WO2006089517A1

WO2006089517A1 - Implanting a self-expanding stent by means of hydraulic power

Info

Publication number: WO2006089517A1
Application number: PCT/DE2006/000276
Authority: WO
Inventors: Ernst-Peter Strecker
Original assignee: Ernst-Peter Strecker
Priority date: 2005-02-25
Filing date: 2006-02-16
Publication date: 2006-08-31
Also published as: DE112006001056A5

Abstract

Selbst expandierende Stents werden zur Platzierung des Stents vom in den Patienten eingeführten Katheter (1) durch ein Druckmedium aus dem Katheterlumen in das zu behandelnde Hohlorgan wie z.B. ein Blutgefäß (3) herausgeschoben. Der Druck (p) wirkt entweder direkt auf den Stent, oder auf Kolben (4) , die durch den von proximal eingebrachten Druck (p) den Stent aus dem Katheter (1) herausbefördern.

Description

Description:

Implantation of a self-expanding stent by means of hydraulic force

Introduction:

Stents have established themselves as a means of treating pathologically altered body vessels and hollow organs and opened up new treatment options. Self-expanding stents have some technical advantages, such as a smaller insertion diameter and greater flexibility and elasticity of the stent, compared to balloon-expandable stents. The self-expanding stent delivery systems currently in use consist of a sheath in which the stent is kept unexpanded and a pusher system which drives the stent out of the sheath into the vessel to be treated. This pusher contains a channel for the angiography guide wire. The disadvantages of this system are that the pusher must be loaded with a high force to expel the stent to drive out the stent or pull back the shell. That's why the pusher is usually made of relatively rigid material. When the stent is driven out, there is a great deal of friction not only between the stent and the sheath, but also between the pusher and the sheath. Because of this, this system is poorly suited for meandering vessels. It happens that the introduced catheter-stent assembly fails in the patient and that the pusher can not be advanced or the sheath can not be withdrawn, especially in cases of implantation of gastrointestinal stents. Self-expanding stents are therefore not used for coronary arteries for said technical reasons. Another technical problem with currently available stent application systems is the so-called "jump effect" which can be observed when the remaining portion of the stent, which remains in the application system after almost complete release, leaves the outer sheath, in an abrupt manner, as the stent emerges the surrounding sheath releases the energies within the delivery system consisting of compression of the pusher and pulling on the sheath, this uncontrolled release of the last portion of the stent occurring at the end of the release process may lead to misplacement of the stent and / or injury to the inner vessel wall lead to a significant reduction in the technical and clinical success of stent therapy. The solution of the problem:

The force to drive the stent out of the catheter (sheath) is not transmitted through a pusher but through a fluid or gas column. Applicable would be the principle of hydraulics or pneumatics, i. the force to drive the stent out of the sheath is transmitted through a liquid or gas column. The hydraulic principle ensures a smoother and more controllable and metered power transmission to the stent, which is to be released from the surrounding shell. The principle of hydraulics is already partially used in connection with a commercially available product, the embolic spiral: a thread-like wire structure located in a catheter is flushed out of the catheter by flushing liquid and thus brought into the vessel to be treated, where it is a ball unfolds and closes the vessel lumen. However, since the embolization coil is a small, thin and faint filamentary structure that has little radial expansion force, little force is needed to force the coil out of the catheter as there are no significant frictional forces. In the said application, it is not necessary to give the ball for the implantation of a specific shape and this controlled and thrust out of the catheter. The power transmission through a piston has not been used. However, the application of such guarantees a more accurate placement.

The embolization coil is in contrast to self-expanding stents, which have a very strong radial force and thus cause high frictional forces in the catheter. The technique described here (system for releasing a stent by means of hydraulic or pneumatic principle) transmits a stronger effect than the known technique described above and is therefore not comparable with this.

Description of the principle of the invention:

The following versions can be used in hydraulics or pneumatics:

The stent to be placed is a coil stent, e.g. a double coil stent, a meander stent, or a helix stent that does not completely fill the lumen of the catheter prior to release in its stretched state (Fig.1, 2). The printing medium, e.g. Liquid or gas, flows partially past the coil stent and serves as a lubricant to reduce the frictional forces between stent and catheter.

The tip of the coil stent, so the wire is formed like a piston. The piston has such a large diameter that it fills the inner lumen of the catheter (Fig.3,4). Fluid that is forced into the catheter from the proximal end hits the piston and forces it out of the catheter (Fig.3). The piston seals the gap (gap) so that the pressure medium can not flow past between the piston surface and the catheter inner wall. The piston attached to the anterior end of the stent portion then pulls the stent behind and out of the catheter (Fig. 4). Thus, the helical coil is not compressed by proximal, whereby the resulting friction energy is lower. In another embodiment, further pistons are attached to the stent wire (Figs. 5,6), at the posterior end of the stent, or in the middle, which in turn act as additional force transmitters. The pistons are of a smaller diameter than the inner diameter of the surrounding catheter or are provided with holes, thus creating a leak so that at the beginning of the release the pressure medium, e.g. a liquid, can penetrate to the first piston.

With a smaller diameter piston, the dimensions of the piston may be such that the piston, together with the portion of wire in the catheter, can rotate about its longitudinal axis within the surrounding catheter while the elongated helix wire stent is being expelled. The portion of the helix stent already implanted in the vessel then no longer moves, but only the portion of the stent remaining in the catheter. As a result, a proper placement of the stent is achieved in its predetermined form. In this case, damage to the vessel wall is avoided, which could be caused by a moving stent in the vessel. Also avoided is an undesirable unfavorable rejection of the helical shape. In another embodiment, however, the additional pistons could be the same size and all fill the lumen of the catheter.

At least the foremost piston lies flat on the wall of the vessel after implantation of the stent, so that no turbulence arises (FIG. 6). The pistons attached to the stent wire may be made of biodegradable material and dissolve in the blood so as not to obstruct blood flow (Figure 4).

The front tip of the stent is shaped like a ball that is picked up by a forked wire. The fork wire is firmly connected to a piston, which together form the stent carrier (carrier); the piston is located proximally behind the end of the stent (Fig.7,8). Fluid that is forced into the catheter from the proximal end strikes the piston and moves the stent held on the fork wire out of the catheter along with the forked wire. The stent disengages from the fork wire and the fork wire is then removed along with the catheter and the in-flask.

