Minimally Invasive Exchange of the HeartMate 2 (HM2) Left Ventricular Assist Device (LVAD) to HeartWare Ventricular Assist Device (HVAD) or HeartMate 3 (HM3)

Abstract

Purpose Exchange of the HM2 LVAD may be necessary for pump thrombosis, malfunction, or infection. We describe a novel minimally invasive technique for exchange of HM2 to the new generation intrapericardial pumps, HVAD or HM3, and present our clinical experience with this technique. Methods Retrospective data of patients who underwent exchange of HM2 to HVAD or HM3 since June 2014 were reviewed. Patient characteristics, operative outcomes, and post-operative complications were compiled. Kaplan-Meier methodology was used to analyze survival following pump exchange. Results The study included 13 patients. The average age was 60 years. Indications for exchange were recurrent thrombosis in a second HM2 (12) and infection (1). All cases were done on cardiopulmonary bypass (CPB) with femoral cannulation. Surgical approach was via a left subcostal incision and left anterior thoracotomy in all cases and additional sternotomy in one case. Outflow graft-to-graft anastomosis was done in the subcostal incision. The new device was inserted in the previous apical ventriculotomy after removal of the HM2 inflow cannula. Mean duration of support on the second HM2 pump was 656 days. The mean CPB and surgical times were 112 and 291 minutes, respectively. Mean ICU and hospital lengths of stay were 7 and 16 days, respectively. 30-day post-op survival was 92% with 1 death on day 24 from sepsis. There was 1 re-operation for post-op bleed, 2 wound infections, and 2 cases of right ventricular insufficiency. No neurological events or recurrent pump thrombosis were reported. Mean survival at 1, 2, and 3 years was 69%, 40%, and 40%, respectively. Conclusion Exchange of the HM2 to new generation intrapericardial pumps may be indicated in cases of recurrent pump thrombosis, inflow cannula malposition, or device infection. This can be accomplished by a minimally invasive approach with a low surgical mortality and excellent long-term outcomes.