MXPA98003776A - Device for deployment of endoluminal protesis, for use with variable length protesis and with retracc capacity - Google Patents

Abstract

The present invention relates to a device for deploying endoluminal prostheses for use with an endoluminal prosthesis, said device comprising: a) an outer sheath having a proximal end and a distal end, b) an inner symbol having a proximal end and a distal end, said inner symbol slidably disposed within said outer sheath, and c) means for fastening the prosthesis on said distal end of said inner symbol for engaging a proximal end of a prosthesis and pulling the prosthesis to said distal end of said outer sheath without engaging the distal end of the prosthesis when the prosthesis is pulled completely into said outer sheath, said restraining means of the prosthesis comprising a tear-resistant ampoule, white

Description

DEVICE FOR DEPLOYMENT OF ENDOLU INALES PROSTHESIS > FOR YOUR USE COM PROSTHESIS OF VARIABLE LENGTH AND THAT HAS CAPACITY OF RETRACTION BACKGROUND OF THE INVENTION 1. - Field of the Invention The invention relates to devices for deploying endoluminal prostheses. More particularly, the invention relates to a displacement device which accommodates prostheses of different lengths and which allows retraction of a prosthesis before full deployment. 2. - State of the Art Translucent prostheses are well known in medical techniques for their implantation in blood vessels »bile ducts or other similar organs of the living body. These prostheses are commonly known as fixators and are used to maintain »open or dilate tubular structures or to support tubular structures that are being anastomosed. When biocompatible materials are used as a cover or coating for the fixative, the prosthesis is called a fixative graft. If used specifically in blood vessels, grafting with a fixator is known as an endovascular graft. A fixator or graft can be inserted into the body by stretching it longitudinally or by compressing it radially until its diameter is reduced sufficiently so that it can be introduced into the catheter. The graft with fixator is delivered through the catheter to the deployment site and then released from the catheter, after which it expands on its own. Fixative grafts introduced in this way are known as grafts with endolute fixatives. A typical state of the art fixator is shown herein as described in the U.S. Patent. No. 4,655,771 to Wallsten or to U.S. Patent No. 1,205,743 to Didcott, in Figures 1, 2 and 2a according to the prior art. Didcott and Wallsten disclose a tubular body fastener 10 composed of wire elements 12"each of which extends in helical configuration with the centerline 14 of the fastener 10 as the common axis. Half of the elements 12 is rolled in one direction while the other half is wound in the opposite direction. With this configuration, the diameter in the fixator is variable by the axial movement of the ends 9 »11 of the fixator. Typically, the intersecting elements form a configuration similar to a braid and are arranged so that the diameter of the fastener 10 expands normally as shown in Figures 1 and. The diameter can be contracted by pulling the ends 9 »11 of the fixer 10 away from one another as shown by the arrows ÍS, 18 in Figure 2. When the ends of the body are released» the diameter of the fixator ÍO expands on its own and pull the ends 9, 11 of the fastener closer to each other. The ratio of shrinkage to stretch and radial pressure of fixators can usually be determined from basic braid equations. A complete technical discussion of the braid equations and the mechanical properties of fixators is found in Jed eb »M.R. and Clerc, C.O. , "A Study of the Geometric and Mechanical Properties of a Self - Expanding Metal! Ic Sten - Theory and Experiment", Journal of Appl ed Biomaterials; Vol. 4, pp. 77-T5 (1993). The fact that fasteners undergo several dimensional changes from their compressed form to their uncompressed form causes complexities in their placement. The placement of a fixator that has some degree of elongation and radial force as a result of compression is very difficult for several reasons. First, you may have to push the fixator out of the catheter over a long distance "depending on your angle of inclination. This can be extremely difficult in view of the increased frictional forces and the various bent sections found in the catheter as it traverses a sinuous path. Secondly, the fixer can shrink significantly in its length as it expands in its diameter, making it difficult to place it precisely in a duct. In third place, the protuberances or inclusions of plaques, thrombosis clots and others in a lumen of the blood vessel can alter the diameter of the fixator, which consequently alters the length of the fixative. Those skilled in the art will appreciate the importance of extreme pressure in the placement of! endováscular graft (EVG). For example, in aneurysmal vessel