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Dive into the research topics where Mehran Anvari is active.

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Featured researches published by Mehran Anvari.


Annals of Surgery | 2007

Laparoscopic colectomy for cancer is not inferior to open surgery based on 5-year data from the COST Study Group trial

James W. Fleshman; Daniel J. Sargent; Erin M. Green; Mehran Anvari; Steven J. Stryker; Robert W. Beart; Michael D. Hellinger; Richard J. Flanagan; Walter R. Peters; Heidi Nelson

Purpose:Oncologic concerns from high wound recurrence rates prompted a multi-institutional randomized trial to test the hypothesis that disease-free and overall survival are equivalent, regardless of whether patients receive laparoscopic-assisted or open colectomy. Methods:Eight hundred seventy-two patients with curable colon cancer were randomly assigned to undergo laparoscopic-assisted or open colectomy at 1 of 48 institutions by 1 of 66 credentialed surgeons. Patients were followed for 8 years, with 5-year data on 90% of patients. The primary end point was time to recurrence, tested using a noninferiority trial design. Secondary endpoints included overall survival and disease-free survival. (Kaplan–Meier) Results:As of March 1, 2007, 170 patients have recurred and 252 have died. Patients have been followed a median of 7 years (range 5–10 years). Disease-free 5-year survival (Open 68.4%, Laparoscopic 69.2%, P = 0.94) and overall 5-year survival (Open 74.6%, Laparoscopic 76.4%, P = 0.93) are similar for the 2 groups. Overall recurrence rates were similar for the 2 groups (Open 21.8%, Laparoscopic 19.4%, P = 0.25). These recurrences were distributed similarly between the 2 treatment groups. Sites of first recurrence were distributed similarly between the treatment arms (Open: wound 0.5%, liver 5.8%, lung 4.6%, other 8.4%; Laparoscopic: wound 0.9%, liver 5.5%, lung 4.6%, other 6.1%). Conclusion:Laparoscopic colectomy for curable colon cancer is not inferior to open surgery based on long-term oncologic endpoints from a prospective randomized trial.


Diseases of The Colon & Rectum | 1999

Laparoscopic vs. open abdominoperineal resection for cancer.

James W. Fleshman; Steven D. Wexner; Mehran Anvari; Jean-François Latulippe; Elisa H. Birnbaum; Ira J. Kodner; Thomas E. Read; Juan J. Nogueras; Eric G. Weiss

PURPOSE: The aim of this study was to compare the safety and efficacy of laparoscopic abdominoperineal resection and open abdominoperineal resection for cancer. METHODS: Records of 194 patients who underwent laparoscopic abdominoperineal resection (42 patients) or open abdominoperineal resection (152 patients) at three institutions between 1991 and 1997 were reviewed. Follow-up was through office charts, American College of Surgeons cancer registry, or telephone contact. Tumors included (laparoscopic abdominoperineal resection and open abdominoperineal resection, respectively) adenocarcinoma (86 and 92 percent), squamous (12 and 7 percent), and gastrointestinal stromal (2 and 1.4 percent) types; Stages I (17 and 26 percent), II (24 and 33 percent), III (43 and 32 percent), and IV (14 and 9 percent); and those with invasion of pelvic structures (14 and 16 percent). RESULTS: Laparoscopic abdominoperineal resection was converted to open abdominoperineal resection in 21 percent because of vessel injury (33 percent), poor exposure (22 percent), adhesions (22 percent), inguinal hernia (11 percent), or radiation fibrosis (11 percent). Perineal infections occurred more often in the laparoscopic abdominoperineal resection group (24vs. 8 percent;P=0.02). Late stoma complications were similar. Mean hospital stay was shorter after laparoscopic abdominoperineal resection (7vs. 12 days). Radial margins were positive in 12 percent of laparoscopic abdominoperineal resection and 12.5 percent of open abdominoperineal resection specimens. Tumor recurrence was similar for both local (19 and 14 percent) and distant (38 and 26 percent) recurrence. Survival rates were similar by Kaplan-Meier curves, with median follow-up of 19 and 24 months, respectively (P=0.22; log rank). CONCLUSION: Laparoscopic abdominoperineal resection can be performed safely and results in a shorter hospital stay. A randomized, prospective trial is needed to determine the long-term outcome of cancer treatment.


