NONINVASIVE ESTIMATION OF THE INTERNAL MAMMARY ARTERY BYPASS GRAFT PATENCY - A 6-YEAR FOLLOW-UP

Echo Doppler of the internal mammary artery (IMA) can be considered a good clinical and diagnostic tool in detecting the flow in the IMA bypass graft. The aim of the present study was to evaluate the reliability of transcutaneous echo-Doppler ultrasonography in the detection of early and long-term pathologies of the IMA bypass graft. The study was carried out on 161 consecutive patients (127 men and 34 women, mean age fifty-two +/- ten years) who had undergone surgical myocardial revascularization by anastomosis of the left IMA pedicle to the left anterior descending coronary artery. All patients underwent echo-Doppler examination in resting conditions, during forced hyperventilation and Valsalva maneuver four times per year. Supine exercise test was performed annually for five years, and selective angiography of the IMA graft (IMAg) was done when symptoms and/or conventional stress test and/or echo-Doppler examination required it. The results showed that, for anatomic reasons only, in 87% (140 patients), it was possible to study the IMAg. In these patients, 16 stenoses greater-than-or-equal-to 40%-99%, 5 occlusions, and 3 intercostal steals were detected. These results, compared with selective angiography, showed high sensitivity, specificity, and accuracy of echo-Doppler of the IMAg.