Bending-adjustable guide cannula for pulmonary artery interventional therapy

Abstract

The invention relates to a bending-adjustable guide cannula for pulmonary artery interventional therapy. The bending-adjustable guide cannula comprises an outer sheath and an inner tube, the sheath is long enough to penetrate through the heart from the peripheral vein to be communicated to the pulmonary artery; the far end of the outer sheath is arranged to be a first bending part B with the inherent bending angle ranging from 80 degrees to 100 degrees. The inner tube is slidably arranged in the outer sheath in a penetrating mode, and the far end of the inner tube is provided with an inner tube bending adjusting section capable of being controlled to deflect through a pull wire; and the bending part is a second bending part A. By adjusting the handheld part, the axial distance between the two bending points of the fixed bend B and the adjustable bend A can be dynamically changed, in combination with the 360-degree rotating capacity of the inner tube and fine control over the angle of the bend adjusting section through the rotary knob, an operator can construct various composite bends in real time in the operation, pulmonary artery branch openings originating from different angles are accurately anchored, and the operation efficiency is improved. And a strong active supporting force is provided.

Description

Technical Field

[0001] This invention relates to an adjustable guide cannula for balloon pulmonary artery angioplasty, belonging to the field of pulmonary artery interventional therapy technology. Background Technology

[0002] Chronic thromboembolic pulmonary hypertension (CPPH) is characterized by chronic thrombus obstruction within the pulmonary artery lumen and secondary pulmonary vascular remodeling, leading to progressively increasing pulmonary vascular resistance and ultimately right heart failure or even death. Balloon pulmonary angioplasty is currently an effective interventional method for treating patients with chronic thromboembolic pulmonary hypertension who are not candidates for surgical intervention. In balloon pulmonary angioplasty, the delivery sheath serves as the channel for the balloon catheter, guidewire, and other instruments to enter and exit the pulmonary artery. Currently used delivery catheters are mostly universal catheters used in coronary artery or congenital heart disease interventional treatments, lacking dedicated catheters designed specifically for pulmonary artery anatomy, which presents the following significant drawbacks:

[0003] 1) Difficulty in catheter placement, frequent catheter changes: Conventional sheaths have a fixed, curved tip that cannot be adjusted; even with adjustable curved sheaths, there are two bends ( Figure 1 The problem of a fixed distance between the two curved sections (A and B).

[0004] 2) Precise positioning is impossible in complex pulmonary artery branches (left, right, upper, middle, and lower). Furthermore, balloon pulmonary angioplasty requires handling multiple vessels in a single procedure, and intraoperative intervention in different pulmonary artery branches is challenging ( Figure 1 As shown in the figure, it is necessary to frequently change different curved catheters, which not only increases the operation time, but also increases the risk of air embolism, thrombosis and vascular damage.

[0005] 3) Poor stability of the delivery system: The path from peripheral veins (e.g., from the femoral vein in the groin) to the pulmonary artery is tortuous, requiring the sheath shape to conform to the anatomical structure of the left and right pulmonary artery trunks and to have high support to push the instruments. Traditional sheaths lack the anatomical curves specifically designed for the pulmonary artery trunks, or their insufficient rigidity leads to inadequate support and system instability, affecting surgical procedures.

[0006] Therefore, it is necessary to design a special guiding cannula suitable for balloon pulmonary artery angioplasty based on the anatomical characteristics of the heart and pulmonary arteries. Summary of the Invention

[0007] The purpose of this invention is to provide an adjustable guide cannula for pulmonary artery interventional therapy, which simultaneously has a fixed bend, an adjustable bend, and a distance between the two bends. Figure 1 The adjustable spacing between the two bends (A and B) significantly improves the catheter placement rate and support force, thereby increasing the success rate of the operation and reducing the operation time and risk.

[0008] The present invention adopts the following technical solution:

[0009] An adjustable guide cannula for pulmonary artery interventional therapy includes: an outer sheath 1 and an inner tube 2; the outer sheath 1 is of a length adapted to pass through the heart from a peripheral vein to the pulmonary artery; the distal end of the outer sheath 1 is configured as a first bend B with an inherent bending angle of 80°-100°; the inner tube 2 is slidably inserted into the outer sheath 1, and its distal end has an inner tube bending section 21 whose deflection can be controlled by a pull wire 4; its bending portion is a second bend A.

