Abstract

Abstract Background Abdominoperineal excision (APE) for low rectal cancer is associated with higher rates of circumferential resection margin (CRM) involvement and intraoperative perforation (IOPs) than anterior resection for higher tumours. This multicentre observational study was designed to confirm that extralevator APE can improve outcomes and investigated the morbidity associated with such extensive surgery. Methods Some 176 extralevator APE procedures from 11 European colorectal surgeons were compared with 124 standard excisions from one UK centre. Clinical and pathological data were collected along with specimen photographs. Tissue morphometry was performed on the distal ten slices of the excision. Results Extralevator APE removed more tissue from outside the smooth muscle layer per slice (median area 2120 versus 1259 mm2; P < 0·001) leading to a reduction in CRM involvement (from 49·6 to 20·3 per cent; P < 0·001) and IOP (from 28·2 to 8·2 per cent; P < 0·001) compared with standard surgery. However, extralevator surgery was associated with an increase in perineal wound complications (from 20 to 38·0 per cent; P = 0·019). Conclusion Extralevator APE is associated with less CRM involvement and IOP than standard surgery.