ANCHORED CORONARY SINUS OCCLUSION CATHETER WITH IMPROVED USABILITY

Abstract

The invention relates to a catheter assembly for the intermittent occlusion of the coronary sinus (CS, 60). The catheter assembly comprises a shaft (17, 126). The shaft (17, 126) has a plurality of lumens (7A, 7B, 35, 38, 40, 40A, 40B), a distal end (22) with a distal tip (20A, 20B, 20C), an occlusion device (24, 56, 142) fixed to the distal tip (20A, 20B, 20C) and operable through at least one of the plurality of lumens (7A, 7B, 35, 38, 40, 40A, 40B) and a proximal handle (10). The catheter assembly further having at least one of the following: the occlusion device (24, 142) having a diameter of 5 - 20 mm and adapted to occlude the coronary sinus ostium, means of measuring the pressure at the distal tip (20 a, 20B, 20C) of the catheter assembly and distally to the occlusion device (24, 142), preferably using an optical pressure sensor (28), an anchoring device (30, 54, 65, 80, 90A, 122) for anchoring the occlusion device (24, 142) in a predefined position in the coronary sinus (CS, 60), preferably in the ostium, the distal end (22) being deflectable/steerable with deflection being controlled by an actuator arranged at the proximal handle (10).

Claims

1. A catheter assembly for the intermittent occlusion of the coronary sinus comprising a shaft, the shaft having a plurality of lumens, a distal end with a distal tip, an occlusion device fixed to the distal tip and operable through at least one of the plurality of lumens and a proximal handle, the catheter assembly further having at least one of the following: the occlusion device having a diameter of 5–20 mm and adapted to occlude the coronary sinus ostium, means of measuring the pressure at the distal tip of the catheter assembly and distally to the occlusion device, an anchoring device for anchoring the occlusion device in a predefined position in the coronary sinus the distal end being deflectable/steerable with deflection being controlled by an actuator arranged at the proximal handle.

2. The catheter assembly according to claim 1, wherein the handle comprises a deflection actuator and a first locking mechanism for steering and locking the distal tip in a desired configuration.

3. The catheter assembly according to claim 1, wherein the anchoring device comprises an expandable anchor.

4. The catheter assembly according to claim 3, wherein the expandable anchor is adapted to be arranged distally to the occlusion device.

5. The catheter assembly according to claim 3, wherein the expandable anchor is adapted to be arranged proximally to the occlusion device.

6. The catheter assembly according to claim 3, wherein the expandable anchor is arranged circumferentially around the occlusion device.

7. The catheter assembly according to claim 1, wherein the shaft comprises distal and/or proximal markers for angiographic identification of the position of the anchoring device in the coronary sinus.

8. The catheter assembly according to claim 1, wherein the actuator of the handle is formed by a lever for controlling the movement of the distal tip.

9. The catheter assembly according to claim 1, wherein the plurality of lumens is encompassed by an outer braided shaft.

10. The catheter assembly according to claim 9, wherein the catheter assembly comprises at least one deflection wire, arranged in the outer braided shaft.

11. The catheter assembly according to claim 1, wherein the distal end is deflectable up to at least + 90° to -90°.

12. The catheter assembly according to claim 3, wherein the assembly comprises a second locking mechanism for axially locking the anchor with respect to the occlusion device.

13. The catheter assembly according to claim 1, wherein the handle comprises fixation members for a fixed positioning of the handle during long-term operation of the device.

14. The catheter assembly according to claim 1, wherein the occlusion device and/or anchoring device is/are arranged circumferentially around the shaft.

15. The catheter assembly according to claim 1, wherein the occlusion device is an inflatable balloon.

16. The catheter assembly according to claim 15, wherein the balloon has an axial length of 5 to 20 mm and/or a diameter of 5 to 20 mm.

17. The catheter assembly according to claim 1, wherein at least two lumens of the plurality of lumen are adapted to control an expansion and contraction of the occlusion device.

18. The catheter assembly according to claim 1, wherein the anchoring device is made of a resilient material.

19. A method for the intermittent occlusion of the coronary sinus, the method comprising: a) placing an anchoring device in a pre-defined location, b) determining a distance between the anchoring device and a position for placing an occlusion device, c) placing an occlusion device at said position, d) fixing the occlusion device in said position by locking the anchoring device to the catheter, e) expanding the occlusion device to occlude the coronary sinus.

20. The method according to claim 19, wherein a) is preceded by: f) advancing a catheter comprising said anchoring device into the right atrium, g) directing a distal end of the catheter towards the ostium of the coronary sinus, h) locking the distal end in a first configuration by means of a first locking mechanism; and i) advancing the anchoring device to said pre-defined location.

