CATHETER DEVICE FOR CTO RECANALIZATION

Description

[0001] The invention relates to a catheter device (1) for recanalizing an occlusion (O) in a vessel (G), with a proximal balloon (3) arranged at the distal end section (2a) for anchoring the catheter shaft (2) in the vessel (G) and for widening the occlusion (O) and a distal balloon (4) arranged at the distal end section (2a) for widening the occlusion (O).

[0002] Such catheter devices are used in particular to recanalize or reopen a chronic, essentially complete occlusion (Chronic Total Occlusion or CTO for short) of a patient's vessel.

[0003] Such CTOs occur in approximately 20% of all patients in the cardiac catheterization laboratory. The average procedure duration is typically approximately two to 2.5 hours. The number of guidewires, balloon catheters, and stents used is usually greater than in typical percutaneous coronary interventions (PCI) that do not involve a CTO.

[0004] For the treatment or recanalization of chronic total occlusions (CTOs), a catheter device is known from the prior art according to WO2007 / 100365A1, for example, which has two balloons arranged one behind the other, through which a guidewire extends. This guidewire is used to position the two balloons prior to occlusion, with the guidewire first being guided through the occlusion. US20060271090A1 also discloses a double-balloon system. WO1995016487A1 discloses a diagnostic catheter system, and WO9907354A2 discloses therapies for inducing ventricular asystole.

[0005] In such systems, the guide wire lumen provided for receiving the guide wire in the two balloons can prove to be disadvantageous, since a corresponding installation space must be provided for this, so that the device has a comparatively large diameter in the area of ​​the balloons.

[0006] Furthermore, such balloon systems regularly experience recoil effects during balloon inflation, as the leading (distal balloon) increases in diameter during unfolding / dilatation and therefore tends to be pushed out of the narrowed area.

[0007] Based on this, the present invention is therefore based on the object of providing a catheter device which is improved with regard to the problems described above.

[0008] This object is achieved by a catheter device having the features of claim 1.

[0009] Advantageous embodiments are specified in the subclaims and are described below.

[0010] Accordingly, a catheter device for recanalizing an occlusion (in particular CTO) in a vessel is proposed, comprising: a catheter shaft extending along a longitudinal axis and having a distal end portion, a proximal balloon arranged at the distal end portion for anchoring the catheter shaft in the vessel and for expanding the occlusion, which balloon is arranged at the distal end portion of the catheter shaft, wherein the proximal balloon has a balloon interior into which a fluid medium can be introduced to deploy the proximal balloon, a distal balloon arranged at the distal end portion for initially expanding the occlusion, wherein the distal balloon has a balloon interior into which a fluid medium can be introduced to deploy the proximal balloon, and a guide wire lumen surrounded by the catheter shaft and a guide wire that can be guided in the guide wire lumen, wherein the catheter shaft has an opening at the distal end portion that communicates with the guide wire lumen,through which the guide wire can be guided out of the guide wire lumen and out of the catheter shaft.

[0011] According to the invention, the opening is arranged such that the guidewire, with a section of the guidewire extending out of the guidewire lumen through the opening, extends outside the distal balloon and, in particular, can be guided past the distal balloon, so that the guidewire can be inserted into the occlusion, in particular past the distal balloon, in order to position the catheter shaft, in particular with respect to the occlusion. The guidewire lumen passes through the distal end section, whereby the guidewire lumen runs within the proximal balloon or through the proximal balloon, but does not pass through the distal balloon.

[0012] According to one embodiment, the opening is arranged along the longitudinal axis of the catheter shaft between the balloon interior of the proximal balloon and the balloon interior of the distal balloon. In particular, the opening can be provided along said longitudinal axis at the distal end of the proximal balloon or between the distal end of the proximal balloon and a proximal end of the distal balloon. The opening is preferably arranged in or close to the axial center of the proximal balloon. The opening is therefore not arranged in the periphery or on the outside of the proximal balloon. Such an arrangement makes it possible to open the occlusion both by extending the guide wire beyond the opening with the guide wire and by using the guide element.

[0013] When, in the context of the present invention, reference is made to a proximal component or a proximal region and a corresponding distal component or a distal region, this means that the distal component or the distal region is located farther away from an operator of the catheter device along the length of the catheter shaft than the proximal component or the proximal region. This region can be, for example, an end section or an end of a component of the catheter device.

