Liver transplantation for the Abernathy malformation

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.

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.

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.

Congenital Portosystemic Shunts: Current Diagnosis and Management

Congenital portosystemic shunts are increasingly recognized in several settings and at any age. The following are some of the most common presentations: prenatal ultrasound, neonatal cholestasis, incidental finding on abdominal imaging, or systemic complications such as unexplained cardiopulmonary or neurological disease, or the presence of liver nodules in a noncirrhotic liver. The purpose of the present review is to summarize clinical presentation and current recommendations for management, and highlight areas of future research. Illustrative examples from the veterinary literature complement our current lack of knowledge of this rare malformation often masquerading as a multisystem disease.

Type I congenital extrahepatic portosystemic shunt treated by orthotopic liver transplantation: A case report

BACKGROUND

Congenital extrahepatic portosystemic shunt, also known as Abernethy deformation, is a rare malformation caused by dysplasia in the portal vein system. There are few reports of liver transplantation as a treatment for Abernethy deformation, and our report is the first case in China. This is the second reported case with congenital extrahepatic portosystemic shunt combined with focal nodular hyperplasia and hepatopulmonary treated with liver transplantation.

CASE SUMMARY

The patient was a 14-year-old girl, diagnosed preoperatively as type Ib Abernethy deformation, intrahepatic multiple space-occupying lesion, and hepatopulmonary syndrome. The patient recovered well after undergoing classic orthotopic liver transplantation. Liver function, pulmonary function, and portal vein computed tomography angiography imaging were reexamined 20 mo postoperatively, and no abnormality was observed.

CONCLUSION

Liver transplantation is an effective treatment for type I Abernethy deformation combined with focal nodular hyperplasia and hepatopulmonary syndrome.

Review article: Update on current and emergent data on hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a frequent pulmonary complication of end-stage liver disease, characterized by impaired arterial oxygenation induced by intrapulmonary vascular dilatation. Its prevalence ranges from 4% to 47% in patients with cirrhosis due to the different diagnostic criteria applied among different studies. Nitric oxide overproduction and angiogenesis seem to be the hallmarks of a complicated pathogenetic mechanism, leading to intrapulmonary shunting and ventilation-perfusion mismatch. A classification of HPS according to the severity of hypoxemia has been suggested. Contrast-enhanced echocardiography represents the gold standard method for the detection of intrapulmonary vascular dilatations which is required, in combination with an elevated alveolar arterial gradient to set the diagnosis. The only effective treatment which can modify the syndrome’s natural history is liver transplantation. Although it is usually asymptomatic, HPS imparts a high risk of pretransplantation mortality, independently of the severity of liver disease, while there is variable data concerning survival rates after liver transplantation. The potential of myocardial involvement in the setting of HPS has also gained increasing interest in recent research. The aim of this review is to critically approach the existing literature of HPS and emphasize unclear points that remain to be unraveled by future research.

Live donor liver transplantation for a child presented with severe hepatopulmonary syndrome and nodular liver lesions due to Abernethy malformation

A 15-year-old boy first presented with severe lung lesions and hypoxia and he was considered as a lung transplant candidate. Upon evaluation, hepatopulmonary syndrome, multiple nodular liver lesions, and Abernethy type 1b malformation were diagnosed. The patient underwent successful right lobe live donor liver transplantation, and all of the symptoms disappeared soon after the transplant. He is currently alive and well with excellent liver and lung functions 4 years after surgery.

Proposed management algorithm for severe hypoxemia after liver transplantation in the hepatopulmonary syndrome

The hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, intrapulmonary vascular dilatation, and abnormal gas exchange, and is found in 10-32% of patients with liver disease. Liver transplantation is the only known cure for HPS, but patients can develop severe posttransplant hypoxemia, defined as a need for 100% inspired oxygen to maintain a saturation of ≥85%. This complication is seen in 6-21% of patients and carries a 45% mortality. Its management requires the application of specific strategies targeting the underlying physiologic abnormalities in HPS, but awareness of these strategies and knowledge on their optimal use is limited. We reviewed existing literature to identify strategies that can be used for this complication, and developed a clinical management algorithm based on best evidence and expert opinion. Evidence was limited to case reports and case series, and we determined which treatments to include in the algorithm and their recommended sequence based on their relative likelihood of success, invasiveness, and risk. Recommended therapies include: Trendelenburg positioning, inhaled epoprostenol or nitric oxide, methylene blue, embolization of abnormal pulmonary vessels, and extracorporeal life support. Availability and use of this pragmatic algorithm may improve management of this complication, and will benefit from prospective validation.

