Transjugular portosystemic shunts in pediatric patients awaiting liver transplantation

The role of surgical shunts in the treatment of pediatric portal hypertension

BACKGROUND

Portal diversion by surgical shunt plays a major role in the treatment of medically refractory portal hypertension. We evaluate our center's experience with surgical shunts for the treatment of pediatric portal hypertension.

METHODS

All patients who underwent surgical shunt at a single institution from 2008 to 2017 were reviewed. The primary outcome was intervention-free shunt patency.

RESULTS

In this study, 34 pediatric patients underwent portal shunt creation. The median age was 7.7 years (interquartile range 4.3-12.0). Twenty-nine patients (85%) had prehepatic portal hypertension and 5 patients (15%) had intrahepatic portal hypertension. The primary manifestations of portal hypertension were esophageal varices (97%) and gastrointestinal bleeding (77%). Eighteen patients (53%) underwent meso-Rex bypass, 10 patients (29%) underwent splenorenal shunt, and 6 patients (18%) underwent mesocaval shunt. Outcomes were notable for minimal wound complications (9%), rebleeding events (12%), and mortality (3%). In the postoperative setting, 10 patients (29%) experienced a shunt complication (occlusion or stenosis), 4 of which occurred in the early postoperative period and required urgent intervention. The 1-year and 5-year "primary patency" patency rates were 71% and 66%, respectively.

CONCLUSION

Children suffer significant morbidity from the sequelae of portal hypertension. Our experience reinforces the feasibility of surgical shunts as an effective treatment option associated with low rates of morbidity and mortality.

Long-term outcome of transjugular intrahepatic portosystemic shunt for portal hypertension in autosomal recessive polycystic kidney disease

BACKGROUND

Autosomal recessive polycystic kidney disease (ARPKD) with congenital hepatic fibrosis (CHF) causes portal hypertension and its complications. A transjugular intrahepatic portosystemic shunt (TIPSS) could serve as a symptomatic treatment for portal hypertension-related symptoms in these children.

AIMS

To study the effect of TIPSS on portal hypertension, liver and kidney function and the long term complications.

MATERIALS AND METHODS

We report on 5 children with CHF treated with a TIPSS to manage severe portal hypertension related symptoms.

RESULTS

Mean follow-up time was 7 years and 2 months. At the end of follow-up there was a reduction of spleen size (p = 0.715) and hypersplenism with a rise in platelet count (p = 0.465). Esophageal varices and ascites disappeared in all patients. Liver and kidney function remained stable. In two patients endotipsitis was suspected and two patients developed an in-stent stenosis. There was no sign of encephalopathy in our patients.

CONCLUSION

TIPSS using ePTFE-covered stent is a feasible and effective alternative for surgical portosystemic shunting in children with CHF, also on the long term. It can postpone the need of a liver transplantation but close monitoring remains important for early diagnosis of endotipsitis or stent dysfunction related to stenosis.

Management of ascites in children

Ascites is the pathologic accumulation of fluid within the peritoneal cavity. There are many causes of fetal, neonatal and pediatric ascites; however, chronic liver disease and subsequent cirrhosis remain the most common. The medical and surgical management of ascites in children is dependent on targeting the underlying etiology. Broad categories of management strategies include: sodium restriction, diuresis, paracentesis, intravenous albumin, prevention and treatment of infection, surgical and endovascular shunts and liver transplantation. This review updates and expands the discussion of the unique considerations regarding the management of cirrhotic and non-cirrhotic ascites in the pediatric patient.

Pathophysiologie der Leberkrankheiten

In der sinusoidalen Membran beginnt die Gallebildung. Rezeptoren und Transporter erleichtern die Aufnahme und den Eintritt von Gallensäuren, Bilirubin, Fettsäuren und anderen Gallekomponenten in die Leberzelle. Diese enthält Rezeptoren für Glykoproteine, Asialoglykoprotein, Immunglobulin A (Ig A), vasoaktives intestinales Peptid (VIP), Insulin, Glukagon und „epidermal growth factor“ (EGF). Ein primär aktiver Transport erfolgt durch die Na+-K+-ATPase, die einen Ionengradienten an der Zellmembran aufbaut und innerhalb der Zelle ein negatives elektrisches Potenzial erzeugt (wodurch die Diffusion erleichtert wird). Dieser Ionengradient ermöglicht die Arbeit anderer Carrier gegen das Konzentrationsgefälle, z. B. von NTCP (Natrium-Taurocholsäure-Kotransport-Polypeptid), das auch für zahlreiche Medikamente, Östrogene und zyklische Oligopeptide spezifisch ist. Transporter für organische Anionen (OATP1) und anorganische Ionen wurden ebenfalls nachgewiesen.

