Histomorphology of right versus left internal thoracic artery and risk factors for intimal hyperplasia

Abstract

Objectives: We compared the histological and morphometric properties of the right and left internal thoracic arteries and examined risk factors for intimal hyperplasia. Methods: Paired segments of the right and left internal thoracic arteries obtained from 72 patients were studied. The transverse sections just distal to the most distal anastomoses were microscopically examined. Results: No significant difference was found between the right and left internal thoracic arteries in the median value of the lumen area (1.60 vs 1.52 mm2, P = 0.33], intimal area (0.07 vs 0.05 mm2, P = 0.80), width of intima (23 vs 21 μm, P = 0.88], width of media (149 vs 148 μm, P = 0.49), intima-to-media ratio (0.19 vs 0.17, P = 0.96) or percentage of luminal narrowing (3.6 vs 3.6, P = 0.86). No atherosclerotic lesion or medial calcification was seen in either artery. Intimal hyperplasia was identified in 72 segments from 50 patients. In a multivariate logistic regression model, estimated glomerular filtration rate (GRF) was significantly associated with intimal hyperplasia (odds ratio 1.35 per 10-ml/min/1.73 m2 increase, 95% confidence interval 1.16-1.56, P < 0.01). In multivariate linear regression models, estimated GRF was significantly associated with the intima-to-media ratio (β-coefficient -0.009, 95% confidence interval -0.013 to -0.005, P < 0.01) and percentage of luminal narrowing (β-coefficient -0.011, 95% confidence interval -0.014 to -0.008, P < 0.01). Conclusions: The right and left internal thoracic arteries have equivalent histological and morphometric properties. Lower estimated GRF is significantly associated with intimal hyperplasia. © The Author 2013. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.