JP2002537943A - Minimally invasive medical device placement and retrieval system - Google Patents

Abstract

(57) Abstract: The present invention is a working element attached to a flexible and long shaft, having a proximal outer portion, wherein the shaft extends proximally from the working element. A collection cover slidably attached to the shaft of a medical device, having a disposition shape, compressible to a compressed state for disposition, elastically returning to the disposition approximately, and having a diameter A proximal portion reduced in direction and a distal opening that defines a distal opening that is distally open and has a maximum dimension that is greater than or equal to the maximum dimension of the proximal profile of the working element of the medical device. A medical device retrieval system comprising a distal end, a cover having an elongated lumen defined at the proximal site and the distal end.

Description

DETAILED DESCRIPTION OF THE INVENTION

FIELD OF THE INVENTION The present invention relates generally to minimally invasive surgery, such as angioplasty and arterial surgery.
It has particular utility for the retrieval of deployed medical devices. The present invention
In one embodiment, a vascular filter is provided that minimizes the risk of releasing contaminants into the patient's bloodstream during collection.

BACKGROUND OF THE INVENTION In medical surgery, minimally invasive medical devices may be used to capture or remove material from a patient's vasculature or other tubular organs. For example, in one surgery,
The balloon catheter is positioned so that the deflated balloon is located distal to the vascular occlusion. These vascular occlusions are generally relatively soft and accumulate without calcification along the arterial wall. The balloon can then be inflated and pulled proximally. This causes the atheroma to exfoliate and be pulled proximally along with the balloon. In recent surgery, a suction catheter is moved distally to a position near a balloon to aspirate material that has detached from a blood vessel.

[0003] Many other minimally invasive surgical procedures have been employed to treat vascular occlusions. Rotational artery surgery and balloon angioplasty are also types of such procedures. As the use of vascular stents has increased, it has become apparent that tissue or other material accumulates within the stent, reducing the patency of the vessel through the stent. In the process of increasing the patency of a blood vessel using such a technique, there is a danger that the substance causing the occlusion in the blood vessel is only suspended downstream together with the blood flow to the blood vessel. Therefore, the importance of taking measures to capture exfoliated material is becoming increasingly recognized.

[0004] Numerous studies have proposed various traps and filters for trapping particulate matter and other obturator particles detached by such procedures. Some filters are permanently implanted in the vessel. The obturator captured by the filter is sucked from the inside of the filter or dissolved by the drug. Other filters are originally intended for temporary use and are usually removed after angioplasty, arterial surgery, or other procedure is completed. Generally, the purpose is to retrieve the filter with the captured thrombus. Unfortunately, many of these temporary filters are relatively difficult or complex to pull the trap back into the catheter used for introduction without releasing the captured thrombus into the bloodstream.

[0005] One example of a particularly useful vascular filter is disclosed in US Ser. No. 08 / 272,425.
And International Patent Application No. PCT / US95 / 08613, which is also published as International Publication No. WO 96/01591. That teaching is specifically incorporated herein by reference.

FIGS. 11 to 16 of WO 96/01591 are attached hereto as FIGS. 1 to 6 of the present application. FIG. 1 is a vascular trap suitable for temporarily filtering embolic particles from blood flowing through a patient's vasculature. This device is frequently used to filter emboli from the patient's blood during other medical procedures, for example, with a rotating blade during arterial surgery and a balloon catheter during angioplasty. Is done. Alternatively, at the time of cleaning the stent, it is used together with a device for cleaning the inner space of the stent. It will be appreciated, however, that the trap may be used for other similar applications, such as in a vessel other than the vascular system in a patient.

The vascular trap 250 of FIGS. 1A and 1B comprises a generally umbrella-shaped basket 270 mounted near the distal tip of a guidewire 260. The guidewire of this embodiment includes a tapered distal section 262 with a helically wound coil 264 extending over a length distal to the wire. Guidewires having such distal ends are known in the art. Basket 270 is coil 26
4, and is preferably attached to a guidewire near the proximal end of the tapered portion as shown.

The basket 270 (shown in a contracted state in FIG. 11A) of the device shown in WO 96/01591 includes a distal band 272 and a proximal band 274. The distal band is
It is formed of a radiopaque material such as gold, platinum, or tungsten, and is attached directly to the guidewire 260 shaft. The attachment is made by any suitable means, for example, welding, brazing or soldering. Alternatively, distal band 272 may be formed from beads of a biocompatible cement material, for example, a curable organic resin. In WO96 / 01591, if you want to increase the visibility of the band by fluoroscopy,
It is stated that radiopaque metals and the like may be embedded in cement-based materials. Proximal belt 27
The hypotube 4 may be formed of a hypotube sized so that it can slide on the guide wire during placement. The inventors of the prior application suggest that the hypotube may be formed of a metal material, and a thin-walled tube of a NiTi alloy is sufficient. If desired, the proximal band may be formed of a more radiopaque metal, or the surface of the NiTi alloy band may be provided with a radiopaque coating.

As taught in some detail in WO 96/01591, the basket 270 is formed from a metal fabric. Most preferably, the metal fabric of this embodiment is initially formed as a tubular braid, and before cutting the metal fabric to a predetermined length, the ends of the wires forming the braid are banded at 272, 274.
These bands 272, 274 help prevent the metal fabric from unraveling during the forming process (the method of forming the basket 270 is described in detail in WO 96/01591, and this process is still described in It is believed that this will provide a suitable method of manufacturing such a basket, a process which will be described later in connection with FIG. 6).

When the device is in a contracted state (as shown in FIG. 1A) for placement in a patient's vessel, the basket 270 of the device is said to contract toward the axis of the guidewire 260. The distal band 272 and the proximal band 274 are spaced apart from each other along the length of the guidewire, and the metal fabric of the device extends between the bands. The publication states that the basket preferably abuts the outer surface of the guidewire when in a contracted condition so that the device can be placed through a relatively small lumen of a catheter or other medical device.

When the device is placed in the patient's vasculature, the basket is in an expanded configuration, wherein the basket expands outwardly of the outer surface of the guidewire. As best shown in FIG. 1B, the shape of the basket 270 when deployed is similar to a conventional umbrella or parachute, and is radially outward from a guide wire traveling proximally from the distal band 272. It has a dome-shaped structure that curves to the right. It is understood that any other suitable shape, such as a conical shape in which the device tilts linearly than the smoothly curved configuration shown in FIG. 1B, can easily accomplish the desired filtering function. Like. Although a relatively flat disk may be sufficient, it is preferable to have a cavity or cavity (described below) to more effectively retain the captured obturator or other material. In this expanded configuration, the two bands 272, 274 are close together, and preferably the distal band 272 is slightly spaced from the proximal band 272 as shown.

When transitioning from the contracted state (FIG. 1A) to the expanded state (FIG. 1B), the metal fabric of the device is folded back and the proximal portion 282 of the basket in the contracted state is distal of the basket in the contracted state. It is received in the side portion 284. This forms a bilayer structure having a proximal edge 286 radially outwardly spaced from the guidewire, defining a proximally facing cup-shaped cavity 288 of the basket. As blood (or other bodily fluids) passes through the basket in a distal direction, particulate matter in the blood, such as emboli, released into the bloodstream during arterial or angioplasty procedures may cause basket 288 cavities. Captured within.