[0014] Due to the inventive design of the catheter device, it is possible to make the distal balloon relatively small, since it no longer has to accommodate the guide wire lumen.

[0015] According to one embodiment of the invention, the distal balloon preferably has a diameter that, in the deployed state of the distal balloon, is significantly smaller than the diameter of the deployed proximal balloon. The distal balloon is therefore also referred to as a microballoon. The diameter of the proximal balloon is preferably designed in particular such that the proximal balloon, in an deployed state, can adhere to the patient's vessel wall to anchor the catheter shaft. In particular embodiments, the diameter of the proximal balloon in the deployed state is preferably more than twice as large, more preferably more than 4 times as large, and most preferably more than 10 times as large as the diameter of the distal balloon in the deployed state. Furthermore, it is preferred if the distal balloon is designed to be more rigid than the proximal balloon.

[0016] To recanalize the CTO, the catheter device or catheter shaft can be inserted and positioned over the guidewire into the patient's body or the affected vessel. The guidewire is then retracted, and the distal balloon is guided into the occlusion. Simultaneous dilation of the distal or microballoon and the proximal balloon bursts the occlusion at the entrance. In subsequent steps, the proximal balloon is deflated, advanced into the occlusion, and dilated again until complete opening of the vessel or recanalization of the occlusion is achieved.

[0017] The device according to the invention simplifies CTO recanalization because the distal balloon is relatively thin and can therefore be more easily moved into the occlusion. Furthermore, recoil generated during dilation of the distal balloon can be easily absorbed by the proximal balloon, as it can be anchored to the inner wall of the vessel (see above).

[0018] Furthermore, according to one embodiment of the invention, it is provided that the catheter device has an elongated guide element which is formed separately from the guide wire and which projects with a distal end portion from the second balloon in the distal direction.

[0019] Furthermore, according to one embodiment of the invention, it is provided that the guide element extends through the balloon interior of the distal balloon, wherein that distal end portion of the guide element is led out of the distal balloon at a distal end of the distal balloon.

[0020] According to one embodiment of the invention, the guide element can be formed, for example, by a wire. The wire can have a radiopaque core made of platinum or a platinum alloy, wherein the core can be coated with a cobalt-chromium alloy. Furthermore, the guide element or wire can have an X-ray marker. Furthermore, in one embodiment, the guide element is inclined from the tip of the distal balloon toward the section leading out of the guide wire lumen, in which the guide wire can extend outside the distal balloon distal to the opening of the distal end section.

[0021] Furthermore, according to one embodiment of the invention, the guide wire lumen of the catheter shaft is surrounded by a wall. According to one embodiment, the wall of the guide wire lumen extends through the balloon interior of the proximal balloon.

[0022] Furthermore, according to one embodiment of the invention, the catheter shaft has a lumen (inflation lumen) surrounded by a wall, through which a fluid medium can be introduced into the balloon interior of the proximal balloon and into the balloon interior of the distal balloon for, in particular, simultaneous inflation of the proximal and distal balloons. Thus, the proximal balloon and the distal balloon can be inflated with a fluid medium via a single (inflation) lumen.

[0023] According to one embodiment of the invention, it is provided that the lumen opens into the balloon interior of the proximal balloon, wherein the balloon interior of the distal balloon is in flow connection with the lumen via the balloon interior of the proximal balloon.

[0024] Such a design has the advantage that the moment the guide element and the distal balloon are to be inserted further into the occlusion, the anchoring in the vessel by the proximal balloon must be released, which also causes the distal balloon to be inserted into the occlusion to lose volume and be advanced more easily. Therefore, it is not necessary to first release the anchoring by the proximal balloon and then adjust the volume of the distal balloon, as would be necessary with a design that has separate (inflation) lumens for the distal and proximal balloons.

[0025] Furthermore, according to one embodiment of the invention, it is provided that the wall of the lumen extends through the balloon interior of the proximal balloon, wherein the lumen is in flow connection with the balloon interior of the distal balloon, and wherein the wall of the lumen has at least one lateral outlet opening arranged in the balloon interior of the proximal balloon, via which a fluid medium for unfolding the proximal balloon can be introduced into the balloon interior of the proximal balloon.

