Portal vein complications after liver transplantation for biliary atresia

Biliary atresia is associated with polygenic susceptibility in ciliogenesis and planar polarity effector genes

BACKGROUND & AIMS

Biliary atresia (BA) is poorly understood and leads to liver transplantation (LT), with the requirement for and associated risks of lifelong immunosuppression, in most children. We performed a genome-wide association study (GWAS) to determine the genetic basis of BA.

METHODS

We performed a GWAS in 811 European BA cases treated with LT in US, Canadian and UK centers, and 4,654 genetically matched controls. Whole-genome sequencing of 100 cases evaluated synthetic association with rare variants. Functional studies included whole liver transcriptome analysis of 64 BA cases and perturbations in experimental models.

RESULTS

A GWAS of common single nucleotide polymorphisms (SNPs), i.e. allele frequencies >1%, identified intronic SNPs rs6446628 in AFAP1 with genome-wide significance (p = 3.93E-8) and rs34599046 in TUSC3 at sub-threshold genome-wide significance (p = 1.34E-7), both supported by credible peaks of neighboring SNPs. Like other previously reported BA-associated genes, AFAP1 and TUSC3 are ciliogenesis and planar polarity effectors (CPLANE). In gene-set-based GWAS, BA was associated with 6,005 SNPs in 102 CPLANE genes (p = 5.84E-15). Compared with non-CPLANE genes, more CPLANE genes harbored rare variants (allele frequency <1%) that were assigned Human Phenotype Ontology terms related to hepatobiliary anomalies by predictive algorithms, 87% vs. 40%, p <0.0001. Rare variants were present in multiple genes distinct from those with BA-associated common variants in most BA cases. AFAP1 and TUSC3 knockdown blocked ciliogenesis in mouse tracheal cells. Inhibition of ciliogenesis caused biliary dysgenesis in zebrafish. AFAP1 and TUSC3 were expressed in fetal liver organoids, as well as fetal and BA livers, but not in normal or disease-control livers. Integrative analysis of BA-associated variants and liver transcripts revealed abnormal vasculogenesis and epithelial tube formation, explaining portal vein anomalies that co-exist with BA.

CONCLUSIONS

BA is associated with polygenic susceptibility in CPLANE genes. Rare variants contribute to polygenic risk in vulnerable pathways via unique genes.

IMPACT AND IMPLICATIONS

Liver transplantation is needed to cure most children born with biliary atresia, a poorly understood rare disease. Transplant immunosuppression increases the likelihood of life-threatening infections and cancers. To improve care by preventing this disease and its progression to transplantation, we examined its genetic basis. We find that this disease is associated with both common and rare mutations in highly specialized genes which maintain normal communication and movement of cells, and their organization into bile ducts and blood vessels during early development of the human embryo. Because defects in these genes also cause other birth defects, our findings could lead to preventive strategies to lower the incidence of biliary atresia and potentially other birth defects.

The Yin and the Yang of Hemostasis in End-Stage Liver Disease

Patients with end-stage liver disease (ESLD) undergoing liver transplantation (LT) are prone to thromboses both while on the waiting list and in the perioperative period. This hypercoagulability is associated with significant endothelial dysfunction (ED) due to nitric oxide dysregulation. ED and increased thrombin generation are the main factors responsible for this hypercoagulability. Sepsis alone can significantly alter a patient's coagulation profile. In combination with ESLD, however, sepsis or septic shock are responsible for very complex changes. This makes both the assessment and management of coagulation in septic patients with ESLD very challenging. Viscoelastic testing (VET) is the preferred method of coagulation management in patients with cirrhosis because, as with standard laboratory testing, VET can assess the entire coagulation system including the interaction between both pro- and anticoagulants and platelets.

Long-term outcome of primary percutaneous stent angioplasty for pediatric posttransplantation portal vein stenosis

This study aims to evaluate the long-term efficacy and reintervention rate after primary percutaneous portal vein stent angioplasty for portal vein stenosis (PVS) in pediatric liver transplantation (LT) recipients. From 2004 to 2020, a total of 470 pediatric LTs were performed in our center. All cases were screened for interventional PVS treatment and analyzed retrospectively. We identified 44 patients with 46 percutaneous angioplasties for posttransplantation PVS. The median interval from LT to percutaneous catheter intervention was 5 months (16 days-104 months) with a median follow-up (f/u) period after catheter intervention of 5.7 years (2-156 months). In 40 patients, an endovascular stent was placed as primary (n = 38) or secondary (n = 2) intervention. The median age at stent placement was 23 (6-179) months with a median weight of 10 kg (6-46 kg). Technical success and relief of PVS were achieved in all patients irrespective of age or weight. Adverse events occurred peri-interventionally in two patients and were resolved with standard care. All primary portal vein (PV) stents remained patent until the end of f/u. Reinterventions have been successfully performed in 10 patients for suspected or proven restenosis, resulting in a primary patency rate of 75% and an assisted patency rate of 25%. The median time to reintervention was 6.2 years (range 1-10 years). The need for reintervention was independent of age or weight at both transplantation and initial angioplasty as well as of additional risk factors due to portal hypertension. Percutaneous transhepatic PV stent angioplasty in children is safe and effective in all age groups, with excellent long-term patency. Primary stent angioplasty should be considered as first-line treatment for PVS after pediatric LT.

Predictors of portal vein complications after pediatric liver transplantation: A German center experience

BACKGROUND

Portal vein complications (PVCs) after pediatric liver transplantation (LT) are sometimes asymptomatic, especially in the early phase, and can threaten both the graft and patient's survival. Therefore, the purpose of this study is to analyze the risk factors for portal vein thrombosis (PVT) and portal vein stenosis (PVS) after pediatric LT.

METHODS

All pediatric patients (n = 115) who underwent primary LT at Regensburg University Hospital between January 2010 and April 2017 were included in this study. The pre-, intra-, and postoperative parameters of all patients were retrospectively reviewed and risk factors for both PVT and PVS were analyzed.

RESULTS

Of the 115 patients, living donor LT was performed on 57 (49.5%) patients, and biliary atresia was the primary diagnosis in 65 patients (56%). After pediatric LT, 9% of patients developed PVT, and 16.5% developed PVS. Patient weight ≤7 kg [odds ratio (OR) 9.35, 95% confidence interval (CI) 1.03-84.9, p = .04] and GRWR >3% (OR 15.4, 95% CI 1.98-129.5, p = .01) were the independent risk factors for the development of PVT and PVS, respectively upon multivariate analysis. The overall patient survival rates at 1, 3, and 5 years were 91%, 90%, and 89%, respectively, and there was no difference in patient survival among those with and without PVCs.

CONCLUSIONS

Pediatric patients with body weight <7 kg and/or receiving a graft with GRWR >3% may develop PVCs and so require certain surgical modifications, close follow-up, and prophylactic anticoagulant therapy following transplant.

