[Echo-Doppler evaluation of the internal mammary artery bypass on the left coronary artery: a 4-year follow-up].

: In this study ultrasonographic techniques are suggested to monitor internal mammary artery bypass graft on the anterior descending coronary artery. One hundred and fourty patients were studied using 3 different ultrasonographic methods: zero-crossing continuous wave Doppler, fast Fourier transform (FFT) continuous wave Doppler and high resolution echo-Doppler. The patients underwent the ultrasonographic examinations 3 times a year for 4 years. By means of FFT Doppler analysis and echo-Doppler it was possible to perform the study in 138 patients and by zero-crossing system in 127 patients. Ultrasonographic techniques showed pathologies of the graft in 17 (13%) patients: 15 with obstructive pathologies and 2 with haemodetournament of the second intercostal artery.