Protocol Biopsies in Pediatric Liver Transplantation Recipients Improve Graft Histology and Personalize Immunosuppression.

OBJECTIVES: Protocol liver biopsies (PLBs) are part of the follow-up program at many pediatric liver transplant centers, but the impact on clinical decision-making and allograft histology following adjustments of immunosuppression (IS) after PLB has not been thoroughly analyzed. METHODS: Following our previous single-center cohort study, we have now evaluated histological findings of 178 PLBs of 118 pediatric patients transplanted at our center between 1998 and 2017. In particular, we focused on the changes in allograft histology in the follow-up biopsy of a subgroup of 22 patients, in which the histologic findings led to an adjustment of immunosuppressive therapy. All biopsies of this sub-study group were reevaluated by an experienced pathologist. RESULTS: The overall frequency and severity of fibrosis increased over time after orthotopic liver transplantation. Patients with donor-specific antibodies (DSAs) had a higher prevalence of fibrosis than DSA-negative patients. Graft inflammation decreased significantly after intensifying IS, but renal function needs to be monitored. A significant increase in fibrosis was detected in children with reduced IS. CONCLUSION: The adjustment of IS following PLBs has a significant impact on allograft histology. Since chronic inflammatory changes may lead to graft failure, adjustment of IS seems to be of major importance for the long-term outcome.

Liver Transplantation for Acute Intermittent Porphyria.

Recurrent attacks of acute intermittent porphyria (AIP) result in poor quality of life and significant risks of morbidity and mortality. Liver transplantation (LT) offers a cure, but published data on outcomes after LT are limited. We assessed the pretransplant characteristics, complications, and outcomes for patients with AIP who received a transplant. Data were collected retrospectively from the European Liver Transplant Registry and from questionnaires sent to identified transplant and porphyria centers. We studied 38 patients who received transplants in 12 countries from 2002 to 2019. Median age at LT was 37 years (range, 18-58), and 34 (89%) of the patients were women. A total of 9 patients died during follow-up, and 2 patients were retransplanted. The 1-year and 5-year overall survival rates were 92% and 82%, which are comparable with other metabolic diseases transplanted during the same period. Advanced pretransplant neurological impairment was associated with increased mortality. The 5-year survival rate was 94% among 19 patients with moderate or no neuropathy at LT and 83% among 10 patients with severe neuropathy (P = 0.04). Pretransplant renal impairment was common. A total of 19 (51%) patients had a GFR < 60 mL/minute. Although few patients improved their renal function after LT, neurological impairments improved, and no worsening of neurological symptoms was recorded. No patient had AIP attacks after LT, except for a patient who received an auxiliary graft. LT is a curative treatment option for patients with recurrent attacks of AIP. Severe neuropathy and impaired renal function are common and increase the risk for poor outcomes. If other treatment options fail, an evaluation for LT should be performed early.

Outcome of liver transplantation and prevalence of liver fibrosis in Crigler-Najjar syndrome.

INTRODUCTION: Crigler-Najjar syndrome (CNS) is a rare inherited disorder that is characterized by high levels of non-hemolytic, unconjugated hyperbilirubinemia leading to brain damage and even death. Liver transplantation (LT) can correct the metabolic defect, but there are little data regarding LT in this patient cohort. The liver parenchyma has been considered to be structurally normal in CNS, but there is growing evidence of clinically silent but histologically significant fibrosis in CNS patients. PATIENTS AND METHODS: We included 13 patients in our retrospective study who underwent LT at our center. Patient survival, graft function, and long-term complications were evaluated over a median follow-up period of 10 years (range: 1-16 years). In addition, the prevalence of histologically relevant fibrosis was characterized. RESULTS: The overall survival among our LT patients was 100%. The graft survival was only 61.5%. During the follow-up period, 5 LT patients had to undergo retransplantation. More than 45% of our patients showed histological signs of fibrosis. CONCLUSION: LT remains the only definite therapeutic option for severe CNS but needs to be considered thoroughly regarding the clinical risk-benefit-ratio and impact on quality of life. Furthermore, hepatic parenchymal injury needs to be considered while evaluating future therapeutic options for CNS.

