final Federal Agency Actions on the Route 250 Bypass Interchange at McIntire Road...

Science.gov (United States)

2010-10-13

... on the Route 250 Bypass Interchange at McIntire Road Project in Virginia AGENCY: Federal Highway.... 139(l)(1). The actions relate to the Route 250 Bypass Interchange at McIntire Road project in the City... Virginia: Route 250 Bypass Interchange at McIntire Road. The project would involve construction of a grade...

Effects of angiotensin-converting enzyme inhibition in low-risk patients early after coronary artery bypass surgery

NARCIS (Netherlands)

Rouleau, Jean L.; Warnica, Wayne J.; Baillot, Richard; Block, Pierre J.; Chocron, Sidney; Johnstone, David; Myers, Martin G.; Calciu, Cristina-Dana; Dalle-Ave, Sonia; Martineau, Pierre; Mormont, Christine; van Gilst, Wiek H.

2008-01-01

Background-Early after coronary artery bypass surgery (CABG), activation of numerous neurohumoral and endogenous vasodilator systems occurs that could be influenced favorably by angiotensin-converting enzyme inhibitors. Methods and Results-The Ischemia Management with Accupril post -bypass Graft via

Changes in hormones and biomarkers in polycystic ovarian syndrome treated with gastric bypass.

Science.gov (United States)

Eid, George M; McCloskey, Carol; Titchner, Rebecca; Korytkowski, Mary; Gross, Debra; Grabowski, Cynthia; Wilson, Mark

2014-01-01

Small retrospective studies have demonstrated reduction in weight and co-morbid hirsutism and diabetes in women with polycystic ovary syndrome (PCOS) treated with Roux-en-Y gastric bypass. The objective of this study was to prospectively determine clinical improvements in obese women with PCOS treated with gastric bypass and identify postoperative biomarker changes. Data were collected on obese women with PCOS undergoing Roux-en-Y gastric bypass over 1 year. Testosterone, follicle stimulating hormone, lutenizing hormone, insulin, fasting glucose, and lipid levels were obtained preoperatively at baseline, and 6 and 12 months after surgery. Testosterone was used as the primary hormonal biomarker. A physical examination for body mass index (BMI) and hirsutism, and information on menstrual pattern were collected at baseline and 3, 6, and 12 months after surgery. Data were available for 14 women. Mean BMI decreased from 44.8±5.9 kg/m(2) at baseline to 29.2±5.9 kg/m(2) at 12 months postoperatively. Significant improvements were seen in testosterone, fasting glucose, insulin, cholesterol, and triglyceride at 12 months (Pirregular menses were reported in 10 patients; all patients were experiencing regular menses 6 and 12 months after surgery. Hirsutism was present in 11 patients at baseline and only 7 patients at 12 months. Improvements in biomarkers, menstrual cycling, and hirsutism was not correlated with degree of weight change. Gastric bypass achieved significant reductions in BMI, testosterone, and markers of glucose and lipid metabolism. These data confirm reports of previous retrospective studies showing weight reduction and health improvement in women with PCOS treated with gastric bypass. Published by Elsevier Inc.

Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

Science.gov (United States)

Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

2003-01-01

OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and

Carotid disease in diabetic patients undergoing coronary artery bypass grafting

International Nuclear Information System (INIS)

Shahid, M.; Abid, A.R.; Dar, M.A.; Noeman, A.; Amin, S.; Azhar, M.

2012-01-01

Objective: To compare the severity of carotid artery disease in diabetic and non-diabetic patients undergoing coronary artery bypass grafting. Methods: From January to June 2008, 379 patients undergoing elective coronary artery bypass surgery were preoperatively evaluated for the presence of carotid stenoses by duplex scanning. Patients were divided into two groups, Group I, 156 (41.2%) diabetic patients and Group II, 223 (58.8%) non-diabetic patients. Results: There were 314 (82.8%) males and 65 (17.2%) females with a mean age of 57.2+-9.1 years. In diabetic group there were 125 (80.1%) males and 31 (19.9%) females with a mean age of 56.3+-8.9 years. Left main stem stenosis was present in 59 (37.8%) diabetics and 45 (20.2%) non-diabetics (p 70% stenosis was present in 20 (5.3%) with 13 (8.3%) diabetics and 7 (3.1%) non-diabetics (p<0.025). Stenosis of 50-70% was observed in 30 (7.9%) of which 17 (10.9%) were diabetics and 13 (5.8%) were non-diabetics. Conclusion: Presence of diabetes mellitus is associated with diffuse coronary artery disease and significant carotid artery disease in patients undergoing coronary artery bypass grafting. (author)

Breast cancer biomarkers predict weight loss after gastric bypass surgery

Directory of Open Access Journals (Sweden)

Sauter Edward R

2012-01-01

Full Text Available Abstract Background Obesity has long been associated with postmenopausal breast cancer risk and more recently with premenopausal breast cancer risk. We previously observed that nipple aspirate fluid (n levels of prostate specific antigen (PSA were associated with obesity. Serum (s levels of adiponectin are lower in women with higher body mass index (BMI and with breast cancer. We conducted a prospective study of obese women who underwent gastric bypass surgery to determine: 1 change in n- and s-adiponectin and nPSA after surgery and 2 if biomarker change is related to change in BMI. Samples (30-s, 28-n and BMI were obtained from women 0, 3, 6 and 12 months after surgery. Findings There was a significant increase after surgery in pre- but not postmenopausal women at all time points in s-adiponectin and at 3 and 6 months in n-adiponectin. Low n-PSA and high s-adiponectin values were highly correlated with decrease in BMI from baseline. Conclusions Adiponectin increases locally in the breast and systemically in premenopausal women after gastric bypass. s-adiponectin in pre- and nPSA in postmenopausal women correlated with greater weight loss. This study provides preliminary evidence for biologic markers to predict weight loss after gastric bypass surgery.

Presentation of a quality management program in off-pump coronary bypass surgery.