[0010] Preferably, the inherent bending angle of the inner tube bending section 21 is 145-155°, and it has self-resetting elasticity in its natural state; the first bending part B of the outer sheath 1 also has self-resetting elasticity in its natural state.

[0011] Preferably, the inner tube 2 is provided with a handle 3 at its proximal end, which is provided with a knob 31 and a hand-held part 32; the knob 31 is connected to the pull cable 4 and is used to control the deflection of the inner tube bending section 21; the hand-held part 32 is integrally connected to the inner tube 2 and is used to drive the inner tube 2 to move axially and rotate circumferentially relative to the outer sheath 1.

[0012] Furthermore, by rotating the handheld part 32, the relative circumferential position of the inner tube bending section 21 and the outer sheath fixing bending section 11 is changed, thereby adjusting the direction of the second bending section A; by axially moving the handheld part 32, the relative axial position of the inner tube bending section 21 and the outer sheath fixing bending section 11 is changed, thereby adjusting the double-bend distance between the first bending section B and the second bending section A.

[0013] Furthermore, a pipe is embedded in the inner wall along the axial direction, and the pull wire 4 is installed inside it;

[0014] Furthermore, the near end of the pull wire 4 is wound and fixed to the rotating shaft of the knob 31, and the knob 31 is provided with a component for locking the rotation.

[0015] Furthermore, the inner tube bending section 21 is a unidirectional adjustable bending section, and the pull wire 4 is a bundle, with a minimum of one wire.

[0016] Preferably, a hemostatic valve 5 is provided at the proximal end of the outer sheath 1.

[0017] Preferably, the outer sheath 1 is equipped with a sheath core unit 6, the tip of which protrudes from the distal end of the outer sheath, and the sheath core unit 6 has a channel inside for the guide wire to pass through; the sheath core unit 6 is used to drive the outer sheath 1 from the peripheral blood vessels into the designated position of the pulmonary artery, and then remove it.

[0018] Preferably, the inner tube 2 has a metal braided layer or coil embedded in its wall to enhance its bending resistance and torque transmission capability.

[0019] The beneficial effects of this invention are as follows:

[0020] 1) Improve delivery rate and accuracy, simplify operations and reduce risks:

[0021] The integrated fixed bend (first bend B, adapting to the anatomy of the main pulmonary artery), adjustable bend (second bend A, adapting to variations in pulmonary artery branches), and dual sheath design allow the catheter to adapt to complex pathways from the main pulmonary artery to secondary branches in a single procedure, achieving "one catheter, multiple functions." This eliminates the need for frequent intraoperative catheter changes, enabling precise access to the target vessel. A single catheter can be continuously and dynamically adjusted intraoperatively, rapidly responding to individual differences in vascular anatomy, even when dealing with different branch vessels. This shortens surgical time and reduces the potential damage and risks of thrombosis and air embolism caused by blind manipulation with the catheter and vessel out of sync and frequent instrument exchanges.

[0022] 2) Enhance system support stability and improve surgical success rate:

[0023] The hardened outer sheath, adapted to the main pulmonary artery, minimizes system sway caused by cardiac activity. Adjustable bend spacing (between A and B) and a flexible bend shape securely hold the distal end of the catheter at the vascular opening, forming a stable mechanical support platform. This effectively resists the reaction forces generated during balloon or guidewire advancement, preventing system slippage or displacement and facilitating guidewire passage through narrowed or occluded vessels. Stable support and precise delivery ensure the safe and effective delivery of therapeutic devices (such as balloons) to the lesion site, laying a solid foundation for the successful implementation of balloon pulmonary angioplasty. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the adjustable guide cannula of the present invention used in pulmonary artery interventional therapy.

[0025] Figure 2 This is a schematic diagram of the outer sheath assembly (including sheath core unit 6).

[0026] Figure 3 This is a structural diagram of the inner tube assembly (including the handle).

[0027] Figure 4 This is a cross-sectional schematic diagram of the area where the inner tube and the outer tube are nested together.

