HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) CME Test (opens in a new window) Erratum (v24,p1514) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gallego, C. Articles by García-Hidalgo, E. Search for Related Content PubMed PubMed Citation Articles by Gallego, C. Articles by García-Hidalgo, E. Related Collections Pediatric Radiology Vascular and/or Interventional Radiology

Congenital Hepatic Shunts¹

¹ From the Department of Radiology, Hospital Universitario 12 de Octubre, Carretera de Andalucía km 5,400, 28041 Madrid, Spain (C.G., M.M., G.G., E.G.H.); the Department of Radiology, Hospital Universitario del Niño Jesús, Madrid, Spain (C.M.); and the Department of Radiology, Hospital Madrid, Madrid, Spain (P.M.). Presented as an education exhibit at the 2002 RSNA scientific assembly. Received February 28, 2003; revision requested June 10 and received August 5; accepted August 11. All authors have no financial relationships to disclose. Address correspondence to C.G. (e-mail: mamengallego@terra.es).

	Abstract

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Abnormal vascular connections within the hepatic parenchyma are occasionally seen at ultrasonography (US) and require further evaluation. The radiologic findings in 42 children with infantile hepatic hemangioma (n = 28), vascular malformations (n = 10), or infradiaphragmatic total anomalous pulmonary venous return (TAPVR) (n = 4) associated with congenital vascular shunting were retrospectively reviewed. Arteriovenous connections are seen in infantile hepatic hemangiomas and arteriovenous malformations and manifest with aortic tapering at the level of the celiac trunk, hepatic artery enlargement with a low resistivity index (RI), and increased flow velocities in the hepatic veins that may assume an arterialized spectral pattern in late-stage disease. Congenital arterioportal shunts demonstrate a low RI in the hepatic artery, hepatofugal arterialized flow in the portal vein, and rapid development of signs of portal hypertension. Portosystemic shunting may be intra- or extrahepatic. A pulsatile triphasic spectral pattern is seen in the portomesenteric venous system in children with portosystemic shunting, and macroscopic connections between the portal system and the hepatic veins are evident. Infradiaphragmatic TAPVR is associated with a tortuous vessel that parallels the aorta, ends at the intrahepatic left portal vein or the ductus venosus, and has hepatopetal flow. Familiarity with the US features of various congenital abnormal hepatic vascular connections will aid in diagnosis and treatment.

© RSNA, 2004

Index Terms: Arteriovenous malformations, hepatic, 761.1494 • Heart, failure, 51.714 • Liver, abnormalities, 95.14 • Liver, angiography, 761.124 Liver, CT, 761.1211 • Liver, MR, 761.1214 • Liver, US, 761.1298 • Shunts, arteriohepatic, 95.14 • Shunts, arterioportal, 95.14 • Shunts, arteriovenous, 95.14 • Shunts, portosystemic, 95.14

	LEARNING OBJECTIVES FOR TEST 4

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
After reading this article and taking the test, the reader will be able to:

• Discuss the radiologic features of congenital diseases associated with hepatic vascular shunts.
  
• Describe the clinical manifestations, prognosis, and treatment of these disease entities.
  
• Identify the most helpful procedures for ensuring correct diagnosis and optimal treatment in affected patients.
  

	Introduction

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Congenital hepatic shunts are rare anomalies that can either be discovered in a symptomatic infant or seen incidentally in a child who undergoes ultrasonography (US) for other reasons.

Intrahepatic vascular shunts consist of abnormal communications between the hepatic arteries, portal veins, and hepatic or systemic veins. They can be observed in neoplasms, vascular malformations, and infradiaphragmatic total anomalous pulmonary venous return (TAPVR).

We retrospectively reviewed the clinical charts of 42 pediatric patients with infantile hemangioma (n = 28), vascular malformations (n = 10), or infradiaphragmatic TAPVR (n = 4). Initial and follow-up B-mode and Doppler US images were obtained in all patients. US was supplemented with computed tomography (CT), magnetic resonance (MR) imaging, nuclear medicine studies, and angiography with embolization as needed.

In this article, we briefly review the embryologic development of the vitelline, umbilical, and cardinal veins to help elucidate the proposed origin of various types of congenital intrahepatic vascular shunts. We also discuss the common clinical findings, radiologic features, prognosis, and treatment of some of these anomalies as they are observed in neoplasms, vascular malformations (arteriovenous malformations [AVMs], arterioportal fistulas, portosystemic shunts [extrahepatic and intrahepatic portosystemic shunts, portovenous shunts]), and infradiaphragmatic TAPVR.

	Embryologic Development

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Early in the formation of the lungs (4th week of gestation), the blood coming from the lung buds drains to the splanchnic plexus, which is connected to the paired common cardinal (veins of the fetus proper) and umbilicovitelline venous systems (Fig 1) (1). The pulmonary venous plexus at first retains its vascular connections with the cardinal and umbilicovitelline systems (day 25–27 of the embryonic period). The primitive pulmonary vein, whose origin is still controversial, arises at day 29 and communicates with the pulmonary venous plexus by day 30 (2). The primitive pulmonary vein enlarges and is incorporated into the left atrium, and the pulmonary venous plexus gradually loosens its connections with the cardinal and vitelline systems.

View larger version (49K): [in this window] [in a new window] [Download PPT slide]   Figure 1.  Drawings illustrate the embryologic development of the pulmonary venous system. By day 19, the pulmonary venous plexus (1) drains both the cardinal (2) and umbilicovitelline (3, 4) venous systems. Next, the pulmonary venous plexus gradually loosens its connections with the umbilicovitelline venous system while connecting with the emerging common pulmonary vein (7), whose origin is still controversial. The pulmonary vein is incorporated into the left atrium (6), resulting in the final configuration of the normal pulmonary venous return. 5 = common sinoatrial chamber, 8 = left ventricle, 9 = right cardiac chambers, 10 = superior vena cava.

View larger version (50K): [in this window] [in a new window] [Download PPT slide]   Figure 2.  Drawings illustrate the embryologic development of the hepatic venous system. Initially, the vitelline veins (1) enter the embryo with the yolk stalk and anastomose with each other around the duodenum (2) before passing through the septum transversum (3) on their way to the sinus venosum (4). The umbilical veins (5) course on either side of the septum transversum and come into contact with the sinusoids. The proximal part of the left vitelline vein involutes, and all the blood coming from the left side of the liver is redistributed to the right vitelline vein. The entire right umbilical vein, part of the left umbilical vein, and the left sinus venosus also degenerate. In the final configuration of the fetal hepatic venous system, the left umbilical vein brings all the oxygenated blood to the embryo. The ductus venosus (6) connects the umbilical vein with the inferior vena cava (IVC) (7). The portal venous system (8) originates from a selective involution of the anastomotic network around the duodenum.

The paired umbilical veins bring oxygenated blood to the embryo and course at both sides of the liver, ending up in the sinus venosus. They soon come in contact with the hepatic sinusoids and are transformed. The entire right umbilical vein and that portion of the left umbilical vein between the liver and the sinus venosus degenerate. The persistent portion of the left umbilical vein carries all the blood from the placenta to the fetus. A large channel known as the ductus venosus develops in the liver and connects the umbilical vein with the IVC, bypassing the sinusoidal circulation of the liver.

	Neoplasms

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Only a few congenital hepatic neoplasms have a vasoproliferative component that is sufficient to lead to the development of arteriovenous or portovenous shunting. The majority of congenital hepatic neoplasms are infantile hemangiomas, also known as hemangioendotheliomas. The differential diagnosis includes congenital hepatoblastoma and angiosarcoma (4,5). Other hepatic masses to be considered in the neonatal period are hamartoma (5–7) and metastatic neuroblastoma (8).

Infantile hemangiomas are benign vascular tumors that exhibit hypercellularity and endothelial multiplication, resulting in a large cell mass that simultaneously involves the formation and dilatation of feeding and draining vascular channels. During involution, endothelial hyperplasia decreases, whereas fibrous tissue grows between vascular spaces. The presence of low-resistance tumoral vessels and the association with large feeding arteries and draining veins explain the frequent observation of arteriovenous shunting, even though hemangiomas are not AVMs but neoplasms (9).

Clinical Findings
Most infantile hemangiomas manifest clinically before 6 months of age. Although some of these neoplasms are discovered in asymptomatic infants, most are symptomatic. High-output congestive heart failure (CHF), hepatomegaly, anemia, thrombocytopenia, respiratory distress, hemorrhage, and jaundice are common clinical findings. Accompanying manifestations include hemangiomas of the skin and other organs (hemangiomatosis) and hypothyroidism (10).

