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An in vitro study of silk stent morphology

  • Interventional Neuroradiology
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Abstract

Introduction

Morphology of the Silk stent (Balt, Montmorency, France) after deployment is not fully understood, especially in tortuous vessels. An in vitro study was conducted to study morphology and flow-diverting parameters of this stent.

Methods

Two sets of different-sized and curved polytetrafluoroethylene tubes were studied. To simulate the aneurysm neck, a small hole was created in a tube. A stent was placed in each of the different tubes. Angiographic computerized tomography and macroscopic photography were then obtained. The images were analyzed to calculate a Percentage of Area Coverage (PAC).

Results

Good stent conformability was observed. The PAC was 21% in the straight model with matched stent and vessel diameter. In the straight model with an oversized stent, the PAC was increased. In the curved models, dynamic wire repositioning occurred. The repositioning was affected by the size of the stent and the angle of the vessel curve. Compared to the straight model, this increased the PAC in two instances: on the convexity (oversized stent), and on the concavity (matched stent and vessel diameter). The PAC did not significantly change at the sides of the curve.

Conclusions

By design, the wires of the silk stent move relative to each other. In a curved model, the PAC is different at the convexity, concavity, and lateral walls. The stent diameter affects the PAC. These results are clinically relevant because it is desirable to maximize and minimize the PAC across the aneurysm neck and branch vessel orifice, respectively.

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Abbreviations

PAC:

Percentage of area coverage

PTFE:

Polytetrafluoroethylene tubes

ACT:

Angiographic computerized tomography

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Conflict of interest statement

We declare that we have no conflict of interest. The stents and PTFE tubes were provided by Balt Company, France.

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Correspondence to Thaweesak Aurboonyawat.

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Aurboonyawat, T., Blanc, R., Schmidt, P. et al. An in vitro study of silk stent morphology. Neuroradiology 53, 659–667 (2011). https://doi.org/10.1007/s00234-010-0784-4

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  • DOI: https://doi.org/10.1007/s00234-010-0784-4

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