Patent Application
20240189102
The present invention relates to an assembly for replacing a heart valve by a percutaneous route or to a coronary angioplasty assembly, comprising a valve delivery catheter and, if appropriate, an introduction device commonly referred to as an “introducer”.
The present invention relates more particularly to improved assistance in the replacement by cardiac shutdown by means of a cardiac stimulator.
Although described with reference to the replacement of an aortic valve, the assembly according to the invention may be used as a coronary angioplasty assembly which optionally necessitates the placement of a prosthesis commonly referred to as a “stent”, in particularly in an emergency situation or even in complex interventional procedures.
Similarly, although described with reference to the replacement of an aortic valve, the assembly according to the invention may also be used for replacing another valve of the heart, such as the tricuspid valve or the mitral valve.
Generally, the introducer and/or the delivery catheter of the assembly according to the invention may be implanted in a patient by a percutaneous route, more precisely by a transfemoral, transaortic, carotid or subclavian route.
A commonly known disease of the heart is that associated with calcified narrowing of the tricuspid valve or of the aortic valve, the latter being the valve which separates a cavity of the heart, namely the left ventricle, from the aorta and which, in the open position, allows the blood to flow from the heart to the rest of the body of a human being.
Severe or very severe narrowing prevents the aortic valve from opening normally and thus generates the disease also referred to as calcified aortic valve stenosis.
Treatment of this disease involves replacing the defective aortic valve.
Replacement of a defective aortic valve is most commonly performed by opening the chest, placing the patient under extracorporeal circulation, temporarily stopping the heart, and then opening the heart with the aim of removing the native valve and replacing the latter with an artificial or prosthetic valve.
These successive steps of the operation have the major disadvantages of entailing a relatively long period of hospitalization of the patient, of being complex and costly, and of being limited to only some of the patients affected, since the physician and/or surgeon often considers that so-called “open heart” surgery cannot be performed because it is too risky in light of the general state of the patient, especially on account of the heart having to be stopped and of extracorporeal circulation having to be provided.
To overcome this disadvantage, it has been proposed to replace a heart valve using a minimally invasive approach, but still requiring extracorporeal circulation. Mention may be made of the international patent applications WO 93/01768 and WO 97/28807, and of the U.S. Pat. Nos. 5,814,097, 5,370,685 or 5,545,214, which illustrate known minimally invasive techniques and also instruments for implementing these techniques.
However, it has been felt that the existing techniques are not entirely satisfactory and that they may be improved.
In particular, these techniques have the following major disadvantages:
To overcome the drawbacks of these techniques, one approach has been the placement of artificial aortic valves, called percutaneous valves, inspired by the techniques of endovascular treatment that involve introduction of a catheter inside a blood vessel, such as the aorta.
Thus, the native aortic valve, which has been rendered defective by calcification, is replaced by an artificial valve without the need for the onerous heart surgery that is normally required as has been explained above.
An artificial valve may currently be put into place by different percutaneous routes: a transfemoral route, i.e. by introduction from the femoral artery to the heart, or a transapical route, or a transaortic route, or a carotid route, or else a subclavian route, that is to say any route that does not require open heart surgery through an opening in the chest and that does not require extracorporeal circulation.
The operation itself involves placing an artificial valve (prosthesis), which reproduces the general shape of a normal native aortic valve, at the region of the calcified (diseased) native aortic valve, the latter being left in place and crushed by the prosthesis.
To do this, the artificial valve made of pericardium, a fine membrane surrounding the heart, of porcine or bovine origin, is fixed beforehand to the interior of a tubular and radially expansible metal called mesh, a stent, which is composed of an arrangement of wires made of shape-memory material, for example nickel-titanium alloy or cobalt-chromium alloy, or stainless steel 316L for coronary stents.
The assembly composed of valve and mesh is then compressed at the end of a tubular sheath, called a delivery catheter, which may be introduced either directly into an artery or into the inside of an introducer permitting access to the artery while maintaining hemostasis.
An interventionalist then slides the assembly composed of valve and mesh into the introducer or directly into the delivery catheter until said assembly arrives at the diseased aortic valve. Before being fitted in place, the assembly composed of valve and mesh is then placed at the region of the diseased valve by inflation of a balloon.
