Cardiopulmonary manifestations of portovenous shunts from congenital absence of the portal vein: pulmonary hypertension and pulmonary vascular dilatation

Liver Transplantation as a Treatment for Unresectable Hepatic Adenoma in a Patient With Abernethy Syndrome

Abernethy syndrome is a rare congenital anomaly characterized by an intrahepatic or extrahepatic portosystemic shunt. Most patients are asymptomatic; however, due to the alteration in, or lack of, a portovenous flow, patients with Abernethy syndrome are at high risk of developing sequelae of liver failure. Once these complications develop, the only definitive treatment is transplantation. Patients with Abernethy syndrome are also at a higher risk of developing benign and malignant liver lesions, including hepatic adenomas. Here, we describe the first case of deceased donor liver transplantation as a treatment for a patient with type 1 Abernethy syndrome complicated by large, unresectable hepatic adenoma, found to have focal hepatocellular carcinoma on pathologic examination. Our male patient was found to have elevated liver enzymes at age 33, during a routine outpatient medical appointment. Despite being asymptomatic, his history of prior liver resection prompted CT imaging, which revealed two large liver lesions concerning for hepatic adenomas. When surveillance imaging showed a significant growth of the liver lesions, biopsy was pursued, which confirmed a diagnosis of hepatic adenomas. However, given the size of these lesions, resection was not a viable option for the patient. Instead, the patient underwent liver transplantation at age 41, which he tolerated well. Our case demonstrates the utility of deceased donor liver transplantation as a treatment for patients with Abernethy syndrome complicated by unresectable adenomas.

Is pulmonary arterial hypertension associated with schistosomiasis distinct from pulmonary arterial hypertension associated with portal hypertension?

Pulmonary arterial hypertension associated with schistosomiasis (SchPAH) and pulmonary arterial hypertension associated with portal hypertension (PoPAH) are lung diseases that develop in the presence of liver diseases. However, mechanistic pathways by which the underlying liver conditions and other drivers contribute to the development and progression of pulmonary arterial hypertension (PAH) are unclear for both etiologies. In turn, these unknowns limit certainty of strategies to prevent, diagnose, and reverse the resultant PAH. Here we consider specific mechanisms that contribute to SchPAH and PoPAH, identifying those that may be shared and those that appear to be unique to each etiology, in the hope that this exploration will both highlight known causal drivers and identify knowledge gaps appropriate for future research. Overall, the key pathophysiologic differences that we identify between SchPAH and PoPAH suggest that they are not variants of a single condition.

Congenital absence of the portal vein: Define the portosystemic shunt, avoid liver transplantation

Liver transplantation has been historically recommended for patients with congenital absence of the portal vein associated with extrahepatic congenital portosystemic shunts. Here, based on a case report of a 2-year-old girl and a thorough review of all published cases from 1974 to 2020, we show that such a diagnosis most often conceals a hypoplastic portal vein, which can be successfully re-permeabilized through the closure of the shunt in order to re-establish a physiological vascular anatomy. This highlights the importance of achieving a detailed anatomical description of extrahepatic congenital portosystemic shunts with a balloon occlusion test in order to plan the best surgical approach and avoid unnecessary liver transplantation.

The multisystem nature of isomerism: left isomerism complicated by Abernethy malformation and portopulmonary hypertension

Isomerism, also referred to as "heterotaxy" is a complex set of anatomic and functional perturbations. One of the most obvious manifestations of isomerism is the disturbance of organ arrangement, such that the thoracic organs are no longer asymmetric on the left and right. We report the case of a 14-year-old female in whom exercise-induced dyspnea led to a late diagnosis of left isomerism complicated by Abernethy malformation and portopulmonary hypertension. A comprehensive evaluation revealed two anatomic left lungs and hyparterial bronchi, bilateral left atria, an interrupted inferior caval vein with azygos continuation, multiple spleens, sinus node dysfunction, hepatic hypertrophy with focal nodular hyperplasia, and absence of the portal vein. Pulmonary vasodilator therapy was initiated resulting in clinical improvement. This case exhibits unique features including a late diagnosis of isomerism with Abernethy malformation and portopulmonary hypertension. The patient's presentation, medical workup, and future treatment emphasise the importance of multidisciplinary care in children with complex multisystem disease. We review the multiple cardiac and extracardiac manifestations of isomerism.