[0026] Furthermore, according to one embodiment, a proximal end portion of the guide element is connected to the wall of the guide wire lumen. This applies in particular if the lumen does not extend through the balloon interior of the proximal balloon or does not extend completely to the distal balloon.

[0027] According to an alternative embodiment of the invention, the proximal end portion of the guide element is connected to the wall of the lumen. This may be particularly the case if said lumen or the wall of the lumen extends through the interior of the proximal balloon.

[0028] Furthermore, according to an embodiment of the invention, it is provided that a proximal end of the distal balloon is connected to the wall of the guide wire lumen and / or to the wall of the lumen.

[0029] Furthermore, according to one embodiment of the invention, it is provided that the lumen and the guide wire lumen extend side by side in the catheter shaft along the longitudinal axis.

[0030] According to an alternative embodiment, the lumen and the guidewire lumen can also be arranged coaxially with each other, with the guidewire lumen being surrounded by said lumen. In this case, the wall of the lumen encloses the wall of the guidewire lumen.

[0031] According to a further embodiment of the invention, it is provided that the catheter device has at least one X-ray marker for the proximal balloon, which is arranged in the balloon interior of the proximal balloon on the wall of the guide wire lumen.

[0032] Further features and advantages of the invention will be explained in the description of exemplary embodiments of the invention with reference to the figures. They show: Fig. 1 is a schematic sectional view of an embodiment of a catheter device according to the invention; Fig. 2 is a schematic sectional view of a further embodiment of a catheter device according to the invention; Fig. 3 is a schematic sectional view of a further embodiment of a catheter device according to the invention; Fig. 4 is a sectional view of an embodiment of the catheter shaft of the catheter device; Fig. 5 is a sectional view of an alternative embodiment of the catheter shaft of the catheter device; and Fig. 6 shows a possible recanalization of a total occlusion (CTO) using a catheter device according to the invention.

[0033] The Figures 1 to 3 show embodiments of a catheter device 1 according to the invention for recanalizing an occlusion O in a vessel G (cf. Figures 6(A) to 6(M)). The catheter device accordingly has a catheter shaft 2 extending along a longitudinal axis x, which has a distal end section 2a on which a proximal balloon 3 is arranged for anchoring the catheter shaft 2 in the vessel G, which balloon is further configured to expand the occlusion O, wherein the proximal balloon 3 has a balloon interior 30 into which a fluid medium (e.g. physiological saline solution, contrast agent) can be introduced to deploy the proximal balloon 3. The catheter device 1 further has a distal balloon 4 arranged at the distal end section 2a for initially expanding the occlusion O, wherein the distal balloon 4 also has a balloon interior 40 into which a fluid medium (e.g. physiological saline solution, contrast agent) can be introduced to deploy the proximal balloon 3.The device 1 further comprises a guide wire lumen 5 formed by the catheter shaft 2 and a guide wire 500 which can be guided in the guide wire lumen 5, wherein the catheter shaft 2 has an opening 20 at the distal end section 2a, through which the guide wire 500 can be guided out of the guide wire lumen 5 and out of the catheter shaft 2.

[0034] According to the invention, the opening 20 is arranged such that the guide wire 500 extends outside the distal balloon 4 with a section 500a of the guide wire 500 led out of the guide wire lumen 5 via the opening 20 and can be introduced into the occlusion, in particular past the distal balloon, in order to guide the catheter shaft 2 to the target location.

[0035] In particular, the opening 20 is arranged along the longitudinal axis x of the catheter shaft 2 between a distal end 3a of the proximal balloon and a proximal end 4b of the distal balloon 4.

[0036] The guide wire 500 can, for example, have a diameter of 0.36 mm, wherein the inner diameter of the guide wire lumen 5 is designed larger so that the guide wire 500 can slide well in the guide wire lumen 5.

[0037] For introducing or positioning the distal balloon 4 into the occlusion O, the catheter device 1 preferably has an elongated guide element 6 which is designed separately from the guide wire 500, which is in particular designed to be X-ray visible and which protrudes from the distal balloon 4 with a distal end section 6a. According to one embodiment, the distal end section 6a can have a length (along the longitudinal axis x) in the range from 2 mm to 10 mm. The guide element 6 extends in particular along the longitudinal axis x through the balloon interior 40 of the distal balloon 4, wherein said distal end section 6a of the guide element 6 is guided out of the distal balloon 4 at a distal end 4a of the distal balloon 4.

