Transapical beating heart cardioscopy technique for off-pump visualization of heart valves

Abstract

Objective: Endoscopic methods to perform intracardiac procedures are of enormous interest, with the introduction of transcatheter techniques for complex cardiac procedures. In the present study, we demonstrate the use of a novel transapical cardioscopy system to visualize intracardiac structures in a porcine model.

Methods: The cardioscope was designed to mount a miniature CCD camera at its tip and was covered in a blunt convex Plexiglass top that allowed displacement and visualization of the tissue in front of the cardioscope. Transapical access for 11-mm cardioscopy was performed by way of a median sternotomy (n = 4) and minithoracotomy (n = 1) in an anesthetized porcine model, and various cardiac structures were imaged under beating heart conditions. The images from the camera were projected onto a monitor for the operator to guide cardioscope positioning.

Results: Video images and identification of structures on the left side of an in vivo beating porcine heart were obtained. Initially, the papillary muscle and mitral valve components were evaluated. The left atrium was entered, and the pulmonary vein orifices and atrial appendage were confirmed. Next, the camera was positioned within the left ventricle, and the ventricular portion of the trileaflet aortic valve was inspected. Using direct visualization, the camera was passed into the proximal ascending aorta. The left and right coronary arteries were also visualized. A catheter was introduced by way of a side port to confirm the position of the aortic valve leaflets during visualization. The pig experienced no significant decrease in blood pressure and maintained a stable heart rate throughout the procedure. The port was removed, and the transapical incision was closed with minimal blood loss during the procedure and closure of the orifice.

Conclusions: Transapical cardioscopy is a novel approach that allows for precise visualization of intracardiac structures within a beating porcine heart without the use of cardiopulmonary bypass. This technique might allow for more successful minimally invasive valvular, intracardiac, or ascending aortic procedures without the use of radiation.