The Transition to Microsurgical Technique for Hepatic Artery Reconstruction in Pediatric Liver Transplantation

BACKGROUND

Hepatic artery thrombosis represents a potentially fatal complication following liver transplantation. Rates of hepatic artery thrombosis are significantly higher in children, with mortality reported up to 80 percent. Microsurgical anastomosis has been shown to decrease the rate of hepatic artery thrombosis and now represents the standard of care at the authors' institution. In this article, the authors present the largest study of its type directly comparing rates of hepatic artery thrombosis with and without microsurgical reconstruction of the hepatic artery.

METHODS

All pediatric patients who underwent primary orthotopic liver transplantation between 1989 and 2018 were included. Patients were divided into two cohorts: standard anastomosis with loupes, and microsurgical anastomosis under the operating microscope. The authors' primary outcome was the rate of hepatic artery thrombosis. Secondary outcomes were graft survival, patient survival, retransplantation rate, requirement for intraoperative blood products, and length of stay.

RESULTS

Two hundred thirty-one children met criteria for inclusion. One hundred eighty cases were performed with loupe magnification and 51 cases were performed under the microscope. The hepatic artery thrombosis rate was lower, but not significantly so (p = 0.114), in the microsurgical group [n = 1 (2.0 percent)] compared with the standard cohort [n = 15 (8.3 percent)]. Survival analysis revealed a significant increase in graft survival with microsurgical anastomosis (p = 0.020), but not patient survival (p = 0.196). The retransplantation rate was significantly lower with microsurgical anastomosis (p = 0.021).

CONCLUSIONS

Microsurgical anastomosis was associated with a clinically important decrease in hepatic artery thrombosis compared with standard loupe anastomosis. The graft survival rate was significantly higher in the microsurgical cohort, with a reduced retransplantation rate at 1 year. On this basis, the authors recommend microsurgical hepatic artery anastomosis in cases of pediatric liver transplantation. .

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Living donor liver transplantation for small infants aged less than 6 months: The experience of a single institute

PURPOSE

Liver transplantation (LT) for small infants < 6 months old is rare but becoming common as perioperative care improves. In Taiwan, living donor LT (LDLT) has expanded indications but is rarely performed for this age group because of unfavorable outcomes in the literature. We evaluated LDLT outcomes of patients <6 months old.

METHODS

We identified infants < 6 months old undergoing LDLT between 2004 and 2019 at our hospital. Variables related to recipients, donors, surgeries, and outcomes were analyzed.

RESULTS

Nine patients were identified. Indications for LT were biliary atresia (n = 2), Alagille syndrome (n = 1), protein C deficiency (n = 1), and acute liver failure (n = 5), including two patients with neonatal hemochromatosis, one with herpes simplex hepatitis, one with giant cell hepatitis with autoimmune hemolytic anemia, and one with hemophagocytic lymphohistiocytosis. Median age and weight at LT were 129 days and 4.8 kg, respectively. Graft types included left lateral segment (LLS, n = 4), hyper-reduced LLS (n = 4), and monosegment (n = 1). The median graft-to-recipient weight ratio was 4%. The median follow-up period was 14 months (range, 8 days to 127 months) with two mortalities, and two patients were totally weaned off immunosuppressants. Adjuvant therapies were required for patients with giant cell hepatitis and hemophagocytosis. Preoperative reconstructive imaging for estimating graft thickness facilitated surgical planning.

CONCLUSION

Although LDLT is difficult to perform for small infants, outcomes are favorable and mainly dependent on underlying causes in addition to technical innovations.

Hyponatremia Is Protective Against the Development of Portal Vein Thrombosis in Patients Undergoing Liver Transplant

BACKGROUND

Both hyponatremia and portal vein thrombosis (PVT) reflect the severity of liver dysfunction and are independently associated with increased morbidity in cirrhotic patients. In this study, we analyzed effects of hyponatremia on PVT development.

METHODS

Data on adult liver transplants (LTs) in the Model for End-Stage Liver Disease era through September 2016 were obtained. Receiver operating curves and multivariable logistic regression models were constructed to evaluate the association between serum sodium level and PVT. Based on the receiver operating curves, hyponatremia was defined as a sodium level below 125 mEq/L.

RESULTS

Of the 49,155 recipients included, 16% had hyponatremia (n = 7828) and 9% had PVT (n = 4414) at transplant. Subjects with hyponatremia had lower rates of PVT at the time of LT (4.4% vs 10.1%, P < .001), incidence of nonalcoholic steatohepatitis (10.8% vs 16.5%, P < .001), diabetes (19.7% vs 24.3%, P < .001), and need for dialysis (8.8% vs 16.0%, P < .001) as well as higher rates of chronic hepatitis C and B (37.6% vs 29.1%, P < .001 and 2.9% vs 1.7%, P < .001). Multivariable regression analysis confirmed that hyponatremia was independently associated with a decreased likelihood of PVT (odds ratio [OR], 0.44, P < .001). African American patients had a lower incidence of PVT (OR, 0.70; P < .001). Variables associated with a higher incidence of PVT were: nonalcoholic steatohepatitis (OR, 1.15; P = .005), moderate-to-severe ascites (OR, 1.10; P = .008), and Hispanic ethnicity (OR, 1.2; P < .001).

CONCLUSION

Hyponatremia is associated with a lower rate of PVT independent of severity of liver disease and other thrombotic risk factors. This protective effect should be taken into consideration during the perioperative management of hyponatremia in patients undergoing LT.

Hypercoagulability in End-stage Liver Disease: Review of Epidemiology, Etiology, and Management

In this review, we analyze the epidemiology of thromboses related to end-stage liver disease (ESLD), discuss causes of hypercoagulability, describe susceptible populations, and critically evaluate proposed prophylaxis and treatment of thromboses. Classically, ESLD has been regarded as a model for coagulopathy, and patients were deemed to be at high risk for bleeding complications. Patients with ESLD are not auto-anticoagulated, and they do not have a lower risk of portal vein thrombosis, intracardiac thrombus formation, pulmonary embolism or hepatic artery thrombosis. Though the cause of hypercoagulability is multifactorial, endothelial dysfunction likely plays a central role for all patients with ESLD. Some subpopulations, such as patients with nonalcoholic steatohepatitis and autoimmune conditions, are at increased risk of thrombotic events as are patients of Hispanic ethnicity. The science behind prophylaxis of different types of clotting and treatment of thromboses is developing rapidly. A number of medications, including low molecular weight heparin, unfractionated heparin, aspirin, vitamin K antagonists, and direct oral anticoagulants can be used, but clear guidelines are lacking. Acute intraoperative clotting can be associated with high mortality. Routine use of transesophageal echocardiography can be helpful in early recognition and treatment of intraoperative thrombosis. Heparin should be reserved for cases of intracardiac thrombus/pulmonary embolism without hemodynamic instability. In unstable patients, low dose of recombinant tissue plasminogen activator can be used. In this new era of heightened awareness of thrombotic events in ESLD patients, prospective randomized trials are urgently needed to best guide clinical practice.

