Obstruction within the circuit of a left ventricular assist device (LVAD) is a challenging situation for clinicians to definitively diagnose and manage. Available diagnostic tools are limited in their ability to visualize large portions within the device and cannulas, often leading to uncertainty as to whether redo surgery is required or if there are feasible medical or percutaneous alternatives. Here, we report a case of LVAD outflow graft obstruction, which by computed tomographic angiography (CTA) appeared to be intramural thrombus, but by intravascular ultrasound (IVUS) was shown to be compression external to the graft.

A 62-year-old female with a continuous flow LVAD (HeartMate II Abbott, IL) 5 years prior presented to the emergency department with frequent low-flow alarms and syncope. The patient’s post-LVAD course had been complicated by outflow graft infection 1 year after initial implantation, necessitating an outflow graft replacement. She had also experienced multiple bleeding events for which her warfarin therapeutic goal was lowered.

In the preceding year, her LVAD flows had steadily declined from 4.5 to 5.0 L/min to 2.7 to 2.8 L/min with an increasing frequency of low-flow alarms not responsive to the intravenous fluid administration or changes in LVAD …

左心室辅助设备（LVAD）回路内的阻塞对于临床医生进行明确的诊断和管理是一个挑战性的情况。可用的诊断工具在可视化设备和插管中大部分的能力上受到限制，通常导致不确定是否需要重做手术或是否存在可行的医学或经皮替代疗法。在这里，我们报道一例LVAD流出物梗阻，通过计算机断层血管造影（CTA）似乎是壁内血栓，但通过血管内超声（IVUS）显示出在移植物外部受压。

一名5岁之前连续流LVAD（伊利诺伊州伊利诺伊州阿特伯特，HeartMate II）的62岁女性因频繁出现低流量警报和晕厥而被送往急诊科。初次植入后1年，患者的LVAD病程复杂，并伴有流出物移植感染，因此必须更换流出物。她还经历了多次出血事件，因此降低了华法林的治疗目标。

在前一年中，由于对静脉输液或LVAD变化无反应的低流量警报频率增加，她的LVAD流量从4.5升至5.0 L / min稳步下降至2.7升至2.8 L / min。