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 after angioplasty and endoluminal procedures. Recently, Doppler ultrasound scanning has been used to detect asymptomatic cerebral emboli. We determined whether asymptomatic embolic signals (ES) could be detected distal to a significant iliac artery stenosis of >60% both before and soon after iliac percutaneous transluminal angioplasty (PTA).

METHODS

A 2-MHz Doppler scan probe was used to monitor for ES in the common femoral artery before and after 10 successful iliac artery PTAs and at various standardized times in the following 24 hours. The same protocol was used 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 Doppler 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 subjects but in only one of 10 renal subjects (P =.0003) and at 2 hours in eight of 10 iliac subjects but in only one of 10 renal subjects (P =.001). The occurrence of ES became less frequent, and ES were present at a lower frequency 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 ultrasound scanning in patients with iliac artery stenosis both before and soon after iliac PTA despite preangioplasty aspirin and intra-angioplasty heparin therapies. The occurrences of ES were particularly frequent in the 2 hours after PTA. This technique can be used further to study factors that control plaque stability and to evaluate the effect of therapeutic interventions.