Mechanical design of an intracranial stent for treating cerebral aneurysms

Shobayashi, Yasuhiro; Tanoue, Tetsuya; Tateshima, Satoshi; Tanishita, Kazuo

doi:10.1016/j.medengphy.2010.07.002

Cited by 19 publications

(12 citation statements)

References 24 publications

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“…In general, for a wide-necked aneurysm, closed-cell designs adapt less to the aneurysm geometry than open-cell designs. Closed-cell designs can be designed to have a low bending stiffness (Shobayashi et al, 2010); however for the more flexible (C2) design investigated, the low straightening observed with the open-cell design is not reached. As demonstrated here, open-cell stents like the N1, are more adaptable to the global vessel curvature and tortuosity, and induce a low straightening of the vessel.…”

Section: Discussionmentioning

confidence: 99%

“…2). The geometries of the closed-cell models were composed of hexagons according to Pythagorean tessellation theory (Shobayashi et al, 2010). All stents were constructed with the same strut thickness and width.…”

Section: Stent Modelsmentioning

confidence: 99%

“…The current intracranial stents in use can be categorized by design in two major groups: open and closed-cell self-expanding nitinol stents. Although it has been shown that both designs can successfully assist coiling, each type is associated with its own limitations (Shobayashi et al, 2010;Krischek et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Previous experimental and numerical research on intracranial stenting has focused on idealized vessel geometries and experimental setups when assessing the mechanical behavior of stents (Shobayashi et al, 2010;Krischek et al, 2011;Bernardini et al, 2012). While allowing a straightforward comparison of stent behavior, the model simplifications do not allow to capture certain in vivo conditions.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Our capricious vessels: The influence of stent design and vessel geometry on the mechanics of intracranial aneurysm stent deployment

Bock

Iannaccone

Santis

et al. 2012

Journal of Biomechanics

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Section: Discussionmentioning

confidence: 99%

Section: Stent Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Our capricious vessels: The influence of stent design and vessel geometry on the mechanics of intracranial aneurysm stent deployment

Bock

Iannaccone

Santis

et al. 2012

Journal of Biomechanics

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“…11,25 A constitutive model that simulates the super-elastic plastic behaviour of nitinol was used in this study to model the stent material. This thermo-mechanical coupled super-elastic plastic model is implemented by an in-built UMAT for ABAQUS/ Standard finite element solver.…”

Section: Materials Propertiesmentioning

confidence: 99%

An Experimental and Computational Study on the Effect of Caval Valved Stent Oversizing

Ismail

Kumar

Kabinejadian

et al. 2016

Cardiovasc Eng Tech

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Heterotopic implantation of transcatheter tricuspid valve is a new treatment option for tricuspid regurgitation. Transcatheter tricuspid valves are implanted onto the cavoatrial junction in order to avoid the challenging task of anchoring the valve onto the complex tricuspid valve annulus. However, little is known about optimum extent of oversizing of the valved stent in a vena cava. In this study, we implanted valves of the same diameter onto the larger sized inferior vena cava (IVC) and a smaller sized superior vena cava (SVC). The valve in the IVC was oversized by 10.7% while the valve in the SVC was oversized by 21.6%. Finite element analysis was performed (i) to assess the strain on the nitinol stent during manufacturing and deployment; (ii) the stents were deployed in a patient-specific vena cava model and the intramural stress of the vena cava was calculated computationally. These valves were fabricated and placed in a silicone model of a patient-specific right atrium which was part of a mock circulatory system that emulated the patho-physiological flow rate and pressure of a patient with tricuspid regurgitation. Flow measurements were conducted by particle image velocimetry (PIV). It was found that the maximum crimping strain on the nitinol stent was 6.85% which was lower than the critical threshold of 10%. The maximum stress on the vena cava was located at the spot where the hooks met the wall. The maximum stress on the IVC was 0.5098 MPa while the maximum stress on the SVC was 0.7 MPa. The maximum Reynolds shear stress (mRSS) in the vena cava was found to be higher in the IVC than SVC with the highest mRSS being 1741 dynes/cm(2) found in the region of high flow during the peak flow phase. The overtly oversized valve in the SVC did not cause flow disturbances and exhibited mostly laminar flows. The mRSS at the downstream of the vena cava valve and the middle of the atrium remained at low magnitudes. However, velocity fluctuations were high in the IVC in all the time points measured. In conclusion, oversizing the valve may assist anchorage; yet, careful consideration should be taken in choosing the extent of oversizing as it may lead to adverse effects.

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Design and biocompatibility of endovascular aneurysm filling devices

Rodríguez

Hwang

Horn

et al. 2014

J. Biomed. Mater. Res.

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The rupture of an intracranial aneurysm, which can result in severe mental disabilities or death, affects approximately 30,000 people in the United States annually. The traditional surgical method of treating these arterial malformations involves a full craniotomy procedure, wherein a clip is placed around the aneurysm neck. In recent decades, research and device development have focused on new endovascular treatment methods to occlude the aneurysm void space. These methods, some of which are currently in clinical use, utilize metal, polymeric, or hybrid devices delivered via catheter to the aneurysm site. In this review, we present several such devices, including those that have been approved for clinical use, and some that are currently in development. We present several design requirements for a successful aneurysm filling device and discuss the success or failure of current and past technologies. We also present novel polymeric based aneurysm filling methods that are currently being tested in animal models that could result in superior healing.

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Mechanical design of an intracranial stent for treating cerebral aneurysms

Cited by 19 publications

References 24 publications

Our capricious vessels: The influence of stent design and vessel geometry on the mechanics of intracranial aneurysm stent deployment

Our capricious vessels: The influence of stent design and vessel geometry on the mechanics of intracranial aneurysm stent deployment

An Experimental and Computational Study on the Effect of Caval Valved Stent Oversizing

Design and biocompatibility of endovascular aneurysm filling devices

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