Nineteen studies (2,383 participants, range nine to 332) were included: one RCT, 10 prospective designs and eight retrospective designs. The RCT was rated as good quality. Most of the prospective and retrospective studies were rated as fair quality.
Compared to open sigmoid resections, laparoscopic sigmoid resection was associated with significantly lower rates of wound infections (fixed-effect RR 0.54, 95% CI 0.36 to 0.80; 15 studies), blood transfusions (fixed-effect RR 0.25, 95% CI 0.10 to 0.60; four studies), ileus (fixed-effects RR 0.37, 95% CI 0.20 to 0.66; eight studies) and incisional hernia (fixed-effect RR 0.27, 95% CI 0.12 to 0.64; seven studies). Random effects effect sizes did not differ significantly from fixed-effect estimates.
No significant differences between groups were found for anastomotic leak and stricture, bowel perforation and enterotomy, intra-abdominal bleeding and abscess formation, small-bowel obstruction, wound dehiscence, myocardial infarction, pneumonias, pulmonary emboli, urinary tract infections, need for rehospitalisation and need for reoperation.
There was no evidence of heterogeneity in all complications analysed.