title: Incidence and time course of carotid in-stent restenosis in a consecutive series of 295 patients.
abstract: OBJECTIVE
  In-stent restenosis (ISR) is a potentially preventable cause of stroke in carotid artery stent (CAS) patients. Understanding the frequency and timing of ISR would be useful in developing optimal protocols for carotid stent surveillance. The time course and frequency of moderate and severe ISR in our single institution prospective registry of CAS procedures is reported here.
  
  
  METHODS
  Data were collected prospectively from 296 consecutive elective CAS procedures. Doppler surveillance was performed at 1, 6 and 12 months and annually thereafter in some cases. Moderate ISR (>50%) was defined as a peak systolic velocity (PSV) > 200 cm/s. Severe ISR (>70%) was defined as PSV > 200 cm/s and end diastolic velocity > 125 cm/s or internal carotid artery/common carotid artery ratio >4. Patients with severe ISR underwent digital subtraction angiography for confirmation and possible retreatment.
  
  
  RESULTS
  Clinical follow-up at 1 year was 98%. Clinical and ultrasound follow-up at 1 month was 100%, at 6 months 96% and at 1 year 91%. The incidence of all ISR at 6 months was 8%; 5% moderate and 3% severe. Two patients had asymptomatic occlusions at 6 months (0.8%). Patients with moderate ISR at 6 months did not progress to severe ISR. There were two strokes caused by stent thrombosis, one acute and one delayed.
  
  
  CONCLUSIONS
  Doppler surveillance is important for detecting ISR after CAS procedures. Severe ISR (>70%) should be retreated in most cases as ISR may progress to occlusion. Asymptomatic patients with moderate ISR (50-69%) at 6 months can be safely followed conservatively. Progression of ISR after 6-12 months is uncommon over a 2-3 year period.
authors: Forsyth Medical Center, 3155 Maplewood Avenue, Winston-Salem, North Carolina 27106, USA. dvheck@triad.rr.com
authors: D
authors: D
authors: Heck
mesh_terms: D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality; D009369:Neoplasms / Q000401:mortality; D011446:Prospective Studies; D012042:Registries / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D015607:Stents / Q000009:adverse effects / Q000706:statistics & numerical data*; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000628:therapy*; D018608:Ultrasonography, Doppler