Impact of Intraoperative Decision-Making on Pathological Margin Status in Patients Undergoing Pelvic Exenteration for Locally Recurrent Rectal Cancer.

BACKGROUND: A key component of preoperative preparation for pelvic exenteration surgery is development of an operative plan in a multidisciplinary setting, based on the extent of local tumor invasion on preoperative imaging. Changes to the extent of resection or operative plan may occur intraoperatively based on intraoperative findings.

OBJECTIVE: To report the frequency and extent of intraoperative deviation from the planned extent of resection during pelvic exenteration for locally recurrent rectal cancer, and whether this resulted in a more or less radical resection.

DESIGN: Retrospective observational study.

SETTINGS: A high-volume pelvic exenteration center.

PATIENTS: Patients who underwent pelvic exenteration for locally recurrent rectal cancer between January 2015 and December 2020.

MAIN OUTCOME MEASURES: Frequency and extent of intraoperative deviation from the planned extent of resection, R0 resection rate.

RESULTS: 136 patients underwent pelvic exenteration for locally recurrent rectal cancer, of which 110 (81%) had R0 resection margins. 12 patients were excluded due to missing information and 49 patients (40%) had a change to the operative plan. Operative changes were major in 30 patients (61%), more radical in 40 patients (82%), and margin relevant in 24 patients (49%). In patients where there was a change to the operative plan and R0 resection was achieved, the median distance to a relevant margin was 2.5 mm (range, 0.1-10mm). Of eight patients with a change in operative plan and R1 resection, three were margin relevant of which all were considered major, and two were more radical and one was less radical.

LIMITATIONS: Generalizability outside of specialist units may be limited.

CONCLUSIONS: Intraoperative changes to the planned extent of resection occur commonly and most often results in an unanticipated major, more radical resection. Such changes may contribute to high rates of R0 resection margins in specialist PE units that employ an ultra-radical approach in these patients. See Video Abstract.