Intraoperative renal replacement therapy during liver transplantation in children: Safety, efficacy and impact on survival.

BACKGROUND: Intraoperative Continuous Renal Replacement Therapy (iCRRT) can prevent life-threatening complications, facilitate fluid management, and maintain metabolic homeostasis during liver transplantation (LT) in adults. There is a paucity of data in pediatric LT. We evaluated the safety, efficacy, and impact on survival of iCRRT in pediatric LT. METHODS: We conducted a retrospective cohort study of all children requiring CRRT pre-OLT at a quaternary children's hospital from 2014 to 2022. Demographic characteristics, intraoperative events, and post-LT outcomes were compared between those who received iCRRT and those who did not. RESULTS: Out of 306 patients who received LT, 30 (10%) were supported with CRRT at least 24 h prior to LT, of which 11 (36%) received iCRRT. The two cohorts were similar in demographics, diagnosis of liver disease, and severity of illness. The iCRRT patients experienced massive blood loss and increased transfusion requirements. There was no difference in intraoperative metabolic balance. One-year post-LT mortality rates were similar. CONCLUSION: ICRRT is safe in critically ill children with pre-LT renal dysfunction. It optimizes fluid and blood product resuscitation while maintaining metabolic homeostasis. Candidates need to be carefully chosen for this highly resource-intensive therapy to benefit this fragile population.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

A novel risk score for predicting prolonged length of stay following pediatric kidney transplant.

BACKGROUND: Kidney transplants (KT) are accepted as the kidney replacement therapy of choice for children with kidney failure. The surgery itself may be more difficult especially in small children, and often leads to significant hospital stays. There is little research on predicting prolonged length of stay (LOS) in children. We aim to examine the factors associated with prolonged LOS following pediatric KT to help clinicians make informed decisions, better counsel families, and potentially reduce preventable causes of prolonged stay. METHODS: We retrospectively analyzed the United Network for Organ Sharing database for all KT recipients less than 18 years old between January 2014 and July 2022 (n = 3693). Donor and recipient factors were tested in univariate and multivariate logistic analysis using stepwise elimination of non-significant factors to create a final regression model predicting LOS longer than 14 days. Values were assigned to significant factors to create risk scores for each individual patient. RESULTS: In the final model, only primary diagnosis of focal segmental glomerulosclerosis, dialysis prior to KT, geographic region, and recipient weight prior to KT were significant predictors of LOS longer than 14 days. The C-statistic of the model is 0.7308. The C-statistic of the risk score is 0.7221. CONCLUSIONS: Knowledge of the risk factors affecting prolonged LOS following pediatric KT can help identify patients at risk of increased resource use and potential hospital-acquired complications. Using our index, we identified some of these specific risk factors and created a risk score that can stratify pediatric recipients into low, medium, or high risk groups. A higher resolution version of the Graphical abstract is available as Supplementary information.

Good outcomes after pediatric intraperitoneal kidney transplant.

BACKGROUND: Kidney transplantation in small children is technically challenging. Consideration of whether to use intraperitoneal versus extraperitoneal placement of the graft depends on patient size, clinical history, anatomy, and surgical preference. We report a large single-center experience of intraperitoneal kidney transplantation and their outcomes. METHODS: We conducted a retrospective review of pediatric patients who underwent kidney transplantation from April 2011 to March 2018 at a single large volume center. We identified those with intraperitoneal placement and assessed their outcomes, including graft and patient survival, rejection episodes, and surgical or non-surgical complications. RESULTS: Forty-six of 168 pediatric kidney transplants (27%) were placed intraperitoneally in children mean age 5.5 ± 2.3 years (range 1.6-10 years) with median body weight 18.2 ± 5 kg (range 11.4-28.6 kg) during the study period. Two patients (4%) had vascular complications; 10 (22%) had urologic complications requiring intervention; all retained graft function. Thirteen patients (28%) had prolonged post-operative ileus. Eight (17%) patients had rejection episodes ≤6 months post-transplant. Only one case resulted in graft loss and was associated with recurrent focal segmental glomerular sclerosis (FSGS). Two patients (4%) had chronic rejection and subsequent graft loss by 5-year follow-up. At 7-year follow-up, graft survival was 93% and patient survival was 98%. CONCLUSIONS: The intraperitoneal approach offers access to the great vessels, which allows greater inflow and outflow and more abdominal capacity for an adult donor kidney, which is beneficial in very small patients. Risk of graft failure and surgical complications were not increased when compared to other published data on pediatric kidney transplants.

