A New Quantitative Classification of the Extrahepatic Biliary Tract Related to Cystic Duct Implantation

Matteo Renzulli; Stefano Brocchi; Giovanni Marasco; Daniele Spinelli; Caterina Balacchi; Massimo Barakat; Irene Pettinari; Rita Golfieri

doi:10.1007/s11605-020-04852-8

A New Quantitative Classification of the Extrahepatic Biliary Tract Related to Cystic Duct Implantation

J Gastrointest Surg. 2021 Sep;25(9):2268-2279. doi: 10.1007/s11605-020-04852-8. Epub 2020 Dec 2.

Authors

Matteo Renzulli¹, Stefano Brocchi², Giovanni Marasco³, Daniele Spinelli², Caterina Balacchi², Massimo Barakat², Irene Pettinari², Rita Golfieri²

Affiliations

¹ Department of Radiology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, Bologna, Italy. matteo.renzulli@aosp.bo.it.
² Department of Radiology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, Bologna, Italy.
³ Department of Medical and Surgical Sciences, S. Orsola Hospital, University of Bologna, Bologna, Italy.

Abstract

Background: Knowledge regarding biliary anatomy and its variations, including the cystic duct (CD), is important in the pre-surgical setting and for predicting biliary diseases. However, no large series has focused on CD evaluation using a quantitative analysis. The primary aim of this prospective study was to create a 'taxonomic' classification of CD anatomy in a large cohort of subjects who underwent magnetic resonance cholangiopancreatography (MRCP). The secondary aim was to evaluate the correlations between extrahepatic bile duct (EHBD) variants and biliary diseases.

Methods: We enrolled patients who underwent MRCP for different clinical indications from January 2017 to May 2019. Demographical, anatomical and clinical data were evaluated using statistical analyses, as appropriate. The anatomical assessment of EHBD was performed using the standard classification for CD in low, medium, and high insertions, and the lengths of CD to the duodenal papilla (DP), and EHBD was determined to conduct a new quantitative analysis.

Results: The final study population comprised 1004 subjects. A new classification for EHBD as per the percentile distribution of the ratio CDDP/EHBD was designed, and the following categories were obtained: type 1 (below the 25th percentile) for CDDP/EHBD ratio ≤ 50%; type 2 (25th to 75th percentile) for CDDP/EHBD ratio 51-75% and type 3 (above the 75th percentiles) for CDDP/EHBD ratio > 75%. Type 1 of the new classification of CD implantation was significantly superior in terms of the detection of low, medial and intra-pancreatic CD that was significantly correlated with a high risk of choledochal lithiasis in comparison with the standard classification (P < 0.001).

Conclusions: The new classification of CD implantation enables identification of the vast majority of intra-pancreatic CDs that are correlated with a high risk of choledochal lithiasis in a single category (type 1) that is easy to identify using imaging.

Keywords: Anatomy; Biliary tract; Cholangiopancreatography; Cystic duct; Lithiasis; Magnetic resonance.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bile Ducts, Extrahepatic* / diagnostic imaging
Biliary Tract*
Cholangiopancreatography, Magnetic Resonance
Cystic Duct / diagnostic imaging
Humans
Prospective Studies