IGG3 anti‐HLA donor‐specific antibodies and graft function in pediatric kidney transplant recipients

Anti‐HLA DSAs are associated with ABMR and graft loss in KT recipients, yet the influence of DSA IgG subclass on outcomes in pediatric KT recipients is not completely understood. We performed a single‐center retrospective chart review of pediatric KT recipients with anti‐HLA DSAs, aiming to study the association between specific DSA IgG subclasses and graft outcomes, including ABMR and significant graft dysfunction (graft loss or 50% decrease in eGFR). Thirty‐six patients (mean age 15.4y) with DSAs initially detected 1 month‐14.3 years post‐transplantation were followed for a median of 2.8 years. Rates of IgG1, 2, 3, and 4 subclass detection were 92%, 33%, 58%, and 25%, respectively. Twenty‐two patients (61%) had clinical ABMR, whereas 19% had subclinical ABMR, and 13 (36%) experienced significant graft dysfunction. Patients with IgG3+ DSAs had a higher risk of graft dysfunction compared with IgG3‐ patients (52% vs 13%, P = .03). In a multiple Cox proportional regression analysis, the presence of IgG3+ DSA was independently associated with significant graft dysfunction (HR 10.45, 95% CI 1.97‐55.55, P = .006). In conclusion, IgG3 subclass DSAs are associated with graft dysfunction and may be useful for risk stratification and treatment decisions in DSA‐positive pediatric KT recipients.     

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.     

Transient elastography for non‐invasive evaluation of post‐transplant liver graft fibrosis in children

As graft survival in pediatric LT is often affected by progressive fibrosis, numerous centers carry out protocol liver biopsies. Follow‐up biopsy protocols differ from center to center, but all biopsies are progressively spaced out, as time from transplant increases. Therefore, there is a need for non‐invasive techniques to evaluate graft fibrosis progression in those children who have no clinical or serological signs of liver damage. Indirect markers, such as the APRI, should be relied on with caution because their sensitivity in predicting fibrosis can be strongly influenced by the etiology of liver disease, severity of fibrosis, and patient age. A valid alternative could be TE, a non‐invasive technique already validated in adults, which estimates the stiffness of the cylindrical volume of liver tissue, 100‐fold the size of a standard needle biopsy sample. The aims of this study were to evaluate the reliability of TE in children after LT and to compare both the TE and the APRI index results with the histological scores of fibrosis on liver biopsies. A total of 36 pediatric LT recipients were studied. All patients underwent both TE and biopsy within a year (median interval ‐0.012 months) at an interval from LT of 0.36 to 19.47 years (median 3.02 years). Fibrosis was assessed on the biopsy specimens at histology and staged according to METAVIR. There was a statistically significant correlation between TE stiffness values and METAVIR scores (P = .005). The diagnostic accuracy of TE for the diagnosis of significant fibrosis (F ≥ 2) was measured as the area under the curve (AUROC = 0.865), and it demonstrated that the method had a good diagnostic performance. APRI was not so accurate in assessing graft fibrosis when compared to METAVIR (AUROC = 0.592). A liver stiffness cutoff value of 5.6 kPa at TE was identified as the best predictor for a significant graft fibrosis (METAVIR F ≥ 2) on liver biopsy, with a 75% sensitivity, a 95.8% specificity, a 90% positive predictive value, and an 88.5% negative predictive value. These data suggest that TE may represent a non‐invasive, reliable tool for the assessment of graft fibrosis in the follow‐up of LT children, alerting the clinicians to the indication for a liver biopsy, with the aim of reducing the number of protocol liver biopsies.     

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh—Study with long‐term follow‐up

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft‐to‐recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end‐point was the occurrence of postoperative abdominal wall infection. Secondary end‐points included 1‐ and 5‐year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no‐BM group. No significant differences between the two groups were observed for 1‐ and 5‐year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no‐BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.     

