[Pitfall of minimally invasive direct coronary artery bypass].

Six thoroughly selected patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB). While monitoring left ventricular function with transesophageal echocardiography, MIDCAB was done by performing small left thoracotomy through the fourth intercostal space, dissection of the left internal thoracic artery without thoracoscopy, ischemic preconditioning, and grafting of the internal thoracic artery to the left anterior descending coronary artery with 8-0 polypropylene continuous suture. A home-made cardiac stabilizer and Visuflow enabled us to perform precise suturing of the internal thoracic artery. The patency of all grafts was confirmed by early transthoracic Doppler echocardiography and selective angiography. A new stenosis of the coronary artery distal to the anastomosis was detected probably due to coronary snaring in one patient. The anastomosis sites were confined to the distal segments of the left anterior descending coronary artery in MIDCAB patients. The optimal anastomosis site may be missed in the patients with proximal left anterior descending artery disease. An experimental study of myocardial tissue oxygen saturation using near infrared spectroscopy showed that two times of coronary occlusion and reperfusion provided satisfactory effects of ischemic preconditioning. Measurement of the myocardial tissue oxygen saturation may be helpful for confirming effective ischemic preconditioning and a safe coronary occlusion during MIDCAB. Although MIDCAB is an attractive procedure, we should consider the accuracy of anastomosis, the risk of possible incomplete revascularization, the indications, and long-term results.