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Featured researches published by Samuel Eldar.


World Journal of Surgery | 1997

Laparoscopic Cholecystectomy for Acute Cholecystitis: Prospective Trial

Samuel Eldar; Edmond Sabo; Nash E; Jack Abrahamson; Ibrahim Matter

Abstract. This prospective study determines the indications for and the optimal timing of laparoscopic cholecystectomy (LC) following the onset of acute cholecystitis. It also evaluates preoperative and operative factors associated with conversion from laparoscopic cholecystectomy to open cholecystectomy in the presence of acute cholecystitis. Having been established as the procedure of choice for elective cholelithiasis, LC is now also used for management of acute cholecystitis. Under these circumstances the procedure may be difficult and challenging. Certain favorable and unfavorable conditions may be present that influence the conversion and complication rates. Information about these conditions may be helpful for elucidating the optimal circumstances for LC or when the procedure is best avoided. We performed LC on an emergency basis as soon as the diagnosis was made on all patients presenting with acute cholecystitis from January 1994 to December 1995. All preoperative, operative, and postoperative data were collected on standardized forms. Of the 137 patients registered, 130 were eligible for the audit. Seven patients found by laparoscopic intraoperative cholangiography to have choledocholithiasis were converted for common bile duct exploration and were excluded from the study. Altogether 93 patients (72%) underwent successful LC and 37 (28%) needed conversion to open cholecystectomy. The conversion rate of acute gangrenous cholecystitis (49%) was significantly higher than that for uncomplicated acute cholecystitis (4.5%) (p< 0.00001) and for hydrops (28.5%) and empyema of the gallbladder (28.5%) (p= 0.004). The difference in conversion between the group with acute necrotizing (gangrenous) cholecystitis and the two groups with hydrops and empyema of the gallbladder was not statistically significant (p= 0.07). The complication rates of acute cholecystitis, hydrops, empyema of the gallbladder, and gangrenous cholecystitis were 9.0%, 9.5%, 14.0%, and 20.0%, respectively (p= NS). Patients with an operative delay of 96 hours or less from the onset of acute cholecystitis had a conversion rate of 23%, whereas a delay of more than 96 hours was associated with a conversion rate of 47% (p= 0.022). The complication rate was 8.5% in the laparoscopic group and 27% in the converted group (p= 0.013). Patients over 65 years of age, with a history of biliary disease, a nonpalpable gallbladder, WBC count over 13,000/cc, and acute gangrenous cholecystitis were independently associated with a high LC conversion rate; male patients, finding large bile stones, serum bilirubin over 0.8 mg/dl, and WBC count over 13,000/cc were independently associated with a high complication rate following laparoscopic surgery with or without conversion. Generally, LC can be performed safely for acute cholecystitis, with acceptably low conversion and complication rates. Different forms of cholecystitis carry various conversion and complication rates in selected cases. LC for acute cholecystitis should be performed within 96 hours of the onset of disease. Predictors of conversion and complications may be helpful when planning the laparoscopic approach to acute cholecystitis.


American Journal of Surgery | 1997

Delay of surgery in acute appendicitis

Samuel Eldar; Nash E; Edmond Sabo; Ibrahim Matter; Kunin J; Jorge G. Mogilner; Jack Abrahamson

BACKGROUND AND OBJECTIVES It is generally assumed that delayed diagnosis of acute appendicitis results in higher morbidity but this assumption is not strongly supported in the literature. We attempt to define the effect of patient and physician delay on the outcome of patients with acute appendicitis. PATIENTS AND METHODS We studied 486 patients admitted between 1980 and 1992. Patient delay in presenting to a physician and surgeon delay from hospital admission to operation were studied in relation to stage of disease at operation as well as to postoperative complications. RESULTS Postoperative complications occurred in 10% of cases with simple acute appendicitis versus about 20% of cases with gangrenous or perforated appendicitis (P <0.001). The mean patient delay from onset of symptoms to presentation to a physician was 1.7 days in simple acute appendicitis versus 2.3 days in gangrenous or perforated appendicitis (P <0.001). Mean surgeon delay was 13.6 hours in simple acute appendicitis versus 14.5 hours in advanced appendicitis (P = NS). CONCLUSION Delay in patient presentation adversely affects the stage of disease in acute appendicitis and leads to increased incidence of infectious complications and to prolonged hospital stay. Conversely, physician delay does not affect the stage of disease. A surgeons decision to observe patients in hospital in order to clarify the diagnosis is justified, as it does not adversely affect outcome.


Surgical Endoscopy and Other Interventional Techniques | 2000

Laparoscopic cholecystectomy for acute cholecystitis: can the need for conversion and the probability of complications be predicted? A prospective study.