Donor‐specific anti‐HLA antibody production following pediatric ABO‐incompatible heart transplantation

ABO‐i heart transplantation can be performed in infants with end‐stage heart failure to increase organ availability. The development of newly detected DSAs is associated with decreased cardiac graft survival, and the effect of ABO‐i transplantation on DSA production is unknown. We examined DSA production and rejection frequency in infant recipients of ABO‐i and ABO‐c heart transplants via a retrospective cohort study of infant heart transplant recipients transplanted at a single pediatric center between January 2004 and November 2014. Patients were included if they were less than 1 year of age at transplant and had a minimum of 6 months follow‐up. DSA positivity was examined under two categories, either the lowest level detectable (MFI > 500) or a level presumed to have clinical relevance in our immunogenetics laboratory (MFI > 5000). Of 52 patients, 36 received ABO‐c transplants and 16 received ABO‐i transplants. Compared to ABO‐c recipients, the ABO‐i group showed a consistent but statistically non‐significant finding of less frequent ndDSA positivity (69.4% ABO‐c vs 43.8% ABO‐i with MFI >500, P = 0.122; 41.7% ABO‐c vs 25% ABO‐i with MFI >5000, P = 0.353). Additionally, ABO‐i patients were less likely to have any form of rejection (12.5% vs 47.2%, P = 0.027) or acute cellular rejection (6.3% vs 38.9%, P = 0.021). Our data suggest that infants receiving ABO‐i heart transplants may be less likely to develop ndDSAs or have rejection compared to same age ABO‐c recipients. Larger multicenter studies are needed to confirm results from this single center study.     

AST‐to‐platelet ratio index in non‐invasive assessment of long‐term graft fibrosis following pediatric liver transplantation

Long‐term graft fibrosis occurs in the majority of pediatric liver transplant recipients. Serial biopsies to monitor graft health are impractical and invasive. The APRI has been evaluated in pediatric liver disease, but not in the context of post‐transplantation fibrosis. We aimed to investigate the validity of APRI as a predictor of long‐term graft fibrosis in pediatric liver transplant recipients. This was a retrospective, observational study of a cohort of children who underwent liver transplantation at King's College Hospital between 1989 and 2003, with a relevant dataset available. Protocol liver biopsies were performed at 10‐yr follow‐up and fibrosis was graded using the Ishak scoring system, with S3‐6 denoting “significant fibrosis.” APRI was calculated concurrently with biopsy. A total of 39 asymptomatic patients (20 males; median age at transplant, 1.43 yr) underwent protocol liver biopsies at a median of 10.39 yr post‐transplantation. APRI was associated with significant fibrosis (p = 0.012). AUROC for APRI as a predictor of significant fibrosis was 0.74 (p = 0.013). The optimal cutoff APRI value for significant fibrosis was 0.45 (sensitivity = 0.67; specificity = 0.79; PPV = 0.67; NPV = 0.79). APRI appears to be a useful non‐invasive adjunct in the assessment of significant graft fibrosis in the long‐term follow‐up of pediatric liver transplant survivors.     

The histological quantification of alpha‐smooth muscle actin predicts future graft fibrosis in pediatric liver transplant recipients

Activated hepatic stellate cells express cytoplasmic ASMA prior to secreting collagen and consequent liver fibrosis. We hypothesized that quantifying ASMA could predict severity of future fibrosis after LT. For this, 32 pairs of protocol biopsies, that is, “baseline” and “follow‐up” biopsies taken at 1‐ to 2‐year intervals from 18 stable pediatric LT recipients, transplanted between 2006 and 2012 were selected. Morphometric quantification of “ASMA‐positive area percentage” was performed on the baseline biopsy. Histological and fibrosis assessment using Metavir and LAFSc was performed on all biopsies. The difference of fibrosis severity between the “baseline” and “follow‐up” was termed “prospective change in fibrosis.” Significant association was seen between extent of ASMA positivity on baseline biopsy and “prospective change in fibrosis” using Metavir (P=.02), cumulative LAFSc (P=.02), and portal LAFSc (P=.01) values. ASMA‐positive area percentage >1.05 predicted increased fibrosis on next biopsy with 90.0% specificity. Additionally, an association was observed between extent of ASMA positivity and concomitant ductular reaction (P=.06), but not with histological inflammation in the portal tract or lobular area. Hence, ASMA quantification can predict the future course of fibrosis.     