Radiologic Features
At US, infantile hemangioma may manifest as a localized mass or as multifocal diffuse masses. Localized hemangiomas manifest with areas of both increased and decreased echogenicity relative to adjacent parenchyma, with or without calcifications (Fig 3). Diffuse hepatic hemangioma consists of multiple well-defined, solid hypoechoic nodules of varying size. Other associated features include large draining veins and varices, enlarged feeding arteries, and aortic tapering at the branching point of the celiac artery (8,10,11).

View larger version (154K): [in this window] [in a new window] [Download PPT slide]   Figure 3a.  Localized infantile hemangioma in a newborn with hepatomegaly and CHF. (a) Transverse US image of the liver depicts a localized heterogeneous mass in the right hepatic lobe (arrowheads) with coarse calcifications (arrow). (b) Color Doppler US image demonstrates the highly vascular nature of the mass. (c) Color duplex US image of the enlarged hepatic artery (arrowhead) demonstrates high-velocity flow and a low resistivity index (RI). (d) Coronal single-shot fast spin-echo MR image of the abdomen shows a hyperintense mass in the right hepatic lobe (arrows) with flow voids within and around the lesion (arrowheads). (e) Axial contrast material-enhanced gradient-echo T1-weighted MR image of the liver (arterial phase) depicts intense peripheral uptake with early filling of the draining veins (arrows), a finding that indicates the presence of arteriovenous shunting in the lesion.

View larger version (117K): [in this window] [in a new window] [Download PPT slide]   Figure 3b.  Localized infantile hemangioma in a newborn with hepatomegaly and CHF. (a) Transverse US image of the liver depicts a localized heterogeneous mass in the right hepatic lobe (arrowheads) with coarse calcifications (arrow). (b) Color Doppler US image demonstrates the highly vascular nature of the mass. (c) Color duplex US image of the enlarged hepatic artery (arrowhead) demonstrates high-velocity flow and a low resistivity index (RI). (d) Coronal single-shot fast spin-echo MR image of the abdomen shows a hyperintense mass in the right hepatic lobe (arrows) with flow voids within and around the lesion (arrowheads). (e) Axial contrast material-enhanced gradient-echo T1-weighted MR image of the liver (arterial phase) depicts intense peripheral uptake with early filling of the draining veins (arrows), a finding that indicates the presence of arteriovenous shunting in the lesion.

View larger version (116K): [in this window] [in a new window] [Download PPT slide]   Figure 3c.  Localized infantile hemangioma in a newborn with hepatomegaly and CHF. (a) Transverse US image of the liver depicts a localized heterogeneous mass in the right hepatic lobe (arrowheads) with coarse calcifications (arrow). (b) Color Doppler US image demonstrates the highly vascular nature of the mass. (c) Color duplex US image of the enlarged hepatic artery (arrowhead) demonstrates high-velocity flow and a low resistivity index (RI). (d) Coronal single-shot fast spin-echo MR image of the abdomen shows a hyperintense mass in the right hepatic lobe (arrows) with flow voids within and around the lesion (arrowheads). (e) Axial contrast material-enhanced gradient-echo T1-weighted MR image of the liver (arterial phase) depicts intense peripheral uptake with early filling of the draining veins (arrows), a finding that indicates the presence of arteriovenous shunting in the lesion.

View larger version (155K): [in this window] [in a new window] [Download PPT slide]   Figure 3d.  Localized infantile hemangioma in a newborn with hepatomegaly and CHF. (a) Transverse US image of the liver depicts a localized heterogeneous mass in the right hepatic lobe (arrowheads) with coarse calcifications (arrow). (b) Color Doppler US image demonstrates the highly vascular nature of the mass. (c) Color duplex US image of the enlarged hepatic artery (arrowhead) demonstrates high-velocity flow and a low resistivity index (RI). (d) Coronal single-shot fast spin-echo MR image of the abdomen shows a hyperintense mass in the right hepatic lobe (arrows) with flow voids within and around the lesion (arrowheads). (e) Axial contrast material-enhanced gradient-echo T1-weighted MR image of the liver (arterial phase) depicts intense peripheral uptake with early filling of the draining veins (arrows), a finding that indicates the presence of arteriovenous shunting in the lesion.

View larger version (142K): [in this window] [in a new window] [Download PPT slide]   Figure 3e.  Localized infantile hemangioma in a newborn with hepatomegaly and CHF. (a) Transverse US image of the liver depicts a localized heterogeneous mass in the right hepatic lobe (arrowheads) with coarse calcifications (arrow). (b) Color Doppler US image demonstrates the highly vascular nature of the mass. (c) Color duplex US image of the enlarged hepatic artery (arrowhead) demonstrates high-velocity flow and a low resistivity index (RI). (d) Coronal single-shot fast spin-echo MR image of the abdomen shows a hyperintense mass in the right hepatic lobe (arrows) with flow voids within and around the lesion (arrowheads). (e) Axial contrast material-enhanced gradient-echo T1-weighted MR image of the liver (arterial phase) depicts intense peripheral uptake with early filling of the draining veins (arrows), a finding that indicates the presence of arteriovenous shunting in the lesion.

Technetium-99m red blood cell scintigraphy demonstrates a homogeneous progressive centripetal increase in radiotracer uptake, although central necrotic areas may not demonstrate uptake (13).

Unenhanced CT scans demonstrate hepatomegaly, well-defined low-attenuation masses, and mottled calcifications (Fig 4). Contrast-enhanced CT scans show early peripheral enhancement with central progression, central necrotic areas, and mild enhancement or attenuation similar to that of adjacent parenchyma on delayed images (6,8,10,14). MR imaging is the single most useful tool for diagnosing hemangiomas. Nodules are well differentiated from adjacent parenchyma, and multiple flow voids are seen within or around the lesions. Hemangiomas are typically hypointense on T1-weighted MR images and hyperintense on T2-weighted images. At dynamic contrast-enhanced imaging, peripheral nodular enhancement with centripetal filling and persistent enhancement on delayed images are characteristic findings (Fig 3). Large masses can demonstrate heterogeneous signal intensity and focal areas of nonenhancement due to central necrosis, fibrosis, or hemorrhage. Small hemangiomas occasionally fill in diffusely at early phases of the dynamic study (6,8,15).

View larger version (99K): [in this window] [in a new window] [Download PPT slide]   Figure 4a.  Infantile hemangioma in a newborn with hepatomegaly. (a) Unenhanced abdominal CT scan depicts a well-defined mass with heterogeneous low attenuation and coarse calcifications (arrowheads) in the left hepatic lobe. (b) Tc-99m red blood cell scintigram demonstrates a large varix within the tumor. (c) Selective celiac axis arteriogram shows that the mass is highly vascularized and is supplied by the left hepatic artery (black arrow) and the anterosuperior and anteroinferior pancreaticoduodenal arteries (arrowheads). A central varix (white arrow) is observed at the arterial phase, a finding that reflects the presence of arteriovenous shunting.

View larger version (142K): [in this window] [in a new window] [Download PPT slide]   Figure 4b.  Infantile hemangioma in a newborn with hepatomegaly. (a) Unenhanced abdominal CT scan depicts a well-defined mass with heterogeneous low attenuation and coarse calcifications (arrowheads) in the left hepatic lobe. (b) Tc-99m red blood cell scintigram demonstrates a large varix within the tumor. (c) Selective celiac axis arteriogram shows that the mass is highly vascularized and is supplied by the left hepatic artery (black arrow) and the anterosuperior and anteroinferior pancreaticoduodenal arteries (arrowheads). A central varix (white arrow) is observed at the arterial phase, a finding that reflects the presence of arteriovenous shunting.

View larger version (89K): [in this window] [in a new window] [Download PPT slide]   Figure 4c.  Infantile hemangioma in a newborn with hepatomegaly. (a) Unenhanced abdominal CT scan depicts a well-defined mass with heterogeneous low attenuation and coarse calcifications (arrowheads) in the left hepatic lobe. (b) Tc-99m red blood cell scintigram demonstrates a large varix within the tumor. (c) Selective celiac axis arteriogram shows that the mass is highly vascularized and is supplied by the left hepatic artery (black arrow) and the anterosuperior and anteroinferior pancreaticoduodenal arteries (arrowheads). A central varix (white arrow) is observed at the arterial phase, a finding that reflects the presence of arteriovenous shunting.

Prognosis
The natural history of infantile hepatic hemangioma consists of a growth period during the first 6 months, with progressive regression and involution over the next 2–3 years.

The mortality rate in patients with CHF is approximately 80%–90% if left untreated, 60%–65% when only supportive measures are taken, and 30% with specific treatment (10,17).

Tumors that do not behave like typical hemangiomas—absence of associated cutaneous hemangiomas, initial manifestation after 6 months of age, atypical radiologic findings, unresponsiveness to treatment—may represent a different type of neoplasm, and biopsy should be performed.