[0038] Furthermore, according to one embodiment, the wire or the guide element 6 can have a diameter of 0.1 mm.

[0039] Furthermore, according to one embodiment, the distal balloon 4 can have a diameter D2 in the range of 1.0 mm to 2.0 mm at 6 atm. In this regard, it is further provided that the diameter D2 is smaller than the diameter D1 of the fully dilated or expanded proximal balloon 3.

[0040] Furthermore, according to one embodiment, the distal balloon 4 can have a length in the range of 2 mm to 10 mm along the longitudinal axis x.

[0041] Furthermore, according to one embodiment, a double wall thickness of the distal balloon 4 can be in the range of 0.02 mm to 0.04 mm. Furthermore, according to one embodiment, the profile diameter of the distal balloon 4 (folded onto the guide element 6, which has a diameter of 0.1 mm) can be less than or equal to 0.2 mm.

[0042] Furthermore, according to one embodiment, the distal balloon 4 can be made of one of the following materials: polyamide, in particular PA12, polyethylene terephthalate, polyurethane, or polyether blockamides such as Pebax (brand name). Furthermore, the distal balloon can have a hydrophilic or hydrophobic coating on its outer surface.

[0043] Furthermore, it is provided that the guide wire lumen 5 of the catheter shaft 2 is surrounded by a wall 50. For tracking the proximal balloon 3, it can further be provided that the catheter device 1 has at least one X-ray marker 8, which is arranged in the balloon interior 30 of the proximal balloon 3 on a wall 50 surrounding the guide wire lumen 5. Furthermore, it is provided that the wall 50 of the guide wire lumen 5 extends through the balloon interior 30 of the proximal balloon 3 along the longitudinal axis x and thereby borders the said opening 20 of the distal end section 2a of the catheter shaft 2 on the end face.

[0044] Furthermore, the catheter shaft has the following Figures 1 to 3a lumen 7 surrounded by a wall 70, through which a fluid medium, e.g. physiological saline solution or contrast agent, can be introduced into the balloon interior 30 of the proximal balloon 3 and into the balloon interior 40 of the distal balloon 4 in order to unfold the proximal and distal balloons 3, 4.

[0045] According to the Figure 1In the embodiment shown, it is provided that the wall 70 of the lumen 7 extends along the longitudinal axis x through the balloon interior 30 of the proximal balloon 3, wherein the lumen 7 is in flow connection with the balloon interior 40 of the distal balloon 4 or opens into the balloon interior 40, so that the distal balloon 4 can be dilated via the lumen 7. For dilating the proximal balloon 3, the wall 70 of the lumen 7 further has lateral outlet openings 71 arranged in the balloon interior 30 of the proximal balloon 3, so that the fluid medium can also be introduced into the balloon interior 30 of the proximal balloon 3 via the outlet opening 71 for unfolding the proximal balloon 3.

[0046] Furthermore, according to Figure 1provided that a proximal end section 6b of the guide element 6 extending through the balloon interior 40 of the distal balloon 4 is fixed to the wall 70 of the lumen 7 via a material connection 6c, for example.

[0047] Figure 2 shows an alternative embodiment, wherein the wall 70 of the lumen 7 ends at the proximal end 3b of the proximal balloon or the lumen 7 opens into the balloon interior 30 of the proximal balloon 3. The balloon interior 30 of the proximal balloon 3 is in flow connection with the balloon interior 40 of the distal balloon 4, so that the distal balloon 4 can be dilated or inflated via the proximal balloon 3. In the embodiment according to Figure 2 is in contrast to Figure 1 provided that the proximal end section 6b of the guide element 6 is connected to the wall 50 of the guide wire lumen 5 via a material connection 6d.

[0048] Figure 3 shows a further embodiment of a catheter device according to the invention, wherein here the wall 70 of the lumen 7 also extends through the balloon interior 30 of the proximal balloon 3, but ends along the longitudinal axis x in front of the distal end 3a of the proximal balloon 3, wherein an end-side outlet opening 72 of the wall 70 faces the distal balloon 4 and is fluidically connected to it via the circumferential distal end 3a of the proximal balloon 3. The proximal end section 6b of the guide element / wire 6 projects into the distal end 3a of the proximal balloon 3 and is connected to the wall 50 of the guide wire lumen 5 via a, for example, materially bonded connection 6d.

