---
title: I have been told I have Mirizzi syndrome. What does that change?
publication: Medical Insights Korea
section: faq
category: Gallbladder
canonical_url: https://medicalinsightskorea.com/faq/what-does-a-diagnosis-of-mirizzi-syndrome-change
author: David Seo
published: 2026-10-15T11:00:00+09:00
modified: 2026-10-15T11:00:00+09:00
content_type: reference
license: Quotation permitted with attribution to Medical Insights Korea and a link to the canonical URL.
---

# I have been told I have Mirizzi syndrome. What does that change?

A stone lodged in the neck of the gallbladder, pressing on the bile duct beside it, turns a routine operation into one that is far more often converted to open surgery.

## Answer

Mirizzi syndrome is a gallstone impacted at the neck of the gallbladder that first compresses the bile duct from outside and can go on to erode into it, and it changes the operation rather than the diagnosis of gallstones: a systematic review of laparoscopic treatment reported conversion to open surgery in 41 percent of cases, complications in 20 percent and reoperation in 6 percent.

## Key takeaways

- Mirizzi syndrome begins with a gallstone impacted at the gallbladder neck, which obstructs the bile duct first by pressure from outside and can then erode into the duct to form a fistula between the two.
- In the series that produced the most widely used classification, 219 patients with Mirizzi syndrome or cholecystobiliary fistula were identified among 17,395 patients operated on for benign biliary tract disease.
- In that series, type I lesions — external compression of the bile duct with no fistula — accounted for 11 percent of cases, type II for 41 percent, type III for 44 percent and type IV for 4 percent, and the majority of patients had obstructive jaundice.
- The type number describes how much of the bile duct circumference the fistula involves: less than one third in type II, up to two thirds in type III, and complete destruction of the duct in type IV.
- A systematic review of ten studies of laparoscopic treatment of Mirizzi syndrome reported a conversion rate of 41 percent, a complication rate of 20 percent and a reoperation rate of 6 percent, and found the risks of conversion and of procedure-related complications to be similar in type I and type II disease.
- Knowing about it before the operation is the point of the imaging: in 52 patients at a Korean hospital, magnetic resonance cholangiopancreatography combined with CT had a sensitivity of 96.0 percent for Mirizzi syndrome against 42.0 percent for CT alone.
- Mirizzi syndrome is uncommon, reported at an incidence of less than 1 percent a year among people with symptomatic gallstone disease in Western developed countries.

## Full article

Gallstones usually sit loose in the gallbladder. Occasionally one lodges in the narrow neck where the gallbladder drains, and sits there long enough to press on the bile duct that runs alongside. That is Mirizzi syndrome. The stone is an ordinary gallstone; what makes the diagnosis matter is where it has stopped and what it is pressing against.

It is not a different disease from gallstones, and it is not cancer. It is a mechanical complication of a common condition, and the reason it is named separately is that it changes the operation.

### What the classification is counting

The widely used classification came out of a Chilean series published in 1989, in which 219 patients with Mirizzi syndrome or a cholecystobiliary fistula were identified among 17,395 patients having surgery for benign biliary tract disease. The types describe one thing: how far the stone has got into the bile duct.

**Csendes classification of Mirizzi syndrome and cholecystobiliary fistula, with the proportion of 219 patients in each type**

| Type | What is found | Share of the series |
| --- | --- | --- |
| I | External compression of the bile duct, no fistula | 11% |
| II | Fistula involving less than one third of the duct circumference | 41% |
| III | Fistula involving up to two thirds of the circumference | 44% |
| IV | Complete destruction of the bile duct | 4% |

Most patients in that series presented with obstructive jaundice. That is the usual route to the diagnosis: yellowing, dark urine and abnormal liver blood tests in someone whose problem looks at first like ordinary gallstone disease.

### Why it changes the operation

The anatomy a surgeon relies on to take a gallbladder out safely is exactly the anatomy that inflammation around an impacted stone destroys. The gallbladder neck, the cystic duct and the bile duct become a single mass of scarred tissue, and the structure that must not be cut is in the middle of it.

**41%** — conversion from laparoscopic to open surgery in a systematic review of ten studies of laparoscopic treatment of Mirizzi syndrome  
_Source: Antoniou SA et al., Surgical Endoscopy, 2010_

That review also reported complications in 20 percent of patients and reoperation in 6 percent, and found that the risk of conversion and of procedure-related complications did not differ meaningfully between type I and type II disease. Converting to an open operation is not a complication in itself — it is the decision that avoids one.

