Intrahepatic portosystemic venous shunts: Color Doppler sonography

Imaging features, classification and clinical features of intrahepatic congenital portosystemic shunts

Congenital portosystemic shunts (CPSS) are a rare developmental anomaly diverting blood flow from the portal venous system and the liver to the systemic venous system. This case series examines the sonographic imaging findings, shunt classification, ultrasound shunt ratios, and outcomes in nine children (5 females, 4 males) admitted to our institution between 2015 and 2022 were included in this study. The shunts were initially categorized by the Parks classification and were followed by serial ultrasounds. Clinical presentation, clinical course, laboratory data, shunt ratios, and time to shunt closure were all followed on subsequent ultrasounds. The most common type of CPPS was the Type 3 shunt. In cases where shunt ratios were measured, the shunt ratio gradually decreased in tandem with decreasing ammonia levels until spontaneous closure was achieved. Predictors of lack of shunt closure included high shunt ratios and Type 4 shunts. Patients with CPPS can be followed with the shunt ratio calculation obtained from sonographic imaging, which may correlate to ammonia levels and indicate risk of hepatic encephalopathy as well as predict speed and timing of closure.

Value of contrast-enhanced ultrasound for vascular diseases of the liver - current indications and open questions

Contrast-enhanced ultrasonography (CEUS) is a widely available and well-tolerated technique that can expand the diagnosis of a variety of vascular liver diseases. This paper presents an overview of the current possibilities of the use of CEUS in vascular liver diseases. Particularly where Doppler sonography has technical limitations, CEUS provides additional opportunities to visualize vascular thrombosis and other obstructions restricting blood flow. When CT or MRI contrast agents cannot be used because of severe allergy or renal insufficiency, CEUS can be a valuable diagnostic alternative and has demonstrated comparable diagnostic performance in at least some vascular liver diseases, such as portal vein thrombosis. In addition, CEUS works without radiation and, therefore, might be particularly suitable for young patients and children. This may be useful, for example, in congenital disorders such as persistent umbilical vein or preduodenal portal vein. Vascular liver disease is rare and comprehensive data are still lacking, but the available literature provides promising insights into potential new ways to study vascular liver disease. Although most studies are based on small sample sizes or even case reports, the high diagnostic utility is undisputed.

Radiologic Evaluation of Portosystemic Shunts in Humans and Small Animals: Review of the Literature with Clinical Case Reports

The portal venous system is a network of vessels that carry blood from the capillary beds of the major abdominal organs to the liver. During embryology, the portal venous system can develop aberrantly, leading to vascular connections between the portal and systemic venous circulation known as portosystemic shunts. The purpose of this comparative review with a few short representative case reports was to present the similarities and differences in portosystemic shunts in humans and small animals and their radiologic evaluation. Aberrant vascular connections between the portal and systemic venous circulation enable portal blood to bypass metabolism and detoxification in the liver, leading to significant clinical implications. Portosystemic shunts are very rare in humans, but these connections are much more common in small animals, affecting up to 0.6% of small animals. Portosystemic shunts can be congenital or acquired and are divided into intrahepatic and extrahepatic types. Because of its ability to accurately assess abdominal structures, large vessels, and their flow dynamics without anesthesia, ultrasonography has become the first imaging modality employed for the diagnostic evaluation of portosystemic shunts in both humans and small animals. This is usually followed by contrast-enhanced computed tomographic angiography in order to better define the exact shunt anatomy and to plan treatment. It is important to understand the embryology, anatomy, pathology, and pathophysiology of portosystemic shunts in order to understand the findings of radiologic imaging and to initiate appropriate treatment.

Rare cause of neonatal pulmonary hypertension: Congenital intrahepatic portosystemic shunt through an aneurysm

Congenital portosystemic shunt is a rare congenital anomaly with abnormal communication between portal venous and systemic venous systems. It can be intrahepatic or extrahepatic. Typically, the intrahepatic shunts are managed conservatively as many of them close spontaneously. We present and discuss clinical, radiological findings of an intrahepatic shunt showing the early occurrence of pulmonary arterial hypertension in the neonatal period which required therapeutic intervention.

Abernethy syndrome in Slovenian children: Five case reports and review of literature

BACKGROUND

Abernethy syndrome is a congenital vascular anomaly in which the portal blood completely or partially bypasses the liver through a congenital portosystemic shunt. Although the number of recognized and reported cases is gradually increasing, Abernethy syndrome is still a rare disease entity, with an estimated prevalence between 1 per 30000 to 1 per 50000 cases. With this case series, we aimed to contribute to the growing knowledge of potential clinical presentations, course and complications of congenital portosystemic shunts (CPSS) in children.