[0049] Furthermore, it is provided in particular that a proximal end 4b of the distal balloon 4 is connected, on the one hand, via a material-locking connection 4d, for example, to the distal end 3a of the proximal balloon 3 and, on the other hand, via a material-locking connection 4c, for example, to a distal end 50a of the wall 50 of the guide wire lumen 5. The distal end 50a of the wall 50 of the guide wire lumen can further be connected, for example, via a material-locking connection 5c, to the distal end 3a of the proximal balloon 3. Finally, in particular the proximal end 3b of the proximal balloon 3 is connected, for example, via a material-locking connection 3c, to the shaft 2 or the wall 50 of the guide wire lumen and / or the wall 70 of the lumen 7.

[0050] The catheter shaft 2 can enclose or limit the lumen 7 or the guide wire lumen 5 in various ways. Figures 4 and 5 show two basic possibilities, both of which are used in the Figures 1 to 3 shown embodiments can be used. According to Figure 4 The guide wire lumen 5 and the lumen 7 can extend adjacent to one another in the catheter shaft 2. The two walls 50 and 70 are connected to one another along the longitudinal axis x or are formed integrally with one another.

[0051] Alternatively, the lumen 7 and the guide wire lumen 5 can be Figure 5 be arranged coaxially to one another, wherein the guide wire lumen 5 is surrounded by the lumen 7. The wall 50 of the guide wire lumen 5 extends into the lumen 7 surrounded by the outer wall 70.

[0052] The Figures 6(A) to 6(M) show by way of example the use of a catheter device 1 according to the invention (e.g. according to the type of Figures 1 to 3 ) to recanalize a total occlusion O of a vessel G.

[0053] After initial assessment of the narrowing (CTO) O (cf. Fig. 6(A)) the guide wire 500 of the catheter device 1 is guided through the occlusion O (cf. Fig. 6(B) ). Using the guide wire 500, the catheter shaft 2 of the device 1 is then positioned in the vessel or artery G (cf. Fig. 6(C) ).

[0054] After positioning the catheter shaft 2, the guide wire 500 is withdrawn (see Fig. 6(D) ) and the distal balloon 4 is positioned with respect to the occlusion O (cf. Fig. 6(E) ) and introduced into it (cf. Fig. 6(F) ).

[0055] The proximal balloon 3 and the distal balloon 4 are then inflated to widen the occlusion O (see Fig. 6(G) ). The proximal balloon 3 serves to anchor the catheter shaft 2 in the vessel G.

[0056] Thereafter, the two balloons 3, 4 are deflated and partially inserted into the constriction O via the guide wire 500 and the elongated guide element 6 (cf. Fig. 6(H)). The two balloons 3, 4 are then dilated, with the distal balloon 4 widening the occlusion O more and the proximal balloon 3 anchoring the shaft 2 in the vessel G (cf. Fig. 6(I) ).

[0057] Subsequently, according to Fig. 6(J) the two balloons 3, 4 are deflated and inserted further into the occlusion O. After this, the two balloons 3, 4 are dilated again to further expand the lesion O (see Fig. 6(K) ).

[0058] Subsequently, according to Fig. 6(L) both balloons 3, 4 are deflated and the proximal balloon 3 is inserted centrally into the occlusion O and then dilated (cf. Fig. 6(M) ) to dilate the vessel G to the final diameter at the site of occlusion O.

[0059] The device 1 according to the invention advantageously enables recanalization of a CTO by means of a single device 1, thereby saving time during the procedure and correspondingly reducing the risk for the patient.

Claims

1. A catheter device (1) for recanalizing an occlusion (O) in a vessel (G), comprising: - a catheter shaft (2) extending along a longitudinal axis (x) and having a distal end section (2a), - a proximal balloon (3) arranged at the distal end section (2a) for anchoring the catheter shaft (2) in the vessel (G) and for expanding the occlusion (O), wherein the proximal balloon (3) has a balloon interior (30) into which a fluid medium can be introduced for deploying the proximal balloon (3), - a distal balloon (4) arranged at the distal end section (2a) for expanding the occlusion (O), wherein the distal balloon (4) has a balloon interior (40) into which a fluid medium can be introduced for deploying the proximal balloon (3), and - a guide wire lumen (5) surrounded by the catheter shaft (2) and a guide wire (500) which can be guided in the guide wire lumen (5), wherein the catheter shaft (2) has an opening (20) at the distal end section (2a), via which the guide wire (500) can be guided out of the guide wire lumen (5) and out of the catheter shaft (2), characterized in that the guide wire lumen passes through the distal end section, wherein the guide wire lumen passes inside the proximal balloon or through the proximal balloon but not through the distal balloon and the opening (20) is arranged along the longitudinal axis of the catheter shaft between the balloon interior of the proximal balloon and the balloon interior of the distal balloon in such a way that the guide wire (500) extends with a section (500a) of the guide wire (500) led out of the guide wire lumen (5) via the opening (20) outside the distal balloon (4).

