Pediatric liver transplantation for acute liver failure at a single center: A 10‐yr experience

Heffron TG, Pillen T, Smallwood G, Rodriguez J, Sekar S, Henry S, Vos M, Casper K, Gupta NA, Fasola CG, Romero R. Pediatric liver transplantation for acute liver failure at a single center: A 10‐yr experience.
Pediatr Transplantation 2010:14:228–232. © 2009 John Wiley & Sons A/S. Abstract: Children transplanted for ALF urgently require an optimal graft and have lower post‐transplant survival compared with children transplanted for chronic liver disease. Over 10 yr, 33 consecutive children transplanted for ALF were followed. Demographics, encephalopathy, intubation, dialysis, laboratory values, graft type ABOI, XL (GRWR > 5%), DDSLT, LDLT and WLT were evaluated. Complications and survival were determined. ALF accounted for 33/201 (16.4%) of transplants during this period. Twelve of 33 received ABOI, five XL grafts, 18 DDSLT, and three LDLT. Waiting time pretransplant was 2.1 days. One‐ and three‐yr patient survival in the ALF group was 93.4% and 88.9%, and graft survivals were 86.4% and 77.7%. Median follow‐up was 1452 days. ABOI one‐ and three yr patient and graft survival in the ALF was 91.6% and 78.6%. No difference in graft or patient survival was noted in the ALF and chronic liver disease group or the ABOI and the ABO compatible group. A combination of ABO incompatible donor livers, XL grafts, DDSLT, LDLT and WLT led to a short wait time and subsequent graft and patient survival comparable to patients with non‐acute disease.     

Liver transplantation for hereditary tyrosinemia type I: analysis of the UNOS database

Patients with HT-1 can develop progressive liver disease and have a high incidence of HCC. LT is indicated in patients with fulminant liver failure, HCC or decompensated chronic liver disease refractory to NTBC. To determine the need for LT and outcomes after LT in children with HT-1. Children with HT-1 who had LT between 10/1987 and 5/2008 were identified from the UNOS database. Of 11,467 children in the UNOS database, 125 (1.1%) required LT secondary to HT-1. Mean age at LT was two and half yr (s.d. ± 3.6 yr). Mean age at LT during the first 10 yr of the study (1.82, s.d. ± 2.86 yr) was significantly lower than in the last decade (3.70, s.d. ± 4.42 yr), p = 0.01. Nearly half of the patients (58, 46.4%) were transplanted between 1988 and 1992. Overall, one- and five-yr patient survival was 90.4% and 90.4%, respectively. LT is a valuable option for children with HT-1 with fulminant liver failure or when medical treatment fails. The rate of LT for children with HT-1 has decreased and age at transplant increased over the last decade most probably reflecting the effect of early diagnosis and treatment with NTBC.     

An institutional experience of pre‐emptive liver transplantation for pediatric primary hyperoxaluria type 1

Primary hyperoxaluria type 1 (PH1) is an inherited metabolic disease that culminates in ESRF. Pre‐emptive liver transplantation (pLTx) treats the metabolic defect and avoids the need for kidney transplantation (KTx). An institutional experience of pediatric PH1 LTx is reported and compared to the literature. Between 2004 and 2015, eight children underwent pLTx for PH1. Three underwent pLTx with a median GFR of 40 (30–46) mL/min/1.73 m² and five underwent sequential combined liver‐kidney transplantation (cLKTx); all were on RRT at the time of cLKTx. In one case of pLTx, KTx was required eight and a half yr later. pLTx was performed in older (median 8 vs. 2 yr) and larger children (median 27 vs. 7.75 kg) that had a milder PH1 phenotype. In pediatric PH1, pLTx, ideally, should be performed before renal and extrarenal systemic oxalosis complications have occurred, and pLTx can be used “early” or “late.” Early is when renal function is preserved with the aim to avoid renal replacement. However, in late (GFR < 30 mL/min/1.73 m²), the aim is to stabilize renal function and delay the need for KTx. Ultimately, transplant strategy depends on PH1 phenotype, disease stage, child size, and organ availability.     

