Influence of Inflow Cannula Length in Axial-flow Pumps on Neurologic Adverse Event Rate: Results From a Multi-center Analysis

Background: The application of axial-flow pumps in patients with end-stage heart failure reveals a significantly reduced infectious complication rate as compared with rates observed with pulsatile devices. The remaining adverse event rate relates mainly to thromboembolic complications with neurologic consequences. We investigated the dependence of the neurologic adverse event rate on the length of the inflow cannula. Methods: A total of 216 consecutive patients with an axial-flow pump (INCOR; Berlin Heart GmbH, Berlin, Germany) were included in a retrospective multi-center analysis. In 138 patients, a short inflow cannula (24-mm tip length into the left ventricle), and in 78 patients a long inflow cannula (tip length 34 mm) was applied. Results: Patients with a long inflow cannula (LC) demonstrated a better survival rate than those with a short inflow cannula (SC) at the end of the observation period (LC, 63.4%; SC, 52.9%; p = 0.05). The thromboembolic adverse event rate was also significantly lower. Only 3 of the 78 patients (3.8%) with an LC had a thromboembolic adverse event (thromboembolic events per patient-year = 0.11) as compared with 32 (23.2%) of SC patients (thromboembolic events per patient-year = 0.50, p <0.001). Conclusions: Patients with a long inflow cannula had a better survival rate and a lower incidence of cerebrovascular adverse events than patients with a short inflow cannula.