Abstract:

Aim: Low anterior resection (LAR) and intersphincteric resection (ISR) are the standard surgical options for low and very low rectal cancers, respectively. Unlike LAR, dissection in between the internal and external sphincter in ISR may functionally compromise sphincter integrity post-surgery. The aim was to compare anal sphincter function using anorectal manometry (ARM) in patients undergoing LAR and ISR, prior to stoma closure. Method: Retrospective review of 50 cases of rectal cancer operated between January 2017 to October 2019 and referred for ARM before stoma closure. Patients with anorectal dysfunction were referred for physiotherapy and reassessed. Results: Of the 50 patients, 25 patients had undergone LAR and 25 patients had undergone ISR. No difference was seen between the groups with relation to mean Cleveland Clinic Florida Fecal Incontinence Score [(CCFFIS); 4.76±2.93 vs. 5.28±3.57], mean resting pressure (56.22±15.48 vs. 51.10±19.83 mmHg), mean squeeze pressure (128.68±47.15 vs. 126.09±41.90 mmHg) and mean squeeze duration (25.98±10.90 vs. 24.55±13.12 seconds). In the LAR and ISR groups 8/25 (32%) and 11/25 (44%) had inadequate sphincter function on manometry (p>0.05). Significantly lower squeeze pressure (145.36±43.30 vs. 114.37±40.70 mmHg) and higher CCFFIS score was seen in those patients who underwent ARM a year after surgery. Conclusion: Both ISR and LAR had similar losses in anal sphincter function, with greater degree of dysfunction in patients having stoma for a prolonged period.

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