Bladeless Heart Pump Design: Modeling and Numerical Analysis

In this paper, the design of a new type of heart pump is presented. The uniqueness of this pump concept is that the mechanical energy is transferred to the fluid by the rotation of flat disks without blades. Both theoretical and numerical analysis are used to determine the pump design parameters. The pump design parameters are calculated using the Navier–Stokes equations. The application of computational fluid dynamics is used to define the geometric design. The pump head and flow have to be within strictly defined limits to ensure normal blood circulation. The negative impact of the pump on the blood must be minimal (no stagnation and recirculation zones, shear stress in the acceptable range). It is also important to achieve the smallest possible pump volume. For the pump operating point of ∆p = 65 mmHg, Q = 5.43 L/min, and ω = 6000 rpm, the design parameters are inner radius R1 = 12 mm, outer radius R2 = 15 mm, the distance between disk of h = 1 mm, and the number of disks is n = 6. The shear stress in the rotor is in range 46–108 Pa and the pump residence time is 0.0194 s.

Sustained Use of the Impella 5.0 Heart Pump Enables Bridge to Clinical Decisions in 34 Patients

We studied whether sustained hemodynamic support (>7 d) with the Impella 5.0 heart pump can be used as a bridge to clinical decisions in patients who present with cardiogenic shock, and whether such support can improve their outcomes. We retrospectively reviewed cases of patients who had Impella 5.0 support at our hospital from August 2017 through May 2019. Thirty-four patients (23 with cardiogenic shock and 11 with severely decompensated heart failure) underwent sustained support for a mean duration of 11.7 ± 9.3 days (range, ≤48 d). Of 29 patients (85.3%) who survived to next therapy, 15 were weaned from the Impella, 8 underwent durable left ventricular assist device placement, 4 were escalated to venoarterial extracorporeal membrane oxygenation support, and 2 underwent heart transplantation. The 30-day survival rate was 76.5% (26 of 34 patients). Only 2 patients had a major adverse event: one each had an ischemic stroke and flail mitral leaflet. None of the devices malfunctioned. Sustained hemodynamic support with the Impella 5.0 not only improved outcomes in patients who presented with cardiogenic shock, but also provided time for multidisciplinary evaluation of potential cardiac recovery, or the need for durable left ventricular assist device implantation or heart transplantation. Our study shows the value of using the Impella 5.0 as a bridge to clinical decisions.