[Histological findings at the aorta ascendens after measurement of blood flow with ultrasonic doppler technique in chronic experiments with rabbits (author's transl)].

Following implantation of an ultrasonic transducer in the aortic wall of the rabbit, media destructions and pressure necrosis were ascertained when the transducer was fitted closley around the vessel. When the transducer however was fitted widley around the vessel few departures from the normal structure were registered. After ultrasound stress 0.2--0.5 Watt/cm2 5 Min. per die with a mean exposition at 86.6 days, necrosis of the media and proliferations of the intima were noted in the area of the ultrasound application. When the transducer were not protected this resulted in sharp incisures of the vessels giving undeniable proof of ultrasound damages in spite of the low efficiency. Alltogether the histological findings show, that provided correct methodology vasal measurement of blood is possible in chronic experiments.