[Anatomic variants of the biliary tree with MR Cholangiography: feasibility and surgical applications]. ACTA ACUST UNITED AC. 2007;144:505-507. [PMID: 18235361 DOI: 10.1016/s0021-7697(07)79775-2]

Anatomic variations of the intra-hepatic biliary tree in the Caribbean: A systematic review

BACKGROUND

In the classic descriptions of the human liver, the common hepatic duct forms at the confluence of left and right hepatic ducts. Many authors have documented variations in the intra-hepatic ductal system, but to the best of our knowledge there has been no report on bile duct variations in Caribbean populations.

AIM

To evaluate the variations in bile duct anatomy using magnetic resonance cholangiography (MRC) in unselected patients at a major hepatobiliary referral centre in the Eastern Caribbean. Knowledge of the intra-hepatic biliary anatomy is important to optimize service delivery for any physician treating liver and biliary disorders.

METHODS

This study was carried out at a tertiary referral hospital for hepatobiliary diseases in the Eastern Caribbean. We retrospectively evaluated magnetic resonance cholangiograms in 152 consecutive patients at this facility over a two-year period from April 1, 2017 to March 31, 2019. Two consultant radiologists experienced in MRC interpretation reviewed all scans and described biliary anatomy according to the Huang’s classification. A systematic review of published studies was performed and relevant data were extracted in order to calculate the global prevalence of each biliary variant. The variants in our population were compared to the global population.

RESULTS

There were 152 MRCs evaluated in this study in 86 males and 66 females. There were 109 (71.7%) persons with “classic” biliary anatomy (type A1) and variants were present in 43 (28.3%) persons. There was no statistical relationship between the presence of anatomic variants and gender or ethnicity. We encountered the following variants: 29 (19.1%) type A2, 7 (4.6%) type A3, 6 (3.95%) type A4, 0 type A5 and a single variant (quadrification) that did not fit the classification system. Compared to the global prevalence, our population had a significantly greater occurrence of A1 anatomy (71.7% vs 62.6%; P = 0.0227) and A2 trifurcations (19.1% vs 11.5%; P = 0.0069), but a significantly lower incidence of A3 variants (4.61% vs 11.5%; P = 0.0047).

CONCLUSION

There are significant differences in intra-hepatic biliary anatomy in this unselected Eastern Caribbean population compared to global statistics. Specifically, persons of Caribbean descent have a greater incidence of Huang A2 trifurcations and a lower incidence of Huang A3 variants.

Anatomic variations of intrahepatic bile ducts in a European series and meta-analysis of the literature

BACKGROUND

Accurate knowledge of biliary anatomy and its variants is essential to ensure successful hepatic surgery; however, data from European countries are lacking.

METHODS

Two hundred cholangiograms obtained from patients submitted to whole liver transplantation were reviewed; donors' characteristics were related to the prevalence of typical biliary anatomy and its variants. A comprehensive literature search was performed with MEDLINE and EMBASE from 1980 to 2010 to investigate whether geographical origin could be related to biliary abnormalities.

RESULTS

Typical biliary anatomy was observed in 64.5% of cases, but female donors more frequently presented an anatomic variation; typical anatomy was present in 55.0% of females and in 74.0% of males (P = 0.005). Twenty-two reports were identified by the literature search with a total of 7,559 cases, including the present series; heterogeneity was low (Q = 14.60; I2 < 5.0%) after exclusion of three outlier reports. Prevalence of typical biliary anatomy was similar in Europeans and Americans (∼60%); a slightly higher prevalence was observed in Asiatics (∼65%).

CONCLUSIONS

Anatomic variants seem to be more frequent in females, probably as a consequence of different embryologic development. Available data suggest that typical biliary anatomy can be more frequent in Asiatics, but an accurate means of classification is essential to making comparison realistic.