Presence of donor specific HLA class 2 antibodies (DSA class 2) is associated with development of graft fibrosis more than 10 years after liver transplantation-a retrospective single center study.

Here the impact of donor specific human leukocyte antigen (HLA) class 2 antibodies (DSA cl 2) on long term outcome after liver transplantation (LT) was investigated. Altogether 156 (44 pediatric and 112 adult) LT recipients were included in the study. Graft fibrosis was assessed by liver elastography and biopsy. DSA cl 2 were determined by Luminex technology. 46% of LT recipients were positive for DSA cl 2 after a median follow-up of 15 years. In the multivariate analysis DSA cl 2 were significantly associated with immunosuppressive monotherapy (OR 5.42; 95% CI: 1.02-28.90; p = .048). Compared to DSA cl 2 negative patients, positive recipients had significantly more graft fibrosis based on the liver stiffness (mean 9.4 ± 9.0 kPa vs. 6.5 ± 6.3 kPa; p < .002) and fibrosis stages determined by liver elastography (p = .016) and the performed liver biopsies (p = .002). Also, a significantly higher incidence of chronic rejections (11% vs. 2%; p = .045) and graft losses (6% vs. 0%; p = .043) were found. In the multivariate regression analysis DSA cl 2 were significantly associated with graft fibrosis (OR 4.57; 95% CI 1.59-13.10; p = .005). So, these data suggest that development of DSA cl 2 occurs more often with immunosuppressive monotherapy and may ultimately result in chronic rejection and graft fibrosis.

Short- and long-term results of liver transplantation according to age at transplant: a single-center experience of 351 children.

Pediatric liver transplantation (PLT) has very good results at experienced transplant centers. However, there is still an ongoing discussion about inferior outcomes, especially in young infants. The aim of this retrospective study was to evaluate outcomes of infants compared to older recipients in a single center over 20 years. We conducted a retrospective study of children who received liver transplants at our center between 1991 and 2011. Only patients without other limiting organ involvement were included and compared according to age. The inclusion criteria were fulfilled by 351 patients (173 vs. 178). The most common indication in both groups was biliary atresia (82.1% vs. 49.4%). The 1-, 5-, and 10-year patient survivals were 93.8%/91.8%/91.1% and 93%/90.8%/90.1%, and the graft survivals were 90.4%/83.5%/79.6% and 89.4%/81.8%/77.5%, respectively. Complications such as postoperative bleeding, biliary complications, or perfusion impairment occurred more often in infants. Leading indications for retransplantation (vascular complications/primary nonfunction) and leading causes of death (sepsis/multiorgan failure) were the same in both groups. Significant predictors for patient loss were decade of transplantation, retransplantation, postoperative bleeding, and infections for infants. Predictors for graft loss were bowel perforation, arterial thrombosis, and age >12 months. Children can have excellent results, independent of age at PLT.

Intravesical monitoring of intra-abdominal pressure after renal transplantation in children: A safety and feasibility study.

IAH after RTX can threaten graft viability. This study aimed to assess the feasibility and safety of longitudinal IAP measurements as an IAH screening method in children after RTX. A cohort of eight children with a mean ± SD [range] age 9.6 ± 6.2 [2-17] years who underwent RTX and 18 control patients were evaluated between May 2017 and February 2018. We compared longitudinal IAP measurements using a Foley manometer to other clinical monitoring data. In total, 29 IAP measurements were performed in RTX patients and 121 in controls. The mean post-operative IAP was 7.4 ± 4.3 [1-16] mm Hg following RTX and 8.1 ± 3.7 [1-19] mm Hg in controls. We noted IAH in 9 (31%) of 29 IAP measurements after RTX and in 41 (34%) of 121 IAP measurements in controls. No graft dysfunction occurred in RTX patients despite elevated IAP values. The mean ± SD [range] time expenditure for IAP measurement was 2.1 ± 0.4 [0.6-3.2] minutes. No severe complications occurred during the IAP measurements. Analysis of longitudinal IAP measurements demonstrated that IAP measurement is safe and feasible in children recovering from renal transplantation in the PICU.

