Congenital Extrahepatic Portosystemic Shunt (Abernethy Malformation Type Ib) With Associated Hepatocellular Carcinoma: Case Report and Literature Review

Abernethy syndrome as a cause of liver transplantation

Congenital portosystemic shunts are rare abnormalities in which blood flow from the liver is diverted to the systemic circulation. We would like to present the case of a 48-year-old male, during his neurological follow-up he was diagnosed with a congenital intrahepatic portosystemic shunt. Embolization of the portosystemic communicating veins was attempted on two occasions, but without success. Due to the poor clinical course, the patient was presented to our transplant committee and a liver transplant was decided upon.

Diagnostic approach to hepatic vascular lesions: a paediatric perspective

The pathological evaluation of hepatic vascular lesions in children requires special consideration. Inconsistent terminology, rarity of pathology specimens and overlapping pathological features between various lesions may pose a serious diagnostic challenge. In this review, we highlight the importance of using the International Society for the Study of Vascular Anomalies (ISSVA) classification scheme to characterise these lesions. Selected entities are discussed, including hepatic vascular tumours exclusively seen in the paediatric age group, hepatic infantile haemangioma and hepatic congenital haemangioma. Vascular malformations, with emphasis on their syndromic associations (venous malformation in blue rubber bleb naevus syndrome) and complications (hepatocellular nodules in Abernethy malformation) are also covered.

Congenital Extrahepatic Portosystemic Shunt Complicated by the Development of Hepatoblastoma: A Case Report and Review of Literature

Congenital portosystemic shunts (CPSS) or congenital extrahepatic portosystemic shunts (CEPS) is a rare malformation. This congenital anomaly presents with a diverse array of clinical manifestations, ranging from asymptomatic to severe complications such as cardiac failure, pronounced pulmonary hypertension, and widespread pulmonary arteriovenous malformations. CPSS increases the risk of developing benign or malignant liver tumors, including nodular regenerative hyperplasia, focal nodular hyperplasia, hepatic adenoma, hepatocellular carcinoma, and hepatoblastoma. We report a case of a 15-month-old boy, identified with Abernethy's malformation type Ib, who presented with an abdominal mass during a follow-up. A comprehensive assessment established a diagnosis of hepatoblastoma. The patient was transferred to a specialized liver transplant center for further treatment and management. This is a review of literature highlighting the complexity of Abernethy malformation and its associated risk of liver tumors.

Diagnosis and management of Abernethy syndrome

Abernethy syndrome (AS or extrahepatic portosystemic shunt) is an uncommon congenital malformation consisting of agenesis or hypoplasia of the portal vein (PV) in such a way that splanchnic venous blood drains directly into the systemic circulation through aberrant communications, resulting in a portosystemic shunt that bypasses the liver AS is an underdiagnosed condition with unknown incidence and complication rate given that symptoms are usually absent. AS identification is increasingly common because of improved imaging techniques, hence prognostic implications and clinical management need be understood. This editorial reviews the natural history of AS and its diagnostic-therapeutic implications, illustrating the process with a series of cases from our institution.

Significance of a multidisciplinary approach to congenital extrahepatic portosystemic shunt: A changing paradigm for the treatment

AIM

To review the current institutional practice to treat patients with congenital extrahepatic portosystemic shunt (CEPS) and to determine the optimal strategy.

METHODS

We retrospectively reviewed the records of 55 patients diagnosed with CEPS at our center between December 2008 and March 2022.

RESULTS

Among these 55 patients, 44 (80.0%) received treatment for CEPS at a median age of 4.7 years. The most common indication for treatment was cardiopulmonary complications (45.5%). Therapeutic intervention included shunt closure by endovascular techniques (50.0%) or surgery (40.9%), and liver transplantation (9.1%). A total of 11 were classified as short shunt types, and surgical ligation was performed in all to preserve the major vascular system and prevent complications (p < 0.001). Children who received a surgical ligation were more likely to develop complications after shunt closure (p = 0.02). Among seven patients with portopulmonary hypertension (POPH), one patient, who received a shunt ligation at <1 year-of-age, was only able to completely discontinue medication. Most other CEPS-related complications were completely resolved. Post-treatment complications, including thrombosis and symptoms of portal hypertension, were seen in 16 patients. After shunt closure, one patient was scheduled to undergo liver transplantation for progressive POPH and large residual hepatocellular adenoma. During follow-up, one patient without any treatment for CEPS developed POPH 16 years from the diagnosis.

CONCLUSION

Earlier therapeutic interventions should be strongly considered for patients with POPH related to CEPS. However, in view of the invasiveness and treatment complications, special attention should be paid to the management of patients with short shunt types.

