Mirizzi Syndrome: Diagnosis and Management
Recommended Treatment Approach
For suspected Mirizzi syndrome, proceed with MRCP or endoscopic ultrasound for diagnosis, followed by open cholecystectomy as the definitive treatment, with the specific surgical approach determined by the Csendes classification type identified intraoperatively. 1, 2
Understanding Mirizzi Syndrome
Mirizzi syndrome is a rare but important complication of gallstone disease, occurring in less than 1% of patients with gallstones, characterized by extrinsic compression of the common hepatic duct by an impacted stone in the cystic duct or gallbladder infundibulum. 1, 2 The majority of cases are identified at surgery rather than preoperatively, making a high index of suspicion critical. 1, 3
Diagnostic Strategy
Initial Imaging
- Ultrasound should be performed first, looking specifically for: 4, 2
- Shrunken gallbladder with impacted stone(s) in the cystic duct
- Dilated intrahepatic and common hepatic ducts
- Normal-sized distal common bile duct (distinguishing feature)
- Ultrasound can suggest Mirizzi syndrome in approximately 78% of cases 5
Advanced Imaging for Confirmation
MRCP is the preferred non-invasive diagnostic test, with diagnostic accuracy of approximately 82% and the advantage of showing extent of inflammation to differentiate from gallbladder malignancy. 2, 5
CT scanning plays a crucial role in excluding malignancy at the porta hepatis or liver, which can mimic Mirizzi syndrome. 2
Endoscopic Evaluation
ERCP is considered the gold standard for diagnosis, delineating the cause, level, and extent of biliary obstruction, as well as identifying cholecystobiliary fistulas. 2, 6
ERCP has diagnostic sensitivity of approximately 71% (5 of 7 cases in one series) and provides therapeutic options including stone extraction and biliary stent placement. 6
Intraoperative choledochoscopy is highly effective for confirming the diagnosis during surgery when preoperative imaging is equivocal. 5
Surgical Management by Type
Type I Mirizzi Syndrome (External Compression Only)
Cholecystectomy alone is effective and sufficient. 5
Laparoscopic cholecystectomy may be attempted in highly selected Type I cases with strict patient selection, though conversion to open should have a low threshold. 5, 6
Type II and III Mirizzi Syndrome (Cholecystobiliary Fistula)
Partial cholecystectomy without removal of the gallbladder portion around the fistula margin is the recommended approach. 5
Choledochoplasty may be required depending on the extent of ductal involvement. 5
Four patients with Type II disease had successful fistula closure surgically in one series. 3
Type IV Mirizzi Syndrome (Large Fistula)
- Hepaticojejunostomy is required for all Type IV cases due to extensive ductal destruction. 5
Critical Surgical Principles
Open surgery remains the current standard for managing Mirizzi syndrome with good short- and long-term results and low mortality and morbidity. 2, 5
Key Operative Considerations:
Laparoscopic management is contraindicated in most cases due to increased risk of bile duct injury, morbidity, and mortality. 2
Early recognition during dissection is essential to avoid iatrogenic bile duct injury. 3
A judicious approach with careful dissection around the porta hepatis is mandatory. 3
Role of Endoscopic Therapy
Endoscopic treatment serves as an alternative only in patients who are poor surgical candidates (elderly, multiple comorbidities) or as a temporizing measure to provide biliary drainage before elective surgery. 2
ERCP with stone extraction and biliary stent placement can relieve obstruction temporarily. 2
Endoscopically-directed shock-wave lithotripsy has been reported for clearing the biliary tree in post-cholecystectomy Mirizzi syndrome. 7
Common Pitfalls to Avoid
Misdiagnosis as simple choledocholithiasis is common, even on MRCP, leading to inappropriate management. 7
Attempting laparoscopic cholecystectomy without recognizing Mirizzi syndrome significantly increases the risk of major bile duct injury. 2, 5
Failure to consider malignancy in the differential diagnosis, particularly in older patients with atypical presentations. 2
Inadequate preoperative imaging when clinical suspicion exists—combining ultrasound, MRCP, and ERCP improves diagnostic sensitivity substantially. 5