All patients with infantile hemangioma should be screened for hypothyroidism, which worsens CHF and may be the leading cause of death.

Treatment
Asymptomatic patients can be closely followed up without treatment. Standard treatment for symptomatic hemangiomas is administration of corticosteroids. If there is no clinical improvement, treatment with interferon- should be attempted. Embolization or surgery should be reserved for patients in whom CHF remains after a reasonable trial of medical therapy (8,14,19). Chemotherapy and radiation therapy have also been used with variable degrees of success.

	Vascular Malformations

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Following Mullicken and Glowacki classification, hepatic vascular malformations can be further subdivided into fast-flow (AVMs, arterioportal fistulas), slow-flow (portosystemic shunts, venous and lymphatic malformations), and combined forms (20). Among slow-flow malformations, only portosystemic fistulas shunt blood from one venous system to another.

Arteriovenous Malformations
AVMs are neither tumors with growth potential nor capable of regression; they are congenital abnormalities in the formation of blood vessels that shunt blood through direct arteriovenous connections without abnormal neoplastic tissue between the anomalous vessels. Hepatic AVMs are usually localized in one lobe of the liver (8,9,20,21).

Clinical Findings.— A hepatic AVM manifests clinically in neonates with CHF, anemia, hepatomegaly, and portal hypertension but can also manifest in late childhood in the clinical setting of hereditary hemorrhagic telangiectasia with CHF, hepatic ischemia, and portal hypertension (8,21,22).

Radiologic Features.— The radiologic features of AVMs may overlap with those of localized hemangiomas. US findings include a nest of tortuous enlarged vessels located in one lobe of the liver with high peak Doppler shifts in both arteries and veins, a low arterial RI, and increased pulsatility of veins (Fig 5). An arterialized spectral pattern can be seen in the hepatic veins during late stages of the disease (22,23).

View larger version (138K): [in this window] [in a new window] [Download PPT slide]   Figure 5a.  Congenital hepatic AVM in a neonate with CHF. (a) Transverse US image of the liver shows a nest of dilated, tortuous anechoic structures (arrowheads) with normal intervening liver parenchyma. No mass effect is seen within the liver. (b) Color Doppler US image demonstrates the vascular nature of the mass. (c) Duplex US image of an intrahepatic arterial vessel demonstrates high-velocity flow and a low RI related to arteriovenous shunting. (d) Duplex US image shows a hyperpulsatile pattern of the portal vein at an intrahepatic portal venous branch.

View larger version (136K): [in this window] [in a new window] [Download PPT slide]   Figure 5b.  Congenital hepatic AVM in a neonate with CHF. (a) Transverse US image of the liver shows a nest of dilated, tortuous anechoic structures (arrowheads) with normal intervening liver parenchyma. No mass effect is seen within the liver. (b) Color Doppler US image demonstrates the vascular nature of the mass. (c) Duplex US image of an intrahepatic arterial vessel demonstrates high-velocity flow and a low RI related to arteriovenous shunting. (d) Duplex US image shows a hyperpulsatile pattern of the portal vein at an intrahepatic portal venous branch.

View larger version (118K): [in this window] [in a new window] [Download PPT slide]   Figure 5c.  Congenital hepatic AVM in a neonate with CHF. (a) Transverse US image of the liver shows a nest of dilated, tortuous anechoic structures (arrowheads) with normal intervening liver parenchyma. No mass effect is seen within the liver. (b) Color Doppler US image demonstrates the vascular nature of the mass. (c) Duplex US image of an intrahepatic arterial vessel demonstrates high-velocity flow and a low RI related to arteriovenous shunting. (d) Duplex US image shows a hyperpulsatile pattern of the portal vein at an intrahepatic portal venous branch.

View larger version (106K): [in this window] [in a new window] [Download PPT slide]   Figure 5d.  Congenital hepatic AVM in a neonate with CHF. (a) Transverse US image of the liver shows a nest of dilated, tortuous anechoic structures (arrowheads) with normal intervening liver parenchyma. No mass effect is seen within the liver. (b) Color Doppler US image demonstrates the vascular nature of the mass. (c) Duplex US image of an intrahepatic arterial vessel demonstrates high-velocity flow and a low RI related to arteriovenous shunting. (d) Duplex US image shows a hyperpulsatile pattern of the portal vein at an intrahepatic portal venous branch.

Angiographic findings include poor regional demarcation of the lesion, obvious arteriovenous shunting, variable puddling of contrast material in vascular spaces, and no parenchymal blush (Fig 6) (17,21).

View larger version (134K): [in this window] [in a new window] [Download PPT slide]   Figure 6a.  Suspected hepatic AVM. (a) Selective hepatic angiogram demonstrates a highly vascular mass with poor regional demarcation and puddling of contrast material in vascular spaces (arrows). (b) Late arterial phase angiogram shows obvious arteriovenous shunting with early filling of the IVC (arrows).

View larger version (136K): [in this window] [in a new window] [Download PPT slide]   Figure 6b.  Suspected hepatic AVM. (a) Selective hepatic angiogram demonstrates a highly vascular mass with poor regional demarcation and puddling of contrast material in vascular spaces (arrows). (b) Late arterial phase angiogram shows obvious arteriovenous shunting with early filling of the IVC (arrows).

Treatment.— Pharmaceutic therapy for AVMs consists of supportive measures (administration of digoxin and diuretics). If these measures fail to control CHF, embolization and surgical resection are the preferred treatments. Liver transplantation has been advocated in diffuse AVMs of the liver.

Arterioportal Fistulas
Arterioportal fistulas may be intra- or extrahepatic and acquired or congenital. The most common causes of acquired arterioportal fistulas are cirrhosis and hepatic neoplasms, blunt or penetrating trauma, percutaneous liver biopsy, transhepatic cholangiography, gastrectomy, and biliary surgery. Congenital arterioportal fistulas are a rare cause of portal hypertension. They can be associated with hereditary hemorrhagic telangiectasia, Ehlers-Danlos syndrome, and biliary atresia, although in most case reports they are not associated with any other disease (8,25).

Clinical Findings.— Patient age at presentation varies, but most congenital arterioportal fistulas are symptomatic within the 1st year of life. It is always difficult to determine whether a late-onset fistula is congenital or acquired. The initial symptom is portal hypertension; hepatofugal flow develops in the portal vein, which becomes arterialized. Splenomegaly, hypersplenism, variceal formation and bleeding, and ascites develop, but liver function test results remain within normal limits at first. Intestinal dysfunction results in malabsorption, diarrhea, and esteatorrhea (26,27).

Radiologic Features.— Doppler US is the single most useful imaging modality for making the diagnosis (Fig 7). Common findings include enlargement of the hepatic artery and dilatation of the segment of the portal vein where the fistula is located. Doppler US features of congenital arterioportal fistula include pulsatile hepatofugal flow in the portal vein and color speckling in the hepatic parenchyma adjacent to the fistula (vibration artifact) (25).

View larger version (130K): [in this window] [in a new window] [Download PPT slide]   Figure 7a.  Arterioportal fistula in a 3-month-old infant with biliary atresia. (a) Longitudinal color Doppler US image of the liver demonstrates color aliasing in the portal vein and neighboring liver parenchyma, a finding that reflects the presence of a fistula. (b) Color duplex US image demonstrates pulsatile hepatofugal high-velocity flow in the main portal vein. (c) Axial contrast-enhanced fat-suppressed gradient-echo T1-weighted MR image of the liver depicts a dilated main portal vein with marked enhancement (arrow) similar to that of the aorta (arrowhead) and hepatic artery (not shown). Ascites due to portal hypertension is also seen (*). (d) Selective hepatic arteriogram demonstrates retrograde filling of the portal (solid arrow), splenic (open arrow), and superior mesenteric (arrowhead) veins. Feathered arrow indicates the gastroduodenal artery. (e) Celiac axis angiogram obtained after embolization of the right hepatic artery with a microcoil (arrow) shows complete resolution of the fistula. One week later, the fistula recurred through arterial collateralization, and the patient underwent liver transplantation.

View larger version (146K): [in this window] [in a new window] [Download PPT slide]   Figure 7b.  Arterioportal fistula in a 3-month-old infant with biliary atresia. (a) Longitudinal color Doppler US image of the liver demonstrates color aliasing in the portal vein and neighboring liver parenchyma, a finding that reflects the presence of a fistula. (b) Color duplex US image demonstrates pulsatile hepatofugal high-velocity flow in the main portal vein. (c) Axial contrast-enhanced fat-suppressed gradient-echo T1-weighted MR image of the liver depicts a dilated main portal vein with marked enhancement (arrow) similar to that of the aorta (arrowhead) and hepatic artery (not shown). Ascites due to portal hypertension is also seen (*). (d) Selective hepatic arteriogram demonstrates retrograde filling of the portal (solid arrow), splenic (open arrow), and superior mesenteric (arrowhead) veins. Feathered arrow indicates the gastroduodenal artery. (e) Celiac axis angiogram obtained after embolization of the right hepatic artery with a microcoil (arrow) shows complete resolution of the fistula. One week later, the fistula recurred through arterial collateralization, and the patient underwent liver transplantation.