[0013] WO 96/01591 states that the exact dimensions of the metal fabric may be set to desired dimensions depending on the application. When the device 250 is used, for example, as a vascular filter for capturing an obturator released into the blood, it is desirable that the hole in the metal fabric (that is, the opening between the intersecting metal lines) is about 1.0 mm. And According to the present inventors, this is the minimum size of a particle that can cause harmful side effects if left freely floating in the blood vessels. However, it also states that the holes should not be made too small, as blood (or other bodily fluids) must pass freely through the walls of the basket 270. Therefore, if necessary, the basket may be coated with an appropriate antithrombotic agent so as not to occlude the blood vessel in which the basket is placed.

When forming the basket 270 using a metal cloth having a hole of 1.0 mm,
During the forming process, the wires are turned relative to each other, and locally (eg, near the proximal edge 286) the holes tend to be larger than 1.0 mm. However, since the basket wall is effectively doubled with metal fabrics 282 and 284,
The effective dimensions of the holes in this device are sufficiently reduced in these places to some extent.

The device 250 of FIG. 11 is provided with a connecting member 290 for contracting the basket 270 when it is withdrawn. The basket may include four independent tether wires, each extending proximally from the proximal edge 286 of the basket in the deployed position. However, according to the author of the publication,
The four tie wires shown are each formed of two long wires that extend around one location on the proximal edge of the basket. By entanglement of these tether wires with wires of a metal fabric, the tether wires can be held at predetermined positions during use. As the tether wire is pulled or pulled down toward the guidewire, the wire extending along the proximal edge of the basket acts as a drawstring, with the proximal end of the basket radially inward and toward the guidewire. Pull. This closes the basket and traps material trapped in the basket cavity 288 during use, allowing the basket to be withdrawn without the use of a cover.

Tether wire 290 may extend along substantially the entire length of the guidewire so as to extend out of the patient's body during use of device 250. If one wishes to retract the basket for retrieval, the operator need only grasp the guidewire 260 firmly and pull the tether wire against the guidewire. However, this operation is relatively cumbersome, and it is extremely difficult to do it effectively without breaking the tie wire if the device is located at a specific site beyond a meandering path, for example, in the brain. It is.

To address this problem, the authors suggest that the tether wire 290 be attached to the guidewire 260 at a location proximally spaced apart from the basket, as shown in FIGS. 1A and 1B. . The tether wire may be attached to, for example, a metal strap 292 and the strap 292 may be secured to a guidewire shaft. When it is desired to close the proximal end of the basket for retrieval, it suggests that the outer catheter (not shown) be moved toward the basket 270. As the outer catheter strikes the radially extending tie wire, its distal end pulls the tie wire toward the guidewire as the catheter advances, thereby pulling and closing the proximal end of the basket.

FIGS. 2A and 2B show a modified embodiment of the apparatus shown in FIGS. 1A and 1B, again following the teachings of WO 96/01591. FIG. 2A shows the device retracted into catheter C for deployment, and FIG. 2B shows the device in a deployed configuration.
2A and 2B, basket 270 is substantially the same as that described above in connection with FIGS. 1A and 1B. However, in the embodiment of FIG. 12, the distal band 272 is attached to the distal tip of the guidewire 260 '. Guidewire 260 'is of the type referred to in the art as a "movable core" guidewire. In this type of guidewire, the core wire 265 is received within the lumen of the spiral wire coil 266 and extends distally beyond the distal tip of the coil 266. A thin, long safety wire 268 extends along the entire length of the lumen of the coil 266 to prevent loss of the coil fragment if the coil breaks, with its distal end remote from the coil. It can be attached to the position end.

In the embodiment of FIGS. 1A and 1B, the proximal end of the tether wire 290 is attached to a metal strap 292, which itself is attached to the axis of a guidewire 260. 2A and 2B, the tie wire is not attached to the core wire 265 itself, but is attached to the coil 266 of the guidewire. The tether wire may be attached to the coil by any suitable means such as laser spot welding, soldering or brazing. The tether wire 290 may be attached to the coil 266 at substantially one point in the longitudinal direction of the coil. For example, as shown, a tether wire may be attached to the coil near the distal end of the coil. However, if necessary, a connecting wire may be attached to the coil at a position further away from the basket 270 in the proximal direction.

The outer catheter referred to but not shown in connection with FIG. 1A is shown in FIGS.
B. A basket 270 is positioned within the patient's vasculature, substantially as shown in FIG.
When the basket has attained the expanded shape as shown in FIG. 2 and has performed its intended filtering function, the outer catheter C may be pushed distally toward the basket 270. As the catheter is pushed forward, the tether wire is drawn into the distal end of the catheter, which is much narrower than the proximal edge 286 of the basket. This pulls the tether wire in the direction of the guide wire as described above to help the basket close.

3 to 5 show a further alternative embodiment of the vascular trap according to WO 96/01591. The vascular trap 300 includes a basket 320 received on a guidewire 310. In many respects, this basket 320 is very similar to the basket 270 shown in FIGS. Basket 320 includes a proximal band 322 and a distal band 324. 2A and 2B, the distal band may be attached near the distal end of the guidewire. However, if necessary, a structure as shown in FIGS. 1A and 1B in which the guide wire extends farther than the basket can be employed.

The basket includes a distal portion 325 and a proximal portion 326, particularly in a contracted condition (shown in FIG. 3), the distal end of the distal portion having a distal band 324.
And the proximal end of the proximal portion is attached to the proximal band 322. When the basket 320 is in the expanded configuration (shown in FIG. 4), the proximal portion 326
Is received in the distal portion 325 and defines a proximal edge 328 of the proximal edge of the device. The wall of the basket thus formed includes a cavity 329 that captures solids carried in the liquid, such as obturators in the blood stream of the patient.

The basket 320 of FIGS. 3-5 has a slightly different shape than the basket 270 of the previous figures. The main difference between the two baskets is that the basket 320 has a slightly shorter axial length than the basket 270. The difference in basket shape in this way is intended to explain that the basket of the vascular trap according to the present invention can take a variety of shapes, and is largely different from the shape shown in each figure. It doesn't make sense.

In the vascular traps 250, 250 ′ of FIGS. 1 and 2, a tether wire is used to close the basket 270 to pull the proximal end of the basket 270 for retrieval. However, in the embodiment shown in FIGS.
A basket cover 340 provided on the proximal side with respect to 0 is included. The basket cover can also be formed of a metallic tubular braid, which contracts substantially along the outer surface of the guidewire 310. However, the cover 340 is not directly fixed anywhere on the guidewire, but is intended to be able to slide over the guidewire.
The cover 340 includes a distal hypotube 342 and a proximal manipulating hypotube 344, particularly as can be seen from FIGS.
A distal hypotube is attached to the distal side of cover 340, and a proximal manipulating hypotube 344 is attached to the proximal end of the cover.

FIG. 5 shows an expanded cover 340 that is arranged. As shown in FIG. 5, the cover has a structure similar to basket 320 but is oriented to open distally rather than proximally like a basket. As can be seen from FIGS. 3 and 4 where the cover is in the contracted state, the cover is positioned on the front distal side 352.
And a proximal portion 354. When deployed and deployed distally from the distal end of the deployment catheter C, the cover 340 resiliently returns to the expanded configuration and the distal hypotube 342 over the guidewire for the proximal manipulation hypotube. It slides axially proximally toward tube 344. As a result, the cover in the contracted state is inverted and the distal portion 352 is generally received within the proximal portion 354 to define the distal edge 358 of the cover.

