A left common iliac vein extra-vessel stent and surgical method

Abstract

The application discloses a left common iliac vein extra-vascular stent and a surgical method, and belongs to the field of medical devices. The stent comprises a middle section connecting sleeve frame, an inferior vena cava sleeve frame and a left iliac vein sleeve frame, which are integrally formed and have an included angle of 135-145 degrees, are provided with elastic silica gel limiting clamps and are made of silica rubber material, and the cross-linking density and flexibility are controlled by adjusting the vinyl content. The surgical method is a laparoscopic minimally invasive approach, and the stent is implanted and the position is adjusted after the target blood vessel is exposed. The application avoids direct contact between the built-in stent and the intima, reduces the risk of intimal hyperplasia and thrombosis, is resistant to fatigue and creep, fits the anatomical structure, is fixed and stable, has a minimally invasive recovery, can be customized and adapted, and improves the clinical efficacy and safety.

Description

Technical Field

[0001] This application belongs to the field of medical devices, and specifically relates to a left common iliac vein stent and surgical method. Background Technology

[0002] Currently, most implantable iliac vein stents use nickel-titanium shape memory alloy (Nitinol) or medical-grade stainless steel as the base material. They are fabricated into honeycomb or mesh-like stent structures using laser precision cutting technology to balance sufficient radial support with excellent flexibility and compliance. They are mainly divided into two types: self-expanding and balloon-expandable. In clinical implantation, the femoral vein is usually percutaneously punctured. The diseased segment is first pre-dilated with a balloon, and then, using a sheathed integrated delivery system or an adjustable stiffness guidewire, the stent is precisely placed at the stenosis or occlusion site under fluoroscopy or intravascular ultrasound (IVUS) guidance.

[0003] However, existing in-situ iliac vein stents still have many limitations: First, the contact area between the stent and the vessel wall is large and hemodynamic disturbances are significant, resulting in a high risk of restenosis due to stent displacement, compression, or overturning. Second, long-term implantation can easily lead to intimal hyperplasia and excessive tissue proliferation, causing in-stent restenosis and significantly affecting vascular patency. Third, the materials have insufficient fatigue resistance and creep resistance under continuous low pressure and high pulsation in the vein, which may result in permanent deformation or even breakage. Fourth, given the special anatomical structure of the iliac vein, which is thick, flat, tortuous, and bifurcated, the compliance and wall-fitting of existing stents are poor, making insertion difficult and increasing the risk of stress concentration damage to the vessel wall. In addition, some drug-eluting coatings or antithrombotic coatings are prone to detachment and have poor biocompatibility, which may induce chronic inflammation, thrombosis, and fibrosis, thus limiting the improvement of their efficacy and safety. Summary of the Invention

[0004] This application provides To achieve the above objectives, this application provides a left common iliac vein stent and surgical method, including a mid-segment connecting sleeve, an inferior vena cava sleeve coaxially disposed on the upper side of the mid-segment connecting sleeve, and two vascular perforations penetrating the other side of the mid-segment connecting sleeve to accommodate branch vessels of the left internal iliac vein and the left external iliac vein. The vascular perforation located on the left internal iliac vein side is provided with a left iliac vein sleeve. A looping groove is opened on the same side of both the inferior vena cava sleeve and the left iliac vein sleeve. A first limiting clamp is provided on the looping groove of the inferior vena cava sleeve, and a second limiting clamp is provided on the looping groove of the left iliac vein sleeve.

[0005] In one embodiment, both the first and second limiting straps are made of elastic silicone material and gradually converge in a direction away from the middle connecting sleeve.

[0006] In one embodiment, the relative angle between the left iliac vein stent and the inferior vena cava stent is 135 degrees to 145 degrees, and the mid-section connecting stent, the inferior vena cava stent, and the left iliac vein stent are integrally formed.

[0007] In one embodiment, the mid-segment connecting sleeve, the inferior vena cava sleeve, and the left iliac vein sleeve are made of silicone rubber. The crosslinking density and flexibility of the silicone rubber are adjusted by changing the content and distribution of vinyl groups in the raw rubber molecular chains of the silicone rubber material.

