[size=20px]At birth, an infant with Hirschsprung Disease underwent ileostomy at the transition zone located 30 cm proximal to the ileocecal valve. Now 2 years of age, he is gaining weight with a gradually thickening ileostomy effluent. The next step in management of this infant should be:

 

A Continued observation

 

B Ileoanal pullthrough

 

C Ileoanal pullthrough and proximal diverting stoma

 

D Duhamel ileoproctostomy with preservation of a 5-10 cm rectal “spur”

 

E Martin ileocolostomy (descending colon)[/size]

B

E

D

B

B

D

correct answer

B Ileoanal pullthrough

 

 

Approximately 10% of infants born with Hirschsprung Disease (HD) have aganglionosis involving the entire colon, often with extension into the small bowel. In comparison to short segment disease, patients with long segment HD are more challenging to diagnose, face higher rates of complication and present challenges in identifying the optimal timing and type of definitive reconstruction.

 

Reconstruction for long segment HD has evolved from procedures that retained varying lengths of the aganglionic colon for its absorptive capacity, including Martin’s total or partial ileocolostomy, Kimura’s right colon patch, and modifications of the Duhamel operation. Recently there has been a trend away from pullthroughs which retain significant lengths of aganglionic colon to procedures which utilize ganglionic small bowel only. The most frequently performed reconstructions for long segment HD with extension into small bowel from contemporary reports are ganglionic small bowel pullthoughs either as straight conduits or J-pouches with short (4-5 cm) limbs; or a Duhamel operation with an ileoproctostomy of varying length, with avoidance of a potentially obstructive limb of aganglionic rectum above the anastomosis (“Duhamel spur”) which can compress the ileal limb leading to obstruction and enterocolitis.

 

Two factors to be considered in the timing of pullthrough for long segment HD are evidence of adequate somatic growth and a stoma effluent that is unlikely to cause severe, refractory perianal excoriation. A recent systematic review of long segment HD confirmed an inverse relationship between age at definitive procedure and skin excoriation but offered no specific guidance for optimal timing. Pena has recommended colectomy and straight ileoanal anastomosis with diverting ileostomy in the newborn, with ileostomy closure delayed until the child is toilet trained for urine and able to tolerate rectal irrigations for expected episodes of HAEC. A 3-decade experience with long segment HD from Ann Arbor revealed 4 of 25 patients had one stage pullthroughs as newborns, while 16/21 underwent initial stomas with pullthroughs (most commonly a straight ileoanal) delayed until a median age of 1 year. The rate of postoperative HAEC was > 50% and 20% had significant skin excoriation including patients in both immediate and delayed pullthrough groups.

 

A report from Helsinki described 11 patients with a transition zone between the mid small bowel and terminal ileum. Nine of 11 patients underwent an initial stoma and had their pull through delayed until a median of 11 months of age. Five of 11 patients underwent a straight pullthrough while 4 underwent a J-pouch pullthrough. One patient was left with an end jejunostomy. The rate of HAEC was 76%, but was reported as easy to manage. Functional outcomes at a median 6.5y followup were good in terms of preservation of continuity, frequency of bowel movements, continence and freedom from severe skin excoriation.

 

Contemporary expert recommendations support straight ileoanal pullthrough as the preferred conduit, which should be diverted to avoid severe skin excoriation if done in the newborn period. This assumes absolute certainty of location of the transition zone. If a stoma is created initially, the pull through should be delayed until the infant is growing and shows some evidence of stoma effluent thickening. Parents should be counselled preoperatively on the likelihood of skin excoriation and HAEC postoperatively.

B