21. The method according to claim 19, wherein the anchoring device is expanded in said pre-defined location.

22. The method according to claim 19, wherein step e) is followed by: j) collapsing the anchoring device, k) unlocking the second locking mechanism, 1) withdrawing the anchoring device, m) unlocking the first locking mechanism to allow free movement of the distal end, and n) withdrawing the catheter from the right atrium.

23. The method according to claim 19, said method being performed with a catheter assembly according to claim 1.

24. The catheter assembly according to claim 1 comprising means of measuring the pressure at the distal tip of the catheter assembly and distally to the occlusion device using an optical pressure sensor.

25. The catheter assembly according to claim 1 comprising an anchoring device for anchoring the occlusion device in the ostium.

26. The catheter assembly according to claim 3, wherein the expandable anchor consists of individual expandable members.

27. The catheter assembly according to claim 12, wherein the locking mechanism is a rotational knob located around the centre of the proximal handle.

28. The catheter assembly according to claim 16, wherein the balloon has a toroidal shape.

29. The catheter assembly according to claim 18, wherein the resilient material is a shape memory material.

30. Method according to claim 19, wherein the anchoring device in step a) is placed into the coronary sinus.

31. The method according to claim 19, wherein the position for placing the occlusion device is in the ostium.

32. The method according to claim 19, wherein the fixation in step d) is performed by means of a second locking mechanism.

Description

[0099] The invention will be described in more details with the aid of figures. The figures describe preferred embodiments and are not to be understood as limiting. They show:

[0100] FIG. 1 The engineering drawing of the distal tip of a commercial PICSO catheter.

[0101] FIG. 2 Current PICSO catheter proximal hub.

[0102] FIG. 3 3D Echocardiographic image of the coronary sinus.

[0103] FIG. 4 An overall catheter design according to the invention.

[0104] FIG. 5 A catheter shaft in a cross section along the plane A-A in FIG. 4 with three internal lumens.

[0105] FIG. 6 An alternative catheter shaft in a cross section along the plane A-A in FIG. 4 with four internal lumens.

[0106] FIG. 7 View B-B in FIG. 4; handle rear end.

[0107] FIG. 8 View C-C in FIG. 4; distal end with balloon inflated.

[0108] FIG. 9 First anchor on distal guidewire with outer sleeve; anchor not deployed.

[0109] FIG. 10 Anchor on distal guidewire with outer sleeve according to FIG. 9; anchor deployed.

[0110] FIG. 11 Second anchor design on distal guidewire without outer sleeve; anchor not deployed.

[0111] FIG. 12 Anchor on distal guidewire without outer sleeve according to FIG. 11; anchor deployed.

[0112] FIG. 13 View A-A of FIG. 12. The optical pressure sensor (78) may be integrated here or on the guide sheath (28) .

[0113] FIG. 14 Anchor on guide sheath: “Balloon in cage” design.

[0114] FIG. 15 Anchor in guide sheath distal to balloon.

[0115] FIG. 16 Anchor on guide sheath proximal to balloon.

[0116] FIG. 17 Guide sheath with locking mechanism of guidewire or PICSO catheter either proximal or distal or a combination of the two.

[0117] FIG. 18 Anchor of guide sheath in the Right Atrium (RA) or Inferia Vena Cava (IVC).

[0118] FIG. 19 Individual anchor wires; balloon in cage solution.

[0119] FIG. 20 Individual anchor wires, anchor distal to occlusion device.

[0120] FIG. 21 Individual anchor wires; anchor proximal to occlusion balloon.

[0121] FIG. 22 Individual anchor wires; anchor in outer sleeve.

[0122] FIG. 23 Anchor design without outer sleeve according to the second embodiment (anchor in open position).

[0123] FIG. 24 Anchor design without outer sleeve; individual wires and anchor in open position.

[0124] FIG. 25 Position of anchor design No. 1-3 in the coronary sinus.

[0125] FIG. 26 Potential position of anchor design No. 4 in the coronary sinus.

[0126] FIG. 27 Cross section A-A of FIG. 20 with balloon locking mechanism.

[0127] FIG. 28 Cross section A-A of FIG. 20 with mechanical locking mechanism.

[0128] FIG. 29 New vs old occlusion balloon design and location.

[0129] FIG. 30 Distal end with different bend radius.

[0130] FIG. 31 Flexible distal end of the shaft; cross section.

[0131] FIG. 32 Braided wires on the outside of the shaft and covered with an outer sleeve.

[0132] FIG. 33 Braided wire in extruded holes.

[0133] FIG. 34 Anchor off center and anchor in center.