disease, as it is found in the abdominal aorta in which the distance between the renal arteries and the aneurysm is quite short (less than 3 cm), the poor placement of an EVG over the renal arteries or only in e! Aneurysm can be fatal. Proper fixation of the fixator becomes impossible when the fixator is too long or too short for the body cavity in which it is being deployed. To be effective, the dimensions of a vessel must be known with great precision and the fixer must be made to match the vessel specifcations. Several difficulties arise, however, when it comes to determining the proper length of fixer needed for any particular cavity. One such problem "especially present with the own expansion fixer design, as described by Wallsten and Didcott" is that it is often difficult to predict exactly how long the fixator should be cut in order to fit properly within a particular blood vessel. For example »when an EVG is deployed in an aortic aneurysm» the far end! of the fixative can be established in the aneurysm area! if the fixator is cut too short in length »thus not following the aneurysm and causing potential problems» such as the rupture of the aneurysm. On the other hand, if the EVG is cut too long, the distal end of the EVG can be extended to the iliac arteries. will cause the coagulation of the iliac artery against! ateral. Also »if it is deployed in a vessel with multiple branching and the EVG that is too long, it can inadvertently cover an arterial branch, thus occluding the branch and stopping at the mentioning of the organ to which it is destined to nourish. It is known that the deployment length of an EVG fixator is currently approaching using several hagiographic techniques (X-ray recognitions of the olfactory blood vessels following the injection of a substantial radiopaque). In particular, this is done by injecting radiopaque dye into a beaker and photographing the dye with an X-ray apparatus as it moves through the beaker. It is also known that Computed Tomography (CT) scans and the like are used to show the arterial diameters from which the desired length of the deployment fixator can be extrapolated. Other novel methods to visualize the steps include spiral CT scan and intravascular ultrasound (IVUS). Patent application serial number 08 / 466,934 discloses an apparatus and a method for measuring the desired length of a prosthetic device that is to be implanted in a cavity in the body of a patient. The apparatus generally includes an angle that is connected to the proximal end! of a fixator and a sheath that slides over the plunger and the fixator. A next portion! from! The plunger is provided with a scale to measure an indication of the length of the fixator that unfolds removably in the body cavity. The proximal movement of the sheath to partially deploy e! Fixator inside the body cavity using the plunger and the sheath. Once the fixator bridges the body cavity, the scale is used to determine the length of the deployed portion of the fixator. The fixator is retracted into the sheath and the apparatus is then removed from the body cavity. The indicated length is used to cut a fixator for its implant using the conventional fixator inserter. Figure 3 according to the prior art shows a conventional fixator inserter 20 which it has an outer sheath 22 and a plunger 24 which is movable through the sheath. The proximal end 23 of the sheath 22 is provided with a travadora mechanism 26 to reverse the relative positions of the sheath 22 and the plunger 24. A narrow catheter 28 extends from the proximal end of the sheath 22. far away! 25 of the plunger 24 and terminates it in the dilator tip 30. The dilator tip 30 typically has a cylindrical proximal end and a conically tapered distal end 34. The contiguous lumen 36 extends through the plunger 24 of the catheter 2B and the dilatation tip 30 so that the entire instrument 20 can be guided over a guidewire 33 a! implant site. A fixator (not shown) is placed on the inserter radially compressing and axially expanding (elongating) the fixator in the space between the distal end 25 of the plunger and the proximal end 32 of the tip 30 and sliding the sheath 22 over the f jador After the inserter 20 is guided to the implant site with the help of a guide wire 3S, the piston 24 is held stationary, the sleeve 22 is pulled proximally and the clamp of the sheath 22 is released. * 5 This is a notable limitation that the inserter 20 than the length of the catheter 28, and therefore the distance between the distal end 25 of the plunger 24 and the proximal end! 32 of the tip of the machine 30 »be fixed. Therefore, the inserter 20 will only accommodate fasteners having an axially expanded length that is substantially equal to the length of the catheter 28. In this way, during an implant procedure in e. which the fixer can be adjusted to the size »you must have many different size cutters at hand and you have to use more than one inserter.