Liver transplant in a recently COVID-19 positive child with hepatoblastoma.

We describe the successful pediatric liver transplant for unresectable hepatoblastoma in a 4-year-old male with COVID-19 prior to transplant. The first negative NP swab was documented 1 month after initial diagnosis, when SARS-CoV-2 antibodies were also detected. The patient was actively listed for liver transplant after completing four blocks of a SIOPEL-4 based regimen due to his PRETEXT IV disease which remained unresectable. Following three additional negative NP swabs and resolution of symptoms for 4 weeks, he underwent a whole-organ pediatric liver transplant. COVID-19 positivity determined via NP swab SARS-CoV-2 real-time RT-PCR (Hologic Aptima SARS-CoV-2 RT-PCR assay). IgG and IgM total SARS- CoV-2 antibodies detected by Ortho Clinical Diagnostics VITROS® Immunodiagnostics Products Anti-SARS-CoV-2 Test. Patient received standard prednisone and tacrolimus-based immunosuppression without induction therapy following transplant. Post-transplant course was remarkable for neutropenia and thrombocytopenia, with discharge home on post-transplant day #11. Surveillance tests have remained negative with persistent SARS-CoV-2 IgG antibodies at 6 weeks after transplant. We describe one of the earliest, if not the first case of liver transplant following recent recovery from COVID-19 in a pediatric patient with a lethal malignant liver tumor. A better understanding of how to balance the risk profile of transplant in the setting of COVID-19 with disease progression if transplant is not performed is needed. We followed existing ASTS guidelines to document clearance of the viral infection and resolution of symptoms before transplant. This case highlights that pediatric liver transplantation can be safely performed upon clearance of COVID-19.

The pediatric solid organ transplant experience with COVID-19: An initial multi-center, multi-organ case series.

The clinical course of COVID-19 in pediatric solid organ transplant recipients remains ambiguous. Though preliminary experiences with adult transplant recipients have been published, literature centered on the pediatric population is limited. We herein report a multi-center, multi-organ cohort analysis of COVID-19-positive transplant recipients ≤ 18 years at time of transplant. Data were collected via institutions' respective electronic medical record systems. Local review boards approved this cross-institutional study. Among 5 transplant centers, 26 patients (62% male) were reviewed with a median age of 8 years. Six were heart recipients, 8 kidney, 10 liver, and 2 lung. Presenting symptoms included cough (n = 12 (46%)), fever (n = 9 (35%)), dry/sore throat (n = 3 (12%)), rhinorrhea (n = 3 (12%)), anosmia (n = 2 (8%)), chest pain (n = 2 (8%)), diarrhea (n = 2 (8%)), dyspnea (n = 1 (4%)), and headache (n = 1 (4%)). Six patients (23%) were asymptomatic. No patient required supplemental oxygen, intubation, or ECMO. Eight patients (31%) were hospitalized at time of diagnosis, 3 of whom were already admitted for unrelated problems. Post-transplant immunosuppression was reduced for only 2 patients (8%). All symptomatic patients recovered within 7 days. Our multi-institutional experience suggests the prognoses of pediatric transplant recipients infected with COVID-19 may mirror those of immunocompetent children, with infrequent hospitalization and minimal treatment, if any, required.

