Imperforate Anus Repair


The establishment of colorectal continuity when there is absence of an anal orifice, and/ or closure of fistula if present.


There are four classes or description of imperforate anus:

  1. Stemosis of the anus or distal rectum- treated by dilation and/ or incision.
  2. Membranous barrier at the anal opening – treated with incision and dilation.
  3. Rectum ends in a blind pouch above the perineum, usually associated with various fistulas. Correction will depend on the pathology present.
  4. Anal canal and distal rectum end in a blind pouch proximally. The more proximal rectum ends in a blind pouch above the distal segment.
    • Type IV is a rare and usually treated by a preliminary colostomy, with a second-stage repair several months later.
    • Type III may also be initially treated with a colostomy, with definitive repair occurring around three months of age depending on the child’s general health status.
  • Modified lithotomy or supine with frog-leg-like position.
  • A folded towel is placed under the buttocks to elevate anal area.
Packs/ Drapes
  • Pediatric lap sheet with extra fenestration created for combined approach.
  • Peadiatric lap sheet with abdominal opening covered and hole created for a perineal approach.
  • Pediatric laparotomy tray
  • Hegar dilators
Supplies/ Equipment
  • Thermal blanket
  • Handheld cautery
  • Suction
  • Scale
  • Basin set
  • Blades
  • Needle counter
  • Nerve stimulator
Procedure Overview
Imperforate Anus Class III
  1. Identification of the tract is accomplished using a small clamp inserted into the fistula.
  2. A perinea incision is then made in the midline of the tract.
  3. Dissection carried through the skin and subcutaneous tissue.
  4. The fistula is identified and divided; the exterior end is not closed, to allow postoperative drainage.
  5. The rectum is freed on all sides and the rectoanal repair is started using absorbable sutures.
  6. The rectum is opened and the bowel wall is trimmed back.
  7. Traction sutures are placed through the skin and the full thickness of bowel.
  8. Repeated dilation may be necessary as the opening may shrink in the next few months.