Pediatric liver transplantation using a hepatitis B surface antigen-positive donor liver graft for 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 systemic circulation. Herein, we report a case of pediatric deceased donor liver transplantation (DDLT) for symptomatic CAPV with whole liver graft from a hepatitis B surface antigen (HBsAg)-positive donor. A 4-year-old boy suffered from CAPV and secondary portal hypertension. He was also diagnosed with DiGeorge syndrome and heart anomalies. After waiting for 4 months, a 5-year-old donor weighing 19 kg with positive HBsAg was allocated to this 4-year-old patient weighing 15 kg. Recipient operation was performed according to the standard procedures of pediatric DDLT. Portal vein reconstruction was performed using interposition of a vascular homograft conduit to the superior mesenteric vein-splenic vein confluence. The patient recovered uneventfully from DDLT. He has been administered with lamivudine to prevent hepatitis B virus infection. This patient has been doing well for 5 years after DDLT without growth retardation. In conclusion, CAPV patients can have various vascular anomalies, thus 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.

Clinical characteristics and therapeutic outcomes of pulmonary arterial hypertension secondary to congenital portosystemic shunts

The aim of this retrospective study was to investigate the clinical characteristics and therapeutic outcomes of pulmonary arterial hypertension (PAH) secondary to congenital portosystemic shunts (CPSS). Thirty-three pediatric patients diagnosed in our institution with CPSS between 2012 and 2019 were enrolled in this study. The patients were divided into PAH and non-PAH groups. The PAH group included 15 patients who presented with unexplained PAH when CPSS was diagnosed. Two patients with microangiopathic hemolytic anemia died of right heart failure shortly after diagnosis. One patient received a liver transplant at the age of 4.3 years and showed a mild decrease in pulmonary artery pressure (PAP) 4 years after the operation. Seven patients underwent one-stage shunt closure at a median age of 2.8 years (1.4-13 years). Follow-up examinations, from 1.6 to 4.1 years after intervention, showed marked reduction of PAP in one patient and stabilization of PAH in six others. However, in one patient who underwent two-stage shunt closure, a marked increase in PAP was noted after partial ligation of the shunt. The remaining four patients received only pulmonary vasodilator therapy, and one of them died of right heart failure 12 years after the PAH diagnosis. The non-PAH group included 18 patients without evidence of PAH upon CPSS diagnosis. Shunt closure was carried out in eight of these patients, but one patient subsequently developed PAH after the resolution of hepatopulmonary syndrome.Conclusion: CPSS may be a more likely cause of unexplained PAH in pediatric patients than previously thought. Shunt closure or liver transplantation may prevent the progression of PAH, or even improve it for the majority of CPSS patients.

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.

Polysplenia Syndrome as a Risk Factor for Early Progression of Pulmonary Hypertension

BACKGROUND

Recent progress in surgical and intensive care has improved the prognosis of congenital heart disease (CHD) associated with heterotaxy syndrome. Less is known, however, about pulmonary vascular complications in these patients. Methods and Results: We reviewed medical records of 236 patients who were diagnosed with polysplenia syndrome at 2 institutions for pediatric cardiology in Japan from 1978 to 2015. We selected and compared the clinical records of 16 patients with polysplenia who had incomplete atrioventricular septal defect (AVSD) as the polysplenia group, and 22 age-matched patients with incomplete AVSD without any syndromes including polysplenia as the control group. Although the severity of systemic to pulmonary shunt was not significantly different between the groups, mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance index (PVRI) were significantly higher in the polysplenia group than the control (mPAP, 37.3 vs. 19.1 mmHg, P=0.001; PVRI, 5.7 vs. 1.4 WU∙m², P=0.014) before surgical intervention. On regression analysis, polysplenia influenced the development of pulmonary hypertension (PH) regardless of age at evaluation or degree of systemic to pulmonary shunt in the patients with incomplete AVSD.

CONCLUSIONS

Polysplenia syndrome is an independent risk factor for CHD-associated PH. Earlier intervention may be required to adjust the pulmonary blood flow in polysplenia syndrome with CHD to avoid the progression of PH.

Congenital absence of the portal vein: translated version

Congenital portosystemic shunt (CPS) is classified into type I (congenital absence of the portal vein) and type II, depending on the presence or absence of the intrahepatic portal vein. Reports still exist on cases in which psychiatric diseases or mental retardation was diagnosed or cases in which diagnosis and treatment are not performed until severe pulmonary complications occur, indicating the need to recognize CPS. Herein, we reviewed epidemiology, etiology, classification, symptom, diagnosis, and treatment based on clinical view points of CPS. For clinical view points, classification according to (1) the presence or absence of the intrahepatic portal venous system (IPVS) and (2) the extrahepatic or intrahepatic of shunt sites, facilitates the understanding of pathophysiological conditions and is useful in selecting a treatment for symptomatic CPS. Radiological and pathological examinations are important in IPVS evaluations, and IPVS evaluations are currently essential to make diagnoses by portography with balloon occlusion and liver biopsy. Symptomatic CPS (hepatic nodular lesions, portosystemic encephalopathy, and pulmonary complications, etc.) is an indication of treatment by shunt closure, but an indication of treatment for asymptomatic CPS is the challenge going forward.

