Catheter with retractable sleeve and method of using catheter system

Abstract

Apparatus and method for delivering and deploying an intravascular device into the vessel including an outer and inner tube that are axially linked by a housing structure at the proximal end of the catheter, and a retractable sleeve structure having a middle tube and sleeve tip. The sleeve tip is sealed to the inner tube at the distal end, and continuously extends into the middle tube. At the proximal end of the sleeve structure, the middle tube is sealed to either a housing structure or slideable proximal ring, forming a sealed chamber between the inner tube and the sleeve structure. A radial space is formed between the sleeve tip and the inner tube optimized for intravascular device placement. During retraction of the sleeve structure, the fold of the sleeve tip peels away from the device, which expands to its deployed state while minimizing axial forces and friction.

Description

(19) *EP004721709A2* (11) EP 4 721 709 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: 08.04.2026 Bulletin 2026 / 15 (21) Application number: 26159445.1 (22) Date of filing: 23.07.2013 (51) International Patent Classification (IPC): A61F 2 / 95 (2013.01) (52) Cooperative Patent Classification (CPC): A61F 2 / 966; A61F 2 / 9517; A61F 2 / 9522; A61F 2250 / 0003 (84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 27.07.2012 US 201213560132 (62) Document number(s) of the earlier application(s) in accordance with Art. 76 EPC: 17167574.7 / 3 213 719 13824514.7 / 2 877 124 (71) Applicant: Medinol Ltd. 6158101 Tel Aviv (IL) (72) Inventors: • COHEN, ltshak 4720810 Ramat Hasharon (IL) • MAXIMUK, Shahar 7583204 Rishon Lezion (IL) • MOISEYEV, Gilad 5352718 Givatayim (IL) (74) Representative: Kuhnen & Wacker Patent‑ und Rechtsanwaltsbüro PartG mbB Prinz-Ludwig-Straße 40A 85354 Freising (DE) Remarks: This application was filed on 18‑02‑2026 as a divisional application to the application mentioned under INID code 62. (54) CATHETER WITH RETRACTABLE SLEEVE AND METHOD OF USING CATHETER SYSTEM (57) Apparatus and method for delivering and de- ploying an intravascular device into the vessel including anouterand inner tube thatareaxially linkedbyahousing structure at the proximal end of the catheter, and a retractable sleeve structure having a middle tube and sleeve tip. The sleeve tip is sealed to the inner tube at the distal end, andcontinuously extends into themiddle tube. At the proximal end of the sleeve structure, the middle tube is sealed to either a housing structure or slideable proximal ring, forming a sealed chamber between the inner tube and the sleeve structure. A radial space is formed between the sleeve tip and the inner tube opti- mized for intravascular device placement. During retrac- tion of the sleeve structure, the fold of the sleeve tip peels away from the device, which expands to its deployed state while minimizing axial forces and friction. EP 4 72 1 70 9 A 2 Processed by Luminess, 75001 PARIS (FR) 2 1 EP 4 721 709 A2 2 Description FIELD OF THE INVENTION

[0001] The present invention relates to the field of catheters, in particular a catheter system with a retract- able sleeve structure for use, for example, in delivery and deployment of an intravascular device. The catheter system is specifically designed for use in the delivery of an intravascular device through tortuous vessels and its deployment therein. BACKGROUND

[0002] Transluminally implantable intravascular de- vices, such as stents or grafts, are initially mounted upon or within a delivery catheter and then crimped into a compact configuration of a relatively small diameter to facilitate insertion and transluminal advancement of the device into the desired lesion requiring treatment. There- after, such devices are radially expanded to a larger operative diameter either by removing a constraining layer thereby releasing thedeviceor by inflatingaballoon on which the device is crimped. When expanded the device serves to support the vessel against its tendency to reclose and may also serve as a matrix for releasing a medically active substance.

[0003] It will be appreciated that the term "stent" may be used herein below as a general and non-limiting example of a catheter-mounted intravascular device. Both self-expanding and balloon expandable stents are well known and widely available in a variety of de- signs and configurations.

[0004] Prior art catheter systems for stent delivery provided a restraining sheath overlying the stent. One problem that arises when mounting the stent on the catheter system aswell as during retraction of the sheath is excessive friction and rubbing between the sheath and the stent that may complicate and sometimes render stent deployment impossible. In addition, stents are often coated with a special polymer, a drug, or a combination thereof. Excessive friction and rubbing between the stent and the constraining sheath may cause damage to the integrity of the coated surfacematerial of the stent by the friction between the sheath and the external surface of the stent. Moreover, such friction tends to increase even more when using longer stents or stents with a narrower crimping profile. Accordingly, it is an object of the inven- tion to minimize friction between the catheter and the stent during deployment.

[0005] Another problem in the art arises with stents having relatively low axial rigidity, where axial friction forces applied during deployment or mounting of the stent on the catheter system may shorten the stent. It is therefore advantageous to have a catheter system that minimizes axial friction forces applied to the stent during deployment and mounting.

