Long-term efficacy and short-term outcomes of intersphincteric resection abdominoperineal resection in patients with ultra-low rectal cancer.

Background: Ultra-low rectal cancer (ULRC), defined as a lesion located within 5 cm of the anal verge, poses considerable clinical challenges because the treatment decision must balance oncological eradication with preservation of anal function. Historically, abdominoperineal resection (APR) has served as a standard approach for tumor eradication in these patients, but a permanent stoma significantly reduces patients' quality of life. In contrast, intersphincteric resection (ISR) can maintain anal function, thereby improving quality of life; however, the debate surrounding short-term postoperative complications and long-term prognosis has not been fully resolved. Therefore, large-scale multicenter retrospective cohort studies are crucial to address this issue and provide more reliable data.

Aim: To address a persistent debate in ULRC management, we compared ISR and APR outcomes through rigorous methodology.

Methods: A retrospective analysis of patients undergoing surgery at three centers in China between 2012 and 2023 was performed with propensity score matching (PSM).

Results: A total of 803 patients (435 in the ISR group and 368 in the APR group) met the inclusion criteria, with 289 comprising each of the two groups after PSM. Over a median follow-up of 47.2 months, the absolute 5-year overall survival (OS) improved by 6.7% with ISR (80.8% 74.1%, = 0.032). Cox regression analysis confirmed ISR (HR = 0.554, 95%CI: 0.371-0.828, = 0.004) as an independent protective factor for OS and reduced local recurrence (9.5% 12.9%, = 0.019). With respect to short-term complications, despite higher anastomotic leakage rates (11.4% 1.0%), ISR significantly reduced total complications (29.4% 42.2%, = 0.001) and hospitalization duration (9.8 days 12.9 days, < 0.001). Moreover, incision infection, urinary retention, circumferential resection margins, and hospitalization time were greater in the APR group ( < 0.05).

Conclusion: The long-term prognosis of ULRC treated with ISR is excellent, with no increase in overall surgical complications or hospital stay duration, indicating that ISR is a feasible alternative to APR for managing ULRC.