Effective shunt closure for pulmonary hypertension and liver dysfunction in congenital portosystemic venous shunt

OBJECTIVE

Congenital portosystemic venous shunt (CPSVS) is a rare vascular malformation with a high risk of mortality from pulmonary arterial hypertension (PAH), but the treatment outcome of CPSVS closure remains elusive. Our aim was to investigate the clinical features and establish the optimal management of CPSVS with or without PAH.

METHODS

Twenty-four patients with CPSVS treated in Kyushu University Hospital between 1990 and 2015 were enrolled in this study. The patients were divided into a PAH group (n = 9) and a non-PAH group (n = 15). Clinical characteristics and outcomes were evaluated.

RESULTS

The first manifestation of CPSVS at diagnosis (28.5 [1-216] months) was hypergalactosemia in 13 (54%) or PAH in six (25%) patients. PAH was the cause of all three deaths. The PAH group had higher levels of serum total bile acid, manganese, and total bilirubin, along with higher pulmonary vascular resistance index (PVRI) than the non-PAH group (7.2 [5.1-38.1] vs 1.2 [0.5-3.3] unit/m² , P < 0.001). Five of nine PAH patients underwent CPSVS closure at a median of 38 months (range 21-118) after PAH diagnosis. Pulmonary artery pressure improved after CPSVS closure with PAH-specific therapy, but normal range was not achieved. CPSVS closure improved the hepatic synthetic function of four PAH patients. Eigh-t of 15 non-PAH patients who received CPSVS closure did not develop PAH for a median of 34.5 months (range 6-164) after the procedure.

CONCLUSIONS

CPSVS closure with PAH-specific therapy successfully controlled PAH. Early CPSVS closure may prevent the occurrence and progression of PAH with CPSVS.

Pulmonary hypertension's variegated landscape: a snapshot

The many types of pulmonary hypertension (PH) are so protean in their biological origin, histological expression, and natural history that it is difficult to create a summary picture of the disease, or to easily compare and contrast characteristics of one type of PH with another. For newcomers to the field, however, such a picture would facilitate a broad understanding of PH. In this paper, we suggest that four characteristics are fundamental to describing the nature of various types of PH, and that taken together they define a number of patterns of PH expression. These characteristics are histopathology, developmental origin, associated clinical conditions, and potential for resolution. The “snapshot” is a way to concisely display the ways that these signal characteristics intersect in select specific types of PH, and is an effort to summarize these patterns in a way that facilitates a “big picture” comprehension of this disease.

Portopulmonary Hypertension in Liver Disease Presenting in Childhood

OBJECTIVE

Portopulmonary hypertension (POPH) is a known complication of cirrhosis in adults, but there is little information on its incidence and outcome in children with liver disease. We report 14 patients with POPH and present a synthesis of the medical literature.

METHODS

Diagnosis of POPH in the 14 patients was based on right-sided heart catheterization displaying mean pulmonary artery pressure (mPAP) >25 mmHg, indexed pulmonary vascular resistances >3 Wood units · m, and pulmonary wedge pressure <15 mmHg. A literature review added 84 patients.

RESULTS

In our unit, POPH was found in 0.5% of the children with portal hypertension, 0.9% of the children with end-stage liver disease awaiting transplantation, and 3 children with congenital portosystemic shunts (CPSSs). Analysis of 98 reported patients, including the 14 presented here, showed the cause of liver disease to be chronic liver disease or portal cavernoma in 76 instances (34 with a history of surgical portosystemic shunt) and CPSS in 22 instances. There was a precession with proven hypoxemia caused by hepatopulmonary syndrome in 6 patients. Median survival was 3 months in 56 untreated patients. An 80% 5-year probability of survival in 42 patients was treated by CPSS closure, pulmonary vasodilators, and/or liver transplantation. Mean pretransplant mPAP was 34 and 49 mmHg in transplant survivors and nonsurvivors, respectively.

CONCLUSIONS

POPH is a rare but extremely severe complication of childhood liver disease. Portosystemic shunts, whether congenital or acquired, likely play an important causative role. Early diagnosis is crucial and requires systematic screening by echocardiography in children at risk.