Clinical implications of pulmonary shunting on saline contrast echocardiography

Pulmonary right-to-left shunting can be encountered using transthoracic contrast echocardiography (TTCE) with agitated saline. Diseases associated with pulmonary shunting on saline TTCE include hereditary hemorrhagic telangiectasia (HHT), hepatopulmonary syndrome, and some congenital heart defects after partial or complete cavopulmonary anastomosis. Furthermore, small pulmonary shunts on saline TTCE are also documented in a proportion of healthy individuals. Pulmonary shunting carries the risk for severe neurologic complications due to paradoxical embolization. In HHT, additional chest computed tomography is recommended in case of any pulmonary shunt detected on saline TTCE, to evaluate the feasibility for transcatheter embolotherapy of pulmonary arteriovenous malformations. Furthermore, antibiotic prophylaxis is advised in case of any pulmonary shunt on saline TTCE to prevent brain abscesses after procedures with risk for bacteremia. The present review provides an overview of important aspects of pulmonary shunting and its detection using saline TTCE. Furthermore, advances in understanding the clinical implications of different pulmonary shunt grades on saline TTCE are described. It appears that small pulmonary shunts on saline TTCE (grade 1) lack any clinical implication, as these shunts cannot be used as a diagnostic criterion for HHT, are not associated with an increased risk for neurologic complications, and represent pulmonary arteriovenous malformations too small for subsequent endovascular treatment. This implies that additional chest computed tomography could be safely withheld in all persons with only small pulmonary shunts on saline TTCE and sets the stage for further discussion about the need for antibiotic prophylaxis in these subjects. Besides further optimization of the current screening algorithm for the detection of pulmonary arteriovenous malformations in HHT, these observations can be of additional clinical importance in other diseases associated with pulmonary shunting and in those healthy individuals with documented small pulmonary shunts on saline TTCE.

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.

Pediatric orthotopic living-donor liver transplantation cures pulmonary hypertension caused by Abernethy malformation type Ib

A 3.3-yr-old boy was diagnosed with PH caused by a PSS of Abernethy malformation type Ib. After control of PH, he underwent OLDLT at 4.9 yr. His PV flowed directly into the confluence of the CCLMHV and the IVC. To shorten the anhepatic phase, hepatic arterial flow was partially maintained. Removal of the native liver began simultaneously with the graft harvest. The proximal PV was cut at the optimal point for reconstruction. The distal PV was cut at the concrescence of the PV and the CCLMHV. After IVC-plasty, the LHV of the graft was attached with an anterior patch by venous grafting and was then anastomosed to the IVC. Although the mPAP temporarily increased above the mean arterial pressure, mPAP was stable during OLDLT. FNH and steatosis were confirmed histopathologically. In summary, pediatric OLDLT was performed successfully in PH caused by PSS.

Shunt diameter in agenesis of the ductus venosus with extrahepatic portosystemic shunt impacts on prognosis

OBJECTIVES

Agenesis of the ductus venosus (ADV) is a rare condition in which there are two variants of umbilical vein drainage: intrahepatic shunt or extrahepatic (portosystemic) shunt. It has been posited that the extrahepatic variant carries a poorer prognosis. However, in the absence of associated anomalies there is still a wide variation in outcome. We evaluated the portal system in cases of ADV and aimed to identify parameters that might predict outcome.

METHODS

We conducted a retrospective study of cases of ADV with extrahepatic shunt that had been examined in two centers, and collected new cases prospectively. The route of the shunt was depicted using two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. In an attempt to characterize portal system and shunt developmental variations and their possible impact on outcome, the diameter of the shunt was compared with the diameter of the umbilical vein and the entire portal vasculature was assessed. Poor outcome was defined as persistent morbidity or fetal or neonatal death.

RESULTS

Twenty-two cases of ADV were identified: nine retrospectively and 13 prospectively. Aberrant shunts from the umbilical vein were identified to the right atrium, coronary sinus, inferior vena cava (IVC) and iliac vein. In seven of 22 cases (32%) a wide connection was observed. In six of these seven cases (86%) the outcome was poor, including four with severe associated anomalies and two with hepatic dysfunction. In five of these cases, cardiomegaly with tricuspid regurgitation was observed, as well as underdevelopment of the portal system. In only five of 15 cases with a narrow shunt (33%) was the outcome poor, and in all five cases the poor outcome was related to associated anomalies.

CONCLUSION

In cases of ADV with extrahepatic shunt, portal system development is impacted by the diameter of the shunt. If the shunt is narrow, the portal system will have developed normally. A wide shunt is associated with underdevelopment or absence of the portal system. In cases of ADV with extrahepatic shunt, prognosis is determined by the severity of associated anomalies, the diameter of the shunt and development of the portal system.