Stable long‐term renal function after pediatric liver transplantation

Herlenius G, Hansson S, Krantz M, Olausson M, Kullberg‐Lindh C, Friman S. Stable long‐term renal function after pediatric liver transplantation.
Pediatr Transplantation 2010: 14:409–416. © 2010 John Wiley & Sons A/S. Abstract: Long‐term exposure to calcineurin inhibitors increases the risk of CKD in children after LT. The aims of this study were to study renal function by measuring GFRm before and yearly after LT, to describe the prevalence of CKD (stage III: GFR 30–60 mL/min/1.73 m²) and to investigate if age and underlying liver disease had an impact on long‐term renal function. Thirty‐six patients with a median age of 2.9 years (0.1–16 yr) were studied. Median follow‐up was 6.5 (2–14 yr). GFRm decreased significantly during the first six months post‐transplantation with 23% (p < 0.001). Thereafter renal function stabilized. At six months, 17% (n = 5) of the children presented CKD stage III and at five yr the prevalence of CKD III was 18% in 29 children. However, in 13 children with a 10‐year follow‐up it was 0%. None of the children required renal replacement therapy after LT. When analyzing renal function of those children younger than two yr (n = 14) and older than two yr (n = 17) at the time of transplantation, we found that in both cohorts the filtration rate remained remarkably stable during the five‐yr observational period. However, there was a statistically significant (p < 0.05) difference in the percentual decrease in GFRm between the groups during the first six months after LT 13% and 31%, respectively. Baseline GFRm according to diagnosis did not differ between the groups. During the first six months after LT, patients transplanted for hepatic malignancy (n = 6) and those with metabolic liver disease (n = 4) had a percentage loss of GFRm of 32% and 35%, respectively. The corresponding loss of GFRm in patients with other diseases was 10‐19%. Six months post‐transplantation mean GFRm in the group with malignant liver disease was 65 ± 15 mL/min/1.73 m² and in the group with other diseases (n = 24) 82 ± 17 mL/min/1.73 m² (p < 0.05). At one, three and five yr post‐transplantation there was no longer a statistically significant difference between these cohorts. Our findings suggest that there can be a long‐term recovery of renal function after LT in children.     

Basiliximab with delayed introduction of calcineurin inhibitors as a renal‐sparing protocol following liver transplantation in children with renal impairment

Renal impairment is frequently compromised in patients with end‐stage liver disease and is associated with increased long‐term mortality post‐LT. In contrast to CNI, basiliximab is an immunosuppressive agent with minimal nephrotoxic potential. This study reviews the experience of a single pediatric liver transplant center's renal‐sparing approach with the use of basiliximab and MMF to compensate for delayed entry of CNI in children with renal impairment at the time of organ availability. There were no differences in renal function between pediatric patients with and without pre‐LT renal impairment within the first year (cGFR: 135 mL/min/1.73 m² vs. 144 mL/min/1.73 m²; p = 0.56) or at 5–8 yr following LT, (129 mL/min/1.73 m² vs. 130 mL/min/1.73 m²; p = 0.97). In addition, there was no difference in ACR rates (50% vs. 43%, p = 0.62) between patients in the basiliximab group and those patients receiving standard CNI and steroid strategies. The utilization of a renal‐sparing approach with basiliximab alongside delayed entry and lower early target trough levels of CNI in children with renal impairment at the time of LT is safe and maintains excellent long‐term kidney function.     