[0006] Yet another problem known in the art is related to thesizeof theproximal portionor thehandleof catheter systems of self-expandable stents. Deploying such stents requires pulling the constraining sheath backward in theproximal directiona lengthwhichequals at least the length of the stent. When using longer stents (i.e. 100 millimeters and more) this limitation becomes a disad- vantage as it leads to relatively long handles with a bulky mechanical structure that may be uncomfortable to op- erate. It is therefore advantageous to have a catheter system with a relatively short handle. SUMMARY OF THE INVENTION

[0007] The present invention relates to a catheter sys- tem with a retractable sleeve structure and a method of using the catheter system. The catheter system com- prises a multi-component tubular structure capable of deploying an intravascular device while minimizing axial frictional loads on the device during deployment. The catheter system of the invention uses a retractable sleeve structure filled with fluid during delivery and de- ployment. The catheter system comprises an inner tube disposed coaxially with an outer tube, wherein the inner tube comprises an interior lumen for a guide wire and an exterior surface onwhich a retractable sleeve structure is mounted. The outer tube forms a lumen for each of the guide wire, inner tube and the retractable sleeve struc- ture.

[0008] The retractable sleeve structure extends through the length of the inner tube and forms a sealed chamber therewith. The retractable sleeve structure comprises a middle tube and a distal sleeve tip, the sleeve tip forming a fold over the distal end of the in- travascular device thereby creating a double layered sheath around the device. The double layered sheath, when pressurized with fluid, may be pulled back, thereby releasing the device without exerting any friction forces thereon.

[0009] The invention also relates to a method of de- ploying an intravascular device. The method comprises the steps of filling the sealed chamber with fluid, navigat- ing the catheter to a target site, positioning the sleeve tip with a mounted device at the target site, pressurizing the fluid and pulling the retractable sleeve structure proxi- mally, thereby causing the sleeve tip to unfold and re- lease thedevice at the target site exertingminimal friction forces on the device. In one embodiment the retractable sleeve structure is pulled back by sliding a handle con- nected to aproximal portion of themiddle tube. In another embodiment the retractable sleeve structure is pulled back by applying a force to a collapsible proximal portion of the middle tube using, for example, a knob or wheel. The force in the proximal direction may push the collap- sible proximal portion towards the proximal end of the housing structure, thereby collapsing the collapsible por- tion, for example, in an accordion-like fashion. This em- bodiment has an advantage that it enables the use of a shorter guidewireandshorter housingcompared toother 5 10 15 20 25 30 35 40 45 50 55 3 3 EP 4 721 709 A2 4 catheter systems, and is particularly useful when using relatively longstents. Inanother embodiment, the retract- able sleeve structure includes a rear retractable portion that is affixed to an insertion tube and folds back onto itself, thus retracting the sleeve tip and deploying the stent. In yet another embodiment, the inner tube includes a curved portion at the proximal end that coils within the housing structure; thus, the retractable sleeve structure is retracted over the curved portion during deployment. These embodiments likewise have an advantage that they enable the use of a shorter housing compared to other catheter systems, and further enable easier opera- tion of the retractable sleeve structure.

[0010] Another aspect of the invention relates to a method of mounting an intravascular device onto the catheter system. In one embodiment the method com- prises the steps of retracting the sleeve tip to an unfolded position, filling the retractable sleeve structure with fluid, andholding a crimped intravascular device onto the inner tubewith a separate device, and advancing the sleeve tip over the crimped intravascular device thereby forming a fold over a portion of the crimped intravascular device. In this mounting embodiment, the intravascular device is released, the catheter system is pulled proximally, and the process is incrementally repeated until the intravas- cular device is mostly or entirely located under the fold of the sleeve tip. Once the intravascular device is fully sheathed by the fold, the method may further comprise releasing fluid into the sealed chamber for storage. This aspect of the invention may be useful in particular to mount an intravascular device onto a catheter system for later deployment according to the method of deploy- ing an intravascular device indicated above.

[0011] Storage of the catheter system may be accom- plished at a neutral air pressure. However, prior to use, the air in the retractable sleeve structure is replaced with fluid through the use of a sealable port. During this process, any residual air in the sleeve structure may be evacuated through a micro-orifice in the fold of the sleeve tip. DESCRIPTION OF DRAWINGS

[0012] Figure 1A illustrates a cross-section of the catheter system in a pre-deployment state according to the principles of the invention. Figure 1B illustrates an enlarged portion of Figure 1A. Figure 2 illustrates a cross-section of the catheter system in a stage of partial deployment of an intra- vascular device as the sleeve tip of the retractable sleeve structure is partially withdrawn by sliding the handle one-third of the distance toward the proximal end of the housing structure. Figure 3 illustrates a cross-section of the catheter system in a stage of partial deployment of an intra- vascular device as the sleeve tip of the retractable sleeve structure is partially withdrawn by sliding the handle two thirds of the distance toward the proximal end of the housing structure. Figure 4 illustrates a cross-section of the catheter system in a post-deployment state according to the principles of the invention. Figure 5A‑5B illustrate a cross-section of one alter- native embodiment of the catheter systemaccording to the principles of the present invention in pre-de- ployment and post-deployment stages. Figures 6A‑6B illustrate a cross-section of another alternative embodiment of the catheter system ac- cording to the principles of the present invention in pre-deployment and post-deployment stages. Figures 7A‑7B illustrate a cross-section of another alternative embodiment of the catheter system ac- cording to the principles of the present invention in pre-deployment and post-deployment stages. Figures 8A‑8D illustrate a half of a cross-section view of a method of placing the intravascular device onto the catheter system and under the constraining sheath.

