Oncologic safety and bowel function after ultralow anterior resection with or without intersphincteric resection for low lying rectal cancer: Comparative cross sectional study

Background: Despite acceptable oncologic outcomes of sphincter preserving surgeries for low rectal cancer, bowel dysfunction occurs. This study aimed to compare the oncologic and functional bowel outcomes between ultralow anterior resection (ULAR) and intersphincteric resection (ISR) for low rectal cancer. Methods: One hundred sixty-four patients who underwent ULAR with or without ISR for low rectal cancer between December 2010 and May 2018 were included. The Wexner and Memorial Sloan Kettering Cancer Center (MSKCC) scores were used to evaluate the bowel function of patients. Overall survival (OS) and disease-free survival (DFS) were compared between patients. Results: The ISR group had higher incidence of major fecal incontinence than the ULAR group (75.9% vs 49.3%; P =.016). The median Wexner score decreased from 12 to 9 (P =.062) at 1-year follow-up. However, the frequency and urgency/soilage subscales of MSKCC score improved significantly in the ULAR group. ISR and follow-up interval less than 1-year significantly increased the major incontinence risk. The OS in the ULAR and ISR groups was 91.4% and 91.7%. Whereas the DFS in both groups was 79% and 79.2%, respectively. Conclusion: ULAR and ISR are comparable in oncologic outcomes. Severe bowel dysfunctions and major incontinence were noted in ISR group. Careful selection of patients is mandatory.