In WO 96/01591, the hypotube 344 for operating the proximal side of the cover is used.
May extend over substantially the entire length of catheter 310 such that a portion thereof extends out of the patient's body when device 300 is in place. By grasping the operation hypotube and moving it with respect to the guide wire 310,
The operator operates the cover 3 for the basket 320 fixed to the guide wire.
40 relative positions can be controlled. After the basket is positioned and used to filter objects carried in the fluid (eg, obturators in blood), the cover 340 is removed, as described in more detail below in connection with the use of the device 300. The trap may be pulled proximally toward the cover by placing and moving the guidewire proximally with respect to the operating hypotube 344.

The inner diameter of the distal edge 358 of the cover is desirably slightly larger than the outer diameter of the proximal edge 328 of the basket. In this way, when the basket is pulled proximally toward the cover, the basket is substantially contained within the cover. Thus, the cover catches obturators (not shown) and other particulate matter retained within the cavity 330 of the basket. Next, the collecting sheath S is pushed out to the distal side and is brought into contact with the outer surface of the cover 340. This causes the cover to shrink around the basket and adhere to the outer surface of the basket. Then, the slightly contracted structure can be pulled out of the vasculature inside the patient's body and taken out of the patient's body. By housing the basket in the cover, the possibility of debris that has been filtered out of the basket being dissipated during basket retrieval is substantially eliminated.

FIG. 6 shows a molding element 370 used to make the basket 270 proposed in WO 96/01591. Basket 3 of trap 300
20 and cover 340 may be slightly different in shape, but molding these portions of trap 300 using similar molding elements with a slight change in the dimensions of molding element 370 while leaving the basic shape and structure of the molding elements intact. Can be. The molding element 370
It is to be understood that is merely one of the possible forming elements for obtaining a shape such as the shape of the basket 270, and in WO 96/01591 various other forming elements are suggested and varied. It is stated that the availability of various molding elements is familiar to those skilled in the art.

The forming element 370 of FIG. 6 includes an outer mold portion 372 defining a curved inner surface 374 and an inner mold portion 37 having an outer surface 378 having substantially the same shape as the curved inner surface 374 of the outer mold portion.
6. The inner mold section 376 is dimensioned to be received in the outer mold section with a piece of metal fabric (not shown) between the inner and outer mold sections. In a preferred embodiment, the inner surface 374 of the outer mold portion and the outer surface 378 of the inner mold portion each have a recess (375, 379, respectively) for receiving an end of a metal braid. The molding surface of the molding element 370, to which the metal fabric is molded, can be considered to include both the inner surface 374 of the outer mold portion and the outer surface 378 of the inner mold portion.

In the suggestion of WO 96/01591, the two mold parts 372, 376 are separated,
A tubular braid of metal fabric of a fixed length (not shown in FIG. 6) is placed between the two mold parts. Preferably, one end of the metal fabric is located in recess 375 of the outer mold portion and the other end is located in recess 379 of the inner mold portion. As described above, the ends of the tubular fabric are tightened prior to this forming process to reduce the likelihood of the fabric being loosened. The inner and outer mold parts are then brought closer together. As the ends of the wires approach each other, the tubular braid is folded and the surface of the tubular braid is deformed to substantially coincide with the inner surface 374 of the outer mold portion or the outer surface 378 of the inner mold portion, and traps 250, 250 'Has the same shape as the basket 270. Next, the inner and outer mold parts are fixed at predetermined positions with respect to each other, and the metal fabric is heat-treated to fix the wire in this deformed state.

In this international application, the traps 250, 250 ', 300
It also suggests how to use. Such traps are used in combination with other medical devices, and are usually collected from the patient's body after use. WO96
/ 01591 describes the use of such a trap, taking balloon angioplasty and arterial surgery as examples. In balloon angioplasty, a balloon catheter having an inflatable balloon at its end is placed in a blood vessel such that the balloon enters the stenosis. Such a balloon usually has a through hole in the center, and is arranged by moving the balloon catheter along a guide wire or the like. When properly placed, the balloon is inflated and abuts the stenosis to push the stenosis radially outward. As a result, the stenosis is pressed against the blood vessel wall, thereby improving the patency of the blood vessel.

However, when treating a stenosis in this way, there is a danger that debris will come off and enter the blood flowing through the blood vessel. If left unchecked, the obturator may flow downstream, causing a thrombus at the distal end of the vessel. Depending on where the obturator has settled,
The formation of this thrombus can cause serious damage to tissues and organs. WO9
No. 6/01591 suggests that a balloon catheter be used in conjunction with a vascular trap 250, 250 ', or 300 to prevent, or at least greatly limit, such thrombus formation. The device must be large enough to pass through the lumen of the particular balloon catheter used for angioplasty.

In one method suggested in WO 96/01591, the trap is placed first. The trap basket (270 or 320) is guided through an introducer catheter (eg, catheter C in FIGS. 12-15) to a location downstream of a given treatment site. The basket is then pushed distally from the end of the catheter. Then, the basket resiliently returns to a substantially expanded shape from the contracted state in the catheter. Once the trap is in place, the introducer catheter can be exchanged for a balloon catheter and the balloon catheter can be moved along the guidewire (260 or 310) of the vascular trap. The balloon is then positioned within the stenosis and inflated as described above. Once the angioplasty is complete, the balloon may be deflated again, pulled proximally and withdrawn from the patient.

WO 96/01591 also states that the balloon catheter can perform the same function as the introduction catheter in the above embodiment. In this embodiment, the balloon catheter is placed in the patient's blood vessel such that its distal end is downstream of the stenosis. Next, the vascular trap of the present invention (25
0, 250 'or 300) is passed through the lumen of the balloon catheter and the basket is pushed out of the distal end of the catheter. Once the basket has been resiliently restored to the desired expanded configuration, the balloon catheter may be pulled along the axis of the device's guidewire until it is properly positioned at the stenosis.

[0035] If desired, the balloon catheter may be provided with a standard length of catheter that extends distally beyond the distal end of the balloon. In this case, the balloon may be positioned within the stenosis and the basket may be pushed out from the distal end of the distal extension of the catheter. In such embodiments, the length of the distal extension of the catheter is set so that the basket can be properly positioned relative to the balloon when the basket exits the distal end of the catheter. This eliminates the need for an independent operation to retract the balloon to a position within the stenosis after placing the basket. The balloon may then be inflated, deflated, and withdrawn as described above.

According to the teachings of WO 96/01591, the same procedure can be followed for placing the vascular trap of the present invention for use in arterial surgery. In this procedure, a cutting head with a through hole is attached to the distal end of an elongated hollow shaft. The traps may be placed in any of the above ways, but in most cases the first method will be employed.
That is, the basket is arranged using the introduction catheter, the introduction catheter is withdrawn, and the incision device is guided along the guide wire of the vascular trap. The publication also emphasizes that the devices 250, 250'300 can be used in other medical procedures not only in the patient's vasculature but also in other vessels.

Since the trap is located downstream of the stenosis, even if debris is released during the operation, the particulate matter floats distally toward the basket and is captured in the basket. The proximal edge (288 or 328) of the basket is preferably larger than the vessel lumen to prevent the obturator from floating through the trap. WO
In 96/01591, the natural dimensions of the proximal edge (ie, with the basket fully restored to its expanded configuration) are such that the basket abuts the vessel wall tightly. It suggests that it be slightly larger than the inner diameter of the vessel.