In the case of conventional self-expanding, slotted tube stents, e.g. from Nitinol, or braided and knitted tubular stents, the catheter is internally fitted with a plunger which pushes the stent through the catheter and pushes it out of the catheter (Fig.9,10). The plunger remains in the catheter, this is done by a fuse, e.g. ensures a thread that is anchored in the catheter. In order to prevent the terminal piston from leaving the catheter after release of the stent, there is a side hole in the wall of the catheter (FIG. 10). As long as the stent, or portions of the stent, are still in the catheter, the side hole is closed by the piston. After release of the stent, the piston is at the catheter tip and the side hole is open, so that serving as a pressure medium, inflowing liquid can now escape through the side hole. This reduces the pressure on the piston, so that the piston does not move further (Fig.10). The distance of the side hole from the catheter tip must be at least as large as the length of the piston (Fig.9,10).

Such a piston has centrally a hole-shaped channel through which the guide wire is inserted. The hole is so large that the guidewire fills it completely and seals it so that no pressure loss can occur. Such a piston, like the pistons in a motor, also has additional seals, e.g. Sealing rings (Fig.11,12).

The piston as a whole is flexible and flexible so that the system can be pushed through tortuous arteries and also released in an arterial curve.

In another embodiment, the small diameter tube or stent in the catheter constitutes the plunger itself. The opening of the small diameter tubular stent is filled by the guide wire so that there is no pressure loss occurs when the stent is squeezed out. The distal tip of the catheter is resilient and conical so that the step between the guidewire and the catheter containing the stent is balanced (Fig.13). As the stent emerges, the cone continues and allows passage without pressure loss (Fig.14).

In another embodiment, the gap between guidewire and lumen of the collapsed stent is filled by a biodegradable substance. Also, the gaps between the individual stent struts at the rear end of the stent are filled with the polymer so that the stent end so compressed gets the effect of a piston. Upon deployment of the stent in the vessel, this polymer-like substance ruptures and completely releases the stent (FIGS. 15 and 16).

In the catheter is located at the distal end of an elongated piston, which is provided with a conical tip. Coaxially through the tip first leads a channel, which then leads obliquely to the outer surface of the piston and receives the guide wire (Fig.17). The system shown corresponds to a fast exchange system. At the distal portion of this piston there is a carrier with a stent bed, in which the stent is inserted in the low-profile state and is held in its small diameter by the sheath of the introducer catheter, the stent is elastically self-expanding. The introducer catheter has an elongated slot. This slot is located above the side opening of the piston. The guidewire is inserted into the distal opening of the cutlery prior to insertion of the catheter stent assembly and retrograded through the plunger until it projects out of the side opening of the plunger and out the overlying longitudinal slot of the catheter. The catheter is placed in a hollow vessel, e.g. Artery, introduced into the body until the unfolded stent is in the area of the site to be treated. Then, the pressure is applied to the pressure medium in the catheter, whereby the piston is pushed forward.

In another case, the pressurization causes the plunger to remain in position while the catheter is withdrawn. Thus, as the plunger is driven out, the catheter must be retracted to the same extent to strike the site in the artery to be treated with the expanding stent. As the plunger moves relative to the catheter, the plunger, including the guidewire, slips distally, with the guidewire also moving distally in the elongated slot. So the stent is then released for expansion. This is the case when the distal end of the catheter no longer covers the bed of the stent. Slipping out of the piston is prevented by the wire during Stepping out of the lateral hole of the piston, a continued slipping of the piston blocked (Fig.18).

Such a securing effect, which prevents leakage of the piston from the catheter, can also be achieved by a side hole in the catheter itself, as described in Fig.9 and Fig.10. When the piston has slid forward, the side hole opens and the pressure in the system is released.

The system described in Figure 17 (without side hole in the catheter, through which the pressure can escape) can also be used as a closed system (Fig.18), ie, that the pressure medium does not have to be introduced by the user, but before use in the Catheter is installed. The doctor then needs to pressurize the system only with the pressure, the pressure syringe or the pressure vessel is already firmly connected to the catheter. Thus, connections between hoses to be made by the doctor are eliminated. Amongst other things, the advantage of the closed system for the pressure medium is that it avoids the accidental ingress of air into the system.

A likewise closed for the hydraulic pressure transmission embodiment is, as described in Figure 19, a catheter-stent system in which the hydraulic fluid is not introduced by the doctor, but was previously filled by the producer. The catheter-stent assembly thus produced is not introduced via a guide wire, but through the sheath of a catheter lock, which is provided at the proximal end, ie outside the patient, with a hemostatic valve.

First, therefore, the assembly is introduced through the previously introduced lock. Then, the pump is pressurized, whereby the stent is expelled from the catheter by pressure on the piston. Previously, the sluice was withdrawn, at least the length of the unfolded stent. As the stent is driven out, the catheter is withdrawn to assure accurate placement of the deploying stent.

The advantage of the closed hydraulic system is that the system is air or gas free to apply to the attending physician, and thus the stent release can be better controlled.

The piston and stent are best advanced if the system does not contain air but is filled only with fluid. If air has previously entered the system, it must be vented. A double-lumen catheter-stent assembly is shown in FIGS. 20 and 21. The catheter has a thinner and a thicker lumen. Before the system is introduced into the hollow organ to be treated and also before the guidewire is introduced, the system is vented, via the thin-lumen portion of the system. The thin-lumen portion later also serves to pressurize. The advantage of the thin-lumen tube here is that it is in principle more rigid, the wall tension is lower here than in a wide tube (Figure 22). For a rigid pipe, the pressure can therefore be better dosed, because the walls expand less with increased pressure. For venting, the system is purged to remove residual air. For this purpose, the pressure medium initially passes from the proximal outside of the catheter via a syringe through the thin-lumen tube into the main pressure chamber. The seals are now where no guide wire is inserted, _open> so that the air from the pressure chamber via the non-closing valve can escape, after proximally. The rinse fluid exits the stent carrier system from its tip. Upon exiting the irrigation fluid, the tip of the system is closed, eg, with a finger, until the fluid has exited the proximal end of the catheter via the second valve located more proximally. Thereafter, the stopcock is closed at the proximal end of the thin-lumen catheter opening. The guidewire is inserted over the tip of the stent-carrier system and passed through the catheter. Only then is the vented system introduced into the hollow organ to be treated. The pressurization for propulsion of the stent carrier for stent delivery is via the thin lumen of the system, wherein the pressure chamber increases its volume and the stent carrier is conveyed out of the surrounding catheter. The volume of the syringe (pump) for pressurization is at least as large as that of the pressure chamber in the state after release of the stent. The piston area of the stent carrier has two seals for better sealing. The smaller is located between the guide wire and the inner wall of the stent carrier, the second consists of a disc of elastic Kunsttoff eg silicone and seals the gap between the guide wire and the catheter. When bending the catheter this is oval in cross-section, the disc-shaped seal will adapt to this circumstance.

