Novel strategy to improve end-organ function with pulsatile cardiopulmonary bypass.

he advent of cardiopulmonary bypass (CPB) has enabled cardiovascular surgeons to perform complex, life-saving procedures with relative ease while protecting end-organ function. Altering the normal pulsatile blood flow to non-pulsatile continuous flow has raised concerns over potential detrimental hemodynamic and physiologic consequences. Concerns over long-term non-pulsatile flow drove the design for the original pulsatile mechanical circulatory support devices. Unfortunately, the increased number of mobile parts required to generate pulsatile flow has rendered this technology inadequate for destination mechanical assistance.1 Secondand third-generation continuous flow left ventricular assist devices (LVAD) such as the HeartMate II (Thoratec, Pleasanton, CA, USA) and HVAD (HeartWare, Framingham, MA, USA) use minimal wearable parts, which has decreased concerns over long-term durability and pump failure.2 Over the past several years we have witnessed thousands of patients survive for years with preserved end-organ function in the presence of non-pulsatile LVAD flow. Although patients are living longer with these non-pulsatile flow devices, it has become evident that there is a new subset of pathology that is germane to continuous flow. The advent of de novo aortic insufficiency, gastrointestinal and cerebrovascular arteriovenous malformations, and acquired von Willebrand disease has been witnessed in this patient population.3 Though these long-term issues are not directly applicable to CPB, because of its acuity, they stress the importance of pulsatile flow in normal circulatory function.