Transluminal implantation

(54) Name Device for implantation (56) Published publications: W0 86/03398 (A61F 2/04, A61M 25/00, 37/04) (57) Abstract:

Device for implantation by insertion into a difficult-to-access site of a substantially tubular, radially expandable prosthesis (2), comprising in combination one such prosthesis (2) and concentrically therewith a flexible probe (1) with means (200) to maintain said prosthesis (2) in a radially contracted state and to release it at the desired location. Said means for retaining the prosthesis include a tube (5) which concentrically surrounds the probe (1) and radially surrounds the prosthesis (2) to form a space therefor. The probe (1) has a central axial channel (4) which allows the supply of a fluid displacement medium at its other end, and is provided with at least one radial opening (27) which opens into the prosthesis space to allow for the purge space of the prosthesis space to be removed. gases therefrom before implantation.

<img file="SE454482B_D0001.tif" />

DB 647289

<img file="SE454482B_D0002.tif" />

The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code

454 482 &gt;

TECHNICAL FIELD Λ

The present invention relates to a device for transluminal implantation of a substantially tubular, expandable and preferably self-fixing implant, such as a graft or prosthesis. BACKGROUND

Published PCT application WO / SE85 / 00503 discloses a device for transluminal implantation comprising a substantially tubular, radially expandable prosthesis, the device in combination including such prosthesis and concentrically therewith a flexible probe with means for retaining said prosthesis in a radially contracted state and to release it at the desired location. Said means for maintaining and releasing the prosthesis include a tube concentrically surrounding the probe, one end of the tube being connected to the probe and the tube being twisted within itself to form a double-walled portion radially surrounding the prosthesis to form a space therefor. The prosthesis can be exposed by axial relative movement between the ends of the tube.

In a preferred embodiment of the device according to the PCT application, the tube is leak tight and both ends thereof are tightly connected to the probe. In addition, the surface of the probe connected to the hose is leak-tight between the slopes of the hose end, whereby the hose and the probe form a chamber which can be pressurized using a liquid, thereby reducing the contact pressure between the hose cradles in the double-walled portion, thereby causing friction between the outer wall and the inner hose wall at axial relative motion between them is reduced.

Although this known transluminal implant device works in an excellent manner when practically used, it has been found in practice that the prosthesis space after the insertion of the prosthesis contains gases, mostly air, which are enclosed in said space and within the prosthetic thread elements. . Such gases, when removing the prosthesis in, for example, a blood vessel, may cause problems when released into the bloodstream.

The main object of the invention is to eliminate said problems with gases contained in the prosthetic space. For the aforementioned

454 482, the device according to the invention is characterized in that the probe has a central axial channel which can be used for supplying a liquid displacement medium at its other end. The constriction can take place without closing the duct at its front end, but the duct can, if desired, be restricted or closed to improve the constriction efficiency. The probe is further provided with at least one radially open aperture which opens into the prosthetic compartment to allow for the flushing of the prosthetic compartment to remove gas therefrom for implantation.

According to a preferred embodiment of the device according to the invention, a plurality of openings arranged in the probe are substantially evenly distributed around the probe, and said openings are preferably positioned behind the prosthesis seen in the direction of the transluminal transmission of the device.

The invention also provides means for eliminating the risk of conceivable release of gases between the walls of the hose in its double-walled portion in the event of failure of the hose within said portion. For this purpose, the device according to the invention is characterized by at least one small hole extending through the hose wall at the front end of the double-walled portion to enable constriction by the purge of gases present between the walls of the hose in said double-walled portion. The size of such a hole is selected such that it allows for the outflow of the gases but prevents or substantially reduces the passage of the liquid used for the pressurization. It is preferred to provide a plurality of such holes at the front end of the double-walled portion, and such plurality of holes are advantageously positioned substantially evenly distributed around the front end of said hose portion. Although the size of such a hole is dependent on the nature of the fluid used to pressurize the chamber formed by the tube and the probe, a suitable size is between about 0.001 and 0.1 mm. When using isotonic saline as a pressurizing liquid, a preferred diameter of the hole is about 0.05 mm.

For further details of the device according to the invention, reference is made to the aforementioned PCT application, the entire contents of which are incorporated herein by reference thereto. The present invention will be further described hereinafter in the form of non-limiting examples of embodiments thereof, reference being made to

454 482 gores to the attached drawings.