Surgical Aspects of Liver Transplantation and Domino Liver Transplantation in Maple Syrup Urine Disease: Analysis of 15 Donor-Recipient Pairs.

Liver transplantation (LT) has been shown to be a feasible treatment in patients with severe forms of maple syrup urine disease (MSUD). Because of a sufficient extrahepatic enzyme activity in non-MSUD individuals, the organ of MSUD patients can be used as a domino graft. We performed a retrospective data collection of all LTs for MSUD carried out at the University Medical Center Hamburg-Eppendorf (2016-2018). Moreover, data from all consecutive domino LTs of the MSUD grafts either transplanted at our institution or allocated to other transplant centers were analyzed. During the study period, 15 LTs in MSUD patients were performed (12 children, 3 adults; median age, 10.9 years; range, 0.3-26.1 years). Biliary complications occurred in 20%, and 13.3% suffered from bleeding complications. No further surgical problems occurred. At present, all MSUD patients are alive with a well-functioning liver graft and on an unrestricted diet. In total, 14 consecutive domino LTs were performed. No surgical complications requiring intervention occurred. One patient died because of HCC relapse, and all other patients are alive with good liver graft function. In conclusion, the use of MSUD livers as domino grafts is safe and allows application of LT in MSUD patients without net extraction of a liver graft from the limited donor pool.

Impact on the hepatic flow velocity after pediatric combined liver-kidney transplantation compared to isolated pediatric liver transplantation-A matched-pair analysis.

BACKGROUND: Combined liver-kidney transplantation (CLKT) in children is still a rarely performed procedure. Our aim was to analyze the effect of the simultaneous transplantation of the kidney in pediatric CLKT on the liver graft flow velocity, and vascular complications compared to singular liver transplantation (LTX) in children. METHODS: All pediatric CLKT performed at our institution from 1998 to 2016 were matched with singular LTX and retrospectively analyzed. RESULTS: Overall 30 CLKT were performed in 28 children (median age 8 years, range 1-16) and matched with 30 children undergoing singular LTX (median age 7.9 years, range 1-16). No significant differences were found concerning the systolic peak flow velocity of the hepatic artery (HA) or the resistance index (RI). Vascular complications of the hepatic vessels occurred in 16.7% (CLKT) and 6.7% (LTX). The 1-/5- and 10-year patient survival was 93.3%/93.3% and 93.3% (CLKT) and 100%/100% and 92.9% (LTX). 1-/5-and 10-year liver graft survival was 76.7%/73.2% and 73.2% (CLKT) and 84.4%/75.9% and 69.6% (LTX). CONCLUSION: The simultaneous transplantation of the kidney in CLKT had no negative impact on hepatic flow velocity or vascular complications. Frequent Doppler ultrasound examinations, accurate volume management, and avoidance of abdominal pressure might be an explanation for the results and an excellent graft- and patient survival.

Persistence of post-operative color Doppler abnormalities is linked to reduced graft survival in pediatric patients after liver transplantation.