Complications of congenital portosystemic shunts: liver tumors are affected by shunt severity, but pulmonary and neurocognitive associations are not

BACKGROUND AND PURPOSE

Congenital portosystemic shunts (CPSS) are associated with multisystem complications, with the most common being liver tumors. The purpose of this study is to investigate the incidence of complications of CPSS, and to determine the natural history of liver tumors and their relationship with shunt closure.

METHODS

Single-center retrospective cohort study of patients with CPSS referred from 1990 to 2020. Data on demographics, laboratory, radiological and histological investigations, clinical evolution, and surgery were reviewed. Mann-Whitney for continuous data and Fisher's exact test for categorical data were used. A p value of 0.05 was considered significant.

RESULTS

54 patients were investigated for CPSS with a median age of 1.1 years (IQR 0.2-11.8 years) at presentation-7 intrahepatic shunts resolved spontaneously and were excluded. Type 1 (without intrahepatic portal flow) had a higher rate of all hepatic tumors than Type 2 (partial intrahepatic portal flow) [18/22(82%) vs. 9/25(36%); p = 0.003); and malignant tumors (6/22(27%) vs 1/25(4%); (p = 0.04). Following shunt closure, 4/11(36%) of patients experienced partial and 3/11(27%) complete tumor regression. Pulmonary hypertension and hepatopulmonary syndrome affected 4(9%), and 3(6%) patients, respectively. Pulmonary complications affected 1 patient with Type 1 and 6 with Type 2 shunts (p = 0.1). Neurocognitive anomalies were identified in 16/47(34%) patients, 8/22(35%) with Type 1 shunts and 8/25(32%) with Type 2 shunts (p = 0.76). 9/47 (19%) required special needs schooling.

CONCLUSIONS

Severity of portal venous deprivation (Type 1 CPSS) increases the risk of hepatic tumors and surgical closure is associated with a reduction in size or complete resolution of benign tumors.

Liver Transplantation for Pediatric Hepatocellular Carcinoma: A Systematic Review

Simple Summary

Hepatocellular carcinoma is a type of primary liver cancer and the second most common type of liver cancer in children. Although partial hepatectomy can be curative, many children present with tumors that are not amenable to resection and thus the only potentially curative option is liver transplantation. In this systematic review, we have pooled the data from the worldwide literature and showed that survival after liver transplantation for pediatric hepatocellular carcinoma is favorable and many children do well even if their tumors exceed certain potentially restrictive criteria originally developed to select adults with hepatocellular carcinoma for liver transplantation.

Abstract

Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatocellular carcinoma (HCC). We performed a systematic review of the MEDLINE, Scopus, Cochrane Library, and Web of Science databases (end-of-search date: 31 July 2020). Our outcomes were overall survival (OS) and disease-free survival (DFS). We evaluated the effect of clinically relevant variables on outcomes using the Kaplan–Meier method and log-rank test. Sixty-seven studies reporting on 245 children undergoing LT for HCC were included. DFS data were available for 150 patients and the 1-, 3-, and 5-year DFS rates were 92.3%, 89.1%, and 84.5%, respectively. Sixty of the two hundred and thirty-eight patients (25.2%) died over a mean follow up of 46.8 ± 47.4 months. OS data were available for 222 patients and the 1-, 3-, and 5-year OS rates were 87.9%, 78.8%, and 74.3%, respectively. Although no difference was observed between children transplanted within vs. beyond Milan criteria (p = 0.15), superior OS was observed in children transplanted within vs. beyond UCSF criteria (p = 0.02). LT can yield favorable outcomes for pediatric HCC beyond Milan but not beyond UCSF criteria. Further research is required to determine appropriate LT selection criteria for pediatric HCC.

Liver Transplantation for Hepatic Adenoma: A UNOS Database Analysis and Systematic Review of the Literature

BACKGROUND

Liver transplantation (LT) has been employed for hepatic adenoma (HA) on a case-oriented basis. We aimed to describe the characteristics, waitlist, and post-LT outcomes of patients requiring LT for HA.

METHODS

All patients listed or transplanted for HA in the United States were identified in the United Network for Organ Sharing (UNOS) database (1987-2020). A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement.

RESULTS

A total of 199 HA patients were listed for LT in UNOS and the crude waitlist mortality was 9.0%. A total of 142 HA patients underwent LT; 118 of these were among those listed with an indication of HA who underwent LT, and 24 were diagnosed incidentally. Most did not experience hepatocellular carcinoma transformation (89.4%). Over a median follow-up of 62.9 mo, death was reported in 18.3%. The 1-, 3-, and 5-y patient survival rates were 94.2%, 89.7%, and 86.3% in the UNOS cohort. The systematic review yielded 61 articles reporting on 99 nonoverlapping patients undergoing LT for HA and 2 articles reporting on multicenter studies. The most common LT indications were suspected malignancy (39.7%), unresectable HA (31.7%), and increasing size (27.0%), whereas 53.1% had glycogen storage disease. Over a median follow-up of 36.5 mo, death was reported in 6.0% (n=5/84). The 1-, 3-, and 5-y patient survival rates were all 95.0% in the systematic review.