Journal of The American College of Surgeons | 2003

Five-year comprehensive outcomes evaluation in 181 patients after laparoscopic Nissen fundoplication☆

Mehran Anvari; Christopher J. Allen

BACKGROUND We conducted an objective followup of 181 patients after laparoscopic Nissen fundoplication during a 5-year period after surgery. STUDY DESIGN Patients underwent 24-hour pH recording, esophageal manometry, and symptom score assessment for six gastroesophageal reflux disease symptoms preoperatively and at 6 months, 2 years, and 5 years after surgery. RESULTS Laparoscopic fundoplication was associated with a significant (p < 0.0001) increase in lower esophageal sphincter pressure and a significant (p < 0.0001) drop in duration of acid reflux in 24 hours, and symptom score, 6, 24, and 60 months after surgery when compared with preoperative values. Twenty-one patients (12%) have experienced recurrence of reflux-type symptoms, but only six have required repeat surgery. Lower esophageal sphincter tone dropped between 6 months and 5 years after surgery, but was still an effective antireflux barrier. Patient satisfaction with surgery dropped over the 5-year followup but remained high, at 86%, after 5 years. CONCLUSIONS Laparoscopic Nissen fundoplication remains an effective antireflux procedure at 5 years.


Annals of Surgery | 2010

Randomized Controlled Trials of Surgical Interventions

Forough Farrokhyar; Paul J. Karanicolas; Achilleas Thoma; Marko Simunovic; Mohit Bhandari; P. J. Devereaux; Mehran Anvari; Anthony Adili; Gordon H. Guyatt

Background and Objectives:Surgical trials pose many methodological challenges often not present in trials of medical interventions. If not properly accounted for, these challenges may introduce significant biases and threaten the validity of the results. Methods:We systematically reviewed the significance of randomized controlled trials in the evaluation of surgical interventions, discussed the methodological challenges encountered in designing and conducting randomized controlled trials of surgical treatments, and proposed possible solutions to overcome these challenges. Conclusions:Many barriers and issues of surgical trials affecting internal validity can be overcome with proper methodology, and in most cases these issues do not restrict their conduct. Researchers should consider their research question carefully and design a surgical trial that contains features appropriate for the question. In doing so, they must ensure that the trial is valid, feasible, and affordable—a difficult feat, but one well worth the challenge.


American Journal of Surgery | 1999

Laparoscopic pancreatic surgery

Adrian Park; Richard W. Schwartz; Ved Tandan; Mehran Anvari

BACKGROUND Potential applications for laparoscopic surgery in pancreatic disease include (1) staging of pancreatic malignancies; (2) palliation of pancreatic malignancies; (3) pancreatic resections for benign and malignant disease; and (4) pancreatic drainage procedures. METHODS A review of the literature is presented. In addition, original data on a series of 5 laparoscopic pancreatic distal resections and 10 laparoscopic cystogastrostomies are presented. RESULTS AND CONCLUSIONS Laparoscopy may have a role in the staging of patients with pancreatic malignancies; however, with high-quality preoperative imaging, the percentage of patients who will benefit from laparoscopy may be as low as 5%. For palliation, both cholecystoenterostomy and choledochoenterostomy can be performed laparoscopically. The former is technically straightforward but has a higher failure rate; the latter is technically difficult and currently not suitable for widespread adoption. Laparoscopic gastroenterostomy is a straightforward means of palliating gastrointestinal obstruction. Patients appear to benefit from laparoscopic distal pancreatic resection but not from laparoscopic pancreaticoduodenectomy. Patients appear to benefit from laparoscopic pseudocyst decompression.


Thorax | 1998

Gastro-oesophageal reflux related cough and its response to laparoscopic fundoplication.

