Reporting Standards for Carotid Artery Angioplasty and Stent Placement

Carotid artery stenting: Current state of evidence and future directions

Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for carotid artery stenosis. Several randomized controlled trials (RCTs) have compared CEA to CAS in the treatment of carotid artery stenosis. These studies have suggested that CAS is more strongly associated with periprocedural stroke; however, CEA is more strongly associated with myocardial infarction. Published long-term outcomes report that CAS and CEA are similar. A reduction in complications associated with CAS has also been demonstrated over time. The symptomatic status of the patient and history of previous CEA or cervical radiotherapy are significant factors when deciding between CEA or CAS. Numerous carotid artery stents are available, varying in material, shape and design but with minimal evidence comparing stent types. The role of cerebral protection devices is unclear. Dual antiplatelet therapy is typically prescribed to prevent in-stent thrombosis, and however, evidence comparing periprocedural and postprocedural antiplatelet therapy is scarce, resulting in inconsistent guidelines. Several RCTs are underway that will aim to clarify some of these uncertainties. In this review, we summarize the development of varying techniques of CAS and studies comparing CAS to CEA as treatment options for carotid artery stenosis.

Carotid artery stenting in a single center, single operator, single type of device and 15 years of follow-up

Background

Revascularization with carotid stent (CAS) is considered the therapeutic alternative to endarterectomy (CEA). However, its role compared to CEA remains questioned, mainly due of the heterogeneity of long-term results. The objective of this study was to report the efficacy and durability of CAS in terms of stroke prevention in a "real world experience".

Method

This was a single-center retrospective analysis of 344 patients treated with CAS between January 2001 and December 2015.The primary outcome of the trial was stroke, myocardial infarction, or death during a periprocedural period or any stroke event over a 15-year follow-up. The secondary aim was to identify risk factors for 30-day complications, long-term neurological complications, and intra-stent restenosis.

Results

The primary composite end point (any stroke, myocardial infarction, or death during the periprocedural period) was 2.3%. The use of an EPD was protective against major complications.Long-term follow-up was achieved in 294 patients (85,5%) with a median of 50 months (range 0-155 months). Fifty-six (16,3%) died within this period, most commonly of nonvascular causes (4 patients had stroke-related deaths). During the follow-up period, 8 strokes and 3 TIAs were diagnosed (3.2%).ISR determined by sequential ultrasound was assessed in 4.4% of the patients and remained asymptomatic in all but 2 patients (0.6%). All patients with restenosis underwent revascularization with balloon angioplasty.

Conclusion

The long-term follow-up results of our study validate CAS as a safe and durable procedure with which to prevent ipsilateral stroke, with an acceptable rate of restenosis, recurrence and mortality.

Recommendations for carotid stenting in Korea

Carotid artery angioplasty with stenting (CAS) is being performed in many hospitals in Korea. Most of the guidelines which are being used are similar, but the practical aspects such as techniques are different between hospitals. For example, usage of various protective devices, the oral antiplatelet regimen prior to procedure and placing of temporary pacemaker to prevent bradycardia are different between hospitals. In this article, we summarize and propose the guidelines for CAS which is currently being accepted in Korea. These guidelines may be helpful in providing protocol to neurointerventionalist who perform CAS and to standardize the process including reporting of CAS in the future comparative trials in Korea.

Neointimal hyperplasia after stent placement across size-discrepant vessels in an animal study

PURPOSE

To examine differences in neointimal hyperplasia (NIH) after placing a self-expanding (SE) stent across size-discrepant vessels.

MATERIALS AND METHODS

The subjects were 6 beagles, and the target vessels were the abdominal aorta and the external iliac artery (EIA). A nitinol SE stent was placed which was normal-sized in the aorta and oversized in the EIA. Angiography and intravascular ultrasound (IVUS) were performed immediately and after 1 and 3 months; histopathologic examinations were then performed. Furthermore, the chronic outward force (COF) on the same type of stent was investigated in vitro.

RESULTS

On IVUS, thickened intima was seen on the EIA at 1 month (5.1 ± 4.2 mm(2)) and at 3 months (7.8 ± 2.5 mm(2)). For the aorta, thickening of the intima was negligible at any time. Histopathologically, the percentage of the vessel obliterated by NIH was significantly greater on the iliac side than on the aortic side (33.2 ± 10.4 vs. 13.4 ± 4.4 %). The COF exerted when stent diameter reached that of the EIA and the aorta was 0.73 and 0.17 N/mm(2), respectively.

CONCLUSIONS

When a non-tapered stent is placed in vessels with a large discrepancy in diameter, attention must be paid to increased NIH in the oversized side.