Development of a Flexible Inflow Cannula With Titanium Inflow Tip for the NEDO Biventricular Assist Device

Abstract

A newly designed flexible inflow cannula has been developed for a biventricular assist device (BVAD). The inflow tip was designed for long-term ventricle drainage. Considering the anatomic differences between the right and left ventricles, a flexible inflow cannula, as a mass production model with a titanium tip, was developed and investigated in chronic BVAD animal experiments using the NEDO permanently implantable centrifugal blood pump. These flexible inflow cannulae consist of flexible plastic tubing with wire supported, titanium left and right tips. The right titanium inflow tip was designed with inner and outer stoppers to be inserted into the right ventricle wall and a beak shape to avoid sucking. The left tip was designed to be inserted into the left ventricle cavity. Five chronic BVAD bovine studies were performed to investigate the new beak shaped titanium tip. In these studies, the new beak shaped titanium tip and cannula prevented stenosis by a proliferation of pseudoneointimal, and supplied adequate blood flow to the pump without sucking. This newly designed inflow cannula with the beak shaped titanium tip was successfully implanted for 90 days. ASAIO Journal 2004; 50:381-386.

Management of ventricular arrhythmias in patients with ventricular assist devices

“…Moving forward, additional studies relating the clinical occurrence of ventricular arrhythmias to molecular and physiological shifts within the myocardium will be invaluable in better defining which mechanisms are most strongly implicated in the time-dependent risks of ventricular arrhythmias in VAD-supported hearts. Further device evolution, including inflow cannula modifications [19,63] and inlet pressure control systems that adjust rotor speeds and prevent suction [23,[64][65][66], may reduce the incidence of ventricular arrhythmias among VAD-supported patients. Prospective trials assessing the benefits of de-novo prophylactic ICD placement and the need to replace ICDs in patients free of post-VAD ventricular arrhythmias would be particularly welcome.…”

Ex Vivo Assessment of a Parabolic-Tip Inflow Cannula for Pediatric Continuous-Flow VADs

“…This, in part, has served as a basis towards the development of ‘beak’, ‘corona’, and ‘trumpet’ designs with varied success due to thrombosis or thromboembolic complications related to insertion depth rather than inlet tip geometry. 22–24 …”

In Vitro Evaluation of Ventricular Cannulation for Rotodynamic Cardiac Assist Devices

“…[10] These remedies may however increase the possibility of thrombus formation due to flow disturbances causing shear activation of platelets and increased exposure time of stagnant blood to exposed myocardium at the apical wound site.…”