To reverse or not to reverse the radial artery in coronary artery bypass graft surgery? Histopathologic concerns and media thickness.

BACKGROUND AND AIMS: Radial artery (RA) is a popular coronary artery bypass grafting (CABG) conduit. The challenging issue is vasospasm. A few studies are available on histopathological differences between RA's proximal and distal ends. This study aims to compare histopathological features of the proximal and distal end of RA to find the best technique for anastomosis.

METHODS: In this matched case-control study, 80 patients were included who underwent CABG and used RA as a graft. Ten subjects were excluded. RA was harvested by open technique, and a cocktail of Papaverine, Verapamil, and Nitroglycerine was frequently applied topically. One centimeter of proximal and distal ends of the RA was evaluated considering its Histopathology. Clinical signs of RA graft vasospasm were monitored from harvesting until the post-operative period. Intima, media, and intima-media thickness (IMT) index were compared between the two cohorts.

RESULTS: Vasospasm occurred in 1.41% of patients. The mean intimal thickness in the proximal and distal ends were, respectively, 0.20 (standard deviation [SD] 0.17 mm) vs. 0.31 (SD 0.18 mm) (p < 0.001). The mean media thickness in the distal end was higher than the proximal end (0.98 [SD 0.36] vs. 1.09 [SD 0.37], p = 0.004). IMT index of the proximal and distal ends showed a statistically significant difference (0.22 [SD 0.17] vs. 0.31 [SD 0.19]) (p < 0.001).

CONCLUSION: The overall incidence rate of vasospasm in our study is comparable with other studies using the same cocktail. Proximal RA has a relatively lower medial thickness compared to the distal part, which may induce less vasospasm in CABG patients.