Bare crown stent release assembly for ascending aortic covered stent delivery system

Abstract

The present invention discloses a bare crown stent release assembly for an ascending aortic covered stent delivery system, belonging to the technical field of minimally invasive surgery, and is designed to solve problems such as the difficulty for existing stents to accurately reach the set position. The bare crown stent release assembly for the ascending aortic covered stent delivery system of the present invention includes a proximal bare crown stent, a balloon dilator, and a balloon dilator release knob. The balloon dilator and the balloon dilator release knob are respectively arranged on the ascending aortic covered stent delivery system. The balloon dilator is located inside the proximal bare crown stent, and the balloon dilator release knob is configured to control the dilation and contraction of the balloon dilator; the proximal bare crown stent is configured to expand along with the dilation of the balloon dilator. The bare crown stent release assembly for the ascending aortic covered stent delivery system of the present invention can make the proximal bare crown stent accurately fit with the inner wall of the target diseased blood vessel, and solves the problem that minimally invasive surgery is not suitable for ascending aortic dissection.

Description

Technical Field

[0001] The present invention relates to the technical field of minimally invasive surgery, and particularly to a bare crown stent release assembly for an ascending aortic covered stent delivery system and an ascending aortic covered stent delivery system including the bare crown stent release assembly. Background Art

[0002] Aortic aneurysms located in the ascending aorta often involve the aortic sinus, causing deformation of the aortic valve annulus and separation of the valve leaflets, resulting in aortic valve insufficiency, and long-term effects causing heart failure. Currently, only open surgical treatment can be used, such as open thoracotomy and artificial blood vessel replacement, such as Bentall surgery (using a polyester blood vessel with an artificial aortic valve and reimplanting the coronary artery into the polyester blood vessel), Wheat surgery, etc. When performing open surgical treatment, cardiac arrest and extracorporeal circulation are required, and the surgical trauma is huge, with high mortality and complication rates.

[0003] Due to the complex anatomical structure of the ascending aorta, there are the heart, valves, and coronary arteries at the proximal end near the heart, and supra-arch branch arteries supplying blood to the brain and upper extremities at the back. Coupled with the high blood flow pressure, fast flow rate, large pulsation and deformation amplitude of the blood vessel wall in the ascending aorta, and the critical nature of ascending aortic dissection, it forces the stent to be difficult to accurately locate in an extremely limited area. The anchoring of the stent must overcome the pulsation and deformation of the blood vessel wall, prevent backward displacement or even tearing of the dissection, and avoid the stent extending forward into the sinus to prevent damage to the valve and blockage of the coronary artery, resulting in the difficulty of applying endovascular minimally invasive technology to the treatment of the ascending aorta. Summary of the Invention

[0004] An object of the present invention is to provide a bare crown stent release assembly for an ascending aortic covered stent delivery system that can accurately fit the inner wall of the target diseased blood vessel with the proximal bare crown stent.

[0005] Another object of the present invention is to provide an ascending aortic covered stent delivery system that can realize the application of endovascular minimally invasive technology to the treatment of the ascending aorta.

[0006] To achieve this purpose, on the one hand, the present invention adopts the following technical solutions:

[0007] A bare crown stent release assembly for an ascending aortic covered stent delivery system includes a proximal bare crown stent, a chronic dilator, and a chronic dilator release knob. The chronic dilator and the chronic dilator release knob are respectively arranged on the ascending aortic covered stent delivery system. The chronic dilator is located inside the proximal bare crown stent, and the chronic dilator release knob is configured to control the expansion and contraction of the chronic dilator; the proximal bare crown stent is configured to expand with the expansion of the chronic dilator.

[0008] In particular, the bare crown stent release assembly further includes a tensioning rope buckle. The proximal bare crown stent is tied to the chronic dilator through the tensioning rope buckle, and the restraint on the proximal bare crown stent can be released when the tensioning rope buckle is loosened.

[0009] In particular, the bare crown stent release assembly further includes a bare crown stent release switch. One end of the tensioning rope buckle is connected to the bare crown stent release switch, and the bare crown stent release switch is configured to be able to loosen the tensioning rope buckle.

[0010] In particular, the proximal bare crown stent is respectively tied to the chronic dilator through a plurality of the tensioning rope buckles. All the tensioning rope buckles are connected in sequence and there is a set distance between two adjacent tensioning rope buckles.

