US20030229374A1 - Embolic protection system - Google Patents

Abstract

An embolic protection system comprises an embolic protection filter1having a collapsed delivery configuration and an expanded deployed configuration. The filter1is housed in the collapsed configuration in a reception space of a delivery catheter20.The delivery catheter20containing the filter1is housed in a sealed sterile pouch35.The filter1may be coated with a non-thrombogenic coating and an adhesion preventer9such as a silicon gel is used to substantially prevent adhesion of adjacent folds of the filter1when the filter is in the collapsed configuration in the delivery catheter20.

Description

• This invention relates to an embolic protection filter, which is movable between a collapsed configuration for transport through a vasculature and an expanded configuration for deployment in a vasculature.[0001]
• It is known to collapse down and load an embolic protection filter into a delivery catheter. The collapsed filter may then be transported through a vasculature using the delivery catheter until the filter is located at a desired site in the vasculature where the filter may be deployed out of the delivery catheter.[0002]
• It is also known to coat embolic protection filters with a biocompatible coating to minimise the risk of fibrin build-up on the filter, and the risk of clots forming in the blood stream.[0003]
• Many of these biocompatible coatings have hydrophilic properties. These hydrophilic coatings interact with water molecules. Water molecules may be absorbed during manufacture, sterilisation, storage or in use. Often the quantity of water absorbed is low leading to the biocompatible coating swelling slightly, and the coating becoming sticky or tacky.[0004]
• Filter membranes in this state have the potential for self-adherence and this can lead to the collapsed filter becoming stuck to itself in the collapsed configuration with the result that the filter will fail to expand fully, or even expand at all, when deployed in the vasculature. Failure of an embolic protection filter to correctly deploy in a vasculature can potentially lead to embolic material migrating downstream through the vascular system with potentially life-threatening consequences.[0005]
• Another problem which arises with a low profile filter loaded into a catheter pod is the difficulty in successfully flushing the device to remove any air. Because the filter assumes a packed configuration in the pod it is difficult to remove air from the filter. It may also be easier for the filter to remove itself from the pod due to the flushing pressure in preference to the filter being flushed of air.[0006]
• This invention is therefore aimed at overcoming at least some of the problems associated with known embolic protection systems.[0007]
STATEMENTS OF INVENTION
• An embolic protection system comprising:[0008]
• an embolic protection filter having a collapsed delivery configuration and an expanded deployed configuration;[0009]
• a delivery catheter having a reception space, an embolic protection filter being housed in the collapsed configuration in the reception space of the delivery catheter; and[0010]
• a sealed sterile pouch housing the delivery catheter containing the filter in the collapsed configuration.[0011]
• In one embodiment the filter in the collapsed configuration is at least partially folded.[0012]
• In another embodiment the system comprises an adhesion preventer to substantially prevent adhesion of adjacent folds of the filter to one another in the collapsed configuration.[0013]
• In a further embodiment the adhesion preventing material is selected from one or more of:[0014]
• a silicon fluid;[0015]
• a silicon gel;[0016]
• a lipid filled fluid/gel;[0017]
• a heparin filled fluid/gel; and[0018]
• an aqueous solution.[0019]
• The invention also provides a medical device movable between a collapsed configuration for transport through a vasculature and an expanded configuration for deployment in a vasculature:[0020]
• the device having a collapsed configuration in which the device is at least partially folded and an expanded configuration: and[0021]
• the device comprising an adhesion preventer to prevent adhesion of adjacent folds of the device in the collapsed configuration to one another.[0022]
• In a preferred embodiment the device comprises a collapsible body and a support structure to support the body in the expanded configuration. The collapsible body may be located at least partially externally of the support structure. The support structure may be located at least partially externally of the collapsible body.[0023]
• In one embodiment the adhesion preventer comprises means to space adjacent folds of the device apart. Preferably the means to space adjacent folds of the device apart comprises a filler material applied to a surface of the device. The filler material may comprise a silicon fluid, or a silicon gel, or a lipid filled fluid/gel, or a heparin filled fluid/gel, or an aqueous material.[0024]
• In one case the means to space adjacent folds of the device apart comprises one or more arms for extending between adjacent folds of the device. The support structure may comprise the arm. In a preferred embodiment the arm is provided by a tool which is suitable to assist loading of the device into a catheter.[0025]
• Preferably the biocompatible surface is provided as a coating of biocompatible material on the device.[0026]
• The biocompatible surface may be provided on an external surface of the device.[0027]
• The biocompatible surface may be provided on an internal surface of the device.[0028]
• According to another aspect the invention provides a method for providing embolic protection during a vascular procedure comprising the steps of:[0029]
• providing an embolic protection system comprising a sealed sterile pouch containing a delivery catheter with a reception space, an embolic protection filter being housed in the reception space in collapsed configuration;[0030]
• opening the pouch; and[0031]
• removing the delivery catheter containing the embolic protection filter in the collapsed configuration from the pouch.[0032]
• In one embodiment the method comprises the step of flushing the filter in the collapsed configuration within the delivery catheter.[0033]
• In another embodiment the filter is flushed prior to sealing of the pouch.[0034]
• In another aspect of the invention, there is provided a medical device movable between a collapsed configuration for transport through a vasculature and an expanded configuration for deployment in a vasculature, the device comprising:[0035]
• a storage space for storing a biocompatible material during transport through a vasculature; and[0036]
• means to deliver the biocompatible material from the storage space to a surface of the device when deployed in a vasculature.[0037]
• The storage space may be provided in a wall of the device.[0038]
• Preferably the means to deliver the biocompatible material comprises one or more channels from the storage space to the surface of the device. Ideally the channel is a capillary channel.[0039]
• In one case the biocompatible material is delivered to an external surface of the device. In another case the biocompatible material is delivered to an internal surface of the device.[0040]
• In a preferred embodiment the device comprises a delivery actuator to at least partially cause delivery of the biocompatible material from the storage space to the surface of the device. Ideally the actuator is at least partially of a temperature memory material.[0041]
• The biocompatible material may be a hydrophilic material.[0042]
• In one preferred case the device is an embolic protection filter. Ideally the filter has an inlet end and an outlet end, the inlet end having one or more inlet openings sized to allow blood and embolic material enter the filter, the outlet end having a plurality of outlet openings sized to allow through passage of blood but to retain undesired embolic material within the filter.[0043]
• In a further aspect, the invention provides a method of loading a medical device into a catheter, the method comprising the steps of:[0044]
• collapsing the medical device down to a wrapped configuration;[0045]
• controlling the wrap of the medical device during collapse; and[0046]
• positioning the medical device at least partially within the catheter.[0047]
• The medical device may be at least partially collapsed down by passing the medical device through a funnel. Preferably the wrap of the medical device is at least partially controlled by formations on the funnel.[0048]
• In another embodiment the medical device is at least partially collapsed down by directing a jet of fluid over the medical device. Ideally the wrap of the medical device is at least partially controlled by directing a jet of fluid over the medical device.[0049]
• Most preferably the medical device is at least partially collapsed during positioning of the medical device at least partially within the catheter.[0050]
• According to another aspect of the invention, there is provided a system for loading a medical device into a catheter, the system comprising:[0051]
• means to collapse a medical device down to a wrapped configuration; and[0052]
• means to control the wrap of the medical device.[0053]
• In one embodiment the means to collapse comprises a funnel through which a medical device may be passed. Preferably the means to control the wrap comprises one or more formations on the funnel. Ideally the formation comprises an inward protrusion on a wall of the funnel. The protrusion may be in the form of a finger extending from an end of the funnel. Preferably the finger extends generally longitudinally. The finger may extend generally in a spiral. Most preferably the finger extends from an outlet end of the funnel. Ideally the system comprises four fingers spaced-apart around the circumference of the funnel. The fingers are preferably equi-spaced apart.[0054]