The method of withdrawing the basket depends on which embodiment of the vascular trap is used, ie, whether the device includes a cover 340. 1 or 2 does not have such a cover. However, it includes a tether 290 that extends from the proximal edge 288 of the basket to the connection with the guidewire. In either embodiment, the retrieval catheter may be introduced along the guidewire and pushed toward the basket. This pulls the tether toward the guidewire and effectively closes the proximal end of basket 270, as described in connection with FIGS. Once the basket is sufficiently closed, such as when the proximal edge of the basket strikes the distal tip of the retrieval catheter, the catheter and vascular trap can be withdrawn from the patient's body together. By sufficiently closing the proximal end of the basket in this manner, the obturator captured by the basket during deployment can be retained in the basket until the basket is removed from the patient's body.

If desired, a tether 290 can be pulled using a device such as a balloon catheter to deflate the basket. In this case, the trap can be removed by pulling the vascular trap together with the balloon catheter without separately introducing a collection catheter for trap collection.

When withdrawing the embodiment shown in FIGS. 3-5, a cover 340 is placed over the proximal edge of the basket before withdrawing the vascular trap 300. Once the treatment procedure is complete and the debris has been trapped in the basket, the cover 340 is resiliently substantially restored to its expanded configuration. Once the cover 340 has been placed proximal to the basket, the basket 320 may be pulled toward the cover 340 until it hits or is received within the cover, as described above in connection with FIG.

In practice, the cover 3 of FIGS. 3 to 5 is restricted by the vessel to be placed.
40 cannot be restored to its fully expanded configuration. As previously mentioned, the cover 340 is preferably formed larger than the basket 320 to receive the basket. However, it is not desirable for obturators or other debris to pass through the periphery of the basket, and to prevent this, it is desirable that the basket be dimensioned to abut the vessel wall. Thus, the distal edge 358 of the cover will abut the vessel wall before expanding to full size. However, the walls of vessels, such as blood vessels, for example, are almost always elastic. Thus, the cover 340 pushes the vessel wall stronger than a smaller basket, causing the vessel to stretch slightly larger than the basket. In this state, the cover still has room in its cavity 356 to expand to a size that can accommodate the basket. Otherwise, the basket can be sealed simply by bringing the distal edge 358 of the cover into close contact with the proximal edge 328 of the basket.

The basket is received in the cover or, less preferably, at both edges 358,
Once the cover 340 has been engaged with the basket 320 by abutting 328, the device can be withdrawn proximally from the patient's vasculature. The cover prevents the obturator trapped in the basket during placement from accidentally dissipating during the extraction process.

The vascular traps 250, 250 ′, 300 shown in FIGS. 1-6 have significant advantages over conventional devices. Since the embodiment of FIGS. 3 to 5 has a cover,
The user can withdraw the basket with the obturator trapped in the basket without any extra precautionary measures, which could potentially inadvertently release such obturator into the bloodstream. Promising in that it can be minimized.

SUMMARY OF THE INVENTION The present invention provides a medical device collection system and a method for collecting medical devices. According to one embodiment of the present invention, a medical device retrieval system includes a medical device and a retrieval cover. Medical devices consist of a working element mounted on a flexible, elongated shaft.
The working element has a proximal profile and an axis extending proximally from the working element. The collection cover is slidably mounted on the shaft of the medical device. The cover has an arrangement shape, is compressible to a compressed state for arrangement, and resiliently restores substantially to the arrangement state. The cover has a proximal portion radially reduced in configuration and a distal side opening distally and having a maximum dimension greater than or equal to the maximum dimension of the proximal profile of the working element of the medical device. A distal end defining an opening of the distal end, and an elongated lumen defined between the proximal site and the distal end. The cover, when in a compressed state, is compressed radially inward toward the axis and opens distally with the distal end defining the distal-most portion of the cover. Preferably, the collection cover, regardless of the state of the device,
The device is configured to maintain its normal orientation, with the distal end always at the distal-most portion of the cover.

The medical device retrieval system may further include a retrieval sheath slidable on the axis of the medical device. When such a sheath is included, the sheath is desirably located at the distal end of the cover when the cover is in the deployed position. The inner diameter of the collecting sheath is smaller than the outer shape of the cover in the deployed state. The sheath slides distally over the cover, compressing the cover around the medical device.

According to another embodiment, the present invention provides a medical device retrieval system comprising a medical device, a retrieval sheath, a deployment stylet, and a retrieval cover. Medical devices consist of a working element mounted on a flexible, elongated shaft having a constant outer diameter. The working element has a proximal profile, and the shaft extends proximally from the working element. The retrieval sheath is slidable on the axis of the medical device and preferably has a distal end chamfered with the lumen. The deployment stylet is slidable on an axis of the medical device and has a distal tip portion. The distal tip portion tapers from a first diameter near the diameter of the distal lumen of the sheath to a second diameter very close to the outer diameter of the medical device shaft.
This is the shaft of the medical device and the distal end of the retrieval sheath as the deployment stylet is positioned such that the distal tip extends distally beyond the distal end of the retrieval sheath. It becomes a transition part between the side ends. The retrieval cover is slidable on the axis of the medical device and is replaceable with the stylet along the axis. The cover has an arrangement shape, is compressible to a compressed state for sliding in the lumen of the collecting sheath, and elastically returns to the almost arranged state. In the deployed state, the cover includes a radially reduced proximal portion, a distal end that opens distally, and an elongated portion defined between the proximal portion and the distal end. Has an internal cavity. The distal end defines a distal opening having a maximum dimension that is greater than or equal to the maximum dimension of the proximal profile of the medical device. When the cover is in a compressed state, the distal end is compressed radially inward with the distal end defining the distal-most end portion of the cover toward the axis,
Open distally.

Another embodiment of the present invention provides a retrievable medical device system that includes a medical device, a retrieval cover, and a retrieval sheath. Medical devices consist of a working element mounted on a flexible, elongated shaft. The collection cover is slidable on the axis of the medical device. The cover has a radially reduced proximal portion, a distal end that opens distally,
It has an elongated cylindrical wall extending between them and defining a cavity. The working element of the medical device is fully retained within the cover cavity as the tubular wall extends distally beyond the medical device. The retrieval sheath has a lumen and is slidable relative to the medical device and the cover. At least a length and cover of the proximal working element of the medical device are retained in the lumen of the retrieval sheath. At this time, the collecting sheath is in a state of regularly compressing a certain length on the proximal side of the cover so that the middle portion of the wall is in close contact with the surface of the medical device. Thereby, the obturator or other substance held in the medical device can be effectively captured.

As mentioned above, the present invention proposes a method. One such method involves the storage of particles or other forms of material in the vessels of the patient. The first step in practicing this method is a working element, a flexible and elongated shaft that follows a passage in the vessel,
Disposing a cover that is slidable with respect to the shaft and that opens distally and a collection sheath that is movable with respect to the cover on the shaft. A medical device placed within a blood vessel strikes the wall of the vessel and captures material within the vessel. During or after placement of such a medical device, while entrapping material in the vessel, the cover and retrieval sheath are spaced apart proximally of the working element along the axis of the medical device. I do. The cover is radially compressed against the inner surface of the retrieval sheath with the distal end opening distally and a wall defining a cavity within the lumen of the retrieval sheath. When the cover is moved distally with respect to the retrieval sheath, the cover expands radially into a deployed configuration, with the cavity expanding radially with the distal end open distally. The cover expands radially outward and is placed without being turned over. The cover is then moved distally against the surface of the medical device, forming an enclosed space therebetween. Then, the collecting sheath may be moved to the distal side with respect to the cover to shrink the cover around the medical device, and may be brought into close contact with the surface of the medical device.

