Preemptive Venoarterial Extracorporeal Membrane Oxygenation for Liver Transplantation-Judicious Candidate Selection

Portopulmonary hypertension is a relatively common pathologic condition in patients with end-stage liver disease. Traditionally, severe pulmonary hypertension is regarded as a contraindication to liver transplantation (LT) due to a high perioperative mortality rate. Recently, extracorporeal membrane oxygenation (ECMO) has been utilized for intraoperative management of LT. As venoarterial (VA) ECMO may benefit certain high-risk LT patients by reducing the ventricular workload by the equivalent of the programmed flow rate, its usage requires multidisciplinary planning with considerations of the associated complications. We highlighted two cases at our single-center institution as examples of high-risk pulmonary hypertension patients undergoing LT on planned VA ECMO. These patients both survived the intraoperative period; however, they had drastically different postoperative outcomes, generating discussions on the importance of judicious patient selection. Since ECMO has removed the barrier of intraoperative survivability, the patient selection process may need to put weight on the patient's potential for postoperative recovery and rehabilitation. Considerations on LT recipients undergoing preemptive ECMO need to expand from the ability of the patients to withstand the demands of the surgery during the immediate perioperative period to the long-term postoperative recovery course.

Efficacy and safety of prolonged-release tacrolimus in stable pediatric allograft recipients converted from immediate-release tacrolimus - a Phase 2, open-label, single-arm, one-way crossover study

There are limited clinical data regarding prolonged‐release tacrolimus (PR‐T) use in pediatric transplant recipients. This Phase 2 study assessed the efficacy and safety of PR‐T in stable pediatric kidney, liver, and heart transplant recipients (aged ≥5 to ≤16 years) over 1 year following conversion from immediate‐release tacrolimus (IR‐T), on a 1:1 mg total‐daily‐dose basis. Endpoints included the incidence of acute rejection (AR), a composite endpoint of efficacy failure (death, graft loss, biopsy‐confirmed AR, and unknown outcome), and safety. Tacrolimus dose and whole‐blood trough levels (target 3.5–15 ng/ml) were also evaluated. Overall, 79 patients (kidney, n = 48; liver, n = 29; heart, n = 2) were assessed. Following conversion, tacrolimus dose and trough levels remained stable; however, 7.6–17.7% of patients across follow‐up visits had trough levels below the target range. Two (2.5%) patients had AR, and 3 (3.8%) had efficacy failure. No graft loss or deaths were reported. No new safety signals were identified. Drug‐related treatment‐emergent adverse events occurred in 28 patients (35.4%); most were mild, and all resolved. This study suggests that IR‐T to PR‐T conversion is effective and well tolerated over 1 year in pediatric transplant recipients and highlights the importance of therapeutic drug monitoring to maintain target tacrolimus trough levels.