> **Conversion is a plan, not a failure**  
> A 41 percent conversion rate does not mean that four operations in ten go wrong. It means that in four cases in ten the surgeon judged, on seeing the anatomy, that finishing through small incisions was not the safer route. The complication these decisions are made to avoid is injury to the bile duct, which in Korean multicentre data occurs in 0.7 percent of ordinary laparoscopic cholecystectomies.

### Why the scan before surgery matters so much here

Mirizzi syndrome found during an operation is a worse situation than Mirizzi syndrome known about beforehand, because the plan, the time allotted and sometimes the surgeon are different. Imaging is what makes the difference, and CT on its own is not enough.

**Diagnostic performance for Mirizzi syndrome in 52 patients with surgically proven findings at a Korean hospital, 13 of whom had the syndrome**

|  | MRCP combined with CT | CT alone |
| --- | --- | --- |
| Sensitivity | 96.0% | 42.0% |
| Specificity | 93.5% | 98.5% |
| Accuracy | 94.0% | 85.0% |

The gap is in sensitivity, which is the measure that counts when the question is whether a condition is present at all. CT alone missed more than half of the cases. The combined protocol also produced better agreement between the two radiologists reading it.

If the diagnosis has been made before surgery, the useful questions are what type is suspected, whether magnetic resonance cholangiopancreatography has been done as well as CT, and whether the operation is planned as laparoscopic with the possibility of conversion or as open from the start.

**Related**

- [Is not all gallstone surgery the same?](https://medicalinsightskorea.com/columns/surgery/not-every-gallbladder-is-the-same-operation) — A surgeon on why two gallbladders that look alike on a scan are not the same operation
- [Korea's own bile duct injury figure: 0.7 percent](https://medicalinsightskorea.com/news/korea-cholecystectomy-bile-duct-injury-rate)
- [What surgeons do instead of converting to open surgery](https://medicalinsightskorea.com/news/difficult-gallbladder-bailout-subtotal-vs-conversion)
- [How risky is gallbladder removal?](https://medicalinsightskorea.com/faq/how-risky-is-gallbladder-surgery)

## Sources

- Csendes A, Díaz JC, Burdiles P, Maluenda F, Nava O. Mirizzi syndrome and cholecystobiliary fistula: a unifying classification. British Journal of Surgery 1989;76(11):1139-1143. doi:10.1002/bjs.1800761110. PMID:2597969. https://doi.org/10.1002/bjs.1800761110
- Antoniou SA, Antoniou GA, Makridis C. Laparoscopic treatment of Mirizzi syndrome: a systematic review. Surgical Endoscopy 2010;24(1):33-39. doi:10.1007/s00464-009-0520-5. PMID:19466486. https://doi.org/10.1007/s00464-009-0520-5
- Yun EJ, Choi CS, Yoon DY, Seo YL, Chang SK, Kim JS, Woo JY. Combination of magnetic resonance cholangiopancreatography and computed tomography for preoperative diagnosis of the Mirizzi syndrome. Journal of Computer Assisted Tomography 2009;33(4):636-640. doi:10.1097/rct.0b013e31817710d5. PMID:19638864. https://doi.org/10.1097/rct.0b013e31817710d5
- Beltrán MA. Mirizzi syndrome: history, current knowledge and proposal of a simplified classification. World Journal of Gastroenterology 2012;18(34):4639-4650. doi:10.3748/wjg.v18.i34.4639. PMID:23002333. https://doi.org/10.3748/wjg.v18.i34.4639
- Abou-Saif A, Al-Kawas FH. Complications of gallstone disease: Mirizzi syndrome, cholecystocholedochal fistula, and gallstone ileus. American Journal of Gastroenterology 2002;97(2):249-254. doi:10.1111/j.1572-0241.2002.05451.x. PMID:11866258. https://doi.org/10.1111/j.1572-0241.2002.05451.x
- Lee H, Han IW, Choi JE, Lee HK. Surgical risk calculator development for postoperative outcomes after laparoscopic cholecystectomy: a multicenter prospective cohort study. Annals of Surgical Treatment and Research 2025;108(6):352-361. doi:10.4174/astr.2025.108.6.352. PMID:40503269. https://doi.org/10.4174/astr.2025.108.6.352

## Citation

David Seo (2026). "I have been told I have Mirizzi syndrome. What does that change?". Medical Insights Korea. https://medicalinsightskorea.com/faq/what-does-a-diagnosis-of-mirizzi-syndrome-change

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