CONCLUSIONS

LT for HA can lead to excellent long-term outcomes in well-selected patients. Prospective granular data are needed to develop more optimal selection criteria and further improve outcomes.

Transcatheter closure of congenital portosystemic shunts – A multicenter experience

Background:

Congenital portosystemic shunts (CPSS) are rare and present variably with hepatic encephalopathy, pulmonary arteriovenous malformations (PAVMs), and pulmonary hypertension (PH).

Objective:

The objective of the study was to see the feasibility of transcatheter closure of CPSS and their outcome.

Materials and Methods:

We analyzed the data of 24 patients of CPSS who underwent transcatheter closure from five institutions (March 2013 to April 2019). Baseline evaluation included echocardiography with bubble contrast study, ultrasound examination of the abdomen, computed tomography angiogram, and cardiac catheterization with test balloon occlusion of the CPSS. The evaluation showed cyanosis due to PAVM in 12, PH in 8, and respiratory distress in 2. Two had both cyanosis and PH. Criteria for eligibility for complete catheter closure of CPSS included demonstration of intrahepatic portal vein (PV) radicals together with a PV pressure of ≤18 mmHg on occlusion.

Results:

The median age and weight were 8 years (0.5–21) and 19.5 kg (4.2–73), respectively. Transcatheter closure was performed in 21 patients (22 procedures) using a variety of occlusive devices and stent-graft exclusion was done in one patient. Closure was not done in 3 in view of high portal venous pressures and hypoplastic PVs. During the follow-up (median: 42 months and range: 61 days–4.8 years), saturation normalized in 14 patients with PAVM. PH declined in all eight patients who underwent the procedure. Respiratory distress improved in two patients.

Conclusions:

Early and short-term follow-up results of catheter closure of CPSS appear promising. However, further, follow-up is needed to demonstrate long-term effectiveness.

Congenital extrahepatic portosystemic shunt type II occluded with cardiac closure device

Congenital extrahepatic portosystemic shunts are a rare cause of lower gastrointestinal bleeding in children. They result from the connection of a systemic vessel with the portomesenteric vasculature before the division of the main portal vein. Herein, we report a case of a congenital extrahepatic portosystemic shunts type II in a 4-year-old male diagnosed by Doppler ultrasonography during the investigation of abdominal pain and recurrent hematochezia, later confirmed by computed tomography. Conventional angiography with a balloon occlusion test revealed patent intrahepatic portal branches not depicted by previous imaging techniques. Successful shunt closure was achieved by endovascular approach with an Amplatzer Septal Occluder without complications.

Living donor liver transplantation in a pediatric patient with congenital absence of the portal vein

Congenital absence of the portal vein (CAPV) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. We report a case of pediatric living donor liver transplantation (LDLT) for CAPV combined with focal nodular hyperplasia (FNH) and hepatocellular adenoma. A 9-year-old girl who had been diagnosed with multiple FNH had CAPV. Her blood ammonia level was raised to 137 μg/dL. However, she did not complain of any symptoms. To treat CAPV and FNH, we decided to perform LDLT. The graft was a left liver graft from 39-year-old mother of the patient. Recipient hepatectomy was performed according to standard procedures of pediatric LDLT. Portal vein reconstruction was performed using interposition of an iliac vein homograft conduit to the superior mesenteric vein-splenic vein confluence. The CAPV-associated congenital splenorenal shunt was securely ligated. The pathology report of the explant liver showed a 2 cm-sized hepatocellular adenoma and multiple FNH lesions measuring up to 7.1 cm. The patient recovered uneventfully from the LDLT operation. The reconstructed portal vein was maintained well without any hemodynamic abnormalities. In conclusion, as CAPV patients can have various vascular anomalies, combined vascular anomalies should be thoroughly assessed before and during liver transplantation operation. The most effective reconstruction techniques should be used to achieve satisfactory results following liver transplantation.

Longterm Outcome of Liver Transplantation for Congenital Extrahepatic Portosystemic Shunt

Liver transplantation (LT) is often viewed as the last resort for the treatment of congenital extrahepatic portosystemic shunt (CEPS) due to advancement of imaging and interventional radiology techniques. However, some patients still require LT, and criteria for LT are yet to be determined. We conducted a national survey of patients undergoing LT for CEPS between June 1998 and August 2018 and evaluated the clinical data and outcomes with a review of previously reported patients from the English-language medical literature. A total of 26 patients underwent LT in Japan at a median age of 5.2 years old. The most common indications for LT were persistent hyperammonemia (54%) and liver mass (50%), followed by pulmonary complications (38%). Pulmonary complications in all patients, including intrapulmonary shunt and pulmonary hypertension (PH), were improved after LT. Regarding the 29 previously reported patients in the English-language literature, a liver nodule (49%), including hepatoblastoma and hepatocellular carcinoma, was the most common indication for LT, followed by pulmonary complications (34%). A total of 25 (96%) patients in our survey and 26 (90%) patients in the literature review were alive with a median follow-up period of 9.5 and 1.6 years, respectively. Although LT has a limited role in management of CEPS, our study indicated that LT was safe as an alternative treatment for select patients with malignant tumor or pulmonary complications and those with complications related to new portosystemic collateral vessels after shunt closure, such as PH or hepatopulmonary syndrome.

