Design of braided composite cardiovascular catheters based on required axial, flexural, and torsional rigidities

Abstract

Cardiovascular catheterization is a common medical procedure. A single braided catheter with different rigidities at the proximal and distal ends can, if properly designed, provide the necessary control and flexibility and thus replace the current two-piece (external catheter/internal guidewire) system. An analytical model based on classical laminate plate theory was developed in order to predict the elastic properties of angle-plied, single-overlap two-dimensional fiber composite tubular braids, which are required for the determination of the axial, flexural, and torsional rigidities. In this work the analytical model has been used to design one-piece cardiovascular catheters with axial, flexural, and torsional rigidities similar to those values for existing two-piece catheters, thus validating the model as a tool for designing braided cardiovascular catheters.

Design of a sensorized guiding catheter for in situ laser fenestration of endovascular stent

“…The next step will be the manufacturing of catheters according to the user feedback and the mechanical specifications listed in this work. Future studies will include accurate mechanical testing of the obtained catheter according to the methods proposed in the literature [24,25]. In vitro testing, involving a larger number of surgeons and using a simulator with a more realistic anatomical shape, will be performed for a further validation of the catheter prior to animal testing [44].…”

“…As compared to diagnostic catheters, guiding catheters have a stiffer shaft, larger internal diameter, and feature sufficient axial and torsional rigidity, allowing the user to easily push the catheter through the vascular system to control the torque for proper manipulation. The flexural rigidity should be variable, decreasing towards the tip, to allow passage of the catheter through tortuous sections of the cardiovascular system without causing injury to the arterial wall [25]. For these reasons, composite tube designs using more plastic materials are usually employed.…”

“…Several studies have evaluated the optimal rigidity values for diagnostic and guiding catheters designed for various endovascular applications [19][20][21][22][23][24][25]. As compared to diagnostic catheters, guiding catheters have a stiffer shaft, larger internal diameter, and feature sufficient axial and torsional rigidity, allowing the user to easily push the catheter through the vascular system to control the torque for proper manipulation.…”

“…The employed computational algorithms are based on mechanics of composite materials and composite laminate theory [36,37]. Different solutions were analyzed in order to obtain catheters with variable flexural stiffness (flexibility increasing toward the catheter tip), in consideration of the rigidity ranges reported in [25] as target values. More specifically, a three-layer braided design was considered and the following plastic materials, commonly employed for endovascular catheter fabrication, were selected: PellethaneV R 2363 series (Lubrizol Corporation, Wickliffe, OH, USA), PebaxV R 33 series (Arkema Inc., Philadelphia, PA, USA), and TEFLONV R polytetrafluoroethylene (PTFE) (DuPont Corp., Wilmington, DE, USA).…”

“…For our specific application, a three layer braided solution was selected and literature values for braided catheters [25] were considered as target rigidity values (Table 1).…”