Prevalence of Different Hepatobiliary Tree Variants on Magnetic Resonance Cholangiopancreatography in Patients Visiting a Tertiary Care Teaching Hospital in Karachi

Abstract

Introduction Hepatobiliary tree variant anatomy is crucial to understand the preoperative planning of hepatobiliary surgeries. Although the presence of variant anatomy is not an absolute contraindication for liver transplantation, inadvertent mapping can lead to postoperative biliary complications. These variants are also important to be recognized in various hepatobiliary surgeries and interventional procedures. Magnetic resonance cholangiopancreatography (MRCP) is an excellent non-invasive imaging tool that can identify biliary anatomy. The purpose of the current study is focused on determining anatomical variants of the biliary tree on MRCP in our population visiting a teaching hospital in Karachi. Methods This cross-sectional study was conducted on patients referred to Dr. Ziauddin Hospital for MRCP. MRCP was performed on MAGNETOM Avanto, SIEMENS, Belgium, Germany. Images were analyzed on a workstation by two radiologists and a postgraduate trainee. A senior radiologist reviewed equivocal cases. SPSS 22.0 (SPSS Inc., Chicago, IL) was used for statistical analysis. Chi-square test was used to see the link between anatomical variants of biliary tree and gender. P-value of ≤0.05 was considered as statistically significant. Results We recruited 369 patients undergoing MRCP consecutively for our study. Out of 369, 342 patients were eligible for analysis (139 males and 203 females). Standard anatomy was found to be prevalent in 65.8%. Type 3 was the leading variant. A statistically significant difference was recorded for the type 2 anatomic variant which was more frequent in males than females (p-value <0.001), while types 1, 3, and 4 anatomic variants were found to be more in females than males but this difference was not statistically significant. Few other variants were also recorded. Conclusion This study is robust evidence regarding biliary variants in Pakistan. It is important to consider these variants in our region, owing to an increased trend of liver transplants and other hepatobiliary procedures.

Keywords: biliary tree; biliary tree variants; hepatobiliary anatomy; hepatobiliary surgeries; liver transplant; mrcp.

Figure 1. Graphical representation of the four most common anatomic variants recorded in our study (n=332)

Figure 2. MRCP images demonstrating anatomical variants of biliary tree recorded in our study

*Segmental branch. MRCP: magnetic resonance cholangiopancreatography.