Bilateral lung transplantation for pediatric pulmonary arterial hypertension: perioperative management and one-year follow-up

Abstract

Background: Bilateral lung transplantation (LuTx) remains the only established treatment for children with end-stage pulmonary arterial hypertension (PAH). Although PAH is the second most common indication for LuTx, little is known about optimal perioperative management and midterm clinical outcomes.

Methods: Prospective observational study on consecutive children with PAH who underwent LuTx with scheduled postoperative VA-ECMO support at Hannover Medical School from December 2013 to June 2020.

Results: Twelve patients with PAH underwent LuTx (mean age 11.9 years; age range 1.9-17.8). Underlying diagnoses included idiopathic (n = 4) or heritable PAH (n = 4), PAH associated with congenital heart disease (n = 2), pulmonary veno-occlusive disease (n = 1), and pulmonary capillary hemangiomatosis (n = 1). The mean waiting time was 58.5 days (range 1-220d). Three patients were bridged to LuTx on VA-ECMO. Intraoperative VA-ECMO/cardiopulmonary bypass was applied and VA-ECMO was continued postoperatively in all patients (mean ECMO-duration 185 h; range 73-363 h; early extubation). The median postoperative ventilation time was 28 h (range 17-145 h). Echocardiographic conventional and strain analysis showed that 12 months after LuTx, all patients had normal biventricular systolic function. All PAH patients are alive 2 years after LuTx (median follow-up 53 months, range 26-104 months).

Conclusion: LuTx in children with end-stage PAH resulted in excellent midterm outcomes (100% survival 2 years post-LuTx). Postoperative VA-ECMO facilitates early extubation with rapid gain of allograft function and sustained biventricular reverse-remodeling and systolic function after RV pressure unloading and LV volume loading.

Keywords: awake ECMO; children; extracorporeal membrane oxygenation (ECMO); lung transplantation; pediatric; pulmonary arterial hypertension.

Figure 1

Schematic treatment and weaning algorithm of VA-ECMO treatment after LuTx. All patients were treated according to this interdisciplinary, in-house consensus standard. ECMO, extracorporeal membrane oxygenation; d, day; LuTx, lung transplantation.

Figure 2

VA-ECMO duration and length of invasive mechanical ventilation pre/post-LuTx. VA-ECMO duration pre- and post-LuTx (in hours; blue) and time on respirator pre-ECMO and on-ECMO (in hours; green) are shown. VA-ECMO, veno-arterial extracorporeal membrane oxygenation; h, hours; LuTx, lung transplantation.

Figure 3

Results of right ventricular strain and strain rate, as well as TAPSE and RV end-systolic remodeling index analysis pre- and post-LuTx. The time points of echocardiography were prior to LuTx (range 0–75 days) and approximately 12 months (range 11–29 months) post-LuTx. The paired two-tailed t-test was used. *p < 0.05; **p < 0.01; ****p < 0.0001, n = 5 (A–H), n = 12 (I,J). (A, C, E, G) show the individual changes of each patient pre and post-LuTx. The box and whisker plots (third column) show the median, IQR, and 10–90th percentile. The scatter plots (fourth column) show the 95% confidence interval for the median. RV, right ventricle; RV 4CSL, RV 4-chamber longitudinal strain; RVES RI, right ventricular end-systolic remodeling index; TAPSE, tricuspid annular plane systolic excursion.

Figure 4

Lung function course of patients with PAH pre- and post-LuTx. Patient #5 was too young to perform spirometry pre-LuTx and during year one post-LuTx. Patient #12 was unable to perform spirometry pre-LuTx. Post-Tx FEV1-Baseline value is computed as the mean of the best two postoperative FEV1 measurements taken >3 months apart to define CLAD starting >3 months post-LuTx. FEV1 >80% of baseline defines the stage CLAD0 (Verleden et al. J Heart Lung Transplant. 2019; 38:493–503. doi: 10.1016/j.healun.2019.03.009) (19). FEV1, forced expiratory volume in 1 s; LuTx, lung transplantation; pp, percent predicted [reference values are taken from Quanjer PH et al. Eur Respir J. 2012 Dec;40(6):1324–43. doi: 10.1183/09031936.00080312] (37).