Mid-term Outcome of HeartWare HVAD in Small Patients in Japan

Abstract

Objectives: We investigated the impact of cuff position on the inflow cannula direction and wedge thrombus formation during mid-term HeartWare ventricular assist device (HVAD) support in relatively small patients.

Patients and Methods: Thirty-one patients, including five pediatric patients, underwent HVAD implantation between August 2011 to August 2020 in our institute. Two patients were implanted the HVAD in the true apex and other 29 patients were implanted in the posterior apex. Postoperatively, the direction of the inflow cannula was evaluated by three-dimensional computed tomography, and wedge thrombus was investigated at the time of heart transplantation.

Results: The patients' average body surface area (BSA) was 1.58 ± 0.33 m². Twenty-three had dilated cardiomyopathy and five had ischemic cardiomyopathy. Two patients required the right ventricular assist device (RVAD), and one was weaned from temporary RVAD on postoperative day 20, but another required permanent RVAD implantation using HVAD. The mean support duration was 578 ± 498 days. Fifteen patients successfully bridged to heart transplantation. The survival rate with HVAD support at 3 years was 90.2%. The angle between the inflow cannula and the posterior wall was 34.3 ± 21.6° in patients with posterior apex implantation of HVAD and 5.9 ± 10.2° in those with true apex implantation. Wedge thrombus around the inflow cannula was seen all patients with true apex implantation and one with the posterior apex (8%).

Conclusion: HVAD could be safely used in small patients for mid-term support, and implantation at the posterior apex could be an important option for small patients to prevent wedge thrombus formation during LVAD support.