Subclinical cardiovascular changes in pediatric solid organ transplant recipients: A systematic review and meta‐analysis

CV disease is a major cause of morbidity and mortality following solid organ transplantation in adults. While the prevalence of multiple cardiometabolic risk factors is increased in pediatric solid organ transplant recipients, it is not clear whether they have subclinical CV changes. cIMT, central pWV, and CAC are indicative of subclinical CV disease, and, in adults, predict future CV events. The objective of this systematic review and meta‐analysis was to investigate the prevalence of subclinical CV changes, as measured by cIMT, pWV, and CAC among pediatric solid organ transplant recipients. We searched MEDLINE^® and EMBASE and conducted meta‐analysis for studies that evaluated cIMT, central pWV, and CAC among pediatric solid organ transplant recipients (kidney, lung, intestine and liver). The search identified nine eligible studies that included a total of 259 patients and 685 healthy controls. Eight studies reported on kidney transplant recipients and one study on a combined cohort of kidney and liver transplant recipients. The mean cIMT of transplant recipients was significantly higher than that of healthy controls (mean difference = 0.05 mm, 95% CI 0.02–0.07; p < 0.0001) with an estimated pooled prevalence of elevated cIMT of 56.0% (95% CI 17.0–95.0). The one study that assessed pWV showed increased vascular stiffness in transplant recipients compared to healthy controls. No studies assessing for CAC were found. There were limited data regarding subclinical CV disease following pediatric solid organ transplantation. In conclusion, kidney transplantation in childhood is associated with a higher prevalence of subclinical CV changes compared to healthy children. Longitudinal studies are needed to determine whether children have increased CV morbidity and mortality after transplantation.     

Parental functioning improves the developmental quotient of pediatric liver transplant recipients

Psychomotor development in pediatric liver transplant (LT) recipients depends on several factors. Our aim was to evaluate the importance of parental involvement and family dynamics on psychomotor development by assessing (i) children and parents individually, (ii) the parent–child relationship, and (iii) the correlation between parental functioning and patient outcome, all before and after LT. Age‐appropriate scales were used before and after LT. Twenty‐one patients, 19 mothers, and 16 fathers were evaluated. Developmental quotient (DQ): No subjects scored in the “very good” range. The proportion of children with deficits increased from LT to two yr: 17.6% vs. 28.6%. Subjects 0–2 yr were more likely to have normal DQ at transplant (66.7% vs. 50% for older children). Abnormal DQ was more prevalent two yr post‐LT in children older at LT (p = 0.02). The mother–child relationship was normal in 59% of families pre‐LT and in 67% at two yr. The relationship was more favorable when the child received a transplant as an infant (p = 0.014 at 12 months post‐LT). Normal DQ was associated with higher maternal global functioning score pre‐LT (p = 0.03). Paternal performance scores were higher than maternal scores. Children transplanted after two yr of age suffer greater long‐term deficits than those transplanted as infants.     

Transmission of clear cell tumor in a graft liver from cadaveric donor: Case report

Backes AN, Tannuri ACA, de Mello ES, Gibelli NEM, de Castro Andrade W, Tannuri U. Transmission of clear cell tumor in a graft liver from cadaveric donor: Case report. Abstract: Neoplasms in children after organ transplantation are related to the type and intensity of immunosuppression and the donor–recipient serostatus, especially in relation to the Epstein–Barr virus. The patient was a two‐yr‐old female child with biliary atresia who underwent a liver transplantation from a female cadaver donor. Two adults received kidney transplants from the same donor. Nine months after transplantation, one of the adult recipients developed an urothelial tumor in the kidney graft. Imaging tests were repeated monthly in the liver‐transplanted child and revealed no abnormalities. However, one yr and two months after the transplantation, the patient developed episodes of fever. At that time, imaging and liver biopsy showed a clear cell tumor of urothelial origin in the graft and the disease was limited to the liver. The patient underwent liver retransplantation, and she is currently free of tumor recurrence. Although rare, the occurrence of tumors in the post‐transplant period from cadaver donors, without previously diagnosed tumors, is one of the many problems encountered in the complex world of organ transplantation.     

