Twelve studies were included in the review; nine were RCTs (808 participants) and three were retrospective cohort studies (364 participants). Four RCTs scored 3 or more on the Jaded scale. Mean follow-up ranged between four weeks and five years (where reported).
Antimicrobial prophylaxis (four RCTs, three retrospective cohorts)
There were no statistically significant differences between antibiotic prophylaxis and no prophylaxis for surgical site infection, primary healing, recurrence rate, or secondary outcomes (two RCTs). By contrast, the retrospective cohort study showed that patients who received prophylaxis were at statistically significantly lower risk for surgical site infection (OR 0.18, 95% CI 0.07 to 0.4) and had shorter time to healing (p=0.001).
Studies that compared short-course versus long-course antibiotics showed inconsistent findings for surgical site infections, and found no statistically significant differences for primary healing or recurrence rate (two RCTs). The two cohort studies showed no statistically significant differences in surgical site infections between the two treatment groups.
Gentamicin collagen sponges (five RCTs)
Two RCTs that compared gentamicin collagen sponges versus plain sterile gauzes showed conflicting findings for surgical site infections and wound healing. One of these RCTs reported no statistically significant differences for secondary outcomes.
Two RCTs showed that time to healing was statistically significantly shorter with gentamicin collagen sponges and primary suture closure (median 10 and 17 days) compared with open healing by granulation (median 50 and 68 days, p<0.001). Recurrence rates were similar in both treatment groups. One RCT showed that patients who received gentamicin collagen sponges reported statistically significantly better results compared with antibiotics for the outcomes of lower surgical site infections, recurrence rates, faster healing, and shorter hospitalisations (fully reported in the review).