Liver and systemic hemodynamics in children with cirrhosis: Impact on the surgical management in pediatric living donor liver transplantation

Cirrhosis in adults is associated with modifications of systemic and liver hemodynamics, whereas little is known about the pediatric population. The aim of this work was to investigate whether alterations of hepatic and systemic hemodynamics were correlated with cirrhosis severity in children. The impact of hemodynamic findings on surgical management in pediatric living donor liver transplantation (LT) was evaluated. Liver and systemic hemodynamics were studied prospectively in 52 children (median age, 1 year; 33 with biliary atresia [BA]). The hemodynamics of native liver were studied preoperatively by Doppler ultrasound and intraoperatively using invasive flowmetry. Portosystemic gradient was invasively measured. Systemic hemodynamics were studied preoperatively by Doppler transthoracic echocardiography and intraoperatively by using transpulmonary thermodilution. Hemodynamic parameters were correlated with Pediatric End-Stage Liver Disease (PELD) score and the histological degree of fibrosis (collagen proportionate area [CPA]). Cirrhosis was associated with a 60% reduction of pretransplant total liver flow (n = 46; median, 36 mL/minute/100 g of liver) compared with noncirrhotic livers (n = 6; median, 86 mL/minute/100 g; P = 0.002). Total blood flow into the native liver was negatively correlated with PELD (P < 0.001) and liver CPA (P = 0.005). Median portosystemic gradient was 14.5 mm Hg in children with cirrhosis and positively correlated with PELD (P < 0.001). Portal vein (PV) hypoplasia was observed mainly in children with BA (P = 0.02). Systemic hemodynamics were not altered in our children with cirrhosis. Twenty-one children met the intraoperative criteria for PV reconstruction using a portoplasty technique during the LT procedure and had a smaller PV diameter at pretransplant Doppler ultrasound (median = 3.4 mm; P < 0.001). Cirrhosis in children appears also as a hemodynamic disease of the liver, correlated with cirrhosis severity. Surgical technique for PV reconstruction during LT was adapted accordingly. Liver Transplantation 23 1440-1450 2017 AASLD.

Outcomes of Percutaneous Portal Vein Intervention in a Single UK Paediatric Liver Transplantation Programme

Introduction

Percutaneous transluminal angioplasty (PTA), with or without stent placement, has become the treatment of choice for portal vein complications (PVC) following liver transplantation. We aimed to assess long-term outcomes of intervention in paediatric transplant recipients, in a single institution.

Materials and Methods

227 children received 255 transplants between November 2000 and September 2016. 30 patients developed PVC of whom 21 had percutaneous intervention. Retrospective clinical and procedural outcome data on these 21 patients were collected.

Results

21 patients, with median age 1.7 years (range 0.4–16.2), underwent 42 procedures with PTA with or without stenting. 36 procedures were for PV stenosis and 6 for PV thrombosis. Treatment was with primary PTA, with stenting reserved for suboptimal PTA result or restenosis within 3 months. 28 procedures were performed with PTA and 13 with stenting. Technical success (>50% reduction in mean pressure gradient, absolute pressure gradient ≤4 mmHg or venographic stenosis <30%) was achieved in 41 procedures. Failure to recanalise a thrombosed PV occurred in 1 procedure. There were no major procedural complications. Patients were followed-up with serial Doppler ultrasound surveillance. Kaplan–Meier estimated median primary patency was 9.9 months, with primary-assisted patency of 95% after median follow-up of 45.5 months (range 11.1–171.6).

Conclusion

With regular surveillance, excellent patency rates can be achieved following percutaneous intervention for PVC post-paediatric liver transplantation.

Living donor liver transplantation for biliary atresia - An Indian experience

LT has played a significant role in improving the outcome of children with BA. We review our five-yr experience of LDLT for children with BA. Records of all children who underwent LDLT in our institution over a five-yr period (August 2010-June 2015) were reviewed and those with a primary diagnosis of BA were selected for our study. Data were extracted from a prospectively maintained database. Additional data were collected by review of case notes and imaging studies. Analysis was carried out using standard statistical means. One hundred and thirty-two children underwent LDLT at our center over the study period, of which 58 children (31 females) had a primary diagnosis of BA. Thirty-three (56.9%) children had undergone a prior KPE and 25 (43.1%) had a primary LT. Thirty-four children had at least one post-op complication, of which 13 had minor complications (Clavien grades I and II) and 21 had major complications (Clavien grade >II). Thirty-day survival was 96.6% and one-yr survival was 91.4%. Univariate analysis of variables comparing children who did and did not have a KPE prior to LT showed that age at LT, weight at LT, PELD, and GRWR were significantly different. LDLT provides excellent outcomes in children with BA. Primary LDLT and LT after KPE provide equivalent results, although the former is technically more challenging as the child is younger.

Pediatric Thromboembolism in Japan

OBJECTIVES

To investigate the clinical and epidemiologic characteristics of thromboembolism in Japanese children.

METHODS

Clinical data of 77 patients with thromboembolism from a national tertiary pediatric care center were reviewed.

RESULTS

Incidence of thromboembolism was calculated to be 15 per 10,000 hospital admissions. Infants younger than one year of age made up the largest age group (25 patients, including nine neonates younger than 30 d). The occurrence of thromboembolism increased over the years in the index population. Thromboembolism was diagnosed as follows: portal vein thrombosis (n = 15), obstruction of central venous catheter (n = 13) and cerebral infarction (n = 9). Among the 77 patients, there were eight mortalities and six significant sequelae.

CONCLUSIONS

In pediatric care, especially in intensive care, we should pay more attention to thromboembolism in order to detect it promptly.

Recent Trends in the Diagnosis and Management of Biliary Atresia in Developing Countries

NEED AND PURPOSE OF REVIEW

Biliary atresia is a progressive obstructive cholangiopathy and is fatal if left untreated within 2 years of life. Delay in referral is because of difficulties in differentiating it from physiologic jaundice and identifying an abnormal stool color. This paper presents an overview on the diagnosis and discusses the current strategies in the management of this disease in developing countries.

METHODS

Articles were retrieved from the PubMed database using the terms biliary atresia, Kasai portoenterostomy and pediatric liver transplantation. Contents of the article are also based on personal experience of the authors.

CONCLUSION

A national screening program using stool color cards as part of standard care in the neonatal period will greatly improve early detection of biliary atresia. Outcomes will improve if it is diagnosed at the earliest after birth, the child is referred to an experienced pediatric hepatobiliary unit for evaluation, and undergoes an early Kasai procedure. If an early Kasai portoenterostomy is performed, nearly half of all children survive into adolescence, and about one-third are likely to have a long-term, symptom-free life with normal liver biochemistry. Sequential treatment combining Kasai as first line and liver transplantation as second line results in 90% survival for children with biliary atresia.