Science.gov (United States)

Bougioukakis, Petros; Kluegl, Stefan J; Babin-Ebell, Joerg; Tagarakis, Giorgios I; Mandewirth, Martin; Zacher, Michael; Diegeler, Anno

2014-01-01

To increase the number of off-pump coronary procedures at our institution, a new surgical team was formed. The first 3 years of "learning period" were accompanied by a quality management program aimed to control and adjust the surgical process and to ensure the safety and quality of the procedure. All patients were operated on by the same surgeon between January 2004 and December 2006; all procedures were performed under the following quality management protocol. First, a flow chart regulated surgical and anesthetic details. Second, an online file, named "disturbance file," was used to report work flow interruption, disturbance, and intraoperative events, that is, myocardial ischemia, hypotension, conversion to cardiopulmonary bypass, and any violation of the protocol. Each event was coded with 1 point and added to a score (the higher the score is, the greater the disturbance). Outcome parameters known as major events-major cardiac and cerebral events: mortality within 30 days/myocardial infarction confirmed by electrocardiogram or significantly high levels of total creatine kinase-myocardial muscle creatine kinase/reintervention within 30 days/stroke--and new-onset dialysis were also measured. Success was defined as freedom from any of those events and depicted in a cumulative sum control (CUSUM) chart. Outcome data and CUSUM were correlated with the intraoperative Disturbance Index. In total, 490 off-pump coronary bypass operations were performed by the named surgeon during the study period. The 30-day mortality was reduced from 4.0% to 1.9%. Disturbance Index score of greater than 1 declined from 41.6% to 23.3%. All major cardiac and cerebral events declined. The CUSUM chart showed two critical periods during the learning period, which made an adjustment of the protocol necessary. Quality management control is efficient in improving the postoperative results of a surgical procedure. A learning period is of cardinal importance for any new team wishing to engage

Stagnant loop syndrome resulting from small-bowel irradiation injury and intestinal by-pass

International Nuclear Information System (INIS)

Swan, R.W.

1974-01-01

Stagnant or blind-loop syndrome includes vitamin B12 malabsorption, steatorrhea, and bacterial overgrowth of the small intestine. A case is presented to demonstrate this syndrome occurring after small-bowel irradiation injury with exaggeration postenterocolic by-pass. Alteration of normal small-bowel flora is basic to development of the stagnant-loop syndrome. Certain strains of bacteria as Bacteriodes and E. coli are capable of producing a malabsorption state. Definitive therapy for this syndrome developing after severe irradiation injury and intestinal by-pass includes antibiotics. Rapid symptomatic relief from diarrhea and improved malabsorption studies usually follow appropriate antibiotic therapy. Recolonization of the loop(s) with the offending bacterial species may produce exacerbation of symptoms. Since antibiotics are effective, recognition of this syndrome is important. Foul diarrheal stools should not be considered a necessary consequence of irradiation injury and intestinal by-pass

Evaluation of the influence of bypass flow gap distribution on the core hot spot in a prismatic VHTR core

International Nuclear Information System (INIS)

Kim, Min-Hwan; Lim, Hong-Sik

2011-01-01

Highlights: → A procedure to evaluate the local gap size variation between graphite blocks was developed and applied to a prismatic core VHTR. → The analysis for the core bypass flow and hot spot was carried out based on the calculated gap distributions. → The predicted gap size is large enough to affect the flow distribution in the core. → The bypass gap and flow distributions are closely related to the local hot spot temperature and its location. → The core restraint mechanism preventing outward movement of graphite block reduces the bypass gap size and hot spot temperature. - Abstract: Core bypass flow in VHTR is one of the key issues for core thermal margins and efficiency. The bypass flow in the prismatic core varies during core cycles due to the irradiation shrinkage/swelling and thermal expansion of the graphite blocks. A procedure to evaluate the local gap size variation between graphite blocks was developed and applied to a prismatic core VHTR. The influence of the core restraint mechanism on the bypass flow gap was evaluated. The predicted gap size is as much as 8 mm when the graphite block is exposed to its allowable limit of fast neutron fluence. The analysis for the core bypass flow and hot spot was carried out based on the calculated gap distributions. The results indicate that the bypass gap and flow distributions are closely related to the local hot spot and its location and the core restraint mechanism preventing outward movement of the graphite block by a fastening device reduces the bypass gap size, which results in the decrease of maximum fuel temperature not less than 100 deg. C, when compared to the case without it.

Coronary artery bypass surgery in the diabetic patient.

LENUS (Irish Health Repository)

Maher, M

2012-02-03

Coronary artery and peripheral occlusive arterial disease frequently complicate diabetes mellitus, with death due to atherosclerotic coronary artery disease being three times more likely in diabetic compared to non-diabetic patients. The profile of 32 diabetic patients and 32 matched controls who underwent coronary artery bypass (CABG) is studied and their early and late postoperative outcomes are described. The mean age was 61 +\\/- 1 year in both groups. The diabetic group comprised 26 non-insulin dependent and 6 insulin dependent diabetics, who had a mean duration of diabetes of 8.5 years (range 2 months--35 years). The median number of grafts per patient performed in the diabetic group and the control group was 3.5 and 3 respectively. There was no mortality in the series, however considerably greater wound morbidity rates were encountered in the diabetic group when compared to matched controls. One renal transplant patient in the diabetic group suffered irreversible acute tubular necrosis and became dialysis dependent post-operatively. Longterm follow-up showed no longterm mortality in either group, with full relief of angina achieved in 75% of diabetic patients compared with 87.5% of matched controls. In addition diabetic patients suffered greater longterm cardiac morbidity than the control group (21.8% versus 12.5%). The results of this study suggest that CABG is a safe operation for the diabetic patient. Diabetic patients receive satisfactory symptomatic relief of angina, but suffer increased perioperative wound complications and greater incidence of longterm cardiac morbidity.

Are the Early Postoperative Outcomes of Coronary Artery Bypass Grafting Surgery in Elderly Women Worse Compared to Men's?