(Detailed Description of Preferred Embodiment) FIGS. 8 to 12 are diagrams schematically showing the operation of one embodiment of the present invention. FIG. 8 shows an operating portion when the medical device collection system 10 of the present invention is in a completely arranged state. As mentioned above, the retrieval system of the present invention is intended for use with a medical device having a working element mounted on a flexible elongated shaft. In the figure, this medical device has the characteristics of a vascular trap similar to the vascular trap 250 of FIG. 11, but the connecting member 290 is omitted. The working element of the medical device is the basket 12, which may be considered as substantially described in the above description of the basket 270. The shaft in this design simply consists of a guide wire 14.
The construction and operation of the basket 12 is substantially the same as the description of the basket shown in FIGS. 1-5, but preferably the proximal band 13 of the basket is attached to a guidewire and the distal band 15 is It can slide on the wire. This allows
As the basket 12 attempts to assume a radially expanded configuration away from the delivery catheter, the distal end of the device in a collapsed state (272 in FIG. 1A) will have its proximal end (272).
Slide close to.

It will be appreciated that the medical device can be changed as needed. For example, the medical device used in connection with the present retrieval system can be replaced by a balloon catheter, in which case the working element is the balloon portion of the catheter, and the shaft extends close to the balloon. It becomes the main body.

Other components of the present recovery system 10 are mainly a recovery sheath 20 and a cover 30. It will be understood that the figures are for illustrative purposes only and are not drawn to scale. In actual operation, the collecting sheath 20 and the cover shaft 40 are, by far, much smaller. These elements are merely enlarged to make the various components in the accompanying drawings easier to see.

The cover 30 includes a radially expandable body 31 mounted on a shaft 40. Preferably, the body has a proximal portion 32 that is radially compressed up to the immediate vicinity of the shaft 40 and is attached directly to the shaft. A tubular wall 34 extends distally from the proximal site and terminates at a distal open end 36. The body 31 defines a cavity 38 that houses the working elements of the medical device, as described in further detail below. Most of the length of the cavity is defined by a generally cylindrical wall 34.

The radially expandable body 31 may be formed of a suitable material. As will be described in further detail below, the body is preferably retracted into the sheath 20 for deployment, radially expanded into the deployed configuration, and easily retracted by the retrieval sheath to facilitate medical delivery. In close contact with the working elements of the equipment. Any material can be used as long as such a function can be realized.

In one embodiment (not shown), the body 31 is formed of a flexible plastic material,
The cylindrical plastic member may be obliquely shaped so as to be reinforced with one or more metal rings or the like so as to have a funnel shape.

The illustrated embodiment is shown as being constructed from a series of flexible metal wires. As described in some detail in International Publication No. WO 96/01591, such radially expandable devices are formed of a material that is resilient and can be heat treated to substantially form the desired shape. It is advantageous to manufacture using a metal fabric having a thread line. Materials such as Elgiloy, Hastelloy, Incoloy, certain grades of stainless steel, shape memory alloys and the like. Among them, a shape memory alloy such as nitinol is particularly preferable.

In one useful embodiment, the radially expandable body 31 is made of WO96 / 015.
Starting with a metal fabric consisting of Nitinol and Platinum, formed using the technique outlined in No. 91. For example, the cloth may be a substantially cylindrical cloth formed of 48 wires having a diameter of about 0.0015 inches and a pick ratio of 80 to 100 per inch. To increase the visibility of the device in an X-ray fluorescence transmission device without unduly affecting the elasticity of the fabric, a relatively small percentage of the 48 wires used to form the metal fabric (E.g., four to six) may be formed of platinum or other relatively radiopaque material. If necessary, the wire may be coated with a therapeutically useful agent or antithrombotic material. For example, the wire may be heparin or a known platelet inactivator, such as 2B-3
It may be coated with an A antagonist.

The radially expandable main body 31 is attached to a shaft 40 that can slide in the axial direction. This shaft may take the form of a metallic hypotube, as described in connection with the embodiment of FIGS. More preferably, however, the shaft 40 is made of a flexible plastic material of the type commonly used for forming medical catheters. If friction of the shaft 40 with the retrieval sheath 20 and / or the shaft 14 of the medical device is a concern, the cover shaft 40 may be made of polytetrafluoroethylene or other suitable low friction material. Can also be formed.

The radially expandable body 31 may be attached to the shaft 40 by any suitable means. Possibly, the end of the wire defining the body 31 may be cast in the plastic defining the flexible shaft 40. However, the illustrated embodiment is
A pair of marker strips 46 for tightening the proximal end to the outside of the sheath and attaching the body to the shaft
, 48 can be made somewhat easier. If these fasteners are formed of a radiopaque material, it will be easier to track their position when the cover 30 is placed. In the illustrated embodiment, the cover comprises an outer layer and an inner layer of metal fabric, much like the basket 270 described above in connection with FIGS.
In this condition, the proximal marking strip 46 is used to clamp the outer layer of metal fabric to the outside of the shaft 40, and the distal marking strip 48 clamps to the shaft of the inner layer of metal fabric. It may be used for

In the illustrated embodiment, the shaft 40 has a lumen 44 through which the shaft 14 of the medical device passes, such that the cover 30 follows the shaft when deployed. The shaft 40 shown in FIGS. 8 and 9 extends distally beyond the distal marker strip 48 such that the distal tip 42 of the shaft is received within the cavity 38 of the cover. This not only facilitates manufacturing, but also reduces the likelihood that a guidewire or other device passing through the lumen 44 of the shaft 40 will get caught on the metal fabric defining the radially expandable body 31.

The retrieval sheath 20 may take the form of a standard medical catheter having a distal portion as described below. The sheath has a generally cylindrical wall defining a lumen 24 for slidably receiving the medical device shaft 14 and the cover shaft 40. 8 and 9, the difference in diameter of these three elements 20, 40, 14 is exaggerated to illustrate the operation of the device. In practice, their diameters do not differ as much as shown.

The distal tip portion 22 of the retrieval sheath 20 is chamfered to form a smooth tip (the advantages of this tip configuration are described below with reference to FIGS. 7, 13 and 14). This will be described in detail in the description). If necessary, a marker strip 26 may be incorporated into the wall of the retrieval sheath 20 near the distal tip portion 22. This helps the operator visually recognize the relative positions of the collection sheath 20, cover 30, and basket 12 during operation.

FIG. 9 is a schematic sectional view of the device shown in FIG. 8, showing a state before the cover is arranged. In operation, the medical device is usually first placed in a predetermined position.
As outlined above in connection with FIGS. 1 and 2 above, the basket 12 is positioned distal to a particular treatment site and the treatment device (eg, a balloon catheter or an arterial surgery device) is placed on the axis 14 of the trap. Guided to perform the intended treatment. When using the collection system of the present invention having such a trap, the collection sheath 20 and the cover 30 are used.
Is usually arranged after the basket 12 has been moved to a predetermined position for a while, and these three elements are not arranged almost simultaneously. However, it will be appreciated that in different circumstances, for example, when the cover 30 and the retrieval sheath 20 are used in conjunction with a Foley catheter or the like, simultaneous placement is also appropriate.

