LVAD Outflow Graft Stenosis

Abstract

Introduction Left Ventricular Assist Device (LVAD) outflow graft obstruction is a known long-term complication, etiologies for obstruction include thrombosis, kinking as well as external compression. Here we present a clinical case presenting with low LVAD flows due to external compression of the outflow graft with marked improvement after surgical intervention. Case Report A 60-year-old woman with chronic systolic heart failure secondary to non-ischemic cardiomyopathy with a HeartWare LVAD implanted 2018 presented with one month of low flows prior to admission. She was in atrial fibrillation (AF) with rapid ventricular response and volume overloaded. Despite AF rhythm control and volume optimization, flows never returned to prior baseline (Figure A). Gated cardiac CT demonstrated narrowing within the bend relief down to 3.7mm. During an echo guided ramp study aortic valve opening frequency decreased only minimally with speed up titration with slight improvement in flows. Ventriculography was significant for narrowing of the proximal outflow graft with most contrast exiting through LVOT, however, a kink in the outflow tract vs external compression could not be distinguished (Figure B). Percutaneous stenting was deemed to be too high-risk due to the proximity to the rotor blade. In the OR, fibrinous tissue between the outflow graft and the externally reinforced goretex graft covering the strain relief was identified. Via a limited left subcostal incision, the goretex graft was sharply opened from distal end to proximal end resulting in immediate LVAD flow normalization (Figures C and D). The patient discharged home on post-operative day 5. Summary Mechanical LVAD outflow graft obstructions can be catastrophic and addressing its causes requires a multidisciplinary approach. Here we present a case where a symptomatic, mechanical outflow graft obstruction was identified via multimodal imaging. The mechanical obstruction was ultimately amendable to a minimally invasive surgical approach and avoided pump exchange or even cardiac transplant. Left Ventricular Assist Device (LVAD) outflow graft obstruction is a known long-term complication, etiologies for obstruction include thrombosis, kinking as well as external compression. Here we present a clinical case presenting with low LVAD flows due to external compression of the outflow graft with marked improvement after surgical intervention. A 60-year-old woman with chronic systolic heart failure secondary to non-ischemic cardiomyopathy with a HeartWare LVAD implanted 2018 presented with one month of low flows prior to admission. She was in atrial fibrillation (AF) with rapid ventricular response and volume overloaded. Despite AF rhythm control and volume optimization, flows never returned to prior baseline (Figure A). Gated cardiac CT demonstrated narrowing within the bend relief down to 3.7mm. During an echo guided ramp study aortic valve opening frequency decreased only minimally with speed up titration with slight improvement in flows. Ventriculography was significant for narrowing of the proximal outflow graft with most contrast exiting through LVOT, however, a kink in the outflow tract vs external compression could not be distinguished (Figure B). Percutaneous stenting was deemed to be too high-risk due to the proximity to the rotor blade. In the OR, fibrinous tissue between the outflow graft and the externally reinforced goretex graft covering the strain relief was identified. Via a limited left subcostal incision, the goretex graft was sharply opened from distal end to proximal end resulting in immediate LVAD flow normalization (Figures C and D). The patient discharged home on post-operative day 5. Mechanical LVAD outflow graft obstructions can be catastrophic and addressing its causes requires a multidisciplinary approach. Here we present a case where a symptomatic, mechanical outflow graft obstruction was identified via multimodal imaging. The mechanical obstruction was ultimately amendable to a minimally invasive surgical approach and avoided pump exchange or even cardiac transplant.