Use of color Doppler imaging in assessment of preoperative and postoperative flow characteristics of internal thoracic artery in myocardial revascularization.

Between January 1993 and February 1993, the left internal thoracic arteries of 40 consecutive patients scheduled for aortocoronary bypass operation were examined by transthoracic B-mode imaging. Perioperative measurements correlated well with preoperative noninvasive measurements (r = 0.914). In the postoperative period, B-mode images could not be obtained in 17 (44.7%) of 38 patients. Adequate Doppler spectra of the internal thoracic artery were obtained in all patients preoperatively and in 36 (94.7%) of 38 patients postoperatively. Preoperatively a triphasic wave form was obtained with a large systolic peak followed by small reversed and diastolic components in all patients. Postoperatively this triphasic wave form had been converted into a combined systolic-diastolic wave form. In all patients peak systolic velocity of the internal thoracic artery decreased (96.4 +/- 15.3 vs 64.2 +/- 18.9 cm/sec., P < 0.05), and peak diastolic velocity increased (21.7 +/- 8.8 vs 28.3 +/- 11.2 cm/sec., P < 0.05) significantly in the postoperative period as compared with the preoperative values. A slight decrease in peak systolic and diastolic velocities was detected at twelve months postoperatively. This study indicates that transthoracic B-mode imaging and Doppler spectrum analysis are reliable techniques in the preoperative and postoperative assessment of the internal thoracic artery in myocardial revascularization.