[0013] The intravascular devices shown in these Fig- ures are two-dimensional representations of the intra- vascular device embodiments of the instant invention. The skilled artisan will recognize that the device is a three-dimensional structure having a cylindrical portion, as described further below. DETAILED DESCRIPTION OF THE INVENTION

[0014] The catheter system with a retractable sleeve structure of the invention allows an intravascular device to be delivered to a target vessel without subjecting the device to frictional forces during deployment associated with other delivery systems using a constraining sheath. The catheter system of the invention includes an elon- gate inner tube defining proximal and distal ends and a lumen extending longitudinally therethrough wherein a guide wire is movably disposed. The catheter system further includes an elongate outer tube having a proximal and a distal end, wherein the inner tube coaxially extends therethrough along the entire length. The inner tube and outer tube are affixed to a housing structure in the prox- imal portion of the catheter system, the housing structure includes a distal opening to which the outer tube is affixed, as well as a proximal opening to which the inner tube is affixed. "Distal" is definedherein asbeing closer to the insertion end of the catheter (i.e. the end typically inserted into the body) and the term "proximal" is defined as being closer to the end of the catheter that generally remains outside the body, as demarcated by line X in the Figures herein.

[0015] A retractable sleeve structure havingaproximal and a distal end extends through the axial space created between the inner and the outer tubes. The retractable 5 10 15 20 25 30 35 40 45 50 55 4 5 EP 4 721 709 A2 6 sleeve structure comprises amiddle tubeanda sleeve tip which coaxially extends substantially along the length of the inner and outer tubes. The retractable sleeve struc- ture may be sealingly connected to the inner tube at the distal end with a distal ring thereby forming a sealed chamber. In a pre-deployment state the intravascular device is mounted in a radial space created between the inner tube and a double layered sheath created by folding the sleeve tip onto itself.

[0016] The outer tube, the middle tube and inner tube may be manufactured from kink resistant and flexible materials or composite structures, for example polyether ether ketone (PEEK), polyethylene terephthalate (PET), Polyimide (PI), braided Nylon 12 or suitable materials readily understood in the art. The method of affixing the outer tube and inner tube to the housing structure can be achieved throughmethods that are well known in the art. Non-limiting examples of joining methods include fusing (e.g. heat fusion), welding (e.g. ultrasonic welding) and joining byadhesivemethods (e.g., gluing).Combinations of thesemethods andmaterials are contemplated by this invention.

[0017] The sleeve tip is manufactured from materials having sufficient radial rigidity to prevent expansion be- yond a desired maximum diameter. Non-limiting exam- ples include ultra-thin polyethylene terephthalate (PET) or a Polyimide (PI). Advantages of a sleeve tip formed by PET include flexibility. In one embodiment, the sleeve tip is formed of a material about 5‑20 micrometers thick, preferably 10 micrometers thick. The two adjacent por- tionsof the sleeve tip createdby the fold, i.e. the inner and outer portions of the fold, aremaintained apart from each other preferably by a few micrometers so as to avoid rubbing against each other; such separation is enabled by pressurizing sealed chamber Alternatively, or in addi- tion, the interior surface of the sleeve tip material may be coated with a dry hydrogel which when wetted - e.g. by the fillingof the retractable sleevewith fluid -will swell and form a sufficiently rigid sleeve tip, minimizing or cancel- ling the need for pressurization. Hydrogels useful in this embodiment include for example, polyvinylpyrrolidone (PVP) or TG‑2000 (Life Science Polymers), but other hydrogels known in the art will be equally useful. The method of combining or joining the sleeve tip and other components of the retractable sleeve structure can be achieved throughmethods that are well known in the art. Non-limiting examples of joining methods include fusing (e.g. heat fusion), welding (e.g. ultrasonic welding) and joining byadhesivemethods (e.g.,gluing).Combinations of thesematerials andmethods are contemplated by this invention. In oneembodiment, for example, thedistal end of the middle tube is joined to the proximal end of the sleeve tip by a middle connection ring that provides adhesion.

[0018] In one embodiment, a proximal ring sealingly connects the retractable sleeve structure to the inner tube within the housing. The proximal end of the retract- able sleeve structure may further comprise a handle designed to facilitatemoving the retractable sleeve struc- ture fromadistal positionwithin the housing structure to a proximal position. The retractable sleeve structure further comprises a sealable port. The retractable sleeve structure together with the inner tube form a sealed chamber, in which fluid may be added or removed through the sealable port. For the purpose of this appli- cation, "fluid" is understood according to its proper defini- tion in the area of physics, inclusive of any substance that moves when exposed to shearing forces. "Fluid" there- fore includes without limitation, substances in a gaseous phase as well as substances in a partial or wholly liquid phase, such as water, water-based solutions, saline, oils or gels. The retractable sleevestructuremaybe retracted bysliding thehandle fromafirst distal position toasecond more proximal position, thereby withdrawing and unfold- ing the sleeve tip and releasing the device. Because the outer tube and the inner tube are fixedly connected to the housing structure, the outer and inner tubes are not affected by sliding the handle of the retractable sleeve structure.