Color Doppler US is a readily available imaging modality for the evaluation of liver transplants. The aim of our study was to evaluate the temporal course of color Doppler US findings in children after LTX and to investigate the effect of resolving and persisting abnormalities during follow-up on long-term outcome. All children who underwent LTX during January 2000 until December 2003 (155 LTX in 137 patients, 75 male and 62 female; mean age at LTX 4.1 ± 4.8 years; range, 0.1-16.3 years) were retrospectively evaluated. Following a predefined ultrasound protocol with prospective documentation, intraoperative, post-operative, and follow-up examinations were evaluated for color Doppler abnormalities. The time of occurrence and temporal course of the findings were recorded. Graft survival rates and graft survival times were compared. Abnormal color Doppler US examinations were noted in 98 of 155 grafts during the entire observational period (63.2%). In 57 of 98 grafts (58.2%), abnormalities were limited to the perioperative period (<30 days after LTX). Survival of grafts with transient perioperative abnormalities was similar to transplantations with regular color Doppler US examinations (graft survival rates, 80.7% vs 84.2%, P = .622; mean graft survival time, 2596.92 vs 2511.40 days, P = .67). Grafts with persisting color Doppler US abnormalities in the follow-up period (>30 days after LTX; 37/98 LTX, 37.8%) showed reduced survival compared with regular courses (graft survival rate 62.2% vs 80.7%, P = .047), indicating underlying organ-specific alterations. Standardized longitudinal evaluation during the perioperative and the follow-up period can enhance the prognostic capabilities of color Doppler US in children following LTX.

Monitoring intra-abdominal pressure after liver transplantation in children.

IAH after LTX can impair perfusion and threaten graft viability. This study aimed to assess the feasibility of longitudinal IAP measurements as an IAH screening method in children after LTX. A cohort of 23 children with a mean age (range) 3.1 (3 months-14 years) who underwent LTX between May 2017 and February 2018 were evaluated retrospectively. Longitudinal IAP measurements were compared to bedside Doppler US monitoring data. In total, 425 IAP measurements and 257 US examinations were performed. The mean ± SD (range) time expenditure for IAP measurement was 1.9 ± 0.4 (0.5-3.2) minutes. The mean post-operative IAP was 7.9 ± 3.6 (1-25) mm Hg. IAH (IAP ≥ 10 mm Hg) was noted in 102 (24%) of 257 measurements. Agitation had a significant impact on IAP (estimate: 9.3 mm Hg, CI: 6.72-11.97, P < .01). In patients with TAC, IAP was increased (6.7 ± 2.1 vs 8.7 ± 3.1 mm Hg, P = .02) while peak portal venous velocities decreased (38 ± 27 vs 26 ± 22 cm/s, P = .03) after patch reduction. An abdominal compartment syndrome with severely impaired vascular flow was noted in one patient. Episodes of elevated IAP were noted in a large proportion of patients, underscoring the need for IAP monitoring in pediatric liver transplant recipients. The safety and low time expenditure associated with IAP measurement could be included easily into standard nursing procedures for these patients.

Long-term follow-up after full-split liver transplantation and its applicability in the recent transplant era.

INTRODUCTION: Full-split liver transplantation (LTX) offers the possibility to expand the donor pool by utilization of one liver for two adults. The aim of our study was to analyze the long-term outcome in a large series and its applicability in the recent transplant era. METHODS: We performed a retrospective analysis of all full-split LTX from deceased donors (1999-2015). Additionally, the potential of full-split LTX was retrospectively analyzed in all whole organ LTX recipients between 2006 and 2015 (after introduction of the MELD allocation). RESULTS: We performed 44 full-split LTX, thereof 82% before introduction of the MELD-based allocation system in Germany. Analysis showed highly selected recipients (median MELD score 8 points) and organ data (median donor age 30 years). 5- and 10-year patient survival rates after full-left and full-right LTX were 90.7%/90.7% and 85.2%/56.8% (P = .301), corresponding graft survival rates were 80.5%/80.5% in full-left grafts and 73.7%/36.8% in full-right graft (P = .198). CONCLUSION: In the past, in case of strict donor and recipient selection, full-split LTX was a feasible method with a good outcome. Due to introduction of the national waiting list with a patient-oriented allocation based on the MELD score in 2006, full-split LTX seems to be not any longer applicable.

Outcome following right-extended split liver transplantation in the recent transplant era: Single-center analysis of a German transplant center.