It is also remarkable that the inserter 20 in particular the plunger 24 is not provided in any way for attaching the fixator. Therefore, as the fixer is being deployed, there is no way to reverse the deployment procedure. Once the fixator is actually expanded enough to merge with the wall of a vessel it can not be relocated and can not be pulled back to the tip.

BRIEF DESCRIPTION OF THE INVENTION It is therefore an object of the invention to provide a device for the deployment of endoluminal prostheses that is adjustable for use with prostheses of different lengths. It is also an object of the invention to provide a device for deployment of endoluminal prostheses that allows retraction of the prosthesis during deployment. According to these objects to be considered in detail below, a device for deployment of endoluminal prostheses according to the present invention includes a hollow plunger that is slidably mounted on a narrow inner catheter and an outer sheath through which the catheter and the plunger are slidable. The distal end of! The plunger is provided with a soft retractor bulb and the distal end of the inner catheter is provided with a dilator tip. The proximal end of! The plunger is provided with a locking mechanism for temporarily locking the relative portions of the plunger and the catheter, and the proximal end of the outer sheath is provided with a locking mechanism for temporarily locking the relative positions of the plunger and the outer sheath. The deployment device according to the invention accommodates prostheses of different lengths by adjusting the distance between the distal end of the plunger and the doctoring tip. This distance is adjusted by moving the plunger and / or and the catheter with respect to each other and locking their relative positions with the locking mechanism on e! plunger. In addition, the retractor bulb provides secure engagement of the distal end of the plunger to the proximal end of an endoluminal prosthesis such that the prosthesis can be retracted back to the outer sheath even after the B0% is deployed. The retractor bulb is preferably made of a soft, tear-resistant material that is molded conically or frustroconically with its base at its distal end. The diameter of the bulb base is preferably 0.127 mm larger than the inner diameter of the sheath and 0.051 mm smaller than the inner diameter of the sheath. The distance between the base of the vial and the far end! of the plunger is preferably between 1.27 mm and 9.53 mm. Suitable materials for the retractor bulb include soft elastic materials such as those with hardness in the range from Shore SOA to Shore SSD such as polyurethane, silicone rubber, polyolefin, sponge rubber, hydrogeum, nylon pebax, polyester ester, etc. . The catheter, the plunger and the sheath are preferably made of polyethylene »through-going» TEFLON »FEP» polyolefin »polyester, etc., with Shore hardness of material preferably inside! Shore range 70A to Shore 100D. According to a preferred aspect of the invention, the locking mechanisms on the plunger and the sheath are provided with hemostasis valves and washing holes so that the cellular spaces between the catheter and the plunger can be washed with heparanised saline. between the plunger and the sheath. Other objects and further advantages of the invention will become apparent to those skilled in the art with reference to the detailed description considered in conjunction with the figures provided.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a sectional side vertical view of a fastener according to the prior art expanded and in an unstressed position. Figure 1 is a cross-sectional view along the line 1A-1A of Figure 1? Figure 2 is a vertical view! sectional side of a fighter according to the prior art stretched and contracted; Figure 2a is a cross-sectional view along the line 2A-2A of Figure 2 »Figure 3 is a transparent side vertical view sectioned in partial section of a fixator inserter according to the prior art; Figure 4 is a vertical sectional side view sectioned in partial section of a deployment device according to the invention; Figures 5-7 are views similar to that of Figure 4 of a device according to the invention in preparatory stages of operation in which the fastener is loaded into the device for subsequent deployment; Figures 8 and 9 are views similar to that of Figure 7 of a device according to the invention that is located at the site of a neurism with the help of a guidewire; and Figures 10-12 are transparent side vertical views sectioned in partial section of a device according to the invention during the first, second and third stages of deployment of a fixator.