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Early diagnosis of acoustic neuroma by quantitative neurootological and neuroradiological tests

Energy Technology Data Exchange (ETDEWEB)

Haid, C T

1983-02-01

Every patient with unilateral and sensoneural loss of hearing, independent of vertigo anamnesis or X-rays must be further examined by a vestibular test. Between 1974 and 1980, 80 acoustic neuromas could be diagnosed, including 12 early stage neuromas. This relatively high detection quote of small neuromas is due to a special diagnostical program: All 80 patients with acoustic neuroma had a pathological vestibular result. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the caloric test: 95% of the patients with a neurinoma showed a pathological result in the positional test. So every patient suffering from an unidentified unilateral and sensoneural hearing loss combined with a pathological result in the positional test must be further examined by a cisternomeatography or computerized tomography (using air-insufflation). Every fifth of these patients showed unique hints of an acoustic neuroma in the neuroradiological test.

Four cases of acoustic neuromas with normal hearing.

Science.gov (United States)

Valente, M; Peterein, J; Goebel, J; Neely, J G

1995-05-01

In 95 percent of the cases, patients with acoustic neuromas will have some magnitude of hearing loss in the affected ear. This paper reports on four patients who had acoustic neuromas and normal hearing. Results from the case history, audiometric evaluation, auditory brainstem response (ABR), electroneurography (ENOG), and vestibular evaluation are reported for each patient. For all patients, the presence of unilateral tinnitus was the most common complaint. Audiologically, elevated or absent acoustic reflex thresholds and abnormal ABR findings were the most powerful diagnostic tools.

The Top 50 Most-Cited Articles on Acoustic Neuroma.

Science.gov (United States)

Alfaifi, Abrar; AlMutairi, Othman; Allhaidan, Maha; Alsaleh, Saad; Ajlan, Abdulrazag

2018-03-01

Acoustic neuroma is the most common extra-axial primary cerebellopontine angle tumor in adults. A plethora of studies have been published on acoustic neuroma, but none of the previous works have highlighted the most influential articles. Our objective was to perform a bibliometric analysis of the 50 most-cited articles on acoustic neuroma. We performed a title-specific search on the Scopus database using the following search terms: "acoustic neuroma," "vestibular schwannoma," and "cerebellopontine angle." We recorded the 50 most-cited articles and reviewed them. The 50 most-cited articles had an average of 175 citations per article. All articles were published between 1980 and 2006, with 1997 the most prolific year, when 7 articles were published. The journals Neurosurgery and Laryngoscope published 10 and 8 of these articles, respectively. The most common study categories were nonsurgical management (17/50) and surgical management (13/50). Studies were predominantly published by otolaryngologists (22/50) and neurosurgeons (14/50). Douglas Kondziolka was the author with the highest number of contributions, with 7 publications. The majority of the articles were produced in the United States (64%). Identifying articles on acoustic neuroma with the most impact provides an important overview of the historical development of treatment methods and publication trends related to this condition. A finalized, comprehensive list of the most important works represents an excellent tool that can serve as a guide for evidence-based clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Stereotactic radiosurgery for acoustic neuroma: a Canadian perspective

International Nuclear Information System (INIS)

Ross, I.B.; Tator, C.H.

1998-01-01

Stereotactically delivered radiation is now an accepted treatment for patients with acoustic neuroma. In some cases, patient preference may be the reason for its selection, while in others neurosurgeons may select it for patients who are elderly or have significant risk factors for conventional surgery. The majority of patients with acoustic neuroma treatment with stereotactic radiosurgery have been treated with the Gamma Knife, with follow ups of over 25 years in some instances. Other radiosurgical modalities utilizing the linear accelerator have been developed and appear promising, but there is no long-term: follow up. Canada does not possess a Gamma Knife facility, and its government-funded hospital and medical insurance agencies have made it difficult for patients to obtain reimbursement for Gamma Knife treatments in other countries. We review the literature to date on the various forms of radiation treatment for acoustic neuroma and discuss the current issues facing physicians and patients in Canada who wish to obtain their treatment of choice. (author)

Summary and consensus in 7th International Conference on acoustic neuroma: An update for the management of sporadic acoustic neuromas

Directory of Open Access Journals (Sweden)

Hao Wu

2016-12-01

Full Text Available Sporadic vestibular schwannoma (acoustic neuroma is a benign tumor arising from cochleovestibular nerve. Nowadays, various specialties and medical centers are treating this disease, and the multidisciplinary collaboration is the trend. In an effort to promote a uniform standard for reporting clinical results, even for treatment indications, the mainly controversies were posed and discussed during the 7th International Conference on acoustic neuroma, and the agreement was summarized by the Committee of this conference. The main symptoms grading and tumor stage should note its name of classification for making them comparable. The goal of the modern managements for vestibular schwannoma is to improve the quality of life with lower mortality, lower morbidity and better neurological function preservation. The experience of surgical team and their preference might be a major factor for the outcome. Because of lacking of long-term follow-up large data after radiotherapy, and with the development of microsurgery, radiotherapy is now less recommended except for recurrent cases or elderly patients. Keywords: Sporadic acoustic neuroma, Vestibular schwannoma, Management, Symptoms grading, Tumor stage, Microsurgery, Radiotherapy

''Dural tail'' adjacent to acoustic neuroma on MRI: a case report

International Nuclear Information System (INIS)

Lunardi, P.; Mastronardi, L.; Nardacci, B.; Acqui, M.; Fortuna, A.

1993-01-01

A 'dural tail' on Gd-DTPA-enhanced MRI has been often observed adjacent to meningiomas and considered to be useful in distinguishing meningioma of the cerebellopontine angle from acoustic neuroma. However, demonstration of a dural tail adjacent to an acoustic neuroma indicates that this sign is not specific. (orig.)

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

International Nuclear Information System (INIS)

Litre, Fabien; Rousseaux, Pascal; Jovenin, Nicolas; Bazin, Arnaud; Peruzzi, Philippe; Wdowczyk, Didier; Colin, Philippe

2013-01-01

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

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Litre, Fabien [Hôpital Maison Blanche, Reims Cedex (France); Rousseaux, Pascal [Hôpital Maison Blanche, Reims Cedex (France); Jovenin, Nicolas [Institut Jean Godinot, Reims Cedex (France); Bazin, Arnaud; Peruzzi, Philippe [Hôpital Maison Blanche, Reims Cedex (France); Wdowczyk, Didier; Colin, Philippe [Institut du Cancer Reims Courlancy, Reims (France)

2013-02-15

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss.

Dose and diameter relationships for facial, trigeminal, and acoustic neuropathies following acoustic neuroma radiosurgery

International Nuclear Information System (INIS)

Flickinger, John C.; Kondziolka, Douglas; Lunsford, L. Dade

1996-01-01

Purpose and objective: To define the relationships between dose and tumor diameter for the risks of developing trigeminal, facial, and acoustic neuropathies after acoustic neuroma radiosurgery, a large single-institution experience was analyzed. Materials and methods: Two hundred and thirty-eight patients with unilateral acoustic neuromas who underwent Gamma knife radiosurgery between 1987-1994 with 6-91 months of follow-up (median 30 months) were studied. Minimum tumor doses were 12-20 Gy (median 15 Gy). Transverse tumor diameter varied from 0.3-5.5 cm (median 2.1 cm). The relationships of dose and diameter to the development of cranial neuropathies were delineated by multivariate logistic regression. Results: The development of post-radiosurgery neuropathies affecting cranial nerves V, VII, and VIII were correlated with minimum tumor dose and transverse tumor diameter (P min for VIII where P=0.10). A comparison of the dose-diameter response curves showed the acoustic nerve to be the most sensitive to doses of 12-16 Gy and the facial nerve to be the least sensitive. Conclusion: The risks of developing trigeminal, facial, and acoustic neuropathies following acoustic neuroma radiosurgery can be predicted from the transverse tumor diameter and the minimum tumor dose using models constructed from data presently available

Long-term mobile phone use and acoustic neuroma risk.

Science.gov (United States)

Pettersson, David; Mathiesen, Tiit; Prochazka, Michaela; Bergenheim, Tommy; Florentzson, Rut; Harder, Henrik; Nyberg, Gunnar; Siesjö, Peter; Feychting, Maria

2014-03-01

There is concern about potential effects of radiofrequency fields generated by mobile phones on cancer risk. Most previous studies have found no association between mobile phone use and acoustic neuroma, although information about long-term use is limited. We conducted a population-based, nation-wide, case-control study of acoustic neuroma in Sweden. Eligible cases were persons aged 20 to 69 years, who were diagnosed between 2002 and 2007. Controls were randomly selected from the population registry, matched on age, sex, and residential area. Postal questionnaires were completed by 451 cases (83%) and 710 controls (65%). Ever having used mobile phones regularly (defined as weekly use for at least 6 months) was associated with an odds ratio (OR) of 1.18 (95% confidence interval = 0.88 to 1.59). The association was weaker for the longest induction time (≥10 years) (1.11 [0.76 to 1.61]) and for regular use on the tumor side (0.98 [0.68 to 1.43]). The OR for the highest quartile of cumulative calling time (≥680 hours) was 1.46 (0.98 to 2.17). Restricting analyses to histologically confirmed cases reduced all ORs; the OR for ≥680 hours was 1.14 (0.63 to 2.07). A similar pattern was seen for cordless land-line phones, although with slightly higher ORs. Analyses of the complete history of laterality of mobile phone revealed considerable bias in laterality analyses. The findings do not support the hypothesis that long-term mobile phone use increases the risk of acoustic neuroma. The study suggests that phone use might increase the likelihood that an acoustic neuroma case is detected and that there could be bias in the laterality analyses performed in previous studies.

Acoustic neuromas: single dose vs fractionated therapy

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Fuss, M; Debus, J; Lohr, F; Engenhart-Cabillic, R; Wannenmacher, M

1997-07-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

International Nuclear Information System (INIS)

Fuss, Martin; Debus, Juergen; Lohr, Frank; Huber, Peter; Rhein, Bernhard; Engenhart-Cabillic, Rita; Wannenmacher, Michael

2000-01-01

Purpose: Analysis of local tumor control and functional outcome following conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Patients and Methods: From 11/1989 to 9/1999 51 patients with acoustic neuromas have been treated by FSRT. Mean total dose was 57.6 ± 2.5 Gy. Forty-two patients have been followed for at least 12 months and were subject of an outcome analysis. Mean follow-up was 42 months. We analyzed local control, hearing preservation, and facial and trigeminal nerve functional preservation. We evaluated influences of tumor size, age, and association with neurofibromatosis Type 2 (NF2) on outcome and treatment related toxicity. Results: Actuarial 2- and 5-year tumor control rates were 100% and 97.7%, respectively. Actuarial useful hearing preservation rate was 85% at 2 and 5 years. New hearing loss was diagnosed in 4 NF2 patients. Pretreatment normal facial nerve function was preserved in all cases. Two cases of new or impaired trigeminal nerve dysesthesia required medication. No other cranial nerve deficit was observed. In Patients without NF2 tumor size or age had no influence on tumor control and cranial nerve toxicity. Diagnosis of NF2 was associated with higher risk of hearing impairment (p 0.0002), the hearing preservation rate in this subgroup was 60%. Conclusion: FSRT has been shown to be an effective means of local tumor control. Excellent hearing preservation rates and 5th and 7th nerve functional preservation rates were achieved. The results support the conclusion that FSRT can be recommended to patients with acoustic neuromas where special attention has to be taken to preserve useful hearing and normal cranial nerve function. For NF2 patients, FSRT may be the treatment of choice with superior functional outcome compared to treatment alternatives.

[Clinical and radiological evolution of a group of untreated acoustic neuromas].

Science.gov (United States)

Escorihuela-García, Vicente; Llópez-Carratalá, Ignacio; Orts-Alborch, Miguel; Marco-Algarra, Jaime

2014-01-01

The acoustic neuroma is a benign tumour that originates in the vestibular branch of the eighth cranial nerve. The main treatment is surgery, but many authors suggest that with elderly patients or in small neuromas we can opt for watchful waiting. This was a retrospective study from 2007 to 2013 that included 27 patients diagnosed of acoustic neuroma that had not been treated due to the size of the tumour, age and comorbidities, or by patient choice. We evaluated overall condition, hearing thresholds, degree of canal paresis and central disorders. After 6 years of follow up, clinical manifestations of 18 patients remained unchanged, 5 patients underwent hearing loss and developed tinnitus, 2 cases had more intense tinnitus and 2 cases had dizziness. The radiological controls by magnetic resonance imaging showed that the initial maximum diameters (5-16mm) increased by 1.7mm on average, with annual growth rates below 0.5mm. In selected cases, such as for small neuromas and in elderly patients, the conservative option of close monitoring with magnetic resonance imaging is an important alternative given that, in our cases, clinical features and radiological image did not suffer major changes. If there were any such changes, therapeutic options could be proposed. Copyright © 2013 Elsevier España, S.L. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Acoustic neuromas: single dose vs fractionated therapy

International Nuclear Information System (INIS)

Fuss, M.; Debus, J.; Lohr, F.; Engenhart-Cabillic, R.; Wannenmacher, M.

1997-01-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

MR of acoustic neuromas

International Nuclear Information System (INIS)

Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide

1989-01-01

In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T 1 -weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author)

The treatment for acoustic neuromas. Indication and results of gamma knife radiosurgery and surgery

International Nuclear Information System (INIS)

Iwai, Yoshiyasu; Yamanaka, Kazuhiro; Uyama, Taichi; Morikawa, Toshie; Honda, Yuji; Matsusaka, Yasuhiro; Komiyama, Masaki; Yasui, Toshihiro

2004-01-01

We evaluated the treatment results of acoustic neuromas in the era of radiosurgery. We treated acoustic neuromas using the following strategy. Small to medium size tumors (below 3 cm) were treated by gamma knife radiosurgery and large tumors (above 3 cm) were treated using a combination of surgery and radiosurgery. Using gamma knife radiosurgery we were able to achieve 96.4% of clinical tumor growth control with 0.7% incidence of trigeminal neuropathy (without new facial neuropathy). We used low dose radiosurgery (average tumor marginal dose 11.8 Gy) with a follow-up of an average of 54 months. For the 17 patients with large tumors treated by the combination of surgery and radiosurgery who could be followed up for over 24 months after radiosurgery, we were able to preserve normal facial function (House-Brackmann grade I-II) in 70.6% of the patients after subtotal removal. High clinical tumor growth control for residual tumor was achieved in 94.1% of subjects with an average of 40 months follow-up. By using this strategy, the treatment outcome for acoustic neuroma is improved from the standpoint of functional outcome and maintaining the patient's quality of life. (author)

Calculating the tumor volume of acoustic neuromas: comparison of ABC/2 formula with planimetry method.

Science.gov (United States)

Yu, Yi-Lin; Lee, Meei-Shyuan; Juan, Chun-Jung; Hueng, Dueng-Yuan

2013-08-01

The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (6 ml). The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R2=0.985). Pearson correlation coefficient (r=0.993, pABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. Copyright © 2013 Elsevier B.V. All rights reserved.

Impact of facial paralysis on patients with acoustic neuroma.

Science.gov (United States)

Cross, T; Sheard, C E; Garrud, P; Nikolopoulos, T P; O'Donoghue, G M

2000-09-01

To assess the psychological distress, the ways of coping with that stress, and the self-esteem of patients with facial paralysis after acoustic neuroma surgery. Possible predictors and associations between these measures were also explored. Four validated questionnaires were completed by patients with facial paralysis after acoustic neuroma surgery: 1) the Derriford Appearance Scale (DAS) to measure psychological distress, 2) the COPE questionnaire to measure how patients cope with facial paralysis, 3) the Personal Report questionnaire to measure the self-esteem of patients, and 4) the Facial Paralysis Questionnaire (FPQ) to measure the severity of facial paralysis. One hundred three patients with facial paralysis after surgical removal of acoustic tumors. Distress spanned a wide range in these patients. There was no statistically significant association between the level of distress and the grade of facial paralysis or between time since operation and levels of distress. Women had higher levels of distress (P = .02) and a significant negative correlation was found between levels of distress and age (r = -0.28, P = .005). High levels of distress were associated with low levels of self-esteem, as shown by the significant negative correlation between level of distress and self-esteem (r = -0.59, P = .01). A significant correlation between distress and maladaptive coping (r = 0.31, P = .002) was also found. Stepwise multiple regression of the distress scores revealed that self-esteem was the most important contributing factor (standardized coefficient beta -0.60, P = .0001), followed by age (beta -0.24, P = .006) and sex (beta -0.21, P = .04). This model explained 44% of the distress variance. Clinicians must be aware of the distress felt by some patients experiencing facial palsy after acoustic neuroma surgery and that the level of distress may not be related to the clinical grade of the facial nerve paralysis. People with low self-esteem, young people, and women

Stereotactic radiosurgery using the gamma knife for acoustic neuromas

International Nuclear Information System (INIS)

Foote, Robert L.; Coffey, Robert J.; Swanson, Jerry W.; Harner, Stephen G.; Beatty, Charles W.; Kline, Robert W.; Stevens, Lorna N.; Hu, Theresa C.

1995-01-01

Purpose: To assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Methods and Materials: Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompassed within the prescribed isodose line varied from 266 to 8,667 mm 3 (median: 3,135 mm 3 ). Tumors ≤ 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. The median number of isocenters per tumor was 5 (range: 1-12). Results: At a median follow-up of 16 months (range: 2.5-36 months), all patients were alive. Thirty-five patients had follow-up imaging studies. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% ± 17.3, respectively. Conclusion: Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients

The use of multimedia as an adjunct to the informed consent process for Morton's neuroma resection surgery.

Science.gov (United States)

Wang, Calvin; Ammon, Peter; Beischer, Andrew D

2014-10-01

The purpose of this study was to assess if a computer-based multimedia education module (MEM) improved patients' comprehension when used as an adjunct to the standard verbal consent process for Morton's neuroma resection surgery. Nineteen patients (15 females and 4 males) considered candidates for Morton's neuroma resection surgery were prospectively recruited. A standardized verbal discussion was had with each patient regarding risks and benefits of surgery, alternative treatments, and the usual postoperative course. Patient understanding was then assessed with a questionnaire. Each patient subsequently viewed the MEM and the questionnaire was repeated. Patients also rated ease of understanding and satisfaction with both methods of patient education. Patients answered a significantly greater proportion of correct answers after viewing the MEM module (85%), compared to verbal discussion alone (61%) (P = .002). Patients rated both the ease of understanding of the module and amount of information provided by the module as a mean of 9.3 cm on a 10 cm Visual Analog Scale (VAS). The majority of patients (76%) rated the multimedia tool as having answered their questions about surgery as well or better than the treating surgeon. An interactive multimedia educational tool was a useful adjunct to the informed consent process for patients considering Morton's neuroma resection surgery. Level II, prospective cohort study. © The Author(s) 2014.

Calculation of cranial nerve complication probability for acoustic neuroma radiosurgery

International Nuclear Information System (INIS)

Meeks, Sanford L.; Buatti, John M.; Foote, Kelly D.; Friedman, William A.; Bova, Francis J.

2000-01-01

Purpose: Estimations of complications from stereotactic radiosurgery usually rely simply on dose-volume or dose-diameter isoeffect curves. Due to the sparse clinical data available, these curves have typically not considered the target location in the brain, target histology, or treatment plan conformality as parameters in the calculation. In this study, a predictive model was generated to estimate the probability of cranial neuropathies as a result of acoustic schwannoma radiosurgery. Methods and Materials: The dose-volume histogram reduction scheme was used to calculate the normal tissue complication probability (NTCP) from brainstem dose-volume histograms. The model's fitting parameters were optimized to provide the best fit to the observed complication data for acoustic neuroma patients treated with stereotactic radiosurgery at the University of Florida. The calculation was then applied to the remainder of the patients in the database. Results: The best fit to our clinical data was obtained using n = 0.04, m = 0.15, and no. alphano. /no. betano. = 2.1 Gy -1 . Although the fitting parameter m is relatively consistent with ranges found in the literature, both the volume parameter, n, and no. alphano. /no. betano. are much smaller than the values quoted in the literature. The fit to our clinical data indicates that brainstem, or possibly a specific portion of the brainstem, is more radiosensitive than the parameters in the literature indicate, and that there is very little volume effect; in other words, irradiation of a small fraction of the brainstem yields NTCPs that are nearly as high as those calculated for entire volume irradiation. These new fitting parameters are specific to acoustic neuroma radiosurgery, and the small volume effect that we observe may be an artifact of the fixed relationship of acoustic tumors to specific regions of the brainstem. Applying the model to our patient database, we calculate an average NTCP of 7.2% for patients who had no

Enhanced intrinsic radiosensitivity after treatment with stereotactic radiosurgery for an acoustic neuroma

International Nuclear Information System (INIS)

Adams, Gerard; Martin, Olga A.; Roos, Daniel E.; Lobachevsky, Pavel N.; Potter, Andrew E.; Zacest, Andrew C.; Bezak, Eva; Bonner, William M.; Martin, Roger F.; Leong, Trevor

2012-01-01

Enhanced radiosensitivity is an uncommon phenomenon attributable to deficient DNA repair after radiotherapy which can be assessed with the γ-H2AX assay. Reports of radiosensitivity after stereotactic radiosurgery (SRS) are uncommon. We describe a case where the clinical, radiological and laboratory findings suggest enhanced radiosensitivity after SRS for an acoustic neuroma.

Haemorrhagic acoustic neuroma with features of a vascular malformation. A case report

Energy Technology Data Exchange (ETDEWEB)

Benhaiem-Sigaux, N. [Dept. of Pathology, Hopital Henri Mondor, Creteil (France); Ricolfi, F. [Dept. of Neuroradiology, Henri Mondor Hospital, Creteil (France); Torres-Diaz, A.; Keravel, Y. [Dept. of Neurosurgery, Henri Mondo Hospital, Creteil (France); Poirier, J. [Dept. of Histology, Pitie-Salpetriere Hospital, Paris (France)

1999-10-01

A 55-year-old man with hearing loss presented with vertigo and vomiting. CT tomography and MRI demonstrated a cerebellopontine angle mass with foci of haemorrhage. An angiomatous tumour, with large abnormal veins adhering to the capsule, was completely removed. Histologically, the tumour was an acoustic neuroma with abnormal vascularisation and limited intratumoral haemorrhage. (orig.)

Haemorrhagic acoustic neuroma with features of a vascular malformation. A case report

International Nuclear Information System (INIS)

Benhaiem-Sigaux, N.; Ricolfi, F.; Torres-Diaz, A.; Keravel, Y.; Poirier, J.

1999-01-01

A 55-year-old man with hearing loss presented with vertigo and vomiting. CT tomography and MRI demonstrated a cerebellopontine angle mass with foci of haemorrhage. An angiomatous tumour, with large abnormal veins adhering to the capsule, was completely removed. Histologically, the tumour was an acoustic neuroma with abnormal vascularisation and limited intratumoral haemorrhage. (orig.)

Radiosurgery supported in the lineal accelerator for the acoustic neuroma treatment

International Nuclear Information System (INIS)

Santos Ortega, M.; Gutierrez Diaz, J.; Rodriguez Villaba, S.; Garcia Berrocal, I.; Samblas Garcia, J.; Bustos Perez de Salcedo, J.C.; Ortiz de Urbina, D.; Donckaster Clavero, G.; Delgado Rodriguez, J.M.; Sansivirini Valle, F.

1996-01-01

Radiosurgery becomes in a great interest technique in acoustic neuroma treatments. We present preliminary results over 74 neurinomas patients in our Unit. From August 1991 to August 1994, 74 consecutive patients with acoustic neuromas, median age 50 yrs. has been treated in our Unit. A SRS 200 radiosurgery system was employed using a 6 MV photon beam Linear Accelerator as radiation source. In every case treatment dose was lesser than 18 gy (14-16 Gy). Before treatment all patients were evaluated with MRI and neurological examination, acoustic test included. This screening was repeated each six months during the follow up. Tumoral control was defined both, as no changes or diminishing in tumoral size, observed in sequential MRI studies with gadolinium and comparable techniques. The median fallow up is 18 months. Tumor control is 88,5%. In 30 patients control means dismissing in tumoral size. In 10 patients tumoral progression was evident, in a half of their a neurofibromatosis type II was previously diagnosed. The neurological function during the follow up shown improve or estabilitation in symptoms, for 85% VII pair patients, 83% in VII pair patients, 86% in V pair patients and 83% in cerebellar disfunction patients. Although preliminaries, this dates showing the efficacy of radiosurgery in tumoral control of patients with neurinomas with doses laser than 18 Gy. This dose are safe with toxicities around 15%, mainly in transitory presentations. (Auhtor) 67 refs

Acoustic neuroma: predominance of Antoni type B cells in tumors of patients with vestibular paresis.

NARCIS (Netherlands)

Stipkovits, E.M.; Graamans, K.; Jansen, G.H.; Velthof, M.A.

2001-01-01

OBJECTIVE: This study aimed to investigate whether in patients with acoustic neuroma (AN), the presence or absence of vestibular symptoms is related to the histologic characteristics of the tumor. STUDY DESIGN: The study design was a retrospective clinical study. SETTING: The study was conducted at

A case-case study of mobile phone use and acoustic neuroma risk in Japan.

Science.gov (United States)

Sato, Yasuto; Akiba, Suminori; Kubo, Osami; Yamaguchi, Naohito

2011-02-01

Results of case-control studies of mobile phone use and acoustic neuroma have been inconsistent. We conducted a case-case study of mobile phone use and acoustic neuroma using a self-administered postal questionnaire. A total of 1589 cases identified in 22 hospitals throughout Japan were invited to participate, and 787 cases (51%) actually participated. Associations between laterality of mobile phone use prior to the reference dates (1 and 5 years before diagnosis) and tumor location were analyzed. The overall risk ratio was 1.08 (95% confidence interval (CI), 0.93-1.28) for regular mobile phone use until 1 year before diagnosis and 1.14 (95% CI, 0.96-1.40) for regular mobile phone use until 5 years before diagnosis. A significantly increased risk was identified for mobile phone use for >20 min/day on average, with risk ratios of 2.74 at 1 year before diagnosis, and 3.08 at 5 years before diagnosis. Cases with ipsilateral combination of tumor location and more frequently used ear were found to have tumors with smaller diameters, suggesting an effect of detection bias. Furthermore, analysis of the distribution of left and right tumors suggested an effect of tumor-side-related recall bias for recall of mobile phone use at 5 years before diagnosis. The increased risk identified for mobile phone users with average call duration >20 min/day should be interpreted with caution, taking into account the possibilities of detection and recall biases. However, we could not conclude that the increased risk was entirely explicable by these biases, leaving open the possibility that mobile phone use increased the risk of acoustic neuroma. Copyright © 2010 Wiley-Liss, Inc.

Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery

International Nuclear Information System (INIS)

Karpinos, Marianna; Teh, Bin S.; Zeck, Otto; Carpenter, L. Steven; Phan, Chris; Mai, W.-Y.; Lu, Hsin H.; Chiu, J. Kam; Butler, E. Brian; Gormley, William B.; Woo, Shiao Y.

2002-01-01

Purpose: Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery. Our objective was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome, and patient satisfaction. Methods and Materials: To compare radiosurgery with microsurgery, we analyzed 96 patients with unilateral acoustic neuromas treated with Leksell Gamma Knife or microsurgery at Memorial Hermann Hospital, Houston, Texas, between 1993 and 2000. Radiosurgery technique involved multiple isocenter (1-30 single fraction fixed-frame magnetic resonance imaging) image-based treatment with a mean dose prescription of 14.5 Gy. Microsurgery included translabyrinthine, suboccipital, and middle fossa approaches with intraoperative neurophysiologic monitoring. Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group. The tumors were divided into small 4.0 cm. Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months (3-84 months) vs. 24 months (3-72 months). Results: There was no statistical significance in tumor growth control between the two groups, 100% in the microsurgery group vs. 91% in the radiosurgery group (p>0.05). Radiosurgery was more effective than microsurgery in measurable hearing preservation, 57.5% vs. 14.4% (p=0.01). There was no difference in serviceable hearing preservation between the two groups. Microsurgery was associated with a greater rate of facial and trigeminal neuropathy in the immediate postoperative period and at long-term follow-up. The rate of development of facial neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (35% vs. 0%, p<0.01 in the immediate postsurgical period and 35.3% vs. 6.1%, p=0.008, at long

Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery

Energy Technology Data Exchange (ETDEWEB)

Karpinos, Marianna; Teh, Bin S; Zeck, Otto; Carpenter, L Steven; Phan, Chris; Mai, W -Y; Lu, Hsin H; Chiu, J Kam; Butler, E Brian; Gormley, William B; Woo, Shiao Y

2002-12-01

Purpose: Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery. Our objective was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome, and patient satisfaction. Methods and Materials: To compare radiosurgery with microsurgery, we analyzed 96 patients with unilateral acoustic neuromas treated with Leksell Gamma Knife or microsurgery at Memorial Hermann Hospital, Houston, Texas, between 1993 and 2000. Radiosurgery technique involved multiple isocenter (1-30 single fraction fixed-frame magnetic resonance imaging) image-based treatment with a mean dose prescription of 14.5 Gy. Microsurgery included translabyrinthine, suboccipital, and middle fossa approaches with intraoperative neurophysiologic monitoring. Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group. The tumors were divided into small <2.0 cm, medium 2.0-3.9 cm, or large >4.0 cm. Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months (3-84 months) vs. 24 months (3-72 months). Results: There was no statistical significance in tumor growth control between the two groups, 100% in the microsurgery group vs. 91% in the radiosurgery group (p>0.05). Radiosurgery was more effective than microsurgery in measurable hearing preservation, 57.5% vs. 14.4% (p=0.01). There was no difference in serviceable hearing preservation between the two groups. Microsurgery was associated with a greater rate of facial and trigeminal neuropathy in the immediate postoperative period and at long-term follow-up. The rate of development of facial neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (35% vs. 0%, p<0.01 in the immediate postsurgical period and 35

SU-E-T-14: A Comparative Study Between Forward and Inverse Planning in Gamma Knife Radiosurgery for Acoustic Neuroma Tumours

Energy Technology Data Exchange (ETDEWEB)

Gopishankar, N; Agarwal, Priyanka; Bisht, Raj Kishor; Kale, S S; Rath, G K; Chander, S; Sharma, B S [All India Institute of Medical Sciences, New Delhi (India)

2015-06-15

Purpose: To evaluate forward and inverse planning methods for acoustic neuroma cases treated in Gamma Knife Perfexion. Methods: Five patients with acoustic neuroma tumour abutting brainstem were planned twice in LGP TPS (Version 10.1) using TMR10 algorithm. First plan was entirely based on forward planning (FP) in which each shot was chosen manually. Second plan was generated using inverse planning (IP) for which planning parameters like coverage, selectivity, gradient index (GI) and beam-on time threshold were set. Number of shots in IP was automatically selected by objective function using iterative process. In both planning methods MRI MPRAGE sequence images were used for tumour localization and planning. A planning dose of 12Gy at 50% isodose level was chosen. Results and Discussion: Number of shots used in FP was greater than IP and beam-on time in FP was in average 1.4 times more than IP. One advantage of FP was that the brainstem volume subjected to 6Gy dose (25% isodose) was less in FP than IP. Our results showed use of more number of shots as in FP results in GI less than or equal to 2.55 which is close to its lower limit. Dose homogeneity index (DHI) analysis of FP and IP showed average values of 0.59 and 0.67 respectively. General trend in GK for planning in acoustic neuroma cases is to use small collimator shots to avoid dose to adjacent critical structures. More number of shots and prolonged treatment time causes inconvenience to the patients. Similarly overuse of automatic shot shaping as in IP results in increased scatter dose. A compromise is required in shot selection for these cases. Conclusion: IP method could be used in acoustic neuroma cases to decrease treatment time provided the source sector openings near brainstem are shielded or adjusted appropriately to reduce brainstem dose.

Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: early results of a prospective clinical study

International Nuclear Information System (INIS)

Meijer, O.W.M.; Wolbers, J.G.; Baayen, J.C.; Slotman, B.J.

2000-01-01

Purpose: To prospectively assess the local control and toxicity rate in acoustic neuroma patients treated with linear accelerator-based radiosurgery and fractionated stereotactic radiation therapy. Methods and Materials: We evaluated 37 consecutive patients treated with stereotactic radiation therapy for acoustic neuroma. All patients had progressive tumors, progressive symptoms, or both. Mean tumor diameter was 2.3 cm (range 0.8-3.3) on magnetic resonance (MR) scan. Dentate patients were given a dose of 5 x 4 Gy or 5 x 5 Gy and edentate patients were given a dose of 1 x 10 Gy or 1 x 12.50 Gy prescribed to the 80% isodose. All patients were treated with a single isocenter. Results: With a mean follow-up period of 25 months (range 12-61), the actuarial local control rate at 5 years was 91% (only 1 patient failed). The actuarial rate of hearing preservation at 5 years was 66% in previously-hearing patients. The actuarial rate of freedom from trigeminal nerve toxicity was 97% at 5 years. No patient developed facial nerve toxicity or other complications. Conclusion: In this unselected series, fractionated stereotactic radiation therapy and linear accelerator-based radiosurgery give excellent local control in acoustic neuroma. It combines a high rate of preservation of hearing with a very low rate of other toxicity, although follow-up is relatively short

Vestibular Schwannoma or acoustic neuroma

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Hekmatara M

1997-04-01

Full Text Available Vestibular schwannoma is the most common tumor of the posterior fossa of the skull. Patients referred with the primary otologic symptoms such as hearing loss, tinnitus, vertigo, imbalance, and the cranial nerve palsy. Thirty-three patients were operated and treated by a team of otolaryngologist and neurosurgeon, anudiometrist, and internist. Patients'chiefcomplaint was due to 94% hearing loss and 27% tinnitus. They scarcely complain of vertigo. If a patient refers with the palsy or paralysis of facial nerve preoperation, we must think of the facial nerve schwannoma or hemangioma or congential cholestoma or malignant metastases rather than acoustic neuroma. The best way for preoperative diagnosis is audiometry, ABR (Auditory Brain Response, and SDS (speech discrimination score with 90% success, but computer Tomography (CT scan and MRI (Magnetic Resonance Image are the valuable anatomic diagnostic radiographic devices. The best method of operation is translabirynthine approach (TLA, since it has the advantages such as an easy access to nerve paths and being the nearest path to CPA (Cerebellopontine Angle. Physicians ought to talk to patients about the importance of the microscopic surgery, surgical methods, and their probable diverse effects such as hearing loss, facial nerve palsy, and intracranial problems.

MR of acoustic neuromas; Relationship to cranial nerves

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Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide [Kanazawa Univ. (Japan). School of Medicine

1989-08-01

In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T{sub 1}-weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author).

Prognostic factors for hearing preservation following observation-only versus stereotactic irradiation (STI) in patients with acoustic neuroma

International Nuclear Information System (INIS)

Sakamoto, Tooru

1998-01-01

Prognostic factors for hearing preservation following observation-only versus STI were compared in patients with acoustic neuroma. There were 48 patients with acoustic neuroma treated by fractionated STI. Between 1991 and 1997, patients were given 36 Gy in 20 fractions over 5 weeks (36 Gy/20 Fr/5 wks) to 44 Gy/22 Fr/6 wks followed by a 4 Gy boost. A linear accelerator was used for irradiation. Twenty-three patients with acoustic neuroma who were followed without any treatment (observation-only group) were selected as matched controls. The largest hearing loss was observed at the frequency of 2 kHz in the observation-only group and at 1-2 kHz in the STI group. Hearing loss at lkHz was more frequent in the STI group (p<0.01). There were no significant prognostic factors which predicted hearing preservation in the observation-only group. Stereotactic irradiation has been suggested to damage to cochlear nerve function in patients whose cochlear nerve had been impaired already. Tumor control rate of STI appeared to be as good as single fraction radiosurgery rates in the literature and better than in the observation-only group. Hearing preservation rate in the STI group was as good as in the observation-only group and appeared to be better than single fraction radiosurgery. In conclusion, because there were no factors predictive of hearing preservation in the observation-only group, it is difficult to select patients for observation only. Fractionated STI is potentially the treatment of choice, resulting in the same hearing preservation rate as achieved with observation only, although longer follow-up periods are needed. (author)

Environmental risk factors for sporadic acoustic neuroma (Interphone Study Group, Germany)

DEFF Research Database (Denmark)

Schlehofer, B; Schlaefer, K; Blettner, M

2007-01-01

The only known risk factor for sporadic acoustic neuroma is high-dose ionising radiation. Environmental exposures, such as radiofrequency electromagnetic fields and noise are under discussion, as well as an association with allergic diseases. We performed a population-based case-control study.......31; 95% CI 1.15-4.66), and for hay fever (OR=2.20; 95% CI 1.09-4.45), but not for ionising radiation (OR=0.91; 95 % CI 0.51-1.61) or regular mobile phone use (OR=0.67; 95% CI 0.38-1.19). The study confirms results of recently published studies, although the pathogenetic mechanisms are still unknown....

Risk of a second cancer from scattered radiation in acoustic neuroma treatment

Science.gov (United States)

Yoon, Myonggeun; Lee, Hyunho; Sung, Jiwon; Shin, Dongoh; Park, Sungho; Chung, Weon Kuu; Jahng, Geon-Ho; Kim, Dong Wook

2014-06-01

The present study aimed to compare the risk of a secondary cancer from scattered and leakage doses in patients receiving intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) of a secondary cancer were estimated using the corresponding secondary doses measured at various organs by using radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, liver, bowel, bladder, prostate (or ovary), and rectum were 14.6, 1.7, 0.9, 0.8, 0.6, 0.6, and 0.6 cGy, respectively, for IMRT whereas they were 19.1, 1.8, 2.0, 0.6, 0.4, 0.4, and 0.4 cGy, respectively, for VMAT, and 22.8, 4.6, 1.4, 0.7, 0.5, 0.5, and 0.5 cGy, respectively, for SRS. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A lifetime attributable risk evaluation estimated that more than 0.03% of acoustic neuroma (AN) patients would get radiation-induced cancer within 20 years of receiving radiation therapy. The organ with the highest radiation-induced cancer risk after radiation treatment for AN was the thyroid. We found that the LAR could be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

Risk of a second cancer from scattered radiation in acoustic neuroma treatment

Energy Technology Data Exchange (ETDEWEB)

Yoon, Myonggeun; Lee, Hyunho; Sung, Jiwon [Korea University, Seoul (Korea, Republic of); Shin, Dongoh [Kyung Hee University Medical Center, Seoul (Korea, Republic of); Park, Sungho [Ulsan University Hospital, Ulsan (Korea, Republic of); Chung, Weonkuu; Jahng, Geonho; Kim, Dongwook [Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of)

2014-06-15

The present study aimed to compare the risk of a secondary cancer from scattered and leakage doses in patients receiving intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) of a secondary cancer were estimated using the corresponding secondary doses measured at various organs by using radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, liver, bowel, bladder, prostate (or ovary), and rectum were 14.6, 1.7, 0.9, 0.8, 0.6, 0.6, and 0.6 cGy, respectively, for IMRT whereas they were 19.1, 1.8, 2.0, 0.6, 0.4, 0.4, and 0.4 cGy, respectively, for VMAT, and 22.8, 4.6, 1.4, 0.7, 0.5, 0.5, and 0.5 cGy, respectively, for SRS. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A lifetime attributable risk evaluation estimated that more than 0.03% of acoustic neuroma (AN) patients would get radiation-induced cancer within 20 years of receiving radiation therapy. The organ with the highest radiation-induced cancer risk after radiation treatment for AN was the thyroid. We found that the LAR could be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

VESTIBULAR SCHWANNOMA (ACOUSTIC NEUROMA) MIMICKING TEMPOROMANDIBULAR DISORDERS: A CASE REPORT

Science.gov (United States)

Bisi, Maurício A.; Selaimen, Caio M. P.; Chaves, Karen D.; Bisi, Melissa C.; Grossi, Márcio L.

2006-01-01

Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma). Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI) has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case. PMID:19089251

Validation of the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale.

Science.gov (United States)

Lodder, Wouter L; Adan, Guleed H; Chean, Chung S; Lesser, Tristram H; Leong, Samuel C

2017-06-01

The objective of this study is to evaluate the strength of content validity within the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale and to compare how it correlates with a facial dysfunction-specific QOL instrument (Facial Clinimetric Evaluation, FaCE). The study design is online questionnaire survey. Members of the British Acoustic Neuroma Association received both PANQOL questionnaires and the FaCE scale. 158 respondents with self-identified facial paralysis or dysfunction had completed PANQOL and FaCE data sets for analysis. The mean composite PANQOL score was 53.5 (range 19.2-93.5), whilst the mean total FaCE score was 50.9 (range 10-95). The total scores of the PANQOL and FaCE correlated moderate (r = 0.48). Strong correlation (r = 0.63) was observed between the PANQOL's facial dysfunction domain and the FaCE total score. Of all the FaCE domains, social function was strongly correlated with the PANQOL facial dysfunction domain (r = 0.66), whilst there was very weak-to-moderate correlation (range 0.01-0.43) to the other FaCE domains. The current study has demonstrated a strong correlation between the facial dysfunction domains of PANQOL with a facial paralysis-specific QOL instrument.

Intermedius nerve involvement and testing in acoustic neuromas.

Science.gov (United States)

Thomsen, J; Zilstorff, K

1975-01-01

The clinical findings in 125 patients with surgically confirmed acoustic neuromas are presented, with special regard to the involvement of the intermedius nerve in the diagnosis. In assessing the function of the intermedius nerve the examination of the nasolacrimal reflex and the sensation of taste on the anterior two-thirds of the tongue are used. The methods of investigation are described in detail. The material consisted of 20 medium-sized and 105 large tumours; no intracanalicular tumor was found. Hearing loss was the initial symptom in 85% of the patients, 10% had tinitus and 4% vertigo as the first symptom. Apart from the VIII cranial nerve symptoms, a defective nasolacrimal reflex was the most significant evidence of cerebellopontine angle pathology. The test was positive in 65% of the medium-sized tumours, in the entire material, 85%. The figures are higher than the incidence of trigeminal nerve symptoms. This in contrast to the reports of most authors. The tests described are simple and quick to perform, and it is emphasized that they should be applied to all patients with unilateral hearing loss of unknown origin.

Biliary stricture due to neuroma after an innocent blunt abdominal trauma.

Science.gov (United States)

Katsinelos, P; Dimiropoulos, S; Galanis, I; Tsolkas, P; Paroutoglu, G; Arvaniti, M; Katsiba, D; Baltaglannis, S; Pilpilidis, I; Papagiannis, A; Vaslliadis, I

2002-10-01

A traumatic neuroma of the biliary tract is rarely associated with biliary obstruction. However, when it arises in the common bile duct (CBD) and is associated with obstructive jaundice, it is difficult to distinguish it from bile duct cancer. We describe a patient who developed obstructive jaundice and itching, due to CBD stricture, 8 years after innocent blunt abdominal trauma. The stricture was resected and hepatico-jejunal anastomosis was performed. Histological examination revealed a traumatic neuroma and a fibrous scar around the common bile duct. Symptoms disappeared following surgical removal of the lesion. Blunt abdominal injury may cause the late onset of a fibrous scar and traumatic neuroma in the common bile duct. To our knowledge, a traumatic neuroma of the biliary tract after blunt abdominal trauma has not been reported previously. We review the clinical picture of this relatively rare problem, along with its diagnosis, pathogenesis and treatment.

Traumatic facial nerve neuroma with facial palsy presenting in infancy.

Science.gov (United States)

Clark, James H; Burger, Peter C; Boahene, Derek Kofi; Niparko, John K

2010-07-01

To describe the management of traumatic neuroma of the facial nerve in a child and literature review. Sixteen-month-old male subject. Radiological imaging and surgery. Facial nerve function. The patient presented at 16 months with a right facial palsy and was found to have a right facial nerve traumatic neuroma. A transmastoid, middle fossa resection of the right facial nerve lesion was undertaken with a successful facial nerve-to-hypoglossal nerve anastomosis. The facial palsy improved postoperatively. A traumatic neuroma should be considered in an infant who presents with facial palsy, even in the absence of an obvious history of trauma. The treatment of such lesion is complex in any age group but especially in young children. Symptoms, age, lesion size, growth rate, and facial nerve function determine the appropriate management.

Acoustic neuroma risk in relation to mobile telephone use: Results of the INTERPHONE international case-control study

DEFF Research Database (Denmark)

Berg-Beckhoff, Gabi

2011-01-01

Background: The rapid increase in mobile telephone use has generated concern about possible health risks of radiofrequency electromagnetic fields from these devices. Methods: A case-control study of 1105 patients with newly diagnosed acoustic neuroma (vestibular schwannoma) and 2145 controls...... was conducted in 13 countries using a common protocol. Past mobile phone use was assessed by personal interview. In the primary analysis, exposure time was censored at one year before the reference date (date of diagnosis for cases and date of diagnosis of the matched case for controls); analyses censoring...

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997-2003 and 2007-2009 and use of mobile and cordless phones.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Mild, Kjell Hansson

2013-10-01

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20-80 years, diagnosed during 1997-2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007-2009 including both men and women aged 18-75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0-4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8-21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1-2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8-4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1-2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7-26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1-2.0 increasing to OR = 8.1, 95% CI = 2.0-32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2-9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless phones. OR increased per 100 h

Traumatic neuroma after torticollis surgery: a rare occurrence

African Journals Online (AJOL)

2 Serrano Falcón C, Serrano Falcn MDM, Ruiz Villaverde R, Linares Solano J,. Serrano Ortega S. Amputation neuromas after neck surgery. Dermatol Online. J 2005; 11:2. 3 Lee IJ, Lim SY, Song HS, Park MC. Complete tight fibrous band release and resection in congenital muscular torticollis. J Plast Reconstr Aes Surg ...

Hypofractionated stereotactic radiotherapy of acoustic neuroma. Volume changes and hearing results after 89-month median follow-up

International Nuclear Information System (INIS)

Kranzinger, Manfred; Fastner, Gerd; Zehentmayr, Franz; Sedlmayer, Felix; Oberascher, Gerhard; Merz, Florian; Rahim, Hassan; Nairz, Olaf

2014-01-01

The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity. In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 x 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995). No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9 %) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1 %. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4 %. Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery. (orig.) [de

[Treatment of painful neuromas via end-to-side neurorraphy].

Science.gov (United States)

Aszmann, O C; Moser, V; Frey, M

2010-08-01

Management of the painful neuroma has been subject to controversy since the earliest descriptions of this disabling problem. Today, treatment is limited to resection of the neuroma and implantation of the nerve in a muscle at a location where it is safe from irritation and trauma. This however is not attainable in many cases and it is our clinical experience, that nerves without a target remain a source of constant discomfort and pain. Recently we reported of the feasibility of neuroma prevention through end-to-side neurorraphy into adjacent sensory and/or motor nerves to provide a target for axons deprived of their endorgan. Here we report of our first clinical experience with this method in sixteen patients with longstanding upper and lower extremity neuromas. 16 patients were included in this study. All had neuromas of different sensory nerves of both the upper and lower extremity. 11 were of iatrogenic origin, 5 were caused by different traumas. 8 had previous attempts to surgically treat the neuroma. Finally, all were treated by end-to-side neurorraphy into adjacent nerves. Postoperatively quantitative sensorymotor testing was performed to evaluate possible changes of nerve function of the recipient nerves. Pain was evaluated by visual analogue score and changes in pain medication. In no patient a sensory or motor deficit or painful sensations were induced in the target area of the recipient nerve. Some had dysaesthesias for about 6 months, which finally subsided. All but 1 patient improved in their symptoms at a follow-up of more than 2 years. Previous experimental work and present clinical results suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented without inducing sensory or motor dysfunctions in the recipient nerve. Georg Thieme Verlag KG Stuttgart New York.

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997–2003 and 2007–2009 and use of mobile and cordless phones

Science.gov (United States)

HARDELL, LENNART; CARLBERG, MICHAEL; SÖDERQVIST, FREDRIK; MILD, KJELL HANSSON

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20–80 years, diagnosed during 1997–2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007–2009 including both men and women aged 18–75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0–4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8–21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1–2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8–4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1–2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7–26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1–2.0 increasing to OR = 8.1, 95% CI = 2.0–32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2–9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless

Management of a patient undergoing sitting position craniotomy for acoustic neuroma with co-existing interstitial lung disease

Directory of Open Access Journals (Sweden)

Deepa Suvarna

2015-01-01

Full Text Available A 38-year-old woman with acoustic neuroma associated with occupational interstitial lung disease (ILD was successfully managed for sitting position craniotomy using carefully titrated desflurane-based anaesthesia. The anaesthetic challenges included maintenance an adequate depth of anaesthesia, reducing perioperative airway events and ensuring smooth recovery. While dealing with ILD patient in sitting position, careful risk assessment is important because it will help us predict the course of the perioperative events. Balanced general anaesthesia using desflurane fulfilled the requirement of good depth and smooth recovery in this patient. Though there are reports of maintenance of anaesthesia with other inhalational agents, there are scanty reports of using desflurane in these cases.

Associação entre tamanho e potencial proliferativo em neurinomas do acústico Size and proliferative index correlation in acoustic neuromas

Directory of Open Access Journals (Sweden)

Oswaldo Inácio de Tella

2006-03-01

Full Text Available Schwanomas do acústico são os tumores mais freqüentes localizados no ângulo pontocerebelar. Os mecanismos moleculares que levam a sua geração e crescimento ainda não são bem conhecidos. Várias características clínicas, radiológicas e imuno-histoquímicas já foram estudadas e correlacionadas ao crescimento tumoral. Estudamos e correlacionamos aspectos clínicos e imuno-histoquímicos (MIB-1 de 11 schwanomas do acústico operados no Hospital São Paulo/UNIFESP. O tamanho dos tumores correlacionou-se com o índice proliferativo (Ki-67, não havendo correlação com significância estatística entre a idade dos pacientes, duração dos sintomas e índice proliferativo.Acoustic neuromas are the most common tumors in the cerebellopontine angle. The molecular mechanisms involved in generation and growth of these tumors are not completly elucidated. Many radiological, clinic and imunohistochemystry data were correlated to tumor growth. We studied 11 acoustic neuromas surgically treated at Hospital São Paulo/Unifesp and correlated clinical and radiological data with proliferative index (Ki-67. The size of the tumors were positively correlationated with proliferative index. No other correlation had statistic significativity.

