Catheter delivery system

Abstract

A method for delivering catheters, and stents composed of soft, compliant polymers through anatomical passages. These devices have a bulbous anchorage end with a diameter greater than the rest of the catheter. To facilitate implant and delivery a pusher catheter or sheath with an internal lumen larger than the outer diameter of the catheter but smaller than the outer diameter of the bulbous anchorage end. The distal end of pusher catheter or the sheath physically engages the proximal end of the bulbous anchorage end and applies an axial force to coaxially advance the catheter over a guidewire though anatomical passages. This method allows a physician to move the catheter to an anatomical site without the device exhibiting buckling due to axial force applied. Similarly, this delivery method will allow more force to be applied to the distal end of the catheter diminishing the likelihood of buckling.

Description

FIELD OF INVENTION[0001]The present invention relates to a catheter delivery method and apparatus for delivering catheters or stents, specifically catheters or stents composed of soft, compliant polymers or other suitable materials, through anatomical passages, vascular networks, lumens and cavities.BACKGROUND OF INVENTION[0002]Specifically-trained physicians often implant a catheter or stent over a guidewire, proximate to, vascular and non-vascular occlusions; or to maintain patency of an anatomical lumen. To implant these devices, a physician must pass the device through vascular and non-vascular anatomical passages and cavities to reach the intended anatomical site which may exhibit an occlusion or an increased resistance when advancing the catheter or stent to the intended location.[0003]One accepted method for passing these devices through anatomical passages includes placing the distal end (defined as the end that is farthest from the Physician) of a guidewire proximate to the...

AI Technical Summary

Benefits of technology

[0026]In one embodiment of the subject invention, the method does not require that the guidewire by hydrophilically coated to exhibit a reduction in forces.

Problems solved by technology

Unfortunately, these obstacles require the physician to push the catheter or stent with increasingly excessive axial forces, and depending on the device design or the material from which the device is fabricated, buckling may occur.

Buckling of the device, due to excessive axial forces, is undesired as it may result in a damaged catheter, patient discomfort, accidental perforation of surrounding anatomy and prevention of catheter implantation to its intended location.

Therefore, the axial load is limited by the column strength of the device.

Unfortunately, shorter catheters are not practical; nor are they typically used in conventional applications where pushing a catheter is the method of delivery.

While this slow advance of the catheter does provide immediate tactile feedback to the physician should the catheter confront an obstruction during advancement, the process is long and tedious.

This increased axial force often causes the catheter, especially smaller diameter devices, to buckle.

These lubricous polymer coatings, which are typically are very thin, and relatively fragile, reduce the coefficient of friction of the device, which results in a reduced axial load.

These coated devices, which are flexible enough to bend tangentially at these boundaries, continue advancing along the anatomical path; however, these tangential bends may add external pressure to the coating at the points of contact.

Ultimately, once the coating is compromised, any further contact between the device and anatomical boundaries at these tangential bends will exhibit an increased level of relative friction, such as dry on dry surfaces that results in increased axial loads required to push or advance the catheter along.

In addition, this high friction may result in patient discomfort.

While these designs are more effective they result in undesirable and uncomfortable products as well as increased manufacturing costs.

These more rigid materials often cause patient discomfort and in many cases result in complications due to their increased ability to perforate surrounding anatomy during implantation.

However, using a more rigid material either as part of the catheter, stent or sheath still results in patent pain and or discomfort.

However, even a combination of these techniques results in patient discomfort, slow advancement and eventual buckling of the catheter or stent when increased axial loads are required to advance into or through anatomical passages.

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