***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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    ***EXAMPLES*** 
    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 Purpose Laparoscopic surgery of colon cancer has been accepted to be oncologically adequate compared with open resection . However , the situation in rectal cancer remains unclear , because anatomy and complex surgical procedures might specifically influence the long-term outcome . This study was design ed to analyze perioperative and long-term outcome of patients with rectal cancer after laparoscopic vs. open access surgery .  Methods A total of 389 patients ( 1998–2005 ) were prospect ively analyzed ; 114 patients had laparoscopic beginning , and 25 patients had conversion  and were separately analyzed . Eighty-nine patients remained in the laparoscopic group and 275 had open access surgery .  Results Both groups were comparable regarding age , gender , tumor localization , stage , and complications . Differences were found in harvested lymph nodes ( laparoscopic 13.5/open access 16.9 ; P = 0.001 ) and hospitalization ( 15.1/18.7 days ; P = 0.037 ) . Local recurrence rate and metachronous metastasis were comparable . In patients with deep anterior resection with total mesenteric excision , favorable long-term survival in the laparoscopic group was found ( P = 0.035 , log-rank ) . Conclusions Minimally invasive surgery is equivalent in the treatment of rectal cancer and shows advantages of shorter hospitalization and faster recovery . Especially in patients with low rectal cancer , minimally invasive surgery with exact preparation of the total mesenteric excision seems to be favorable compared with open access surgery 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 BACKGROUND Animal studies have documented significantly better preserved postoperative cell-mediated immune function , as measured by serial delayed-type hypersensitivity ( DTH ) challenges , after laparoscopic-assisted than after open bowel resection . Similarly , in humans , the DTH responses after open cholecystectomy have been shown to be significantly smaller than preoperative responses ; whereas after laparoscopic cholecystectomy , no significant change in DTH response has been noted . The purpose of this study was to assess cell-mediated immune function via serial DTH skin testing in patients undergoing laparoscopic or open colectomy .  METHODS A total of 35 subjects underwent either laparoscopic ( n = 18 ) or open colectomy ( n = 17 ) in this prospect i ve but not r and omized study . Only patients who were judged to be immunoresponsive by virtue of having responded successfully to a preoperative DTH challenge were eligible for entry in the study .  DTH challenges were carried out at three time points in all patients : preoperatively , immediately following surgery , and on the third postoperative day ( POD 3 ) . Responses were measured 48 h after each challenge and the area of in duration calculated . There were no significant differences between the laparoscopic ( LC ) and open ( OC ) colorectal resection groups in regard to demographics , indications for surgery , or type of resection carried out . The percentage of patients transfused was similar in both groups ( 17 % , LC ; 12 % OC ; p = NS ) . In the LC group , all cases were completed without conversion using minimally invasive methods . There were no perioperative deaths , and the rate of postoperative complications was similar in both groups . The preoperative and postoperative DTH results were analyzed and compared within each surgical group using several methods . RESULTS In regards to the OC group results , the median sum-total DTH responses for the day of surgery challenges ( 0.44 + /- 69 cm2 ) and the POD 3 challenges ( 0.72 + /- 3.37 cm2 ) were significantly smaller than the preoperative results ( 3.61 + /- 3.83 cm2 , p < 0.0005 vs op day and p < 0.0003 vs POD 3 results ) . When the LC group results were similarly analyzed , no significant difference in DTH response was noted between the pre- and the postoperative challenge results . Additionally , when the median percent change from baseline was calculated and considered for the OC group 's DTH results , both postoperative challenge time points demonstrated significantly decreased responses when compared to their preoperative results ( vs day of surgery , p < 0.007 ; vs POD 3 , p < 0.006 ) . Similar analysis of the LC group 's results yielded nonsignificant differences between the pre- and postoperative responses . Lastly , when the LC and the OC groups median percent change from baseline results were directly compared for each of the postoperative challenges , a significant difference was noted for the POD 0 challenge ( LC , -21 % ; OC 88 % ; p < 0.004 ) but not for the POD 3 challenge . CONCLUSIONS The postoperative DTH responses of the open surgery patients were significantly smaller than their preoperative responses . This was not the case for the laparoscopic group ( a combination of fully laparoscopic and laparoscopic-assisted resections ) . When the open and laparoscopic groups results are directly compared , regarding the results of the day of surgery DTH challenges , the LC groups median percent change from baseline was significantly less than that observed in the OC group . These results imply that open colorectal resection is associated with a significant suppression