Directory of Open Access Journals (Sweden)

Ahmet Yüksel

Full Text Available Abstract Objective: To investigate the impact of gender difference in early postoperative outcomes in elderly patients (aged 70 or older undergoing coronary artery bypass grafting surgery. Methods: Between October 2009 and December 2013, a total of 223 elderly patients (aged 70 or older undergoing isolated primary coronary artery bypass grafting surgery were included in this retrospective observational cohort study. Patients were divided into two groups according to their gender. The patients' medical records were collected, their baseline preoperative characteristics, operative data, and postoperative outcomes were retrospectively reviewed, and the effect of gender difference in the early postoperative outcomes was analyzed. Results: Group 1 (female patients and Group 2 (male patients consisted of 71 and 152 patients, respectively. Mean age of patients was 74.4±3.6 years (range: 70-84 years. The level of EuroSCORE I, the incidence of hypertension and hyperlipidemia were significantly higher in Group 1, while the rate of smoking was significantly higher in Group 2. Mean postoperative intubation time, length of intensive care unit and hospital stay were longer in female patients than in male patients, but these differences were not statistically significant. No statistically significant difference between two groups in terms of the transfusion of blood products was observed. The rates of in-hospital mortality and major postoperative complications were statistically similar between the two groups. Conclusion: In conclusion, the female gender was not associated with worse early postoperative outcomes in elderly patients undergoing coronary artery bypass grafting surgery.

Oxide fuel fabrication technology development of the FaCT project (1). Overall review of fuel technology development of the FaCT project

International Nuclear Information System (INIS)

Abe, Tomoyuki; Namekawa, Takashi; Tanaka, Kenya

2011-01-01

The FaCT project is in progress in Japan for the commercialization of fast reactor cycle system. The development goal of the fuel in the FaCT project is a low-decontaminated TRU homo-recycling in a closed cycle and extension in average discharge burn-up to 150 GWd/t. Research and development on innovative technologies concerning the short process, remote maintenance and cooling system of automatic fuel production equipments, long life cladding material and control of oxygen potential have been conducted in phase I of the FaCT project. As the result of various test including 600 g batch MOX tests, it is concluded that the short process is available to fuel pellet fabrication of the FaCT project. Although cold mock-up tests on test model of some typical process equipments suggest possibilities of remote maintenance of automatic fuel fabrication equipment, it is concluded that it still needs further efforts to judge the operability of the completely remote fabrication for low-decontaminated TRU fuel. A cold mock-up test on fuel pin assembling equipment show that influence of decay heat of MA can be managed by cooling system. Irradiation tests in BOR-60 indicate that 9Cr-ODS possess the satisfactory in-reactor performance as the long life cladding material if homogeneity of alloy element is adequately controlled. Modification of cladding tube fabrication process to ensure homogeneity and further development of measures to control oxygen potential inside the fuel pin are necessary to reach the burn-up target of the FaCT project. (author)

Patient-controlled analgesia after coronary bypass: Remifentanil or sufentanil?

Science.gov (United States)

Alavi, Seyed Mostafa; Ghoreishi, Seyed Mohammadmehran; Chitsazan, Mitra; Ghandi, Iman; Fard, Alireza Jahangiri; Hosseini, Seyed Saeed; Mahjoobifard, Maziar; Fani, Kamal

2014-07-01

adequate pain control after cardiac surgery is mandatory to reduce its remarkable morbidity. In this study, we aimed to compare the efficacy of patient-controlled analgesia with remifentanil or sufentanil for pain management after coronary artery bypass grafting. 249 patients who underwent coronary artery bypass were randomly assigned to receive patient-controlled analgesia with remifentanil or sufentanil during the first 24 h postoperatively. Pain intensity during patient-controlled analgesia was assessed using 4 different pain rating scales. patients given remifentanil had lower Visual Analog Scale scores at 24 h compared to those given sufentanil (p = 0.002). The Numeric Rating Scale at 24 h was also significantly lower in patients using remifentanil (p = 0.004). The Faces Pain Scale scores at 4, 18, and 24 h were significantly lower in patients using remifentanil compared to those using sufentanil (p = 0.045, 0.036, and 0.011, respectively). No significant differences between groups were seen in the pain intensity assessed by the Behavior Rating Scale at any time point during the first 24 h postoperatively. our study showed that both remifentanil and sufentanil patient-controlled analgesia can provide acceptable analgesia after coronary artery bypass. The difference between their efficacies was inconspicuous until 24 h postoperatively. Remifentanil seems to result in better pain relief at 24 h postoperatively. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Functional Dissection of the Blocking and Bypass Activities of the Fab-8 Boundary in the Drosophila Bithorax Complex.

Science.gov (United States)

Kyrchanova, Olga; Mogila, Vladic; Wolle, Daniel; Deshpande, Girish; Parshikov, Alexander; Cléard, Fabienne; Karch, Francois; Schedl, Paul; Georgiev, Pavel

2016-07-01

Functionally autonomous regulatory domains direct the parasegment-specific expression of the Drosophila Bithorax complex (BX-C) homeotic genes. Autonomy is conferred by boundary/insulator elements that separate each regulatory domain from its neighbors. For six of the nine parasegment (PS) regulatory domains in the complex, at least one boundary is located between the domain and its target homeotic gene. Consequently, BX-C boundaries must not only block adventitious interactions between neighboring regulatory domains, but also be permissive (bypass) for regulatory interactions between the domains and their gene targets. To elucidate how the BX-C boundaries combine these two contradictory activities, we have used a boundary replacement strategy. We show that a 337 bp fragment spanning the Fab-8 boundary nuclease hypersensitive site and lacking all but 83 bp of the 625 bp Fab-8 PTS (promoter targeting sequence) fully rescues a Fab-7 deletion. It blocks crosstalk between the iab-6 and iab-7 regulatory domains, and has bypass activity that enables the two downstream domains, iab-5 and iab-6, to regulate Abdominal-B (Abd-B) transcription in spite of two intervening boundary elements. Fab-8 has two dCTCF sites and we show that they are necessary both for blocking and bypass activity. However, CTCF sites on their own are not sufficient for bypass. While multimerized dCTCF (or Su(Hw)) sites have blocking activity, they fail to support bypass. Moreover, this bypass defect is not rescued by the full length PTS. Finally, we show that orientation is critical for the proper functioning the Fab-8 replacement. Though the inverted Fab-8 boundary still blocks crosstalk, it disrupts the topology of the Abd-B regulatory domains and does not support bypass. Importantly, altering the orientation of the Fab-8 dCTCF sites is not sufficient to disrupt bypass, indicating that orientation dependence is conferred by other factors.

