Wound drainage for lower limb arterial surgery

Background Drains are often used in leg wounds after vascular surgery procedures despite uncertainty regarding their benefits. Drains are placed with the aim of reducing the incidence and size of blood or fluid collections. Conversely, drains may predispose patients to infection and may prolong hospitalisation. Surgeons need robust data regarding the effects of drains on complications following lower limb arterial surgery. Objectives To determine whether routine placement of wound drains results in fewer complications following lower limb arterial surgery than no drains. Search methods In June 2016 we searched: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE and EBSCO CINAHL. We also searched clinical trial registries for ongoing studies. There were no restrictions with respect to language, date of publication or study setting. Selection criteria We considered randomized controlled trials (RCTs) that evaluated the use of any type of drain in lower limb arterial surgery. Data collection and analysis Two authors independently determined study eligibility, extracted data and performed an assessment of bias. An effort was made to contact authors for missing data. The methods and results of each eligible study were summarised and we planned to pool data in meta-analyses when it was considered appropriate, based upon clinical and statistical homogeneity. Main results We identified three eligible trials involving a total of 222 participants with 333 groin wounds. Suction drainage was compared with no drainage in all studies. Two studies were parallel-group, randomized controlled trials, and one was a split-body, randomized controlled trial. Trial settings were not clearly described. Patients undergoing bypass and endarterectomy procedures were included, but none of the studies provided details on the severity of the underlying arterial disease. We deemed all of the studies to be at a high risk of bias in three or more domains of the 'Risk of bias' assessment and overall the evidence was of very low quality. Two out of three studies had unit of analysis errors (with multiple wounds within patients analysed as independent) and it was not possible to judge the appropriateness of the analysis of the third. Meta-analysis was not appropriate, firstly because of clinical heterogeneity, and secondly because we were not able to adjust for the analysis errors in the individual trials. One trial yielded data on surgical site infections (SSI; the primary outcome of the review): there was no clear difference between drained and non-drained wounds for SSI (risk ratio 1.33; 95% confidence interval 0.30 to 5.94; 50 participants with bilateral groin wounds; very low quality evidence). It was not possible to evaluate any other outcomes from this trial. The results from the other two studies are unreliable because of analysis errors and reporting omissions. Authors' conclusions The data upon which to base practice in this area are limited and prone to biases. Complete uncertainty remains regarding the potential benefits and harms associated with the use of wound drains in lower limb arterial surgery due to the small number of completed studies and weaknesses in their design and conduct. Higher quality evidence is needed to inform clinical decision making. To our knowledge, no trials on this topic are currently active.