Patent Application
20060074477
The present invention relates to a medical device. More specifically, the invention relates to a catheter, which includes a multi-exchange (MX) component and stent delivery system.
Cardiovascular disease, including atherosclerosis, is a leading cause of death in the U.S. One method for treating atherosclerosis and other forms of coronary narrowing is percutaneous transluminal coronary angioplasty, commonly referred to as “angioplasty” or “PTCA”. The objective in angioplasty is to enlarge the affected coronary vessel from within by radial expansion. The procedure is accomplished by inflating a balloon of a balloon catheter within the narrowed lumen. The balloon expands in the coronary vessel in several different radial dimensions and opens the vessel based on the nature of the plaque. For example, soft, fatty plaque deposits are flattened by the balloon, while hardened deposits are cracked and split to enlarge the lumen.
More than one procedure may be necessary to effectively dilate the coronary vessel. For example, often successive dilatations using balloon catheters with balloons of increasingly larger diameters may be required. Once dilation is complete, to help prevent closure of the vessel, reinforce a vessel wall, and/or prevent restenosis, an intravascular prosthesis, or a stent, is generally implanted inside the lumen. The stent may be a self-expanding stent or a balloon-expandable stent. Once the stent is in place, the procedure may be repeated in other narrowed lumen areas of the coronary vessel. Stents may also be used to open narrowed coronary vessels without first using a balloon catheter to open the lumen, for example when damage rather than plaque is the cause of the narrowed vessel.
Generally, a guidewire is first fed through the vasculature to the treatment site and the catheter is tracked along the guidewire in to the correct position within the vessel. In order to accomplish multiple dilatations and/or one or more stent placements, the original catheter must be removed, and additional catheters must be tracked to the treatment site. When catheters are exchanged, it is advantageous to leave the guidewire in place while the first catheter is removed and to insert the second catheter over the same guidewire. Thus, there is no need to reestablish the path to the treatment site through the vasculature by inserting a new guidewire. To remove a catheter while leaving the guidewire in place, however, a clinician must maintain control of the proximal end of the guidewire while the catheter is retracted proximally and removed.
There are several types of catheters commonly used in angioplasty procedures. An over-the-wire (OTW) catheter includes a guidewire lumen that runs the entire length of the catheter and is attached to, or enveloped within, a catheter shaft. Thus, the entire length of an OTW catheter is tracked over a guidewire.
If a catheter exchange is required while using a standard OTW catheter, the clinician must add an extension to the proximal end of the guidewire or have a very long guidewire in order to maintain control of the proximal end of the guidewire as the entire OTW catheter is retracted and removed. A second or subsequent catheter is then backloaded onto the proximal end of the guidewire and tracked to the treatment site. Multiple operators are required to hold the extended or very long guidewire in place and maintain its sterility while catheters are exchanged.
A rapid-exchange (RX) catheter avoids the need for multiple operators when exchanging the catheter and therefore is often referred to as a “single operator” catheter. With a RX catheter, the guidewire runs along the outside of the catheter, except where it enters a short guidewire lumen that extends within only a comparatively short segment of the catheter at a distalmost end of the catheter shaft. The guidewire can be held in place without an extension when the RX catheter is removed from the body. Once the original RX catheter is removed, a subsequent RX catheter may be threaded onto the in-dwelling guidewire and tracked to the treatment site. Although the RX catheter may provide the advantages discussed above, it presents several difficulties.
Without a full-length guidewire lumen, the proximal shaft of a RX catheter lacks an OTW catheter's stiffness and optimal transmission of force along the catheter length, which aids a clinician when pushing the distal end of the catheter through tightly narrowed and/or tortuous blood vessels. Even if the catheter buckles slightly when the distal tip of an OTW catheter is forced through a narrowed area, there is very little misalignment with the guidewire, such that most of the push force is transmitted to the distal tip.
Further, it is not possible to exchange guidewires with a RX catheter. A guidewire exchange may be needed when, for example, the guidewire becomes damaged during the procedure; a different shape, length, or size of guidewire is needed; and/or the guidewire is unintentionally withdrawn. A guidewire cannot be directed back into the RX catheter's proximal guidewire port, which is located at a distal end of the RX catheter positioned near the treatment site within the patient.
At the proximal end, the RX catheter and the guide wire extend side-by-side from the body of a patient, making it awkward to seal the system against blood loss during manipulation of the components. The sealing, or “anti-backbleed” function is typically accomplished with a “Tuohy-Borst” fitting that has a manually adjustable gasket with a hole that does not conform well to the side-by-side arrangement of a catheter shaft and guide wire.
