cystobiliary fistula a common complication of hepatic hydatid cyst .pptx

review on hydatid cystobiliary fistula.

1. Hydatid cystobiliary communication (fistula) Dr Karrar Adil

2. Introduction: Liver hydatid disease is a common public health problem all around the World . Infestation of humans with larval form incidentally causes hydatid cyst formation in different organs, most commonly liver. Rupture of the cyst is the most common complication as the cyst enlarges. The cyst may rupture into the peritoneal cavity, pleural cavity, blood stream or most commonly intrabiliary rupture .

3. The cystobiliary communication (CBC) is classified into 2 main types: Minor (simple or occult) fistula. Major (frank ) fistula. Minor fistula (10-37%) is usually asymptomatic and may be diagnosed intra-operatively or post operatively by an external biliary fistula . Frank fistula (5% to 17%) is a wide communication between the cyst and the biliary system that allows the contents of the cyst to drain into the biliary system causing obstructive jaundice, cholangitis, secondary infection of the cyst, or even anaphylaxis.

4. Predictors of cystobiliary communication : cyst size > 10 cm. multiple cysts. calcified wall. cysts location (segment 4 and 5). recurrent disease. preoperative jaundice. p reoperative elevated serum alkaline phosphatase (ALP ).

5. Pathogenesis : Intracystic pressure is 30-80 cm H2O. this pressure is generally higher than the intraluminal pressure of the biliary radicals. This high pressure is the cause of CBC. Two theories have been proposed about the pathogenesis of CBC. First : the hydatid cyst progressively compresses the biliary tract wall , which causes necrosis and eventually CBC. Second : small biliary radicals in the pericystic wall generate high intracystic pressure, resulting in atrophy followed by the rupture of the biliary radicals .

6. Because intracystic pressure is higher than the intraluminal biliary pressure, Flow is therefore toward the biliary system, and bile may not be present in the cavity despite occult CBC. Once the cyst has been drained, leakage follows because the pressure gradient is reversed, and bile flows into the residual cavity rather than through the papilla of Vater . The fact that most of occult CBC cases appear as biliary leakage also supports this view.

7. Diagnosis : Frank CBC is easily diagnosed preoperatively with : History and physical examination (jaundice). Blood investigations : Hyperbilirubinemia . high levels of alkalene phosphatase (ALP) or gama glutamile transpherase (GGT ). Imaging : Abdominal ultrasound . Abdominal CT scan. M agnetic resonance ( MRI). ERCP (both diagnostic and therapeutic).

8. In contrast, it is unlikely to identify occult CBCs pre-operatively. It is either diagnosed intra-operatively or it may arise as external biliary fistula, biliary peritonitis or biliary abscess in postoperative period.

9. A 54-year-old man with air content within a hepatic hydatid cyst. Coronal reformatted CT image on portal venous phase shows air bubbles (arrowhead) within a unilocular calcified hydatid cyst. This finding was suggestive of occult cysto -biliary communication, which was later confirmed at surgery.

10. Management : The management strategy of CBC depends on when it is diagnosed. Pre -operatively diagnosed frank fistulae presenting with obstructive jaundice and/or cholangitis can be effectively managed by: ERCP. open CBD exploration. followed by partial pericystectomy with omentoplasty .

11. Intra -operatively diagnosed CBC : There are several methods for intraoperative detection of CBC like leaving gauze in the cavity after opening the cyst , compressing gallbladder , intra-operative cholangiography , explore the cyst cavity with laparoscopic camera . For major communication (>5mm): intraoperative cholangiogram is performed and if any filling defects are noted in CBD, exploration followed by T tube drainage is done. For minor communication (<5mm): direct suturing if cyst wall is not calcified, suturing with omentoplasty if the cyst wall is calcified.

12. Occult CBF not detected pre- or intra-operatively usually presents with post -operative biliary fistula. It is defined as persistent biliary drainage for more than 10 days post operatively (regardless of amount). It can be low output (<300ml/day) or a high output (>300ml/day) fistula. low output fistulas can be managed conservatively with external drainage, they usually resolve by 6 to 17 days. high output fistulas : ERCP with sphincterotomy ± stenting can be done with a success rate of 83 to 100% with resolution of biliary fistula in 2 to 4 weeks.

13. Thank you…