Histopathology of livers in patients with congenital portosystemic shunts (Abernethy malformation): a case series of 22 patients

Expert management of congenital portosystemic shunts and their complications

Congenital portosystemic shunts are often associated with systemic complications, the most challenging of which are liver nodules, pulmonary hypertension, endocrine abnormalities, and neurocognitive dysfunction. In the present paper, we offer expert clinical guidance on the management of liver nodules, pulmonary hypertension, and endocrine abnormalities, and we make recommendations regarding shunt closure and follow-up.

Focal nodular hyperplasia-like nodules arising in the setting of hepatic vascular disorders with portosystemic shunting show β-catenin activation

Hepatocellular nodules can develop in the setting of chronic hepatic vascular disorders including those characterized by portosystemic shunts such as Abernethy malformation and post-Fontan procedure. The nodules can range from benign lesions such as regenerative nodules, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) to malignant neoplasms such as hepatocellular carcinoma (HCC). In many instances, these nodules are difficult to place into well-defined categories based on radiologic or histologic features. Nodular lesions that resemble FNH are common in this context and have been described as FNH-like nodules, the nature of which is not well-established. This study examines 6 liver resections from patients with vascular disease characterized by portosystemic shunts. A wide range of nodules were present in these cases, including regenerative nodules (n = 2), FNH and FNH-like (n = 30), HCA (n = 10), HCA-like (n = 13), and HCC (n = 2). Six nodules from 3 patients were categorized as FNH-like due to one or more features such as nodular architecture, fibrous septa, and ductular reaction, but lack of typical map-like glutamine synthetase (GS) staining. Further characterization of these 6 FNH-like nodules showed diffuse GS staining in all nodules (3 diffuse homogeneous, 3 diffuse heterogeneous). Targeted next-generation sequencing identified CTNNB1 alterations in all tested FNH-like nodules (n = 4). These results indicate that FNH-like nodules in the setting of chronic hepatic vascular disorders can be neoplastic. Since the presence of β-catenin activation portends a potential risk for malignant progression, GS and β-catenin immunohistochemistry should be obtained in all cases showing FNH-like morphology, with molecular analysis performed in cases with indeterminate staining pattern.

A rare presentation of type II Abernethy malformation and nephrotic syndrome: Case report and review

Type II Abernethy malformation is an extremely reported congenital extrahepatic portosystemic shunt in complication with nephrotic syndrome. We present the case of an 8-year-old boy who presented with symptoms of type II Abernethy malformation and nephrotic syndrome. This diagnosis of this type II Abernethy malformation was based on physical examination, blood tests, urinalysis, nephrotic and hepatic function tests, routine clinical lipid measurements, abdominal ultrasonography, and computed tomographic angiography. A kidney biopsy revealed the pathological features of nephrotic syndrome. This is the second reported patient diagnosed with type II Abernethy malformation and nephrotic syndrome. Captopril treatment was effective in improving the symptoms of this case. A patient with type II Abernethy malformation related to immune complex-mediated glomerular injury was effectively improved with medication. Type II Abernethy malformation is a causative factor of immune complex-mediated glomerular injury in nephrotic syndrome. Captopril treatment significantly improved the symptoms in this case.

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.

Vascular anomalies associated with hepatic shunting

Congenital vascular anomalies affecting the liver have been described in the scientific literature for decades. Understanding these malformations begins with knowledge of hepatic vascular embryology. Surgeons have applied numerous classification systems to describe both intrahepatic and extrahepatic shunts, which can confuse the reader and clinician. In our experience, focusing on one classification system for extrahepatic shunts and one for intrahepatic shunts is better. Today many patients with these shunts carry good long-term prognosis thanks to advances in imaging to better detect shunts earlier and classify them. Timely intervention by skilled radiologists and surgeons have also limited complications arising from dynamic shunts and can avoid a liver transplant. Congenital hepatic shunts are not the only vascular condition affecting the liver. Hereditary hemorrhagic telangiectasia, also known as Osler Weber Rendu syndrome, particularly type 2, may have varying severity of hepatic involvement which warrants longitudinal care from an experienced hepatologist. Lastly, congenital hemangiomas, often first identified on the skin and oral mucosa, also can affect the liver. While most will resolve in infancy and childhood, the pediatric hepatologist must understand how and when to treat persistent lesions and their complications. This article serves as a concise reference to help clinicians better care for patients with these rare conditions.

