Is Mirizzi syndrome the same as biliary colic?

Mirizzi Syndrome vs. Biliary Colic: Understanding the Difference

Mirizzi syndrome is not the same as biliary colic; it 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

Mirizzi Syndrome: Definition and Pathophysiology

• Mirizzi syndrome affects less than 1% of patients with gallstones and is characterized by obstruction of the common hepatic duct due to external compression from an impacted gallstone in the gallbladder neck or cystic duct 1
• The condition can progress from external compression to mucosal ulceration and eventually to cholecystobiliary fistula formation 2
• The Csendes classification system is widely used to categorize Mirizzi syndrome into five types based on the presence and severity of cholecystobiliary fistula 2

Clinical Presentation of Mirizzi Syndrome

• Patients with Mirizzi syndrome typically present with obstructive jaundice and often have a longstanding history of gallstones 2
• The clinical presentation is non-specific and can mimic gallbladder, biliary, or pancreatic malignancy 2
• Some patients may present with Charcot's triad (jaundice, fever, and right upper quadrant pain), which was observed in a significant number of cases in clinical studies 3

Biliary Colic: How It Differs

• Biliary colic is the most common symptom of gallstone disease, occurring in 20-30% of patients with gallstones 4
• Unlike Mirizzi syndrome, biliary colic does not involve obstruction of the common hepatic or bile ducts but rather results from temporary obstruction of the cystic duct 4
• Biliary colic typically presents as episodic right upper quadrant pain without the obstructive jaundice characteristic of Mirizzi syndrome 4

Diagnostic Approach

• Ultrasonography is typically the first imaging investigation for suspected Mirizzi syndrome, which may show a large stone in the gallbladder neck 5
• Endoscopic retrograde cholangiopancreatography (ERCP) is valuable for diagnosis, demonstrating a filling defect in the biliary tract at the cystic duct level 5
• CT scanning can also be helpful in the diagnostic workup 3
• Preoperative diagnosis of Mirizzi syndrome is crucial for surgical planning but is often challenging, with many cases only identified during surgery 2

Treatment Considerations

• Open cholecystectomy is the current standard treatment for Mirizzi syndrome, as recommended by clinical guidelines 1
• Laparoscopic cholecystectomy is generally contraindicated in Mirizzi syndrome due to the high risk of bile duct injury, though it may be attempted in less severe cases 5, 2
• For cases with cholecystobiliary fistula, partial cholecystectomy with choledochoplasty using a gallbladder flap may be the treatment of choice 5
• Intraoperative cholangiography is recommended when biliary anatomy is unclear 1

Clinical Pitfalls and Caveats

• Mirizzi syndrome is often misdiagnosed preoperatively despite advances in imaging techniques 3
• The presence of dense adhesions and distorted anatomy at Calot's triangle increases the risk of bile duct injury during surgery 2
• Early recognition during surgery is crucial to avoid bile duct injury, which can occur if the condition is not identified 1
• Conversion from laparoscopic to open surgery should be considered whenever the surgeon cannot safely manage the procedure laparoscopically 1

In summary, while biliary colic is a common symptom of uncomplicated gallstone disease, Mirizzi syndrome represents a rare but serious complication that requires careful preoperative evaluation and appropriate surgical management to prevent bile duct injury and other complications.