Evaluation of bend relief disconnection in patients supported by a HeartMate II left ventricular assist device.

L eft ventricular assist devices (LVADs) are an established treatment for patients with end-stage heart failure as either a bridge to cardiac transplantation 1 or as lifelong support, also known as destination therapy.) is a continuous flow device that was approved by the US Food and Drug Administration in 2008, after a pivotal trial in 133 patients awaiting transplantation. 3 More patients have been implanted with the HM II than any other durable LVAD. Actuarial survival with continuous-flow LVADs has improved to 80% at 1 year and 70% at 2 years, leading to a growing population of patients with heart failure living with long-term mechanical circulatory support. 4 The HM II titanium axial flow rotary pump is placed in the abdominal musculature or within a preperitoneal pocket in the left upper quadrant. Blood enters the LVAD via an inflow cannula at the LV apex and exits through an outflow cannula connected via a graft to the ascending aorta. The outflow bend relief is a polytetrafluoroethylene tube at the junction of the outflow cannula and the pump housing designed to prevent kinking of the outflow cannula. In February 2010, Thoratec modified the outflow cannula bend relief with a snap ring design that allowed disconnec-tion of the bend relief to facilitate assessment of the underlying cannula for bleeding or malposition. Between February 2010 and February 2012, the manufacturer distributed >3800 modified outflow cannula bend reliefs to 226 hospitals and distributors worldwide. In April 2012, the US Food and Drug Administration issued a class I recall for the HM II LVAD after reports of disconnection of the bend relief from the out-flow grafts. 5 The initial reported worldwide incidence of disconnected outflow graft bend reliefs was 0.75% (29 of 3852 patients), with 1 death from multisystem organ failure.