[0028] In the picture:

[0029] 1. Outer sheath, 2. Inner tube, 3. Handle, 4. Pull cord, 5. Hemostatic valve, 6. Sheath core unit;

[0030] 11. Outer sheath fixing bend section; 12. Outer sheath main body section;

[0031] 21. Inner pipe bending section; 22. Inner pipe main body section;

[0032] 31. Knob; 32. Hand grip;

[0033] A. Second bend, B. First bend. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] See Figure 1 An adjustable guiding cannula for pulmonary artery interventional therapy includes: an outer sheath 1 and an inner tube 2; the outer sheath 1 is of a length adapted to pass through the heart from a peripheral vein (generally the femoral vein in the groin) to the pulmonary artery, therefore, Figure 1 The length of the outer sheath 1 shown is insufficient in proportion; it is actually a relatively long section of pipe.

[0036] Combination Figure 1-2 The outer sheath 1 is driven into the human blood vessel by the sheath core unit 6. After the outer sheath 1 is in place, the sheath core unit 6 is removed. This action and process is the existing technology. However, the outer sheath 1 of the existing technology is only a short length and does not extend into the pulmonary artery.

[0037] Combination Figure 1-2 The distal end of the outer sheath 1 is configured as a first curved portion B with an inherent bending angle of 80°-100° (preferably 90°); the "inherent bending angle" refers to the bending state of the outer sheath in its natural state. The outer sheath itself has a certain elasticity and can change its bending angle under the action of external force, and will tend to self-reset after the external force is completely removed.

[0038] Combination Figure 1-3 The inner tube 2 is slidably inserted into the outer sheath 1, and its distal end has an inner tube bending section 21 that can be deflected by a pull wire 4; the bending part is the second bending part A. The inherent bending angle of the inner tube bending section 21 is 145-155° (preferably 150°). Similarly, this "inherent bending angle" refers to the bending state of the outer sheath in its natural state. The inner tube 2 itself has a certain elasticity and can change its bending angle under the action of external force, and will tend to self-reset after the external force is completely removed.

[0039] See Figure 3 and combined Figure 1 The inner tube 2 is provided with a handle 3 at its proximal end, which is provided with a knob 31 and a hand-held part 32; the knob 31 is connected to the pull cable 4 and is used to control the deflection of the inner tube bending section 21; the hand-held part 32 is integrally connected to the inner tube 2 and is used to drive the inner tube 2 to move axially and rotate circumferentially relative to the outer sheath 1.

[0040] It should be noted that the inner tube 2 is inserted from the proximal end of the outer sheath 1 after the outer sheath 1 is pushed into place, until it extends out of the outer sheath 1 at the pulmonary artery.

[0041] Continue to combine Figure 1 and Figure 3 By rotating the handheld part 32, the relative circumferential position of the inner tube bending section 21 and the outer sheath fixing bending section 11 is changed to adjust the direction of the second bending section A; at the same time, by axially moving the handheld part 32, the relative axial position of the inner tube bending section 21 and the outer sheath fixing bending section 11 is changed to adjust the double bending distance between the first bending section B and the second bending section A.

[0042] Thus, it can be seen that in this invention, the distance between the first curved portion B and the second curved portion A can be adjusted. In the prior art, there are two methods:

[0043] The first method uses a very short sheath. After the sheath is positioned, the inner tube is inserted. The direction of the inner tube is adjusted solely by the elasticity of the inner tube itself. When dealing with different pulmonary artery branches, the inner tube needs to be replaced, which is a rather complicated operation.

[0044] The second method involves setting two pull lines at different parts of the inner tube and using bidirectional adjustable pull lines to adjust the bending of different parts of the inner tube, so that the inner tube itself produces two bending sections A and B. However, this method cannot adjust the distance between the two bending sections A and B.

[0045] Therefore, the core of this application is that by adjusting the handheld part 32, the axial distance between the two bending points, "fixed bend B" and "adjustable bend A", can be dynamically changed. Combined with the 360-degree rotation capability of the inner tube itself and the precise control of the bend angle by the knob, the operator can construct a variety of composite bends (such as "S" shape, "C" shape, etc.) in real time during the operation to accurately anchor to the pulmonary artery branch openings originating from different angles and provide strong active support.

[0046] See Figure 4 A pipe is embedded in the inner wall along the axial direction, and the pull wire 4 is installed inside it;

[0047] See Figure 3 The near end of the pull wire 4 is wound and fixed to the rotating shaft of the knob 31, and the knob 31 is provided with a component for locking the rotation.

[0048] See Figure 3 In this embodiment, the inner tube bending section 21 is a unidirectional adjustable bending section, and the pull wire 4 is a bundle, with a minimum of one wire.

