REPRODUCIBILITY OF ULTRASOUND ASSESSMENT OF COMMON CAROTID AND FEMORAL-ARTERY COMPLIANCE AND DISTENSIBILITY IN THE ANESTHETIZED RAT

Objective: To validate ultrasound assessment of common carotid and fem oral artery compliance and distensibility in the anesthetized rat. Mat erials and methods: A reproducibility study was performed by taking me asurements twice on two different days in anesthetized Wistar-Kyoto (W KY) rats. The common carotid or femoral arterial diameter on one side and the contralateral arterial blood pressure were measured using a 10 -MHz probe echo-Doppler device and an arterial catheter, respectively. The pressure and diameter data were stored in a computer programmed t o calculate the arterial compliance and distensibility coefficients (R eneman formulas) and compliance and distensibility indices (arctangent model of Langewouters). A second experimental session was repeated 1 day later, and mean values, day-to-day mean differences and repeatabil ity coefficients were calculated for each parameter. Results: For both the common carotid and the femoral artery, the mean values for heart rate, mean arterial pressure, arterial diameter, arterial compliance a nd arterial distensibility were similar on the first and second days; mean day-to-day differences were small and repeatability coefficients were in the range 5-10% of the mean value for diameter and mean arteri al pressure and 10-20% of the mean value for compliance and distensibi lity. Conclusions: In the anesthetized rat, ultrasound evaluation of t he mechanical properties of the common carotid and femoral arteries is a reliable and reproducible technique.