Unique clinical conditions associated with different acinar regions of fibrosis in long‐term surviving pediatric liver grafts

In the majority of long‐term survivors after PLTx, graft fibrosis has been identified. Recently, subtypes of graft fibrosis have been described based on their predominant acinar localization. We aimed to evaluate whether the development of portal, perisinusoidal, and centrilobular distribution of graft fibrosis is related to patient or transplantation‐related parameters. We reviewed the histological features in protocol liver biopsies taken at 1 and 5 years after PLTx of 47 children on a tacrolimus‐based immunosuppressive regimen. Fibrosis was assessed according to the LAFSc. The prevalence of portal fibrosis increased from 31% to 62%, sinusoidal from 68% to 79%, and centrilobular from 76% to 85%. The presence of portal fibrosis was associated with total bilirubin and γGT levels (each P<.02) and tended to be associated with biliary complications (P=.06). Sinusoidal fibrosis was associated with prior rejection episodes (P<.02) and centrilobular fibrosis with the presence of HLA mismatches (P=.02). In conclusion, using the LAFSc, we found a high incidence of progressive fibrosis in the 1‐year and 5‐year protocol biopsies after PLTx. Progression of fibrosis was observed in all acinar compartments, and each of the three locations is associated with different clinical conditions.     

Detection of graft fibrosis by vibration‐controlled transient elastography in pediatric liver transplant recipients

Pediatric liver transplant recipients are at risk of developing graft fibrosis which can affect patient survival. VCTE is a non‐invasive tool that measures LSM and has been shown to correlate with hepatic fibrosis. The aim of this study was to therefore evaluate the ability of LSM to predict fibrosis in pediatric liver transplant recipients with different graft types. We performed a cross‐sectional study evaluating LSM of 28 pediatric liver transplant recipients who underwent a total of 20 liver biopsies within 1 month of LSM. LSM was compared to liver histology as well as graft type: WL or PL. The median LSM of all post‐transplant patients was 5.6 kPa (range = 2.7‐18.3). There was a statistically significant correlation between LSM and METAVIR fibrosis score (P = .001) and LAF score (P < .001). There was no difference in LSM between graft type (P = .088). The AUROC curve for LSM predicting any significant fibrosis (F ≥ 2) was 0.863. A cutoff value of 7.25 had a sensitivity of 71%, specificity of 100%, NPV of 87%, and PPV of 100% for significant fibrosis. LSM by VCTE is feasible in pediatric liver transplant recipients regardless of graft type. We found a significant correlation between LSM and hepatic fibrosis and established a cutoff value that may help determine which patients warrant further evaluation for graft fibrosis.     

Evaluation of the current post‐transplantation Human Leukocyte Antigen antibody screening in pediatric renal transplant recipients

The necessity of post‐transplant monitoring for donor‐specific antibodies (DSAs) is unclear. This study evaluates the clinical relevance of post‐transplantation donor‐specific HLA antibodies in pediatric renal transplant recipients, aiming at better stratification of patients at risk of graft dysfunction and better recommendations for post‐transplant monitoring. A cohort of 68 pediatric kidney recipients, involving 76 transplantations between 2004 and 2014, was studied retrospectively. All patients were screened for HLA antibodies at 1, 3, 6, and 12 months after transplantation and yearly thereafter. Samples testing positive were further analyzed to detect DSA. A biopsy was performed on clinical indication. We studied the baseline characteristics of the patients with biopsy, with DSA, and with rejection. We assessed the effect of post‐transplant DSA on clinical outcome, including antibody‐mediated acute rejection and GFR decrease. In our cohort, the prevalence of DSA was 19% (13/68 transplantations). Most patients with HLA antibodies after transplantation were DSA‐positive (76%; 13/17). A clear association between DSA and subsequent rejection was found. At the end of the study period, a significantly lower GFR was found in patients with biopsy, DSA, or rejection. Based on our observations, we recommend routine post‐transplantation screening for HLA and DSA. The presence of DSA justifies a renal biopsy even in the absence of clinical signs of rejection.     

Indirect immunohistochemical evaluation of graft fibrosis and interface hepatitis after pediatric liver transplantation

Nagai S, Ito M, Kamei H, Nakamura T, Ando H, Kiuchi T. Indirect immunohistochemical evaluation of graft fibrosis and interface hepatitis after pediatric liver transplantation.
Pediatr Transplantation 2010:14:342–350. © 2009 John Wiley & Sons A/S. Abstract: Fibrosis or IH following pediatric liver transplantation is recognized as major causes of graft loss, but the etiology remains unclear. To determine this issue, we used an indirect immunohistochemistry technique with post‐transplant serum samples from recipients and normal human liver tissues from living liver donors, and the association between occult antibody reaction to the liver and the occurrence of fibrosis or IH was evaluated. Forty‐three recipients were evaluated, and both hepatocytes and biliary epithelial cells were evaluated for staining intensity. Fibrosis and IH occurred in 13 and six patients, respectively. According to staining results for the hepatocytes and biliary epithelial cells, 18 and 11 patients, respectively, were classified into the positive group. According to log‐rank analysis, positive reaction for hepatocytes was associated with increased rates of fibrosis and IH (p = 0.002 and 0.048, respectively), while positive reaction for biliary epithelial cells was associated with an increased rate of fibrosis (p = 0.014). Multivariate analysis revealed that positive reaction for hepatocytes and biliary epithelial cells was independently associated with fibrosis occurrence (p = 0.020 and 0.047, respectively). In conclusion, immune‐mediated reactions by occult antibodies may underlie the pathogeneses of fibrosis and IH.     

