抄録
The difference between diabetics and nondiabetics in the pattern of major coronary circulation, distal to the complete obstruction through nonvisualized collaterals are seen on the cine-angiography. Distal circulation to the complete or near-complete obstruction via nonvisualized collaterals shows approximately one second delay filling, although that filling of nondiabetics has immediate. In order to explain this difference, major coronary arteries and their small intramural branches were histologically examined in each 9 cases of diabetics and nondiabetics. The degree of major coronary stenosis were macroscopically determined with every 5mm length.
The several samples of the muscles containing obstructed and nonobstructed arteries were obtained to see the state of intramural small arteries. Tissue were stained HE, EVG, Azan and PAS. The histological findings were classified into five lesions according to the descriptions of Blumenthal and Saphier; 1) Hemodynamic lesions: Fibrous or fibroelastic intimal thickening or plaque formation. 2) Atheromatous lesions: Atheromatous thickening with lipid in intima or in plaque. Atheromatous hyalinized thickened intima. 3) Thrombotic lesions: Mass of fibrin or enmeshing erythrocytes attached to the endothelial surface. 4) Inflamatory lesions: Perivascular cellular infiltration, perivascular adventitial fibrosis, intimal fibrosis and hyalinization and fibrous changes in the media. 5) Proliferative lesions: Endothelial proliferation forming mounds, papillary projection and bridges. Intramural small arteries were divided into three group, 20-60 microns (small), 70-150 microns (medium) and 160-500 microns (large) according to their calibers.
The degree of lesions were expressed as the percentage, the number of abnormal vessels in the total number of examined ones. These were as the following:
Diabetic group Nondiabetic group
small 44.8% 32.3%
medium 61.3% 33.8%
large 62.1% 38.9%
total 54.2% 34.0%
In the cases of complete or near-complete obstruction, distal filling from the proximal portion as bridgning collaterals must be due to anastomoses via intramural small arteries. Although these small vessels are not visualized angiographically, the filling delay to the distal segment beyond the obstruction in diabetics are believed due to small vessel disease, being seen more frequently in diabetic patients. These abnormalities would affect the prognosis of the diabetic patient to be worse than nondiabetics with the same degree of major coronary artery obstruction.