MDCT, MR and interventional radiology in biliary atresia candidates for liver transplantation

The multi-detector computed tomography (MDCT) scan and magnetic resonance (MR) of the abdomen play a key role in the work-up to liver transplantation (LT) by identifying congenital anomalies or cirrhosis-related modifications, conditions that can require changes in surgical technique. Moreover, the MDCT and MR scans allow identification of cirrhotic liver hepatic masses, extrahepatic porto-systemic shunts, eventual thrombosis of portal system and radiological signs of portal hypertension associated with biliary atresia (BA). The aim of this paper is to review MDCT, MR imaging and interventional radiology procedures performed to evaluate morphological changes and degree of portal hypertension in pediatric patients with end-stage liver disease secondary to BA, who are candidates for LT. Advances in the field of MR, MDCT and in percutaneous minimally invasive techniques have increased the importance of radiology in the management of pediatric patients with BA who are candidates for LT.

Measurement of hepatic vein pressure gradient in children with chronic liver diseases

BACKGROUND & AIMS

The aim of this study is to present our preliminary experience with Hepatic Vein Pressure Gradient (HVPG) measurements in pediatric patients with chronic liver disease.

METHODS

Institutional review board approval was obtained. HVPG was measured in 20 pediatric patients, mean age 82+/-54 months, with chronic liver disease, without extrahepatic portal vein obstruction. In nine patients the end-stage liver disease was secondary to biliary atresia; in the remaining 11, to various causes. Eleven patients had esophageal varices at endoscopy, 14 had perigastric and periesophageal collaterals at imaging scan, three had ascites, 12 had low platelet count, and all had splenomegaly.

RESULTS

Hepatic vein catheterization was technically possible in all patients without complications. HVPG values were elevated in all but three patients, ranging between 2 and 33 mmHg (mean 11.3+/-7.2 mmHg), thus indicating a sinusoidal component in portal hypertension. A salient finding was the presence of hepatic venovenous shunts in 7 out of 9 patients with biliary atresia; however, the HVPG could still be measured distal to the shunts, but in three patients (with an HVPG of 8 mmHg) it was determined in an area with a small venovenous communication still visible, therefore underestimating the actual portal pressure gradient. No venovenous shunts were detected in the non-biliary atresia patients.

CONCLUSIONS

HVPG is a feasible procedure in pediatric patients. Patients with biliary atresia very frequently have communicating vessels between hepatic veins. This hitherto unacknowledged finding can lead to the underestimation of portal pressure by HVPG measurement.

Alternative technique for transjugular intrahepatic portosystemic shunt in a young child

Liver transplantation is safer, more readily available and is increasingly being carried out in younger patients. Therapeutic bridging procedures such as transjugular intrahepatic portosystemic shunt have therefore become more relevant to paediatrics, especially in the group of patients who are too unstable for surgery or in whom a liver graft is not available. We describe a transjugular intrahepatic portosystemic shunt procedure in a 4-year-old child with life-threatening variceal bleeding in whom the conventional procedure had failed. This technique may provide an alternative to conventional transjugular intrahepatic portosystemic shunt in this group.

Transjugular Intrahepatic Portosystemic Shunt Creation in a Polycystic Liver Facilitated by Hybrid Cross-sectional/Angiographic Imaging

Polycystic liver disease (PCLD) has long been considered to represent a contraindication to transjugular intrahepatic portosystemic shunt (TIPS) creation, primarily because of the risk of hemorrhage. Three-dimensional (3D) navigation within the enlarged and potentially disorienting parenchyma can now be performed during the procedure with the development of C-arm cone-beam computed tomography, which relies on the same equipment already used for angiography. Such a hybrid 3D reconstruction-enabled angiography system was used for safe image guidance of a TIPS procedure in a patient with PCLD. This technology has the potential to expedite any image-guided procedure that requires 3D navigation.

Interventional Radiology in Liver Transplantation

Radiology is a key specialty within a liver transplant program. Interventional techniques not only contribute to graft and recipient survival but also allow appropriate patient selection and ensure that recipients with severe liver decompensation, hepatocellular carcinoma or portal hypertension are transplanted with the best chance of prolonged survival. Equally inappropriate selection for these techniques may adversely affect survival. Liver transplantation is a dynamic field of innovative surgical techniques with a requirement for interventional radiology to parallel these developments. This paper reviews the current practice within a major European center for adult and pediatric transplantation.

