Biomaterial-Related External Outflow Graft Obstruction in HeartMate 3 Left Ventricular Assist Device: A Single-Center Case Series

HeartMate 3 (HM3) left ventricular assist devices (LVADs) have improved hemocompatibility and reduced morbidity; however, late device-related complications continue to be recognized. External outflow graft obstruction at the bend relief region (EOGO-BR) is an uncommon but potentially life-threatening condition, and data regarding its diagnosis and management remain limited. Three symptomatic male patients with biomaterial-related EOGO-BR following HM3 implantation were retrospectively reviewed. Clinical presentation, diagnostic imaging, surgical management, and outcomes were evaluated. All patients presented with low-flow alarms associated with heart failure symptoms, including dyspnea, fatigue, and reduced exercise tolerance. Computed tomography angiography (CTA) demonstrated external compression of the outflow graft in all cases and was the primary diagnostic modality. Surgical evacuation of accumulated biomaterial via left thoracotomy resulted in immediate restoration of LVAD flow in all patients. Two patients showed favorable postoperative recovery with sustained clinical improvement during follow-up. One patient, who presented with concomitant sepsis, died despite surgical intervention and advanced mechanical circulatory support. External outflow graft obstruction at the bend relief region represents an uncommon but serious late complication of HM3 LVAD support. Computed tomography angiography is a valuable diagnostic tool for timely identification. Surgical removal of accumulated biomaterial provides immediate hemodynamic improvement and appears to be an effective and durable treatment strategy in selected patients.