Mid-term angiographic results of radial artery (RA) graft in CABG: Does the proximal site of anastomosis affect graft patency?

Abstract

Use of arterial conduits in coronary artery bypass grafting (CABG) is based on the documented excellent patency rates of left internal thoracic (mammary) artery (LITA). Alternative arterial conduits such as radial artery and gastroepiploic artery also showed superior long-term patency rates compared to vein grafts. Free arterial grafts are being used increasingly to replace the long saphenous vein as a conduit. This study was undertaken to compare two methods of radial artery grafting as a free graft and a composite graft. Between January 1997 and October 2003 a total of 441 patients were operated for coronary artery bypass grafting using radial artery (RA) as one of the conduits. Among these patients, 125 patients received radial artery as a composite graft; In 68 patients RA was used with left internal thoracic artery as a composite y graft (n=68), and in 57 patients it was used with right internal thoracic artery (RITA) as an in situ composite pedicle graft (n=57). In the remaining 316 patients the radial artery was used as a free graft. Angiographic evaluation of radial artery graft was carried out in 63 patients who consented. Angiograms were carried out after an interval of 6–72 months (mean of 28.15±21.17 months). Of these 63 patients who underwent reangiography, the different surgical strategies used were RITA+RA composite in situ graft (n=34), LITA+RA composite y graft (n=17) and aorto coronary (free) RA graft (n=12). There were 3 hospital deaths in the series 441 patients. Among the 63 patients who underwent check angiography 60 patients were in NYHA C1 I and 3 patients were in C1 II. None of the patients had perioperative myocardial infarction. Angiographically overall radial artery graft patency rate was 94.1% (59 patients). In patients with RITA and RA in situ grafts patency rate was 94.1%, LITA+RA composite y graft patency was 94.1% and aorto coronary (free) radial artery grafts patency was 91.6%. In 63 selected asymptomatic patients studied, we found that radial artery graft when used as an aortocoronary (free) graft or as a composite y graft with left internal thoracic artery or in situ pedicle graft with right internal thoracic artery the patency rates were comparable in all three groups.