Objective: To compare the morphometry and endothelial nitric oxide synthase (eNOS) expression of radial artery (RA) between young and elderly patients with coronary atherosclerotic heart disease.
Methods: From February 2008 to June 2009, 219 patients underwent coronary artery bypass grafting (CABG) with autologous RA, 57 patients aged beyond 70 years and 64 patients aged under 60 years. Before RA was harvested, a modified Allen test was routinely performed. If positive, RA would be further evaluated with Doppler ultrasound examination. In both groups RA was collected for HE staining to evaluate percentage of luminal narrowing (LN) and relationship between intima and media width at maximum intimal thickness (IMR). Immunofluorescence and Western blot were used to investigate the location and expression level of eNOS within the wall of RA.
Results: Morphometry of RA in both young and elderly patients represented mild or moderate intimal hyperplasia, and medial calcification was not found. LN in elderly patients was (22 ± 6)%, while in young patients, it was (23 ± 6)%. IMR in elderly patients was 0.36 ± 0.21, while in young patients, it was 0.42 ± 0.19. There was no significant difference in both LN and IMR between two groups (P > 0.05). Immunofluorescence indicated RA in both groups revealed a high expression of eNOS in intima and media, particularly in the smooth muscle of media. The values of relative integrated optical density in elderly patients was 1.21 ± 0.13, while in young patients, it was 1.25 ± 0.12. Also there was no significant difference in the expression level of eNOS within the wall of RA (P > 0.05).
Conclusion: After preoperative assessment with modified Allen's test and Doppler analysis, RA used as graft in the elderly has similar quality and function with young patients, and it may lead to a high patency in long term.