Left Ventricular Assist Device Outflow Cannula Obstruction

Abstract

One of the dreaded complications of left ventricular assist device implantation is mechanical obstruction of the device secondary to pump thrombosis or mechanical outflow cannula obstruction. We describe a case of outflow cannula obstruction caused by kinking and twisting of the outflow graft after surgical manipulation of the pump. ( Level of Difficulty: Beginner. )

A novel approach to stenting a stenotic graft housing a Berlin Heart cannula by utilizing an adapted left ventricular assist device circuit

“…Addressing problems with the aortic graft in adult patients with third-generation devices is well described including percutaneous stenting of the graft to improve flow and device embolization to de-commission the ventricular assist device (VAD) carried out via percutaneous arterial access. 1 In smaller children (often on second-generation devices) the size of the arterial access required and the angle into the pump make this approach more challenging. Relatively small sheath access is becoming increasingly recognized as an approach for diagnostic and therapeutic intervention directly through the arterial limb of an extracorporeal membrane oxygenation circuit.…”

“…When this cannot be achieved further imaging is considered to ensure that the inflow and outflow grafts are free from obstruction. Addressing problems with the aortic graft in adult patients with third‐generation devices is well described including percutaneous stenting of the graft to improve flow and device embolization to de‐commission the ventricular assist device (VAD) carried out via percutaneous arterial access 1 . In smaller children (often on second‐generation devices) the size of the arterial access required and the angle into the pump make this approach more challenging.…”

Integrated Imaging to Investigate Low-Flow Alarms of Left Ventricular Assist Devices

“…In this issue of JACC: Case Reports, Asawaeer et al. ( 9 ) reappraised the topics of LVAD complications and the choice of imaging techniques for identification of these complications. They reported the case of a 66-year-old man who underwent HeartMate II (Abbott Laboratories, Abbott Park, Illinois) LVAD implantation in 2013 for end-stage ischemic heart failure and who recently presented with exertional dyspnea and low-flow, high-power LVAD alarms.…”

“…At this point, CT angiography revealed an obstruction of the outflow cannula secondary to kinking and twisting, which were apparently attributed to device replacement. Interestingly, evaluation of the explanted pump showed thrombosis of the inflow stator region, which was considered the original cause of the low-flow alarm ( 9 ).…”

“…Asawaeer et al. ( 9 ) should be commended for presenting this interesting case and also for providing a simple diagnostic flowchart for the use of imaging techniques to assess patients with low-flow alarms. A schematic depiction of the main causes of low-flow LVAD alarms is provided in the Central Illustration .…”