There are also valve delivery catheters comprising an assembly composed of valve and mesh without a balloon, in which catheters the valve is self-expanding, permitting placement of a valve which expands radially by simple retraction of the sheath surrounding it, and therefore without having to inflate a balloon beforehand.
For further details, reference may be made to the U.S. Pat. Nos. 7,018,406, 7,892,281, 8,652,202 and 8,747,459.
During the placement proper, it is necessary to temporarily arrest the heart for a short period by rapid ventricular stimulation in order to minimize the flow across the valve, i.e. between valvules, and to avoid or at least reduce the potential embolization.
This temporary arrest of the heart, also commonly referred to as “cardiac shutdown”, thus involves having the heart beat at 150 to 200 beats per minute such that there is no longer any effective contraction, which leads to a drop in the pressures and simulates ventricular tachycardia or fibrillation and then stabilization of the heart.
This stabilization of the heart permits the stabilization of the balloon and thus increases the precision of placement of the artificial valve in a matter of a few seconds.
There are bipolar stimulation catheters, with two electrodes, referred to as electrosystolic stimulation probes, for temporary intracardiac stimulation of the right ventricle.
These electrosystolic stimulation probes have a number of disadvantages, as are set out below.
Firstly, such a probe constitutes a central venous access with an of added risk vascular complication in the targeted population of patients. The French registry “France 2”, which lists the aortic valve replacement operations, currently designated by the English language acronym TAV1 (Transcatheter Aortic Valve Implantation), has indicated a rate of risk of substantial vascular complications equal to 4.7%. This result is reported on page 1709 of publication [1]. Secondly, this probe is relatively rigid.
Hence, its placement in the right ventricle, which is fragile and whose wall is finer than that of the left ventricle, poses a considerable risk of the phenomenon well known to interventionalists under the term “tamponade”, which is a manifestation of substantial circulatory insufficiency, which may even lead to the death of the patient.
It should also be noted that this risk exists both during the intervention, that is to say during the placement of the electrosystolic probe, and also in the post-operative period, on account of the mobilization of the patients in their beds and therefore of the probe which is still present and which may then pierce the wall of the right ventricle.
Moreover, there is a risk of the electro-systolic stimulation probe moving at the crucial moment of placement of the valve. This is because a stimulation probe is not fixed in a wall of the heart and may therefore move and thus generate a loss of capture of the electrical stimulation signal.
The heart is then no longer stimulated and therefore performs substantial movements, which impede the placement of the valve or of the balloon.
Another risk associated with the use of such probes is the risk of infection at the puncture site. The registry France 2 has indicated a rate of less than 1%: see publication [1].
Finally, an interventionalist does not consider as negligible the additional operating time associated with the placement of a temporary stimulation probe, which is an operation that is not always easy to perform.
Publication [2] puts forward the advantages of performing this ventricular stimulation on the left ventricle and not on the right ventricle and of doing so not by means of a specific transvenous stimulation catheter but by using an external cardiac stimulator with the guide wire used for interventions of this type.
Thus, the recommended technique described in publication [2] involves using the guide wire which supports the stent expansion balloon and is introduced into the left ventricle, as a part connected to the cathode of a cardiac stimulator, and a cutaneous electrode or needle inserted in the subcutaneous tissue as a support for the anode of the cardiac stimulator.
Publications [3] and [4], in the case of a coronary angioplasty intervention on a pig population, validates the efficacy of temporary cardiac stimulation with a lower stimulation voltage, in which the guide wire supporting the stent expansion balloon is used as a part connected to the cathode of a cardiac stimulator, a and cutaneous electrode or needle inserted in the subcutaneous tissue is used as a support for the anode of the cardiac stimulator.
Thus, these recommended techniques have the advantages of avoiding the need to implant an additional dedicated catheter, of avoiding an additional access to the heart, of reducing the time and cost of the operation, but also of reducing the rate of complications associated with the implantation of the dedicated catheter, all of this while permitting a stimulation that is equal to that achieved by transvenous stimulation.