Hepatopulmonary Syndrome in an Adolescent With Insidious Hypoxia and Small Intrahepatic Portal Venous Shunts: Posttransplant Benefit From Sildenafil

We report a patient without known preexisting liver disease who presented with hepatopulmonary syndrome (HPS) due to aberrant intrahepatic portal venous development leading to portosystemic shunting. Liver transplantation resulted in resolution of portal hypertension and HPS and sildenafil was safely tolerated in the treatment of persistent fatigue and hypoxemia. Twelve months later, patient has normal allograft function and has returned to normal activity.

Lobular diameters of autopsied dog livers give clues for an appropriate liver biopsy methodology

Hepatobiliary diseases of animals are frequently diagnosed by a combination of imaging, clinical pathology, and histopathology. A standardized surgical liver biopsy protocol, however, has not been established in veterinary medicine with regard to the selection of lobe and site of the liver to yield the most diagnostic information. To address this matter, we histologically examined 33 livers of autopsied dogs from which tissue samples of 4 different lobes as well as 4 different sites of each lobe were prepared. We measured the hepatic lobular diameter (HLD) as an objective variable to refer to the inter-lobar or inter-site difference among the biopsied samples. A measurement of 2,623 hepatic lobules resulted in 1.042 mm as the average of all the HLD values. Statistical analysis further revealed that the HLD tended to be small in a superficial 2 mm area of the liver parenchyma regardless of biopsy location, thus this area should be evaluated carefully by pathologists. The results also suggest that the HLD values of the quadrate lobe may measure smaller than those in the other lobes. Therefore, one would be able to obtain representative data of the entire liver by taking a sample from any single lobe except for the quadrate lobe. HLD measurements are needed in order to accumulate potentially useful information on the microanatomy and pathophysiology of the liver.

Portal venous deprivation in patients with portosystemic shunts and its effect on liver tumors

AIMS

To outline the use of radiological investigations in patients with congenital portosystemic shunts (CPS) and to assess the degree of portal venous deprivation in relation to the development of liver tumors.

METHODS

Single center retrospective cohort study of all patients with CPS referred from 1990 to 2016. Radiological investigations were reviewed for the presence of intrahepatic portal veins. Two groups were defined: Group 1 - without evidence of preservation of an intrahepatic portal venous system and, Group 2 - with evidence of intrahepatic portal venous flow. These groups were compared for the development of liver tumors, serum ammonia, and nature of subsequent surgical intervention. The ratio of infraceliac to supraceliac aortic diameter and hepatic enhancement in biphasic CT scans were also used to infer hepatic arterial in-flow and compared to age matched controls. Nonparametric tests were used throughout. A P value of 0.05 was considered significant. Data are quoted as median (IQR).

RESULTS

45 patients (Group 1, n = 12: Group 2, n = 33) were investigated for CPS at a median age of 8 months (1 month-14 years). Liver tumors were more common in Group 1 than Group 2 [11/12 (92%) versus 10/33 (29%); P < 0.001]. Aortic ratio was significantly lower in patients with CPS compared to control (0.82 versus 0.96; P < 0.001), but there was no difference between patients with or without tumors (0.82 versus 0.82; P = 0.52). Enhancement of the liver parenchyma was greater in portal venous rather than arterial phases by a median difference of 28 (15-50) Hounsfield units in controls, compared to 15 (8.5-23.5) in CPS patients (P = 0.04). A single stage closure was possible in 2/6 (33%) operated patients in Group 1 and 14/20 (70%) in Group 2 (P = 0.32).

CONCLUSIONS

Patients without radiological evidence of intrahepatic portal venous flow were significantly more likely to have associated hepatic tumors with a relative risk 3.1.

LEVELS OF EVIDENCE

This manuscript includes data that are III and IV Levels-of-Evidence.

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.

Patent ductus venosus in an infant with direct hyperbilirubinemia

Patent ductus venosus is caused by a defect in obliteration of ductus venosus after birth. Ductus venosus connects umbilical vein and inferior vena cava during fetal period. Patent ductus venosus is a very rare cause of cholestatic jaundice.