Cardiovascular risk factors in children after kidney transplantation – From short‐term to long‐term follow‐up

Cardiovascular‐related mortality is 100‐fold higher in pediatric renal transplant recipients than in the age‐matched general population. Seventy‐seven post‐renal transplant children's charts were reviewed for cardiovascular risk factors at two and six months after transplantation (short term) and at two yr after transplantation and the last follow‐up visit (mean 7.14 ± 3.5 yr) (long term). Significant reduction was seen in cardiovascular risk factors prevalence from two months after transplantation to last follow‐up respectively: Hypertension from 52.1% to 14%, hypercholesterolemia from 48.7% to 33%, hypertriglyceridemia from 50% to 12.5%, anemia from 29.6% to 18.3%, hyperparathyroidism from 32% to 18.3% and hyperglycemia from 11.7% to 10%, and left ventricular hypertrophy from 25.8% at short term to 15%. There was an increase in the prevalence of obesity from 1.5% to 3.9% and of CKD 3–5 from 4.75% to 24%. The need for antihypertensive treatment decreased from 54% to 42%, and the percentage of patients controlled by one medication rose from 26% to 34%, whereas the percentage controlled by 2, 3, and 4 medications decreased from 21.9%, 5.5%, and 1.4% to 6%, 2%, and 0. Children after renal transplantation appear to have high rates of cardiovascular risk factors, mainly on short‐term follow‐up.     

Extended follow‐up of pediatric liver transplantation patients receiving once daily calcineurin inhibitor

We describe longitudinal results in a cohort of pediatric liver transplant patients successfully minimized to once daily CNI monotherapy for longer than five yr and assess changes in liver biochemistries and liver histology. A retrospective chart review of all pediatric liver transplant patients at a single center was performed. Biopsies and serum biochemistries (AST, ALT, total bilirubin, direct bilirubin, INR, creatinine) are reported at time points: PM, five‐yr, seven‐yr, and nine‐yr post‐minimization. Biopsies were assessed for inflammation and fibrosis using Ishak and Batts grading systems. Successful minimization to daily CNI monotherapy was defined as normal liver enzymes with no episodes of rejection. Thirty‐three patients have successfully remained on once daily CNI for >5 yr, and 19/33 of these patients have serial liver biopsies available for review. We report on the clinical and histological findings of these 19 patients. All 19 patients continue to have normal liver biochemistries. On post‐minimization biopsies, fibrosis progressed by ≥2 stages in one patient (5.3%) despite normal liver biochemistries. Carefully selected patients can tolerate minimization to once daily CNI monotherapy as few have progression of fibrosis.     

Epstein‐Barr viral load monitoring for diagnosing post‐transplant lymphoproliferative disorder in pediatric liver transplant recipients

This study aimed to investigate the incidence of PTLD in pediatric liver transplant recipients and the risk factors for the development of PTLD. We also determined clinically useful quantitative EBV PCR parameters for aiding in the diagnosis of EBV‐associated PTLD in the pediatric liver transplant recipients at our institute. We reviewed children < 18 years old who had undergone liver transplantations and quantitative analysis of whole blood EBV load at our institute from January 2006 to March 2015. A total of 142 liver transplant recipients were included, and their median age was 1.5 years. Clinically significant high‐level EBV DNAemia ≥ 10 000 copies/mL at least twice was observed in 53.5% and PTLD occurred in 9.9%. Among PTLD group, graft failure and mortality rate were as high as 21.4% and 14.3%, respectively. Deceased donor, presence of high‐level EBV DNAemia, and primary CMV infection following transplant were associated with an increased risk for PTLD in the multivariate analysis. The peak titer at 10 875 copies/mL could be used as a cutoff value with a sensitivity of 92.9% and a specificity of 37.9%; the rate of increase in EBV load suggested a sensitivity of 64.3% and a specificity of 70.9% at the cutoff value of 44 000 copies/mL/week. In conclusion, the incidence of PTLD following liver transplant in children was as high as 10%. PTLD is associated with significant morbidity and mortality. Close monitoring of EBV DNAemia is crucial for the early diagnosis and proper treatment of PTLD in pediatric liver transplant recipients.     