MRI features of peripheral traumatic neuromas

Energy Technology Data Exchange (ETDEWEB)

Ahlawat, Shivani [Johns Hopkins University School of Medicine, Musculoskeletal Radiology Section, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Belzberg, Allan J. [The Johns Hopkins Hospital, Department of Neurosurgery, Baltimore, MD (United States); Montgomery, Elizabeth A. [The Johns Hopkins Hospital, Pathology, Oncology and Orthopedic Surgery, Baltimore, MD (United States); Fayad, Laura M. [Department of Orthopedic Surgery, Department of Radiology and Radiological Science, Musculoskeletal Imaging Section Chief, The Johns Hopkins Medical Institutions, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Orthopedic Surgery, Baltimore, MD (United States)

2016-04-15

To describe the MRI appearance of traumatic neuromas on non-contrast and contrast-enhanced MRI sequences. This IRB-approved, HIPAA-compliant study retrospectively reviewed 13 subjects with 20 neuromas. Two observers reviewed pre-operative MRIs for imaging features of neuroma (size, margin, capsule, signal intensity, heterogeneity, enhancement, neurogenic features and denervation) and the nerve segment distal to the traumatic neuroma. Descriptive statistics were reported. Pearson's correlation was used to examine the relationship between size of neuroma and parent nerve. Of 20 neuromas, 13 were neuromas-in-continuity and seven were end-bulb neuromas. Neuromas had a mean size of 1.5 cm (range 0.6-4.8 cm), 100 % (20/20) had indistinct margins and 0 % (0/20) had a capsule. Eighty-eight percent (7/8) showed enhancement. All 100 % (20/20) had tail sign; 35 % (7/20) demonstrated discontinuity from the parent nerve. None showed a target sign. There was moderate positive correlation (r = 0.68, p = 0.001) with larger neuromas arising from larger parent nerves. MRI evaluation of the nerve segment distal to the neuroma showed increased size (mean size 0.5 cm ± 0.4 cm) compared to the parent nerve (mean size 0.3 cm ± 0.2 cm). Since MRI features of neuromas include enhancement, intravenous contrast medium cannot be used to distinguish neuromas from peripheral nerve sheath tumours. The clinical history of trauma with the lack of a target sign are likely the most useful clues. (orig.)

Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): Long-term results in 106 patients treated in a single institution

International Nuclear Information System (INIS)

Combs, Stephanie E.; Volk, Sigrid; Schulz-Ertner, Daniela; Huber, Peter E.; Thilmann, Christoph; Debus, Juergen

2005-01-01

Purpose: To assess the long-term outcome and toxicity of fractionated stereotactic radiotherapy for acoustic neuromas in 106 patients treated in a single institution. Patients and Methods: Between October 1989 and January 2004, fractionated stereotactic radiotherapy (FSRT) was performed in 106 patients with acoustic neuroma (AN). The median total dose applied was 57.6 Gy in median single fractions of 1.8 Gy in five fractions per week. The median irradiated tumor volume was 3.9 mL (range, 2.7-30.7 mL). The median follow-up time was 48.5 months (range, 3-172 months). Results: Fractionated stereotactic radiotherapy was well tolerated in all patients. Actuarial local tumor control rates at 3- and 5- years after FSRT were 94.3% and 93%, respectively. Actuarial useful hearing preservation was 94% at 5 years. The presence of neurofibromatosis (NF-2) significantly adversely influenced hearing preservation in patients that presented with useful hearing at the initiation of RT (p = 0.00062). Actuarial hearing preservation without the diagnosis of NF-2 was 98%. In cases with NF-2, the hearing preservation rate was 64%. Cranial nerve toxicity other than hearing impairment was rare. The rate of radiation induced toxicity to the trigeminal and facial nerve was 3.4% and 2.3%, respectively. Conclusion: Fractionated stereotactic radiotherapy is safe and efficacious for the treatment of AN, with mild toxicity with regard to hearing loss and cranial nerve function. FSRT might be considered as an equieffective treatment modality compared to neurosurgery and therefore represents an interesting alternative therapy for patients with AN

[Operative treatment of painful neuromas].

Science.gov (United States)

Stokvis, Annemieke; Coert, J Henk

2011-01-01

3-5% of patients with traumatic or iatrogenic peripheral nerve injury develop a painful neuroma, especially following trauma of small cutaneous sensory nerve branches. Neuroma pain is difficult to treat and often leads to loss of function and reduction of quality of life. Patients with a painful neuroma present with spontaneous electric, shooting or burning pain, allodynia, hyperalgesia and cold intolerance. The diagnosis is based on the medical history and physical examination, supplemented by Tinel's test and a diagnostic nerve blockade. Lasting pain relief is possible by means of surgical neuroma treatment performed by a plastic surgeon. Surgical treatment consists of repair or denervation of the nerve with relocation of the nerve stump in bone or muscle tissue or a vein. Referral of neuroma patients without delay to a plastic surgeon or multidisciplinary consultation is important, because the symptoms become increasingly difficult to treat over time. 3-5% of patients with traumatic or iatrogenic peripheral nerve injury develop a painful neuroma, especially following trauma of small cutaneous sensory nerve branches. Neuroma pain is difficult to treat and often leads to loss of function and reduction of quality of life. Patients with a painful neuroma present with spontaneous electric, shooting or burning pain, allodynia, hyperalgesia and cold intolerance. The diagnosis is based on the medical history and physical examination, supplemented by Tinel's test and a diagnostic nerve blockade. Lasting pain relief is possible by means of surgical neuroma treatment performed by a plastic surgeon. Surgical treatment consists of repair or denervation of the nerve with relocation of the nerve stump in bone or muscle tissue or a vein. Referral of neuroma patients without delay to a plastic surgeon or multidisciplinary consultation is important, because the symptoms become increasingly difficult to treat over time.

Swimming Training Reduces Neuroma Pain by Regulating Neurotrophins.

Science.gov (United States)

Tian, Jinge; Yu, Tingting; Xu, Yongming; Pu, Shaofeng; Lv, Yingying; Zhang, Xin; DU, Dongping

2018-01-01

Neuroma formation after peripheral nerve transection leads to severe neuropathic pain in amputees. Previous studies suggested that physical exercise could bring beneficial effect on alleviating neuropathic pain. However, the effect of exercise on neuroma pain still remained unclear. In addition, long-term exercise can affect the expression of neurotrophins (NT), such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), which play key roles in nociceptor sensitization and nerve sprouting after nerve injury. Here, we investigated whether long-term swimming exercise could relieve neuroma pain by modulating NT expression. We used a tibial neuroma transposition (TNT) rat model to mimic neuroma pain. After TNT surgery, rats performed swimming exercise for 5 wk. Neuroma pain and tactile sensitivities were detected using von Frey filaments. Immunofluorescence was applied to analyze neuroma formation. NGF and BDNF expressions in peripheral neuroma, dorsal root ganglion, and the spinal cord were measured using enzyme-linked immunosorbent assay and Western blotting. TNT led to neuroma formation, induced neuroma pain, and mechanical allodynia in hind paw. Five-week swimming exercise inhibited neuroma formation and relieved mechanical allodynia in the hind paw and neuroma pain in the lateral ankle. The analgesic effect lasted for at least 1 wk, even when the exercise ceased. TNT elevated the expressions of BDNF and NGF in peripheral neuroma, dorsal root ganglion, and the spinal cord to different extents. Swimming also decreased the elevation of NT expression. Swimming exercise not only inhibits neuroma formation induced by nerve transection but also relieves pain behavior. These effects might be associated with the modulation of NT.

Acoustic Neuroma Educational Video

Medline Plus

Full Text Available ... Back Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic ... 205-8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home ...

Probabilistic Multiple-Bias Modeling Applied to the Canadian Data From the Interphone Study of Mobile Phone Use and Risk of Glioma, Meningioma, Acoustic Neuroma, and Parotid Gland Tumors.

Science.gov (United States)

Momoli, F; Siemiatycki, J; McBride, M L; Parent, M-É; Richardson, L; Bedard, D; Platt, R; Vrijheid, M; Cardis, E; Krewski, D

2017-10-01

We undertook a re-analysis of the Canadian data from the 13-country case-control Interphone Study (2001-2004), in which researchers evaluated the associations of mobile phone use with the risks of brain, acoustic neuroma, and parotid gland tumors. In the main publication of the multinational Interphone Study, investigators concluded that biases and errors prevented a causal interpretation. We applied a probabilistic multiple-bias model to address possible biases simultaneously, using validation data from billing records and nonparticipant questionnaires as information on recall error and selective participation. In our modeling, we sought to adjust for these sources of uncertainty and to facilitate interpretation. For glioma, when comparing those in the highest quartile of use (>558 lifetime hours) to those who were not regular users, the odds ratio was 2.0 (95% confidence interval: 1.2, 3.4). After adjustment for selection and recall biases, the odds ratio was 2.2 (95% limits: 1.3, 4.1). There was little evidence of an increase in the risk of meningioma, acoustic neuroma, or parotid gland tumors in relation to mobile phone use. Adjustments for selection and recall biases did not materially affect interpretation in our results from Canadian data. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Distal anterior inferior cerebellar artery syndrome after acoustic neuroma surgery.

Science.gov (United States)

Hegarty, Joseph L; Jackler, Robert K; Rigby, Peter L; Pitts, Lawrence H; Cheung, Steven W

2002-07-01

To define a clinicopathologic syndrome associated with persistent cerebellar dysfunction after acoustic neuroma (AN) excision. Case series derived from radiographic and clinical chart review. Tertiary referral center. In 12 patients with AN, persistent cerebellar dysfunction developed after AN removal. Each case demonstrated abnormality in the ipsilateral cerebellar peduncle on postoperative magnetic resonance imaging. Cerebellar function and ambulatory status over the first postoperative year. On magnetic resonance imaging scans, the extent of cerebellar peduncle infarcts was variable. It ranged from focal brain injury (2 cm) spanning the full thickness of the peduncle. Peduncular infarcts were associated with large tumor size (average 3.8 cm, range 2.0-5.5 cm diameter). The long-term functional outcomes (>1 yr) varied. Dysmetria was unchanged or improved in over half of the patients (6 of 11 patients). Gait recovered to normal or to preoperative levels in 5 patients. In the 6 patients with persistent impaired mobility, 2 had mild gait disturbance, 3 required regular use of a cane, and 1 has been dependent on a walker. One patient had sustained mild motor weakness. Three of 11 patients remained dependent on others for activities of daily living. Peduncle injury most likely stems from interruption of distal branches of the anterior inferior cerebellar artery (AICA). These small vessels are intimately related to the capsule of the tumor and may supply both the neoplasm and the brain parenchyma. It has long been recognized that interruption of the proximal segment of the AICA results in severe injury to the pons, with devastating neurologic sequelae. A limited AICA syndrome caused by loss of its distal ramifications seems a more plausible explanation for peduncular infarction than either venous insufficiency or direct surgical trauma.

SU-E-T-208: Incidence Cancer Risk From the Radiation Treatment for Acoustic Neuroma Patient

Energy Technology Data Exchange (ETDEWEB)

Kim, D [Kyung Hee University International Med. Serv., Seoul (Korea, Republic of); Chung, W [Kyung Hee University Hospital at Gangdong, Seoul, Seoul (Korea, Republic of); Shin, D [Kyung Hee University Hospital, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

2014-06-01

Purpose: The present study aimed to compare the incidence risk of a secondary cancer from therapeutic doses in patients receiving intensitymodulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Methods: Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their incidnece excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were estimated using the corresponding therapeutic doses measured at various organs by radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. Results: When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, normal liver, colon, bladder, prostate (or ovary), and rectum were measured. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A LAR were estimated that more than 0.03% of AN patients would get radiation-induced cancer. Conclusion: The tyroid was highest radiation-induced cancer risk after radiation treatment for AN. We found that LAR can be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

Morton neuroma: MRI diagnostic value

International Nuclear Information System (INIS)

Yelin, Enrique G.; Aparicio, Rocio; Dutto, Santiago; Rodriguez Lucero, Javier

2004-01-01

Objective: To evaluate the diagnostic value of MRI in Morton's Neuroma (MN). Material and methods: 23 patients with clinical diagnosis of MN were examined under two different protocols, with a 1.5 T Magnet. 1) T1, FSET2, FIR, T1 with contrast enhancement and fat suppression; 2) T1, FSET2, FIR without contrast enhancement (i.v. Gadolinium). Results: In the first group MN was found in 7 patients. In the second group 14 patients were studied, 7 with positive MR for neuroma, and 9 with negative MR. 6 were true-negative and 3 were false-negative. The Fisher Test between both groups was p < 0.05. Conclusion: MRI is effective for the diagnosis of Morton neuroma. The use of gadolinium and fat suppression significantly improved the detection of Morton neuroma, allowing better measurements of the lesion. These findings do not correlate with previous papers that do not encourage the use of i.v. Gadolinium. (author)

SU-F-T-611: Critical Analysis and Efficacy of Linac Based (Beam Modulator) and Cyberknife Treatment Plans for Acoustic Neuroma/schwannoma

International Nuclear Information System (INIS)

KP, Karrthick; Kataria, T; Thiyagarajan, R; Selvan, T; Abhishek, A

2016-01-01

Purpose: To study the critical analysis and efficacy of Linac and Cyberknife (CK) treatment plans for acoustic neuroma/schwannoma. Methods: Twelve of acoustic neuroma/schwannoma patients were taken for these study that. Treatment plans were generated in Multiplan treatment planning system (TPS) for CK using 5,7.5 and 10mm diameter collimators. Target volumes were in the range of 0.280 cc to 9.256 cc. Prescription dose (Rx) ranges from 1150cGy to 1950cGy delivered over 1 to 3 Fractions. For same patients stereotactic Volumetric modulated arc plans were generated using Elekta Linac with MLC thickness of 4mm in Monaco TPS. Appropriate calculation algorithms and grid size were used with same Rx and organ at risk (OAR) constrains for both Linac and CK plans. Treatment plans were developed to achieve at least 95% of the target volume to receive the Rx. The dosimetric indices such as conformity index (CI), coverage, OAR dose and volume receiving 50% of Rx (V50%) were used to evaluate the plans. Results: Target volumes ranges from 0.280 cc to 3.5cc shows the CI of 1.16±0.109 and 1.53±0.360 for cyberknife and Linac plans respectively. For small volume targets, the OARs were well spared in CK plans. There are no significant differences in CI and OAR doses were observed between CK and Linac plans that have the target volume >3.5 cc. Perhaps the V50% were lesser in CK plans, and found to be 12.8± 8.4 and 22.8 ± 15.0 for CK and Linac respectively. Conclusion: The analysis shows the importance of collimator size for small volume targets. The target volumes >3.5 cc can be treated in Linac as comparable with CK. For targets <3.5cc CK plans showed superior plan quality with better CI and OAR sparing than the Linac based plans. Further studies may require evaluating the clinical advantage of CK robotic system.

Occupation and risk of glioma, meningioma and acoustic neuroma: results from a German case-control study (interphone study group, Germany)

DEFF Research Database (Denmark)

Samkange-Zeeb, F; Schlehofer, B; Schüz, J

2010-01-01

/electronic and transport, and the risk of glioma, meningioma and acoustic neuroma. METHODS: In a population-based case-control study involving a total of 844 cases and 1688 controls conducted from 2000 to 2003, detailed information on life-long job histories was collected during personal interviews and used to create job...... calendars for each participant. Job title, job activity, job number, and the starting and ending dates of the activity were recorded for all activities with duration of at least 1 year. Reported occupational activities were coded according to the International Standard Classification of Occupations 1988...... (ISCO 88). For the analyses we focused on six a priori defined occupational sectors, namely chemical, metal, agricultural, construction, electrical/electronic and transport. Multiple conditional logistic regression analysis was used to estimate odds ratios and their 95% confidence intervals. RESULTS...

Use of piezosurgery for internal auditory canal drilling in acoustic neuroma surgery.

Science.gov (United States)

Grauvogel, Juergen; Scheiwe, Christian; Kaminsky, Jan

2011-10-01

Piezosurgery is based on microvibrations generated by the piezoelectrical effect and has a selective bone-cutting ability with preservation of soft tissue. This study examined the applicability of Piezosurgery compared to rotating drills (RD) for internal auditory canal (IAC) opening in acoustic neuroma (AN) surgery. Piezosurgery was used in eight patients for IAC drilling in AN surgery. After exposition of the IAC and tumor, the posterior wall of the IAC was drilled using Piezosurgery instead of RD. Piezosurgery was evaluated with respect to practicability, safety, preciseness of bone cutting, preservation of cranial nerves, influences on neurophysiological monitoring, and facial nerve and hearing outcome. Piezosurgery was successfully used for selective bone cutting, while cranial nerves were structurally and functionally preserved, which could be measured by means of neuromonitoring. Piezosurgery guaranteed a safe and precise cut by removing bone layer by layer in a shaping way. Compared to RD, limited influence on neurophysiological monitoring attributable to Piezosurgery was noted, allowing for continuous neuromonitoring. No disadvantage due to microvibrations was noticed concerning hearing function. The angled tip showed better handling in right-sided than in left-sided tumors in the hands of a right-handed surgeon. The short, thick handpiece may be improved for more convenient handling. Piezosurgery is a safe tool for selective bone cutting for opening of the IAC with preservation of facial nerve and hearing function in AN surgery. Piezosurgery has the potential to replace RD for this indication because of its safe and precise bone-cutting properties.

CT and MRI of haemorrhage into intracranial neuromas

Energy Technology Data Exchange (ETDEWEB)

Asari, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Katayama, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Itoh, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Tsuchida, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Ohmoto, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan))

1993-04-01

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spin-echo pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effectie than CT in detecting haemorrhage into the tumours and in staging it. (orig.)

Use of mobile phones and cordless phones is associated with increased risk for glioma and acoustic neuroma.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Hansson Mild, Kjell

2013-04-01

The International Agency for Research on Cancer (IARC) at WHO evaluation of the carcinogenic effect of RF-EMF on humans took place during a 24-31 May 2011 meeting at Lyon in France. The Working Group consisted of 30 scientists and categorised the radiofrequency electromagnetic fields from mobile phones, and from other devices that emit similar non-ionising electromagnetic fields (RF-EMF), as Group 2B, i.e., a 'possible', human carcinogen. The decision on mobile phones was based mainly on the Hardell group of studies from Sweden and the IARC Interphone study. We give an overview of current epidemiological evidence for an increased risk for brain tumours including a meta-analysis of the Hardell group and Interphone results for mobile phone use. Results for cordless phones are lacking in Interphone. The meta-analysis gave for glioma in the most exposed part of the brain, the temporal lobe, odds ratio (OR)=1.71, 95% confidence interval (CI)=1.04-2.81 in the ≥10 years (>10 years in the Hardell group) latency group. Ipsilateral mobile phone use ≥1640h in total gave OR=2.29, 95% CI=1.56-3.37. The results for meningioma were OR=1.25, 95% CI=0.31-4.98 and OR=1.35, 95% CI=0.81-2.23, respectively. Regarding acoustic neuroma ipsilateral mobile phone use in the latency group ≥10 years gave OR=1.81, 95% CI=0.73-4.45. For ipsilateral cumulative use ≥1640h OR=2.55, 95% CI=1.50-4.40 was obtained. Also use of cordless phones increased the risk for glioma and acoustic neuroma in the Hardell group studies. Survival of patients with glioma was analysed in the Hardell group studies yielding in the >10 years latency period hazard ratio (HR)=1.2, 95% CI=1.002-1.5 for use of wireless phones. This increased HR was based on results for astrocytoma WHO grade IV (glioblastoma multiforme). Decreased HR was found for low-grade astrocytoma, WHO grades I-II, which might be caused by RF-EMF exposure leading to tumour-associated symptoms and earlier detection and surgery with better

Ultrasonography and magnetic resonance imaging in the diagnosis of Morton's neuroma.

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Fazal, Muhammad Ali; Khan, Ishrat; Thomas, Cherian

2012-01-01

Magnetic resonance imaging (MRI) and ultrasonography are used widely for the diagnosis of Morton's neuroma. The aim of this study was to assess the accuracy of these two modalities as diagnostic tools in Morton's neuroma. Fifty feet of 47 consecutive patients (39 women and 8 men; mean age, 46 years; age range, 36-64 years) who presented between January 1, 2005, and June 30, 2008, were included in the study. Twenty-five feet were investigated with ultrasonography and 25 with MRI. Morton's neuroma was confirmed surgically and histologically in all of the patients. A Student unpaired t test was applied. Twenty-two MRIs were diagnostic (sensitivity, 88%). Three patients with negative MRI findings underwent ultrasonography and were found to have a neuroma smaller than 5 mm. Twenty-four ultrasound scans demonstrated the neuroma (sensitivity, 96%), with five neuromas being smaller than 5 mm. Ultrasonography has a slightly higher sensitivity in the diagnosis of Morton's neuroma, particularly of neuromas smaller than 5 mm, and should be the preferred imaging modality in suspected cases, and MRI should be reserved for cases with equivocal diagnosis.

An evidence-based case of acoustic/vestibular schwannoma

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Girish Gupta

2015-01-01

Full Text Available A vestibular schwannoma, often called an acoustic neuroma/schwannoma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulo-cochlear nerve (8 th cranial nerve. This tumor arises from the Schwann cells responsible for the myelin sheath that helps keep peripheral nerves insulated. [1] Approximately, 3000 cases are diagnosed each year in the United States with a prevalence of about 1 in 100,000 worldwide. It comprises 5-10% of all intracranial neoplasms in adults. Incidence peaks in the fifth and sixth decades and both sexes are affected equally. Studies in Denmark published in 2004 show the incidence of 17.4/million. Most acoustic neuromas are diagnosed in patients between the ages of 30 and 60, and men and women appear to be affected equally. [2] The case illustrated here is a rare one of acoustic/vestibular schwannoma a surgical conditions, treated with Lycopodium, which produced improvement on both subjective and objective parameters.

Palisaded encapsulated neuroma

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Adesh S Manchanda

2015-01-01

Full Text Available Palisaded encapsulated neuroma (PEN is a benign cutaneous or mucosal neural tumor which, usually, presents as a solitary, firm, asymptomatic, papule or nodule showing striking predilection for the face. It occurs commonly in middle age, and there is no sex predilection. Oral PEN are not common, and these lesions must be distinguished from other peripheral nerve sheath tumors such as the neurofibroma, neurilemma (schwannoma, and traumatic neuroma. The major challenge in dealing with lesions of PEN is to avoid the misdiagnosis of neural tumors that may be associated with systemic syndromes such as neurofibromatosis and multiple endocrine neoplasia syndrome type 2B. Here, we present a case of benign PEN of the gingiva in the left anterior mandibular region, laying importance on immunohistochemical staining in diagnosing such lesions.

A free vein graft cap influences neuroma formation after nerve transection.

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Galeano, Mariarosaria; Manasseri, Benedetto; Risitano, Giovanni; Geuna, Stefano; Di Scipio, Federica; La Rosa, Paola; Delia, Gabriele; D'Alcontres, Francesco Stagno; Colonna, Michele R

2009-01-01

: Neuroma formation is a major problem in nerve surgery and consensus about its prevention has not been reached. It has been suggested that vein covering can reduce neuroma formation in transected nerves. In this article, the Authors propose an easy and novel method of covering by nerve stump capping with a free vein graft. : Neuroma-like lesions were created on the rat thigh sectioning the femoral nerve above its division in 16 animals. The proximal nerve stump was invaginated into the lumen of a 1.5 cm long femoral free vein graft on the right side, and the vein was closed on itself by microsurgical sutures to form a cap for the nerve stump. On the left side acting as the control neuroma, the nerve was cut and left uncovered. Histological and immunohistochemical assessment was used to quantify the degree of neuroma formation. : Significant differences were found in both neuroma size and axon-glia organization between the treated and control sides indicating that free vein graft capping reduced neuroma formation in comparison to uncovered nerve stumps. : Our results confirm that vein-covering of a transected nerve stump can be effective in reducing neuroma formation. Moreover, unlike previous works that buried the nerve into an adjacent vein left in place, our experiments showed that also the use of a free vein graft cap can hinder neuroma formation. Although translation of rat experiments to the clinics should be dealt with caution, our data suggest a careful clinical use of the technique. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

Validation of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) for Spanish-Speaking Patients.

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Medina, Maria Del Mar; Carrillo, Alvaro; Polo, Ruben; Fernandez, Borja; Alonso, Daniel; Vaca, Miguel; Cordero, Adela; Perez, Cecilia; Muriel, Alfonso; Cobeta, Ignacio

2017-04-01

Objective To perform translation, cross-cultural adaptation, and validation of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) to the Spanish language. Study Design Prospective study. Setting Tertiary neurotologic referral center. Subjects and Methods PANQOL was translated and translated back, and a pretest trial was performed. The study included 27 individuals diagnosed with vestibular schwannoma. Inclusion criteria were adults with untreated vestibular schwannoma, diagnosed in the past 12 months. Feasibility, internal consistency, test-retest reliability, construct validity, and ceiling and floor effects were assessed for the present study. Results The mean overall score of the PANQOL was 69.21 (0-100 scale, lowest to highest quality of life). Cronbach's α was 0.87. Intraclass correlation coefficient was performed for each item, with an overall score of 0.92. The κ coefficient scores were between moderate and almost perfect in more than 92% of patients. Anxiety and energy domains of the PANQOL were correlated with both physical and mental components of the SF-12. Hearing, balance, and pain domains were correlated with the SF-12 physical component. Facial and general domains were not significantly correlated with any component of the SF-12. Furthermore, the overall score of the PANQOL was correlated with the physical component of the SF-12. Conclusion Feasibility, internal consistency, reliability, and construct validity outcomes in the current study support the validity of the Spanish version of the PANQOL.

A quantitative evaluation of gross versus histologic neuroma formation in a rabbit forelimb amputation model: potential implications for the operative treatment and study of neuromas

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Kuiken Todd A

2011-10-01

Full Text Available Abstract Background Surgical treatment of neuromas involves excision of neuromas proximally to the level of grossly "normal" fascicles; however, proximal changes at the axonal level may have both functional and therapeutic implications with regard to amputated nerves. In order to better understand the retrograde "zone of injury" that occurs after nerve transection, we investigated the gross and histologic changes in transected nerves using a rabbit forelimb amputation model. Methods Four New Zealand White rabbits underwent a forelimb amputation with transection and preservation of the median, radial, and ulnar nerves. After 8 weeks, serial sections of the amputated nerves were then obtained in a distal-to-proximal direction toward the brachial plexus. Quantitative histomorphometric analysis was performed on all nerve specimens. Results All nerves demonstrated statistically significant increases in nerve cross-sectional area between treatment and control limbs at the distal nerve end, but these differences were not observed 10 mm more proximal to the neuroma bulb. At the axonal level, an increased number of myelinated fibers were seen at the distal end of all amputated nerves. The number of myelinated fibers progressively decreased in proximal sections, normalizing at 15 mm proximally, or the level of the brachial plexus. The cross-sectional area of myelinated fibers was significantly decreased in all sections of the treatment nerves, indicating that atrophic axonal changes proceed proximally at least to the level of the brachial plexus. Conclusions Morphologic changes at the axonal level extend beyond the region of gross neuroma formation in a distal-to-proximal fashion after nerve transection. This discrepancy between gross and histologic neuromas signifies the need for improved standardization among neuroma models, while also providing a fresh perspective on how we should view neuromas during peripheral nerve surgery.

Ultrasound-Guided Hyaluronic Acid Injection for the Management of Morton's Neuroma.

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Lee, Kang; Hwang, Il-Yeong; Ryu, Chang Hyun; Lee, Jae Woo; Kang, Seung Woo

2018-02-01

Morton's neuroma is one of the common causes of forefoot pain. In the present study, hyaluronic acid injection was performed on patients to determine the efficacy and adverse effects of hyaluronic acid in management of Morton's neuroma. Eighty-three patients with Morton's neuroma in their third intermetatarsal space with definite Mulder's click were included in the study. Those with severe forefoot deformities such as forefoot cavus or hallux valgus on plain X-rays were excluded. Ultrasound-guided hyaluronic acid injections were performed on all patients weekly for 3 weeks. Pain during walking using visual analogue scale (VAS) and AOFAS Forefoot Scale were prospectively evaluated preinjection, and at 2, 4, 6, 12 months postinjection. Significant improvement in VAS and AOFAS Forefoot Scale were seen overall at 2 months after hyaluronic acid injections ( P hyaluronic injection was clinically effective for pain relief and functional improvement for at least 12 months in patients with Morton's neuroma. However, numbness associated with Morton's neuroma should be addressed more cautiously since it may persist without much improvement. Level IV, retrospective case series.

Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus

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Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

2011-01-01

Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

Ultrasonographic features of traumatic neuromas in breast cancer patients after mastectomy

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Sung, Hwa Sung; Kim, Young Seon [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

2017-01-15

The purpose of this study was to evaluate the ultrasonographic (US) features of traumatic neuromas in breast cancer patients after mastectomy. This study was performed with approval from our Institutional Review Board, and the requirement for informed consent was waived. Six traumatic neuromas in five patients were included in this study. The US findings of traumatic neuromas were evaluated retrospectively by two radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. The final assessment was also recorded. On US, all six lesions presented as a mass within the pectoralis muscle layer (mean size, 4.8 mm; range, 3.9 to 5.5 mm). Of the six masses, four had an oval shape with a circumscribed margin, and two had an irregular shape and an indistinct margin. They were all hypoechoic. Two lesions showed a non-parallel orientation. On color Doppler examinations, two lesions showed internal vascularity. Strain elastography was performed for four neuromas, resulting in scores of 1 (n=1), 4 (n=2), and 5 (n=1). The final assessment categories were BI-RADS 3 (n=2), 4A (n=2), and 4B (n=2). On US, an oval shape, circumscribed margin, parallel orientation, and hypoechogenicity were the most frequent features of traumatic neuromas in breast cancer patients after mastectomy. Neuromas may show increased vascularity on color Doppler imaging and present as a hard mass on elastography.

Ultrasonographic features of traumatic neuromas in breast cancer patients after mastectomy

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Hwa Sung Sung

2017-01-01

Full Text Available Purpose The purpose of this study was to evaluate the ultrasonographic (US features of traumatic neuromas in breast cancer patients after mastectomy. Methods This study was performed with approval from our Institutional Review Board, and the requirement for informed consent was waived. Six traumatic neuromas in five patients were included in this study. The US findings of traumatic neuromas were evaluated retrospectively by two radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS lexicon. The final assessment was also recorded. Results On US, all six lesions presented as a mass within the pectoralis muscle layer (mean size, 4.8 mm; range, 3.9 to 5.5 mm. Of the six masses, four had an oval shape with a circumscribed margin, and two had an irregular shape and an indistinct margin. They were all hypoechoic. Two lesions showed a non-parallel orientation. On color Doppler examinations, two lesions showed internal vascularity. Strain elastography was performed for four neuromas, resulting in scores of 1 (n=1, 4 (n=2, and 5 (n=1. The final assessment categories were BI-RADS 3 (n=2, 4A (n=2, and 4B (n=2. Conclusion On US, an oval shape, circumscribed margin, parallel orientation, and hypoechogenicity were the most frequent features of traumatic neuromas in breast cancer patients after mastectomy. Neuromas may show increased vascularity on color Doppler imaging and present as a hard mass on elastography.

Hypofractionated stereotactic radiotherapy of acoustic neuroma. Volume changes and hearing results after 89-month median follow-up

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Kranzinger, Manfred; Fastner, Gerd [Paracelsus Medical University Clinics (PMU), University Clinic of Radiotherapy and Radio-Oncology, Salzburg County Hospital, Salzburg (Austria); Zehentmayr, Franz; Sedlmayer, Felix [Paracelsus Medical University Clinics (PMU), University Clinic of Radiotherapy and Radio-Oncology, Salzburg County Hospital, Salzburg (Austria); Salzburg County Hospital, Paracelsus Medical University Clinics, radART - Institute for Research and Development on Advanced Radiation Technologies, Salzburg (Austria); Oberascher, Gerhard [Paracelsus Medical University Clinics (PMU), University Clinic of Ear, Nose and Throat Diseases, Salzburg County Hospital, Salzburg (Austria); Merz, Florian; Rahim, Hassan [Salzburg County Hospital, Paracelsus Medical University Clinics, Medical Radiation Protection Unit, Salzburg (Austria); Nairz, Olaf [Clinic Bad Trissl, Oberaudorf (Germany)

2014-09-15

The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity. In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 x 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995). No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9 %) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1 %. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4 %. Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery. (orig.) [German] Ziel der Studie war die Evaluierung der Toxizitaet und der lokalen Tumorkontrolle einer hypofraktionierten stereotaktischen Bestrahlung mit besonderem Augenmerk auf Veraenderungen von Tumorvolumen und

Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma

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LIU Bai-yun; TIAN Yong-ji; LIU Wen; LIU Shu-ling; QIAO Hui; ZHANG Jun-ting; JIA Gui-jun

2007-01-01

Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function.Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation (TCEMEP) for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed.Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis (H-B grade 3), and 5 had mild facial paralysis (H-B grade 2). In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal.Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.

Multistep translation and cultural adaptation of the Penn acoustic neuroma quality-of-life scale for German-speaking patients.

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Kristin, Julia; Glaas, Marcel Fabian; Stenin, Igor; Albrecht, Angelika; Klenzner, Thomas; Schipper, Jörg; Eysel-Gosepath, Katrin

2017-11-01

Monitoring the health-related quality of life (HRQOL) for patients with vestibular schwannoma (VS) has garnered increasing interest. In German-speaking countries, there is no disease-specific questionnaire available similar to the "Penn Acoustic Neuroma Quality-of-life Scale" (PANQOL). We translated the PANQOL for German-speaking patients based on a multistep protocol that included not only a forward-backward translation but also linguistic and sociocultural adaptations. The process consists of translation, synthesis, back translation, review by an expert committee, administration of the prefinal version to our patients, submission and appraisal of all written documents by our research team. The required multidisciplinary team for translation comprised head and neck surgeons, language professionals (German and English), a professional translator, and bilingual participants. A total of 123 patients with VS underwent microsurgical procedures via different approaches at our clinic between January 2007 and January 2017. Among these, 72 patients who underwent the translabyrinthine approach participated in the testing of the German-translated PANQOL. The first German version of the PANQOL questionnaire was created by a multistep translation process. The responses indicate that the questionnaire is simple to administer and applicable to our patients. The use of a multistep process to translate quality-of-life questionnaires is complex and time-consuming. However, this process was performed properly and resulted in a version of the PANQOL for assessing the quality of life of German-speaking patients with VS.

Intratemporal facial nerve neuromas and their mimics: CT and MR findings

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Han, Moon Hee; Chang, Kee Hyun; Lee, Kyung Hwan; Cha, Sang Hoon; Kim, Chong Sun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Sang Joon [Chungang Gil General Hospital, Seoul (Korea, Republic of)

1992-05-15

CT and MR findings of nine cases with intra temporal facial nerve neuromas were described and compared with CT findings of 3 cases with facial nerve palsy and facial nerve canal erosion which may mimic facial nerve neuroma. The tympanic segment of the facial nerve was involved in 8 cases, mastoid segment in 7 cases and labyrinthine segment in 5 cases. The lesions were easily diagnosed with high resolution CT with bone algorithms by showing the expansion of bony structures along the course of the facial nerves. In 4 cases with large vertical segment tumors, extensive destruction of mastoid air cells and external auditory canals posed difficulty in making a diagnosis. Two out of 5 cases with labyrinthine segment involvement were presented as middle cranial fossa masses. MRI with enhancement was performed in 4 cases and was useful in characterizing the lesion as a tumor with its superior sensitivity to enhancement. Three cases of facial neuroma-mimicking lesion including post-inflammatory peri neural thickening, peri neural extension from parotid adenoid cystic carcinoma, and congenita; cholesteatoma showed irregular erosion or mild expansion of the facial nerve canal which may be helpful for differential diagnosis from neuromas.

Endobronchial neurogenic tumor: A combination of traumatic neuroma and neurofibroma

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Amit Tandon

2017-01-01

Full Text Available Traumatic neuromas are uncommon and benign lesions arising from a peripheral nerve injury during surgery. Here we describe a case with histopathologic features of both a traumatic neuroma and neurofibroma in a patient without integumentary physical exam findings nor prior surgical history. A 54 year old male was admitted for surgical debridement of a foot ulcer. During pre-operative evaluation and review of imaging multiple CT scans revealed a stable, 4 mm endobronchial lesion in the left lower lobe. Given history of nicotine abuse, bronchoscopy was performed. Bronchoscopy showed a pearly, polypoid lesion. Histopathological results showed strong positivity for S-100 protein and spindle cell proliferation. Repeat CT chest showed no new lesions in the bronchial tree. The rarity of this case is noted not only by the limited number of bronchial neurogenic tumors, but the combined features in this case of a traumatic neuroma and neurofibroma which has not been described.

Penile Traumatic Neuroma: A Late Complication of Penile Dorsal Neurotomy to Treat Premature Ejaculation

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Hyun Jun Park

2016-09-01

Conclusion: The main complications of SDN are recurrence of premature ejaculation, pain or paresthesia on the glans penis, and erectile dysfunction. However, no traumatic neuroma has been reported as a complication. We report that a traumatic neuroma can occur after SDN.

Filippo Civinini (1805-1844 and the discovery of plantar neuroma

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P. Marson

2011-09-01

Full Text Available Pathological abnormality (neuroma related to the painful foot condition commonly called “Morton’s metatarsalgia” was first observed in 1835 by Filippo Civinini (1805-1844 of Pistoia, in course of a cadaverous dissection, and clearly described in the anatomic letter entitled “Su un nervoso gangliare rigonfiamento alla pianta del piede” (“On the neural gangliar swelling of the foot sole”. In this study a brief review on the history of Morton’s metatarsalgia is carried out, and the importance of Civinini in the discovery of the neuroma of the III intermetatarsal web is underlined.

Palisaded Encapsulated (Solitary Circumscribed) Neuroma of the Buccal Mucosa: a Rare Case.

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Atarbashi-Moghadam, Saede; Lotfi, Ali; Salehi Zalani, Saman; Mokhtari, Sepideh

2017-12-01

The rarity of oral soft tissue spindle cell tumors combined with overlapping microscopic patterns can make challenges in their diagnosis and treatment. Oral cavity palisaded encapsulated neuroma is an uncommon lesion which occurs often on the hard palate. It is essential for oral pathologists to be familiar with its histopathology of this lesion is essential since many lesions are probably diagnosed microscopically as neurofibroma or schwannoma. Here, we report a case of oral palisaded encapsulated (solitary circumscribed) neuroma in an unusual site.

Recurrent neuroma formation after lateral arm free flap coverage with neurorraphy to the posteroantebrachial nerve.

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Peterson, Steven L; Gordon, Michael J

2004-09-01

We report a patient with previous wrist trauma and development of a symptomatic neuroma of the palmar cutaneous branch of the median nerve. The patient had previously been successfully treated with lateral arm free flap coverage with neurorrhaphy to a segment of the posteroantebrachial cutaneous nerve carried with the flap. Two years following this procedure the patient experienced re-onset of symptoms prompting surgical exploration of the area. At the time of operation a recurrent neuroma was found at the free distal terminus of the transferred posteroantebrachial cutaneous nerve. The neuroma was repositioned into the distal radius via a burr hole with relief of symptoms.

Hearing preservation after low dose linac radiosurgery for acoustic neuroma depends on initial hearing and time

International Nuclear Information System (INIS)

Roos, Daniel E.; Potter, Andrew E.; Zacest, Andrew C.

2011-01-01

Purpose: To assess long term outcomes and factors determining hearing preservation after low dose linac stereotactic radiosurgery (SRS) for acoustic neuroma (AN) at the Royal Adelaide Hospital using prospectively collected data. Material and methods: Between 1994 and 2010, 102 patients had SRS for AN. Five patients had neurofibromatosis type 2, six sporadic cases had relapsed after surgery, and the remaining 91 sporadic cases had primary SRS. Dose was 12 or 14 Gy. Sustained changes ⩾ 2 mm in any diameter were deemed significant, and useful hearing was defined as inter-aural pure tone average (PTA) ⩽ 50 dB. Possible prognostic factors for hearing retention were tested by dividing the patients at pre-specified cutpoints: age (60 years), maximum tumour diameter (20 mm), initial PTA (20 dB) and dose (12 vs 14 Gy). Results: Eighty-four of the 91 sporadic primary SRS cases were evaluable for tumour control with at least one post-treatment MRI. Their median follow-up was 65 mo (range 10–184 mo). Eighty-two (97.6%) were controlled, the remaining two requiring salvage surgery for progression at 5.75 and 9.75 years. Also, one of the post-operative cases required surgery at 2.1 years after SRS. For the 50 sporadic primary SRS patients with initially useful hearing, median age was 56 (range 21–76), median initial PTA 16 dB (range −11 to +45 dB) and median tumour diameter 21 mm (range 10–33 mm). Four received 14 Gy, the rest 12 Gy. After SRS, 19 patients (38%) retained useful hearing. The Kaplan–Meier estimated preservation rate at 5 years was 50% (95% CI 36–64%) but by 10 years, this had fallen to 23% (95% CI 12–41%). On univariate analysis, the only significant factor was initial PTA (P < 0.0001). The estimated risk of hearing loss after SRS for patients with initial PTA ⩾ 20 dB was 5.0 (95% CI 2.2–11.2) times that with PTA < 20 dB. Conclusions: Tumour control was excellent (99/102 = 97% freedom from surgical salvage). Hearing preservation was strongly

Novel experimental surgical strategy to prevent traumatic neuroma formation by combining a 3D-printed Y-tube with an autograft.

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Bolleboom, Anne; de Ruiter, Godard C W; Coert, J Henk; Tuk, Bastiaan; Holstege, Jan C; van Neck, Johan W

2018-02-09

OBJECTIVE Traumatic neuromas may develop after nerve injury at the proximal nerve stump, which can lead to neuropathic pain. These neuromas are often resistant to therapy, and excision of the neuroma frequently leads to recurrence. In this study, the authors present a novel surgical strategy to prevent neuroma formation based on the principle of centro-central anastomosis (CCA), but rather than directly connecting the nerve ends to an autograft, they created a loop using a 3D-printed polyethylene Y-shaped conduit with an autograft in the distal outlets. METHODS The 3D-printed Y-tube with autograft was investigated in a model of rat sciatic nerve transection in which the Y-tube was placed on the proximal sciatic nerve stump and a peroneal graft was placed between the distal outlets of the Y-tube to form a closed loop. This model was compared with a CCA model, in which a loop was created between the proximal tibial and peroneal nerves with a peroneal autograft. Additional control groups consisted of the closed Y-tube and the extended-arm Y-tube. Results were analyzed at 12 weeks of survival using nerve morphometry for the occurrence of neuroma formation and axonal regeneration in plastic semi-thin sections. RESULTS Among the different surgical groups, the Y-tube with interposed autograft was the only model that did not result in neuroma formation at 12 weeks of survival. In addition, a 13% reduction in the number of myelinated axons regenerating through the interposed autograft was observed in the Y-tube with autograft model. In the CCA model, the authors also observed a decrease of 17% in the number of myelinated axons, but neuroma formation was present in this model. The closed Y-tube resulted in minimal nerve regeneration inside the tube together with extensive neuroma formation before the entrance of the tube. The extended-arm Y-tube model clearly showed that the majority of the regenerating axons merged into the Y-tube arm, which was connected to the autograft

Novel model for end-neuroma formation in the amputated rabbit forelimb

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Kuiken Todd A

2010-03-01

Full Text Available Abstract Background The forelimb amputee poses many reconstructive challenges in the clinical setting, and there is a paucity of established surgical models for study. To further elucidate the pathogenic process in amputation neuroma formation, we created a reproducible, well-tolerated rabbit forelimb amputation model. Methods Upon approval from the Institutional Animal Care and Use Committee, 5 New Zealand White rabbits underwent left forelimb amputation. During this initial surgery, the median, radial and ulnar nerves were transected 1.6-2.5 (mean 2.0 cm distal to the brachial plexus, transposed onto the anterior chest wall and preserved at length. Six weeks subsequent to the amputation, the distal 5 mm of each neuroma was excised, and the remaining stump underwent histomorphometric analysis. Results The nerve cross sectional areas increased by factors of 1.99, 3.17, and 2.59 in the median (p = 0.077, radial (p Conclusion Given that the surgical model appears well-tolerated by the rabbits and that patterns of morphologic change are consistent and reproducible, we are encouraged to further investigate the utility of this model in the pathogenesis of neuroma formation.

Three Cycles of Radiofrequency Ablation Are More Efficacious Than Two in the Management of Morton's Neuroma.

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Brooks, David; Parr, Adam; Bryceson, William

2018-04-01

Morton's neuroma is a common cause of forefoot pain. Outcomes of conservative therapy are mixed and many patients undergo operative intervention. Radiofrequency ablation has recently gained favor as a treatment option, although the optimal regime is unknown. This study investigates the effectiveness of 2 versus 3 cycles of radiofrequency ablation for the treatment of Morton's neuroma. We surveyed a cohort of patients with Morton's neuroma who had progressed to radiofrequency ablation after failed conservative treatment. Patients received either 2 or 3 cycles of radiofrequency ablation by a single surgeon. We assessed patients based on their change in numerical pain rating scale, symptom improvement, complications, and progression to surgical excision through a series of telephone interviews. Outcomes between the 2 treatment arms were compared by parametric tests. Twenty-eight patients were included in the study. Eighteen patients with 21 neuromas received 2 cycles and 10 patients with 11 neuromas received 3 cycles. Mean time of follow-up was 12.9 months. Overall, 88% of patients were either very or moderately satisfied with their outcome. In patients who received 2 cycles mean numerical pain scores decreased from 7.9 ± 1.1 to 3.4 ± 2.4 postprocedure. Three patients progressed to operative excision. In patients who received 3 cycles, numerical pain scores decreased from 8.0 ± 1.0 to 1.5 ± 2.0 postprocedure. One patient progressed to operative excision. Patients who received 3 cycles had reduced medium-term pain postoperatively compared with 2 cycles (3.4 ± 2.4 vs 1.5 ± 2.0, P = .011). Radiofrequency ablation provides a high rate of patient satisfaction in the treatment of Morton's neuroma with few side effects. It appears that 3 cycles may be superior to 2 cycles but a randomized controlled trial will be required to confirm these results. Intervention, Level III: Comparative study without concurrent controls.

[An improved case of bedridden mental impairment with normal pressure hydrocephalus associated with acoustic neurinoma after tumor resection].

Science.gov (United States)

Sugimoto, Seiichiro; Sugimoto, Akiko; Saita, Kazuko; Kishi, Masahiko; Shioya, Keiichi; Higa, Toshinobu

2008-08-01

A 67-year-old woman developed gait disturbance, dysarthria, cognitive impairment and incontinence at age 65, and became bedridden. She showed mutism, stupor and lower limb spasticity. Cranial CT and MRI revealed marked ventricular enlargement and a cerebellopontine angle tumor. CSF study showed normal pressure (125 mmH2O) and elevated protein (143 mg/dl). Radionuclide cisternography showed redistribution of radionuclide to the ventricles and intraventricular residual radionuclide after 72 hours, which allowed a diagnosis of normal pressure hydrocephalus. After removal of the tumor, ventricle size and CSF protein decreased, and the symptoms of cognitive impairment and motor dysfunction resolved. Histological examination showed acoustic neurinoma. Over the half of hydrocephalus following acoustic neurinoma shows a tendency to improve by surgical resection of the tumor. Neurologists who see cognitively impaired spastic bedridden patients should not overlook this pathology.

T1-nerve root neuroma presenting with apical mass and Horner's syndrome

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Podnar Simon

2007-03-01

Full Text Available Abstract Background The appearance of dumbbell neuroma of the first thoracic root is extremely rare. The extradural component of a T1-dumbbell neuroma may present as an apical mass. The diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and its intrathoracic extension demanded an extended posterior midline approach in the sitting position. Case presentation A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness in the affected forearm with some tingling in his fingers bilaterally. During the last two years the hand weakness was continuous and hypotrophy of the medial flexor and intrinsic hand muscles had become apparent. Electrophysiological studies revealed an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy in the upper extremity was negative. Repeated electrophysiological studies revealed fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed a large round apical mass on the affected side. A Horner's syndrome was noted at this point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural tumor with extension into the apex of the ipsilateral lung. The patient underwent surgery in sitting position using a left dorsal midline approach. Although the T1 root could not be preserved, the patient's neurological condition was unchanged after the surgery. Conclusion Extended posterior midline exposure described here using hemilaminectomy, unilateral facetectomy and costo-transversectomy is efficient and safe for one-stage removal of dumbbell tumors at the T1

Stereotactic radiotherapy for vestibular schwannoma

DEFF Research Database (Denmark)

Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno

2014-01-01

BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess...... the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL......; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical...

Validation of self-reported start year of mobile phone use in a Swedish case-control study on radiofrequency fields and acoustic neuroma risk.

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Pettersson, David; Bottai, Matteo; Mathiesen, Tiit; Prochazka, Michaela; Feychting, Maria

2015-01-01

The possible effect of radiofrequency exposure from mobile phones on tumor risk has been studied since the late 1990s. Yet, empirical information about recall of the start of mobile phone use among adult cases and controls has never been reported. Limited knowledge about recall errors hampers interpretations of the epidemiological evidence. We used network operator data to validate the self-reported start year of mobile phone use in a case-control study of mobile phone use and acoustic neuroma risk. The answers of 96 (29%) cases and 111 (22%) controls could be included in the validation. The larger proportion of cases reflects a more complete and detailed reporting of subscription history. Misclassification was substantial, with large random errors, small systematic errors, and no significant differences between cases and controls. The average difference between self-reported and operator start year was -0.62 (95% confidence interval: -1.42, 0.17) years for cases and -0.71 (-1.50, 0.07) years for controls, standard deviations were 3.92 and 4.17 years, respectively. Agreement between self-reported and operator-recorded data categorized into short, intermediate and long-term use was moderate (kappa statistic: 0.42). Should an association exist, dilution of risk estimates and distortion of exposure-response patterns for time since first mobile phone use could result from the large random errors in self-reported start year. Retrospective collection of operator data likely leads to a selection of "good reporters", with a higher proportion of cases. Thus, differential recall cannot be entirely excluded.

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

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Aszmann, Oskar C; Korak, Klaus J; Rab, Matthias; Grünbeck, Matthias; Lassmann, Hans; Frey, Manfred

2003-11-01

The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

Acoustic Neuroma

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... below: ? Brain Tumors Brain Disorders AVMs Radiosurgery Gamma Knife Linac Radiotherapy Overview Childhood Brain Tumors Radiation Therapy Radiation Injury Treatment Day Making a Decision Centers of Excellence BRAIN TALK® ...

