Abdominoperineal excision in Australasia: clinical outcomes, predictive factors and recent trends of nonrestorative rectal cancer surgery

Aim: The decision to perform an abdominoperineal excision (APR) rather than restorative bowel resection relies on a number of clinical factors. There remains great variability in APR rates internationally. The aim of this study was to demonstrate trends of APR surgery in low rectal cancer (< 6 cm from the anal verge) in Australasia and identify predictors of nonrestoration. Method: This study reviewed a prospectively maintained colorectal registry – the Binational Colorectal Cancer Audit (BCCA) – from general/colorectal surgical units across Australia and New Zealand. Data were analysed to determine factors predictive of nonrestorative resection. Patients were analysed based on the presence (control) or absence (comparison) of a primary anastomosis. Results: Of 3628 patients with rectal cancer, 2096 were diagnosed with low rectal cancer between 2007 and 2017. The incidence of APR remained constant over the study period, with 58% of all resections of low rectal cancer being APR. The majority of resections were performed by consultants in urban hospitals (86% vs 14%). Tumours ≤ 3 cm from the anal verge, T4, M1 disease and neoadjuvant therapy were the greatest predictors of APR (P < 0.001). A significantly increased rate of restorative surgery was observed in public hospital settings (59% vs 41%, P < 0.05). The rate of positive circumferential resection margin (CRM) was 7.95%, with significantly increased rates in patients undergoing APR (12.2% vs 6.2%, P < 0.001). CRM positivity was increased in open approaches, T4, N2 and M1 staged disease and in an emergency/urgent setting (P < 0.001 and P < 0.045, respectively). Significantly increased wound and pulmonary complications were observed in the APR cohort (P < 0.01). Conclusion: The rates of APR in Australia and New Zealand remain high but are comparable to international figures, with one-third of rectal cancers being treated by APR. The main determinants of APR are tumour height, T stage and neoadjuvant therapy requirement. CRM positivity was higher in APR patients.