A. Brodsky; Ibrahim Matter; Edmund Sabo; Ayala Cohen; Jack Abrahamson; Samuel Eldar

AbstractBackground: Laparoscopic cholecystectomy (LC) in acute cholecystitis is associated with a relatively high rate of conversion to an open procedure as well as a high rate of complications. The aim of this study was to analyze prospectively whether the need to convert and the probability of complications is predictable. Methods: A total of 215 patients undergoing LC for acute cholecystitis were studied prospectively by analyzing the data accumulated in the process of investigation and treatment. Factors associated with conversion and complications were assessed to determine their predictive power. Results: Conversion was indicated in 44 patients (20.5%), and complications occurred in 36 patients (17%). Male gender and age >60 years were associated with conversion, but these factors had no sensitivity and no positive predictive value. The same factors, together with a disease duration of >96 h, a nonpalpable gallbladder, a white blood count (WBC) of >18,000/cc3, and advanced cholecystitis, predicted conversion with a sensitivity of 74%, a specificity of 86%, a positive predictive value of ∼40%, and a negative predictive value of 96%. However, these data became available only when LC was underway. Male gender and a temperature of >38°C were associated with complications, but these factors had no sensitivity and no positive predictive value. Progression along the stages of admission and therapy did not add predictive factors or improve the predictive characteristics. Male gender, abdominal scar, bilirubin >1 mg%, advanced cholecystitis, and conversion to open cholecystectomy were associated with infectious complications. Their sensitivity and positive predictive value remained 0 despite progression along the stages of admission and therapy. Conclusion: Although certain preoperative factors are associated with the need to convert a LC for acute cholecystitis, they have limited predictive power. Factors with higher predictive power are obtained only during LC. The need to convert can only be established during an attempt at LC. Preoperative and operative factors associated with total and infectious complications have no predictive power.


American Journal of Surgery | 1984

Cancer of the breast after prophylactic subcutaneous mastectomy

Samuel Eldar; Michael M. Meguid; J. David Beatty

We have reported a case of carcinoma of the breast in a patient that occurred after bilateral prophylactic subcutaneous mastectomy. We recommend that the patient and physician be aware of the limitations of prophylactic mastectomy in terms of cancer prevention and that patients who undergo prophylactic mastectomy continue to be carefully followed.


American Journal of Surgery | 1999

The impact of patient delay and physician delay on the outcome of laparoscopic cholecystectomy for acute cholecystitis

Samuel Eldar; Arie Eitan; Amitai Bickel; Edmond Sabo; Ayala Cohen; Jack Abrahamson; Ibrahim Matter

BACKGROUND Laparoscopic cholecystectomy is now used in the management of acute cholecystitis. Under these circumstances unfavorable conditions may result in conversion and complications. Information about these conditions may help in planning the laparoscopic approach or in proceeding directly to open cholecystectomy. This study was initiated to evaluate perioperative factors associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis. Special attention was paid to the duration of complaints until surgery, to the delay on the part of the patient, and to the delay on the part of the physician. METHODS Between January 1994 and December 1997, we attempted to perform laparoscopic cholecystectomy on 348 patients with acute cholecystitis. All perioperative data were collected on standardized forms. RESULTS There were 182 cases (52%) of acute uncomplicated cholecystitis, 90 (26%) of gangrenous cholecystitis, 33 of hydrops (9.5%), and 43 of empyema of the gallbladder (12.5%). Seventy six patients (22%) needed conversion to open cholecystectomy and complications occurred in 57 cases. Advanced cholecystitis was associated with significant patient delay (P = 0.01), and it had a significantly higher conversion rate (39%) compared with early cholecystitis (14.5%); (P <0.00001). Conversion rates were also associated with male gender (P = 0.0017), a history of biliary disease (P = 0.0085), and a patient delay of >48 hours (P = 0.028). The total and infectious complication rates were associated with an age older than 60 years (P = 0.023 and 0.007, respectively) and male gender (P = 0.026 and 0.014, respectively). CONCLUSIONS In acute cholecystitis, patient delay is associated with a high conversion rate. Early timing of laparoscopic cholecystectomy tends to reduce the conversion rate, as well as the total and the infectious complication rates. Male gender, a history of biliary disease, and advanced cholecystitis are associated with conversion. Male and older patients are associated with a high total and infectious complication rates.


The American Journal of Gastroenterology | 1999

Cancer antigen 125: a sensitive marker of ascites in patients with liver cirrhosis.