[0049] Furthermore, it should be noted that using a pull wire to adjust the bending degree of the inner tube is existing technology and is not a contribution of this application to the prior art. Therefore, its detailed structure is not described in detail in this embodiment. For the convenience of the reader, only some principle explanations are given.

[0050] See Figure 2 The proximal end of the outer sheath 1 is provided with a hemostatic valve 5.

[0051] exist Figure 2 The document also shows a sheath core unit 6, which is equipped with an outer sheath 1. The tip of the sheath core unit 6 extends from the distal end of the outer sheath, and the sheath core unit 6 has an internal channel for a guidewire to pass through. The sheath core unit 6 is used to guide the outer sheath 1 from a peripheral blood vessel to a designated location in the pulmonary artery, where it is then removed. The sheath core unit 6 functions as a support to move the sheath 1, and it has a guidewire at its center. The sheath core unit 6 itself is prior art and is not the focus of this application.

[0052] In this embodiment, preferably, the inner tube 2 has a metal braided layer or coil embedded in its wall to enhance its resistance to bending and torque transmission capability. This is not shown in the accompanying drawings.

[0053] Further explanation of the principle:

[0054] See Figure 2 The outer sheath 1 is made of polymer material, and its distal portion is pre-formed by heat setting into a fixed bend shape that conforms to the anatomical course of the right ventricular outflow tract to the left / right pulmonary artery trunk, namely the fixed bend segment 11 of the outer sheath. The proximal end is a straight tubular main body segment 12 of the outer sheath. A hemostatic valve 5 is provided at the proximal end of the outer sheath to prevent blood leakage. In addition, a sheath core unit 6 is provided, which has a channel for the guidewire to pass through. It can be inserted into the outer sheath, and the head end of the sheath core unit protrudes from the distal end of the outer sheath.

[0055] See Figure 3 The inner tube 2 is made of a highly elastic, bend-resistant polymer material (such as Pebax). Its distal portion (the bending section 21) has a supporting metal braided mesh or coil embedded in its wall, with a pre-reserved weak area for easy bending. At least one pull wire 4 runs through the inner tube wall, its distal end fixed near the tip of the bending section 21, and its proximal end wound and fixed to the pivot of the first knob 31 inside the handle 3. The proximal end of the inner tube is divided into the inner tube main body section 22.

[0056] Combination Figure 1 and Figure 3The handle 3 is fixedly connected to the proximal end of the inner tube body section 22. The knob 31 is connected to the pull cable 4. Rotating the knob 31 clockwise or counterclockwise can precisely pull or release the pull cable 4, thereby causing the inner tube bending section 21 to deflect in one direction. The handhold 32 is connected to the handle 3 body through a threaded structure. Rotating the handhold 32 can drive the entire inner tube 2 to move forward, backward, or rotate circumferentially relative to the outer sheath 1.

[0057] Surgical procedure:

[0058] Under guidewire guidance, the assembled outer sheath 1 and sheath core unit 6 are first advanced to the left / right main pulmonary artery, then the sheath core unit 6 is withdrawn, leaving the outer sheath 1 intact. Next, the inner cannula 2 is inserted through the outer sheath 1 to complete the in vivo assembly of the cannula. Subsequently, the operator can perform precise procedures using the following steps:

[0059] Preliminary positioning: Using the fixed bend 11 of the outer sheath 1, point the tip of the outer sheath catheter toward the opening of the target pulmonary artery.

[0060] Depth of insertion: Under X-ray fluoroscopy, the inner tube tip is inserted into the vicinity of the target segment-level branch.

[0061] Shape matching: Rotate knob 31 to deflect inner tube bending section 21, rotate and / or push handpiece 32 to make inner tube bending section 21 and outer sheath fixing bending section 11 form a composite bend suitable for the target blood vessel angle. At this time, inner tube 2 is coaxially inserted into the target blood vessel. The double-bend structure can provide extremely strong radial support and axial stability.

[0062] Treatment completion: Keep the guiding cannula stable and deliver the guidewire, balloon catheter, and other treatment instruments through its lumen to the lesion for dilation. The shape can be adjusted as needed during the procedure to accommodate different branches.

