Prevalence of Pancreato-Biliary Maljunction in Children with Choledochal Cyst – A Prospective Observational Study

BACKGROUND: Pancreatico-biliary maljunction (PBM) is often found to be associated with choledochal cysts (CCs). According to a European multicenter study, the prevalence of PBM in cases of CC is found to be 72.2%, however, there is no Indian study depicting the prevalence of PBM in Indian children with CCs, which is one of the main postulated factors in the etiopathogenesis of CC. In this study, we have attempted to observe prospectively the prevalence of PBM in children with CC and correlate this to its morphological and biochemical parameters. The association between the presence of PBM and histopathological findings such as epithelial changes of the mucosa of the CC, inflammation, metaplasia or dysplasia, and histopathology of the liver has also been evaluated. MATERIALS AND METHODS: We carried out a single center, prospective observational study with a single arm study group. We prospectively selected all patients of CC admitted for surgery from November 2018 to October 2020. Data on biochemical, radiological, and histopathological parameters were collected and analyzed. RESULTS: We included a total of 20 patients in our study. The mean age of the participants was 6.22 ± 4.32 years. Among them, 11 (55.0%) were male and 9 (45%) were female. Abdominal pain was the most common presenting complaint among our patients (75.0%) and had a significant association with the presence of a PBM (P = 0.001). In symptomatic children, the mean duration of symptoms was 4.50 ± 2.26 months for jaundice, 4.50 ± 1.98 months for abdominal distension, and 5.07 ± 2.02 months for abdominal pain. Among the 3 children with cholangitis, the mean number of episodes was 3.33 ± 2.08, with a median of four episodes. Fourteen (70.0%) of the children had type I a CC, 1 (5.0%) participant each for types I b, I c, II and IV a and 2 (10.0%) of them had type IV b cyst. The mean size of the cyst (cm) was 7.41 ± 3.03 with a median of 6.85 cm. Among the children, 9 (45%) showed the presence of PBM on magnetic resonance cholangiopancreatography (MRCP), with 7 (77.8%) showing Komi's C-P type and 2 (22.2%) showing Komi's PC type. The mean common channel length (mm) on MRCP was 8.11 ± 2.47 with a median length of 8.00 mm. The biochemical analysis of a bile fluid amylase and lipase is the functional indicator of the presence of a PBM. Histopathological examination showed the presence of ulceration in the walls of the CC in 10 (50.0%) of the specimens. There was a significant association of the presence of PBM and ulceration in the mucosa of the CC (P ≤ 0.001), with the median levels being the highest in the PBM present group. CONCLUSION: Abdominal pain is the most common complaint in a child with CC, and when present, it is significantly associated with the presence of a PBM. MRCP is the gold standard tool to detect CCs and find out the morphology of PBM. The prevalence of PBM in children with CC of 45% with a mean common channel length of 8.11 mm. The biochemical analysis of a bile amylase and lipase is the functional indicator of the presence of a PBM and there is a significant association of their higher levels and presence of PBM. The presence of chronic inflammation and microscopic ulcers is significant histologic parameters depicting the presence of a PBM.