Remission of severe restless legs syndrome and periodic limb movements in sleep after bilateral excision of multiple foot neuromas: a case report

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Lettau Ludwig A

2010-09-01

Full Text Available Abstract Introduction Restless legs syndrome is a sensorimotor neurological disorder characterized by an urge to move the legs in response to uncomfortable leg sensations. While asleep, 70 to 90 percent of patients with restless legs syndrome have periodic limb movements in sleep. Frequent periodic limb movements in sleep and related brain arousals as documented by polysomnography are associated with poorer quality of sleep and daytime fatigue. Restless legs syndrome in middle age is sometimes associated with neuropathic foot dysesthesias. The causes of restless legs syndrome and periodic limb movements in sleep are unknown, but the sensorimotor symptoms are hypothesized to originate in the central nervous system. We have previously determined that bilateral forefoot digital nerve impingement masses (neuromas may be a cause of both neuropathic foot dysesthesias and the leg restlessness of restless legs syndrome. To the best of our knowledge, this case is the first report of bilateral foot neuromas as a cause of periodic limb movements in sleep. Case presentation A 42-year-old Caucasian woman with severe restless legs syndrome and periodic limb movements in sleep and bilateral neuropathic foot dysesthesias was diagnosed as having neuromas in the second, third, and fourth metatarsal head interspaces of both feet. The third interspace neuromas represented regrowth (or 'stump' neuromas that had developed since bilateral third interspace neuroma excision five years earlier. Because intensive conservative treatments including repeated neuroma injections and various restless legs syndrome medications had failed, radical surgery was recommended. All six neuromas were excised. Leg restlessness, foot dysesthesias and subjective sleep quality improved immediately. Assessment after 18 days showed an 84 to 100 percent reduction of visual analog scale scores for specific dysesthesias and marked reductions of pre-operative scores of the Pittsburgh sleep

The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review

International Nuclear Information System (INIS)

Xu, Z.; Duan, X.; Yu, X.; Wang, H.; Dong, X.; Xiang, Z.

2015-01-01

Aim: To determine the accuracy of MRI versus ultrasound for Morton's neuroma. Materials and methods: A search was undertaken for clinical studies published in any language in PubMed up to the date of December 2013. Studies assessing the accuracy of the ultrasound or MRI for the diagnosis of Morton's neuroma were included. Data were pooled for meta-analysis. Study selection, data collection, and extraction were performed independently by two authors. Meta-disc 1.4 and Revman 5.2 software were applied for statistical analysis. Results: The study included 12 studies; 217 patients underwent MRI and 241 underwent ultrasound examinations. There appeared greater diagnostic accuracy for ultrasound than MRI for the diagnosis of Morton's neuroma (ultrasound sensitivity 90%, specificity 88%, positive likelihood ratio 2.77, negative likelihood ratio 0.16 versus MRI sensitivity 93%, specificity 68%, positive likelihood ratio 1.89, negative likelihood ratio 0.19). Conclusions: The available evidence suggests that ultrasound can provide better accuracy for the diagnosis of Morton's neuroma than MRI

Traumatic Neuroma in a Breast Cancer Patient After Modified Radical Mastectomy: A Case Report

International Nuclear Information System (INIS)

Kim, Eun Young; Kang, Doo Kyoung; Kim, Tae Hee; Kim, Ku Sang; Yim, Hyunee

2011-01-01

Traumatic neuromas are rare benign lesions that develop from non-neoplastic proliferation of axons, schwann cells, and fibroblasts at the proximal end of transected or injured nerves as a result of trauma or surgery. We present the case of a traumatic neuroma in a 47-year-old female who was treated with a right modified radical mastectomy for breast cancer 14 years ago. Ultrasound examination revealed an oval-shaped hypoechoic nodule at the 9-O'clock position in the right chest wall. Color Doppler imaging showed no increased blood flow and a positron emission tomography-computed tomography examination revealed no fluorodeoxyglucose uptake in this nodule. The typical histologic findings were present.

Vestibular schwannoma (acoustic neuroma mimicking temporomandibular disorders: a case report Schwannoma vestibular (neurinoma do acústico imitando desordens temporomandibulares: um relato de caso

Directory of Open Access Journals (Sweden)

Maurício A. Bisi

2006-12-01

Full Text Available Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma. Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case.Aproximadamente 6 a 16% dos pacientes com sintomas de neuralgia trigeminal apresentam tumores intracranianos, sendo mais comum o schwannoma vestibular (neurinoma do acústico. Alguns sintomas relatados pelos pacientes são perda da audição, zumbido, dores de cabeça, vertigens e distúrbios trigeminais. Uma resposta muscular aumentada na musculatura associada da cabeça e do pescoço também pode ser observada, o que pode mimetizar sinais e sintomas de desordens temporomandibulares. Nestes casos é de grande valia o uso de imagem de ressonância magnética (IRM para detecção de tumores. É importante, também, a diferenciação de dores miofasciais e neurálgicas, pois ambas podem apresentar características semelhantes, mas com origens e tratamentos diferentes. O objetivo desse trabalho foi demonstrar através de relato de caso clínico a associação entre sintomas de neuralgia trigeminal, tumores intracranianos e disfunção temporomandibular.

Ultrasound versus magnetic resonance imaging for Morton neuroma: systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Bignotti, Bianca; Martinoli, Carlo [University of Genoa, Radiology Department, Genoa, Genova (Italy); Signori, Alessio; Sormani, Maria Pia [University of Genoa, Institute of Statistics, Department of Health Sciences, Genoa (Italy); Molfetta, Luigi [University of Genoa, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics (DINOGMI), Genoa (Italy); Tagliafico, Alberto [University of Genoa, Institute of Anatomy, Department of Experimental Medicine, Genoa (Italy)

2015-08-15

To compare ultrasound (US) and magnetic resonance imaging (MRI) in the diagnosis of Morton's neuroma. Studies that assessed the diagnostic accuracy of US and MRI for Morton's neuroma were retrieved from major medical libraries independently by two reviewers up to 1 April 2014. Predefined inclusion and exclusion criteria were adopted. 277 studies were initially found, and the meta-analysis was conducted on 14 studies. US sensitivity was studied in five studies, MRI sensitivity in three studies, and both in six studies. All studies used surgery as the reference standard. A high sensitivity (SE) of diagnostic testing was observed for both US (SE (95 % CI) = 0.91 (0.83-0.96)) and MRI (SE (95 % CI) = 0.90 (0.82-0.96)) with no significant differences between the two modalities in diagnosis (Q test p = 0.88). For MRI, specificity of test was 1.00 with a pooled estimation of 1.00 (0.73-1.00), while the pooled specificity was 0.854 (95 % CI: 0.41-1.00) for US. No differences were observed between US and MRI in study design (p = 0.76). This meta-analysis shows that the SE of US (0.91) is equal to (p = 0.88) that of MRI (0.90) for identification of Morton's neuroma. (orig.)

Traumatic Neuroma in a Breast Cancer Patient After Modified Radical Mastectomy: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Young; Kang, Doo Kyoung; Kim, Tae Hee [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Kim, Ku Sang [Dept. of Surgery, Ajou University School of Medicine, Suwon (Korea, Republic of); Yim, Hyunee [Dept. of Pathology, Ajou University School of Medicine, Suwon (Korea, Republic of)

2011-05-15

Traumatic neuromas are rare benign lesions that develop from non-neoplastic proliferation of axons, schwann cells, and fibroblasts at the proximal end of transected or injured nerves as a result of trauma or surgery. We present the case of a traumatic neuroma in a 47-year-old female who was treated with a right modified radical mastectomy for breast cancer 14 years ago. Ultrasound examination revealed an oval-shaped hypoechoic nodule at the 9-O'clock position in the right chest wall. Color Doppler imaging showed no increased blood flow and a positron emission tomography-computed tomography examination revealed no fluorodeoxyglucose uptake in this nodule. The typical histologic findings were present.

Reexcision Perineural Invasion and Epithelial Sheath Neuroma Possibly on a Spectrum of Postinjury Reactive Hyperplasia Mediated by IL-6.

Science.gov (United States)

Wang, James Y; Nuovo, Gerard; Kline, Mitchell; Magro, Cynthia M

2017-01-01

Epithelial sheath neuroma is a rarely recognized but established entity in the medical literature. First described in 2000 by Requena et al, there have only been 7 published cases to date, mostly in female patients and presenting as symptomatic solitary lesions on the back without a known history of trauma. In 2006, Beer et al described and reviewed a dozen cases in which epithelial sheath neuroma-like features were seen in the advent of a surgical procedure, which was termed "re-excision perineural invasion" and attributed to possible eccrine duct implantation during surgery. Our case is a 66-year-old male patient who underwent an excision of a melanocytic neoplasm in which a reactive epithelial sheath neuroma was incidentally discovered in the excision specimen, adjacent to the biopsy site cicatrix. Histologically, there was benign cutaneous nerve hyperplasia with a proliferation of squamous epithelium in intimate apposition to the nerve bundles in the superficial dermis. We postulate that the process active in the formation of re-excision perineural invasion is the same as in epithelial sheath neuroma and that minor trauma not appreciable on histologic examination is responsible in the latter entity. We performed IL-6 staining and documented that IL-6 was upregulated at the interface of the nerve and reactive epithelium, but was absent in nerves distant from the site of surgery, suggesting that IL-6 may be essential to the lesion's development. The recognition of reactive epithelial sheath neuroma including the subcategory of re-excision perineural invasion is crucial for the dermatopathologist to prevent mislabeling this reactive entity as a perineural squamous cell carcinoma, which has clinical consequences for the patient such as wider re-excision and radiation treatment. Additionally, we have identified a potential pathophysiologic basis for this lesion.

Observations at the CNS-PNS border of ventral roots connected to a neuroma

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Sten Remahl

2010-10-01

Full Text Available Previous studies have shown that numerous sprouts originating from a neuroma, after nerve injury in neonatal animals, can invade spinal nerve roots. In this study the border between the central and peripheral nervous system (CNS-PNS border of ventral roots in kittens was examined with both light and electron microscopy after early postnatal sciatic nerve resection. A transient ingrowth of substance P positive axons was observed into the CNS, but no spouts remained 6 weeks after the injury. Using serial sections and electron microscopy it was possible to identify small bundles of unmyelinated axons that penetrated from the root fascicles for a short distance into the CNS. These axons ended blindly, sometimes with a growth cone-like terminal swelling filled with vesicles. The axon bundles were accompanied by p75 positive cells in both the root fascicles and the pia mater, but not in the CNS. It may thus be suggested that neurotrophin presenting p75 positive cells could facilitate axonal growth into the pia mater and that the lack of such cells in the CNS compartment might contribute to the failure of growth into the CNS. A maldevelopment of myelin sheaths at the CNS-PNS border of motor axons was observed and it seems possible that this could have consequences for the propagation of action potential across this region after neonatal nerve injury.

Treatment of Acoustic Neuroma

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... Home Learn Treatment Options Overview English English Arabic Catalan Chinese (Simplified) Chinese (Traditional) Danish French German Greek ... for delivering stereotactic radiation have improved, an increasing number of patients have chosen to receive stereotactic radiosurgery ...

Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Full Text Available ... info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English Arabic Catalan Chinese (Simplified) Chinese ( ...

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Acoustic Neuroma Educational Video

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Full Text Available ... Opportunities Support Overview Patient Events Fundraising Programs Join Team ANA Legacy Society Ways to Give Help us fundraise Caregiver Overview Resources Support Groups Back Is a support group for me? Find ...

Acoustic Neuroma Educational Video

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Manual therapy in the management of a patient with a symptomatic Morton's Neuroma: A case report.

Science.gov (United States)

Sault, Josiah D; Morris, Matthew V; Jayaseelan, Dhinu J; Emerson-Kavchak, Alicia J

2016-02-01

Patients with Morton's neuroma are rarely referred to physical therapy. This case reports the resolution of pain, increase in local pressure pain thresholds, and improvement of scores on the Lower Extremity Functional Scale and Foot and Ankle Ability Measure following a course of joint based manual therapy for a patient who had failed standard conservative medical treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Roentgenographic features of neurofibromatosis von Recklinghausen

Energy Technology Data Exchange (ETDEWEB)

Galanski, M.; Vogelsang, H.; Cramer, B.M.; Thun, F.; Peters, P.E.

1983-10-01

The basic abnormality of neurofibromatosis consists not only of a maldevelopment of the neuroectoderm but also of the mesoderm. Therefore any organ or system of the body may be involved. Following a short clinical review of the central (acoustic) and peripheral type the well known and the more unusual radiographic findings are summarized. They include cranial and intracranial manifestations (orbitosphenoid dysplasia, bone defects of the skull, acoustic neuroma, glioma of the optic nerve and chiasm, meningioma), spinal lesions (scoliosis, vetebral scalloping, meningocele, neuroma, ependymoma), skeletal abnormalities (pseudarthrosis), cardiovascular manifestations, pulmonary fibrosis, tumors of the gastrointestinal and urinary tract and different endocrinopathies. Some of the roentgeologic symptoms are very characteristic and allow definitive diagnosis.

How Loud Is Too Loud?

Science.gov (United States)

... Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

Hearing loss as an unusual consequence of metastatic gastric adenocarcinoma

Directory of Open Access Journals (Sweden)

CE Owers

2010-10-01

Full Text Available A sixty-one year old man was referred with a history of progressive dysphagia, vomiting and weight loss with some back pain. Upper gastrointestinal endoscopy and biopsies revealed a gastro-oesophageal junction adenocarcinoma. Despite the absence of metastatic disease on computed tomography, positron emission tomography demonstrated multiple vertebral and sternal deposits. He was reviewed in an ENT clinic with a sudden onset of hearing loss accompanied by dizziness, but no focal neurology. Magnetic resonance imaging identified bilateral 2cm lesions at the internal auditory meatus, consistent with a diagnosis of bilateral acoustic neuromas. The patient subsequently died of carcinomatosis and, because of the potential familial significance of bilateral acoustic neuromas, a limited post-mortem examination was carried out. Unexpectedly, this revealed bilateral adenocarcinoma metastases infiltrating the internal auditory meatus affecting the acoustic nerves. The authors believe this a very rare presentation of metastatic gastric disease.

Brain tumor - primary - adults

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... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

Direct costs of microsurgical management of radiosurgically amenable intracranial pathology in Germany: an analysis of meningiomas, acoustic neuromas, metastases and arteriovenous malformations of less than 3 cm in diameter

International Nuclear Information System (INIS)

Wellis, G.; Nagel, R.; Vollmar, C.; Steiger, H.-J.

2003-01-01

The purpose of the analysis was to appreciate and compare the effective direct costs of microsurgical treatment of intracranial pathology potentially amenable to radiosurgery as they arose in 1998-99. Treatment costs of 127 microsurgically treated patients harboring an arteriovenous malformation (AVM), acoustic neuroma, meningioma or brain metastasis potentially amenable to radiosurgery were reviewed. Costs for the surgical procedure, ICU rare, medical and nursing care on the ward, interclinical bills (ICB) for services provided by other departments and the overhead for basic hotel service were added. For comparison gamma knife costs were calculated by dividing the global operating cost of the gamma knife centre by the number of patients treated in 1999. Average hospitalization time for the entire microsurgical patients was 15.4 + 8.6 days. The patients spent an average of 1.2 ± 2.8 days on ICU. Average operating time for all patients, including preparation, was 393 ± 118 minutes. Average costs for the microsurgical therapy were Eur 10814 ± 6108. These consisted of Eur 1417 ± 426 for the surgical procedure, Eur 1188 ± 2658 for ICU care, Eur 2333 ± 1582 for medical and nursing care on the ward, Eur 1671 ± 1433 for interclinical bills and Eur 4204 ± 2338 for basic hotel service (overhead, Eur 273 per day). 70 % of the microsurgically treated patients needed ancillary inpatient rehabilitation or radiotherapy resulting in an average additional cost for all patients of Eur 2744. Furthermore 20 % of the microsurgically treated patients required an unplanned readmission after discharge, resulting in an average additional costs for all patients of Eur 1684. Average overall costs per patient including ancillary therapy and unplanned read-missions amounted to Eur 15242. For comparison, gamma knife treatment costs per patient amounted to Eur 7920 in 1999. The current analysis showed that for established radiosurgical indications the primary costs of microsurgery

How Loud Is Too Loud?

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Full Text Available ... Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

Automated gamma knife radiosurgery treatment planning with image registration, data-mining, and Nelder-Mead simplex optimization

International Nuclear Information System (INIS)

Lee, Kuan J.; Barber, David C.; Walton, Lee

2006-01-01

Gamma knife treatments are usually planned manually, requiring much expertise and time. We describe a new, fully automatic method of treatment planning. The treatment volume to be planned is first compared with a database of past treatments to find volumes closely matching in size and shape. The treatment parameters of the closest matches are used as starting points for the new treatment plan. Further optimization is performed with the Nelder-Mead simplex method: the coordinates and weight of the isocenters are allowed to vary until a maximally conformal plan specific to the new treatment volume is found. The method was tested on a randomly selected set of 10 acoustic neuromas and 10 meningiomas. Typically, matching a new volume took under 30 seconds. The time for simplex optimization, on a 3 GHz Xeon processor, ranged from under a minute for small volumes ( 30 000 cubic mm,>20 isocenters). In 8/10 acoustic neuromas and 8/10 meningiomas, the automatic method found plans with conformation number equal or better than that of the manual plan. In 4/10 acoustic neuromas and 5/10 meningiomas, both overtreatment and undertreatment ratios were equal or better in automated plans. In conclusion, data-mining of past treatments can be used to derive starting parameters for treatment planning. These parameters can then be computer optimized to give good plans automatically

How Loud Is Too Loud?

Medline Plus

Full Text Available ... to the Brain Video Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

[Repeat hepatic resections].

Science.gov (United States)

Popescu, I; Ciurea, S; Braşoveanu, V; Pietrăreanu, D; Tulbure, D; Georgescu, S; Stănescu, D; Herlea, V

1998-01-01

Five cases of iterative liver resections are presented, out of a total of 150 hepatectomies performed between 1.01.1995-1.01.1998. The resections were carried out for recurrent adenoma (one case), cholangiocarcinoma (two cases), hepatocellular carcinoma (one case), colo-rectal cancer metastasis (one case). Only cases with at least one major hepatic resection were included. Re-resections were more difficult than the primary resection due, first of all, to the modified vascular anatomy. Intraoperative ultrasound permitted localization of intrahepatic recurrences. Iterative liver resection appears to be the best therapeutical choice for patients with recurrent liver tumors.

How Loud Is Too Loud?

Medline Plus

Full Text Available ... Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who Can I Turn to for Help with My Hearing ... Free Publications Glossary Have a question? Information specialists can answer your questions in English or Spanish. Voice: ( ...

[Laparoscopic liver resection: lessons learned after 132 resections].

Science.gov (United States)

Robles Campos, Ricardo; Marín Hernández, Caridad; Lopez-Conesa, Asunción; Olivares Ripoll, Vicente; Paredes Quiles, Miriam; Parrilla Paricio, Pascual

2013-10-01

After 20 years of experience in laparoscopic liver surgery there is still no clear definition of the best approach (totally laparoscopic [TLS] or hand-assisted [HAS]), the indications for surgery, position, instrumentation, immediate and long-term postoperative results, etc. To report our experience in laparoscopic liver resections (LLRs). Over a period of 10 years we performed 132 LLRs in 129 patients: 112 malignant tumours (90 hepatic metastases; 22 primary malignant tumours) and 20 benign lesions (18 benign tumours; 2 hydatid cysts). Twenty-eight cases received TLS and 104 had HAS. 6 right hepatectomies (2 as the second stage of a two-stage liver resection); 6 left hepatectomies; 9 resections of 3 segments; 42 resections of 2 segments; 64 resections of one segment; and 5 cases of local resections. There was no perioperative mortality, and morbidity was 3%. With TLS the resection was completed in 23/28 cases, whereas with HAS it was completed in all 104 cases. Transfusion: 4,5%; operating time: 150min; and mean length of stay: 3,5 days. The 1-, 3- and 5-year survival rates for the primary malignant tumours were 100, 86 and 62%, and for colorectal metastases 92, 82 and 52%, respectively. LLR via both TLS and HAS in selected cases are similar to the results of open surgery (similar 5-year morbidity, mortality and survival rates) but with the advantages of minimally invasive surgery. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

Accumulation of Kv7.2 channels in putative ectopic transduction zones of mice nerve-end neuromas

Directory of Open Access Journals (Sweden)

Lopez-García Jose A

2011-08-01

Full Text Available Abstract Background Modulation of M-type currents has been proposed as a new strategy for the treatment of neuropathic pain due to their role in regulating neuronal excitability. Using electrophysiological techniques we showed previously that the opening of Kv7 channels with retigabine, blocked ectopic discharges from axotomized fibers but did not alter transduction at intact skin afferents. We hypothesized that after nerve damage, accumulation of Kv7 channels in afferent fibers may increase M-type currents which then acquired a more important role at regulating fiber excitability. Findings In this study, we used an immunohistochemical approach to examine patterns of expression of Kv7.2 channels in afferent fibers after axotomy and compared them to patterns of expression of voltage gated Na+ channels (Nav which are key electrogenic elements in peripheral axons known to accumulate in experimental and human neuromas. Axotomy induced an enlargement and narrowing of the nodes of Ranvier at the proximal end of the neuroma together with a dramatic demyelination and loss of structure at its distal end in which naked accumulations of Nav were present. In addition, axotomy also induced accumulations of Kv7.2 that co-localized with those of Nav channels. Conclusions Whilst Nav channels are mandatory for initiation of action potentials, (i.e. responsible for the generation/propagation of ectopic discharges an increased accumulation of Kv7.2 channels after axotomy may represent a homeostatic compensation to over excitability in axotomized fibers, opening a window for a peripheral action of M-current modulators under conditions of neuropathy.

Reconstruction of complicated skull base defects utilizing free tissue transfer.

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Djalilian, Hamid R; Gapany, Markus; Levine, Samuel C

2002-11-01

We managed five patients with large skull base defects complicated by complex infections with microvascular free tissue transfer. The first patient developed an infection, cerebrospinal fluid (CSF) leak, and meningitis after undergoing a translabyrinthine resection of an acoustic neuroma. The second patient had a history of a gunshot wound to the temporal bone, with a large defect and an infected cholesteatoma that caused several episodes of meningitis. The third through the fifth patients had persistent CSF leakage and infection refractory to conventional therapy. In all cases prior attempts of closure with fat grafts or regional flaps had failed. Rectus abdominis myofascial free flap, radial forearm free flap or a gracilis muscle free flap was used after debridement of the infected cavities. The CSF leaks, local infections, and meningitis were controlled within a week. In our experience, microvascular free tissue provides the necessary bulk of viable, well-vascularized tissue, which not only assures a mechanical seal but also helps clear the local infection.

Impact of video-endoscopy on the results of retrosigmoid-transmeatal microsurgery of vestibular schwannoma: prospective study

Czech Academy of Sciences Publication Activity Database

Chovanec, M.; Zvěřina, E.; Profant, Oliver; Skřivan, J.; Čakrt, O.; Lisý, J.; Betka, J.

2013-01-01

Roč. 270, č. 4 (2013), s. 1277-1284 ISSN 0937-4477 Grant - others:GA MZd(CZ) NS9909 Institutional support: RVO:68378041 Keywords : vestibular schwannoma * acoustic neuroma * endoscopy-assisted microsurgery Subject RIV: FH - Neurology Impact factor: 1.608, year: 2013

Clinicodemographic aspect of resectable pancreatic cancer and prognostic factors for resectable cancer

Directory of Open Access Journals (Sweden)

Chiang Kun-Chun

2012-05-01

Full Text Available Abstract Background Pancreatic adenocarcinoma (PCA is one of the most lethal human malignancies, and radical surgery remains the cornerstone of treatment. After resection, the overall 5-year survival rate is only 10% to 29%. At the time of presentation, however, about 40% of patients generally have distant metastases and another 40% are usually diagnosed with locally advanced cancers. The remaining 20% of patients are indicated for surgery on the basis of the results of preoperative imaging studies; however, about half of these patients are found to be unsuitable for resection during surgical exploration. In the current study, we aimed to determine the clinicopathological characteristics that predict the resectability of PCA and to conduct a prognostic analysis of PCA after resection to identify favorable survival factors. Methods We retrospectively reviewed the medical files of 688 patients (422 men and 266 women who had undergone surgery for histopathologically proven PCA in the Department of Surgery at Chang Gung Memorial Hospital in Taiwan from 1981 to 2006. We compared the clinical characteristics of patients who underwent resection and patients who did not undergo resection in order to identify the predictive factors for successful resectability of PCA, and we conducted prognostic analysis for PCA after resection. Results A carbohydrate antigen 19–9 (CA 19–9 level of 37 U/ml or greater and a tumor size of 3 cm or more independently predicted resectability of PCA. In terms of survival after resection, PCA patients with better nutritional status (measured as having an albumin level greater than 3.5 g/dl, radical resection, early tumor stage and better-differentiated tumors were associated with favorable survival. Conclusions Besides traditional imaging studies, preoperative CA 19–9 levels and tumor size can also be used to determine the resectability of PCA. Better nutritional status, curative resection, early tumor stage and well

Long-Term Follow-up of Acoustic Schwannoma Radiosurgery With Marginal Tumor Doses of 12 to 13 Gy

International Nuclear Information System (INIS)

Chopra, Rahul; Kondziolka, Douglas; Niranjan, Ajay; Lunsford, L. Dade; Flickinger, John C.

2007-01-01

Purpose: To define long-term tumor control and clinical outcomes of radiosurgery with marginal tumor doses of 12 to 13 Gy for unilateral acoustic schwannoma. Methods and Materials: A total of 216 patients with previously untreated unilateral acoustic schwannoma underwent Gamma Knife radiosurgery between 1992 and 2000 with marginal tumor doses of 12 to 13 Gy (median, 13 Gy). Median follow-up was 5.7 years (maximum, 12 years; 41 patients with >8 years). Treatment volumes were 0.08-37.5 cm 3 (median, 1.3 cm 3 ). Results: The 10-year actuarial resection-free control rate was 98.3% ± 1.0%. Three patients required tumor resection: 2 for tumor growth and 1 partial resection for an enlarging adjacent subarachnoid cyst. Among 121 hearing patients with >3 years of follow-up, crude hearing preservation rates were 71% for keeping the same Gardner-Robertson hearing level, 74% for serviceable hearing, and 95% for any testable hearing. For 25 of these patients with intracanalicular tumors, the respective rates for preserving the same Gardner-Robertson level, serviceable hearing, and testable hearing were 80%, 88%, and 96%. Ten-year actuarial rates for preserving the same Gardner-Robertson hearing levels, serviceable hearing, any testable hearing, and unchanged facial and trigeminal nerve function were 44.0% ± 11.7%, 44.5% ± 10.5%, 85.3% ± 6.2%, 100%, and 94.9% ± 1.8%, respectively. Conclusions: Acoustic schwannoma radiosurgery with 12 to 13 Gy provides high rates of long-term tumor control and cranial nerve preservation after long-term follow-up

Morphometrical differences between resectable and non-resectable pancreatic cancer: a fractal analysis.

Science.gov (United States)

Vasilescu, Catalin; Giza, Dana Elena; Petrisor, Petre; Dobrescu, Radu; Popescu, Irinel; Herlea, Vlad

2012-01-01

Pancreatic cancer is a highly aggressive cancer with a rising incidence and poor prognosis despite active surgical treatment. Candidates for surgical resection should be carefully selected. In order to avoid unnecessary laparotomy it is useful to identify reliable factors that may predict resectability. Nuclear morphometry and fractal dimension of pancreatic nuclear features could provide important preoperative information in assessing pancreas resectability. Sixty-one patients diagnosed with pancreatic cancer were enrolled in this retrospective study between 2003 and 2005. Patients were divided into two groups: one resectable cancer group and one with non-resectable pancreatic cancer. Morphometric parameters measured were: nuclear area, length of minor axis and length of major axis. Nuclear shape and chromatin distribution of the pancreatic tumor cells were both estimated using fractal dimension. Morphometric measurements have shown significant differences between the nuclear area of the resectable group and the non-resectable group (61.9 ± 19.8µm vs. 42.2 ± 15.6µm). Fractal dimension of the nuclear outlines and chromatin distribution was found to have a higher value in the non-resectable group (p<0.05). Objective measurements should be performed to improve risk assessment and therapeutic decisions in pancreatic cancer. Nuclear morphometry of the pancreatic nuclear features can provide important pre-operative information in resectability assessment. The fractal dimension of the nuclear shape and chromatin distribution may be considered a new promising adjunctive tool for conventional pathological analysis.

Prostate resection - minimally invasive

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... thermotherapy; TUMT; Urolift; BPH - resection; Benign prostatic hyperplasia (hypertrophy) - resection; Prostate - enlarged - resection ... passing an instrument through the opening in your penis (meatus). You will be given general anesthesia (asleep ...

[Endoscopic full-thickness resection].

Science.gov (United States)

Meier, B; Schmidt, A; Caca, K

2016-08-01

Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

Clinical Experience With Radiation Therapy in the Management of Neurofibromatosis-Associated Central Nervous System Tumors

International Nuclear Information System (INIS)

Wentworth, Stacy; Pinn, Melva; Bourland, J. Daniel; Guzman, Allan F. de; Ekstrand, Kenneth; Ellis, Thomas L.; Glazier, Steven S.; McMullen, Kevin P.; Munley, Michael; Stieber, Volker W.; Tatter, Stephen B.; Shaw, Edward G.

2009-01-01

Purpose: Patients with neurofibromatosis (NF) develop tumors of the central nervous system (CNS). Radiation therapy (RT) is used to treat these lesions. To better define the efficacy of RT in these patients, we reviewed our 20-year experience. Methods and Materials: Eighteen patients with NF with CNS tumors were treated from 1986 to 2007. Median follow-up was 48 months. Progression was defined as growth or recurrence of an irradiated tumor on serial imaging. Progression-free survival (PFS) was measured from the date of RT completion to the date of last follow-up imaging study. Actuarial rates of overall survival (OS) and PFS were calculated according to the Kaplan-Meier method. Results: Eighty-two tumors in 18 patients were irradiated, with an average of five tumors/patient. Median age at treatment was 25 years (range, 4.3-64 years). Tumor types included acoustic neuroma (16%), ependymoma (6%), low-grade glioma (11%), meningioma (60%), and schwanomma/neurofibroma (7%). The most common indication for treatment was growth on serial imaging. Most patients (67%) received stereotactic radiosurgery (median dose, 1,200 cGy; range, 1,000-2,400 cGy). The OS rate at 5 years was 94%. Five-year PFS rates were 75% (acoustic neuroma), 100% (ependymoma), 75% (low-grade glioma), 86% (meningioma), and 100% (schwanomma/neurofibroma). Thirteen acoustic neuromas had a local control rate of 94% with a 50% hearing preservation rate. Conclusions: RT provided local control, OS, and PFS rates similar to or better than published data for tumors in non-NF patients. Radiation therapy should be considered in NF patients with imaging progression of CNS tumors

Radiosurgery for acoustic neurinomas: Early experience

International Nuclear Information System (INIS)

Linskey, M.E.; Lunsford, L.D.; Flickinger, J.C.

1990-01-01

We reviewed our early experience with the first 26 patients with acoustic neurinomas (21 unilateral, 5 bilateral) treated by stereotactic radiosurgery using the first North American 201-source cobalt-60 gamma knife. Follow-up ranged from 6 to 19 months (median, 13 months). Serial postoperative imaging showed either a decrease in tumor size (11 patients) or growth arrest (15 patients). Loss of central contrast enhancement was a characteristic change (18 patients). Seven patients had good or serviceable hearing preoperatively. In all 7 the preoperative hearing status was retained immediately after radiosurgery. At follow-up, 3 had preserved hearing, 1 had reduced hearing, and 3 had lost all hearing in the treated ear. Hearing in 1 patient that was nonserviceable preoperatively later improved to a serviceable hearing level. Delayed facial paresis developed in 6 patients, and delayed trigeminal sensory loss developed in 7 patients, none of whom had significant deficits before radiosurgery. Both facial and trigeminal deficits tended to improve within 3 to 6 months of onset with excellent recovery anticipated. Lower cranial nerve dysfunction was not observed. All 26 patients remain at their preoperative employment or functional status. At present, stereotactic radiosurgery is an alternative treatment for acoustic neurinomas in patients who are elderly, have significant concomitant medical problems, have a tumor in their only hearing ear, have bilateral acoustic neurinomas, refuse microsurgical excision, or have recurrent tumor despite surgical resection. Although longer and more extensive follow-up is required, the control of tumor growth and the acceptable rate of complications in this early experience testifies to the future expanding role of this technique in the management of selected acoustic neurinomas

Augmented reality in bone tumour resection

Science.gov (United States)

Park, Y. K.; Gupta, S.; Yoon, C.; Han, I.; Kim, H-S.; Choi, H.; Hong, J.

2017-01-01

Objectives We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. Methods We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. Results The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137–143. PMID:28258117

Acoustic cloaking and transformation acoustics

International Nuclear Information System (INIS)

Chen Huanyang; Chan, C T

2010-01-01

In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

Molecular genetic approach to human meningioma: loss of genes on chromosome 22

International Nuclear Information System (INIS)

Seizinger, B.R.; De La Monte, S.; Atkins, L.; Gusella, J.F.; Martuza, R.L.

1987-01-01

A molecular genetic approach employing polymorphic DNA markers has been used to investigate the role of chromosomal aberrations in meningioma, one of the most common tumors of the human nervous system. Comparison of the alleles detected by DNA markers in tumor DNA versus DNA from normal tissue revealed chromosomal alterations present in primary surgical specimens. In agreement with cytogenetic studies of cultured meningiomas, the most frequent alteration detected was loss of heterozygosity on chromosome 22. Forty of 51 patients were constitutionally heterozygous for at least one chromosome 22 DNA marker. Seventeen of the 40 constitutionally heterozygotic patients (43%) displayed hemizygosity for the corresponding marker in their meningioma tumor tissues. Loss of heterozygosity was also detected at a significantly lower frequency for markers on several other autosomes. In view of the striking association between acoustic neuroma and meningioma in bilateral acoustic neurofibromatosis and the discovery that acoustic neuromas display specific loss of genes on chromosome 22, the authors propose that a common mechanism involving chromosome 22 is operative in the development of both tumor types. Fine-structure mapping to reveal partial deletions in meningiomas may provide the means to clone and characterize a gene (or genes) of importance for tumorigenesis in this and possibly other clinically associated tumors of the human nervous system

Immediate side effects of stereotactic radiotherapy and radiosurgery

International Nuclear Information System (INIS)

Werner-Wasik, Maria; Rudoler, Shari; Preston, Peter E.; Downes, Beverly M.; Andrews, David; Corn, Benjamin W.; Rosenstock, Jeffrey; Curran, Walter J.

1996-01-01

Purpose/Objective: Despite increased utilization of fractionated stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS), the incidence and nature of immediate side effects (ISE) associated with these treatment techniques is not well defined. Materials and Methods: Intracranial lesions in 78 adult patients were treated with SRT or SRS, using a dedicated linear accelerator. They comprised 13 gliomas, 2 ependymomas, 19 metastatic tumors, 15 meningiomas, 12 acoustic neuromas, 4 pituitary adenomas, 1 optic neuroma, 1 chondrosarcoma and 11 arteriovenous malformations (AVM). SRT was used in 51 and SRS in 27 patients. Mean target volume was 9.0 cc. Eleven patients received prior external beam radiation therapy within 2 months before SRT/SRS. Any side effects occurring during and up to two weeks after radiation course were defined as ISE and were graded as mild, moderate or severe. The incidence of ISE and the significance of their association with several pretreatment variables were analyzed. Results: Overall, (28(78)) (35%) patients experienced one or more ISE. Most of ISE (87%) were mild and consisted of nausea (5), dizziness/vertigo (5), seizures (7) and new persistent headaches (17). Two episodes of worsening neurological deficit and 2 of orbital pain were graded as moderate. Two patients experienced severe ISE, requiring hospitalization (1 seizure and 1 worsening neurological deficit). ISE in 5 cases prompted computerized tomography of the brain which revealed increased perilesional edema in 3 cases. The incidence of ISE by diagnosis was as follows: 46% ((6(13))) for gliomas, 50% ((6(12))) for acoustic neuromas, 36% ((4(11))) for AVM, 33% ((5(15))) for meningiomas and 21% ((4(19))) for metastases. Increasing dose to the margin and increasing maximum dose were associated with a higher incidence of ISE (p=0.02 and 0.005, respectively). Prior recent conventional external beam radiation therapy, target volume, number of isocenters, collimator size, dose

Neurofibromatosis type 2 and auditory brainstem implantation

Institute of Scientific and Technical Information of China (English)

XIAO Hong-jun; Dennis K.K. Au; Yau Hui; Chun-kuen Chow; Yiu-wah Fan; William Ignace Wei

2007-01-01

@@ Neurofibromatosis type 2 (NF-2) is one of the most common single gene disorders in the nervous system.For approximately 96% of patients with NF-2 present with bilateral Schwannomas involving the eighth cranial nerves, which may be accompanied by Schwannomas involving other cranial, spinal or peripheral nerves, NF-2 is also referred to as "bilateral acoustic neuromas".

[Pelvic reconstructions after bone tumor resection].

Science.gov (United States)

Anract, Philippe; Biau, David; Babinet, Antoine; Tomeno, Bernard

2014-02-01

The three more frequent primitive malignant bone tumour which concerned the iliac bone are chondrosarcoma, following Ewing sarcoma and osteosarcoma. Wide resection remains the most important part of the treatment associated with chemotherapy for osteosarcoma and the Ewing sarcoma. Iliac wing resections and obdurate ring don't required reconstruction. However, acetabular resections and iliac wing resection with disruption of the pelvic ring required reconstruction to provide acceptable functional result. Acetabular reconstruction remains high technical demanding challenge. After isolated acetabular resection or associated to obdurate ring, our usual method of reconstruction is homolateral proximal femoral autograft and total hip prosthesis but it is possible to also used : saddle prosthesis, Mac Minn prosthesis with auto or allograft, modular prosthesis or custom made prosthesis, massive allograft with or without prosthesis and femoro-ilac arthrodesis. After resection of the iliac wing plus acetabulum, reconstruction can be performed by femoro-obturatrice and femora-sacral arthrodesis, homolateral proximal femoral autograft and prosthesis, femoral medialisation, massive allograft and massive allograft. Carcinological results are lesser than resection for distal limb tumor, local recurrence rate range 17 to 45%. Functional results after Iliac wing and obdurate ring are good. However, acetabular reconstruction provide uncertain functional results. The lesser results arrive after hemipelvic or acetabular and iliac wing resection-reconstruction, especially when gluteus muscles were also resected. The most favourable results arrive after isolated acetabular or acetabular plus obturateur ring resection-reconstruction.

Endoscopic resection of subepithelial tumors.

Science.gov (United States)

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

2014-12-16

Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods.

Endoscopic Transsphenoidal Resection of Craniopharyngioma.

Science.gov (United States)

Liew, Kong Yew; Narayanan, Prepageran; Waran, Vicknes

2018-02-01

Objectives  To demonstrate, step-by-step, the technique and efficacy of endoscopic transsphenoidal approach in resection of a suprasellar craniopharyngioma. Design  The video shows a step-by-step approach to the resection, covering the exposure, access, resection, and confirmation of resection and reconstruction. Setting  The surgery was performed in the University of Malaya Medical Centre, a tertiary referral center in the capital of Malaysia. Participants  Surgery was performed jointly by Professor Prepageran from the department of otorhinolaryngology and Professor Vicknes Waran from the division of neurosurgery. Both surgeons are from the University of Malaya. Video compilation, editing, and voice narration was done by Dr. Kong Yew Liew. Main Outcome Measures  Completeness of resection and avoidance of intra- and postoperative complications. Results  Based on intraoperative views and MRI findings, the tumor was completely resected with the patient suffering only transient diabetes insipidus. Conclusion  Central suprasellar tumors can be removed completely via an endoscopic transsphenoidal approach with minimal morbidity to the patient. The link to the video can be found at: https://youtu.be/ZNIHfk12cYg .

Knife-assisted snare resection: a novel technique for resection of scarred polyps in the colon.

Science.gov (United States)

Chedgy, Fergus J Q; Bhattacharyya, Rupam; Kandiah, Kesavan; Longcroft-Wheaton, Gaius; Bhandari, Pradeep

2016-03-01

There have been significant advances in the management of complex colorectal polyps. Previous failed resection or polyp recurrence is associated with significant fibrosis, making endoscopic resection extremely challenging; the traditional approach to these lesions is surgery. The aim of this study was to evaluate the efficacy of a novel, knife-assisted snare resection (KAR) technique in the resection of scarred colonic polyps. This was a prospective cohort study of patients, in whom the KAR technique was used to resect scarred colonic polyps > 2  cm in size. Patients had previously undergone endoscopic mucosal resection (EMR) and developed recurrence, or EMR had been attempted but was aborted as a result of technical difficulty. A total of 42 patients underwent KAR of large (median 40  mm) scarred polyps. Surgery for benign disease was avoided in 38 of 41 patients (93 %). No life-threatening complications occurred. Recurrence was seen in six patients (16 %), five of whom underwent further endoscopic resection. The overall cure rate for KAR in complex scarred colonic polyps was 90 %. KAR of scarred colonic polyps by an expert endoscopist was an effective and safe technique with low recurrence rates. © Georg Thieme Verlag KG Stuttgart · New York.

[Duodenum-preserving total pancreatic head resection and pancreatic head resection with segmental duodenostomy].

Science.gov (United States)

Takada, Tadahiro; Yasuda, Hideki; Nagashima, Ikuo; Amano, Hodaka; Yoshiada, Masahiro; Toyota, Naoyuki

2003-06-01

A duodenum-preserving pancreatic head resection (DPPHR) was first reported by Beger et al. in 1980. However, its application has been limited to chronic pancreatitis because of it is a subtotal pancreatic head resection. In 1990, we reported duodenum-preserving total pancreatic head resection (DPTPHR) in 26 cases. This opened the way for total pancreatic head resection, expanding the application of this approach to tumorigenic morbidities such as intraductal papillary mucinous tumor (IMPT), other benign tumors, and small pancreatic cancers. On the other hand, Nakao et al. reported pancreatic head resection with segmental duodenectomy (PHRSD) as an alternative pylorus-preserving pancreatoduodenectomy technique in 24 cases. Hirata et al. also reported this technique as a new pylorus-preserving pancreatoduodenostomy with increased vessel preservation. When performing DPTPHR, the surgeon should ensure adequate duodenal blood supply. Avoidance of duodenal ischemia is very important in this operation, and thus it is necessary to maintain blood flow in the posterior pancreatoduodenal artery and to preserve the mesoduodenal vessels. Postoperative pancreatic functional tests reveal that DPTPHR is superior to PPPD, including PHSRD, because the entire duodenum and duodenal integrity is very important for postoperative pancreatic function.

Acoustic Neuroma: Questions to Discuss with Your Doctor

Science.gov (United States)

... or how a bite of bread tastes with dinner. Leverage your strengths for a more positive life Strengths are built-in capacities for certain thoughts, feelings, and behaviors. 5 ways to keep your memory sharp The way you live, what you eat and drink, and how you treat your body ...

Learning endoscopic resection in the esophagus

NARCIS (Netherlands)

van Vilsteren, Frederike G. I.; Pouw, Roos E.; Herrero, Lorenza Alvarez; Bisschops, Raf; Houben, Martin; Peters, Frans T. M.; Schenk, B. E.; Weusten, Bas L. A. M.; Schoon, Erik J.; Bergman, Jacques J. G. H. M.

Background: Endoscopic resection is the cornerstone of endoscopic management of esophageal early neoplasia. However, endoscopic resection is a complex technique requiring knowledge and expertise. Our aims were to identify the most important learning points in performing endoscopic resection in a

The value of liver resection for focal nodular hyperplasia: resection yes or no?

Science.gov (United States)

Hau, Hans Michael; Atanasov, Georgi; Tautenhahn, Hans-Michael; Ascherl, Rudolf; Wiltberger, Georg; Schoenberg, Markus Bo; Morgül, Mehmet Haluk; Uhlmann, Dirk; Moche, Michael; Fuchs, Jochen; Schmelzle, Moritz; Bartels, Michael

2015-10-22

Focal nodular hyperplasia (FNH) are benign lesions in the liver. Although liver resection is generally not indicated in these patients, rare indications for surgical approaches indeed exist. We here report on our single-center experience with patients undergoing liver resection for FNH, focussing on preoperative diagnostic algorithms and quality of life (QoL) after surgery. Medical records of 100 consecutive patients undergoing liver resection for FNH between 1992 and 2012 were retrospectively analyzed with regard to diagnostic pathways and indications for surgery. Quality of life (QoL) before and after surgery was evaluated using validated assessment tools. Student's t test, one-way ANOVA, χ (2), and binary logistic regression analyses such as Wilcoxon-Mann-Whitney test were used, as indicated. A combination of at least two preoperative diagnostic imaging approaches was applied in 99 cases, of which 70 patients were subjected to further imaging or tumor biopsy. In most patients, there was more than one indication for liver resection, including tumor-associated symptoms with abdominal discomfort (n = 46, 40.7 %), balance of risk for malignancy/history of cancer (n = 54, 47.8 %/n = 18; 33.3 %), tumor enlargement/jaundice of vascular and biliary structures (n = 13, 11.5 %), such as incidental findings during elective operation (n = 1, 0.9 %). Postoperative morbidity was 19 %, with serious complications (>grade 2, Clavien-Dindo classification) being evident in 8 %. Perioperative mortality was 0 %. Liver resection was associated with a significant overall improvement in general health (very good-excellent: preoperatively 47.4 % vs. postoperatively 68.1 %; p = 0.015). Liver resection remains a valuable therapeutic option in the treatment of either symptomatic FNH or if malignancy cannot finally be ruled out. If clinically indicated, liver resection for FNH represents a safe approach and may lead to significant improvements of QoL especially in

Which patients with resectable pancreatic cancer truly benefit from oncological resection: is it destiny or biology?

Science.gov (United States)

Zheng, Lei; Wolfgang, Christopher L

2015-01-01

Pancreatic cancer has a dismal prognosis. A technically perfect surgical operation may still not provide a survival advantage for patients with technically resectable pancreatic cancer. Appropriate selection of patients for surgical resections is an imminent issue. Recent studies have provided an important clue on what serum biomarkers may be used to select out the patients who would unlikely benefit from the surgical resection.

Duodenal endoscopic full-thickness resection (with video).

Science.gov (United States)

Schmidt, Arthur; Meier, Benjamin; Cahyadi, Oscar; Caca, Karel

2015-10-01

Endoscopic resection of duodenal non-lifting adenomas and subepithelial tumors is challenging and harbors a significant risk of adverse events. We report on a novel technique for duodenal endoscopic full-thickness resection (EFTR) by using an over-the-scope device. Data of 4 consecutive patients who underwent duodenal EFTR were analyzed retrospectively. Main outcome measures were technical success, R0 resection, histologic confirmation of full-thickness resection, and adverse events. Resections were done with a novel, over-the-scope device (full-thickness resection device, FTRD). Four patients (median age 60 years) with non-lifting adenomas (2 patients) or subepithelial tumors (2 patients) underwent EFTR in the duodenum. All lesions could be resected successfully. Mean procedure time was 67.5 minutes (range 50-85 minutes). Minor bleeding was observed in 2 cases; blood transfusions were not required. There was no immediate or delayed perforation. Mean diameter of the resection specimen was 28.3 mm (range 22-40 mm). Histology confirmed complete (R0) full-thickness resection in 3 of 4 cases. To date, 2-month endoscopic follow-up has been obtained in 3 patients. In all cases, the over-the-scope clip was still in place and could be removed without adverse events; recurrences were not observed. EFTR in the duodenum with the FTRD is a promising technique that has the potential to spare surgical resections. Modifications of the device should be made to facilitate introduction by mouth. Prospective studies are needed to further evaluate efficacy and safety for duodenal resections. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Virtual MRI endoscopy of the intracranial cerebrospinal fluid spaces

International Nuclear Information System (INIS)

Shigematsu, Y.; Korogi, Y.; Hirai, T.; Okuda, T.; Ikushima, I.; Sugahara, T.; Liang, L.; Ge, Y.; Takahashi, M.

1998-01-01

We used constructive interference in steady state (CISS) 3D Fourier transform (3DFT) MRI data sets to obtain three-dimensional (3D) virtual MRI endoscopic views of the intracranial cerebrospinal fluid (CSF) spaces, processing them with a commercially available perspective endoscopic algorithm. We investigated the potential of the intracranial virtual MRI endoscopy applied to visualisation of the pathology in 13 patients with surgically confirmed trigeminal neuralgia (3), hemifacial spasm (3), acoustic neuroma (3), suprasellar germinoma (1), Langerhans cell histiocytosis (1), lateral ventricle nodules (1) and pituitary dwarfism (1). All images were acquired using a 1.5-T imager employing a circular polarised head coil. The CISS-3DFT data sets were transferred to a workstation for processing with the perspective endoscopic algorithm. Postprocessing for virtual MRI endoscopy was possible for all data sets. The lesions in 12 patients, and their complex anatomical relationships with the surrounding structures, were well seen on the 3D images. A small acoustic neuroma in the internal auditory meatus was not seen using virtual endoscopy. Although virtual MRI endoscopy has limitations, it provides 3D images which cannot be acquired using any other procedure. (orig.)

Virtual MRI endoscopy of the intracranial cerebrospinal fluid spaces

Energy Technology Data Exchange (ETDEWEB)

Shigematsu, Y.; Korogi, Y.; Hirai, T. [Kumamoto Univ. (Japan). Dept. of Radiology; Okuda, T.; Ikushima, I.; Sugahara, T.; Liang, L.; Ge, Y.; Takahashi, M.

1998-10-01

We used constructive interference in steady state (CISS) 3D Fourier transform (3DFT) MRI data sets to obtain three-dimensional (3D) virtual MRI endoscopic views of the intracranial cerebrospinal fluid (CSF) spaces, processing them with a commercially available perspective endoscopic algorithm. We investigated the potential of the intracranial virtual MRI endoscopy applied to visualisation of the pathology in 13 patients with surgically confirmed trigeminal neuralgia (3), hemifacial spasm (3), acoustic neuroma (3), suprasellar germinoma (1), Langerhans cell histiocytosis (1), lateral ventricle nodules (1) and pituitary dwarfism (1). All images were acquired using a 1.5-T imager employing a circular polarised head coil. The CISS-3DFT data sets were transferred to a workstation for processing with the perspective endoscopic algorithm. Postprocessing for virtual MRI endoscopy was possible for all data sets. The lesions in 12 patients, and their complex anatomical relationships with the surrounding structures, were well seen on the 3D images. A small acoustic neuroma in the internal auditory meatus was not seen using virtual endoscopy. Although virtual MRI endoscopy has limitations, it provides 3D images which cannot be acquired using any other procedure. (orig.) With 6 figs., 16 refs.

