Prevalence, presentation, and endovascular management of hemodynamically or clinically significant arterio-portal fistulae in living and cadaveric donor liver transplant recipients

Transplant Hepatic Artery Complications

Hepatic artery complications can be divided into 2 different categories, nonocclusive and steno-occlusive disease. Steno-occlusive disease is a collective term that encompasses hepatic artery thrombosis, hepatic artery stenosis, and hepatic arterial kinks, while nonocclusive arterial disease encompasses less than 5% of complications and is a collective term used to describe arteriovenous fistulae, pseudoaneurysms, arterial rupture and nonocclusive hepatic artery hypoperfusion syndrome. This article details the angiographic techniques and definitions needed to accurately diagnose arterial transplant complications and describes the technical aspects and results of endoluminal management of these arterial complications. In addition, this article discusses the presentation, etiology and indications for treatment, including surgical management of these various complications.

Arterioportal Fistulas (APFs) in Pediatric Patients: Single Center Experience with Interventional Radiological versus Conservative Management and Clinical Outcomes

Arterioportal fistulas (APFs) are uncommon vascular abnormalities with a heterogeneous etiology. In pediatric orthotopic liver transplantation (OLT), APFs are frequently iatrogenic, following percutaneous liver interventions. The aim of this study was to report the 10-year experience of a tertiary referral center for pediatric OLT in the interventional radiological (IR) and conservative management of acquired APFs. A retrospective search was performed to retrieve pediatric patients (<18 years old) with a diagnosis of APF at color Doppler ultrasound (CDUS) or computed tomography angiography (CTA) from 2010 to 2020. Criteria for IR treatment were the presence of hemodynamic alterations at CDUS (resistive index <0.5; portal flow reversal) or clinical manifestations (bleeding; portal hypertension). Conservatively managed patients served as a control population. Clinical and imaging follow-up was analyzed. Twenty-three pediatric patients (median age, 4 years; interquartile range = 11 years; 15 males) with 24 APFs were retrieved. Twenty patients were OLT recipients with acquired APFs (16 iatrogenic). Twelve out of twenty-three patients were managed conservatively. The remaining 11 underwent angiography with confirmation of a shunt in 10, who underwent a total of 16 embolization procedures (14 endovascular; 2 transhepatic). Technical success was reached in 12/16 (75%) procedures. Clinical success was achieved in 8/11 (73%) patients; three clinical failures resulted in one death and two OLTs. After a median follow-up time of 42 months (range 1–107), successfully treated patients showed an improvement in hemodynamic parameters at CDUS. Conservatively managed patients showed a stable persistence of the shunts in six cases, spontaneous resolution in four, reduction in one and mild shunt increase in one. In pediatric patients undergoing liver interventions, APFs should be investigated. Although asymptomatic in most cases, IR treatment of APFs should be considered whenever hemodynamic changes are found at CDUS.

Intrahepatic Arterioportal Fistula: A Rare Cause of Portal Hypertension After Deceased Donor Liver Transplant

A 43-year-old male patient, who received a deceased donor liver transplant for background ethanol-related decompensated cirrhosis, presented 7 months after transplant with mild abdominal distension and pain. On evaluation, the patient had thrombocytopenia, high serum-ascites albumin gradient ascites, and deranged liver functions. The Doppler study of the splenoportal axis showed hepatofugal flow in the recipient's portal vein, normal hepatic veins, a normal liver, splenomegaly, mild ascites, and multiple periportal collaterals. A transjugular liver biopsy and a hepatic venous pressure gradient measurement were done, which suggested mild portal tract inflammation with portal tract fibrosis with prominent portal venous thickening and normal hepatic venous pressure gradient (4 mm). However, the patient had a progressive increase in ascites and a dramatic increase in serum bilirubin level. A triple-phase computed tomography was done that showed rapid contrast flow in both the portal and hepatic arterial phase, suggesting arterialization of the portal flow with possible suspicion of a communicating arterioportal fistula. The patient underwent digital subtraction angiography, which was followed by an embolization of the arterioportal fistula. After embolization, serum bilirubin gradually decreased and ascites resolved. A repeat Doppler of the portal venous system showed established hepatopetal flow with progressively rising portal flow velocities.