[0019] The invention also relates to a method of de- ploying an intravascular device. The first deployment step comprises pressurizing the retractable sleeve struc- ture with fluid. In one embodiment, the retractable sleeve structure is packagedat neutral air pressure such that the operator will pressurize the retractable sleeve structure with fluid prior to its use. During pressurization of the retractable sleeve structure with fluid, it may be neces- sary to remove remaining air from the sleeve. In certain embodiments, a micro-orifice in the sleeve tip allows remaining air to evacuate the sealed chamber prior to or while the sealed chamber is filled with a pressurized fluid by applying a pressure of 1‑10 atm through the sealableport. Themicro-orificepreferablyhasadiameter in the rangeof 30‑40micrometers, thusallowingair toexit the sealed chamber while generally minimizing the pres- surized fluid flow through the micro-orifice. Insertion and pressurizationof thefluid canbeachievedusingmethods that are well known in the art. In one embodiment, phy- siologically-compatible fluid is used in the sealed cham- ber, such as, for example, a physiologically-compatible saline solution. Other biocompatible fluids may similarly be used as is known in the art. The sealed chamber may be filled to a pressure in the range of 1‑10 Atm. In one preferred embodiment, the sealed chamber is pressur- ized to 4 Atm.

[0020] Employment of a pressurized fluid may provide an advantage by maintaining the adjacent inner and outer portions of the fold of the sleeve tip apart from each otherbyat least a fewmicrometers soas toavoid rubbing. The method of evacuating air through a micro-orifice in the distal portion of the sleeve tip may be advantageous compared to other methods known in the art for evacuat- ing air (e.g. by application of a vacuum) because the micro-orifice enables evacuation of a greater percentage of residual air from the sealed chamber.

[0021] In one embodiment, use of a fluidmay comprise 5 10 15 20 25 30 35 40 45 50 55 5 7 EP 4 721 709 A2 8 a hydrogel or other material with similar properties, in- cluding water absorbency and hydrophilic properties. In this embodiment, hydrogel is applied during the manu- facturing stage, for example, by coating the inner surface of the sleeve tip. Hydrogel may also be introduced through the sealable port following the manufacturing stage. Upon contact with an aqueous liquid, hydrogel increases in volume, thus assisting in evacuating air through the micro-orifice, while simultaneously increas- ing the axial rigidity of the sleeve tip. The method of applying hydrogel to the sealed chamber is thus advan- tageous in evacuating air and providing the desired level of axial rigidity upon introduction of an aqueous liquid without the need to pressurize the fluid within the sealed chamber as a separate step.

[0022] The method of deploying an intravascular de- vice further comprises navigating the sleeve tip to the target site in thebody lumenso that themounteddevice is positioned at the target site for deployment. The sleeve tip is delivered to the target site in the body lumen by methods known in the art. The employment of thin, flexible, light-weight materials, as well as the use of pressurized fluid --and / or a hydrogel-- in the retractable sleeve structure, enables the navigation of the catheter system via tortuous lumen while minimizing axial and frictional forces applied on the catheter.

[0023] Referring now to the drawings wherein the fig- ures are for purposes of illustrating preferred embodi- ments of the present invention only, and not for purposes of limiting the scope of the invention in any way, Figure 1A showsone embodiment of the catheter system20 in a pre-deployment state having a proximal end and a distal end. The catheter system includes a guide wire 9 com- prising a distal end 13 extending into the lumen during deployment and a proximal end 14 that remains outside the body during deployment. The guide wire 9 extends through the lumen of inner tube 5. The inner tube 5 has a proximal end and a distal end. The inner tube 5 extends through housing structure 8 having a distal end 8a and a proximal end 8b. In this embodiment, the housing struc- ture 8 has a length equal to or greater than a distance 2L, i.e. a length twice distanceL (detailed herein below). The housing structure 8 includes a distal opening 31 and a proximal opening 32. The inner tube 5 extends through distal opening 31 of the housing structure 8 to the prox- imal opening 32, to which the inner tube 5 is affixed. In Figure 1A, the inner tube 5 traverses the proximal open- ing32 through thehousingstructure8.Outer tube3 forms a lumen throughwhichextends the inner tube5andguide wire 9.The outer tube 3 is affixed to the housing structure 8 at distal opening 31.

[0024] The outer tube 3 and the inner tube 5 are affixed to the housing structure 8, and form a consistent radial space between the outer surface of the inner tube 5 and the internal surface of the outer tube 3. A retractable sleeve structure 2 extends through the radial space formed by outer tube 3 and inner tube 5. The retractable sleeve structure 2 comprises middle tube 4 having a proximal end and a distal end and a sleeve tip 16 having a proximal end and a distal end. The sleeve tip 16 may have a micro-orifice 18 to permit air to evacuate the sealed chamber 15 prior to or while the sealed chamber 15 is filledwith apressurized fluid10 through the sealable port 11. In one embodiment, as shown in Figure 1A, the proximal end of middle tube 4 is sealingly connected to the inner tube 5 via proximal ring 7. In the embodiment of Figure 1A, the proximal ring 7 forms a fluid-tight, move- able seal against inner tube 5. The retractable sleeve structure 2 further comprises a handle 6 which may be utilized to control movement of the retractable sleeve structure2, includingmovement of the slideable proximal ring 7 along inner tube 5. As shown in Figure 1A, the sealable port 11 is located in the handle 6; the sealable port 11may be used to control the contents and pressure of fluids in the sealed chamber 15 formed by the retract- able sleeve structure 2 together with the inner tube 5. In another embodiment, the sealable port 11 may be posi- tioned on the middle tube 4 separate from the handle 6. Thedistal endofmiddle tube4 is fixed to theproximal end of the sleeve tip16.Thedistal endof the sleeve tip16may be sealed to the inner tube 5 via a distal ring 12 as shown in Figure 1A. Pressurized fluid 10 is introduced into the sealed chamber 15 formed by the retractable sleeve structure 2 and inner tube 5 through the sealable port 11. Similarly, the pressure of the fluid in the retractable sleeve structure may be controlled via the sealable port 11. Generally, the housing structure of any embodiment described herein may be an open or closed structure.

