Application of a plain abdominal radiograph transition zone (PARTZ) in Hirschsprung's disease

BACKGROUND: A standard contrast enema for Hirschsprung's disease can sometimes be inconclusive in delineating a transition zone especially in neonates and infants. The aim of this study was to determine the utility and diagnostic accuracy of a plain abdominal radiograph transition zone (PARTZ) in predicting the level of aganglionosis. METHODS: A prospective observational study of neonates and infants with biopsy proven Hirschsprung's disease was carried out from March 2004 through March 2006. All patients underwent a plain abdominal radiograph and a contrast enema followed by a rectal biopsy. The transition zone on a plain radiograph (PARTZ) and contrast enema (CETZ) were compared with operative and pathology reports. Results were analyzed by chi square test and expressed as their p values and 95% confidence intervals. RESULTS: PARTZ and CETZ suggestive of Hirschsprung's disease was seen in 24(89%) and 18(67%) patients respectively. The PARTZ and CETZ matched with the pathologic level of transition zone in 22(92%) and 13(72%) patients, p = 0.001, 95% CI (-1.87 to -0.79). In the 9 (33%) patients in whom contrast enema failed to reveal a transition zone, PARTZ was seen in 6/9(66%) patients and correlated with the pathological level of aganglionosis in 4/6(67%) patients, p = 0.001 95% CI (-1.87 to -0.79). The overall accuracy of PARTZ and CETZ was 96% and 84% respectively, p = 0.008, 95% CI (-6.09 to -3.6). CONCLUSION: A plain abdominal radiographic transition zone is reliable in predicting the level of transition zone in cases of inconclusive contrast enema. It may be particularly helpful developing countries where laparoscopic techniques are not available to accurately identify the transition zone.