Influence of angioplasty and stenting on intracranial artery stenosis: preliminary results of high-resolution vessel wall imaging evaluation

Peritherapeutic intra-arterial flow changes predict long-term stent patency in patients with severe intracranial artery stenosis receiving PTAS

BACKGROUND AND PURPOSE

The quantitative intra-arterial flow dynamics following percutaneous transluminal angioplasty and stenting (PTAS) for severe intracranial artery stenosis have never been investigated. We aimed to evaluate peritherapeutic intracranial artery flow dynamics following PTAS with quantitative magnetic resonance angiography (qMRA) to predict long-term stent patency.

DESIGN

This is a prospective, single-center study.

METHODS

We recruited participants with severe symptomatic stenosis from intracranial internal carotid artery (ICA) to M1 segment of middle cerebral artery (MCA) between 2018 and 2022. qMRA was performed before (preprocedural), within 24 h after (early postprocedural) and 12 months after (delayed postprocedural) PTAS, and parameters including bilateral M1 segments and basilar artery (BA) flow were recorded. The calibrated M1 ratio was calculated using contralateral M1 (cM1) and BA (cMB) flows as references. We assessed differences in qMRA parameters between subjects with and without significant 12-month in-stent restenosis (ISR).

RESULTS

Forty-four subjects (12 with + 32 without ISR ≥ 50 %) were included. The early postprocedural M1 flow was higher than preprocedural M1 flow in subjects with (p = 0.030) and without (p = 0.031) ISR. The early postprocedural healthy-side M1 flow was lower than preprocedural healthy-side M1 flow (p = 0.014) in subjects without ISR. Both the early (p < 0.001) and delayed (p = 0.014) cM1s were greater than the preprocedural cM1. The residual stenosis grade was positively correlated with delayed postprocedural cM1 in all subjects (r2 = 0.190; p = 0.003).

CONCLUSIONS

The cM1 and a distinct flow dynamic pattern on early qMRA (within 24 h after PTAS) may predict 12-month ISR.

Percutaneous transluminal angioplasty and stenting for severe stenosis of the intracranial carotid artery and its branches: Comparison of the Wingspan stent vs the Credo stent

BACKGROUND

Despite the widespread use of the Wingspan stent system for treating severe medically refractory intracranial artery stenosis (SMR-ICAS), a new Credo stent system was approved because it could integrate stent delivery within the balloon catheter. However, the therapeutic outcomes of these two systems have not been compared. This preliminary study aimed to compare the results of percutaneous angioplasty and stenting (PTAS) in SMR-ICAS patients treated with either Wingspan or Credo stents within the anterior cerebral circulation.

METHODS

SMR-ICAS patients with >70% stenosis in the anterior circulation who underwent PTAS using either the Wingspan or Credo stent system were retrospectively analyzed. We evaluated the technical success, safety, and outcomes of the two-stent systems.

RESULTS

A total of 29 patients were analyzed, including 17 patients treated with Wingspan stents and 12 with Credo stents. The outcomes of the Wingspan stent vs Credo stent were as follows: technical success (16/17 [94%] vs 11/12 [92%], p = 1.00); periprocedural intracranial hemorrhage (2/17 [12%] vs 0/12 [0%], p = 0.50); silent embolic ischemic lesions on periprocedural magnetic resonance imaging (MRI) (13/17 [76%] vs 7/12 [58%], p = 0.42); and significant (>50%) in-stent restenosis in 1 year (4/17 [24%] vs 2/12 [17%], p = 1.00). No recurrent stroke or mortality was noted within 30 days after the procedures or during the 1-year follow-up period.

CONCLUSION

The technical success, safety, and outcomes of the Credo stent system were comparable to those of the Wingspan stent system in the management of SMR-ICAS patients. Further large-scale studies are warranted to substantiate these findings.

Diagnostic value of high-resolution vessel wall imaging technique in intracranial arterial stenosis and occlusion: a comparative analysis with digital subtraction angiography

OBJECTIVE

To analyze the diagnostic value of HR-VWI in intracranial arterial stenosis and occlusion and compare it with DSA.

METHODS

A retrospective analysis of clinical data of 59 patients with intracranial arterial stenosis in our hospital was conducted to compare the diagnostic results of the two methods for different degrees of intracranial stenosis and various morphological plaques.

RESULTS

The diagnosis of stenosis and occlusion by both methods showed no significant difference (p > 0.05). Comparison of plaque morphology detected by HR-VWI with pathological examination results showed no significant difference (p > 0.05); however, there was a significant difference between plaque morphology detected by DSA and pathological examination results (p < 0.05). Additionally, there was a significant difference between plaque morphology detected by HR-VWI and DSA (p < 0.05).

CONCLUSION

HR-VWI technique is comparable to DSA technique in diagnosing intracranial arterial stenosis and occlusion, but it is superior to DSA in plaque morphology diagnosis.

Emerging Concept of Intracranial Arterial Diseases: The Role of High Resolution Vessel Wall MRI

Intracranial arterial disease (ICAD) is a heterogeneous condition characterized by distinct pathologies, including atherosclerosis. Advances in magnetic resonance technology have enabled the visualization of intracranial arteries using high-resolution vessel wall imaging (HR-VWI). This review summarizes the anatomical, embryological, and histological differences between the intracranial and extracranial arteries. Next, we review the heterogeneous pathophysiology of ICAD, including atherosclerosis, moyamoya or RNF213 spectrum disease, intracranial dissection, and vasculitis. We also discuss how advances in HR-VWI can be used to differentiate ICAD etiologies. We emphasize that one should consider clinical presentation and timing of imaging in the absence of pathology-radiology correlation data. Future research should focus on understanding the temporal profile of HR-VWI findings and developing quantitative interpretative approaches to improve the decision-making and management of ICAD.