Abstract 2531: Altered Structure of Small Cerebral Arteries in Patients With Essential Hypertension
Objective Structural alterations in the microcirculation may be considered an important mechanism of organ damage. An increased media to lumen ratio of subcutaneous small resistance arteries (M/L) may predict the subsequent development of cardio-cerebrovascular events in a high risk population (Rizzoni et al, Circulation 2003). In animal models of experimental or genetic hypertension, alterations in the structure of small cerebral arteries were observed. However, no evaluation with reliable techniques was ever performed in humans.
Design and Methods Thirteen subjects were included in the present study. They were 7 hypertensive patients (HP) and 6 normotensive subjects (NS). All subjects underwent a neurosurgical intervention (trauma, meningioma, etc.). A small portion of morphologically normal cerebral tissue was excised and rapidly put in chilled physiological saline solution. Cerebral small resistance arteries (diameter around 200 μm) were dissected and mounted on an isometric myograph, and the tunica media to internal lumen ratio was measured (M/L). In addition, cortical microvessel density (MVD) was also evaluated. The tissue was sectioned and stained for CD31, and MVD was measured with an automated image analyzer.
Results: are reported in the Table⇓ (*=P<0.05, **=P<0.01 vs. NS). M/L was significantly greater in HP compared with NS. There was a tendency to observe microvascular rarefaction in HP (P=0.10), but the difference in MVD did not reach statistical significance.
Conclusions For the first time, in the present study, structural alterations of human cerebral small vessels were evaluated with a reliable micromyographic technique. Our results indicate that structural alterations of small cerebral vessels are present in HP compared with NS, similar to those previously observed in subcutaneous tissue. Structural alterations in the cerebral microcirculation may be involved in clinical events observed in human essential hypertension