[0011] In particular, the tensioning rope buckle is formed by tying a rope with the ability of elastic deformation.

[0012] In particular, front barbs and rear barbs are provided on the proximal bare crown stent. The front barbs are in the proximal position relative to the rear barbs. The tip of the front barb faces the distal end, and the tip of the rear barb faces the proximal end.

[0013] In particular, the inclination angles of both the front barbs and the rear barbs are between 30° and 45°.

[0014] On the other hand, the present invention adopts the following technical solutions:

[0015] An ascending aortic covered stent delivery system includes a stent delivery device and further includes the above-mentioned bare crown stent release assembly for the ascending aortic covered stent delivery system. The stent delivery device includes an outer sheath tube, a single-lumen middle tube, a single-lumen inner tube, and an adjustment handle. A chronic dilator release knob is provided on the adjustment handle.

[0016] In particular, one end of the chronic dilator is connected to the head end of the single-lumen middle tube and the other end is connected to the single-lumen inner tube. The single-lumen inner tube is inserted into the single-lumen middle tube. The ends of the single-lumen middle tube, the single-lumen inner tube, and the outer sheath tube are respectively connected to the adjustment handle. The chronic dilator release knob is configured to be able to drive the single-lumen inner tube to move relative to the single-lumen middle tube.

[0017] In particular, a metal protection sleeve is inserted inside the outer sheath tube. When the proximal bare crown stent is in a contracted state, at least part of it is located in the metal protection sleeve.

[0018] The release knob of the bare crown stent for the ascending aortic covered stent delivery system of the present invention can control the expansion and contraction of the chronic dilator. When the chronic dilator expands, it can gradually expand the proximal bare crown stent until the proximal bare crown stent fits against the inner wall of the target diseased blood vessel, thereby performing endovascular exclusion of the ascending aorta to treat ascending aortic dissection or aneurysm. This solves the problem that minimally invasive surgery is not suitable for ascending aortic dissection, reduces the perioperative mortality and complication rates, and requires shorter hospitalization and postoperative monitoring time. The chronic dilator has a function similar to balloon dilation, which improves the wall apposition of the covered stent, ensures that the covered stent does not shift after anchoring while shortening the balloon dilation time, and solves problems such as easy stagnation and reflux of aortic blood flow caused by long-term balloon dilation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the ascending aortic covered stent delivery system provided by the specific embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of the stent delivery device provided by the specific embodiment of the present invention;

[0021] Figure 3 is a schematic internal structural diagram of the stent delivery device provided by the specific embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of the stent delivery device after retracting the outer sheath tube provided by the specific embodiment of the present invention;

[0023] Figure 5 is a schematic structural diagram of the chronic dilator of the stent delivery device after inflation provided by the specific embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram of the proximal bare crown stent provided by the specific embodiment of the present invention;

[0025] Figure 7 is a schematic structural diagram of the covered stent provided by the specific embodiment of the present invention;

[0026] Figures 8 to 12 are respectively schematic diagrams of the process of the stent delivery device delivering the covered stent.

[0027] In the figure:

[0028] 100. Stent delivery device; 110. Outer sheath tube; 111. Metal protection sleeve; 120. Adjustable bending tube; 130. Single-chamber inner middle tube; 140. Single-chamber inner tube; 150. Flexible TIP head; 160. Chronic dilator; 174. Chronic dilator release knob; 176. Bare crown stent release switch; 200. Covered stent; 210. Proximal bare crown stent; 211. Front barbs; 212. Rear barbs; 220. Distal covered stent; 301. External thread slider. Detailed implementation mode

[0029] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation modes.

[0030] This implementation mode discloses a bare crown stent release assembly for an ascending aortic covered stent delivery system and an ascending aortic covered stent delivery system including the bare crown stent release assembly. As Figures 1 to 7 shown, the ascending aortic covered stent delivery system includes a stent delivery device 100 and a covered stent 200. Among them, the stent delivery device 100 includes an outer sheath tube 110, a single-chamber inner middle tube 130, a single-chamber inner tube 140, a chronic dilator 160, an adjustment handle, and a chronic dilator release knob 174 provided on the adjustment handle. The covered stent 200 includes a proximal bare crown stent 210 and a distal covered stent 220 connected to each other.

