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Successful Embolization of Congenital Intrahepatic Arterioportal Fistula in Two Infants

1999; Lippincott Williams & Wilkins; Volume: 29; Issue: 2 Linguagem: Inglês

10.1097/00005176-199908000-00021

1536-4801

Thierry Lamireau, Jean‐François Chateil, Philippe Petit, François Portier, M. Panuel, Nicolas Grenier,

Liver Disease and Transplantation

Intrahepatic arterioportal fistula (IAPF) is a rare condition and an uncommon cause of portal hypertension. It has been reported to be secondary to abdominal trauma, iatrogenic procedures, hepatocellular carcinoma, cirrhosis. and cavernous hemangiomas. It may also be congenital, including hereditary telangectatic diseases, arteriovenous malformations, and aneurysms (1). Symptoms of congenital IAPF often occur in adulthood (1-4); few cases are reported in infancy. We report the cases of two infants with a congenital IAPF who were successfully treated with transcatheter embolization within the first months of life. CASE 1 A male infant had diarrhea and vomiting at the age of 2 months. He had been admitted to the hospital at birth with suspected but unconfirmed maternofetal infection. No umbilical catheterization had been performed. On admission, his weight was 4300 g, and his body temperature was 37.4°C. Abdominal distension was noted. Plain radiographs of the abdomen showed few air fluid levels. Laboratory investigations showed serum hemoglobin 95 g/l and normal serum albumin (529 µmol/l). Shortly after admission, hematemesis, melena, ascites, and splenomegaly developed. Findings in auscultation of the abdomen were normal. Serum hemoglobin declined to 63 g/l, which prompted blood transfusion. Esophagogastroduodenoscopy (EGD) showed very prominent esophageal varices and congestive gastric mucosa. Abdominal sonography revealed a 3-cm-diameter hypoechogenic formation in segment IV of the liver. Color Doppler flow examination (Fig. 1) showed the vascular origin of the lesion, with a high arterial inflow through the hepatic artery, an aneurysmal dilation of the left portal vein, and an arterialized retrograde outflow in the portal trunk. The angiography, performed under general anesthesia with a femoral approach, confirmed the IAPF, supplied from a dilated hepatic artery (arising from the celiac trunk) through two branches, and draining into the portal bifurcation. During the same procedure, after superselective catheterization with a coaxial catheter (Tracker 25; Target Therapeutics, Fremont, CA, U.S.A.), each arterial feeding branch was occluded with a 3 mm-diameter flower-type steel coil (Target Therapeutics). Postembolization injection confirmed the occlusion of the fistula, with opacification of the distal branches of the hepatic artery, indicating a normal distribution. During the next few postembolization days, diarrhea and abdominal distension resolved, and splenomegaly decreased. On day 15, no esophageal varices were visible on EGD, and no vascular flux was noted in the fistula on Doppler examination. The infant continued to make an unremarkable recovery. At the age of 3 years, clinical examination showed normal growth and no hepatosplenomegaly. Color-flow sonography of the liver showed a hypoechogenic mass with no residual flow, corresponding to the thrombosed venous aneurysm. Normal portal flow was present.FIG. 1: Case 1: Abdominal color-flow sonography showing a large vascular lesion localized in segment IV of the liver.CASE 2 Splenomegaly was found during a routine clinical examination of an asymptomatic 4-month-old boy. He was born at term and had no medical history. Laboratory tests revealed anemia (serum hemoglobin 7.4 g/dl). Ultrasound examination confirmed the splenomegaly and showed a large anechoic formation in the medical segment of the left hepatic lobe. Its vascular nature was shown on color Doppler flow examination. A pulsatile hepatofugal flow was found in the main portal vein, and splenomegaly was attributed to this finding. Selective hepatic artery angiography (Fig. 2A) visualized the fistula, the vascular pouch, and the retrograde filling of the portal venous system. Superselective angiography showed that the feeding artery was unique. Embolization was performed with the same technique used in case 1 and led to complete occlusion with no flow in the fistula (Fig. 2C). Two days later, thrombosis of the pouch occurred, and a normal portal flow was observed on ultrasound and Doppler examination. Follow-up was uneventful, and findings in a color Doppler examination obtained when the patient was 5 years of age were normal.FIG. 2: Case 2: Angiography. (A) In the early phase, a large bilobate aneurysm is opacified and shown to be fed by one branch of the left hepatic artery. (B) In the arteriolar phase, a retrograde opacification of the portal bifurcation (arrow) is seen. (C) embolization is performed with coils positioned within the feeding branches of the malformation. The postembolization opacification of the left hepatic artery shows complete occlusion of the feeding branch.DISCUSSION Congenital malformation from the hepatic artery to the portal vein is rare (1), and only a few cases have been described in infancy (1,5-20). Symptoms are mainly caused by portal hypertension (5-10) with ascites, splenomegaly, and gastrointestinal bleeding from