INTRODUCTION: When a sufficiently high-quality liver is available, classic liver graft splitting is performed. In such cases, a small child receives the left-lateral split graft, with subsequent transplantation of the right-extended graft in an adult. METHODS: We analyzed 64 patients who received right-extended liver grafts from 2007 to 2015, and compared outcomes between cases of external vs in-house graft splitting. RESULTS: We found excellent donor data and comparable recipient characteristics. Cold ischemic time was significantly longer for external (14 ± 2 hours; n = 38) vs internal (12 ± 2 hours; n = 26) liver graft splitting. Compared to the internal splitting group, the external liver graft splitting group showed significantly reduced 1- and 5-year patient survival (100% vs 84%; P = .035) and higher rates of biliary (24% vs 12%) and vascular (8% vs 0%) complications. CONCLUSIONS: The outcomes following right-extended split LTX are disappointing given the excellent organ quality. External liver graft splitting was associated with worse outcome and surgical complication rates. This may be related to the prolonged cold ischemic time due to twofold transportation, as well as the ignorance of the splitting procedure details and related pitfalls.

Chronic pancreatitis in patients with liver cirrhosis negatively affects graft survival after liver transplantation.

BACKGROUND: Limited data exists concerning the coincidence of chronic pancreatitis (CP) and liver cirrhosis with respect to the patient outcome after liver transplantation (LT). The aim of the study was to identify risk factors for graft loss after liver transplantation and to evaluate the impact of CP on graft survival. METHODS: We analyzed the data of 421 cirrhotic patients who underwent evaluation for primary liver transplantation from January 2007 to January 2014. Diagnosis of CP based on morphologic findings which were graded according to the Cambridge and Manchester classification. (Graft) survival after LT was analyzed by Cox regression analysis. Recipient- and donor-related risk factors for graft loss were evaluated using univariate and multivariate analysis. RESULTS: 40/421 cirrhotic patients suffered from CP (9.5%). 250/421 (59.4%) patients underwent LT between January 2007 and January 2014. In total, 89 patients died or were in need of a re-transplantation during follow-up until August 2017. Patients with CP (N = 26) were at increased risk for graft loss after LT (hazard ratio = 2.183; 95% confidence interval = 1.232-3.868). CP (P = 0.001), a MELD score ≥24 (P = 0.021), absence of esophageal or gastrical varices (P = 0.018), the age of the donor (P = 0.008) and infections after transplantation (P = 0.030) were independent risk factors for organ loss after transplantation in the multivariate Cox regression analysis. CONCLUSION: Patients with chronic pancreatitis are at increased risk for graft loss after LT. A high MELD score, the absence of esophageal or gastrical varices, an advanced donor age and post-transplant infections negatively affect graft survival, too.

The first case of domino-split-liver transplantation in maple syrup urine disease.

The enzymatic defect in MSUD results in accumulation of neurotoxic metabolites of BCAAs. LTX has shown to be a feasible strategy in patients non-responsive to diet. Because of sufficient enzyme activity in extrahepatic tissues in healthy people, the MSUD liver graft is a suitable domino organ. We present the first case of a technical challenging ex situ split of a MSUD domino organ transplanted into two pediatric recipients. The domino graft donor was a 21-year-old female (58 kg) suffering from MSUD with recurrent metabolic decompensation despite strict diet. The organ was allocated to a 14-year-old girl (55 kg) with primary sclerosing cholangitis. Due to excellent organ quality and suitable anatomy, a backward split for a girl of 3 months (5 kg) with decompensated liver cirrhosis due to biliary atresia was performed. The postoperative course was without relevant complications, and the three recipients were discharged on postoperative days 28, 29, and 45, respectively, with good organ function. BCAAs in plasma were normal in the two domino graft recipients, and the MSUD patient showed mildly elevated but stable BCAA concentrations despite an unrestricted diet. Split-domino LTX enabled successful transplantation of three patients of the waiting list with only one deceased donor graft.