Carinal resection and reconstruction following inflammatory myofibroblastic tumor resection: A case report

Directory of Open Access Journals (Sweden)

Julia G. Lyon

2016-02-01

Full Text Available Inflammatory myofibroblastic tumors (IMT are rare tumors of the respiratory tract that most commonly occur in the lung and are rarely seen in the trachea. They present most often in young patients. We report on a case of an IMT of the carina in a seven year old girl, requiring carinal resection and reconstruction with a novel technique in pediatric airway surgery. Attempts at endoscopic excision of the carinal IMT were unsuccessful. An open approach for resection of the involved carina, distal trachea, and proximal mainstem bronchi was performed via sternotomy and cardiopulmonary bypass. The resulting triangular defect in the trachea and bronchi was reconstructed with anastomosis of the proximal trachea and left mainstem bronchus using a rotational flap of the right lateral mainstem bronchial wall. The remaining right mainstem bronchus was anastomosed, end to side, to the intact trachea proximal to the primary anastomosis. Bronchoscopy and MRI 22 months post resection and reconstruction revealed a healthy neo-carina and patent distal airway with no evidence of recurrent IMT. Pediatric patients with carinal inflammatory myofibroblastic tumors can be successfully managed with open resection and reconstruction of the airway.

Smooth muscle adaptation after intestinal transection and resection.

Science.gov (United States)

Thompson, J S; Quigley, E M; Adrian, T E

1996-09-01

Changes in motor function occur in the intestinal remnant after intestinal resection. Smooth muscle adaptation also occurs, particularly after extensive resection. The time course of these changes and their interrelationship are unclear. Our aim was to evaluate changes in canine smooth muscle structure and function during intestinal adaptation after transection and resection. Twenty-five dogs underwent either transection (N = 10), 50% distal resection (N = 10), or 50% proximal resection (N = 5). Thickness and length of the circular (CM) and longitudinal (LM) muscle layers were measured four and 12 weeks after resection. In vitro length-tension properties and response to a cholinergic agonist were studied in mid-jejunum and mid-ileum. Transection alone caused increased CM length in the jejunum proximal to the transection but did not affect LM length or muscle thickness. A 50% resection resulted in increased length of CM throughout the intestine and thickening of CM and LM near the anastomosis. Active tension of jejunal CM increased transiently four weeks after resection. Active tension in jejunal LM was decreased 12 weeks after transection and resection. Sensitivity of CM to carbachol was similar after transection and resection. It is concluded that: (1) Structural adaptation of both circular and longitudinal muscle occurs after intestinal resection. (2) This process is influenced by the site of the intestinal remnant. (3) Only minor and transient changes occur in smooth muscle function after resection. (4) Factors other than muscle adaptation are likely involved in the changes in motor function seen following massive bowel resection.

Open resections for congenital lung malformations

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Mullassery Dhanya

2008-01-01

Full Text Available Aim: Pediatric lung resection is a relatively uncommon procedure that is usually performed for congenital lesions. In recent years, thoracoscopic resection has become increasingly popular, particularly for small peripheral lesions. The aim of this study was to review our experience with traditional open lung resection in order to evaluate the existing "gold standard." Materials and Methods: We carried out a retrospective analysis of all children having lung resection for congenital lesions at our institution between 1997 and 2004. Data were collected from analysis of case notes, operative records and clinical consultation. The mean follow-up was 37.95 months. The data were analyzed using SPSS. Results: Forty-one children (13 F/28 M underwent major lung resections during the study period. Their median age was 4.66 months (1 day-9 years. The resected lesions included 21 congenital cystic adenomatoid malformations, 14 congenital lobar emphysema, four sequestrations and one bronchogenic cyst. Fifty percent of the lesions were diagnosed antenatally. Twenty-six patients had a complete lobectomy while 15 patients had parenchymal sparing resection of the lesion alone. Mean postoperative stay was 5.7 days. There have been no complications in any of the patients. All patients are currently alive, asymptomatic and well. None of the patients have any significant chest deformity. Conclusions: We conclude that open lung resection enables parenchymal sparing surgery, is versatile, has few complications and produces very good long-term results. It remains the "gold standard" against which minimally invasive techniques may be judged.

Hepatic resection for colorectal metastases - a national perspective.

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Heriot, A. G.; Reynolds, J.; Marks, C. G.; Karanjia, N.

2004-01-01

BACKGROUND: Many consultant surgeons are uncertain about peri-operative assessment and postoperative follow-up of patients for colorectal liver metastases, and indications for referral for hepatic resection. The aim of this study was to assess the views the consultant surgeons who manage these patients. METHODS: A postal questionnaire was sent to all consultant members of the Association of Coloproctology of Great Britain and Ireland and of the Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland. The questionnaire assessed current practice for preoperative assessment and follow-up of patients with colorectal malignancy and timing of and criteria for hepatic resection of metastases. Number of referrals/resections were also assessed. RESULTS: The response rate was 47%. Half of the consultants held joint clinics with an oncologist and 89% assessed the liver for secondaries prior to colorectal resection. Ultrasound was used by 75%. Whilst 99% would consider referring a patient with a solitary liver metastasis for resection, only 62% would consider resection for more than 3 unilobar metastases. The majority (83%) thought resections should be performed within the 6 months following colorectal resection. During follow-up, 52% requested blood CEA levels and 72% liver ultrasound. Half would consider chemotherapy prior to liver resection and 76% performed at least one hepatic resection per year with a median number of 2 resections each year. CONCLUSIONS: A substantial proportion of patients are assessed for colorectal liver metastases preoperatively and during follow-up though there is spectrum of frequency of assessment and modality for imaging. Virtually all patients with solitary hepatic metastases are considered for liver resection. Patients with more than one metastasis are likely to be not considered for resection. Many surgeons are carrying out less than 3 resections each year. PMID:15527578

Benchmarking circumferential resection margin (R1) resection rate for rectal cancer in the neoadjuvant era.

Science.gov (United States)

Chambers, W; Collins, G; Warren, B; Cunningham, C; Mortensen, N; Lindsey, I

2010-09-01

Circumferential resection margin (CRM) involvement (R1) is used to audit rectal cancer surgical quality. However, when downsizing chemoradiation (dCRT) is used, CRM audits both dCRT and surgery, its use reflecting a high casemix of locally advanced tumours. We aimed to evaluate predictors of R1 and benchmark R1 rates in the dCRT era, and to assess the influence of failure of steps in the multidisciplinary team (MDT) process to CRM involvement. A retrospective analysis of prospectively collected rectal cancer data was undertaken. Patients were classified according to CRM status. Uni- and multivariate analysis was undertaken of risk factors for R1 resection. The contribution of the steps of the MDT process to CRM involvement was assessed. Two hundred and ten rectal cancers were evaluated (68% T3 or T4 on preoperative staging). R1 (microscopic) and R2 (macroscopic) resections occurred in 20 (10%) and 6 patients (3%), respectively. Of several factors associated with R1 resections on univariate analysis, only total mesorectal excision (TME) specimen defects and threatened/involved CRM on preoperative imaging remained as independent predictors of R1 resections on multivariate analysis. Causes of R1 failure by MDT step classification found that less than half were associated with and only 15% solely attributable to a suboptimal TME specimen. Total mesorectal excision specimen defects and staging-predicted threatened or involved CRM are independent strong predictors of R1 resections. In most R1 resections, the TME specimen was intact. It is important to remember the contribution of both the local staging casemix and dCRT failure when using R1 rates to assess purely surgical competence.

Liver resection over the last decade

DEFF Research Database (Denmark)

Wettergren, A.; Larsen, P.N.; Rasmussen, A.

2008-01-01

after resection of hepatic metastases from colorectal cancer and hepatocellular carcinoma was estimated. RESULTS: 141 patients (71M/70F), median age 58 years (1-78), underwent a liver resection in the ten-year period. The number of resections increased from two in 1995 to 32 in 2004. Median hospital...... stay was 9 days (3-38). The most frequent complication was biliary leakage (7.8%), haemorrhage (2.8%) and hepatic insufficiency (2.8%). 30-days mortality was 1.4%. The actuarial 5-survival after hepatic resection for colorectal liver metastases and hepatocellular carcinoma was 39% and 42%, respectively...

Liver resection over the last decade

DEFF Research Database (Denmark)

Wettergren, A.; Larsen, P.N.; Rasmussen, A.

2008-01-01

of hepatic metastases from colorectal cancer and hepatocellular carcinoma in our institution. MATERIALS AND METHODS: The patients who underwent their primary liver resection from 1.1.1995-31.12.2004 in our institution were included. The surgical outcome was reviewed retrospectively and the five-year survival...... after resection of hepatic metastases from colorectal cancer and hepatocellular carcinoma was estimated. RESULTS: 141 patients (71M/70F), median age 58 years (1-78), underwent a liver resection in the ten-year period. The number of resections increased from two in 1995 to 32 in 2004. Median hospital...

The resection angle in apical surgery

DEFF Research Database (Denmark)

von Arx, Thomas; Janner, Simone F M; Jensen, Simon S

2016-01-01

OBJECTIVES: The primary objective of the present radiographic study was to analyse the resection angle in apical surgery and its correlation with treatment outcome, type of treated tooth, surgical depth and level of root-end filling. MATERIALS AND METHODS: In the context of a prospective clinical...... study, cone beam computed tomography (CBCT) scans were taken before and 1 year after apical surgery to measure the angle of the resection plane relative to the longitudinal axis of the root. Further, the surgical depth (distance from the buccal cortex to the most lingual/palatal point of the resection...... or with the retrofilling length. CONCLUSIONS: Statistically significant differences were observed comparing resection angles of different tooth groups. However, the angle had no significant effect on treatment outcome. CLINICAL RELEVANCE: Contrary to common belief, the resection angle in maxillary anterior teeth...

Use of acoustic vortices in acoustic levitation

DEFF Research Database (Denmark)

Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller

2009-01-01

Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without...

Acoustic emission

International Nuclear Information System (INIS)

Nichols, R.W.

1976-01-01

The volume contains six papers which together provide an overall review of the inspection technique known as acoustic emission or stress wave emission. The titles are: a welder's introduction to acoustic emission technology; use of acoustic emission for detection of defects as they arise during fabrication; examples of laboratory application and assessment of acoustic emission in the United Kingdom; (Part I: acoustic emission behaviour of low alloy steels; Part II: fatigue crack assessment from proof testing and continuous monitoring); inspection of selected areas of engineering structures by acoustic emission; Japanese experience in laboratory and practical applications of acoustic emission to welded structures; and ASME acoustic emission code status. (U.K.)

Robotic liver surgery: results for 70 resections.

Science.gov (United States)

Giulianotti, Pier Cristoforo; Coratti, Andrea; Sbrana, Fabio; Addeo, Pietro; Bianco, Francesco Maria; Buchs, Nicolas Christian; Annechiarico, Mario; Benedetti, Enrico

2011-01-01

Robotic surgery is gaining popularity for digestive surgery; however, its use for liver surgery is reported scarcely. This article reviews a surgeon's experience with the use of robotic surgery for liver resections. From March 2002 to March 2009, 70 robotic liver resections were performed at 2 different centers by a single surgeon. The surgical procedure and postoperative outcome data were reviewed retrospectively. Malignant tumors were indications for resections in 42 (60%) patients, whereas benign tumors were indications in 28 (40%) patients. The median age was 60 years (range, 21-84) and 57% of patients were female. Major liver resections (≥ 3 liver segments) were performed in 27 (38.5%) patients. There were 4 conversions to open surgery (5.7%). The median operative time for a major resection was 313 min (range, 220-480) and 198 min (range, 90-459) for minor resection. The median blood loss was 150 mL (range, 20-1,800) for minor resection and 300 mL (range, 100-2,000) for major resection. The mortality rate was 0%, and the overall rate of complications was 21%. Major morbidity occurred in 4 patients in the major hepatectomies group (14.8%) and in 4 patients in the minor hepatectomies group (9.3%). All complications were managed conservatively and none required reoperation. This preliminary experience shows that robotic surgery can be used safely for liver resections with a limited conversion rate, blood loss, and postoperative morbidity. Robotics offers a new technical option for minimally invasive liver surgery. Copyright © 2011 Mosby, Inc. All rights reserved.

Translational illusion of acoustic sources by transformation acoustics.

Science.gov (United States)

Sun, Fei; Li, Shichao; He, Sailing

2017-09-01

An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

Managing Potentially Resectable Metastatic Colon Cancer

OpenAIRE

Marshall, John L.

2008-01-01

For patients with metastatic colon cancer, management has evolved from resecting a single liver metastasis and having only one chemotherapy medicine, to resecting multiple metastases including those outside the liver as well as using combination chemotherapy (based on recent supportive trials) to improve outcomes. This success has also raised many questions, including the role of adjuvant chemotherapy to downstage borderline resectable tumors, whether patients who receive preoperative chemoth...

Robotic vascular resections during Whipple procedure.

Science.gov (United States)

Allan, Bassan J; Novak, Stephanie M; Hogg, Melissa E; Zeh, Herbert J

2018-01-01

Indications for resection of pancreatic cancers have evolved to include selected patients with involvement of peri-pancreatic vascular structures. Open Whipple procedures have been the standard approach for patients requiring reconstruction of the portal vein (PV) or superior mesenteric vein (SMV). Recently, high-volume centers are performing minimally invasive Whipple procedures with portovenous resections. Our institution has performed seventy robotic Whipple procedures with concomitant vascular resections. This report outlines our technique.

Augmented reality in bone tumour resection: An experimental study.

Science.gov (United States)

Cho, H S; Park, Y K; Gupta, S; Yoon, C; Han, I; Kim, H-S; Choi, H; Hong, J

2017-03-01

We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137-143. © 2017 Cho et al.

Contemporary Management of Localized Resectable Pancreatic Cancer.

Science.gov (United States)

Kommalapati, Anuhya; Tella, Sri Harsha; Goyal, Gaurav; Ma, Wen Wee; Mahipal, Amit

2018-01-20

Pancreatic cancer is the third most common cause of cancer deaths in the United States. Surgical resection with negative margins still constitutes the cornerstone of potentially curative therapy, but is possible only in 15-20% of patients at the time of initial diagnosis. Accumulating evidence suggests that the neoadjuvant approach may improve R0 resection rate in localized resectable and borderline resectable diseases, and potentially downstage locally advanced disease to achieve surgical resection, though the impact on survival is to be determined. Despite advancements in the last decade in developing effective combinational chemo-radio therapeutic options, preoperative treatment strategies, and better peri-operative care, pancreatic cancer continues to carry a dismal prognosis in the majority. Prodigious efforts are currently being made in optimizing the neoadjuvant therapy with a better toxicity profile, developing novel agents, imaging techniques, and identification of biomarkers for the disease. Advancement in our understanding of the tumor microenvironment and molecular pathology is urgently needed to facilitate the development of novel targeted and immunotherapies for this setting. In this review, we detail the current literature on contemporary management of resectable, borderline resectable and locally advanced pancreatic cancer with a focus on future directions in the field.

Impact of selective pituitary gland incision or resection on hormonal function after adenoma or cyst resection.

Science.gov (United States)

Barkhoudarian, Garni; Cutler, Aaron R; Yost, Sam; Lobo, Bjorn; Eisenberg, Amalia; Kelly, Daniel F

2015-12-01

With the resection of pituitary lesions, the anterior pituitary gland often obstructs transsphenoidal access to the lesion. In such cases, a gland incision and/or partial gland resection may be required to obtain adequate exposure. We investigate this technique and determine the associated risk of post-operative hypopituitarism. All patients who underwent surgical resection of a pituitary adenoma or Rathke cleft cyst (RCC) between July 2007 and January 2013 were analyzed for pre- and post-operative hormone function. The cohort of patients with gland incision/resection were compared to a case-matched control cohort of pituitary surgery patients. Total hypophysectomy patients were excluded from outcome analysis. Of 372 operations over this period, an anterior pituitary gland incision or partial gland resection was performed in 79 cases (21.2 %). These include 53 gland incisions, 12 partial hemi-hypophysectomies and 14 resections of thinned/attenuated anterior gland. Diagnoses included 64 adenomas and 15 RCCs. New permanent hypopituitarism occurred in three patients (3.8 %), including permanent DI (3) and growth hormone deficiency (1). There was no significant difference in the rate of worsening gland dysfunction nor gain of function. Compared to a control cohort, there was a significantly lower incidence of transient DI (1.25 vs. 11.1 %, p = 0.009) but no significant difference in permanent DI (3.8 vs. 4.0 %) in the gland incision group. Selective gland incisions and gland resections were performed in over 20 % of our cases. This technique appears to minimize traction on compressed normal pituitary gland during removal of large lesions and facilitates better visualization and removal of cysts, microadenomas and macroadenomas.

Can immediate second resection be an alternative to standardized second transurethral resection of bladder tumors?

Directory of Open Access Journals (Sweden)

Engin Doğantekin

2016-03-01

Full Text Available This study analyzed the impact of an immediate second transurethral resection of bladder tumor (TURBT protocol on residual tumor status at the initial TURBT session and the recurrence rate in the primary resection area. We prospectively evaluated and randomized 47 consecutive patients who underwent TURBT sessions for bladder cancer. In accordance with the inclusion criteria, of the 47 consecutive patients, 19 (Group I underwent immediate second resection of the tumor bed after complete TUR and 28 (Group II did not. After standard TURBT, Group I underwent a second cystoscopy and resection of the bed of the tumor or an ignored tumor, which was performed by a different urologist. After 4–6 weeks, delayed second TURB was performed, and all pathological results were evaluated. Tumors were detected in two patients during the immediate second resection. Of these, one was a misdiagnosed tumor, whereas the other was diagnosed at the bed of the tumor by pathological examination. Tumors were detected in nine patients at the delayed second TURB, of which only one was part of Group I, while the others were part of Group II (p = 0.04. The results of this study demonstrated that residual tumors may remain after initial TURB, either in the tumor bed or in a different location within the bladder. Although this was a pilot study enrolling only a small number of patients, our initial results supported the assertion that immediate second resection can be an alternative to standard second TURBT.

[Laparoscopic resection of stomach in case of stomach ulcer].

Science.gov (United States)

Sazhin, I V; Sazhin, V P; Nuzhdikhin, A V

2014-01-01

Laparoscopic resection of stomach was done in 84 patients with complicated peptic ulcer of stomach and duodenum. There were 1.2% post-operative complications in case of laparoscopic resection of stomach in comparison with open resection, which had 33.3% complications. There were not deaths in case of laparoscopic resection of stomach. This indication was about 4% in patients after open resection. It was determined that functionalefficiency afterlaparoscopic resection was in 1.6-1.8 times higher than afteropen resectionof stomach.

Circumferential resection margin (CRM) positivity after MRI assessment and adjuvant treatment in 189 patients undergoing rectal cancer resection.

Science.gov (United States)

Simpson, G S; Eardley, N; McNicol, F; Healey, P; Hughes, M; Rooney, P S

2014-05-01

The management of rectal cancer relies on accurate MRI staging. Multi-modal treatments can downstage rectal cancer prior to surgery and may have an effect on MRI accuracy. We aim to correlate the findings of MRI staging of rectal cancer with histological analysis, the effect of neoadjuvant therapy on this and the implications of circumferential resection margin (CRM) positivity following neoadjuvant therapy. An analysis of histological data and radiological staging of all cases of rectal cancer in a single centre between 2006 and 2011 were conducted. Two hundred forty-one patients had histologically proved rectal cancer during the study period. One hundred eighty-two patients underwent resection. Median age was 66.6 years, and male to female ratio was 13:5. R1 resection rate was 11.1%. MRI assessments of the circumferential resection margin in patients without neoadjuvant radiotherapy were 93.6 and 88.1% in patients who underwent neoadjuvant radiotherapy. Eighteen patients had predicted positive margins following chemoradiotherapy, of which 38.9% had an involved CRM on histological analysis. MRI assessment of the circumferential resection margin in rectal cancer is associated with high accuracy. Neoadjuvant chemoradiotherapy has a detrimental effect on this accuracy, although accuracy remains high. In the presence of persistently predicted positive margins, complete resection remains achievable but may necessitate a more radical approach to resection.

Linear accelerator based stereotactic radiosurgery with micro multi-leaf collimator : technological advancement in precision radiotherapy

International Nuclear Information System (INIS)

Dayananda, S.; Kinhikar, R.A.; Saju, Sherley; Deshpande, D.D.; Jalali, R.; Sarin, R.; Shrivastava, S.K.; Dinshaw, K.A.

2003-01-01

Stereotactic Radiosurgery (SRS) is an advancement on precision radiotherapy, in which stereo tactically guided localized high dose is delivered to the lesion (target) in a single fraction, while sparing the surrounding normal tissue. Radiosurgery has been used to treat variety of benign and malignant lesions as well as functional disorders in brain such as arteriovenous malformation (AVM), acoustic neuroma, solitary primary brain tumor, single metastasis, pituitary adenoma etc

Urethral strictures after bipolar transurethral resection of prostate may be linked to slow resection rate

Directory of Open Access Journals (Sweden)

Guan Hee Tan

2017-05-01

Full Text Available Purpose: This study aimed to determine the urethral stricture (US rate and identify clinical and surgical risk factors associated with US occurrence after transurethral resection of the prostate using the bipolar Gyrus PlasmaKinetic Tissue Management System (PKTURP. Materials and Methods: This was an age-matched case-control study of US occurrence after PK-TURP. Retrospective data were collected from the hospital records of patients who had a minimum of 36 months of follow-up information. Among the data collected for analysis were prostate-specific antigen level, estimated prostate weight, the amount of prostate resected, operative time, history of urinary tract infection, previous transurethral resection of the prostate, and whether the PK-TURP was combined with other endourological procedures. The resection rate was calculated from the collected data. Univariate and multivariate analyses were performed to identify clinical and surgical risk factors related to US formation. Results: A total of 373 patients underwent PK-TURP between 2003 and 2009. There were 13 cases of US (3.5%, and most of them (10 of 13, 76.9% presented within 24 months of surgery. Most of the US cases (11 of 13, 84.6% occurred at the bulbar urethra. Multivariable logistic regression analyses identified slow resection rate as the only risk factor significantly associated with US occurrence. Conclusions: The US rate of 3.5% after PK-TURP in this study is comparable to contemporary series. A slow resection rate seems to be related to US occurrence. This should be confirmed by further studies; meanwhile, we must be mindful of this possibility when operating with the PK-TURP system.

Computer Navigation-aided Resection of Sacral Chordomas

Directory of Open Access Journals (Sweden)

Yong-Kun Yang

2016-01-01

Full Text Available Background: Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas. Methods: Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old. Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months. Results: Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7% exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30. Conclusions: Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

Quality of Life in 807 Patients with Vestibular Schwannoma: Comparing Treatment Modalities.

Science.gov (United States)

Soulier, Géke; van Leeuwen, Bibian M; Putter, Hein; Jansen, Jeroen C; Malessy, Martijn J A; van Benthem, Peter Paul G; van der Mey, Andel G L; Stiggelbout, Anne M

2017-07-01

Objective In vestibular schwannoma treatment, the choice among treatment modalities is controversial. The first aim of this study was to examine the quality of life of patients with vestibular schwannoma having undergone observation, radiation therapy, or microsurgical resection. The second aim was to examine the relationship between perceived symptoms and quality of life. Last, the association between quality of life and time since treatment was studied. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods A total of 1208 patients treated for sporadic vestibular schwannoma between 2004 and 2014 were mailed the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL) questionnaire and additional questions on symptoms associated with vestibular schwannoma. Total and domain scores were calculated and compared among treatment groups. Propensity scores were used, and results were stratified according to tumor size to control for potential confounders. Correlations were calculated to examine the relationship between self-reported symptoms and quality of life, as well as between quality of life and time since treatment. Results Patients with small tumors (≤10 mm) under observation showed a higher PANQOL score when compared with the radiation therapy and microsurgical resection groups. A strong negative correlation was found between self-reported symptoms and quality of life, with balance problems and vertigo having the largest impact. No correlation was found between PANQOL score and time since treatment. Conclusion This study suggests that patients with small vestibular schwannomas experience better quality of life when managed with observation than do patients who have undergone active treatment.

Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

Science.gov (United States)

Begault, Durand R.; Ahumada, Al (Technical Monitor)

1997-01-01

These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

Communication Acoustics

DEFF Research Database (Denmark)

Blauert, Jens

Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

Safe Resection and Primary Anastomosis of Gangrenous Sigmoid ...

African Journals Online (AJOL)

%) of the sigmoid volvulus was gangrenous and 85.2% of all the sigmoid volvulus was managed by resection and primary anastomosis. Complications seen after resection and primary anastomosis were anastomotic leak at 4.5%, resection.

[Robot-assisted liver resection].

Science.gov (United States)

Aselmann, H; Möller, T; Kersebaum, J-N; Egberts, J H; Croner, R; Brunner, M; Grützmann, R; Becker, T

2017-06-01

Robotic liver resection can overcome some of the limitations of laparoscopic liver surgery; therefore, it is a promising tool to increase the proportion of minimally invasive liver resections. The present article gives an overview of the current literature. Furthermore, the results of a nationwide survey on robotic liver surgery among hospitals in Germany with a DaVinci system used in general visceral surgery and the perioperative results of two German robotic centers are presented.

Laparoscopic resection of hilar cholangiocarcinoma.

Science.gov (United States)

Lee, Woohyung; Han, Ho-Seong; Yoon, Yoo-Seok; Cho, Jai Young; Choi, YoungRok; Shin, Hong Kyung; Jang, Jae Yool; Choi, Hanlim

2015-10-01

Laparoscopic resection of hilar cholangiocarcinoma is technically challenging because it involves complicated laparoscopic procedures that include laparoscopic hepatoduodenal lymphadenectomy, hemihepatectomy with caudate lobectomy, and hepaticojejunostomy. There are currently very few reports describing this type of surgery. Between August 2014 and December 2014, 5 patients underwent total laparoscopic or laparoscopic-assisted surgery for hilar cholangiocarcinoma. Two patients with type I or II hilar cholangiocarcinoma underwent radical hilar resection. Three patients with type IIIa or IIIb cholangiocarcinoma underwent extended hemihepatectomy together with caudate lobectomy. The median (range) age, operation time, blood loss, and length of hospital stay were 63 years (43-76 years), 610 minutes (410-665 minutes), 650 mL (450-1,300 mL), and 12 days (9-21 days), respectively. Four patients had a negative margin, but 1 patient was diagnosed with high-grade dysplasia on the proximal resection margin. The median tumor size was 3.0 cm. One patient experienced postoperative biliary leakage, which resolved spontaneously. Laparoscopic resection is a feasible surgical approach in selected patients with hilar cholangiocarcinoma.

Acoustic source for generating an acoustic beam

Science.gov (United States)

Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

2016-05-31

An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

Endoscopic full-thickness resection: Current status.

Science.gov (United States)

Schmidt, Arthur; Meier, Benjamin; Caca, Karel

2015-08-21

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

Science.gov (United States)

Zuckerwar, Allan J. (Inventor); Davis, David C. (Inventor)

1995-01-01

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

Immediate side effects of stereotactic radiotherapy and radiosurgery

International Nuclear Information System (INIS)

Werner-Wasik, Maria; Rudoler, Shari; Preston, Peter E.; Hauck, Walter W.; Downes, Beverly M.; Leeper, Dennis; Andrews, David; Corn, Benjamin W.; Curran, Walter J.

1999-01-01

Purpose: Despite increased utilization of fractionated stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS), the incidence and nature of immediate side effects (ISE) associated with these treatment techniques are not well defined. We report immediate side effects from a series of 78 patients. Materials and Methods: Intracranial lesions in 78 adult patients were treated with SRT or SRS, using a dedicated linear accelerator. Those lesions included 13 gliomas, 2 ependymomas, 19 metastatic tumors, 15 meningiomas, 12 acoustic neuromas, 4 pituitary adenomas, 1 optic neuroma, 1 chondrosarcoma, and 11 arteriovenous malformations (AVM). SRT was used in 51 and SRS in 27 patients. Mean target volume was 9.0 cc. Eleven patients received prior external-beam radiation therapy within 2 months before SRT/SRS. Any side effects occurring during and up to 2 weeks after the course of radiation were defined as ISE and were graded as mild, moderate, or severe. The incidence of ISE and the significance of their association with several treatment and pretreatment variables were analyzed. Results: Overall, 28 (35%) of 78 patients experienced one or more ISE. Most of the ISE (87%) were mild, and consisted of nausea (in 5), dizziness/vertigo (in 5), seizures (in 6), and new persistent headaches (in 17). Two episodes of worsening neurological deficit and 2 of orbital pain were graded as moderate. Two patients experienced severe ISE, requiring hospitalization (1 seizure and 1 worsening neurological deficit). ISE in 6 cases prompted computerized tomography of the brain, which revealed increased perilesional edema in 3 cases. The incidence of ISE by diagnosis was as follows: 46% (6 of 13) for gliomas, 50% (6 of 12) for acoustic neuromas, 36% (4 of 11) for AVM, 33% (5 of 15) for meningiomas, and 21% (4 of 19) for metastases. A higher incidence of dizziness/vertigo (4 of 12 = 33%) was seen among acoustic neuroma patients than among other patients (p < 0.01). There was no

Laparoscopic resection for diverticular disease.

Science.gov (United States)

Bruce, C J; Coller, J A; Murray, J J; Schoetz, D J; Roberts, P L; Rusin, L C

1996-10-01

The role of laparoscopic surgery in treatment of patients with diverticulitis is unclear. A retrospective comparison of laparoscopic with conventional surgery for patients with chronic diverticulitis was performed to assess morbidity, recovery from surgery, and cost. Records of patients undergoing elective resection for uncomplicated diverticulitis from 1992 to 1994 at a single institution were reviewed. Laparoscopic resection involved complete intracorporeal dissection, bowel division, and anastomosis with extracorporeal placement of an anvil. Sigmoid and left colon resections were performed laparoscopically in 25 patients and by open technique in 17 patients by two independent operating teams. No significant differences existed in age, gender, weight, comorbidities, or operations performed. In the laparoscopic group, three operations were converted to open laparotomy (12 percent) because of unclear anatomy. Major complications occurred in two patients who underwent laparoscopic resection, both requiring laparotomy, and in one patient in the conventional surgery group who underwent computed tomographic-guided drainage of an abscess. Patients who underwent laparoscopic resection tolerated a regular diet sooner than patients who underwent conventional surgery (3.2 +/- 0.9 vs. 5.7 +/- 1.1 days; P < 0.001) and were discharged from the hospital earlier (4.2 +/- 1.1 vs. 6.8 +/- 1.1 days; P < 0.001). Overall costs were higher in the laparoscopic group than the open surgery group ($10,230 +/- 49.1 vs. $7,068 +/- 37.1; P < 0.001) because of a significantly longer total operating room time (397 +/- 9.1 vs. 115 +/- 5.1 min; P < 0.001). Follow-up studies with a mean of one year revealed two port site infections in the laparoscopic group and one wound infection in the open group. Of patients undergoing conventional resection, one patient experienced a postoperative bowel obstruction that was managed nonoperatively, and, in one patient, an incarcerated incisional hernia

Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

Science.gov (United States)

Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

2009-01-01

Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

Augmented reality in a tumor resection model.

Science.gov (United States)

Chauvet, Pauline; Collins, Toby; Debize, Clement; Novais-Gameiro, Lorraine; Pereira, Bruno; Bartoli, Adrien; Canis, Michel; Bourdel, Nicolas

2018-03-01

Augmented Reality (AR) guidance is a technology that allows a surgeon to see sub-surface structures, by overlaying pre-operative imaging data on a live laparoscopic video. Our objectives were to evaluate a state-of-the-art AR guidance system in a tumor surgical resection model, comparing the accuracy of the resection with and without the system. Our system has three phases. Phase 1: using the MRI images, the kidney's and pseudotumor's surfaces are segmented to construct a 3D model. Phase 2: the intra-operative 3D model of the kidney is computed. Phase 3: the pre-operative and intra-operative models are registered, and the laparoscopic view is augmented with the pre-operative data. We performed a prospective experimental study on ex vivo porcine kidneys. Alginate was injected into the parenchyma to create pseudotumors measuring 4-10 mm. The kidneys were then analyzed by MRI. Next, the kidneys were placed into pelvictrainers, and the pseudotumors were laparoscopically resected. The AR guidance system allows the surgeon to see tumors and margins using classical laparoscopic instruments, and a classical screen. The resection margins were measured microscopically to evaluate the accuracy of resection. Ninety tumors were segmented: 28 were used to optimize the AR software, and 62 were used to randomly compare surgical resection: 29 tumors were resected using AR and 33 without AR. The analysis of our pathological results showed 4 failures (tumor with positive margins) (13.8%) in the AR group, and 10 (30.3%) in the Non-AR group. There was no complete miss in the AR group, while there were 4 complete misses in the non-AR group. In total, 14 (42.4%) tumors were completely missed or had a positive margin in the non-AR group. Our AR system enhances the accuracy of surgical resection, particularly for small tumors. Crucial information such as resection margins and vascularization could also be displayed.

Interior acoustic cloak

Directory of Open Access Journals (Sweden)

Wael Akl

2014-12-01

Full Text Available Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which are invariably heavy and bulky. The transformation acoustics relationships that govern the operation of this class of interior acoustic cloaks are presented. Physical insights are given to relate these relationships to the reasons behind the effectiveness of the proposed interior acoustic cloaks. Finite element models are presented to demonstrate the characteristics of interior acoustic cloaks used in treating the interior walls of circular and square cavities both in the time and frequency domains. The obtained results emphasize the effectiveness of the proposed interior cloaks in eliminating the reflections of the acoustic waves from the walls of the treated cavities and thereby rendering these cavities acoustically quiet. It is important to note here that the proposed interior acoustic cloaks can find applications in acoustic cavities such as aircraft cabins and auditoriums as well as many other critical applications.

Non-Exposure, Device-Assisted Endoscopic Full-thickness Resection.

Science.gov (United States)

Bauder, Markus; Schmidt, Arthur; Caca, Karel

2016-04-01

Recent developments have expanded the frontier of interventional endoscopy toward more extended resections following surgical principles. This article presents two new device-assisted techniques for endoscopic full-thickness resection in the upper and lower gastrointestinal tract. Both methods are nonexposure techniques avoiding exposure of gastrointestinal contents to the peritoneal cavity by a "close first-cut later" principle. The full-thickness resection device is a novel over-the-scope device designed for clip-assisted full-thickness resection of colorectal lesions. Endoscopic full-thickness resection of gastric subepithelial tumors can be performed after placing transmural sutures underneath the tumor with a suturing device originally designed for endoscopic antireflux therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Locally advanced pancreatic adenocarcinoma. Chemoradiotherapy, reevaluation and secondary resection

International Nuclear Information System (INIS)

Delpero, J.R.; Turrini, O.

2006-01-01

Induction chemoradiotherapy (CRT) may down-stage locally advanced pancreatic tumors but secondary resections are unfrequent. However some responders' patients may benefit of a RO resection. Patients and methods. We report 18 resections among 29 locally advanced pancreatic cancers; 15 patients were treated with neo-adjuvant 5-FU-cisplatin based (13) or taxotere based (2 patients) chemoradiotherapy (45 Gy), and 3 patients without histologically proven adenocarcinoma were resected without any preoperative treatment. Results. The morbidity rate was 28% and the mortality rate was 7%; one patient died after resection (5.5%) and one died after exploration (9%). The RO resection rate was 50%. The median survival for the resected patients was not reached and the actuarial survival at 3 years was 59%. Two specimens showed no residual tumor and the two patients were alive at 15 and 46 months without recurrence; one specimen showed less than 10% viable tumoral cells and the patient was alive at 36 months without recurrence. A mesenteric infarction was the cause of a late death at 3 years in a disease free patient (radiation induced injury of the superior mesenteric artery). The median survival of the 11 non-resected patients was 21 months and the actuarial survival at 2 years was 0%. When the number of the resected patients (18) was reported to the entire cohort of the patients with locally advanced pancreatic cancer treated during the same period in our institution, the secondary resectability rate was 9%. Conclusion. Preoperative chemoradiotherapy identifies poor surgical candidates through observation and may enhance the margin status of patients undergoing secondary resection for locally advanced tumors. However it remains difficult to evaluate the results in the literature because of the variations in the definitions of resectability. The best therapeutic strategy remains to be defined, because the majority of patients ultimately succumb with distant metastatic disease

Murine Ileocolic Bowel Resection with Primary Anastomosis

Science.gov (United States)

Perry, Troy; Borowiec, Anna; Dicken, Bryan; Fedorak, Richard; Madsen, Karen

2014-01-01

Intestinal resections are frequently required for treatment of diseases involving the gastrointestinal tract, with Crohn’s disease and colon cancer being two common examples. Despite the frequency of these procedures, a significant knowledge gap remains in describing the inherent effects of intestinal resection on host physiology and disease pathophysiology. This article provides detailed instructions for an ileocolic resection with primary end-to-end anastomosis in mice, as well as essential aspects of peri-operative care to maximize post-operative success. When followed closely, this procedure yields a 95% long-term survival rate, no failure to thrive, and minimizes post-operative complications of bowel obstruction and anastomotic leak. The technical challenges of performing the procedure in mice are a barrier to its wide spread use in research. The skills described in this article can be acquired without previous surgical experience. Once mastered, the murine ileocolic resection procedure will provide a reproducible tool for studying the effects of intestinal resection in models of human disease. PMID:25406841

Responsive acoustic surfaces

DEFF Research Database (Denmark)

Peters, Brady; Tamke, Martin; Nielsen, Stig Anton

2011-01-01

Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... for the acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

Flat acoustic lens by acoustic grating with curled slits

KAUST Repository

Peng, Pai

2014-10-01

We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

The long-term results of resection and multiple resections in Crohn's disease.

Science.gov (United States)

Krupnick, A S; Morris, J B

2000-01-01

Crohn's disease is a panenteric, transmural inflammatory disease of unknown origin. Although primarily managed medically, 70% to 90% of patients will require surgical intervention. Surgery for small bowel Crohn's is usually necessary for unrelenting stenotic complications of the disease. Fistula, abscess, and perforation can also necessitate surgical intervention. Most patients benefit from resection or strictureplasty with an improved quality of life and remission of disease, but recurrence is common and 33% to 82% of patients will need a second operation, and 22% to 33% will require more than two resections. Short-bowel syndrome is unavoidable in a small percentage of Crohn's patients because of recurrent resection of affected small bowel and inflammatory destruction of the remaining mucosa. Although previously a lethal and unrelenting disease with death caused by malnutrition, patients with short-bowel syndrome today can lead productive lives with maintenance on total parenteral nutrition (TPN). This lifestyle, however, does not come without a price. Severe TPN-related complications, such as sepsis of indwelling central venous catheters and liver failure, do occur. Future developments will focus on more powerful and effective anti-inflammatory medication specifically targeting the immune mechanisms responsible for Crohn's disease. Successful medical management of the disease will alleviate the need for surgical resection and reduce the frequency of short-bowel syndrome. Improving the efficacy of immunosuppression and the understanding of tolerance induction should increase the safety and applicability of small-bowel transplant for those with short gut. Tissue engineering offers the potential to avoid immunosuppression altogether and supplement intestinal length using the patient's own tissues.

Parametric Room Acoustic workflows with real-time acoustic simulation

DEFF Research Database (Denmark)

Parigi, Dario

2017-01-01

The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages......The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages...

Awake craniotomy for tumor resection.

Science.gov (United States)

Attari, Mohammadali; Salimi, Sohrab

2013-01-01

Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.

Awake craniotomy for tumor resection

Directory of Open Access Journals (Sweden)

Mohammadali Attari

2013-01-01

Full Text Available Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.

World Health Organization, radiofrequency radiation and health - a hard nut to crack (Review)

OpenAIRE

Hardell, Lennart

2017-01-01

In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health...

Mobile phones and head tumours. The discrepancies in cause-effect relationships in the epidemiological studies - how do they arise?

OpenAIRE

Levis, Angelo G; Minicuci, Nadia; Ricci, Paolo; Gennaro, Valerio; Garbisa, Spiridione

2011-01-01

Abstract Background Whether or not there is a relationship between use of mobile phones (analogue and digital cellulars, and cordless) and head tumour risk (brain tumours, acoustic neuromas, and salivary gland tumours) is still a matter of debate; progress requires a critical analysis of the methodological elements necessary for an impartial evaluation of contradictory studies. Methods A close examination of the protocols and results from all case-control and cohort studies, pooled- and meta-...

Laparoscopic liver resection for malignancy: a review of the literature.

Science.gov (United States)

Alkhalili, Eyas; Berber, Eren

2014-10-07

To review the published literature about laparoscopic liver resection for malignancy. A PubMed search was performed for original published studies until June 2013 and original series containing at least 30 patients were reviewed. All forms of hepatic resections have been described ranging from simple wedge resections to extended right or left hepatectomies. The usual approach is pure laparoscopic, but hand-assisted, as well as robotic approaches have been described. Most studies showed comparable results to open resection in terms of operative blood loss, postoperative morbidity and mortality. Many of them showed decreased postoperative pain, shorter hospital stays, and even lower costs. Oncological results including resection margin status and long-term survival were not inferior to open resection. In the hands of experienced surgeons, laparoscopic liver resection for malignant lesions is safe and offers some short-term advantages over open resection. Oncologically, similar survival rates have been observed in patients treated with the laparoscopic approach when compared to their open resection counterparts.

Transurethral resection of very large prostates. A retrospective study

DEFF Research Database (Denmark)

Waaddegaard, P; Hansen, B J; Christensen, S W

1991-01-01

Twenty-one patients with benign prostatic hypertrophy (BPH), and a weight of transurethrally resected tissue exceeding 80 g (Group 1), were compared to a control group of 30 patients with a weight of resected tissue less than 80 g (Group 2) with regard to the peri- and postoperative course...... resections performed had a longer operating time and a greater perioperative blood loss than the group of minor resections. No differences were found with regard to other peri- or postoperative complications or subjective results. Transurethral resection is safe and efficient in treating BPH, also with very...

A numerical study on acoustic behavior in gas turbine combustor with acoustic resonator

International Nuclear Information System (INIS)

Park, I Sun; Sohn, Chae Hoon

2005-01-01

Acoustic behavior in gas turbine combustor with acoustic resonator is investigated numerically by adopting linear acoustic analysis. Helmholtz-type resonator is employed as acoustic resonator to suppress acoustic instability passively. The tuning frequency of acoustic resonator is adjusted by varying its length. Through harmonic analysis, acoustic-pressure responses of chamber to acoustic excitation are obtained and the resonant acoustic modes are identified. Acoustic damping effect of acoustic resonator is quantified by damping factor. As the tuning frequency of acoustic resonator approaches the target frequency of the resonant mode to be suppressed, mode split from the original resonant mode to lower and upper modes appears and thereby complex patterns of acoustic responses show up. Considering mode split and damping effect as a function of tuning frequency, it is desirable to make acoustic resonator tuned to broad-band frequencies near the maximum frequency of those of the possible upper modes

Acoustical Imaging

CERN Document Server

Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

2012-01-01

The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

Extrahepatic bile duct resection in combination with liver resection for hilar cholangiocarcinoma : A report of 42 cases

NARCIS (Netherlands)

IJitsma, AJC; Appeltans, BMG; de Jong, KP; Porte, RJ; Peeters, PMJG; Slooff, MJH

2004-01-01

From September 1986 until December 2001, 42 patients (20 males and 22 females) underwent a combined extrahepatic bile duct resection (EHBDR) and liver resection (LR) for hilar cholangiocarcinoma (HC). The aim of this study was to analyze patient survival, morbidity, and mortality as well as to seek

Clinicoroentgenological assessment of the state of the resected larynx

Energy Technology Data Exchange (ETDEWEB)

Demidov, V.P.; Bityutskij, P.G.; Sorokina, N.A.; Kozhanov, L.G. (Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Onkologii)

A study was made of an X-ray picture of the larynx and the state of the pharyngoesophageal anastomosis after salvage operations in 72 patients. Horizontal resection was performed in 42 patients, frontal-lateral in 27 and reconstructive laryngectomy in 3. An analysis of clinicoroentgenological changes showed that their nature depended on the type of resection and the area of resected anatomical structures and elements in the larynx as well as on concomitant manifestations of tumor recurrence or inflammatory disorders. Accurate data on resection type and the area of resectable laryngeal structures are indispensable in assessing X-ray changes.

Elevator Muscle Anterior Resection: A New Technique for Blepharoptosis.

Science.gov (United States)

Zigiotti, Gian Luigi; Delia, Gabriele; Grenga, Pierluigi; Pichi, Francesco; Rechichi, Miguel; Jaroudi, Mahmoud O; d'Alcontres, Francesco Stagno; Lupo, Flavia; Meduri, Alessandro

2016-01-01

Blepharoptosis is a condition of inadequate upper eyelid position, with a downward displacement of the upper eyelid margin resulting in obstruction of the superior visual field. Levator resection is an effective technique that is routinely used to correct aponeurotic ptosis. The anterior levator resection is the procedure of choice in moderate blepharoptosis when there is moderate to good levator muscle function, furthermore, with an anterior approach, a greater resection can be achieved than by a conjunctival approach. The authors describe a modification in the Putterman technique with a resection done over a plicated elevator, plication that was suggested by Mustardè. The technique has been named as elevator muscle anterior resection. The elevator muscle anterior resection inspires from the Fasanella-Servat operation by the use of a clamp, making the operation simple and predictable.

Role of hilar resection in the treatment of hilar cholangiocarcinoma.

Science.gov (United States)

Otani, Kazuhiro; Chijiiwa, Kazuo; Kai, Masahiro; Ohuchida, Jiro; Nagano, Motoaki; Kondo, Kazuhiro

2012-05-01

The aim of this study was to clarify the role of bile duct resection without hepatectomy (hilar resection) in hilar cholangiocarcinoma. We retrospectively compared surgical results for hilar cholangiocarcinoma between 8 patients treated with hilar resection and 21 patients treated with hepatectomy. All hilar resections were performed for Bismuth type I or II tumors with T2 or less lesions, whereas hepatectomy was done for type III or IV tumors excluding one type II tumor. R0 resection was equally achieved in both groups (62.5% in hilar resection group and 76.2% in hepatectomy group, p=0.469) and overall 5-year survival rates were comparable (21.9% vs. 23.6%, p=0.874). With respect to gross tumor appearance, R0 resection was achieved in all patients with papillary tumor in both groups with the excellent 5-year survivals (100% vs. 100%). In patients with nodular and flat tumors, R0 resection was achieved less frequently in the hilar resection vs. hepatectomy group (50% vs. 77.8%) mainly due to failure to clear the proximal ductal margin, resulting in poorer 5-year survival (0% vs. 18.7%). Hilar resection may be indicated for papillary T1 or 2 tumors in Bismuth type I or II cholangiocarcinoma.

Transcallosal, Transchoroidal Resection of a Recurrent Craniopharyngioma.

Science.gov (United States)

Jean, Walter C

2018-04-01

Objective  To demonstrate the transchoroidal approach for the resection of a recurrent craniopharyngioma. Design  Video case report. Setting  Microsurgical resection. Participant  The patient was a 27-year-old woman with a history of a craniopharyngioma, resected twice during the year prior to presentation to our unit. Both operations were done via the left anterolateral corridor, and afterward, she was blind in the left eye and was treated with Desmopressin (DDAVP) for diabetes insipidus (DI). Serial magnetic resonance imaging (MRI) showed progression of the tumor residual, and she was referred for further surgical intervention. Main Outcome Measures  Pre- and postoperative MRIs measured the degree of resection. Results  For this, her third surgery, a transcallosal, transchoroidal approach, was chosen to offer the widest possible exposure. Given her history, an aggressive total resection was the best strategy. The patient was placed supine with the head neutral. A right frontal craniotomy allowed access to the interhemispheric fissure. By opening the corpus callosum, the left lateral ventricle was entered. The transchoroidal approach started with dissection of the tenia fornicis to open the choroidal fissure. After this, sufficient exposure to the posterior parts of the tumor was gained. Resection proceeded to the bottom of the tumor, exposing the basilar apex and interpeduncular cistern, and continued back anteriorly. In the end, a microscopic total resection was achieved. With a long hospital stay to treat her brittle DI, the patient slowly returned to neurological baseline. Conclusion  The transchoroidal approach is an effective way to remove large tumors in the third ventricle. The link to the video can be found at: https://youtu.be/2-Aqjaay8dg .

Topological Acoustics

Science.gov (United States)

Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

2015-03-01

The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

Laparoscopic liver resection assisted by the laparoscopic Habib Sealer.

Science.gov (United States)

Jiao, Long R; Ayav, Ahmet; Navarra, Giuseppe; Sommerville, Craig; Pai, Madhava; Damrah, Osama; Khorsandi, Shrin; Habib, Nagy A

2008-11-01

Radiofrequency has been used as a tool for liver resection since 2002. A new laparoscopic device is reported in this article that assists liver resection laparoscopically. From October 2006 to the present, patients suitable for liver resection were assessed carefully for laparoscopic resection with the laparoscopic Habib Sealer (LHS). Detailed data of patients resected laparoscopically with this device were collected prospectively and analyzed. In all, 28 patients underwent attempted laparoscopic liver resection. Four cases had to be converted to an open approach because of extensive adhesions from previous colonic operations. Twenty-four patients completed the procedure comprising tumorectomy (n = 7), multiple tumoretcomies (n = 5), segmentectomy (n = 3), and bisegmentectomies (n = 9). Vascular clamping of portal triads was not used. The mean resection time was 60 +/- 23 min (mean +/- SD), and blood loss was 48 +/- 54 mL. None of the patients received any transfusion of blood or blood products perioperatively or postoperatively. Postoperatively, 1 patient developed severe exacerbation of asthma that required steroid therapy, and 1 other patient had a transient episode of liver failure that required supportive care. The mean duration of hospital stay was 5.6 +/- 2 days (mean +/- SD). At a short-term follow up, no recurrence was detected in patients with liver cancer. Laparoscopic liver resection can be performed safely with this new laparoscopic liver resection device with a significantly low risk of intraoperative bleeding or postoperative complications.

Should spikes on post-resection ECoG guide pediatric epilepsy surgery?

