Our evolution in the treatment of hepatic artery and portal vein thrombosis in pediatric liver transplantation: Success with catheter-directed therapies.

BACKGROUND: In pediatric liver transplant recipients, hepatic artery thrombosis and portal vein thrombosis are major causes of acute graft failure and mortality within 30 days of transplantation. There is, however, a strong possibility of graft salvage if flow can be re-established to reduce ischemic injury. The current standard treatment is surgical revascularization, and if unsuccessful, retransplantation. Due to our success in treating these complications with catheter-directed therapies, we sought to summarize and publish the outcomes of all patients who experienced hepatic artery thrombosis or portal vein thrombosis within 30 days of liver transplantation. METHODS: We conducted a retrospective cohort analysis of 27 pediatric liver transplant recipients who experienced hepatic artery thrombosis (n = 13), portal vein thrombosis (n = 9), or both (n = 5) between September 2012 and March 2021. We collected and tabulated data on the patients and therapies performed to treat them, including success rates, primary and secondary patency, and clinical outcomes. RESULTS: Among these patients, 6 were managed with anticoagulation and relisting for transplant and 21 had a primary revascularization attempt. Surgical recanalization was attempted in 7 patients of which 3 had successful recanalization (43%) and catheter-directed recanalization was attempted in 14 patients with 100% success in re-establishing blood flow to the graft. Additionally, patency was increased, and mortality was decreased in patients treated with catheter-directed recanalization compared to surgical revascularization or anticoagulation alone. CONCLUSION: This data illustrates the need to further investigate catheter-directed thrombolysis as a potential first-line treatment for postoperative HAT and PVT in pediatric liver transplant recipients.

A new chapter in an evolving pandemic: Successful pediatric liver transplantation with SARS-CoV-2+ donors.

BACKGROUND: Amid a viral pandemic with poorly understood transmissibility and pathogenicity in the pediatric patient, we report the first pediatric liver transplants utilizing allografts from SARS-CoV-2+ donors. METHODS: We describe the outcomes of two pediatric liver transplant recipients who received organs from SARS-CoV-2 nucleic acid test-positive (NAT+) donors. Data were obtained through the respective electronic medical record system and UNet DonorNet platform. RESULTS: The first donor was a 3-year-old boy succumbing to head trauma. One of four nasopharyngeal (NP) swabs and 1 of 3 bronchoalveolar lavage (BAL) NAT tests demonstrated SARS-CoV-2 infection before organ procurement. The second donor was a 16-month-old boy with cardiopulmonary arrest of unknown etiology. Three NAT tests (2 NP swab/1 BAL) prior to procurement failed to detect SARS-CoV-2. The diagnosis was made when the medical examiner repeated 2 NP swab NATs and an archive plasma NAT, all positive for SARS-CoV-2. Both 2-year-old recipients continue to do well 8 months post-transplant, with excellent graft function and no evidence of SARS-CoV-2 transmission. CONCLUSIONS: This is the first report to describe successful pediatric liver transplantation from SARS-CoV-2+ donors. These data reinforce the adult transplant experience and support the judicious use of SARS-CoV-2+ donors for liver transplantation in children. With SARS-CoV-2 becoming endemic, the concern for donor-derived viral transmission must now be weighed against the realized benefit of life-saving transplantation in the pediatric population as we continue to work toward donor pool maximization.

Multisystem inflammatory syndrome in children associated with SARS-CoV-2 in a solid organ transplant recipient.

We present the case of a 3-year-old female liver transplant recipient with a history of Caroli disease who presented with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction (RT-PCR) test and was ultimately diagnosed with multisystem inflammatory syndrome in children (MIS-C) complicated by portal vein thrombosis. To the best of our knowledge, this is the first case report of MIS-C in a pediatric solid organ transplant (SOT) recipient. Based on our patient, MIS-C could be a potential complication of Coronavirus disease 2019 (COVID-19) in SOT recipients and may have a negative outcome on transplant graft function.

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.

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.

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.