Date Published: September 29, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Theodoros Mariolis-Sapsakos, Vasileios Kalles, Konstantinos Papatheodorou, Nikolaos Goutas, Ioannis Papapanagiotou, Ioannis Flessas, Ioannis Kaklamanos, Demetrios L. Arvanitis, Evangelos Konstantinou, Markos N. Sgantzos.
Purpose. Thorough understanding of biliary anatomy is required when performing surgical interventions in the hepatobiliary system. This study describes the anatomical variations of right bile ducts in terms of branching and drainage patterns, and determines their frequency. Methods. We studied 73 samples of cadaveric material, focusing on the relationship of the right anterior and posterior segmental branches, the way they form the right hepatic duct, and the main variations of their drainage pattern. Results. The anatomy of the right hepatic duct was typical in 65.75% of samples. Ectopic drainage of the right anterior duct into the common hepatic duct was found in 15.07% and triple confluence in 9.59%. Ectopic drainage of the right posterior duct into the common hepatic duct was discovered in 2.74% and ectopic drainage of the right posterior duct into the left hepatic duct in 4.11%. Ectopic drainage of the right anterior duct into the left hepatic ductal system and ectopic drainage of the right posterior duct into the cystic duct was found in 1.37%. Conclusion. The branching pattern of the right hepatic duct was atypical in 34.25% of cases. Thus, knowledge of the anatomical variations of the extrahepatic bile ducts is important in many surgical cases.
Anatomic variations of the extrahepatic bile ducts are important during surgical procedures such as laparoscopic cholecystectomy, liver resection (hepatectomy, segmentectomy), and living donor transplantation [1, 2]. It has been shown that the frequency of bile duct injuries occurring during laparoscopic cholecystectomies is twice as high as those occurring during open cholecystectomies . Furthermore, evaluation of the biliary anatomy is essential before hepatic lobectomy or segmentectomy, as inaccurate determination of existing biliary anatomic variations may potentiate ligature or section of aberrant ducts, leading to major complications such as leakage or atrophy of the residual liver . Therefore, it is apparent that thorough knowledge and successful detection and recognition of such anatomic variations can lead to decreased morbidity and mortality rates during hepatobiliary surgery.
The material we used in our study consists of 73 samples from cadaveric incisions that took place at the Laboratory of Forensics and Toxicology of the University of Athens during the period of October 2010 to December 2011. The study received appropriate approval from the University of Athens’ ethics committee. Our material derives from 35 males and 38 females. Samples with cirrhosis, hepatobiliary cancer, hepatobiliary injuries, and previous operations in the liver or the biliary system were excluded from the study.
The right hepatic duct drains the segments of the right liver lobe (V–VIII) and has two major branches: the right posterior branch draining the posterior segments, VI and VII, and the right anterior duct draining the anterior segments, V and VIII. The right posterior duct has an almost horizontal course, whereas the right anterior duct tends to have a more vertical course. The right posterior duct usually runs posterior to the right anterior duct and fuses it from a left (medial) approach to form the right hepatic duct. The left hepatic duct is formed by segmental tributaries draining segments II–IV. The common hepatic duct is formed by fusion of the right hepatic duct, which is usually short, and the left hepatic duct. The cystic duct classically joins the common hepatic duct below the confluence of the right and left hepatic ducts . This typical anatomy of the right hepatic duct and of the common hepatic duct formation was encountered in 48 of our samples (65,75%) (Figure 1(a)).
Thorough knowledge of anatomical variations is of key importance during surgical procedures, especially when it comes to anatomic areas with high rates of variations, such as the hepatobiliary system. Many anatomical studies have been conducted in order to determine the specific anatomical variations, using cadaveric material, intraoperative data, or imaging such as ultrasonography and magnetic resonance cholangiography [2, 5, 6].
In summary, atypical branching patterns of the right hepatic duct were found in 34,25% of cases. The two most common variations were the ectopic drainage of the right anterior duct into the common hepatic duct (15,07%), and trifurcation of the right anterior segmental duct, right posterior segmental duct, and left hepatic duct (9,59%).