Diaphragmatic hernias after pediatric liver transplantation: Experience of a high‐volume transplant center

Diaphragmatic hernias (DHs) are rare complications after pediatric liver transplantation (PLT). It is now widely accepted that DHs after liver transplantation (LT) is a pediatric related condition. PLTs (under of age 18) performed between January 2013 and June 2019 at Malatya Inonu University Institute of Liver Transplantation were retrospectively scanned. Study group consisting DHs and a control group were compared. Among 280 PLTs, 8 of them were complicated with DHs (%2.9). Median age of the patients with DH was 3.0 (0.8‐9.5) years. Median graft recipient weight ratio was 2.5 (0.9‐4.4). Five patients were below 5th percentiles in terms of pediatric weight growth chart at the time of LT. Also, 6 patients were below 5th percentiles in terms of pediatric height growth chart. There was no statistical difference between study and control groups. There are many risk factors mentioned in literature that may be primarily responsible for DHs after PLT. These factors are left lobe and large‐for‐size grafts, malnutrition, trauma or diathermy of diaphragmatic nerve and vessels and immunosuppressants. In our study, we could not specify any reason that differs in DHs. In our aspect, narrow diaphragma and thorax are exposed to high intra‐abdominal pressure from abdomen. Large‐for‐size grafts, which are specific to children, also may contribute to this affect. Excessive diathermy and trauma to diaphragmatic collaterals may aggravate the risk of DH. More patients are needed to make an exact conclusion, in order to evaluate with comparable study on this aspect.     

Long‐term follow‐up of de novo allergy in pediatric liver transplantation – 10 yr experience of a single center

We conducted a study to clarify the incidence, clinical course, and risk factors of de novo allergies after liver transplantation. Ninety‐three patients who had been followed longer than one yr and who had no previous allergy history were included. Forty‐two patients (45.2%) developed de novo allergy. Of them, food allergy developed in 35 (37.6%). Respiratory allergy was observed in three (3.2%), and a patient (1.1%) had drug allergy. Fifty‐two (55.9%) of the 93 patients developed eosinophilia. The median age of patients with de novo allergy was 15 months (IR 11.3–20 months). De novo allergy developed five months after liver transplantation (IR 2.3–9.5 months) and lasted for 16 months (IR 8–34.5 months). Younger age at liver transplantation displayed statistically significant differences in development of allergy between allergy and non‐allergy groups. Twenty‐nine (69.0%) patients improved from allergy during the follow‐up period. No patient with de novo gastrointestinal allergy progressed to any respiratory allergy such as asthma. Older age at transplantation, EBV non‐risk, and CMV non‐risk had statistical significance in allergy improvement. Younger age at transplant predisposes to the development of allergy, while improvement of allergy is achieved more in older age.     

The use of transient elastography and non‐invasive serum markers of fibrosis in pediatric liver transplant recipients

The use of non‐invasive markers to diagnose liver allograft fibrosis is not well established in children after LTx. TE, FT, and ELF score were performed in 117 liver‐transplanted children (60M, 8.9 [0.5–18.5] yr) and 336 healthy controls. Liver biopsy was available in 36 children. Results of histology and non‐invasive markers were compared using correlation coefficient or Mann–Whitney U‐test as appropriate. TE correlated best with histological degree of fibrosis (r = 0.85 vs. r = 0.04 [FT] or r = ?0.38 [ELF]). Liver stiffness values for transplanted children without fibrosis were significantly higher than those of healthy controls (7.55 [5.4–20.4] kPa vs. 4.5 [2.5–8.9] kPa). Presence of rejection was a potent confounder for the performance of TE. Both TE and FT reflected clinical changes (acute rejection, cholestasis, increasing fibrosis) in a total of 16 patients who underwent serial measurements. TE correlates better with histological degree of fibrosis in liver‐transplanted children than FT or ELF, but an individual baseline value needs to be determined for each patient. Normal or cutoff values for pathological degrees of fibrosis cannot be transferred from non‐transplanted children. Follow‐up studies, preferably with protocol biopsies, might help to improve the diagnostic quality of TE.     

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.