In the dual lumen catheter-stent system, the small lumen used for pressurization is relatively thick-walled compared to the guidewire lumen. The small lumen is therefore surrounded by a large amount of wall mass (FIG. 22). This guarantees that the pressure on the wall of the small lumen can not expand and thus the release of the stent from the carrier system is well controlled. A second variant is that instead of a double-lumen catheter, there is only one lumen. A hollow wire (tube) is introduced into this lumen via a valve, through which air is forced out when flushing with liquid (Fig. 23). This system can be introduced into the body via a guide wire. The guidewire is passed coaxially through the system via the opening of the stent carrier and then passes outwardly proximally via the hemostatic valve (Figure 24). However, before the catheter is inserted, the system is flushed through a thin tube that extends into the channel of the stent carrier (Fig. 23), whereby irrigation fluid will run in through the tube. This happens z. B. by a small syringe. The proximal end is raised, allowing the air in the system to escape from the distal tip of the stent carrier. Then the tube is withdrawn slowly through the valve and also with injection of the liquid. The guide wire can now be introduced into the catheter (Fig.24), which has become completely free of air. In this case, liquid enters the pump via the pump attachment. When the guidewire has passed out of the hemostatic valve, the hydraulic pump, which is also vented, is attached and expelled by pressure of the stent carriers, with the catheter being withdrawn accordingly.

When the system is pressurized, there is initially a jerky advance of the piston. This is avoided by a special piston shape, e.g. by a bellows (Figures 25 and 26), which the stent discharge can be better dosed. The bellows consists of a hose with transverse to the longitudinal axis extending folds, which serves as a piston. This tube is wrapped by the catheter.

The folded tube has transverse folds which are pushed together in the unexpanded state, as a result of which the tube is shortened. If liquid pressure is introduced outside the patient at the end of the tube, the tube expands in the longitudinal direction when the other, opposite opening is closed by a piston. The plug-shaped piston will then drive the stent out. The advantage of this system is that the collapsed and compressed hose is connected directly to the hose carrying the pressure medium. As a result, the liquid is trapped in a closed space, so the liquid can not come out between the piston and cylinder or in the body. This would be advantageous when using a so-called closed system. Furthermore, it is possible to dispense with seals between the piston and the catheter inner wall as well as between the piston and the guide wire.

Also, the product could be free of air from the outset, so a vent as described above, would not be necessary. In another embodiment (Figure 27), the guidewire is inserted distally into the system through the stent or, as shown in Figure 18, the stent carrier, and then slides into the centrally located opening of the bellows-connected pusher of the stent Piston or a stent carrier. The wire then continues to pass through an obliquely outwardly extending channel in the slide and from there past the bellows, between the bellows surface and the inner wall of the catheter to the outside. At the end of the catheter is a haemostatic valve. The pressurization is carried out as previously described. An advantage of this embodiment is that the guidewire extends within the catheter.

The catheter-stent device is longitudinally flexible in order to be able to insert the catheter through tortuous vessels or via vessel outlets. When pressurized, however, the inner diameter of the catheter does not change. This can be achieved by reinforcements in the catheter wall, e.g. be achieved in the form of wire rings or -gef lecht. Between the wall reinforcements there is stretchable plastic to ensure flexibility.

In another embodiment (Figs. 27 and 28), the stent-bearing system remains in position during stent release as only the sheath surrounding the stent system moves and the stent carrier is held by a support tube. The system is also particularly advantageous for the exact positioning of the stent, since when retracting the sheath surrounding the stent this does not have to be moved through the hemostatic valve of the catheter lock. Thus, the sheath surrounding the stent does not contact the hemostatic valve of the introducer sheath, which reduces the frictional force and allows the end of the sheath to slide on the stabilization catheter within the vessel.

An advantage of this embodiment is further that it can be used e.g. in case of possible misplacement it is possible to manually push the catheter surrounding the stent back over the stent which has not yet fully expanded from the outside, the holding tube being held in position outside the patient and the pusher catheter being pushed forward into the patient ; The sheath catheter is thus pushed over the not yet fully expanded stent.

The system described in FIGS. 27 and 28 could also be designed such that the holding tube and the stabilization catheter are made of one part, the distal part of the holding tube located in the piston being made smaller in its diameter. In another development, the catheter-stent system is also ventable, but has only a single lumen rather than a double, and therefore may be very small caliber. In this embodiment, the carrier system supporting the stent remains in position during stent release since only the sheath surrounding the stent system moves (Figs. 30 and 31).

Prior to insertion of the guidewire into the catheter system, the lumen of the catheter is flushed by introducing liquid through the stopcock located at the proximal end. Air is removed from the catheter system. The irrigation fluid can flow out at the distal end of the catheter because the seal located here does not close tightly unless a guidewire is inserted; the seal located at the proximal end of the catheter prevents the flushing fluid from draining proximally.

Then, a guidewire is inserted into the system and the catheter system is inserted over the guidewire into the body. The seal valve at the distal end of the catheter closes completely when inserted guidewire and is additionally secured by two metal rings. Since this sealing valve is distal to the pressure chamber, the inner lumen of the catheter is operatively included in the pressure chamber and is pressurized.

The system has three successive sheaths which abut one another: a flexible sheath surrounding the stent and an annular sheath surrounding the sheath, a sheath surrounding the catheter sheath, and an annular, slit removable sheath proximate thereto. After placement of the catheter system to the site to be treated, the annular sheath is removed manually; As long as this annular sheath is on the system, it prevents premature accidental slipping back of the sheath surrounding the catheter sheath as well as the sheath surrounding the stent.

Then, even before the pressurization occurs, the sheath surrounding the catheter shaft is retracted proximally.

The sheath surrounding the catheter sheath may be omitted if the sheath surrounding the stent is mechanically held in place by the pressure of the compressed stent during the insertion process so that it can not slide back before the pressurization occurs.

The pressure medium p introduced via the tap located at the proximal catheter end runs distally in the inner lumen of the catheter system, namely between the guide wire and the catheter inner wall through the side opening into the pressure chamber. There causes the pressure medium, because all seals are closed at the proximal and distal end of the catheter, that surrounding the stent shell by the proximal end of the shell attached annular, the catheter shaft enclosing piston is pushed back proximally.

After stent release, the entire catheter system in this state can be removed from the

Body of the patient are removed, with the guide wire remains in position to perform more endovascular treatments can.

Advantage of this design is that it can be vented, but only one lumen has instead of a double. So the outer diameter can be kept very small. The stent can be positioned very precisely because not the main catheter, but only the surrounding sheath moves. In this embodiment, the attack surface of the pressure (p), so the piston surface, annular and relatively large, in contrast to pistons, the inside of the

Catheters are lying; As a result, a favorable power transmission is achieved.

