Experimental study on establishment of an animal model of chronic aortic insufficiency

AIM:To explore the feasibility of establishing a chronic aortic valve regurgitation animal model by interventional destruction of the aortic valve. METHODS: Ten healthy dogs weighing an average of (18.3±4.6) kg were used. The hard wire was advanced to pierce the aortic valve leaflets under ultrasound guidance. At the same time, a balloon was inflated in the valve leaflet perforation. Angiography revealed obvious reflux through the valve leaflet perforation. Color Doppler echocardiogram was immediately used to evaluate aortic valve regurgitation and left ventricular ejection fraction. After 2 months, all surviving dogs were examined to evaluate aortic valve regurgitation and left ventricular ejection fraction with color Doppler echocardiography. RESULTS: Acute aortic valve rupture was not established in two dogs because the guide wire perforated the myocardium and led to cardiac tamponade. The operation on the other eight dogs was successful and instant aortic valve regurgitation by intraoperative echocardiography was (5.2±0.8) ml/sec. Two of the 8 dogs died of heart failure, respectively, on day 20 and day 35 and the other six dogs survived up to 2 months. Decrease of exercise tolerance was found in all surviving dogs. Compared with those immediately postoperative, the instant aortic valve regurgitation was (8.4±1.2) ml/sec, left ventricular volume was (69.5±6.8) ml and the left ventricular wall thickness (8.6±1.7) mm was significantly increased. Left ventricular ejection fraction was significantly decreased (42.5±1.1)%. Differences were all statistically significant (P<0.05). CONCLUSION: It is feasible to establish a chronic aortic insufficiency animal model by percutaneous aortic valve puncture plus balloon dilation with satisfactory results.