Morphologic changes of the saphenous vein Y-composite graft based on the left internal thoracic artery: 1-year intravascular ultrasound study.

Abstract

We evaluated vessel wall characteristics and changes in the lumen diameter (LD) of saphenous vein (SV) conduits harvested with minimal manipulation and used as Y-composite grafts based on the in situ left internal thoracic artery (ITA) 1 year after coronary revascularization. Twenty-eight patients who underwent off-pump coronary revascularization using minimally manipulated SV Y-composite grafts were studied. Quantitative angiography was performed early and 1 year postoperatively to evaluate changes in the conduits. An intravascular ultrasound study of the proximal left ITA and SV conduits was also performed after 1-year postoperative angiography. The mean LD of the SV conduit decreased during the first year postoperatively (3.58 ± 0.61 mm to 2.71 ± 0.42 mm; P < .001). The mean LD of the proximal left ITA increased (2.41 ± 0.25 mm to 2.63 ± 0.30 mm; P < .001), but was unchanged in the distal left ITA conduits. An intravascular ultrasound study demonstrated that the intima-media (IM) thickness and the proportion of IM to vessel area were 0.31 ± 0.12 mm and 29.1% ± 8.3% in the SV, and 0.23 ± 0.08 mm and 25.1% ± 8.6% in the proximal left ITA, respectively. Absolute and percentage decreases in SV diameter were greater in SV grafts with a larger diameter initially and with single distal anastomosis than those without. However, those decreases did not result in an increased proportion of IM to vessel area. Saphenous vein conduits harvested with minimal manipulation and used as Y-composite grafts based on the left ITA revealed decreased LD without accompanying abnormal IM thickening based on the flow requirements at 1 year postoperatively.