The system shown in FIG. 32 also works without a valve when a so-called closed system is used, as described in FIG. 17 and FIG. In the embodiment described in Fig. 32, the proximal portion of the catheter has a smaller diameter than the stent carrier. This ensures that the pressure medium can act on a larger surface compared to the previously described embodiments. As a result, relatively lower pressure in the hydraulic system is necessary. In addition, this embodiment includes a device for flushing and venting the stent bed. About a channel leading from the outside to the stent bed a rinsing liquid can be introduced through a syringe with cannula. The flushing of the stent bed removes interfering air from the stent bed, which may be in the space between the catheter sheath and stent carrier and between the stent struts. Removal of air improves the stent's ability to be placed, as air present in the stent bed would cause the stent or portions of the stent to pop out of the stent bed in an uncontrolled manner. Furthermore, the removal of air from the stent bed prevents the escape of air into the artery. The leakage of air into the artery would result in an air embolism, especially in the treatment of supra-aortic arteries, e.g. The carotid artery is significant because air embolisms in the brain have serious effects on the patient. The flushing of the stent bed also causes.daß the individual components that move against each other, are lubricated and the movement is facilitated and controllable.

Fig. 33 also shows a hydraulic stent delivery system in which the sheath which retains the stent in a small radius slides back. Unlike the previous two illustrations, this system is designed as a "fast exchange system" with the guidewire pushed in over the distal tip and then laterally behind the piston system, ie proximally, out of the catheter. The side hole for the guide wire is set so far proximally that the piston in its maximum zurückgeglittenen position, the stent bed for the folded stent completely free. By a channel in the catheter, the pressure channel and the pressure chamber is flushed before beginning the procedure on the patient to flush out disturbing air out. There is a connection between the channel used for the pressurization, the pressure chamber and the channel which receives the guidewire. The fluid passes from the proximal direction through the catheter, to the pressure chamber and from there via an oblique channel into the channel, which receives the guide wire. The fluid may drain distally over the seal valve, as this valve is open as long as no guidewire has been inserted; the second sealing valve, which is placed in the immediate vicinity of the mouth of the inclined channel is closed even if no guide wire has been introduced. The rinsing fluid thus drains only via the distal opening of the catheter-stent system. To treat the patient, the system is then placed over the guidewire at the site in the body to be treated, now the guidewire closes the forward seal; the rear, ie proximal seal is also closed by the wire. Now the pressurization can begin, the liquid pushes the annular piston proximally, releasing the stent; the pressure does not escape through the sealing valves.

In the embodiment shown in Fig. 34, sealing rings are not needed in the pressure-conducting or guidewire-receiving channel because the guidewire-receiving channel is not in communication with the pressurized system. Also in this embodiment, the pressurization causes, as described in Fig.33, that the catheter sheath holding the stent slips proximally. Before that, the system is vented. For this, the supplying catheter is double-lumened, that is to say provided with two channels which open into the pressure chamber. To vent the system, liquid is introduced via the one catheter lumen and the air is forced out via the second catheter lumen. For pressurization, one of the two catheter lumens is then closed proximally, while the pressure is applied via the other lumen in order to drive the annular piston back. The guidewire extends obliquely from the catheter tip through the stent carrier, as in the system described in Fig. 33, to exit it through a side hole.

The embodiment shown in FIG. 35 is a further development of the catheter-stent system depicted in FIG. The feeding catheter is only provided with a lumen. In This lumen is another thin catheter or tube that extends out of the catheter lumen via a seal valve at the proximal end of the system. The catheter lumen is provided with the pressurizing pump or syringe through a side faucet on the outside catheter end. Before inserting the catheter-stent system into the patient, the pressurization system is vented by the flushing liquid is introduced via the side valve via the catheter lumen into the pressure chamber. From there, the air or liquid to be escaped flows back out through the second, coaxially located tube extending into the pressure chamber. If the user observes that fluid escapes outside via the coaxial catheter, it can be concluded that the system is vented. The coaxial tube can then either be withdrawn to improve or even leave the flexibility of the system. When the tube is withdrawn entirely, the seal valve completely closes the proximal end of the catheter to prevent the pressure from escaping. As in the system described in Fig. 34, the channel passing obliquely through the stent carrier has no connection to the pressure system, sealing valves within the channels are therefore unnecessary.

The embodiments described in Figures 32, 33, 34 and 35 also have the advantage that the stent bed can be rinsed. This facilitates stent release since any air present may be removed from the stent bed and the stent bed made slippery. For this purpose, the stent bed is provided with an outwardly leading, punctiform channel, introduced via the rinsing liquid. The rinsing fluid then exits from the existing between the stent and Stentbettbegrenzung small spaces again.

The embodiment described in Fig. 36 shows another technique for rinsing the stent bed.

The catheter has, as described in Fig. 35, a large lumen containing a coaxial catheter. This extends beyond the pressure chamber and into the stent bed. Pressurizing chambers and flushing liquid conducting channels are separated by a sealing valve in the distal portion of the main lumen of the catheter, which seals the inserted coaxial catheter from the main lumen. First, the coaxial catheter is inserted distally so far that the stent bed is rinsed. Then the stent bed is rinsed via the coaxial catheter. Then it is retracted so far through the valve that the distal sealing valve closes as shown in FIG. The distal opening of the coaxial catheter is then in the pressure chamber. The further procedure of venting and purging the pressure chamber is then as described in Fig.35.

legends

FIG. 1:

Fig. 1 shows an elongate spiral stent (2 ') in the catheter (1) prior to placement in a hollow organ (3) to be treated, e.g. an artery. The spiral stent almost fills the inner lumen of the catheter in the patient with its transverse diameter. By pressure p by means of a pressure medium, the spiral stent (2 ') is conveyed through the catheter (1) from the proximal (1') to the distal opening (1 "), where the pressure medium flowing past the stent wire also serves as a lubricant; thus, the friction between the elongated elastic wire and the inner wall of the catheter is reduced, and the pressure gradient between the pressure medium proximal to the spiral stent and the distal portion in the catheter advances the spiral stent in the direction of the patient's opening (1 ").

FIG. 2:

FIG. 2 shows the partial implantation of the spiral stent (2 ^! ) In the vessel (3) to be treated.

A part of the spiral stent is still in the stretched state in the application catheter

(1), this portion will still be transported out of the catheter by the pressure medium p. The pressure medium used is a fluid with good body compatibility, e.g. physiological saline, or even a high viscosity fluid, e.g. one

X-ray contrast agent.

FIG. 3:

In this embodiment, the distal end of a catheter in the stretched spiral stent (2 ¹ ) with a piston (4) is provided, which is adapted to the diameter of the lumen of the patient catheter (1). This provides a better seal between the pressure medium and the inner wall of the catheter as the pressure medium conveys the stent through the catheter. Through the piston (4) the spiral stent is pulled through the catheter; Since the stent is thus not compressed, less friction arises.

