Appendix tip biopsy for Total colonic aganglionosis: technical aspects and diagnostic accuracy in a prospective cohort of 107 pediatric patients.

INTRODUCTION: The diagnosis of Total colonic aganglionosis (TCA) remains challenging, frequently resulting in delayed treatment and multiple surgical procedures. Appendix biopsy has been proposed as a diagnostic technique. Concerns exist regarding reliability. This study evaluated the diagnostic accuracy and technical applicability of appendix tip biopsy in children with suspected TCA. METHODS: A prospective observational study was conducted in 107 consecutive children (≤ 15 years) undergoing abdominal surgery with appendix tip biopsy between October 2022 and September 2024. Patients were allocated to three groups: Hirschsprung disease without TCA (n = 25), TCA (n = 19), and non-Hirschsprung controls (n = 63). Histopathological examination assessed the presence or absence of ganglion cells at the tips of the appendix. RESULTS: Ganglion cells were identified in 24/25 (96%) patients with Hirschsprung disease not involving the entire colon and in 61/63 (96.8%) controls. Ganglion cells were absent in all patients with TCA. Three inconclusive specimens resulted from inadequate sampling or very advanced inflammatory tissue destruction. Appendix tip biopsy achieved a sensitivity of 100%, specificity of 96.6%, positive predictive value of 86.4%, negative predictive value of 100%, and an overall diagnostic accuracy of 97.2%. Assessment was unaffected by patient age, including neonates, and generally possible in appendicitis when adequate full-thickness biopsy was obtained. CONCLUSIONS: Appendix tip biopsy is an accurate and tissue-sparing adjunct for diagnosing total colonic aganglionosis. When combined with appropriate histopathological assessment, it provides rapid diagnostic information while preserving the proximal appendix for potential future reconstructive procedures. These findings support its incorporation into the diagnostic pathway for children with suspected TCA.