Mary Froehlich, MD, Joshua C MacDavid, MD, Christian Chan, MD, Nathan Ozobia, MD. UNLV School of Medicine, Department of Surgery
The purpose of this review is to review previous definitions and anatomic boundaries in cholecystectomy as described by Calot and Strasberg as well as to introduce our concept of the hepato-cystic Quadrangle of Ozobia. The one thing that is consistent about the anatomy of the hepato-biliary complex is its inconsistency. The hepato-biliary complex is here by defined as the structures that occupy the hepato-cystic quadrangle. This space spans the area between the hepatoduodenal ligament and the gallbladder in surgical position, with appropriately placed traction forces on the gallbladder. The inferior border is an imaginary line connecting the neck of the gallbladder to the hepato-duodenal ligament. The superior border is the undersurface of the liver. The lateral border is an imaginary line connecting the neck of the gallbladder to the undersurface of the right lobe of the liver. Medially, the border is the entire length of the hepato-duodenal ligament. The quadrangle can be further subdivided into four quadrants by visually bisecting the quadrangle, vertically and horizontally to obtain Quadrant’s 1-4 (Q1-Q4). Q1 contains: the cystic artery or arteries, cystic duct and lymph node of Lund, lymphatics, Calot’s triangle and the Critical View of Safety (CVS). Q2 contains: the medial end of the cystic artery, right hepatic artery, right hepatic duct, tributaries to the right hepatic vein close to the liver surface, and the lateral portion of the porta hepatis. Q3 contains: the medial portion of the right hepatic artery, left hepatic artery, proximal common hepatic duct, portal vein, and the medial portion of the porta-hepatis. Q4 contains: the distal common hepatic duct, cystic duct and common hepatic duct confluence continuing on to the CBD, proper hepatic artery, and the portal vein. During uncomplicated cholecystectomies, laparoscopic or open, the above contents are in their respective quadrants. However, anomalous distribution of vessels and ducts is the rule rather than the exception and must be looked for as interrogation of each quadrant is entertained. For the most part, during uncomplicated cholecystectomies, laparoscopic or open, dissection should be limited to Quadrants 1 and 2, while keeping in mind the boundaries and contents of Q3 and Q4. A strong knowledge of the quadrangle and strict adherence to dissection in Q1 and when necessary, the lower border of Q2 should be standard practice to reduce the chance of biliary tract injuries.
View Poster
This abstract was accepted for Poster presentation at the 2020 SAGES Virtual Meeting in the Biliary topic. Its program number was: P199 and its Abstract ID was: 100085