FIG. 4:

Fig. 4 shows the spiral stent (2 ') with piston (4) in partially implanted state. The piston has now become smaller in size, since he after reaching the body vessel (3) by the Body juices or by a liquid introduced via the catheter is built and decreases in size, so melts.

FIG. 5:

5 shows a longitudinally stretched in the catheter (1) spiral stent (2 ') with a plurality of pistons (4).

The distal piston (4 ') may have a larger diameter than the downstream piston, but in any case is so large that it fills the lumen of the catheter.

FIG. 6:

The pressure medium, which is introduced from the proximal direction, flows past the proximal piston (4), whereby the distal (4 ^J ) is expelled from the stent. Then the next one follows

Piston, which carries the remaining portion from the catheter. This will ensure that the print medium also acts on the end of the stent and conveys it out.

In a case where the portions between the pistons are completely filled with liquid, it is not necessary for the pistons to allow a discharge because a liquid is not compressible and thus the pressure is passed.

The distal piston (4 ^J ) is mounted on the wire / spiral stent so that it contacts the

Vascular wall of the vessel to be treated (3) applies to keep flow turbulence as low as possible.

FIG. 7:

The stretched spiral stent (2 ') is carried by a carrier (5) (carrier) through the catheter (1). The carrier consists of a piston (4 ") on which a rod with a Y-shaped end is mounted perpendicularly in the direction of the distal catheter opening (1"). The stretched spiral stent is provided with a ball head (2 ") which is engaged in the Y-shaped extension of the support rod 5. The wearer carrying the stent is conveyed through the catheter by the pressure medium p.

FIG. 8:

Fig. 8 shows the carrier (5) with partially implanted spiral stent (2 '). The spiral stent has now released itself with its head out of the Y-shaped forceps and is driven out by the piston (4 ") on.

FIG. 9: Fig. 9 shows a longitudinal section through the catheter-piston-stent system. A plunger (4) is placed in the catheter (1) in the patient as in a cylinder and is pushed through the pressure medium p from the proximal direction towards the catheter distal opening (1 ") in the patient The piston and stent and catheter are flexible so that the system can also be used in tortuous arteries It is intended to prevent the piston from being transported out of the catheter into the patient vessel to be treated after the stent has been pushed out of the catheter into the hollow organ, in order to slow down the propulsion of the piston.

FIG. 10: The pressure medium conveys the stent (2) distally in the catheter (1) until the piston has passed the side hole (6) located in the catheter (1). As a result, the pressure medium can escape, whereby a further advance of the piston is omitted and the piston can not leave the catheter.

FIG. 11:

The stent (2) is loaded in the distal end of the patient's catheter (1) behind the catheter opening in its small, unexpanded state. The catheter here is of smaller lumen, at the proximal end of the stent chamber is a step which prevents the plunger (4) from slipping out of the catheter after the stent has been delivered from its chamber. The stent is not conveyed directly from the piston in this case, but by a piston on the upstream slide (4 "'), which has at its distal end the diameter of the stent chamber and thus smaller in diameter than the rear part of the piston in the piston and slide there is a bore (7 ^! ) for receiving the guidewire (7) The bore is provided with a sealing ring (8) which seals the guidewire against the pistons A further sealing ring is found on the surface of the piston. to prevent leakage of pressure medium between the plunger and the inner surface of the catheter, the proximal end of the plunger (4) and the distal end of the pusher (4 '") are funnel-shaped to facilitate probing with the guidewire.

FIG. 12:

The stent (2) has been pushed out here by the piston. The slide portion (4 ") of the piston (4) is as far as possible distally, whereby a further advancement of the piston is prevented by the fact that the rear portion of the piston with his shoulder, the one has larger diameter, can not enter the front, reduced in diameter portion of the catheter (1).

FIG. 13: A small diameter stent (2) is loaded in the catheter (1). The inner diameter (lumen) of this stent is equal to the outer diameter of the guidewire (7). The tip of the catheter (1 ') is distally conical and covers the step formation between guidewire and stent. The catheter is elastically movable in the area of its tip (hatched part). The stent (2) is transported distally by the pressure medium p within the catheter.

FIG. 14: When the stent (2) emerges, the catheter tip (1 ') consisting of elastic material expands.

FIG. 15:

Longitudinal section through the catheter / piston / stent system.

A self-expanding stent (2) is loaded in its small diameter in the catheter (1). The proximal end of such a stent (2) serves as a piston, wherein over a certain distance the spaces between the stent struts and the space between stent and guidewire (7) are dissipated by a rapidly dissolving substance in the blood, e.g. a polymer (9) are sealed. During the exit of the stent from the distal

Catheter opening (1 ") becomes the polymer from the pressure medium, e.g., gas or a particular one

Liquid, dissolved, causing the stent unfolds.

In another embodiment, it is also possible that the printing medium, e.g. a gas or certain liquids, this polymer does not dissolve. In this case, the polymer is not released until after the stent has exited the vascular system by the body fluids, e.g. Blood or intestinal juices, dissolved, in which case the stent reaches its useful size.

FIG. 16:

Self-expanding implanted stent according to Fig. 15, on the stent struts (2 ") still

Remains of the polymer (9) adhere.

FIG. 17:

Longitudinal section through a catheter / piston / stent system according to the Rapid Exchange System

(fast-introducing system, also called monorail).

The angiography guide wire (7) does not run centrally through the entire catheter here

(1), but only in the distal portion of the catheter. The guidewire is at the top of the

Carrier system (11), which the stent bed (11 ¹ ) and a downstream Kolbenantei! (11 "), first centrally inserted and then laterally out of the piston portion through a side hole (11 '") executed, and then runs next to the catheter (1) via the catheter introducer to the outside. Opposite the lateral opening in the piston (11 "') provided for the guidewire (7), there is a longitudinal slot (10) in the catheter which allows the piston to slide forward in the catheter while the guidewire exits laterally Sealing rings (8) sealed The piston transporting the stent is advanced through the pressure medium p.

FIG. 18:

Released stent (2) from FIG. 17.

The piston was advanced completely distally by the pressure medium p in the direction of the catheter distal end (1 ") until the stent bed (11 ') now exposed in the hollow organ (3) releases the stent for deployment the guide wire (J) at the distal edge of the longitudinal slit in the catheter (10 ') is turned off. in this state, the carrier system (11) is so far moved out of the catheter, that the stent bed (11 ^J) is located outside the catheter (1 ) is located in the hollow organ (3) and the stent (2) can expand to its useful size, but the posterior part of the carrier (11 ") acting as a piston remains in the catheter. The catheter / piston system can be retracted in its entirety over the guidewire after release of the stent, leaving the guidewire (7) still in the deployed stent for eventual further therapeutic action.

