Cardioscopy-guided surgery: Intracardiac mitral and tricuspid valve repair under direct visualization in the beating heart

Objective: Cardioscopy is a novel imaging method that allows closed-chest, real-time fiberoptic imaging of intracardiac structures. This study tested the feasibility and safety of cardioscopy as a platform for mitral and tricuspid valve surgery in the beating heart. Methods: Through a median sternotomy, cardiopulmonary bypass was established in 10 calves. Lactated Ringer's solution was administered through the pulmonary artery to eliminate residual blood volumes in the lung vasculature and was drained through a left ventricular cannula. A fiberoptic cardioscope within its translucent outer sheath was inserted through the left ventricle. Irrigating solution was continuously administered through the cardioscope sheath for clearer visualization. An endoscopic clip was used for edge-to-edge repair of the mitral and tricuspid valves. After mitral valve clipping, the cardioscope was inserted into the right ventricle. The solution was administered from the right atrium and continuously drained from the pulmonary artery. After tricuspid valve repair, the animal was weaned from cardiopulmonary bypass. Results: Successful double-valve repair was carried out in all 10 cases. All calves were weaned from cardiopulmonary bypass with dobutamine only. Hematocrit values were maintained during the procedure (pre 29.0% ± 3.1% vs post 28.5% ± 3.6%, P = .70). Conclusions: This study showed the technical feasibility of beating heart valve surgery using direct cardioscopic visualization. Cardioscopy represents a promising platform for future interventions and surgery under direct visualization in the beating heart.