What is the relationship between Mirizzi syndrome and gallstones (cholelithiasis)?

From the Guidelines

Mirizzi syndrome should be suspected in patients with gallstones and obstructive jaundice, and diagnosed using imaging studies such as ultrasound, CT scan, MRCP, or ERCP, with surgical intervention being the definitive treatment. The diagnosis of Mirizzi syndrome can be challenging, as it is an uncommon condition that mimics common bile duct stones (CBDS), occurring in less than 1% of patients with gallstones 1. According to the 2020 World Society of Emergency Surgery updated guidelines, investigations for CBDS, such as liver function tests (LFTs), may help in the diagnosis of Mirizzi syndrome, although the vast majority of cases are identified at surgery 1.

Some key points to consider in the diagnosis and treatment of Mirizzi syndrome include:

• The role of LFTs, such as gamma-glutamyl transpeptidase (GGT), in diagnosing CBDS, with a sensitivity of 80.6% and a specificity of 75.3% 1
• The importance of early follow-up in the diagnosis of CBDS, with significant decreases in LFTs within the non-CBD groups at 4-day follow-up 1
• The use of imaging studies, such as ultrasound, CT scan, MRCP, or ERCP, to show the obstructing stone and biliary dilatation above the level of obstruction
• The classification of Mirizzi syndrome based on the extent of bile duct involvement, with different surgical approaches for each type
• The potential need for preoperative ERCP with stent placement to decompress the biliary system before definitive surgery
• The importance of antibiotics in the treatment of cholangitis, typically using broad-spectrum coverage like piperacillin-tazobactam or a combination of ceftriaxone and metronidazole.

In terms of treatment, surgical intervention is the definitive treatment for Mirizzi syndrome, with the approach depending on the type of Mirizzi syndrome and the extent of bile duct involvement 1. Overall, the diagnosis and treatment of Mirizzi syndrome require a multidisciplinary approach, with careful consideration of the patient's symptoms, imaging studies, and laboratory results.

From the Research

Mirizzi Syndrome and Stones

• Mirizzi syndrome is a complication of gallstone disease, characterized by compression of the extrahepatic biliary duct with an impacted stone 2, 3, 4, 5, 6
• The syndrome can result in significant morbidity and mortality if not recognized preoperatively 2
• Preoperative diagnosis of Mirizzi syndrome can be difficult, despite the availability of multiple imaging modalities such as ultrasonography, CT, and magnetic resonance cholangiopancreatography (MRCP) 2, 3, 4, 5, 6

Diagnosis

• Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in the diagnosis of Mirizzi syndrome, as it delineates the cause, level, and extent of biliary obstruction, as well as ductal abnormalities, including fistula 2, 4, 5, 6
• ERCP can also provide therapeutic options, such as stone extraction and biliary stent placement 2, 4, 5, 6
• Other diagnostic tools, such as ultrasonography, CT, and MRI, can provide supportive evidence for the diagnosis of Mirizzi syndrome 2, 3, 4, 5

Treatment

• Treatment of Mirizzi syndrome is primarily surgical, with open surgery being the current standard for managing patients with the syndrome 2, 4, 5
• Laparoscopic management is contraindicated in many patients due to the increased risk of morbidity and mortality associated with this approach 2
• Endoscopic treatment may serve as an alternative in patients who are poor surgical candidates, such as elderly patients or those with multiple comorbidities 2, 3, 4, 6
• ERCP can also be used as a bridge-to-surgery procedure, especially in cases with a more difficult biliary anatomy due to the type of fistula 6