The malfunction is a blockage in the flow of blood anywhere along a vessel (upstream or downstream) and it is mainly due to the bio-incompatible presence of a fairly complex mechanical apparatus.
[citation needed] Thrombosis of CF LVADSs can occur as a result of various factors,[3] which can be divided into three categories: the pump, the patient, and the clinician.
[7][8] A complex balance exists between over-anticoagulation and under-anticoagulation, in a patient population where the coagulation system response to the CF LVAD device varies greatly between individuals.
[citation needed] Unfortunately, robust and individually-tailored anticoagulation therapy protocols do not exist in most institutions, which usually utilize a "one size fits all" approach.
One anticoagulation protocol example targets the therapeutic window of coumadin of an international normalized ratio (INR) goal of 2–3 and full-dose aspirin for antiplatelet activity.
It has received reports and information from a variety of sources indicating an increase in the rate of pump thrombosis events in patients implanted with LVADs.
Information also shows that patients are experiencing pump thrombosis events earlier than observed during the clinical trials conducted to support product approvals in 2008 Bridge To Transplant (BTT) and 2010 Destination Therapy (DT).
Prevention of GI bleeding in VAD patients often includes keeping pump speeds lower to potentially minimize the proliferation of AV malformations.
[19] The unexpected abrupt increase in LVAD thrombosis was accompanied by elevated lactate dehydrogenase (LDH) levels with outcomes of different management strategies in a multi-institutional study.
[24] Computational fluid dynamics (CFD) is an invaluable tool in the development of VADs, enabling new designs to be tested rapidly and undesirable flow characteristics eliminated in successive versions before prototypes are manufactured.
CFD is used for predicting pressure-flow characteristics and efficiency curves, revealing the detailed flow field to help eliminate regions of recirculation or stagnation and for calculating fluid dynamic forces.