Pediatric transplantation: preventing thrombosis

Due to progressive advances in surgical techniques, immunosuppressive therapies, and supportive care, outcomes from both solid organ transplantation and hematopoietic stem cell transplantation continue to improve. Thrombosis remains a challenging management issue in this context, with implications for both graft survival and long-term quality of life. Unfortunately, there remains a general paucity of pediatric-specific data regarding thrombosis incidence, risk stratification, and the safety or efficacy of preventative strategies with which to guide treatment algorithms. This review summarizes the available evidence and rationale underlying the spectrum of current practices aimed at preventing thrombosis in the transplant recipient, with a particular focus on risk factors, pathophysiology, and described antithrombotic regimens.

Management and long-term consequences of portal vein thrombosis after liver transplantation in children

Portal vein thrombosis (PVT) occurs in ≤12% of pediatric recipients of liver transplantation (LT). Known complications of PVT include portal hypertension, allograft loss, and mortality. The management of PVT is varied. A single-center, case-control study of pediatric LT recipients with portal vein (PV) changes after LT was performed. Cases were categorized as early PVT (if PVT was detected within 30 days of transplantation) or late PVT (if PVT was detected more than 30 days after transplantation or if early PVT persisted beyond 30 days). Two non-PVT control patients were matched on the basis of the recipient weight, transplant indication, and allograft type to each patient with PVT. Thirty-two of the 415 LT recipients (7.7%) received 37 allografts and developed PVT. In comparison with control patients, a higher proportion of patients with PVT had PVT present before LT (13.3% versus 0%, P = 0.01). Patients with early PVT usually returned to the operating room, and 9 of 15 patients (60%) had PV flow restored. Patients with late PVT had lower white blood cell (4.9 [1000/μL] versus 6.8 [1000/μL], P < 0.01) and platelet counts (140 [1000/μL] versus 259 [1000/μL], P < 0.01), an elevated international normalized ratio (1.2 versus 1.0, P < 0.001), and more gastrointestinal bleeding (25% versus 8.3%, P = 0.03) compared to controls. Patients with PVT were also less frequently at the expected grade level (52% versus 88%, P < 0.001). The patient survival rates were 84%, 78%, and 78% and 91%, 84%, and 79% for cases and controls at 1, 5, and 10 years, respectively. The allograft survival rates were 90%, 80%, and 80% for cases and 94%, 89%, and 87% for controls at 1, 5, and 10 years, respectively. In conclusion, patients with early and late PVT had preserved allograft function, and there was no impact on mortality. Patients diagnosed with early PVT often underwent operative interventions with successful restoration of flow. Patients diagnosed with late PVT experienced variceal bleeding, and some required portosystemic shunting procedures. Academic delays were also more common. In late PVT, the clinical presentation dictates care because the optimal management algorithm has not yet been determined. Multi-institutional studies are needed to confirm these findings and improve patient outcomes.

Meso-Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: review and perspectives

Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long-term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long-term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children.

Four hundred thirty consecutive pediatric living donor liver transplants: variables associated with posttransplant patient and graft survival

The availability of living donors allows transplant teams to indicate living donor liver transplantation (LDLT) early in the course of liver disease before the occurrence of life-threatening complications. Late referral to transplant centers is still a problem and can compromise the success of the procedure. The aim of this study was to examine the perioperative factors associated with patient and graft survival for 430 consecutive pediatric LDLT procedures at Sirio-Libanes Hospital/A. C. Camargo Hospital (São Paulo, Brazil) between October 1995 and April 2011. The studied pretransplant variables included the following: recipient age and body weight, Pediatric End-Stage Liver Disease score, z score for height/age, bilirubin, albumin, international normalized ratio, hemoglobin, sodium, presence of ascites, and previous surgery. The analyzed technical aspects included the graft-to-recipient weight ratio and the use of vascular grafts for portal vein reconstruction. In addition, the occurrence of hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and biliary complications was also analyzed. The liver grafts included 348 left lateral segments, 5 monosegments, 51 left lobes, and 9 right lobes. In a univariate analysis, an age < 12 months, a low body weight (≤10 kg), malnutrition, hyperbilirubinemia, and HAT were associated with decreased patient and graft survival after LDLT. In a multivariate analysis, a body weight ≤ 10 kg and HAT were significantly associated with decreased patient and graft survival. The use of vascular grafts significantly increased the occurrence of PVT. In conclusion, a low body weight (≤10 kg) and the occurrence of HAT independently determined worse patient and graft survival in this large cohort of pediatric LDLT patients.

Intra-operative management of low portal vein flow in pediatric living donor liver transplantation

For pediatric living donor liver transplantation, portal vein complications cause significant morbidity and graft failure. Routine intra-operative Doppler ultrasound is performed after graft reperfusion to evaluate the flow of portal vein. This retrospective study reviewed 65 children who had undergone living donor liver transplantation. Seven patients were detected with suboptimal portal vein flow velocity following vascular reconstruction and abdominal closure. They underwent immediate on-table interventions to improve the portal vein flow. Both surgical and endovascular modalities were employed, namely, graft re-positioning, collateral shunt ligation, thrombectomy, revision of anastomosis, inferior mesenteric vein cannulation, and endovascular stenting. The ultrasonographic follow-up assessment for all seven patients demonstrated patent portal vein and satisfactory flow. We reviewed our experience on the different modalities and proposed an approach for our future intra-operative management to improve portal vein flow at the time of liver transplantation.

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.

Portal vein thrombosis and outcomes for pediatric liver transplant candidates and recipients in the United States

The effect of occlusive portal vein thrombosis (PVT) on the mortality of pediatric liver transplant candidates and recipients is poorly defined. Using standard multivariate techniques, we studied the relationship between PVT and waiting-list and posttransplant survival rates with data from the Scientific Registry of Transplant Recipients (September 2001 to December 2007). In all, 5087 liver transplant candidates and 3630 liver transplant recipients were evaluated during the period. PVT was found in 1.4% of the liver transplant candidates (n = 70) and in 3.7% of the liver transplant recipients (n = 136). PVT was not associated with increased wait-list mortality [hazard ratio (HR) = 1.1, 95% confidence interval (CI) = 0.5-2.4, P = 0.77]. Conversely, PVT patients had a significantly lower unadjusted survival rate in the posttransplant period (P = 0.01). PVT was independently associated with increased posttransplant mortality in multivariate models (30-day survival: HR = 2.9, 95% CI = 1.6-5.3, P = 0.001; overall survival: HR = 1.7, 95% CI = 1.1-2.4, P = 0.01). The presence of PVT in pediatric liver candidates was not associated with increased wait-list mortality but was clearly associated with posttransplant mortality, especially in the immediate postoperative period.

Liver transplantation in children weighing 5 kg or less: analysis of the UNOS database

LT is a major medical and surgical challenge in very small patients. Aim of the study is to determine the outcomes after LT in infants ≤ 5 kg at transplant in a large cohort of patients.

METHODS

Infants ≤ 5 kg who had LT between 10/1987 and 5/2008 were identified from the UNOS database. Risk factors for death and graft loss were analyzed by multivariate logistic regression.