[0031] Among them, the proximal bare crown stent 210, the chronic dilator 160, and the chronic dilator release knob 174 together form a bare crown stent release assembly. The chronic dilator 160 and the chronic dilator release knob 174 are respectively arranged on the ascending aortic covered stent delivery system. The chronic dilator 160 is located inside the proximal bare crown stent 210. The chronic dilator release knob 174 is configured to control the expansion and contraction of the chronic dilator 160; the proximal bare crown stent 210 is configured to expand with the expansion of the chronic dilator 160.

[0032] The chronic dilator release knob 174 of the bare crown stent release assembly can control the expansion and contraction of the chronic dilator 160 as needed. When the chronic dilator 160 expands, it can cause the proximal bare crown stent 210 to gradually expand until the proximal bare crown stent 210 fits against the inner wall of the target diseased blood vessel, thereby performing endovascular exclusion of the ascending aorta to treat ascending aortic dissection or aneurysm, solving the problem that minimally invasive surgery is not suitable for ascending aortic dissection, reducing the perioperative mortality and complication incidence, and requiring shorter hospitalization and postoperative monitoring time. The chronic dilator 160 has a function similar to balloon dilation, improving the wall apposition of the covered stent 200, ensuring that the covered stent 200 does not shift after anchoring while shortening the balloon dilation time, and solving problems such as easy aortic blood flow stasis and reflux caused by long-term balloon dilation.

[0033] Based on the above structure, the bare crown stent release assembly further includes a tensioning rope buckle (not shown). The proximal bare crown stent 210 is tied to the chronic dilator 160 through the tensioning rope buckle. When the tensioning rope buckle is loosened, the restraint on the proximal bare crown stent 210 can be released. As the chronic dilator 160 expands, the proximal bare crown stent 210 will be slowly released; after the tensioning rope buckle is removed, the proximal bare crown stent 210 is completely released. After the proximal bare crown stent 210 is completely released, the chronic dilator 160 can still be used to perform a similar "post-balloon dilation" action on the proximal bare crown stent 210.

[0034] The specific way of loosening the tensioning rope buckle is not limited. Preferably, the bare crown stent release assembly further includes a bare crown stent release switch 176. One end of the tensioning rope buckle is connected to the bare crown stent release switch 176, and the bare crown stent release switch 176 is configured to be able to loosen the tensioning rope buckle, thereby completing the complete release of the proximal bare crown stent 210.

[0035] To improve the firmness of tying, the proximal bare crown stent 210 is tied to the chronic dilator 160 through a plurality of tensioning rope buckles respectively. All the tensioning rope buckles are connected in sequence and there is a set distance between two adjacent tensioning rope buckles to prevent the proximal bare crown stent 210 from being restricted by the tensioning rope buckle when it expands. Preferably, the tensioning rope buckle is formed by tying a rope with elastic deformation ability, allowing a larger range for the proximal bare crown stent 210 to stretch.

[0036] Based on the above structure, as Figure 6 and Figure 7 shown, on the proximal bare crown stent 210, there are provided a front barb 211 and a rear barb 212. The front barb 211 is at the proximal position relative to the rear barb 212. The tip of the front barb 211 faces the distal end, and the tip of the rear barb 212 faces the proximal end.

[0037] The settings of the front barb 211 and the rear barb 212 make the proximal bare crown stent 210 anchor more firmly in a very limited area, sufficient to resist adverse conditions such as high blood pressure and high blood flow velocity, ensuring that the overall release position and release angle of the covered stent 200 are accurate enough, with better wall adhesion, avoiding the formation of endoleak or displacement, and not interfering with the aortic valve and coronary artery inlet.

[0038] The proximal bare crown stent 210 is composed of two parts: a proximal end and a distal end. The proximal end is in the shape of an outward-expanded horn, and the outward expansion inclination angle is 10° - 30°. The proximal bare crown stent 210 is preferably made of nitinol alloy material and laser engraved into a plurality of rhombic structures connected in sequence. All the rhombic structures are wound into a circle, and the evenly arranged rhombic structures reduce the irritation to the blood vessel inner wall while having a certain radial force, and the force on the blood vessel inner wall is uniform.