• In another embodiment the means to collapse comprises one or more fluid jets for directing a jet of fluid over the medical device. The means to control the wrap may comprise one or more fluid jets for directing a jet of fluid over the medical device.[0055]
• The invention provides in a further aspect a method of loading a medical device into a catheter, the method comprising the steps of:[0056]
• collapsing the medical device;[0057]
• positioning the collapsed medical device at least partially within the catheter; and[0058]
• flushing a liquid through the catheter and the collapsed medical device.[0059]
• The method may comprise the step of sealing the catheter with flushing liquid therein.[0060]
• In another aspect of the invention, there is provided a method of delivering a medical device to a desired location in a vasculature, the method comprising the steps of:[0061]
• providing a catheter with a collapsed medical device positioned at least partially within the catheter;[0062]
• flushing a liquid through the catheter and the collapsed medical device; and[0063]
• introducing the catheter into a vasculature and advancing the catheter through the vasculature.[0064]
• Preferably the method comprises the step of monitoring the extent to which the collapsed medical device has been flushed. Ideally the flushing step is terminated when the collapsed medical device has been fully flushed.[0065]
• The liquid may be flushed distally through the catheter. The liquid may be flushed proximally through the catheter.[0066]
• Desirably the liquid is flushed through the catheter by creating a pressure differential across the collapsed medical device.[0067]
• In a further aspect, the invention provides a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein, a wall of the catheter around the reception space having flushing openings through the wall to facilitate flushing of a collapsed medical device in the reception space.[0068]
• The concentration of the flushing openings may increase distally along the reception space. The concentration of the flushing openings may increase proximally along the reception space. The concentration of the flushing openings may increase from a centre of the reception space towards proximal and distal ends of the reception space.[0069]
• The catheter preferably comprises means to indicate the extent of flushing of the reception space. Ideally the means to indicate comprises one or more perfusion openings in the catheter wall at an end of the reception space.[0070]
• The means to indicate may be provided by a separate component. Preferably the means to indicate is provided by a stylet extendable through the catheter.[0071]
• In one case the means to indicate comprises an element configured to change colour upon contact with a flushing liquid. Preferably the element comprises litmus.[0072]
• In a preferred embodiment the catheter comprises a seal for sealing the reception space with a collapsed medical device and flushing liquid therein. The seal may extend along substantially the full length of the catheter.[0073]
• The invention provides in another aspect a catheter assembly comprising a catheter of the invention and a collapsible medical device receivable in the reception space of the catheter, the medical device having one or more flushing openings in a body of the medical device to facilitate flushing of the medical device when collapsed in the reception space.[0074]
• Preferably the medical device body comprises a coiled spring.[0075]
• According to another aspect of the invention, there is provided a catheter assembly comprising:[0076]
• a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and[0077]
• means for reinforcing against creep a wall of the catheter around the reception space.[0078]
• In one case the means for reinforcing reinforce the catheter wall against longitudinal creep. In another case the means for reinforcing reinforce the catheter wall against radial creep.[0079]
• In a preferred embodiment the means for reinforcing comprises a clamp for positioning around the catheter wall. The clamp may comprise a sleeve.[0080]
• In another case the assembly comprises a tray for the catheter, and the clamp is provided by the tray.[0081]
• Ideally the clamp is configured to provide non-uniform reinforcement along the catheter wall. Most preferably the clamp comprises one or more formations to provide non-uniform reinforcement along the catheter wall.[0082]
• In another embodiment the means for reinforcing comprises one or more reinforcing elements in the catheter wall. Preferably the catheter wall is of a composite construction.[0083]
• In a further aspect, the invention provides a catheter assembly comprising:[0084]
• a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and[0085]
• means for elongating a medical device received in the reception space to resist creeping of the medical device.[0086]
• The means for elongating may comprise a tensioning wire attachable to a medical device.[0087]
• The invention provides in another aspect a method of loading a medical device into a catheter, the method comprising the steps of:[0088]
• collapsing the medical device;[0089]
• positioning the collapsed medical device at least partially within the catheter; and[0090]
• applying pressure to the catheter and/or to the collapsed medical device to distribute loading stresses on the catheter and/or on the collapsed medical device.[0091]
• The pressure is preferably applied longitudinally.[0092]
• The pressure may be applied radially.[0093]
• In one case the applied pressure is substantially constant over time. In another case the applied pressure varies over time. Ideally the applied pressure varies cyclically over time.[0094]
• In a further aspect of the invention, there is provided a catheter assembly comprising:[0095]
• a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and[0096]
• means for applying pressure to a wall of the catheter around the reception space and/or to a collapsed medical device received in the reception space to distribute loading stresses in the catheter wall and/or the collapsed medical device.[0097]
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:[0098]
• FIG. 1 is a side, partially cross sectional view of an embolic protection filter;[0099]
• FIGS.[0100]2(a) to2(c) are schematic views illustrating the coating of the filter with an adhesion preventing material;
• FIGS.[0101]2(d) and2(e) are schematic views illustrating the loading of the filter into a delivery catheter;
• FIG. 2([0102]f) is a schematic view of the filter loaded into a delivery catheter in a hoop mounted in a sterile pouch with an enlarged detail of a distal end of the delivery catheter with the filter in place;
• FIG. 2([0103]g) and2(h) are schematic views illustrating the removal of the hoop from the pouch;
• FIGS.[0104]2(i) and2(j) are schematic views illustrating the removal of the delivery catheter from the hoop;
• FIG. 2([0105]k) is a schematic view illustrating the flushing of the delivery catheter;
• FIGS.[0106]2(l) to2(n) are schematic views illustrating the loading of the delivery catheter onto a pre-deployed guidewire;
• FIG. 3 is a schematic view illustrating the loading of a delivery catheter in an arrangement in which a guidewire extends through the delivery catheter prior to entry into the vasculature;[0107]
• FIG. 4 is a cross sectional view of the filter in the collapsed loaded configuration of[0108]2(e);
• FIG. 5 is a cross sectional view of an alternative filter in the collapsed loaded configuration;[0109]
• FIG. 6 is an enlarged cross sectional view showing the region between adjacent parts of the filter body in the collapsed configuration;[0110]
• FIG. 7 to[0111]16 are enlarged cross-sectional views illustrating the interaction of various adhesion prevention materials with hydrophilic coatings in various arrangements;
• FIG. 17 is a schematic view illustrating an alternative method for coating a filter with an adhesion preventing material;[0112]
• FIG. 18 is a schematic view illustrating an alternative method of loading a filter into a delivery catheter;[0113]
• FIG. 19 is an end view of another embolic protection filter loaded into a catheter;[0114]
• FIG. 20 is an enlarged view of portion of another filter;[0115]
• FIGS.[0116]21 is an enlarged perspective view of part of another filter according to the invention;
• FIGS. 22 and 24 are cross-sectional, side views of a funnel according to the invention;[0117]
• FIG. 23 is an enlarged cross-sectional, end view of a filter passing through the funnel of FIGS. 22 and 23;[0118]
• FIG. 25 is an enlarged view along line XXV-XXV in FIG. 23;[0119]
• FIG. 26 is a schematic, side view illustrating loading of a medical device into a catheter;[0120]
• FIG. 27 is a side, cross-sectional view of a catheter according to the invention;[0121]
• FIG. 28 is a schematic representation of 1/porosity along a part of the catheter of FIG. 27;[0122]
• FIG. 29 is a side, cross-sectional view of another catheter according to the invention;[0123]
• FIG. 30 is a schematic representation of 1/porosity along a part of the catheter of FIG. 29;[0124]
• FIG. 31 is a side, cross-sectional view of a further catheter according to the invention;[0125]
• FIG. 32 is a schematic representation of 1/porosity along a part of the catheter of FIG. 31;[0126]
• FIGS. 33 and 35 to[0127]38 are schematic views of a catheter according to the invention, in use;
• FIGS. 34 and 39 to[0128]40 are schematic views of another catheter according to the invention, in use;
• FIGS. 41 and 42 are side, cross-sectional views of further catheters according to the invention, in use;[0129]
• FIGS.[0130]43 to45 are side, partially cross-sectional views of medical devices according to the invention;
• FIG. 46 is a schematic view of a loaded catheter according to the invention;[0131]