RESULTS

Of 11,467 children, 570 (5%) were ≤ 5 kg at LT. Mean age and weight at LT were 0.11 ± 0.48 yr, 4.32 ± 0.74 kg, respectively. One- and five-yr patient and graft survival were 77.7%, 72.2% and 66.1%, 57.6%, respectively. The primary cause of death was infection (25.9%). Recipient age was a predictor of graft loss. Patient and graft survival have improved over time. Life support at transplant was identified as a risk factor for both death and graft loss (p < 0.02, p < 0.01, respectively).

CONCLUSION

LT recipients ≤5 kg have high mortality and graft loss. Over time, graft survival has improved, although it is still inferior to the overall reported outcomes of pediatric LT. Being on life support at transplant is a significant risk factor for death and graft loss in very small recipients.

Impact of pre-transplant liver hemodynamics and portal reconstruction techniques on post-transplant portal vein complications in pediatric liver transplantation: a retrospective analysis in 197 recipients

BACKGROUND AND OBJECTIVE

Portal vein (PV) complications are the most frequent vascular complications in pediatric liver transplant (LT). We hypothesized that pre-LT liver hemodynamic parameters and PV reconstruction technique could predict the risk of PV complications post-LT.

METHODS

Three hundred seventy-three children had a primary LT. A detailed ultrasound study of the pre-LT native liver hemodynamics was available in 198 cases, with details of PV anastomosis available for 197 of these: end-to-end anastomosis (n = 146, 74%), interposition vein graft technique (n = 28, 14%), or portoplasty (latero-lateral anastomosis of vein graft and recipient PV) (n = 23, 12%).

RESULTS

Overall 5-year patient survival rate was 90%. Among the 198 patients with pre-LT hemodynamic data, 79 (40%) had PV hypoplasia (diameter ≤4 mm), 64 (32%) had a pathological portal flow (nonhepatopetal flow), and 47 (24%) had an arterial resistance index (ARI) ≥1. Abnormal hemodynamics were mostly observed in biliary atresia (BA). Among these 3 parameters, only ARI ≥1 was significantly correlated with a higher rate of PV complications post-LT (P = 0.041). PV complication-free survival at 5 years were 91% for end-to-end anastomosis, 91% for portoplasty, and 62% for interposition vein graft technique (P = 0.002). At multivariate analysis, the use of an interposition vein graft was the only factor to be significantly associated with a higher rate of PV complications post-LT (P = 0.003).

CONCLUSIONS

PV hypoplasia with liver hemodynamic disturbances was mainly observed in BA. Hepatic ARI ≥1 might be a good predictor of PV complications post-LT. Latero-lateral portoplasty seemed to provide the best results when end-to-end anastomosis is not feasible.

Graft rotation and late portal vein complications in pediatric living donor liver transplantation using left-sided grafts: long-term computed tomography observations

Right-side rotation of the graft is an uncommon event after pediatric living donor liver transplantation (LDLT) with a left-sided graft. However, graft rotation might lead to gradual portal vein (PV) stretching and late portal vein complications (PVCs). The goal of this study was to quantify the degree of graft rotation (R) by computed tomography (CT) and to determine the effect of graft rotation on the development of late PVCs. One hundred ten patients underwent LDLT with left-sided grafts between 1996 and 2009; CT images were available and were reviewed for 66 of these patients. To quantify R, the following variables were measured with CT: the longest distance between the midline and the extrahepatic PV at the level of the hepatic hilum (A), the distance between the midline and the center of the superior mesenteric vein at the level of the confluence of the splenic vein and superior mesenteric vein (B), and the inner transverse diameter of the body cavity at the level at which A was measured (C). R was calculated as (A - B)/C. In patients with a patent PV (n = 59) and in patients with late PVCs (n = 7), the median R values were 0.16 (range = 0.03-0.38) and 0.25 (range = 0.13-0.39), respectively; there was a significant difference between the 2 groups (P = 0.003). Multivariate analysis showed that R ≥ 0.2 was the only independent risk factor for the development of late PVCs (P = 0.021). In conclusion, the gradual stretching of the PV after right-side rotation of left-sided grafts might play an important role in the development of late PVCs. PV patency should be closely monitored when graft rotation is noted during clinical follow-up.

Posttransplant bilioportal fistula with portal vein thrombosis: a case report

An 8-year-old female patient, known to have post-Kasai biliary atresia with mild intrapulmonary shunting, underwent living donor liver transplantation because of recurrent cholangitis. After the treatment of postoperative biliary stricture with percutaneous transhepatic biliary drainage, the patient subsequently developed hematochezia with portal vein thrombosis. The intraoperative findings showed portal vein thrombosis with a bilioportal fistula. We performed closure of the bilioportal fistula and reconstruction of the portal vein with a native internal jugular vein interposition graft. A bilioportal fistula due to percutaneous hepatobiliary procedures is a reportedly a rare complication following liver transplantation. The patient is currently doing well after a successful surgical intervention.

Risk factors for portal vein complications in pediatric living donor liver transplantation

BACKGROUND

Portal vein (PV) complications in pediatric living donor liver transplantation (LDLT) are often asymptomatic in the early stages after transplantation and can be serious enough to lead to graft failure. There have been few reports on risk factors for PV complications in LDLT. The aim of this study is to investigate the influence of hepatic inflow upon PV complications and to predict patients at risk for these complications.

MATERIAL/METHOD

From 1997 to 2008, 46 pediatric patients underwent LDLT at our center. Portal venous and hepatic arterial flows and PV diameter were analyzed.

RESULTS

PV complications were identified in seven patients (15.2%) and occurred at a younger age and lower weight. As a result of appropriate treatment, none of the patients suffered graft failure. Analysis of the 46 patients and 27 patients under two yr of age identified smaller PV diameter in recipient and larger discrepancy of PV diameter as risk factors. Portal venous flow tended to be low, in contrast to hepatic arterial flow, which tended to be high.

CONCLUSION

PV size strongly influences PV complications. Other factors such as younger age, low portal venous flow, and high hepatic arterial flow may be risk factors for PV complications.

Long-term outcomes of pediatric living donor liver transplantation at a single institution

There have only been a few studies on the long-term outcomes and prognostic factors after pediatric LDLT. We conducted a retrospective, single-center assessment of the outcomes as well as the demographic and clinical factors that influenced the poor outcomes in 113 children aged <16 (median age 21 months; 6 months-15.5 yr) who underwent 115 LDLTs, predominantly for biliary atresia (60.9%) and FHF (14.8%), between 1994 and 2006 at Asan Medical Center. Left lateral segment or left lobe grafts were implanted into most of these children (86.9%) according to routine procedures. The overall rates of graft survival at one, five, and 10 yr were 89.6%, 83.0%, and 81.5%, respectively, and the overall rates of patient survival were 92.9%, 86.3%, and 84.8%, respectively. Virus-related disease (41.2%) and chronic rejection (29.4%) were the major causes of mortality. On multivariate analysis, UNOS status 1a and 1b and chronic rejection were significant risk factors for both graft and patient loss, whereas the PELD score >25 was a significant risk factor for graft loss. Patient and graft survival may be related not only to post-operative complications, but also to the patient's preoperative clinical condition.

