[Create a standard mini-swine model of chronic ischemic myocardium by thoracoscopy]

To create a standard mini-swine model of chronic ischemic myocardium by endoscopy for the research of gene transfer and stem cell.

Twenty-three male China experimental minipigs were used, aged from 8 to 11 months with a mean of (9.3 +/- 1.8) months and weighed from 20 to 30 kg with a mean of (29.3 +/- 4.3) kg. The myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX) with an Ameroid constrictor. The Ameroid constrictor was implanted around LCX by endoscopy. Selective coronary angiography, electrocardiogram and Echo-Doppler study were performed perioperatively to evaluate the degree of stenosis.

Chronic ischemic myocardial models were successfully generated in 20 of 23 swine by full-endoscopy. Ameroid constrictors were placed at the LCX accurately. Three swine died of anesthetic accident, cardiac arrhythmia at secondary coronary angiography, and pulmonary infection within 6 weeks after operation respectively. Operation time was 25 to 65 min with a mean of (46 +/- 9) min. The blood loss was 30 to 60 ml with a mean of (55 +/- 12) ml. Six weeks later, coronary angiography revealed the total occlusion and partial stenosis (> 85%) of the LCX occurred in 7 and 13 swine respectively. Cardiac systolic and diastolic dysfunction were found in all swine. The ejection fraction value was (65.0 +/- 6.3)% before operation and (41.0 +/- 9.3)% after operation (P = 0.008). The fractional shortening value was (36.2 +/- 4.3)% before operation and (34.2 +/- 2.3)% after operation (P = 0.027).

The endoscopic surgery is a less invasive way to create a standard mini-swine model of chronic ischemic myocardium with effective results.