[0025] In one embodiment, the retractable sleeve structure has, while pressurized, a substantially constant outer diameter along the longitudinal extent of themiddle tube 4 and sleeve tip 16. The sleeve tip 16 radially extends a radial distance W from inner tube 5 and folds onto itself forming a sheath around the crimped device 1. While the device may be any transluminally implantable intravascular device, the device 1 depicted in Figure 1A and other Figures is a cylindrical stent, here illustrated in a crimped state. Fold 17 of the retractable sleeve struc- ture 2 extends a longitudinal distance Lwhich is equal to or greater than the length of the intravascular device. In other words, the length of thematerial making up the fold is equal to or greater than twice the length of themounted intravascular device.

[0026] Figure 1B shows an enlarged portion of the catheter system 20, including the fold 17 of the sleeve tip 16 that forms a radial distanceW between the retract- able sleeve structure 2 and the inner tube 5. The space formed between the sleeve tip 16 and inner tube 5 is suitable for mounting a device 1 prior to deployment. In this embodiment the fold length L (shown in Figure 1A) closely matches the length of the mounted device 1.

[0027] In one embodiment, themethod of deploying an intravascular device further comprises retracting the re- tractable sleeve structure 2, whereby the sleeve tip 16 is withdrawn or peeled away from the device in a proximal direction, thereby releasing the device 1. Figure 1A and 5 10 15 20 25 30 35 40 45 50 55 6 9 EP 4 721 709 A2 10 Figures 2 through 4 illustrate the steps according to one embodiment of the invention. With reference to Figure 1A, the handle 6 of the retractable sleeve structure 2 begins in a first position near the distal end of the housing structure 8. In one embodiment of this invention, the retraction step comprises applying a proximally-directed force on the handle 6, thereby sliding the proximal ring 7 in a longitudinal direction along the inner tube 5. As shown inFigure2,as theproximal ring7slidesadistance of approximately one-third of 2L, and the sleeve tip 16 withdraws a longitudinal distance of approximately one- third of L. Because the outer tube 3 and inner tube 5 are fixedly connected to the housing structure 8 - which remains stationary during this step - only the retractable sleeve structure is affected by applying a proximally- directed force to the handle 6 and sliding the handle 6 in a proximal direction. This step is further illustrated by Figure 3,wherein the handle 6 and proximal ring 7 slides a distance of approximately two-thirds of 2L, and the sleeve tip 16 therefore withdraws a longitudinal distance of approximately two-thirds of L. The step is completed, as shown in Figure 4 with the full deployment of the device 1 by sliding the proximal ring 7 and handle 6 the entire distance 2L to a second position adjacent to the proximal end 8b of the housing structure 8, thereby withdrawing the sleeve tip 16 a distanceL.The retraction of the retractable sleeve structure 2 thereby releases the device 1 while minimizing friction on the exterior surface of the device 1. The device 1 is then able to expand into the target site of the body lumen. Throughout the pro- cess, the proximal ring 7 maintains a fluid-tight seal against inner tube 5, thus maintaining pressurization of the retractable sleeve structure 2.

[0028] Figure 4 shows the catheter system 20 in a post-deployment state. The retraction of the retractable sleeve structure 2 released the device 1 within the body lumen. As the retractable sleeve structure 2 is retracted, the sleeve tip 16 is peeled away from the intravascular device thereby releasing it into the body lumen. Retrac- tion of the sleeve structure a distance of 2L will result in withdrawal of the sleeve tip16a lengthL, thuseliminating the fold.

[0029] Figure 5A shows another embodiment of the catheter system 20,wherein the retractable sleeve struc- ture 2 further comprises a collapsible proximal portion sleeve 24 sealingly attached at its proximal end to the proximal end 8b of the housing structure 8, and sealingly attached at its distal end to the middle tube 4. The collapsible proximal portion sleeve 24 is manufactured of a highly flexible material, such as, for example ultra- thin polyethylene terephthalate (PET)or aPolyimide (PI). In this embodiment, the proximal end of the retractable sleeve structure 2 is integral with the proximal portion of the housing structure 8, and further includes a spout 28 which comprises a sealable port 29. By contrast with the handle comprising a sealable port of the previous embo- diment, the spout 28 does not move during the deploy- ment process. Rather, as shown in Figure 5A, the re- tractable sleeve structure 2 includes a handle 23which in this embodiment is formed as a knob positioned at the distal portion within the housing structure 8. During de- ployment, a radial force is applied to the handle 23, thereby axially compressing the retractable sleeve struc- ture 2; simultaneously, a force in the proximal direction is applied to the handle 23, thereby collapsing the proximal portion sleeve 24, for example, into accordion-like folds as shown in Figure 5B. In order to collect and collapse in an accordion-like manner a distance of 2L, the knobmay be moved back and forth several times as shown by the two sided arrow. As the proximal portion sleeve 24 col- lapses, the sleeve tip 16 therefore withdraws. The sleeve tip 16may have amicro-orifice 18 as shown in Figure 5A to permit air to evacuate the sealed chamber 15 during this process, or prior to or while the sealed chamber 15 is filled with a pressurized fluid 10 through the sealable port 29. In other embodiments, the proximal portion sleeve 24 may collapse in other manners as known in the art. Because the embodiment illustrated in Figures 5A and 5B is based on collapsible proximal portion sleeve 24, this embodiment has the advantage of not requiring housing structures equal to or longer than twice the length of the stent (i.e. the length of the housing can be shorter than 2L), thereby making the catheter system more compact and easier to use.

