[Evaluation of the patency of left internal mammary artery graft by transcutaneous Doppler flow velocity analysis].

OBJECTIVE

To analyze the features of Doppler flow velocity curve of left internal mammary artery by-pass grafts in relation with their permeability as assessed by selective angiography.

METHODS

Twenty-five consecutive patients with a left mammary artery graft were studied by angiography and transcutaneous Doppler technique. From the Doppler tracings, peak velocity and time-velocity integral of the systolic and diastolic components were determined. Patency of the graft and the characteristics of the distal native coronary artery were evaluated at angiography.

RESULTS

Doppler flow signal was obtained in 23 (92%) of 25 analyzed patients. The graft was angiographically patent in 17 (68%) of 25 patients; in 15 (88%) of them the Doppler flow velocity signal was mainly diastolic and in only 2 (12%) it was predominantly systolic. In 8 (32%) of the 25 patients the graft was angiographically occluded, 6 (75%) of these patients showing a predominantly systolic Doppler signal, while the remaining 2 (25%) patients were those in whom the signal could not be elicited. Sensitivity and specificity of a predominantly diastolic Doppler flow pattern for the presence of graft patency was 88% and 100% respectively, with a predictive positive value of 100% and a negative one of 80%.

CONCLUSIONS

Doppler flow velocity pattern of internal mammary artery by-pass grafts is related with patency of the graft, the presence of a predominantly diastolic curve being highly indicative of a patent graft.