Steps of the Procedure

How is a myectomy performed?

Lynn initially described this operation via a transanal approach. A transverse incision is made approximately one cm from the dentate line in the posterior rectal wall [1]. A mucosal flap is raised proximally and a 0.5 to 1 cm strip of muscle is excised. The length of the myectomy corresponds with the pathologic process and is usually several cm long. The mucosal flap is closed at the completion of the myectomy. Thomas et al advocated approaching the posterior rectum, in a fashion that would later be popularized by Pena for imperforate anus, via an incision from the coccyx to the posterior rectum. Once exposed, the overlying rectal serosa is divided in a longitudinal fashion and the myectomy is performed. Care is taken not to enter the mucosa in a similar fashion to a pyloromyotomy [2][3]. When a myectomy is performed for short segment Hirschsprung disease, the operation is both diagnostic and potentially therapeutic. In the case where the aganglionosis extends beyond the proximal margin a pull through operation is required.