Guidelines for noninvasive evaluation of asymptomatic carotid bruits.

Basic recommendations for follow-up utilizing OPG/CPA results are as follows: Grade 1: Repeat studies in 12 months in the absence of specific focal TIAs or increase of bifurcation level bruit. Grade 2: Serial studies in 6 to 12 months in the absence of focal TIAs which provide their own indications for evaluation. If stability is established, 12-month interval testing is adequate. Grade 3: Serial studies in 3 to 6 months until a progression trend is established. Anticipation of major surgery with possible hypotension or severe blood loss is an indication for arteriography and possible endarterectomy. Grade 4: If repeat studies confirm grade 4 status, prophylactic carotid arteriography and endarterectomy should be seriously considered. If surgery is not employed, repeat OPG/CPA evaluation at 2 to 4 month intervals detects further progression toward total occlusion. Grade 5: Indications for arteriography in anticipation of surgery are tempered by the lower probability (30%) of a surgically correctable stenosis and the clinical status of the patient. In conclusion, we feel that OPG/CPA represents one valid means of noninvasively evaluating the presence and underlying hemodynamic significance of an asymptomatic bruit with sufficient reliability to justify angiography and prophylactic carotid endarterectomy on the basis of appropriate findings.