[0134] FIG. 35 The anatomy of the coronary sinus showing the coronary sinus ostium and the emptying of the small and middle cardiac veins close to the ostium.

[0135] FIG. 36 The right atrium (RA) anatomy (Guiraudon, G., 2013, Revisiting right atrial isolation rationale for atrial fibrillation functional anatomy of interatrial connections. J Interv Card Electrophysio, 267-273) with the inferior vena cava (IVC) and the coronary sinus (CS). The CS ostium is the circular member with openign into the RA.

DESCRIPTION OF EMBODIMENTS

A. State of the Art

[0136] FIG. 1 shows an engineering drawing of the distal tip of a commercial PICSO catheter. The catheter in size M (Medium) has the following dimensions: the balloon length (A) is 25 mm, the balloon diameter (B) is 15.5 mm, the distance of marker bands (C) is 28.5 mm, the distance of a distal marker band to the balloon-tip (D) is 8.5 mm ± 1.5 mm, the working length is 1000 mm, the extension line length is 1500 mm, the catheter profile is 8.5 F and the maximal guidewire size is 0.032”. The catheter in size L (Large) has the following dimensions: the balloon length (A) is 35 mm, the balloon diameter (B) is 20 mm, the distance of marker bands (C) is 33 mm, the distance of the distal marker band to the balloon-tip (D) is 8.5 mm ± 1.5 mm, the working length is 1010 mm, the extension line length is 1500 mm, the catheter profile is 9 F and the maximal guidewire size is 0.032”.

[0137] FIG. 2 shows the current PICSO catheter proximal hub. The hub has the following features: a catheter shaft 1 with strain relief. A hypo-tube ends here in the hub. A drive lumen 3 is connected to the hub 2 for inflating and deflating the PICSO impulse catheter. At the distal end of the drive lumen a drive lumen connector is mounted for connecting to the console. A pressure lumen 5 measures the balloon pressure of the PICSO Impulse Catheter. At the distal end of the pressure lumen is the pressure lumen connector mounted. The hub 4 further comprises a fluid filled line port 4 for the coronary sinus pressure measurement and can be manually flushed with heparinized saline solution. The fluid filled line may be used for applying contrast agent and drawing blood samples. The fluid filled line can be connected with a male luer lock for the extension line to be connected to the console. The current handle has the disadvantages that the many connections to the handle are needed due to the lack of steerability and that the small fish-like handle is difficult to grasp.

[0138] FIG. 3 shows a 3D Echocardiographic image of the coronary sinus (A) showing the “trumpet″-like coronary sinus Ostium (B) which empties into the right atrium (C).

B. The Overall Catheter/Sheath Design

[0139] The proposed catheter as shown in FIG. 4 shows a handle, bi-directional guide sheath, improved balloon design, integrated optical pressure sensor and a distal guidewire with anchor. The anchor may alternatively be placed directly on the steerable sheath as later figures will show.

[0140] In detail, the catheter includes an ergonomic handle (10) with a lever (12A-B) for controlling the flexing of a distal tip (20A-C). The handle contains a first locking mechanism (15) which locks the distal tip in the desired location. In addition, fixation members (16A-B) in the form of holes are integrated on the handle for easier fixed position of the handle while the PICSO therapy is underway. The main shaft (17) of the catheter is tapered and comes down to a size of typically 12-16 F (4 - 5.4 mm) in outer diameter at the distal end.

[0141] An occlusion balloon (24) is located directly on the distal tip of the bi-directional catheter and has a different shape than the balloons on current PICSO catheters. The location of the occlusion balloon enables occlusion of the CS close to the CS ostium thereby improving the efficacy of the PICSO procedure. The reason for this improved efficacy is that the small and middle cardiac veins empty close to the CS ostium (see 35). Therefore, the further out in the coronary sinus the occlusion balloon can sit, the more CS blood flow it will occlude.

[0142] A right balance between the occlusion balloon location, which influences efficacy, and the correct design and position of an anchor can be determined. This influences safety. As the location of the occlusion balloon will occlude more of the blood volume flow in the CS, there will be a higher force on the balloon during CS occlusion. This force will have to be sustained by the anchor and proper anchor designs and locations are therefore critical.

[0143] The balloon design is different from current balloon designs as it occludes the CS ostium with a diameter of 5 - 20 mm and a relative short landing zone, i.e. then zone where it contacts the CS tissue wall Therefore, instead of being an elongated member 25 - 35 mm long with an outer diameter of 15.5-20 mm, this current design has a relatively short width (25) of 5 - 20 mm and a diameter (26) of 5 - 20 mm.

[0144] Only a partial occlusion of the coronary sinus is needed to increase the coronary sinus pressure. An occlusion of 85 - 95% will already give a substantial pressure increase in the coronary sinus.

