DELAYED IMPROVEMENT IN CAROTID-ARTERY DIAMETER AFTER CAROTID ANGIOPLASTY

Background and Purpose Carotid percutaneous transluminal angioplasty ( PTA) is a new method of treating carotid artery stenosis. There has be en concern about restenosis after carotid PTA. This study was performe d to ascertain the change in percent stenosis 1 year after carotid PTA . Methods Twelve patients with symptomatic carotid stenosis were treat ed by PTA, and the anatomic result was studied by digital subtraction angiography at 1 year, supplemented by duplex ultrasound examinations at 1 month and 6 months. Results The mean severity of stenosis treated , measured by the common carotid method, was 82% (range, 69% to 98%). The immediate result of PTA was a reduction in the severity of stenosi s in all patients to a mean of 51% (P<.005). Six of the 12 patients sh owed a further improvement in lumen diameter of greater than or equal to 14% at 1-year angiographic follow-up from a mean stenosis of 47% (r ange, 24% to 76%) immediately after PTA to 28% (range, 0% to 52%) at 1 year. This indicates an active process of remodeling in response to c arotid PTA. PTA initially reduced the stenosis by greater than or equa l to 20% in 9 of the 12 arteries, and 8 of these remodeled or remained largely unchanged compared with only 1 of the 3 with a suboptimal ini tial dilation. In 3 patients the lumen diameter improved by <5%. Three other patients restenosed with an increase in stenosis after PTA of 9 %, 16%, and 66% at 1 year, but all were asymptomatic. The duplex findi ngs showed that remodeling occurred at variable times between PTA and 1 year. Conclusions Remodeling of the carotid artery after PTA has not been described before. Our results confirm that carotid angioplasty h as an acceptable patency rate at 1 year. It has been suggested that en dovascular treatment of carotid stenosis should include placement of a stent. Our results indicate that this may not be necessary unless the initial PTA result is a reduction in stenosis of <20%.