Arterial-portal fistula treated with hepatic arterial embolization and portal venous aneurysm stent-graft exclusion complicated by type 2 endoleak

Intrahepatic arterioportal fistulas may be complicated by portal hypertension. An associated portal venous aneurysm (PVA) may impinge upon adjacent structures or rupture. We present a 65-year-old man with an intrahepatic Intrahepatic arterioportal fistula and 6.4 × 5.8 cm right portal vein aneurysm extending within 0.4 cm of the hepatic margin, associated with pain concerning for impending rupture. The PVA was refractory to transarterial embolization due to recruitment of arterial collaterals. Therefore, it was additionally excluded from the portal vein with a 12 mm × 9.5 cm venous stent graft. Although endovascular therapy thrombosed the aneurysm and improved symptoms, it was complicated by a type 2 endoleak into the PVA.

Case Report of Multiple Bilobar Hepatic Arterio-Portal Fistulas Post-Liver Transplantation Managed Conservatively

Multiple intrahepatic arterio-portal fistulas are rare. The majority are isolated and occur secondary to liver trauma including iatrogenic interventions such as liver biopsy. Post-liver transplantation 18 cases have been reported, all secondary to an interventional radiological procedure. We report multiple bi-lobar arterio-portal fistulas in a liver transplant recipient recognized 1 year after transplantation. The donor died due to intracerebral bleeding following blunt head and abdominal trauma. In the present case, the etiology is not very clear. The patient was managed conservatively and to date has not required intervention.

Portal Vein Thrombosis and Arterioportal Fistula in Post Liver Transplant Recipient: A Case Report

An intrahepatic Arterioportal Fistula Refers (APF) to abnormal shunt or fistulous connection between the portal venous system and a hepatic arterial system within the liver. Here, we present a case of portal vein thrombosis with APF in post-transplant liver, developed 2 years and 6 months after transplantation. The condition was diagnosed by Triphasic CT angiography. In this case report we have discussed various causes and pathophysiology of APF with its imaging findings.

Arterioportal fistulas in liver transplant recipients

Arterioportal fistulas (APFs) are classified into intrahepatic (>75% of all reported) and extrahepatic (<25% of all reported ). Anecdotally, investigators are more likely to report more sensational cases (typically extrahepatic APFs), so the actual prevalence of intrahepatic APFs is probably much higher (likely >90% of APFs). All reported APFs in liver transplant recipients have been intrahepatic. Hemodynamically significant APFs in liver transplant recipients are rare, occurring in 0.2%; however, APFs (hemodynamically significant or not) are not uncommonly seen in hepatic angiograms of liver transplant recipients (up to 5.4% of hepatic arteriograms in transplants). Interestingly, hemodynamically significant APFs warranting endovascular treatment are reported more commonly in the literature in native compared with transplanted livers (n >280-300 versus n = 13, respectively). This article discusses APFs that are specific to liver transplant recipients; their incidence, etiology, pathogenesis, natural history, clinical presentation, and endovascular management are discussed in detail.

Application of Amplatzer vascular occluder in hepatic artery closure as a method of treatment of high-flow arterioportal fistula before liver transplantation

Background:

Arterioportal fistula (APF) is an abnormal, direct connection between hepatic artery or its branch and the portal vein. Fistula can be acquired or, rarely, congenital. One of the acquired causes of fistula is a liver biopsy. Patients with liver cirrhosis are particularly vulnerable to its development due to the large number of performed biopsies. APF increases mortality and morbidity of liver transplantation procedure and may be a contraindication to it. The authors present a patient with liver cirrhosis, in whom percutaneous APF closure facilitated liver transplantation.

Case Report:

We describe a case of a 50-year-old patient with liver cirrhosis and APF, probably formed as a result of liver biopsy. Due to the presence of a high-flow fistula, which elevated portal hypertension, patient did not qualify for the liver transplantation. Patient was transferred to the interventional radiology department, where the fistula’s vascular supply was endovascularly closed using the Amplatzer occluder. This subsequently enabled the execution of transplantation.

Conclusions:

Percutaneous closure of APF should be considered a relatively simple and fast-acting tool to facilitate or even enable liver transplant surgery. Currently, there are more and more products available such as e.g. Amplatzer occluder to simplify the procedure and shorten the duration of exposure to ionizing radiation.