Case Report: Membranoproliferative Glomerulonephritis, a Rare Clinical Manifestation of Abernethy Malformation Type II

This report describes an 8-year-old male who presented with clinical manifestations including systemic edema, heavy proteinuria, hypoproteinemia, and persistent hypocomplementemia. Arachnoid cysts and focal nodular hyperplasia were also detected. Imaging examination and renal biopsy were performed, and Abernethy malformation type II with immune complex-mediated membranoproliferative glomerulonephritis was considered the diagnosis. Due to the persistence of embryonic vessels, Abernethy malformation is a rare congenital vascular malformation of the splanchnic venous system, which can be classified as type I (end-to-side shunt) and type II (side-to-side shunt). Abernethy malformation with glomerulonephritis remains extremely rare. In the patient described, glomerulonephritis mediated by immune complex with "full-house" positive immunohistochemistry was confirmed on renal biopsy. In addition, he was treated with glucocorticoids and tacrolimus. Whether surgical treatment is necessary should be determined according to the state of the disease in the later stages. The present case reflects the association between the congenital portosystemic shunt and the renal region and, to the authors' knowledge, may be the first report to describe arachnoid cysts as a symptom of Abernethy malformation.

Hyperandrogenism and malignant degeneration of hepatic adenomas in the setting of Abernethy malformation

Abernethy malformation refer to a congenital absence of intrahepatic portal veins leading to a primarily extrahepatic congenital portosystemic shunt. The lack of intrahepatic portal veins leads to a characteristic set of physical exam and imaging findings that may include hyperandrogenism and liver masses such as hepatic adenomas or focal nodular hyperplasia. In this case report, we describe a 20-year-old female who presented with an enlarging hepatic adenoma. A separate hepatic adenoma had previously been biopsied and noted to have undergone malignant degeneration into hepatocellular carcinoma. For each lesion, she was treated with combination transarterial embolization and microwave ablation. On follow-up imaging after therapy, it was then noted that her extrahepatic portal vein drained directly into the inferior vena cava, consistent with congenital portosystemic shunt. Recognition of this vascular anomaly is critical in treatment planning, as early intervention with either medical therapy or surgery can prevent the metabolic sequela of this unique constellation of symptoms.

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.

Radiological and surgical differences between congenital end-to-side (Abernethy malformation) and side-to-side portocaval shunts

OBJECTIVE

Distinguishing retrohepatic end-to-side portocaval shunts (ES-PCS) and side-to-side portocaval shunts (SS-PCS) can be difficult, but it is essential for determining the treatment strategy. Our experience with retrohepatic PCS is analyzed.

METHODS

Since 2007, 9 children (5/9 ES-PCS and 4/9 SS-PCS) were surgically treated. Radiology studies included Doppler-ultrasound, CT/MRI and angiography/occlusion test (8/9).

RESULTS

CT in 5/5 ES-PCS revealed the portal vein (PV) entering the left side of the vena cava with a uniform shape. 4/4 SS-PCS showed aneurysmal PV containing the origin of the main intrahepatic portal branches (IHPB) entering the cava anterior aspect or slightly to the right with a variable length (from long to short/wide). ES-PCS anatomy showed caudate lobe absence with the fistula entering the left cava aspect free of parenchyma, but anterior through the caudate lobe in SS-PCS. With the angiography/occlusion test, the IHPB was undeveloped in ES-PCS (portal pressure > 38 mmHg) and hypoplasic in SS-PCS (portal pressure < 25 mmHg). ES-PCS treatment included: 1/5 hepatectomy and 4/5 definitive banding (one by laparoscopy); while in SS-PCS: 1/4 liver transplantation, 2/4 1-step closure (one by laparoscopy), and 1/4 definitive banding.

CONCLUSION

Fistula shape, cava relationship, IHPB and portal pressures differ between the two shunt types. A question arises regarding the need for secondary complete closure after banding.

LEVEL OF EVIDENCE

Level IV.

