What is the condition where a common hepatic duct obstruction is caused by an impacted stone in the cystic duct or infundibulum of the gallbladder?

Mirizzi Syndrome: Common Hepatic Duct Obstruction by Impacted Gallstone

The condition where a common hepatic duct obstruction is caused by an impacted stone in the cystic duct or infundibulum of the gallbladder is Mirizzi Syndrome (answer C). 1, 2

Definition and Pathophysiology

• Mirizzi Syndrome is characterized by extrinsic compression of the common hepatic duct due to a gallstone impacted in the cystic duct or gallbladder neck/infundibulum 1
• The modern definition includes four components:
  • Anatomic arrangement where the cystic duct runs parallel to the common hepatic duct
  • Impaction of a stone in the cystic duct or gallbladder neck
  • Mechanical obstruction of the common hepatic duct by the stone or secondary inflammation
  • Intermittent or constant jaundice that can lead to recurrent cholangitis 1
• It occurs in fewer than 0.5% of patients with cholelithiasis, making it a rare complication 1, 3

Clinical Presentation

• Prominent jaundice is a common clinical manifestation 2
• Patients typically present with right upper quadrant or epigastric pain, especially when associated with jaundice and/or fever 4
• Intermittent symptomatology can make Mirizzi Syndrome difficult to diagnose preoperatively 1
• Laboratory findings often show elevated liver function tests, particularly elevated bilirubin 5
• In severe cases, patients may develop cholangitis with fever and chills 4

Diagnostic Approach

• Ultrasound examination typically shows a large stone in the neck of the gallbladder 2
• MRCP (Magnetic Resonance Cholangiopancreatography) is excellent for detection of cholelithiasis/choledocholithiasis with reported sensitivity of 85-100% and specificity of 90% 5
• ERCP (Endoscopic Retrograde Cholangiopancreatography) may demonstrate a filling defect in the biliary tract at the cystic duct level 2
• CT may be useful but is not the first-line imaging test for suspected biliary causes of right upper quadrant pain 5
• Preoperative recognition is crucial to prevent injury to the common bile duct during surgery 3

Classification

• Mirizzi Syndrome has been classified by Csendes into different types (I-IV) based on the presence and extent of cholecystobiliary fistulas 1
• Type I: External compression of the common bile duct without fistula
• Type II-IV: Presence of cholecystobiliary fistulas of increasing severity 1

Management Considerations

• Mirizzi Syndrome is considered a contraindication for laparoscopic cholecystectomy due to the high risk of common bile duct injury 2
• Open surgical approach is generally recommended when this syndrome is diagnosed or strongly suspected 1
• Surgical options include:
  • Simple cholecystectomy (for Type I without fistula)
  • Partial cholecystectomy with choledochoplasty using gallbladder flap and T-tube insertion (for cases with cholecystobiliary fistulas) 2
  • Roux-en-Y hepaticojejunostomy when the vascularity or viability of the hepatic duct is questionable 1
• Combined endoscopic and surgical management may be appropriate in selected cases 3

Clinical Pitfalls and Caveats

• Post-cholecystectomy Mirizzi Syndrome (PCMS) can occur in patients with a history of cholecystectomy, presenting with similar symptoms due to retained stones 6
• Mirizzi Syndrome can be misdiagnosed as simple choledocholithiasis on imaging studies 6
• The syndrome may mimic other conditions causing obstructive jaundice 7
• Failure to recognize this condition preoperatively increases the risk of bile duct injury during surgery 2, 3
• When suspected, achieving the critical view of safety (CVS) during laparoscopic cholecystectomy may be difficult or impossible, necessitating conversion to open surgery 5

Understanding Mirizzi Syndrome is essential for proper diagnosis and management of this rare but clinically significant cause of obstructive jaundice.