Comparison of Anorectal Function and Quality of Life Measures in Patients Following Intersphincteric Resection and Lower Anterior Resection

This study explored postoperative outcomes for patients with lower rectal cancer who underwent low anterior resection (LAR) or intersphincteric resection (ISR). A total of 49 patients (33 LAR, 16 ISR) were followed using anorectal manometry and quality of life (QOL) questionnaires over a year, pre- and post surgery. The primary aim of this study is to clarify differences in anal manometry, sphincter function, fecal incontinence, and QOL between the two surgical arms. The secondary aim was to identify indicators suitable for assessing relationships between anorectal manometry measurements, fecal incontinence, and QOL. Anorectal manometry elements (AMEs), such as atmospheric maximum mean squeeze pressure (aMSP), maximum tolerable volume (MTV), and incremental maximum mean squeeze pressure (iMSP), showed no significant differences during the observation period. However, maximum resting pressure (MRP), high-pressure zone length (HPZ), and threshold volume (TV) were significantly worse in the ISR group. Fecal incontinence, measured by Wexner and Kirwan scores, was significantly better in the LAR group. We observed no differences in SF36 between the two groups. Multi-correlation analysis revealed positive and negative correlations among these factors, with inverse correlations between anorectal manometry measurements and incontinence assessments decreasing post-surgery. We found no correlation between SF36 and anorectal manometry at any time. The findings indicate that surgical technique affects postoperative anal function, fecal incontinence, and SF36. However, combined assessment methods should be used with caution when deriving relationships between anal function and SF36.