[0145] Referring back to FIG. 4, the bi-directional movement of the distal tip is controlled by the lever (12A-B) making it possible to continuously flex the distal tip in both directions from an unflexed position (20A) to the flexed positions (20B and 20C). The drawing shows a 90 degrees flex but the design will allow for a flex to 120 degrees and beyond. The balloon (24) may be inflated in all positions but for ease of rendering it is only shown inflated in the straight position (20A). The shaft has a distal flexible portion (22) allowing bending. The flexible portion (22) of the shaft may be manufactured with different lengths to accommodate for a different bend radiuses (see FIG. 30). This makes the entry into the CS easier depending on the size of the right atrium.

[0146] At the handle’s proximal end, there are four members: a center lumen from which the anchoring guidewire’s (30) proximal end (5)protrudes, a pressure sensor cable (7) which is connected to the console and the balloon inflation/deflation/ measurement lumens (9A-B) also connected to the console.

[0147] Alternatively, the pressure sensor (28) may be integrated into the anchoring guidewire (30) in which case only three members protrude from the proximal end.

[0148] The three lumen A-A cross-section of the shaft (FIG. 5) shows the center lumen (35) which can accommodate the anchoring guide-wire (30, not shown in FIG. 5. In this 10F design, the center lumen has inner diameter of 2 mm which allows for passing a guidewire with the integrated anchor and, potentially, optical pressure sensor. The optical pressure lumen (38) allows for feeding the pressure sensor cable from the handle to the distal tip. The balloon inflation/deflation lumen (40) passes helium gas from the console to the occlusion balloon. This gas is shuttled back and forth to inflate and deflate the balloon. Finally, an outer braided shaft (42) provides mechanical stability and accommodates the deflection wires (45A-B) to steer the distal end.

[0149] In an alternative design, the A-A cross-section has four lumens (FIG. 6). The difference from FIG. 5 is that the optical pressure lumen (38) is smaller and there are two lumens (40A-B) for controlling the occlusion balloon. The balloon inflation/drive lumen (40A) shuttles the helium gas to and from the balloon. The balloon pressure measurement lumen (40B) monitors the internal balloon pressure. The advantage of this design is that the internal balloon pressure can constantly be monitored for safety reason. This balloon pressure value will also provide important information as the balloon starts to occlude the vessel. As the balloon starts to get closer to the vessel wall, a flutter will be seen in the pressure measurement reading and this will disappear when the balloon is in physical contact with the coronary sinus wall. The vessel occlusion pressure can therefore be easily detected and any additional volume infused into the balloon will expand the balloon and therefore stretch the vessel. Based on experimental and preclinical data, the safe balloon occlusion pressure and volume can therefore be identified before entering clinical trials. In yet another revision of this design, the optical pressure sensor may not be incorporated at all allowing the device to be compatible with existing PICSO consoles. The pressure lumen (38) will then be a fluid-filled line as described above.

[0150] In these designs, the inner lumen facilitates the delivery of the anchoring guidewire with or without an optical sensor. The center lumen has an inner diameter of typically at least 2 mm. Assuming a 10 F compatible sheath, the outer diameter will typically be 4.5 - 5 mm leaving the remaining internal area between the center lumen outer diameter and inner diameter of the shaft for the lumens as described above.

[0151] The rear view of the handle (view B-B, FIG. 7) shows the features of the proximal end of a guide sheath and handle. In the center, the anchoring guidewire’s proximal end (5) is shown which may include the integrated pressure sensor or not (in case if mounted on the sheath itself (28)). The anchoring guidewire can be locked to the sheath itself in order to gain stability. This can be done with a first variant of a second proximal locking mechanism (8A) in the handle itself which is activated by a rotational knob located around the center of the lumen (6A, rotation No. 1) or, alternatively, on the outer diameter of the handle (6B, rotation No. 2). Each rotation is indicated by the curved arrows. As shown in more detail in FIGS. 27/28, locking can be achieved by increasing the radial extension of a member arranged coaxially between the anchoring guide wire and the sheath. The member can be e.g. mechanical similar to a shutter or it can be an inflatable balloon.

[0152] As shown in FIG. 8, a second variant of a second locking mechanism may also be activated at the distal end of the sheath (8B). The locking rotation (6A or 6B) may activate proximal (8A) and distal (8B) locking members as follows: [0153] 1. Only the proximal lock (8A) [0154] 2. Only the distal lock (8B) [0155] 3. The proximal and distal locks (8A and 8B)

[0156] The rear end of the handle includes the fiber optical cable output (9) when the pressure sensor (28) is mounted on the distal tip of the flexible shaft. If the pressure sensor is integrated in the anchoring guidewire (30), then the optical cable will exit the assembly through this member. If only one inflation/deflation lumen is used, then the inflation/drive lumen (7A) exits the rear end of the handle. If the balloon inflation/deflation is controlled by two lumens, then the inflation/drive lumen (7A) and the balloon pressure measurement lumen (7B) exit the rear end of the handle.

