Background and purpose: We assessed whether intentional undersized dilatation of targeted lesions during carotid artery stenting (CAS) carried a higher risk of in-stent restenosis (ISR) and correlation to subsequent ischemic stroke in qualifying arteries in the follow-up period.
Methods: Consecutive patients undergoing CAS between April 2003 and May 2010 were retrospectively reviewed. The use of a filter device as a distal embolic protection device (EPD) was first approved by Japanese governmental health insurance in April 2008; previously, transient balloon occlusion was used off-label. Until March 2008 (Group A), the target diameter of balloon dilatation was 80-100% of the normal vessel diameter just distal to the stenotic lesion. Moderately undersized dilatation (70-80% of the normal vessel diameter) using the distal EPD was adopted in April 2008 (Group B) in an attempt to reduce the amount of released plaque debris.
Results: We analyzed 132 CAS procedures (125 patients) in Group A and 53 CAS procedures (52 patients) in Group B. The mean follow-up period was 35.4 months (35.3 months in Group A and 36.0 months in Group B). Eight lesions (4.3%; 7 in Group A and 1 in Group B) developed ISR. None of the patients had symptomatic ISR, and ISR did not increase in Group B (odds ratio, 0.34; 95% confidence interval, 0.04-2.86; p = 0.32).
Conclusions: Undersized dilatation of targeted lesions did not increase the risk of developing ISR, and we suggest it as a viable treatment option to prevent ischemic events during CAS.
Keywords: carotid stenosis; endovascular therapy; restenosis; risk factor; stent.