View larger version (110K): [in this window] [in a new window] [Download PPT slide]   Figure 7c.  Arterioportal fistula in a 3-month-old infant with biliary atresia. (a) Longitudinal color Doppler US image of the liver demonstrates color aliasing in the portal vein and neighboring liver parenchyma, a finding that reflects the presence of a fistula. (b) Color duplex US image demonstrates pulsatile hepatofugal high-velocity flow in the main portal vein. (c) Axial contrast-enhanced fat-suppressed gradient-echo T1-weighted MR image of the liver depicts a dilated main portal vein with marked enhancement (arrow) similar to that of the aorta (arrowhead) and hepatic artery (not shown). Ascites due to portal hypertension is also seen (*). (d) Selective hepatic arteriogram demonstrates retrograde filling of the portal (solid arrow), splenic (open arrow), and superior mesenteric (arrowhead) veins. Feathered arrow indicates the gastroduodenal artery. (e) Celiac axis angiogram obtained after embolization of the right hepatic artery with a microcoil (arrow) shows complete resolution of the fistula. One week later, the fistula recurred through arterial collateralization, and the patient underwent liver transplantation.

View larger version (87K): [in this window] [in a new window] [Download PPT slide]   Figure 7d.  Arterioportal fistula in a 3-month-old infant with biliary atresia. (a) Longitudinal color Doppler US image of the liver demonstrates color aliasing in the portal vein and neighboring liver parenchyma, a finding that reflects the presence of a fistula. (b) Color duplex US image demonstrates pulsatile hepatofugal high-velocity flow in the main portal vein. (c) Axial contrast-enhanced fat-suppressed gradient-echo T1-weighted MR image of the liver depicts a dilated main portal vein with marked enhancement (arrow) similar to that of the aorta (arrowhead) and hepatic artery (not shown). Ascites due to portal hypertension is also seen (*). (d) Selective hepatic arteriogram demonstrates retrograde filling of the portal (solid arrow), splenic (open arrow), and superior mesenteric (arrowhead) veins. Feathered arrow indicates the gastroduodenal artery. (e) Celiac axis angiogram obtained after embolization of the right hepatic artery with a microcoil (arrow) shows complete resolution of the fistula. One week later, the fistula recurred through arterial collateralization, and the patient underwent liver transplantation.

View larger version (99K): [in this window] [in a new window] [Download PPT slide]   Figure 7e.  Arterioportal fistula in a 3-month-old infant with biliary atresia. (a) Longitudinal color Doppler US image of the liver demonstrates color aliasing in the portal vein and neighboring liver parenchyma, a finding that reflects the presence of a fistula. (b) Color duplex US image demonstrates pulsatile hepatofugal high-velocity flow in the main portal vein. (c) Axial contrast-enhanced fat-suppressed gradient-echo T1-weighted MR image of the liver depicts a dilated main portal vein with marked enhancement (arrow) similar to that of the aorta (arrowhead) and hepatic artery (not shown). Ascites due to portal hypertension is also seen (*). (d) Selective hepatic arteriogram demonstrates retrograde filling of the portal (solid arrow), splenic (open arrow), and superior mesenteric (arrowhead) veins. Feathered arrow indicates the gastroduodenal artery. (e) Celiac axis angiogram obtained after embolization of the right hepatic artery with a microcoil (arrow) shows complete resolution of the fistula. One week later, the fistula recurred through arterial collateralization, and the patient underwent liver transplantation.

Arteriography should be performed early for diagnostic purposes and possible embolization (Fig 7).

Prognosis.— If left untreated, arterialization of the portal vein causes early onset of portal hypertension. Hepatoportal sclerosis and fibrosis of the portal radicles subsequently develop, further contributing to portal hypertension. Congenital hepatic arterioportal fistula in infants with biliary atresia is difficult to resolve because these infants are abnormally dependent on arterial inflow, and ligation or embolization of the hepatic artery could lead to fatal hepatic necrosis.

Treatment.— Embolization of the feeding artery with or without subsequent surgery is currently the preferred therapeutic option. It is important to closely observe affected patients because the fistula can recur through arterial collateralization. If the symptoms cannot be controlled with therapeutic maneuvers, liver transplantation is the only remaining option (8,26,27).

Portosystemic Shunts
The complicated development of the IVC and the close relationship of its development with that of the vitelline veins may explain the occurrence of congenital portosystemic anastomoses. Congenital portosystemic shunting has been recognized as an important disorder in children and should be differentiated from metabolic deficiencies involving hyperammonemia or galactosemia (30–34). Both extrahepatic and intrahepatic portosystemic shunts have been described.

Extrahepatic Portosystemic Shunts.— Because the first study of extrahepatic portosystemic shunts was conducted by Abernethy in 1793, these anomalies are also known as Abernethy malformations. Morgan and Superina (35) classified extrahepatic portosystemic shunts into two types. In Type 1, there is a complete diversion of portal blood into the vena cava, with congenital absence of the portal vein. These vascular malformations are further subdivided into those in which the splenic and superior mesenteric veins end up separately at the systemic veins, and those in which the splenic and superior mesenteric veins join to form a common trunk that ends up at the IVC, right atrium, or iliac veins. In Type 2, the portal vein is intact, but some of the portal flow is diverted into the vena cava through a side-to-side extrahepatic communication.

The pathogenesis of congenital absence of the portal vein may be attributed to excessive involution of the peri-intestinal vitelline venous loop (36) or to total failure of the vitelline veins to establish the critical anastomosis with the hepatic sinusoids or umbilical veins (37). It has been proposed that extrahepatic portosystemic shunts originate with the persistence of subcardinohepatic anastomosis with the vitelline veins (38).

In earlier reports, congenital absence of the portal vein was associated with severe malformations that included heterotaxy, Goldenhar syndrome, biliary atresia, mental retardation, and genitourinary malformations. Since the advent of cross-sectional imaging and with the widespread use of US, extrahepatic portosystemic shunts have been discovered in otherwise healthy children. The frequent association of systemic diversion of portal blood flow with hepatic tumors (hepatoma, adenoma, focal nodular hyperplasia, hepatocellular carcinoma) (36,39–42) has led some to suggest that this phenomenon may affect hepatic development, function, and regenerative capacity.

Absence of the portal vein may go unobserved at US because its US features (eg, decreased liver size, increased intrahepatic peribiliary echogenicity) may be subtle. At the hepatic hilus, only two tubular structures (enlarged hepatic artery, common bile duct) are recognized. Once the malformation is discovered, the aim should be to identify the abnormal portosystemic shunt. Cross-sectional imaging (CT and MR imaging) is very helpful in depicting the course of the portosystemic shunt and in identifying the absent vessels and the type of malformation (Figs 8, 9). Postprocessing volume-rendering techniques provide superb information regarding an extrahepatic portosystemic shunt.

View larger version (148K): [in this window] [in a new window] [Download PPT slide]   Figure 8a.  Extrahepatic portosystemic shunt in a 14-year-old boy with rectal bleeding and congenital absence of the portal vein. (a) Transverse color Doppler US image of the liver demonstrates a single vessel at the hepatic hilum (arrow) that represents the hepatic artery. A huge venous vessel (arrowheads) is seen behind the pancreatic gland (*). This vessel was seen to course toward the pelvis and to have hepatofugal flow. (b) Contrast-enhanced CT scan of the abdomen shows absence of the portal vein. A single hepatic artery (arrow) is seen at the hepatoduodenal ligament. (c) On a contrast-enhanced CT scan of the abdomen, the portosystemic shunting vessel (arrows) is seen coursing behind the pancreas. (d) Selective superior mesenteric artery angiogram (venous phase) depicts a huge inferior mesenteric vein (black arrow) that drains all the mesenteric venous flow through the iliac vein into the IVC (arrowhead). Note the absence of the main and intrahepatic portal veins. White arrow indicates the superior mesenteric vein.

View larger version (124K): [in this window] [in a new window] [Download PPT slide]   Figure 8b.  Extrahepatic portosystemic shunt in a 14-year-old boy with rectal bleeding and congenital absence of the portal vein. (a) Transverse color Doppler US image of the liver demonstrates a single vessel at the hepatic hilum (arrow) that represents the hepatic artery. A huge venous vessel (arrowheads) is seen behind the pancreatic gland (*). This vessel was seen to course toward the pelvis and to have hepatofugal flow. (b) Contrast-enhanced CT scan of the abdomen shows absence of the portal vein. A single hepatic artery (arrow) is seen at the hepatoduodenal ligament. (c) On a contrast-enhanced CT scan of the abdomen, the portosystemic shunting vessel (arrows) is seen coursing behind the pancreas. (d) Selective superior mesenteric artery angiogram (venous phase) depicts a huge inferior mesenteric vein (black arrow) that drains all the mesenteric venous flow through the iliac vein into the IVC (arrowhead). Note the absence of the main and intrahepatic portal veins. White arrow indicates the superior mesenteric vein.