Science.gov (United States)

Greiner, Hansel M; Horn, Paul S; Tenney, Jeffrey R; Arya, Ravindra; Jain, Sejal V; Holland, Katherine D; Leach, James L; Miles, Lili; Rose, Douglas F; Fujiwara, Hisako; Mangano, Francesco T

2016-05-01

There is wide variation in clinical practice regarding the role of electrocorticography immediately after resection (post-resection ECoG) for pediatric epilepsy surgery. Results can guide further resection of potentially epileptogenic tissue. We hypothesized that post-resection ECoG spiking represents a biomarker of the epileptogenic zone and predicts seizure outcome in children undergoing epilepsy surgery. We retrospectively identified 124 children with post-resection ECoG performed on the margins of resection. ECoG records were scored in a blinded fashion based on presence of frequent spiking. For patients identified as having additional resection based on clinical post-resection ECoG interpretation, these "second-look" ECoG results were re-reviewed for ongoing discharges or completeness of resection. Frequent spike populations were grouped using a standard scoring system into three ranges: 0.1-0.5Hz, 0.5-1Hz, >1Hz. Seizure outcomes were determined at minimum 12-month followup. Of 124 patients who met inclusion criteria, 60 (48%) had an identified spike population on post-resection ECoG. Thirty (50%) of these had further resection based on clinical interpretation. Overall, good outcome (ILAE 1) was seen in 56/124 (45%). Completeness of resection of spiking (absence of spiking on initial post-resection ECoG or resolution of spiking after further resection) showed a trend toward good outcome (OR 2.03, p=0.099). Patients with completeness of resection had good outcome in 41/80 (51%) of cases; patients with continued spikes had good outcome in 15/44 (35%) of cases. Post-resection ECoG identifies residual epileptogenic tissue in a significant number of children. Lower frequency or absence of discharges on initial recording showed a trend toward good outcome. Completeness of resection demonstrated on final ECoG recording did not show a significant difference in outcome. This suggests that post-resection discharges represent a prognostic marker rather than a remediable

High transmission acoustic focusing by impedance-matched acoustic meta-surfaces

KAUST Repository

Al Jahdali, Rasha

2016-01-19

Impedance is an important issue in the design of acoustic lenses because mismatched impedance is detrimental to real focusing applications. Here, we report two designs of acoustic lenses that focus acoustic waves in water and air, respectively. They are tailored by acoustic meta-surfaces, which are rigid thin plates decorated with periodically distributed sub-wavelength slits. Their respective building blocks are constructed from the coiling-up spaces in water and the layered structures in air. Analytic analysis based on coupled-mode theory and transfer matrix reveals that the impedances of the lenses are matched to those of the background media. With these impedance-matched acoustic lenses, we demonstrate the acoustic focusing effect by finite-element simulations.

High transmission acoustic focusing by impedance-matched acoustic meta-surfaces

KAUST Repository

Al Jahdali, Rasha; Wu, Ying

2016-01-01

Impedance is an important issue in the design of acoustic lenses because mismatched impedance is detrimental to real focusing applications. Here, we report two designs of acoustic lenses that focus acoustic waves in water and air, respectively. They are tailored by acoustic meta-surfaces, which are rigid thin plates decorated with periodically distributed sub-wavelength slits. Their respective building blocks are constructed from the coiling-up spaces in water and the layered structures in air. Analytic analysis based on coupled-mode theory and transfer matrix reveals that the impedances of the lenses are matched to those of the background media. With these impedance-matched acoustic lenses, we demonstrate the acoustic focusing effect by finite-element simulations.

The Relationship of Amount of Resection and Time for Recovery of Bell’s Phenomenon after Levator Resection in Congenital Ptosis

Science.gov (United States)

Goel, Ruchi; Kishore, Divya; Nagpal, Smriti; Jain, Sparshi; Agarwal, Tushar

2017-01-01

Background: Recovery of Bell`s phenomenon after levator resection is unpredicatable. Delayed recovery can result in vision threatening corneal complications. Aim: To study the variability of Bell’s phenomenon and time taken for its recovery following levator resection for blepharoptosis and to correlate it with the amount of resection. Methods: A prospective observational study was conducted on 32 eyes of 32 patients diagnosed as unilateral simple congenital blepharoptosis who underwent levator resection at a tertiary care center between July 2013 and May 2015. Patients were followed up for 5 months and correction of ptosis, type of Bell`s, duration of Bell`s recovery and complications were noted. Results: The study group ranged from 16-25 years with 15:17 male: female ratio. There were 9 mild, 16 moderate and 7 severe ptosis. Satisfactory correction was achieved in all cases. Good Bell`s recovery occurred in 13 eyes on first post-op day, in 2-14 days in 19 eyes and 28 days in 1 eye. Inverse Bell`s was noted along with lid oedema and ecchymosis in 2 patients. Large resections (23-26mm) were associated with poor Bell`s on the first postoperative day (p=0.027, Fisher`s exact test). However, the duration required for recovery of Bell`s phenomenon did not show any significant difference with the amount of resection. (p=0.248, Mann Whitney test). Larger resections resulted in greater lagophthalmos (correlation=0.830, p<0.0001). Patients with recovery of Bell`s delayed for more than 7 days were associated with greater number of complications (p=0.001 Fisher`s Exact Test). Conclusion: Close monitoring for Bell`s recovery is required following levator resection. PMID:28584563

Animal study assessing safety of an acoustic coupling fluid that holds the potential to avoid surgically induced artifacts in 3D ultrasound guided operations

International Nuclear Information System (INIS)

Jakola, Asgeir S; Jørgensen, Arve; Selbekk, Tormod; Michler, Ralf-Peter; Solheim, Ole; Torp, Sverre H; Sagberg, Lisa M; Aadahl, Petter; Unsgård, Geirmund

2014-01-01

Use of ultrasound in brain tumor surgery is common. The difference in attenuation between brain and isotonic saline may cause artifacts that degrade the ultrasound images, potentially affecting resection grades and safety. Our research group has developed an acoustic coupling fluid that attenuates ultrasound energy like the normal brain. We aimed to test in animals if the newly developed acoustic coupling fluid may have harmful effects. Eight rats were included for intraparenchymal injection into the brain, and if no adverse reactions were detected, 6 pigs were to be included with injection of the coupling fluid into the subarachnoid space. Animal behavior, EEG registrations, histopathology and immunohistochemistry were used in assessment. In total, 14 animals were included, 8 rats and 6 pigs. We did not detect any clinical adverse effects, seizure activity on EEG or histopathological signs of tissue damage. The novel acoustic coupling fluid intended for brain tumor surgery appears safe in rats and pigs under the tested circumstances

Vibro-acoustics

CERN Document Server

Nilsson, Anders

2015-01-01

This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

Acoustics an introduction

CERN Document Server

Kuttruff, Heinrich

2006-01-01

This definitive textbook provides students with a comprehensive introduction to acoustics. Beginning with the basic physical ideas, Acoustics balances the fundamentals with engineering aspects, applications and electroacoustics, also covering music, speech and the properties of human hearing. The concepts of acoustics are exposed and applied in:room acousticssound insulation in buildingsnoise controlunderwater sound and ultrasoundScientifically thorough, but with mathematics kept to a minimum, Acoustics is the perfect introduction to acoustics for students at any level of mechanical, electrical or civil engineering courses and an accessible resource for architects, musicians or sound engineers requiring a technical understanding of acoustics and their applications.

Intersphincteric Resection and Coloanal Anastomosis in Treatment of Distal Rectal Cancer

Directory of Open Access Journals (Sweden)

Gokhan Cipe

2012-01-01

Full Text Available In the treatment of distal rectal cancer, abdominoperineal resection is traditionally performed. However, the recognition of shorter safe distal resection line, intersphincteric resection technique has given a chance of sphincter-saving surgery for patients with distal rectal cancer during last two decades and still is being performed as an alternative choice of abdominoperineal resection. The first aim of this study is to assess the morbidity, mortality, oncological, and functional outcomes of intersphincteric resection. The second aim is to compare outcomes of patients who underwent intersphincteric resection with the outcomes of patients who underwent abdominoperineal resection.

Interior acoustic cloak

OpenAIRE

Wael Akl; A. Baz

2014-01-01

Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which a...

部分肌松下多组颅神经监护在小脑桥脑角区肿瘤切除术患者中的应用%Intraoperative cranial nerves monitoring under partial neuromuscular relaxation during cerebellopontine angle tumor resection

Institute of Scientific and Technical Information of China (English)

张军; 杨程; 顾华华; 梁伟民

2008-01-01

Objective To evaluate the efficacy of multiple cranial nerves monitoring under partial neuromuscular relaxation during cerebellopontine angle(CPA)tumor resection.Methods Seventy elective patients undergoing CPA tumor resection via microneurosurgery were randomly allocated to 2 equal groups: Group FN receiving intraoperative facial nerve(NF)monitoring and Group MN receiving monitoring of multiple nerves:trigeminal nerve,glossopharyngeal nerve,accessory nerve or hypoglossal nerve other than the FN which were considered at risk by the neurosurgeon preoperatively.The manipulation procedure were modified according to cranial nerves monitoring and neuromuscular relaxation was maintained at train of four stimulation(TOF)=3 by continuous vencronium infusion during the acoustic neuroma resection.The function of the cranial nerves monitored were evaluated preoperatively and 8 days postoperativelv.Results Discernable and legible images of electromyographic wave complex were obtained during cranial nerve mapping and monitoring under intraoperative partial neuromuscular relaxation form all the patients.The facial nerve function of 4 patients exacerbated(from H-B grade Ⅰ-Ⅱ to gradeⅢ-Ⅳ)in both groups,and one new glossopharyngeal nerve function deficiency was found in Group FN,and one new hypoglossal nerve function deficiency was found in Group MN postoperatively.Conclusion Intraoperative cranial nenves monitoring under partial neuromuscular relaxation is feasible.Multiple cranial nerves combined with facial nerve monitoring seems unable to increase the short-term protective effects of nerve function after CPA tumor resection.%目的 评价全身麻醉下小脑桥脑角区肿瘤切除术患者中,在部分肌松条件下多组颅神经监护的效率.方法 70例择期行小脑桥脑角区肿瘤显微手术患者,随机分为两组,一组术中只进行面神经监护(FN组,n=35),�

Pluridirectional High-Energy Agile Scanning Electron Radiotherapy (PHASER): Extremely Rapid Treatment for Early Lung Cancer

Science.gov (United States)

2015-09-01

esophagus , and anal cancer cases. We performed Monte Carlo (MC) dose calculations and we optimized the dose in a research version of RayStation... esophagus , and anal cancer cases. We 44 performed Monte Carlo (MC) dose calculations and we optimized the dose in a research version of...clinical cases were: acoustic neuroma, and liver, lung, esophagus and anal cancer 120 cases. Target sizes ranged from 1.2 cm3 to 990.4 cm3 (Table 1

Vertebral Column Resection for Rigid Spinal Deformity.

Science.gov (United States)

Saifi, Comron; Laratta, Joseph L; Petridis, Petros; Shillingford, Jamal N; Lehman, Ronald A; Lenke, Lawrence G

2017-05-01

Broad narrative review. To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. A literature review of posterior vertebral column resection was performed. The authors' surgical technique is outlined in detail. The authors' experience and the literature regarding vertebral column resection are discussed at length. Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50-70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.

Seizure outcomes in non-resective epilepsy surgery: An update

Science.gov (United States)

Englot, Dario J.; Birk, Harjus; Chang, Edward F.

2016-01-01

In approximately 30% of patients with epilepsy, seizures are refractory to medical therapy, leading to significant morbidity and increased mortality. Substantial evidence has demonstrated the benefit of surgical resection in patients with drug-resistant focal epilepsy, and in the present journal, we recently reviewed seizure outcomes in resective epilepsy surgery. However, not all patients are candidates for or amenable to open surgical resection for epilepsy. Fortunately, several non-resective surgical options are now available at various epilepsy centers, including novel therapies which have been pioneered in recent years. Ablative procedures such as stereotactic laser ablation and stereotactic radiosurgery offer minimally invasive alternatives to open surgery with relatively favorable seizure outcomes, particularly in patients with mesial temporal lobe epilepsy. For certain individuals who are not candidates for ablation or resection, palliative neuromodulation procedures such as vagus nerve stimulation, deep brain stimulation, or responsive neurostimulation may result in a significant decrease in seizure frequency and improved quality of life. Finally, disconnection procedures such as multiple subpial transections and corpus callosotomy continue to play a role in select patients with an eloquent epileptogenic zone or intractable atonic seizures, respectively. Overall, open surgical resection remains the gold standard treatment for drug-resistant epilepsy, although it is significantly under-utilized. While non-resective epilepsy procedures have not replaced the need for resection, there is hope that these additional surgical options will increase the number of patients who receive treatment for this devastating disorder - particularly individuals who are not candidates for or who have failed resection. PMID:27206422

Hilar cholangiocarcinoma: controversies on the extent of surgical resection aiming at cure.

Science.gov (United States)

Xiang, Shuai; Lau, Wan Yee; Chen, Xiao-ping

2015-02-01

Hilar cholangiocarcinoma is the most common malignant tumor affecting the extrahepatic bile duct. Surgical treatment offers the only possibility of cure, and it requires removal of all tumoral tissues with adequate resection margins. The aims of this review are to summarize the findings and to discuss the controversies on the extent of surgical resection aiming at cure for hilar cholangiocarcinoma. The English medical literatures on hilar cholangiocarcinoma were studied to review on the relevance of adequate resection margins, routine caudate lobe resection, extent of liver resection, and combined vascular resection on perioperative and long-term survival outcomes of patients with resectable hilar cholangiocarcinoma. Complete resection of tumor represents the most important prognostic factor of long-term survival for hilar cholangiocarcinoma. The primary aim of surgery is to achieve R0 resection. When R1 resection is shown intraoperatively, further resection is recommended. Combined hepatic resection is now generally accepted as a standard procedure even for Bismuth type I/II tumors. Routine caudate lobe resection is also advocated for cure. The extent of hepatic resection remains controversial. Most surgeons recommend major hepatic resection. However, minor hepatic resection has also been advocated in most patients. The decision to carry out right- or left-sided hepatectomy is made according to the predominant site of the lesion. Portal vein resection should be considered when its involvement by tumor is suspected. The curative treatment of hilar cholangiocarcinoma remains challenging. Advances in hepatobiliary techniques have improved the perioperative and long-term survival outcomes of this tumor.

Coblation-assisted endonasal endoscopic resection of juvenile nasopharyngeal angiofibroma.

Science.gov (United States)

Ye, L; Zhou, X; Li, J; Jin, J

2011-09-01

Juvenile nasopharyngeal angiofibroma may be successfully resected using endoscopic techniques. However, the use of coblation technology for such resection has not been described. This study aimed to document cases of Fisch class I juvenile nasopharyngeal angiofibroma with limited nasopharyngeal and nasal cavity extension, which were completely resected using an endoscopic coblation technique. We retrospectively studied 23 patients with juvenile nasopharyngeal angiofibroma who underwent resection with either traditional endoscopic instruments (n = 12) or coblation (n = 11). Intra-operative blood loss and overall operative time were recorded. The mean tumour resection time for coblation and traditional endoscopic instruments was 87 and 136 minutes, respectively (t = 9.962, p angiofibroma (Fisch class I), with good surgical margins and minimal blood loss.

Acoustic energy harvesting based on a planar acoustic metamaterial

Science.gov (United States)

Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

2016-06-01

We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

Vestibular schwannoma with contralateral facial pain – case report

Directory of Open Access Journals (Sweden)

Ghodsi Mohammad

2003-03-01

Full Text Available Abstract Background Vestibular schwannoma (acoustic neuroma most commonly presents with ipsilateral disturbances of acoustic, vestibular, trigeminal and facial nerves. Presentation of vestibular schwannoma with contralateral facial pain is quite uncommon. Case presentation Among 156 cases of operated vestibular schwannoma, we found one case with unusual presentation of contralateral hemifacial pain. Conclusion The presentation of contralateral facial pain in the vestibular schwannoma is rare. It seems that displacement and distortion of the brainstem and compression of the contralateral trigeminal nerve in Meckel's cave by the large mass lesion may lead to this atypical presentation. The best practice in these patients is removal of the tumour, although persistent contralateral pain after operation has been reported.

Panel acoustic contribution analysis.

Science.gov (United States)

Wu, Sean F; Natarajan, Logesh Kumar

2013-02-01

Formulations are derived to analyze the relative panel acoustic contributions of a vibrating structure. The essence of this analysis is to correlate the acoustic power flow from each panel to the radiated acoustic pressure at any field point. The acoustic power is obtained by integrating the normal component of the surface acoustic intensity, which is the product of the surface acoustic pressure and normal surface velocity reconstructed by using the Helmholtz equation least squares based nearfield acoustical holography, over each panel. The significance of this methodology is that it enables one to analyze and rank relative acoustic contributions of individual panels of a complex vibrating structure to acoustic radiation anywhere in the field based on a single set of the acoustic pressures measured in the near field. Moreover, this approach is valid for both interior and exterior regions. Examples of using this method to analyze and rank the relative acoustic contributions of a scaled vehicle cabin are demonstrated.

Determinants of survival after liver resection for metastatic colorectal carcinoma.

Science.gov (United States)

Parau, Angela; Todor, Nicolae; Vlad, Liviu

2015-01-01

Prognostic factors for survival after liver resection for metastatic colorectal cancer identified up to date are quite inconsistent with a great inter-study variability. In this study we aimed to identify predictors of outcome in our patient population. A series of 70 consecutive patients from the oncological hepatobiliary database, who had undergone curative hepatic surgical resection for hepatic metastases of colorectal origin, operated between 2006 and 2011, were identified. At 44.6 months (range 13.7-73), 30 of 70 patients (42.85%) were alive. Patient demographics, primary tumor and liver tumor factors, operative factors, pathologic findings, recurrence patterns, disease-free survival (DFS), overall survival (OS) and cancer-specific survival (CSS) were analyzed. Clinicopathologic variables were tested using univariate and multivariate analyses. The 3-year CSS after first hepatic resection was 54%. Median CSS survival after first hepatic resection was 40.2 months. Median CSS after second hepatic resection was 24.2 months. The 3-year DFS after first hepatic resection was 14%. Median disease free survival after first hepatic resection was 18 months. The 3-year DFS after second hepatic resection was 27% and median DFS after second hepatic resection 12 months. The 30-day mortality and morbidity rate after first hepatic resection was 5.71% and 12.78%, respectively. In univariate analysis CSS was significantly reduced for the following factors: age >53 years, advanced T stage of primary tumor, moderately- poorly differentiated tumor, positive and narrow resection margin, preoperative CEA level >30 ng/ml, DFS <18 months. Perioperative chemotherapy related to metastasectomy showed a trend in improving CSS (p=0.07). Perioperative chemotherapy improved DFS in a statistically significant way (p=0.03). Perioperative chemotherapy and achievement of resection margins beyond 1 mm were the major determinants of both CSS and DFS after first liver resection in multivariate

Curative resection of transverse colon cancer via minilaparotomy.

Science.gov (United States)

Ishida, Hideyuki; Ishiguro, Tohru; Ishibashi, Keiichiro; Ohsawa, Tomonori; Okada, Norimichi; Kumamoto, Kensuke; Haga, Norihiro

2011-01-01

Minilaparotomy has been reported to be a minimally invasive alternative to laparoscopically assisted surgery. We retrospectively evaluated the usefulness of minilaparotomy for the resection of transverse colon cancer, which has generally been considered difficult to resect laparoscopically. Patients for whom curative resection was attempted for transverse colon cancer (n = 21) or sigmoid colon cancer (n = 81) via minilaparotomy (skin incision, transverse colon cancer as well as those with sigmoid colon cancer.

Catecholamine crisis during induction of general anesthesia : A case report.

Science.gov (United States)

Sonntagbauer, M; Koch, A; Strouhal, U; Zacharowski, K; Weber, C F

2018-03-01

Catecholamine crises associated with pheochromocytoma may cause life-threatening cardiovascular conditions. We report the case of a 75-year-old male who developed a hypertensive crisis during induction of general anesthesia for elective resection of a cervical neuroma due to an undiagnosed pheochromocytoma. Hemodynamic instability occurred immediately after the injection of fentanyl, propofol and rocuronium, prior to laryngoscopy and in the absence of any manipulation of the abdomen. In this case report, we present the management of this incident and discuss the underlying pathophysiology triggering a catecholamine crisis.

Springer Handbook of Acoustics

CERN Document Server

Rossing, Thomas D

2007-01-01

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

Magnetic resonance imaging surveillance following vestibular schwannoma resection.

Science.gov (United States)

Carlson, Matthew L; Van Abel, Kathryn M; Driscoll, Colin L; Neff, Brian A; Beatty, Charles W; Lane, John I; Castner, Marina L; Lohse, Christine M; Link, Michael J

2012-02-01

To describe the incidence, pattern, and course of postoperative enhancement within the operative bed using serial gadolinium-enhanced magnetic resonance imaging (MRI) following vestibular schwannoma (VS) resection and to identify clinical and radiologic variables associated with recurrence. Retrospective cohort study. All patients who underwent microsurgical resection of VS between January 2000 and January 2010 at a single tertiary referral center were reviewed. Postoperative enhancement patterns were characterized on serial MRI studies. Clinical follow-up and outcomes were recorded. During the last 10 years, 350 patients underwent microsurgical VS resection, and of these, 203 patients met study criteria (mean radiologic follow-up, 3.5 years). A total of 144 patients underwent gross total resection (GTR), 32 received near-total resection (NTR), and the remaining 27 underwent subtotal resection (STR); 98.5% of patients demonstrated enhancement within the operative bed following resection (58.5% linear, 41.5% nodular). Stable enhancement patterns were seen in 24.5% of patients, regression in 66.0%, and resolution in only 3.5% of patients on the most recent postoperative MRI. Twelve patients recurred a mean of 3.0 years following surgery. The average maximum linear diameter growth rate among recurrent tumors was 2.3 mm per year. Those receiving STR were more than nine times more likely to experience recurrence compared to those undergoing NTR or GTR (P assist the clinician in determining an appropriate postoperative MRI surveillance schedule. Future studies using standardized terminology and consistent study metrics are needed to further refine surveillance recommendations. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Robotic Liver Resection: A Case-Matched Comparison.

Science.gov (United States)

Kingham, T Peter; Leung, Universe; Kuk, Deborah; Gönen, Mithat; D'Angelica, Michael I; Allen, Peter J; DeMatteo, Ronald P; Laudone, Vincent P; Jarnagin, William R; Fong, Yuman

2016-06-01

In recent years, increasingly sophisticated tools have allowed for more complex robotic surgery. Robotic hepatectomy, however, is still in its infancy. Our goals were to examine the adoption of robotic hepatectomy and to compare outcomes between open and robotic liver resections. The robotic hepatectomy experience of 64 patients was compared to a modern case-matched series of 64 open hepatectomy patients at the same center. Matching was according to benign/malignant diagnosis and number of segments resected. Patient data were obtained retrospectively. The main outcomes and measures were operative time, estimated blood loss, conversion rate (robotic to open), Pringle maneuver use, single non-anatomic wedge resection rate, resection margin size, complication rates (infectious, hepatic, pulmonary, cardiac), hospital stay length, ICU stay length, readmission rate, and 90-day mortality rate. Sixty-four robotic hepatectomies were performed in 2010-2014. Forty-one percent were segmental and 34 % were wedge resections. There was a 6 % conversion rate, a 3 % 90-day mortality rate, and an 11 % morbidity rate. Compared to 64 matched patients who underwent open hepatectomy (2004-2012), there was a shorter median OR time (p = 0.02), lower median estimated blood loss (p optimization of outcomes and prospective examination of the economic cost of each approach.

Resection for secondary malignancy of the pancreas.

Science.gov (United States)

Hung, Jui-Hsia; Wang, Shin-E; Shyr, Yi-Ming; Su, Cheng-Hsi; Chen, Tien-Hua; Wu, Chew-Wun

2012-01-01

This study tried to clarify the role of pancreatic resection in the treatment of secondary malignancy with metastasis or local invasion to the pancreas in terms of surgical risk and survival benefit. Data of secondary malignancy of the pancreas from our 19 patients and cases reported in the English literature were pooled together for analysis. There were 329 cases of resected secondary malignancy of the pancreas, including 241 cases of metastasis and 88 cases of local invasion. The most common primary tumor metastatic to the pancreas and amenable to resection was renal cell carcinoma (RCC) (73.9%). More than half (52.3%) of the primary cancers with local invasion to the pancreas were colon cancer, and nearly half (40.9%) were stomach cancer. The median metastatic interval was 84 months (7 years) for overall primary tumors and 108 months (9 years) for RCC. The 5-year survival for secondary malignancy of the pancreas after resection was 61.1% for metastasis and 58.9% for local invasion, with 72.8% for RCC metastasis, 69.0% for colon cancer, and 43.8% for stomach cancer with local invasion to the pancreas. Pancreatic resection should not be precluded for secondary malignancy of the pancreas because long-term survival could be achieved with acceptable surgical risk in selected patients.

3-Tesla functional magnetic resonance imaging-guided tumor resection

Energy Technology Data Exchange (ETDEWEB)

Hall, W.A. [Univ. of Minnesota Medical School, Minneapolis, MN (United States). Depts. of Neurosurgery; Univ. of Minnesota Medical School, Minneapolis, MN (United States). Dept. of Radiation Oncology; Univ. of Minnesota Medical School, Minneapolis, MN (United States). Dept. of Radiology; University of Minnesota Medical Center (MMC), Minneapolis, MN (United States); Truwit, C.L. [Univ. of Minnesota Medical School, Minneapolis, MN (United States). Dept. of Radiology; Univ. of Minnesota Medical School, Minneapolis, MN (United States). Dept. of Pediatrics; Univ. of Minnesota Medical School, Minneapolis, MN (United States). Dept. of Neurology; Hennepin Country Medical Center, Minneapolis, MN (United States). Dept. of Radiology

2006-12-15

Objective: We sought to determine the safety and efficacy of using 3-tesla (T) functional magnetic resonance imaging (fMRI) to guide brain tumor resection. Material and methods: From February 2004 to March 2006, fMRI was performed on 13 patients before surgical resection. Functional imaging was used to identify eloquent cortices for motor (8), speech (3), and motor and speech (2) activation using two different 3-T magnetic resonance (MR) scanners. Surgical resection was accomplished using a 1.5-T intraoperative MR system. Appropriate MR scan sequences were performed intraoperatively to determine and maximize the extent of the surgical resection. Results: Tumors included six oligodendrogliomas, three meningiomas, two astrocytomas and two glioblastomas multiforme. The fMRI data was accurate in all cases. After surgery, two patients had hemiparesis, two had worsening of their speech, and one had worsening of speech and motor function. Neurological function returned to normal in all patients within 1 month. Complete resections were possible in 10 patients (77%). Two patients had incomplete resections because of the proximity of their tumors to functional areas. Biopsy was performed in another patient with an astrocytoma in the motor strip. Conclusion: 3-T fMRI was accurate for locating neurologic function before tumor resection near eloquent cortex. (orig.)

3-Tesla functional magnetic resonance imaging-guided tumor resection

International Nuclear Information System (INIS)

Hall, W.A.; Truwit, C.L.; Univ. of Minnesota Medical School, Minneapolis, MN; Univ. of Minnesota Medical School, Minneapolis, MN; Hennepin Country Medical Center, Minneapolis, MN

2006-01-01

Objective: We sought to determine the safety and efficacy of using 3-tesla (T) functional magnetic resonance imaging (fMRI) to guide brain tumor resection. Material and methods: From February 2004 to March 2006, fMRI was performed on 13 patients before surgical resection. Functional imaging was used to identify eloquent cortices for motor (8), speech (3), and motor and speech (2) activation using two different 3-T magnetic resonance (MR) scanners. Surgical resection was accomplished using a 1.5-T intraoperative MR system. Appropriate MR scan sequences were performed intraoperatively to determine and maximize the extent of the surgical resection. Results: Tumors included six oligodendrogliomas, three meningiomas, two astrocytomas and two glioblastomas multiforme. The fMRI data was accurate in all cases. After surgery, two patients had hemiparesis, two had worsening of their speech, and one had worsening of speech and motor function. Neurological function returned to normal in all patients within 1 month. Complete resections were possible in 10 patients (77%). Two patients had incomplete resections because of the proximity of their tumors to functional areas. Biopsy was performed in another patient with an astrocytoma in the motor strip. Conclusion: 3-T fMRI was accurate for locating neurologic function before tumor resection near eloquent cortex. (orig.)

Small bowel resection

Science.gov (United States)

... Ileostomy and your diet Ileostomy - caring for your stoma Ileostomy - changing your pouch Ileostomy - discharge Ileostomy - what to ask your doctor Low-fiber diet Preventing falls Small bowel resection - discharge Surgical wound care - open Types of ileostomy Ulcerative colitis - discharge When ...

Evaluation The Result Of Treating 1200 Patients Brain Tumor And Some Intracranial Diseases By Rotating GAMMA Knife (RGK) At The Nuclear Medicine And Oncology Center, Bach Mai Hospital

International Nuclear Information System (INIS)

Mai Trong Khoa; Nguyen Quang Hung; Tran Dinh Ha

2011-01-01

The paper is evaluating results of treating brain tumor and some intracranial diseases by rotating gamma knife (RGK) at The Nuclear Medicine and Oncology Center, Bach Mai Hospital, from July 2007 to August 2010, for 1200 patients treated with RGK. In 1200 patients - average age: 42.6 years old, Male/Female ratio:1/1.08 - pituitary tumors accounted for 19.8%, meningioma 18.3%, arteriovenous malformations (AVM) (16.7%), acoustic neuroma (8.7%), brain metastases (7.5%), craniopharyngeal tumor (5.0%), pineal tumor (3.5%), cavernoma (6%), astrocytoma (5.2%), meduloblastoma (2.9%), ependymoma (2.6%), others (3.8%). Average target volume: minimum 0.6cm 3 , maximum 27.6cm 3 , median 6.2 ± 4.6 cm 3 . Average radiosurgery dose changed depend on nature of the tumor: pituitary tumor (12.4 Gy), meningioma (18.8 Gy), AVM (18 Gy), acoustic neuroma (14.6 Gy), brain metastases (18.2 Gy), craniopharyngeal tumor (12.8 Gy), pineal tumor (16.3 Gy), cavernoma (17.5 Gy), astrocytoma (14.6 Gy), medulloblastoma (16.1 Gy), ependymoma (16.3 Gy), others (15 Gy). Conclusions: Almost case have improved clinical symptoms significantly: 80.2% after 1 month (complete response 20.2%), 100% at 36th month (complete response: 94%). Size of the tumor were reduced remarkably. Treatment were safe, no death or severe complications were observed within and after radiosurgery. (author)

A model for morbidity after lung resection in octogenarians.

Science.gov (United States)

Berry, Mark F; Onaitis, Mark W; Tong, Betty C; Harpole, David H; D'Amico, Thomas A

2011-06-01

Age is an important risk factor for morbidity after lung resection. This study was performed to identify specific risk factors for complications after lung resection in octogenarians. A prospective database containing patients aged 80 years or older, who underwent lung resection at a single institution between January 2000 and June 2009, was reviewed. Preoperative, histopathologic, perioperative, and outcome variables were assessed. Morbidity was measured as a patient having any perioperative event as defined by the Society of Thoracic Surgeons General Thoracic Surgery Database. A multivariable risk model for morbidity was developed using a panel of established preoperative and operative variables. Survival was calculated using the Kaplan-Meier method. During the study period, 193 patients aged 80 years or older (median age 82 years) underwent lung resection: wedge resection in 77, segmentectomy in 13, lobectomy in 96, bilobectomy in four, and pneumonectomy in three. Resection was accomplished via thoracoscopy in 149 patients (77%). Operative mortality was 3.6% (seven patients) and morbidity was 46% (89 patients). A total of 181 (94%) patients were discharged directly home. Postoperative events included atrial arrhythmia in 38 patients (20%), prolonged air leak in 24 patients (12%), postoperative transfusion in 22 patients (11%), delirium in 16 patients (8%), need for bronchoscopy in 14 patients (7%), and pneumonia in 10 patients (5%). Significant predictors of morbidity by multivariable analysis included resection greater than wedge (odds ratio 2.98, p=0.006), thoracotomy as operative approach (odds ratio 2.6, p=0.03), and % predicted forced expiratory volume in 1s (odds ratio 1.28 for each 10% decrement, p=0.01). Octogenarians can undergo lung resection with low mortality. Extent of resection, use of a thoracotomy, and impaired lung function increase the risk of complications. Careful evaluation is necessary to select the most appropriate approach in

Robotic vascular resections during Whipple procedure

OpenAIRE

Allan, Bassan J.; Novak, Stephanie M.; Hogg, Melissa E.; Zeh, Herbert J.

2018-01-01

Indications for resection of pancreatic cancers have evolved to include selected patients with involvement of peri-pancreatic vascular structures. Open Whipple procedures have been the standard approach for patients requiring reconstruction of the portal vein (PV) or superior mesenteric vein (SMV). Recently, high-volume centers are performing minimally invasive Whipple procedures with portovenous resections. Our institution has performed seventy robotic Whipple procedures with concomitant vas...

High intensity focused ultrasound (HIFU) therapy for local treatment of hepatocellular carcinoma: Role of partial rib resection

International Nuclear Information System (INIS)

Zhu Hui; Zhou Kun; Zhang Lian; Jin Chengbin; Peng Song; Yang Wei; Li Kequan; Su Haibing; Chen Wenzhi; Bai Jin; Wu Feng; Wang, Zhibiao

2009-01-01

Objective: It has long been known that high intensity focused ultrasound (HIFU) can kill tissue through coagulative necrosis. However, it is only in recent years that practical clinical applications are becoming possible. Since the ribs have strong reflections to ultrasonic beams, they may affect the deposition of ultrasound energy, decreasing the efficacy of HIFU treatment and increasing the chance of adverse events when the intra-abdominal tumours concealed by ribs are treated. The aim of this study was to evaluate the influence of partial rib resection on the efficacy and safety of HIFU treatment. Methods: This prospective study was approved by the ethics committee at Chongqing University of Medical Sciences. An informed consent form was obtained from each patient and family member. A total of 16 patients with hepatocellular carcinoma (HCC), consisting of 13 males and 3 females, were studied. All patients had the successful HIFU treatment. To create a better acoustic pathway for HIFU treatment, all of the 16 patients had the ribs that shield the tumour mass to be removed. Magnetic resonance imaging (MRI) was used to evaluate the efficacy of HIFU treatment. Results: Sixteen cases had 23 nodules, including 12 cases with a single nodule, 1 case with 2 nodules, 3 cases with 3 nodules. The mean diameter of tumours was 7.0 ± 2.1 cm (5-10 cm). According to TNM classification, 9 patients were diagnosed as stage II, 4 patients were stage III, and 3 patients were stage IV. Follow-up imaging showed an absence of tumour blood supply and shrinkage of all treated lesions. The survival rates at 1, 2, 3, 4, and 5 years were 100%, 83.3%, 69.4%, 55.6%, and 55.6%, respectively. No serious complications were observed in the patients treated with HIFU. Conclusion: Partial rib resection can create a better acoustic pathway of HIFU therapy. Even though it is an invasive treatment, this measure offers patients an improved prospect of complete tumour ablation when no other treatment is

Short-term outcomes following laparoscopic resection for colon cancer.

LENUS (Irish Health Repository)

Kavanagh, Dara O

2011-03-01

Laparoscopic resection for colon cancer has been proven to have a similar oncological efficacy compared to open resection. Despite this, it is performed by a minority of colorectal surgeons. The aim of our study was to evaluate the short-term clinical, oncological and survival outcomes in all patients undergoing laparoscopic resection for colon cancer.

Large bowel resection

Science.gov (United States)

... blockage in the intestine due to scar tissue Colon cancer Diverticular disease (disease of the large bowel) Other reasons for bowel resection are: Familial polyposis (polyps are growths on the lining of the colon or rectum) Injuries that damage the large bowel ...

Pancreatectomy with Mesenteric and Portal Vein Resection for Borderline Resectable Pancreatic Cancer: Multicenter Study of 406 Patients.

Science.gov (United States)

Ramacciato, Giovanni; Nigri, Giuseppe; Petrucciani, Niccolò; Pinna, Antonio Daniele; Ravaioli, Matteo; Jovine, Elio; Minni, Francesco; Grazi, Gian Luca; Chirletti, Piero; Tisone, Giuseppe; Napoli, Niccolò; Boggi, Ugo

2016-06-01

The role of pancreatectomy with en bloc venous resection and the prognostic impact of pathological venous invasion are still debated. The authors analyzed perioperative, survival results, and prognostic factors of pancreatectomy with en bloc portal (PV) or superior mesenteric vein (SMV) resection for borderline resectable pancreatic carcinoma, focusing on predictive factors of histological venous invasion and its prognostic role. A multicenter database of 406 patients submitted to pancreatectomy with en bloc SMV and/or PV resection for pancreatic adenocarcinoma was analyzed retrospectively. Univariate and multivariate analysis of factors related to histological venous invasion were performed using logistic regression model. Prognostic factors were analyzed with log-rank test and multivariate proportional hazard regression analysis. Complications occurred in 51.9 % of patients and postoperative death in 7.1 %. Histological invasion of the resected vein was confirmed in 56.7 % of specimens. Five-year survival was 24.4 % with median survival of 24 months. Vein invasion at preoperative computed tomography (CT), N status, number of metastatic lymph nodes, preoperative serum albumin were related to pathological venous invasion at univariate analysis, and vein invasion at CT was independently related to venous invasion at multivariate analysis. Use of preoperative biliary drain was significantly associated with postoperative complications. Multivariate proportional hazard regression analysis demonstrated a significant correlation between overall survival and histological venous invasion and administration of adjuvant therapy. This study identifies predictive factors of pathological venous invasion and prognostic factors for overall survival, including pathological venous invasion, which may help with patients' selection for different treatment protocols.

[Current Status of Endoscopic Resection of Early Gastric Cancer in Korea].

Science.gov (United States)

Jung, Hwoon Yong

2017-09-25

Endoscopic resection (Endoscopic mucosal resection [EMR] and endoscopic submucosal dissection [ESD]) is already established as a first-line treatment modality for selected early gastric cancer (EGC). In Korea, the number of endoscopic resection of EGC was explosively increased because of a National Cancer Screening Program and development of devices and techniques. There were many reports on the short-term and long-term outcomes after endoscopic resection in patients with EGC. Long-term outcome in terms of recurrence and death is excellent in both absolute and selected expanded criteria. Furthermore, endoscopic resection might be positioned as primary treatment modality replacing surgical gastrectomy. To obtain these results, selection of patients, perfect en bloc procedure, thorough pathological examination of resected specimen, accurate interpretation of whole process of endoscopic resection, and rational strategy for follow-up is necessary.

Robotic versus laparoscopic resection of liver tumours

Science.gov (United States)

Berber, Eren; Akyildiz, Hizir Yakup; Aucejo, Federico; Gunasekaran, Ganesh; Chalikonda, Sricharan; Fung, John

2010-01-01

Background There are scant data in the literature regarding the role of robotic liver surgery. The aim of the present study was to develop techniques for robotic liver tumour resection and to draw a comparison with laparoscopic resection. Methods Over a 1-year period, nine patients underwent robotic resection of peripherally located malignant lesions measuring <5 cm. These patients were compared prospectively with 23 patients who underwent laparoscopic resection of similar tumours at the same institution. Statistical analyses were performed using Student's t-test, χ2-test and Kaplan–Meier survival. All data are expressed as mean ± SEM. Results The groups were similar with regards to age, gender and tumour type (P = NS). Tumour size was similar in both groups (robotic −3.2 ± 1.3 cm vs. laparoscopic −2.9 ± 1.3 cm, P = 0.6). Skin-to-skin operative time was 259 ± 28 min in the robotic vs. 234 ± 17 min in the laparoscopic group (P = 0.4). There was no difference between the two groups regarding estimated blood loss (EBL) and resection margin status. Conversion to an open operation was only necessary in one patient in the robotic group. Complications were observed in one patient in the robotic and four patients in the laparoscopic groups. The patients were followed up for a mean of 14 months and disease-free survival (DFS) was equivalent in both groups (P = 0.6). Conclusion The results of this initial study suggest that, for selected liver lesions, a robotic approach provides similar peri-operative outcomes compared with laparoscopic liver resection (LLR). PMID:20887327

Microsurgical Resection of Suprasellar Craniopharyngioma-Technical Purview.

Science.gov (United States)

Nanda, Anil; Narayan, Vinayak; Mohammed, Nasser; Savardekar, Amey R; Patra, Devi Prasad

2018-04-01

Objectives  Complete surgical resection is an important prognostic factor for recurrence and is the best management for craniopharyngioma. This operative video demonstrates the technical nuances in achieving complete resection of a suprasellar craniopharyngioma. Design and Setting  The surgery was performed in a middle-aged lady who presented with the history of progressive bitemporal hemianopia and excessive sleepiness over 8 months. On imaging, suprasellar craniopharyngioma was identified. The tumor was approached through opticocarotid cistern and lamina terminalis. Exposure of bilateral optic nerves, right internal carotid artery, anterior cerebral artery, and its perforator branches was then afforded and the tumor was gross totally resected. Results  The author demonstrates step-by-step technique of microsurgical resection of suprasellar craniopharyngioma. The narrow corridor to deeper structures, intricacies of multiple perforator vessels, and the technique of arachnoid and capsule dissection are the main challenging factors for the gross total resection of craniopharyngioma. The tumor portion which lies under the ipsilateral optic nerve is a blind spot region with a high chance of leaving residual tumor. Mobilization of optic nerve may endanger visual function too. The use of handheld mirror ['mirror-technique'] helps in better visualization of this blind spot and achieve complete excision. Conclusions  The technical pearls of craniopharyngioma surgery include the optimum utilization of translamina terminalis route, wide opening of the cisterns, meticulous separation of deep perforator vessels, capsular mobilization/traction avoidance, and the use of "mirror-technique" for blind-spot visualization. These surgical strategies help to achieve complete resection without causing neurological deficit. The link to the video can be found at: https://youtu.be/9wHJ4AUpG50 .

Development of ion-acoustic double layers through ion-acoustic fluctuations

International Nuclear Information System (INIS)

Sekar, A.N.; Saxena, Y.C.

1985-01-01

Experimental results on the formation of ion acoustic double layers resembling asymmetric ion-holes are presented. In a double plasma device, modified suitably to inject electron beam into the target plasma, modulation of the beam through step potential leads to excitation of ion-acoustic fluctuation. The ion-acoustic fluctuation, growing away from the grids separating source and target plasmas, developed into weak asymmetric ion-acoustic double layer. The observations are in qualitative agreement with theoretical models and computer simulations. (author)

Acoustic tweezers via sub-time-of-flight regime surface acoustic waves.

Science.gov (United States)

Collins, David J; Devendran, Citsabehsan; Ma, Zhichao; Ng, Jia Wei; Neild, Adrian; Ai, Ye

2016-07-01

Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides.

MDCT assessment of resectability in hilar cholangiocarcinoma.

Science.gov (United States)

Ni, Qihong; Wang, Haolu; Zhang, Yunhe; Qian, Lijun; Chi, Jiachang; Liang, Xiaowen; Chen, Tao; Wang, Jian

2017-03-01

The purpose of this study is to investigate the value of multidetector computed tomography (MDCT) assessment of resectability in hilar cholangiocarcinoma, and to identify the factors associated with unresectability and accurate evaluation of resectability. From January 2007 to June 2015, a total of 77 consecutive patients were included. All patients had preoperative MDCT (with MPR and MinIP) and surgical treatment, and were pathologically proven with hilar cholangiocarcinoma. The MDCT images were reviewed retrospectively by two senior radiologists and one hepatobiliary surgeon. The surgical findings and pathologic results were considered to be the gold standard. The Chi square test was used to identify factors associated with unresectability and accurate evaluation of resectability. The sensitivity, specificity, and overall accuracy of MDCT assessment were 83.3 %, 75.9 %, and 80.5 %, respectively. The main causes of inaccuracy were incorrect evaluation of N2 lymph node metastasis (4/15) and distant metastasis (4/15). Bismuth type IV tumor, main or bilateral hepatic artery involvement, and main or bilateral portal vein involvement were highly associated with unresectability (P hilar cholangiocarcinoma. Bismuth type IV tumor and main or bilateral vascular involvement highly suggest the unresectability of hilar cholangiocarcinoma. Patients without biliary drainage have a more accurate MDCT evaluation of resectability. We suggest MDCT should be performed before biliary drainage to achieve an accurate evaluation of resectability in hilar cholangiocarcinoma.

Acoustic textiles

CERN Document Server

Nayak, Rajkishore

2016-01-01

This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

Architectural acoustics

National Research Council Canada - National Science Library

Long, Marshall

2014-01-01

.... Beginning with a brief history, it reviews the fundamentals of acoustics, human perception and reaction to sound, acoustic noise measurements, noise metrics, and environmental noise characterization...

Superselective transarterial chemoembolization vs hepatic resection for resectable early-stage hepatocellular carcinoma in patients with Child-Pugh class a liver function

International Nuclear Information System (INIS)

Hsu, Kuo-Feng; Chu, Chi-Hung; Chan, De-Chuan; Yu, Jyh-Cherng; Shih, Ming-Lang; Hsieh, Huan-Fa; Hsieh, Tsai-Yuan; Yu, Chih-Yung; Hsieh, Chung-Bao

2012-01-01

Purpose: In contrast to hepatic resection (HR) for resectable early-stage HCC, the efficacy of transarterial chemoembolization (TACE) is controversial. This study is designed to compare the long-term outcome of TACE using superselective technique with hepatic resection for the treating resectable early-stage HCC and Child-Pugh class A liver function. Methods: In total, 185 consecutive patients with resectable early-stage HCC and Child-Pugh class A liver function were included: 73 patients received superselective TACE (group I) and 112 patients underwent HR (group II). We evaluated the therapy-related recurrence and long-term outcome and in both groups. The risk factors of recurrence and mortality were assessed by Cox's model. Results: The mean survival time of group 1 patient was similar to that of group 2 patient (40.8 ± 19.8 vs 46.7 ± 24.6 months respectively, p = 0.91). The 1-, 3-, and 5-year overall survival rates after TACE (group I)and HR (group II) were 91%, 66%, and 52% and 93%, 71%, and 57%, respectively (p = 0.239). The 1-, 3-, and 5-year recurrence-free survival rates in groups 1 and 2 were 68%, 28%, and 17% and 78%, 55%, and 35%, respectively (p < 0.0001). Serum albumin, tumour size, tumour number and recurrence interval were independent risk factors for mortality. Serum albumin level, tumour size, tumour number, and treatment modality of TACE or HR could predict HCC recurrence. Conclusion: TACE is an efficient and safe treatment for resectable early-stage HCC with overall survival rates similar to that of HR. Thus, TACE is indicated in selected patients with resectable early-stage HCC.

Selection and Outcome of Portal Vein Resection in Pancreatic Cancer

International Nuclear Information System (INIS)

Nakao, Akimasa

2010-01-01

Pancreatic cancer has the worst prognosis of all gastrointestinal neoplasms. Five-year survival of pancreatic cancer after pancreatectomy is very low, and surgical resection is the only option to cure this dismal disease. The standard surgical procedure is pancreatoduodenectomy (PD) for pancreatic head cancer. The morbidity and especially the mortality of PD have been greatly reduced. Portal vein resection in pancreatic cancer surgery is one attempt to increase resectability and radicality, and the procedure has become safe to perform. Clinicohistopathological studies have shown that the most important indication for portal vein resection in patients with pancreatic cancer is the ability to obtain cancer-free surgical margins. Otherwise, portal vein resection is contraindicated

Selection and Outcome of Portal Vein Resection in Pancreatic Cancer

Energy Technology Data Exchange (ETDEWEB)

Nakao, Akimasa [Department of Surgery II, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

2010-11-24

Pancreatic cancer has the worst prognosis of all gastrointestinal neoplasms. Five-year survival of pancreatic cancer after pancreatectomy is very low, and surgical resection is the only option to cure this dismal disease. The standard surgical procedure is pancreatoduodenectomy (PD) for pancreatic head cancer. The morbidity and especially the mortality of PD have been greatly reduced. Portal vein resection in pancreatic cancer surgery is one attempt to increase resectability and radicality, and the procedure has become safe to perform. Clinicohistopathological studies have shown that the most important indication for portal vein resection in patients with pancreatic cancer is the ability to obtain cancer-free surgical margins. Otherwise, portal vein resection is contraindicated.

Supersonic acoustic intensity with statistically optimized near-field acoustic holography

DEFF Research Database (Denmark)

Fernandez Grande, Efren; Jacobsen, Finn

2011-01-01

The concept of supersonic acoustic intensity was introduced some years ago for estimating the fraction of the flow of energy radiated by a source that propagates to the far field. It differs from the usual (active) intensity by excluding the near-field energy resulting from evanescent waves...... to the information provided by the near-field acoustic holography technique. This study proposes a version of the supersonic acoustic intensity applied to statistically optimized near-field acoustic holography (SONAH). The theory, numerical results and an experimental study are presented. The possibility of using...

Comparison of microscopic and endoscopic view of the internal acoustic meatus: A cadaveric study.

Science.gov (United States)

Montibeller, Guilherme Ramina; Hendrix, Philipp; Fries, Fabian N; Becker, Kurt W; Oertel, Joachim

2018-04-01

The endoscope is thought to provide an improved exposure of the internal acoustic meatus after retrosigmoid craniotomy for microsurgical resection of intrameatal tumors. The aim of this study is to quantify the differences in internal acoustic meatus (IAM) exposure comparing microscopic and endoscopic visualization. A retrosigmoid approach was performed on 5 cadaver heads. A millimeter gauge was introduced into the internal acoustic meatus, and examinations with a surgical microscope and 0°, 30° and 70° rigid endoscopes were performed. The extent of IAM depth visualized with the microscope and the different angled endoscopes were analyzed. The microscopic view allowed an average IAM depth visualization of 2.8 mm. The endoscope allowed an improved exposure of IAM in all cases. The 0°, 30° and 70° endoscopes permitted an exposure that was respectively 96% (5.5 mm), 139% (6.7 mm) and 200% (8.4 mm) more lateral than the microscopic view. Angled optics, however, provided an image distortion, specifically the 70° endoscope. The endoscope provides a superior visualization of the IAM compared to the microscope when using a retrosigmoid approach. The 30° endoscope represented an ideal compromise of superior visualization with marginal image distortion. Additional implementation of the endoscope into microsurgery of intrameatal tumors likely facilitates complete tumor removal and might spare facial and vestibulocochlear function. Clin. Anat. 31:398-403, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Hepatic resection and regeneration. Past and present

International Nuclear Information System (INIS)

Hatsuse, Kazuo

2007-01-01

Hepatic surgery has been performed on condition that the liver regenerates after hepatic resection, and the development of liver anatomy due to Glisson, Rex, and Couinaud has thrown light on hepatic surgery Understanding of feeding and drainage vessels became feasible for systemic hepatic resection; however, it seems to have been the most important problem to control the bleeding during hepatic resection. New types of devices such as cavitron ultrasonic surgical aspirator (CUSA) and Microwave coagulation were exploited to control blood loss during hepatic surgery. Pringle maneuver for exclusion feeding vessels of the liver and the decrease of central venous pressure during anesthesia enabled further decrease of blood loss. Nowadays, 3D-CT imaging may depict feeding and drainage vessels in relation to liver mass, and surgeons can simulate hepatic surgery in virtual reality before surgery, allowing hepatectomy to be performed without blood transfusion. Thus, hepatic resection has been a safe procedure, but there's been a significant research on how much of the liver can be resected without hepatic failure. A prediction scoring system based on ICGR15, resection rates, and age is mostly reliable in some criteria. Even if hepatectomy is performed with a good prediction score, the massive bleeding and associated infection may induce postoperative hepatic failure, while the criteria of postoperative hepatic failure have not yet established. Hepatic failure is supposed to be induced by the apoptosis of mature hepatocytes and necrosis originated from microcirculation disturbance of the liver. Prostaglandin E1 for the improvement of microcirculation, steroid for the inhibition of cytokines inducing apoptosis, and blood purification to exclude cytokines have been tried separately or concomitantly. New therapeutic approaches, especially hepatic regeneration from the stem cell, are expected. (author)

From scratch: developing a hepatic resection service for metastatic colorectal cancer.