CASE SUMMARY

Five children are presented in this case series: One female and four males, two with an intrahepatic CPSS and three with an extrahepatic CPSS. The first patient, who was diagnosed with an intrahepatic CPSS, presented with gastrointestinal bleeding, abdominal pain and hyperammonaemia at six years of age. He underwent a percutaneous embolization of his shunt and has remained asymptomatic ever since. The second patient presented with direct hyperbilirubinemia in the neonatal period and his intrahepatic CPSS later spontaneously regressed. The third patient had pulmonary hypertension and hyperammonaemia due to complete portal vein agenesis and underwent liver transplantation at five years of age. The fourth patient was diagnosed immediately after birth, when evaluated due to another congenital vascular anomaly, and the last patient presented as a teenager with recurrent bone fractures associated with severe osteoporosis. In addition, the last two patients are characterised by benign liver nodules; however, they are clinically stable on symptomatic therapy.

CONCLUSION

Abernethy syndrome is a rare anomaly with diverse clinical features, affecting almost all organ systems and presenting at any age.

Sonographic Appearances of Portal Vein Abnormalities

Portal venous system evaluation is required in many clinical circumstances, as substantial morbidity and mortality can be associated with a spectrum of portal vein abnormalities. Portal venous system pathologies can be congenital or acquired, and the knowledge of their imaging appearances will allow for a confident diagnosis and appropriate treatment options. In addition, a firm understanding of anatomical variants is important for planning surgical procedures and percutaneous interventions of the liver. This article will review various imaging appearances of portal venous systems abnormalities.

Liver vascular anatomy: a refresher

To prevent and decrease procedural complications, it is important to identify variants of hepatic vascular anatomy before interventional radiologic procedures, surgery, and liver transplantation. Knowledge of the vascular variants helps in selecting patients and in exploring alternative management options. Non-invasive detailed demonstration of the hepatic vascular anatomy is possible with advanced multi-detector computed tomography (CT) and magnetic resonance (MR) imaging. The objective of this review is to provide a brief overview of clinically relevant hepatic vascular anatomy and important variants.

Congenital Intrahepatic Portosystemic Venous Shunt With an Associated Aneurysm: Sonographic Diagnosis

Intrahepatic portosystemic venous shunts with associated aneurysms are extremely rare anomalous communications between intrahepatic portal veins and systemic veins through intrahepatic venous channels. Intrahepatic portosystemic venous shunts are usually asymptomatic but can be the cause of hepatic encephalopathy and hypoglycemia, especially when a high degree of shunting exists. The sonographic incidental finding of an aneurysmal vascular connection between the left portal vein and left hepatic vein as diagnosed by sonography is presented and discussed. When evaluating patients with suspected symptoms of hepatobiliary disease, sonographers and radiologists should carefully scan and meticulously assess the liver for signs of abnormal venous communications.

Neonatal Cholestasis as Initial Presentation of Portosystemic Shunt: A Case Report

Congenital intrahepatic portosystemic shunts are rare in children. Portosystemic venous malformations are characterized by extreme clinical variability. We report a full-term 33-day-old male infant presenting with neonatal jaundice. On physical examination, he had generalized icterus and the liver was palpable 3.5 cm below the right costal margin. He had no other symptoms. Laboratory tests showed AST 632 U/L, ALT 198 U/L, total bilirubin 12.1 mg/dL, conjugated bilirubin 10.2 mg/dL, alkaline phosphatase 753 U/L, GGT 47 U/L and glucose 67 U/L. Colour Doppler ultrasonography showed the left portal vein was more dilated than the right portal branch and communication with dilated left hepatic vein. There was no evidence of portal hypertension, heart failure, hepatopulmonary syndrome and encephalopathy during his hospital stay, so he was discharged from the pediatric department and his parents advised to attend monthly follow-up. Congenital portosystemic shunts are rarely observed in the childhood period.¹ Depending on anatomic characteristics they may be intrahepatic or extrahepatic.² Intrahepatic portosystemic shunts (PSS) are observed between the portal vein and hepatic vein or vena cava inferior.3, 4 Small shunts may close themselves before the age of 2 years.⁵ With the increase in use of imaging methods, diagnosing PSS has become easier, with an increase in the number of cases reported.⁶ Neonatal cholestatis is a frequent complication of PSS.¹ We present a case presenting with neonatal cholestasis diagnosed with congenital intrahepatic PSS.

Altered Doppler flow patterns in cirrhosis patients: an overview

Doppler ultrasonography of the hepatic vasculature is an integral part of evaluating precirrhotic and cirrhotic patients. While the reversal of the portal venous flow is a well-recognized phenomenon, other flow patterns, although not as easily understood, may play an important role in assessing the disease status. This article discusses the different characteristic flow patterns observed from the portal vein, hepatic artery, and hepatic vein in patients with liver cirrhosis or related complications and procedures. Knowledge of these different flow patterns provides additional information that may reinforce the diagnosis of cirrhosis, help in staging, and offer prognostic information for determining the direction of therapy. Doppler ultrasonography is invaluable when liver transplantation is being considered and aids in the diagnosis of cirrhosis and portal hypertension.

