Prophylactic subcutaneous drainage reduces post-operative incisional infections in colorectal surgeries: a meta-analysis of randomized controlled trials

Background Due to lack of high-level evidences, prophylactic subcutaneous drainage has so far not been recommended in relevant guidelines as a countermeasure against incisional infections. This meta-analysis aims to clarify the efficacy of subcutaneous drainage in reducing incisional infections in colorectal surgeries. Methods Cochrane Library, Embase, and PubMed were searched for randomized controlled trials comparing the incidence rate of incisional infections between patients receiving prophylactic subcutaneous drainage (interventions) and those not receiving (controls) after digestive surgeries. Results from included RCTs were pooled multiple times according to different surgical types. Heterogeneity, publication bias, and certainty of evidences were estimated. Results Eight randomized controlled trials were included. Three RCTs each included patients receiving all sorts of digestive surgeries (gastrointestinal, hepatobiliary, and pancreatic); pooled incisional infection rates between the drainage group and the control group were not significantly different (RR = 0.76, 95%CI: 0.48-1.21, p = 0.25). Four RCTs included patients receiving colorectal surgeries; pooled incisional infection rate in the drainage group was significantly lower than that in the control group (RR = 0.34, 95%CI: 0.19-0.61, p = 0.0004). Four RCTs included patients receiving upper GI and/or HBP surgeries; pooled incisional infection rates in the drainage group and the non-drainage group were not significantly different (RR = 0.85, 95%CI: 0.54-1.34, p = 0.49). Conclusions Prophylactic subcutaneous drainage significantly reduces post-operative incisional infections in colorectal surgeries but was not efficacious in digestive surgeries in general.