[0157] FIG. 7 also shows a lever (12) which controls the flexing of the distal end. This lever is communicating with the first internal mechanism of the handle controlling the deflection wires (45A-B) through the members (13A-C).

[0158] View C-C (FIG. 8) shows a view from the distal end of the shaft with the balloon (24) inflated. The integrated pressure sensor (28) is also shown as well as the distal end of the anchoring guidewire (30), the distal locking mechanism (8B) and the shaft itself (17). If the pressure sensor is integrated in the anchoring guidewire, then the pressure sensor will not be on the shaft but as an integrated member of the guidewire.

[0159] In an alternative and simpler overall design of the invention, a steerable design is foreseen in which no occlusion balloon (24) and no pressure sensor (28) are arranged on the steerable sheath. This variant allows placement of commercially available PICSO catheters and keeping the first locking mechanism in the handle (6A-B and 8A) as well as the second distal locking mechanism (8B). This simpler design may also include anchoring mechanisms of the sheath on the external diameter of the sheath as described in anchor design 6 and 8 (see FIGS. 16 and 18).

[0160] In this simpler overall design, the inner lumen will facilitate the delivery of a commercial guide sheath or PICSO catheter. The center lumen will therefore at least accommodate an 8F PICSO catheter (2.67 mm) so that the ID of the sheath typically is not smaller than 3.5 mm including the locking mechanism. The sheath outer diameter will then typically be around 14 F (4.67 mm) but not larger than 16 F (5.33 mm).

C. The Optical Pressure Sensor

[0161] There are several commercial pressure sensors. For example, the optical pressure sensor can be a FISO optical pressure sensor (FISO Technologies Inc., CA) with a distal end with OD 0.31 mm (FISO, 2020, https://fiso.com/wp-content/uploads/2018/10/MC-00263_-Medical-Pressure-Monitoring-Product-Datasheet_R7.pdf. Retrieved from FISO: www.fiso.com) which are available to be integrated into medical devices. However, none of these have to date been used in a CS occlusion catheter.

[0162] As shown in FIG. 4, the optical pressure sensor resides distal to the occlusion balloon. This is for safety reasons and to measure the CS pressure during the PICSO procedure. In FIG. 4 the sensor is integrated at the tip of the steerable sheath. Alternatively, the sensor may also be integrated into the distal end of the anchoring guide-wire (30) which allows for CS pressure measurements further into the vessel and distal to the anchoring member. This has the advantage that possible clotting of the anchoring member may be detected as well.

D. The Different Anchor Designs

[0163] There are several embodiments for the anchor design. Mainly they can be divided in three groups: [0164] 1. Anchors residing in the coronary sinus itself. [0165] 2. Locking mechanisms in the guide sheath. [0166] 3. Anchors residing in the right atrium or inferior vena cava (IVC).

I. Anchor Design No. 1: Anchor on Distal Guidewire With Outer Sleeve

[0167] A first anchor embodiment is shown in FIG. 9. In this design, the anchor (54) resides in the CS (60) further into the CS from the location of the sheath occlusion balloon and into the main part of the CS as shown in FIG. 25.

[0168] Further referring to FIG. 9, the anchor (54) is mounted on a flexible and atraumatic guidewire (50). Also, on the guidewire (50) and proximal to the anchor (54), a seal or sealing balloon (56) is mounted. The seal or sealing balloon (56) is permanently in contact with the inner diameter of the outer sleeve (30a). This seal or sealing balloon blocks blood from entering the sleeve and acts as a safety mechanism to avoid potential clotor microthrombi formation.

[0169] The anchor (54) itself is shown as a braided member of a reshapeable material such as nitinol which expands and presses with an adequate force against the CS wall. However, the anchor may use different forms such as individual wires (described below) or other possible expandable embodiments. However, all anchors must allow blood to flow through the anchor when opened and not to cause any thrombi during the overall procedure time.

[0170] The guidewire may be advanced forward relative to the outer sleeve (30a) and retracted again into the sleeve after the procedure is completed. Referring to FIG. 10, the metal-based anchor deploys when the anchor (54) exits the distal end of the sleeve (30a) and will be compressed when retracted into the distal sleeve again. The blood flow (62A-B) will pass through the anchor. However, due to the seal or sealing balloon (56) the blood will not enter the outer sleeve (30a) and be diverted around the sleeve (62B).