Asymptomatic presentation of a congenital malformation of the portal vein with portosystemic shunt

Malformations of the portal venous system consist of congenital and acquired anomalies. Congenital portosystemic shunts represent rare vascular developmental anomalies that allow partial or complete diversion of blood flow from the portal venous system to the systemic venous system, bypassing the liver. Congenital portosystemic shunts may be associated with malformations or congenital absence of the portal vein, and it was first described by John Abernethy in 1793. Most cases are diagnosed in early childhood, but some congenital shunts may remain asymptomatic and are encountered incidentally because of the widespread use of computed tomography and magnetic resonance imaging. In this report, we discuss the case of a 40-year-old female who presented to the Emergency Department with right upper quadrant pain, nausea, and vomiting. Clinical presentation and abdominal computed tomography angiography were consistent with the diagnosis of calculous cholecystitis and congenital absence of portal vein with intrahepatic portosystemic shunts. We discuss the importance of radiology in diagnosing such incidental malformations, coupled with a review of the current literature on this topic.

A basic understanding of congenital extrahepatic portosystemic shunt: incidence, mechanism, complications, diagnosis, and treatment

Extrahepatic portosystemic shunt belongs to a family of rare vascular abnormalities. The clinical importance and manifestations of this vascular abnormality range from asymptomatic cases to liver or metabolic dysfunctions of various degrees. Congenital extrahepatic portosystemic shunt, also termed as Abernethy malformation, is a very rare congenital vascular malformation in which splenomesenteric blood drains into a systemic vein, bypassing the liver through a complete or partial extrahepatic shunt. So far, limited cases of congenital extrahepatic portosystemic shunt have been reported. In this review, incidence, mechanisms, complications, diagnoses and treatments of congenital extrahepatic portosystemic shunt are described.

An Interesting Case of Congenital Intrahepatic Porto-hepatic Shunt as a Cause of Unexplained Encephalopathy

Congenital portosystemic shunts can be divided into two types: intrahepatic shunts in which there is an abnormal connection between the branches of the portal vein and either the inferior vena cava or the hepatic veins and less commonly the extrahepatic type in which the portal system is connected to one of the branches of the mesenteric veins. Here we describe a 73-year-old woman who was admitted to the hospital with clinical evidence of encephalopathy and was found to have hyperammonemia. Abdominal computed tomography angiography was performed and revealed a dilated portal vein measuring up to 1.8 cm at the porta-hepatis along with dilated superior mesenteric and splenic veins. Multiple dilated vascular channels were identified within the right hepatic lobe. An intrahepatic portosystemic shunt between an enlarged middle hepatic vein and two separate branches of the right portal vein was demonstrated. A liver biopsy showed normal architecture with no evidence of inflammation or fibrosis. Portosystemic shunts are rare and often detected in adulthood but should be considered as an important cause of unexplained encephalopathy in the absence of cirrhotic liver disease or hepatic trauma. Given that the size of such shunts increases with age, older persons are more prone to the effect of toxic metabolites.This age-associated increase in shunt size may help explain why some patients remain asymptomatic until later in their life which may account for the late presentation in our patient.

Congenital Portosystemic Shunts in Children: Associations, Complications, and Outcomes

BACKGROUND

Congenital portosystemic shunt (CPSS) is a rare malformation in which splanchnic venous flow bypasses the liver. CPSS is associated with other congenital anomalies and syndromes and can be associated with life-threatening complications. CPSS and their management remain underreported in the literature. Here, we review the clinical characteristics, management, and outcomes of a cohort of children and young adults with CPSS from two pediatric centers.

METHODS

Cases of CPSS from Cincinnati Children's Hospital Medical Center and C.S. Mott Children's Hospital were reviewed to define CPSS anatomy, associated anomalies, complications, interventions, and outcomes. The imaging features and histopathology of liver lesions were characterized in detail.

RESULTS

A total of 11 cases were identified. Median age was 10 years (range 0-26); 8 (73%) cases were female. Associated anomalies included six patients with heterotaxy (55%), five patients with congenital heart disease (45%), three patients with Turner syndrome (27%), and two patients with omphalocele, exstrophy, imperforate anus, spinal defects (OEIS) complex (18%). Eight (73%) cases had hyperammonemia ± encephalopathy. A 4-month-old presented with hepatopulmonary syndrome, and 12-year-old presented with pulmonary hypertension. Eight patients (73%) had liver lesions including five with premalignant adenomas and three with well-differentiated hepatocellular carcinoma (HCC). Four children underwent successful CPSS occlusion/ligation. Three children underwent liver transplant (2) or resection (1) for HCC without recurrence at extended follow-up.

CONCLUSIONS

CPSS is associated with multiple anomalies (heterotaxy, congenital heart disease) and syndromes (Turner syndrome). CPSS liver lesions should be very carefully evaluated due to risk of premalignant adenomas and HCC. Serious complications of CPSS can occur at a young age but can be managed endovascularly or with open surgery.