Lymphocele after pediatric kidney transplantation: Incidence and risk factors

Lymphocele is a well‐known postoperative complication after kidney transplantation. The aim of this study was to analyze time trend incidence, risk factors, and outcome of post‐transplant lymphocele in a large pediatric cohort. This is a retrospective single institution review of 241 pediatric kidney transplants performed from 2000 to 2013. Etiology of end‐stage renal disease, recipient age and gender, transplant year, BMI percentile for age, type of dialysis, living/non‐living related donor, acute rejection, and multiple transplantations were analyzed in association with lymphocele formation. Fourteen of 241 (5.81%) children developed a postoperative lymphocele. There has been a reduction in the incidence of lymphocele after 2006 (3.22% vs. 8.55%, p < 0.05). Significant risk factors for lymphocele were older age (≥11 yr), transplant before 2006, male gender, BMI percentile for age ≥95%, and multiple transplantations (p < 0.05). The one‐yr graft survival was significantly reduced in the group with lymphocele compared with control (81.2% vs. 92.51%, p < 0.04). This is the first pediatric report showing the following risk factors associated with post‐transplant lymphocele: age ≥11 yr, male gender, BMI for age ≥95%, and multiple transplantations. A lymphocele can contribute to graft loss in the first‐year post‐transplant.     

A single center experience of donation after cardiac death liver transplantation in pediatric recipients

Bartlett A, Vara R, Muiesan P, Mariott P, Dhawan A, Mieli‐Vergani G, Rela M, Heaton N. A single center experience of donation after cardiac death liver transplantation in pediatric recipients.
Pediatr Transplantation 2010:14: 388–392. © 2009 John Wiley & Sons A/S. Abstract: Many centers are now performing DCD adult LT. There has been a reluctance to transplant pediatric recipients with DCD livers due to concern over the medium to long‐term outcome. We describe the outcome of 14 children (median age seven yr, 8 months–16 yr) that underwent LT with DCD grafts from July 2001 to December 2007. Donors had a median age of 23 yr (10–64), intensive care stay of five d (2–14) and bilirubin of 9 mmol/L (6–60). Median warm and cold ischemic time was 16 min (11–29) and seven h (5.5–8.4). Livers were transplanted as a whole organ (4), reduced graft (8), formal split (1) or auxiliary transplant (1). Compared to DBD recipients AST was significantly higher on the first three post‐operative days and there was no difference in the INR, bilirubin or GGT out to 12 months. There were no biliary or vascular complications and patient and graft survival is 100% at a median follow‐up of 41.8 months (1.7–74 months). LT with DCD grafts in pediatric recipients can be performed with low morbidity and excellent short‐to‐medium term patient and graft outcome.     

Transplantation for infantile nephronophthisis with loss‐of‐function mutation in NPHP3: Lesson from a case

The choice of KT only or CLKT for infantile NPHP with mild liver fibrosis is understudied. A 5‐year‐old girl was transferred to our center for KT due to ESRD. Her primary disease was infantile NPHP with compound heterozygous NPHP3 mutations: c.458A>C(p.Q153P)/missense mutation and c.2032A>T(p. K678X)/nonsense mutation. The patient had elevated liver enzymes and biopsy‐proven liver fibrosis. As liver synthesis was acceptable, only KT was performed. However, liver fibrosis progressed at 1.5 years after transplantation, manifested with portal hypertension and hypersplenism. Common causes for portal hypertension were excluded, and the progression was attributed to NPHP. AMR attacked allograft at about 2 years post‐transplant. To solve both the liver and the kidney problems, CLKT was performed. Her liver and kidney function recovered initially, but she unfortunately died of pneumonia and subsequent intracranial hemorrhage two weeks later. Nonsense mutation in NPHP3 gene may be correlated with rapid progression of liver disease in infantile NPHP. More studies are required to determine the role of CLKT in these cases; however, combined transplantation may improve long‐term graft and patient survival.     