Further, the lack of a full-length guide wire lumen in a RX catheter deprives the clinician of an additional lumen that may be used for other purposes, such as pressure measurement, injection of contrast dye distal to the stenosis, or infusing a drug.
A catheter capable of faster and more simple guidewire and catheter exchange than an OTW catheter and that addresses the deficiencies of a RX catheter is sold by Medtronic Vascular, Inc. of Santa Rosa, Calif. under the trademarks MULTI-EXCHANGE, ZIPPER MX, ZIPPER, MX and/or MXII (hereinafter referred to as the “MX catheter”) and is disclosed in U.S. Pat. No. 4,988,356 to Crittenden et al., U.S. Application Publication Nos: 2003/0191491 to Duane; 2004/0059291 to MacDonnell et al.; 2004/0122363 to Gribbons et al.; and U.S. patent application Ser. No. 10/722,191 filed Nov. 24, 2003. The above noted patent and applications are each incorporated by reference in their entirety herein.
The MX catheter includes a catheter shaft having a guide way that extends longitudinally along the catheter shaft and that extends radially from a guidewire lumen to an outer surface of the catheter shaft. A guide member through which the shaft is slidably coupled cooperates with the longitudinal guide way such that a guidewire may extend transversely into or out of the guidewire lumen at any location along the longitudinal guide way's length. By moving the shaft with respect to the guide member, the effective over-the-wire length of the MX catheter is adjustable.
When using the MX catheter, the guidewire is maneuvered through the patient's vascular system such that a distal end of the guidewire is positioned across the treatment site. With the guide member positioned near a distal end of the catheter, a proximal end of the guidewire is threaded into a guidewire lumen opening at the distal end of the catheter and out through a proximal end of the guide member. By securing the guide member and the proximal end of the guidewire in a fixed position, the catheter may then be tracked over the guidewire by advancing the catheter first through the guide member and into the vasculature. In doing so, as the catheter advances, the guide member opens the guidewire lumen, feeds the guidewire into the lumen and closes the lumen again so that the advancing guidewire lumen envelops the guidewire. The MX catheter may be advanced over the guidewire in this manner until the distal end of the catheter is positioned at the treatment site and nearly the entire length of the guidewire is enveloped within the guidewire lumen.
Furthermore, the MX catheter may be exchanged with another catheter by reversing the operation described above and withdrawing the proximal end of the catheter from the patient while holding the proximal end of the guidewire and the guide member in a fixed position. As the MX catheter is retracted, the guide member opens the guidewire lumen, leads the guidewire from the lumen, and closes the lumen. When the catheter has been withdrawn only the distal portion of the catheter is still over the guidewire. The distal portion is of a sufficiently short length that the MX catheter may be drawn over the proximal end of the guidewire without releasing control of the guidewire or disturbing its position within the patient. The MX catheter permits catheter exchange without the very long or extended guidewire of the OTW catheter, without requiring withdrawal of the initially placed guidewire, and without many of the other difficulties discussed in association with RX catheters.
Heretofore, self-expanding stent delivery systems have incorporated either OTW or RX catheter systems, and clinicians have experienced the difficulties described above with respect to both OTW and RX catheters. Therefore, there exists the need to provide a self-expanding stent delivery system including the herein described benefits of a multi-exchange catheter.
The catheter of the present invention provides a catheter that allows for easy guidewire exchange, easy catheter exchange, and accurate self-expanding stent deployment, by introducing a catheter for a self-expanding stent that features an MX catheter design. The catheter of the present invention includes a proximal shaft including a longitudinal guide way along the length of the proximal shaft. The catheter also includes a guide member for accessing a guidewire lumen defined by the proximal shaft and for drawing a guidewire into and out of the guidewire lumen as the guide member moves along the proximal shaft.
In one aspect of the present invention, the catheter includes a sliding mechanism positioned near a proximal end of the catheter. The sliding mechanism is coupled to a proximal end of a link, which has a distal end coupled to a distal outer shaft located near a distal end of the catheter. When a stent is properly positioned over a treatment site, the sliding mechanism draws the link proximally, which draws the distal outer shaft proximally. Since the distal outer shaft retains a self-expanding stent in a compressed state when it is in a distal position, the stent radially expands once the distal outer shaft has been retracted proximally to a proximal position.
