Intestinal atresia

Key points

Grosfeld classification

Type 1: Membrane

Type 2: Blind ends joined by fibrous cord, no gap in mesentery

Type 3a: Disconnected ends and mesenteric defect

Type 3b: Distal segment has apple peel/Christmas tree appearance

Type 4: Multiple distal atresias (string of sausages) - poor prognosis

15-20% of colonic atresia is actually type IV SB atresia

Colonic - closed loop obstruction - perforation in 10%

Most common location is small bowel

Antenatal findings

Polyhydramnios

Ultrasound is more reliable in detecting proximal vs. distal intestinal atresia

Foetal MRI may be more accurate than US

On finding an atresia, consider an underlying cause e.g. Cystic Fibrosis, Hirschprungs disease

Histology of atresia

Proximal segment:

Smooth muscle hypertrophy + hyperplasia

Nerve hypoplasia + decreased number of interstitial cells of Cajal

Procedure

Assess:

• General bowel condition (perforation, further atresias, segmental volvulus, thick meconium suggesting meconium ileus)

• Total length of proximal segment + length of dilated bowel

• Total length of distal bowel + quality

• Always aim to preserve bowel length - but if adequate distal bowel can resect proximal segment. If poor quality/short distal bowel, perform anastomosis, but expect dysmotility - may require tapering/STEP at later date

  
  

• If anastomosis not possible (due to size discrepancy, unstable patient, perforation contamination, peel) make stoma

References

Osuchukwu OO, Rentea RM. Ileal Atresia. [Updated 2023 Apr 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557400/