LAUSR

Introduction Left ventricular assist device (LVAD) outflow graft obstruction is a well-known and significant complication. The typical management involves treatment of presumed thrombosis of the graft with intensified anticoagulation or surgery. More recently, endovascular stenting has been reported as a possible treatment option. We describe the management of a LVAD outflow cannula obstruction with never reported intravascular ultrasound (IVUS)-guided covered endovascular stenting. Case report A 68 year-old female with non-ischemic cardiomyopathy status-post LVAD implantation in March 2016 presented with persistent symptomatic low flow alarms and clinical signs of heart failure. Symptoms seemed to worsen when she laid on her right side. She was compliant with her anticoagulation and lactate dehydrogenase level was found to be near her baseline. A CT scan with IV contrast revealed intraluminal obstruction of the LVAD outflow graft secondary to a kinked portion of the outflow cannula near the bend relief with a possible thrombotic component. The severe angulation of the cannula likely developed due to the patient's gradual weight gain of 28kg in the 24 months since LVAD implantation. Given the patient's risk profile, a percutaneous endovascular stenting approach was taken. IVUS was used to visualize the obstruction and kinking of the graft. A balloon-expandable covered stent was deployed at the stenotic site while the LVAD was briefly stopped to avoid stent/balloon migration. A covered stent was used to minimize the risk of thrombus migration/extrusion. IVUS was used again after post-dilation of the stent to confirm placement with no thrombus extrusion. Several hours later the patient had recurrent low-flow alarms. A repeat CT scan revealed that the kink had migrated and been transmitted within the outflow cannula towards the LVAD. The patient returned to the angiography suite where 2 balloon expandable stents were deployed more proximally within the outflow cannula and in an overlapping fashion with the original covered stent. Non-covered stents were used for the second procedure as there was no suspected thrombotic component. IVUS showed no significant residual kinking post-stenting. This was confirmed with a repeat CT scan. The patient recovered without any hemodynamic or neurologic sequelae. Conclusion Percutaneous endovascular stenting is an emerging option for treatment of outflow tract obstruction in LVAD patients that are not candidates for surgery. IVUS can be a valuable tool during intervention to confirm proper stent position, thrombus isolation, and outflow cannula geometry.