***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Purpose : This study evaluated the risk factors for anastomotic leakage after  laparoscopic surgery  for rectal cancer using a stapling technique . Methods : The total prospect i ve registry of 111 patients with rectal cancer who initially underwent laparoscopic low anterior resection using a stapling technique  was review ed . Univariate and multivariate analyses were carried out to identify relevant risk factors . Results : Overall anastomotic leakage rate was 5.4 % ( 6/111 ) . Univariate analysis demonstrated that body mass index ( BMI ) ( P=0.0377 ) was significantly associated with anastomotic leakage . After univariate analysis , the variables of BMI and the size of the circular stapler ( P=0.0923 ) were selected for multivariate analysis , as their P values were < 0.2 , and multivariate analysis demonstrated that BMI was independently predictive of developing anastomotic leakage ( P=0.0458 ) . Conclusions : Laparoscopic surgery for rectal cancer using a stapling technique can be performed safely without increasing the risk of anastomotic leakage , and increased BMI might be a potential risk factor for anastomotic leakage Objective : To assess with a single-blinded , multicenter , r and omized trial , the postoperative results in patients undergoing sphincter-saving rectal resection for cancer without preoperative mechanical bowel preparation ( MBP ) .  Background : The collective evidence from literature strongly suggests that MBP , before elective colonic surgery , is of no benefit in terms of postoperative morbidity . Very few data and no r and omized study are available for rectal surgery and preliminary results conclude toward the safety of rectal resection without MBP . Methods : From October 2007 to January 2009 , patients scheduled for elective rectal cancer sphincter-saving resection were r and omized to receive preoperative MBP ( ie , retro grade enema and oral laxatives ) or not . Primary endpoint was the overall 30-day morbidity rate . Secondary endpoints included mortality rate , anastomotic leakage rate , major morbidity rate ( Dindo III or more ) , degree of discomfort for the patient , and hospital stay . Results : A total of 178 patients ( 103 men ) , including 89 in both groups ( no-MBP and MBP groups ) , were included in the study . The overall and infectious morbidity rates were significantly higher in no-MBP versus MBP group , 44 % versus 27 % , P = 0.018 , and 34 % versus 16 % , P = 0.005 , respectively . Regarding both anastomotic leakage and major morbidity rates , there was no significant difference between no-MBP and MBP group : 19 % versus 10 % ( P = 0.09 ) and 18 % versus 11 % ( P = 0.69 ) , respectively . Moderate or severe discomfort was reported by 40 % of prepared patients . Mortality rate ( 1.1 % vs 3.4 % ) and mean hospital stay ( 16 vs 14 days ) did not differ significantly between both groups . Conclusions : This first r and omized trial demonstrated that rectal cancer surgery without MBP was associated with higher risk of overall and infectious morbidity rates without any significant increase of anastomotic leakage rate . Thus , it suggests continuing to perform MBP before elective rectal resection for cancer . This study is registered with clinical trials.gov , number NCT00554892 PURPOSE : This study was design ed to identify the clinical features of anastomotic leakage after laparoscopic resection of rectal cancer and to evaluate the outcomes of laparoscopic management for this problem . METHODS : Prospect ively collected data were obtained from 307 patients with rectal cancer who underwent laparoscopic proctectomy and primary anastomosis .  