Science.gov (United States)

Wylie, Neil; Hider, Phillip; Armstrong, Delwyn; Rajkomar, Kheman; Srinivasa, Sanket; Rodgers, Michael; Brown, Anna; Koea, Jonathan

2018-05-01

Waitemata District Health Board has New Zealand's largest catchment and busiest colorectal unit. The upper gastrointestinal unit was established in 2005, in part to provide a hepatic resection service for patients with colorectal carcinoma metastatic to the liver. The aim of this investigation was to report on quality indicators for the hepatic resection of colorectal carcinoma in the development of a regional resection service. Prospectively collected data on patients undergoing hepatic resection for colorectal carcinoma between 2005 and 2014 was reviewed and correlated with costing data and national hepatic resection rates. A total of 123 patients underwent 138 hepatic resections for metastatic colorectal cancer with a median hospital stay of 8 days (range 4-37 days), a zero 30-day mortality and a median cost of NZ$21 374 for minor hepatectomy and NZ$43 133 for major hepatectomy. Actuarial 5-year disease-free survival was 44%, with 28 patients alive and disease free at 5 years post-resection. Median overall survival was not reached. Review of national hepatic resection rates indicate that Waitemata District Health Board performs one sixth of all hepatic resections in New Zealand and that this treatment modality may be underutilized in the management of patients with metastatic colorectal cancer. A regional hepatic resection centre for colorectal metastases can be established in areas of population need and can provide a high-quality, cost-effective service. © 2016 Royal Australasian College of Surgeons.

[Laparoscopic resection of the sigmoid colon for the diverticular disease].

Science.gov (United States)

Vrbenský, L; Simša, J

2013-07-01

Laparoscopic resection of the sigmoid colon for diverticular disease is nowadays a fully accepted alternative to traditional open procedures. The aim of this work is to summarize the indications, advantages and risks of laparoscopic sigmoid resection for diverticular disease. Review of the literature and recent findings concerning the significance of laparoscopic resection for diverticulosis of the sigmoid colon. The article presents the indications, risks, techniques and perioperative care in patients after laparoscopic resection of the sigmoid colon for diverticular disease.

A new concept for esophageal resection--prevascularization: an experimental study.

Science.gov (United States)

Pap-Szekeres, J; Cserni, G; Furka, I; Svebis, M; Cserni, T; Brath, E; Nemeth, N; Miko, I

2005-01-01

We aim to elaborate upon a basically new animal model for esophageal resection. A total of 17 operations on 10 dogs were performed in order to develop a model in which resection of the cervical part of the esophagus involves two steps. The first step comprises omental flap transplantation from the abdomen to the cervical region by a microsurgical method, this omental flap improving the blood supply to the organ (prevascularization). The second step is segmental resection of the esophagus 14 days later. Of the five transplanted grafts, four still survived one week after the operation; for technical reasons, one flap had thrombotized. In the two long-term survival cases with esophageal resection after prevascularizastion, there were no major complications: the resections were successful, and the omental flap 'grew into' the tissue structure of the esophagus, assisting the healing of the anastomosis. Segmental resection of the cervical part of the esophagus was performed successfully via a new type of operation on dogs.

Acoustic Metamaterials in Aeronautics

Directory of Open Access Journals (Sweden)

Giorgio Palma

2018-06-01

Full Text Available Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing the production of sub-wavelength acoustic absorbers, acoustic invisibility, perfect acoustic mirrors and acoustic lenses for hyper focusing, and acoustic illusions and enabling new degrees of freedom in the control of the acoustic field. The zero, or even negative, refractive sound index of metamaterials offers possibilities for the control of acoustic patterns and sound at sub-wavelength scales. Despite the tremendous growth in research on acoustic metamaterials during the last decade, the potential of metamaterial-based technologies in aeronautics has still not been fully explored, and its utilization is still in its infancy. Thus, the principal concepts mentioned above could very well provide a means to develop devices that allow the mitigation of the impact of civil aviation noise on the community. This paper gives a review of the most relevant works on acoustic metamaterials, analyzing them for their potential applicability in aeronautics, and, in this process, identifying possible implementation areas and interesting metabehaviors. It also identifies some technical challenges and possible future directions for research with the goal of unveiling the potential of metamaterials technology in aeronautics.

Calibration of acoustic emission transducers

International Nuclear Information System (INIS)

Leschek, W.C.

1976-01-01

A method is described for calibrating an acoustic emission transducer to be used in a pre-set frequency range. The absolute reception sensitivity of a reference transducer is determined at frequencies selected within the frequency range. The reference transducer and the acoustic emission transducer are put into acoustic communication with the surface of a limited acoustic medium representing an equivalent acoustic load appreciably identical to that of the medium in which the use of the acoustic emission transducer is intended. A blank random acoustic noise is emitted in the acoustic medium in order to establish a diffuse and reverberating sound field, after which the output responses of the reference transducer and of the acoustic emission transducer are obtained with respect to the diffuse and reverberating field, for selected frequencies. The output response of the acoustic emission transducer is compared with that of the reference transducer for the selected frequencies, so as to determine the reception sensitivity of the acoustic emission transducer [fr

Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

International Nuclear Information System (INIS)

Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

2017-01-01

Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers. - Highlights: • Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. • Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. • However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. • Optical tweezers can trap, move and positioned micron size particles with subnanometer accuracy in three dimensions. • One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. • Acoustical tweezers overcome this limitation since the force scales as the field intensity divided by its propagation speed. • However, the feasibility of single beam acoustical tweezers was demonstrated only recently. • We propose a review of the strong similarities but also the specificities of acoustical

Ileocolic junction resection in dogs and cats: 18 cases.

Science.gov (United States)

Fernandez, Yordan; Seth, Mayank; Murgia, Daniela; Puig, Jordi

2017-12-01

There is limited veterinary literature about dogs or cats with ileocolic junction resection and its long-term follow-up. To evaluate the long-term outcome in a cohort of dogs and cats that underwent resection of the ileocolic junction without extensive (≥50%) small or large bowel resection. Medical records of dogs and cats that had the ileocolic junction resected were reviewed. Follow-up information was obtained either by telephone interview or e-mail correspondence with the referring veterinary surgeons. Nine dogs and nine cats were included. The most common cause of ileocolic junction resection was intussusception in dogs (5/9) and neoplasia in cats (6/9). Two dogs with ileocolic junction lymphoma died postoperatively. Only 2 of 15 animals, for which long-term follow-up information was available, had soft stools. However, three dogs with suspected chronic enteropathy required long-term treatment with hypoallergenic diets alone or in combination with medical treatment to avoid the development of diarrhoea. Four of 6 cats with ileocolic junction neoplasia were euthanised as a consequence of progressive disease. Dogs and cats undergoing ileocolic junction resection and surviving the perioperative period may have a good long-term outcome with mild or absent clinical signs but long-term medical management may be required.

Resection of pancreatic cancer in Europe and USA

DEFF Research Database (Denmark)

Huang, Lei; Jansen, Lina; Balavarca, Yesilda

2018-01-01

European population-based cancer registries and the US Surveillance, Epidemiology, and End Results Program database during 2003-2016 were analysed. Age-standardised resection rates for overall and stage I-II PaCs were computed. Associations between resection and demographic and clinical parameters were...

Endoscopic full-thickness resection of gastric subepithelial tumors: a single-center series.

Science.gov (United States)

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; von Renteln, Daniel; Muehleisen, Helmut; Caca, Karel

2015-02-01

Endoscopic full-thickness resection of gastric subepithelial tumors with a full-thickness suturing device has been described as feasible in two small case series. The aim of this study was to evaluate the efficacy, safety, and clinical outcome of this resection technique. After 31 patients underwent endoscopic full-thickness resection, the data were analyzed retrospectively. Before snare resection, 1 to 3 full-thickness sutures were placed underneath each tumor with a device originally designed for endoscopic anti-reflux therapy. All tumors were resected successfully. Bleeding occurred in 12 patients (38.7 %); endoscopic hemostasis could be achieved in all cases. Perforation occurred in 3 patients (9.6 %), and all perforations could be managed endoscopically. Complete resection was histologically confirmed in 28 of 31 patients (90.3 %). Mean follow-up was 213 days (range, 1 - 1737), and no tumor recurrences were observed. Endoscopic full-thickness resection of gastric subepithelial tumors with the suturing technique described above is feasible and effective. After the resection of gastrointestinal stromal tumors (GISTs), we did not observe any recurrences during follow-up, indicating that endoscopic full-thickness resection may be an alternative to surgical resection for selected patients. © Georg Thieme Verlag KG Stuttgart · New York.

[Robot-assisted pancreatic resection].

Science.gov (United States)

Müssle, B; Distler, M; Weitz, J; Welsch, T

2017-06-01

Although robot-assisted pancreatic surgery has been considered critically in the past, it is nowadays an established standard technique in some centers, for distal pancreatectomy and pancreatic head resection. Compared with the laparoscopic approach, the use of robot-assisted surgery seems to be advantageous for acquiring the skills for pancreatic, bile duct and vascular anastomoses during pancreatic head resection and total pancreatectomy. On the other hand, the use of the robot is associated with increased costs and only highly effective and professional robotic programs in centers for pancreatic surgery will achieve top surgical and oncological quality, acceptable operation times and a reduction in duration of hospital stay. Moreover, new technologies, such as intraoperative fluorescence guidance and augmented reality will define additional indications for robot-assisted pancreatic surgery.

Laparoscopic liver resection for hepatocellular carcinoma in cirrhotic patients. Feasibility of nonanatomic resection in difficult tumor locations

Directory of Open Access Journals (Sweden)

Marco Casaccia

2011-01-01

Full Text Available Background: Surgical resection for hepatocellular carcinoma (HCC in cirrhotic patients remains controversial because of high morbidity and recurrence rates. Laparoscopic resection of liver tumors has recently been developed and could reduce morbidity. The aim of this study was to evaluate retrospectively our results for laparoscopic liver resection (LLR for HCC including lesions in the posterosuperior segments of the liver in terms of feasibility, outcome, recurrence and survival. Materials and Methods: Between June 2005 and February 2009, we performed 20 LLR for HCC. Median age of the patients was 66 years. The underlying cirrhosis was staged as Child A in 17 cases and Child B in 3. Results: LLR included anatomic resection in six cases and nonanatomic resection in 14. Eleven procedures were associated in nine (45% patients. Median tumor size and surgical margins were 3.1 cm and 15 mm, respectively. A conversion to laparotomy occurred in one (5% patient for hemorrhage. Mortality and morbidity rates were 0% and 15% (3/20. Median hospital stay was 8 days (range: 5-16 days. Over a mean follow-up period of 26 months (range: 19-62 months, 10 (50% patients presented recurrence, mainly at distance from the surgical site. Treatment of recurrence was possible in all the patients, including orthotopic liver transplantation in three cases. Conclusions: LLR for HCC in selected patients is a safe procedure with good short-term results. It can also be proposed in tumor locations with a difficult surgical access maintaining a low morbidity rate and good oncological adequacy. This approach could have an impact on the therapeutic strategy of HCC complicating cirrhosis as a treatment with curative intent or as a bridge to liver transplantation.

Radiation acoustics and its applications

International Nuclear Information System (INIS)

Lyamshev, L.M.

1992-01-01

Radiation acoustics is a new branch of acoustics, developing on the boundary of acoustics, nuclear physics, elementary particles and high-energy physics. Its fundamentals are laying in the research of acoustical effects due to the interaction of penetrating radiation with matter. The study of radiation-acoustical effects leads to the new opportunities in the penetration radiation research (acoustical detection, radiation-acoustical dosimetry), study of the physical parameters of matter, in a solution of some applied problems of nondestructive testing, and also for the radiation-acoustical influence on physical and chemical structure of the matter. Results of theoretical and experimental investigations are given. Different mechanisms of the sound generation by penetrating radiation of liquids and solids are considered. Some applications - the radiation acoustical microscopy and visualisation, the acoustical detection of high energy X-ray particles and possibility of using of high energy neutrino beams in geoacoustics - are discussed

Neurologic deficit after resection of the sacrum.

Science.gov (United States)

Biagini, R; Ruggieri, P; Mercuri, M; Capanna, R; Briccoli, A; Perin, S; Orsini, U; Demitri, S; Arlecchini, S

1997-01-01

The authors describe neurologic deficit (sensory, motor, and sphincteral) resulting from sacrifice of the sacral nerve roots removed during resection of the sacrum. The anatomical and functional bases of sphincteral continence and the amount of neurologic deficit are discussed based on level of sacral resection. A large review of the literature on the subject is reported and discussed. The authors emphasize how the neurophysiological bases of sphincteral continence (rectum and bladder) and of sexual ability are still not well known, and how the literature reveals disagreement on the subject. A score system is proposed to evaluate neurologic deficit. The clinical model of neurologic deficit caused by resection of the sacrum may be extended to an evaluation of post-traumatic deficit.

Parametric Room Acoustic Workflows

DEFF Research Database (Denmark)

Parigi, Dario; Svidt, Kjeld; Molin, Erik

2017-01-01

The paper investigates and assesses different room acoustics software and the opportunities they offer to engage in parametric acoustics workflow and to influence architectural designs. The first step consists in the testing and benchmarking of different tools on the basis of accuracy, speed...... and interoperability with Grasshopper 3d. The focus will be placed to the benchmarking of three different acoustic analysis tools based on raytracing. To compare the accuracy and speed of the acoustic evaluation across different tools, a homogeneous set of acoustic parameters is chosen. The room acoustics parameters...... included in the set are reverberation time (EDT, RT30), clarity (C50), loudness (G), and definition (D50). Scenarios are discussed for determining at different design stages the most suitable acoustic tool. Those scenarios are characterized, by the use of less accurate but fast evaluation tools to be used...

Intersphincteric Resection and Coloanal Anastomosis in Treatment of Distal Rectal Cancer

OpenAIRE

Cipe, Gokhan; Muslumanoglu, Mahmut; Yardimci, Erkan; Memmi, Naim; Aysan, Erhan

2012-01-01

In the treatment of distal rectal cancer, abdominoperineal resection is traditionally performed. However, the recognition of shorter safe distal resection line, intersphincteric resection technique has given a chance of sphincter-saving surgery for patients with distal rectal cancer during last two decades and still is being performed as an alternative choice of abdominoperineal resection. The first aim of this study is to assess the morbidity, mortality, oncological, and functional outcomes ...

Results of postoperative radiotherapy for resectable hilar cholangiocarcinoma

NARCIS (Netherlands)

Gerhards, Michael F.; van Gulik, Thomas M.; González González, Dioniso; Rauws, Erik A. J.; Gouma, Dirk J.

2003-01-01

The aim of this study was to assess the value of radiotherapy, and especially intraluminal brachytherapy, after resection of hilar cholangio-carcinoma by analyzing long-term complications and survival. Between 1983 and 1998, 112 patients underwent resection of a hilar cholangio-carcinoma. Of the 91

Resection of the Tooth Apex with Diode Laser

Directory of Open Access Journals (Sweden)

Uzunov Tz.

2014-06-01

Full Text Available An “in vitro” experimental study has been carried out on 70 extracted teeth. A laser resection of the root apex has been carried out with diode laser beam with a wavelength of - 810 ± 10 nm. Sequentially a radiation with increasing power has been applied, as follows: 1,3 W, 2W, 3W, 4W, 5W, 6W, 7W, in electro surgery mode. Successful resection of the tooth apex has been performed at: 3W; 4W; 5W; 6W and 7W power. It was established that when laser resected the tooth apex carbonizes.

Transanal stent in anterior resection does not prevent anastomotic leakage

DEFF Research Database (Denmark)

Bülow, Steffen; Bulut, O; Christensen, Ib Jarle

2006-01-01

OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS AND METH....... On this basis it was decided to discontinue the study prematurely for ethical reasons. CONCLUSION: Decompression of the anastomosis with a transanal stent does not reduce the risk of anastomotic leakage after anterior resection.......OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS...... AND METHODS: Randomized open trial of 194 patients operated in 11 hospitals during September 2000 to September 2003 with anterior resection for a mobile rectal tumour, 115 men and 79 women, median age 68 years (range 37-90 years). The surgeon decided upon the use of a protective ileostomy, and after...

Parenteral Nutrition in Liver Resection

Directory of Open Access Journals (Sweden)

Carlo Chiarla

2012-01-01

Full Text Available Albeit a very large number of experiments have assessed the impact of various substrates on liver regeneration after partial hepatectomy, a limited number of clinical studies have evaluated artificial nutrition in liver resection patients. This is a peculiar topic because many patients do not need artificial nutrition, while several patients need it because of malnutrition and/or prolonged inability to feeding caused by complications. The optimal nutritional regimen to support liver regeneration, within other postoperative problems or complications, is not yet exactly defined. This short review addresses relevant aspects and potential developments in the issue of postoperative parenteral nutrition after liver resection.

High-Frequency Seafloor Acoustics

CERN Document Server

Jackson, Darrell R

2007-01-01

High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

Use of coblation in resection of juvenile nasopharyngeal angiofibroma.

Science.gov (United States)

Cannon, Daniel E; Poetker, David M; Loehrl, Todd A; Chun, Robert H

2013-06-01

We present a series of 4 patients with juvenile nasopharyngeal angiofibroma (JNA) who underwent Coblation-assisted endoscopic resection after preoperative embolization, and discuss the use and advantages of endoscopic Coblation-assisted resection of JNA. Our limited case series suggests that Coblation may be used in the resection of JNA after embolization in a relatively safe, efficient, and effective manner. Coblation allows for decreased bleeding, less need for instrumentation, and improved visualization. There are limited published data in the literature to date on the use of Coblation in endoscopic JNA resection. We describe its use in a more extensive tumor than those previously reported. Further studies are needed to fully define the safety and utility of Coblation technology for this application.

Acoustic evaluation of wood quality in standing trees. Part I, Acoustic wave behavior

Science.gov (United States)

Xiping Wang; Robert J. Ross; Peter Carter

2007-01-01

Acoustic wave velocities in standing trees or live softwood species were measured by the time-of-flight (TOF) method. Tree velocities were compared with acoustic velocities measured in corresponding butt logs through a resonance acoustic method. The experimental data showed a skewed relationship between tree and log acoustic measurements. For most trees tested,...

Room Acoustics

Science.gov (United States)

Kuttruff, Heinrich; Mommertz, Eckard

The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

Acoustic scaling: A re-evaluation of the acoustic model of Manchester Studio 7

Science.gov (United States)

Walker, R.

1984-12-01

The reasons for the reconstruction and re-evaluation of the acoustic scale mode of a large music studio are discussed. The design and construction of the model using mechanical and structural considerations rather than purely acoustic absorption criteria is described and the results obtained are given. The results confirm that structural elements within the studio gave rise to unexpected and unwanted low-frequency acoustic absorption. The results also show that at least for the relatively well understood mechanisms of sound energy absorption physical modelling of the structural and internal components gives an acoustically accurate scale model, within the usual tolerances of acoustic design. The poor reliability of measurements of acoustic absorption coefficients, is well illustrated. The conclusion is reached that such acoustic scale modelling is a valid and, for large scale projects, financially justifiable technique for predicting fundamental acoustic effects. It is not appropriate for the prediction of fine details because such small details are unlikely to be reproduced exactly at a different size without extensive measurements of the material's performance at both scales.

Comparison of Endoscopic and Open Resection for Small Gastric Gastrointestinal Stromal Tumor

Directory of Open Access Journals (Sweden)

Fan Feng

2015-12-01

Full Text Available The National Comprehensive Cancer Network recommends conservative follow-up for gastric gastrointestinal stromal tumors (GISTs less than 2 cm. We have previously reported that the mitotic index of 22.22% of small gastric GISTs exceeded 5 per 50 high-power fields and recommended that all small gastric GISTs should be resected once diagnosed. The aim of the present study is to compare the safety and outcomes of endoscopic and open resection of small gastric GISTs. From May 2010 to March 2014, a total of 90 small gastric GIST patients were enrolled in the present study, including 40 patients who underwent surgical resection and 50 patients who underwent endoscopic resection. The clinicopathological characteristics, resection-related factors, and clinical outcomes were recorded and analyzed. The clinicopathological characteristics were comparable between the two groups except for tumor location and DOG-1 expression. Compared with the surgical resection group, the operation time was shorter (P = .000, blood loss was less (P = .000, pain intensity was lower (P < .05, duration of first flatus and defecation was shorter (P < .05, and medical cost of hospitalization was lower (P = .027 in the endoscopic resection group. The complications and postoperative hospital stay were comparable between the two groups. No in situ recurrence or liver metastasis was observed during follow-up. Endoscopic resection of small gastric GISTs is safe and feasible compared with surgical resection, although perforation could not be totally avoided during and after resection. The clinical outcome of endoscopic resection is also favorable.

Role of radiation therapy in patients with resectable pancreatic cancer.

Science.gov (United States)

Palta, Manisha; Willett, Christopher; Czito, Brian

2011-07-01

The 5-year overall survival of patients with pancreatic cancer is approximately 5%, with potentially resectable disease representing the curable minority. Although surgical resection remains the cornerstone of treatment, local and distant failure rates are high after complete resection, and debate continues as to the appropriate adjuvant therapy. Many oncologists advocate for adjuvant chemotherapy alone, given that high rates of systemic metastases are the primary cause of patient mortality. Others, however, view locoregional failure as a significant contributor to morbidity and mortality, thereby justifying the use of adjuvant chemoradiation. As in other gastrointestinal malignancies, neoadjuvant chemoradiotherapy offers potential advantages in resectable patients, and clinical investigation of this approach has shown promising results; however, phase III data are lacking. Further therapeutic advances and prospective trials are needed to better define the optimal role of adjuvant and neoadjuvant treatment in patients with resectable pancreatic cancer.

Liver resection with bipolar radiofrequency device: Habib 4X.

Science.gov (United States)

Pai, Madhava; Jiao, Long R; Khorsandi, Shirin; Canelo, Ruben; Spalding, Duncan R C; Habib, Nagy A

2008-01-01

Intraoperative blood loss has been shown to be an important factor correlating with morbidity and mortality in liver surgery. In spite of the technological advances in hepatic parenchymal transection devices, bleeding remains the single most important complication of liver surgery. The role of radiofrequency (RF) in liver surgery has been expanded from tumour ablation to major hepatic resections in the last decade. Habib 4X, a new bipolar RF device designed specifically for liver resection is described here. Habib 4X is a bipolar, handheld, disposable RF device and consists of two pairs of opposing electrodes which is introduced perpendicularly into the liver, along the intended transection line. It produces controlled RF energy between the electrodes and the heat produced seals even major biliary and blood vessels and enables resection of the liver parenchyma with a scalpel without blood loss or biliary leak. Three hundred and eleven patients underwent 384 liver resections from January 2002 to October 2007 with this device. There were 109 major resections and none of the patients had vascular inflow occlusion (Pringle's manoeuvre). Mean intraoperative blood loss was 305 ml (range 0-4300) ml, with less than 5% (n=18) rate of transfusion. Habib 4X is an additional device for hepatobiliary surgeons to perform liver resections with minimal blood loss and low morbidity and mortality rates.

Type of Resection (Whipple vs. Distal) Does Not Affect the National Failure to Provide Post-resection Adjuvant Chemotherapy in Localized Pancreatic Cancer.

Science.gov (United States)

Bergquist, John R; Ivanics, Tommy; Shubert, Christopher R; Habermann, Elizabeth B; Smoot, Rory L; Kendrick, Michael L; Nagorney, David M; Farnell, Michael B; Truty, Mark J

2017-06-01

Adjuvant chemotherapy improves survival after curative intent resection for localized pancreatic adenocarcinoma (PDAC). Given the differences in perioperative morbidity, we hypothesized that patients undergoing distal partial pancreatectomy (DPP) would receive adjuvant therapy more often those undergoing pancreatoduodenectomy (PD). The National Cancer Data Base (2004-2012) identified patients with localized PDAC undergoing DPP and PD, excluding neoadjuvant cases, and factors associated with receipt of adjuvant therapy were identified. Overall survival (OS) was analyzed using multivariable Cox proportional hazards regression. Overall, 13,501 patients were included (DPP, n = 1933; PD, n = 11,568). Prognostic characteristics were similar, except DPP patients had fewer N1 lesions, less often positive margins, more minimally invasive resections, and shorter hospital stay. The proportion of patients not receiving adjuvant chemotherapy was equivalent (DPP 33.7%, PD 32.0%; p = 0.148). The type of procedure was not independently associated with adjuvant chemotherapy (hazard ratio 0.96, 95% confidence interval 0.90-1.02; p = 0.150), and patients receiving adjuvant chemotherapy had improved unadjusted and adjusted OS compared with surgery alone. The type of resection did not predict adjusted mortality (p = 0.870). Receipt of adjuvant chemotherapy did not vary by type of resection but improved survival independent of procedure performed. Factors other than type of resection appear to be driving the nationwide rates of post-resection adjuvant chemotherapy in localized PDAC.

Learning Transurethral Resection of the Prostate: A Comparison of ...

African Journals Online (AJOL)

2018-01-30

Jan 30, 2018 ... benign prostate enlargement (BPE) are of limited use in the resource‑poor ... trans‑urethral resection of the prostate, resected weight, retropubic prostatectomy ..... digital rectal examination and total prostate specific antigen.

CALCULATION OF ACOUSTIC EFFICIENCY OF PORTABLE ACOUSTIC SCREEN

Directory of Open Access Journals (Sweden)

Aleksandr Skvortsov

2016-03-01

Full Text Available The research of influence of life environment adverse factors on physical development and health of population is an actual problem of ecology. The aspects of the most actual problems of the modern world, namely environmental industrial noise pollution are considered in the article. Industrial facilities everywhere have noisy equipment. Noise is a significant factors of negative influenceon people and environment. Combined effects of noise and of other physical pollutions on people may cause amplification of their negative impact. If the noise pollution level from the object in a residential area exceeds the permissible levels (MPL, noise protection measures can be initiated. Today, the most common design decisions for noise protection are sound absorbing construction, noise screens and barriers, acousting housings, soundproff cabins. Many of them are popular, others are less known. The article deals with one of the most wide spread means of noise protection – a portable acoustic screen. The aim of the research is to determine the efficiency of portable acoustic screens. It is shown that the installation of such structures can reduce the average value of the sound level. The authors analyzed acoustic screens as device to reduce noise pollution. The authors offer a potable acoustic screen differing from the used easyness, mobility, minimum price and good sound protective properties. Effectiveness, a sound absorption coefficient and sound conductivity coefficient of a portable acoustic screen are evaluated. The descriptions of the algorithm calculations and the combination of technical solutions have practical originality. The results of the research demonstrate the advantages of the proposed solutions for reducing noise levels in the agro-industrial complex.

Laparoscopic liver resection: wedge resections to living donor hepatectomy, are we heading in the right direction?

Science.gov (United States)

Cherian, P Thomas; Mishra, Ashish Kumar; Kumar, Palaniappen; Sachan, Vijayant Kumar; Bharathan, Anand; Srikanth, Gadiyaram; Senadhipan, Baiju; Rela, Mohamad S

2014-10-07

Despite inception over 15 years ago and over 3000 completed procedures, laparoscopic liver resection has remained mainly in the domain of selected centers and enthusiasts. Requirement of extensive open liver resection (OLR) experience, in-depth understanding of anatomy and considerable laparoscopic technical expertise may have delayed wide application. However healthy scepticism of its actual benefits and presence of a potential publication bias; concern about its safety and technical learning curve, are probably equally responsible. Given that a large proportion of our work, at least in transplantation is still OLR, we have attempted to provide an entirely unbiased, mature opinion of its pros and cons in the current invited review. We have divided this review into two sections as we believe they merit separate attention on technical and ethical grounds. The first part deals with laparoscopic liver resection (LLR) in patients who present with benign or malignant liver pathology, wherein we have discussed its overall outcomes; its feasibility based on type of pathology and type of resection and included a small section on application of LLR in special scenarios like cirrhosis. The second part deals with the laparoscopic living donor hepatectomy (LDH) experience to date, including its potential impact on transplantation in general. Donor safety, graft outcomes after LDH and criterion to select ideal donors for LLR are discussed. Within each section we have provided practical points to improve safety in LLR and attempted to reach reasonable recommendations on the utilization of LLR for units that wish to develop such a service.

Effects of subsampling of passive acoustic recordings on acoustic metrics.

Science.gov (United States)

Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

2015-07-01

Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species.

Preoperative gemcitabine-based chemoradiation therapy for resectable pancreatic cancer

International Nuclear Information System (INIS)

Takahashi, Hidenori; Ohigashi, Hiroaki; Goto, Kunihito; Marubashi, Shigeru; Yano, Masahiko; Ishikawa, Osamu

2013-01-01

During the period from 2002 to 2011, a total of 240 consecutive patients with resectable pancreatic cancer received preoperative chemoradiation therapy (CRT). Among 240 patients, 201 patients underwent the subsequent pancreatectomy (resection rate: 84%). The 5-year overall survival of resected cases was 56% and the median survival of 39 unresected cases was 11 months. The 5-year locoregional recurrence rate of resected cases was 15%. The 5-year overall survival of the entire cohort (n=240) was 47%. The preoperative CRT and subsequent pancreatectomy provided a favorable surgical result, which was contributed by several characteristics of preoperative CRT: the prominent locoregional treatment effect with lower incidence of locoregional recurrence, and the discrimination between patients who are likely to benefit from subsequent surgery and those who are not. (author)

Tracheal schwannoma: Completely resected with therapeutic bronchoscopic techniques

Directory of Open Access Journals (Sweden)

Barney Thomas Jesudason Isaac

2015-01-01

Full Text Available Tracheal schwannomas are rare benign tumors of the trachea. There are only a few reported cases in the literature. Surgeons have generally resected these tumors, whereas bronchoscopists have attempted to remove them bronchoscopically. We report a case of tracheal schwannoma which was completely resected using bronchoscopic techniques.

Anti-sound and Acoustical Cloaks

Directory of Open Access Journals (Sweden)

Veturia CHIROIU

2016-12-01

Full Text Available The principles by which the acoustics can be mimicked in order to reduce or cancel the vibrational field are based on anti-sound concept which can be materialized by acoustic cloaks. Geometric transformations open an elegant way towards the unconstrained control of sound through acoustic metamaterials. Acoustic cloaks can be achieved through geometric transformations which bring exotic metamaterial properties into the acoustic equations. Our paper brings new ideas concerning the technological keys for manufacturing of novel metamaterials based on the spatial compression of Cantor structures, and the architecture of 3D acoustic cloaks in a given frequency band, with application to architectural acoustics.

Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

Science.gov (United States)

Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

2017-07-01

Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers.

Acoustic transparency and slow sound using detuned acoustic resonators

DEFF Research Database (Denmark)

Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.

2011-01-01

We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

Prematurity reduces functional adaptation to intestinal resection in piglets

DEFF Research Database (Denmark)

Aunsholt, Lise; Thymann, Thomas; Qvist, Niels

2015-01-01

Background: Necrotizing enterocolitis and congenital gastrointestinal malformations in infants often require intestinal resection, with a subsequent risk of short bowel syndrome (SBS). We hypothesized that immediate intestinal adaptation following resection of the distal intestine with placement ...

[On the recurrence risk with partial larynx resections (author's transl)].

Science.gov (United States)

Flach, M

1978-06-01

28 cases of recurrences after 127 vertical and horizontal partial larynx resections (22 per cent) were analysed. Unfavourable preconditions for partial resections are the affliction of the ary cartilage and arrest of vocal chord movility. The hemiresections according to Hautant have the heighest recidivation percentage (40 per cent) judging from the observations available. Radical operations after failured partial resections are uncertain as to their prognoses.

Computational Ocean Acoustics

CERN Document Server

Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

2011-01-01

Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

Acoustic Test Results of Melamine Foam with Application to Payload Fairing Acoustic Attenuation Systems

Science.gov (United States)

Hughes, William O.; McNelis, Anne M.

2014-01-01

A spacecraft at launch is subjected to a harsh acoustic and vibration environment resulting from the passage of acoustic energy, created during the liftoff of a launch vehicle, through the vehicle's payload fairing. In order to ensure the mission success of the spacecraft it is often necessary to reduce the resulting internal acoustic sound pressure levels through the usage of acoustic attenuation systems. Melamine foam, lining the interior walls of the payload fairing, is often utilized as the main component of such a system. In order to better understand the acoustic properties of melamine foam, with the goal of developing improved acoustic attenuation systems, NASA has recently performed panel level testing on numerous configurations of melamine foam acoustic treatments at the Riverbank Acoustical Laboratory. Parameters assessed included the foam's thickness and density, as well as the effects of a top outer cover sheet material and mass barriers embedded within the foam. This testing followed the ASTM C423 standard for absorption and the ASTM E90 standard for transmission loss. The acoustic test data obtained and subsequent conclusions are the subjects of this paper.

Bilateral carotid body tumor resection in a female patient

Directory of Open Access Journals (Sweden)

Alfred Burgess

Full Text Available Introduction: Carotid body tumors also called carotid paragangliomas are rare neuroendocrine neoplasms derived from neural crest cells, approximately 3% of all paragangliomas occur in the head and neck area (Xiao and She, 2015; although they represent 65% of the head and neck paragangliomas (Georgiadis et al., 2008. Presentation of case: We present the therapeutic management of a 65-year-old woman with bilateral carotid body tumors. The patient presented to medical clinic for unrelated signs and symptoms of weight loss, dyspepsia, and epigastric pain. Physical examination showed bilateral non-tender neck masses for which imaging studies were ordered resulting in the diagnosis of bilateral carotid tumor. Surgical resection was staged with one week of distance between each tumor resection. Discussion: Carotid Body Tumors can arise from the paraganglia located within the adventitia of the medial aspect of the carotid bifurcation.Resection is the only curative treatment. Carotid body tumors resection represents a special challenge due to potential neurovascular complications. Conclusions: Surgical resection of carotid body tumors represents a special challenge to the surgeon because of the complex anatomical location of the tumor, including close relationship with the cranial nerves, involvement of the carotid vessels and large vascularization of the tumor. With the advance of diagnosis and improvement in surgical techniques as well as the understanding of biological behavior of tumors, surgical treatment has become a safer alternative for treating these tumors. Keywords: Carotid body tumor, Bilateral, Paraganglioma, Resection

Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

KAUST Repository

Elayouch, A.

2017-01-05

We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties. Our study reveals that the phenomenon of acoustically induced transparency is accompanied by an effect of near-zero density. Indeed, the dynamic effective parameters obtained from experimental data show the presence of a frequency band where the effective mass density is close to zero, with high transmission levels reaching 0.7. Furthermore, we demonstrate that such effective parameters lead to wave guiding in a 90-degrees-bent channel. This kind of acoustic metamaterial can, therefore, give rise to acoustic functions like controlling the wavefront, which may lead to very promising applications in acoustic cloacking or imaging.

Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

Science.gov (United States)

Jena, D. P.; Panigrahi, S. N.

2016-03-01

Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

Acoustic comfort in eating establishments

DEFF Research Database (Denmark)

Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas

2014-01-01

The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating establishment...

Springer handbook of acoustics

CERN Document Server

2014-01-01

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

Controversies in the Management of Borderline Resectable Proximal Pancreatic Adenocarcinoma with Vascular Involvement

Directory of Open Access Journals (Sweden)

Olga N. Tucker

2008-01-01

Full Text Available Synchronous major vessel resection during pancreaticoduodenectomy (PD for borderline resectable pancreatic adenocarcinoma remains controversial. In the 1970s, regional pancreatectomy advocated by Fortner was associated with unacceptably high morbidity and mortality rates, with no impact on long-term survival. With the establishment of a multidisciplinary approach, improvements in preoperative staging techniques, surgical expertise, and perioperative care reduced mortality rates and improved 5-year-survival rates are now achieved following resection in high-volume centres. Perioperative morbidity and mortality following PD with portal vein resection are comparable to standard PD, with reported 5-year-survival rates of up to 17%. Segmental resection and reconstruction of the common hepatic artery/proper hepatic artery (CHA/PHA can be performed to achieve an R0 resection in selected patients with limited involvement of the CHA/PHA at the origin of the gastroduodenal artery (GDA. PD with concomitant major vessel resection for borderline resectable tumours should be performed when a margin-negative resection is anticipated at high-volume centres with expertise in complex pancreatic surgery. Where an incomplete (R1 or R2 resection is likely neoadjuvant treatment with systemic chemotherapy followed by chemoradiation as part of a clinical trial should be offered to all patients.

Hand-assisted laparoscopic liver resection using Habib's technique: early experience.

Science.gov (United States)

Vávra, Petr; Ihnat, Peter; Vavrova, Michaela; Martinek, Lubomir; Dostalik, Jan; Habib, Nagy

2012-03-01

Hand-assisted laparoscopic liver surgery, a newly developed technique based on an innovative concept, has proved useful and safe for a variety of less invasive hepatectomies. Radiofrequency-assisted hepatic resection has been reported to be safe, associated with minimal morbidity and mortality and decreased intraoperative blood loss and transfusion requirements. We describe how we perform hand-assisted laparoscopic radiofrequency-assisted hepatic resection using a bipolar radiofrequency device. The use of the hand port has allowed the surgeon to use his hand in direct liver manipulation, mobilization, and retraction. It was also useful for tactile tumour localization. Radiofrequency-assisted hepatic parenchymal transection was performed on 15 patients using a bipolar device (Habib 4X) with minimal blood loss (74 ml), and very decent operative and resection times (92 min, 33 min respectively). This combined procedure offers a safe, effective and rapid liver resection technique. This might encourage surgeons to perform a minimally invasive approach for liver resection more frequently.

Acoustical Imaging

CERN Document Server

Akiyama, Iwaki

2009-01-01

The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

Battlefield acoustics

CERN Document Server

Damarla, Thyagaraju

2015-01-01

This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

Acoustic insulator for combined well equipment of acoustic and radioactivity logging

International Nuclear Information System (INIS)

Arkad'ev, E.A.; Gorbachev, Yu.I.; Dseban', I.P.; Yagodov, G.I.

1977-01-01

The design of an acoustic insulator for cobined well equipment of acoustic and radioactivity logaing made on the basis of studying the velocity of elastic waves propagation and attenuation in cable structures of various marks is described. It is shown that the cable probe of electric loggign equipment which is recommended as an acoustic insulator for combined well equipment has the necessary sound-insulating properties

Sociodemographic factors and vestibular schwannoma: a Danish nationwide cohort study

DEFF Research Database (Denmark)

Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren

2010-01-01

Vestibular schwannoma (VS) (or acoustic neuroma) accounts for about 5%-6% of all intracranial tumors; little is known about the etiology. We investigated the association between various sociodemographic indicators and VS in a cohort of 3.26 million Danish residents, with 1087 cases identified in 35...... 308 974 person-years under risk, with data accrued from 1993 to 2006. Complete ascertainment of cases was ensured by using population-based and clinical cancer registries. Information on sociodemographic indicators was obtained on an annually updated individual level from Statistics Denmark. Log...

Acoustic and streaming velocity components in a resonant waveguide at high acoustic levels.

Science.gov (United States)

Daru, Virginie; Reyt, Ida; Bailliet, Hélène; Weisman, Catherine; Baltean-Carlès, Diana

2017-01-01

Rayleigh streaming is a steady flow generated by the interaction between an acoustic wave and a solid wall, generally assumed to be second order in a Mach number expansion. Acoustic streaming is well known in the case of a stationary plane wave at low amplitude: it has a half-wavelength spatial periodicity and the maximum axial streaming velocity is a quadratic function of the acoustic velocity amplitude at antinode. For higher acoustic levels, additional streaming cells have been observed. Results of laser Doppler velocimetry measurements are here compared to direct numerical simulations. The evolution of axial and radial velocity components for both acoustic and streaming velocities is studied from low to high acoustic amplitudes. Two streaming flow regimes are pointed out, the axial streaming dependency on acoustics going from quadratic to linear. The evolution of streaming flow is different for outer cells and for inner cells. Also, the hypothesis of radial streaming velocity being of second order in a Mach number expansion, is not valid at high amplitudes. The change of regime occurs when the radial streaming velocity amplitude becomes larger than the radial acoustic velocity amplitude, high levels being therefore characterized by nonlinear interaction of the different velocity components.

Controlling sound with acoustic metamaterials

DEFF Research Database (Denmark)

Cummer, Steven A. ; Christensen, Johan; Alù, Andrea

2016-01-01

Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales....... The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create......-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview...

Surgical resection of large encephalocele: a report of two cases and consideration of resectability based on developmental morphology.

Science.gov (United States)

Ohba, Hideo; Yamaguchi, Satoshi; Sadatomo, Takashi; Takeda, Masaaki; Kolakshyapati, Manish; Kurisu, Kaoru

2017-03-01

The first-line treatment of encephalocele is reduction of herniated structures. Large irreducible encephalocele entails resection of the lesion. In such case, it is essential to ascertain preoperatively if the herniated structure encloses critical venous drainage. Two cases of encephalocele presenting with large occipital mass underwent magnetic resonance (MR) imaging. In first case, the skin mass enclosed the broad space containing cerebrospinal fluid and a part of occipital lobe and cerebellum. The second case had occipital mass harboring a large portion of cerebrum enclosing dilated ventricular space. Both cases had common venous anomalies such as split superior sagittal sinus and high-positioned torcular herophili. They underwent resection of encephalocele without subsequent venous congestion. We could explain the pattern of venous anomalies in encephalocele based on normal developmental theory. Developmental theory connotes that major dural sinuses cannot herniate into the sac of encephalocele. Irrespective to its size, encephalocele can be resected safely at the neck without subsequent venous congestion.

Education in acoustics in Argentina

Science.gov (United States)

Miyara, Federico

2002-11-01

Over the last decades, education in acoustics (EA) in Argentina has experienced ups and downs due to economic and political issues interfering with long term projects. Unlike other countries, like Chile, where EA has reached maturity in spite of the acoustical industry having shown little development, Argentina has several well-established manufacturers of acoustic materials and equipment but no specific career with a major in acoustics. At the university level, acoustics is taught as a complementary--often elective--course for careers such as architecture, communication engineering, or music. In spite of this there are several research centers with programs covering environmental and community noise, effects of noise on man, acoustic signal processing, musical acoustics and acoustic emission, and several national and international meetings are held each year in which results are communicated and discussed. Several books on a variety of topics such as sound system, architectural acoustics, and noise control have been published as well. Another chapter in EA is technical and vocational education, ranging between secondary and postsecondary levels, with technical training on sound system operation or design. Over the last years there have been several attempts to implement master degrees in acoustics or audio engineering, with little or no success.

Review of Progress in Acoustic Levitation

Science.gov (United States)

Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

2018-04-01

Acoustic levitation uses acoustic radiation forces to counteract gravity and suspend objects in mid-air. Although acoustic levitation was first demonstrated almost a century ago, for a long time, it was limited to objects much smaller than the acoustic wavelength levitating at fixed positions in space. Recent advances in acoustic levitation now allow not only suspending but also rotating and translating objects in three dimensions. Acoustic levitation is also no longer restricted to small objects and can now be employed to levitate objects larger than the acoustic wavelength. This article reviews the progress of acoustic levitation, focusing on the working mechanism of different types of acoustic levitation devices developed to date. We start with a brief review of the theory. Then, we review the acoustic levitation methods to suspend objects at fixed positions, followed by the techniques that allow the manipulation of objects. Finally, we present a brief summary and offer some future perspectives for acoustic levitation.

Endoscopic lesions in Crohn's disease early after ileocecal resection

NARCIS (Netherlands)

Tytgat, G. N.; Mulder, C. J.; Brummelkamp, W. H.

1988-01-01

Fifty patients with Crohn's disease were studied endoscopically 6 weeks to 6 months (median 9 weeks) after ileocecal or ileocolonic resection for evidence of non-resected abnormality. Only 8 of the 50 patients were endoscopically free of abnormalities. Microscopic examination of the surgical

Duodenum-preserving total pancreatic head resection for benign cystic neoplastic lesions.

Science.gov (United States)

Beger, Hans G; Schwarz, Michael; Poch, Bertram

2012-11-01

Cystic neoplasms of the pancreas are diagnosed frequently due to early use of abdominal imaging techniques. Intraductal papillary mucinous neoplasm, mucinous cystic neoplasm, and serous pseudopapillary neoplasia are considered pre-cancerous lesions because of frequent transformation to cancer. Complete surgical resection of the benign lesion is a pancreatic cancer preventive treatment. The application for a limited surgical resection for the benign lesions is increasingly used to reduce the surgical trauma with a short- and long-term benefit compared to major surgical procedures. Duodenum-preserving total pancreatic head resection introduced for inflammatory tumors in the pancreatic head transfers to the patient with a benign cystic lesion located in the pancreatic head, the advantages of a minimalized surgical treatment. Based on the experience of 17 patients treated for cystic neoplastic lesions with duodenum-preserving total pancreatic head resection, the surgical technique of total pancreatic head resection for adenoma, borderline tumors, and carcinoma in situ of cystic neoplasm is presented. A segmental resection of the peripapillary duodenum is recommended in case of suspected tissue ischemia of the peripapillary duodenum. In 305 patients, collected from the literature by PubMed search, in about 40% of the patients a segmental resection of the duodenum and 60% a duodenum and common bile duct-preserving total pancreatic head resection has been performed. Hospital mortality of the 17 patients was 0%. In 305 patients collected, the hospital mortality was 0.65%, 13.2% experienced a delay of gastric emptying and a pancreatic fistula in 18.2%. Recurrence of the disease was 1.5%. Thirty-two of 175 patients had carcinoma in situ. Duodenum-preserving total pancreatic head resection for benign cystic neoplastic lesions is a safe surgical procedure with low post-operative morbidity and mortality.

Defining Glioblastoma Resectability Through the Wisdom of the Crowd: A Proof-of-Principle Study.

Science.gov (United States)

Sonabend, Adam M; Zacharia, Brad E; Cloney, Michael B; Sonabend, Aarón; Showers, Christopher; Ebiana, Victoria; Nazarian, Matthew; Swanson, Kristin R; Baldock, Anne; Brem, Henry; Bruce, Jeffrey N; Butler, William; Cahill, Daniel P; Carter, Bob; Orringer, Daniel A; Roberts, David W; Sagher, Oren; Sanai, Nader; Schwartz, Theodore H; Silbergeld, Daniel L; Sisti, Michael B; Thompson, Reid C; Waziri, Allen E; McKhann, Guy

2017-04-01

Extent of resection (EOR) correlates with glioblastoma outcomes. Resectability and EOR depend on anatomical, clinical, and surgeon factors. Resectability likely influences outcome in and of itself, but an accurate measurement of resectability remains elusive. An understanding of resectability and the factors that influence it may provide a means to control a confounder in clinical trials and provide reference for decision making. To provide proof of concept of the use of the collective wisdom of experienced brain tumor surgeons in assessing glioblastoma resectability. We surveyed 13 academic tumor neurosurgeons nationwide to assess the resectability of newly diagnosed glioblastoma. Participants reviewed 20 cases, including digital imaging and communications in medicine-formatted pre- and postoperative magnetic resonance images and clinical vignettes. The selected cases involved a variety of anatomical locations and a range of EOR. Participants were asked about surgical goal, eg, gross total resection, subtotal resection (STR), or biopsy, and rationale for their decision. We calculated a "resectability index" for each lesion by pooling responses from all 13 surgeons. Neurosurgeons' individual surgical goals varied significantly ( P = .015), but the resectability index calculated from the surgeons' pooled responses was strongly correlated with the percentage of contrast-enhancing residual tumor ( R = 0.817, P < .001). The collective STR goal predicted intraoperative decision of intentional STR documented on operative notes ( P < .01) and nonresectable residual ( P < .01), but not resectable residual. In this pilot study, we demonstrate the feasibility of measuring the resectability of glioblastoma through crowdsourcing. This tool could be used to quantify resectability, a potential confounder in neuro-oncology clinical trials. Copyright © 2016 by the Congress of Neurological Surgeons

Interaction of surface plasmon polaritons and acoustic waves inside an acoustic cavity.

Science.gov (United States)

Khokhlov, Nikolai; Knyazev, Grigoriy; Glavin, Boris; Shtykov, Yakov; Romanov, Oleg; Belotelov, Vladimir

2017-09-15

In this Letter, we introduce an approach for manipulation of active plasmon polaritons via acoustic waves at sub-terahertz frequency range. The acoustic structures considered are designed as phononic Fabry-Perot microresonators where mirrors are presented with an acoustic superlattice and the structure's surface, and a plasmonic grating is placed on top of the acoustic cavity so formed. It provides phonon localization in the vicinity of the plasmonic grating at frequencies within the phononic stop band enhancing phonon-light interaction. We consider phonon excitation by shining a femtosecond laser pulse on the plasmonic grating. Appropriate theoretical model was used to describe the acoustic process caused by the pump laser pulse in the GaAs/AlAs-based acoustic cavity with a gold grating on top. Strongest modulation is achieved upon excitation of propagating surface plasmon polaritons and hybridization of propagating and localized plasmons. The relative changes in the optical reflectivity of the structure are more than an order of magnitude higher than for the structure without the plasmonic film.

Acoustic biosensors.

Science.gov (United States)

Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

2016-06-30

Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Liver resection for non-cirrhotic hepatocellular carcinoma in south ...

African Journals Online (AJOL)

Background. We describe the clinicopathologic features and outcome of South African patients who have undergone hepatic resection for hepatocellular carcinoma (HCC) arising in a non-cirrhotic liver. Methods. We utilised the prospective liver resection database in the Surgical Gastroenterology Unit at Groote Schuur ...

Cave acoustics in prehistory: Exploring the association of Palaeolithic visual motifs and acoustic response.

Science.gov (United States)

Fazenda, Bruno; Scarre, Chris; Till, Rupert; Pasalodos, Raquel Jiménez; Guerra, Manuel Rojo; Tejedor, Cristina; Peredo, Roberto Ontañón; Watson, Aaron; Wyatt, Simon; Benito, Carlos García; Drinkall, Helen; Foulds, Frederick

2017-09-01

During the 1980 s, acoustic studies of Upper Palaeolithic imagery in French caves-using the technology then available-suggested a relationship between acoustic response and the location of visual motifs. This paper presents an investigation, using modern acoustic measurement techniques, into such relationships within the caves of La Garma, Las Chimeneas, La Pasiega, El Castillo, and Tito Bustillo in Northern Spain. It addresses methodological issues concerning acoustic measurement at enclosed archaeological sites and outlines a general framework for extraction of acoustic features that may be used to support archaeological hypotheses. The analysis explores possible associations between the position of visual motifs (which may be up to 40 000 yrs old) and localized acoustic responses. Results suggest that motifs, in general, and lines and dots, in particular, are statistically more likely to be found in places where reverberation is moderate and where the low frequency acoustic response has evidence of resonant behavior. The work presented suggests that an association of the location of Palaeolithic motifs with acoustic features is a statistically weak but tenable hypothesis, and that an appreciation of sound could have influenced behavior among Palaeolithic societies of this region.

