EVALUATION OF CHANGES IN SKELETAL-MUSCLE BLOOD-FLOW IN THE DOG WITH CONTRAST ULTRASONOGRAPHY

Intraoperative methods to assess skeletal muscle blood now or muscle-f lap perfusion during vascular reconstructive surgery are limited. At p resent, techniques enable only anatomic identification of the degree o f patency of large vessels. We report here the first use of ultrasonog raphy to assess dynamic changes in skeletal muscle perfusion. Baseline blood flow in the adductor muscle group of the hindlimbs of seven dog s was measured with an electromagnetic flow probe and with contrast ul trasound using the contrast agent Albunex. Blood now was manip ulated in each dog pharmacologically with random administration of intraarter ial injections of Neo-Synephrine and papaverine. After each change in blood flow detected by electromagnetic now probe, no iv also was asses sed qualitatively by four independent observers who graded video-recor ded contrast enhancement in the muscle group on a 0 to 4 scale. Videod ensitometry also was used to generate time versus intensity curves in the adductor muscle region of interest. Peak pixel intensity was deter mined during each flow condition. A total of 21 flow measurements were made with each assessment scheme (electromagnetic flow probe, video e nhancement, videodensitometry) for each condition (7 control, 7 papave rine, 7 Neo-Synephrine). Changes in blood now assessed by video enhanc ement scores and changes in peak pixel intensity correlated with chang es measured by electromagnetic flow probe (r = 0.84 and 0.66, respecti vely). We conclude that contrast ultrasound may be used to detect chan ges in skeletal muscle perfusion intraoperatively. Measures of muscle perfused by visual inspection of contrast enhancement and videodensito metric data were in agreement with direct measurements of changes in s keletal muscle blood now.