Diagnosis and Treatment Strategies of Outflow Graft Obstruction in the Fully Magnetically Levitated Continuous-Flow centrifugal Left Ventricular Assist Device: A Multicenter Case Series

Abstract

Outflow graft obstruction in left ventricular assist devices (LVADs) is a rare complication whose clinical presentation may be subtle. We present six cases of outflow graft obstruction in patients on HeartMate 3 LVAD detected between 648 and 1,222 days on support. Detection principles are described and treatment strategies discussed. Three patients were successfully managed with stents, one underwent surgical revision, one patient died despite emergency treatment, and the last patient without symptoms was listed for heart transplantation.

Outflow graft obstruction in patients with the HM 3 LVAD: A percutaneous approach

“…The relatively high incidence of OGO in this series is likely explained by the important contribution of OG external compression as a cause of OGO (Figures 1(C), 3(A), and 4(A)). This notion is supported by recent work by Wert et al describing a series of HM3 cases with OGO not accounted for by twist alone, 8 and by Gertz et.al who recently described four case of OGO, for which intravascular ultrasound (IVUS) confirmed external compression as the underlying etiology in three cases. 9 External compression occurs a result of accumulation of biomaterial composed of proteins, blood cells and platelets that presumably leaks from through the OG and accumulates between the BR or Gore-Tex wrap and the OG, causing luminal narrowing.…”

“…9 External compression occurs a result of accumulation of biomaterial composed of proteins, blood cells and platelets that presumably leaks from through the OG and accumulates between the BR or Gore-Tex wrap and the OG, causing luminal narrowing. 4,5,[8][9][10][11][12] In our series, only two patients had proven OG twist (cases 1 and 2) and both cases likely had a component of compression, as indicated by the CTA obtained after surgical untwisting and clipping in case 1, and by the presentation with OGO one year after surgical untwisting with clip placement in the other case.…”

Primary results of long‐term outcomes in the MOMENTUM 3 pivotal trial and continued access protocol study phase: a study of 2200 HeartMate 3 left ventricular assist device implants

“…As we explore longer‐term outcomes, we need to stay vigilant for complications that may result from degeneration of peripheral pump components. A rare complication of outflow graft compression has been recognized in some late survivors of LVAD implantation that presents with a decrease in pump flow 27 . Continuous reduction of the adverse event burden will be necessary to improve the patient journey and experience in the longer term.…”

“…A rare complication of outflow graft compression has been recognized in some late survivors of LVAD implantation that presents with a decrease in pump flow. 27 Continuous reduction of the adverse event burden will be necessary to improve the patient journey and experience in the longer term. Trials to evaluate reduced exposure to anticoagulation regimens or to avoid the use of aspirin are ongoing in an effort to further control bleeding events.…”

Pump thrombosis and dynamic outflow graft compression: complications in left ventricular assist device therapy

“…Computed tomography angiography is an important tool when planning therapeutic intervention for outflow tract obstruction and may point towards the underlying mechanism. Interventional therapy and stenting of the outflow tract obstruction may be an option 11 to prevent a surgical redo procedure. The heart team's decision to proceed with a surgical revision was based on the technical difficulties encountered during the pump exchange surgery and the substantial outflow graft kinking seen in CTA.…”