• FIG. 47 is an enlarged, schematic view of the loaded catheter of FIG. 46;[0132]
• FIG. 48 is a plan view of another loaded catheter according to the invention;[0133]
• FIG. 49 is a schematic view of a further loaded catheter according to the invention;[0134]
• FIG. 50 is a partially cross-sectional, side view of a catheter assembly according to the invention;[0135]
• FIG. 51 is a partially cross-sectional, side view of another catheter assembly according to the invention;[0136]
• FIG. 52 is a partially cross-sectional, side view of a further catheter assembly according to the invention on a tray;[0137]
• FIG. 53 is a partially cross-sectional, side view of another catheter assembly according to the invention;[0138]
• FIGS. 54 and 56 are side views of another catheter assembly according to the invention in use;[0139]
• FIGS. 55 and 57 are side views of a further catheter assembly according to the invention in use;[0140]
• FIG. 58 is a partially cross-sectional, side view of another catheter assembly according to the invention;[0141]
• FIG. 59 is a side view of a medical device according to the invention; and[0142]
• FIG. 60 is a cross-sectional, side view of the medical device of FIG. 59 loaded into a catheter.[0143]
DETAILED DESCRIPTION
• Referring to the drawings and initially to FIG. 1 thereof, there is illustrated an[0144]embolic protection filter1 which in this case comprises acollapsible filter body2 and afilter support3 for thefilter body2. In the embodiment of FIG. 1, thefilter body2 is located externally of thefilter support3. Thefilter support3 is mounted around aninner tube8. Theinner tube8 has aguidewire lumen12 therethrough, through which a guidewire may pass for exchange of thefilter1 over the guidewire.
• The[0145]filter body2 has aninlet end4 and anoutlet end5. Theinlet end4 has one or more, and in this case two,large inlet openings6 which are sized to allow blood and embolic material enter thefilter body2. Theoutlet end5 has a plurality ofsmall outlet openings7 which are sized to allow through passage of blood but to retain undesired embolic material within thefilter body2. In this way, thefilter1 captures and safely retains any undesired embolic material in the blood stream within thefilter body2 while facilitating continued flow of blood through the vascular system. Emboli are thus prevented from flowing further downstream through the vascular system, which could otherwise have potentially catastrophic results.
• The[0146]filter1 is movable between a low profile, collapsed configuration (FIG. 2 (e)) for transport through a vasculature, and an expanded configuration (FIG. 1) for deployment in the vasculature. As particularly illustrated in FIG. 1, in this expanded configuration, thefilter body2 is supported in the expanded configuration by thefilter support3 so as to maximise the internal volume of thefilter body2 to capture and safely retain as much embolic material as possible.
• The[0147]filter body2 may be of an oriented polymeric material, as described in International Patent Application No. PCT/IE01/00087 (U.S. Ser. No. 09/887,893), the relevant contents of which are incorporated herein by reference
• The[0148]filter1 may have a coating of a biocompatible material, in this case a hydrophilic material, around the external surface of thefilter body2 and around the internal surface of thefilter body2.
• Fluid mechanics dictates that blood flowing through a pore or series of pores is subjected to shearing forces. Filtration devices are by their nature shearing devices. Excessive shearing forces can causes the activation of platelets which can cause the formation of thrombus. Activated platelets adhere to surfaces and attract more platelets to the site. Passing platelets stick to those already at the site and this leads to a cascade. Fibrin deposition is also a consequence and can form an insoluble threadlike mesh on the filter membrane. Fibrin formation on the filter is undesirable. It may have embolic potential if it enters the blood stream. It may also act to block filter pores reducing the blood flow through the filter and causing localised high shear zones in the remaining open holes.[0149]
• Biocompatible coatings or surfaces are often used to prevent thrombus and fibrin formation on a filter. Biocompatible coatings with hydrophilic properties aid biocompatibility by providing a non-thrombogenic and non-stick surface.[0150]
• The fluid membrane interactions resulting from the activation of the hydrophilic surface layer, which is liquid or substantially liquid, allows the device to resist fibrin build-up and minimise the risk of clots forming in the blood stream. The interactive surface layer, being of a liquid form could typically contain silicone, lipids, heparin or the like.[0151]
• As illustrated in FIG. 4, when the[0152]filter1 is in the collapsed configuration, thefilter body2 is tightly folded over upon itself. FIG. 5 illustrates a similar arrangement to FIG. 4 but with no longitudinal support/frame shown.
• To prevent the relatively sticky hydrophilic coating on one fold of the[0153]filter body2 adhering to an adjacent fold of thefilter body2, an adhesion preventing material9, such as a silicon fluid, or a silicon gel, or an aqueous material, is applied to the external surface of thefilter body2 and to the internal surface of thefilter body2 prior to loading thefilter1 into adelivery catheter20.
• The adhesion preventing material[0154]9 may be applied in any convenient manner such as by dipping thefilter1 into abath15 of the adhesion preventer9 as illustrated in FIGS.2(a) to2(c).
• As illustrated partially in FIGS. 4 and 5, the adhesion preventing material[0155]9 provides a means of spacing adjacent folds of thefilter body2 apart. Any hydrophilic coating on one fold of thefilter body2 is thus prevented from adhering to an adjacent fold of thefilter body2, even when thefilter body2 is tightly wrapped down in the collapsed configuration.
• The[0156]delivery catheter20 may comprise an outer catheter shaft with an expansible pod at a distal end of the outer catheter shaft, and an inner catheter shaft extending through the outer catheter shaft. In the delivery configuration illustrated, the pod extends distally of the inner shaft to facilitate reception of thecollapsed filter1 within the pod. The inner shaft is movable distally relative to the outer shaft to deploy thefilter1 out of the pod.
• The delivery catheter may be similar to that described in our International Patent Applications Nos. PCT/IE98/00093 (U.S. Ser. No. 09/188,472), PCT/IE01/00052 (U.S. Ser. No. 09/838,544) and PCT/IE01/00053 (U.S. Ser. No. 09/838,545), the relevant contents of which are incorporated herein by reference.[0157]
• In use, when the adhesion preventing material[0158]9 has been applied to the filter body2 (FIG. 2(d)), thefilter1 is then collapsed and loaded into the delivery catheter20 (FIG. 2(e)). A funnel may be used to assist collapse of thefilter1 during loading into thedelivery catheter20.
• The[0159]delivery catheter20 with thefilter1 loaded in a collapsed configuration may be threaded through ahoop30 which in turn is packaged aseptically in a sterile pouch35 (FIG. 2(f)) having abacking sheet36 and acover sheet37 with apull tab38 for opening the pouch as illustrated in FIG. 2(g). Thehoop30 containing the delivery catheter can then be removed as illustrated in FIG. 2(h). Thedelivery catheter20 is removed from the hoop as illustrated in FIG. 2(i) and20). The removeddelivery catheter20 may then be flushed using a saline injector40 (FIG. 2(k)). Alternatively or additionally the filter and delivery catheter may be pre-flushed prior to packaging.
• In the arrangements illustrated in FIGS.[0160]2(e) to2(n) thedelivery catheter20 with the filter at the distal end thereof may be threaded over the proximal end of a guidewire which has been deployed in the vasculature of a patient. Alternatively, as illustrated in FIG. 3 the delivery system may comprise adelivery catheter46 with a guidewire47 extending therethrough to which a filter is connected and the delivery system is led through the vasculature Via a guide catheter, sheath or catheter.
• The loaded[0161]delivery catheter20 is advanced through the vasculature to deliver thecollapsed filter1 to a desired site in the vasculature. The site of deployment of thefilter1 in the vasculature is typically downstream of a treatment site, such as a region of stenosis in the vasculature.
• The[0162]filter1 is deployed out of thedelivery catheter20 at the desired site in the vasculature. Thefilter support3 expands radially outwardly to support thefilter body2 in tubular apposition with the interior wall of the vasculature. During the subsequent performance of a treatment procedure, on the vasculature thefilter1 captures and safely retains any embolic material in the blood stream within thefilter body2.
• After completion of the treatment procedure, the[0163]filter1 is collapsed down and retrieved into a retrieval catheter with any retained embolic material within thefilter body2. The retrieval catheter is then withdrawn from the vasculature with thefilter1 within the retrieval catheter.
• The delivery, deployment and retrieval of the embolic protection filter of the invention, as described above, is similar to that described in our International Patent Applications Nos. PCT/IE98/00093 (U.S. Ser. No. 09/188,472), PCT/IE01/00052 (U.S. Ser. No. 09/838,544) and PCT/IE01/00053 (U.S. Ser. No. 09/838,545), the relevant contents of which are incorporated herein by reference. The[0164]filter1 may be slidably exchanged over the guidewire without any attachment means between thefilter1 and the guidewire. A distal stop on the guidewire assists in retrieval of thefilter1. The guidewire may remain in the vasculature after retrieval of thefilter1.