View larger version (110K): [in this window] [in a new window] [Download PPT slide]   Figure 8c.  Extrahepatic portosystemic shunt in a 14-year-old boy with rectal bleeding and congenital absence of the portal vein. (a) Transverse color Doppler US image of the liver demonstrates a single vessel at the hepatic hilum (arrow) that represents the hepatic artery. A huge venous vessel (arrowheads) is seen behind the pancreatic gland (*). This vessel was seen to course toward the pelvis and to have hepatofugal flow. (b) Contrast-enhanced CT scan of the abdomen shows absence of the portal vein. A single hepatic artery (arrow) is seen at the hepatoduodenal ligament. (c) On a contrast-enhanced CT scan of the abdomen, the portosystemic shunting vessel (arrows) is seen coursing behind the pancreas. (d) Selective superior mesenteric artery angiogram (venous phase) depicts a huge inferior mesenteric vein (black arrow) that drains all the mesenteric venous flow through the iliac vein into the IVC (arrowhead). Note the absence of the main and intrahepatic portal veins. White arrow indicates the superior mesenteric vein.

View larger version (165K): [in this window] [in a new window] [Download PPT slide]   Figure 8d.  Extrahepatic portosystemic shunt in a 14-year-old boy with rectal bleeding and congenital absence of the portal vein. (a) Transverse color Doppler US image of the liver demonstrates a single vessel at the hepatic hilum (arrow) that represents the hepatic artery. A huge venous vessel (arrowheads) is seen behind the pancreatic gland (*). This vessel was seen to course toward the pelvis and to have hepatofugal flow. (b) Contrast-enhanced CT scan of the abdomen shows absence of the portal vein. A single hepatic artery (arrow) is seen at the hepatoduodenal ligament. (c) On a contrast-enhanced CT scan of the abdomen, the portosystemic shunting vessel (arrows) is seen coursing behind the pancreas. (d) Selective superior mesenteric artery angiogram (venous phase) depicts a huge inferior mesenteric vein (black arrow) that drains all the mesenteric venous flow through the iliac vein into the IVC (arrowhead). Note the absence of the main and intrahepatic portal veins. White arrow indicates the superior mesenteric vein.

View larger version (155K): [in this window] [in a new window] [Download PPT slide]   Figure 9a.  Extrahepatic portosystemic venous shunt in an asymptomatic 8-year-old boy with portal vein agenesis. (a) Abdominal radiograph shows the liver with a relatively small volume (arrows). (b) Contrast-enhanced CT scan of the abdomen demonstrates a single vessel at the hepatic hilum (arrowhead) that represents the hepatic artery. No intra- or extrahepatic portal vein was identified. (c) Contrast-enhanced CT scan of the abdomen obtained at a lower level shows a portosystemic venous shunt (arrowheads) between the splenomesenteric confluence and the suprarenal IVC. (d) Selective splenic artery angiogram (venous phase) depicts absence of the portal vein and the presence of an extrahepatic portosystemic venous shunt (black arrow) to the IVC (arrowhead). White arrow indicates the splenic vein.

View larger version (127K): [in this window] [in a new window] [Download PPT slide]   Figure 9b.  Extrahepatic portosystemic venous shunt in an asymptomatic 8-year-old boy with portal vein agenesis. (a) Abdominal radiograph shows the liver with a relatively small volume (arrows). (b) Contrast-enhanced CT scan of the abdomen demonstrates a single vessel at the hepatic hilum (arrowhead) that represents the hepatic artery. No intra- or extrahepatic portal vein was identified. (c) Contrast-enhanced CT scan of the abdomen obtained at a lower level shows a portosystemic venous shunt (arrowheads) between the splenomesenteric confluence and the suprarenal IVC. (d) Selective splenic artery angiogram (venous phase) depicts absence of the portal vein and the presence of an extrahepatic portosystemic venous shunt (black arrow) to the IVC (arrowhead). White arrow indicates the splenic vein.

View larger version (126K): [in this window] [in a new window] [Download PPT slide]   Figure 9c.  Extrahepatic portosystemic venous shunt in an asymptomatic 8-year-old boy with portal vein agenesis. (a) Abdominal radiograph shows the liver with a relatively small volume (arrows). (b) Contrast-enhanced CT scan of the abdomen demonstrates a single vessel at the hepatic hilum (arrowhead) that represents the hepatic artery. No intra- or extrahepatic portal vein was identified. (c) Contrast-enhanced CT scan of the abdomen obtained at a lower level shows a portosystemic venous shunt (arrowheads) between the splenomesenteric confluence and the suprarenal IVC. (d) Selective splenic artery angiogram (venous phase) depicts absence of the portal vein and the presence of an extrahepatic portosystemic venous shunt (black arrow) to the IVC (arrowhead). White arrow indicates the splenic vein.

View larger version (100K): [in this window] [in a new window] [Download PPT slide]   Figure 9d.  Extrahepatic portosystemic venous shunt in an asymptomatic 8-year-old boy with portal vein agenesis. (a) Abdominal radiograph shows the liver with a relatively small volume (arrows). (b) Contrast-enhanced CT scan of the abdomen demonstrates a single vessel at the hepatic hilum (arrowhead) that represents the hepatic artery. No intra- or extrahepatic portal vein was identified. (c) Contrast-enhanced CT scan of the abdomen obtained at a lower level shows a portosystemic venous shunt (arrowheads) between the splenomesenteric confluence and the suprarenal IVC. (d) Selective splenic artery angiogram (venous phase) depicts absence of the portal vein and the presence of an extrahepatic portosystemic venous shunt (black arrow) to the IVC (arrowhead). White arrow indicates the splenic vein.

View larger version (179K): [in this window] [in a new window] [Download PPT slide]   Figure 10a.  Intrahepatic portosystemic venous shunt seen incidentally in a neonate. (a) Transverse US image of the right hepatic lobe shows a communication (arrowhead) between a branch of the right portal vein (curved arrow) and a hepatic vein (straight arrow). (b) Color Doppler US image demonstrates the vascular nature of the communication. The shunt disappeared the following year.

View larger version (158K): [in this window] [in a new window] [Download PPT slide]   Figure 10b.  Intrahepatic portosystemic venous shunt seen incidentally in a neonate. (a) Transverse US image of the right hepatic lobe shows a communication (arrowhead) between a branch of the right portal vein (curved arrow) and a hepatic vein (straight arrow). (b) Color Doppler US image demonstrates the vascular nature of the communication. The shunt disappeared the following year.

View larger version (150K): [in this window] [in a new window] [Download PPT slide]   Figure 11a.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (134K): [in this window] [in a new window] [Download PPT slide]   Figure 11b.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (94K): [in this window] [in a new window] [Download PPT slide]   Figure 11c.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (152K): [in this window] [in a new window] [Download PPT slide]   Figure 11d.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (159K): [in this window] [in a new window] [Download PPT slide]   Figure 11e.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (156K): [in this window] [in a new window] [Download PPT slide]   Figure 11f.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (148K): [in this window] [in a new window] [Download PPT slide]   Figure 11g.  Multiple peripheral intrahepatic portosystemic venous shunts in an asymptomatic neonate. (a) Transverse US image demonstrates liver heterogeneity and multiple tubular structures (arrows) with a cystic component (arrowheads). (b) Color Doppler US image of one of the lesions demonstrates its vascular nature, with feeding (white arrow) and draining (black arrow) vessels. (c) Color duplex US image shows a turbulent triphasic pattern in the portal vein, a finding that raises suspicion for portosystemic venous shunting. Normal flow velocities and RI in the hepatic artery exclude an arteriovenous shunt. (d) Coronal half-Fourier single-shot spin-echo train image of the liver shows that the largest lesions have flow voids (arrows). (e) Coronal half-Fourier single-shot spin-echo train image of the liver demonstrates a communication between a lesion (arrow) and the middle hepatic vein (arrowhead). (f) Axial two-dimensional time-of-flight MR image (arterial phase) reveals that there is no arterial flow in the lesions (arrowhead). Solid arrow indicates the aorta, feathered arrow indicates the hepatic artery. (g) Axial two-dimensional time-of-flight MR image (venous phase) depicts venous flow in the lesions (arrowhead). Solid arrow indicates the IVC, feathered arrow indicates the portal vein. The shunts resolved spontaneously at age 6 months.