Pediatric post‐transplant metabolic syndrome: New clouds on the horizon

Liver transplantation (LT) is a standard treatment for children with end‐stage liver disease, standing at more than 90% survival rate after one yr, and at over a 70% survival rate after five yr. The majority of transplanted children enjoy an excellent quality of life but complications can occur in the long term, and can develop subclinically in otherwise well children; there are various underestimated nutritional and metabolic aspects, including the so‐called post‐transplant metabolic syndrome (PTMS). During the post‐transplant period, the use of immunosuppressants, corticosteroids, calcineurin inhibitors, and the presence of risk factors, including non‐alcoholic fatty liver disease (NAFLD), and kidney and bone complications have been largely implicated in PTMS development. Strategies to reduce the progression of PMTS should include careful screening of patients for diabetes, dyslipidemia, and obesity, and to support weight reduction with a carefully constructed program, particularly based on diet modification and exercise. With early identification and appropriate and aggressive management, excellent long‐term health outcomes and acceptable graft survival can be achieved.     

Isolated liver transplantation in children with cystic fibrosis – An Australian experience

Nightingale S, O’Loughlin EV, Dorney SFA, Shun A, Verran DJ, Strasser SI, McCaughan GW, Jermyn V, Van Asperen P, Gaskin KJ, Stormon MO. Isolated liver transplantation in children with cystic fibrosis – An Australian experience.
Pediatr Transplantation 2010: 14:779–785. © 2010 John Wiley & Sons A/S. Abstract: CF liver disease is an uncommon indication for pediatric LT. Determining optimal timing and type (isolated liver versus multi‐organ) of transplantation for those with severe liver disease can be challenging and involves consideration of the extent of liver disease (PHT, synthetic dysfunction) and extrahepatic factors such as pulmonary function. We present the experience of isolated LT for CF at our center. Eight children received one allograft each (3.9% of all grafts). One‐ and four‐yr survivals are both 75%. The two deaths occurred within the first two months after LT, and in both cases, invasive fungal infections were implicated, one following treatment for acute severe rejection. All had significant PHT, and six had synthetic dysfunction. All had roux‐en Y biliary anastomoses and none developed long‐term biliary complications. Seven had pulmonary colonization with Pseudomonas aeruginosa and six with fungus at time of transplantation. Mean pre‐LT FEV1 was 80% (range 59–116%) predicted, and lung function post‐LT was stable. Isolated LT in children with CF is successful in those with relatively preserved pulmonary function, which does not appear to deteriorate as a consequence. Roux‐en Y biliary anastomosis and antifungal prophylaxis should be a part of management of these patients.     

Cardiometabolic risks vary by weight status in pediatric kidney and liver transplant recipients: A cross‐sectional,single‐center study in the USA

There is an increasing need to understand long‐term metabolic changes and resultant comorbidities because life expectancy is increasing after pediatric kidney and liver transplants. We evaluated differences in classic and novel cardiometabolic biomarkers among obese and normal weight adolescent transplant recipients. We enrolled a total of 80 adolescent (mean±SD, 14.8 years ±3.0) transplant recipients (63 kidney, 17 liver) with mean duration from transplantation of 6.0 (±4.1) years. Among kidney transplant recipients, overweight and obese individuals had higher leptin (16.7 vs 7.5 μg/mL, P<.001), lower HDL (1.1 vs 1.3 mmol/L, P=.02), higher free fatty acid (0.6 vs 0.5 mmol/L, P=.03), higher apoB‐to‐apoA1 ratio (0.8 vs 0.6, P=.03), and higher glucose (5.8 vs 4.3 mmol/L, P=.03) concentrations compared to normal weight individuals. Regardless of obesity status, over half of all participants (57.5%) were considered at high cardiometabolic risk using consensus guidelines, and this was more pronounced for kidney transplant recipients (61.9%). Post‐transplantation adolescents have increased cardiometabolic risk characterized by traditional risk factors of obesity and diabetes. The presence of obesity significantly worsens biomarkers of cardiometabolic risk. Future studies should explore whether treatment of obesity can improve the health and long‐term outcomes for children undergoing solid organ transplant.     