[0063] In summary, the present invention has the following two core advantages:

[0064] 1) Improved accuracy and precision, simplified operation, and reduced risk: The integrated fixed bend (first bend B, adaptable to the anatomy of the main pulmonary artery), adjustable bend (second bend A, adaptable to variations in pulmonary artery branches), and dual sheath design allow the catheter to adapt to complex pathways from the main pulmonary artery to secondary branches in a single procedure, achieving "one catheter, multiple functions." This eliminates the need for frequent intraoperative catheter changes, enabling precise access to the target vessel. A single catheter can be continuously and dynamically adjusted intraoperatively, rapidly responding to individual differences in vascular anatomy, even when dealing with different branch vessels. This shortens surgical time and reduces the potential damage and risks of thrombosis and air embolism caused by blind manipulation with the catheter and vessel out of sync and frequent instrument exchanges.

[0065] 2) Enhanced system stability and improved surgical success rate: The hardened outer sheath, adapted to the main pulmonary artery, minimizes system sway caused by cardiac activity. Adjustable bend spacing (between A and B) and a flexible bend shape securely hold the distal end of the catheter at the vascular opening, forming a stable mechanical support platform. This effectively resists the reaction forces generated during balloon or guidewire advancement, preventing system slippage or displacement and facilitating guidewire passage through narrowed or occluded vessels. Stable support and precise delivery ensure the safe and effective delivery of therapeutic devices (such as balloons) to the lesion site, laying a solid foundation for the successful implementation of balloon pulmonary artery angioplasty.

[0066] The above are preferred embodiments of the present invention. Those skilled in the art can make various modifications or improvements based on these embodiments. Without departing from the overall concept of the present invention, such modifications or improvements should fall within the scope of protection claimed by the present invention.

Claims

1. An adjustable guide cannula for pulmonary artery interventional therapy, characterized in that, include: Outer sheath (1), inner tube (2); The length of the outer sheath (1) is adapted to be sufficient to pass through the heart from the peripheral veins to the pulmonary artery; the distal end of the outer sheath (1) is configured as a first bend (B) with an inherent bending angle of 80°-100°. The inner tube (2) is slidably inserted into the outer sheath (1), and its distal end has an inner tube bending section (21) that can be deflected by a pull wire (4); the bending part is the second bending part (A).

2. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 1, characterized in that: The inherent bending angle of the inner tube bending section (21) is 145-155°, and it has self-resetting elasticity in its natural state; the first bending part (B) of the outer sheath (1) also has self-resetting elasticity in its natural state.

3. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 1, characterized in that: The inner tube (2) has a handle (3) at its proximal end, which has a knob (31) and a hand grip (32). The knob (31) is connected to the pull wire (4) and is used to control the deflection of the inner tube bending section (21); The handheld part (32) is integrally connected to the inner tube (2) and is used to drive the inner tube (2) to move axially and rotate circumferentially relative to the outer sheath (1).

4. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 3, characterized in that: By rotating the hand-held part (32), the relative circumferential position of the inner tube bending section (21) and the outer sheath fixing bending section (11) is changed, so as to adjust the direction of the second bending part (A); By axially moving the handpiece (32), the relative axial position of the inner tube bending section (21) and the outer sheath fixing bending section (11) is changed, so as to adjust the double bend distance between the first bending section (B) and the second bending section (A).

5. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 3, characterized in that: A pipe is embedded in the inner wall along the axial direction, and the pull wire (4) is installed inside it.

6. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 5, characterized in that: The proximal end of the pull wire (4) is wound and fixed to the pivot of the knob (31). The knob (31) is provided with a component for locking the rotation.

7. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 2, characterized in that: The inner tube bending section (21) is a unidirectional adjustable bending section, and the pull wire (4) is a bundle, with a minimum of one wire.

8. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 1, characterized in that: The proximal end of the outer sheath (1) is provided with a hemostatic valve (5).

9. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 1, characterized in that: The outer sheath (1) is equipped with a sheath core unit (6), the head end of which protrudes from the distal end of the outer sheath. The sheath core unit (6) has a channel inside for the guide wire to pass through. The sheath core unit (6) is used to drive the outer sheath (1) from the peripheral blood vessels into the designated position of the pulmonary artery, and then remove it.

10. The adjustable guide cannula for pulmonary artery interventional therapy as described in claim 1, characterized in that: The inner tube (2) has a metal braided layer or coil embedded in its wall to enhance its resistance to bending and torque transmission.

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