Linear Pressure Profiles and Symmetric Findings in the Stimulated Gracilis Muscle

Abstract

PURPOSE: This is the first report of linear pressure profiles and symmetric findings in preoperative and postoperative (after gracilis muscle retraining) patients. Length of the anal canal and symmetry have been well documented in the literature as significant parameters in the maintenance of anal incontinence. Significant improvement of these parameters should play a critical role in the functional outcome of the stimulated gracilis. METHODS: Six patients underwent preoperative and postoperative anorectal manometry using an eight-channel radial catheter. Pressures were collected at 8 Hz using an automated continuous pullout technique (1 mm/sec). Preoperative and posttraining resting and squeeze pressures, pressure volumes, anal canal length, and linear and cross-sectional images were compared. RESULTS: Resting pressures significantly improved from 13.7 mmHg to 26.8 mmHg (P < 0.02). The squeeze pressure significantly improved from 28.67 mmHg to 62.9mmHg (P < 0.02). The pressure volume increased from 10,429 mmHg3 to 26,162 mmHg3. Anal canal length increased from an abnormal length of 2.95 cm to normal length of 3.55 cm (P < 0.04). The percentage of sphincter asymmetry decreased from 28.6 percent to 23.5 percent (P < 0.01). The most striking observation was the impact the gracilis muscle had on correcting the geographic cross sections as it wrapped more than 360 degrees from the proximal to distal anal canal. Patients were significantly improved, with four of the six patients completely continent to solid stool. Two of the six patients had minor episodes of seepage. Preoperatively, all patients were grossly incontinent to solid stool. CONCLUSIONS: Significant improvement in resting pressure, pressure volume, anal canal length, and cross-sectional symmetry has led to a significant improvement in anal incontinence after dynamic myoplasty.