• Referring now to FIG. 6,[0165]hydrophilic coating material50 on adjacent parts of thefilter membrane51, when folded are illustrated by wavy lines. In the invention molecules of the adhesion prevention material9 are interspersed between thecoating50, thus preventing thecoating50 from adjacent membranes interacting and becoming attached.
• FIGS.[0166]7 to9 illustrate the interaction of the molecules of thehydrophilic coatings50 of adjacent filter membrane layers when water is excluded or included. FIG. 8 describes two non-contacting hydrophilically coated surfaces. In the case where these two coatings are brought into intimate contact in the presence of water the hydrophilic chains become entangled and adhered as shown in FIG. 9. This may be the case with a wrapped down filter membrane (intimate pressurised contact) which sees moisture (sterilisation or atmospheric exposure). This may hinder/prevent filter deployment from a sheath in the vasculature. FIG. 7 describes two hydrophilically activated (water present) surfaces which are in relatively close contact. Removing the activation reagent (water) from the hydrophilic surfaces and compressing results in the coated surfaces becoming stuck together.
• FIGS. 10 and 11 illustrate the reversible activation/de-activation of the hydrophilic properties of the surface with the addition/removal of water. FIG. 10 shows the nonactivated case. FIG. 11 shows an activated hydrophilic surface with a swollen and lubricious configuration.[0167]
• FIG. 12 schematically illustrates the use of an adhesion prevention material[0168]9 of relatively large molecular weight such as a high viscosity silicone fluid with a viscosity in the region of 5,000 10,000 centipoise.
• FIG. 13 schematically illustrates the use of an adhesion prevention material[0169]9 of relatively low molecular weight such as a low viscosity silicone fluid with a viscosity in the region of 1-100 centipoise. In general, adhesion prevention materials can be processed in such a way as to tailor the required molecular weight.
• Exemplary examples of adhesion preventers are silicone fluids, PDMS (poly dimethyl siloxane), PEO (polyethylene oxide), PEG (polyethylene glycol), PPO(polypropylene oxide), PPG(polypropylene glycol), lipophilic fluids, hydrophilic fluids, co-polymers of PDMS and PEO and/or PPO and surfactants. Examples of low molecular weight adhesion preventers are silicone fluids and aqueous solutions.[0170]
• FIG. 14 illustrates the use of the adhesion prevention material[0171]9 to prevent sticking of the hydrophilic coatings on adjacent filter membrane portions when folded into the collapsed configuration even when the hydrophilic is activated. This shows the case where the hydrophilically coated surfaces with adhesion preventer of FIG. 6 are in pressurised contact and have been activated with water. The adhesion preventer is dispersed between the activated hydrophilic chains and prevents the coatings sticking together even though they are in intimate contact. The adhesion preventer does not evaporate from the system and retains its ability to prevent the molecular interaction (such as van der Waal's forces) of neighbouring hydrophilic chains. The adhesion preventer acts to enable successful deployment of the pre-loaded filter in the vasculature.
• FIGS. 15 and 16 schematically illustrate the benefits of using a hydrophilic coating in blood contacting applications. Most thrombogenic coatings are also hydrophilic. FIG. 16 illustrates the[0172]base membrane51 without a hydrophilic surface. When blood contacting, this non-hydrophilicallycoated membrane51 is not a very passive surface. Cells and/orbiological material55 may adhere to the surface and cause a cascade of fibrin/clot build-up. FIG. 15 shows themembrane51 with a hydrophilic coating activated withwater56. This is now extremely lubricious with a high water content. Due to this high water content hydrophilic cellular and biological material adhesion and cascade is minimised.
• FIG. 17 illustrates another method of applying an adhesion prevention material[0173]9 prior to loading into a delivery catheter.
• It will be appreciated that the adhesion preventing material[0174]9 may be applied to the external surface of thefilter body2 and to the internal surface of thefilter body2 during collapse and loading of thefilter1 into thedelivery catheter20, as illustrated in FIG. 18.
• In FIG. 19, there is illustrated another[0175]embolic protection filter60 according to the invention, which is similar to thefilter1 described above, and similar elements in FIG. 9 are assigned the same reference numerals. In this case, thefilter support3 comprises a plurality ofarms63 Are these shown which are configured to extend between adjacent folds of thefilter body2 as thefilter60 is collapsed down and loaded into thedelivery catheter pod22. Thus thefilter support3 provides the means of spacing adjacent folds of thefilter body2 apart, and so the hydrophilic coating on one fold of thefilter body2 is prevented from adhering to an adjacent fold of thefilter body2, even when thefilter60 is stored in a collapsed configuration within thepod22 for a relatively long period of time.
• The surface properties of the[0176]filter support3 and/or thefilter body2 may be configured to minimise the possibility of adhering to one another. Furthermore, the surface formations on thefilter support3 and/or on thefilter body2 may be configured to minimise the possibility of adhering to one another, as illustrated in FIG. 20.
• In FIG. 21, there is illustrated a further[0177]embolic protection filter70 according to the invention, which is similar to thefilter1 described above. In this case, thefilter body71 comprises a storage space in thewall72 of thefilter body71 for storing a biocompatible material, such as a hydrophilic material, in thewall72 of thefilter body71 during transport through a vasculature. By storing the hydrophilic material in thewall72 of thefilter body71 away from theexternal surface73 of thefilter body2 and theinternal surface74 of thefilter body2, thefilter70 may be collapsed down without the risk of one fold of thefilter body2 adhering to an adjacent fold of thefilter body2. Thefilter70 can thus be collapsed down and loaded into a delivery catheter for a relatively long period of time while ensuring that thefilter70 will expand fully radially outwardly when deployed in a vasculature.
• The[0178]filter body2 comprises a plurality of capillary channels75 from the storage space in thewall72 of thefilter body2 to theexternal surface73 of thefilter body2 and to theinternal surface74 of thefilter body2. The channels75 provide a means of delivering the hydrophilic material from the storage space in thewall72 to the external andinternal surfaces73,74 when thefilter70 is deployed in a vasculature.
• Referring to FIGS.[0179]22 to25, there is illustrated a system according to the invention for loading a medical device, such as theembolic protection filter1 described previously, into a catheter, such as thedelivery catheter20 described previously.
• The system comprises a[0180]funnel80 through which thefilter1 may be passed to collapse thefilter1 down to a wrapped configuration. Four inwardly protrudingformations81 are provided on the wall of thefunnel80. The protrudingformations81 extend longitudinally from anoutlet end82 of thefunnel80 in the form of four elongate fingers, and theformations81 are equi-spaced around the circumference of thefunnel80.
• The protruding[0181]formations81 control the wrapping down of thefilter1 as thefilter1 is passed through thefunnel80 to collapse thefilter1.
• In use, the[0182]funnel80 is mounted to the distal end of thepod22 of the delivery catheter20 (FIG. 22). Thefilter1 is then passed through thefunnel80 to collapse thefilter1 down to the wrapped configuration. As illustrated in FIG. 23, when thefilter1 enters thefunnel80 at theinlet end83 of thefunnel80, thefilter1 is in the expanded configuration. When thefilter1 exits thefunnel80 at theoutlet end82, thefilter1 is collapsed down in the wrapped configuration, as illustrated in FIGS. 24 and 25.
• In addition, as the[0183]filter1 is passed through thefunnel80, the protrudingformations81 engage thefilter body2 and thereby control the wrap of thefilter1. By thus controlling the wrapping of thefilter1, a more uniform collapsed configuration may be achieved.
• It will be appreciated that alternative means of collapsing the[0184]filter1, and/or alternative means of controlling the wrap of thefilter1 may also be employed in addition to or as an alternative to thefunnel80.
• For example one or more fluid jets[0185]90 may be provided to direct a jet of fluid, such as air or a hydrophilic fluid, over thefilter1 to collapse thefilter1 down to the wrapped configuration, as illustrated in FIG. 26. By appropriately selecting the pressure of the fluid in each jet90 the wrap of thefilter1 may also be controlled by the jet of fluid passing over thefilter1.
• Referring to FIG. 27, there is illustrated a[0186]medical catheter100 according to the invention. Thecatheter100 comprises acatheter shaft101 with anexpandable pod102 mounted to the distal end of theshaft101. Thepod102 defines areception space104 suitable for receiving a collapsed medical device, such as an embolic protection filter, therein. In this manner, thecatheter100 may be configured for use as a delivery catheter to transport an embolic protection filter through a vasculature to a desired location in the vasculature downstream of a treatment site.
• The wall of the[0187]pod102 around thereception space104 has a plurality of flushingopenings103 through the pod wall and evenly spaced along thepod102. The provision of these flushingopenings103 in the pod wall enables the filter to be effectively flushed of all air bubbles, while the collapsed filter is positioned within thereception space104, without the risk of the pressure of the flushing liquid disturbing or forcing the collapsed filter out of thereception space104.
