The Usefulness of Anal Manometry in the Surgical Treatment of Anal Fissure and Anal Stenosis

Abstract

Evaluation of anal function in surgery for anal fissure and anal stenosis has traditionally relied on the surgeon's digital assessment and the patient's subjective evaluation. We conducted a study to evaluate anal sphincter function using anal manometry before and after the sliding skin graft (SSG) procedure performed at our hospital. Among the cases, 12.9% had a preoperative maximum resting pressure (MRP) of less than 45 mmHg, and 20.9% had a high MRP of 85 mmHg or more, indicating significant variation in preoperative MRP between cases. Additionally, the median MRP significantly decreased from 64.3 mmHg preoperatively to 51.1 mmHg postoperatively. In cases with a high preoperative MRP, a greater resection of the sphincter resulted in a significant decrease in postoperative MRP, whereas in cases with a low preoperative MRP, minimizing the amount of sphincter resection resulted in no significant decrease in postoperative MRP, and the rate of MRP decrease was mild. Understanding the sphincter function of each case preoperatively and using it as a guide for sphincter resection during SSG was useful for preserving anal function postoperatively.