[0030] The method of deploying the intravascular de- vice of Figures 5A and 5B is accomplished by retracting the retractable sleeve structure 2 through a series of steps involving a handle 23, as shown in Figures 5A and 5B. The retraction begins, as shown in Figure 5A, with the handle 23 in a first position near the distal end 8a of the housing structure 8 along the collapsible proximal portion sleeve 24 of the retractable sleeve structure 2. The first step comprises applying a compression force to the handle 23, thereby gripping the handle 23 against the proximal portion sleeve 24. As illustrated by Figure 5B, the next step comprises pulling the handle 23 in a prox- imal direction while maintaining a compression force, thereby collapsing the collapsible proximal portion sleeve 24 toward the proximal end 8b of the housing structure 8 and releasing the intravascular device. In one embodiment, the collapsible proximal portion sleeve 24 folds inanaccordion-likemanner, as shown inFigure5B. Themethod further comprises reducing the compression force on the handle 23 and returning the handle 23 to the first position near the distal end 8a of the housing struc- ture 8. These steps are repeated until the collapsible proximal portion sleeve 24 of the retractable sleeve structure 2 has fully collapsed, thereby withdrawing the sleeve tip 16 and releasing the device 1, viewed either through an imaging medium (e.g. angiography) or as indicated by an abrupt increase in resistance to the retraction force on the handle 23. In another embodiment of the invention, employment of a wheel in this step may be used to apply a force to the proximal portion sleeve 24 in the proximal direction.

[0031] Figure 6A shows another embodiment of the 5 10 15 20 25 30 35 40 45 50 55 7 11 EP 4 721 709 A2 12 catheter system 20,wherein the retractable sleeve struc- ture further comprises a rear retractable portion 25. The rear retractable portion 25 has a distal end 26 that is joined to the proximal end of the middle tube 4, and is sealingly attached at its proximal end to an insertion tube 27. The rear retractable portion 25may bemanufactured from flexible materials, for example, polyethylene ter- ephthalate (PET), Polyimide (PI), Nylon 12 or suitable materials readily understood in the art. The insertion tube 27 surrounds the inner tube 5 with a lumen between the insertion tube 27 and inner tube 5 to enable fluid or air to pass from the insertion tube 27 to the sealed chamber 15 at the distal end of the insertion tube 27. At the proximal end of the insertion tube 27, the insertion tube 27 con- nects to a spout 28 affixed to the inner tube 5. The spout 28 further comprises a sealable port 29 for controlling the contents and pressure of the fluids in the sealed chamber 15. In another embodiment, the sealable port 28 may be positioned on the rear retractable portion 25 separate from the spout 29. As shown in Figure 6A, the sleeve tip 16 may have a micro-orifice 18 to permit air to evacuate the sealed chamber 15 prior to or while the sealed chamber 15 is filled with a pressurized fluid 10 through the sealable port 29. The insertion tube 27 may be manufactured from a metal or a biocompatible polymer. During deployment, a force is applied in the proximal direction at the proximal end of the rear retractable por- tion 25. Thus, the rear retractable portion 25 folds onto itself and over the insertion tube 27 in the proximal direction, as shown in Figure 6B. During this process, the sleeve tip 16 therefore withdraws. Because the em- bodiment illustrated in Figures 6A and 6B is based on rear retractable portion 25, this embodiment has the advantage of not requiring housing structures equal to or longer than twice the length of the stent (i.e. the length of the housing can be shorter than 2L), thereby making the catheter system more compact and easier to use.

[0032] The method of deploying the intravascular de- vice of Figures 6A and 6B is accomplished by retracting the rear retractable portion 25 through one of several possible means. In one embodiment, the housing struc- ture 8 includes a wheel 35 having an edge 36 that con- tacts theexterior surface37of the rear retractable portion 25,asshown inFigure6C.Upon rotation of thewheel35, frictional force of the edge 36 against the exterior surface 37 results in the rear retractable portion 25 folding onto itself and over the insertion tube 27. Other mechanical means readily known to one skilled in the art may be employed to apply a proximal force to the rear retractable portion 25.