Donor and transplant candidate selection for solid organ transplantation during the COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus responsible for a worldwide pandemic has forced drastic changes in medical practice in an alarmingly short period of time. Caregivers must modify their strategies as well as optimize the utilization of resources to ensure public and patient safety. For organ transplantation, in particular, the loss of lifesaving organs for transplantation could lead to increased waitlist mortality. The priority is to select uninfected donors to transplant uninfected recipients while maintaining safety for health care systems in the backdrop of a virulent pandemic. We do not yet have a standard approach to evaluating donors and recipients with possible SARS-CoV-2 infection. Our current communication shares a protocol for donor and transplant recipient selection during the coronavirus disease 2019 (COVID-19) pandemic to continue lifesaving solid organ transplantation for heart, lung, liver, and kidney recipients. The initial results using this protocol are presented here and meant to encourage dialogue between providers, offering ideas to improve safety in solid organ transplantation with limited health care resources. This protocol was created utilizing the guidelines of various organizations and from the clinical experience of the authors and will continue to evolve as more is understood about SARS-CoV-2 and how it affects organ donors and transplant recipients.

The decreasing predictive power of MELD in an era of changing etiology of liver disease.

The field of liver transplantation has shifted considerably in the MELD era, including changing allocation, immunosuppression, and liver failure etiologies, as well as better supportive therapies. Our aim was to evaluate the predictive accuracy of the MELD score over time. The United Network for Organ Sharing provided de-identified data on 120 156 patients listed for liver transplant from 2002-2016. The ability of the MELD score to predict 90-day mortality was evaluated by a concordance (C-) statistic and corroborated with competing risk analysis. The MELD score's concordance with 90-day mortality has downtrended from 0.80 in 2003 to 0.70 in 2015. While lab MELD scores at listing and transplant climbed in that interval, score at waitlist death remained steady near 35. Listing age increased from 50 to 54 years. HCV-positive status at listing dropped from 33 to 17%. The concordance of MELD and mortality does not differ with age (>60 = 0.73, <60 = 0.74), but is lower in diseases that are increasing most rapidly-alcoholic liver disease and non-alcoholic fatty liver disease-and higher in those that are declining, particularly in HCV-positive patients (HCV positive = 0.77; negative = 0.73). While MELD still predicts mortality, its accuracy has decreased; changing etiology of disease may contribute.

Intraoperative blood loss and transfusion during primary pediatric liver transplantation: A single-center experience.

Children undergoing liver transplantation are at a significant risk for intraoperative hemorrhage and thrombotic complications, we aim to identify novel risk factors for massive intraoperative blood loss and transfusion in PLT recipients and describe its impact on graft survival and hospital LOS. We reviewed all primary PLTs performed at our institution between September 2007 and September 2016. Data are presented as n (%) or median (interquartile range). EBL was standardized by weight. Massive EBL and MT were defined as greater than the 85th percentile of the cohort. 250 transplantations were performed during the study period. 38 (15%) recipients had massive EBL, and LOS was 31.5 (15-58) days compared to 11 (7-21) days among those without massive EBL (P < 0.001). MT median LOS was 34 (14-59) days compared to 11 (7-21) days among those without MT (P = 0.001). Upon backward stepwise regression, technical variant graft, operative time, and transfusion of FFP, platelet, and/or cryoprecipitate were significant independent risk factors for massive EBL and MT, while admission from home was a protective factor. Recipient weight was a significant independent risk factor for MT alone. Massive EBL and MT were not statistically significant for overall graft survival. MT was, however, a significant risk factor for 30-day graft loss. PLT recipients with massive EBL or MT had significantly longer LOS and increased 30-day graft loss in patients who required MT. We identified longer operative time and technical variant graft were significant independent risk factors for massive EBL and MT, while being admitted from home was a protective factor.

Cold ischemia time is an important risk factor for post-liver transplant prolonged length of stay.

