Mirizzi's syndrome

Overview
Mirizzi's syndrome is a rare cause of acquired jaundice. It is caused by chronic cholecystitis and large gallstones resulting in stenosis of the common hepatic duct.

Epidemiology
Occurs in approximately 0.1% of patients with gallstone disease and 0.7-1.4% of patients undergoing cholecystectomy

It affects males and females equally, but tends to affect older people more often. There is no evidence of race having any bearing on the epidemiology.

Pathophysiology
Multiple and large gallstones can reside chronically in the Hartmann's pouch of the gallbladder, causing inflammation, necrosis, scarring and ultimately fistula formation into the adjacent common bile duct (CBD). As a result, the CBD becomes obstructed by either scar or stone, resulting in jaundice. It can be divided into four types. Type I does not involve a fistula at all. Type II- IV involve fistulas of different sizes.

Type II is classified as a fistula of <33%of the CBD width, Type III Mirizzi Syndrome involves a fistula between 33% and 66% of the CBD width, and Type IV involves a fistula of greater than 66% of the CBD width.

Features
Mirizzi syndrome has no consistent or unique clinical features that distinguish it from other more common forms of obstructive jaundice. Symptoms of recurrent cholangitis, jaundice, right upper quadrant pain, and elevated bilirubin and alkaline phosphatase may or may not be present. Acute presentations of the syndrome include pancreatitis or cholecystitis.

Diagnosis
CT scan or ultrasonography usually make the diagnosis. Often, ERCP is used to define the lesion anatomically prior to surgery.

Treatment
The treatment of choice is surgical excision of the gallbladder, and reconstruction of the common hepatic duct and common bile duct.

Eponym
It is named for Pablo Mirizzi.