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.

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. 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. 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. 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. © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.