Comparative Demography of Biliary Atresia and Choledochal Malformation in London

Objective: Choledochal malformation (CM) and biliary atresia (BA) are the two most important bile duct pathologies arising in infancy and childhood. The aim was to investigate for evidence of shared demographic features in a common temporo-spatial area.

Methods: Patients identified prospectively and defined as being born within metropolitan London in the period 1999-2022. Index of Multiple Deprivation (IMD) Rank Index (based on maternal post-code - England 2019) and live-birth data taken from the Office of National Statistics to assess incidence and differences assessed using the Poisson distribution and Chi² tests. P ≤ 0.05 was regarded as significant.

Results: 280 patients (BA n = 202; CM n = 78). The incidence of BA and CM in London was 7.45/100,000 (1 in 13,430) and 2.9/100,000 (i.e. 1 in 34,480) with no change over the period. The incidence of BA in Inner London was significantly higher at 9.42/100,000 (1 in 10,650) (P = 0.006). Marked female predominance evident in the CM group (77 % vs. 54.4 %; P = 0.0006) with more patients of non-white ethnicity in both groups (BA = 52.4 %; CM = 55 %, P = 0.32). No difference in IMDR between BA and CM (11,557 vs. 11,594; P = 0.26), with a marked difference between Inner and Outer boroughs for CM (8976 vs. 16,717; P < 0.001), but less so in BA (10,384 vs. 12,891; P = 0.039). IMDR was higher in those of white ethnicity for BA (11,979 vs. 10,660; P = 0.03).

Conclusions: Inner London has the highest incidence of BA than anywhere in Europe or North America. The calculated incidence of CM is higher than anticipated and the first to be based on actual observation.