Pump position and thrombosis in ventricular assist devices: Correlation of radiographs and CT data

Malpositioning of left ventricular assist devices (LVAD) is a risk factor for thrombosis, but its identification from clinical imaging remains challenging. X-rays and CT scans were analyzed and parameters identified that correlated to pump thrombosis. Retrospective imaging data of patients ( n = 115) with HeartmateII (HMII) or HVAD were analyzed in two groups (pump-thrombosis PT, n = 15 vs matched control group NT, n = 15) using routine X-rays and CT scans. In CT, directional deviations of the inflow cannula in three-chamber and two-chamber view (α and β angles) were identified. In HVAD PT frontal radiographs showed reduced pump body area and smaller minor axis (PT 41.3 ± 4.8 mm vs NT 34.9 ± 6.0 mm, p = 0.026), and in the lateral radiographs the visibility of the inflow cannula served as a predictive parameter for PT. In HMII patients, no parameters were associated with PT. The angle α differed significantly (NT −1.2 ± 7.5°, PT −22.0 ± 4.7°, p = 0.006) in HVAD patients. Further, correlations of x-ray parameters with CT angles α and β showed that radiographs can be used to identify malpositioned pumps. Well-aligned inflow cannula positions are essential. HVAD patients with a posterior rotation of the inflow cannula have a higher risk of pump thrombosis. This risk can reliably be identified from routine radiographs.

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Limited Efficacy of Thrombolytics for Pump Thrombosis in Durable Left Ventricular Assist Devices

The Annals of Thoracic Surgery ◽

10.1016/j.athoracsur.2020.03.061 ◽

2020 ◽

Vol 110 (6) ◽

pp. 2047-2054

Author(s):

Laura Seese ◽

Gavin Hickey ◽

Mary Keebler ◽

Floyd Thoma ◽

Arman Kilic

Keyword(s):

Left Ventricular ◽

Ventricular Assist Devices ◽

Left Ventricular Assist Devices ◽

Ventricular Assist ◽

Assist Devices ◽

Limited Efficacy ◽

Pump Thrombosis ◽

Left Ventricular Assist

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Blood damage in Left Ventricular Assist Devices: Pump thrombosis or system thrombosis?

The International Journal of Artificial Organs ◽

10.1177/0391398818806162 ◽

2018 ◽

Vol 42 (3) ◽

pp. 113-124 ◽

Cited By ~ 6

Author(s):

Matteo Selmi ◽

Wei-Che Chiu ◽

Venkat Keshav Chivukula ◽

Giulio Melisurgo ◽

Jennifer Ann Beckman ◽

...

Keyword(s):

Left Ventricular Assist Device ◽

Ventricular Assist Device ◽

Left Ventricular ◽

Ventricular Assist Devices ◽

Left Ventricular Assist Devices ◽

Assist Device ◽

Ventricular Assist ◽

Assist Devices ◽

Pump Thrombosis ◽

Left Ventricular Assist

Introduction: Despite significant technical advancements in the design and manufacture of Left Ventricular Assist Devices, post-implant thrombotic and thromboembolic complications continue to affect long-term outcomes. Previous efforts, aimed at optimizing pump design as a means of reducing supraphysiologic shear stresses generated within the pump and associated prothrombotic shear-mediated platelet injury, have only partially altered the device hemocompatibility. Methods: We examined hemodynamic mechanisms that synergize with hypershear within the pump to contribute to the thrombogenic potential of the overall Left Ventricular Assist Device system. Results: Numerical simulations of blood flow in differing regions of the Left Ventricular Assist Device system, that is the diseased native left ventricle, the pump inflow cannula, the impeller, the outflow graft and the anastomosed downstream aorta, reveal that prothrombotic hemodynamic conditions might occur at these specific sites. Furthermore, we show that beyond hypershear, additional hemodynamic abnormalities exist within the pump, which may elicit platelet activation, such as recirculation zones and stagnant platelet trajectories. We also provide evidences that particular Left Ventricular Assist Device implantation configurations and specific post-implant patient management strategies, such as those allowing aortic valve opening, are more hemodynamically favorable and reduce the thrombotic risk. Conclusion: We extend the perspective of pump thrombosis secondary to the supraphysiologic shear stress environment of the pump to one of Left Ventricular Assist Device system thrombosis, raising the importance of comprehensive characterization of the different prothrombotic risk factors of the total system as the target to achieve enhanced hemocompatibility and improved clinical outcomes.

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