Eli Zuckerman; Amos Lanir; Edmund Sabo; Tsila Rosenvald-Zuckerman; Ibrahim Matter; Daniel Yeshurun; Samuel Eldar

ObjectiveCancer antigen 125 (CA 125) is a high molecular mass glycoprotein, usually used for monitoring the course of epithelial ovarian cancer. Recently it has been shown that liver cirrhosis is associated with increased levels of CA 125, particularly in the presence of ascites. The aim of this study was to evaluate CA 125 as a marker for the detection of ascites in patients with chronic liver disease.MethodsA total of 170 patients were studied. All had ultrasound scanning for detection of ascites. Group I consisted of 123 patients with chronic liver disease without ascites; whereas group II consisted of 47 patients with chronic liver disease with ascites. CA 125 levels were measured in all patients and also simultaneously in the ascitic fluid of 31 patients from group II.ResultsOf 47 patients, 46 (97.8%) of group II had elevated serum levels of CA 125 (mean 321 ± 283 U/ml) as compared with only nine of 123 (7.3%) patients of group I [mean 13 ± 15 U/ml]), p < 0.001. The mean CA 125 concentration in the ascitic fluid of 31 cirrhotic patients (group II) was 624 ± 397 U/ml and was always higher than corresponding serum levels (p < 0.01). Serum CA 125 levels correlated with the amount of ascitic fluid (r = 0.78). A profound decrease in serum CA 125 concentration was noted 2–3 and 10 days after large volume paracentesis. CA 125 was more sensitive and preceded ultrasonography in detection of ascites in few cirrhotic patients.ConclusionsCA 125 is a highly sensitive marker to detect ascites in patients with liver cirrhosis. This marker may be useful to detect small to moderate amounts of ascitic fluid in cirrhotic patients when physical examination is difficult or equivocal for ascites.


The Journal of Pathology | 2002

Neuropilin-2 is a novel marker expressed in pancreatic islet cells and endocrine pancreatic tumours.

Tzafra Cohen; Yael Herzog; Asia Brodzky; Joel K. Greenson; Samuel Eldar; Zoya Gluzman-Poltorak; Gera Neufeld; Murray B. Resnick

Neuropilin‐2 (NP‐2) is a cell surface transmembrane protein originally characterized as a receptor for the type 3 semaphorins, and more recently for a number of vascular endothelial growth factor (VEGF) isoforms. NP‐2 expression has been recently localized to a subset of neuroendocrine cells in the gastrointestinal tract. The aim of this study was to define the expression pattern of NP‐2 in normal pancreatic islets and to determine the utility of NP‐2 expression as a diagnostic marker of pancreatic endocrine tumours. Paraffin‐embedded tissue sections from 30 endocrine pancreatic tumours (EPTs) and from normal pancreas were immunostained with a rabbit polyclonal antibody generated towards NP‐2. Nineteen of the tumours were hormonally functional (nine insulinomas, nine gastrinomas, and one glucagonoma). The NP‐2 staining pattern was correlated with islet cell hormone expression. In addition, NP‐2 expression was evaluated in other normal neuroendocrine tissues and neuroendocrine neoplasms. In normal pancreas, NP‐2 stained a distinct subset of islet cells situated primarily at the islet periphery. Double immunohistochemical staining revealed co‐localization with glucagon‐expressing cells. Moderate to strong NP‐2 staining was present in 27 of 30 EPTs. Serial staining of the pancreatic tumours with insulin, gastrin, glucagon, pancreatic polypeptide (PP) or somatostatin did not reveal a distinct pattern of co‐localization. NP‐2 expression was not detected in neuroendocrine cells outside the gastroenteropancreatic system, or in their corresponding neoplasms, except for focal staining in one bronchial carcinoid tumour. In conclusion, the vast majority of EPTs examined expressed NP‐2, suggesting its utility as a diagnostic marker for these tumours. The function of NP‐2 in islet cell biology or tumourigenesis remains to be elucidated. Copyright


Diseases of The Colon & Rectum | 1995

Is mechanical bowel preparation necessary before primary colonic anastomosis

Moshe Schein; Ahmad Assalia; Samuel Eldar; Dietmar H. Wittmann; Ronald Lee Nichols

The necessity of preoperative or intraoperative mechanical bowel preparation of the colon, before primary anastomosis, has been recently challenged in clinical elective and emergency situations. PURPOSE: This experimental study in dogs investigated the safety of segmental resection and primary anastomosis in the unprepared or loaded colon. METHODS: Two segments of the descended colon were resected and anastomosed in each animal. Group I (12 anastomoses) received preoperative mechanical bowel preparation; the colon was not prepared in Group II (16 anastomoses); in Group III (12 anastomoses), a preliminary distal colonic obstruction was produced, and during the subsequent resection the colon was loaded. Postoperatively, animals were observed clinically, and anastomoses were assessed at autopsy on the ninth day. RESULTS: All animals recovered uneventfully. At autopsy there was no evidence of anastomotic leakage. CONCLUSIONS: In light of recent clinical reports and this experimental study, the ritual of mechanical bowel preparation should be further scrutinized.


European Journal of Surgery | 2000

Laparoscopic cholecystectomy for acute cholecystitis: how do fever and leucocytosis relate to conversion and complications?