No-touch hepatic hilum technique to treat early portal vein thrombosis after pediatric liver transplantation

A 'no-touch' hilum technique used to treat early portal vein complications post-liver transplantation in five children with body weight <10 kg is described. Four patients developed thrombosis and one portal flow absence secondary to collateral steal flow. A vascular sheath was placed through the previous laparotomy in the ileocolic vein (n = 2), inferior mesenteric vein (n = 1) or graft umbilical vein (n = 1). Portal clots were mechanically fragmented with balloon angioplasty. In addition, coil embolization of competitive collaterals (n = 3) and stent placement (n = 1) were performed. The catheter was left in place and exteriorized through the wound (n = 2) or a different transabdominal wall puncture (n = 3). A continuous transcatheter perfusion of heparin was subsequently administered. One patient developed recurrent thrombosis 24 h later which was resolved with the same technique. Catheters were removed surgically after a mean of 10.6 days. All patients presented portal vein patency at the end of follow-up. Three patients are alive after 5 months, 1.5 and 3.5 years, respectively; one patient required retransplantation 18 days postprocedure and the remaining patient died of adenovirus infection 2 months postprocedure. In conclusion, treatment of early portal vein complications following pediatric liver transplantation with this novel technique is feasible and effective.

Reduction of left-lateral segment from living donors for liver transplantation in infants weighing less than 7 kg: technical aspects and outcome

LLS reduction has been frequently used in infants weighing <7 kg. Twenty recipients weighing <7 kg at the time of LDLT, median age 11.0 months and body weight 5.6 kg, were treated with an RLLS (n = 12) or LLS (n = 8) graft. Absolute indication of size reduction was that the estimated GRWR was >4.0%. Even if the preoperative GRWR was <4.0%, the RLLS graft was considered to ensure a size match. A flatfish-type LLS was preferred to a blowfish-type to make an RLLS graft for such a small infantile population. The RLLS recipients had significantly more flatfish-type grafts, while the LLS recipients had more blowfish-type grafts. Primary full-layer wound closure could be performed successfully in all LLS recipients, while in the RLLS group, two patients were forced to have partial skin closure. There were no graft losses related to graft compression. Reducing an LLS is a useful procedure to promote the comfortable accommodation of the graft in an infant weighing <7 kg. Flatfish-type LLS allowed more flexibility to make the suitable volume.

Incidence, impact, and treatment of portal and hepatic venous complications following pediatric liver transplantation: a single-center 12 year experience

PVT or PVS and HVOO are known causes of graft and patient loss after pediatric liver transplantation. Increased incidences of these complications have been reported in partial livers including DDSLT or LDLT. From 1997 to 2008, 241 consecutive pediatric patients received 271 hepatic grafts at a single center. Median follow-up is 1856 days. Surgical technique, demographics, lab values, and radiologic imaging procedures were obtained utilizing OTTR to evaluate the relationship of portal and hepatic complications with risk factors, patient and graft survival. Grafts were composed of 115/271 (42.4%) partial livers of which 90 (33.2%) were DDSLT and 25 (9.2%) LDLT. Of 271 patients, 156 (57.6%) received whole-sized grafts. There were six PVC in five patients with one patient requiring retransplantation (0.34%) and no patient deaths. Utilizing all three hepatic vein orifices on the recipient hepatic vena cava and the donor hepatic vein cut short enables a wide hepatic outflow tract unlikely to twist. None of the 241 patients developed early or late complications of the hepatic vein. None of the last 128 consecutive patients who received 144 grafts over seven and a half yr have developed either early or late complications of the hepatic or portal vein. Partial-graft actuarial survival was similar to whole-graft survival (87.2% vs. 85.3% at one yr; 76.6% vs. 80.2 at three yr; p = 0.488). Likewise, patient survival was similar between partial grafts and whole grafts (93.8% vs. 93.1% at one yr; 89.8% vs. 87.2% at three yr; p = 0.688) with median follow-up of 1822 (+/-1334) days. Patients receiving partial livers were significantly younger and smaller than patients receiving whole livers (p < 0.001). Portal and hepatic venous complications may have negative effects on patient or graft survival after pediatric liver transplantation. In our series, there was one graft and no patient loss related to portal or hepatic venous complications after pediatric liver transplantation over 12 yr.

Thrombotic events after pediatric liver transplantation

TE may contribute to morbidity and mortality after LT. The objectives were to determine the incidence of early TE post-pediatric LT and compare differences between children with and without TE. A retrospective review of 88 transplanted children (January 2002-October 2007) was performed to determine the incidence of Doppler-confirmed DVT and ATE in the first month post-LT. Fourteen (16%) patients developed TE: DVT in seven (8%) and ATE in seven (8%) patients. Six of 88 (6.8%) developed symptomatic CVL-related DVT. Median (range) time post-LT to DVT and ATE were 7 (4-18) and 8 (1-31) days, respectively. There was no significant difference in age/body weight at LT between patients with or without DVT and ATE. There was no significant difference between patients with or without HAT in age and weight at LT, cold ischemic time, duration of surgery, hematocrit levels, whole-organ graft type, intraoperative FFP, high-risk CMV status, or early acute cellular rejection. In conclusion, the incidence of early TE post-pediatric LT was 16%, including DVT in 8%. Prospective studies are necessary to evaluate the role of prophylactic anticoagulation and potential modifiable risk factors post-pediatric LT.

Clinical practice: management of biliary atresia

Biliary atresia is a rare, serious and challenging disease in newborn children. Its aetiology remains unknown. Optimal management at specialist centres with resultant better overall outcomes is achieved through a multidisciplinary team approach. The Kasai portoenterostomy performed early in life remains the only surgical repair procedure. Two thirds of patients will clear their jaundice after a Kasai procedure, but only about one third will retain their livers after the first decade of life. Failure of this procedure leaves liver transplantation as the only chance for survival, and this disease is the commonest indication for liver transplantation in children. With modern medical care and refinements in surgical techniques, survival after either or both of these procedures is about 90%. Early referral to specialist centres and long-term specialist care remains the key to successful treatment of this condition.