Congenital Extrahepatic Portosystemic Shunts (Abernethy Malformation): An International Observational Study

Congenital extrahepatic portosystemic shunt (CEPS) or Abernethy malformation is a rare condition in which splanchnic venous blood bypasses the liver draining directly into systemic circulation through a congenital shunt. Patients may develop hepatic encephalopathy (HE), pulmonary hypertension (PaHT), or liver tumors, among other complications. However, the actual incidence of such complications is unknown, mainly because of the lack of a protocolized approach to these patients. This study characterizes the clinical manifestations and outcome of a large cohort of CEPS patients with the aim of proposing a guide for their management. This is an observational, multicenter, international study. Sixty-six patients were included; median age at the end of follow-up was 30 years. Nineteen patients (28%) presented HE. Ten-, 20-, and 30-year HE incidence rates were 13%, 24%, and 28%, respectively. No clinical factors predicted HE. Twenty-five patients had benign nodular lesions. Ten patients developed adenomas (median age, 18 years), and another 8 developed HCC (median age, 39 years). Of 10 patients with dyspnea, PaHT was diagnosed in 8 and hepatopulmonary syndrome in 2. Pulmonary complications were only screened for in 19 asymptomatic patients, and PaHT was identified in 2. Six patients underwent liver transplantation for hepatocellular carcinoma or adenoma. Shunt closure was performed in 15 patients with improvement/stability/cure of CEPS manifestations. Conclusion: CEPS patients may develop severe complications. Screening for asymptomatic complications and close surveillance is needed. Shunt closure should be considered both as a therapeutic and prophylactic approach.

Abernethy malformation and hepatocellular carcinoma: a serious consequence of a rare disease

Congenital portosystemic shunts (CPSS) are a rare vascular consequence of embryogenetic vascular alterations or the persistence of the fetal circulation elements, first described by John Abernethy in 1793 and classified by Morgan and Superina, into complete and partial portosystemic shunts. Its prevalence to this day has not been defined. We present a patient series of a 44-year-old and 47-year-old man and woman, with this rare congenital malformation and underlining hepatocellular carcinoma (HCC) treatment strategies. Over half of the individuals with CPSS have benign or malignant liver tumours, ranging from nodular regenerative hyperplasia, focal nodular hyperplasia, adenomas, HCC and hepatoblastomas. Additionally, it is known that half of individuals with Abernethy malformation type Ib will develop one or multiple types of tumours. There seems to be a direct association with tumorigenesis and CPSS, which is the primary consequence of absent portal flow. Surgery is the treatment of choice, either as a curative resection or orthotopic liver transplantation if recommended as per the criteria, in which replacing the hepatic parenchyma in the setting of an Abernathy malformation will correct the underlining hyper-arterialisation.

Case Report: Hepatic Adenoma in a Child With a Congenital Extrahepatic Portosystemic Shunt

Congenital extrahepatic portosystemic shunts (CEPS), previously also described as Abernethy malformations, are rare malformations in which the extrahepatic portal system directly communicates with the vena cava inferior, thereby bypassing the liver. A hypoplastic portal vein (PV) exists in most cases. CEPS have been associated with the development of liver nodules, ranging from mostly focal nodular hyperplasia (FNH) to hepatic adenoma (HA) and even hepatocellular carcinoma (HCC). Tumor development in CEPS may be due to changes in perfusion pressures, oxygen supply or endocrine imbalances. It is important to rule out CEPS in children with liver tumors, because resection could impede future shunt occlusion procedures, and benign masses may regress after shunt occlusion. Here, we review the case of a 9-years-old male with CEPS and hepatic nuclear Factor 1-alpha (HNF-1-alpha) inactivated HA to raise awareness of this condition and review histopathological changes in the liver of CEPS.

A case report on an incidental discovery of congenital portosystemic shunt

RATIONALE

Congenital portosystemic shunt (Abernethy malformation) is a rare entity causing the portal blood to drain directly into the systemic circulation, eluding the liver. These shunts arise through disturbances in the embryonic development.

PATIENT CONCERNS

A 9-year-old male patient was referred to our department for further evaluation of a vascular malformation which was diagnosed in another facility when the patient was 2 years old, following a routine abdominal ultrasound. The patient had no complaints and the physical examination was normal at all times.

DIAGNOSIS

Laboratory tests and esogastroduodenoscopy were normal. The abdominal ultrasound showed a side-to-side shunt between a short portal trunk and the inferior vena cava. A hepatic mass suggestive for focal noduar hyperplasia was seen in the left liver lobe. Abdominal angio-computed tomography (angio-CT) was performed and the ultrasonographic anomalies were confirmed. Multiple other vascular malformations were diagnosed-hepatic artery emerging from the superior mesenteric artery, with early division; hepatic veins forming a short common trunk before draining into the inferior vena cava; supranumerary right renal artery emerging from the aorta, tributary for the upper renal pole. Ecocardiography showed left superior vena cava persistence. The final diagnosis was Abernathy malformation type IB. In the meantime the patient was diagnosed with allergic asthma.