THE BASIC LAWS AND FEATURES OF CYTOKINE DYNAMICS IN PROCESS AND EARLY TERMS AFTER CARDIOPULMONARY BYPASS

Directory of Open Access Journals (Sweden)

S. I. Suskov

2011-01-01

Full Text Available The basic variants of cytokines reactions defining type of organ dysfunctions are revealed in the course of car- diopulmonary bypass and in the early postoperative period. Their character and expression, depends on gravity preoperative an immunodeficiency and initial degree of heart insufficiency. Diphasic dynamics of development of system inflammatory reaction is confirmed after cardiopulmonary bypass: increase of levels proinflammatory cytokines is in the first phase and anti-inflammatory cytokines with development immunodepression and cellular anergy in is the second phase. Also, key role IL-1Ra is revealed in restraint of hyperactivation of system inflam- matory reaction. Blood whey levels IL-6, IL-8, G-CSF, TNF-α and IL-1Ra should be defined to cardiopulmonary bypass, in 10–12 hours, 24 hours and 3 days after cardiopulmonary bypass and may be used as prognostic criteria of development of postoperative complications. 

78 FR 14117 - Draft Environmental Impact Statement/Environmental Impact Report for Yolo Bypass Salmonid Habitat...

Science.gov (United States)

2013-03-04

...The Bureau of Reclamation and California Department of Water Resources intend to prepare an environmental impact statement/ environmental impact report (EIS/EIR) for the implementation of actions I.6.1 and I.7 identified in the National Marine Fisheries Service's 2009 Biological Opinion and Conference Opinion on the Long-term Operation of the Central Valley Project and State Water Project Reasonable and Prudent Alternative. These actions consist of salmonid habitat restoration efforts within the lower Sacramento River basin and fish passage through the Yolo Bypass. We are seeking suggestions and information on the alternatives and topics to be addressed and any other important issues related to the proposed action.

Coronary artery bypass grafting and sensorineural hearing loss, a cohort study

Directory of Open Access Journals (Sweden)

Ashraf Omer

2005-12-01

Full Text Available Abstract Background Sudden sensorineural hearing loss is routinely encountered by the otologist. The etiology is varied and often identifiable. One of the relatively less frequent causes is surgery. Apart from being an established entity with otological surgeries, sensorineural hearing loss has also been known to occur after non-otological procedures under general anesthesia. Commonest amongst these procedures is cardiopulmonary bypass, an association that has long been recognized. However, despite the proposition of diverse hypotheses in the past, the pathophysiology remains unclear. Methods The study is a prospective matched cohort study that will be carried out in Aga Khan University Hospital, Karachi, Pakistan. Participants among exposed would include all those patients who would be undergoing coronary artery bypass surgery in the hospital who fall under the criteria for inclusion. Unexposed group would comprise of patients undergoing a non-bypass procedure of similar duration under the same type of anesthesia who meet the selection criteria. Both these groups will undergo audiometric testing at our hospital on three different occasions during the course of this study. Initially before the procedure to test the baseline hearing capacity; then one week after the procedure to assess any changes in hearing ability following the surgery; and finally a third audiogram at six weeks follow-up to assess further changes in any hearing deficits noted during the second phase of testing. Certain variables including the subjects' demographics and those concerning the procedure itself will be noted and used later for risk factors analysis. A detailed past medical and surgical history will also be obtained. Data analysis would include calculation of relative risk and significance of the results, by running the chi-square test. Other statistical tests like Fisher exact test may then be employed to facilitate data interpretation. Continuous scale may then be

Transfusion practice in coronary artery bypass surgery in Denmark: a multicenter audit

DEFF Research Database (Denmark)

Andreasen, J.J.; Westen, M; Pallesen, PA

2007-01-01

of antifibrinolytic drugs, use of cardiopulmonary bypass (CPB), cross-clamp time, time on CPB, lowest hemoglobin during CPB, and number of distal anastomoses. The percentage of patients transfused with allogeneic red blood cells ranged from 30.0% to 64.2%. Several patients (12.1-42.7%) transfused with red blood cells......Transfusion rates in coronary artery bypass grafting (CABG) continue to vary substantially, although guidelines for allogeneic transfusion have been developed. In order to evaluate ongoing transfusion practices, we performed a multicenter audit in four Danish hospitals regarding the use...

Endovascular management of an acquired aortobronchial fistula following aortic bypass for coarctation.

LENUS (Irish Health Repository)

O'Sullivan, Katie E

2013-09-20

Aortobronchial fistula (ABF) in the setting of aortic coarctation repair is very rare but uniformly fatal if untreated. Endovascular stenting of the descending aorta is now the first-choice approach for ABF presenting with haemoptysis and offers a less-invasive technique with improved outcomes, compared with open repair. We report a case of late ABF occurring following bypass for aortic coarctation. Management focused on two key manoeuvres: use of a covered endovascular stent to occlude the aortic bypass thus controlling the fistula and dilatation and stenting of native coarctation.

Perioperative pentoxifylline therapy attenuates early postoperative neuro-cognitive decline in patients undergoing coronary artery bypass grafting surgery using cardiopulmonary bypass

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Sambhunath Das

2015-01-01

Full Text Available Background: Postoperative cognitive decline (POCD after coronary artery bypass grafting (CABG is a common problem. Studies show that pentoxifylline administration reduces inflammation induced by cardiopulmonary bypass and brain injury after ischaemia. Hence the perioperative use of pentoxifylline in attenuating POCD was evaluated in the study. Materials and Methods: Eighty patients were divided randomly into two groups from 106 patients scheduled for CABG surgery. The study group was administered pentoxifylline 400 mg twice daily orally from day of admission to 7th day after surgery, whereas the control group patients received placebo. Neurocognitive assessment was assessed by an independent clinical psychologist one day after admission to hospital and again on 7th postoperative day. The data was analyzed and a P < 0.05 was considered significant results. Results: Pentoxifylline-treated group showed no statistically significant difference in animal naming test scores (10.3 ± 2.2 versus 9.4 ± 2.5, P = 0.07, digit symbol substitution test (26.1 ± 7.47 vs 22.2 ± 6.07, P = 0.09 and 8 subtests of Post Graduate Institute-memory scale. The control group had significant POCD as detected by animal naming test (10.5 ± 3.7 versus 8.6 ± 3.9, P = 0.008, digit symbol substitution test (20.2 ± 8.2 versus 14.7 ± 8.9, P = 0.008 and five subtests of memory scale (P = 0.01, 0.04, 0.003, 0.005 and 0.02. The incidence of POCD was 50% in placebo-treated group compared to 22.5% in pentoxifylline group. Conclusions: The perioperative use of pentoxifylline attenuates the early postoperative neurocognitive decline after CABG using cardiopulmonary bypass.

Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate

Science.gov (United States)

Kamman, J. H.; Hall, C. L.

1975-01-01

Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

Hemoglobin Level to Facilitate Off-Pump Coronary Artery Bypass without Transfusion.

Science.gov (United States)

Kim, Kun Il; Lee, Won Yong; Ko, Ho Hyun; Kim, Hyoung Soo; Jeong, Jae Han

2014-08-01

Conservation of blood during cardiac surgery is important because of the shortage of donor blood, risks associated with transfusion, and the costs of allogeneic blood products. This retrospective study explored the feasibility of off-pump coronary artery bypass (OPCAB) without transfusion. One hundred and two consecutive patients underwent OPCAB from January 2007 to June 2012 at Hallym University Sacred Heart Hospital. Excluding 10 chronic renal failures patients, 102 patients were enrolled. Their characteristics, clinical data, and laboratory data were analyzed. We investigated the success rate of OPCAB without transfusion according to pre-operative hemoglobin (Hb), and the cutoff point of the Hb level and the risk factors for transfusion. We implemented multidisciplinary blood-saving protocols. The overall operative mortality and the success rate of OPCAB without transfusion were 2.9% (3/102) and 73.5% (75/102). The success rates in patients with Hb70 years, diagnosis of acute myocardial infarction, preoperative Hb and creatinine levels, and operation time. The events precipitating the need for transfusion were low Hb level in 9 patients and hypotension or excessive bleeding in 18 patients. The preoperative Hb level of >11 facilitates OPCAB without transfusion. These results suggest that transfusion-free OPCAB can be performed by modifying the risk factors and correctable causes of transfusion and improving various blood salvage methods.

Effects of massage therapy on sleep quality after coronary artery bypass graft surgery.

Science.gov (United States)

Nerbass, Flavia Baggio; Feltrim, Maria Ignez Zanetti; Souza, Silvia Alves de; Ykeda, Daisy Satomi; Lorenzi-Filho, Geraldo

2010-01-01

Having poor sleep quality is common among patients following cardiopulmonary artery bypass graft surgery. Pain, stress, anxiety and poor sleep quality may be improved by massage therapy. This study evaluated whether massage therapy is an effective technique for improving sleep quality in patients following cardiopulmonary artery bypass graft surgery. Participants included cardiopulmonary artery bypass graft surgery patients who were randomized into a control group and a massage therapy group following discharge from the intensive care unit (Day 0), during the postoperative period. The control group and the massage therapy group comprised participants who were subjected to three nights without massage and three nights with massage therapy, respectively. The patients were evaluated on the following mornings (i.e., Day 1 to Day 3) using a visual analogue scale for pain in the chest, back and shoulders, in addition to fatigue and sleep. Participants kept a sleep diary during the study period. Fifty-seven cardiopulmonary artery bypass graft surgery patients were enrolled in the study during the preoperative period, 17 of whom were excluded due to postoperative complications. The remaining 40 participants (male: 67.5%, age: 61.9 years ± 8.9 years, body mass index: 27.2 kg/m² ± 3.7 kg/m²) were randomized into control (n = 20) and massage therapy (n = 20) groups. Pain in the chest, shoulders, and back decreased significantly in both groups from Day 1 to Day 3. The participants in the massage therapy group had fewer complaints of fatigue on Day 1 (p=0.006) and Day 2 (p=0.028) in addition, they reported a more effective sleep during all three days (p=0.019) when compared with the participants in the control group. Massage therapy is an effective technique for improving patient recovery from cardiopulmonary artery bypass graft surgery because it reduces fatigue and improves sleep.

Percutaneous transhepatic biliary stenting vs. surgical bypass in advanced malignant biliary obstruction: cost- effectiveness analysis.

Science.gov (United States)

Yao, Li Qin; Tang, Cheng Wu; Zheng, Yin Yuan; Feng, Wen Ming; Huang, San Xiong; Bao, Ying

2013-01-01

This study aims to compare the clinical outcomes and costs between percutaneous transhepatic biliary stenting (PTBS) and surgical bypass. We randomly assigned 142 patients with unresectable malignant biliary obstruction between 2005 and 2010 to receive PTBS or surgical bypass as palliative treatment. PTBS was successfully performed in 70 patients who formed the PTBS group (failed in 7 patients). Sixty five patients underwent surgical bypass treatment. Additional gastrojejunostomy was performed in five patients. The effectiveness of biliary drainage, hospital stay, complications, cost, survival time and mortality were compared. Patients in PTBS group had shorter hospital stay and lower initial and overall expense than the surgical group (pPTBS group was significantly lower than surgical group (3/75 vs. 11/65, p=0.0342). Late complication in PTBS group did not differ significantly from surgical group (9/70 vs. 6/65, p=0.6823). The survival curves in the two groups showed no significant difference (p=0.1032). PTBD is a better palliative treatment than surgical bypass for unresectable malignant biliary obstruction for its high effectiveness of biliary drainage and acceptable expense and complication.

Efficacy of duplex ultrasound surveillance after infrainguinal vein bypass may be enhanced by identification of characteristics predictive of graft stenosis development.