In another aspect of the present invention, the sliding mechanism is coupled to a proximal end of the proximal shaft, which is coupled at a distal end to the distal outer shaft. In this case, the sliding mechanism draws the proximal shaft proximally, which draws the distal outer shaft proximally. As the distal outer shaft is retracted to a proximal position, the self-expanding stent is allowed to radially expand.
Other aspects of the present invention include, but are not limited to, using different types of guide members with a catheter of the present invention, a stop to keep the stent from moving proximally as the distal outer shaft is retracted, maintaining a distal inner shaft in a distal position, such that the entire catheter is not retracted when distal outer shaft is retracted, radiopaque markers, and a valve relief to minimize backbleed as the catheter is moved into and out of the vasculature.
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of embodiments of the invention, as illustrated in the accompanying drawings.
The present invention is now described with reference to the figures where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention.
Handle 102 includes a longitudinal opening 104 through which a sliding mechanism 106 slides proximally (towards the clinician) and distally (towards the treatment site). Sliding mechanism 106 is coupled to a proximal end of link 332. A distal end of link 332 is coupled to an anchor joint 334 of distal outer shaft 116.
Catheter 100 is advanced through the vasculature with distal outer shaft 116 in a distal position. When catheter 100 reaches the treatment site an operator slides sliding mechanism 106 proximally. As sliding mechanism 106 longitudinally slides, link 332 is pulled in a proximal direction, thereby sliding distal outer shaft 116 in a proximal direction. Since distal outer shaft 116 holds self-expanding stent 230 in a collapsed state, retracting distal outer shaft 116 mechanically deploys self-expanding stent 230. Handle 102 and sliding mechanism 106 may be made from a thermoformed or injection-molded thermoplastic material, for example, acrylonitrile-butadiene-styrene (ABS), a high density polyethylene or polycarbonate.
The distal end of handle 102 is coupled to a proximal end of proximal shaft 108 via a heat or ultrasonic weld or an adhesive treatment as would be known to one of ordinary skill in the art. With reference to
Proximal shaft 108 may be, for example, an extruded, molded or thermoformed polymer, such as a nylon, high density polyethylene or PEBAX. Longitudinal guideway 110 may be formed, for example, using either a single, moveable blade, a “collet”-type arrangement of numerous blades, or by directional laser. Proximal shaft guidewire lumen 437 and link lumen 438 may have inside diameters of, for example, from about 0.015 inches to about 0.025 inches. Proximal shaft 108 may be, for example, oval in shape, with an outside diameter of about 0.030 inches to about 0.040 inches by about 0.055 inches to about 0.06 inches.
The distal end of proximal shaft 108 is attached to a proximal end of a distal inner shaft 224 and a spacer shaft 222. The shafts are bonded together using a heat or ultrasonic weld or an adhesive treatment as would be known to one of ordinary skill in the art. Support mandrels and/or wires may be placed within each shaft during bonding to ensure that the guidewire lumen 437 and link lumen 438 remain open during the bonding process and to provide a smooth transition between the lumens of proximal shaft and distal inner shaft 224.
Distal inner shaft 224 also includes a guidewire lumen 436. Guidewire lumen 436 runs longitudinally through distal inner shaft 224 and communicates with guidewire lumen 437 of proximal shaft 108. Distal inner shaft 224 may be manufactured, for example, by extruding, molding or thermoforming a polymer, such as nylon, high density polyethylene, or PEBAX. In another embodiment, distal inner shaft 224 includes a reinforcing component (not shown), such as a wire braid. Distal inner shaft 224 may have an inside diameter of, for example, about 0.015 inches to about 0.025 inches and an outside diameter of, for example, about 0.025 inches to about 0.030 inches.
A distal end of distal inner shaft 224 is coupled to a proximal end of a catheter tip 120. Catheter tip 120 also includes a guidewire lumen 227 extending therethrough and communicating with guidewire lumen 436 of distal inner shaft 224. Catheter tip 120 has a tapered distal end that includes a guidewire exit port 111, where catheter 100 is fed over guidewire 112. Catheter tip 120 may be a thermoplastic material, for example, nylon, high density polyethylene or PEBAX, or an elastomer, and may be bonded with the distal end of distal inner shaft 224 using a heat or ultrasonic weld or an adhesive treatment as would be known to one of ordinary skill in the art. Catheter tip 120 also includes a radiopaque marker 228, for example, at a distal or proximal end of catheter tip 120. Catheter tip 120 also includes a groove 225. Groove 225 shoulders the distal end of distal outer shaft 116, when in a distal position.
