Left Ventricular Assist Device Graft Obstruction Relieved by Transcutaneous Stenting in a Teenage Patient

Abstract

<h3>Introduction</h3> We describe a case of LVAD outflow graft stenosis from external outflow graft compression in a teenage patient successfully treated with percutaneous stenting. <h3>Case Report</h3> 17-year-old female with a continuous flow left ventricular assist device implanted 3 years prior for heart failure secondary to cardiomyopathy due to a TTN gene mutation. She presented with 1 week of worsening shortness of breath and 3 kilogram weight gain. LVAD flows were 3 liters-per-minute (L/min). The patient was referred for transcatheter stent therapy due to concern for outflow cannula obstruction. Hemodynamics during initial catheterization showed a gradient of 30 mmHg across the conduit. A stent was deployed in the distal aspect of the outflow cannula. A second stent was placed to reinforce the area of persistent stenosis. Post-intervention hemodynamics showed an improvement in the gradient to 13 mmHg. She re-presented 3 months later due to LVAD low flow alarm, decreased flows to 0.3 L/min, and decreased wattage of 2.9 watts (Figure 1). CT angiography (CTA) demonstrated 80% narrowing of the outflow conduit, proximal to previously placed outflow graft stents (Figure 2a-b). Low density material between the outflow graft and circumferential wrap was identified by radiology. The previously placed stents were first re-dilated. Three additional stents were placed within the LVAD outflow cannula. We placed the stents from aortic end toward LVAD inflow. In total, the outflow graft was stented for a length of approximately 7.5cm (Figure 3). Angiography showed mild residual narrowing at the anastomotic site. LVAD flows improved to 3.5L/min. Repeat CTA showed no residual evidence of stenosis. <h3>Summary</h3> To our knowledge this is the first reported case of external compression of an LVAD outflow graft from an overwrap treated with successful transcatheter stent treatment in the pediatric population. By stenting the outflow graft we believe we pushed the built-up material into the mediastinum, relieving the obstruction.