Guidance of a pathological grading system of ganglion cells for intraoperative rapid biopsy of Hirschsprung disease for determining surgical margin and predicting bowel function

Objective To assess the practicability of a pathological grading system for ganglion cells in frozen sections for determining surgical margin of Hirschsprung's disease (HSCR) and predicting bowel function. Methods A total of 205 HSCR children were hospitalized from January 2014 to August 2018. There were 158 boys (77.1%) and 47 girls (22.9%). The clinical types of HSCR included short-segment (S-HSCR) (n=155, 75.6%), long-segment (L-HSCR) (n=30, 14.6%) and total colonic aganglionosis (TCA) (n=20, 9.8%). Medical records and detailed pathologic results of intraoperative frozen sections were reviewed. Based upon the histopathological features of ganglion cells in frozen sections, ganglion cells were divided into six degrees. The identification of grades I-III ganglion cells was regarded as a symbol of an acceptable surgical margin and vice versa. Follow-up data were collected for evaluating the clinical outcomes. And a validated pediatric incontinence and constipation scoring system (PICSS) was utilized for predicting bowel function. Results The final pathologic results of proximal resected bowel were presented as follows: grade I (n=6, 2.9%), grade II (n=102, 49.8%), grade III (n=85, 41.5%) and grade IV (n=12, 5.8%). Thirty-three HSCR children (16.1%) required further resection of proximal bowel since initial specimens submitted for pathologic evaluation showed an unacceptable surgical margin. The median follow-up period was 24.8(3.0-54.4) months. A marked correlation was observed between the pathologic grade of proximal resected margin and postoperative constipation (P=0.011) and soiling (P<0.001). The results of PICSS hinted at a positive correlation between postoperative bowel function and better pathologic grade. Conclusions A pathological grading system of ganglion cells in frozen sections guides pediatric surgeons in precisely determining surgical margin during surgery and an excellent pathologic grade is correlated with satisfactory clinical outcomes. This pathologic grade system may provide a new method for intraoperative histopathologic consultations for preventing insufficient resection of affected colon. Key words: Hirschsprung disease; Pathologic diagnosis; Histopathology; Intraoperative frozen section analysis