Limited resection for duodenal gastrointestinal stromal tumors: Surgical management and clinical outcome

Science.gov (United States)

Hoeppner, Jens; Kulemann, Birte; Marjanovic, Goran; Bronsert, Peter; Hopt, Ulrich Theodor

2013-01-01

AIM: To analyze our experience in patients with duodenal gastrointestinal stromal tumors (GIST) and review the appropriate surgical approach. METHODS: We retrospectively reviewed the medical records of all patients with duodenal GIST surgically treated at our medical institution between 2002 and 2011. Patient files, operative reports, radiological charts and pathology were analyzed. For surgical therapy open and laparoscopic wedge resections and segmental resections were performed for limited resection (LR). For extended resection pancreatoduodenectomy was performed. Age, gender, clinical symptoms of the tumor, anatomical localization, tumor size, mitotic count, type of resection resectional status, neoadjuvant therapy, adjuvant therapy, risk classification and follow-up details were investigated in this retrospective study. RESULTS: Nine patients (5 males/4 females) with a median age of 58 years were surgically treated. The median follow-up period was 45 mo (range 6-111 mo). The initial symptom in 6 of 9 patients was gastrointestinal bleeding (67%). Tumors were found in all four parts of the duodenum, but were predominantly located in the first and second part of the duodenum with each 3 of 9 patients (33%). Two patients received neoadjuvant medical treatment with 400 mg imatinib per day for 12 wk before resection. In one patient, the GIST resection was done by pancreatoduodenectomy. The 8 LRs included a segmental resection of pars 4 of the duodenum, 5 wedge resections with primary closure and a wedge resection with luminal closure by Roux-Y duodeno-jejunostomy. One of these LRs was done minimally invasive; seven were done in open fashion. The median diameter of the tumors was 54 mm (14-110 mm). Using the Fletcher classification scheme, 3/9 (33%) tumors had high risk, 1/9 (11%) had intermediate risk, 4/9 (44%) had low risk, and 1/9 (11%) had very low risk for aggressive behaviour. Seven resections showed microscopically negative transsection margins (R0), two

The effects of two counterpropagating surface acoustic wave beams on single electron acoustic charge transport

International Nuclear Information System (INIS)

He Jianhong; Guo Huazhong; Song Li; Zhang Wei; Gao Jie; Lu Chuan

2010-01-01

We present a comprehensive study of the effects of two counterpropagating surface acoustic waves on the acoustoelectric current of single electron transport devices. A significant improvement in the accuracy of current quantization is achieved as a result of an additional surface acoustic wave beam. The experiments reveal the sinusoidally periodical modulation in the acoustoelectric current characteristic as a function of the relative phase of the two surface acoustic wave beams. Besides, by using standing surface acoustic waves, the acoustoelectric current is detected which we consider as the so-called anomalous acoustoelectric current produced by acoustic wave mechanical deformations. This kind current is contributed to one component of the acoustoelectric current in surface acoustic wave device, which could enable us to establish a more adequate description of acoustoelectric effects on single-electron acoustic charge transport.

Localized Acoustic Surface Modes

KAUST Repository

Farhat, Mohamed

2015-08-04

We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

Acoustic Signals and Systems

DEFF Research Database (Denmark)

2008-01-01

The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

Optical measurement of acoustic radiation pressure of the near-field acoustic levitation through transparent object

OpenAIRE

Nakamura, Satoshi; Furusawa, Toshiaki; Sasao, Yasuhiro; Katsura, Kogure; Naoki, Kondo

2013-01-01

It is known that macroscopic objects can be levitated for few to several hundred micrometers by near-field acoustic field and this phenomenon is called near-field acoustic levitation (NFAL). Although there are various experiments conducted to measure integrated acoustic pressure on the object surface, up to now there was no direct method to measure pressure distribution. In this study we measured the acoustic radiation pressure of the near-field acoustic levitation via pressure-sensitive paint.

Rapid rehabilitation in elderly patients after laparoscopic colonic resection

DEFF Research Database (Denmark)

Bardram, L.; Funch-Jensen, Peter; Kehlet, H.

2000-01-01

. Routine use of morphine and traditional tubes, drains and prolonged bladder catheterization was avoided. RESULTS: Laparoscopic resection was intended in 50 consecutive patients, of median age 81 years. The conversion rate to open resection was 22 per cent. In patients in whom the procedure was completed...

Results of a pancreatectomy with a limited venous resection for pancreatic cancer.

Science.gov (United States)

Illuminati, Giulio; Carboni, Fabio; Lorusso, Riccardo; D'Urso, Antonio; Ceccanei, Gianluca; Papaspyropoulos, Vassilios; Pacile, Maria Antonietta; Santoro, Eugenio

2008-01-01

The indications for a pancreatectomy with a partial resection of the portal or superior mesenteric vein for pancreatic cancer, when the vein is involved by the tumor, remain controversial. It can be assumed that when such involvement is not extensive, resection of the tumor and the involved venous segment, followed by venous reconstruction will extend the potential benefits of this resection to a larger number of patients. The further hypothesis of this study is that whenever involvement of the vein by the tumor does not exceed 2 cm in length, this involvement is more likely due to the location of the tumor being close to the vein rather than because of its aggressive biological behavior. Consequently, in these instances a pancreatectomy with a resection of the involved segment of portal or superior mesenteric vein for pancreatic cancer is indicated, as it will yield results that are superposable to those of a pancreatectomy for cancer without vascular involvement. Twenty-nine patients with carcinoma of the pancreas involving the portal or superior mesenteric vein over a length of 2 cm or less underwent a macroscopically curative resection of the pancreas en bloc with the involved segment of the vein. The venous reconstruction procedures included a tangential resection/lateral suture in 15 cases, a resection/end-to-end anastomosis in 11, and a resection/patch closure in 3. Postoperative mortality was 3.4%; morbidity was 21%. Local recurrence was 14%. Cumulative (standard error) survival rate was 17% (9%) at 3 years. A pancreatectomy combined with a resection of the portal or superior mesenteric vein for cancer with venous involvement not exceeding 2 cm is indicated in order to extend the potential benefits of a curative resection.

Observation of self-excited acoustic vortices in defect-mediated dust acoustic wave turbulence.

Science.gov (United States)

Tsai, Ya-Yi; I, Lin

2014-07-01

Using the self-excited dust acoustic wave as a platform, we demonstrate experimental observation of self-excited fluctuating acoustic vortex pairs with ± 1 topological charges through spontaneous waveform undulation in defect-mediated turbulence for three-dimensional traveling nonlinear longitudinal waves. The acoustic vortex pair has helical waveforms with opposite chirality around the low-density hole filament pair in xyt space (the xy plane is the plane normal to the wave propagation direction). It is generated through ruptures of sequential crest surfaces and reconnections with their trailing ruptured crest surfaces. The initial rupture is originated from the amplitude reduction induced by the formation of the kinked wave crest strip with strong stretching through the undulation instability. Increasing rupture causes the separation of the acoustic vortex pair after generation. A similar reverse process is followed for the acoustic vortex annihilating with the opposite-charged acoustic vortex from the same or another pair generation.

Pancreatic insufficiency after different resections for benign tumours.

Science.gov (United States)

Falconi, M; Mantovani, W; Crippa, S; Mascetta, G; Salvia, R; Pederzoli, P

2008-01-01

Pancreatic resections for benign diseases may lead to long-term endocrine/exocrine impairment. The aim of this study was to compare postoperative and long-term results after different pancreatic resections for benign disease. Between 1990 and 1999, 62 patients underwent pancreaticoduodenectomy (PD), 36 atypical resection (AR) and 64 left pancreatectomy (LP) for benign tumours. Exocrine and endocrine pancreatic function was evaluated by 72-h faecal chymotrypsin and oral glucose tolerance test. The incidence of pancreatic fistula was significantly higher after AR than after LP (11 of 36 versus seven of 64; P = 0.028). The long-term incidence of endocrine pancreatic insufficiency was significantly lower after AR than after PD (P insufficiency was more common after PD (P endocrine and exocrine insufficiency was higher for PD and LP than for AR (32, 27 and 3 per cent respectively at 1 year; 58, 29 and 3 per cent at 5 years; P pancreatic resections are associated with different risks of developing long-term pancreatic insufficiency. AR represents the best option in terms of long-term endocrine and exocrine function, although it is associated with more postoperative complications. Copyright (c) 2007 British Journal of Surgery Society Ltd.

Acoustic Emission Technology and Application

International Nuclear Information System (INIS)

Joo, Y. S.; Lim, S. H.; Eom, H. S.; Kim, J. H.; Jung, H. K.

2003-10-01

Acoustic emission is the elastic wave that is generated by the rapid release of energy from the localized sources within a material. After the observation of acoustic emission phenomenon in 1950, the research and further investigation had been performed. Acoustic emission examination becomes a rapidly matured nondestructive testing method with demonstrated capabilities for characterizing material behavior and for detecting the defect. It is of interest as a possible passive monitoring technique for detecting, locating and characterizing the defects in component and structure. Acoustic emission technology has recently strengthened the on-line monitoring application for the detection of incipient failures and the assurance of structural integrity. The field of acoustic emission testing is still growing vigorously and presents many challenges. Especially, acoustic emission has been successfully applied in the leak detection of primary pressure boundary of nuclear power plants. In this state-of-art report, the principle, measurement and field applications of acoustic emission technique is reviewed and summarized. Acoustic emission technology will contribute to the assurance of nuclear safety as the on-line monitoring technique of structural integrity of NSSS components and structures

Arthroscopic Talocalcaneal Coalition Resection in Children.

Science.gov (United States)

Knörr, Jorge; Soldado, Francisco; Menendez, Mariano E; Domenech, Pedro; Sanchez, Mikel; Sales de Gauzy, Jérôme

2015-12-01

To present the technique and outcomes of arthroscopic talocalcaneal coalition (TCC) resection in pediatric patients. We performed a prospective study of 16 consecutive feet with persistent symptomatic TCCs in 15 children. The mean age was 11.8 years (range, 8 to 15 years), and the mean follow-up period was 28 months (range, 12 to 44 months). A posterior arthroscopic TCC resection was performed. The plantar footprint, subtalar motion, pain, and the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scale score were evaluated preoperatively and postoperatively. Preoperative computed tomography (CT) scans were used to classify the coalition according to the Rozansky classification, to measure the percentage of involvement of the surface area, and to determine the degree of hindfoot valgus. Postoperative CT scans at 1 year (n = 15) and 3 years (n = 5) were used to assess recurrences. Patient satisfaction was also evaluated. The TCC distribution according to the Rozansky classification was type I in 7 cases, type II in 3, type III in 3, and type IV in 3. In all cases the arthroscopic approach enabled complete coalition resection. All patients increased by at least 1 stage in the footprint classification and showed clinical subtalar mobility after surgery. All patients showed a statistically significant improvement in pain after surgery except for 1 patient in whom complex regional pain syndrome developed (P < .001). The mean American Orthopaedic Foot & Ankle Society score was 56.8 (range, 45 to 62) preoperatively versus 90.9 (range, 36 to 100) postoperatively, showing a statistically significant increase (P < .001). Preoperative CT scans showed that all TCCs involved the medial subtalar joint facet, with mean involvement of 40.8% of the articular surface. All postoperative CT scans showed complete synostosis resections with no recurrences at final follow-up. At final follow-up, all patients were either satisfied (n = 4 [27%]) or extremely satisfied (n = 10 [67

Determining gastric cancer resectability by dynamic MDCT

Energy Technology Data Exchange (ETDEWEB)

Pan, Zilai; Zhang, Huan; Du, Lianjun; Ding, Bei; Song, Qi; Ling, Huawei; Huang, Baisong; Chen, Kemin [Jiaotong University, Department of Radiology, Shanghai (China); Yan, Chao [Jiaotong University, Department of Surgery, Shanghai (China)

2010-03-15

Multi-detector row CT (MDCT) has been widely used to detect primary lesions and to evaluate TNM staging. In this study we evaluated the accuracy of dynamic MDCT in the preoperative determination of the resectability of gastric cancer. MDCT was used to image 350 cases of gastric cancer diagnosed by biopsy before surgery. MDCT findings regarding TNM staging and resectability were correlated with surgical and pathological findings. The accuracy of MDCT for staging gastric cancer was high, especially for tumour stage T1 (94.3%), lymph node stage N2 (87.3%), and for predicting distant metastases (>96.6%). When resectability was considered to be the outcome, the total accuracy of MDCT was 87.4%, sensitivity was 89.7% and specificity was 76.7%. Results showed high sensitivity for identifying peritoneal seeding (90.0%) and for predicting liver metastasis (80.0%). Dynamic enhanced MDCT is useful for TNM staging of gastric cancers and for predicting tumour respectability preoperatively. (orig.)

Determining gastric cancer resectability by dynamic MDCT

International Nuclear Information System (INIS)

Pan, Zilai; Zhang, Huan; Du, Lianjun; Ding, Bei; Song, Qi; Ling, Huawei; Huang, Baisong; Chen, Kemin; Yan, Chao

2010-01-01

Multi-detector row CT (MDCT) has been widely used to detect primary lesions and to evaluate TNM staging. In this study we evaluated the accuracy of dynamic MDCT in the preoperative determination of the resectability of gastric cancer. MDCT was used to image 350 cases of gastric cancer diagnosed by biopsy before surgery. MDCT findings regarding TNM staging and resectability were correlated with surgical and pathological findings. The accuracy of MDCT for staging gastric cancer was high, especially for tumour stage T1 (94.3%), lymph node stage N2 (87.3%), and for predicting distant metastases (>96.6%). When resectability was considered to be the outcome, the total accuracy of MDCT was 87.4%, sensitivity was 89.7% and specificity was 76.7%. Results showed high sensitivity for identifying peritoneal seeding (90.0%) and for predicting liver metastasis (80.0%). Dynamic enhanced MDCT is useful for TNM staging of gastric cancers and for predicting tumour respectability preoperatively. (orig.)

Acoustic building infiltration measurement system

Science.gov (United States)

Muehleisen, Ralph T.; Raman, Ganesh

2018-04-10

Systems and methods of detecting and identifying a leak from a container or building. Acoustic pressure and velocity are measured. Acoustic properties are acquired from the measured values. The acoustic properties are converted to infiltration/leakage information. Nearfield Acoustic Holography (NAH) may be one method to detect the leakages from a container by locating the noise sources.

Enhanced recovery after esophageal resection.

Science.gov (United States)

Vorwald, Peter; Bruna Esteban, Marcos; Ortega Lucea, Sonia; Ramírez Rodríguez, Jose Manuel

2018-03-21

ERAS is a multimodal perioperative care program which replaces traditional practices concerning analgesia, intravenous fluids, nutrition, mobilization as well as a number of other perioperative items, whose implementation is supported by evidence-based best practices. According to the RICA guidelines published in 2015, a review of the literature and the consensus established at a multidisciplinary meeting in 2015, we present a protocol that contains the basic procedures of an ERAS pathway for resective esophageal surgery. The measures involved in this ERAS pathway are structured into 3areas: preoperative, perioperative and postoperative. The consensus document integrates all the analyzed items in a unique time chart. ERAS programs in esophageal resection surgery can reduce postoperative morbidity, mortality, hospitalization and hospital costs. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

The accidental (acoustical) tourist

Science.gov (United States)

Van Kirk, Wayne

2002-11-01

The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

Laparoscopic anterior resection and total mesorectal excision for rectal cancer: a prospective nonrandomized study.

Science.gov (United States)

Palanivelu, C; Sendhilkumar, K; Jani, Kalpesh; Rajan, P S; Maheshkumar, G S; Shetty, Roshan; Parthasarthi, R

2007-04-01

The purpose of this study was to present our experience of laparoscopic total mesorectal resection, including ultralow resection and coloanal anastomosis. Between 1993 and 2005, patients fit for general anesthesia, with resectable cancers, and with lower edge of tumor beyond 5 cm of the anal verge were subjected to laparoscopic anterior resection with sphincter preservation. Double stapling technique is used to establish bowel continuity. A total of 170 patients, 88 males and 82 females, were subjected to successful laparoscopic anterior resection, which included high anterior resection (n=90), low anterior resection (n=52), ultralow anterior resection (n=20), and coloanal anastomosis (n=8). The average age of patients was 58.4 years (12-90 years). Mean operating time was 130 min and mean hospital stay was 7 days. The morbidity was 13.5% with nil mortality. With an average follow-up of 49 months (range 9 years to 3 months), 9 patients developed local recurrence and 45 patients developed distant metastasis. In selected cases, laparoscopic anterior resection is possible for all levels of rectal tumors, allowing sphincter preservation and maintaining oncological safety.

Acoustic field modulation in regenerators

Science.gov (United States)

Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

2016-12-01

The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

Effect of lung resection on pleuro-pulmonary mechanics and fluid balance.

Science.gov (United States)

Salito, C; Bovio, D; Orsetti, G; Salati, M; Brunelli, A; Aliverti, A; Miserocchi, G

2016-01-15

The aim of the study was to determine in human patients the effect of lung resection on lung compliance and on pleuro-pulmonary fluid balance. Pre and post-operative values of compliance were measured in anesthetized patients undergoing resection for lung cancer (N=11) through double-lumen bronchial intubation. Lung compliance was measured for 10-12 cm H2O increase in alveolar pressure from 5 cm H2O PEEP in control and repeated after resection. No air leak was assessed and pleural fluid was collected during hospital stay. A significant negative correlation (r(2)=0.68) was found between compliance at 10 min and resected mass. Based on the pre-operative estimated lung weight, the decrease in compliance following lung resection exceeded by 10-15% that expected from resected mass. Significant negative relationships were found by relating pleural fluid drainage flow to the remaining lung mass and to post-operative lung compliance. Following lung re-expansion, data suggest a causative relationship between the decrease in compliance and the perturbation in pleuro-pulmonary fluid balance. Copyright © 2015 Elsevier B.V. All rights reserved.

Ares I Scale Model Acoustic Tests Instrumentation for Acoustic and Pressure Measurements

Science.gov (United States)

Vargas, Magda B.; Counter, Douglas D.

2011-01-01

The Ares I Scale Model Acoustic Test (ASMAT) was a development test performed at the Marshall Space Flight Center (MSFC) East Test Area (ETA) Test Stand 116. The test article included a 5% scale Ares I vehicle model and tower mounted on the Mobile Launcher. Acoustic and pressure data were measured by approximately 200 instruments located throughout the test article. There were four primary ASMAT instrument suites: ignition overpressure (IOP), lift-off acoustics (LOA), ground acoustics (GA), and spatial correlation (SC). Each instrumentation suite incorporated different sensor models which were selected based upon measurement requirements. These requirements included the type of measurement, exposure to the environment, instrumentation check-outs and data acquisition. The sensors were attached to the test article using different mounts and brackets dependent upon the location of the sensor. This presentation addresses the observed effect of the sensors and mounts on the acoustic and pressure measurements.

Agorá Acoustics - Effects of arcades on the acoustics of public squares

DEFF Research Database (Denmark)

Paini, Dario; Gade, Anders Christian; Rindel, Jens Holger

2005-01-01

This paper is part of a PhD work, dealing with the acoustics of the public squares (‘Agorá Acoustics’), especially when music (amplified or not) is played. Consequently, our approach will be to evaluate public squares using the same set of acoustics concepts for subjective evaluation and objective...... measurements as applied for concert halls and theatres. In this paper the acoustical effects of arcades will be studied, in terms of reverberation (EDT and T30), clarity (C80), intelligibility (STI) and other acoustical parameters. For this purpose, also the theory of coupled rooms is applied and compared...... with results. An acoustic modelling program, ODEON 7.0, was used for this investigation. Three different sizes of public squares were considered. In order to evaluate the ‘real’ effects of the arcades on the open square, models of all three squares were designed both with and without arcades. The sound source...

Understanding acoustics an experimentalist’s view of acoustics and vibration

CERN Document Server

Garrett, Steven L

2017-01-01

This textbook provides a unified approach to acoustics and vibration suitable for use in advanced undergraduate and first-year graduate courses on vibration and fluids. The book includes thorough treatment of vibration of harmonic oscillators, coupled oscillators, isotropic elasticity, and waves in solids including the use of resonance techniques for determination of elastic moduli. Drawing on 35 years of experience teaching introductory graduate acoustics at the Naval Postgraduate School and Penn State, the author presents a hydrodynamic approach to the acoustics of sound in fluids that provides a uniform methodology for analysis of lumped-element systems and wave propagation that can incorporate attenuation mechanisms and complex media. This view provides a consistent and reliable approach that can be extended with confidence to more complex fluids and future applications. Understanding Acoustics opens with a mathematical introduction that includes graphing and statistical uncertainty, followed by five chap...

Laparoscopic resection of large gastric gastrointestinal stromal tumours

Directory of Open Access Journals (Sweden)

Sebastian Smolarek

2015-12-01

Full Text Available Introduction : Gastrointestinal stromal tumours (GISTs are a rare class of neoplasms that are seen most commonly in the stomach. Due to their malignant potential, surgical resection is the recommended method for management of these tumours. Many reports have described the ability to excise small and medium sized GISTs laparoscopically, but laparoscopic resection of GISTs greater than 5 cm is still a matter of debate. Aim: To investigate the feasibility and effectiveness of laparoscopic surgical techniques for management of large gastric GISTs greater than 4 cm and to detail characteristics of this type of tumour. Material and methods: The study cohort consisted of 11 patients with suspected gastric GISTs who were treated from 2011 to April 2014 in a single institution. All patients underwent laparoscopic resection of a gastric GIST. Results : Eleven patients underwent laparoscopic resection of a suspected gastric GIST between April 2011 and April 2014. The cohort consisted of 6 males and 5 females. Mean age was 67 years (range: 43–92 years. Sixty-four percent of these patients presented with symptomatic tumours. Four (36.4% patients underwent laparoscopic transgastric resection (LTR, 3 (27.3% laparoscopic sleeve gastrectomy (LSG, 3 (27.3% laparoscopic wedge resection (LWR and 1 (9% laparoscopic distal gastrectomy (LDG. The mean operative time was 215 min. The mean tumour size was 6 cm (range: 4–9 cm. The mean tumour size for LTR was 5.5 cm (range: 4–6.3 cm, for LWR 5.3 cm (range: 4.5–7 cm, for LSG 6.5 cm (range: 4–9 cm and for LDG 9 cm. We experienced only minor postoperative complications. Conclusions : Laparoscopic procedures can be successfully performed during management of large gastric GISTs, bigger than 4 cm, and should be considered for all non-metastatic cases. The appropriate approach can be determined by assessing the anatomical location of each tumour.

Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

Directory of Open Access Journals (Sweden)

Shilei Liu

2017-07-01

Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

Science.gov (United States)

Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong

2017-01-01

Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955

Hand-Assisted Laparoscopic (HAL) Multiple Segmental Colorectal Resections: Are They Feasible and Safe?

Science.gov (United States)

Taggarshe, Deepa; Attuwaybi, Bashir O; Matier, Brian; Visco, Jeffrey J; Butler, Bryan N

2015-04-01

The objective of this study was to evaluate the short-term outcomes of synchronous hand-assisted laparoscopic (HAL) segmental colorectal resections. The surgical options for synchronous colonic pathology include extensive colonic resection with single anastomosis, multiple synchronous segmental resections with multiple anastomoses, or staged resections. Traditionally, multiple open, synchronous, segmental resections have been performed. There is a lack of data on HAL multiple segmental colorectal resections. A retrospective chart review was compiled on all patients who underwent HAL synchronous segmental colorectal resections by all the colorectal surgeons from our Group during the period of 1999 to 2014. Demographics, operative details, and short-term outcomes are reported. During the period, 9 patients underwent HAL synchronous multiple segmental colorectal resections. There were 5 women and 4 men, with median age of 54 (24-83) years and median BMI of 24 (19.8-38.7) kg/m(2). Two patients were on long-term corticosteroid therapy. The median operative time was 210 (120-330) minutes and median operative blood loss was 200 (75-300) mLs. The median duration for return of bowel function was 2 days and the median length of stay was 3.5 days. We had 2 minor wound infections. There were no deaths. Synchronous segmental colorectal resections with anastomoses using the hand-assisted laparoscopic technique are safe. Early conversion to open and use of stomas are advisable in challenging cases.

Outcomes of patients with abdominoperineal resection (APR) and low anterior resection (LAR) who had very low rectal cancer.

Science.gov (United States)

Yeom, Seung-Seop; Park, In Ja; Jung, Sung Woo; Oh, Se Heon; Lee, Jong Lyul; Yoon, Yong Sik; Kim, Chan Wook; Lim, Seok-Byung; Kim, Nayoung; Yu, Chang Sik; Kim, Jin Cheon

2017-10-01

We compared the oncological outcomes of sphincter-saving resection (SSR) and abdominoperineal resection (APR) in 409 consecutive patients with very low rectal cancer (i.e., tumors within 3 cm from the anal verge); 335 (81.9%) patients underwent APR and 74 (18.1%) underwent SSR. The APR group comprised higher proportions of men (67.5% vs 55.4%, P = .049) and advanced-stage patients (P cancer stages. RFS was associated with ypT and ypN stages in patients who received PCRT, while pN stage, lymphovascular invasion (LVI), and circumferential resection margin (CRM) involvement were risk factors for RFS in those who did not receive PCRT. Notably, SSR was not found to be a risk factor for RFS in either subgroup. Patients who were stratified according to cancer stage and PCRT also showed no differences in RFS according to the mode of surgery. Our results demonstrate that, regardless of PCRT administration, SSR is an effective treatment for very low rectal cancer, while CRM is an important prognostic factor for patients who did not receive PCRT.

Laparoscopic Versus Open Resection for Colorectal Liver Metastases: The OSLO-COMET Randomized Controlled Trial.

Science.gov (United States)

Fretland, Åsmund Avdem; Dagenborg, Vegar Johansen; Bjørnelv, Gudrun Maria Waaler; Kazaryan, Airazat M; Kristiansen, Ronny; Fagerland, Morten Wang; Hausken, John; Tønnessen, Tor Inge; Abildgaard, Andreas; Barkhatov, Leonid; Yaqub, Sheraz; Røsok, Bård I; Bjørnbeth, Bjørn Atle; Andersen, Marit Helen; Flatmark, Kjersti; Aas, Eline; Edwin, Bjørn

2018-02-01

To perform the first randomized controlled trial to compare laparoscopic and open liver resection. Laparoscopic liver resection is increasingly used for the surgical treatment of liver tumors. However, high-level evidence to conclude that laparoscopic liver resection is superior to open liver resection is lacking. Explanatory, assessor-blinded, single center, randomized superiority trial recruiting patients from Oslo University Hospital, Oslo, Norway from February 2012 to January 2016. A total of 280 patients with resectable liver metastases from colorectal cancer were randomly assigned to undergo laparoscopic (n = 133) or open (n = 147) parenchyma-sparing liver resection. The primary outcome was postoperative complications within 30 days (Accordion grade 2 or higher). Secondary outcomes included cost-effectiveness, postoperative hospital stay, blood loss, operation time, and resection margins. The postoperative complication rate was 19% in the laparoscopic-surgery group and 31% in the open-surgery group (12 percentage points difference [95% confidence interval 1.67-21.8; P = 0.021]). The postoperative hospital stay was shorter for laparoscopic surgery (53 vs 96 hours, P < 0.001), whereas there were no differences in blood loss, operation time, and resection margins. Mortality at 90 days did not differ significantly from the laparoscopic group (0 patients) to the open group (1 patient). In a 4-month perspective, the costs were equal, whereas patients in the laparoscopic-surgery group gained 0.011 quality-adjusted life years compared to patients in the open-surgery group (P = 0.001). In patients undergoing parenchyma-sparing liver resection for colorectal metastases, laparoscopic surgery was associated with significantly less postoperative complications compared to open surgery. Laparoscopic resection was cost-effective compared to open resection with a 67% probability. The rate of free resection margins was the same in both groups. Our results support the continued

Deep Water Acoustics

Science.gov (United States)

2016-06-28

the Deep Water project and participate in the NPAL Workshops, including Art Baggeroer (MIT), J. Beron- Vera (UMiami), M. Brown (UMiami), T...Kathleen E . Wage. The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea. J. Acoust. Soc. Am., 134(4...estimate of the angle α during PhilSea09, made from ADCP measurements at the site of the DVLA. Sim. A B1 B2 B3 C D E F Prof. # 0 4 4 4 5 10 16 20 α

Acoustic Levitation With Less Equipment

Science.gov (United States)

Barmatz, M. B.; Jacobi, N.

1983-01-01

Certain chamber shapes require fewer than three acoustic drivers. Levitation at center of spherical chamber attained using only one acoustic driver. Exitation of lowest spherical mode produces asymmetric acoustic potential well.

Anisotropy of acoustic properties in paratellurite

International Nuclear Information System (INIS)

Parygin, Vladimir N.

1996-01-01

One of the peculiarities of the TeO 2 crystal consists of its strong acoustic anisotropy. This anisotropy demonstrates itself by acoustic energy walk-off and anisotropic distortion of an acoustic beam. Four constants completely characterise the acoustic anisotropy of the medium. In this paper these constants are calculated for various directions of the acoustic beam in crystal. (authors)

Variable-Position Acoustic Levitation

Science.gov (United States)

Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

1983-01-01

Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

Validation of an imageable surgical resection animal model of Glioblastoma (GBM).

Science.gov (United States)

Sweeney, Kieron J; Jarzabek, Monika A; Dicker, Patrick; O'Brien, Donncha F; Callanan, John J; Byrne, Annette T; Prehn, Jochen H M

2014-08-15

Glioblastoma (GBM) is the most common and malignant primary brain tumour having a median survival of just 12-18 months following standard therapy protocols. Local recurrence, post-resection and adjuvant therapy occurs in most cases. U87MG-luc2-bearing GBM xenografts underwent 4.5mm craniectomy and tumour resection using microsurgical techniques. The cranial defect was repaired using a novel modified cranial window technique consisting of a circular microscope coverslip held in place with glue. Immediate post-operative bioluminescence imaging (BLI) revealed a gross total resection rate of 75%. At censor point 4 weeks post-resection, Kaplan-Meier survival analysis revealed 100% survival in the surgical group compared to 0% in the non-surgical cohort (p=0.01). No neurological defects or infections in the surgical group were observed. GBM recurrence was reliably imaged using facile non-invasive optical bioluminescence (BLI) imaging with recurrence observed at week 4. For the first time, we have used a novel cranial defect repair method to extend and improve intracranial surgical resection methods for application in translational GBM rodent disease models. Combining BLI and the cranial window technique described herein facilitates non-invasive serial imaging follow-up. Within the current context we have developed a robust methodology for establishing a clinically relevant imageable GBM surgical resection model that appropriately mimics GBM recurrence post resection in patients. Copyright © 2014 Elsevier B.V. All rights reserved.

Photo-acoustic and video-acoustic methods for sensing distant sound sources

Science.gov (United States)

Slater, Dan; Kozacik, Stephen; Kelmelis, Eric

2017-05-01

Long range telescopic video imagery of distant terrestrial scenes, aircraft, rockets and other aerospace vehicles can be a powerful observational tool. But what about the associated acoustic activity? A new technology, Remote Acoustic Sensing (RAS), may provide a method to remotely listen to the acoustic activity near these distant objects. Local acoustic activity sometimes weakly modulates the ambient illumination in a way that can be remotely sensed. RAS is a new type of microphone that separates an acoustic transducer into two spatially separated components: 1) a naturally formed in situ acousto-optic modulator (AOM) located within the distant scene and 2) a remote sensing readout device that recovers the distant audio. These two elements are passively coupled over long distances at the speed of light by naturally occurring ambient light energy or other electromagnetic fields. Stereophonic, multichannel and acoustic beam forming are all possible using RAS techniques and when combined with high-definition video imagery it can help to provide a more cinema like immersive viewing experience. A practical implementation of a remote acousto-optic readout device can be a challenging engineering problem. The acoustic influence on the optical signal is generally weak and often with a strong bias term. The optical signal is further degraded by atmospheric seeing turbulence. In this paper, we consider two fundamentally different optical readout approaches: 1) a low pixel count photodiode based RAS photoreceiver and 2) audio extraction directly from a video stream. Most of our RAS experiments to date have used the first method for reasons of performance and simplicity. But there are potential advantages to extracting audio directly from a video stream. These advantages include the straight forward ability to work with multiple AOMs (useful for acoustic beam forming), simpler optical configurations, and a potential ability to use certain preexisting video recordings. However

Does acid-base equilibrium correlate with remnant liver volume during stepwise liver resection?

Science.gov (United States)

Golriz, Mohammad; Abbasi, Sepehr; Fathi, Parham; Majlesara, Ali; Brenner, Thorsten; Mehrabi, Arianeb

2017-10-01

Small for size and flow syndrome (SFSF) is one of the most challenging complications following extended hepatectomy (EH). After EH, hepatic artery flow decreases and portal vein flow increases per 100 g of remnant liver volume (RLV). This causes hypoxia followed by metabolic acidosis. A correlation between acidosis and posthepatectomy liver failure has been postulated but not studied systematically in a large animal model or clinical setting. In our study, we performed stepwise liver resections on nine pigs to defined SFSF limits as follows: step 1: segment II/III resection, step 2: segment IV resection, step 3: segment V/VIII resection (RLV: 75, 50, and 25%, respectively). Blood gas values were measured before and after each step using four catheters inserted into the carotid artery, internal jugular vein, hepatic artery, and portal vein. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. EH correlated with reduced BE in the hepatic artery. Pco 2 values increased after 75% resection in the jugular vein. In contrast, arterial Po 2 increased after every resection, whereas the venous Po 2 decreased slightly. There were differences in venous [Formula: see text], BE in the hepatic artery, and Pco 2 in the jugular vein after 75% liver resection. Because 75% resection is the limit for SFSF, these noninvasive blood evaluations may be used to predict SFSF. Further studies with long-term follow-up are required to validate this correlation. NEW & NOTEWORTHY This is the first study to evaluate acid-base parameters in major central and hepatic vessels during stepwise liver resection. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. Extended hepatectomy correlated with reduced BE in the hepatic artery. Because 75% resection is the limit for small for size and flow

Clinical predictors of resectability of pancreatic adenocarcinoma.

Science.gov (United States)

Almadi, Majid A; Alharbi, Othman; Azzam, Nahla; Altayeb, Mohannad; Javed, Moammed; Alsaif, Faisal; Hassanain, Mazen; Alsharabi, Abdulsalam; Al-Saleh, Khalid; Aljebreen, Abdulrahman M

2013-01-01

Identifying patient-related factors as well as symptoms and signs that can predict pancreatic cancer at a resectable stage, which could be used in an attempt to identify patients at an early stage of pancreatic cancer that would be appropriate for surgical resection and those at an unresectable stage be sparred unnecessary surgery. A retrospective chart review was conducted at a major tertiary care, university hospital in Riyadh, Saudi Arabia. The study population included individuals who underwent a computed tomography and a pancreatic mass was reported as well as the endoscopic reporting database of endoscopic procedures where the indication was a pancreatic mass, between April 1996 and April 2012. Any patient with a histologically confirmed diagnosis of adenocarcinoma of the pancreas was included in the analysis. We included patients' demographic information (age, gender), height, weight, body mass index, historical data (smoking, comorbidities), symptoms (abdominal pain and its duration, anorexia and its duration, weight loss and its amount, and over what duration, vomiting, abdominal distention, itching and its duration, change in bowel movements, change in urine color), jaundice and its duration. Other variables were also collected including laboratory values, location of the mass, the investigation undertaken, and the stage of the tumor. A total of 61 patients were included, the mean age was 61.2 ± 1.51 years, 25 (41%) were females. The tumors were located in the head (83.6%), body (10.9%), tail (1.8%), and in multiple locations (3.6%) of the pancreas. Half of the patients (50%) had Stage IV, 16.7% stages IIB and III, and only 8.3% were stages IB and IIA. On univariable analysis a lower hemoglobin level predicted resectability odds ratio 0.65 (95% confidence interval, 0.42-0.98), whereas on multivariable regression none of the variables included in the model could predict resectability of pancreatic cancer. A CA 19-9 cutoff level of 166 ng/mL had a

Two-stage multilevel en bloc spondylectomy with resection and replacement of the aorta.

Science.gov (United States)

Gösling, Thomas; Pichlmaier, Maximilian A; Länger, Florian; Krettek, Christian; Hüfner, Tobias

2013-05-01

We report a case of multilevel spondylectomy in which resection and replacement of the adjacent aorta were done. Although spondylectomy is nowadays an established technique, no report on a combined aortic resection and replacement has been reported so far. The case of a 43-year-old man with a primary chondrosarcoma of the thoracic spine is presented. The local pathology necessitated resection of the aorta. We did a two-stage procedure with resection and replacement of the aorta using a heart-lung machine followed by secondary tumor resection and spinal reconstruction. The procedure was successful. A tumor-free margin was achieved. The patient is free of disease 48 months after surgery. En bloc spondylectomy in combination with aortic resection is feasible and might expand the possibility of producing tumor-free margins in special situations.

Single incision laparoscopic colorectal resection: Our experience

Directory of Open Access Journals (Sweden)

Chinnusamy Palanivelu

2012-01-01

Full Text Available Background: A prospective case series of single incision multiport laparoscopic colorectal resections for malignancy using conventional laparoscopic trocars and instruments is described. Materials and Methods: Eleven patients (seven men and four women with colonic or rectal pathology underwent single incision multiport laparoscopic colectomy/rectal resection from July till December 2010. Four trocars were placed in a single transumblical incision. The bowel was mobilized laparoscopically and vessels controlled intracorporeally with either intra or extracorporeal anastomosis. Results: Three patients had carcinoma in the caecum, one in the hepatic flexure, two in the rectosigmoid, one in the descending colon, two in the rectum and two had ulcerative pancolitis (one with high grade dysplasia and another with carcinoma rectum. There was no conversion to standard multiport laparoscopy or open surgery. The median age was 52 years (range 24-78 years. The average operating time was 130 min (range 90-210 min. The average incision length was 3.2 cm (2.5-4.0 cm. There were no postoperative complications. The average length of stay was 4.5 days (range 3-8 days. Histopathology showed adequate proximal and distal resection margins with an average lymph node yield of 25 nodes (range 16-30 nodes. Conclusion: Single incision multiport laparoscopic colorectal surgery for malignancy is feasible without extra cost or specialized ports/instrumentation. It does not compromise the oncological radicality of resection. Short-term results are encouraging. Long-term results are awaited.

Expanded Endoscopic Endonasal Resection of Retrochiasmatic Craniopharyngioma.

Science.gov (United States)

Davanzo, Justin R; Goyal, Neerav; Zacharia, Brad E

2018-02-01

This video abstract demonstrates the use of the expanded endoscopic endonasal approach for the resection of a retrochiasmatic craniopharyngioma. These tumors are notoriously difficult to treat, and many approaches have been tried to facilitate safe and effective resection. The endoscopic endonasal approach has been increasingly utilized for selected sellar/suprasellar pathology. We present the case of a 39-year-old man who was found to have a cystic, partially calcified suprasellar mass consistent with a craniopharyngioma. To facilitate robust skull base repair, a vascularized nasoseptal flap was harvested. A wide sphenoidotomy was performed and the sella and tuberculum were exposed. After the dural opening and arachnoid dissection, the stalk was identified, merging seamlessly with the tumor capsule. The lesion was then internally debulked with the use of an ultrasonic aspirator. The capsule was then dissected off of the optic chiasm, thalamus, and hypothalamus. The cavity was inspected with an angled endoscope to ensure complete resection. A multilayered reconstruction was performed using autologous fascia lata, the previously harvested nasoseptal flap, and dural sealant. Postoperatively, the patient did have expected panhypopituitarism but remained neurologically intact and had improvement in his vision. In conclusion, this video demonstrates how an expanded endonasal approach can be used to safely resect a craniopharyngioma, even when in close proximity to delicate structures such as the optic chiasm. The link to the video can be found at: https://youtu.be/tahjHmrXhc4 .

Magnetoactive Acoustic Metamaterials.

Science.gov (United States)

Yu, Kunhao; Fang, Nicholas X; Huang, Guoliang; Wang, Qiming

2018-04-11

Acoustic metamaterials with negative constitutive parameters (modulus and/or mass density) have shown great potential in diverse applications ranging from sonic cloaking, abnormal refraction and superlensing, to noise canceling. In conventional acoustic metamaterials, the negative constitutive parameters are engineered via tailored structures with fixed geometries; therefore, the relationships between constitutive parameters and acoustic frequencies are typically fixed to form a 2D phase space once the structures are fabricated. Here, by means of a model system of magnetoactive lattice structures, stimuli-responsive acoustic metamaterials are demonstrated to be able to extend the 2D phase space to 3D through rapidly and repeatedly switching signs of constitutive parameters with remote magnetic fields. It is shown for the first time that effective modulus can be reversibly switched between positive and negative within controlled frequency regimes through lattice buckling modulated by theoretically predicted magnetic fields. The magnetically triggered negative-modulus and cavity-induced negative density are integrated to achieve flexible switching between single-negative and double-negative. This strategy opens promising avenues for remote, rapid, and reversible modulation of acoustic transportation, refraction, imaging, and focusing in subwavelength regimes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electron/electron acoustic instability

International Nuclear Information System (INIS)

Gary, S.P.

1987-01-01

The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

Contralateral Supracerebellar-Infratentorial Approach for Resection of Thalamic Cavernous Malformations.

Science.gov (United States)

Mascitelli, Justin; Burkhardt, Jan-Karl; Gandhi, Sirin; Lawton, Michael T

2018-02-26

Surgical resection of cavernous malformations (CM) in the posterior thalamus, pineal region, and midbrain tectum is technically challenging owing to the presence of adjacent eloquent cortex and critical neurovascular structures. Various supracerebellar infratentorial (SCIT) approaches have been used in the surgical armamentarium targeting lesions in this region, including the median, paramedian, and extreme lateral variants. Surgical view of a posterior thalamic CM from the traditional ipsilateral vantage point may be obscured by occipital lobe and tentorium. To describe a novel surgical approach via a contralateral SCIT (cSCIT) trajectory for resecting posterior thalamic CMs. From 1997 to 2017, 75 patients underwent the SCIT approach for cerebrovascular/oncologic pathology by the senior author. Of these, 30 patients underwent the SCIT approach for CM resection, and 3 patients underwent the cSCIT approach. Historical patient data, radiographic features, surgical technique, and postoperative neurological outcomes were evaluated in each patient. All 3 patients presented with symptomatic CMs within the right posterior thalamus with radiographic evidence of hemorrhage. All surgeries were performed in the sitting position. There were no intraoperative complications. Neuroimaging demonstrated complete CM resection in all cases. There were no new or worsening neurological deficits or evidence of rebleeding/recurrence noted postoperatively. This study establishes the surgical feasibility of a contralateral SCIT approach in resection of symptomatic thalamic CMs It demonstrates the application for this procedure in extending the surgical trajectory superiorly and laterally and maximizing safe resectability of these deep CMs with gravity-assisted brain retraction.

Acoustic imaging system

Science.gov (United States)

Smith, Richard W.

1979-01-01

An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

Perspective: Acoustic metamaterials in transition

KAUST Repository

Wu, Ying

2017-12-15

Acoustic metamaterials derive their novel characteristics from the interaction between acoustic waves with designed structures. Since its inception seventeen years ago, the field has been driven by fundamental geometric and physical principles that guide the structure design rules as well as provide the basis for wave functionalities. Recent examples include resonance-based acoustic metasurfaces that offer flexible control of acoustic wave propagation such as focusing and re-direction; parity-time (PT)-symmetric acoustics that utilizes the general concept of pairing loss and gain to achieve perfect absorption at a single frequency; and topological phononics that can provide one-way edge state propagation. However, such novel functionalities are not without constraints. Metasurface elements rely on resonances to enhance their coupling to the incident wave; hence, its functionality is limited to a narrow frequency band. Topological phononics is the result of the special lattice symmetry that must be fixed at the fabrication stage. Overcoming such constraints naturally forms the basis for further developments. We identify two emergent directions: Integration of acoustic metamaterial elements for achieving broadband characteristics as well as acoustic wave manipulation tasks more complex than the single demonstrative functionality; and active acoustic metamaterials that can adapt to environment as well as to go beyond the constraints on the passive acoustic metamaterials. Examples of a successful recent integration of multi-resonators in achieving broadband sound absorption can be found in optimal sound-absorbing structures, which utilize causality constraint as a design tool in realizing the target-set absorption spectrum with a minimal sample thickness. Active acoustic metamaterials have also demonstrated the capability to tune bandgaps as well as to alter property of resonances in real time through stiffening of the spring constants, in addition to the PT symmetric

Canada Basin Acoustic Propagation Experiment (CANAPE)

Science.gov (United States)

2015-09-30

acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

Transmission acoustic microscopy investigation

Science.gov (United States)

Maev, Roman; Kolosov, Oleg; Levin, Vadim; Lobkis, Oleg

The nature of acoustic contrast, i.e. the connection of the amplitude and phase of the output signal of the acoustic microscope with the local values of the acoustic parameters of the sample (density, elasticity, viscosity) is a central problem of acoustic microscopy. A considerable number of studies have been devoted to the formation of the output signal of the reflection scanning acoustic microscope. For the transmission acoustic microscope (TAM) this problem has remained almost unstudied. Experimental investigation of the confocal system of the TAM was carried out on an independently manufactured laboratory mockup of the TAM with the working frequency of the 420 MHz. Acoustic lenses with the radius of curvature of about 500 microns and aperture angle of 45 deg were polished out in the end faces of two cylindrical sound conductors made from Al2O3 single crystals with an axis parallel to the axis C of the crystal (the length of the sound conductor is 20 mm; diameter, 6 mm). At the end faces of the sound conductor, opposite to the lenses, CdS transducers with a diameter of 2 mm were disposed. The electric channel of the TAM provided a possibility for registering the amplitude of the microscope output signal in the case of the dynamic range of the 50 dB.

Shallow-Water Mud Acoustics

Science.gov (United States)

2015-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow-Water Mud Acoustics William L. Siegmann...models and methods that explain observed material and acoustic properties of different physical types of shallow-ocean mud sediments. Other goals...are to assess prior data relating to the acoustic properties of mud and to provide guidance in the development and interpretation of experiments. A

Tutorial on architectural acoustics

Science.gov (United States)

Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

2002-11-01

This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

Postoperative dysesthesia in lumbar three-column resection osteotomies.

Science.gov (United States)

Zhang, Zhengfeng; Wang, Honggang; Zheng, Wenjie

2016-08-01

Three-column lumbar spinal resection osteotomies including pedicle subtraction osteotomy (PSO), vertebral column resection (VCR), and total en bloc spondylectomy (TES) can potentially lead to dorsal root ganglion (DRG) injury which may cause postoperative dysesthesia (POD). The purpose of retrospective study was to describe the uncommon complication of POD in lumbar spinal resection osteotomies. Between January 2009 and December 2013, 64 patients were treated with lumbar three-column spinal resection osteotomies (PSO, n = 31; VCR, n = 29; TES, n = 4) in investigator group. POD was defined as dysesthetic pain or burning dysesthesia at a proper DRG innervated region, whether spontaneous or evoked. Non-steroidal antiinflammatory drugs, central none-opioid analgesic agent, neuropathic pain drugs and/or intervertebral foramen block were selectively used to treat POD. There were 5 cases of POD (5/64, 7.8 %), which consisted of 1 patient in PSO (1/31, 3.2 %), 3 patients in PVCR (3/29, 10.3 %), and 1 patient in TES (1/4, 25 %). After the treatment by drugs administration plus DRG block, all patients presented pain relief with duration from 8 to 38 days. A gradual pain moving to distal end of a proper DRG innervated region was found as the beginning of end. Although POD is a unique and rare complication and maybe misdiagnosed as nerve root injury in lumbar spinal resection osteotomies, combination drug therapy and DRG block have an effective result of pain relief. The appearance of a gradual pain moving to distal end of a proper DRG innervated region during recovering may be used as a sign for the good prognosis.

Surgical resection of synchronously metastatic adrenocortical cancer.

Science.gov (United States)

Dy, Benzon M; Strajina, Veljko; Cayo, Ashley K; Richards, Melanie L; Farley, David R; Grant, Clive S; Harmsen, William S; Evans, Doug B; Grubbs, Elizabeth G; Bible, Keith C; Young, William F; Perrier, Nancy D; Que, Florencia G; Nagorney, David M; Lee, Jeffrey E; Thompson, Geoffrey B

2015-01-01

Metastatic adrenocortical carcinoma (ACC) is rapidly fatal, with few options for treatment. Patients with metachronous recurrence may benefit from surgical resection. The survival benefit in patients with hematogenous metastasis at initial presentation is unknown. A review of all patients undergoing surgery (European Network for the Study of Adrenal Tumors) stage IV ACC between January 2000 and December 2012 from two referral centers was performed. Kaplan-Meier estimates were analyzed for disease-free and overall survival (OS). We identified 27 patients undergoing surgery for stage IV ACC. Metastases were present in the lung (19), liver (11), and brain (1). A complete resection (R0) was achieved in 11 patients. The median OS was improved in patients undergoing R0 versus R2 resection (860 vs. 390 days; p = 0.02). The 1- and 2-year OS was also improved in patients undergoing R0 versus R2 resection (69.9 %, 46.9 % vs. 53.0 %, 22.1 %; p = 0.02). Patients undergoing neoadjuvant therapy (eight patients) had a trend towards improved survival at 1, 2, and 5 years versus no neoadjuvant therapy (18 patients) [83.3 %, 62.5 %, 41.7 % vs. 56.8 %, 26.6 %, 8.9 %; p = 0.1]. Adjuvant therapy was associated with improved recurrence-free survival at 6 months and 1 year (67 %, 33 % vs. 40 %, 20 %; p = 0.04) but not improved OS (p = 0.63). Sex (p = 0.13), age (p = 0.95), and location of metastasis (lung, p = 0.51; liver, p = 0.67) did not correlate with OS after operative intervention. Symptoms of hormonal excess improved in 86 % of patients. Operative intervention, especially when an R0 resection can be achieved, following systemic therapy may improve outcomes, including OS, in select patients with stage IV ACC. Response to neoadjuvant chemotherapy may be of use in defining which patients may benefit from surgical intervention. Adjuvant therapy was associated with decreased recurrence but did not improve OS.

[Transanal laparoscopic radical resection with telescopic anastomosis for low rectal cancer].

