Imperforate anus: I. Its surgical anatomy

Abstract

A detailed dissection of 9 newborn imperforate anus pelves and postoperative follow-up of 12 older children with imperforate anus were carried out. From the dissections, the following observations were made: 1. the external sphincter is always present in imperforate anus; 2. the internal sphincter is minimally present if at all; 3. the puborectalis muscle is at, but not above, the pubococcygeal line if the blind pouch is at or above that line; 4. the puborectalis muscle is as much below the pubococcygeal line as the bowel has descended below that line and it is wrapped around the bowel in sling fashion; 5. there is rarely approximation and coordination of the external sphincter and puborectalis, except in the lowest types of imperforate anus. The salient points uncovered in the follow-up of the postoperative patients include: 1. sensation was intact in its entirety in all cases where the distal bowel was undisturbed; 2. there was a suggestion of some sensory receptors in the puborectalis muscle itself; 3. there was apparent mucosal ingrowth of sensory fibers from the mucocutaneous line for a minimum distance of 1 to 2 cm. in all cases. A detailed dissection of 9 newborn imperforate anus pelves and postoperative follow-up of 12 older children with imperforate anus were carried out. From the dissections, the following observations were made: 1. the external sphincter is always present in imperforate anus; 2. the internal sphincter is minimally present if at all; 3. the puborectalis muscle is at, but not above, the pubococcygeal line if the blind pouch is at or above that line; 4. the puborectalis muscle is as much below the pubococcygeal line as the bowel has descended below that line and it is wrapped around the bowel in sling fashion; 5. there is rarely approximation and coordination of the external sphincter and puborectalis, except in the lowest types of imperforate anus. The salient points uncovered in the follow-up of the postoperative patients include: 1. sensation was intact in its entirety in all cases where the distal bowel was undisturbed; 2. there was a suggestion of some sensory receptors in the puborectalis muscle itself; 3. there was apparent mucosal ingrowth of sensory fibers from the mucocutaneous line for a minimum distance of 1 to 2 cm. in all cases. Le rationamento e le technica de un operation sacroabdominoperinee es delineate pro le casos de ano imperforate le quales require un chirurgia de “transtraction” abdominoperinee. Le rationamento e le technica de un operation sacroabdominoperinee es delineate pro le casos de ano imperforate le quales require un chirurgia de “transtraction” abdominoperinee.