Stapled versus handsewn methods for colorectal anastomosis surgery

BACKGROUND: Previous systematic reviews comparing stapled and handsewn colorectal anastomosis that are available in the medical literature have not shown either technique to be superior. An update of this systematic review was performed to find out if there are any data that properly answer this question. OBJECTIVES: To compare the safety and effectiveness of stapled and handsewn colorectal anastomosis surgery. The following primary hypothesis was tested: the stapled technique is more effective because it decreases the level of complications. SEARCH METHODS: A computerized search was performed in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE according to the strategies of the Colorectal Cancer Group of The Cochrane Collaboration. There were no limits upon language, date or other criteria. A revised search strategy was performed for this updated version of the review May 2011. SELECTION CRITERIA: All randomised controlled trials (RCTs) in which stapled and handsewn colorectal anastomosis techniques were compared. Participants were adult patients undergoing elective colorectal anastomosis surgery. The interventions were endoluminal circular stapler and handsewn colorectal anastomosis surgery. Outcomes considered were a) mortality; b) overall anastomotic dehiscence; c) clinical anastomotic dehiscence; d) radiological anastomotic dehiscence; e) stricture; f) anastomotic haemorrhage; g) reoperation; h) wound infection; i) anastomosis duration; and j) hospital stay. DATA COLLECTION AND ANALYSIS: Data were independently analysed by the two review authors (CBN, SASL) and cross-checked. The methodological quality of each trial was assessed by the same two authors. After searching the literature for this update, no study was added to those in the previous version of this review. Details of randomizations (generation and concealment), blinding, whether an intention-to-treat analysis was done or not, and the number of patients lost to follow-up were recorded. The analysis of the risk of bias was updated according to the software Review Manager 5.1. The results of each RCT were summarized on an intention-to-treat basis in 2 x 2 tables for each outcome. External validity was defined by the characteristics of the participants, interventions and the outcomes. The RCTs were stratified according to the level of colorectal anastomosis. The risk difference (RD) method (random-effects model) and number needed to treat (NNT) for dichotomous outcome measures and weighted mean differences (WMD) for continuous outcomes measures, with the corresponding 95% confidence intervals (CI), were presented in this review. Statistical heterogeneity was evaluated using a funnel plot and the Chi(2) test. MAIN RESULTS: Of the 1233 patients enrolled in nine identified trials, 622 were treated with staples and 611 with manual suture. The following main results were obtained. a) Mortality, result based on 901 patients: RD -0.6%, 95% CI -2.8% to +1.6%. b) Overall dehiscence, result based on 1233 patients: RD 0.2%, 95% CI -5.0% to +5.3%. c) Clinical anastomotic dehiscence, result based on 1233 patients: RD -1.4%, 95% CI -5.2 to +2.3%. d) Radiological anastomotic dehiscence, result based on 825 patients: RD 1.2%, 95% CI -4.8% to +7.3%. e) Stricture, result based on 1042 patients: RD 4.6%, 95% CI 1.2% to 8.1%; NNT 17, 95% CI 12 to 31. f) Anastomotic haemorrhage, result based on 662 patients: RD 2.7%, 95% CI -0.1% to +5.5%. g) Reoperation, result based on 544 patients: RD 3.9%, 95% CI 0.3% to 7.4%. h) Wound infection, result based on 567 patients: RD 1.0%, 95% CI -2.2% to +4.3%. i) Anastomosis duration, result based on one study (159 patients): WMD -7.6 minutes, 95% CI -12.9 to -2.2 minutes. j) Hospital stay, result based on one study (159 patients): WMD 2.0 days, 95% CI -3.27 to +7.2 days. AUTHORS' CONCLUSIONS: The evidence found was insufficient to demonstrate any superiority of stapled over handsewn techniques in colorectal anastomosis surgery, regardless of the level of anastomosis. There were no randomised clinical trials comparing these two types of anastomosis in elective conditions in the last decade. The relevance of this research question has possibly lost its strength where elective surgery is concerned. However, in risk situations, such as emergency surgery, trauma and inflammatory bowel disease, new clinical trials are needed.