Novel ventricular apical cannula: in vitro evaluation using transparent, compliant ventricular casts

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Device Design

Background:

• The design of cannulas for left ventricular (LV) circulatory support impacts hemodynamic performance.
• Previous in vivo studies demonstrated that cannula design affects bypass flow rate and ventricular fluid dynamics.
• Cannula tip geometry can prevent ventricular collapse and aid surgical placement.

Purpose of the Study:

• To investigate the anatomic interaction and fluid dynamics of apical cannulation for LV support.
• To compare the hemodynamic effects of conventional cannula tips versus a novel trumpet-shaped design.
• To evaluate the impact of cannula geometry on preventing apical stasis and recirculation.

Main Methods:

• Fabrication of transparent, compliant casts of bovine LV geometries (end-systolic and end-diastolic).
• In vitro flow visualization using fluorescent particle tracking velocimetry.
• Testing of conventional and novel trumpet-shaped cannula tips in pulsatile flow conditions simulating a beating heart.

Main Results:

• The trumpet-shaped cannula demonstrated superior performance compared to conventional designs.
• This novel tip facilitated excellent placement and beneficial stenting of the LV apex.
• Improved blood flow was observed, with reduced apical stasis and recirculation.

Conclusions:

• The trumpet-shaped cannula design is strongly advocated for LV circulatory support.
• This geometry offers significant advantages in hemodynamic function, placement, and prevention of adverse effects.
• Further research will involve in vitro endoscopy, quantitative velocimetry, and application to dilated human ventricles.