Short course preoperative radiotherapy is the single most important risk factor for perineal wound complications after abdominoperineal excision of the rectum

Aim To determine factors associated with perineal wound complications following abdominoperineal excision of the rectum (APER) for rectal adenocarcinoma and their effects on time to healing. Patients and methods We studied all cases of APER performed in our unit by four consultants over 7 years. Seven out of nine factors considered important in wound healing were analysed using logistic regression and a multivariate model was built to examine interactions. Wound persistence was calculated using the Kaplan-Meier method. Results Data were available for 94 of 96 patients [male:female, 3:2, median age 72.5 (IQR: 64-78)]. Thirty-nine (41%) patients had 25 Gray, 3-portal, fractionated 5-day short course preoperative radiotherapy (SCPRT). Dukes stages were A (34%), B (26%), C (40%). Perineal wound complications occurred in 44 (47%), 16% of these requiring return to theatre. Local recurrences occurred in 13 (15%). There was no evidence to suggest that either patient gender, age, smoking status, preoperative albumin or haemoglobin level, or T stage were associated with the development of wound complications. The odds of wound complications for a patient who had SCPRT was over 10 times that for a patient who did not have preoperative radiotherapy (odds ratio 10.15, 95% CI: 3.80-27.05, n = 94). Seventy-four per cent of SCPRT and 96% of non-SCPRT wounds had healed by 1 year. Estimated failed wound healing rates at 30 and 90 days were 64% (95% CI: 46-78) and 48% (95% CI: 30-64) in SCPRT patients compared with 23% (95% CI: 12-35) and 9% (95% CI: 3-20) in non-SCPRT patients (log rank test P < 0.0001). Conclusion Patients who have an APER are over 10 times more likely to have a perineal wound complication if they have SCPRT than not. Two-thirds of these will not have healed by 1 month, half by 3 months and over a quarter will still remain unhealed at 1 year. This has important implications for patient management decisions. Large prospective studies are needed to evaluate the effects of a selective policy for radiotherapy administered to patients requiring APER.