Editorial

Background. The quality of surgical beating heart revascularization is frequently questioned, especially when the surgical access is limited. Nevertheless, the number of off-pump coronary procedures is expanding worldwide.

Methods. Since getting started with minimally invasive direct coronary artery bypass to anterior myocardial vessels in June 1996, 306 patients received left internal mammary artery grafting through an anterior minithoracotomy. Risk increasing comorbidities were present in 168 of them. Particular attention was paid to early postoperative angiographic results and complications.

Results. The 30-day mortality summed up at 1.0% and was limited to patients with additional risks for conventional bypass grafting. Early postoperative control angiographies in 232 patients confirmed a global patency rate of 97.8%, revealing in addition four unexpected malinsertions to diagonal branches. In surviving patients major complications like myocardial infarction, stroke, or multiorgan failure were completely absent.

Conclusions. Minimally invasive direct coronary artery bypass grafting appears to allow for a safe and effective revascularization of the left anterior descending artery by use of the left internal mammary artery. Especially patients with risk increasing comorbidities should benefit from this approach, provided the surgical indication based on a dominating left anterior descending artery lesion. Angiographic minimally invasive direct coronary artery bypass results seem to fulfill the expectations generated by results obtained in conventional left internal mammary artery grafting and appear to be superior to interventional means.

Background. In the progress toward “off-pump” endoscopic coronary artery surgical procedures, new techniques for coronary artery anastomoses are being developed. One such approach is the use of nonpenetrating titanium clips. We evaluated the quality of anastomoses achieved using this technique in a porcine model of saphenous vein–carotid artery grafting using scanning electron microscopy.

Methods. Bilateral saphenous vein–carotid artery interposition grafts were implanted in 10 “white race” pigs, using the nonpenetrating clips in one side of the neck and conventional hand suturing on the opposite side. One week after operation, the grafts were harvested.

Results. All grafts were patent 7 days after operation, and 40 anastomoses underwent scanning electron microscopic study. In all samples, the luminal surfaces of both the carotid artery and vein graft were covered by a continuous layer of endothelial cells up to the anastomosis. Anastomotic sites in all clipped samples and most of the sutured anastomoses were completely endothelialized, and anastomotic clefts were indistinguishable. However, in 25% of sutured specimens, the suture material remained clearly visible inside the lumen of the vessel, and the subendothelial matrix remained exposed, with extensive fibrin, red blood cells, and platelet deposition on its surface.

Conclusions. Because the endothelial coverage consistently appeared to be complete and the subendothelial matrix was not exposed, it is likely that the risk of early anastomotic thrombosis is reduced by using the nonpenetrating titanium clips.

The techniques of performing coronary revascularization without cardiopulmonary bypass are rapidly evolving. However, concern remains regarding the accuracy of coronary artery anastomoses performed on the beating heart. This report reviews the use of intraoperative angiography in the critical appraisal of“ off-pump” coronary artery bypass graft (CABG) surgery.

Intraoperative angiography was performed in 24 consecutive patients undergoing CABG surgery without cardiopulmonary bypass. In all, 24 left internal mammary artery (LIMA) grafts and 18 saphenous vein bypass grafts were assessed for patency, anastomosis quality, distal and proximal runoff, and correct placement.

All of the saphenous vein-to-coronary artery anastomoses were widely patent, although two patients (8%) required revision of their LIMA grafts on the basis of angiographic findings.

Intraoperative angiography permits the surgeon to immediately appraise the CABG and to revise, if necessary, any graft abnormality, thus potentially eliminating the need for early repeated surgery. The practice of routine intraoperative angiography is likely to improve the outcome of CABG surgery on the beating heart.

The importance of the angiographic assessment of coronary bypass grafts performed on the beating heart has been recognized. We describe a simple technique for intraoperative angiography of left internal mammary artery to left anterior descending coronary artery grafts that does not require selective left internal mammary artery catheterization. This method allows immediate appraisal of the graft, hence enabling the surgeon to revise any graft or anastomosis abnormality immediately and to verify optimal results of beating heart operations.

Background. Intraoperative angiography was performed to confirm graft patency immediately after minimally invasive coronary bypass operations.

Methods. In 26 patients who had internal mammary artery grafting, intraoperative coronary angiography was performed with a portable digital fluoroscope.

Results. High-resolution angiograms were obtained in all cases. Angiography documented vasospasm of the graft or native vessel in 9 patients (graft in 3, native in 2, graft and native in 4 others), which responded promptly to intracoronary vasodilators in all. Angiography identified technically unsuspected and clinically silent fixed stenoses (>50%) in 11 patients, attributable to graft kinking in 2, anastomotic obstruction in 6 (total occlusion in 4), and stenosis of the left anterior descending artery just distal to the anastomosis in three cases (total occlusion in one). In 9 of 11 patients, fixed stenoses were sufficiently severe to warrant intraoperative intervention by surgical revision (n = 5) or angioplasty via the graft (n = 4).

Conclusions. Intraoperative angiography after minimally invasive coronary artery bypass operations can immediately identify dynamic and fixed obstructions and facilitate their prompt treatment, thereby ensuring that each patient leaves the operating room with an optimal surgical result.

We report a case of total occlusion of the left anterior descending coronary artery with atheromatous debris after “off-pump” grafting. Atheroma break-off and distal embolization probably occurred from proximal snare occlusion of the target coronary artery, and this was recognized by intraoperative angiography. Alternatives to suture snaring should be considered whenever an atherosclerotic artery is to be grafted without cardiopulmonary bypass.