Anal sphincter reconstruction with a pudendal nerve anastomosis following abdominoperineal resection: report of a case.

PURPOSE AND METHODS: We report herein a case of a patient with rectal carcinoma in whom a new anus was constructed following an abdominoperineal resection of the anorectum. This is the first reported case in which reconstruction of the anal sphincter was performed using the lower part of the gluteus maximus muscle with a pudendal nerve anastomosis. The pudendal nerve anastomosis maneuver was designed to achieve proper innervation and function of the external anal sphincter. This newly reconstructed sphincter was physiologically evaluated after surgery.

RESULTS: The patient's defunctioning colostomy was not closed following his initial surgery because part of the transposed muscle was devitalized by infection following blood flow damage. However, purposeful contraction of the new sphincter was easy to achieve without special training. The patient's rectal sensation for the desire to defecate was satisfactory. Electromyographic studies demonstrated that the newly reconstructed anal sphincter had characteristics of the original external anal sphincter.

CONCLUSIONS: This method is a promising procedure for reconstructing the anal sphincter.