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring now to Figure 4, an endoluminal prosthesis deployment device 50 according to the present invention includes a hollow plunger 52 which is slidably mounted on a narrow inner catheter 54 and an outer sheath 56 through which the catheter 54 and plunger 52 are slideable. The plunger 52, the catheter 54 and the sheath 56 are preferably made of polyethylene, polyoamide, TEFLON, FEP, polyolefin, polyurethane, polyester, etc. The distal end 58 of the plunger 52 is provided with a soft retractor bulb 60 and the distal end 62 of the inner catheter 54 is provided with a dilator tip 64. The dilator tip 64 has a frustroconical portion 64a distal and a cylindrical portion 64b proximal defining it. the step 64c between them and is preferably constructed of any of the aforementioned materials with respect to the retractor bulb and the catheter. The proximal end GG of! plunger 52 is provided with a locking mechanism 68 for temporarily locking the reactive positions of the plunger 52 and the catheter 54 »and the proximal end 70 of the outer sheath 56 is provided with a locking mechanism 72 for temporarily locking the relative portions of the plunger 52 and the outer sheath 56. The retractor bulb 60 is preferably made of a soft "tear-resistant" material that is molded conically or frustro-conically with its base 60a at the distal end. The diameter of the base 60a of the ampule 60 is preferably between 0.127 mm greater than the inner diameter of the sheath 56 and 0.051 mm smaller than the inner diameter of the sheath 56. The retractor bulb 60 is located at the distal end of the plunger 52 so that the distance between the base 60a of the ampule 60 and the distal end 58 of the plunger 52 is preferably between 1.27 mm and 9.53 mm. Suitable materials for the retractor bulb 60 include polyurethane »silicone rubber» polyolefin »sponge rubber» hydrogel »nylon pebax. Eglicolated polyester »etc .. with hardness in the range from Shore 30A to Shore 55D. From the above it will be appreciated that the distance between the vial 60 and the dilator tip 64 can be temporarily adjusted and locked in order to accommodate fasteners of different lengths. The locking mechanisms 68 and 72 each include a body 68a »72a having a lateral fluid hole 68b, 72b, a proximal threaded end 68c» 72c. a screw cap 6Sd, 72d, and ring at 0 6Be »72e between the cap 68d, 72d and the proximal end 6Bc, 72c of! body 68a »72a. Tightening the caps 68d, 72d compresses the rings at 0 68e »72e to form mechanical and fluid seals between the plunger 52 and the catheter 54 between the sheath 56 and the plunger 52» respectively »preferably the O-rings maintain a fluid seal when Tas caps are loosened. The proximal end 54a of catheter 54 is preferably provided with a hub 54b »a latuer 54c and a conduit (not shown) receiving a guidewire 74. The device 50 is designed to be used in conjunction with a guide wire 74 as shown in FIG. describes in detail later. Turning now to FIGS. 5-7 the deployment device 50 according to the invention is "loaded" with a fixator or other endolute prosthesis 80 that is previously cut to the desired length. The proximal end 80a of the prosthesis is placed on the retractor bulb 60 and the prosthesis is stretched such that the diameter of the proximal end! it is reduced to fit inside the sheath 56. The plunger 52 and / or the sheath 56 move away from each other so that the ampule 60 is pulled into the sheath 56 with the proximal end SOa of the prosthesis 80 being captured between the vial 60 and the interior of the sheath 56 as shown in Figure 5. The plunger 52 and / or the sheath 56 move further apart from one another until the prosthesis 80 is contained substantially within the sheath 56 as shown in FIG. Figure 6. After the prosthesis 80 is completely inside the sheath 56, the proximal end 64b of the dilator tip 64 is pulled to the distal end 56a of the sheath 56, as shown in Figure 7 »moving the plunger 52 and / or e! catheter 54 one from another. When the device 50 is loaded with the prosthesis 80 or shown in Figure 7, the caps 68b, and 72d of the respective locking mechanisms 68, 72 are tightened so that the relative positions of the plunger 52, the catheter 54 and the funda 56 lock. Using the fluid orifices 68b, "72b, the annular spaces between the plunger and the catheter and between the plunger and the sheath are washed with haparanized saline solution Slots or channels (not shown) in the c-portion 64b of the tip dilator 64 extending from the more proximal end of dilator tip 64 to step 64c allows fluid to exit the space between plunger 52 and sheath 56, and between plunger 52 and catheter 54 during the washing procedure. 