What is Mirizzi Syndrome?
Mirizzi syndrome is a rare complication of gallstone disease where a stone becomes impacted in the cystic duct or gallbladder neck, causing extrinsic compression of the common hepatic duct or common bile duct, resulting in obstructive jaundice. 1
Epidemiology and Incidence
- Mirizzi syndrome occurs in less than 1% of patients with gallstones, making it an uncommon but important diagnosis to recognize 2, 1
- The reported incidence ranges from 0.66% among patients undergoing cholecystectomy for cholelithiasis 3
- It is more prevalent in the female population and most commonly seen in adults, particularly the elderly with long-standing gallstone history 4, 5
Pathophysiology
- The condition results from a gallstone impacted in the cystic duct or Hartmann's pouch that causes extrinsic compression of the hepatic duct 4, 6
- In more advanced cases, it can progress to fistula formation between the gallbladder and common bile duct (or hepatic duct variants) 6, 7
- The inflammatory response secondary to the impacted stone leads to the biliary obstruction 7
Clinical Presentation
- Patients typically present with obstructive jaundice, abdominal pain, and fever 4, 6
- The symptomatology is nonspecific and similar to other causes of cholecystitis and biliary obstruction, making diagnosis challenging 4
- Some patients may present with prominent jaundice as the primary clinical feature 7
Diagnostic Approach
- Ultrasound can raise suspicion in 77.8% of cases, typically showing a large stone in the neck of the gallbladder 3
- Magnetic resonance cholangiopancreatography (MRCP) has higher diagnostic sensitivity at 82.3% and is essential for diagnosis 3, 5
- Endoscopic retrograde cholangiopancreatography (ERCP) may demonstrate a filling defect in the biliary tract at the cystic duct level 7, 5
- Intraoperative cholangiography is useful when biliary anatomy is unclear or when there is suspicion of bile duct injury 1
Clinical Significance and Risk
- Mirizzi syndrome is considered an at-risk condition that requires thorough preoperative evaluation before cholecystectomy 2, 1
- Severe inflammation and adhesion at Calot's triangle make cholecystectomy potentially very dangerous in these patients 6
- The condition mimics common bile duct stones but requires different surgical management 2
- Pre-operative investigations may help in diagnosis, although the vast majority of cases are identified at surgery 2
Management Principles
- Open cholecystectomy is the current standard treatment with good short and long-term outcomes 1, 3
- Laparoscopic surgery should be confined to type I Mirizzi syndrome with very strict patient selection 3
- Laparoscopic cholecystectomy is generally considered a contraindication due to high risk of common duct injury 7
- Conversion to open surgery should be considered whenever the surgeon cannot safely manage the procedure laparoscopically 1
Key Clinical Pitfall
The most important pitfall is misdiagnosing Mirizzi syndrome as simple choledocholithiasis, which can lead to inappropriate surgical approach and increased risk of bile duct injury during laparoscopic cholecystectomy 2, 7. An exhaustive preoperative work-up is mandatory to detect this at-risk condition and choose the best surgical approach 2.