Radiographic transition zone as a predictor of aganglionic extent in Hirschsprungs Disease :A prospective observational study.

Hirschsprung disease is a congenital disorder characterized by the absence of ganglion cells in the Meissners plexus of the submucosa and the Auerbachs plexus of the muscularis in the terminal rectum  extending variably proximally  The prevalence of HD ranges from 1 to 1.63 per 10,000 births  occurring in approximately 1 in 5000 live births  with a male predominance of 4:1 About 65% of HD cases are diagnosed before 1 month of age, and 95% before 1 year of age .

The presence of a transition zone on contrast enema, as defined by Swenson, is the most accurate radiological finding for HD, observed in approximately 80% of cases . Several studies have shown that the location of the transition zone correlates well with the level of aganglionosis, while other studies have found discrepancies in this correlation .

Traditionally, surgical correction  involved an initial diverting colostomy with confirmation of the level of aganglionosis by full-thickness biopsy, followed by a definitive pull-through procedure at a later date . Recently single-stage procedures have become routine avoiding initial colostomy and reducing the number of hospitalizations . Single-stage trans-anal endorectal pull-through and laparoscopy-assisted pull-through procedures are safe and effective offering better cosmesis reduced postoperative pain and shorter hospital stays . However  accurate knowledge of the anticipated transition zone is essential for performing a single-stage procedure .

Therefore, a study is planned to evaluate the accuracy of the radiological transition zone in identifying the level of aganglionosis in children with Hirschsprungs disease