Moreover, compared to the electrosystolic stimulation probes for the right ventricle, which pose the risk of tamponade as explained above, the guide wire used for this technique is very stable and bears permanently against the relatively thick wall of the left ventricle, since it serves as a rail for advancing the stent/balloon/valve assembly through the valve.
This being so, this technique nonetheless requires the placement of an additional electrode or subcutaneous needle, which has to be precise, and the placement and retention of crocodile clips on two supports spaced apart from each other.
There is therefore still a need to improve the operation of replacement of a heart valve that requires temporary shutdown during placement of the artificial valve, particularly in order to make the placement and manipulation of the cardiac stimulator electrodes quicker and easier for the surgeon(s) in charge of the operation.
The object of the invention is to respond at least in part to this need.
To do this, the invention relates, according to a first alternative, to an assembly for replacing a heart valve by a percutaneous route, comprising:
According to a second alternative, the invention relates to an assembly for replacing a heart valve by a percutaneous route, comprising:
According to one embodiment, the electrode of the cardiac stimulator connected to the electrically conductive element of the introducer or of the delivery catheter is the anode, while the electrode connected to the metallic part of the guide wire is the cathode.
Thus, the invention essentially consists in integrating the metal support of an electrode of the cardiac stimulator directly in the sheath for insertion into the artery of a patient.
This insertion sheath may be that of an introducer, or directly that of a delivery catheter of reduced size compared to that of an introducer. A valve delivery catheter does not in fact require an introducer, since it may be introduced directly into the artery of a patient.
In other words, a cardiac stimulation support function is added to an introducer or to a delivery catheter whose basic function is to penetrate inside an artery of a patient in order to permit the passage of a valve/stent/balloon assembly, or an assembly composed of self-expansible valve and stent, for replacing a defective aortic valve.
By virtue of the invention, it is no longer necessary to insert a needle into the subcutaneous tissue, or a cutaneous electrode, to serve as a support for the electrode, typically the anode of a cardiac stimulator.
It is also no longer necessary to use and fit in place an electrosystolic probe according to the prior art, commonly called a temporary probe.
Moreover, by virtue of the invention, stimulation intensity that is needed for cardiac shutdown is lower than in the solutions according to the prior art, on account of a lower impedance of the vascular system in relation to the subcutaneous tissue.
The electrical conducting element is advantageously a metal wire or strip which is accommodated at least in part within the thickness of the sheath and of which a distal portion is exposed at the outer periphery of the sheath.
The one or more surgeons in charge of the operation are thus able to easily connect the electrode, typically anode of the cardiac the stimulator, to a proximal portion of the metal wire or strip at the periphery of the introducer or of the delivery catheter, then to connect the other electrode as usual, typically the cathode, to the guide wire of the valve-stent-balloon assembly or of the assembly composed of self-expanding wire and stent.
In an assembly according to the invention, provision is made that another portion of metal wire or strip, distal from the one on which the electrical connection is made, and outside the body of the human being on whom the operation is performed, is exposed, that is to say not covered by the tubular insertion sheath, in order to be directly in contact with the subcutaneous tissues of the body or with the vascular space.
Thus, the step for preparing for shutdown of the heart is simpler and quicker to carry out.
Moreover, the inventor considers that an introducer according to the invention or a delivery catheter according to the invention may reduce the risks of complications associated with the electro-systolic stimulation probes according to the prior art which are placed in the right ventricle.
The introducer or the delivery catheter according to the invention may be introduced by a transapical route or by a transfemoral route, the latter being preferred since it is less invasive for weakened patients.
The introducer the delivery catheter or according to the invention may incorporate a peripheral perfusion system usually called a flush, which may be put in place in order to clear any possible blood clots from the interior of the introducer or of the catheter.
The introducer or the delivery catheter according to the invention may be formed on the basis of an already existing introducer or delivery catheter, respectively. It is only necessary to provide one additional production step which involves accommodating the metal wire or strip inside the insertion sheath and leaving the proximal and distal portions of the metal wire (strip) exposed.
Thus, for an assembly for replacing the aortic valve, the introducer may advantageously be produced on the basis of the same dimensions, shapes and materials as a known introducer, for example the one with the commercial name “Edwards eSheath insertion set”, sold commercially by the company Edwards Lifesciences.