Risk analysis of cold ischemia time (CIT) in liver transplantation has largely focused on patient and graft survival. Posttransplant length of stay is a sensitive marker of morbidity and cost. We hypothesize that CIT is a risk factor for posttransplant prolonged length of stay (PLOS) and aim to conduct an hour-by-hour analysis of CIT and PLOS. We retrospectively reviewed all adult, first-time liver transplants between March 2002 and September 2016 in the United Network for Organ Sharing database. The 67,426 recipients were categorized by hourly CIT increments. Multivariate logistic regression of PLOS (defined as >30 days), CIT groups, and an extensive list of confounding variables was performed. Linear regression between length of stay and CIT as continuous variables was also performed. CIT 1-6 hours was protective against PLOS, whereas CIT >7 hours was associated with increased odds for PLOS. The lowest odds for PLOS were observed with 1-2 hours (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.45-0.92) and 2-3 hours (OR, 0.65; 95% CI, 0.55-0.78) of CIT. OR for PLOS steadily increased with increasing CIT, reaching the greatest odds for PLOS with 13-14 hours (OR, 2.05; 95% CI, 1.57-2.67) and 15-16 hours (OR, 2.06; 95% CI, 1.27-3.33) of CIT. Linear regression revealed a positive correlation between length of stay and CIT with a correlation coefficient of +0.35 (P < 0.001). In conclusion, post-liver transplant length of stay is sensitive to CIT, with a substantial increase in the odds of PLOS observed with nearly every additional hour of cold ischemia. We conclude that CIT should be minimized to protect against the morbidity and cost associated with posttransplant PLOS. Liver Transplantation 24 762-768 2018 AASLD.

Are drowned donors marginal donors? A single pediatric center experience.

Drowning, a common cause of death in the pediatric population, is a potentially large donor pool for OLT. Anecdotally, transplant centers have deemed these organs high risk over concerns for infection and graft dysfunction. We theorized drowned donor liver allografts do not portend worse outcomes and therefore should not be excluded from the donation pool. We reviewed our single-center experience of pediatric OLTs between 1988 and 2015 and identified 33 drowned donor recipients. These OLTs were matched 1:2 to head trauma donor OLTs from our center. A chart review assessed postoperative peak AST and ALT, incidence of HAT, graft and recipient survival. Recipient survival at one year between patients with drowned donor vs head trauma donor allografts was not statistically significant (94% vs 97%, P=.63). HAT incidence was 6.1% in the drowned donor group vs 7.6% in the control group (P=.78). Mean postoperative peak AST and ALT was 683 U/L and 450 U/L for drowned donors vs 1119 U/L and 828 U/L in the matched cohort. These results suggest drowned donor liver allografts do not portend worse outcomes in comparison with those procured from head trauma donors.

Portosystemic shunt as a bridge to liver transplantation in infants: A comparison of two techniques.

Portosystemic shunts can serve as a bridge to liver transplantation in patients with end-stage liver disease by providing portal decompression to treat life-threatening variceal bleeding and prevent recurrent episodes until an organ becomes available. The conventional TIPS procedure, however, is technically challenging to perform in infants due to the small size of their intrahepatic vasculature. We report two cases of emergent creation of portosystemic shunts as a bridge to liver transplantation in infants with life-threatening variceal bleeding using a conventional TIPS technique in the first case and a percutaneous DIPS technique in the other. Both procedures were successful at reducing the portosystemic pressure gradient and preventing further variceal bleeds until a liver transplant could be performed. The novel percutaneous DIPS procedure is a valuable alternative to the conventional TIPS in infants, as it is better suited for small or challenging intrahepatic vascular anatomy.

Poor outcomes for children on the wait list at low-volume kidney transplant centers in the United States.

BACKGROUND: Low case volume has been associated with worse survival outcomes in solid organ transplantation. Our aim was to analyze wait-list outcomes in conjunction with posttransplant outcomes. METHODS: We studied a cohort of 11,488 candidates waitlisted in the Organ Procurement and Transplantation Network (OPTN) for pediatric kidney transplant between 2002 and 2014, including both deceased- and living-donor transplants; 8757 (76 %) candidates received a transplant. Candidates were divided into four groups according to the average volume of yearly transplants performed in the listing center over a 12-year period: more than ten, six to nine, three to five, and fewer than three. We used multivariate Cox regression analysis to identify independent risk factors for wait list and posttransplant mortality. RESULTS: Twenty-seven percent of candidates were listed at low-volume centers in which fewer than three transplants were performed annually. These candidates had a limited transplant rate; only 49 % received a transplant versus 88 % in high-volume centers (more than ten transplants annually) (p < 0.001). Being listed at a low-volume center showed a fourfold increased risk for death while on the wait list [hazard ratio (HR) 4.0 in multivariate Cox regression and 6.1 in multivariate competing risk regression]. It was not a significant risk factor for posttransplant death in multivariate Cox regression. CONCLUSIONS: Pediatric transplant candidates are listed at low-volume transplant centers are transplanted less frequently and have a much greater risk of dying while on the wait list. Further studies are needed to elucidate the reasons behind the significant outcome differences.