Science.gov (United States)

Li, Shiyong; Chen, Gang; Du, Junfeng; Chen, Guang; Wei, Xiaojun; Cui, Wei; Yuan, Qiang; Sun, Liang; Bai, Xue; Zuo, Fuyi; Yu, Bo; Dong, Xing; Ji, Xiqing

2015-06-01

To assess the safety, feasibility and clinical outcome of laparoscopic radical resection for low rectal cancer with telescopic anastomosis or with colostomy by stapler through transanal resection without abdominal incisions. From January 2010 to September 2014, 37 patients underwent laparoscopic radical resection for low rectal cancer through transanal resection without abdominal incisions. The tumors were 4-7 cm above the anal verge. On preoperative assessment, 26 cases were T1N0M0 and 11 were T2N0M0. For all cases, successful surgery was performed. In telescopic anastomosis group, the mean operative time was (178±21) min, with average blood loss of (76±11) ml and (13±7) lymph nodes harvested. Return of bowel function was (3.0±1.2) d and the hospital stay was (12.0±4.2) d without postoperative complications. Patients were followed up for 3-45 months. Twelve months after surgery, 94.6%(35/37) patients achieved anal function Kirwan grade 1, indicating that their anal function returned to normal. Laparoscopic radical resection for low rectal cancer with telescopic anastomosis or colostomy by stapler through transanal resection without abdominal incisions is safe and feasible. Satisfactory clinical outcome can be achieved mini-invasively.

Indications and outcome of childhood preventable bowel resections in a developing country

Directory of Open Access Journals (Sweden)

Uchechukwu Obiora Ezomike

2014-01-01

Full Text Available Background: While many bowel resections in developed countries are due to congenital anomalies, indications for bowel resections in developing countries are mainly from preventable causes. The aim of the following study was to assess the indications for, morbidity and mortality following preventable bowel resection in our centre. Patients and Methods: Retrospective analysis of all cases of bowel resection deemed preventable in children from birth to 18 years from June 2005 to June 2012. Results: There were 22 preventable bowel resections with an age range of 7 days to 17 years (median 6 months and male:female ratio of 2.1:1. There were 2 neonates, 13 infants and 7 older children. The indications were irreducible/gangrenous intussusceptions (13, abdominal gunshot injury (2, gangrenous umbilical hernia (2, blunt abdominal trauma (1, midgut volvulus (1, necrotizing enterocolitis (1, strangulated inguinal hernia (1, post-operative band intestinal obstructions (1. There were 16 right hemicolectomies, 4 small bowel resections and 2 massive bowel resections. Average duration of symptoms before presentation was 3.9 days (range: 3 h-14 days. Average time to surgical intervention was 42 h for survivors and 53 h for non-survivors. Only 19% presented within 24 h of onset of symptoms and all survived. For those presenting after 24 h, the cause of delay was a visit to primary or secondary level hospitals (75% and ignorance (25%. Average duration of post-operative hospital stay is 14 days and 9 patients (41% developed 18 complications. Seven patients died (31.8% mortality which diagnoses were irreducible/gangrenous intussusceptions (5, necrotising enterocolitis (1, midgut volvulus (1. One patient died on the operating table while others had overwhelming sepsis. Conclusion: There is a high rate of morbidity and mortality in these cases of preventable bowel resection. Typhoid intestinal perforation did not feature as an indication for bowel resection in this

Transurethral resection for botryoid bladder rhabdomyosarcoma

Directory of Open Access Journals (Sweden)

Mitsuyuki Nakata

2018-01-01

Full Text Available The outcome of multimodal therapy for localized bladder rhabdomyosarcoma is quite good in terms of morbidity, and conservative surgery is generally recommended. However, in cases originating in the bladder neck, tumorectomy or partial cystectomy has adverse effects on bladder function. A 2-year-old girl underwent transurethral resection of a bladder tumor (TUR-BT, chemotherapy consisting of vincristine, actinomycin-D, and cyclophosphamide, and radiotherapy. She was in remission for 3 years when frequent urination became evident. Her bladder capacity and compliance were low; however, her urinary symptom was controlled using anticholinergic medication. Accordingly, TUR-BT could be an optional approach for bladder rhabdomyosarcoma. Keywords: Rhabdomyosarcoma, Transurethral resection, Conservative surgery

Multimodal treatment for resectable epithelial type malignant pleural mesothelioma

Directory of Open Access Journals (Sweden)

Fukuyama Yasuro

2004-05-01

Full Text Available Abstract Background Malignant pleural mesothelioma is a rare malignancy. The outcome remains poor despite complete surgical resection. Patients and methods Eleven patients with histologicaly proven epithelial type malignant pleural mesothelioma undergoing extrapleural pneumonectomy with systemic chemotherapy and/or radiotherapy before and after surgical resection were retrospectively reviewed. Results Ten out of 11 patients underwent complete surgical resection, of these 7 patients had stage I disease. Of these 7 patients, 5 are alive without any recurrence, a 2-year survival rate of 80% was observed in this group. There was no operative mortality or morbidity. Conclusion Extrapleural pneumonectomy with perioperative adjuvant treatment is safe and effective procedure for epithelial type malignant pleural mesothelioma.

Safety and feasibility of liver resection with continued antiplatelet therapy using aspirin.

Science.gov (United States)

Monden, Kazuteru; Sadamori, Hiroshi; Hioki, Masayoshi; Ohno, Satoshi; Saneto, Hiromi; Ueki, Toru; Yabushita, Kazuhisa; Ono, Kazumi; Sakaguchi, Kousaku; Takakura, Norihisa

2017-07-01

Aspirin is widely used for the secondary prevention of ischemic stroke and cardiovascular disease. Perioperative aspirin may decrease thrombotic morbidity, but may also increase hemorrhagic morbidity. In particular, liver resection carries risks of bleeding, leading to higher risks of hemorrhagic morbidity. Our institution has continued aspirin therapy perioperatively in patients undergoing liver resection. This study examined the safety and feasibility of liver resection while continuing aspirin. We retrospectively evaluated 378 patients who underwent liver resection between January 2010 and January 2016. Patients were grouped according to preoperative aspirin prescription: patients with aspirin therapy (aspirin users, n = 31); and patients without use of aspirin (aspirin non-users, n = 347). Aspirin users were significantly older (P aspirin users than among aspirin non-users, no significant difference was identified. No postoperative hemorrhage was seen among aspirin users. Liver resection can be safely performed while continuing aspirin therapy without increasing hemorrhagic morbidity. Our results suggest that interruption of aspirin therapy is unnecessary for patients undergoing liver resection. © 2017 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

Science.gov (United States)

Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

2017-03-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

Handbook of Engineering Acoustics

CERN Document Server

Möser, Michael

2013-01-01

This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

Ion-acoustic plasma turbulence

International Nuclear Information System (INIS)

Bychenkov, V.Y.; Silin, V.P.

1982-01-01

A theory is developed of the nonlinear state that is established in a plasma as a result of development of ion-acoustic instability. Account is taken simultaneously of the linear induced scattering of the waves by the ions and of the quasilinear relaxation of the electrons by the ion-acoustic pulsations. The distribution of the ion-acoustic turbulence in frequency and in angle is obtained. An Ohm's law is established and expressions are obtained for the electronic heat flux and for the relaxation time of the electron temperature in a turbulent plasma. Anomalously large absorption and scattering of the electromagnetic waves by the ion-acoustic pulsations is predicted

Surgical resection of highly suspicious pulmonary nodules without a tissue diagnosis

International Nuclear Information System (INIS)

Heo, Eun-Young; Lee, Kyung-Won; Jheon, Sanghoon; Lee, Jae-Ho; Lee, Choon-Taek; Yoon, Ho-II

2011-01-01

The safety and efficacy of surgical resection of lung nodule without tissue diagnosis is controversial. We evaluated direct surgical resection of highly suspicious pulmonary nodules and the clinical and radiological predictors of malignancy. Retrospective analyses were performed on 113 patients who underwent surgical resection without prior tissue diagnosis for highly suspicious pulmonary nodules. Clinical and radiological characteristics were compared between histologically proven benign and malignant nodules after resection. Total costs, length of hospitalization and waiting time to surgery were compared with those of patients who had tissue diagnosis prior to surgery. Among 280 patients with pulmonary nodules suspicious for lung cancer, 113 (40.4%) underwent operation without prior tissue diagnosis. Lung nodules were diagnosed as malignant in 96 (85%) of the 113 patients. Except for forced expiratory volume in 1 s, clinical characteristics were not significantly different according to the pathologic results. Forty-five (90%) of 50 patients with ground-glass opacity nodules had a malignancy. Mixed ground-glass opacity, bubble lucency, irregular margin and larger size correlated with malignancy in ground-glass opacity nodules (P<0.05). Fifty-one (81%) of 67 patients with solid nodules had a malignancy. Spiculation, pre-contrast attenuation and contrast enhancement significantly correlated with malignancy in solid nodules (P<0.05). Surgical resection without tissue diagnosis significantly decreased total costs, hospital stay and waiting time (P<0.05). Direct surgical resection of highly suspicious pulmonary nodules can be a valid procedure. However, careful patient selection and further investigations are required to justify direct surgical resection. (author)

A new definition for acoustic dose

International Nuclear Information System (INIS)

Duck, F A

2011-01-01

This paper discusses a recent proposal for definitions of acoustic dose and acoustic dose-rate. Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Its time-derivative, acoustic dose-rate, Q m , in W kg -1 is central to the prediction of both rate of temperature rise and radiation force. These quantities have spatial and temporal dependency, depending on the local field parameters (acoustic pressure, particle velocity, intensity) and local material properties (absorption coefficient, α a , and mass density, ρ 0 ). Spatial and/or temporal averaging can be applied where appropriate. For plane-wave monochromatic conditions in a homogeneous medium, Q m =2α a I/ρ 0 , (I is the time-averaged intensity), a simple expression which may also incorporate frequency dependencies of energy deposition. Acoustic dose and acoustic does-rate are exact analogues for Specific Absorption and Specific Absorption Rate (SAR), quantities central to radiofrequency (RF) and microwave dosimetry. Acoustic dosimetry in the presence of tissue/gas interfaces remains a considerable challenge.

Fundamentals of Shallow Water Acoustics

CERN Document Server

Katsnelson, Boris; Lynch, James

2012-01-01

Shallow water acoustics (SWA), the study of how low and medium frequency sound propagates and scatters on the continental shelves of the world's oceans, has both technical interest and a large number of practical applications. Technically, shallow water poses an interesting medium for the study of acoustic scattering, inverse theory, and propagation physics in a complicated oceanic waveguide. Practically, shallow water acoustics has interest for geophysical exploration, marine mammal studies, and naval applications. Additionally, one notes the very interdisciplinary nature of shallow water acoustics, including acoustical physics, physical oceanography, marine geology, and marine biology. In this specialized volume, the authors, all of whom have extensive at-sea experience in U.S. and Russian research efforts, have tried to summarize the main experimental, theoretical, and computational results in shallow water acoustics, with an emphasis on providing physical insight into the topics presented.

[Total hip endoprosthesis following resection arthroplasty].

Science.gov (United States)

Engelbrecht, E; Siegel, A; Kappus, M

1995-08-01

From 1976 to December 1994, a total of 347 patients underwent implantation of a hip prosthesis at the ENDO-Klinik for treatment of an unsatisfactory condition following resection arthroplasty. From 1976 to 1987, 143 patients were treated and in 1989 the results obtained in these patients were analysed: 99 of them were available for a follow-up examination in 1989, and 64 for a further examination in 1995. In 130 cases infection had been the reason for joint resection. At the time of the prosthesis operation (1-20 years later) intraoperative biopsy revealed that infection was still present in 41 cases (31.5%). Only 15 of these infections had been detected preoperatively by joint aspiration. This shows that the value of resection arthroplasty as a method of treating periprosthetic infection is limited and lends support to the one-stage exchange operation, which is the method we prefer in cases of infected hip prostheses. The operative technique and preparation for implantation of the prosthesis are described, as are septic and aseptic complications and the measures that can be taken to treat them. In spite of the patients' generally poor initial condition and with due consideration for the further revision operations, the medium-term results finally obtained are poor in only 9%.

The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

Science.gov (United States)

Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

2011-01-01

The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

Select Internet Resources on Acoustics

Directory of Open Access Journals (Sweden)

Angela R. Davis

2016-12-01

Full Text Available Merriam-Webster (2016 defines acoustics as, “a science that deals with the production, control, transmission, reception, and effects of sounds.” According to Rossing (2014, the study of acoustics began in ancient Greece with Pythagoras’ study of vibrating strings on musical instruments. Since those early beginnings, famous scientists including Rayleigh, Alexander Graham Bell, and Thomas Edison, have helped expand the field of acoustics to include architectural, physical, engineering, structural, underwater, physiological and psychological, musical acoustics, and speech. Acoustics is a highly interdisciplinary field and researchers may need resources from physics, medicine, and engineering to understand all aspects of their research.

Pancreatoduodenectomy with colon resection for cancer: A nationwide retrospective analysis

NARCIS (Netherlands)

Marsman, E. Madelief; de Rooij, Thijs; van Eijck, Casper H.; Boerma, Djamila; Bonsing, Bert A.; van Dam, Ronald M.; van Dieren, Susan; Erdmann, Joris I.; Gerhards, Michael F.; de Hingh, Ignace H.; Kazemier, Geert; Klaase, Joost; Molenaar, I. Quintus; Patijn, Gijs A.; Scheepers, Joris J.; Tanis, Pieter J.; Busch, Olivier R.; Besselink, Marc G.

2016-01-01

Microscopically radical (R0) resection of pancreatic, periampullary, or colon cancer may occasionally require a pancreatoduodenectomy with colon resection (PD-colon), but the benefits of this procedure have been disputed, and multicenter studies on morbidity and oncologic outcomes after PD-colon are

Incidental Transient Cortical Blindness after Lung Resection

Science.gov (United States)

Oncel, Murat; Sunam, Guven Sadi; Varoglu, Asuman Orhan; Karabagli, Hakan; Yildiran, Huseyin

2016-01-01

Transient vision loss after major surgical procedures is a rare clinical complication. The most common etiologies are cardiac, spinal, head, and neck surgeries. There has been no report on vision loss after lung resection. A 65-year-old man was admitted to our clinic with lung cancer. Resection was performed using right upper lobectomy with no complications. Cortical blindness developed 12 hours later in the postoperative period. Results from magnetic resonance imaging and diffusion-weighted investigations were normal. The neurologic examination was normal. The blood glucose level was 92 mg/dL and blood gas analysis showed a PO 2 of 82 mm Hg. After 24 hours, the patient began to see and could count fingers, and his vision was fully restored within 72 hours after this point. Autonomic dysfunction due to impaired microvascular structures in diabetes mellitus may induce posterior circulation dysfunction, even when the hemodynamic state is normal in the perioperative period. The physician must keep in mind that vision loss may occur after lung resection due to autonomic dysfunction, especially in older patients with diabetes mellitus. PMID:28824977

Handbook of Signal Processing in Acoustics

CERN Document Server

Havelock, David; Vorländer, Michael

2009-01-01

The Handbook of Signal Processing in Acoustics presents signal processing as it is practiced in the field of acoustics. The Handbook is organized by areas of acoustics, with recognized leaders coordinating the self-contained chapters of each section. It brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of signal processing in acoustics. Success in acoustic applications often requires juggling both the acoustic and the signal processing parameters of the problem. This handbook brings the key issues from both into perspective and is complementary to other reference material on the two subjects. It is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.

Mobile phone use and risk of brain neoplasms and other cancers: prospective study.

Science.gov (United States)

Benson, Victoria S; Pirie, Kirstin; Schüz, Joachim; Reeves, Gillian K; Beral, Valerie; Green, Jane

2013-06-01

Results from some retrospective studies suggest a possible increased risk of glioma and acoustic neuroma in users of mobile phones. The relation between mobile phone use and incidence of intracranial central nervous system (CNS) tumours and other cancers was examined in 791,710 middle-aged women in a UK prospective cohort, the Million Women Study. Cox regression models were used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs). Women reported mobile phone use in 1999 to 2005 and again in 2009. During 7 years' follow-up, 51,680 incident invasive cancers and 1,261 incident intracranial CNS tumours occurred. Risk among ever vs never users of mobile phones was not increased for all intracranial CNS tumours (RR = 1.01, 95% CI = 0.90-1.14, P = 0.82), for specified CNS tumour types nor for cancer at 18 other specified sites. For long-term users compared with never users, there was no appreciable association for glioma (10+ years: RR = 0.78, 95% CI = 0.55-1.10, P = 0.16) or meningioma (10+ years: RR = 1.10, 95% CI = 0.66-1.84, P = 0.71). For acoustic neuroma, there was an increase in risk with long term use vs never use (10+ years: RR = 2.46, 95% CI = 1.07-5.64, P = 0.03), the risk increasing with duration of use (trend among users, P = 0.03). In this large prospective study, mobile phone use was not associated with increased incidence of glioma, meningioma or non-CNS cancers.

Extent of liver resection for hilar cholangiocarcinoma (Klatskin tumor): how much is enough?

NARCIS (Netherlands)

van Gulik, Thomas M.; Ruys, Anthony T.; Busch, Oliver R. C.; Rauws, Erik A. J.; Gouma, Dirk J.

2011-01-01

Hilar resection in combination with extended liver resections has resulted in a higher rate of R0 resections and increased survival in patients with hilar cholangiocarcinoma (HCCA). This aggressive surgical approach is, however, associated with high rates of operative morbidity and mortality,

Radiotherapy Results of Carcinoma of Cervix with positive Resection Margin

International Nuclear Information System (INIS)

Huh, Seung Jae; Kim, Dae Yong; Ahn, Yong Chan; Kim, Won Dong; Wu, Hong Gyun; Ha, Sung Whan; Kim, Il Han; Park, Charn Il

1996-01-01

Purpose : Patients with cervical cancer who have positive resection margins after radical hysterectomy are at increased risk for local recurrence. The results of postoperative pelvic radiotherapy for cervix cancer with positive resection margins were analyzed to evaluated the role of radiotherapy. Materials and Methods : Between 1979 and 1992, 60 patients of cervix carcinoma were treated with postoperative radiotherapy after radical hysterectomy because of positive vaginal(48 patients) or parametrial resection margins(12 patients). Patients were treated with external beam radiation therapy(EBRT) alone (12 patients) or EBRT plus vaginal ovoid irradiation (VOI) (48 patients). The median follow-up period was 5 months. Results : The 5-year actuarial disease free and overall survival rates for all patients were 75.2%, 84.1%, respectively. The overall recurrence rate was 23%(14/60). In 48 patients with positive vaginal resection margins, the pelvic recurrence was 8%(4/48). Distant metastasis was 15%(7/48). Of the 43 patients with positive vaginal resection margins treated with EBRT and VOI, recurrence rate was 21%(9/43), while recurrence rate was 40%(2/5) in the EBRT only treated group. In 12 patients with positive parametrial margins, three patients (25%) had distant metastases. The most significant prognostic factor was lymph node metastasis. Complications resulting from radiotherapy occurred at a rate of 32%(19/60) and grade III complications occurred in three patients (5%). Conclusion : Postoperative radiotherapy can produce excellent pelvic control rates in patients with positive resection margins. In patients with positive vaginal margins, whole pelvic EBRT and BOI is recommended

LAPAROSCOPIC PANCREATIC RESECTION. FROM ENUCLEATION TO PANCREATODUODENECTOMY. 11-YEAR EXPERIENCE

Directory of Open Access Journals (Sweden)

Marcel Autran Cesar MACHADO

Full Text Available Context Our experience with laparoscopic pancreatic resection began in 2001. During initial experience, laparoscopy was reserved for selected cases. With increasing experience more complex laparoscopic procedures such as central pancreatectomy and pancreatoduodenectomies were performed. Objectives The aim of this paper is to review our personal experience with laparoscopic pancreatic resection over 11-year period. Methods All patients who underwent laparoscopic pancreatic resection from 2001 through 2012 were reviewed. Preoperative data included age, gender, and indication for surgery. Intraoperative variables included operative time, bleeding, blood transfusion. Diagnosis, tumor size, margin status were determined from final pathology reports. Results Since 2001, 96 patients underwent laparoscopic pancreatectomy. Median age was 55 years old. 60 patients were female and 36 male. Of these, 88 (91.6% were performed totally laparoscopic; 4 (4.2% needed hand-assistance, 1 robotic assistance. Three patients were converted. Four patients needed blood transfusion. Operative time varied according type of operation. Mortality was nil but morbidity was high, mainly due to pancreatic fistula (28.1%. Sixty-one patients underwent distal pancreatectomy, 18 underwent pancreatic enucleation, 7 pylorus-preserving pancreatoduodenectomies, 5 uncinate process resection, 3 central and 2 total pancreatectomies. Conclusions Laparoscopic resection of the pancreas is a reality. Pancreas sparing techniques, such as enucleation, resection of uncinate process and central pancreatectomy, should be used to avoid exocrine and/or endocrine insufficiency that could be detrimental to the patient's quality of life. Laparoscopic pancreatoduodenectomy is a safe operation but should be performed in specialized centers by highly skilled laparoscopic surgeons.

Relaxation time of acoustically disturbed plasma

International Nuclear Information System (INIS)

Mkrtchyan, K.S.; Abrahamyan, A.S.

2005-01-01

The conservation time of an acoustic structure in plasma after relieving of external acoustic influence is investigated. Dependences of the conservation time on discharge parameters are presented. It is asserted that the plasma becomes an anisotropic uniaxial medium with an acoustic superlattice under the acoustic influence

Lung adenocarcinoma with intraoperatively diagnosed pleural seeding: Is main tumor resection beneficial for prognosis?

Science.gov (United States)

Li, Chi; Kuo, Shuenn-Wen; Hsu, Hsao-Hsun; Lin, Mong-Wei; Chen, Jin-Shing

2018-03-01

To evaluate whether main tumor resection improves survival compared with pleural biopsy alone in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding. Forty-three patients with lung adenocarcinoma with pleural seeding diagnosed unexpectedly during surgery performed between January 2006 and December 2014 were included in this retrospective study using a prospectively collected lung cancer database. Each surgeon decided whether to perform main tumor resection or pleural biopsy alone. Main tumor and visible pleural nodule resection was performed in 30 patients (tumor resection group). The remaining 13 patients underwent pleural nodule biopsy alone (open-close group). The clinical T stage was higher in the open-close group than in the tumor resection group (P = .02). The tumor resection group had longer operative times compared with the open-close group (mean, 141.8 vs 80.3 minutes). There were no other statistically significant differences in perioperative parameters. The surgical method was the sole statistically significant prognostic factor. Patients in the tumor resection group had better progression-free survival (3-year survival: 44.5% vs 0%; P = .009) and overall survival (3-year survival: 82.9% vs 38.5%; P = .013) than did the open-close group. There was no significant survival difference between sublobar resection and lobectomy for the main tumor resection. Our study demonstrated improved progression-free and overall survival after main tumor and visible pleural nodule resection in patients with lung adenocarcinoma with intraoperatively diagnosed pleural seeding. Further randomized trials are needed to define the role of main tumor resection in these patients. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Comparison between open and arthroscopic procedure for lateral clavicle resection

NARCIS (Netherlands)

Duindam, N.; Kuiper, J.W.P.; Hoozemans, M.J.M.; Burger, B.J.

2014-01-01

Purpose: Arthroscopic lateral clavicle resection (LCR) is increasingly used, compared to an open approach, but literature does not clearly indicate which approach is preferable. The goal of this study was to compare function and pain between patients who underwent lateral clavicle resection using an

Airy acoustical-sheet spinner tweezers

Science.gov (United States)

Mitri, F. G.

2016-09-01

The Airy acoustical beam exhibits parabolic propagation and spatial acceleration, meaning that the propagation bending angle continuously increases before the beam trajectory reaches a critical angle where it decays after a propagation distance, without applying any external bending force. As such, it is of particular importance to investigate its properties from the standpoint of acoustical radiation force, spin torque, and particle dynamics theories, in the development of novel particle sorting techniques and acoustically mediated clearing systems. This work investigates these effects on a two-dimensional (2D) circular absorptive structure placed in the field of a nonparaxial Airy "acoustical-sheet" (i.e., finite beam in 2D), for potential applications in surface acoustic waves and acousto-fluidics. Based on the characteristics of the acoustic field, the beam is capable of manipulating the circular cylindrical fluid cross-section and guides it along a transverse or parabolic trajectory. This feature of Airy acoustical beams could lead to a unique characteristic in single-beam acoustical tweezers related to acoustical sieving, filtering, and removal of particles and cells from a section of a small channel. The analysis developed here is based on the description of the nonparaxial Airy beam using the angular spectrum decomposition of plane waves in close association with the partial-wave series expansion method in cylindrical coordinates. The numerical results demonstrate the ability of the nonparaxial Airy acoustical-sheet beam to pull, propel, or accelerate a particle along a parabolic trajectory, in addition to particle confinement in the transverse direction of wave propagation. Negative or positive radiation force and spin torque causing rotation in the clockwise or the anticlockwise direction can occur depending on the nondimensional parameter ka (where k is the wavenumber and a is the radius) and the location of the cylinder in the beam. Applications in

Sacral nerve stimulation can be an effective treatment for low anterior resection syndrome.

Science.gov (United States)

Eftaiha, S M; Balachandran, B; Marecik, S J; Mellgren, A; Nordenstam, J; Melich, G; Prasad, L M; Park, J J

2017-10-01

Sacral nerve stimulation has become a preferred method for the treatment of faecal incontinence in patients who fail conservative (non-operative) therapy. In previous small studies, sacral nerve stimulation has demonstrated improvement of faecal incontinence and quality of life in a majority of patients with low anterior resection syndrome. We evaluated the efficacy of sacral nerve stimulation in the treatment of low anterior resection syndrome using a recently developed and validated low anterior resection syndrome instrument to quantify symptoms. A retrospective review of consecutive patients undergoing sacral nerve stimulation for the treatment of low anterior resection syndrome was performed. Procedures took place in the Division of Colon and Rectal Surgery at two academic tertiary medical centres. Pre- and post-treatment Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores were assessed. Twelve patients (50% men) suffering from low anterior resection syndrome with a mean age of 67.8 (±10.8) years underwent sacral nerve test stimulation. Ten patients (83%) proceeded to permanent implantation. Median time from anterior resection to stimulator implant was 16 (range 5-108) months. At a median follow-up of 19.5 (range 4-42) months, there were significant improvements in Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores (P syndrome and may therefore be a viable treatment option. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

Objective review of mediastinal lymph node examination in a lung cancer resection cohort.

Science.gov (United States)

Osarogiagbon, Raymond U; Allen, Jeffrey W; Farooq, Aamer; Wu, James T

2012-02-01

Accurate staging of resected lung cancer requires mediastinal lymph node (MLN) examination. MLN dissection (MLND) and systematic sampling (SS) are acceptable procedures; random sampling (RS) and no sampling (NS) are not. Forty percent of US lung cancer resections have NS. We closely examined the pattern of MLN examination in a lung resection cohort. This is a retrospective review of all lung cancer resections in Memphis, TN, from 2004 to 2007. We compared operating surgeons' claims to the pathology report and an audit of the operation narrative by an independent surgeon. Forty-five percent of resections were reported by surgeons as MLND, 8% RS, and 48% NS. None met pathology criteria for MLND, 9% were SS, 50% were RS, and 42% were NS. The concordance rate between the operating surgeon and pathology report was 39%. The surgeon audit suggested 29% of resections had MLND, 26% RS, and 45% NS. Concordance between operating and auditing surgeons was 71%. Sublobar resection, T1 stage, and age were associated with NS. Most resections had suboptimal MLN examination. Concordance was poor between surgeon claims, objective review of pathology reports, and an independent surgeon audit. The higher concordance between operating and auditing surgeons may suggest incomplete pathology examination of MLN material. The terms used by operating surgeons to describe MLN retrieval were often inaccurate.

RPA coordinates DNA end resection and prevents formation of DNA hairpins.

Science.gov (United States)

Chen, Huan; Lisby, Michael; Symington, Lorraine S

2013-05-23

Replication protein A (RPA) is an essential eukaryotic single-stranded DNA binding protein with a central role in DNA metabolism. RPA directly participates in DNA double-strand break repair by stimulating 5'-3' end resection by the Sgs1/BLM helicase and Dna2 endonuclease in vitro. Here we investigated the role of RPA in end resection in vivo, using a heat-inducible degron system that allows rapid conditional depletion of RPA in Saccharomyces cerevisiae. We found that RPA depletion eliminated both the Sgs1-Dna2- and Exo1-dependent extensive resection pathways and synergized with mre11Δ to prevent end resection. The short single-stranded DNA tails formed in the absence of RPA were unstable due to 3' strand loss and the formation of fold-back hairpin structures that required resection initiation and Pol32-dependent DNA synthesis. Thus, RPA is required to generate ssDNA, and also to protect ssDNA from degradation and inappropriate annealing that could lead to genome rearrangements. Copyright © 2013 Elsevier Inc. All rights reserved.

Combining eastern and western practices for safe and effective endoscopic resection of large complex colorectal lesions.

Science.gov (United States)

Emmanuel, Andrew; Gulati, Shraddha; Burt, Margaret; Hayee, Bu'Hussain; Haji, Amyn

2018-05-01

Endoscopic resection of large colorectal polyps is well established. However, significant differences in technique exist between eastern and western interventional endoscopists. We report the results of endoscopic resection of large complex colorectal lesions from a specialist unit that combines eastern and western techniques for assessment and resection. Endoscopic resections of colorectal lesions of at least 2 cm were included. Lesions were assessed using magnification chromoendoscopy supplemented by colonoscopic ultrasound in selected cases. A lesion-specific approach to resection with endoscopic mucosal resection or endoscopic submucosal dissection (ESD) was used. Surveillance endoscopy was performed at 3 (SC1) and 12 (SC2) months. Four hundred and sixty-six large (≥20 mm) colorectal lesions (mean size 54.8 mm) were resected. Three hundread and fifty-six were resected using endoscopic mucosal resection and 110 by ESD or hybrid ESD. Fifty-one percent of lesions had been subjected to previous failed attempts at resection or heavy manipulation (≥6 biopsies). Nevertheless, endoscopic resection was deemed successful after an initial attempt in 98%. Recurrence occurred in 15% and could be treated with endoscopic resection in most. Only two patients required surgery for perforation. Nine patients had postprocedure bleeding; only two required endoscopic clips. Ninety-six percent of patients without invasive cancer were free from recurrence and had avoided surgery at last follow-up. Combining eastern and western practices for assessment and resection results in safe and effective organ-conserving treatment of complex colorectal lesions. Accurate assessment before and after resection using magnification chromoendoscopy and a lesion-specific approach to resection, incorporating ESD where appropriate, are important factors in achieving these results.

Indications for surgical resection of benign pancreatic tumors

International Nuclear Information System (INIS)

Isenmann, R.; Henne-Bruns, D.

2008-01-01

Benign pancreatic tumors should undergo surgical resection when they are symptomatic or - in the case of incidental discovery - bear malignant potential. This is the case for the majority of benign pancreatic tumors, especially for intraductal papillary mucinous neoplasms or mucinous cystic adenomas. In addition, resection is indicated for all tumors where preoperative diagnostic fails to provide an exact classification. Several different operative techniques are available. The treatment of choice depends on the localization of the tumor, its size and on whether there is evidence of malignant transformation. Partial duodenopancreatectomy is the oncological treatment of choice for tumors of the pancreatic head whereas for tumors of the pancreatic tail a left-sided pancreatectomy is appropriate. Middle pancreatectomy or duodenum-preserving resection of the pancreatic head is not a radical oncologic procedure. They should only be performed in cases of tumors without malignant potential. (orig.) [de

Transoral robotic assisted resection of the parapharyngeal space.

Science.gov (United States)

Mendelsohn, Abie H

2015-02-01

Preliminary case series have reported clinical feasibility and safety of a transoral minimally invasive technique to approach parapharyngeal space masses. With the assistance of the surgical robotic system, tumors within the parapharyngeal space can now be excised safely without neck incisions. A detailed technical description is included. After developing compressive symptoms from a parapharyngeal space lipomatous tumor, the patient was referred by his primary otolaryngologist because of poor open surgical access to the nasopharyngeal component of the tumor. Transoral robotic assisted resection of a 54- × 46-mm parapharyngeal space mass was performed, utilizing 97 minutes of robotic surgical time. Pictorial demonstration of the robotic resection is provided. Parapharyngeal space tumors have traditionally been approached via transcervical skin incisions, typically including blunt dissection from tactile feedback. The transoral robotic approach offers magnified 3D visualization of the parapharyngeal space that allows for complete and safe resection. © 2014 Wiley Periodicals, Inc.

Nódulo reumatóide intermetatarsal com sintomas de neuroma de Morton: diagnóstico diferencial Intermetatarsal rheumatoid node with Morton's neuroma signs: differential diagnosis

Directory of Open Access Journals (Sweden)

Antonio Carlos Flores dos Santos

2004-12-01

Full Text Available Paciente do sexo feminino, com 38 anos de idade, portadora de artrite reumatóide ( AR , com dor intermetarsal no 3º espaço, em ambos os pés, com parestesia dos 3º e 4º dedos. Operada para ressecção de massas hipoecóicas evidenciadas por ecografia. O exame anátomo-patológico definiu degeneração fibrinóide e mixóide ( nódulo reumatóide .A 38 years old female pacient, in treatment by rheumatoid arthritis (RA, with pain in the 3º intermetatarsal space and paresthesia in the 3º toe, bilateral. She was operated for resection of hipoechoicsmasses showed in echographic examination. The anatomopathologic diagnosis was fibrinoid and mixoid degeneration ( rheumatoid nodule.

Department of Cybernetic Acoustics

Science.gov (United States)

The development of the theory, instrumentation and applications of methods and systems for the measurement, analysis, processing and synthesis of acoustic signals within the audio frequency range, particularly of the speech signal and the vibro-acoustic signal emitted by technical and industrial equipments treated as noise and vibration sources was discussed. The research work, both theoretical and experimental, aims at applications in various branches of science, and medicine, such as: acoustical diagnostics and phoniatric rehabilitation of pathological and postoperative states of the speech organ; bilateral ""man-machine'' speech communication based on the analysis, recognition and synthesis of the speech signal; vibro-acoustical diagnostics and continuous monitoring of the state of machines, technical equipments and technological processes.

Endoscopic submucosal dissection for locally recurrent colorectal lesions after previous endoscopic mucosal resection.

Science.gov (United States)

Zhou, Pinghong; Yao, Liqing; Qin, Xinyu; Xu, Meidong; Zhong, Yunshi; Chen, Weifeng

2009-02-01

The objective of this study was to determine the efficacy and safety of endoscopic submucosal dissection for locally recurrent colorectal cancer after previous endoscopic mucosal resection. A total of 16 patients with locally recurrent colorectal lesions were enrolled. A needle knife, an insulated-tip knife and a hook knife were used to resect the lesion along the submucosa. The rate of the curative resection, procedure time, and incidence of complications were evaluated. Of 16 lesions, 15 were completely resected with endoscopic submucosal dissection, yielding an en bloc resection rate of 93.8 percent. Histologic examination confirmed that lateral and basal margins were cancer-free in 14 patients (87.5 percent). The average procedure time was 87.2 +/- 60.7 minutes. None of the patients had immediate or delayed bleeding during or after endoscopic submucosal dissection. Perforation in one patient (6.3 percent) was the only complication and was managed conservatively. The mean follow-up period was 15.5 +/- 6.8 months; none of the patients experienced lesion residue or recurrence. Endoscopic submucosal dissection appears to be effective for locally recurrent colorectal cancer after previous endoscopic mucosal resection, making it possible to resect whole lesions and provide precise histologic information.

What Is the Risk of Anastomotic Leak After Repeat Intestinal Resection in Patients With Crohn's Disease?

Science.gov (United States)

Johnston, W Forrest; Stafford, Caitlin; Francone, Todd D; Read, Thomas E; Marcello, Peter W; Roberts, Patricia L; Ricciardi, Rocco

2017-12-01

Approximately half of Crohn's patients require intestinal resection, and many need repeat resections. The purpose of this study was to evaluate the increased risk of clinical anastomotic leak in patients with a history of previous intestinal resection undergoing repeat resection with anastomosis for Crohn's disease. This was a retrospective analysis of prospectively collected departmental data with 100% capture. The study was conducted at the department of colorectal surgery in a tertiary care teaching hospital between July 2007 and March 2016. A cohort of consecutive patients with Crohn's disease who were treated with intestinal resection and anastomosis, excluding patients with proximal fecal diversion, were included. The cohort was divided into 2 groups, those with no previous resection compared with those with previous resection. Clinical anastomotic leak within 30 days of surgery was measured. Of the 206 patients who met criteria, 83 patients had previous intestinal resection (40%). The 2 groups were similar in terms of patient factors, immune-suppressing medication use, and procedural factors. Overall, 20 clinical anastomotic leaks were identified (10% leak rate). There were 6 leaks (5%) detected in patients with no previous intestinal resection and 14 leaks (17%) detected in patients with a history of previous intestinal resection (p leak in patients with Crohn's disease with previous resection compared with no previous resection was 3.5 (95% CI, 1.3-9.4). Patients with 1 previous resection (n = 53) had a leak rate of 13%, whereas patients with ≥2 previous resections (n = 30) had a leak rate of 23%. The number of previous resections correlated with increasing risk for clinical anastomotic leak (correlation coefficient = 0.998). This was a retrospective study with limited data to perform a multivariate analysis. Repeat intestinal resection in patients with Crohn's disease is associated with an increased rate of anastomotic leakage when compared with initial

Rare post-operative complications of large mediastinal tumor resection

Directory of Open Access Journals (Sweden)

Mohsen Mirmohammadsadeghi

2015-03-01

Full Text Available Background: There are some reports in the literature, which suggest that cardiac tamponade drainage may transiently affect systolic function and also cause acute respiratory distress syndrome (ARDS. We did not find any reports of acute ventricular failure and ARDS secondary to mediastinal tumor resection without tamponade. Case Report: Here we report a 48-year-old woman presenting with massive pericardial effusion without tamponade in whom tumor was resected through median sternotomy using cardiopulmonary bypass. ARDS and acute heart failure were two rare complications that happened at the end of the operation secondary to a sudden decompression of the heart from tumor pressure. Conclusion: ARDS and acute heart failure are two rare complications, which can happen after large mediastinal tumor resection.

A clinical pathway to accelerate recovery after colonic resection

DEFF Research Database (Denmark)

Basse, L; Hjort Jakobsen, D; Billesbølle, P

2000-01-01

-induced organ dysfunction, paralytic ileus, pain, and fatigue. It has been hypothesized that an accelerated multimodal rehabilitation program with optimal pain relief, stress reduction with regional anesthesia, early enteral nutrition, and early mobilization may enhance recovery and reduce the complication rate......OBJECTIVE: To investigate the feasibility of a 48-hour postoperative stay program after colonic resection. SUMMARY BACKGROUND DATA: Postoperative hospital stay after colonic resection is usually 6 to 12 days, with a complication rate of 10% to 20%. Limiting factors for early recovery include stress....... METHODS: Sixty consecutive patients undergoing elective colonic resection were prospectively studied using a well-defined postoperative care program including continuous thoracic epidural analgesia and enforced early mobilization and enteral nutrition, and a planned 48-hour postoperative hospital stay...

Spontaneous regeneration after juvenile ossifying fibroma resection: a case report.

Science.gov (United States)

Espinosa, Sebastián A; Villanueva, Julio; Hampel, Hans; Reyes, Daniel

2006-11-01

A case of unusual bone regeneration after resection of a juvenile ossifying fibroma (JOF) is presented. Secondary mandibular reconstruction with autogenous grafts was delayed due to the rapid bone formation. To the best of our knowledge there are no reports of this unusual response following JOF resection.

High mortality rates after nonelective colon cancer resection : results of a national audit

NARCIS (Netherlands)

Bakker, I. S.; Snijders, H. S.; Grossmann, I.; Karsten, T. M.; Havenga, K.; Wiggers, T.

AimColon cancer resection in a nonelective setting is associated with high rates of morbidity and mortality. The aim of this retrospective study is to identify risk factors for overall mortality after colon cancer resection with a special focus on nonelective resection. MethodData were obtained from

Heterotopic ossification resection after open periarticular combat-related elbow fractures.

Science.gov (United States)

Wilson, Kevin W; Dickens, Jonathan F; Heckert, Reed; Tintle, Scott M; Keeling, John J; Andersen, Romney C; Potter, Benjamin K

2013-01-01

A retrospective review was performed to evaluate the outcomes and complications following heterotopic ossification (HO) resection and lysis of adhesion procedures for posttraumatic contracture, after combat-related open elbow fractures. From 2004 to 2011, HO resection was performed on 30 blast-injured elbows at a mean 10 months after injury. Injuries included 8 (27%) Gustilo-Anderson type II fractures, 8 (27%) type III-A, 10 (33%) III-B, and 4 (13%) III-C. Mean preoperative flexion-extension range of motion (ROM) was 36.4°, compared with mean postoperative ROM of 83.6°. Mean gain of motion was 47.2°. Traumatic brain injury, need for flap, and nerve injury did not appear to have a significant effect on preoperative or postoperative ROM. Complications included one fracture, six recurrent contractures, and one nerve injury. The results and complications of HO resection for elbow contracture following high-energy, open injuries from blast trauma are generally comparable to those reported for HO resection following lower energy, closed injuries.

Topical MMP beacon enabled fluorescence-guided resection of oral carcinoma

Science.gov (United States)

Burgess, Laura; Chen, Juan; Wolter, Nikolaus E.; Wilson, Brian; Zheng, Gang

2016-01-01

Each year almost 300,000 individuals worldwide are diagnosed with oral cancer, more than 90% of these being oral carcinoma [N. Engl. J. Med. 328, 184 19938417385]. Surgical resection is the standard of care, but accurate delineation of the tumor boundaries is challenging, resulting in either under-resection with risk of local recurrence or over-resection with increased functional loss and negative impact on quality of life. This study evaluates, in two pre-clinical in vivo tumor models, the potential of fluorescence-guided resection using molecular beacons activated by metalloproteinases, which are frequently upregulated in human oral cancer. In both models there was rapid (beacon activation upon local application, allowing clear fluoresecence imaging in vivo and confirmed by ex vivo fluorescence microscopy and HPLC, with minimal activation in normal oral tissues. Although the tissue penetration was limited using topical application, these findings support further development of this approach towards translation to first-in-human trials. PMID:27231609

Hysteroscopic resection on virtual reality simulator: What do we measure?

Science.gov (United States)

Panel, P; Neveu, M-E; Villain, C; Debras, F; Fernandez, H; Debras, E

2018-03-03

The objective was to compare results of two groups of population (novices and experts) on a virtual reality simulator of hysteroscopy resection for different metrics and for a multimetric score to assess its construct validity. Nineteen gynecologist who had at least 5 years of experience with hysteroscopy and self-evaluated their expertise at 4/5 or 5/5 were included as expert population. Twenty first-year gynecology residents in Paris were included as novice population. A standardized set of 4 hysteroscopy resection cases (polypectomy, myomectomy, roller ball endometrial ablation and septum resection) was performed on a virtual reality simulator (HystSim™) by the group of novices and experts. Results obtained on the simulator for overall score and for the parameters were compared by applying the Mann-Whitney test. Overall score of novices and experts were significantly different for three resection cases (polypectomy Pvirtual reality simulator. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Acoustic Liners for Turbine Engines

Science.gov (United States)

Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

2016-01-01

An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

EXPERIENCE OF USING ALLOGENIC BIOIMPLANTS IN LARYNGEAL RESECTION

Directory of Open Access Journals (Sweden)

E. N. Novozhilova

2017-01-01

Full Text Available Introduction. Currently, a great importance is being attached to improvement of the surgical component of combination treatment of locally advanced laryngeal cancer. New technological capabilities (transoral microsurgery of the larynx and robotic surgery offer great opportunities for early cancer stages. However, in some cases capabilities of endoscopic laser intervention are limited. Therefore, open laryngeal resection is still relevant as it serves as the only type of radical organ preservation treatment for stages Т2–Т3. But major laryngeal resection is associated with a problem of tissue defect closure.The article describes data on the use of biocompatible materials, their advantages and disadvantages. The study objective is to present experience of using a Russian allogenic bioimplant for plastic reconstruction of the opening of the larynx after laryngeal resection.Materials and methods. The authors present their experience of using a Russian bioimplant produced in collaboration with the Samara Tissue Bank of the Research Institute of Experimental Medicine and Biotechnology of the Samara State Medical University. The material was tested in anterolateral laryngeal resection with simultaneous reconstruction in 5 patients with stages Т2–Т3 laryngeal cancer and in a patient with chondrosarcoma.Conclusion. The Russian biocompatible implant served as a reliable, simple, cheap, and effective variant of plastic material for reconstruction of the larynx.

Acoustic communication for Maya Autonomous Underwater Vehicle - performance evaluation of acoustic modem

Digital Repository Service at National Institute of Oceanography (India)

Afzulpurkar, S.; Maurya, P.; Navelkar, G.S.; Desa, E.S.; Mascarenhas, A.A.M.Q.; Dabholkar, N.A.; Madhan, R.; Prabhudesai, S.P.

traffic. This necessitates monitoring the AUV status and data quality through an acoustic link which needs to perform reliably under such conditions, at long range. To address these situations partially, acoustic communication capability is planned...

Acoustical and optical radiation pressures and the development of single beam acoustical tweezers

OpenAIRE

Thomas , Jean-Louis; Marchiano , Régis; Baresch , Diego

2017-01-01

International audience; Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and positioned micron size particles, biological samples or even atoms with subnanometer accuracy in three dimens...

Brain imaging before primary lung cancer resection: a controversial topic.

Science.gov (United States)

Hudson, Zoe; Internullo, Eveline; Edey, Anthony; Laurence, Isabel; Bianchi, Davide; Addeo, Alfredo

2017-01-01

International and national recommendations for brain imaging in patients planned to undergo potentially curative resection of non-small-cell lung cancer (NSCLC) are variably implemented throughout the United Kingdom [Hudson BJ, Crawford MB, and Curtin J et al (2015) Brain imaging in lung cancer patients without symptoms of brain metastases: a national survey of current practice in England Clin Radiol https://doi.org/10.1016/j.crad.2015.02.007]. However, the recommendations are not based on high-quality evidence and do not take into account cost implications and local resources. Our aim was to determine local practice based on historic outcomes in this patient cohort. This retrospective study took place in a regional thoracic surgical centre in the United Kingdom. Pathology records for all patients who had undergone lung resection with curative intent during the time period January 2012-December 2014 were analysed in October 2015. Electronic pathology and radiology reports were accessed for each patient and data collected about their histological findings, TNM stage, resection margins, and the presence of brain metastases on either pre-operative or post-operative imaging. From the dates given on imaging, we calculated the number of days post-resection that the brain metastases were detected. 585 patients were identified who had undergone resection of their lung cancer. Of these, 471 had accessible electronic radiology records to assess for the radiological evidence of brain metastases. When their electronic records were evaluated, 25/471 (5.3%) patients had radiological evidence of brain metastasis. Of these, five patients had been diagnosed with a brain metastasis at initial presentation and had undergone primary resection of the brain metastasis followed by resection of the lung primary. One patient had been diagnosed with both a primary lung and a primary bowel adenocarcinoma; on review of the case, it was felt that the brain metastasis was more likely to have

Early history of the different forms of neurofibromatosis from ancient Egypt to the British Empire and beyond: First descriptions, medical curiosities, misconceptions, landmarks, and the persons behind the syndromes.

Science.gov (United States)

Ruggieri, Martino; Praticò, Andrea D; Caltabiano, Rosario; Polizzi, Agata

2018-03-01

The earliest examples of neurofibromatosis (in this case type 1, NF1) can be traced in the Ebers Papyrus (Ancient Egypt, 1.500 B.C.), in a Hellenistic statuette (Smyrna, 323 B.C.), in the coinage of the Parthians kings (247 B.C.) and in some 13th century monks' drawings. These earlier examples are somewhat less well defined as compared to the most recent better defined reports credited as having NF1 including an Inca child mummy (1480-1650 AD), Ulisse Aldrovandi's homuncio ("Monstrorum Historia", 1592 A.D.) with mosaic NF1 or the illustrations seen in the 18th century "Buffon's Histoire Naturelle" and "Cruveilhier's Anatomie Pathologique du Corps Human". The first English language report on NF1 was made by Akenside in 1768 and the first systematic review by Robert William Smith in 1849, while Virchow's pupil, Friedrich Daniel von Recklinghausen, in 1882, was the first to understand the origin of skin tumors and to name them neurofibromas. The touching story of Joseph C. Merrick (the "Elephant man," (who had Proteus syndrome and not NF1), in 1884, played an important role in the later misconception of NF1, as did the novel by Vicotr Hugo on the hunchback Quasimodo. The studies by van der Hoeve (1921), Yakovlev and Guthrie (1931), and Van Bogaert (1935), categorized "von Recklinghausen's" neurofibromatosis among the phakomatoses and the neurocutaneous syndromes. The first known mention of an acoustic neuroma (at autopsy) is attributed to Eduard Sandifort (1777 AD) while John H. Wishart made the earliest autoptic description of neurofibromatosis type 2 (NF2), in 1822, in a 21-year-old man with bilateral acoustic neuromas, who manifested signs since his infancy (Wishart subtype NF2). Smith likely described the first case of schwannomatosis in 1849. Older, Virchow, von Recklinghausen, and Verocay first classified "neuromas" and Masson and Penfield first used the word "schwannoma" taking it from Theodore Schwann's works. In 1903 Henneberg and Koch described NF2 in detail

Development of acoustic particle detector

International Nuclear Information System (INIS)

Matsuyama, Tadayoshi; Hinode, Fujio; Konno, Osamu

1999-01-01

To detect acoustic sign from electron, determination of acoustic radiation from high energy electron and detector were studied. When charge particles pass through medium, energy loss generates local expansion and contraction of medium and pressure compression wave. We need caustic element with 10 -5 Pa the minimum acoustic receive sensitivity and from 10 to 100 kHz frequency sensitivity characteristic. Elements were made by Low-Q materials, piezoelectric materials (PZT). Various sharp of elements were constructed and measured. 50 mm spherical element showed 38 m V/Pa, the best sensitivity. Our developed acoustic element could detect acoustic radiation generated by electron beam from accelerator. The wave sharp detected proved the same as bipolar wave, which was given theoretically. The pressure generated by beam was proportional to the energy loss E. 200 MeV electron beam existed about 95% particles on the incident axis. So that acoustic detector on the axis proved to detect sound wave generated on the beam axis. (S.Y.)

Focusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures

KAUST Repository

Xiao, Bingmu

2013-05-01

In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

Oncological superiority of hilar en bloc resection for the treatment of hilar cholangiocarcinoma.

Science.gov (United States)

Neuhaus, Peter; Thelen, Armin; Jonas, Sven; Puhl, Gero; Denecke, Timm; Veltzke-Schlieker, Wilfried; Seehofer, Daniel