The artificial valve may be introduced and positioned in the artery by means of a delivery catheter according to the invention or by means of a conventional valve catheter, itself introduced into the introducer. The artificial valve then occupies a folded position and does not form an obstacle to the introduction and sliding of the valve catheter in the introducer and then in the artery, or in the delivery catheter according to the invention and then in the artery.
Then, in the deployed position, the artificial valve bears against the outer wall of the native heart valve in place of the latter and crushes it.
A conventional valve catheter or a valve catheter according to the invention thus makes it possible to introduce and position the artificial valve at the suitable location, in the same operating maneuver as the one carried out for opening and crushing the native valve. After opening and crushing of the latter, the valve catheter is slid axially in the distal direction in order to bring the artificial valve to the suitable location in the aperture of the native valve.
During the opening and crushing of the native valve, and thereafter, the one or more surgeons operating on the patients apply a cardiac stimulation by means of the external cardiac stimulator, the electrical current circulating between the cathode and the anode of the stimulator, the cathode being connected to the guide wire of the artificial valve and the anode being connected to the metal wire or strip integrated in the outer tubular sheath of the introducer or of the delivery catheter according to the invention.
Simultaneously with the ventricular stimulation, the artificial valve is deployed. The valve catheter is then withdrawn.
In summary, the advantages of an assembly according to the invention, compared to those of the prior art as presented in the preamble, are numerous, and the follow may be mentioned:
According to an advantageous embodiment, the introducer or the delivery catheter according to the invention comprises:
According to an advantageous variant in which the introducer or the delivery catheter comprises a rinsing device with faucets, called a flush, for rinsing the inside of the introducer by means of a suitable rinsing liquid, the proximal portion of the metal wire or strip is exposed at the level of the flush. This variant is advantageous in that it further simplifies the placement of the temporary stimulation, since the flush is directly oriented toward the external cardiac stimulator. Therefore, the placement and the retention of the connection clip may be done from the direction of the external stimulator. It is therefore easier for an interventionalist to control both the hold of the connection clip and the external cardiac stimulator. The proximal portion of the wire at the level of the flush may be configured as an electrical connector, on which it is possible to directly place a complementary connector connected directly to the external cardiac stimulator.
Preferably, the proximal notch and the proximal portion of the metal wire or strip are configured to allow a crocodile clip to be clipped onto said portion. It is thus possible to use these conventional clips without having to use clips that are specially designed for the introducer according to the invention.
More preferably, the distal portion of the metal wire or strip is arranged:
For the alternative with the valve catheter, an electrical contact zone at a distance of between 20 and 60 cm from the distal zone of the catheter is advantageously able to ensure contact at the level of the intravascular endothelium of the aorta.
The cross section of the metal wire or strip is advantageously between 0.25 and 5 mm2.
According to another advantageous embodiment of the invention, the electrically conductive element comprising an electrically conductive covering, such as a carbon covering, deposited on the outer periphery of the sheath.
According to this embodiment, the sheath is advantageously a two-layer covering with an electrically insulating inner layer and the electrically conductive layer deposited on the inner layer.
Preferably, the electrically conductive covering is deposited over the entire height of the outer periphery of the sheath, except for the distal end of the latter. This ensures definite contact between the electrically conductive covering and the subcutaneous tissue of the body or the wall of the femoral artery of the patient into whom the introducer or the delivery catheter according to the invention is introduced.
According to a particularly advantageous variant, the assembly comprises:
The invention also relates to a guide wire for an assembly according to the invention as described above, comprising a metal core covered with an electrically insulated covering on a central portion of length L1, between the proximal end and the distal end of the guide wire, which metal core is not electrically insulated along the rest of the length of the guide wire.
Advantageously, the distal end not electrically insulated, and intended to come into contact with the wall of the left ventricle of a patient's heart, is more flexible than the rest of the guide wire.
Typically for a guide wire with a total length L of the order of 260 cm, the length L2 of the metal core not covered at the distal end and therefore not electrically insulated is of the order of 6 to 10 cm, the length L1 of the electrically insulating covering is of the order of 110 cm, the length of the metal core L3 equal to L−(L1+L2) not covered at the proximal end being of the order of 140 to 144 cm.