Age , sex , tumor location , tumor stage , body mass index , comorbidities , ileostomy , conversion , intraoperative blood loss , operative time , previous abdominal operation , and hospital stay were analyzed for patients with or without anastomotic leakage . Management and outcome of  anastomotic leakage  also were analyzed . RESULTS :  Anastomotic leakage  occurred in 29 patients ( 9.4 percent ) . Diverting ileostomy was initially fashioned in 65 patients ( 21.2 percent ) . Leakage was related to young age , male sex , lower tumor location , and longer operation time . Ten patients ( 34.5 percent ) were successfully managed with conservative treatment . Seventeen patients ( 58.6 percent ) were managed via a laparoscopic approach . Open surgery was performed in two patients who showed diffuse fecal soiling or had previous conversion , respectively . There was no mortality . CONCLUSIONS : When leakage occurs , laparotomy or colostomy is not needed routinely . For surgical intervention , the abdominal cavity should be explored first by laparoscopic visualization because the majority of patients can be successfully managed with laparoscopy and ileostomy PURPOSE : The aim of this study was to investigate the role of omentoplasty , by means of intact omentum , in preventing anastomotic leakages after rectal resection . METHODS : Between 1992 and 1997 a total of 112 patients ( 64 males ) with a mean age of 64.7 ( range , 39–83 ) years were r and omly assigned to undergo omentoplasty ( Group A ) or not ( Group B ) to reinforce the colorectal anastomosis after anterior resection for rectal cancer . The primary end point was anastomotic leakage ; the secondary end point included morbility and mortality related to omentoplasty . RESULTS : The two groups were comparable in terms of preoperative and intraoperative characteristics . Staple-ring disruption at plain abdominal radiographs was detected in seven instances in Group A and in ten in Group B patients ( P = not significant ) . Two leakages were evident clinical ly in Group A and seven in Group B ( P<0.05 ) . Three leaks were documented radiologically in Group A and eight in Group B ( P = not significant ) . No complications related to omentoplasty were observed in Group A. There were two repeat operations for anastomotic leakage in Group B. At follow-up , one stricture developed in Group A and three in Group B ( P = not significant ) CONCLUSIONS : Despite a similar incidence of staple-ring defects , a strikingly lower rate of clinical ly and radiologically detected leaks developed in patients su bmi tted to omentoplasty .  Although not affecting the incidence of anastomotic disruption , omentoplasty seems to contain the severity of anastomotic leakage Purpose The extraperitoneal rectum is anatomically and biologically different from the intraperitoneal rectum , therefore , the surgical outcomes may be different . This study was design ed to assess operative outcomes of laparoscopic resection of extraperitoneal ( ≤7 cm from the anal verge )  vs. intraperitoneal rectal cancer . Methods Prospect i ve data were collected from 312 patients with rectal cancer who underwent laparoscopic resection .  Patients were divided into two groups : extraperitoneal ( EP , n = 138 ) vs. intraperitoneal ( IP , n = 174 ) . Mean follow-up was 33 months . Results Patients with pT3/pT4 accounted for 69.6 percent of EP and 74.1 percent of IP . Circumferential margin was positive in 8.7 percent of EP and 0.6 percent of IP ( P = 0.0004 ) . Anastomotic leakage developed in 9.7 percent of EP vs. 4.6 percent of IP ( P = 0.1081 , overall 6.4 percent ) . Local recurrence rate at three years was 7.6 percent in EP and 0.7 percent in IP ( P = 0.0011 , overall 4 percent ) . By multivariate analysis , extraperitoneal location was a risk factor for local recurrence . Conclusions Laparoscopic resection of rectal cancer , regardless of EP or IP , provided acceptable operative outcomes . There was an increasing tendency for positive circumferential margin , leakage , and local recurrence in EP vs. IP . A multicenter , prospect i ve study is ongoing to identify the high-risk group for local recurrence who may really benefit from neoadjuvant therapy in the era of laparoscopy Anastomotic leakage is a major complication of rectal cancer surgery . The aim of this study was to investigate risk factors associated with symptomatic anastomotic leakage after total mesorectal excision ( TME ) Background Anastomotic leakage is the most significant complication after low anterior resection ( LAR ) for rectal carcinoma , and it is the major cause of postoperative mortality and morbidity . The objective of the present study was to investigate whether the use of a transanal tube as an alternative endoluminal diversion technique for rectal carcinoma can reduce the 30-day leakage rate after LAR . Methods From June 2003 to December 2009 , a total of 398 patients were r and omized to a