Pediatric Acute Liver Failure Secondary to Autoimmune Hepatitis in an Infant With Thrombocytopenia-Absent Radius (TAR) Syndrome: A Case Report.

Thrombocytopenia absent radius (TAR) syndrome is a rare genetic disorder that has been associated with food protein-induced allergic proctocolitis and transient leukemoid reactions, among other manifestations. There has been no prior reports of its association with autoimmune disease, more specifically, autoimmune hepatitis (AIH) or the development of pediatric acute liver failure (PALF). We present a case of an 8-month-old infant with TAR syndrome who presented with PALF, secondary to AIH with elevated liver-kidney microsomal antibody (>1:2560). She received a liver transplant and had a very complicated postoperative course including severe T-cell-mediated rejection, infection, biliary stricture, persistently elevated liver-kidney microsomal antibodies, and antibody-mediated rejection. Ultimately, these complications led to graft failure, severe sepsis, and death. This case highlights a new association of TAR syndrome with AIH and PALF and a potentially aggressive nature of AIH both pre- and post-transplant.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma.

OBJECTIVE: To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence. BACKGROUND: Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver. METHODS: We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed. RESULTS: A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence. CONCLUSIONS: Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered. LEVEL OF EVIDENCE: III.

COVID-19 Vaccine Efficacy and Immunogenicity in End-Stage Renal Disease Patients and Kidney Transplant Recipients.

Purpose of Review: To summarize the current literature with respect to COVID-19 vaccine efficacy patients with end-stage renal disease on dialysis and kidney transplant recipients. Recent Findings: Immunosuppressed patients are at greater risk of morbidity and mortality from COVID-19 infection. Patients with ESRD and KTR are immunosuppressed and mount a weaker antibody response to COVID-19 mRNA vaccination, and factors including immunosuppressant medications have been implicated for this weakened response. Third and fourth doses of vaccine doses have been shown to increase seropositivity and antibody production in kidney transplant recipients and patients on dialysis. Retrospective studies have demonstrated decreased mortality in vaccinated, immunosuppressed patients. Summary: ESRD and KTR patients have decreased antibody response to COVID-19 vaccines, but third and fourth doses have been shown to increase antibody production. Though a correlate of protection between antibody production and efficacy has yet to be fully established in this subset of the population, all US professional bodies who treat ESRD and KTR patients advocate for full vaccination against SARS-CoV-2 based on the data available. Studies demonstrating decreased mortality in vaccinated patients are promising on efficacy. Importantly, because KTR patients mount a weaker antibody response than ESRD patients, vaccination prior to kidney transplantation is critical.

Management of Acute Portal Vein Thrombosis With Serial Mechanical Thrombectomy and tPA in a Pediatric Liver Transplant Recipient: A Case Report.

BACKGROUND: Acute portal vein thrombosis is a major cause of fulminant allograft failure in pediatric liver transplantation. Timely intervention is critical to save the graft and patient. Serial interventional radiologic management of this condition is scarcely reported in the literature. CASE SUMMARY: A recently transplanted 17-year-old male presented to the emergency department with abdominal pain. Rising liver enzymes prompted discovery of a diffuse portal thrombus, which precipitated fulminant liver failure. The adolescent developed respiratory failure, vasodilatory shock, acute kidney injury, and hepatic encephalopathy, complicating treatment. Multiple interventions attempted to clear the thrombus, including interventional radiologic and medical therapies. Uniquely, a continuous infusion catheter was placed at the thrombosis, delivering local tissue plasminogen activator during a 5-day period. Upon thrombus clearance, the patient made a full recovery with no complications during 12 months of follow-up. CONCLUSIONS: When used as a component of multidisciplinary management, continuous locally directed tissue plasminogen activator may be a useful tool for clearance of persistent portal vein thrombosis.