What is Mirizzi syndrome?

Mirizzi Syndrome: Diagnosis and Management

Mirizzi syndrome occurs when a gallstone 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, affecting less than 1% of patients with gallstones. 1

Definition and Pathophysiology

• Mirizzi syndrome is an uncommon complication of gallstone disease with a prevalence of approximately 0.18-0.35% among all patients undergoing cholecystectomy 1, 2, 3
• It is characterized by extrinsic compression of the common hepatic duct by stones impacted in the cystic duct or gallbladder neck, leading to obstructive jaundice 1, 2
• In severe cases, the impacted stone can erode into the bile duct, creating a cholecystocholedochal fistula 3

Clinical Presentation

• The most common presenting symptoms include:
  • Abdominal pain (upper right quadrant) 2
  • Jaundice (intermittent or constant) 4, 2
  • Laboratory findings consistent with obstructive jaundice 3
• Mirizzi syndrome is often not identified preoperatively, making it a diagnostic challenge 5, 4

Diagnostic Approach

• Multiple imaging modalities are used for diagnosis:
  • Ultrasonography (US): Typical findings include a shrunken gallbladder, impacted stone(s) in the cystic duct, dilated intrahepatic bile ducts, and a normal-sized common bile duct 5
  • CT scan: Primarily used to differentiate Mirizzi syndrome from malignancy in the porta hepatis region 5
  • MRI/MRCP: Shows the extent of inflammation around the gallbladder and helps differentiate from gallbladder malignancy 5
  • ERCP: Considered the gold standard for diagnosis as it delineates the cause, level, and extent of biliary obstruction, as well as ductal abnormalities including fistulas 5, 3

Classification

• Type I: External compression of the common bile duct without fistula formation
• Type II: Presence of a cholecystocholedochal fistula 2, 3

Management

• Open cholecystectomy is the current standard treatment for Mirizzi syndrome, with good short and long-term outcomes 1, 5
• Laparoscopic approach:
  • May be considered in selected patients with Type I Mirizzi syndrome 2
  • Has a high conversion rate to open surgery (approximately 67%) 2
  • Generally contraindicated in many patients due to increased risk of bile duct injury 1, 5
• Intraoperative cholangiography is recommended when biliary anatomy is unclear 1
• For Type II Mirizzi syndrome with fistula formation, more complex biliary reconstruction may be required, such as Roux-en-Y cholecystocholedochojejunostomy 4

Alternative Management Options

• Endoscopic treatment:
  • May serve as an alternative in high-risk surgical patients (elderly or those with multiple comorbidities) 5, 6
  • Can provide temporary biliary drainage in preparation for elective surgery 5
  • Options include stone extraction and biliary stent placement 5, 6
• Percutaneous cholecystostomy may be considered in high-surgical-risk patients 6

Complications and Outcomes

• Morbidity rate is approximately 31%, with complications ranging from minor to severe 2
• Mean hospitalization is around 9 days (range 2-40 days) 2
• Early recognition is crucial to avoid bile duct injury during surgery 1

Key Points for Clinical Practice

• Mirizzi syndrome should be suspected in patients with obstructive jaundice and gallstone disease 1, 5
• Thorough preoperative evaluation is essential to minimize surgical complications 1
• Open cholecystectomy remains the standard approach for most cases 1, 2
• Conversion from laparoscopic to open surgery should be considered whenever the operating surgeon cannot safely manage the procedure laparoscopically 1