[0039] The inclination angles of the front barbs 211 and the rear barbs 212 relative to the surface of the body of the proximal bare crown stent 210 are both 30°-45°. After the proximal bare crown stent 210 is completely released, the "balloon-expandable" function of the chronic dilator 160 is used to slowly press the front barbs 211 and the rear barbs 212 into the blood vessel inner wall respectively, so that the proximal bare crown stent 210 can be more firmly and reliably anchored at the set position, reducing the risk of displacement of the proximal bare crown stent 210; the front barbs 211 and the rear barbs 212 have a small area and have little influence on the aortic blood flow, improving the sealing performance of the head end of the proximal bare crown stent 210.

[0040] The specific manner of enabling the chronic dilator 160 to expand and contract is not limited. Preferably, one end of the chronic dilator 160 is connected to the head end of the single-lumen middle tube 130 and the other end is connected to the single-lumen tube 140. The single-lumen tube 140 is inserted into the single-lumen middle tube 130. The ends of the single-lumen middle tube 130, the single-lumen tube 140, and the outer sheath tube 110 are respectively connected to the adjustment handle. The chronic dilator release knob 174 is configured to drive the single-lumen tube 140 to move relative to the single-lumen middle tube 130. Preferably, the end of the single-lumen tube 140 is connected to the external thread slider 301, and the external thread slider 301 is connected to the chronic dilator release knob 174.

[0041] When the distance between the head end of the single-lumen tube 140 and the head end of the single-lumen middle tube 130 gradually increases, the chronic dilator 160 elongates axially and contracts radially, realizing the contraction of the chronic dilator 160; when the distance between the head end of the single-lumen tube 140 and the head end of the single-lumen middle tube 130 gradually decreases, the chronic dilator 160 contracts axially and expands radially, realizing the expansion of the chronic dilator 160.

[0042] On the basis of the above structure, as Figure 2 and Figure 3 shown, a metal protection sleeve 111 with a length of 10 mm - 15 mm is inserted inside the outer sheath tube 110. When the proximal bare crown stent 210 is in a contracted state, at least part of it is located in the metal protection sleeve 111, avoiding damage to the inner wall of the outer sheath tube 110 when the proximal bare crown stent 210 is contracted in the outer sheath tube 110.

[0043] The usage method of the ascending aortic covered stent delivery system is as follows:

[0044] Step 1, construct a channel, as Figure 8 and Figure 9 shown, push the flexible TIP head 150 along the blood vessel until it reaches the set position. Considering that the stent delivery device 100 made of four-layer structure is relatively rigid, the outer sheath tube 110 can be removed first at a position with a large turn, and the covered stent 200 is sent to the target lesion position by using the adjustable bend tube 120.

[0045] Step 2: After the covered stent 200 reaches the target lesion site, as Figure 10 and Figure 11 shown, remove the outer sheath 110 to expose the semi-expanded covered stent 200; push the single-lumen inner tube and the single-lumen middle tube 130 forward as a whole to expose the proximal bare crown stent 210.

[0046] Step 3: Retract the single-lumen inner tube and the single-lumen middle tube 130 until the chronic dilator is aligned with the proximal bare crown stent 210; after adjusting the release angle, retract the single-lumen inner tube alone to radially expand the chronic dilator, and the constrained proximal bare crown stent 210 gradually expands as the chronic dilator expands.

[0047] Step 4: Adjust the angle of the proximal bare crown stent 210 during the process of expanding the chronic dilator until the proximal bare crown stent 210 fits against the inner wall of the target lesion blood vessel. That is, during the release of the proximal bare crown stent 210, the angle of the proximal bare crown stent 210 can be adjusted at any time according to needs.

[0048] Step 5: As Figure 12 shown, first remove the wire to completely release the distal covered stent 220; then push the single-lumen inner tube 140 forward alone to slowly contract the chronic dilator until the chronic dilator is completely separated from the proximal bare crown stent 210, completing the release and angle adjustment of the proximal bare crown stent 210.

[0049] In this usage method, the distal covered stent 220 and the proximal bare crown stent 210 are released separately in sequence. By setting the adjustable bent tube 120 and the chronic dilator, the proximal bare crown stent 210 can adjust the release angle while being slowly released, ensuring that the proximal bare crown stent 210 can be more accurately anchored at the target position, and can be accurately anchored even if the target position is extremely limited, so as to achieve minimally invasive surgery in the ascending aorta lesion blood vessels with extremely complex physiological anatomy and extremely high criticality.