By keeping the periphery of the guide wire insulating only along the length L, but non-insulating at the distal and radial ends, emergency cardiac stimulation is permitted even in case of withdrawal of the delivery catheter. Indeed, in an emergency cardiac situation, the metal core may still serve as connection to an electrode, typically the cathode of the cardiac stimulator, and it is still possible to insert a needle into the subcutaneous tissues or leave the introducer according to the invention in place in order to serve as support for the other electrode, typically the anode of the cardiac stimulator. The electrical insulation between anode and cathode is then obtained by the insulating covering of the guide wire.
The guide wire according to the invention has many advantages, of which the following may be mentioned:
The invention also relates to the use of the assembly with introducer or delivery catheter described above for the replacement of an aortic valve, pulmonary valve, tricuspid valve or mitral valve.
Finally, the invention relates to the use of the assembly with introducer or delivery catheter described above for a coronary angioplasty intervention, particularly in an emergency situation.
This use is advantageous particularly in three intervention situations that may be encountered in coronary angioplasty.
The first is the treatment of an acute infarction which would cause conduction problems in the nature bradycardia or high-level atrio-ventricular block. Using an introducer according to the invention avoids the use of an electrosystolic probe according to the prior art, which is much more invasive and requires a not inconsiderable implantation time.
The second situation concerns the treatment of calcified coronary lesions by reaming inside the coronary vessels in question, usually with a reamer known by the tradename Rotablator®. Using an introducer according to the invention then also does away with the need to use an electrosystolic cardiac stimulation probe according to the prior art.
The third situation concerns the placement of a stent, in certain parts of the coronary vessels near their origins (ostia); these zones are very mobile with respect to the intervention catheter, but these anatomical require very great precision in the implantation of the stent. Using an introducer according to the invention makes it possible to stabilize the stent before and during its placement.
Other advantages and features of the invention will become clearer on reading the detailed description of the invention, which is given by way of a non-limiting example and with reference to the accompanying figures, in which:
In the description below, and in the whole of the present application, the terms “distal” and “proximal” are used with reference to the body of a patient whose defective native aortic valve is replaced by an artificial aortic valve. Thus, the distal end of an introducer is the end situated farthest inside the patient during the operation for replacement.
To simplify matters, the same elements in the device according to the invention and in the device according to the prior art are designated by the same references.
It should be noted that the various elements are not necessarily shown to scale.
Between its proximal end 10 and its distal end 11, this introducer 1 of generally tubular shape comprises a nozzle 12 which is continued by at least one outer tubular sheath 13 formed of two tubular portions 14, 15, from proximal to distal, considered with respect to the introduction into a femoral artery of a patient on whom an operation is to be performed, that is to say from the top downward in
The nozzle 12 generally incorporates within it a set of leaktight valves to provide hemostasis, that is to say to ensure that the blood is retained inside the patient's blood vessels during the intervention.
The tubular sheath 13 may be extensible or non-extensible in order to allow the passage of a surgical intervention device such as a valve catheter, as is explained below. The material from which the sheath 13 is made is a biocompatible material such as silicone. It may also be made of Teflon® or of polyurethane. The sheath may advantageously be covered on the outside with a hydrophilic layer and on the inside with a layer having a low coefficient of friction in order to facilitate the sliding of an intervention device.
The introducer 1 illustrated in
All the elements of the introducer 1 that are present in the proximal or outer zone ZE are intended to remain outside the patient's body, while the entire distal portion 15 of the sheath 13 defining the distal zone ZI is intended to be introduced into a femoral artery of the patient.
The introducer 1 illustrated is, for example, the one sold commercially under the trade name “Edwards eSheath introducer set”, which is sold commercially by Edwards Lifesciences.
The tip of the assembly 21 makes it possible to easily penetrate the deficient native aortic valve.
It will be seen from these figures that, the further the valve catheter 2 slides, the portion 15 of the tubular sheath temporarily deforms radially to form a slight protuberance 150. When the tubular sheath is not extensible, it does not deform radially.
It will be seen from
This introduction of the valve catheter 2 allows the assembly 21 to be brought to the level of the deficient calcified aortic valve that is to be replaced.