Strategy to prevent recurrent portal vein stenosis following interventional radiology in pediatric liver transplantation

Portal vein complications after liver transplantation (LT) are serious complications that can lead to graft liver failure. Although the treatment of interventional radiology (IVR) by means of balloon dilatation for portal vein stenosis (PVS) after LT is an effective method, the high rate of recurrent PVS is an agonizing problem. Anticoagulant therapy for PVS is an important factor for preventing short-term recurrence following IVR, but no established regimen has been reported for the prevention of recurrent PVS following IVR. In our population of 197 pediatric patients who underwent living donor liver transplantation (LDLT), 22 patients (22/197, 11.2%) suffered PVS. In the 9 earliest patients, unfractionated heparin was the only anticoagulant therapy given following IVR. In the 13 more recent patients, 3-agent anticoagulant therapy using low-molecular-weight heparin, warfarin, and aspirin was employed. In the initial group of 9 patients, 5 patients (55.6%) suffered recurrent PVS and required repeat balloon dilatation. Among the 13 more recent patients, none experienced recurrent PVS (P = 0.002). In conclusion, our 3-agent anticoagulant therapy following IVR for PVS in pediatric LDLT can be an effective therapeutic strategy for preventing recurrent PVS.

Surgical complications after living donor liver transplantation in patients with biliary atresia: a relatively high incidence of portal vein complications

BACKGROUND/PURPOSE

The aim of this study is to present the surgical complications in living donor liver transplantation (LDLT) for biliary atresia (BA) as a treatment for end stage liver disease.

PATIENTS AND METHODS

Twenty-nine LDLTs were performed in patients with BA between October 1996 and April 2008 in Department of Pediatric Surgery at Kyushu University Hospital. The initial immunosuppression was a combination of tacrolimus and steroids.

RESULTS

Twenty-eight of 29 cases with BA, who previously underwent Kasai's operation and LDLT was performed at a median age of 9.1 years (range 7 months to 28 years). Only one case was performed primary LDLT. Post-transplant complications included portal vein complications (n = 5), three of which successfully treated by Rex-shunt or ballooning. Others were bile leakage (n = 4), intestinal perforation (n = 4), and so on. The overall survival rate was 86.2% (25/29). One patient died of chronic rejection, surgical complications after LDLT in BA while others died of sepsis, multi-organ failure, and brain hemorrhage.

CONCLUSION

The incidence of portal vein complications and intestinal perforations was relatively high in LDLT for BA, possibly due to inflammation of the hepatoduodenal ligament and colonic adhesion to the liver. It is important to make an accurate diagnosis at an early stage and provide appropriate treatment.

Diagnosis and treatment of pediatric patients with late-onset portal vein stenosis after living donor liver transplantation

Portal vein stenosis (PVS) after living donor liver transplantation (LDLT) is a serious complication that can lead to graft failure. Few studies of the diagnosis and treatment of late-onset (> or = 3 months after liver transplantation) PVS have been reported. One hundred thirty-three pediatric (median age 7.6 years, range 1.3-26.8 years) LDLT recipients were studied. The patients were followed by Doppler ultrasound (every 3 months) and multidetector helical computed tomography (once a year). Twelve patients were diagnosed with late-onset PVS 0.5-6.9 years after LDLT. All cases were successfully treated with balloon dilatation. Five cases required multiple treatments. Early diagnosis of late-onset PVS and interventional radiology therapy treatment may prevent graft loss.

Portal vein complications in pediatric living donor liver transplantation using left-side grafts

The aim of this report is to assess the rate of portal vein complications (PVCs), the success rate of treatment for PVCs and the prognosis of patients with PVCs for pediatric living donor liver transplantation (LDLT). Pre- and postoperative records of 521 pediatric LDLTs, using left-side grafts were retrospectively reviewed. The overall rate of PVC was 9%, with early PVC occurring in nine patients (1.7%) with a mortality rate of 67% and late PVC in 38 patients (7.3%). Fifteen of these patients with late PVC showed complete portal vein occlusion despite various treatments, and in six of them the graft was lost. Histological examination revealed fibrosis in portal areas in 13 patients, around the central veins associated with cholestasis in the parenchyma in 10, and hepatocyte ballooning in 12. Correction of portal vein flow or retransplantation is necessary for the rescue of patients with early PVCs. Graft loss in the long term may be high with the occurrence of liver failure or portal hypertension related causes, such as hepatopulmonary syndrome and gastrointestinal bleeding in patients with late PVCs. For the rescue of these patients, especially for patients with body weight < 6 kg, regular monitoring of portal vein flow is essential.

Focal ischemic necrosis in advanced biliary atresia cirrhosis

This report correlates the clinical and biological findings, liver hemodynamics and histological features of focal INL in an infant with BA cirrhosis. An eight month old boy with BA, with previous successful porto-enterostomy, was admitted with signs of cholangitis and ascites. He was treated with antibiotics and diuretics with subsequent clinical improvement. Eight days later, while being fed with hyper-osmolar milk, he became febrile again: ASAT/ALAT climbed (9000/2300 IU/L), liver function deteriorated. Infectious work-up was negative. Liver-ultrasound showed reversed portal flow and a negative arterial diastolic flow. The patient recovered within five days under supportive treatment. A similar event recurred five days later. INL was suspected and semi-urgent living-related liver transplantation was performed, with uneventful post-operative course. Histology of the explanted liver showed extensive foci of INL of different ages. This report illustrates how the association of reversed portal and arterial diastolic flows, with subsequent liver hypoperfusion, may repeatedly cause foci of INL in BA cirrhosis, and lead to rapid progression to liver failure. Because of precarious hepatic blood supply in such patients, close monitoring of portal and diastolic arterial flows is recommended.

Liver transplantation: vascular complications

Transplantation has become the method of choice for treatment of patients with irreversible severe liver dysfunction. Vascular thrombosis or stenosis, biliary obstruction, hemorrhage, posttransplantation neoplasm, and rejection are some of the most common potential complications. Most complications cause significant morbidity and mortality after liver transplantation. The appearance of vascular complications in posttransplantation patients is illustrated in this article.

Early posttransplantation portal vein stenosis following living donor liver transplantation: percutaneous transhepatic primary stent placement

Surgical treatments have usually been preferred for early posttransplantation portal inflow abnormalities. However, these treatments are limited due to their technical difficulty and multiple complicating factors. The present study reports the efficacy and safety of percutaneous transhepatic primary stent placement to treat early posttransplantation (<or=1 month) portal vein (PV) stenosis. A total of 9 patients who had undergone living donor liver transplantation underwent percutaneous stent placement to treat PV stenosis. The average interval between liver transplantation and stent placement was 13 +/- 10 days. Technical and clinical success was obtained in 7 (77.8%) of the 9 patients. Of the 7 patients with clinical success, 1 died of cerebral hemorrhage within 1 month following stent placement. The remaining 6 patients have remained healthy and without recurrence of PV stenosis until the time this manuscript was completed, and follow-up Doppler ultrasound (US) or computed tomography (CT) obtained 66.6 +/- 16.1 months after stent placement revealed patent portal inflow in all of these 6 patients. Major complications occurred in 3 patients, i.e., 2 cases of hemoperitoneum caused by blood oozing from a transhepatic tract of the liver grafts and 1 case of intrahepatic pseudoaneurysm. These complications were successfully treated using surgical ligation (n = 2) or transarterial coil embolization (n = 1). In conclusion, although we did experience some procedural complications, the percutaneous transhepatic primary stent placements in our study showed acceptable technical and clinical results for treating early posttransplantation PV stenosis. In addition, long-term PV patency following stent placement was excellent. However, additional experience and further studies will be needed to verify the usefulness of primary stent placement in the early posttransplantation period.