Figure 19: closed system for the hydraulic pressure transmission. The hydraulic fluid is already in the system. The catheter-stent assembly is inserted through the sheath of a catheter sheath (12) having a hemostatic valve (8 ') at the proximal end. Pressure is applied by the pump (13), the stent (2) being expelled from the catheter (1) by pressure on the piston (4). Previously, the lock (12) was retracted by at least the length of the unfolded stent. As the stent is driven out, the catheter is withdrawn to assure accurate placement of the deploying stent. To do this, place the platform (18) firmly on the patient and push the catheter (1) into the platform sheath pushing the plunger of the platform (18 ") into the catheter to release the stent. ) has the same diameter as the piston on the stent carrier (4 "). Figure 20: Double-lumen catheter-stent assembly (15), with thin lumen (15 ¹ ) and thick lumen (15 ") portion, before the guidewire has been inserted, is vented through the thin lumen portion (15 ') of the system Pressure medium via a syringe (pump) (13) through the thin-lumen tube in the main pressure chamber (16) is passed and on the still open seals (8, 8 ') can escape Guide wire is inserted over the top of the stent carrier system (5).

Fig. 21: Process of stent release with the system described in Fig. 20, after insertion of the guidewire (7) into the large lumen (15 "). The system is then delivered to the target site and over the thin lumen portion (15 ') of the system The stent carrier (5) has two seals (8) at its distal part The first seal seals the gap between the guidewire and the channel in the stent carrier The second seal seals the outer space between the stent carrier and outer catheter (1) The hemostatic valve at the distal end of the catheter seals the large lumen (15 ") with the wire (7) inserted.

Fig. 22 shows the cross-section of the catheter system (15) which is described in Figs. 20 and 21. The small lumen (15 ') for pressurization is thick-walled compared to the guidewire lumen (15 "), that is, surrounded by a large amount of wall mass.

FIG. 23: Catheter stent system with ventilation system for filling the pressure medium. Before the catheter (1) is introduced into the hollow organ (3) to be treated, the system is flushed through a thin tube (7 ") which extends into the channel of the stent carrier (5). Once the irrigation fluid has emerged from the tip of the stent carrier, the entire system is free of air After withdrawing the hollow wire (7 ") via the valve (8 '), the guidewire (7) is inserted into the now completely air-free catheter (Figure 24).

FIG. 24: Catheter-stent system with ventilation system from FIG. 23. After the guidewire (7) leaves the hemostatic valve (8 ¹ ), the likewise vented hydraulic pump (13) is used for the purpose of pressurizing and expelling the stent carrier from the catheter , whereby the catheter must be withdrawn accordingly. Fig. 25: Representation of another closed hydraulic system, in the stent (2) carrying the catheter (1), another catheter is inserted coaxially, the distal end of which is compressed by transverse folds (19). At the end of this catheter (19) whose opening is closed by the hydraulic piston (4). Pressing the inner catheter proximally extends the collapsed end of the inner catheter and thus advances the plunger to deliver the stent (2) out of the main catheter (1). It is a completely closed system. The hydraulic fluid can not get into the blood between the piston and the inner wall of the catheter.

FIG. 26 shows the distal portion of the bellows-type inner catheter (19) which is stretched by pressurization. The stent (2) has emerged from the catheter (1) and has expanded in the hollow organ (3).

Figure 27 shows the bellows system shown in Figures 25 and 26 in which the guidewire (7) extends outwardly between the bellows inner catheter (19) and the surrounding catheter (1). In the distal portion of the system, the guidewire passes through the spool (4 "') and stent (2) upstream of and connected to the piston (4), or alternatively through one not shown in this figure, but, for example, in FIG illustrated stent carrier (11).

FIG. 28 shows an embodiment in which the system (5) carrying the stent (2) remains in its position during the release of the stent, since only the sheath (1) surrounding the stent system moves. For exact positioning of the stent (2) at the site in the artery to be treated, the stent carrier (5) is held from outside, ie outside the patient, by a holder (20) extending coaxially through the sheath catheter (1). This support consists of a thin tube (20), the proximal end of which is external to the patient, e.g. on the body of the patient, is firmly positioned and the distal end is firmly connected to the stent carrier (5). Upon retraction of the catheter (sheath) (1) surrounding the stent carrier, the stent carrier remains constantly at the desired location and the sheath moves proximally with respect to the stent carrier, releasing the stent (2).

The backward movement of the sheath (1) is caused by the pressure medium being introduced into the pressure chamber (16) via the described tube (20). Here, the volume of the pressure chamber is increased and the piston (4) is pushed back together with the catheter surrounding the stent carrier (1). Piston (4) and enveloping catheter (1) are firmly connected. Stent carrier (5) and piston (4) are removed thus from each other, with the piston moving with the sheath (1); the stent carrier (5) itself is held by the tube (20) in its position. The holding tube (20) extends through an opening in the piston (4); To avoid a pressure drop, there is an additional seal (8). Another seal (8) is located between the proximal end of the stent carrier (5) and the surrounding sheath (1). The guide wire (7) extends in accordance with the previously described rapid exchange system, laterally out of the stent carrier (5). In order to assist in advancing the catheter stent cutlery into the patient, the inner holding tube (20), this is surrounded by a stabilization tube (21). This stabilization tube extends into the proximal piston portion; However, there is provided a gap on which upon enlargement of the pressure chamber (16), the inner portion of the piston (4) via the stabilization catheter (21) slides.

The pressure chamber must be able to increase in length at least as far as it corresponds at least to the length of the stent bed (11 ') which accommodates the stent (2) which has not yet expanded.

The piston part (4) encloses the stabilization catheter (21) at its proximal end; Thus, the coaxial displacement between stabilization catheter and piston (4) is guaranteed.

The stabilization catheter is further surrounded by a pusher catheter (22). When inserting the catheter stent cutlery, the stent carrier-piston system is advanced over the guidewire (7) with the pusher catheter. Since the pusher catheter then abuts against the stent carrier-piston system, it is guaranteed that the catheter (1) surrounding the stent is not pushed back by the pressure of the pusher catheter from the proximal end and thus the stent is not prematurely released.

Figure 29 shows the system described in Figure 28 at a time when the stent (2) was partially released.

Prior to release of the stent (2), the pusher catheter (22) was first retracted at least the length of the stent bed (11 ') accommodating the stent (2). After positioning the stent transporting system in the artery site to be treated, the holding tube (20) is held in position outside the patient. Then, the pressurization takes place, the pressure chamber (16) increases and the piston portion (4) with the attached sheath catheter (1) slides proximally and releases the stent (2). An unwanted displacement of the stent carrier (5) is avoided because it is held by the holding tube (20) from the outside in position. After the stent is placed, the system is pulled by pulling the holding tube over the guide wire and through a catheter lock.

