Establishing a National Rate of Rectal Biopsy Positivity in the Diagnosis of Hirschsprung Disease

Objectives: Although rectal biopsy has long been established as the criterion standard for the diagnosis of Hirschsprung disease, little to no information exists regarding nationwide rates of rectal biopsy positivity or interinstitutional variability. We sought to determine the national rate of rectal biopsy positivity and factors contributing to institutional variability.

Methods: A retrospective review of the Children's Hospital Association's (CHA) Pediatric Health Information System from 2009 to 2018 identified infants <100 days old with ICD-9/ICD-10 procedural codes for rectal biopsy in addition to codes for pull-through procedures within 500 days of life as a proxy for positive biopsy. A subgroup analysis of only patients biopsied at institutions with positive biopsy rates 1 standard deviation above or below the mean positive biopsy rate (deemed high and low outliers) was performed to better delineate these populations.

Results: A total of 7225 children underwent rectal biopsies between 2009 and 2018 at 52 Children's Hospital Association Hospitals. Mean positive biopsy rate for individual institutions was 21.5% (standard deviation ± 6.4%). Linear regression to predict the effect of hospital surgical volume on positive biopsy rate demonstrated no volume outcome relationship (R2 = 0.049). Patients at high outlier hospitals for biopsy positivity were found to travel significantly further to the hospital (232.5 vs 123.1 miles, P < 0.0001) when compared to patients presenting at low outlier hospitals.

Conclusions: There appears to be little interinstitutional variability in the rate of surgery following rectal biopsy for presumed Hirschsprung and no significant relationship to surgical volume. About 1 in every 4 infants undergoing biopsy proceeds to surgery.