Clinical results of 30 consecutive patients of carotid artery stenosis treated with CASPER stent placement: 1-year follow-up and in-stent findings on intravascular ultrasound examination immediately and 6 months after treatment.

Background: The CASPER stent is expected to reduce periprocedural ischemic complications, but there is concern about restenosis in the early period. One-year follow-up results of CASPER stenting and findings on intravascular ultrasound (IVUS) immediately and 6 months after treatment are evaluated.

Methods: Thirty consecutive patients were treated with CASPER stents for carotid artery stenosis. IVUS was performed immediately after stenting, and MRI and carotid ultrasonography were performed the next day, at 1 week, at 2 weeks, and then every 3 months. One-year follow-up results were evaluated. Twenty-five patients underwent follow-up angiography and IVUS after 6 months and their findings were investigated.

Results: All patients were treated without complications during the intraoperative and periprocedural periods. After 6 months, all 25 patients with follow-up angiography and IVUS showed various degrees of intimal formation on IVUS and 8 of them had ≥50% stenosis on angiography. Three of the 30 patients required retreatment within 6 months because of severe restenosis. In these patients, the inner layer of the stent was deformed toward the inside due to intimal hyperplasia on follow-up IVUS, and there was dissociation between the inner and outer layers. All but the 3 of 30 patients with 1-year follow-up did not lead to symptomatic cerebrovascular events or retreatment.

Conclusions: The CASPER stent appears to be effective for preventing periprocedural ischemic complications. IVUS showed various degrees of intimal formation within 6 months after treatment, and it is possible that the CASPER stent is structurally prone to intimal formation or hyperplasia.