Outer radius-wall thickness ratio, a postmortem quantitative histology in human coronary arteries

Although the anatomy, histology and pathology of human coronary arteries ha ve been studied extensively, little is known about the functional relations hip between vessel radius and wall thickness. It is the purpose of this stu dy to present detailed measurements and co describe this relationship cover ing the range from the feeding coronary artery to the arterioles. Human hea rts of 10 adults less than 36+/-3 years old were investigated immediately p ostmortem. Ten cubic tissue blocks, measuring about 10 mm in length on each side, were dissected from the left ventricular wall. After fixation by imm ersion, 15-mu m sections were prepared and outer and inner perimeters of 52 arterial segments were digitalized. Vessel radius and wall thickness were calculated and plotted to show their relationship over the whole range of v essel calibers. Outer vessel radii ranged from 100 to 3,000 mu m and wall t hickness from 80 to 800 mu m. Plotting the outer vessel radius against the wall thickness, the data points were found to cluster around a straight lin e. A significant correlation between the two parameters was found (R-2=0.79 ). This mathematical correlation and the good agreement of the presented re sults with data from other species indicate a common physiologic concept.