Adriana Porta

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. Liver Transpl, 2012.

Modified Pediatric End-Stage Liver Disease Scoring System and Pediatric Liver Transplantation in Brazil

The Pediatric End‐Stage Liver Disease (PELD) scoring system is a formula developed to provide a continuous numerical assessment of the risk of death in order to allocate livers to children in need of transplantation. The PELD scoring system was introduced in Brazil in July 2006. An important change was made in the system: the final number for listing patients less than 12 years old for transplantation was the calculated PELD score multiplied by 3. The consequences of this allocation policy were analyzed in 2 ways in this research: nationally and in the state of São Paulo (SP State). In the analysis of the national data, a comparison of the pre‐PELD era (July 2003 to July 2006) and the post‐PELD era (August 2006 to April 2009) showed that the total number of pediatric transplants for children under 12 years of age decreased 7%. Regionally, in SP State, there was a 62% increase in the number of deceased donor liver transplantation procedures for the pediatric population after the introduction of the modified PELD system. There was also a 6.1‐fold increase in split liver transplantation as well as a statistically significant decrease in the time on the waiting list (P < 0.001). In conclusion, changing the allocation policy in Brazil in order to benefit pediatric patients on the waiting list had different results according to analyses of national and regional data. A significant increase in deceased donor liver transplantation/split liver transplantation and a shorter time on the waiting list were observed in SP State. The modified PELD scoring system is simple and optimizes the utilization of deceased donor liver grafts in centers performing pediatric transplants. Liver Transpl, 2010.

Diagnosis and management of biliary complications in pediatric living donor liver transplant recipients

The incidence of biliary complications (BCs) after living donor liver transplantation (LDLT) can reach 40%. Published data on the pediatric population are limited, and treatment protocols vary. Our aim was to describe the clinical scenario for BCs and treatment approaches after LDLT. Between October 1995 and December 2012, 489 pediatric LDLT procedures were performed. BCs developed in 71 patients (14.5%). Biliary strictures (BSs) developed in 45 (9.2%) patients, and bile leaks (BLs) developed in 33 patients (6.7%). The BL diagnosis was clinical in all cases, and 69.7% of the patients underwent surgery. Nearly half of the BS cases had clinical features or suggestive ultrasound findings. Liver biopsy findings suggested BSs in 51.7%. Percutaneous transhepatic cholangiography was performed in 95.6% of the BS patients. The success rate was 77% [mean number of percutaneous biliary interventions (PBIs) = 3.9 ± 1.98, median drainage time = 8 months]. In conclusion, BL patients can be managed with conservative therapy, even though most of these patients will ultimately be treated with surgery. Diagnosing a BS requires a high degree of clinical suspicion because the available resources for its identification can fail in up to 50% of cases. A higher number of PBIs and the use of a drainage catheter for a longer time may be required to achieve better results with this technique. Liver Transpl 20:882‐892, 2014.

Ascites and serum sodium are markers of increased waiting list mortality in children with chronic liver failure

Ascites is the most common complication of cirrhosis and in adults it is associated with 50% mortality at 5 years if patients do not receive a liver transplant. The occurrence of hyponatremia in these patients has been associated with increased mortality on the waiting list. The importance of serum sodium levels and the presence of ascites in the pediatric setting remain to be clarified. A retrospective analysis of pediatric patients with cirrhosis on the transplant list was carried out between October 2000 and February 2012. The primary objective of this study was to evaluate the association of pretransplant variables with mortality within 90 days following the inclusion of patients on the waiting list. In all, 522 patients were included in the study; 345 (66%) patients were under 1 year of age; 208 (40%) of the children presented ascites. A multivariate Cox proportional hazards analysis was conducted and total bilirubin (P < 0.001, hazard ratio [HR] = 2.09, 95% confidence interval [CI] = 1.35‐3.21), international normalized ratio (INR) (P < 0.001, HR = 9.83, 95% CI = 4.51‐21.45), serum sodium levels (P = 0.03, HR = 0.96, 95% CI = 0.92‐0.99), ascites (P = 0.001, HR = 2.59, 95% CI = 1.44‐4.64), and categorized age (0‐1 versus ≥1 year old) (P = 0.025, HR = 2.33, 95% CI = 1.11‐4.86) were independently associated with risk of death in 90 days. Malnutrition (Z score height/age, weight/age) and serum albumin (pediatric endstage liver disease [PELD] formula) were not included in the final model. Conclusion: The presence of ascites and serum sodium levels are important variables associated with decreased patient survival while candidates wait for a liver graft. Multicenter studies are necessary to validate these findings in order to improve current allocation policies based on the PELD score. (Hepatology 2014;59:1964–1971)

Successful domino liver transplantation in maple syrup urine disease using a related living donor

Maple syrup urine disease (MSUD) is an autosomal recessive disease associated with high levels of branched-chain amino acids. Children with MSUD can present severe neurological damage, but liver transplantation (LT) allows the patient to resume a normal diet and avoid further neurological damage. The use of living related donors has been controversial because parents are obligatory heterozygotes. We report a case of a 2-year-old child with MSUD who underwent a living donor LT. The donor was the patients mother, and his liver was then used as a domino graft. The postoperative course was uneventful in all three subjects. DNA analysis performed after the transplantation (sequencing of the coding regions of BCKDHA, BCKDHB, and DBT genes) showed that the MSUD patient was heterozygous for a pathogenic mutation in the BCKDHB gene. This mutation was not found in his mother, who is an obligatory carrier for MSUD according to the family history and, as expected, presented both normal clinical phenotype and levels of branched-chain amino acids. In conclusion, our data suggest that the use of a related donor in LT for MSUD was effective, and the liver of the MSUD patient was successfully used in domino transplantation. Routine donor genotyping may not be feasible, because the test is not widely available, and, most importantly, the disease is associated with both the presence of allelic and locus heterogeneity. Further studies with this population of patients are required to expand the use of related donors in MSUD.