Pediatric liver transplantation for fibropolycystic liver disease

Fibropolycystic liver disease includes CHF, Caroli's syndrome, and Caroli's disease. Patients with Caroli's disease and Caroli's syndrome have an increased risk of recurrent cholangitis, intrahepatic calculi, biliary cirrhosis, and cholangiocarcinoma. The aim of this study was to examine the post-transplantation outcomes of children with fibropolycystic liver disease. Of the 158 children transplanted at Seoul National University Hospital, there were four patients with Caroli's syndrome, two patients with CHF, and one patient with Caroli's disease. One patient underwent combined liver/kidney transplantation. Associated renal manifestations included ARPKD in three children and nephronophthisis in one child. The indications for LT were recurrent cholangitis, decompensated cirrhosis, and refractory complications of portal hypertension. Both graft and patient survival rates were 100% at a median follow-up period of two yr after LT. Three children with growth failure achieved catch-up growth after LT. In three patients with ARPKD, mean serum creatinine levels increased from 0.53 mg/dL at the time of LT to 0.91 mg/dL at the last follow-up (p = 0.01). LT is an excellent option for children with complications from fibropolycystic liver disease. Renal function should be monitored cautiously after LT in the patients with ARPKD.     

Prope tolerance after pediatric liver transplantation

pT, under mono‐ and infratherapeutic calcineurin inhibition, may constitute an optimal condition combining graft acceptance with low IS load and minimal IS‐related toxicity. We reviewed 171 pediatric (<15.0 yr) survivors beyond one yr after LT, transplanted between April 1999 and June 2007 under tacrolimus‐based regimens (median follow‐up post‐LT: 6.0 yr, range: 0.8–9.5 yr). Their current status regarding IS therapy was analyzed and correlated with initial immunoprophylaxis. pT was defined as tacrolimus monotherapy, with mean trough blood levels <4 ng/mL during the preceding year of follow‐up, combined with normal liver function tests. The 66 children transplanted before April 2001 received a standard tacrolimus–steroid regimen. Beyond April 2001, 105 patients received steroid‐free tacrolimus–basiliximab or tacrolimus–daclizumab immunoprophylaxis. In the latter group, 43 (41%) never experienced any acute rejection episode and never received steroids. In the long term, a total of 79 recipients (47%) developed pT (n = 73) or IS‐free operational tolerance (n = 6), 27 of them belonging to the 43 steroid‐free patients (63%). In contrast, only 52/128 (41%) children treated with steroids subsequently developed prope/operational tolerance (p = 0.012). Steroid‐free tacrolimus‐based IS seems to promote long‐term graft acceptance under minimal/no IS. These results constitute the first evidence that minimization of IS, including steroid avoidance, might be tolerogenic in the long term after pediatric LT.     

Outcomes and predictive factors of pediatric kidney transplants: An analysis of the Thai Transplant Registry

As universal coverage for pediatric kidney transplantation (KT) was introduced in Thailand in 2008, the number of recipients has been increasing. We evaluated predictive factors for graft failure to understand how to improve clinical outcomes in these children. Using data obtained from the National Transplant registry, we assessed the risk of graft failure using the Kaplan–Meier method and Cox proportional hazards regression. Altogether, 201 recipients aged <21 yr at the time of KT were studied. Living donors (LD) were significantly older than deceased donor (DD). Mean cold ischemia time of DD was 17 h. The mean donor glomerular filtration rate (GFR) was 84.0 mL/min/1.73 m². Induction immunosuppressive therapy was administered more frequently in DD than in LDKT. Delayed graft function (DGF) occurred in 36 transplants. Over 719 person years of follow‐up, 42 graft failures occurred. Graft survival at one, three, and five yr post‐transplant were 95%, 88% and 76%, respectively. Two factors independently predicted graft failure in multivariate analysis. The hazard ratios for graft failure in patients with DGF and in patients with donor GFR of ≤30 mL/min/1.73 m² were 2.5 and 9.7, respectively. Pediatric recipients should receive the first priority for allografts from young DD with a good GFR, and DGF should be meticulously prevented.     