View larger version (149K): [in this window] [in a new window] [Download PPT slide]   Figure 12a.  Patent aneurysmal ductus venosus in a 12-year-old girl with mild neurologic disturbances. (a) Longitudinal color Doppler US image of the left hepatic lobe shows an aneurysmal communication (arrow) between the left hepatic (arrowhead) and portal veins. * = IVC. (b) Color duplex US image of the left portal vein (white arrow) demonstrates triphasic flow, a finding that reflects the presence of a portosystemic shunt. Black arrow indicates a patent aneurysmal ductus venosus. (c) Contrast-enhanced CT scan of the liver (early portal venous phase) depicts early asymmetric enhancement of the left hepatic vein (arrow). (d) On a contrast-enhanced CT scan obtained at a lower level, the ductus venosus demonstrates aneurysmal dilatation (arrowhead) and communication with the left portal vein (arrow).

View larger version (102K): [in this window] [in a new window] [Download PPT slide]   Figure 12b.  Patent aneurysmal ductus venosus in a 12-year-old girl with mild neurologic disturbances. (a) Longitudinal color Doppler US image of the left hepatic lobe shows an aneurysmal communication (arrow) between the left hepatic (arrowhead) and portal veins. * = IVC. (b) Color duplex US image of the left portal vein (white arrow) demonstrates triphasic flow, a finding that reflects the presence of a portosystemic shunt. Black arrow indicates a patent aneurysmal ductus venosus. (c) Contrast-enhanced CT scan of the liver (early portal venous phase) depicts early asymmetric enhancement of the left hepatic vein (arrow). (d) On a contrast-enhanced CT scan obtained at a lower level, the ductus venosus demonstrates aneurysmal dilatation (arrowhead) and communication with the left portal vein (arrow).

View larger version (125K): [in this window] [in a new window] [Download PPT slide]   Figure 12c.  Patent aneurysmal ductus venosus in a 12-year-old girl with mild neurologic disturbances. (a) Longitudinal color Doppler US image of the left hepatic lobe shows an aneurysmal communication (arrow) between the left hepatic (arrowhead) and portal veins. * = IVC. (b) Color duplex US image of the left portal vein (white arrow) demonstrates triphasic flow, a finding that reflects the presence of a portosystemic shunt. Black arrow indicates a patent aneurysmal ductus venosus. (c) Contrast-enhanced CT scan of the liver (early portal venous phase) depicts early asymmetric enhancement of the left hepatic vein (arrow). (d) On a contrast-enhanced CT scan obtained at a lower level, the ductus venosus demonstrates aneurysmal dilatation (arrowhead) and communication with the left portal vein (arrow).

View larger version (129K): [in this window] [in a new window] [Download PPT slide]   Figure 12d.  Patent aneurysmal ductus venosus in a 12-year-old girl with mild neurologic disturbances. (a) Longitudinal color Doppler US image of the left hepatic lobe shows an aneurysmal communication (arrow) between the left hepatic (arrowhead) and portal veins. * = IVC. (b) Color duplex US image of the left portal vein (white arrow) demonstrates triphasic flow, a finding that reflects the presence of a portosystemic shunt. Black arrow indicates a patent aneurysmal ductus venosus. (c) Contrast-enhanced CT scan of the liver (early portal venous phase) depicts early asymmetric enhancement of the left hepatic vein (arrow). (d) On a contrast-enhanced CT scan obtained at a lower level, the ductus venosus demonstrates aneurysmal dilatation (arrowhead) and communication with the left portal vein (arrow).

US of the abdomen demonstrates abnormal cystic or tubular anechoic structures communicating between portal venous branches and hepatic veins (Figs 10–12).

Doppler US is the single most important tool for determining the vascular nature of the tubular structures and the shunt ratio. A pulsatile tri- or biphasic spectral pattern in the portal and splenic veins should suggest the presence of a portovenous shunt. Blood flow volumes are measured by multiplying the lumen area by the mean velocity at a given point. The portovenous shunt ratio is calculated by dividing the total blood flow volume in the shunt by that in the portal vein (34). Although the presence of a portosystemic shunt is considered abnormal in all cases, it has been demonstrated that shunt ratios of less than 24%–30% do not cause liver encephalopathy, even in cirrhotic patients (34).

CT and MR imaging both help confirm the diagnosis, but their role has yet to be defined.

Nuclear medicine studies are also useful for calculating the shunt ratio. This ratio can be determined with portal scintigraphy performed with rectal administration of iodine-123 iodoamphetamine. The isotope is promptly absorbed into the inferior mesenteric vein and carried to the liver. When a portosystemic shunt is present, the isotope can be detected in the liver and lungs simultaneously. The shunt ratio is calculated by dividing the total lung counts by the total liver and lung counts. Ratios of less than 5% are considered abnormal (46).

Portovenous Shunts.— Portosystemic venous shunting causes hypergalactosemia, which, if it persists over a long period of time, leads to cataract formation. Other metabolites whose levels may be increased are bile acid, postprandial glucose, and ammonia. Portosystemic encephalopathy usually develops in adults due to the increased sensitivity of the central nervous system to hyperammonemia; however, because portosystemic encephalopathy has been described in children with portosystemic venous shunting that developed either spontaneously or after a precipitating event (gastrointestinal hemorrhage, constipation), the shunt ratio also seems to be an important factor in determining the age at which the onset of encephalopathy occurs (30,31,47). Liver dysfunction is secondary to lack of nutrition in the hepatic cells due to reduced inflow. The liver undergoes fatty degeneration and atrophy, but when the anomaly is corrected, fatty replacement disappears and liver size increases (36,39).

The natural history of portosystemic shunting depends on shunt ratio and patient age. Spontaneous closure is expected to occur in the first 2 years of life when an intrahepatic portosystemic shunt is found; thus, close follow-up is recommended for these children because most of them are asymptomatic.

Children are more resistant to hepatic encephalopathy, even with shunt ratios as high as 60% as measured with Doppler US. Nevertheless, patients with shunt ratios between 30% and 60% are prone to develop encephalopathy with precipitating events, and those with shunt ratios greater than 60%—especially older patients— are at an increased risk for encephalopathy (30,36,46).

Asymptomatic patients can be followed up without treatment. Mild metabolic abnormalities associated with any kind of portosystemic shunting can be relieved with medical therapy, which consists of a protein-free diet and oral administration of lactulose and branched-chain amino acids (31).

In patients of all ages, shunt ratios above 60% should be corrected due to the risk of encephalopathy and liver dysfunction. Both embolization and surgical correction of the shunt have been described (30). When these measures fail, liver transplantation is the only therapeutic option. Congenital absence of the portal vein in a patient with liver failure does not contraindicate liver transplantation; the presence of congenital portosystemic drainage prevents major hemodynamic alterations during the anhepatic period (48).

Resection is the treatment of choice in patients with liver tumors associated with extrahepatic portosystemic shunting. No complications are noted after partial liver resection, and postoperative liver regeneration is adequate.

	Infradiaphragmatic TAPVR

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Infradiaphragmatic TAPVR is a congenital cardiac malformation in which the pulmonary veins fail to connect with the left atrium during cardiac development. Instead, the pulmonary veins drain through a large channel into the portal venous system or the ductus venosus (Fig 13). Infradiaphragmatic TAPVR is the least common type of TAPVR, accounting for 12% of cases. About one-third of patients with TAVPR have associated anomalies such as bicameral heart, hypoplastic left ventricle, truncus arteriosus, heterotaxy syndromes, great artery transposition, and aortic coarctation.

View larger version (49K): [in this window] [in a new window] [Download PPT slide]   Figure 13.  Drawing illustrates the anatomic disposition of the pulmonary veins in infradiaphragmatic TAPVR. The pulmonary veins drain into the left hepatic or left portal vein through a large common channel. Flow is almost always inhibited by one or more stenoses at this channel.

Clinical Findings
Symptoms develop early (within 24–36 hours) and include tachypnea, tachycardia, and cyanosis with significant respiratory distress. Liver enlargement is common.

Radiologic Features
Chest radiography reveals a normal cardiac silhouette with a diffuse reticular pattern fanning out from the hilus, findings that represent pulmonary venous congestion with increased pulmonary lymphatic flow and increased flow through available alternate pulmonary venous pathways. Reflex pulmonary arterial vasoconstriction may also occur.

Echocardiography is the single most useful tool for diagnosing the defect and is sometimes the only procedure performed due to the surgical emergency that this anomaly represents. Apical and subcostal four-chamber views are usually the best for identifying individual pulmonary veins and their confluence in patients with infradiaphragmatic TAPVR (51).