Long-term outcomes after liver transplantation for deoxyguanosine kinase deficiency: a single-center experience and a review of the literature.

Deoxyguanosine kinase (DGUOK) deficiency is a well-known cause of hepatocerebral mitochondrial DNA depletion syndromes, which include a broad spectrum of clinical presentations. Affected patients often develop life-threatening liver failure, but the benefits of liver transplantation (LT) are controversial because of the frequently severe neurological involvement due to the underlying mitochondrial disease. We describe the long-term clinical course of 2 patients from our institution and provide an update on their outcomes after LT with this condition. Another 12 pediatric patients were identified through a systematic search of the literature. All 14 reported patients underwent transplantation in infancy despite mild to moderate neurological impairment in some cases. The 2 DGUOK-deficient patients from our center displayed liver failure and mild to moderate neurological involvement. At the time of this writing, they had been followed for 5 and 8 years after LT, both patients were alive, and they had only mild neurological symptoms. Three of the 12 patients identified through the literature review survived for a long time (17, 12, and 23 years); 8 died during early follow-up; and for 1 patient, no follow-up information was available. The 1-year survival rate was 64%; 36% survived for more than 5 years. The long-term survivors had good quality of life. In conclusion, although survival after LT for DGUOK deficiency is lower than survival after LT for other indications, a significant proportion of patients benefit from LT with long-term survival and a stable neurological situation despite initial neurological abnormalities. Nevertheless, a decision to carry out LT for patients with DGUOK deficiency remains difficult because neurological symptoms may occur and worsen after LT despite their absence before transplantation.

Developments in pediatric liver transplantation since implementation of the new allocation rules in Eurotransplant.

Liver allocation in the Eurotransplant (ET) region has changed from a waiting time to an urgency-based system using the model of end-stage liver disease (MELD) score in 2006. To allow timely transplantation, pediatric recipients are allocated by an assigned pediatric MELD independent of severity of illness. Consequences for children listed at our center were evaluated by retrospective analysis of all primary pediatric liver transplantation (LTX) from deceased donors between 2002 and 2010 (110 LTX before/50 LTX after new allocation). Of 50 children transplanted in the MELD era, 17 (34%) underwent LTX with a high-urgent status that was real in five patients (median lab MELD 22, waiting time five d) and assigned in 12 patients (lab MELD 7, waiting time 35 d). Thirty-three children received a liver by their assigned pediatric MELD (lab MELD 15, waiting time 255 d). Waiting time in the two periods was similar, whereas the wait-list mortality decreased (from about four children/yr to about one child/yr). One- and three-yr patient survival showed no significant difference (94.5/97.7%; p = 0.385) as did one- and three-yr graft survival (80.7/75.2%; and 86.5/82%; p = 0.436 before/after). Introduction of a MELD-based allocation system in ET with assignment of a granted score for pediatric recipients has led to a clear priorization of children resulting in a low wait-list mortality and good clinical outcome.

Outcome of liver re-transplantation in children--impact and special analysis of early re-transplantation.

In case of graft failure, re-LTX is the only life-saving option but it has been associated with inferior results. This study analyzes the outcome following pediatric re-LTX with a main focus on the timely relation between initial transplant and re-LTX. All pediatric LTX at our institution between 2000 and 2010 divided into patients with primary LTX and patients undergoing re-LTX early (≤30 days) or late (>30 days) after previous LTX were analyzed. Two hundred and ninety-eight primary LTX(79%), 33 early (9%), and 46 late (12%) re-LTX were performed. Patient/graft survival was significantly worse for children undergoing early re-LTX compared to primary LTX and late re-LTX (p = 0.024/0.001 and p = 0.015/0.03). One-/five-yr graft survival rates were 66%/49% for early re-LTX compared to 86%/76% for late re-LTX and 90%/74% for primary LTX. The inferior results in children undergoing early re-LTX were due to events occurring in the first six months with similar survival thereafter. No difference in outcome was evident after adjustment of the groups for high-urgency status. Outcome was excellent for primary LTX and late re-LTX, supporting late re-LTX in children. Early re-LTX takes an elevated risk of early graft loss and patient death; however, beyond the early postoperative period, the outcome was comparable.