• Thus the catheter of the invention enables a filter to be loaded into the pod, and then stored in this pre-loaded arrangement until required for use. When the filter and catheter are subsequently required for use, the clinician may then flush the pre-loaded filter within the pod to ensure all air bubbles are removed from the filter and the pod.[0188]
• Therefore it is not necessary for the clinician to load the filter into the pod at the site of use. In this case the clinician simply flushes the filter and the pod, and then inserts the catheter into a vasculature.[0189]
• The catheter of the invention also enables a filter to be loaded into the pod, completely flushed of air bubbles while in the pod at the site of loading, and then stored in this pre-loaded, pre-flushed arrangement until required for use. In this case, it is not necessary for a clinician to load the filter into the pod, or to flush the filter at all before introducing the catheter into a vasculature.[0190]
• It will be appreciated that by appropriately selecting the size, and/or the layout, and/or the concentration of the flushing[0191]openings103 along thepod102, the pressure of the flushing liquid on the collapsed filter in thepod102 may be controlled.
• For example, in the[0192]catheter106 of FIG. 29, the concentration of the flushingopenings103 increases distally along thepod102. This layout of flushingopenings103 results in 1/porosity decreasing distally along thepod102, as illustrated in FIG. 30. The concentration of the flushingopenings103 may alternatively increase proximally along thepod102. As a further alternative, in thecatheter107 of FIG. 31 the concentration of the flushingopenings103 increases from a centre of thepod102 towards the proximal and distal ends of thepod102. This layout of flushingopenings103 results in 1/porosity peaking at the centre of thepod102 and falling off towards the proximal and distal ends of thepod102, as illustrated in FIG. 32.
• In FIG. 33, there is illustrated another[0193]medical catheter110 according to the invention, which is similar to thecatheter100 of FIG. 27, and similar elements in FIG. 33 are assigned the same reference numerals.
• In this case, the[0194]catheter110 comprises three perfusion openings111 in the wall of thepod102 at the proximal end of the pod102 (FIG. 33). It will be understood that any suitable number of perfusion openings may be provided in the catheter110.???? FIG. 34 description. Replace existing FIG. 34 with FIG. 20 frompage 35/59 sent Jan. 5, 2003.
• Referring to FIGS. 35 and 35[0195]a,in use, a medical device such as theembolic protection filter1 described previously may be collapsed down and positioned within thereception space104 at the site of loading. When it is subsequently desired to use thecatheter110 and thecollapsed filter1, a sealing package around thecatheter110, which is held within a holding tube113, is opened as described above. At the site of use, a flushing liquid may be introduced into thereception space104 at the distal end of thepod102, and thecatheter110 and thecollapsed filter1 are flushed proximally, for example by using asyringe112 while thecatheter110 remains within a holding tube113, as illustrated in FIGS. 35 and 35a.
• When the flushing liquid is flushed through the[0196]reception space104 and thecollapsed filter1, some of the flushing liquid will perfuse out through the openings111 at the proximal end of thepod102. Once the clinician sees the flushing liquid perfuse out through the openings111, the clinician can be satisfied that thecollapsed filter1 has been fully flushed of any air bubbles and the flushing step may be terminated.
• In this manner, the perfusion openings[0197]111 provide a means of indicating the extent to which thereception space104 and thecollapsed filter1 have been flushed. By monitoring this extent, the clinician will know when thecollapsed filter1 has been safely flushed of all air bubbles.
• When the flushing step has been terminated, the[0198]syringe112 is removed from thecatheter110. Thecatheter110 may then be quickly and easily removed from the catheter holding tube113.
• In some cases the[0199]catheter110 may be threaded over aguidewire280, and advanced over theguidewire280 through a vasculature to a desired site in the vasculature, such as downstream of a stenosed region of the vasculature.
• In the case of the[0200]guidewire280 of FIG. 36, theguidewire280 has adistal stop281 at the distal end of theguidewire280.
• However the[0201]catheter110 may also be advanced over a standardmedical guidewire290 without any stop formation at the distal end of theguidewire290, as illustrated in FIG. 37.
• As a further alternative, the catheter may be advanced through the vasculature at the same time as the[0202]guidewire300 is advanced through the vasculature, as illustrated in FIG. 38. This may arise in the circumstance in which the filter is constrained relative to theguidewire300.
• It will be appreciated that the flushing liquid may alternatively be introduced into the[0203]catheter110 at the proximal end of theshaft101, so that thecatheter110 and thecollapsed filter1 are flushed distally.
• As illustrated in FIG. 34, a[0204]seal116 may be releasably mounted at the distal end of thepod102 after positioning thecollapsed filter1 in thereception space104. Thecatheter110 and thecollapsed filter1 are then flushed distally using thesyringe112, as illustrated in FIG. 39. When the flushing liquid has fully flushed thecollapsed filter1, the liquid engages against theseal116 which reverses the flow of the flushing liquid. Some of the flushing liquid then flows proximally to the proximal end of thepod102, where the flushing liquid perfuses out through the openings111.
• On initial distal flow of the flushing liquid, it is easiest for the flushing liquid to pass through the filter. The flushing liquid follows the path of least resistance which can be directed by altering the number and size of the openings[0205]111. As pressure then builds up the flushing liquid exits through the openings111.
• When the clinician sees the flushing liquid perfuse out through the openings[0206]111, the flushing step is terminated. Thecatheter110 may then be quickly and easily removed from the catheter holding tube113 for introduction into a vasculature of a patient.
• It will further be appreciated that the[0207]catheter110 may be removed from the holding tube113 before flushing thecollapsed filter1 and the reception space104 (FIG. 39). Thecollapsed filter1 and thereception space104 may alternatively be flushed with a flushing liquid311 at the site of loading (FIG. 40) before thecatheter110 is sealed within the package. When it is subsequently desired to use thecatheter110, the clinician simply needs to remove the holding tube113 from the package, and remove thecatheter110 from the tube113. Thecatheter110 is then ready for introduction into a vasculature. In particular it is not necessary for the clinician to flush thecatheter110 at the site of use.
• A sealing member[0208]310 may be inserted into thefilter1 from the distal end of the filter during the flushing step.
• The means to indicate the extent of flushing of the reception space of the pod and the[0209]collapsed filter1 could alternatively be provided by a component separate from the catheter.
• For example, in FIG. 41 there is illustrated another[0210]catheter120 according to the invention, which is similar to thecatheter110 of FIG. 33, and similar elements in FIG. 41 are assigned the same reference numerals.
• The[0211]catheter120 comprises an exit port121 at the proximal end of thepod102. Astylet122 is extended through thereception space104 and threaded through thecollapsed filter1 to exit thereception space104 through the exit port121 (FIG. 41).
• The[0212]stylet122 comprises anelement123 which is configured to change colour upon contact with the flushing liquid. A suitable material for thecolour change element123 is litmus.
• By monitoring the colour of the[0213]element123, the clinician will be alerted when thecollapsed filter1 has been fully flushed of air bubbles.
• In FIG. 41, the[0214]catheter120 and thecollapsed filter1 are flushed proximally by introducing the flushing liquid into thereception space104 at the distal end of thepod102 using thesyringe124.
• The[0215]catheter120 and thecollapsed filter1 could alternatively be flushed distally by introducing the flushing liquid into thecatheter120 at the proximal end of theshaft100 using thesyringe124, as illustrated in FIG. 42. In this case thestylet122 is reversed so that thecolour change element123 is downstream of thecollapsed filter1. In this way, by monitoring the colour of theelement123, the clinician will be alerted when thecollapsed filter1 has been fully flushed of air bubbles.
• Referring to FIG. 43, there is illustrated another embolic protection filter[0216]130 according to the invention, which is similar to thefilter1, and similar elements are assigned the same reference numbers.
• In this case, the[0217]inner tube8 of the filter130 has a series of flushingopenings131 spread longitudinally along the inner tube8 (FIG. 43). Theseopenings131 assist in the flushing of air bubbles from the filter130 when the collapsed filter130 is positioned in thereception space104 of a catheter, by distributing the flushing liquid throughout the collapsed filter130. Furthermore, the filter130 may be flushed by introducing the flushing liquid into theguidewire lumen12 of theinner tube8. The flushing liquid then flows out of theguidewire lumen12 thorough theflushing openings131 to flush all air bubbles from the collapsed filter130.
• As illustrated in the filter[0218]132 of FIG. 44, the distribution of the flushingopenings131 along theinner tube8 may be selectively altered to achieve a thorough flushing of all air bubbles from the collapsed filter132.