Systematic review of congenital and acquired portal-systemic shunts in otherwise normal livers

BACKGROUND

Portal-systemic shunts (PSSs) are rarely seen in healthy individuals or patients with non-cirrhotic liver disease. They may play an important role in hepatic metabolism as well as in the spread of gastrointestinal metastatic tumours to specific organs. Small spontaneous PSSs may be more common than generally thought. However, epidemiological data are scarce and inconclusive. This systematic review examined the prevalence of reported PSSs and the associated detection methods.

METHODS

Literature up to 2011 was reviewed for adult patients with proven congenital or acquired PSSs. Only PSSs in normal livers were analysed for the methods of diagnosis. Eligible studies were identified by searching relevant databases, including PubMed, Embase, MEDLINE and the Cochrane Library. The selection of eligible articles was carried out using predefined inclusion criteria (adult, non-surgical PSS) and a set of search terms that were established before the articles were identified.

RESULTS

Eighty studies were included describing 112 patients with congenital or acquired PSSs. The majority were diagnosed incidentally using Doppler ultrasound imaging and CT.

CONCLUSION

Congenital and acquired PSSs are rare. They are usually clinically asymptomatic and discovered incidentally by radiological techniques. They may be clinically relevant owing to drug, tumour cell, metabolic and pathogen shunting.

Congenital portosystemic shunts: prenatal manifestations with postnatal confirmation and follow-up

OBJECTIVES

The purpose of this study was to evaluate prenatal sonographic findings that could be helpful for diagnosis of congenital intrahepatic portosystemic venous shunts and the follow-up results.

METHODS

Six neonates with congenital shunts between the portal vein and hepatic vein were enrolled in this study. Prenatal sonography was performed in 5 cases. We categorized the cases according to a previously published classification of intrahepatic portosystemic venous shunts and retrospectively reviewed the prenatal and postnatal sonographic examinations to identify findings that might be helpful for diagnosing shunts prenatally. Follow-up sonographic examinations were done until closure of the shunts. Clinical features were also determined.

RESULTS

According to the original reports, intrahepatic portosystemic venous shunts were diagnosed by prenatal sonography in 2 of 5 cases. In the remaining 3 cases, there were suggestive abnormal findings on retrospective review, including an abnormal intrahepatic tubular structure, a prominent hepatic vein, and congestive heart failure. Postnatal sonography showed type 2 shunts in all 6 cases. In 1 case, there were 2 type 2 lesions between two branches of the left portal vein and the middle and left hepatic veins. On follow-up sonography, 5 of the 6 congenital shunts had spontaneously closed by 11 months of age. One case was treated with coil embolization during the neonatal period. Intrauterine growth restriction was the most commonly clinical feature prenatally.

CONCLUSIONS

Findings such as an abnormal tubular structure, a prominent hepatic vein, and congestive heart failure can be important clues for identifying congenital intrahepatic portosystemic venous shunts on prenatal sonography. The use of prenatal and postnatal sonography is feasible for detection and evaluation of these shunts.

Imaging assessment of congenital and acquired abnormalities of the portal venous system

Abnormalities of the portal venous system are a heterogeneous group of conditions that can cause substantial morbidity and mortality and may lead to complications during surgery or percutaneous interventions involving the portal venous system. High-resolution computed tomography, ultrasonography, and magnetic resonance imaging permit a comprehensive, noninvasive evaluation of the portal venous system, enabling the detection of both structural and functional abnormalities. However, an understanding of the embryologic development of the normal portal venous anatomy and anatomic variants is essential to accurately interpret the imaging findings. Knowledge of the characteristic appearances of abnormalities of the portal venous system allows a more confident diagnosis, permitting timely treatment and more informed guidance of surgical procedures and percutaneous interventions, which may lead to an improved outcome.

Multidetector CT findings of right intrahepatic portosystemic venous shunt

PURPOSE

To evaluate multidetector CT features of right intrahepatic portosystemic venous shunt (IPSVS).

MATERIALS AND METHODS

Pathways of right IPSVS were evaluated from 20 patients. Diameters of right portal veins were measured in IPSVS patients, 30 cirrhotic and 30 healthy patients.

RESULT

Among 22 IPSVSs, shunt between posterior branch and inferior phrenic vein was most common. Diameters of the posterior branch were larger in IPSVS patients than in other groups.

CONCLUSION

Most right IPSVSs drain to inferior phrenic vein through dilated posterior branch.