Detection of distal emboli in patients with peripheral arterial stenosis before and after iliac angioplasty: A prospective study

Purpose: Embolism is believed to be the major cause of end-organ damage aft er angioplasty and endoluminal procedures. Recently, Doppler ultrasound sca nning has been used to detect asymptomatic cerebral emboli. We determined w hether asymptomatic embolic signals (ES) could be detected distal to a sign ificant iliac artery stenosis of >60% both before and soon after iliac perc utaneous transluminal angioplasty (PTA). Methods: A 2-MHz Doppler scan probe was used to monitor for ES in the commo n femoral artery before and after 10 successful iliac artery PTAs and at va rious standardized times in the following 24 hours. The same protocol was u sed to study 10 patients in the control group after renal PTA. In addition, a single recording was performed in a second nonoperative control group of 10 patients who had no evidence of peripheral vascular disease. The Dopple r scan signals were recorded on tape for a later blinded analysis. Results: In the 24 hours before iliac PTA, asymptomatic ES were detected in four of 10 patients during a 1-hour recording but in no controls (P = .025 ). After iliac PTA, ES were detected at 30 minutes in nine of 10 iliac subj ects but in only one of 10 renal subjects (P = .0003) and at 2 hours in eig ht of 10 iliac subjects but in only one of 10 renal subjects (P = .001). Th e occurrence of ES became less frequent, and ES were present at a lower fre quency in eight of 10 iliac PTA subjects at 4 hours and in five of 10 at 24 hours but in no renal PTA subjects at these time points. Conclusions: ES can be detected in the common femoral artery with Doppler u ltrasound scanning in patients with iliac artery stenosis both before and s oon after iliac PTA despite preangioplasty aspirin and intra-angioplasty he parin therapies. The occurrences of ES were particularly frequent in the 2 hours after PTA. This technique can be used further to study factors that c ontrol plaque stability and to evaluate the effect of therapeutic intervent ions.