The Mirizzi syndrome refers to common hepatic duct obstruction caused by an extrinsic compression from an impacted stone in the cystic duct or Hartmann's pouch of the gallbladder [1-3]. It has been estimated to occur in 0.7 to 1.8 percent of all cholecystectomies [4-7]. It is often not recognized preoperatively, which can lead to significant morbidity and biliary injury, particularly with laparoscopic surgery .
The gallbladder consists of the fundus, body, infundibulum, and neck. The infundibulum is an area of tapering between the gallbladder body and neck and Hartmann's pouch is a bulging of the inferior surface of the infundibulum that lies close to the neck of the gallbladder. The gallbladder is connected at its neck to the cystic duct which empties into the common bile duct.
Large gallstones can become impacted in the cystic duct or in Hartmann's pouch. These stones can produce common hepatic duct obstruction (the Mirizzi syndrome) by two mechanisms: mechanical obstruction of the hepatic duct because of the proximity of the cystic duct and the common hepatic duct, and secondary inflammation with frequent episodes of cholangitis [9-11].
There are two classifications that are usually used to clarify the variants of Mirizzi syndrome and to aid in choosing the appropriate therapeutic procedure:
The original classification by McSherry described two types of Mirizzi syndrome :