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

Abstract

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.

Successful embolization of a congenital intra-hepatic arterioportal fistula in a neonate with the MVP Microvascular Plug system (MVP-3Q)

“…IAPFs can be congenital (primary) or acquired (secondary) [2] . Acquired IAPFs are more common and arise following events such as blunt or penetrating liver trauma, hepatic neoplasms, hemangiomas or hepatic artery aneurysms, fine needle liver biopsy, hepatectomy, and percutaneous transhepatic biliary drainage [ 2 , 5 ]. Congenital IAPFs involving the hepatic artery occur in less than 10% of cases [6] .…”

“…In rare cases where the ductus arteriosus remains patent, high-output congestive heart failure can occur [2] . Congenital IAPFs are commonly an isolated finding, but can be associated with syndromes such as hereditary hemorrhagic telangiectasia, Ehlers-Danlos or Trisomy 21 [ 3 , 5 ]. Diagnosis of IAPF usually relies on color-Doppler US, which may show hepatic artery enlargement, pulsatile hepatofugal flow in the portal vein, and portal vein dilatation [3] .…”

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

“…Spontaneous hemorrhage is uncommon and may be due to the rupture of hypervascular tumors or vascular malformations, which are described in dedicated paragraphs. Iatrogenic bleedings follow surgical and percutaneous procedures, such as transplantation, biopsies, and catheter insertions [35]. The risk of iatrogenic hemorrhage may be increased by anticoagulant or antiplatelet therapy or by congenital or acquired coagulopathy.…”

“…Arterio-portal fistulas are relatively common in the population of pediatric liver transplants, due to the number of interventions performed in the regular follow-up (biopsies) or to manage transplant complications (percutaneous cholangiography, transhepatic vascular access) [35]. Treatment by means of the interventional radiological approach is considered a standard of care, even though it is yet without a high level of evidence.…”

“…In such situations, the combined transarterial and transvenous approaches should be considered, in order to obtain the outflow occlusion of the shunt and allow for a safer arterial embolization (Figure 5). The management of small intrahepatic arterio-portal shunts has been also reported with direct transhepatic puncture and thrombin injection [35].…”