Angiographic results after minimally invasive coronary bypass grafting using the minimally invasive direct coronary bypass grafting (MIDCAB) approach

The aim of the study was to evaluate the early and mid-term angiographic results after minimally invasive coronary bypass grafting using an 'off-pump' technique via a lateral minithoracotomy. In 221 out of 271 patients (81.5%) who underwent minimally invasive direct coronary bypass grafting (MIDCAB) the quality of the internal thoracic artery (ITA)-graft and the anastomosis was evaluated by conventional coronary angiography between the 2nd and 6th postoperative day (POD). A subgroup of 130 patients (47.9%) of the initial cohort were repeatedly controlled by angiography 6 months later. The early postoperatively patency rate of the grafts was (96.8%). Moderate anastomotic stenosis between 50 and 75% was found in 13/221 (5.8%) patients, whereas severe stenosis of more than 75% was seen in 10/221 (4.5%) and occlusion of the graft in 3/221 (1.3%) patients. A stress-ECG was performed in patients with a severe stenosis to provoke ST-segment changes or clinical findings of myocardial ischemia. A positive stress test was found in 4/221 patients (1,8%). Early re-intervention was required in 7/221 (3.1%) patients. After 6 months, angiographic follow-up revealed a patency rate of (95.4%). Of 130 patients 5 (3.8%) presented with moderate anastomotic stenosis, whereas 3/130 (2.0%) patients showed a severe stenosis with one patient (0.7%) having myocardial ischemia during stress test. Occlusion of the graft was seen in 3/130 patients (2.3%). During follow-up, 4/130 (3.0%) patients underwent re-intervention. A comparison between early postoperative and 6-months angiogram revealed a decrease or a disappearance of the severity of the stenosis in 4/15 patients (26.6%). Since stenosis of the anastomosis may occur after minimally invasive, beating heart coronary bypass grafting, postoperative angiography should be performed to provide quality control and to guide appropriate further treatment. The latter is necessary if the stenosis is accompanied by reduced run-off and evidence of myocardial ischemia during stress test. An improvement of early stenosis at the anastomosis may be expected in more than 25%.