Approaches to Repairing Outflow Graft Stenosis in Left Ventricular Assist Devices

Abstract

Purpose Durable Left Ventricular Assist Devices (LVAD) are typically implanted with an inflow cannula in the LV apex and an outflow graft anastomosed to the aorta. We describe 4 pts who experienced clinically significant outflow graft stenosis requiring intervention, an underreported but likely increasingly common complication in pts on long term support with a VAD. Methods A retrospective review of our VAD database was performed on pts implanted with a durable VAD at our institution from 2011-2018. Results Four pts were found to have stenosis of the outflow graft confirmed by CT angiogram (Figure). Each of the pts presented with symptoms of acute on chronic LV failure with a decrease in VAD flows, prompting the diagnostic evaluation. The pre-VAD etiology of heart failure was nonischemic cardiomyopathy for 3 pts and transposition of the great arteries with VAD implanted into the systemic ventricle in the 4thpatient. Mean time from implant to diagnosing the stenosis was 722 days. In all pts the cause of the stenosis was external compression from accumulation of fluid or hematoma between the gore-tex applied at the time of implant and the outflow graft. The stenosis was focal in three and diffuse in one pt. Two of the pts were successfully treated with stenting of the outflow graft and one pt was taken for surgical release of the gore-tex. In the 4thpt, the stenosis was an incidental finding as we diagnosed acute thrombus ingestion into the inflow cannula which resolved with thrombolytics. All pts experienced an immediate increase in >2L of VAD flow following each, respective, intervention. Conclusion Outflow graft stenosis in VADs is a serious complication that can lead to decompensated heart failure, the cause of which may be external compression related to gore-tex around the graft. This complication should be included in the differential diagnosis of a drop in VAD flows, and while treatable, should prompt a reassessment of how gore-tex is applied (if at all) at the time of implant.