[0033] Figure 7A shows a cross-sectional view of an- other embodiment of the catheter system 20,wherein the retractable sleeve structure 2 further comprises a curved inner tube portion 30 that is connected to the proximal end of inner tube 5 and extends in a curved direction within the housing structure 8. The curved inner tube portion 30 is manufactured from a metal or a biocompa- tible polymer andmay coil up to and beyond 360 degrees within the housing structure 8. Themiddle tube 4, handle 6 and proximal ring 7 follow the curved inner tube portion 30. Handle 6 further comprises a sealable port 11 for controlling the contents and pressure of fluids in the sealed chamber15. In another embodiment, the sealable port 11may be positioned on the middle tube 4 separate from the handle 6. In this embodiment, the housing structure has a first end 33 that is affixed to outer tube 3 and a second end 34 that is affixed to the curved inner tube portion 30. During deployment, a force in the prox- imal direction isapplied to thehandle6, thereby retracting the handle 6 and the retractable sleeve structure 2 over the curved inner tube portion 30 as shown in Figure 7B. During this process, the sleeve tip 16 therefore with- draws. The sleeve tip 16 may have a micro-orifice 18 to permit air to evacuate the sealed chamber15prior to or while the sealed chamber 15 is filled with a pressurized fluid 10 through the sealable port 11. Because the em- bodiment illustrated in Figures 7A and 7B is based on curved inner tube portion 30, this embodiment has the advantage of not requiring housing structures equal to or longer than twice the length of the stent (i.e. the length of the housing can be shorter than 2L), thereby making the catheter system more compact and easier to use.

[0034] Many different methods may be employed to mount the intravascular device onto the inner tube of the catheter system prior to deployment. One method is illustrated by Figures 8A - 8D. The first step of one embodiment is shown in Figure 8A and comprises com- pressing at least a portion of intravascular device 1, for example a fully crimped stent, around an inner tube 5 usingaholdingdevice19.Thenext step, shown inFigure 8B. comprises applying a force in the distal direction, for example to the handle of the sleeve tip (not shown), such that the retractable sleeve structure moves in the distal direction to incrementally extend longitudinally over an exposed residual portion of the intravascular device. The axial rigidity of the sleeve tip 16 is accomplished by fluid pressurization through means discussed above. The method further comprises releasing the holding device 19 and pulling the catheter system proximally, as shown in Figure 8C. In the next step, the process repeats, as shown in Figure 8D. The holding device 19 is com- pressed against a more distal location on the device 1 than in the previous step and at each cycle the fold of the sleeve tip is extended incrementally in the distal direction to eventually cover or sheath the entire device. In one embodiment, the retractable sleeve structure 2 may be assembled with pressurized fluid in the sealed chamber 15.The sealed chambermaybe deflatedonce thedevice is mounted and prior to use.

[0035] In another embodiment of the intravascular de- vice mounting method, the method comprises placing a intravascular device in a crimped state on the inner tube while the handle of the retractable sleeve structure is positioned near the proximal end of the housing struc- ture, such that the sleeve tip is fully withdrawn. In the next step of this embodiment, a force in the distal direction is 5 10 15 20 25 30 35 40 45 50 55 8 13 EP 4 721 709 A2 14 applied to the handle, such that the retractable sleeve structure moves distally against the mounted intravas- cular device. Upon contact with the mounted intravascu- lar device, the sleeve tip naturally folds around the in- travascular device. A holding device is positioned at the distal end of the intravascular device holding it in place as the sleeve tip folds over the device. The fold of the sleeve tip is extended to cover or sheath the entire intravascular device.

[0036] The device may be any stent or graft device, which are well known in the art. Any stent design may be utilized in connection with the present invention. In one example, the stent consists of separate segments de- signed to expand independently from each other as the sleeve tip is withdrawn; however, it should be understood that the invention is not limited to any particular stent designor structure.Astent or graft havingeither separate segments or a unitary design (i.e.,without separate stent segments designed to expand independently from each other) may be used with this invention, as well as stents that expandatdifferent ratesalong the longitudinal axis of the stent. The invention further contemplates stents or grafts having diameters of variable sizes and different lengths. One non-limiting example design is the NIRflex stent which is manufactured by Medinol, Ltd., as de- scribed in U.S. Patent No. 6,723,119, which is incorpo- rated herein in toto, by reference. Another example of a suitable self-expanding stent is described in US Patent Nos. 6,503,270 and 6,355,059, for example, which are also incorporated herein in toto, by reference.