DRAWINGS schematically show an axial section through a device according to the invention;

is a schematic side view of another embodiment of the device of Fig. 3 being an invention; schematic side view of yet another embodiment of the invention;

Fig. 4 is a side view of another embodiment of the invention;

is a section taken along line AA of FIG.

f igoch

EXAMPLES OF EMBODIMENTS

In FIG.

there is shown a device for implantation of a so-called expandable graft or prosthesis 2 in a living organism to an easily accessible site therein, for example a desired site 1 a vein or artery, the graft 2 being intended to strengthen an incurable section of the vein or artery.

The device generally comprises a probe device 100 having at its insertion end a device 200 for gripping and carrying a graft or prosthesis 2.

The device comprises an elongated flexible probe 1, which preferably has an axially through channel

4.

The tube / tube 1 is flexible and consists of, for example, nylon.

At its forward end, the tube 1 is provided with a rounded skull 3, through which the channel 4 continues. The skull 3 device through a tightly and firmly connected soft and for example pray

<td colspan="2">earns</td><td>to</td><td>under 1</td>

<td>prongs</td><td>channel.</td><td>And s</td><td>long 5</td>

<td>against</td><td>tube</td><td>i yt</td><td>outer face</td>

<td>stands</td><td colspan="2">of polyethylene</td><td>or</td>

easy insertion of is at one end 7. The hose 5, which is polyethylene chloride, is turned to the inside to form a double-walled hose section, the inner wall of which radially comprises said tubing 7. The prosthesis 2 is a radially compressible element of tubular configuration which surrounds the outer end of the tube 1 and is enclosed by the double wall of the hose 5. section 51.52. By withdrawing the second spirit of the hose 5 (upwards in FIG. in the relative tube 1), the double-walled hose section 51.52, fold 6 moves along the hose towards the attachment point of the end of hose 5, thereby causing no sliding movement between the graft 2 and the elongate wall 51. Since

454 4.82 fold 6 moves upwardly in Fig. 1, the graft 2 is exposed in axial direction and can expand to abut a vein or species. The hose 5 is coaxially connected to a flexible actuator tube consisting of a stainless steel helical spring Z, which spring S is externally covered with a removable tight casing of, for example, polyvinyl chloride. The PVC housing 9 is tightly connected to the polyethylene hose by means of a dressing 15. A bushing 10 surrounds the tube 1 and is rigidly connected to the spring 8 and tightly connected to the casing 9. The other end of the bushing has an O-ring seal 12 which seals against the outer surface of the tube 1. The pipe 1, the hose 5, the spring cover 9, the bushing 10 and the seal 12 thus form a closed chamber 25. The bushing 10 has a bore 14 which extends through the wall of the bushing and forms a channel through which a fluid 22, such as a physiological saline, blood substitute, air or the like, can be introduced and pressurized into the space 25. This allows the fluid 22 to penetrate between the tubing walls. 51,52 and separate them so that they can move axially relative to each other with substantially reduced friction.

The channel 4 of the tube 1 can be used to insert a contrast medium 21 into the region of the front end of the device, so that the position of the device can be more easily detected, for example by means of X-ray technology.

In order to expose the graft 2, the operator can with one hand hold the rear end of the tube 1 and with the other hand retract the bushing 10 in the direction of the arrow 20, whereby the twisting fold 6 of the hose 5 is retracted so that the object 2 is exposed.

In Fig. 1, the direction of catching of the device is indicated by arrow 23.

For the purposes of the present invention, the tube 1 is provided with a number of radially extending holes or apertures 27 which provide passages between the channel 4 of the tube 1 and the rear end of the space containing the prosthesis 2.

In the practical use of the device according to the invention, it has been found that gases remain in said space inside and outside the prosthesis 2. The described device makes it possible to remove such gases from said space, preferably by blocking the duct 4 at the front end of the tube. 1 and introducing a suitable liquid at the arrow 21 at the other end of the tube. Such a liquid, which may be, for example, iso

454 482 tonic saline solution or a contrast fluid, flows through the duct 4 and the openings 27 so that the gases contained in the prosthetic compartment within the double-walled section 51.52 are preceded. After removing the gases, the implantation device is ready to be used for implantation.

The device shown in Fig. 1 further comprises small holes 29 arranged at the front end of the double-cradled section 51,52. These holes make it possible to remove gases such as air present in space 25. By introducing a suitable pressure setting liquid at 22 through a hole 14, the gases present in space 25 can be displaced through holes 29 so that space 25 completely filled with pressurizing fluid. The holes 29 are of a size so selected that the gases can pass through the same, whereas the pressurizing fluid cannot pass. In this way, any risk of gases being released into the blood stream is eliminated in the event that the tube 5 fails.