INTERVENTIONS

No surgical cure was pursued because the malformation was an incidental discovery.

OUTCOMES

The patient was followed-up closely from the final diagnosis (when he was 9 years old) to present (he is currently 10 years old) with no change in his status-he remained asymptomatic.

LESSONS

Angio-CT should be the performed whenever a vascular malformation is suspected in order to establish a correct diagnosis, because portosystemic shunts carry a high risk of severe complications. Knowing that patients with portosystemic shunts may have pulmonary hypertension, respiratory complaints should be carefully evaluated-in this particular case, even though the most probable cause for the respiratory symptoms was pulmonary hypertension, it was ruled out by cardiac ultrasonography and further investigations confirmed the diagnosis of allergic asthma.

Pulmonary arterial hypertension caused by congenital extrahepatic portocaval shunt: a case report

BACKGROUND

Congenital extrahepatic portocaval shunt (CEPS), also known as Abernethy malformation, is an extremely rare anomaly of the splanchnic venous system, especially when accompanied by pulmonary arterial hypertension.

CASE PRESENTATION

We report a case of a 15-year-old female who was diagnosed with CEPS (Abernethy type Ib) accompanied by pulmonary arterial hypertension. This case was incidentally identified during abdominal ultrasound examination and confirmed by mesenteric and splenic arteriography. During more than 4 years of follow-up, after receiving sildenafil (80 mg/day), the patient's condition improved in the first year after discharge. However, one year later, the patient's conditions start to deteriorate.

CONCLUSION

This article presents a rare case of Abernethy malformation accompanied by pulmonary arterial hypertension, which can be diagnosed by using abdominal ultrasonography, portal vein computed tomography angiography or mesenteric and splenic arteriography. This malformation had limited treatment and poor prognosis.

Abernethy malformation type 2: varied presentation, management and outcome

PURPOSE

To study the varied presentations and the outcomes in children with Type 2 Abernethy malformation following shunt ligation.

MATERIAL AND METHODS

Children with Type 2 Abernethy who had had been operated between 2013 and 2017 were included in the study. The diagnosis had been confirmed on ultrasonography, CECT or angiography. All patients underwent laparotomy. The shunt was identified, clamped and the bowel congestion was noted. The shunt was ligated if the bowel congestion was not significant or had improved. Relevant follow-up investigations were done to document the resolution or amelioration of symptoms and the patency of the shunt.

RESULTS

Five patients were included in the study with a median age of 6 years. Hepatopulmonary syndrome was the presentation in 4 patients while one patient presented with liver tumor. Ultrasonography and CECT were able to diagnose Type 2 malformation in 4 patients whereas in 1 patient the distal portal vein was not seen. The postoperative period was complicated in 3 patients. At the median follow up at 14 months, good intrahepatic portal flow in all patients. All patients demonstrated improvement/ resolution of symptoms.

CONCLUSION

Abernethy is rare malformation which can have a varied presentation. Additional investigations may be needed to confirm the diagnosis of Type 2 variety. Most patients have gradual improvement of symptoms.

LEVEL OF EVIDENCE

Level IV/ Treatment study.

Liver histopathology in patients with hepatic masses and the Abernethy malformation

BACKGROUND/PURPOSE

The Abernethy malformation (AM) is a congenital venous malformation in which the splanchnic venous return bypasses the liver and drains directly into the systemic circulation. This deprives the liver of hepatotrophic growth factors and allows metabolic products of digestion to enter the systemic veins without the benefit of passing through the liver. The histologic features of liver biopsies in children with an AM were reviewed.

METHODS

A retrospective review of liver biopsies in patients with AM between 1997 and 2017 was performed. Patients were divided into two groups for comparison of histologic features: presence (M+) or absence (M-) of a coexistent liver mass on imaging. Biopsies were reviewed by a pediatric pathologist. Chi-square test was used for statistical analysis between groups. Significance was assigned to p values <0.05.

RESULTS

Eighteen liver biopsies were reviewed. Masses were present in only 6 patients who had a liver biopsy. Masses were observed with similar frequencies in either type of the Abernethy malformation (I or II). Nine of 12 M- patients and 3/6 M+ patients had the type I AM. Histologically, all patients were noted to have small or absent portal veins. Isolated capillaries were seen more frequently in patients with a known liver mass (p = 0.045), while crowding of portal tracts was more commonly seen in patients without a liver mass (p = 0.019).

CONCLUSION

Liver biopsies in patients with AM demonstrate abnormal vascular and parenchymal histologic features. Livers with coexistent masses were more commonly found to have features suggesting an increased dependence on arterial blood supply.

LEVEL OF EVIDENCE

III.

