Risk Factors for Bowel Dysfunction After Sphincter-Preserving Rectal Cancer Surgery

Until recently, no studies have prospectively evaluated bowel function after sphincter-preserving surgery for rectal cancer with the use of a validated bowel function scoring system.The aim of this study was to investigate possible risk factors for altered bowel function after sphincter-preserving surgery.This was a prospective study.The study was conducted between January 2006 and May 2012 at the authors' institution.Patients who underwent sphincter-preserving rectal cancer surgery were recruited.Bowel function was assessed 1 day before (baseline) and at 1 year after sphincter-preserving surgery or temporary ileostomy takedown with the use of the Memorial Sloan Kettering Cancer Center questionnaire. Multivariable analysis was performed to identify the factors associated with altered bowel function after surgery.Overall, 266 patients were eligible for the analysis. The tumor was located in the upper, middle, and lower rectum in 68 (25.5%), 113 (42.5%), and 85 (32.0%) patients. Intersphincteric resection and temporary ileostomy were performed in 18 (6.8%) and 129 (48.5%) patients. The mean Memorial Sloan Kettering Cancer Center score was 64.5 ± 7.6 at 1 year after sphincter-preserving surgery or temporary ileostomy takedown. The Memorial Sloan Kettering Cancer Center score decreased in 163/266 patients (61.3%) between baseline and 1 year after surgery. Tumor location (p = 0.01), operative method (p = 0.03), anastomotic type (p = 0.01), and temporary ileostomy (p = 0.01) were associated with altered bowel function after sphincter-preserving surgery in univariate analyses. In multivariable analysis, only tumor location was independently associated with impaired bowel function after sphincter-preserving rectal cancer surgery.This study was limited by its nonrandomized design and the lack of measurement before preoperative chemoradiotherapy.We suggest that preoperative counseling should be implemented to inform patients of the risk of bowel dysfunction, especially in patients with lower rectal cancer, although this study cannot exclude the effect of chemoradiotherapy owing to the limitation of study.