The Effects of Intersphincteric Space Dissection Approaches on Low Rectal Cancer Outcomes: A Multicenter Retrospective Study in China.

Objective: To evaluate the effects of 2 intersphincteric space (ISS) dissection approaches for intersphincteric resection (ISR) on perioperative safety, oncological prognosis, and anal function.

Background: The dissection of ISS is a crucial aspect of ISR, yet the outcomes associated with various ISS dissection approaches remain uncertain.

Methods: Data were retrospectively collected from 314 patients with rectal cancer who underwent ISR at 5 Chinese tertiary referral medical institutions from January 2015 to December 2020. ISS dissection was performed using 1 of the 2 avenues: the complete transabdominal approach (CTA) and the transabdominal-perineal transanal approach (TPTA). The primary endpoints were 3-year overall survival (OS) and disease-free survival (DFS) rates. The secondary endpoints were postoperative anal function assessed by questionnaires. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to match the clinicopathological characteristics of patients from both cohorts.

Results: After PSM, 140 patients were successfully matched in the CTA and TPTA groups. There were no statistically significant differences between the groups in terms of perioperative complication rates, 3-year OS/DFS, and Wexner incontinence scores within 3 years after ileostomy reversal surgery (P > 0.05). However, the CTA group demonstrated less surgical time and superior low anterior resection syndrome (LARS) scores compared with the TPTA group (P < 0.05). Similar outcomes were observed after conducting IPTW adjustment.

Conclusions: CTA and TPTA showed similar efficacy regarding perioperative safety and oncological outcomes. However, the CTA approach demonstrated a clear superiority in the LARS score.