Long‑term graft patency after coronary artery bypass grafting: Effects of surgical technique

Abstract

The aim of the current study was to identify surgical factors associated with long-term patency of grafts used in coronary artery bypass grafting (CABG). The present study analyzed data from 127 patients who underwent CABG at our institute between 2000 and 2006 and presented for ambulatory examination and coronary computed tomography angiography evaluation of graft patency in 2016 (139.78±36.64 months post-CABG). The 127 patients received 340 grafts (2.68 grafts/patient) and 399 distal anastomoses (3.14 anastomoses/patient), 220 (55.14%) with arterial grafts and 179 (44.86%) with saphenous vein grafts. Graft patency varied according to coronary territory, proximal anastomosis type (in situ graft, composite graft, graft anastomosed to the ascending aorta), Y anastomosis angle (47.21° for patent arterial grafts vs. 56° for occluded), and distal anastomosis angle (in sequential anastomoses irrespective to graft type, 48.60° for patent side-to-side anastomosis vs. 53.97° for occluded, 65.12° for patent end-to-side anastomosis vs. 90.80° for occluded; in single end-to-side anastomosis of arterial grafts, 39.46° for patent and 44.94° for occluded). A single end-to-side anastomosis angle 60° or greater was associated with a 5.149 occlusion odds ratio (OR) (P<0.001) for arterial grafts. Venous grafts were not sensitive to single end-to-side anastomosis angle. In conclusion, a small anastomosis angle for proximal Y and distal anastomoses is associated with a higher long-term patency of the free graft. Radial artery grafts registered higher patency rates when anastomosed to the ascending aorta compared with composite grafting with the left internal thoracic artery, whereas in situ right internal thoracic artery (RITA) anastomosed to the right coronary territory is associated with a lower patency rate compared with free RITA used to revascularise the anterolateral or circumflex territory in composite grafting.

The effect of anastomotic angle and diameter ratio on flow field in the distal end-to-side anastomosis

“…The research results are consistent with previous studies. 14,33 Compared with that of F = 0.78, the flow fields at the anastomosis are smoother when F = 1.11.…”

Impact of target coronary artery stenosis severity measured by instantaneous wave-free ratio on to bypassed graft patency

“…In our study, we excluded technical errors due to errors of the surgeon by means of intraoperative angiography and TTFM. Interestingly, the degree of target vessel stenosis does not impact on SVG patency rate, as perfusion was directly from the aorta with higher pressures compared to arterial grafts [27]. Nevertheless, the process of SVG atherogenesis begins with early circumferential intimal thickening within the first year, followed by multilayered foamcell accumulation.…”

A mathematical model to evaluate hemodynamic effects of the graft anastomosis in coronary surgery

“…In addition to these aforementioned negative Swirl effects, the presence of swirl motion is also an indicator of the presence of recirculation areas that are particularly damaging as they potentially cause stagnation of the blood (Fig. 4 B) and, consequently, early thrombosis of the graft [8][9][10][11][12].…”