Combined liver and kidney transplantation and kidney after liver transplantation in children: Indication,postoperative outcome,and long‐term results

CLKT and sequential KALT are decided on a case‐by‐case basis in children for special indications such as ARPKD or PH1. We report on 21 children who underwent CLKT or KALT at our hospital between 1998 and 2013. Eleven children were diagnosed with PH1 and six with ARPKD. Other diagnosis were Joubert syndrome (n = 1), nephronophthisis (n = 1), CF (n = 1), and hepatocellular carcinoma (n = 1). Children (12 males, nine females) were aged 7.8 ± 6.2 yr (range, 10 months to 18 yr) at time of transplantation. Average wait time was 1.9 ± 0.9 yr (range, four months to 2.3 yr). Fifteen patients received dialysis prior to transplantation. In PH1 patients, four children received CLKT, five received KALT, and two infants have received only an LTx, whereas all six patients with ARPKD received CLKT. In patients with other indications, CLKT was performed in three cases and KALT in one girl. Cumulative 10‐yr survival of all 21 patients was 78.4%. At the time of transfer into adult care, 13 patients retained stable liver and kidney function. Regardless the underlying diagnosis, CLKT and KALT can be performed in children with good surgical outcomes and long‐term survival.     

Liver transplantation for urea cycle disorders in pediatric patients: A single‐center experience

LT has emerged as a surgical treatment for UCDs. We hypothesize that LT can be safely and broadly utilized in the pediatric population to effectively prevent hyperammonemic crises and potentially improve neurocognitive outcomes. To determine the long‐term outcomes of LT for UCDs, charts of children with UCD who underwent LT were retrospectively reviewed at an academic institution between July 2001 and May 2012. A total of 23 patients with UCD underwent LT at a mean age of 3.4 yr. Fifteen (65%) patients received a whole‐liver graft, seven patients (30%) received a reduced‐size graft, and one patient received a living donor graft. Mean five‐yr patient survival was 100%, and allograft survival was 96%. Mean peak blood ammonia (NH₃) at presentation was 772 μmol/L (median 500, range 178–2969, normal <30–50). After transplantation, there were no episodes of hyperammonemia. Eleven patients were diagnosed with some degree of developmental delay before transplantation, which remained stable or improved after transplantation. Patients without developmental delay before transplantation maintained their cognitive abilities at long‐term follow‐up. LT was associated with the eradication of hyperammonemia, removal of dietary restrictions, and potentially improved neurocognitive development. Long‐term follow‐up is underway to evaluate whether LT at an early age (<1 yr) will attain improved neurodevelopmental outcomes.     

Kidney transplantation in children weighing less than 15 kg: Extraperitoneal surgical access–experience with 62 cases

Small children are a challenging group in whom to perform KT. This retrospective study analyzed the results of 62 KTs in children weighing <15 kg, performed between 1998 and 2010, using extraperitoneal access and anastomosis of the renal vessels of donors to the aorta and IVC or iliac vessels of the recipients. Thirty‐two (51.6%) grafts were LRDTs and 30 (48.4%) were DDRTs—28 of them pediatric. The mean age at KT was 3.7 ± 2.2 yr (1–12), and the mean weight was 12.3 ± 2.1 kg (5.6–14.9). Ten children weighed <10 kg, and five (8.1%) children presented previous thrombosis of the venous system. At one and five yr, patient survival was 93.2% and 84.2%, and graft survival was 85.2% and 72.7%. There were no differences between the rates for LRDT and DDRT. There were six vascular complications (four vascular thromboses, one laceration, and one renal artery stenosis) and two perirenal collections. Extraperitoneal access is a valid KT technique in children weighing <15 kg.