Normally, as is likewise shown in
A needle (not shown) is likewise inserted into the subcutaneous tissues of the body C of the patient on whom a procedure is to be performed. A metal wire 4 is fixed on this needle.
A crocodile clip 5 is likewise fixed by being clipped onto the metal wire 4.
This clip 5 is connected to the anode of the cardiac stimulator outside the body.
Thus, when the artificial valve is at the level of the natural aortic valve that is to be replaced, and before putting the artificial valve itself into place, i.e. before inflating the balloon and thus expanding the stent to which the valve is fixed, the surgeon first of all effects rapid ventricular stimulation of the left ventricle.
To do this, an electrical signal is delivered between the cathode and the anode by way of the clips 3 and 5, with the balloon serving as electrical insulator between these two electrodes.
Faced with numerous operations for replacing an aortic valve via a femoral route of the kind that has been briefly described, and in particular faced with the precise and delicate placement of the additional supplementary needle, and also the placement and retention of the connecting crocodile clips on two spaced-apart supports, the inventor of the present invention has thought to integrate the metal wire 4 directly in an introducer 1 or in a delivery catheter 1′.
More precisely, as is shown in
The metal wire or strip 4 may be produced in the form of a metal braid in order to give it the characteristics of flexibility that are necessary to accommodate the deformations of the extensible sheath during the introduction of a valve catheter into the introducer 1.
The metallic material of the wire or strip 4 is also chosen to be biocompatible, for example titanium, or a stainless steel optionally covered with a layer which is both anti-adhesive, in order to permit sliding inside the artery, and also conductive, in order to ensure electrical continuity between the core of the wire or strip and the subcutaneous tissue or the wall of the artery.
A distal notch 17 formed in the portion 15 of the tubular sheath leaves a distal portion 4a of the metal wire or strip 4 exposed. This distal portion 4a thus comes directly into contact with the subcutaneous tissue of the body or the wall of the femoral artery of the patient on whom an operation is performed.
It must of course be ensured that the exposed portion 4a, 4b of the metal wire or strip does not protrude outside the tubular sheath, so as not to risk causing injury during introduction of the catheter 1.
This distal notch 17 is positioned at a distance D from the distal end 11 so as to ensure that there is indeed contact between the distal portion 4a of the metal wire or strip 4 and the cutaneous tissue or the wall of the artery. More preferably, the distance D is such that the distal portion 4a is exposed in a zone corresponding to approximately the half length of the tubular portion 14. It is thereby ensured that there is contact with the vascular space, which may help improve the efficacy of the cardiac stimulation.
At the other end, a proximal notch is formed in a portion of the proximal zone ZE in order to expose a proximal portion 4b of the metal wire or strip 4, such that the latter is accessible from the outside of the body C.
At the level of the proximal notch, the metal wire or strip 4 and the notch 17 are configured in such a way that a connection clip, for example a crocodile clip 5, is fixed by being clipped onto the proximal portion 4b.
According to an advantageous alternative embodiment, illustrated in
This variant is advantageous since the placement of the connection clip 5 is carried out at the side where the external cardiac stimulator is usually situated, which further facilitates the procedure for the interventionalist.
As may be seen from
The guide wire 20 is formed along its entire length by a metal core which is covered by an electrically insulating cover 25 only in a central portion 23 of length L1, between the proximal end 22 and the distal end 24 of the guide wire. Since the metal core does not comprise an insulating cover on its periphery at its distal end 22 and proximal end 24, it is not electrically insulated along the rest of the length of the guide wire.
Advantageously, the distal end 22 not electrically insulated, and intended to come into contact with the wall of the left ventricle of a patient's heart, is more flexible than the rest of the guide wire. More precisely, as is shown in
Thus, in an emergency situation in which it is necessary to stimulate the heart, it is always possible to insert a needle into the subcutaneous tissues if the catheter 1′ is withdrawn or to leave the introducer according to the invention in place in order to serve as a support for another electrode, typically the anode of the cardiac stimulator.