Sarel Halachmi; Noa DiCastro; Ibrahim Matter; Ayala Cohen; Edmond Sabo; Jorge G. Mogilner; Jack Abrahamson; Samuel Eldar

OBJECTIVE To find out whether fever and raised white cell count (WCC) are associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis, and whether their presence could help in deciding the place of laparoscopic procedures. DESIGN Prospective study. SETTING Teaching hospital, Israel. SUBJECTS 256 patients who were treated for clinical acute cholecystitis between January 1994 and November 1997. INTERVENTIONS Emergency laparoscopic cholecystectomy. MAIN OUTCOME MEASURES Raised temperature and WCC; incidence of conversion and complications. RESULTS Raised temperature (>38 degrees C) was independently associated with advanced cholecystitis (p = 0.002, odds ratio [OR] 2.7) and a palpable gallbladder preoperatively (p = 0.02, OR 2.1). Total complications correlated with a temperature of >38 degrees C. Raised WCC (>15 x 10(9)/L) was independently associated with age >45 years (p = 0.02, OR 2.4), a palpable gallbladder preoperatively (p = 0.001, OR 2.9), and a raised temperature (>38 degrees C) (p < 0.0001, OR 6.2). Conversion was associated with a WCC >18 x 10(9)/L (p = 0.0, OR 3.2). CONCLUSION A WCC of >18 x 10(9)/L may assist in predicting conversion, and fever of >38 degrees C may assist in predicting the development of complications.


European Journal of Pediatric Surgery | 2008

Effect of elevated intra-abdominal pressure and hyperoxia on portal vein blood flow, hepatocyte proliferation and apoptosis in a rat model.

Jorge G. Mogilner; Haim Bitterman; Lili Hayari; Vera Brod; Arnold G. Coran; Ron Shaoul; Miriam Lurie; Samuel Eldar; Igor Sukhotnik

BACKGROUND/PURPOSE Indications for a laparoscopic approach for the management of biliary atresia in children are not clearly defined. We have recently shown that persistent intra-abdominal pressure (IAP) significantly decreased portal vein (PV) flow. Ventilation with a high concentration of oxygen after abdomen deflation raises concerns of increased oxidative stress but has also been shown to exert beneficial effects on splanchnic ischemia/reperfusion. The purpose of the present study was to evaluate the effects of IAP and hyperoxia on liver histology, hepatocyte proliferation and apoptosis in a rat model of abdominal compartment syndrome (ACS). METHODS Male Sprague-Dawley rats were anesthetized with intraperitoneal ketamine and xylasine. After a midline laparotomy, the PV was isolated. Ultrasonic blood flow probes were placed on the vessel for continuous measurement of regional blood flow. Mean arterial blood pressure (MABP) was continuously measured. Two large-caliber percutaneous peripheral intravenous catheters were introduced into the peritoneal cavity for inflation of air and measurement of IAP. Rats were divided into three experimental groups: 1) Sham rats were subjected to IAP of 0 mmHg; 2) ACS rats were subjected to IAP of 6 mmHg for 2 hours and were ventilated with air; and 3) ACS-O (2) rats were subjected to IAP of 6 mmHg for 2 hours and were ventilated with 100 % O (2) during the operation and ventilation was continued for 6 hours after operation. Liver structural changes, hepatocyte proliferation (using BrdU assay) and apoptosis (using Tunel assay) were determined 24 hours following operation. RESULTS IAP at 6 mmHg caused a twofold decrease in PV flow compared to sham animals. Hyperoxia resulted in a less significant decrease in PV flow compared to air-ventilated animals. Despite a significant decrease in PV blood flow, 24 hours after abdominal deflation only a few animals demonstrated histological signs of liver damage. The small histological changes were accompanied by increased hepatocyte apoptosis and enhanced hepatocyte proliferation in 25 % of animals, suggesting a liver repair response. CONCLUSIONS Despite a significant decrease in PV blood flow, persistent IAP for 2 hours results in few changes in liver histology, and stimulates hepatocyte proliferation and apoptosis in only a few animals, supporting the presence of a recovering mechanism. Treatment with hyperoxia did not significantly change hepatocyte proliferation and apoptosis.

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Jack Abrahamson

Technion – Israel Institute of Technology

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Ibrahim Matter

Technion – Israel Institute of Technology

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Edmond Sabo

Technion – Israel Institute of Technology

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Nash E

Technion – Israel Institute of Technology

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Jorge G. Mogilner

Technion – Israel Institute of Technology

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Jochanan E. Naschitz

Technion – Israel Institute of Technology

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Jochanan H. Boss

Technion – Israel Institute of Technology

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Ayala Cohen

Technion – Israel Institute of Technology

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Daniel Yeshurun

Baylor College of Medicine

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Edmund Sabo

Technion – Israel Institute of Technology

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