[0050] In the prior art, when the covered stent is released, its proximal end is released first, and the distal end is in a contracted state. At this time, the covered stent is like a "pocket" shape, which is prone to form a "storm" effect, resulting in a greater impact of blood flow on the covered stent. Seriously, it is easy to cause the proximal end of the covered stent to shift, and even stimulate the inner wall of the blood vessel, resulting in dissection rupture, making the covered stent inapplicable to the current extremely complex ascending aorta with physiological anatomy.

[0051] The ascending aortic covered stent and delivery system assembly can successively and stepwise release the distal covered stent 220 and the proximal bare crown stent 210. After removing the outer sheath 110, the distal covered stent 220 constrained by a soft film or tying wire with a diameter of 10 mm - 15 mm is semi-released, enhancing the flexibility while reducing the "storm" effect, and further improving the safety and feasibility of minimally invasive surgery.

[0052] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A bare crown stent release assembly for an ascending aortic covered stent delivery system, characterized in that, It includes a proximal bare crown stent (210), a chronic dilator (160) and a chronic dilator release knob (174). The chronic dilator (160) and the chronic dilator release knob (174) are respectively arranged on the ascending aortic covered stent delivery system. The chronic dilator (160) is located inside the proximal bare crown stent (210). The chronic dilator release knob (174) is configured to control the expansion and contraction of the chronic dilator (160); the proximal bare crown stent (210) is configured to expand with the expansion of the chronic dilator (160), and the chronic dilator release knob (174) controls the expansion and contraction of the chronic dilator (160) as needed.

2. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to claim 1, characterized in that, The bare crown stent release assembly further includes a tension cord buckle. The proximal bare crown stent (210) is tied to the chronic dilator (160) through the tension cord buckle, and the restraint on the proximal bare crown stent (210) can be released when the tension cord buckle is loosened.

3. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to claim 2, characterized in that, The bare crown stent release assembly further includes a bare crown stent release switch (176). One end of the tension cord buckle is connected to the bare crown stent release switch (176), and the bare crown stent release switch (176) is configured to loosen the tension cord buckle.

4. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to claim 2, characterized in that, The proximal bare crown stent (210) is respectively tied to the chronic dilator (160) through a plurality of the tension cord buckles. All the tension cord buckles are connected in sequence and there is a set distance between two adjacent tension cord buckles.

5. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to claim 4, characterized in that, The tension cord buckle is formed by tying a rope with the ability of elastic deformation.

6. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to any one of claims 1 to 5, characterized in that, On the proximal bare crown stent (210), there are a front barb (211) and a rear barb (212). The front barb (211) is in the proximal position relative to the rear barb (212). The tip of the front barb (211) faces the distal end, and the tip of the rear barb (212) faces the proximal end.

7. The bare crown stent release assembly for an ascending aortic covered stent delivery system according to claim 6, characterized in that, The inclination angles of both the front barb (211) and the rear barb (212) are between 30° and 45°.

8. An ascending aortic covered stent delivery system, comprising a stent delivery device (100), characterized in that, It further includes a bare crown stent release assembly for the ascending aortic covered stent delivery system according to any one of claims 1 to 7. The stent delivery device (100) includes an outer sheath tube (110), a single-lumen middle tube (130), a single-lumen inner tube (140) and an adjustment handle. The chronic dilator release knob (174) is arranged on the adjustment handle.

9. The ascending aortic covered stent delivery system according to claim 8, characterized in that, One end of the chronic dilator (160) is connected to the head end of the single-lumen middle tube (130) and the other end is connected to the single-lumen inner tube (140). The single-lumen inner tube (140) is arranged inside the single-lumen middle tube (130). The ends of the single-lumen middle tube (130), the single-lumen inner tube (140) and the outer sheath tube (110) are respectively connected to the adjustment handle. The chronic dilator release knob (174) is configured to drive the single-lumen inner tube (140) to move relative to the single-lumen middle tube (130).

10. The ascending aortic covered stent delivery system according to claim 8, characterized in that, A metal protection sleeve (111) is disposed inside the outer sheath tube (110), and when the proximal bare crown stent (210) is in a contracted state, at least a part of it is located in the metal protection sleeve (111).

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