[0008] A surgical method for external stent placement of the left common iliac vein includes the following steps: S1. Establishing a minimally invasive surgical approach: Using laparoscopic techniques, an observation endoscope is inserted around the umbilicus, and operating channels are established in the left and right lower abdomens respectively, where a trocar is inserted; S2. Exposure and dissection of the target vessel: Under image guidance, identify the branch from the inferior vena cava to the left common iliac vein, and use a fine dissector to gently separate the adventitia of the vessel and the surrounding adhesions, fully exposing the main trunk and branches of the left common iliac vein to form a circular dissection area; S3. Implantation of extravascular stents: By opening the first and second limiting clamps, the inferior vena cava stent and the left iliac vein stent are respectively inserted into the root of the inferior vena cava and the left internal iliac vein. Then the clamps are released to allow them to elastically retract and firmly adhere to the outer wall of the blood vessel. S4. Adjust the relative position of the mid-segment connecting sleeve to ensure that the mid-segment connecting sleeve is located in the vascular branch area and fits tightly against the angle area.

[0009] In one embodiment, in step S1, 3-4 trocar holes are set, and their positions are respectively located around the navel, the lower left abdomen, and the lower right abdomen.

[0010] In one embodiment, in step S2, the annular dissection area needs to completely expose the main segment of the left common iliac vein from its inception to its bifurcation, and the dissection range should ensure that the inferior vena cava stent and the left iliac vein stent can be accurately aligned and stably fixed together with the mid-segment connecting stent when implanted.

[0011] In one embodiment, in step S3, the inferior vena cava stent and the left iliac vein stent are precisely delivered to the predetermined positions at the roots of the inferior vena cava and the left internal iliac vein through the trocar orifice via a guiding device. The insertion action is completed with the aid of real-time image monitoring, and initial fixation is achieved by the elastic retraction of the first limiting clamp and the second limiting clamp.

[0012] In one embodiment, in step S4, the spatial position of the mid-segment connecting sleeve is adjusted by laparoscopy to precisely align it with the angle region of the left common iliac vein branches. The docking status with the inferior vena cava sleeve and the left iliac vein sleeve is confirmed by image guidance to achieve three-dimensional adaptation and ensure all-round support for the left common iliac vein and its branches.

[0013] Compared with the prior art, the beneficial effects of this application are: First, the extravascular implantation method avoids direct contact between the internal stent and the vascular intima, effectively reducing the risk of intimal hyperplasia and thrombosis, minimizing hemodynamic disturbances, and significantly improving long-term patency. Second, the stent body is made of silicone rubber. By adjusting the content and distribution of vinyl groups in the raw rubber molecular chain, the cross-linking density and flexibility are precisely controlled. This ensures sufficient support strength to resist external pressure while possessing excellent anti-fatigue and anti-creep properties, making it less prone to permanent deformation or breakage after long-term implantation. Furthermore, the good biocompatibility of silicone rubber reduces adverse reactions such as chronic inflammation and fibrosis.

[0014] Furthermore, the stent adopts an integrated molding structure. The mid-section connecting sleeve connects the inferior vena cava stent and the left iliac vein stent. The 135°~145° angle between the two is designed to fit the natural anatomical angle, avoiding torsional stress and maintaining stable blood flow. The elastic silicone limiting clip has a constricting opening, which facilitates guiding the blood vessel into the stent during the operation. After release, it elastically retracts and fits tightly against the outer wall of the blood vessel, achieving both stable fixation and allowing for vasodilation and vasoconstriction under the physiological pulsation of the blood vessel, reducing local stress concentration and preventing damage to the adventitia and stent displacement.