[0171] Referring to FIG. 25, an alternative anchor design (122) sits in the mid- (60A) to distal (60B) portion of the CS. The figure shows the different main vessels feeding into the CS: the left atrial oblique vein (110), the great cardiac vein (112) emptying blood from the left anterior side of the myocardium, the posterolateral marginal vein (114), the posterior ventricular vein (116), the middle cardiac vein (118) and the small cardiac vein (120). As shown in the figure, a CS occlusion balloon (124) resides on a steerable guide sheath (126) which sits close the CS ostium. This is an advantage as the occlusion balloon in this position is able to occlude the blood flow from all veins (110 -120) feeding into the CS (60A-B). This will improve the efficacy of the overall procedure.

[0172] This anchor force against the CS wall is strong enough to stabilize the catheter in the CS during balloon occlusion. However, it will not cause intima wall damage, over-stretching nor rupture of the coronary sinus.

[0173] Anchor design No. 1 has the advantage that an independent movement between balloon shaft and anchoring device is possible. The anchor can be placed deeper into the coronary sinus. The balloon occludes more coronary sinus blood flow. The anchor can be axially locked with respect to the balloon.

II. Anchor Design No. 2: Anchor on Distal Guidewire Without Outer Sleeve

[0174] A second anchor embodiment is shown in FIG. 11 which shows an anchor (65) on the guidewire in the unexpanded position. This design is simplified to avoid the outer sleeve and only contains the atraumatic guide wire (30) with the expandable anchor (65). This anchor is fixed at the distal end of the guide wire using a soldering ring or fixation element (72). This element (72) may also act as a marker band for angiographic visibility. On the proximal side, the anchor is fixed in a similar manner to a moveable member (74) which also may act as a proximal marker band. The expansion of the anchor is controlled by a moving element (67) inside the guidewire itself which when advanced expands the anchor (65) in the coronary sinus (60) in a controlled manner and under angiographic guidance. Alternatively, the anchor (65) may be expanded by an outer member (69) which opens the anchor when pushed forward. Using this approach, an optical pressure guidewire (78) can pass in the middle of the guidewire. The expanded anchor with this configuration is shown in FIG. 23.

[0175] Referring to FIG. 12, the anchor (65) is expanded and presses against the CS wall (60). A blood stream (62A) will not be restricted to pass the anchor in the expanded position and the anchor will be designed to avoid any thrombi formation of the blood. This can be achieved with different wire coatings on the anchor wires.

[0176] Anchor design No. 2 is easier to manufacture than design No. 1 as no sealing balloon is needed. The outer diameter of the guidewire and the anchor size can be optimized.

III. Anchor Design No. 3: Optical Pressure Sensor Placed Into the Anchored Distal Guidewire

[0177] FIG. 13 shows view A-A of FIG. 12. Here the guidewire main body (30) is shown as well as the expanded anchor. As discussed above, an optical pressure wire (78) is integrated at the distal end of the guidewire. This will allow for pressure monitoring distal to the anchor which may be an advantage to monitor the very distal CS pressure. This is also a safety aspect of this design as potential clotting of the anchor may be detected by the pressure sensor.

[0178] This configuration is also shown in FIG. 23.

[0179] In another configuration and in case the anchor is placed on the guide sheath itself, the guidewire may only include the guide-wire function and the pressure sensor.

[0180] Anchor design No. 3 has the advantage that the pressure can be measured distal to the anchor and thus may also detect clotting of the anchor. It reduces the number of wires from the rear part of the handle as the optical wire will exit at the rear end of the anchor/guidewire design.

IV. Anchor Design No. 4: Anchor on Guide Sheath: Balloon in a Cage

[0181] FIG. 14 shows an anchor (80) placed on the guide sheath (17) itself.

[0182] In this design, the guidewire (30) passes in the center of the guide sheath and the optical pressure sensor (28) is mounted on the distal tip of the sheath.

[0183] After placement of the sheath into the coronary sinus, the anchor is expanded by pushing a moveable proximal member (84) which also may be a marker band. On the distal side of the sheath, the anchor is fixed to a non-moving member (82) which also may act as an angiographic marker band.

[0184] The anchor (80) is circumferentially arranged around a balloon (24).

[0185] When a stable position is found and the CS wall is expanded sufficiently by the anchor, the occlusion balloon (24) may start to intermittently occlude the CS blood flow.

[0186] The position of this design will naturally have to be further into the CS as shown in FIG. 26.

[0187] Anchor design No. 4 has one integrated member, the locking between sheath and anchor is not needed. There is one location for balloon and anchor.