50 is then ready for introduction to the human body, now referring to Figures 8 and 9 »the deployment device 50 according to the invention is guided to a surgical site (eg aneurysm) 90 with the help of a guidewire 74 which is inserted through the lumen of the catheter 54. The practitioner can monitor the progress of the deployment using a fluoroscope and radiopaque means that is carried out and disseminated throughout the device. ositive 50 as it travels through the patient. In addition »the device 50 and the prosthesis 80 are preferred radiopaque themselves» thus also assisting visualization under the luoroscopy. The device 50 is located as shown in Figure 9, with the prosthesis 80 extending over the aneurysm 90 so that the proximal end SOa of the prosthesis 80 is located proximal to the proximal neck 90a of the aneurysm 90 and the distal end. TOb of the prosthesis BO is located distal to the distal neck! 90b of the aneurysm 90. When the device 50 is positioned in this way, the prosthesis 80 can be deployed. Turning now to Figures 10-12, the deployment of the prosthesis 80 is effected by loosening the cover 72b of the locking mechanism 72 so that the plunger 52 and the sheath 56 are movable with respect to each other. While the stationary plunger 52 is held, the sheath 56 moves proximally so that the distal end 80b of the prosthesis 80 loosens as shown in Figure 10. Those skilled in the art will appreciate that the distal end TOb of the prosthesis 80 it must expand in a distal location of the distal neck! 90b of the aneurysm 90. If the distal end 80b of the prosthesis 80 extends within the aneurysm 90, the deployment procedure can be reversed by moving the sheath 56 in the distal direction to recapture the distal end of the prosthesis. After recapture the device 50 can be relocated and the deployment can be resumed. When the distal end 80b of the prosthesis 80 expands to the appropriate location, as shown in FIG. 1, the deployment procedure continues to move the sheath 56 in the proximal direction so that substantially all of the prosthesis 80 is expanded as shown. It is preferable at this point to stop loosening the proximal end 80a of the prosthesis 80 until it ascertains that the proximal position 80c of the prosthesis 80 is properly located. Those skilled in the art will appreciate that the proximal end 80a of the prosthesis 80 should be expanded in a proximal location! of the proximal neck 90th of! aneurysm 90. If it appears at this stage of deployment, that the proximal end SOa of prosthesis 80 will expand within aneurysm 90, the deployment procedure may be reversed by moving sheath 56 and the distal direction to recapture the entire prosthesis 80 for its relocation or for removal of the body and its repositioning with a prosthesis of different sizes. If it appears "on the other hand" that the prosthesis 80 is positioned correctly as shown in Figure 11, the proximal end 80a of the prosthesis is loosened by moving the sheath 56 proximally until the ampoule 60 is exposed and the proximal end! The prosthesis SOa exits the distal end of the sheath 56. It will be appreciated that after the prosthesis SO is deployed as shown in Figure 12, the deployment device 50 is removed from the body typically with the help of the guidewire 74. Before removing the device 50, it is preferable that the dilating tip 64 be retracted to the distal end of the sheath 56. This can be effected by moving the distal sleeve. moving the plunger pro? imally »or loosening the locking mechanism 68 and moving the catheter proximally. A device for deploying endoluminal prostheses for use with prostheses of varying lengths and having retraction capability has been described and illustrated herein. Although particular embodiments of the invention have been described, the invention is not intended to limit them, since it is intended that the invention be as broad in scope as the technique allows and that the specification be read in the same manner. In this way, although materials and hardnesses of particular materials have been made known, it will be appreciated that other materials and / or hardnesses could be used. Also, while particular working mechanisms have been shown, it will be recognized that other types of working mechanisms could be used with similar results obtained. In addition, while a particular configuration has been disclosed with reference to the retractor bulb, it will be appreciated that others with configurations could also be used. For example, the retractor bulb could be inflatable or it could take the form of a multiple jaw clamp. In addition, while the device with fluid orifices for jet washing has been disclosed, it will be understood that similar devices that bypass the fluid orifices can achieve the same or similar function as described herein. Furthermore, those skilled in the art will appreciate that all slidable materials can be coated with lubricating agents such as hydrogels that provide slippery surfaces, silicone oils and the like to help maneuver the catheter through sinuous paths and remote locations in the body. It can also be appreciated that drugs such as anti-coagulants, anti-lamatories, bactericides and antibiotics can be incorporated into the surface of these delivery catheters to limit blood clots, infections and other detrimental events that may hinder the procedure. It will therefore be appreciated by those skilled in the art that other modifications to the provided dimension may still be made without deviating from their spirit and scope as claimed.

