Enough is enough: how many rectal suction biopsies do you need to diagnose Hirschsprung’s disease?

Abstract Purpose Rectal suction biopsy (RSB) is the gold standard for diagnosing Hirschsprung’s disease (HD) in infants. Despite being a common procedure, no standard exists on the number of biopsy specimens and their respective level within the rectum. Methods We conducted a retrospective review of epidemiological and pathological data of patients who underwent RSB at our institution between January 2011 and May 2022. During RSB we obtain 4 specimens: at 1 cm, 3 cm and 5 cm above the dentate line, besides one specimen at the dentate line. We used a logistic regression model for statistical analysis and included control variables (e.g. underlying disease, weight at first biopsy, gestational age). Results A total of 92 patients underwent 115 biopsies, with an average of 3.77 specimens per session. Of the specimens taken at 1 cm above the dentate line 73.9% were conclusive, at 3 cm 75.9% and at 5 cm 79.2%. Specimens taken at the dentate line were squamous or transitional epithelia in 31.5% and therefore of no use for HD diagnostics. The specimen at 3 cm shows the highest discriminative power whether the biopsy session was diagnostic ( p -value < 1%). Conclusions We propose that a total of three specimens, namely one at 1 cm, one at 3 cm and one at 5 cm above the dentate line, is enough to diagnose or exclude HD.