V. Anchor Design No. 5: Anchor Distal to Balloon (on Guide Sheath)

[0188] The anchor of FIG. 15 is placed on the guide sheath and in this configuration the anchor is placed distal to the balloon (24). Referring to FIG. 15, the anchor (80) is placed close to the distal tip of the steerable guide sheath (17). Again, the anchor may be expanded and collapsed by a moveable member (84) and the fixed member (82) secures the anchor on the distal end. Both these members may be used as angiographic marker bands. The occlusion balloon (24) sits on the guide sheath proximal to the anchor.

[0189] The advantage of this design is that the distance (81) between the anchor and balloon may be adjusted so that the balloon sits closer to the CS ostium thereby occluding more of the CS blood flow.

[0190] Anchor design No. 5 also has an integrated member and thus no locking between the sheath and anchor is needed. When there is a small difference in the outer diameter between the shaft and inner diameter of the CS ostium, the relative movement (81) to expand the anchor (80) can be small. This reduces the distal length of the device.

VI. Anchor Design No. 6: Anchor Proximal to Balloon (on Guide Sheath)

[0191] Referring to FIG. 16, the balloon (24) is placed distal to the anchor (80). As in the two previous designs, the anchor may be expanded and collapsed by a moveable member (84) and the fixed member (82) secures the anchor at the distal end. Both of these members may be used as angiographic marker bands.

[0192] The anchor design No. 6 may allow a better centering of the balloon when procedure starts.

VII. Anchor Design No. 7: Guide Sheath With Locking Mechanism of Guidewire or Picso Catheter Either Proximal or Distal or a Combination of the Two

[0193] In another implementation (FIG. 17) of the anchor, the anchoring effect of the guide wire or a commercial available PICSO catheter is achieved by locking these devices in the guide sheath, or shaft, respectively, itself. This design is for the delivery of these devices only and does not integrate the occlusion balloon or the pressure sensor. However, the guide sheath is bi-directionally steerable as described before (the handle steering mechanism is not shown in FIG. 17).

[0194] Referring to the same figure, the locking mechanism may be located in the proximal handle (8A and/or 8C) and/or in the distal tip of the sheath (8B). The fixation of the PICSO catheter or guide sheath will likely be most effective the more distal to the tip the locking mechanism is incorporated.

[0195] As shown in FIG. 27 and FIG. 28, the locking mechanism may either be mechanical (like a clamp or shutter) or achieved by a balloon which is inflated around the inner member. The advantage of the latter is that the inner diameter of the shaft (17) may have a balloon like lining which is allowed to expand at certain locations when helium or air is pushed down this lining.

[0196] The advantage of the mechanical locking mechanism is that they are more stable than a balloon.

[0197] Anchor design No. 7 provides a very simple guide sheath. It is quick and relatively cheap to develop. It can help current PICSO procedures.

VIII. Anchor Design No. 8: Anchor on Guide Sheath in the Right Atrium or Inferior Vena Cava

[0198] Referring to FIG. 18 showing anchor design No. 8, this solution provides an anchoring mechanism of the sheath completely outside the coronary sinus in the right atrium (RA) or the inferior vena cava (IVC). The RA anchor position (90A) is an expandable metal frame which opens like an umbrella in the RA. The metal frame is fastened with a fixation element (95) proximal to the flexible portion of the shaft. The opening and closing of the umbrella are controlled from the handle of the sheath.

[0199] Alternatively, the expandable metal frame (90B) is placed in the IVC and presses in a radial fashion on the inner diameter of this vessel. The opening and closing of this frame are also controlled from the handle.

[0200] Anchor design No. 8 does not engage the coronary sinus and lowers the risk of CS complications.

IX. Anchor Design No. 9: Individual Anchor Wires Instead of Braided Anchor

[0201] Finally, and instead of using a braided design of the anchor, the anchor may be designed with 2 - 10 individual wires or more independent wires alongside the shaft. These wires are also memory shaped using materials like nitinol.

[0202] FIG. 19 shows a balloon in such a cage design with four individual wires (100, 102, 104 and 106). The wires are expanded with a moveable member as described before.

[0203] FIG. 20 shows a design with an anchor distal to the occlusion balloon again with the four independent wires.

[0204] FIG. 21 shows a design with a balloon distal to the anchor with four independent wires.

[0205] FIG. 22 shows the anchor in the outer sleeve design shown in FIGS. 9 and 10 with the four independent wires and the sealing balloon.

[0206] A similar design can be realized on the guide wire without the outer sleeve and balloon as shown in FIG. 24.

[0207] Anchor design No. 9 is an easy anchor design and easy to manufacture.

[0208] Any variation of the anchor designs may of course also be implemented.