of cell-mediated immune response postoperatively , whereas in this study laparoscopic colorectal resection was not . Further human studies are needed to verify these findings and to determine the clinical significance , if any , of this temporary difference in immune function following colon resection 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 ) Purpose The anastomotic leakage rate after rectal resection has been reported to be approximately 2.5 - 21 percent , but most results were associated with open surgery . The aim of this study was to identify risk factors and their relationship to the experience of the surgeon for anastomotic leakage after laparoscopic rectal resection . Methods Between March 2003 and December 2008 , 156 patients underwent a laparoscopic rectal resection without a diverting ileostomy .  The patients ' characteristics , the details of treatment , the intraoperative results , and the postoperative results were recorded prospect ively . Univariate and multivariate analyses were applied to identify risk factors for anastomotic leakage . Results The majority of operations were performed for malignant disease ( n = 150 ; 96.2 % ) , and 96 patients ( 61.5 % ) were males .  Conversion to open surgery occurred in 1 case ( 0.6 % ) . The anastomotic leak rate was 10.3 % ( 16/156 ) , and there were no mortalities . In the univariate analysis , tumor location , anastomotic level , intraoperative events , and operation time were associated with increased anastomotic leakage rate . In the multivariate analysis , anastomotic level ( odds ratio [ OR ] , 6.855 ; 95 % confidence interval [ CI ] , 1.271 to 36.964 ) and operation time ( OR , 8.115 ; 95 % CI , 1.982 to 33.222 ) were significantly associated with anastomotic leakage . Conclusion The important risk factors for anastomotic leakage after laparoscopic rectal resection without a diverting ileostomy were low anastomosis and long operation time . An additional procedure , such as diverting stoma , may reduce the anastomotic leakage if it is selectively applied in cases with these risk factors BACKGROUND Laparoscopic rectal transection carries the risk of anastomotic leakage because of its technical difficulty and long staple line with an inadequate cutting angle . Our objective was to investigate the risk factors affecting anastomotic leakage after laparoscopic intracorporeal colorectal anastomosis with a double stapling technique . STUDY DESIGN Between November 2006 and September 2008 , 270 consecutive patients underwent laparoscopic sigmoidectomy and anterior resection with double stapling technique for distal sigmoid and rectal cancer . Data were collected prospect ively . Univariate and multivariate analyses were performed to determine risk factors for anastomotic leakage . Additionally , we evaluated the relationship between the number of stapler firings and clinical parameters . RESULTS Anastomotic leakage was noted in 17 ( 6.3 % ) of 270 patients . In univariate analyses , tumor location ( p = 0.021 ) , operation time ( p = 0.025 ) , number of stapler firings ( p = 0.040 ) , and diameter of the circular stapler ( p = 0.022 ) were significant risk factors for anastomotic leakage . Multivariate analyses showed that middle or lower rectal cancer was an independent factor affecting anastomotic leakage ( p = 0.013 ) . The number of stapler firings increased significantly in men ( p = 0.023 ) , in patients with a tumor at a lower level ( p = 0.034 ) , and in those with longer operation times ( p < 0.001 ) . CONCLUSIONS A reduction in the number of linear stapler firings is necessary to avoid anastomotic leakage after laparoscopic colorectal anastomosis with a double stapling technique . We recommend that a diverting ileostomy is m and atory in patients with middle and lower rectal cancer where multiple linear staplers were used Background This study aim ed to prospect ively evaluate operative safety and mid-term oncologic outcomes of laparoscopic rectal cancer resection performed by a single surgeon . Methods Three hundreds twelve patients ( male , 181 ) were enrolled in this analysis . 257 patients ( 82.4 % ) had tumors located below 12 cm from the anal verge . Distribution of TNM stages was 0:I : II : III : IV = 4.2%:17.9%:32.4%:37.2%:8.3 % . 225 patients ( 71.1 % ) had T3/T4 lesions . Pre- and post-operative radiation was given in 6 and 20 patients , respectively . Results Sphincter-preserving operation was performed in 85.9 % . Mean operating time was 212 minutes . Conversion rate was 2.6 % . Overall morbidity rate was 21.1 % . Anastomotic leakage occurred in 6.4 % . Operative mortality rate was 0.3 % . Mean number of harvested nodes was 23 . Mean distal tumor-free margin was 2.8 cm . The circumferential resection margin was positive in 13 patients ( 4.2 % ) . With a mean follow-up of 30 months in the stage I – III patients , the local recurrence rate was 2.9 % . Systemic recurrence occurred in 11.7 % . No port-site recurrence was observed . Conclusion Laparoscopic resection of rectal cancer provided safe operative parameters and adequate mid-term oncologic outcomes . When considering a high volume of advanced and 
    Output:
    
Conclusion Our analysis identified several clinicopathologic factors associated with AL in patients who underwent LAR .
The knowledge of these risk factors may influence treatment- and procedure-related decisions and possibly reduce the leakage rate