Abdominal US depicts the abnormal vessel coming from the thorax through the esophageal hiatus and draining into the portal venous system. Doppler US of the abdomen helps determine the vascular nature of the tubular structure and helps identify the level of obstruction in the venous channel (Fig 14).

View larger version (110K): [in this window] [in a new window] [Download PPT slide]   Figure 14a.  Infradiaphragmatic TAPVR in a newborn with cyanosis and respiratory distress. (a) Longitudinal midline US image of the upper abdomen shows a large vascular channel (arrow) coming from the thorax, with flow moving in the same direction as in the aorta (arrowhead). (b) Transverse US scan of the liver demonstrates a stenotic segment (white arrowheads) of the common pulmonary vein (black arrows) just before it enters the left hepatic vein (white arrow). Black arrowhead indicates the aorta. (c) Oblique color Doppler US image of the liver shows color aliasing in the stenotic segment and left hepatic vein (white arrow). Black arrow indicates the common pulmonary vein, arrowhead indicates the aorta.

View larger version (130K): [in this window] [in a new window] [Download PPT slide]   Figure 14b.  Infradiaphragmatic TAPVR in a newborn with cyanosis and respiratory distress. (a) Longitudinal midline US image of the upper abdomen shows a large vascular channel (arrow) coming from the thorax, with flow moving in the same direction as in the aorta (arrowhead). (b) Transverse US scan of the liver demonstrates a stenotic segment (white arrowheads) of the common pulmonary vein (black arrows) just before it enters the left hepatic vein (white arrow). Black arrowhead indicates the aorta. (c) Oblique color Doppler US image of the liver shows color aliasing in the stenotic segment and left hepatic vein (white arrow). Black arrow indicates the common pulmonary vein, arrowhead indicates the aorta.

View larger version (122K): [in this window] [in a new window] [Download PPT slide]   Figure 14c.  Infradiaphragmatic TAPVR in a newborn with cyanosis and respiratory distress. (a) Longitudinal midline US image of the upper abdomen shows a large vascular channel (arrow) coming from the thorax, with flow moving in the same direction as in the aorta (arrowhead). (b) Transverse US scan of the liver demonstrates a stenotic segment (white arrowheads) of the common pulmonary vein (black arrows) just before it enters the left hepatic vein (white arrow). Black arrowhead indicates the aorta. (c) Oblique color Doppler US image of the liver shows color aliasing in the stenotic segment and left hepatic vein (white arrow). Black arrow indicates the common pulmonary vein, arrowhead indicates the aorta.

View larger version (140K): [in this window] [in a new window] [Download PPT slide]   Figure 15.  Infradiaphragmatic TAPVR. Pulmonary arteriogram (venous phase) demonstrates abnormal confluence of the pulmonary veins into a common channel (arrow) that traverses the diaphragm and courses toward the abdomen.

The outcome of surgical repair for infradiaphragmatic TAPVR is generally excellent. The surgical mortality rate is less than 5% when repair is performed electively in relatively healthy children without obstructed pulmonary veins. As expected, the mortality rate is higher when emergency surgery is performed in critically ill newborns with obstructed pulmonary venous return. The long-term outcome is also excellent.

Treatment
No corrective treatment with catheterization exists for infradiaphragmatic TAPVR, although atrial septostomy is used in some patients when the foramen ovale is restrictive and corrective surgery is delayed for some reason.

The goal of surgery is to redirect pulmonary venous flow entirely to the left atrium. The common pulmonary vein is opened wide and connected side to side to the left atrium. The foramen ovale is closed, and the descending vein is ligated (1,49,50).

	Summary

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 
Familiarity with the US features of the various forms of congenital abnormal hepatic vascular connections will help in making the diagnosis and choosing the best therapeutic approach for affected patients (Fig 16). If an anomalous intrahepatic vascular structure is discovered at US and a congenital hepatic shunt is suspected, further evaluation is required to determine what vessels are involved and what type of shunting is present. The presence of a vertical vein coming from the thorax and draining into the hepatic portal vein suggests infradiaphragmatic TAPVR, and echocardiography should be performed to confirm these findings. If findings include numerous abnormal vessels in one or both lobes of the liver, a decreased RI in the hepatic artery, and hepatopetal flow in the portal vein, infantile hepatic hemangioma or AVM should be suspected. Tc-99m red blood cell scintigraphy and dynamic MR imaging can help differentiate between these two entities. When the RI in the hepatic artery is decreased and pulsatile hepatofugal flow is seen in the portal vein, an arterioportal fistula is the most probable diagnosis, and angiography with embolization should be performed. Congenital portosystemic shunts are diagnosed with Doppler US. Intrahepatic shunts can be single or multiple and may spontaneously regress; thus, follow-up US is recommended. Congenital absence of the portal vein and other extrahepatic portosystemic shunts require CT or MR imaging to determine the location of the anomalous shunting vessel.

View larger version (27K): [in this window] [in a new window] [Download PPT slide]   Figure 16.  Chart illustrates a suggested algorithmic approach that can be used when a congenital hepatic vascular shunt is suspected at US. AP = arterioportal, AV = arteriovenous, CAPV = congenital absence of the portal vein, EPSS = extrahepatic portosystemic shunt, IPSS = intrahepatic portosystemic shunt, iTAPVR = infradiaphragmatic TAPVR, RBCTc99 = Tc-99m red blood cell scintigraphy.

	Footnotes

 
Abbreviations: AVM = arteriovenous malformation, CHF = congestive heart failure, IVC = inferior vena cava, RI = resistivity index, TAPVR = total anomalous pulmonary venous return

	References

Top Abstract LEARNING OBJECTIVES FOR TEST... Introduction Embryologic Development Neoplasms Vascular Malformations Infradiaphragmatic TAPVR Summary References

 

