Resection margin histology may predict intermediate-term outcomes in children with rectosigmoid Hirschsprung disease

Introduction Recent studies suggest that some of the post-surgical morbidity in Hirschsprung disease (HSCR) is due to enteric nervous system structural defects in the proximal, ganglionated bowel that remains after surgery. We hypothesized that resection margin histology would predict intermediate-term outcomes in HSCR patients. Methods Following IRB approval, HSCR patients with rectosigmoid disease born between 2009 and 2016 were reviewed and tissue blocks were obtained for new analyses. Proximal resection margins were analyzed for ganglion size, Hu + neurons/ganglion, and % nitric oxide synthase (NOS) neurons/ganglion as compared to control (non-HSCR) patient samples. Chart reviews were performed for 1- and 2-year outcomes. Patients were contacted for survey to determine Rintala bowel function score. Results 45 patients had recto-sigmoid disease and were further analyzed. HSCR patients had significantly smaller individual ganglion size (4533 μm 2 , range 1744–16,287 vs. 6492 μm 2 , range 1932–30,838, p = 0.0192) and fewer HuC/D + neurons per ganglion (15, range 5.2–34 vs. 21, range 5.2–6.7, p = 0.0214). HSCR patients demonstrated a markedly increased percentage of NOS (relaxation neurotransmitter) neurons (50, range 22–85 vs. 37, range 16–80, p = 0.0266). None of the histology measures correlated with presence/absence of constipation at 1–2 year follow-up ( p = NS). However, smaller ganglion size and higher percentage of NOS neurons correlated with decreased patient-reported quality of life ( r = 0.3838, r = − 0.1809). Conclusion 1–2 year follow-up may be insufficient to determine if resection margin histology correlates with outcomes. Patient-reported quality of life surveys, although limited in number, suggest that neurotransmitter imbalance at the resection margin may predict poor outcomes in HSCR patients. This study supports the concept that the ganglionated portion of the remaining colon post-surgery may not sustain normal bowel function.