Distal outer shaft 116 is longitudinally slidable along an exterior of proximal shaft 108, spacer shaft 222 and distal inner shaft 224 and includes a proximal portion 119 and a bump distal portion 121. As shown in
Located on the inner surface of proximal portion 119 of distal outer shaft 116 is anchor joint 334. Anchor joint 334 secures the distal end of link 332 to distal outer shaft 116. Anchor joint 334 is manufactured by trapping, laminating or bonding link 332 against the inner surface of distal outer shaft 116. Link 332 may be a pullwire as shown in
Bump distal portion 121 of distal outer shaft 116 includes a transition area 231 and a sheath portion 118. The distal end of proximal portion 119 of distal outer shaft 116 is connected to transition area 231 at a proximal end of bump distal portion 121. At transition area 231 an outer diameter of proximal portion 119 bumps radially, or increases, as the transition area 231 extends in the distal direction. As such, sheath portion 118 has a larger diameter where transitional area 231 ends, since sheath portion 118 contains self-expanding stent 230. The distal end of sheath portion 118 slides into and is secured in groove 225 of catheter tip 120. An inner surface of sheath portion 118 is coated with a lubricious solution, for example, silicone or a hydrophilic material, to allow the coated inner surface to easily slide relative to self-expanding stent 230.
Distal outer shaft 116 may be extruded, molded or thermoformed from a polymer, for example, nylon, high density polyethylene or PEBAX. In one embodiment, distal outer shaft 116 includes a reinforcing component (not shown), such as a wire braid. Proximal portion 119 may have an outside diameter of, for example, about 0.035 inches to about 0.06 inches, and sheath portion 118 may have an outside diameter of, for example, about 0.065 inches to about 0.080 inches.
Spacer shaft 222 is coupled to distal inner shaft 224 around an exterior of distal inner shaft 224. As illustrated in
Stent 230 is positioned around distal inner shaft 224 and longitudinally between the distal end of spacer shaft 222 and the proximal end of catheter tip 120. The outer surface of stent 230 contacts the inner surface of distal outer shaft 116 along sheath portion 118.
Stent 230 is any suitable self-expanding stent manufactured from implant quality material. During catheter manufacture, stent 230 may be inserted into a distal end of sheath portion 118 between sheath portion of 118 of distal outer shaft 116 and distal inner shaft 224. In doing so, stent 230 is compressed and rolled down to a small profile. Catheter tip 120 is then secured to the catheter to close the distal end thereof.
Slidably attached to proximal shaft 108 is guide member 114. Guide member 114 has a guidewire exit lumen 123, which allows guidewire 112 to pass therethrough. Additionally, guide member 114 has an inner diameter 517, which may be, for example, oval-shaped if proximal shaft 108 is oval-shaped, and which is slightly greater than an outer diameter 117 of proximal shaft 108, so that guide member 114 may slide with respect to proximal shaft 108. Guide member 114 cooperates with longitudinal guide way 110 in proximal shaft 108 such that guidewire 112 may traverse into or out of guidewire lumen 437 of proximal shaft 108 at any location along the length of longitudinal guide way 110.
Guidewire exit port 123 is located in a recession 544 formed in proximal portion 530. Recession 544 aids insertion of guidewire 112 back through guidewire exit port 123, when feeding the guidewire 112 distally. Additionally, guidewire tube 628 extends distally from guidewire exit port 123 to intersect the guidewire lumen 437 in proximal shaft 108, preferably in a close coaxial relationship with the guidewire lumen 437. Once guidewire 112 is inserted into guidewire exit port 123, guidewire 112 passes through guidewire exit lumen 626, defined by guidewire tube 628, and into the guidewire lumen 437 of proximal shaft 108.
To ensure guidewire tube 628 accesses guidewire lumen 437 through longitudinal guide way 110, spreaders 636 and 640 open longitudinal guide way 110 as guide member 114 slides along proximal shaft 108. Once guide member 114 has passed, the resiliency of proximal shaft 108 closes longitudinal guide way 110. Spreaders 636 and 640 are formed in the body of guide member 114. Spreaders 636 and 640 also align guidewire tube 628 with longitudinal guide way 110. Once guidewire 112 has been led through the vasculature, guidewire 112 may be “backloaded” through guide member 114 by first being fed through guidewire exit port 111 of catheter tip 120, guidewire lumen 227, guidewire lumen 436, and guidewire lumen 437. As the guidewire 112 is fed into distal portion 532 of guide member 114, guidewire 112 will be fed into guidewire exit lumen 626 and out through guidewire exit port 123 rather than continuing proximally along guidewire lumen 437. Having the outer diameter of guidewire tube 628 just slightly smaller than the inner diameter of guidewire lumen 437 ensures that guidewire 112 will not likely be misfed through guide member 114.