FIG. 30: Single-lumen, ventilatable catheter-stent system in which the carrier system (5) carrying the stent (2) remains in position during the stent release, since only the sheath (23) surrounding the catheter shaft of the stent system moves. Before the guidewire is inserted into the catheter system, the lumen of the catheter (1) is flushed via the proximal end cock (17) to purge air from the catheter system. The seal (8) located at the proximal end of the catheter (T) prevents the flushing liquid from flowing out proximally, while the flushing liquid can flow out at the distal end of the catheter (1 "), since the seal (8") located distally there to the pressure chamber (16) leading side opening (24) is located, not tightly closes as long as no guide wire is inserted. To introduce the catheter system into the body, a guidewire (7) is inserted into the catheter system. The sealing valve (8 ") at the distal end of the catheter includes completely sealed with inserted guide wire (7). It is additionally secured by two metal rings (8 ^W). Since this sealing valve is located distally of the pressure chamber (16), the inner lumen of the catheter is operatively with included in the pressure chamber and is pressurized.

After placement of the catheter system to the site to be treated, a sheath-like ring (25) located at the catheter proximal end (T) surrounding the main catheter (1) is removed; this ring has a slot that makes the component so flexible that it can be manually removed from the catheter system. As long as this ring is on the system, it prevents the premature accidental slipping back of the sheath (23) surrounding the catheter sheath as well as the sheath (26) surrounding the stent as the shells abut each other.

Then, even before the pressurization occurs, the sheath (23) surrounding the catheter sheath is retracted proximally.

The pressure medium p introduced via the cock (17) located at the proximal catheter end (T) runs distally in the inner lumen of the catheter system, namely between guide wire (7) and catheter inner wall (1) through the side opening (24) into the pressure chamber (16 ). There, the pressure medium causes, because all seals are closed at the proximal and distal end of the catheter that the stent surrounding the sheath (26) by the attached to the proximal end of the shell annular, the catheter shaft (1) enclosing the piston (26 ') is pushed back proximally , During stent release, the carrier catheter does not move, but only the sheath (26) surrounding the stent when the annular piston surface (26 ') attached to it is pushed back by the applied pressure (p) on the outside of the catheter (1).

FIG. 31: Single-lumen, ventilatable catheter-stent system in which the carrier system (5) carrying the stent (2) remains in its position during the stent release, since only the sheath (23) surrounding the catheter shaft of the stent system moves. The annular sheath located at the proximal end of the catheter (1 ^! ) Has been removed. The sheath (26) surrounding the stent has slid back proximally, as well as the sheath (23) proximal thereto surrounding the catheter sheath. The stent (2) has reached its desired expansion diameter at the site to be treated. The entire catheter system can be removed from the patient's body in this condition with the guidewire (7) remaining in position for further endovascular treatment.

Fig. 32: Single lumen, ventilatable catheter-stent system in which the piston-shaped end (26 ') of the sheath (26) surrounding the stent slides back on the catheter shaft (1) when pressure (p) is applied. Since the catheter shaft (1) has a smaller diameter than the stent carrier (5), this piston (26 ') is particularly large. The system is vented before the guidewire (7) is inserted. The seal (8 ") at the catheter distal end does not close unless a guide wire is inserted, the seal (8) always closes tightly and irrigation fluid introduced via the stopcock (17) removes air from the system and leaves it through the open one Seal (8 ") at the distal end of the catheter. After insertion of the guidewire (7), the system is pressure tight, the seal (8 ") is then closed, pressure (p) acted upon by the cock (17) is transmitted through the channel (16 ') leading into the pressure chamber to the piston (26'). The stent bed (11 ') is rinsed by introducing flushing liquid into the channel (27) with a cannula (27').

Fig. 33: Rapid exchange system in which the guidewire leaves the catheter through a side hole. The stent carrier (5) is provided with two channels, whereby a connection (28) is formed between the pressure-carrying channel of the catheter (1) and the guide wire (7) receiving channel.

The distal valve (8 ") of the catheter is open as long as no guidewire has been inserted, and another sealing valve (8) is located in the guidewire-receiving channel just proximal to the entrance of the thin irrigation channel. The thin connection channel (28) has such a small Diameter that the guide wire (7) can not accidentally get into this, but only in the designated channel with the side opening (6 ¹ ).

Fig. 34: Rapid exchange system with double-lumen catheter (1), which can be vented, wherein pressure or rinsing liquid leading channels (29), which reach to the pressure chamber (16), and the guidewire (7) receiving channel are separated from each other.

Fig. 35: Rapid exchange system with single lumen catheter (1), which can be vented. Pressure and rinsing fluid leading channels and the guidewire (7) receiving channel are separated. Pressure and irrigation fluid are introduced into the system through the main lumen of the catheter (1) or through a coaxially inserted tube (30); Rinse liquid is drained accordingly.

FIG. 36: Ventable rapid-exchange system, in which the stent bed (11 ¹ ) is not rinsed from the outside, but from the main lumen of the catheter (1) into which a coaxial catheter (30) is inserted. Pressure and rinsing fluid leading channels and the guidewire (7) receiving channel are separated. Rinsing fluid is introduced into the system via a coaxial catheter (30). The coaxial catheter is initially fully advanced distally. The stent bed (11 ') and stent (2) are rinsed and vented. Then, the coaxial catheter (30) is retracted beyond the gasket (8). The seal valve (8) always closes tightly, even when the coaxial catheter (30) is removed. Rinsing fluid introduced via the coaxial catheter (30) then rinses and then vents the pressure chamber (16), the rinsing fluid being discharged via the cock (17) located on the catheter (1). Pressurization then takes place via the main catheter, wherein the coaxial catheter (30) can also be completely removed.