Claims (9)

1. NOVELTY OF THE INVENTION
3. A device for deplnt of intact endoTu prostheses for use with an endoluminal prosthesis, said device comprising: a) an outer sheath having a proximal end and a distal end; b) an inner plunger having a proximal end and a distal end »said inner plunger slidably disposed within said outer sheath; and c) means for fastening the prosthesis on said distal end of said inner plunger to engage a proximal end of a prosthesis and pull the prosthesis to said distal end. of said outer sheath without engaging the distal end of the prosthesis when the prosthesis is pulled completely to said outer sheath »said restraining means of the prosthesis comprises a soft tear-resistant ampule». 2. A device according to claim 1, further characterized in that said bulb has a distal end. substantial frustroconical entity. 3. A device according to claim 2, further characterized in that said distal end of said bulb has an outer diameter that is substantially equal to the inner diameter of said outer sheath.
4. 4. - A device according to claim 3, further characterized in that said outer diameter is between 0.127 mm greater than said inner diameter and 0.051 mm smaller than said inner diameter.
5. 5. A device according to claim 1, further characterized in that said distal end of said fastening means is between 2.54 mm and
6. 6.35 mm from said distal end of said plunger. 6. A device according to claim 1, further comprising: d) locking means coupled to one of said outer sheath and said inner plunger to prevent 1 that said plunger slide inside the sheath.
7. 7. A device according to claim 6 further characterized in that said clamping means include an O-ring and a fluid orifice "said fluid orifice being in fluid communication with annular space between said sheath and said plunger.
8. 8. A device for deplnt of endoluminal prostheses for use with an endoluminal prosthesis, said device comprising: a) an outer sheath having a proximal end! and a distal end; b) an inner plunger having a proximal end and a distal end, said inner plunger disposed slidably within said outer sheath; and c) means for securing the prosthesis on said distal end of said inner plunger to engage a proximal end of a prosthesis and pulling the prosthesis to said distal end and said outer sheath without engaging the distal end of the prosthesis when the prosthesis is pulled. completely to said outer sheath; d) an inner catheter having a proximal end and a distal end, said inner catheter being disposed within said inner plunger; e) a tapered tip adhered to said distal end of said inner catheter, said tapered tip having a dimension for substantially covering said distal end of said outer sheath when said outer catheter is moved proximally with respect to said outer sheath such that a prosthesis hooked by said fastening means can not be deployed without first moving said inner catheter distally.
9. 9. A device according to claim?, Further comprising: f) locking means coupled to one of said inner plunger and said inner catheter to prevent 1 iberadora that said interior slide from said plunger. A device according to claim 9, further characterized in that said locking means include an annulus at 0 and a fluid orifice »said fluid orifice being in fluid communication with annular space between said catheter and said piston. 11. A device according to the indication 9. which further comprises: g) a catheter hub coupled to said proximal end of said catheter, the catheter hub including a luer connector. 12. A device for deploying endolute prostheses "comprising said device: a) an outer sheath having a proximal end and a distal end;; b) an inner plunger having a proximal end and a distal end »said inner plunger disposed of! easily inside said outer sheath; c) an inner catheter having a proximal end and a distal end "said inner catheter being slidably disposed within said plunger; and" d) a tapered tip attached to said distal end of said catheter "said tapered tip having a dimension for substantially covering distal end and said outer sheath when said inner catheter is moved proximally with respect to said outer sheath of ta! so that said distal end of said plunger can not move distally beyond said distal end of said outer sheath without first moving said inner catheter of said staple! entity. 13. A device according to claim 12 »further comprising: e) locking means coupled to one of said plunger and said inner catheter to prevent lyreously that said inner catheter slides inside said plunger. 14. A device according to the rei indication 13 »further characterized in that: said locking means include an O-ring and a fluid orifice, said fluid orifice being in fluid communication with an annular space between said catheter and said plunger . 15. A device according to claim 12, further comprising: e) a catheter hub coupled to said proximal end of said catheter, said catheter hub including a Tuer connector.