It is thus entirely possible to provide effective stimulation, since the distal end 22 of the guide wire 20 always ensures electrical contact and, therefore, passage of current from the cathode, and the insulating cover 25 ensures complete insulation between the anode and the cathode along the intravascular trajectory.
The invention thus makes available an assembly with introducer or delivery catheter that may be used more particularly in the replacement of a heart valve by a percutaneous route, overcoming the disadvantages of the prior art and further improving the efficacy of the temporary cardiac stimulation in order to achieve the desired cardiac shutdown.
Indeed, the device according to the invention makes it possible to avoid the precise and delicate placement of a subcutaneous needle for connection to the anode of a cardiac stimulator.
The device according to the invention thus saves time in the replacement procedure.
In addition, the device according to the invention makes it possible to improve the inherent efficacy of the temporary stimulation in order to achieve the desired cardiac shutdown, since the impedance between the two electrodes of the cardiac stimulator is that of the vascular space, since the metal wire or strip comes into contact with the latter during the introduction of the sheath. On account of this impedance being lower than that of the cutaneous tissues encountered by the temporary stimulation probes according to the prior art, it is possible for the external stimulator to deliver an electrical stimulation current which is less than that according to the prior art, for a level of efficacy that is at least just as good.
The invention is not limited to the examples just described; it is possible in particular to combine features of the illustrated examples in variants that have not been illustrated.
Other variants and improvements may be provided without departing from the scope of the invention.
If, in the examples illustrated, the parts serving for connection to a stimulator, and integrated either in an introducer or in a delivery catheter, are exposed portions of a metal wire or strip, it is also conceivable instead to have a continuous covering on the insertion sheath surface that is electrically conductive.
This covering may be made in particular of a conductive carbon.
This introducer 1 comprises a two-layer covering with an electrically insulating inner layer 130 and an electrically conductive covering 4 deposited on the inner layer 130. This conductive covering 4 forms the conductive element intended to be in contact with the subcutaneous tissue of a patient's body. It may advantageously be a covering made of conductive carbon.
Preferably, as is illustrated in
For its part, the proximal end of the introducer 1 comprises a nozzle 12 which incorporates within it a ring 42, in which the sheath 13 is engaged with force.
The nozzle 12 comprises in particular a valve 120 and a port 18 for fluidic purge by means of a suitable rinsing liquid.
The nozzle 12 likewise comprises a connecting tongue 46 which is made of electrically conductive material and of which one end is inserted through the ring 42, so as to establish an electrical contact with the electrically conductive covering 4, and of which the other end protrudes outside the nozzle.
In the example illustrated, the end of the tongue 46 outside the nozzle 12 extends transversely with respect to the axis of the introducer 1 when it is not constrained inside the body of a patient. This connecting tongue 46 is therefore designed to simplify the placement and retention of the connection clip 5, which may be done from the direction of the external cardiac stimulator. It is thus easier for an interventionalist to control the hold of both the connection clip and the external cardiac stimulator.
The surface of the end of the connecting tongue 46 outside the connector piece 12 is adapted to be clamped by a connection clip 5 intended to be connected to an electrode of a cardiac stimulator.
This clip 5 comprises two electrically insulating branches 50, 51, which are articulated on each other, and accommodates a clip component 6 made of electrically conductive material.
As is shown in
Thus, simply by pressing manually on the branches 50, 51 of the clip 5, it is possible to bring the latter from its closed position (
| Number | Date | Country | Kind |
|---|---|---|---|
| 1552955 | Apr 2015 | FR | national |
| 1556582 | Jul 2015 | FR | national |
This application is a continuation that claims the benefit of U.S. non-provisional application Ser. No. 17/194,449 filed on Mar. 8, 2021 which is a continuation of U.S. non-provisional application Ser. No. 15/564,458, filed on Oct. 5, 2017, which is a 371 of PCT/EP2016/057385 filed on Apr. 5, 2016, and claims benefit to French Application Nos. 1552955 filed on Apr. 7, 2015 and U.S. Pat. No. 1,556,582 filed on Juy 10, 2015 which are all incorporated herein in their entirety by reference thereto.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17194449 | Mar 2021 | US |
| Child | 18586972 | US | |
| Parent | 15564458 | Oct 2017 | US |
| Child | 17194449 | US |
