Alternate Names : Anorectal Malformation Repair, Perineal Anoplasty

Definition

Imperforate anus repair is surgery to correct birth defects involving malformation of the rectum and anus.

Normally, the large intestine (colon) empties into a pouch-like portion of bowel (rectum). Through complex nerve and muscle structures, the rectum releases stool through the anus out of the body.

Infants with imperforate anus defect, however, have malformations of the rectum and anus, in which abnormal development of these structures leads to growth of skin over the anus, and incomplete development of the rectum.

As a result, these infants have either no anal opening through which stool can pass or a very small opening with fistulas (channels that connects skin to bowel) that allows only a small amount of stool to pass out of the rectum.

Variations of the defect include:

• Complete absence of an anal opening
• A small tube-like opening (fistula) from the bowel to the skin, vagina, or urethra
• Rectum ends above the pelvic nerve and muscle structures ("high type" imperforate anus)
• Rectum extends completely or partially through the pelvic nerve and muscle structures ("low type" imperforate anus)