1. Duff DF, Nihill MR, Vargo TA, Cooley DA. Infradiaphragmatic total anomalous pulmonary venous return: diagnosis and surgical repair in a 10-year-old child. Br Heart J 1975; 37:1093-1096.[Abstract/Free Full Text]
2. Collins P, Gray H. Embryology and development. In: Collins P, eds. Gray’s anatomy. London, England: Churchill Livingstone, 1999; 321-326.
3. Moore KL. The developing human Philadelphia, Pa: Saunders, 1977; 279-299.
4. Ingram JD, Yerushalmi B, Connell J, Karrer FM, Tyson RW, Sokol RJ. Hepatoblastoma in a neonate: a hypervascular presentation mimicking hemangioendothelioma. Pediatr Radiol 2000; 30:794-797.[CrossRef][Medline]
5. Velasquez G, Katkov H, Formanek A. Primary liver tumors in the pediatric age group: an angiographic challenge. Rofo Fortschr Geb Rontgenstr Nuklearmed 1979; 130:408-417.
6. Horton KM, Bluemke DA, Hruban RH, Soyer P, Fishman EK. CT and MR imaging of benign hepatic and biliary tumors. RadioGraphics 1999; 19:431-451.[Abstract/Free Full Text]
7. Kaufman RA. Is cystic mesenchymal hamartoma of the liver similar to infantile hemangioendothelioma and cavernous hemangioma on dynamic computed tomography? Pediatr Radiol 1992; 22:582-583.[CrossRef][Medline]
8. Burrows PE, Dubois J, Kassarjian A. Pediatric hepatic vascular anomalies. Pediatr Radiol 2001; 31:533-545.[Medline]
9. Prokurat A, Kluge P, Chrupek M, Kosciesza A, Rajszys P. Hemangioma of the liver in children: proliferating vascular tumor or congenital vascular malformation? Med Pediatr Oncol 2002; 39:524-529.[CrossRef][Medline]
10. Keslar PJ, Buck JL, Selby DM. Infantile hemangioendothelioma of the liver revisited. RadioGraphics 1993; 13:657-670.[Abstract]
11. Morita Y, Saito H, Hiromura T, et al. Image diagnosis of infantile hemangioendothelioma of the liver. Rinsho Hoshasen 1988; 33:1677-1683.[Medline]
12. Paltiel HJ, Patriquin HB, Keller MS, Babcock DS, Leithiser RE, Jr. Infantile hepatic hemangioma: Doppler US. Radiology 1992; 182:735-742.[Abstract/Free Full Text]
13. Tsai CC, Yen TC, Tzen KY. The value of Tc-99m red blood cell SPECT in differentiating giant cavernous hemangioma of the liver from other liver solid masses. Clin Nucl Med 2002; 27:578-581.[CrossRef][Medline]
14. Mahboubi S, Sunaryo FP, Glassman MS, Patel K. Computed tomography, management, and follow-up in infantile hemangioendothelioma of the liver in infants and children. J Comput Tomogr 1987; 11:370-375.[CrossRef][Medline]
15. Mortele KJ, Vanzieleghem B, Mortele B, Benoit Y, Ros PR. Solitary hepatic infantile hemangioendothelioma: dynamic gadolinium-enhanced MR imaging findings. Eur Radiol 2002; 12:862-865.[CrossRef][Medline]
16. McHugh K, Burrows PE. Infantile hepatic hemangioendotheliomas: significance of portal venous and systemic collateral arterial supply. J Vasc Intervent Radiol 1992; 3:337-344.[Medline]
17. Fellows KE, Hoffer FA, Markowitz RI, O’Neill JA, Jr. Multiple collaterals to hepatic infantile hemangioendotheliomas and arteriovenous malformations: effect on embolization. Radiology 1991; 181:813-818.[Abstract/Free Full Text]
18. Kassarjian A, Dubois J, Burrows PE. Angiographic classification of hepatic hemangiomas in infants. Radiology 2002; 222:693-698.[Abstract/Free Full Text]
19. Daller JA, Bueno J, Gutierrez J, et al. Hepatic hemangioendothelioma: clinical experience and management strategy. J Pediatr Surg 1999; 34:98-105.[CrossRef][Medline]
20. Mulliken JB, Glowacki J. Hemangiomas and vascular malformations in infants and children: a classification based on endothelial characteristics. Plast Reconstr Surg 1982; 69:412-422.[Medline]
21. Boon LM, Burrows PE, Paltiel HJ, et al. Hepatic vascular anomalies in infancy: a twenty-seven-year experience. J Pediatr 1996; 129:346-354.[CrossRef][Medline]
22. Buscarini E, Buscarini L, Civardi G, Arruzzoli S, Bossalini G, Piantanida M. Hepatic vascular malformations in hereditary hemorrhagic telangiectasia: imaging findings. AJR Am J Roentgenol 1994; 163:1105-1110.[Abstract/Free Full Text]
23. Bodner G, Peer S, Karner M, et al. Nontumorous vascular malformations in the liver: color Doppler ultrasonographic findings. J Ultrasound Med 2002; 21:187-197.[Abstract/Free Full Text]
24. Knudson RP, Alden ER. Symptomatic arteriovenous malformation in infants less than 6 months of age. Pediatrics 1979; 64:238-241.[Abstract/Free Full Text]
25. D’Agostino D, Orsi M. Congenital hepatic arterioportal fistula (letter). J Pediatr Gastroenterol Nutr 1999; 29:487.
26. Altuntas B, Erden A, Karakurt C, Kut A, Senbil N, Yurdakul M. Severe portal hypertension due to congenital hepatoportal arteriovenous fistula associated with intrahepatic portal vein aneurysm. J Clin Ultrasound 1998; 26:357-360.[CrossRef][Medline]
27. Marchand V, Uflacker R, Baker SS, Baker RD. Congenital hepatic arterioportal fistula in a 3-year-old child. J Pediatr Gastroenterol Nutr 1999; 28:435-441.[CrossRef][Medline]
28. Gallego C, Velasco M, Marcuello P, Tejedor D, De Campo L, Friera A. Congenital and acquired anomalies of the portal venous system. RadioGraphics 2002; 22:141-159.[Abstract/Free Full Text]
29. Choi BI, Lee KH, Han JK, Lee JM. Hepatic arterioportal shunts: dynamic CT and MR features. Korean J Radiol 2002; 3:1-15.[Medline]
30. Akahoshi T, Nishizaki T, Wakasugi K, et al. Portal-systemic encephalopathy due to a congenital extrahepatic portosystemic shunt: three cases and literature review. Hepatogastroenterology 2000; 47:1113-1116.[Medline]
31. Florio F, Nardella M, Balzano S, Giacobbe A, Perri F. Congenital intrahepatic portosystemic shunt. Cardiovasc Intervent Radiol 1998; 21:421-424.[CrossRef][Medline]
32. Gitzelmann R, Forster I, Willi UV. Hypergalactosaemia in a newborn: self-limiting intrahepatic portosystemic venous shunt. Eur J Pediatr 1997; 156:719-722.[CrossRef][Medline]
33. Kim SZ, Marz PL, Laor T, Teitelbaum J, Jonas MM, Levy HL. Elevated galactose in newborn screening due to congenital absence of the portal vein. Eur J Pediatr 1998; 157:608-609.[CrossRef][Medline]
34. Kudo M, Tomita S, Tochio H, Minowa K, Todo A. Intrahepatic portosystemic venous shunt: diagnosis by color Doppler imaging. Am J Gastroenterol 1993; 88:723-729.[Medline]
35. Morgan G, Superina R. Congenital absence of the portal vein: two cases and a proposed classification system for portasystemic vascular anomalies. J Pediatr Surg 1994; 29:1239-1241.[CrossRef][Medline]
36. Altavilla G, Cusatelli P. Ultrastructural analysis of the liver with portal vein agenesis: a case report. Ultrastruct Pathol 1998; 22:477-483.[Medline]
37. Howard ER, Davenport M. Congenital extrahepatic portocaval shunts–the Abernethy malformation. J Pediatr Surg 1997; 32:494-497.[CrossRef][Medline]
38. Kohda E, Saeki M, Nakano M, et al. Congenital absence of the portal vein in a boy. Pediatr Radiol 1999; 29:235-237.[CrossRef][Medline]
39. Arana E, Marti-Bonmati L, Martinez V, Hoyos M, Montes H. Portal vein absence and nodular regenerative hyperplasia of the liver with giant inferior mesenteric vein. Abdom Imaging 1997; 22:506-508.[CrossRef][Medline]
40. Grazioli L, Alberti D, Olivetti L, et al. Congenital absence of portal vein with nodular regenerative hyperplasia of the liver. Eur Radiol 2000; 10:820-825.[CrossRef][Medline]
41. Kinjo T, Aoki H, Sunagawa H, Kinjo S, Muto Y. Congenital absence of the portal vein associated with focal nodular hyperplasia of the liver and congenital choledochal cyst: a case report. J Pediatr Surg 2001; 36:622-625.[CrossRef][Medline]
42. Motoori S, Shinozaki M, Goto N, Kondo F. Case report: congenital absence of the portal vein associated with nodular hyperplasia in the liver. J Gastroenterol Hepatol 1997; 12:639-643.[Medline]
43. Park JH, Cha SH, Han JK, Han MC. Intrahepatic portosystemic venous shunt. AJR Am J Roentgenol 1990; 155:527-528.[Free Full Text]
44. Lane MJ, Jeffrey RB, Jr, Katz DS. Spontaneous intrahepatic vascular shunts. AJR Am J Roentgenol 2000; 174:125-131.[Free Full Text]
45. Santamaria G, Pruna X, Serres X, Inaraja L, Zuasnabar A, Castellote A. Congenital intrahepatic portosystemic venous shunt: sonographic and magnetic resonance imaging. Eur Radiol 1996; 6:76-78.[CrossRef][Medline]
46. Uchino T, Endo F, Ikeda S, Shiraki K, Sera Y, Matsuda I. Three brothers with progressive hepatic dysfunction and severe hepatic steatosis due to a patent ductus venosus. Gastroenterology 1996; 110:1964-1968.[CrossRef][Medline]
47. Wakamoto H, Manabe K, Kobayashi H, Hayashi M. Subclinical portal-systemic encephalopathy in a child with congenital absence of the portal vein. Brain Dev 1999; 21:425-428.[CrossRef][Medline]
48. Shinkai M, Ohhama Y, Nishi T, et al. Congenital absence of the portal vein and role of liver transplantation in children. J Pediatr Surg 2001; 36:1026-1031.[CrossRef][Medline]
49. Blanc JF, Bouvier R, Plauchu H, Salle B. Familial infradiaphragmatic total anomalous pulmonary venous return. Pediatrie 1981; 36:463-468.[Medline]
50. Duff DF, Nihill MR, McNamara DG. Infradiaphragmatic total anomalous pulmonary venous return: review of clinical and pathological findings and results of operation in 28 cases. Br Heart J 1977; 39:619-626.[Abstract/Free Full Text]
51. First T, Skovranek J, Tuma S, Marek J, Hucin B, Fiser B. Echocardiographic diagnosis of total anomalous pulmonary venous return. Cesk Pediatr 1989; 44:525-528.[Medline]
52. Livolsi A, Kastler B, Marcellin L, Casanova R, Bintner M, Haddad J. MR diagnosis of subdiaphragmatic anomalous pulmonary venous drainage in a newborn. J Comput Assist Tomogr 1991; 15:1051-1053.[Medline]

This Article Abstract Figures Only Full Text (PDF) CME Test (opens in a new window) Erratum (v24,p1514) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gallego, C. Articles by García-Hidalgo, E. Search for Related Content PubMed PubMed Citation Articles by Gallego, C. Articles by García-Hidalgo, E. Related Collections Pediatric Radiology Vascular and/or Interventional Radiology