Novel Compliant Scaffold with Specific Design for Venous System: Results of a Porcine Model Study

Long-term safety and efficacy of stenting on correcting internal jugular vein and cerebral venous sinus stenosis

OBJECTIVES

To compare the long-term safety and efficacy of stenting in correcting cerebral venous sinus stenosis (CVSS) and internal jugular venous stenosis (IJVS).

METHODS

Patients confirmed with CVSS or IJVS by imaging were enrolled in this real-world study from 2014 through 2021. Clinical characteristics and long-term outcomes of these two diseases entities post-stenting were followed up and compared.

RESULTS

Three hundred and nineteen patients were enrolled in this study, with a mean age of 48.83 years and a BMI of 25.08 on average. In which, 144 patients underwent stenting, the stenotic segments were corrected and the venous blood flow was restored immediately post-stenting. At 6.15 ± 1.67 days follow-up, significant improvement was observed in headache, tinnitus, insomnia, ICP, and mean pressure gradient in both groups (all p < 0.05). At 30.53 ± 4.41 months follow-up post-stenting, the headache, tinnitus, visual loss, papilledema, and insomnia were attenuated remarkably or even completely disappeared. The Frisen papilledema grade scores declined from 2 (0-4) to 1 (0-3) in IJVS group and from 4 (1-5) to 1 (0-4) in CVSS group compared to the baseline. One hundred and twenty-seven out of the 144 patients (95.5%) maintained sufficient blood flow verified by followed up computed tomographic venography or contrast-enhanced magnetic resonance angiography. Adverse events related to stenting included three cases of intraluminal restenosis and three cases of in-stent thrombosis, no intracranial hemorrhage, venous thromboembolisms, stent-adjacent stenosis, and stent displacement occurred.

INTERPRETATION

Using stents to correct IH and related neurological issues has shown to be a safe and effective approach for both IJVS and CVSS.

What are the ideal characteristics of a venous stent?

Historically, the stents used in the venous system were not dedicated scaffolds. They were largely adapted arterial stents. An essential feature of a venous stent is compliance, in order to adapt its crosssectional area to the vein. It should also be crush resistant, corrosion resistant and fatigue resistant. The material should be radiopaque, for follow-up. Another characteristic of the ideal venous stent is flexibility, to adapt its shape to the vein, not vice versa. The scaffold should be uncovered too, in order to avoid the occlusion of collaterals. The ideal venous stent should not migrate, so it is necessary a large diameter and a long length. The radial force is important to prevent migration. However, current stents derived from arterial use display high radial force, which could affect the patency of the thin venous wall. Alternatively, if the stent has an anchor point, that permits a passive anchoring, the radial force required to avoid migration will be lower. Dedicated venous stents were not available until very recently. Furthermore, there is a preclinical study about a new compliant nitinol stent, denominated Petalo CVS. Out of the commonest causes of large veins obstruction, dedicated venous stent could also treat other diseases described more recently, such as the jugular variant of the Eagle syndrome, JEDI syndrome and jugular lesions of the chronic cerebrospinal venous insufficiency that result unfavorable for angioplasty according to Giaquinta classification.