Mechanical Circulatory Support During Lung Transplantation: Choices, Outcomes and Impact of Duration

Abstract

<h3>Purpose</h3> Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has recently replaced cardiopulmonary bypass (CPB) as the method of choice for mechanical circulatory support during lung transplantation (LTx). The aim of this study was to compare the outcomes of using ECMO versus CPB and examine the impact of its duration in a contemporary LTx cohort. <h3>Methods</h3> Between January 2017, and January 2020, 379 LTx were performed at our center. CPB was utilized in 111 and VA ECMO in 33 cases (unmatched cohort). After exclusion of patients who underwent concomitant cardiac procedures or retransplantation (all were in CPB group), the 33 VA ECMO patients were matched to CPB patients with a 1:2 ratio based on primary diagnosis, LTx type (bilateral or single), age, lung allocation score, body mass index, donor type (brain death or cardiac death), and duration of mechanical circulatory support. <h3>Results</h3> In the unmatched cohort, CPB group had a significantly higher incidence of re-exploration for bleeding and hospital mortality compared to ECMO group (15.3% vs 3.0%, <b>p = .047</b>; 10.8% vs 0%, <b>p = .038</b>, respectively). There were no statistically significant differences between CPB and ECMO groups in ICU stay, hospital stay, incidence of primary graft dysfunction (PGD) at 72 hours, postoperative tracheostomy, post-transplant ECMO use, re-admission, or 1-year survival. In the matched cohort, the differences between CPB and ECMO groups in both incidence of re-exploration for bleeding or hospital mortality were found to be statistically insignificant (13.6% vs 3.0%, <i>p</i> = .092; 7.6% vs 0%, <i>p</i> = .125, respectively). The differences between both groups in the other outcome endpoints remained insignificant. In the CPB group, patients with higher grades of PGD at 72 hours had significantly longer duration of CPB (PGD 0, 1, 2, 3 median 217, 209, 250, 289 minutes, <b>p = .014</b>, respectively). In the ECMO group, there were no differences in duration of ECMO between patients with different PGD grades. <h3>Conclusion</h3> Despite having a significantly higher incidence of re-exploration for bleeding and hospital mortality in CPB group in the unmatched cohort, there were no statistically significant differences between the two groups in the studied outcomes in the matched cohort, although there were strong trends. Notably, longer CPB time was associated with higher PGD grades whereas time on ECMO was not associated with PGD grades.