Schistosoma mansoni infection in the liver graft: The impact on donor and recipient outcomes after transplantation.

The increasing number of transplants performed each year has led to the identification of unusual diseases in liver grafts from asymptomatic donors that were unrecognized before liver transplantation. Here we report our experience with patients who received liver grafts infected with schistosomiasis. From September 1991 to August 2010, 482 pediatric liver transplants were performed at A. C. Camargo Hospital/Sírio‐Libanês Hospital (São Paulo, Brazil). For the identification of Schistosoma mansoni infections, pathology slides for the recipients were reviewed; these included postreperfusion and follow‐up liver biopsy samples. We were able to identify 6 cases of schistosomiasis transmitted through infected grafts (5 of these grafts were from living donors). All living donors were confirmed to have normal liver chemistries, negative fecal tests for parasitic diseases, and normal abdominal ultrasound findings. Liver biopsy was not performed before transplantation. In all cases, features of schistosomiasis were absent in the liver explants. The living donors were treated with praziquantel and were taught to avoid risk factors for reinfection. No specific treatment for schistosomiasis was given to the recipients. There were no perioperative deaths, but 2 recipients died after living donor liver transplantation (LDLT) because of Kaposis sarcoma and non‐Hodgkins lymphoma. In conclusion, using liver grafts infected with S. mansoni eggs did not compromise the results of LDLT in this pediatric cohort. Because of the parasites life cycle and the therapeutic target of praziquantel, only donors should be treated for the infection. Three years of follow‐up showed an uneventful recovery for the living donors. Liver Transpl 17:1299–1303, 2011.

Analysis of factors associated with portal vein thrombosis in pediatric living donor liver transplant recipients.

The technique of vascular reconstruction plays a major role in the outcome of living donor liver transplantation (LDLT). An increased use of vascular grafts (VGs) as replacements for sclerotic portal veins has become a standard technique for our group. The aim of this study was to analyze the factors associated with portal vein thrombosis (PVT) in pediatric LDLT. We performed a retrospective analysis of 486 primary pediatric LDLT procedures performed between October 1995 and May 2013. VGs used for portal reconstruction included living donor inferior mesenteric veins, living donor ovarian veins, recipient internal jugular veins, deceased donor iliac arteries, and deceased donor iliac veins. Thirty‐four patients (7.0%) developed PVT. The incidence of PVT dropped from 10.1% to 2%; the overall utilization of VGs increased from 3.5% to 37.1%. In a multivariate analysis, only the use of VGs remained an independent risk factor for the occurrence of PVT (hazard ratio = 7.2, 95% confidence interval = 2.8‐18.7, P < 0.001). There was no difference in survival rates between patients with PVT and patients without PVT. No patient with PVT underwent retransplantation. In conclusion, the use of VGs was independently associated with the development of PVT. Over time, there was a reduction in the incidence of early PVT in this cohort, and there was a trend toward a reduction in total PVT. The occurrence of isolated PVT in this study was not associated with decreased patient or graft survival. Liver Transpl 20:1157–1167, 2014.

Chronic Hepatitis E Virus Infection in a Pediatric Female Liver Transplant Recipient

ABSTRACT We describe a case of chronic hepatitis E virus (HEV) infection in a 13-year-old female liver transplant recipient with recurrent increased aminotransferase levels and acute cellular rejection. This finding demonstrates that chronic HEV infection can occur and should be further investigated in immunocompromised patients in Latin America.

HCC prevalence and histopathological findings in liver explants of patients with hereditary tyrosinemia type 1

Untreated tyrosinemia type 1 (HT1) is manifested by liver failure associated with renal tubular dysfunction, growth failure, and rickets. The indication for liver transplantation (LT) is restricted to non‐responders to 2‐(2‐nitro‐4‐trifluoromethylbenzoyl)‐1, 3‐cyclohexanedione (NTBC) treatment, patients not treated with NTBC or for patients with HCC. The aim of this study is to report on a series of NTBC naive HT1 patients submitted to LT along with the prevalence of HCC in their liver explants.

Technical aspects and outcomes of living donor liver transplantation for pediatric patients with situs inversus

The vascular anomalies encountered in patients with biliary atresia associated with polysplenia syndrome and situs inversus (SI) demand technical refinements when liver transplantation is being performed. The available data describing the technique used in living donor liver transplantation (LDLT) in this population are limited; the short vascular stumps of the donors liver can impart additional technical difficulties during vascular reconstruction. Here we describe our experience with 9 children with biliary atresia and SI who underwent LDLT. In our series, the retrohepatic vena cava was absent for 7 patients, 7 had a preduodenal portal vein (PV), and 4 had a variant arterial anatomy. The donors left hepatic vein was anastomosed to the confluence of the recipients 3 hepatic veins in 7 patients. Vascular grafts were used for PV reconstruction in 3 cases. A left lateral segment graft was used in all but 1 patient who needed a graft reduction. All grafts were placed in the upper left abdomen. There were no vascular complications after transplantation. All patients were alive and well at a median follow‐up of 55 months. In conclusion, LDLT can be successfully performed in pediatric patients with SI. Complex vascular anomalies associated with the use of partial liver grafts obtained from living donors are not associated with an increased occurrence of vascular complications. Liver Transpl 19:431–436, 2013.