Figures 2-5 in the attached drawings are directed to embodiments of the device according to the invention, which, in addition to the characteristic that they enable implantation of an expandable graft or prosthesis, also include means for enlarging a stenosis in a vessel or lumen for implantation of a supporting graft serving as stent to prevent restenosis. In these figures, holes 27 and 29 are not shown, but they operate in the same manner as described in connection with Figure 1.

<img file="SE454482B_D0003.tif" />

is a schematic side view of such an embodiment of the device according to the invention. The device comprises a double-walled section 51.52.

The radially compressed graft 2 is, as previously described, located within the double-cradled section 51.52 and surrounds the central tube 123.

At the front end of the central tube

123 a dilatation balloon 125 is provided which is sealedly connected at both ends to the central tube 123.

Although not shown in detail in the drawing, the balloon 125 can be pressurized separately from the double-rock section 51.52 by pressurizing the central passage 127 of the tube 123. The double-rock section 51.52 can be pressurized by introducing a pressure medium into the annular space 129. formed between the tube

123 and the surrounding hose 5.

454 482

In operation, the device shown in Fig. 2 briefly operates in the following manner.

Following the introduction of the device, which is generally designated 120 at the desired location in, for example, a blood vessel, the balloon 125 is inflated by separate pressurization thereof. The purpose of this inflating of the balloon is to widen the lumen at the site of the stenosis and where the graft 2 will later be implanted.

After expanding the lumen at the desired location, the pressure in the balloon 125 is relieved and the device 120 is moved forward so that the double-walled section 51.52 thereof assumes the correct position in the vessel. By relative movement between the central tube 123 and the tube 5 in the axial direction, the graft 2 can now be released at the desired location in the vessel and provide permanent strengthening of the vessel, whereby, for example, restenosis can be avoided. After the implant lumen, device 120 is then removed from the vessel.

The embodiment shown in Fig. 3 works in the same manner as in Fig. 2, but the dilatation balloon is located behind the double-walled section 51.52. In this embodiment, the double-walled section 51.52 is inflated to avoid friction using the same pressure medium as that used for inflating the balloon 143 to follow the communicating passage therebetween. The function of the device of FIG. 3 is otherwise the same as that of FIG. 2 and the same benefits are obtained.

Fig. 4 shows an embodiment in which the balloon 163 is arranged to surround the double-walled section 51,52. This embodiment, designated 160, contains a central wire or wire 167 surrounded by a hose 165. The hose 165 is surrounded by a balloon 163 which is sealedly connected to the hose at the rear end and to the front portion of the outer wall 52.

In order to provide separate balloon pressure and the double-walled section 51.52, two inner passages 169,171 are arranged inside the hose 165, as shown in Fig. 5 in an enlarged cross-section. The passage 169 can be used to accommodate the central cable 167 and to pressurize the double-walled section 51,52 to reduce friction. The passage 171 can be used to pressurize the dilatation balloon 163 separately from the double-walled section 51.52. Of course, it is conceivable to arrange three internal passages inside the tubing 165, two for individual

454 482 pressure setting and one for a central control cable. This arrangement can of course also be used in the designs of Figs. 2 and 3. In all embodiments containing balloon means, separate pressure sealing can be used for said means and for inflating the double-walled section.

The function of the device shown in Fig. 4 is the same as that of the devices shown in Figs. 2 and 3 with the difference that no axial displacement of the device must be performed after the lumen expansion using the balloon 163, since the position of the lumen expansion is centered. for the graft or prosthesis 2 located within the double-walled section 51.52.

The prosthesis used in the device of the present invention can be of any type as long as it is radially expandable to provide radial expansion and self-fixation upon release in a particularly preferred prosthesis or British Patent Specification 8411519, the reference thereto. This prosthetic vessel or other duct. A graft is described in published the contents of which are incorporated herein by or graft comprising a flexible tubular body composed of a plurality of individual rigid but flexible thread elements, each thread element extending in helix configuration with the body centerline as a common axis, wherein a number of elements having the same winding direction but axially offset relative to each other crosses a number of elements, which are also axially displaced relative to each other but have opposite wind direction. The diameter of such a prosthesis or graft is variable by axial movement of the ends of the body relative to each other.

454 482