• In the[0219]filter133 of FIG. 45, the inner tube is provided in the form of acoiled spring134. The spacings between the coils of thespring134 provide flow pathways for the flushing liquid to pass out of theguidewire lumen12 to achieve a thorough flushing of all air bubbles from thecollapsed filter133.
• FIGS. 46 and 47 illustrate a[0220]further catheter140 according to the invention, which is similar to thecatheter120 of FIGS. 41 and 42, and similar elements in FIGS. 41 and 42 are assigned the same reference numbers.
• The[0221]catheter140 comprises aninlet port142 at the proximal end of thepod102 through which a flushing liquid may be introduced for flushing thereception space104 and thecollapsed filter1.
• The[0222]catheter140 has aseal141 for sealing around thereception space104 with thecollapsed filter1 and some of the flushing liquid sealed within theseal141.
• In use, the[0223]filter1 is collapsed down and positioned within thereception space104. A source of flushing liquid143 is then connected in communication with theinlet port142, and a vacuum is drawn on the loadedfilter1 to create a pressure differential across thecollapsed filter1. This vacuum causes the flushing liquid to be drawn through thereception space104 of thepod102 and thecollapsed filter1 to dispel all air bubbles from thereception space104 and thefilter1.
• The[0224]seal141 is then applied around thepod102 with thecollapsed filter1 and some of the flushing liquid sealed within the seal141 (FIG. 46). Theseal141, in this case, extends proximally over the inlet part142 (FIG. 47).
• The sealed[0225]catheter140 may be stored in this arrangement for potentially long periods of time without the risk of any air bubbles entering thereception space104 or thecollapsed filter1. When thecatheter140 is required for use, theseal141 is broken. Thecatheter140 may then be immediately used to transport thefilter1 through a vasculature without requiring the clinician to flush thereception space104 or thefilter1 before use.
• It will be appreciated that the[0226]catheter140 may be configured for use as a rapid exchange catheter, in which case theflushing inlet port142 may be used as a guidewire rapid exchange port.
• FIG. 48 illustrates another[0227]catheter150 according to the invention, which is similar to thecatheter140 of FIGS. 41 and 42.
• The[0228]catheter150 is an over-the-wire catheter, and theseal151 extends along the full length of thecatheter150 from theproximal end152 to the pod153.
• FIG. 49 illustrates a[0229]further catheter250 according to the invention, which is similar to thecatheter140 of FIGS. 41 and 42, and similar elements in FIG. 44 are assigned the same reference numerals.
• The[0230]catheter250 comprises aplunger251 at the distal end of theseal141.
• When the clinician is ready to use the[0231]catheter250, theplunger251 may be moved proximally through theseal141 to perform an additional flushing step at the site of use. Continued movement of the plunger proximally increases the pressure within theseal141 eventually causing theseal141 to burst. Thus theplunger251 provides a simple, yet effective means of flushing thecollapsed filter1 and thepod102 at the site of use, and of bursting open theseal141.
• In FIG. 50, there is illustrated a catheter assembly[0232]160 according to the invention. The assembly160 comprises acatheter161 and aclamp sleeve162.
• The[0233]catheter161 comprises acatheter shaft163 with anexpansible pod164 at a distal end of theshaft163. Thepod164 defines areception space165 for receiving a collapsed medical device, such as the embolic protection filter described previously.
• The[0234]clamp sleeve162 is releasably mounted to thecatheter161 positioned around thepod164. Thesleeve162 reinforces the pod wall against radial creep when thecollapsed filter1 is loaded within thereception space165.
• In use, the[0235]filter1 is collapsed down and positioned within thereception space165. Theclamp sleeve162 is then positioned around thepod164 to reinforce the pod wall against radial creep. In this way thefilter1 may be stored for a relatively long period of time in the collapsed configuration loaded into the catheter without creep of the filter and/or of the pod occurring.
• When the[0236]catheter161 is required for use, theclamp sleeve162 is demounted from thecatheter161, and thecatheter161 is introduced into a vasculature to transport thefilter1 to the desired site in the vasculature.
• FIG. 51 illustrates another[0237]catheter assembly170 according to the invention, which is similar to the catheter assembly160 of FIG. 45, and similar elements in FIG. 46 are assigned the same reference numerals.
• In this case the[0238]clamp sleeve162 comprises a plurality of inwardly protruding formations171. The formations171 engage thepod164 to provide non-uniform reinforcement against radial creep to thepod164 along the length of thepod164.
• In the case of the catheter assembly[0239]180 of FIG. 52, theclamp181 is provided by atray181 for thecatheter161. Thetray181 has arecess182 suitably configured to receive thecatheter pod164 when thecollapsed filter1 has been loaded into thereception space165. The walls of thetray181 around therecess182 then engage against thepod164 to reinforce against radial creep thepod164 and thecollapsed filter1.
• Referring next to FIG. 53, there is illustrated another catheter assembly[0240]190 according to the invention, which is similar to the assembly160 of FIG. 50, and similar elements in FIG. 53 are assigned the same reference numerals.
• The[0241]pod191 of the catheter190 has one or more reinforcing elements in the wall of thepod191. There elements enhance the radial strength of thepod191 and provide a means of reinforcing the pod wall against radial creep.
• In another case, the pod may be at least partially of a composite construction for reinforcement against creep.[0242]
• In the[0243]catheter assembly200 of FIGS. 54 and 56, theassembly200 comprises atensioning wire221 releasably attached to theinner tube8 of thefilter1.
• The[0244]wire221 provides a means of elongating thefilter1 to ensure thefilter1 remains fully collapsed when loaded into a catheter reception space (FIG. 54). In this manner, thetensioning wire221 aids in resisting radial and longitudinal creep of thefilter1 even if thefilter1 is stored for a relatively long period of time loaded in the catheter.
• The[0245]wire221 also provides a means of accurately holding thefilter1 in position in thepod22 during storage of the loadedcatheter assembly200 and during advancement of thecatheter assembly200 through a vasculature (FIG. 54).
• The[0246]filter1 is deployed out of thepod22 by moving theinner shaft23 distally relative to the outer shaft21 (FIG. 56). This relative distal movement of theinner shaft23 breaks thewire221 to facilitate deployment of thefilter1 out of thepod22.
• The[0247]catheter assembly260 of FIGS. 55 and 57 is similar to thecatheter assembly200 of FIGS. 56 and 58, and similar elements in FIGS. 55 and 57 are assigned the same reference numerals.
• In this case, the[0248]assembly260 comprises two “I”-shapedconnectors261 extending between theinner shaft21 of thedelivery catheter20 and theinner tube8 of thefilter1. Theconnectors261 maintain the position of thefilter1 fixed within thepod22 during storage of the loadedcatheter assembly260 and during advancement of thecatheter assembly260 through a vasculature (FIG. 55).
• To deploy the filter out of the[0249]pod22, theinner shaft23 is moved distally relative to the outer shaft21 (FIG. 57). This relative distal movement of theinner shaft23 breaks theconnectors261 to facilitate deployment of thefilter1 out of thepod22.
• Such temporary tethering/connecting may be applied to other systems and the use is not restricted to a preloaded filter arrangement. They may be used in any suitable delivery system, especially those involving delivery over a bare guidewire.[0250]
• Referring to FIG. 58, there is illustrated a further catheter assembly[0251]210 according to the invention, which is similar to the assembly160 of FIG. 50, and similar elements in FIG. 58 are assigned the same reference numerals.
• The clamp[0252]220, in this case, is in the form of an end-cap releasably mounted over the distal end of thepod164.
• When the[0253]filter1 has been collapsed down and loaded into thereception space165, pressure is applied to thepod164 and/or to thecollapsed filter1. It has been found that by applying such pressures the loading stresses on thecollapsed filter1 and on thepod164 are more evenly distributed.
• The pressure may be applied in the radial direction F[0254]1 and/or in the longitudinal direction F2, and the magnitude of the applied pressure may be varied as desired. In addition, the pressure applied may remain constant over time, or may vary over time, for example in a cyclical manner.
• Referring to FIGS. 59 and 60 there is illustrated a further[0255]embolic protection filter400 according to the invention, which is similar to thefilter1 of FIG. 1, and similar elements in FIGS. 59 and 60 are assigned the same reference numerals.
• In this case, the[0256]filter body2 has a plurality ofsmall outlet openings401 at theoutlet end5 of thefilter400 and extending along thefilter body2 towards theinlet end4, as illustrated in FIG. 59. In FIGS. 59 & 60 I think it is important to make reference to the liquid pores and the gas pores. Both the filter and pod may contain both liquid pores and gas pores. Gas pores provide some back pressure and ensure that no air pockets are generated. A gradient of hole sizes might be used to achieve the best flushing.
• By providing[0257]outlet openings401 along the central portion of thefilter body2, this configuration aids in minimising the possibility of thefilter400 creeping or thepod22 creeping when thefilter400 is loaded within thepod22 for periods of time, as illustrated in FIG. 60.
• The invention is not limited to the embodiments hereinbefore described which may be varied in construction and/or detail.[0258]