2. The catheter device according to claim 1, characterized in that the catheter device (1) has a guide element (6) which is configured separately from the guide wire (500) and is longitudinally extended and which projects from the distal balloon (4) with a distal end section (6a) of the guide element (6).

3. The catheter device according to claim 2, characterized in that the guide element (6) extends through the balloon interior (40) of the distal balloon (4), wherein that distal end section (6a) of the guide element (6) is led out of the distal balloon (4) at a distal end (4a) of the distal balloon (4).

4. The catheter device according to claim 2 or 3, characterized in that the guide element (6) is formed by an X-ray visible wire.

5. The catheter device according to one of the preceding claims, characterized in that a diameter (D1) of the proximal balloon (3) transverse to the longitudinal axis (x) of the catheter shaft (2) in a fully deployed state of the proximal balloon (3) is more than twice as large, further preferably more than 4 times as large and most preferably more than 10 times as large as a diameter (D2) of the distal balloon (4) transverse to the longitudinal axis (x) of the catheter shaft (2) in a fully deployed state of the distal balloon (4).

6. The catheter device according to one of the preceding claims, characterized in that the guide wire lumen (5) of the catheter shaft (2) is surrounded by a wall (50).

7. The catheter device according to claim 2, characterized in that the guide element is inclined from the tip of the distal balloon to the section extending out of the guide wire lumen, in which the guide wire can run outside the distal balloon distal to the opening of the distal end section.

8. The catheter device according to one of the preceding claims, characterized in that the catheter shaft (2) has a lumen (7) which is surrounded by a wall and via which a fluid medium can be introduced into the balloon interior (30) of the proximal balloon (3) and into the balloon interior (40) of the distal balloon (4) in order to deploy the proximal and distal balloons (3, 4).

9. The catheter device according to claim 8, characterized in that the lumen (7) opens into the balloon interior (30) of the proximal balloon (3), wherein the balloon interior (40) of the distal balloon (4) is in flow communication with the lumen (7) via the balloon interior (30) of the proximal balloon (3).

10. The catheter device according to claim 8, characterized in that the wall (70) of the lumen (7) extends through the balloon interior (30) of the proximal balloon (3), wherein the lumen (7) is in flow communication with the balloon interior (40) of the distal balloon (4), and wherein the wall (70) of the lumen (7) has at least one lateral outlet opening (71) arranged in the balloon interior (30) of the proximal balloon (3), via which a fluid medium for deploying the proximal balloon (3) can be introduced into the balloon interior (30) of the proximal balloon (3).

11. The catheter device according to claim 2 and according to claim 6 or one of claims 6 to 11, provided that referring back to claim 6, characterized in that a proximal end section (6b) of the guide element (6) is connected to the wall (50) of the guide wire lumen (5).

12. The catheter device according to claims 2 and according to claim 8 or one of claims 10 to 11 insofar as referring back to claim 9, characterized in that a proximal end section (6b) of the guide element (6) is connected to the wall (70) of the lumen (7).

13. The catheter device according to one of the preceding claims, characterized in that the lumen (7) and the guidewire lumen (5) extend side by side in the catheter shaft (2).

14. The catheter device according to one of claims 1 to 12, characterized in that the lumen (7) and the guidewire lumen (5) are arranged coaxially to each other, wherein the guidewire lumen (5) is surrounded by the lumen (7).

15. The catheter device according to claim 6 and one of claims 7 to 14 insofar as related back to claim 6, characterized in that the catheter device (1) has at least one X-ray marker (8) which is arranged in the balloon interior (30) of the proximal balloon (3) on the wall (50) of the guidewire lumen (5).