Causes and management of portal hypertension in the pediatric population

Therapeutic options for children with portal hypertension now include a broad range of pharmacologic, endoscopic, and surgical procedures. Thoughtful application of all of these options can improve quality of life by decreasing the complications of portal hypertension and can decrease mortality by preventing the consequences of variceal hemorrhage. The development of portal hypertensive gastropathy following palliative procedures such as endoscopic sclerotherapy and band ligation may limit their long-term success in children. The excellent results now obtained with selective portosystemic shunts and liver transplantation assure that definitive surgical treatments will continue to be important components in the treatment of children with portal hypertensive complications or progressive liver disease. Evolving procedures, such as TIPS, represent excellent short-term life-preserving techniques to stabilize critically ill patients while awaiting liver transplantation. Their role in the future, long-term management of children is yet to be defined.

Liver transplantation. The pediatric challenge

Successful liver transplantation in a child is often a hard-won victory, requiring all the combined expertise of a dedicated pediatric transplant team. This article outlines the considerable challenges still facing pediatric liver transplant physicians and surgeons. In looking to the future, where should priorities lie to enhance the success already achieved? First, solutions to the donor shortage must be sought aggressively by increasing the use of from split-liver transplants, judicious application of living-donor programs, and increasing the donation rate, perhaps by innovative means. The major immunologic barriers, to successful xenotransplantation make it unlikely that this option will be tenable in the near future. Second, current immunosuppression is nonspecific, toxic, and unable to be individually adjusted to the patient's immune response. The goal of achieving donor-specific tolerance will require new consideration of induction protocols. Developing a clinically applicable method to measure the recipient's immunoreactivity is of paramount importance, for future studies of new immunosuppressive strategies and to address the immediate concern of long-term over-immunosuppression. The inclusion of pediatric patients in new protocols will require the ongoing insistence of pediatric transplant investigators. Third, the current immunosuppressive drugs have a long-term morbidity and mortality of their own. These long-term effects are particularly important in children who may well have decades of exposure to these therapies. There is now some understanding of their long-term renal toxicity and the risk of malignancy. New drugs may obviate renal toxicity, whereas the risk of malignancy is inherent in any nonspecific immunosuppressive regimen. Although progress is being made in preventing and recognizing PTLD, this entity remains an important ongoing concern. The global effect of long-term immunosuppression on the child's growth, development, and intellectual potential is unknown. Of particular concern is the potential for neurotoxicity from the calcineurin inhibitors. Fourth, recurrent disease and new diseases, perhaps potentiated by immunosuppressive drugs, must be considered. Already the recurrence of autoimmune disease and cryptogenic cirrhosis have been documented in pediatric patients. Now, a new lesion, a nonspecific hepatitis, sometimes with positive autoimmune markers, that may progress to cirrhosis has been recognized. It is not known whether this entity is an unusual form of rejection, an unrecognized viral infection, or a response to immunosuppressive drugs themselves. Finally, pediatric transplant recipients, like any other children, must be protected and nourished physically and mentally if they are to fulfill their potential. After liver transplantation the child's growth, intellectual functioning, and psychologic adaptation may all require special attention from parents, teachers, and physicians alike. There is limited understanding of how the enormous physical intervention of a liver transplantation affects a child's cognitive and psychologic function as the child progresses through life. The persons caring for these children have the difficult responsibility of providing services to evaluate these essential measures of children's health over the long term and to intervene if necessary. Part of the transplant physician's our duty to protect and advocate for children is to fight for equal access to health care. In most of the developing world, economic pressures make it impossible to consider liver transplantation a health care priority. In the United States and in other countries with the medical infrastructure to support liver transplantation, however, health care professionals must strive to be sure that the policies governing candidacy for transplantation and allocation of organs are applied justly and uniformly to all children whose lives are threatened by liver disease. In the current regulatory climate that increasingly takes medical decisions out of the hands of physicians, pediatricians must be even more prepared to protect the unique and often complicated needs of children both before and after transplantation. Only in this way can the challenges of the present and the future be met.

Pediatric solid organ transplantation

Solid organ transplantation offers hope for long-term survival and more normal lifestyles for children. Many of the procedures used are scaled-down versions of those used in adults and are associated with distinct challenges in children. Recent studies have provided insights into how transplantation can best serve these patients.