FIG. 8 shows the cover in the configuration and FIG. 9 shows the cover in a compressed state suitable for the configuration. Even in the compressed state, the catheter body 31 includes a radially reduced proximal portion 32, an elongated tubular wall 34, and a distal opening that opens distally to define the distal-most portion of the cover. It can be seen that it has side edges 36. This is in slight contrast to the structure shown in FIGS. 3 and 4 which shows the cover 340 of the device in a contracted state. In this contracted state, cover 340 is generally cylindrical in shape and has a distal portion 352 and a proximal portion 354, both proximate the outer surface of guidewire 310.
However, once positioned as shown in FIG.
The cover must itself be inverted so as to move substantially into 54 and define the distal edge 358 of the cover. This distal edge 358, in its contracted state, is merely the middle of a long, axially extending configuration of the device, as shown in FIGS.

The structure of the present cover 30 has a number of advantages over the mechanically more complex designs of FIGS. In the cover 340 of FIGS.
Must be inverted before it can be used to close 0. When the C constraint of the deployment catheter is released, the elasticity of the metal fabric forming the cover 340 causes
The distal hypotube 342 is elastically drawn close to the proximal control hypotube 344.

However, the wall of the blood vessel may prevent the cover 340 from completely flipping. In particular, if the inside diameter of the vessel in which the cover is to be placed is significantly smaller than the outside diameter of the fully deployed cover, the distal and proximal portions 352, 354 of the cover will expand and strike the vessel wall, While the distal hypotube cannot be expanded enough to invert the distal portion 352 to be received within the proximal portion 354,
It becomes a sausage-like shape. In such a situation, the cover cannot define a proper cavity for receiving the basket.

In the designs shown in FIGS. 8 to 12, there is no need for the radially expandable body 31 to be flipped in order to be completely arranged. Rather, cavity 38 is always in place. As long as the body 31 is positioned distally beyond the distal tip 22 of the retrieval sheath, this cavity expands to a size that can easily accommodate the working elements of the medical device for use with the cover. .

FIGS. 8 and 9 schematically show the structure of this device and its various components.
FIGS. 10 to 12 are intended to schematically show how the cover 30 is used to collect a basket 12 full of obturators or other particulate matter. FIG. 10 shows a deployment catheter C (described above in connection with FIGS. 1-5) extending through the lumen of the blood vessel to near the position of the basket 12. Basket 1
The gap 2 is filled with the obturator E. By simply pulling the guidewire 12 proximally,
The possibility that the obturator E is released into the bloodstream of the blood vessel is increased by winning because the substantially umbrella-shaped basket 12 is turned over.

In FIG. 10, the retrieval sheath 20 is located near the basket 12 leaving a space between the distal tip portion 22 of the retrieval sheath and the basket 12. In the figure, the cover 30 is still in the lumen 24 of the retrieval sheath 20, and is in a state substantially shown in the cross-sectional view of FIG.

When the collecting sheath is placed at a predetermined position with the cover kept inside, the shaft 40 of the cover 30 may be advanced to the distal side with respect to the sheath 20. This can be achieved by advancing the cover shaft 40 distally without moving the sheath 20, or by pulling the retrieval sheath 20 proximally without relatively moving the cover shaft 40, Easy expandable body 3
1 is exposed beyond the distal tip portion 22 of the sheath 20.

As the body 31 of the cover exits the distal end of the retrieval sheath 20, it attempts to resiliently return to a shape generally shown in FIG. Unlike the cover 340 of FIGS. 3-5, the body 31 of the present invention begins to expand radially to its final shape as soon as the distal end 36 passes through the distal tip 22 of the sheath 20. . Therefore, since the cover 30 does not need to be disposed, even the marker band 46 on the proximal side is located on the distal side of the proximal end 22 of the collecting sheath, as shown in FIG. Rather, as shown in FIG. 11, the proximal portion 32 of the body 31 can remain within the lumen of the sheath 20 without interfering with the operation of the cover 30.

FIG. 11 shows the device with the cover positioned in place and defining a cavity sized to receive the body of the basket 12. To achieve the shape shown in FIG. 11, the basket 12 is drawn into the cavity 38 by pulling the shaft 14 of the vascular trap proximally.

As described above in connection with FIG. 8, in this preferred embodiment of such a vascular trap, the proximal end of the metal fabric defining the basket using the proximal side band 13 is directly connected to a guidewire. Although attached to a shaft 14, the distal connector 15 is slidable along the length of the shaft 14. Thus, when the operator pulls the guidewire 14 proximally, the trap is thereby stretched and turned over. Without suction or without the cover 30, this presents some difficulties.

Prior to pulling the shaft 14 proximally, the distal end 36 of the cover
Is preferably moved to the immediate vicinity. In a preferred embodiment, the distal end 36 of the body 31 of the cover has a maximum dimension that is greater than or equal to the maximum dimension of the proximal profile of the basket 12, ie, the proximal protrusion of the deployed basket. Define a distal opening. If the vessels are large enough, this allows the cover to slide around the basket 12 without exerting too much force on the basket and without deflating the basket. However, it is likely that there is not enough clearance between the basket 12 and the vessel wall to allow the cover to slide easily between the vessel and the basket. Thus, the distal end of the cover typically abuts the surface of basket 12. This creates an enclosed space between the cover and the basket that includes both the basket cavity and the cover cavity 38. Such movement of the cover distally and into contact with the medical device can be accomplished by actually physically moving the cover distally or simply pulling the basket 12 toward the cover. By moving the cover distally with respect to the medical device.

FIG. 11 shows the relative positions of the components of the present invention when the operator continues to pull the guidewire 14 proximally after the cover first strikes the surface of the basket 12. The basket begins to turn over and becomes more elongated than the umbrella shape shown in FIG. Nevertheless, the obturator remains in the enclosed space defined by the cover and the basket.

In a preferred embodiment, the body 31 of the cover has a length that is greater than or equal to the working element of the medical device to be retrieved at the same time. This ensures that the working element is completely enclosed in the cover during the retrieval process, increasing the possibility of successfully retrieving the substance captured by the medical device without inadvertently returning it to the patient. The cover may be about the same length as the working elements of the medical device, but could be longer than necessary. In this way, the operator has great flexibility in using the device without unnecessary costs.

FIG. 12 schematically illustrates the next step in the method of removing a medical device from a patient's vasculature. In the figure, the collecting sheath has moved distally with respect to the cover. As suggested above, this may involve moving the retrieval sheath distally along the cover, or pulling the cover proximally (and preferably also the medical device) without moving the retrieval sheath 20. Made in. As the retrieval sheath is pushed distally with respect to the cover, the cover shrinks around the medical device received within the sheath. This ensures that the cover fits tightly against the surface of the medical device and accommodates particulate matter received in the enclosed space, reducing the likelihood that it will spill and return to the patient's vasculature. This also results in the device having a radially contracted shape that can be easily pulled out of the patient without unnecessary trauma.

As can be seen from the apparatus of FIG. 12, the system has a particular shape unique to the present invention. In this configuration, the working element of the medical device is completely retracted into the cavity 38 of the body 31 of the cover and the distal end 36 of the cover 30 is
Is located more distally than the distal end of. As shown in FIG. 12, at least a fixed length of the proximal side of the basket 12 and cover body 31 is retained within the lumen of the collection sheath 20. The collecting sheath radially compresses the length of the cover so that the intermediate portion of the substantially cylindrical wall 34 of the main body 31 is in close contact with the surface of the basket 12.