esophageal varices. Variceal bleeding is quite a rare event in the first months of life and may lead to investigation for portal obstruction but also for an IAPF. Venous congestion and hyperemia of the small and large bowel may account for protein-losing enteropathy with diarrhea and failure-to-thrive (6,7,11,13,17). Some cases of obstruction (17) or enterocolitis (18) have also been reported. In contrast with hemangiomas and hemangioendotheliomas of the liver (15), cardiac failure is uncommon in IAPF, because of the interposition of the hepatic capillary bed between the malformation and the heart (21). Diagnosis may be clinically suggested by the presence of a continuous murmur in the right upper quadrant of the abdomen. In cases of gastrointestinal bleeding, EGD is indicated to reveal the presence of esophageal varices. Color-flow sonography is the procedure of choice to confirm IAPF (22). It demonstrates a hypoechoic flowing formation, supplied by a dilated hepatic artery draining into the portal vein and showing pulsatile reversed flow on spectral analysis (7,9,10,13). It also documents the features of portal hypertension that include splenomegaly, venous collaterals, and ascites. Angiography is not essential to confirm the diagnosis but better delineates the arterial supply that comes from one or more branches of the hepatic artery and allows treatment of the lesion in the same procedure. Associated collaterals from the phrenic and intercostal arteries (8,15) or from the aorta (13) have been reported. Although spontaneous closure of a small asymptomatic intrahepatic malformation has been described in adults (23), most IAPFs require treatment intended to obliterate the malformation. Excision of the malformation with direct repair of the vessels (11), partial hepatectomy (5,7,15,18), or ligature of the supplying arteries (5-7,10,16,17) have been used to treat congenital IAPF. Arterial embolization has been successfully used in adults to treat different types of hepatic vascular malformations (24-26), as well as acquired (31) or congenital (1,3,4) IAPF. The benefits of this interventional procedure include reduced morbidity, repeated access availability, and reduced costs (1). The fistula-forming components can be reached through a transarterial or a transhepatic approach, and a wide variety of embolization materials are used (1). Embolization with coils induces a proximal occlusion that reduces the risk of hepatic infarction as encountered with distal injection of particles or glue. In small infants, there is a risk of thrombosis of the femoral artery during or after the procedure. This risk is lower in older children. Therefore, it seems reasonable to perform the embolization after the child is 1 year of age, if the patient is asymptomatic. In the two cases we have reported, coil embolization of the hepatic artery or its branches was followed by complete cessation of the blood flow through the malformation and a complete clinical recovery. Use of steel coils is recommended in IAPF for permanent arterial occlusion. The coils have to be positioned in the feeding arteries, beyond the last normal collaterals, to avoid a late reinjection from a retrograde inflow. In our two cases, this adequate positioning of the coils could be obtained without difficulty because of dilatation of the feeding branches. The two patients remained well at the age of 3 and 5 years, respectively. To our knowledge, this is the first report of successful treatment of congenital IAPF with only one embolization procedure in the first months of life. Failure of embolization in the previous reported cases led to repeated embolization procedures (1), arterial ligature (7,8,13,17), or hepatectomy (7,5,15,18), and was complicated by portal vein thrombosis in some cases (5,8). Routh et al. (8) reported successful embolization of the hepatic artery, the right and left phrenic arteries after two unsuccessful surgical procedures in a 4-month-old-boy. Nevertheless, occlusion of the main portal vein with cavernous transformation occurred, leading to persistent portal hypertension and recurrent gastrointestinal bleeding in that patient. In one study by Vauthey et al. (1), failure of three embolization procedures led to the discovery of von Willebrand's disease in a 2-year-old girl with an IAPF, which required two additional procedures and the administration of desmopressin acetate before complete occlusion was obtained. Pashankar and Culham (20) reported the successful treatment with embolization of an IAPF secondary to hepatoportoenterostomy in a 21-month-old boy with biliary atresia. Although this procedure remains controversial (7,26), we believe that transcatheter embolization should be considered the primary treatment in small infants with congenital IAPF. It can provide good results if accurate localization of the malformation, superselective catheterization, and complete and permanent occlusion of all feeding arteries are achieved. Nevertheless, a cautious approach is recommended in young children who also have chronic liver disease, and the procedure should be performed in centers that have substantial experience in superselective catheterization and access to a pediatric liver transplantation unit (20). Acknowledgment: The authors thank Dr. Mickael Fayon for his thorough review of the manuscript.