Science.gov (United States)

Tinder, Chelsey N; Chavanpun, Joe P; Bandyk, Dennis F; Armstrong, Paul A; Back, Martin R; Johnson, Brad L; Shames, Murray L

2008-09-01

Controversy regarding the efficacy of duplex ultrasound surveillance after infrainguinal vein bypass led to an analysis of patient and bypass graft characteristics predictive for development of graft stenosis and a decision of secondary intervention. Retrospective analysis of a contemporary, consecutive series of 353 clinically successful infrainguinal vein bypasses performed in 329 patients for critical (n = 284; 80%) or noncritical (n = 69; 20%) limb ischemia enrolled in a surveillance program to identify and repair duplex-detected graft stenosis. Variables correlated with graft stenosis and bypass repair included: procedure indication, conduit type (saphenous vs nonsaphenous vein; reversed vs nonreversed orientation), prior bypass graft failure, postoperative ankle-brachial index (ABI) < 0.85, and interpretation of the first duplex surveillance study as "normal" or "abnormal" based on peak systolic velocity (PSV) and velocity ratio (Vr) criteria. Overall, 126 (36%) of the 353 infrainguinal bypasses had 174 secondary interventions (endovascular, 100; surgery, 74) based on duplex surveillance; resulting in 3-year Kaplan-Meier primary (46%), assisted-primary (80%), and secondary (81%) patency rates. Characteristics predictive of duplex-detected stenosis leading to intervention (PSV: 443 +/- 94 cm/s; Vr: 8.6 +/- 9) were: "abnormal" initial duplex testing indicating moderate (PSV: 180-300 cm/s, Vr: 2-3.5) stenosis (P < .0001), non-single segment saphenous vein conduit (P < .01), warfarin drug therapy (P < .01), and redo bypass grafting (P < .001). Procedure indication, postoperative ABI level, statin drug therapy, and vein conduit orientation were not predictive of graft revision. The natural history of 141 (40%) bypasses with an abnormal first duplex scan differed from "normal" grafts by more frequent (51% vs 24%, P < .001) and earlier (7 months vs 11 months) graft revision for severe stenosis and a lower 3-year assisted primary patency (68% vs 87%; P < .001). In 52

Brain Aneurysm Statistics and Facts

Science.gov (United States)

... Statistics and Facts A- A A+ Brain Aneurysm Statistics and Facts An estimated 6 million people in ... Understanding the Brain Warning Signs/ Symptoms Brain Aneurysm Statistics and Facts Seeking Medical Attention Risk Factors Aneurysm ...

Association between serum lactate and postoperative outcomes following coronary artery bypass graft surgery

Directory of Open Access Journals (Sweden)

Fatemeh Hasanshiri

2017-02-01

Full Text Available Background: Increased serum lactate during cardio-pulmonary bypass is associated with high mortality and cardiac complications up to 10-20 percent. The aim of this study was to evaluate the effect of serum lactate increase on postoperative outcomes after coronary artery bypass graft (CABG Surgery. Materials and Methods: This descriptive-analytical study was performed on cases (no=116 undergoing CABG at Beheshti hospital in Kashan between 2013-2014. Demographic data, variables related to surgery, serum lactate level and the time of tracheal extubation, length of stay in intensive care unit (ICU and hospital post-surgery left ventricular ejection fraction were collected. These data was compared in two groups: Normal serum lactate ( 2 m mol\\liter group. Results: The postoperative hyperlactatemia was observed in 62.1 % of patients. There were no significant differences between two groups in time of tracheal extubation, length of stay in ICU and hospital. There was a relationship between the mean postoperative serum lactate and blood sugar, bicarbonate, pH, length of cardiopulmonary bypass and the aortic cross clamping time. There was a significant relationship between the serum lactate increment and the left ventricular ejection fraction decrement. Conclusion: Hyperlactatemia is probably associated with such important factors as high blood sugar, longer duration of aortic cross clamp and cardio-pulmonary bypass time. So controlling such factors can reduce the rate of hyperlactatemia and help postoperative recovery.

A Delphi Consensus of the Crucial Steps in Gastric Bypass and Sleeve Gastrectomy Procedures in the Netherlands.

Science.gov (United States)

Kaijser, Mirjam A; van Ramshorst, Gabrielle H; Emous, Marloes; Veeger, Nic J G M; van Wagensveld, Bart A; Pierie, Jean-Pierre E N

2018-04-09

Bariatric procedures are technically complex and skill demanding. In order to standardize the procedures for research and training, a Delphi analysis was performed to reach consensus on the practice of the laparoscopic gastric bypass and sleeve gastrectomy in the Netherlands. After a pre-round identifying all possible steps from literature and expert opinion within our study group, questionnaires were send to 68 registered Dutch bariatric surgeons, with 73 steps for bypass surgery and 51 steps for sleeve gastrectomy. Statistical analysis was performed to identify steps with and without consensus. This process was repeated to reach consensus of all necessary steps. Thirty-eight participants (56%) responded in the first round and 32 participants (47%) in the second round. After the first Delphi round, 19 steps for gastric bypass (26%) and 14 for sleeve gastrectomy (27%) gained full consensus. After the second round, an additional amount of 10 and 12 sub-steps was confirmed as key steps, respectively. Thirteen steps in the gastric bypass and seven in the gastric sleeve were deemed advisable. Our expert panel showed a high level of consensus expressed in a Cronbach's alpha of 0.82 for the gastric bypass and 0.87 for the sleeve gastrectomy. The Delphi consensus defined 29 steps for gastric bypass and 26 for sleeve gastrectomy as being crucial for correct performance of these procedures to the standards of our expert panel. These results offer a clear framework for the technical execution of these procedures.

Efficacy, complications, and cost of a comprehensive blood conservation program for cardiac operations.