transanal tube or not after LAR . Inclusion criteria for r and omization were biopsy-proven carcinoma of the rectum located ≤15 cm above the anal verge , measured with a rigid rectoscope ; age ≥ 18 years ; informed consent ; ability to underst and the study information ; estimated survival of > 6 months ; anterior resection for the lesion ; final negative air leakage test ; intact anastomotic stapler rings ; and the absence of major intraoperative adverse events . Results Patient demographics , tumor size and location , Duke ’s stage , preoperative co-morbidity , and operative details were comparable between the two groups in general analysis and subgroup analysis ( double-staple technique and h and sewn technique ) . The overall rate of symptomatic leakage was 6.78 % ( 27 of 398 patients ) . Patients r and omized to a transanal tube ( n = 200 ) had leakage in 4.0 % ( 8 of 200 patients ) and those without a tube ( n = 198 ) in 9.6 % ( 19 of 198 patients ) ( p = 0.026 ) . With regard to the double-staple technique subgroup , 3.7 % ( 7 of 188 ) patients with a tube presented with a symptomatic anastomotic leakage , compared with 9.3 % ( 17 of 182 ) of those without a tube ( p = 0.028 ) . Of the patients with anastomotic leakage in the double-staple technique subgroup , the need for urgent abdominal reoperation was 28.6 % ( two of seven patients ) in those r and omized to a transanal tube and 82.4 % ( 14 of 17 ) in those without ( p = 0.021 ) . The 30-day mortality after LAR was nil . In the double-staple technique subgroup , a quicker resumption of gastrointestinal motility manifested by a smaller ratio of patients with flatus > postoperative day ( POD ) 3 ( p = 0.019 ) and a smaller ratio of poor gastrointestinal electromyogram on POD 3 ( p < 0.001 ) was associated with use of a transanal tube . Additionally , patients with a tube appeared to have a lower rectal resting pressure by POD 3 ( 4.0 ± 2.2 vs. 5.0 ± 2.2 kPa ; p < 0.001 ) or POD 5 ( 4.3 ± 2.3 vs. 5.6 ± 2.3 kPa ; p < 0.001 ) , compared to the resting pressures patients without the device , respectively . A shorter length of hospital stay was associated with use of a transanal tube both in the double-staple technique subgroup ( p < 0.001 ) and the h and sewn technique subgroup ( p = 0.011 ) . Multivariate logistic regression analysis revealed that body mass index > 25 kg/m2 and a poor gastrointestinal electromyogram on POD 3 were found to be independent risk factors for anastomotic leakage in the low anastomosis subgroup . Conclusions The presence of a transanal tube is effective and safe in decreasing the rate of clinical ly significant anastomotic leaks and in mitigating the clinical consequences of leakage after anterior resection for rectal cancer with the technique of total mesorectal excision and double-staple anastomosis . The potential benefits of transanal tube placement are multifactorial , including drainage , reduction of endoluminal pressure , and promotion of gastrointestinal motility . Obesity and poor gastrointestinal electromyogram on POD 3 are independent risk factors for anastomotic leakage in patients with low anastomosis BACKGROUND Controversy still exists concerning the impact of patient and tumor characteristics on anastomotic dehiscence after resection for rectal cancer . METHODS Between January 1986 and July 2006 , 472 patients underwent curative rectal resection .  Patient and tumor characteristics , details of treatment , and postoperative results were recorded prospect ively . Univariate and multivariate analysis were applied to identify risk factors for anastomotic leakage . RESULTS In our patients , the anastomotic leak rate was 10.4 % ( 49 of 472 patients ) , and mortality was 2.2 % ( 1 of 49 patients ) . In univariate analysis , tumor diameter and absence of a protective stoma were associated with increased anastomotic leak rate , whereas American Society of Anesthesiologists ( ASA ) score and tumor localization showed borderline significance . In multivariate analysis , tumor diameter , tumor localization , and absence of a protective stoma were significantly associated with anastomotic 
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We found considerable risk and mortality for AD requiring reoperation , which largely contributed to the overall postoperative mortality