Fig. 37: Ventable Rapid-exchange system, as shown in Fig. 36, here in the state after venting and rinsing of the stent bed (11 '): the coaxial tube (30) was pulled back beyond the sealing sealing valve (8), so that the proximal opening of the coaxial catheter (30) is in the pressure chamber (16). The sealing valve (8) is closed so that the pressure medium to be filled can not pass in the direction of the stent bed (11 '). The pressurization (p) can take place via the tap of the catheter (17) or the coaxial tube (30). Number key to the drawings

1 catheter

V Proximal portion of the catheter

1 "distal opening of the catheter

2 stents

2 'spiral stent

2 "slotted tube stent

Ball head of the spiral stent

3 hollow organ

4 pistons

4 'distal piston

4 "piston of the carrier (carriers)

4 ' ^« slider of the piston

5 carriers

6 side hole in the catheter 1

6 'side opening for guidewire 7

7 guidewire

7 ^! Bore for receiving the guide wire

7 "hollow wire

8 seal

8 'haemostatic valve

8 "seal valve at the distal end of the catheter

8 '"the seal valve 8" locking rings

9 polymer

10 longitudinal slot in the catheter 1

11 carrier system

11 'stent bed

11 "piston portion of the carrier system

11 '"side hole in the piston portion of the carrier system

12 introducer sheath

13 pump for pressurizing

14 hypodermic syringe for flushing the system

14 'attachment for syringe or pump

15 double-lumen catheter system

15 'thin (small) lumen

15 "thick (large) lumen Pressure chamber 'leading to the pressure chamber channel

stopcock

Platform 'Deckhülle' Piston of the platform bellow-type pleated catheter

Holding tube for stent carrier

Stabilization tube

Pusher catheter surrounding the catheter sheath into the pressure chamber leading side opening in the catheter 1 removable sheath-like ring surrounding the stent envelope 'annular piston of 26 in the stent bed 5 leading flushing channel' cannula for flushing the stent bed. 5

connecting channel

double lumen

Koaxialkatheter

Claims

claims:

Catheter-stent device for the application and implantation of a stent for the treatment of body vessels and hollow organs, characterized in that the stent by a pressure difference between the proximal, located outside the body end and the distal end in the body, in relation to surrounding sheath catheter is moved, this being effected by a pressure medium, with the result that the stent is placed purposefully.

2. Catheter-stent device according to claim 1, characterized in that the stent is pushed out by pistons which are adapted to the lumen of the catheter.

3. A catheter stent device according to claim 1, which serves to release an elongated thread-like elastic wire filament (spiral stent, meander stent), which is conveyed by the pressure difference like a piston through the catheter into the tubular organ, wherein the filament in the Forms organ due to its elasticity to a tubular structure.

The catheter stent device of claim 1, which is for releasing a tubular self-expanding stent, the pressure of the pressure medium acting on the unexpanded stent and forcing it out of the surrounding catheter in a piston-like manner.

5. The catheter stent device of claim 1, wherein the pressure difference in the catheter acts directly on one end of the stent to be released, which is piston-shaped.

The catheter-stent device of claim 1, wherein the pressure medium pushes against one or more stems in a series of piston-shaped extensions of the stent and drives them stepwise out of the surrounding catheter, wherein only the front of the stent mounted piston the lumen in the catheter completely fills, while the subsequent pistons allow a slight flow past the pressure medium, so that after the emergence of the foremost piston, the subsequent stent parts are pushed out by the piston arranged further back.

7. The catheter stent system according Anspruchi, wherein the piston-shaped extensions of the stent are made of material which dissolves in the body fluids.

The catheter-stent system of claim 1, wherein the piston is flexible.

A catheter-stent system according to claim 1, wherein the proximal end of the piston is widened in diameter and the corresponding support catheter is correspondingly narrowed at its distal end to prevent the piston from slipping out.

10. The catheter-stent system according to claim 1, wherein the stent to be placed is driven by a piston in the catheter by means of the pressure medium through the catheter and pushed out of the catheter.

A catheter-stent system according to claim 1 in which the piston has a central channel for receiving a guidewire.

12. The catheter stent system of claim 1, wherein the wall of the catheter surrounding the piston has a side hole which is opened after sliding past the piston distally and after release of the stent, and then through which the pressurized medium can escape, to prevent further propulsion of the piston with the piston slipping out of the catheter into the vessel.

A catheter-stent system according to claim 1, which is a system closed to the printing medium in which a self-expanding stent is mounted on a tubular support having a stent-receiving groove and whose forward end is formed into a point. and its rear end is provided with a sliding piston and provided with a channel for a guide wire which runs centrally in the carrier portion and then extends obliquely outwardly in the piston and opens into a side hole, wherein the guide wire passes through the piston and then through the side hole comes out, and wherein the stent is released by pushing out of the carrier, the piston portion, however, remains in the catheter, since further slipping out of the piston is prevented by blocking the laterally emerging from the side hole guide wire.

14. Catheter-stent system according to claim 1, wherein the end face of the piston of the injection pump is kept the same size as the pressure for the available surface of the catheter located in the piston.

15. Catheter-stent system according to claim 1, wherein the end face of the piston of the injection pump has a different size than the end face of the available for pressurizing piston in the catheter.

16. The catheter stent system according to claim 1, whose shaft has two lumens for performing a flushing and for venting the catheter system.

The catheter-stent system of claim 1, wherein a smaller lumen is preferably for pressurizing and a larger lumen for receiving the guidewire.

18. Catheter-stent system according to claim 1, which contains a catheter-filled and filled with pressure medium, bellows-shaped tube, which changes in its shape by pressurization and moves the stent.

19. A catheter stent system according to claim 1, wherein the portion carrying the stent remains in a fixed position after placement in the target vessel and the stent is released, whereby by pressure the piston slides back together with the surrounding the stent gland envelope catheter.

20. Catheter-stent system according to claim 1, wherein the sheath surrounding the stent can be moved back over the stent back into the starting position with the stent not yet fully expanded.

The catheter-stent system of claim 1, wherein the pressure medium in the pressure chamber and its associated channels is filled prior to use and sealed (sealed).

The catheter-stent system of claim 1, wherein the stent-carrying portion remains in a fixed position after placement of the stent in the organ to be treated and the stent is released, by pressurizing the inner lumen of the catheter, with inserted guide wire and distally as well proximally the pressure chamber sealing valves, an annular piston connected to the stent sheath, is pushed back on the outer surface of the carrier catheter.

23: Catheter-stent system according to claim 1, whose shaft for pressurizing a longitudinally mounted, reaching to the piston catheter, which serves for rinsing and deflating the air pressure system. 24. The catheter-stent system of claim 1, wherein the guidewire is coaxially received in the pressure chamber provided proximally and distally with sealing valves.

The catheter-stent system of claim 1, wherein the catheter surrounding the stent is provided at the proximal end with an annular piston sliding on a smaller diameter delivery catheter after proximal backward compression for stent delivery, the stent carrier receiving the guide wire is provided after the "fast exchange system" with a sloping, from the catheter tip to the proximal leading channel that ends laterally on the catheter, beyond the pressure chamber system.

26: Catheter-stent system according to claim 1, with a device for filling and venting the stent chamber and the hydraulic portion by means of a catheter.

27. The catheter-stent system of claim 1, wherein the catheter sheath surrounding the stent is provided with a hole-like side opening connected to a channel leading into the stent bed and located in the stent carrier over which fluid is introduced to rinse the stent bed and evacuate air and lubrication of the moving parts.