Congenital extrahepatic portosystemic shunt: description of four cases and review of the literature

Congenital extrahepatic portosystemic shunt (CEPS), also known as Abernethy malformation, is a rare condition in which the splenomesenteric blood drains directly into a systemic vein, bypassing the liver through a complete or partial shunt. The diagnosis is frequently made during childhood in the setting of neonatal cholestasis, hypergalactosemia, failure to thrive, mental retardation or other congenital defects. In adulthood, CEPS is usually found incidentally during diagnostic work-up for abdominal pain, liver test abnormalities, liver nodules, portopulmonary hypertension, portopulmonary syndrome or portosystemic encephalopathy. The diagnosis depends on imaging and portal venography, but sometimes only liver biopsy can be resolutive, demonstrating the absence of venules within the portal areas. Here we report four recent cases of Abernethy malformation diagnosed in young adults, in which ultrasound (US) was the initial imaging technique and allowed to suspect the diagnosis. Furthermore, we reviewed clinical presentations, associated anomalies and treatment of the 310 cases of CEPS previously reported in the literature.

Lower gastrointestinal bleeding as a form of presentation in an adult case of Abernethy syndrome

We report the case of a 29-year-old patient who presented with a short history of lower gastrointestinal bleeding. A diagnosis of Abernethy syndrome was made (congenital extrahepatic portosystemic shunt) after this uncommon clinical presentation. The prevalence of this congenital malformation is very low and usually manifests during the pediatric age, according to previously published reports.

Congenital portosystemic shunts: diagnosis and treatment

Congenital portosystemic shunts (CPSS) are rare vascular malformations that create an abnormal connection between portal and systemic veins resulting in complete or partial diversion of the portal flow away from the liver to the systemic venous system. Different anatomic types exist and several classifications have been proposed. They can be associated with other malformations especially cardiac and heterotaxia. The main complications include hepatic encephalopathy, liver tumors, portopulmonary hypertension, and pulmonary arteriovenous shunts. Diagnosis relies on imaging, and prenatal diagnosis is possible. Spontaneous closure of the CPSS is possible in some anatomic forms during the first year of life. When the CPSS remains patent, radiologic or surgical closure of the CPSS may prevent, resolve, or stabilize complications. Interventional radiology plays a key role for both the preoperative evaluation with occlusion test to assess the exact anatomy and to measure portal pressure after occlusion of the CPSS. Endovascular closure is the first option for treatment when possible.

Abernethy Malformation Type II and Concurrent Nodular Hyperplasia in a Rare Female Case

BACKGROUND

Abernethy malformation is a rare splanchnic vascular abnormality characterizing extrahepatic abnormal shunts that is classified into types I and II. Abernethy malformation type I has a female predilection and is associated with a variety of concurrent hepatic benign or malignant tumours while type II with concurrent tumours is very rare in females.

CASE REPORT

We report a rare female case of Abernethy malformation type II with concurrent occupying lesion in the right liver, which was successfully transplanted; the occupying lesion was pathologically proven to be nodular hyperplasia.

CONCLUSION

This case might provide further knowledge regarding Abernethy malformation. On imaging, the anatomy of portal vein should be carefully investigated to categorize Abernethy malformation, and a wide variety of differential diagnosis of concurrent occupying lesions should be taken into account.

Hepatocellular nodules in vascular liver diseases

Hepatocellular nodules have been recognized in vascular liver diseases for a long time and mostly described and studied in the imaging literature. Some confusions in their identification and overlap in their definitions exist, especially in this specific clinical context. Pathology descriptions report the development of nodular regenerative hyperplasia, large regenerative nodule, and focal nodular hyperplasia, as adaptive responses of the liver parenchyma to the modified blood flow. True neoplastic hepatocellular nodules such as hepatocellular adenoma and hepatocellular carcinoma can also appear, mainly in Budd-Chiari syndrome, and have to be correctly diagnosed. This is more difficult for the radiologist in these diseased livers, leading more frequently to perform liver biopsies. We describe the histology of each type of well-differentiated hepatocellular nodules and provide some clues for their differential diagnosis. A review of the literature gives an historical perspective of the problem and enlightens the frequency and the subtypes of hepatocellular nodules found in the most common vascular liver diseases.

Radioembolization for Hepatocellular Carcinoma Arising in the Setting of a Congenital Extrahepatic Portosystemic Shunt (Abernethy Malformation)

In a 50-year-old male with an incidentally discovered hepatocellular carcinoma, a congenital extrahepatic portosystemic shunt with the absence of the portal vein (Abernethy syndrome) was diagnosed by imaging. This study aims to discuss the variant anatomy relevant to this splanchnic vascular malformation, review its association with the development of liver neoplasms, and report the safety and efficacy of TARE followed by resection for a HCC arising in this rare condition.