Flow characteristics of LIMA radial composite sequential bypass grafting and single LIMA and saphenous vein sequential bypass grafting performed under OPCAB

Aim. The present study was aimed to compare the hemodynamic flow characteristics of LIMA radial artery composite sequential bypass grafting and with single LIMA and saphenous vein sequential bypass grafting performed by off-pump coronary artery bypass grafting (OPCAB). Methods. Between March 2007 and February 2008, 121 OPCAB patients were prospectively divided into two groups; Group I (N.=70, left internal thoracic artery [LITA]-left anterior descending [LAD] and Ao-SV sequential grafting), and Group II (N.=51, LITA-RA sequential grafting). The mean flow, pulsatility index (PI) and back flow (BF) were measured using the Transittime flow meter (TTFM). In Group II, the proximal (p-LITA) and distal LITA (d-LITA) flow in relation to the RA side branch anastomosis were measured separately. Results. The mean flow and PI of the proximal SV sequential graft and that of the RA graft were 64.4±37.3 mL/min and 2.6±1.6 versus 27.3±18.6 mL/min and 4.1±4.4, respectively (P<0.05). In Group I, the mean LTTA flow, PI, and BF were 26.9±16.4 mL/min, 2.6±1.5, and 3.1±6.1% whereas in Group II those of the p-LITA were 37.3±21.6mL/min, 2.3±1.0, and 2.0±3.5% and the d-LITA were 18.8±12.2mL/min, 3.9±3.3 and 7.4±11.8% (P<0.01). Conclusion. The results of the present data suggest the hemodynamic flow characteristics of composite bypass grafting to be inferior to the single LIMA and separate aorta-saphenous vein bypass grafting strategy. However, a longer follow up is warranted to assess the implications of these findings on graft durability.