Is There a Difference Between Diabetic and Non-Diabetic ITAs? Histomorphological and Immunohistochemical Examinations of Internal Thoracic Arteries

Abstract BACKGROUND: The relative resistance to arteriosclerosis of the internal thoracic artery is clinically valid. The aim of this study was to evaluate the graduation of intima and media fibrosis in ITA parts and to determine the extent of atherosclerosis using immunohistochemical methods related to patients' risk factors. METHODS: 227 distal ITA segments from 144 male and 83 female patients were examined. Mean age was 66.7 ± 9.03 years. HE and Elastica van Gieson staining was performed to detect intima-/mediafibrosis. Population: insulin-dependent diabetes mellitus (idDM; n = 35), non-insulin-dependent diabetes mellitus (nidDM; n = 32), irradiation of the chest due to cancer (n = 27), control group with isolated hyperlipidemia, hypertension, peripheral vascular disease (n = 133). 12 ITA segments of each group were examined immunohistochemically using CD34, CD68, Tenascin, Collagen III, Collagen IV. RESULTS:HISTOMORPHOLOGICAL EXAMINATIONS using HE and Elastica van Gieson stainings showed for idDM-ITAs no fibrosis in 57 %, slight fibrosis in 34 %, medium in 6 %, no severe, for nidDM-ITAs no fibrosis in 63 %, slight 31 %, medium 3 %, severe 3 %, for ITAs after irradiation: no fibrosis in 37 %, slight in 62 %, no medium or severe fibrosis. Compared to the control group there was no statistically significant difference in diabetic ITAs. IMMUNOHISTOCHEMICAL EXAMINATIONS, scored on a 0 - 3 basis with 0 being the lowest (no reaction), 3 the highest (severe reaction), showed mostly no or slight reaction to CD34, CD68, Tenascin, and Collagen III for intima and media, with comparable results for diabetic or “irradiated” ITAs to those of the control group. The most distinct reaction (medium= 2), was detected for Collagen IV, a marker which outlines basement membranes of endothelia and smooth muscle cells of the vessel wall, but without differences between the four groups. No severe reactions were observed. CONCLUSIONS: The relative resistance of ITA to arteriosclerosis could be demonstrated in 227 ITA segments. Immunohistochemistry supports histomorphological findings. The influence of diabetes mellitus and irradiation remains irrelevant.