Christopher J. Allen; Mehran Anvari

BACKGROUND This study was designed to determine prospectively the rate of cough before and after laparoscopic Nissen fundoplication performed for the control of gastro-oesophageal reflux disease. METHODS One hundred and ninety five consecutive patients (76 men) of mean (SD) age 46.9 (14.1) years with proven gastro-oesophageal reflux disease, who were either on long term omeprazole (n = 187) or who had not responded to a trial of omeprazole (n = 8), took part in the study which was carried out in a university teaching hospital that included a regional respiratory referral centre. Patients underwent oesophageal manometry, 24 hour oesophageal pH testing, and symptom score evaluation by an independent observer before and six months after laparoscopic Nissen fundoplication. RESULTS One hundred and thirty three patients presented with reflux symptoms and 62 with respiratory symptoms; 68% of patients complained of cough before surgery (86% with respiratory symptoms, 60% with gastrointestinal symptoms). The percentage reflux time in 24 hours fell significantly (p<0.0001) from a mean (SD) of 9.38 (10.99)% to 1.22 (2.92)%, lower oesophageal sphincter tone rose significantly (p<0.0001) from a mean (SD) of 7.71 (5.90) mm Hg to 21.74 (10.84) mm Hg, and the cough score fell from a median value of 8.0 (IQR 12.0) to 0 (IQR 3) following surgery. Of the patients with cough, 51% were cough free after surgery and 31% improved. The patients with respiratory symptoms had a higher cough score before (median 12.0 (IQR 5.5) versus 4.0 (IQR 8.75), p<0.0001) and after surgery (median 1 (7.5) versus 0.0 (IQR 1.0), p = 0.0045) than those with gastrointestinal symptoms. CONCLUSIONS Patients who present to gastroenterologists with severe reflux commonly complain of cough. Laparoscopic Nissen fundoplication is effective in the control of cough in patients with gastro-oesophageal reflux disease, with or without primary respiratory disease.


Surgical Innovation | 2006

A Randomized Controlled Trial of Laparoscopic Nissen Fundoplication Versus Proton Pump Inhibitors for Treatment of Patients With Chronic Gastroesophageal Reflux Disease: One-Year Follow-Up

Mehran Anvari; Christopher J. Allen; John K. Marshall; David Armstrong; Ron Goeree; Wendy J. Ungar; Charles H. Goldsmith

A randomized controlled trial conducted in patients with gastroesophageal reflux disease compared optimized medical therapy using proton pump inhibitor (n = 52) with laparoscopic Nissen fundoplication (n = 52). Patients were monitored for 1 year. The primary end point was frequency of gastroesophageal reflux dis-ease symptoms. Surgical patients had improved symptoms, pH control, and overall quality of life health index after surgery at 1 year compared with the medical group. The overall gastroesophageal reflux disease symptom score at 1 year was unchanged in the medical patients, but improved in the surgical patients. Fourteen patients in the medical arm experienced symptom relapse requiring titration of the proton pump inhibitor dose, but 6 had satisfactory symptom remission. No surgical patients required additional treatment for symptom control. Patients controlled on long-term proton pump inhibitor therapy for chronic gastroesophageal reflux disease are excellent surgical candidates and should experience improved symptom control after surgery at 1 year.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2004

Robotic-assisted laparoscopic colorectal surgery.

Mehran Anvari; Daniel W. Birch; Fahad Bamehriz; Robert Gryfe; Trevor Chapman

Robotic assistance provides a number of potential benefits for laparoscopic surgery by addressing several inherent limitations. However, its utility in colorectal surgery has not been determined. This is a report of our initial experience with robot-assisted colon resections. We prospectively followed 10 patients who underwent robotic-assisted laparoscopic colorectal surgery using Zeus Microwrist System. Surgical outcomes were compared with those of 10 consecutive patients who underwent laparoscopic colorectal surgery in the same institution for similar indications prior to the start of robotic-assisted surgery. Six patients in each group had surgery for colorectal malignancy. All 10 robotic-assisted procedures were completed with no intraoperative complications, conversions, or mortality. The average blood loss was less than 150 mL in all cases. Morbidity and hospital stay were comparable to those for the patients undergoing standard laparoscopic procedures. Robotic surgery was associated with a significant increase in operative time of almost 1 hour. This time was reduced significantly after the first 4 cases. The value of robotic assistance in colorectal surgery needs to be further evaluated in a larger comparative study.


