What is the appropriate aganglionic bowel length on contrast enema for attempting single stage transanal endorectal pull-through in Hirschsprung disease?

PURPOSE: To identify influence of different values of age and abnormal bowel length in HD patients selected for single stage TERPT which affects the technique of surgery.

METHODS

This observational study was carried out for over 2.5 years. All children younger than 14 years old with clinical suspicion for HD, typical transitional zone (TZ) on contrast enema (CE) distal to splenic flexure, preoperative diagnosis approved by full thickness biopsy, no previous surgical history and no urgency were included. The distance between the anus and TZ was considered as aganglionic length on CE. Biopsy was taken from distal to proximal of resected bowel to reach circumferentially normal innervated bowel. Paired sample Student's t-test, Pearson correlation test, receiver operating characteristic (ROC) analysis were performed.

RESULTS

Forty-eight patients were enrolled in this study. Measured mean for aganglionic bowel length on CE and pathology were 33.5 ± 17.1 cm and 56.8 ± 33.5 cm, respectively (p < 0.01). Correlation coefficient (R) and coefficient of determination (R2) were 0.632 and 40%, respectively (p < 0.01). The difference between radiologic and pathologic measurements in females was higher than males (mean: 29.3 vs 21.9 cm) but was not statistically significant (p = 0.75). There was statistically significant difference between CE and pathologic results in the infants younger than 10 months (p = .004). Abnormal bowel length equal to 52 cm predicted requirement of laparoscopy assistance/laparotomy with 75% sensitivity and 85% specificity.

CONCLUSION

Our investigation showed it is safe to attempt for single stage TERPT when aganglionic length on CE is less than 52 cm and the child with HD is older than 10 months. Chance of requiring additional laparotomy or laparoscopy assistance is low in these patients.

TYPE OF STUDY: Study of diagnostic test.

LEVEL OF EVIDENCE: Level II.