Preoperative Anal Manometry Predicts Continence After Perineal Proctectomy for Rectal Prolapse

Abstract

This study examines whether preoperative anal manometry and pudendal nerve terminal motor latency predict functional outcome after perineal proctectomy for rectal prolapse. All adult patients treated by perineal proctectomy for rectal prolapse from 1995 to 2004 were identified (N = 106). Forty-five patients underwent anal manometry and pudendal nerve terminal motor latency testing before proctectomy and they form the basis for this study. Perineal proctectomy with levatoroplasty (anterior 88.9 percent; posterior 75.6 percent) was performed in all patients, with a mean resection length of 10.4 cm. Four patients (8.9 percent) developed recurrent prolapse during a 44-month mean follow-up. Preoperative resting and maximal squeeze pressures were 34.2 +/- 18.3 and 60.4 +/- 30.5 mmHg, respectively. Pudendal nerve terminal motor latency testing was prolonged or undetectable in 55.6 percent of patients. Grade 2 or 3 fecal incontinence was reported by 77.8 percent of patients before surgery, and one-third had obstructed defecation. The overall prevalence of incontinence (77.8 vs. 35.6 percent, P < 0.0001) and constipation (33.3 vs. 6.7 percent, P = 0.003) decreased significantly after proctectomy. Patients with preoperative squeeze pressures >60 mmHg (n = 19) had improved postoperative fecal continence relative to those with lower pressures (incontinence rate, 10 vs. 54 percent; P = 0.004), despite having similar degrees of preoperative incontinence. Abnormalities of pudendal nerve function and mean resting pressures were not predictive of postoperative incontinence. Perineal proctectomy provides relief from rectal prolapse, with good intermediate term results. Preoperative anal manometry can predict fecal continence rates after proctectomy, because patients with maximal squeeze pressures >60 mmHg have significantly improved outcomes.