Reyes de Torres Chacon, MD
Several studies in recent years have linked the type of stent used during carotid artery stenting (CAS) to the early recurrence of stroke in the early days (peri-procedural period). However, there are currently no data on the relationship between the type of device and the incidence of stroke and restenosis of the stent in the long term.
This study analyzes the restenosis rate and incidence of new strokes among patients treated with CAS using open-cell stent versus closed-cell stent during follow-up, at least 4 years.
Using data from 855 patients included in the International Carotid Stenting Study (ICSS), 352 patients treated with open-cell stents and 362 with closed-cell stents were analyzed. The restenosis rate was determined at successive visits by performing a carotid duplex and measuring peak systolic velocities in the common carotid artery, in the internal carotid artery, and also the end-diastolic velocity in the internal carotid artery.
Follow-up data demonstrate a higher rate of moderate or higher restenosis in patients treated using closed-cell versus those using open-cell devices (n=154 vs n=113; 5-year risks 46% versus 35.5%; unadjusted HR, 0.68; 95% CI, 0.53- 0.88). Regarding severe restenosis (>70%) or occlusions, no differences are demonstrated between the two groups (open cell n=27 versus closed-cell stenting n=43; cumulative 5-year risks of 8.6% versus 12.7%; unadjusted HR, 0.63; 95% CI, 0.37-1.05; adjusted HR, 0.63; 95% CI, 0.37-1.06).
Regarding the rate of occurrence of new ipsilateral strokes after the first 30 days of the procedure, no differences were found between patients treated with open-cell devices (n=10, 5 year risk 4.6%; 95% CI, 2.4-8.7) versus closed-cell (n=14, 5-year risk 4.3; 95% CI, 2.4-7.5) stenting (HR, 0.78; 95% CI, 0.35-1.75). No differences were found in the patients who died during follow-up in both groups.
According to the authors’ opinion, this study has several limitations, including the use of duplex ultrasound as the only technique to determine restenosis and the absence of randomization when assigning patients to each type of stent (it was done according to the decision of each center).
However, the results obtained may be related to the morphology of both types of stents, since open-cell stents have greater flexibility and respect better the morphology of the supra-aortic trunks, making the vessel walls less rigid and, therefore, decreasing the resistance and velocities of the blood passing through them, compared to closed-cell stents. Although open-cell stents have been shown to have a higher incidence of peri-procedure stroke in the first 30 days after placement (because plaque can protrude through the stent wall into the vessel light in the acute phase), they appear to have a lower rate of complications in long-term follow-up, taking into account the results of this study.