Congenital absence of the portal vein associated with focal nodular hyperplasia of the liver and congenital heart disease (Abernethy malformation): A case report and literature review

Abernethy malformation is a rare congenital malformation defined by an extrahepatic portosystemic shunt. The majority of affected patients are young (<18 years of age) and experience various symptoms, including vomiting, jaundice, dyspnea and coma. The current study presents a case of Abernethy malformation in an asymptomatic adult male patient. The patient exhibited congenital absence of the portal vein, congenital heart disease (postoperative ventricular septal defect status), and multiple liver lesions, confirmed to be focal nodular hyperplasia by biopsy. Ultrasonography and magnetic resonance imaging findings revealing the liver lesions, type II congenital absence of the portal vein and the portosystemic shunt are presented. In addition, the common clinical presentations, associated anomalies, diagnostic workup and treatment options of this disorder are investigated by reviewing 101 previously reported cases.

The role of liver transplantation for congenital extrahepatic portosystemic shunt

BACKGROUND

Congenital extrahepatic portosystemic shunt (CEPS) is reported more frequently because of advances in imaging techniques. Liver transplantation (LT) is a therapeutic option, although the indications for LT are still controversial.

METHODS

This study reviewed 34 cases of LT for CEPS, including 30 cases reported in the English medical literature and the patients treated in our department, to collect the clinical data associated with LT.

RESULTS

The median age at diagnosis and LT was 3.7 and 6.8 years, respectively. Hepatic encephalopathy, including persistent hyperammonemia, was the most common indication of LT. Pulmonary complications, including hepatopulmonary syndrome and pulmonary hypertension, were the second most common indications of LT, and those patients underwent LT soon after the diagnosis. Although a shunt directly draining into the inferior vena cava was the most common type and managed by a simple direct anastomosis of the portal vein at LT, some cases required the modification of the portal vein reconstruction, such as interposition. Thirty patients were alive with a median follow-up period of 18 months.

CONCLUSIONS

LT for CEPS showed an excellent outcome. The development of pulmonary complications is an early indication for LT. Precise planning of portal vein reconstruction is required before LT.

Pulmonary vascular complications of liver disease

Hepatopulmonary syndrome and portopulmonary hypertension are two pulmonary vascular complications of liver disease. The pathophysiology underlying each disorder is distinct, but patients with either condition may be limited by dyspnea. A careful evaluation of concomitant symptoms, the physical examination, pulmonary function testing and arterial blood gas analysis, and echocardiographic, imaging, and hemodynamic studies is crucial to establishing (and distinguishing) these diagnoses. Our understanding of the pathobiology, natural history, and treatment of these disorders has advanced considerably over the past decade; however, the presence of either still increases the risk of morbidity and mortality in patients with underlying liver disease. There is no effective medical treatment for hepatopulmonary syndrome. Although liver transplantation can resolve hepatopulmonary syndrome, there appears to be worse survival even with transplantation. Liver transplantation poses a very high risk of death in those with significant portopulmonary hypertension, where targeted medical therapies may improve functional status and allow successful transplantation in a small number of select patients.

Hepatopulmonary syndrome: update on pathogenesis and clinical features

Hepatopulmonary syndrome (HPS) is a serious vascular complication of liver disease that occurs in 5-32% of patients with cirrhosis. The presence of HPS markedly increases mortality. No effective medical therapies are currently available and liver transplantation is the only established treatment option for HPS. The definition and diagnosis of HPS are established by the presence of a triad of liver disease with intrapulmonary vascular dilation that causes abnormal arterial gas exchange. Experimental biliary cirrhosis induced by common bile duct ligation in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and serves as a pertinent animal model. Pulmonary microvascular dilation and angiogenesis are two central pathogenic features that drive abnormal pulmonary gas exchange in experimental HPS, and thus might underlie HPS in humans. Defining the mechanisms involved in the microvascular alterations of HPS has the potential to lead to effective medical therapies. This Review focuses on the current understanding of the pathogenesis, clinical features and management of HPS.

Congenital portosystemic vascular malformations

Congenital portosystemic shunts are developmental abnormalities of the portal venous system resulting in the diversion of portal blood away from the liver to the systemic venous system. Such malformations are believed to come from an insult occurring between the fourth and eighth week of gestation during the development of hepatic and systemic venous systems, and could explain their frequent association with cardiac and other vascular anomalies. They are currently categorized into end-to-side shunts (type I) or side-to-side shunts (type II). This article aims to review the common symptoms and complications encountered in congenital portosystemic shunts, the surgical and endovascular treatment, and the role of liver transplantation in this disease. We will also focus on the current controversies and the areas where there is potential for future studies.