Science.gov (United States)

Scott, W J; Rode, R; Castlemain, B; Kessler, R; Follis, F; Pett, S B; Wernly, J A

1992-05-01

We reviewed blood use in 118 consecutive patients who underwent primary, elective cardiac operations in 1989. In June 1989 we initiated a blood conservation program that included attempts to limit preoperative aspirin use, intraoperative phlebotomy and hemodilution, use of a cell conservation device (Electromedics, Inc., Englewood, Colo.) to concentrate residual oxygenator contents, reinfusion of chest drainage, and acceptance of a minimum hemoglobin level of 8.0 gm/dl in stable patients. Patient characteristics were similar for patients operated on both before (n = 58) and after (n = 60) initiation of the blood conservation program, except for age and preoperative aspirin use (both greater in postconservation patients). Fewer blood products were transfused (5.8 +/- 5.7 units per patient before conservation versus 4.0 +/- 7.4 units per patient after conservation; p = 0.005). More complete data were available for 82 patients (40 patients before conservation and 42 after conservation). In the postconservation patients, 20 of 42 had 575 +/- 140 ml of blood withdrawn before cardiopulmonary bypass and reinfused afterward, 26 of 42 had 806 +/- 376 ml of blood processed with the cell conservation device returned, and 21 of 42 patients had an average of 287 +/- 127 ml of chest drainage reinfused. Chest tube drainage, postoperative hematologic parameters, and the prevalence of complications were not significantly different between groups. Stepwise linear regression analysis identified intraoperative withdrawal of blood before cardiopulmonary bypass, bypass duration, and preoperative hematocrit value as predictors of blood use. Intraoperative withdrawal of blood before cardiopulmonary bypass is an important conservation measure, and its use should be expanded.

Poppet valve control of throat stability bypass to increase stable airflow range of a Mach 2.5. inlet with 60 percent internal contraction

Science.gov (United States)

Mitchell, G. A.; Sanders, B. W.

1975-01-01

The throat of a Mach 2.5 inlet with a coldpipe termination was fitted with a stability-bypass system. System variations included several stability bypass entrance configurations. Poppet valves controlled the bypass airflow. The inlet stable airflow range achieved with each configuration was determined for both steady state conditions and internal pulse transients. Results are compared with those obtained without a stability bypass system. Transient results were also obtained for the inlet with a choke point at the diffuser exit and for the inlet with large and small stability bypass plenum volumes. Poppet valves at the stability bypass exit provided the inlet with a stable airflow range of 20 percent or greater at all static and transient conditions.

Numerical solution of heat transfer process in a prismatic VHTR core accompanying bypass and cross flows

International Nuclear Information System (INIS)

Wang, Li; Liu, Qiusheng; Fukuda, Katsuya

2016-01-01

Highlights: • Three-dimensional CFD analysis is conducted for the thermal analysis in the reactor core. • Hot spot temperature, coolant channel outlet temperature distribution are affected by bypass flow. • Bypass gap size has significant influence on temperature and flow distribution in the core. • Cross flow has some effect on the temperature distribution of the coolant in the core due to flow mixing in the cross gaps. - Abstract: Bypass flow and cross flow gaps both exist in the core of a very high temperature gas-cooled reactor (VHTR), which is inevitable owing to tolerances in manufacturing, thermal expansion and irradiation shrinkage. The coolant mass flow rate distribution, temperature distribution, and hot spot temperature are significantly affected by bypass and cross flows. In the present study, three-dimensional CFD analysis is conducted for thermal analysis of the reactor core. A validation study for the turbulence model is performed by comparing the friction coefficient with published correlations. A sensitivity study of the near wall mesh is conducted to ensure mesh quality. Parametric studies are performed by changing the size of the bypass and cross gaps using a one-twelfth sector of a fuel block. Simulation results show the influence of the bypass gap size on temperature distribution and coolant mass flow rate distribution in the prismatic core. It is shown that the maximum fuel and coolant channel outlet temperatures increase with an increase in the gap size, which may lead to a structural risk to the fuel block. The cross flow is divided into two types: the cross flow from the bypass gap to the coolant channels and the cross flow from the high-pressure coolant channels to low-pressure coolant channels. These two types of flow have an opposing influence on the temperature gradient. It is found that the presence of the cross flow gaps may have a significant effect on the distribution of the coolant in the core due to flow mixing in the

Milrinone, a phosphodiesterase III inhibitor, prevents reduction of jugular bulb saturation during rewarming from hypothermic cardiopulmonary bypass.

Science.gov (United States)

Iritakenishi, T; Hayashi, Y; Yamanaka, H; Kamibayashi, T; Ueda, K; Mashimo, T

2012-01-01

Inadequate cerebral oxygen balance during cardiopulmonary bypass may cause neuropsychological dysfunction. Milrinone, a phosphodiesterase III inhibitor, augments cerebral blood flow by direct vasodilatation. We conducted a prospective, randomized study in patients undergoing cardiac surgery with cardiopulmonary bypass to clarify the clinical efficacy of milrinone in the imbalance of cerebral oxygen supply and demand during the rewarming period of cardiopulmonary bypass. This is a prospective, randomized and placebo-controlled study. After anesthesia, a 5.5 F fiberoptic oximeter catheter was inserted into the right jugular bulb retrogradely for monitoring the jugular venous oxyhemoglobin saturation (SjO(2)). Patients were randomly assigned to two groups, one receiving a continuous infusion of milrinone, 0.5 µg/kg/min during hypothermic cardiopulmonary bypass, and the other receiving saline as control. Milrinone significantly prevented the reduction of the jugular venous oxyhemoglobin saturation at 10 minutes from the start of rewarming compared with the control group, but did not do so from 10 to 20 minutes after rewarming. Milrinone suppresses the reduction of SjO(2) and improves the balance of cerebral oxygen supply and demand during the early rewarming period of hypothermic cardiopulmonary bypass.

Strategy over operation: neural activation in subtraction and multiplication during fact retrieval and procedural strategy use in children.

Science.gov (United States)

Polspoel, Brecht; Peters, Lien; Vandermosten, Maaike; De Smedt, Bert

2017-09-01

Arithmetic development is characterized by strategy shifts between procedural strategy use and fact retrieval. This study is the first to explicitly investigate children's neural activation associated with the use of these different strategies. Participants were 26 typically developing 4th graders (9- to 10-year-olds), who, in a behavioral session, were asked to verbally report on a trial-by-trial basis how they had solved 100 subtraction and multiplication items. These items were subsequently presented during functional magnetic resonance imaging. An event-related design allowed us to analyze the brain responses during retrieval and procedural trials, based on the children's verbal reports. During procedural strategy use, and more specifically for the decomposition of operands strategy, activation increases were observed in the inferior and superior parietal lobes (intraparietal sulci), inferior to superior frontal gyri, bilateral areas in the occipital lobe, and insular cortex. For retrieval, in comparison to procedural strategy use, we observed increased activity in the bilateral angular and supramarginal gyri, left middle to inferior temporal gyrus, right superior temporal gyrus, and superior medial frontal gyrus. No neural differences were found between the two operations under study. These results are the first in children to provide direct evidence for alternate neural activation when different arithmetic strategies are used and further unravel that previously found effects of operation on brain activity reflect differences in arithmetic strategy use. Hum Brain Mapp 38:4657-4670, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Pulmonary hemodynamics and gas exchange in off pump coronary artery bypass grafting.