Guide member 114 may be molded from a suitable rigid plastic material, for example, nylon, acrylonitrile-butadiene-styrene (ABS), a high density polyethylene, or PEBAX. Alternatively, guide member 114 may be made of a suitable metal, for example stainless steel, or guide member 114 may have both metal components and plastic components. For ease of manufacturing, guide member 114 may be comprised of molded parts that snap fit together. Guidewire tube 628 may be made from 304 stainless steel hypotube or a strong, thin-walled polymer, such as thermoset polyimide (PI) tubing or other comparable materials. Guidewire tube 628 may be fixed or slidably disposed in guide member 114.
To operate self-expanding stent delivery catheter 100, a clinician, for example, maneuvers guidewire 112 through a patient's vascular system until the distal end of guidewire 112 is positioned across the treatment site. In order for the clinician to maintain control over guidewire 112 during the loading of catheter 100, guide member 114 is slidably positioned along proximal shaft 108 at its distal most position along longitudinal guide way 110, just proximal of distal outer shaft 116. Catheter 100 is backloaded onto guidewire 112 until its proximal end exits guidewire exit port 123. Holding guidewire 112 and guide member 114 in a fixed position, proximal shaft 108 is then advanced distally over guidewire 112. As the shaft is advanced, guide member 114 slidingly opens the proximal portion of longitudinal guide way 110 of proximal shaft 108 and envelops more of guidewire 112 in guidewire lumen 437 of proximal shaft 108.
Catheter 100 is advanced over guidewire 112 until sheath 118 is positioned at the treatment site. Radiopaque markers 226 and 228 allow the clinician to monitor the location of the stent using a suitable technique, for example fluoroscopy. When the stent is properly positioned, the clinician slides sliding mechanism 106 in a proximal direction and in doing so mechanically slides distal outer shaft 116 in a proximal direction. As distal outer shaft 116 retracts, it slides relative to self-expanding stent 230 removing sheath portion 118. As sheath portion 118 continues to retract, the distal end of proximal radiopaque marker 226 keeps self-expanding stent 230 in place. As the distal end of distal outer shaft 116 is fully retracted, self-expanding stent 230 is free to deploy against a vessel wall. Once self-expanding stent 230 is in place, catheter 100 is then removed from the body and self-expanding stent 230 is left in place in the vessel.
Alternatively, guidewire 112 may be fully removed by pulling it out through guidewire exit port 123 while keeping catheter 100 in place. Once guidewire 112 is fully removed, a new guidewire may be introduced into guidewire exit port 123 and tracked through guidewire lumens 436, 437, 227 and guidewire exit port 111 to the treatment site.
Two retaining arms 956 are disposed on distal end 952 of outer tubular member 849. Retaining arms 956 consist of two arcuate arms that form a portion of outer tubular member 849. Each arm 956 contains a tab 958 that extends into longitudinal bore 954 of outer tubular member 849 at its distal end 952. When guide member 814 is assembled, the tabs prevent inner body 846 from slipping out of the outer tubular member 849 through its distal end 952. Retaining arms 956 are flexible in the radial direction and may be flexed radially outward to temporarily remove tabs 958 from the longitudinal bore 954 to permit insertion and removal of inner body 846 during the assembly or disassembly of guide member 814. While two tabs 958 are shown positioned one hundred and eighty degrees apart, a different number of tabs may be used, provided they are spaced sufficiently to prevent inner body 846 from slipping out of the outer tubular member 849. Although the stop shoulder 848 and retaining arms 956 are described as integral parts of the outer tubular member, it should be understood that those features may be created by separate elements such as threaded caps.
