Objective: Assess outcome of transapical Valved Stent implantation (TAP) for off-pump aortic
valve replacement using simultaneous intravascular and intracardiac ultrasound guidance
for target-site-identification, per-procedural dimension assessment and deployment
monitoring.
Methods: Valved Stent implantation in 18 pigs (71.4±10.5Kg) via trans-apical approach. Simultaneous
intracardiac (ICUS) and intravascular ultrasound (IVUS) were inserted via femoral
vein and ventricular apex respectively for dimension assessment of the aortic root,
valve and identification of target-site for Valved Stent deployment. The IVUS catheter
transducer was tracked in parallel with ICUS and fluoroscopy in order to mark the
target site. Next, the Valved Stent delivery-system was introduced under fluoroscopy
and ICUS monitoring and the Valved Stent deployed over the native valve. In-vivo assessment
included: leaflet motion, planimetric valve orifice, transvalvular gradient, regurgitation
and paravalvular leaking.
Results: The target location was correctly identified by IVUS and ICUS. No difference between
the aortic root and valve dimensions were found between the IVUS and ICUS measures.
As correctly identified by ICUS and IVUS, of 18 Valved Stents, 12 were accurately
delivered at target site. All of the 12 valves showed good valvular function, 3 valves
had minor paravalvular leak. Three and 3 Valved Stent seated or too or dislodged back
into the left ventricle
Conclusions: IVUS and ICUS precisely identify aortic landing-zone for Valved Stent implantation
and accurately guides delivery and deployment within the left ventricle and the native
valve without the use of angiography. Furthermore ICUS and IVUS independently can
assess postimplantation valve function and allow for post-implantation coronary flow
analysis.