If necessary, the cover 30 and the basket 12 may be further retracted prior to withdrawing the device from the patient's vasculature and housed completely within the lumen of the retrieval sheath 20. However, this is not necessary for the device to operate effectively, and may be left to the choice of the treating physician. Pulling the basket 12, cover 30 and retrieval sheath 20 further proximally, into the deployment catheter C, further contracts from the shape shown in FIG. 12, thereby more securely accommodating particulate matter and allowing the device to move from the vascular system. It is important to note that this makes it easier to extract the.

FIG. 7 illustrates a problem that may be encountered when placing the medical device retrieval system 10 of the present invention across a vascular occlusion. The vaso-occlusion of FIG. 7 has the characteristics of a stent 4 having a stenotic lesion 6 partially occluding the lumen of the blood vessel, but this was selected only for illustration. Similar problems can arise with various other vascular occlusions.

The illustrated deployment sheath 20 has a blunt distal tip 22 ′. Due to the curvature of the vessel in which the stent is located, the retrieval sheath does not easily follow the medical device shaft 14 through the center of the vessel and is swung upwards toward the outside of the curve. This problem is even more pronounced when the collecting sheath is made rigid, for example, by incorporating a metal braid into the sheath wall to facilitate extrusion of the sheath. In some cases, manipulating the distal tip of the retrieval sheath over the occlusion requires significant time and effort. In addition, excessive force or excessive movement of the sheath to pass through the occlusion risks moving the working elements (not shown) of the medical device from the deployed treatment site.

FIG. 13 and FIG. 14 show two solutions to address such difficulties in arrangement. The first solution is shown in FIG. 13, and FIG. 14 shows another improvement which can be used alone or with the device of FIG.

Turning first to FIG. 13, as shown, the retrieval sheath 20 has its lumen 24
A deployment stylet that is slidably received on the mounting stylet. The stylet has a lumen 75 therein for receiving the shaft 14 of the medical device, which allows the stylet to slide on the shaft 15 with the retrieval sheath 20. Stylet 70
Has an elongated tubular body 72 and a tapered distal tip 74. In use, the stylet body 72 extends over the entire length of the retrieval sheath, with the proximal end (not shown) of the sheath proximally beyond the proximal end of the retrieval sheath. Preferably stretched. The operator can then selectively control the stylet independently of the guidewire and the retrieval sheath.

The distal tip 74 of the stylet tapers from its proximal end 76 to a distal end 78. At the proximal end, the distal tip has an outer diameter approximately the same as the diameter of the lumen 24 at the distal end of the retrieval sheath. As shown,
The stylet 70 does not completely fill the sheath lumen 24. This leads to excessive friction when moving the stylet relative to the sheath. The outer diameter of the sheath at the proximal end 76 of the distal portion 74 is such that the outer diameter of the sheath 20 is small enough not to cause a sudden change in diameter that would snag the vascular occlusion and prevent placement of the sheath 20 within the vessel. It may be close to the diameter of the proximal lumen. The transition from the distal tip 74 of the stylet to the outer diameter of the sheath 20 can be further smoothed by providing the distal tip 22 of the sheath 20 with a chamfered distal end.

The distal end 78 of the distal tip portion 74 of the stylet has an outer diameter that is very close to the outer diameter of the shaft 14 of the medical device. It is not conceivable that this distal end 78 would be very thin and move directly against the surface of the shaft 14. Once again, the distal end 78 of the stylet is such that the shaft 14 of the medical device does not abruptly change in diameter so as not to snag the vaso-occlusive and obstruct the placement of the sheath 20 within the vessel. It should be close to the diameter.

When the stylet is positioned such that the distal tip portion 74 of the stylet extends distally beyond the distal tip 22 of the retrieval sheath, the stylet is retrieved from the shaft 14 of the medical device. It is the transition to the distal end of the sheath. This facilitates guiding the medical device to a position beyond the vascular occlusion by moving the shaft 14. FIG.
Shows a stylet positioned such that the proximal end 76 of the distal tip portion 74 is immediately adjacent the distal end 22 of the retrieval sheath, but this is not required.

[0086] If the stylet body 72 has a substantially constant diameter over the entire length of the associated portion, the sheath 20 may be extended so that the body extends beyond the distal end of the sheath. It is possible to move the stylet distally. This does not present a disadvantage because the outer diameter of the body is desirably about the same as the diameter of the proximal end 76 of the distal tip.

The use of the collection sheath with the stylet 70 can vary widely. If desired, it can be used each time the system of the present invention is deployed. But,
As described below, the use of a stylet adds one step to the retrieval process, and can be used only when the operator predicts that there is a vascular occlusion or only when such an occlusion already exists. Good.

In use, the stylet 70 and cover 30 are interchangeable. That is, the stylet or cover moves along the axis 14 within the collection sheath lumen 24, but not both at the same time. One must be removed and replaced with the other. If the operator has foreseen a vessel occlusion (or if it is desired to avoid replacing the device twice if there is an occlusion), the sheath 20 may be placed with the stylet from the beginning. This is accomplished by positioning the stylet 70 relative to the sheath 20 such that the distal tip portion 74 of the stylet extends distally beyond the distal tip of the sheath. Most preferably, both the stylet and the sheath are advanced together along axis 14 (often in most cases) until the distal tip portion 22 of the sheath is in the desired position relative to the working element of the medical device. , As described above in connection with FIG. 11, such that the distal end of the sheath is near the working element but proximally spaced from the working element).

Once the sheath is in place, stylet 70 may be replaced with cover 30. This may be performed in a typical balloon-type angioplasty operation or the like in the same manner as when exchanging the catheter. In most cases, the replacement wire is the shaft 1 of the medical device.
Because it is attached to the proximal end of 4, the stylet 70 can be pulled proximally and placed on the replacement wire. Thereafter, the replacement wire is removed, and the cover is advanced along axis 14 within lumen 24 of the retrieval sheath. Marking band 2 on collection sheath
6 and (for example) the marking strip 13 of the basket 12 allows the final adjustment of the position of the sheath with respect to the medical device before placing the cover.

The cover may then be moved distally relative to the sheath 20 by advancing the cover distally or pulling the sheath proximally. As described above, this causes the body 31 of the cover to expand radially, resulting in a configuration in which the cavity is radially expanded with the distal end open distally. The cover is then moved distally with respect to the working element of the medical device to contact the surface of the medical device and form an enclosed space therebetween. Preferably (although not necessarily due to the configuration of the medical device and the shape of the cover), the cover is advanced further relative to the working element until the entire working element is effectively received in the cavity 38 of the cover. . Thereafter, the retrieval sheath is moved distally with respect to the cover to cause the cover to shrink around the working element and come into close contact with the surface of the working element to retain debris in the cavity.

FIG. 14 shows another improvement of the sheath 20 of the present invention. In this embodiment, the sheath 2
Zero distal length 21 is bent at an angle to the body of the sheath. In the event of a vascular occlusion, the distal bend allows the operator to pass through the occlusion by turning the sheath such that the distal tip 22 of the sheath is offset from the vessel and away from the occlusion. And the sheath can be advanced further. About 5-3
An angle of 0 ° is considered suitable for most purposes without unnecessarily hindering the placement and recovery of the cover 30. The length of the constant length portion 21 on the distal side may be changed as necessary. In most cases, the constant length section on the distal side is no more than 5 cm,
The most suitable would be between 1 cm and 3 cm. As previously described, the sheath 20 having the distal constant length portion 21 of FIG. 14 can be used in place of or with the stylet 70 shown in FIG.

