Novel Bridge to Recovery: Right Ventricular Assist Device for Primary Graft Dysfunction in Pediatric Lung Transplantation

Introduction Primary graft dysfunction (PGD) is an early complication after lung transplantation (LTx). Extracorporeal membrane oxygenation (ECMO) is used for rescue of refractory hypoxemia due to severe PGD, although ventricular assist device support in PGD after LTx is less well documented. Case Report A 9 year old boy with Trisomy 21 underwent bilateral LTx for severe pulmonary arterial hypertension (PAH). Mean PA pressure was 73 mmHg, with a hypertrophied right ventricle (RV) and mild-moderately reduced RV function. He was transplanted with size matched lungs, blood type O- into O+. No HLA antibodies were identified. Marked vasoplegia was seen 8 hours post-operatively. Chest x-ray showed interstitial markings consistent with PGD. At 36 hours, P/F ratio had dropped to 59. Systemic inflammatory response (SIRS) and RV dysfunction resulted in acute kidney injury with Cr 256 µmol/L and hepatic dysfunction with ALT > 4,600. At 40 hours, right ventricular assist device (RVAD) with oxygenator was placed via central cannulation to the main PA and right atrium (RA). Peripheral sites were not available due to prior ECMO. Stenosis was seen of the right upper pulmonary vein. Oxygenation, lung aeration, and biochemical markers improved over 11 days after which he was weaned from RVAD and decannulated. At 8 months post-LTx, he is doing well. Graft function is excellent with most recent FEV1 at 71% predicted, versus 37% pre-transplant. Acute kidney injury has resolved and liver function has returned to normal. Summary This case presents a novel successful approach in providing bridge to recovery for PGD after LTx and RV dysfunction in a pediatric patient with Down syndrome. This was a unique scenario with no peripheral cannulation access, RV systolic and diastolic dysfunction, and multi-system sequelae. Central cannulation (RA-PA) with RVAD/oxygenator allowed adequate support for the PGD to clear. To our knowledge, this is the first publication on RVAD/oxygenator use in pediatric lung PGD. This also documents the first patient with Down syndrome to receive a bilateral LTx in Canada. It is unclear if Down syndrome-related factors increased the risk for PGD; PV stenosis and SIRS may have played a role. Note that RA to aortic cannulation is not advised due to the need to maintain flow to the PAs, since there is no longer bronchial circulation supplying the lungs after transplant.