Inner body 846, generally functions as guide member 114, of the previously discussed embodiment. Inner body 846 has proximal and distal ends, 1060 and 1062 respectively. Catheter receiving bore 847 extends longitudinally through inner body 846 from proximal end 1060 to distal end 1062. In the present embodiment, unlike the embodiment shown in
It shall be understood that the single keel 1064 design may be substituted for the dual spreader 536/540 design, shown in
In
Guide member 1414 has a main body having both proximal and distal ends, 1430 and 1432 respectively. A catheter receiving bore 1547 extends longitudinally through guide member 1414 from proximal end 1430 to distal end 1432. Guide member 1414 includes a proximal spreader member 1540 and a distal spreader member 1536 extending radially into catheter receiving bore 1547. In addition, a tubular guidewire receiver 1570 is mounted to proximal and distal spreader members, 1540 and 1536 respectively, within catheter receiving bore 1547 and is sized to slidably receive guidewire 112. The pair of spreader members serve to locally spread open longitudinal guide way 110 and provide a means for holding tubular guidewire receiver 1570 within guidewire lumen 437 when guide member 1414 is slidably mounted on proximal shaft 108. Tubular guidewire receiver 1570 has a side opening 1566 sized to receive a clamp member 1572. Proximal spreader member 1540 and distal spreader member 1536 serve to align proximal shaft 108 within catheter receiving bore 1547 and especially to align longitudinal guide way 110 with side opening 1566 on tubular guidewire receiver 1570.
Clamp member 1572 extends radially inward from a clamp control member 1474. Clamp control member 1474 and clamp member 1572 extend through the guide member 1414 and allow a clinician to manually engage a clamping force on the guidewire 112. In the present embodiment, a clamp spring 1568 is mounted to clamp control member 1474 and guide member 1414. Clamp spring 1568 holds clamp member 1572 and clamp control member 1474 in a disengaged state when no external force is placed on clamp control member 1474. When clamp control member 1474 is pressed and clamp spring 1568 is compressed, it causes clamp member 1572 to extend further radially into the catheter receiving bore 1547, through side opening 1566 in tubular guidewire receiver 1570 and against guidewire 112. That engagement with guidewire 112 results in a frictional force that resists relative movement between guidewire 112 and guide member 1414 allowing a practitioner to directly control the axial location of guidewire 112 within catheter 100.
Like guide members 114 and 814, guide member 1414 may be molded from a rigid plastic material, such as nylon or nylon based co-polymers, that is preferably lubricous. Alternatively, guide member 1414 may be made of a suitable metal, such as stainless steel, or guide member 1414 may have both metal components and plastic components. For ease in manufacturing, guide member 1414 may be comprised of molded parts that snap-fit together to form the final configuration.
Another embodiment of the present invention catheter 1700 is illustrated in
Proximal shaft 1708 also includes a support shaft 1881 bonded thereto, which defines a link lumen 1838. Link lumen 1838 has a link 1832. Link 1832 may be, for example, a pushtube, such as the flush hypotubing shown in
As shown in detail in
Coupled to an exterior of distal inner shaft 1824 is a spacer shaft 1822. Spacer shaft 1822 has a distal end including a stop flange 1882. Stop flange 1882 includes a proximal radiopaque marker 1826. Stop flange 1882 has an outer diameter that is slightly smaller than the inner diameter of distal outer shaft 1716. Stent 1730 is positioned between an exterior of distal inner shaft 1824 and an interior surface of distal outer shaft 1716, and distally of stop flange 1882 of spacer shaft 1822. As such, stop flange 1882 prevents stent 1730 from sliding proximally as catheter 1700 is advanced through the vasculature and as distal outer shaft 1716 is retracted proximally for deployment of stent 1730. The interior surface of distal outer shaft 1716 may include a lubricious material, such as silicone or a hydrophilic material, to allow the coated inner surface to easily slide relative to stent 1730.
A distal end of distal inner shaft 1824 is coupled to a catheter tip 1820. Catheter tip 1820 defines a guidewire lumen 1827 and a guidewire exit port 1811. Catheter tip 1820 also includes a distal radiopaque marker 1828, which may be positioned as shown in
As shown in
Guide member 1714 is bonded to valve relief 1778. The manually adjustable gasket of a “Tuohy-Borst” fitting, when tightened around a proximal shaft 1708 at the entrance to the body of a patient, does not allow the proximal shaft 1708 to move relative to the gasket. As such, any time the proximal shaft 1708 needs to move, the gasket must be loosened and retightened. Each time the gasket is loosened, backbleeding occurs through the incision. In this embodiment, the “Tuohy-Borst” gasket is connected to valve relief 1778. Both guide member 1714 and valve relief 1778 then maintain a fixed position just exterior to the body of the patient. Thus, rather than moving proximal shaft 1708 through the gasket, proximal shaft 1708 moves in and out of the body through valve relief 1778 without affecting the gasket seal and without as much backbleeding. Proximal shaft 1708 may also rotate within valve relief 1778 so that proximal shaft 1708 may be twisted and turned through tortuous vasculature from a distal position.
While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
