Introduction

Mirizzi syndrome can be defined as a rare complication of gallstone disease. The main characteristic of this syndrome is the obstruction of the hepatic duct by is obstructed by a gallstone that usually gets stuck either in the cystic duct or the neck of the gallbladder. If the condition is not managed properly, patients can experience jaundice, cholangitis, and eventually biliary cirrhosis. Therefore, having a comprehensive understanding of both the diagnosis and treatment of Mirizzi Syndrome is essential for improving patient outcomes and preventing serious complications. An accurate diagnosis is needed to guide the management plan, which may include surgical intervention. This knowledge enables healthcare professionals to make timely decisions, ensuring that patients receive the best possible care and reducing the likelihood of adverse effects.

Aetiology and pathophysiology

As previously mentioned, Mirizzi syndrome occurs due to a gallstone in the cystic duct or Hartmann’s pouch. The gallstone causes a blockage of the common hepatic duct. Depending on the size of the gallstone, it can lead to partial or complete obstruction of bile flow. This obstruction will result in cholestasis and subsequent jaundice. 

Additionally, some patients might develop chronic inflammation and fibrosis, which makes the condition harder to manage and treat, posing some difficulties in surgical management.

Clinical presentation

The main symptoms that patients with Mirizzi syndrome experience are usually obstructive jaundice, which means that the skin and sclera start to develop a yellow colour, the urine also gets darker, and pale stools. Other common symptoms include right upper quadrant abdominal pain, fever, and chills, which indicates secondary bacterial cholangitis. In some cases, patients may also experience nausea and vomiting.

Diagnostic approach

Let’s have a look at how Mirizzi syndrome is typically diagnosed as this represents a crucial factor in providing adequate treatment for patients in a timely manner. 

Laboratory tests

When the GP or other healthcare provider suspects Mirizzi syndrome, they will initially recommend a series of laboratory tests including liver function tests (LFTs). In the case of a positive diagnosis, the test results expected would be increased levels of bilirubin, alkaline phosphatase, and gamma-glutamyl transferase. These findings indicate that obstructive jaundice is present. Additionally, the results of a complete blood count (CBC) may indicate leukocytosis(increased levels of white blood cells) indicating an infection.

Imaging studies

A series of imaging tests can be carried out to confirm the presence of Mirizzi syndrome such as ultrasound, magnetic resonance cholangiopancreatography, endoscopic retrograde cholangiopancreatography or a computed tomography (CT) scan.

Ultrasound

Abdominal ultrasound is often the first imaging modality used, as it is non-invasive and readily available. It can identify gallstones, bile duct dilatation, and the presence of a mass or stricture in the biliary tree. However, ultrasound may have limitations in clearly visualising the exact cause of the obstruction.

Magnetic Resonance Cholangiopancreatography (MRCP)

MRCP is a non-invasive imaging technique that provides detailed visualisation of the biliary and pancreatic ducts. It is useful in identifying the location and cause of biliary obstruction. MRCP can differentiate Mirizzi syndrome from other causes of biliary obstruction, such as malignancies.

Endoscopic Retrograde Cholangiopancreatography (ERCP)

ERCP is both a diagnostic and therapeutic procedure. It allows direct visualisation of the biliary tree and can confirm the diagnosis of Mirizzi Syndrome by demonstrating the presence of a gallstone causing extrinsic compression of the common hepatic duct. Additionally, therapeutic interventions such as stone removal or stent placement can be performed during ERCP.

Computed Tomography (CT) Scan

CT imaging may be used to further evaluate the extent of inflammation, fibrosis, and potential complications such as fistula formation or abscesses. It also shows a relatively clear and detailed image of the anatomy of the patient and is used planning surgical treatment.

Classification

Mirizzi syndrome can be divided into four types as explained below, based on the extent of ductal involvement and if the cholecystocholedochal fistula is present:

1. Type I: External compression of the common hepatic duct by a stone impacted in the cystic duct or Hartmann’s pouch without fistula formation
2. Type II: Presence of a cholecystocholedochal fistula involving less than one-third of the common hepatic duct circumference
3. Type III: When the Cholecystocholedochal fistula is up to two-thirds of the common hepatic duct circumference
4. Type IV: Cholecystocholedochal fistula involving more than two-thirds of the common hepatic duct circumference or complete ductal destruction

Treatment

Non-surgical management

In some cases, initial non-surgical management may be necessary to stabilise the patient, particularly if there is evidence of acute cholangitis or sepsis. This includes the administration of broad-spectrum antibiotics, intravenous fluids, and biliary drainage, which can be achieved endoscopically or percutaneously.

Endoscopic Interventions

Endoscopic interventions, such as ERCP, play a crucial role in both diagnosis and treatment. During ERCP, the impacted stone can sometimes be removed, and a stent may be placed to relieve biliary obstruction temporarily. However, endoscopic stone removal is often challenging due to the anatomic alterations caused by chronic inflammation and fibrosis.

Surgical treatment

Surgery is the primary treatment for Mirizzi syndrome, with the specific procedure chosen based on the syndrome's classification and disease severity. Careful evaluation is necessary to determine the most appropriate surgical approach for each patient.

Cholecystectomy

In Type I Mirizzi Syndrome, a cholecystectomy (removal of the gallbladder) is often sufficient. This can sometimes be performed laparoscopically, although conversion to an open procedure may be necessary due to dense adhesions and inflammation.

Biliary reconstruction

For Types II to IV, where there is significant ductal involvement or a fistula, more complex surgical procedures are required. These may include cholecystectomy combined with biliary reconstruction, such as choledochoplasty or hepaticojejunostomy. These procedures aim to restore biliary continuity and prevent postoperative complications such as bile leaks or strictures.

Laparoscopic approach

Advancements in laparoscopic techniques have allowed for minimally invasive management of Mirizzi Syndrome in selected cases. Laparoscopic cholecystectomy with intraoperative cholangiography can help in identifying and managing biliary obstructions. However, the laparoscopic approach is technically demanding and should be performed by experienced surgeons.

Postoperative care

Postoperative care involves monitoring for complications such as bile leaks, infection, and strictures. Patients may require imaging studies to ensure the patency of the biliary reconstruction and to detect any early signs of complications. Long-term follow-up is essential to monitor liver function and prevent recurrent biliary issues.

Prognosis and complications

The prognosis of Mirizzi syndrome depends on the timely diagnosis and appropriate management. Early intervention can prevent serious complications such as biliary cirrhosis, recurrent cholangitis, and secondary biliary cirrhosis. However, delayed diagnosis or inadequate treatment can lead to significant morbidity and mortality.

Complications

Let’s review the main complications that can occur in the case of a patient diagnosed with Mirizzi Syndrome:

• Cholangitis: Infection of the bile ducts, potentially leading to sepsis
• Biliary Cirrhosis: Chronic obstruction can cause irreversible liver damage
• Fistula Formation: Abnormal connections between the biliary tree and adjacent structures
• Bile duct injury: Surgical interventions carry a risk of bile duct injury, which can result in bile leaks or strictures

Summary

Mirizzi Syndrome can be a difficult condition to diagnose, especially in patients showing signs of obstructive jaundice and a history of gallstones. Diagnosing it accurately requires a keen eye and a mix of imaging techniques, with MRCP and ERCP being the most useful. Surgery is the primary treatment, and the surgical approach depends on how severe the condition is. Acting early and providing good postoperative care is crucial for preventing complications and achieving good results for patients with Mirizzi syndrome.