[0037] It will be appreciated by persons having ordin- ary skill in the art that many variations, additions, mod- ifications, and other applications may be made to what hasbeenparticularly shownanddescribedherein byway of embodiments, without departing from the spirit or scope of the invention. Therefore it is intended that scope of the invention, as defined by the claims below, includes all foreseeable variations, additions, modifications or applications. Claims 1. A retractable catheter system for delivery and de- ployment of an intravascular device, the catheter system having a distal end and a proximal end, comprising: an inner tube having a lumen, a housing structureat theproximal endof said catheter system, said housing structure having a distal end and a proximal end, wherein the inner tube is affixed to the housing structure; and a retractable sleeve com- prising a sleeve tube and a sleeve tip, said sleeve tube having a proximal end and a distal end, said sleeve tube coaxially extending substantially along the length of the inner tube, and the sleeve tip having in the deployed state a distal end sealed to the inner tube and a proximal end fixed to the distal end of the sleeve tube forming a sealed chamber capable of containing a fluid, wherein in a pre-deployment state the sleeve tip forms a double layered sheath and the intravascular device is mounted in a radial space between the inner tube and the sleeve tip. 2. The retractable catheter system of claim 1, wherein the retractable sleeve comprises a sealable port. 3. The retractable catheter system of claim 2 wherein the sealable port is located in a handle. 4. The catheter system of claim 1, wherein the sleeve tip comprises ultra-thin polyethylene terephthalate. 5. The catheter system of claim 1 wherein the fluid is a hydrogel. 6. The retractable catheter sleeve of claim 1 further comprising a distal ring connecting the sleeve tip to the inner tube. 7. A retractable catheter sleeve for delivering an intra- vascular device according to claim 1, said sleeve further comprising: said proximal end of the sleeve tube sealingly connected to the inner tube via a proximal ring, said proximal end of the sleeve tube further comprising a sealable port; and the sleeve tube is sealingly connected to a handle; and said sheath capable of being pressurized with a fluid for deployment, said sheath being capable of retraction to deploy the device. 8. The retractable catheter sleeve of claim 7, wherein the sleeve tip has a micro-orifice at the distal end of the sleeve tip. 9. The retractable catheter sleeve of claim 7 wherein the sleeve tip comprises polyimide. 10. Amethod of deploying an intravascular device using a catheter system according to claim 1, comprising the steps of: navigating said sleeve tip to a target site within a body lumen, pressurizing the retractable sleeve with a fluid; and retracting the sleeve tip to unfold and deploy the intravascular device at the target site. 11. Themethod according to claim 10 further comprises withdrawing the catheter system after deploying the intravascular device from the sleeve tip. 12. The method according to claim 10 wherein the re- tracting the sleeve tip comprises applying a force to a handle connected to the retractable sleeve. 5 10 15 20 25 30 35 40 45 50 55 9 EP 4 721 709 A2 10 EP 4 721 709 A2 11 EP 4 721 709 A2 12 EP 4 721 709 A2 13 EP 4 721 709 A2 14 EP 4 721 709 A2 15 EP 4 721 709 A2 16 EP 4 721 709 A2 17 EP 4 721 709 A2 18 EP 4 721 709 A2 19 EP 4 721 709 A2 20 EP 4 721 709 A2 21 EP 4 721 709 A2 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description • US 6723119 B

[0036] • US 6503270 B

[0036] • US 6355059 B

[0036] 摘要 用于将血管内装置输送及展开到血管内的设备和方法，包括：在 导管近端通过外壳结构轴向地连接的外管和内管，以及具有中间管和 套筒尖端的可回缩套筒结构。所述套筒尖端在远端被密封至内管，并 且连续地延伸到所述中间管中。在所述套筒结构的近端，所述中间管 被密封至所述外壳结构或者可滑动近端环上，从而形成位于所述内管 与所述套筒结构之间的密封腔室。在所述套筒尖端与所述内管之间形 成一径向空间，其被优化以便安置所述血管内装置。在所述套筒结构 的回缩期间，所述套筒尖端的折叠部从所述装置上剥离，所述装置扩 展至其展开状态，同时最小化轴向力和摩擦。

Claims

1. A retractable catheter system for delivery and deployment of an intravascular device, the catheter system having a distal end and a proximal end, comprising: an inner tube having a lumen, a housing structure at the proximal end of said catheter system, said housing structure having a distal end and a proximal end, wherein the inner tube is affixed to the housing structure; and a retractable sleeve comprising a sleeve tube and a sleeve tip, said sleeve tube having a proximal end and a distal end, said sleeve tube coaxially extending substantially along the length of the inner tube, and the sleeve tip having in the deployed state a distal end sealed to the inner tube and a proximal end fixed to the distal end of the sleeve tube forming a sealed chamber capable of containing a fluid, wherein in a pre-deployment state the sleeve tip forms a double layered sheath and the intravascular device is mounted in a radial space between the inner tube and the sleeve tip.

2. The retractable catheter system of claim 1, wherein the retractable sleeve comprises a sealable port.

3. The retractable catheter system of claim 2 wherein the sealable port is located in a handle.

4. The catheter system of claim 1, wherein the sleeve tip comprises ultra-thin polyethylene terephthalate.

5. The catheter system of claim 1 wherein the fluid is a hydrogel.

6. The retractable catheter sleeve of claim 1 further comprising a distal ring connecting the sleeve tip to the inner tube.

7. A retractable catheter sleeve for delivering an intravascular device according to claim 1, said sleeve further comprising: said proximal end of the sleeve tube sealingly connected to the inner tube via a proximal ring, said proximal end of the sleeve tube further comprising a sealable port; and the sleeve tube is sealingly connected to a handle; and said sheath capable of being pressurized with a fluid for deployment, said sheath being capable of retraction to deploy the device.

8. The retractable catheter sleeve of claim 7, wherein the sleeve tip has a micro-orifice at the distal end of the sleeve tip.

9. The retractable catheter sleeve of claim 7 wherein the sleeve tip comprises polyimide.

10. A method of deploying an intravascular device using a catheter system according to claim 1, comprising the steps of: navigating said sleeve tip to a target site within a body lumen, pressurizing the retractable sleeve with a fluid; and retracting the sleeve tip to unfold and deploy the intravascular device at the target site.

11. The method according to claim 10 further comprises withdrawing the catheter system after deploying the intravascular device from the sleeve tip.

12. The method according to claim 10 wherein the retracting the sleeve tip comprises applying a force to a handle connected to the retractable sleeve.

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