Antibiotic prophylaxis for prevention of postoperative wound infection in adults undergoing open elective inguinal or femoral hernia repair.

backgroundInguinal or femoral hernia is a tissue protrusion in the groin region and has a cumulative incidence of 27% in adult men and of 3% in adult women. As most hernias become symptomatic over time, groin hernia repair is one of the most frequently performed surgical procedures worldwide. This type of surgery is considered 'clean' surgery with wound infection rates expected to be lower than 5%. For clean surgical procedures, antibiotic prophylaxis is not generally recommended. However after the introduction of mesh-based hernia repair and the publication of studies that have high wound infection rates the debate as to whether antibiotic prophylaxis is required to prevent postoperative wound infections started again.

objectivesTo determine the effectiveness of antibiotic prophylaxis in reducing postoperative (superficial and deep) wound infections in elective open inguinal and femoral hernia repair. SEARCH

methodsWe searched several electronic databases: Cochrane Registry of Studies Online, MEDLINE Ovid, Embase Ovid, Scopus and Science Citation Index (search performed on 12 November 2019). We also searched two trial registers and the reference list of included studies. SELECTION CRITERIA: We included randomised controlled trials comparing any type of antibiotic prophylaxis versus placebo or no treatment for preventing postoperative wound infections in adults undergoing inguinal or femoral open hernia repair surgery (tissue repair and mesh repair). DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted data and assessed risk of bias. We separately analysed results for two different surgical methods (herniorrhaphy and hernioplasty). Several studies revealed infection rates that were higher than the expected 5% for clean surgery and we therefore divided studies into two subgroups: high infection risk environments (≥ 5% infection rate); and low infection risk environments (< 5% infection rate). We performed meta-analyses with random-effects models. We analysed three outcomes: superficial surgical site infections (SSSI); deep surgical site infections (DSSI); and all postoperative wound infections (SSSI + DSSI). MAIN

resultsIn this review update we identified and included 10 new studies. In total, we included 27 studies with 8308 participants in this review. It is uncertain whether antibiotic prophylaxis as compared to placebo (or no treatment) prevents all types of postoperative wound infections after herniorrhaphy surgery (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.56 to 1.33; 5 studies, 1865 participants; very low quality evidence). Subgroup analysis did not change these results. We could not perform meta-analyses for SSSI or DSSI as these outcomes were not reported separately. Twenty-two studies related to hernioplasty surgery (total of 6443 participants) and we analysed three outcomes: SSSI; DSSI; SSSI + DSSI. Within the low infection risk environment subgroup, antibiotic prophylaxis as compared to placebo probably makes little or no difference for the outcomes 'prevention of all wound infections' (RR 0.71, 95% CI 0.44 to 1.14; moderate-quality evidence) and 'prevention of SSSI' (RR 0.71, 95% CI 0.44 to 1.17, moderate-quality evidence). Within the high infection risk environment subgroup it is uncertain whether antibiotic prophylaxis reduces all types of wound infections (RR 0.58, 95% CI 0.43 to 0.77, very low quality evidence) or SSSI (RR 0.56, 95% CI 0.41 to 0.77, very low quality evidence). When combining participants from both subgroups, antibiotic prophylaxis as compared to placebo probably reduces the risk of all types of wound infections (RR 0.61, 95% CI 0.48 to 0.78) and SSSI (RR 0.60, 95% CI 0.46 to 0.78; moderate-quality evidence). Antibiotic prophylaxis as compared to placebo probably makes little or no difference in reducing the risk of postoperative DSSI (RR 0.65, 95% CI 0.26 to 1.65; moderate-quality evidence), both in a low infection risk environment (RR 0.67, 95% CI 0.11 to 4.13; moderate-quality evidence) and in the high infection risk environment (RR 0.64, 95% CI 0.22 to 1.89; low-quality evidence). AUTHORS'

conclusionsEvidence of very low quality shows that it is uncertain whether antibiotic prophylaxis reduces the risk of postoperative wound infections after herniorrhaphy surgery. Evidence of moderate quality shows that antibiotic prophylaxis probably makes little or no difference in preventing wound infections (i.e. all wound infections, SSSI or DSSI) after hernioplasty surgery in a low infection risk environment. Evidence of low quality shows that antibiotic prophylaxis in a high-risk environment may reduce the risk of all wound infections and SSSI, while evidence of very low quality shows that it is uncertain whether antibiotic prophylaxis reduces DSSI after hernioplasty surgery.