Hepatic Artery Delineation on Ultrasound Volumes Comparing B-Flow and Color Doppler for Postoperative Monitoring of Pediatric Liver Transplants.

(1) Background: Accurate hepatic artery (HA) depiction following pediatric liver transplantation (LT) is essential for graft surveillance but challenging on ultrasound (US). This study assesses if improved HA delineation can be achieved by recording two-dimensional US volumes in Color Doppler (CD) and B-flow technique. (2) Methods: Of 42 consecutive LT, 37 cases were included, and HA delineation was retrospectively rated using a four-point score (0 = HA not detectable, 3 = HA fully detectable, separable from portal vein) within 48 h post-LT (U1) and before discharge (U2). (3) Results: Adding B-flow compared with CD alone showed superior results at neohilar (U1: 2.2 ± 1.0 vs. 1.1 ± 0.8, p < 0.0001; U2: 2.5 ± 0.8 vs. 1.5 ± 0.9, p < 0.0001) and segmental levels (U1: 2.8 ± 0.6 vs. 0.6 ± 0.8, p < 0.0001; U2: 2.8 ± 0.6 vs. 0.7 ± 0.5, p < 0.0001). (4) Conclusions: Standardized US volume recordings combining B-flow and CD can effectively delineate the HA along its vascular course in pediatric LT. The technique should be further evaluated as a standard monitoring instrument to rule out vascular complications after LT.

Favorable Outcome After Single-kidney Transplantation From Small Donors in Children: A Match-controlled CERTAIN Registry Study.

BACKGROUND: Kidney transplantation (KTx) from small donors is associated with inferior graft survival in registry studies, whereas single-center studies show favorable results. METHODS: We compared 175 pediatric KTx from small donors ≤20 kg (SDKTx) with 170 age-matched recipients from adult donors (ADKTx) from 20 centers within the Cooperative European Paediatric Renal Transplant Initiative registry. Graft survival and estimated glomerular filtration rate (eGFR) were analyzed by Cox regression and mixed models. Detailed data on surgical and medical management were tested for association with graft survival. RESULTS: One-year graft survival was lower after SDKTx compared with ADKTx (90.9% versus 96.5%; odds ratio of graft loss, 2.92; 95% confidence interval [CI], 1.10-7.80; P  = 0.032), but 5-y graft survival was comparable (90.9% versus 92.7%; adjusted hazard ratio of graft loss 1.9; 95% CI, 0.85-4.25; P  = 0.119). SDKTx recipients had an annual eGFR increase of 8.7 ±â€…6.2 mL/min/1.73 m² compared with a decrease of 6.9 ±â€…5.7 mL/min/1.73 m² in ADKTx recipients resulting in a superior 5-y eGFR (80.5 ±â€…25.5 in SDKTx versus 65.7 ±â€…23.1 mL/min/1.73 m² in ADKTx; P  = 0.008). At 3 y posttransplant, eGFR after single SDKTx was lower than after en bloc SDKTx (86.6 ±â€…20.4 versus 104.6 ±â€…35.9; P  = 0.043) but superior to ADKTx (68.1 ±â€…23.9 mL/min/1.73 m²). Single-kidney SDKTx recipients had a lower rate of hypertension at 3 y than ADKTx recipients (40.0% versus 64.7%; P  = 0.008). CONCLUSIONS: Compared with ADKTx, 5-y graft function is superior in SDKTx and graft survival is similar, even when performed as single KTx. Utilizing small donor organs, preferably as single kidneys in experienced centers, is a viable option to increase the donor pool for pediatric recipients.