Feasibility study of vascular-endoscopic valvuloplasty. Using a laser and flexible endoscope.

Percutaneous balloon valvuloplasty is generally accepted, but post procedural complications limit its efficacy and reduce long-term success. To eliminate these risks, the authors explored the feasibility of cardioscopy guided percutaneous laser valvuloplasty in an experimental setting. The combined working model consisted of a separate balloon tipped thin fiber optic endoscope, laser balloon catheter, and a Nd-YAG laser transmitter. A porcine pulmonary valve was used as our in vivo target of laser ablation in a beating heart. Under general anesthesia, the endoscopic catheter is delivered into the pulmonary valve area through either the internal jugular or femoral vein under fluoroscopy. Positioning the pulmonary apparatus coaxial to the endoscopic visual field by manipulation of the catheter allowed for targeting and ablation of the commissure of the pulmonary valve under endoscopic view through the balloon filled with saline solution. The ablation energy was 15-30 W, 0.5-1.0 sec, and 2,000-3,000 J total. The animal was then killed and histopathologic study of the ablated area was done. The commissure of the pulmonary valve was smoothly ablated in 4 cases, and the entire ablation procedure was successfully witnessed through endoscopy. The authors encountered some difficulty in laser targeting, limitations to the endoscopic field of vision, and difficulty in holding the position of the apparatus in the beating heart. These are the barriers to overcome for future clinical application of this procedure. However, these results indicate the clear possibility of future use of cardioscopy guided percutaneous laser valvuloplasty in a clinical setting.