Bilateral internal thoracic artery grafting: Long-term clinical and angiographic results of in situ versus Y grafts

Background: We evaluated whether bilateral internal thoracic arteries provide the same long-term results when used as in situ grafts and as Y grafts. Methods and results: From October 1991 to February 2000, 1818 patients had bilateral internal thoracic arteries used as in situ (n = 1378, group A) or as Y grafts (n = 440, group B). The number of anastomoses per patient and the number of bilateral internal thoracic artery anastomoses per patient were higher in group B (3.1 +/- 0.9 and 2.7 +/- 0.9) than in group A (2.9 +/- 0.8 and 2.2 +/- 0.6) (both P < .001). The number of right internal thoracic artery anastomoses per patient rose from 1.0 +/- 0.3 in group A to 1.4 +/- 0.6 in group B (P < .001), and the number of sequential anastomoses per right internal thoracic artery graft rose from 4.1% to 34.3% (P < .001). Thirty-day mortality was 2.0% in group A versus 2.5% in group B (P = not significant). No difference in postoperative course was detected. Eight-year survivals were 95.8% +/- 2.7% in group A versus 94.8% +/- 4.0% in group B (la = not significant), and event-free survivals were 95.2% +/- 2.9% in group A versus 93.6% +/- 4.4% in group B (P = not significant). Early angiograms were obtained in 295 patients (945 anastomoses, 863 distal and 82 proximal Y grafts), 213 patients (611) in group A and 82 patients (334) in group B. Patency rate was 98.8% in group A and 96.0% in group B (P = not significant), whereas grade A patency rate was 97.2% in group A and 96.4% in group B (P = not significant). Late angiograms were obtained in 88 patients (25 in group A and 63 in group B) at a mean of 17.5 +/- 18.4 months: patency rate was 100% in group A and 99.2 in group B (P = not significant), and grade A patency rate was 98.6% in group A and 98.8% in group B (P = not significant). No Y anastomosis was occluded or stenosed. Comment: Survival, incidence of cardiac events, and angiographic patency in the early and late phases are similar for bilateral internal thoracic arteries used either in situ or as Y grafts. However, Y grafting with bilateral internal thoracic arteries increases the number of anastomoses per bilateral thoracic artery, as well as the flexibility of the right internal thoracic artery.