Annals of Surgery | 1998

Laparoscopic Nissen Fundoplication: Two-year Comprehensive Follow-up of a Technique of Minimal Paraesophageal Dissection

Mehran Anvari; Christopher J. Allen

OBJECTIVE To provide a comprehensive follow-up of 381 patients after laparoscopic Nissen fundoplication (LNF) using a technique of minimal paraesophageal dissection. METHODS Patients underwent a 24-hour pH recording, esophageal manometry, and symptom score assessment for six symptoms of gastroesophageal reflux disease preoperatively. To date, 260 patients have undergone repeat studies at 6 months and 108 patients at 2 years. RESULTS LNF was associated with a significant (p < 0.0001) increase in the lower esophageal sphincter (LES) pressure and a significant (p < 0.0001) drop in duration of acid reflux in 24 hours and symptom score 6 and 24 months after surgery when compared to preoperative values. Twelve patients (3%) have experienced recurrence of reflux symptoms, 8 presenting in the first 6 months and 4 by the second year after surgery, but only 1 has required repeat surgery. The incidence of clinical dysphagia was found to be 1.3% of the patient group. CONCLUSIONS LNF remains an effective antireflux procedure at 2 years. Most recurrences occur early, and there is no significant deterioration in the high-pressure zone at the LES, the percentage reflux in 24 hours, or symptom control between 6 months and 2 years after surgery, suggesting that the long-term results should be satisfactory.


Diseases of The Colon & Rectum | 2001

Laparoscopic vs. open resection for colorectal adenocarcinoma.

Dennis Hong; Jeanine Tabet; Mehran Anvari

PURPOSE: To compare the outcome after laparoscopicversus open resection for colorectal adenocarcinoma. METHODS: A retrospective cohort analysis of all patients undergoing elective resection for colorectal adenocarcinoma between November 1992 and June 1999 at a university-affiliated hospital. These included 219 open (mean age, 68.3 years) and 98 laparoscopic (mean age, 70.3 years) resections. Data from converted cases (n=12) were included in the laparoscopic group using the intention-to-treat principle. RESULTS: Operative time, lymph node yield, resection margins and postoperative morbidity and mortality were similar between laparoscopic and open technique. Parenteral analgesic use was less in the laparoscopic group (laparoscopic, 2.7; open, 3.2 days;P=0.021). Time to first flatus (laparoscopic, 1.8; open, 3 days;P<0.0001) and first bowel movement (laparoscopic, 3.5; open, 4.9 days;P<0.0001) was shorter in the laparoscopic group. Resumption of an oral liquid diet (laparoscopic, 2.1; open, 4 days;P<0.0001) and solid diet (laparoscopic, 5.2; open, 7.1 days;P<0.0001) was also quicker in the laparoscopic patients. Length of hospitalization was significantly shorter in the laparoscopic patients (laparoscopic, 6.9; open, 10.9 days;P<0.001). There were less minor complications in the laparoscopic group (laparoscopic, 11.2; open, 21.5 percent;P=0.029) but no difference in major complications or perioperative mortality. Recurrence, disease-free and overall survival were similar between the two groups. No port site recurrences ocurred in the laparoscopic group but there were three wound recurrences in the open group. CONCLUSIONS: Laparoscopic resection for colorectal cancer can be performed safely and effectively in tertiary centers. Earlier discharge from hospital, quicker resumption of oral feeds and less postoperative pain are clear advantages. No adverse effect on recurrence or survival was noted, but results of prospective, randomized trials, currently underway, are needed before laparoscopic resection for colorectal cancer becomes the standard of practice.

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Fady Saleh

University Health Network

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