KEM - DEPARTMENTS
HomeCollegeHospitalAlumniContactDepartmentsSearch
KEM LOGO

Radiology

ENDOVASCULAR MANAGEMENT OF INTRAHEPATIC ARTERIOPORTAL FISTULA .

Case 31: Contributed by Dr. Rashmi Saraf
Other Cases

Case Report :

A 42-year-old lady presented with two months' history of epigastric discomfort and loose stools. There was no history of blood in the stools. Her general examination was normal. On abdominal examination, ascites was present. Blood, urine and stool cultures were negative. Abdominal ultrasound revealed mild hepatomegaly, small hypoechoic lesions in the right lobe of liver, moderate ascites and thickened bowel loops. A colour Doppler examination of the hepatoportal system showed an arteriovenous fistula between the left hepatic artery and left portal vein with centripetal portal venous flow (Fig 1).

Fig. 1

Contrast enhanced CT scan of the abdomen demonstrated the left arterioportal fistula . The small bowel wall was thickened and congested. There was moderate ascites (Figs 2&3).

Fig. 2
Fig. 3


Selective angiogram of the hepatic artery showed the left hepatic artery to be hypertrophied and tortuous. It also showed an aneurysm distally with calcified walls. It fed an arteriovenous fistula through multiple feeders. These drained into the left portal vein which showed aneurysmal dilatation. There was flow reversal in the splenic and superior mesenteric veins. The right hepatic artery was normal. (Fig 3&4).

Fig. 3
Fig. 4

Endovascular management was planned. A 5F guiding catheter was placed in the left hepatic artery hepatic artery and coiled using two steel coils (Cook 35-10-8 and 35-8-5). A check angiogram revealed complete occlusion of left hepatic artery - but the arteriovenous malformation was now fed by an intrahepatic branch of the right hepatic artery. (Fig 5)

Fig. 5

A 5F guiding catheter was placed in the common hepatic artery and a Magic MP microcatheter (Balt) was navigated into the feeder arising from the right hepatic artery. This artery was embolized using 1.5 cc of 33% glue (NBCA). The post embolization angiogram revealed complete occlusion of the arterioportal fistula. (Fig 6)

Fig. 6
Contrast enhanced CT scan abdomen performed two weeks after the procedure showed complete occlusion of the arterioportal fistula, normal bowel wall and resolution of ascites (Fig7). Colour Doppler study revealed absence of flow into the fistula. Portal vein shows normal caliber (Fig 8)
Fig. 7Fig. 8

DISCUSSION:

Hepatic arteriovenous malformations can be of three types

i) direct communication between a systemic artery and a hepatic vein (hepatic arteriovenous fistula)
ii) communication between the hepatic artery and the portal venous system(hepatoportal fistula)
iii) multiple arteriovenous microfistula as part of hereditary hemorrhagic telengiectasia or hemangioma.

Arterioportal fistulas can be extrahepatic or intrahepatic. They may be congenital or acquired after blunt or penetrating trauma, percutaneus liver biopsy, transhepatic cholangiography, gastrectomy or biliary surgery. They can also result from a ruptured hepatic artery aneurysm or hepatocellular carcinoma.

The literature describes two common ages for the presentation of congenital arterioportal fistulas ie before the first year of life or after the fourth decade. It is often difficult to determine whether the late onset fistulas are congenital or acquired - whether a patient will become symptomatic and if so, after what period of time. It depends mainly on the size and location of the fistula. The symptoms of arteriovenous fistula are mainly due to hemodynamic alterations, intestinal dysfunction and hepatic dysfunction. The presenting symptoms are usually abdominal pain, diarrhea and gastrointestinal hemorrhage. These clinical findings are related to portal hypertension or high output heart failure or due to intestinal venous congestion and stasis. High flow in hepatic artery may compromise blood flow distal to its origin resulting in stealing of blood flow from the superior mesenteric artery presenting with abdominal pain and diarrhea (as seen in our patient).

Marking the correct diagnosis of arterioportal fistulas is important as they are easily treatable. Ultrasonography with Doppler study is a noninvasive, fast, reliable diagnostic tool. The roles of CT and MRI are still to be defined. Arteriography should be performed early for diagnostic purposes and possible therapy.

The treatment options depend on the size and localization of fistula. The aim is occlusion of the fistula. The transcatheter method of closure of fistula is simple, safer, cheaper and as effective as surgical closure. Angiographic embolization can be performed with steel coils, detachable balloons or bucrylate. Embolization of the feeder artery can be curative. Coils have the advantages of good control and visibility and can be delivered through small catheters.

In conclusion, percutaneous transcatheter embolization is the treatment of choice for symptomatic hepatic arteriovenous malformations. Detachable coils are easy to use and effective in suitable lesions. Use of cynoacrylate glue is useful in select cases. Controlled and skillful injection of glue is needed to achieve effective embolization and to prevent complications. The actual choice of the embolizing agent should be made according to the size, location and anatomy of the arteriovenous fistula.

This case illustrates unusual late presentation & symptoms of the patient, hemodynamic alteration leading portal hypertension and its successful embolisation alleviating symptoms with satisfactory imaging follow up.


Home | College | Hospital | Alumni | Contact | Departments | Search | Radiology