Claims (103)

1. An embolic protection system comprising:

an embolic protection filter having a collapsed delivery configuration and an expanded deployed configuration;

a delivery catheter having a reception space, an embolic protection filter being housed in the collapsed configuration in the reception space of the delivery catheter; and

a sealed sterile pouch housing the delivery catheter containing the filter in the collapsed configuration.

2. A system as claimed inclaim 1 wherein the filter in the collapsed configuration is at least partially folded.

3. A system as claimed inclaim 2 wherein the system comprises an adhesion preventer to substantially prevent adhesion of adjacent folds of the filter to one another in the collapsed configuration.

4. A system as claimed inclaim 3 wherein the adhesion preventing material is selected from one or more of:

a silicon fluid;

a silicon gel;

a lipid filled fluid/gel;

a heparin filled fluid/gel; and

an aqueous solution.

5. A system as claimed inclaim 1 wherein the device comprises a collapsible body and a support structure to support the body in the expanded configuration.

6. A system as claimed inclaim 5 wherein the collapsible body is located at least partially externally of the support structure.

7. A system as claimed inclaim 5 wherein the support structure is located at least partially externally of the collapsible body.

8. A system as claimed inclaim 3 wherein the adhesion preventer is applied to a surface of the filter.

9. A system as claimed inclaim 1 wherein the filter has a biocompatible surface.

10. A system as claimed inclaim 9 wherein the biocompatible surface is provided as a coating of biocompatible material on the filter.

11. A system as claimed inclaim 10 wherein the biocompatible material is a hydrophilic coating.

12. A system as claimed inclaim 9 wherein the biocompatible surface is provided on an external surface of the filter.

13. A system as claimed inclaim 9 wherein the biocompatible surface is provided on an internal surface of the filter.

14. A system as claimed in any of the claims5 wherein adjacent folds of the filter are spaced-apart by one or more arms for extending between adjacent folds of the filter.

15. A system as claimed inclaim 14 wherein the support structure comprises the arm.

16. A system as claimed inclaim 14 wherein the arm is provided by a tool which is suitable to assist loading of the device into a catheter.

17. A method for providing embolic protection during a vascular procedure comprising the steps of:

providing an embolic protection system comprising a sealed sterile pouch containing a delivery catheter with a reception space, an embolic protection filter being housed in the reception space in collapsed configuration;

opening the pouch; and

removing the delivery catheter containing the embolic protection filter in the collapsed configuration from the pouch.

18. A method as claimed in17 comprising the step of:

flushing the filter in the collapsed configuration within the delivery catheter.

19. A method as claimed in18 wherein the filter is flushed prior to sealing of the pouch.

20. A method as claimed in18 wherein the filter is flushed after removal of the delivery catheter containing the filter in the collapsed configuration from the pouch.

21. A method as claimed inclaim 17 comprising loading the delivery catheter and filter onto a guidewire.

22. A method as claimed inclaim 21 wherein the delivery catheter and filter are loaded onto a guidewire after removal of the delivery catheter containing the filter in the collapsed configuration from the pouch.

23. A method as claimed inclaim 17 comprising loading the delivery catheter and filter into a guide catheter.

24. A method as claimed inclaim 23 wherein the delivery catheter and filter are loaded into a guide catheter after removal of the delivery catheter from the pouch.

25. A method as claimed inclaim 17 comprising the steps of:

advancing a guidewire through a vasculature;

crossing a desired treatment location with the guidewire;

advancing the delivery catheter and filter over the guidewire to deliver the filter to a desired location; and

deploying the filter from the delivery catheter at the desired location.

26. A method as claimed inclaim 25 comprising the steps of:

introducing separate from the embolic protection filter an interventional device over the guidewire to the treatment location for carrying out the interventional procedure, embolic material generated during the treatment procedure being captured by the deployed filter; and

withdrawing the filter from the vasculature.

27. A method as claimed inclaim 25 wherein the treatment location is a region of stenosis.

28. A method as claimed inclaim 26 wherein the interventional procedure includes a balloon dilation of the stenosis while the filter is deployed.

29. A method as claimed inclaim 26 wherein the interventional procedure includes placing a stent at the treatment location while the filter is deployed.

30. A method as claimed inclaim 25 wherein the guidewire is withdrawn after withdrawal of the filter.

31. A method as claimed inclaim 25 wherein the filter comprises a filter body and a filter frame which supports the filter body in the deployed configuration.

32. A method as claimed inclaim 25 wherein the filter is slidably disposed on the guidewire when the filter is in the expanded deployed configuration.

33. A method as claimed in25 wherein the filter is rotatably disposed on the guidewire when the filter is in the expanded deployed configuration.

34. A medical device movable between a collapsed configuration for transport through a vasculature and an expanded configuration for deployment in a vasculature, the device comprising:

a storage space for storing a biocompatible material during transport through a vasculature; and

means to deliver the biocompatible material from the storage space to a surface of the device when deployed in a vasculature.

35. A device as claimed inclaim 34 wherein the storage space is provided in a wall of the device.

36. A device as claimed inclaim 34 wherein the means to deliver the biocompatible material comprises one or more channels from the storage space to the surface of the device.

