Description of a closed window technique for in vivo study of the feline basilar artery.

Abstract

Recent interest in the regulatory functions of large cerebral arteries has led to many studies addressing the specific reactivity of these vessels. Current data originate mainly from in vitro experiments, as in vivo studies of larger intracranial cerebral arteries have been cumbersome so far due to the lack of a suitable animal model. We provide a detailed technical description of a closed transclival window method for in vivo study of the basilar artery in cats. We present our experience with this preparation in 29 animals, which shows that the technique is feasible and allows repeated, accurate, and reproducible measurements of the basilar artery, although possible depressive effects of the anesthesia on vascular reactivity have to be taken into account With hyper-ventilation, the basilar artery constricted by 12.2 ±7.6% of the baseline diameter. The cerebral blood flow response to hypocapnia with this preparation was 2.0±0.4%/torr Paco ; . An exudative clouding of the window occurred in some cats but had no apparent effect on vascular reactivity. We also discuss possible pitfalls in the surgical preparation. (Stroke 1991^2:522-526)

Effect of hematocrit variations on cerebral blood flow and basilar artery diameter in vivo

“…One might argue that the window preparation itself might impair vascular reactivity of the basilar artery, but we found maximum responses of basilar artery diameter grossly ranging between +lO and -25%, which is in good agreement with other data (11). Earlier, we had found that CO2 reactivity of the basilar artery was preserved with this preparation (2). Finally, it should be noted that Hctb in our animals was somewhat lower than what would be considered normal (29 instead of 32%), which is possibly due to the sometimes lengthy surgical preparation (2).…”

“…Earlier, we had found that CO2 reactivity of the basilar artery was preserved with this preparation (2). Finally, it should be noted that Hctb in our animals was somewhat lower than what would be considered normal (29 instead of 32%), which is possibly due to the sometimes lengthy surgical preparation (2). This may to some extent have blunted the viscosity effects of the Hct manipulations because of higher shear rates in the microcirculation.…”

Transcranial doppler sonography and internal jugular bulb saturation during hyperventilation in patients with fulminant hepatic failure

“…Most clinical studies agree that the diameter of large arteries remains almost constant during arterial carbon dioxide (CO 2 ) tension changes. [10][11][12][13][14][15][16] The aim of the present study is to compare absolute and regional CBF determined by the xenon 133 ( 133 Xe) washout technique with TCD velocity and the internal jugular bulb oximetry (svJO 2 ) as a measurement of cerebral CO 2 reactivity in patients with FHF.…”