Vascular reconstruction and complications in living donor liver transplantation in infants weighing less than 6 kilograms: the Kyoto experience

Smaller-size infants undergoing living-donor liver transplantation (LDLT) are at increased risks of vascular complications because of their smaller vascular structures in addition to vascular pedicles of insufficient length for reconstruction. Out of 585 child patients transplanted between June 1990 and March 2005, 64 (10%) weighing less than 6 kg underwent 65 LDLTs. Median age and weight were 6.9 months (range: 1-16 months) and 5 kg (range: 2.8-5.9 kg), respectively. Forty-five lateral segment, 12 monosegment, and 8 reduced monosegment grafts were adopted, and median graft-to-recipient weight ratio was 4.4% (range: 2.3-9.7). Outflow obstruction occurred in only 1 patient (1.5%). Portal vein complication occurred in 9 (14%) including 5 with portal vein thrombosis. Hepatic artery thrombosis (HAT) occurred in 5 (7.7%). Patient and graft survivals were 73% and 72% at 1 yr, and 69% and 68% at 5 yr after LDLT, respectively. Thirteen of 22 grafts (58%) lost during the follow-up period occurred within the first 3 months posttransplantation. Overall graft survival in patients with and without portal vein complication was 67% and 65%, respectively (P = 0.54). Overall graft survival in patients with and without HAT was 40% and 67%, respectively. HAT significantly affected graft survival (P = 0.04). In conclusion, our surgical technique for smaller-size recipients resulted in an acceptable rate of vascular complications. Overcoming early posttransplantation complications will further improve outcomes in infantile LDLT.

Early portal vein thrombosis after pediatric split liver transplantation with left lateral segment graft

Early portal vein thrombosis (PVT) represents a serious complication after liver transplantation (OLTx). From October 1997 through July 2004, 260 OLTx were performed in 231 children, including 189 of left lateral segments (LLS). We retrospectively analyzed the incidence and the outcome of early PVT in this group. A daily doppler US scan was performed during the first week after transplantation. Early PVT occurred in 14 patients (8%), 10 males and four females of median age 0.77 years. The main indication for primary transplantation was biliary atresia (10), followed by Byler's disease (2), acute liver failure on cryptogenetic cirrhosis (1), and Alagille syndrome (1). Four children underwent retransplantation; three cases of thrombectomy and revision of the anastomosis, two children were treated with beta blockers, one of whom had a later failed attempt at percutaneous revascularization and eventually a meso-caval shunt. Five patients were followed with observation and no treatment. Among the four patients who died, three were in the retransplantation group and one in the thrombectomy and revision of the anastomosis group; the overall mortality was 28%. With a median follow up of 399 days, 10 patients are alive with an actuarial survival at 1 and 5 years of 72%, and graft survival rates at 1 and 5 years of 64%. PVT represents a serious complication after pediatric OLTx with LLS grafts. Prompt detection and aggressive surgical treatment in selected cases are required to reduce the mortality and graft loss.

Surgical complications and outcome of paediatric liver transplantation: the Singapore experience

The purpose of this study was to analyse the early and late results of paediatric liver transplantation (LT), with particular reference to complications that required surgical intervention. The charts of all children who underwent LT between 1990 and 2002 were reviewed retrospectively. Results were analysed with a minimum follow up of 9 months. Thirty-five children have undergone 38 LTs; 22 received grafts from their parents, 16 received cadaveric organs and three children had retransplantation. The ages of the children ranged from 12 to 168 months. Biliary atresia was the most frequent indication for transplant (n=27). Twenty-seven children had complications that required surgical or radiological interventional procedures. Vascular complications included hepatic artery thrombosis (n=2), hepatic vein (HV) thrombosis (n=1), and the majority being portal vein thrombosis (n=6). Bile leaks were observed in eight children. Other complications included intestinal perforation (n=2), intra-abdominal abscesses (n=1), wound dehiscence (n=2), post-operative bleed (n=2), intestinal obstruction (n=2), ventral hernia (n=1), and multiple abdominal wound sinuses (n=1). Three children underwent retransplantation, two for hepatic artery thrombosis with multiple episodes of cholangitis and intrahepatic biliomas and the third was done for hepatic vein thrombosis. Patient and graft survival at 1 year is 81.5 and 74.2%, respectively. Paediatric LT is associated with significant morbidity, the main complications being vascular and biliary.

Ascites after orthotopic liver transplantation in children

Ascites is a poorly understood postoperative complication of orthotopic liver transplantation (OLT). It is associated with additional morbidity and can prolong hospitalization considerably. The incidence, the factors predictive of occurrence and the etiology of this complication are not known. The charts of 118 patients with 138 OLT were analyzed according to the following criteria: ascites lasting longer than the first 10 postoperative days, assessed by loss of ascitic fluid through drainage tubes, surgical wounds or paracentesis, with a peak volume of > or =10 mL/kg/day. Patients were divided into three groups: Group 1, no ascites; Group 2, ascites associated with postoperative complications, including chylus ascites; and Group 3, ascites not associated with postoperative complications. Postoperative ascites occurred in 43 of 138 OLT (31.2%). Patients with biliary atresia, preoperative portal hypertension, postoperative pleural effusion or at retransplantation had ascites significantly more often. In 32 of 138 (23.2%) OLT, ascites was associated with postoperative complications, including thrombosis, abdominal infections, intestinal perforation, biliary leak, pancreatitis, and chylus ascites. In 11 of 138 (7.9%) OLT, ascites was the only postoperative complication (group 3). Group three patients were significantly older, and had lower preoperative platelet counts and preoperative ascites more often than group 1 patients. The primary liver diseases were mainly cystic fibrosis of the pancreas, congenital hepatic fibrosis, and North American Indian childhood cirrhosis. The serum-ascites albumin gradient suggested a hepatic origin of ascites. Postoperative ascites is associated with the duration and degree of preoperative portal hypertension. We speculate that the mechanism involved includes a disproportion between venous blood volume and liver uptake capacity of the donor organ.

Paediatric liver transplantation--a review based on 20 years of personal experience

The natural history of most liver diseases requiring liver replacement in children is well known, and the potential of this therapy has been ascertained regarding life expectancy, which currently exceeds 90% in the long term. The timing of liver transplantation must be anticipated, to reduce the physical, psychological and mental impact of chronic liver diseases. Several studies show evidence that the best long-term results with regard to patient and graft survival are obtained with grafts procured from relatively young donors. Since the shortage of post-mortem liver donors will most likely worsen, further development of live, related-donor transplantation can be expected. The main progress to come will concern immunosuppression, taking advantage of the immunological privilege of the liver. Protocols are under development for induction of operational tolerance.