While the preferred embodiment of the invention has been described, it will be appreciated that various changes, adaptations, and modifications can be made thereto without departing from the spirit of the invention and the scope of the appended claims. Let's do it.

[0093]

[Brief description of the drawings]

FIG. 1A is a schematic side view according to WO 96/01591, showing a vascular trap in a contracted state for placement in a patient's vasculature. FIG. 1B is a schematic side view of the medical device of FIG. 1 in an expanded state for use in a patient's vasculature.

FIG. 2A is a schematic side view according to WO 96/01591, showing another vascular trap collapsed in a catheter for placement in a patient's vasculature. FIG. 2B is a schematic side view of the device of FIG. 2A, positioned at the tip of a catheter.

FIG. 3 is a schematic side view according to WO 96/01591, showing a vascular trap and a cover, both deflated in a catheter for placement in a vessel in a patient's body.

FIG. 4 is a schematic side view of the device of FIG. 3 in a partially deployed configuration, with the vascular trap in the deployed configuration, but with the cover retracted within the catheter.

FIG. 5 is a schematic side view of the device of FIG. 3 in a completely deployed configuration.

FIG. 6 illustrates one embodiment of a molding element used to manufacture the vascular trap of FIGS. 1-5.

FIG. 7 is a schematic diagram of a retrieval sheath caught in a vascular occlusion proximal to a desired distal deployment location.

FIG. 8 is a schematic side view of the device according to the invention, in which both the trap and the cover are completely arranged.

FIG. 9 is a schematic cross-sectional view of the device of FIG. 8, with the trap still in place, but with the cover retracted into the retrieval sheath.

FIG. 10 is a schematic view of the above-described device placed in a blood vessel of a patient and holding an obturator.

FIG. 11 is a view similar to FIG. 10, but showing the trap retracted inside the cover.

FIG. 12 is a schematic diagram showing the device shown in FIGS. 10 and 11 with a partial cutout;
5 shows the cover retracted into the retrieval sheath.

FIG. 13 is a schematic partial cross-sectional view of the medical device recovery system of the present invention using a placement stylet.

FIG. 14 is a schematic side view of a distal length portion of another retrieval sheath for use with the present invention.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID , IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW (72 ) Inventor Anderson Kent 55110-5246 Minnesota, USA White Bear Lake Buell Le Road 1861 F-term (reference) 4C060 MM25 4C167 AA31 AA38 BB02 BB36

Claims (9)

[Claims] 1. A medical device comprising a working element mounted on a flexible, elongate shaft, said working element having a proximal profile, wherein said shaft is proximal to said working element. A medical device extending to the side, and a collecting cover slidably mounted on the shaft of the medical device, having an arrangement shape, compressible to a compressed state for arrangement and elastically substantially the arrangement shape Returning to, in the arrangement shape, the proximal portion reduced in the radial direction, and opened to the distal side,
A distal end defining a distal opening having a maximum dimension that is greater than or equal to a maximum dimension of a proximal profile of the working element of the medical device; a distal portion defining the proximal portion and the distal end. In a compressed configuration, compressed radially inward toward the axis, with the distal end distally defining a distal-most portion of the cover. A medical device collection device comprising a cover that opens. 2. The medical device of claim 1, further comprising a retrieval sheath slidable along the axis of the medical device and disposed at a distal end of the cover when the cover is in the deployed configuration. The described system. 3. The retrieval sheath has an inner diameter smaller than the outer diameter of the cover in the deployed configuration, and slides distally over the cover to compress the cover around the medical device. 3. The system according to claim 2, wherein: 4. The retrieval sheath has a body and a distal tip comprising a fixed length portion distal to the retrieval sheath, wherein the distal tip is about 5 to the body. ~ 30
The system according to claim 2, characterized in that the system is bent at an angle between degrees. 5. The system of claim 4, wherein the distal tip portion is between about 1 cm and 5 cm in length. 6. The system of claim 4, wherein the distal tip portion comprises a radiopaque marker band. 7. A medical device comprising a working element mounted on a shaft that is flexible, elongate and has a constant outer diameter, said working element having a proximal outer profile, said shaft comprising: A medical device extending proximally from the working element; and b) a retrieval sheath slidable on an axis of the medical device, having a chamfered distal end and a distal lumen. A retrieval sheath; c) an outer diameter of the medical device from a first diameter close to the diameter of the distal lumen of the sheath with a deployment stylet slidable on an axis of the medical device. A distal tip that tapers distally to a second diameter side that is very close to the distal tip that extends distally beyond the distal end of the retrieval sheath. When the stylet is deployed as such, it has a distal tip that is a transition from the axis of the medical device to the distal end of the retrieval sheath D) a collection cover slidable on the axis of the medical device and replaceable with the stylet along the same axis, the collection cover having an arrangement shape, and sliding in the lumen of the collection sheath. A collection cover that is compressible to a compressed state for movement and elastically returns to the above-mentioned arrangement state, wherein in a disposition shape, a proximal portion reduced in a radial direction, and a distal side A distal end defining a distal opening having a maximum dimension that is greater than or equal to a maximum dimension of a proximal profile of the working element of the medical device; the proximal portion and the distal end. An elongate internal cavity therebetween, and in a compressed configuration, radially inwardly compressed toward the axis, with the distal end defining the distal most end of the cover. A medical device collection system, comprising: a cover that opens to a position side. 8. A medical device comprising: a) a working element mounted on a flexible, elongate shaft; and b) a collecting cover slidable on the shaft of the medical device, radially reduced. A collection cover having a proximal site, a distal end that opens distally, and an elongated tubular wall extending therebetween to define a cavity, wherein the working element of the medical device comprises: A cover that is fully retained within the cavity of the cover when the tubular wall extends distally beyond the medical device; c) has a lumen and is slidable relative to the medical device and the cover. Holding a working element of the medical device and at least a proximal portion of the cover in a lumen thereof, and attaching the working portion of the medical device proximally to the intermediate portion of the wall. A collection sheath that compresses the part so as to be in close contact with the surface of the medical device. Noh medical device system. 9. A working element, a flexible elongate shaft configured to follow a passage in a vessel, a distally open cover slidable relative to the shaft, and Providing a medical device comprising a cover and a retrieval sheath slidable relative to the shaft; b) defining a distal end and a cavity opening distally within a lumen of the retrieval sheath. The cover and the collection sheath, the walls of which are radially compressed against the inner surface of the collection sheath with the defining wall, are spaced along the axis of the medical device and proximal to the working element. Placing the medical device in a blood vessel so as to place the same in a vessel and capturing the intravascular material against the wall of the vessel; c) moving the cover distally with respect to the retrieval sheath; As a result, the cover that expands radially outward and is arranged without turning over is radially expanded, and the distal end is expanded. And d) moving the cover distally with respect to the medical device and holding the cover against the surface of the medical device. E) moving the retrieval sheath distally with respect to the cover to cause the cover to shrink around the medical device and adhere to the surface of the medical device. A method for collecting particulate matter or other foreign matter in the vasculature of a patient, comprising: