Teaching Case

Patient affected by primary biliary cirrhosis (diagnosed by means of percutaneous liver biopsy) was admitted at our institution with two months history of recurrent epigastric pain associated with hypotension, haemoglobin reduction (6 g/dl) and melaena.

Patient affected by primary biliary cirrhosis (diagnosed by means of percutaneous liver biopsy) was admitted at our institution with two months history of recurrent epigastric pain associated with hypotension, haemoglobin reduction (6 g/dl) and melaena.
Gastroscopy showed the presence of blood in the stomach and duodenum although no variceal bleeding was demonstrated.
Abdominal ultrasound examination was performed and revealed an inhomogeneous hypoechoic area with associated dilatation of the right portal branch in the VII-VIII hepatic segments.
CT angiography demonstrated a pseudoaneurysm of the right hepatic branch and the presence of arterio-portal fistula with early opacification of the right portal branch. A segmental dilatation of the intrahepatic biliary ducts around the vascular lesions was also detected (Fig 1-3).
Angiography was performed using a femoral approach and a 5Fr Simmons 1 catheter. Common hepatic and super selective right hepatic arteriography (coaxial 3Fr micro catheter) confirmed the presence of a pseudoaneurysm of the right hepatic artery and the communication with the portal system. The use of a micro catheter allowed catheterisation of the pseudoaneurysm arterial feeder.
Platinum fibered micro-coils were delivered to obtain occlusion of the pseudoaneurysmal sac and the arterio-portal fistula as confirmed by post-embolization runs (Fig 4). The patient had no other episodes of haemorrhage, and at 6 months follow-up the patient is in good health.

The presence of a pseudoaneurysm of the hepatic artery leading to rupture in the portal system can partially explain the clinical manifestations showed by our patient. The presence of a segmental dilatation of the biliary tree and the development of melaena suggest also the presence of a vascular-biliary fistula. The percutaneous liver biopsy performed six months before the onset of the episodes of abdominal pain can explain the development of the fistula.
Arterio-portal fistulae may be congenital (vascular malformations in Rendu-Osler disease) or acquired. Iatrogenic causes (percutaneous liver biopsy, percutaneous liver tumour ablation procedures), trauma and cirrhosis are mostly involved for acquired arterio-portal fistulae; the involvement of the biliary tree has been described as a complication of transhepatic biliary drainage, percutaneous catheterization of the biliary tree or percutaneous liver biopsy. Complications attributable to percutaneous liver interventions are uncommon and strictly related to the calibre of the needles used for procedures. These arterio-portal fistulae may be minute and asymptomatic, such as in cirrhosis, or large.
Congenital vascular malformations, iatrogenic causes and liver neoplasms may lead to large arterio-portal fistulae. Not frequently, these fistulae themselves cause a rapid development of portal hypertension due to the increased flow and pressure in the portal venous system. The involvement of the biliary tree causes haemobilia and associated acute cholecystitis in some cases.

Helical CT performed during the arterial phase shows early and marked enhancement of the main portal vein and segmental branches with an attenuation approaching that of the aorta associated to a non-enhancement of the splenic and mesenteric vein. This pattern related to an increase in portal vein inflow is due to the arterio-portal shunt itself and is associated with a prolonged enhancement of the portal vein during the portal venous phase. The abnormally enhancing veins are often enlarged because of the higher systemic pressures presented by the hepatic artery. Enlarged hepatic arteries may also be seen in the vicinity of the shunt. Reduction or loss of the geographic enhancement of the splenic mesenchyma during the arterial phase has been reported in association with large arterio-portal shunts and has been attributed to diminished splenic artery inflow.
Color and Doppler sonography can identify the presence of an arterio-portal fistula and its hemodynamic significance showing an arterialized portal venous waveform associated to a decrease of the resistive and pulsatility index.
Currently, angiography is performed to confirm the diagnosis and to assess the correct therapeutic approach (surgical or interventional).
Several factors determine the therapeutic approach including the location of fistulae and associated factors of morbidity. In some cases a spontaneous closure of small fistulae has been reported. Due to the development of portal hypertension, even asymptomatic fistulae should be treated. In general, surgery is the procedure of choice for extra hepatic fistulae, while transcatheter arterial embolization is optimal for intrahepatic fistulae. Surgical intervention is also required when interventional procedures have failed. The goals of treatment, both surgical or interventional, are to interrupt the fistula, to preserve the hepatic arterial flow and to close the defect in the portal vein and in the biliary tree when required.