Patent Application
20230310005
The present invention relate to aneurysm treatment devices and more particularly, to improved delivery systems for embolic implants.
Numerous intravascular implant devices are known in the field. Many are deployed mechanically, via systems that combine one or more catheters and wires for delivery. Examples of implants that can be delivered mechanically include embolic elements, stents, grafts, drug delivery implants, flow diverters, filters, stimulation leads, sensing leads, or other implantable structures delivered through a microcatheter. Some obstetric and gastrointestinal implants may also be implanted via similar systems that combine one or more catheters and wires. Devices that may be released or deployed by mechanical means vary greatly in design but can employ a similar delivery catheter and wire system. Many such catheter-based delivery systems include a wire for retention of the implant in the catheter until the time for release of the device. These systems are then actuated by retracting or pulling the wire relative to the catheter. Such a wire is referred to herein as a “pull wire”.
One issue with current catheter-based delivery systems is premature detachment of the implantable device. Premature detachment occurs when the implant is detached from the delivery system before reaching the treatment site. This may occur due to the tortuosity experienced by the delivery system as it passes through the vasculature of the patient, which can cause an increase in friction between the “pull wire” and the delivery system causing the pull wire to move proximally while the delivery system is moving distally.
Accordingly, there is a need for an improved implant delivery system that prevents premature detachment of the implant as it is delivered through tortuous vasculature. This disclosure is directed to this and other considerations.
Disclosed herein are various exemplary systems, devices, and methods for delivering an implantable medical device to a target location of a body vessel. The system can include a generally hollow deliver tube that includes a lumen therethrough, a proximal end, and a distal end. An implant can be disposed on the distal end, and can have a proximal end having a plurality of engagement grooves. A pull member can be disposed within the lumen with a coiled distal end engaged to the engagement grooves. The pull member can be configured to disengage from the engagement grooves in response to being rotated axially or being translated proximally. In another aspect, the implant can have a notch member on a proximal end, and the pull member can include a distal end that is shaped to engage the notch member and disengage in response to the pull member being rotated axially.
In one aspect, a detachment system for delivering an implantable medical device to a target location of a body vessel is disclosed. The detachment system can include a generally hollow delivery tube, which can include a lumen therethrough, a proximal end, and a distal end. The detachment system can include an implant disposed on the distal end of the delivery tube. The implant can have a proximal end which includes a plurality of engagement grooves. The detachment system can include a pull member that is disposed within the lumen. The pull member can have a coiled distal end that is engaged to the engagement grooves. The pull member can be configured to disengage from the engagement grooves and cause the implant to be released in response to the pull member being rotated axially or being translated proximally.
In some embodiments, the detachment system can include a compressed portion of the delivery tube that is between the proximal end and the distal end. The compressed portion can be axially movable from a compressed state to an elongated state. The pull member can be under tension and the compressed portion can be configured to automatically move from the compressed state to the elongated state in response to the pull member disengaging from the engagement grooves.
In some embodiments, the compressed portion of the delivery tube can include a spiral-cut portion of the delivery tube.
In some embodiments, the proximal end of the implant can include a cylindrical shape. In some embodiments, the proximal end of the implant can include a rectangular prism configuration. In some embodiments, the implant can include an embolic coil. In some embodiments, the pull member coiled distal end is wrapped around the implant. In some embodiments, the pull member can be a wire. In some embodiments, the coiled distal end of the pull member is preformed to the engagement grooves of the implant.
In another aspect, a detachment system for delivering an implantable medical device to a target location of a body vessel is disclosed. The detachment system can include a generally hollow delivery tube that includes a lumen, a proximal end, a distal end, and a compressed portion of the delivery tube. The compressed portion of the delivery tube can be located between the proximal end and the distal end, and the compressed portion can be axially movable from a compressed state to an elongated state. The detachment system can include an implant disposed on the distal end of the delivery tube. The implant can have a proximal end which includes a notch member. The detachment system can include a pull member disposed within the lumen. The pull member can include a distal end that is shaped to engage the notch member while the compressed portion of the delivery tube is in the compressed state. The pull member can be configured to be rotated axially to be disengaged from the notch member and cause the compressed portion to move from the compressed state to the elongated state.
In some embodiments, the pull member is at a first position of axial rotation and the distal end of the pull member and the notch member are engaged to each other with an interference engagement. The pull member can be configured to be axially rotated to a second position with respect to the notch member so that the distal end of the pull member is disengaged from the notch member.
In some embodiments, a rotation angle between the first position and the second position can measure approximately 90 degrees. In some embodiments, the compressed portion of the delivery tube can include a spiral-cut portion of the delivery tube.
In some embodiments, the implant can include an embolic coil. In some embodiments, the distal end of the pull member can include a protrusion shaped to engage the notch member and rotate out of the notch member in response to the pull member being rotated axially.
In some embodiments, the tension of the pull member maintains the compressed portion in the compressed state and the disengagement of the pull member from the notch member allows the compressed portion to move from the compressed state to the elongated state and apply a force distally to the implant.
In some embodiments, the tension applied to the pull member due to compression of the compressed portion facilitates the movement of the protrusion from the notch member.
In some embodiments, the proximal end of the implant is at least partially disposed within the lumen of the delivery tube.
In another aspect, a method of detaching an implantable medical device. The medical device can include a hollow delivery tube having a proximal end and a distal end. The method can include providing a compressed portion of the delivery tube between the proximal end and the distal end. The method can include engaging the implantable medical device to a coiled distal end of a pull member, the pull member disposed in a lumen of the delivery tube while the compressed portion is in a compressed state. The method can include translating a pull member proximally, thereby unraveling the coiled distal end of the pull member from the implantable medical device while allowing the compressed portion to extend from the compressed state to an elongated state to release implantable medical device.
In some embodiments, a force required to translate the pull member proximally to disengage the coiled distal end of the pull member from the implantable medical device is between approximately 1 Newton and approximately 4 Newtons.
The above and further aspects of this invention are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. The figures depict one or more implementations of the inventive devices, by way of example only, not by way of limitation.
The following description of certain examples of the invention should not be used to limit the scope of the present invention. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the pertinent art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different or equivalent aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
Any one or more of the teachings, expressions, versions, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, versions, examples, etc. that are described herein. The following-described teachings, expressions, versions, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those skilled in the pertinent art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.
As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. More specifically, “about” or “approximately” may refer to the range of values ±10% of the recited value, e.g. “about 90%” may refer to the range of values from 81% to 99%. In addition, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the systems or methods to human use, although use of the subject invention in a human patient represents a preferred embodiment.
Turning to the figures, as illustrated in
Delivery system 10a can include a compressible portion 120. The compressible portion 120 can be axially adjustable between an elongated condition and a compressed condition. The compressible portion 120 can be formed from a spiral-cut portion of the delivery tube 100, formed by a laser cutting operation. Additionally, or alternatively, the compressible portion can be formed of a wound wire, spiral ribbon, or other arrangement allowing axial adjustment according to the present invention. Preferably, compressible portion 120 is in the elongated condition at rest and automatically or resiliently returns to the elongated condition from a compressed condition, unless otherwise constrained.
As shown in
According to some embodiments, the delivery system 10a can be configured to delivery implant 12 through a patient's vasculature to a treatment site, such as into an aneurysm.
Turning to
In step 406, the method includes rotating the pull member 150 axially to thereby disengage the pull member 150 from the implantable medical device. As pull member 150 is disengaged from implant 12, compressible portion 120 is allowed to extend from a compressed configuration to an elongated configuration, which imparts an elastic force against implant 12, which facilitates a successful deployment of implant 12 to a treatment site.