37. A device as claimed inclaim 36 wherein the channel is a capillary channel.

38. A device as claimed inclaim 34 wherein the biocompatible material is delivered to an external surface of the device.

39. A device as claimed inclaim 34 wherein the biocompatible material is delivered to an internal surface of the device.

40. A device as claimed inclaim 34 wherein the device comprises a delivery actuator to at least partially cause delivery of the biocompatible material from the storage space to the surface of the device.

41. A device as claimed inclaim 40 wherein the actuator is at least partially of a temperature memory material.

42. A device as claimed inclaim 34 wherein the biocompatible material is a hydrophilic material.

43. A device as claimed inclaim 34 wherein the device is an embolic protection filter.

44. A device as claimed inclaim 43 wherein the filter has an inlet end and an outlet end, the inlet end having one or more inlet openings sized to allow blood and embolic material enter the filter, the outlet end having a plurality of outlet openings sized to allow through passage of blood but to retain undesired embolic material within the filter.

45. A method of loading a medical device into a catheter, the method comprising the steps of:

collapsing the medical device down to a wrapped configuration;

controlling the wrap of the medical device during collapse; and

positioning the medical device at least partially within the catheter.

46. A method as claimed inclaim 45 wherein the medical device is at least partially collapsed down by passing the medical device through a funnel.

47. A method as claimed inclaim 46 wherein the wrap of the medical device is at least partially controlled by formations on the funnel.

48. A method as claimed inclaim 45 wherein the medical device is at least partially collapsed down by directing a jet of fluid over the medical device.

49. A method as claimed inclaim 45 wherein the wrap of the medical device is at least partially controlled by directing a jet of fluid over the medical device.

50. A method as claimed inclaim 45 wherein the medical device is at least partially collapsed during positioning of the medical device at least partially within the catheter.

51. A system for loading a medical device into a catheter, the system comprising:

means to collapse a medical device down to a wrapped configuration; and

means to control the wrap of the medical device.

52. A system as claimed inclaim 51 wherein the means to collapse comprises a funnel through which a medical device may be passed.

53. A system as claimed inclaim 52 wherein the means to control the wrap comprises one or more formations on the funnel.

54. A system as claimed inclaim 53 wherein the formation comprises an inward protrusion on a wall of the funnel.

55. A system as claimed inclaim 54 wherein the protrusion is in the form of a finger extending from an end of the funnel.

56. A system as claimed inclaim 55 wherein the finger extends generally longitudinally.

57. A system as claimed inclaim 55 wherein the finger extends generally in a spiral.

58. A system as claimed inclaim 55 wherein the finger extends from an outlet end of the funnel.

59. A system as claimed inclaim 55 wherein the system comprises four fingers spaced-apart around the circumference of the funnel.

60. A system as claimed inclaim 59 wherein the fingers are equi-spaced apart.

61. A system as claimed inclaim 51 wherein the means to collapse comprises one or more fluid jets for directing a jet of fluid over the medical device.

62. A system as claimed inclaim 51 wherein the means to control the wrap comprises one or more fluid jets for directing a jet of fluid over the medical device.

63. A method of loading a medical device into a catheter, the method comprising the steps of:

collapsing the medical device;

positioning the collapsed medical device at least partially within the catheter; and

flushing a liquid through the catheter and the collapsed medical device.

64. A method as claimed inclaim 63 wherein the method comprises the step of sealing the catheter with flushing liquid therein.

65. A method of delivering a medical device to a desired location in a vasculature, the method comprising the steps of:

providing a catheter with a collapsed medical device positioned at least partially within the catheter;

flushing a liquid through the catheter and the collapsed medical device; and

introducing the catheter into a vasculature and advancing the catheter through the vasculature.

66. A method as claimed inclaim 63 wherein the method comprises the step of monitoring the extent to which the collapsed medical device has been flushed.

67. A method as claimed inclaim 66 wherein the flushing step is terminated when the collapsed medical device has been fully flushed.

68. A method as claimed inclaim 63 wherein the liquid is flushed distally through the catheter.

69. A method as claimed inclaim 63 wherein the liquid is flushed proximally through the catheter.

70. A method as claimed inclaim 63 wherein the liquid is flushed through the catheter by creating a pressure differential across the collapsed medical device.

71. A catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein, a wall of the catheter around the reception space having flushing openings through the wall to facilitate flushing of a collapsed medical device in the reception space.

72. A catheter as claimed inclaim 71 wherein the concentration of the flushing openings increases distally along the reception space.

73. A catheter as claimed inclaim 71 wherein the concentration of the flushing openings increases proximally along the reception space.

74. A catheter as claimed inclaim 71 wherein the concentration of the flushing openings increases from a centre of the reception space towards proximal and distal ends of the reception space.

75. A catheter as claimed inclaim 71 wherein the catheter comprises means to indicate the extent of flushing of the reception space.

76. A catheter as claimed inclaim 75 wherein the means to indicate comprises one or more perfusion openings in the catheter wall at an end of the reception space.

77. A catheter as claimed inclaim 75 wherein the means to indicate is provided by a separate component.

78. A catheter as claimed inclaim 77 wherein the means to indicate is provided by a stylet extendable through the catheter.

79. A catheter as claimed inclaim 75 wherein the means to indicate comprises an element configured to change colour upon contact with a flushing liquid.

80. A catheter as claimed inclaim 79 wherein the element comprises litmus.

81. A catheter as claimed inclaim 71 wherein the catheter comprises a seal for sealing the reception space with a collapsed medical device and flushing liquid therein.

82. A catheter as claimed inclaim 81 wherein the seal extends along substantially the full length of the catheter.

83. A catheter assembly comprising a catheter as claimed inclaim 71 and a collapsible medical device receivable in the reception space of the catheter, the medical device having one or more flushing openings in a body of the medical device to facilitate flushing of the medical device when collapsed in the reception space.

84. An assembly as claimed inclaim 83 wherein the medical device body comprises a coiled spring.

85. A catheter assembly comprising:

a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and

means for reinforcing against creep a wall of the catheter around the reception space.

86. An assembly as claimed inclaim 85 wherein the means for reinforcing reinforce the catheter wall against longitudinal creep.

87. An assembly as claimed inclaim 85 or86 wherein the means for reinforcing reinforce the catheter wall against radial creep.

88. An assembly as claimed inclaim 85 to87 wherein the means for reinforcing comprises a clamp for positioning around the catheter wall.

89. An assembly as claimed inclaim 88 wherein the clamp comprises a sleeve.

90. An assembly as claimed inclaim 88 wherein the assembly comprises a tray for the catheter, and the clamp is provided by the tray.

91. An assembly as claimed inclaim 88 wherein the clamp is configured to provide non-uniform reinforcement along the catheter wall.

92. An assembly as claimed inclaim 91 wherein the clamp comprises one or more formations to provide non-uniform reinforcement along the catheter wall.

93. An assembly as claimed inclaim 85 wherein the means for reinforcing comprises one or more reinforcing elements in the catheter wall.

94. An assembly as claimed inclaim 93 wherein the catheter wall is of a composite construction.

95. A catheter assembly comprising:

a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and

means for elongating a medical device received in the reception space to resist creeping of the medical device.

96. An assembly as claimed inclaim 95 wherein the means for elongating comprises a tensioning wire attachable to a medical device.

97. A method of loading a medical device into a catheter, the method comprising the steps of:

collapsing the medical device;

positioning the collapsed medical device at least partially within the catheter; and

applying pressure to the catheter and/or to the collapsed medical device to distribute loading stresses on the catheter and/or on the collapsed medical device.

98. A method as claimed inclaim 97 wherein the pressure is applied longitudinally.

99. A method as claimed inclaim 97 wherein the pressure is applied radially.

100. A method as claimed inclaim 97 wherein the applied pressure is substantially constant over time.

101. A method as claimed inclaim 97 wherein the applied pressure varies over time.

102. A method as claimed inclaim 101 wherein the applied pressure varies cyclically over time.

103. A catheter assembly comprising:

a catheter having a reception space at a distal end of the catheter for receiving a collapsed medical device therein; and

means for applying pressure to a wall of the catheter around the reception space and/or to a collapsed medical device received in the reception space to distribute loading stresses in the catheter wall and/or the collapsed medical device.

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