E. Improved Balloon Design

[0209] The current PICSO catheters have an elongated balloon with a length of 10 - 15 mm. This requires that these balloons (140) are pushed further into the CS to gain stability as shown in FIG. 29. This location reduces the efficacy of the PICSO procedure.

[0210] The proposed new balloons (142) may be placed further out in the CS thereby occluding more of the CS blood flow. These balloons have a larger diameter (up to 20 - 25 mm) than current occlusion balloons and have a short width more suitable to occlude the CS ostium itself. They can be compliant or semi-compliant in design. The balloons may be inflated by hand or automatically from a console.

[0211] Referring to FIG. 4 and FIG. 14, the balloon has a torus shape attached to the shaft (the “neck”) over a relative short length typically 3-15 mm. The radius of the occlusion balloon, however, can be extended substantially more, typically to 10 -25 mm. The preferred design is that the surface contacting the vessel wall is wider than the neck and enables uniform force distribution along the contacting surface.

[0212] In another balloon design, a more pancake shape can be selected to that the neck and contacting surface have more or less the same length.

[0213] In both designs the outer diameter (OD) is preferably larger, typically 10 - 20 mm, than the axial length of the balloon.

F. The Steerable Distal End

[0214] The steerable distal end is shown in FIG. 30 - FIG. 33.

[0215] FIG. 30 shows different bend radiuses of the distal end typically 30 mm (145A), 45 mm (145B) or 60 mm (145C).

[0216] A longitudinal cross-section of the flexible end of the shaft is shown in FIG. 31. Braided wires (148A-B), compatible with 45A and 45 B in FIG. 5, control the flexing of the distal tip and may be locked in any position using the locking mechanism in the handle. The wires are attached to the last member (152) by soldering or other techniques using the two positions 154A-B. The connecting members (150) are hinged together to facilitate the needed flex of the distal end.

[0217] FIG. 32 shows the braided wires (148A-B) on the outside of the inner shaft (159). This makes the assembly of the shaft easier as the wires may be placed on the outside of the solid shaft and allows for a larger internal volume. The wires are protected by an outer sleeve (158).

[0218] In another design and as shown in FIG. 33, the braided wires are fed through extruded holes in the external member (162) of the shaft. This design may be safer but on the expense of the inner volume of the shaft.

G. The Improved Handle Design

[0219] As described in the background of the invention, the current handle designs are not optimized for human manipulation. As shown in FIG. 4, there are several new functions which are integrated in the improved handle design: [0220] 1) A lever mechanism (12A-B) to steer the distal end (20A-C). [0221] 2) A first locking mechanism (15) which can be used to lock the tip in the desired location. [0222] 3) The second locking rotation mechanism (6A-B) is used to activate proximal and distal locking members (8A-B in FIG. 7andFIG. 8). These members are further described and shown in FIG. 27and FIG. 28 as shutter like radially expandable locking members 130 and 132 and in FIG. 17as members 8A-C. If air or helium is used to fixate the PICSO catheter or guidewire, then an inflation port will have to be integrated in the handle as well. [0223] 4) Fixation members for the handle as shown in Figure. [0224] 5) Finally, and as shown in FIG. 7, the rear end of the handle provides connections to the balloon inflation lumens (7A-B) and the optical sensor (9). The distal end of the guidewire (5) with or without an optical sensor or anchor is passed through the center lumen of the shaft. [0225] 6) For later designs, the following functions may also be incorporated in the handle: [0226] a. Advance of the anchor to the right position under angiographic guidance [0227] b. Opening and closing the anchor [0228] c. Repositioning of the anchor

[0229] FIG. 34 shows an experimental set up for testing the devices in a preclincal model. A commercial available guide sheath such as the 8F Oscor sheath with OD 4.10 mm and ID 2.9 mm can accommodate a 2 mm anchor design with a commercial available OpSens pressure wire with OD 0.36 mm. This requires that the anchor is off center for the experimental set-up.

[0230] FIG. 35 shows the anatomy of the coronary sinus showing the coronary sinus ostium and the emptying of the small and middle cardiac veins close to the ostium as well as the other veins emptying into the CS further into the vessel.

[0231] FIG. 36 shows a schematic frontal cross section of the atria centered on the circumferential interatrial view. It shows the three interatrial connections crossing over the sulcus: the Bachmann bundle (BB) crosses the upper quadrant, the coronary sinus (CS) bundle crosses the lower quadrant, and the LA-AV nodal connection (left-right) crosses the anterior quadrant. The AV node has a larger expansion to the right and smaller to the left (L). Shown are also the inferior vena cava (IVC), superior vena cava (SVC), fossa ovale (FO), left atrium (LA) and the left atrial appendage (LAA).