Local gentamicin reduces perineal wound infection after radiotherapy and abdominoperineal resection

Perineal wound complications are frequently observed after abdominoperineal resection (APR) for rectal cancer, especially in preoperatively irradiated patients. This is the first study to investigate whether local application of gentamicin-impregnated collagen fleece reduces deep perineal wound infection after APR for rectal cancer following short-term radiotherapy. Between 2003 and 2007, a consecutive series of 40 patients underwent an APR for rectal cancer after short-course radiotherapy in our hospital. Of these patients, 19 received supplementary application of three reabsorbable gentamicin-impregnated collagen fleece sponges into the sacral cavity before closure of the perineum (group A), and 21 patients underwent primary closure of the perineal wound and served as a control group (group B). All patients received sacral drainage. A superficial perineal wound infection was defined as cellulitis with no evidence of deep tissue infection. A deep perineal wound infection was defined as skin and subcutaneous tissue breakdown with infection extending deep into the subcutaneous tissue or a wound abscess. The two groups were comparable regarding age, sex, tumour stage and level of the tumour. No postoperative mortality was observed in either group. Primary wound healing occurred in 16 patients (84%) in the gentamicin group and 9 patients (43%%) in the control group (p=0.01). The incidences of superficial perineal wound complications were 11% (two patients) in group A who received local application of gentamicin and 29% (six patients) in group B (p=0.15). Six patients (29%) in group B developed a deep infection or wound abscess, resulting in full dehiscence of the wound and sacral cavity. This devastating complication occurred in only one patient (5%) in group A (p=0.05). In most patients deep perineal wound infection was treated with vacuum therapy or drainage. The mean hospital stay of the gentamicin group was 15 days and of the control group 25 days (p=0.04). Based on the results of this study, we recommend local application of gentamicin in the sacral cavity in patients who undergo abdominoperineal resection after shortterm radiotherapy.