Clinical features' diagnostics and treatment of Hirschsprung's disease in adults.

AIM: Hirschsprung's disease first diagnosed in adulthood is symptomatic from early childhood in most cases. However, the condition is frequently masked when constipation is managed effectively by enemas and aperients. One third of the patients will experience progressive symptoms or complications, requiring urgent surgical intervention.

METHOD: Ninety patients with adult Hirschsprung's disease were observed by a combination of investigations: barium enema, anorectal physiology, estimation of acetylcholinesterase activity and a 60mm full-thickness strip biopsy. The latter two modalities were performed in selected patients where there was diagnostic uncertainty. Single-staged resections, mostly modified Duhamel procedures, were performed in patients who were stable and fit, and with only a limited degree of megacolon present, and no other complications. Otherwise patients were temporarily defunctioned prior to staged resection. All patients underwent surgical treatment. Long-term functional outcomes were expressed as good, satisfactory or poor.

RESULTS: Median age was 24.5 years, range 14-47 years, and 72.2% were men. Almost three quarters (73.3%) of the patients had symptoms dating from early childhood. Barium enema was diagnostic in 84.3%, and 36.2% had a positive, but weak rectoanal inhibitory reflex. Acetylcholinesterase staining was positive in 85.7%, but full-thickness strip biopsy was positive in 100% of equivocal cases. A separate cadaveric study of unaffected individuals determined the true length of the normal physiological hypoganglionic zone, mean 24.4 mm and range 7.5-50 mm. Supra-anal short segment Hirschprung's disease was found in 5.6% patients, rectal involvement in 54.4%, rectosigmoid in 38.9% and total aganglionosis of the colon in 1.1%. Resection of the aganglionic zone and proximally dilated colon was performed as a single-staged procedure in 67.8%. Staged surgery was carried out in 32.2%. A modified Duhamel procedure was performed in 91.2% of cases. A good or satisfactory functional outcome was achieved in 96.7%. Long-term functional outcome after resection depends on the degree of preoperative megacolon present. Megacolon limited to the sigmoid colon was associated with a good outcome in 89.7%, but in only 66.7% with more proximal dilatation (P < 0.05).

CONCLUSION: Occasionally, Hirschsprung's disease presents in adulthood, with ongoing symptoms from early childhood or with the development of functional obstruction, faecal impaction and megacolon in later life. Diagnosis often requires multimodal investigation. A 60 mm full-thickness strip biopsy confirms aganglionosis in 100%. A modified Duhamel procedure is the operation of choice.