Science.gov (United States)

Vedin, Jenny; Jensen, Ulf; Ericsson, Anders; Samuelsson, Sten; Vaage, Jarle

2005-10-01

To investigate the influence of cardiopulmonary bypass on pulmonary hemodynamics and gas exchange. Low risk patients admitted for elective coronary artery bypass grafting were randomized to either on (n=25) or off pump (n=25) surgery. Central hemodynamics, gas exchange, and venous admixture were studied during and up to 20 h after surgery. There was no difference in pulmonary vascular resistance index (P=0.16), right ventricular stroke work index (P>0.2), mean pulmonary artery pressure (P>0.2) or pulmonary capillary wedge pressure (P>0.2) between groups. Soon after surgery there was a tendency towards higher cardiac index (P=0.07) in the off pump group. Arterial oxygen tension (P>0.2), hematocrit (P>0.2), venous admixture (P>0.2), and arterial-venous oxygen content difference (P=0.12) did not differ between groups. This prospective, randomized study showed no difference in pulmonary hemodynamics, pulmonary gas exchange, and venous admixture, in low risk patients undergoing off pump compared to on pump coronary artery bypass surgery.

Effects of opium addiction on bleeding after coronary artery bypass graft surgery: report from Iran.

Science.gov (United States)

Nemati, Mohammad Hassan; Astaneh, Behrooz; Ardekani, Gholamreza Safaee

2010-09-01

Opium abuse is a major type of drug abuse in Iran. This study was designed to find the possible relation between opium addiction and excessive bleeding after coronary artery bypass graft (CABG) surgery. In a historical cohort study during a 1.5-year period, consecutive patients scheduled for elective CABG surgery were assigned to two group on the basis of having or not having the criteria for inhalational opium addiction. Before and after operations, the complete blood count, bleeding time, prothrombin time, partial thromboplastin time, and platelet count were checked for all patients. The volumes of infused red blood cells during and after the operation were recorded. After operations, the volumes of bleeding through the patients' chest tubes were recorded. The recorded data were analyzed using SPSS software version 11.5. Independent t, chi-square and repeated measure tests were used; and P Opium-addicted patients received more packed red blood cells during and after the operations. Inhalational opium addiction might lead to more hemorrhage after CABG surgery. It is recommended that cardiac surgeons consider these patients at high risk for major complications after surgery.

Successful use of continuous vasodilator infusion to treat critical vasospasm threatening a distal bypass

OpenAIRE

Gregory A. Magee, MD, MSc; Anastasia Plotkin, MD; Jeniann A. Yi, MD, MS; Kathryn E. Bowser, MD; David P. Kuwayama, MD, MPA

2018-01-01

Vasospasm immediately after lower extremity arterial bypass may represent an uncommon cause of early graft failure. We report a successful case of catheter-directed, intra-arterial continuous vasodilator infusion to salvage a bypass graft threatened by severe, refractory vasospasm after incomplete response to nicardipine, verapamil, and nitroglycerin boluses. A continuous nitroglycerin infusion was administered for 24 hours, by which time the vasospasm resolved. At 12 months postoperatively, ...

Benefits of sequential turbocharging in improving high torque/low speed operation of medium speed diesel engines

Energy Technology Data Exchange (ETDEWEB)

Danyluk, P.; Gutoski, G. [Coltec Industries Inc., Fairbanks Morse Engine Division (United States); Chen, S.K. [PEI Consultants (United States)

1998-12-31

This paper describes the benefits of sequential turbocharging in improving the operating envelope of a medium speed diesel engine. In particular, the high torque, low speed performance envelope can be greatly extended over that of a standard medium speed engine and, in addition, can offer improved operating range over what has been achieved with compressor air bypass/waste gate systems. This paper compares the three approaches on the basis of possible operating envelopes for a specific application, the new U.S. Navy LPD-17 amphibious assault ship, which has a very demanding requirement for high torque at low engine speed and low ambient temperatures. Comparison is made to the earlier approach to extend the operating envelope on the U.S. Navy LSD-41 class engines. The LSD-41 fleet has been in service since 1985 running with a compressor air bypass system developed jointly by Lockheed Shipyard and Coltec Industries for the U.S. Navy. (au)

In situ saphenous vein bypass surgery in diabetic patients

DEFF Research Database (Denmark)

Jensen, L P; Schroeder, T V; Lorentzen, J E

1992-01-01

.005). Indication for surgery was gangrene or ulceration in 57% of diabetics, as opposed to 36% in non-diabetic patients (p = 0.0002). A femoro-popliteal bypass was performed in 18% of patients, whereas 82% received an infrapopliteal procedure, of which 42% were to the distal third of the calf or foot. Diabetic......From 1986 through to 1990 a total of 483 consecutive in situ infra-inguinal vein bypass procedures were performed in 444 patients, of whom 112 (25%) were diabetics (57 insulin dependent diabetes mellitus and 55 non-insulin-dependent diabetes mellitus). Based on a prospective vascular data registry...... this material was analysed to determine the influence of diabetes on the outcome. Preoperative risk factors were equally distributed among diabetic and non-diabetic patients, except for smoking habits (diabetics: 48%; non-diabetics: 64%, p = 0.002) and cardiac disease (diabetics: 45%; non-diabetics: 29%, p = 0...

Extracranial–intracranial bypass for Takayasu’s arteritis: A case report

Directory of Open Access Journals (Sweden)

Richard M. Young, M.D.

2014-12-01

Conclusion: STA–MCA bypass to enhance cerebral blood flow in the setting of stroke symptoms due to Takayasu’s arteritis can serve as a bridge before definitive cardiothoracic treatment of the great vessels.