[0015] Furthermore, the accompanying minimally invasive surgery utilizes laparoscopy to establish the approach, resulting in minimal trauma and rapid recovery. After precisely exposing the target vessel, the stent is delivered via a guiding device and implanted by opening the clamp. The procedure is simple and the positioning is accurate. The mid-segment connecting stent can be adjusted to the branch angle region to achieve three-dimensional adaptation, providing comprehensive support for the vessel branch and dispersing local stress to reduce the risk of compressive injury. Finally, the combination of material control technology and structural design allows for patient-specific customization, precisely matching individual vessel morphology, overcoming the limitations of traditional approximate matching, further improving adaptability and clinical efficacy, and providing a safer and more effective treatment option for diseases such as left common iliac vein compression syndrome. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1A three-dimensional schematic diagram of a left common iliac vein stent provided in this application; Figure 2 This application provides a front view schematic diagram of an external stent for the left common iliac vein; Figure 3 This is a schematic diagram of a surgical procedure for an external stent in the left common iliac vein, as provided in this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Mid-segment connecting sleeve; 2. Inferior vena cava sleeve; 3. Left iliac vein sleeve; 4. First limiting clamp; 5. Mid-segment limiting clamp; 6. Second limiting clamp. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0020] See Figures 1 to 3 As shown, the left common iliac vein external stent provided in this application includes a mid-segment connecting sleeve 1, and an inferior vena cava sleeve 2 coaxially disposed on the upper side of the mid-segment connecting sleeve 1. Two vascular perforations 5 are opened through the mid-segment connecting sleeve 1 on the other side to accommodate the branch vessels of the left internal iliac vein and the left external iliac vein. The two vascular perforations 5 are symmetrically distributed on both sides of the lower end of the mid-segment connecting sleeve 1 and form a stable connection with the left iliac vein sleeve 3, thereby providing effective external support for the branches of the left common iliac vein and avoiding blood flow obstruction caused by compression of the vein due to limb movements.

[0021] The vascular perforation 5 located on the left internal iliac vein side is provided with a left iliac vein sleeve 3. A looping groove is opened on the same side of both the inferior vena cava sleeve 2 and the left iliac vein sleeve 3. A first limiting clamp 4 is provided on the looping groove of the inferior vena cava sleeve 2, and a second limiting clamp 6 is provided on the looping groove of the left iliac vein sleeve 3.

[0022] In this embodiment, the first limiting clamp 4 and the second limiting clamp 6 can effectively fix the inferior vena cava stent 2 and the left iliac vein stent 3 to the outer walls of the inferior vena cava and the left common iliac vein, respectively, while allowing the blood vessels to moderately dilate and contract under physiological pulsation. The mid-segment connecting stent 1 is used to connect the inferior vena cava stent 2 and the left iliac vein stent 3, so that they form a cooperative support structure at the venous branch, avoiding displacement or local compression caused by uneven force on the stent, and ensuring long-term patency.

[0023] When installing the first limiting clamp 4 and the second limiting clamp 6, the inferior vena cava stent 2 and the left iliac vein stent 3 should be aligned with the target vessel positions respectively. Then, by expanding the clamp openings of the first limiting clamp 4 and the second limiting clamp 6, the target vessel can pass through the clamp openings and enter the inferior vena cava stent 2 and the left iliac vein stent 3. After releasing the clamp openings of the first limiting clamp 4 and the second limiting clamp 6, their own elasticity is used to achieve stable wrapping of the inferior vena cava and the left common iliac vein, ensuring that the stent system can maintain its position even in complex changes in body position.

[0024] Optionally, both the first limiting clamp 4 and the second limiting clamp 6 are made of elastic silicone material, and gradually converge away from the middle connecting sleeve 1. This converging structure facilitates the guidance of blood vessels into the sleeve lumen during surgery, and at the same time, after implantation, the gradual fit reduces local stress concentration and avoids damage to the adventitia of blood vessels.

[0025] Optionally, the relative angle between the left iliac vein sleeve 3 and the inferior vena cava sleeve 2 is 135 degrees to 145 degrees, and the middle connecting sleeve 1, the inferior vena cava sleeve 2, and the left iliac vein sleeve 3 are integrally formed structures.

[0026] In this embodiment, the angle design fully conforms to the natural anatomical angle between the left common iliac vein and the inferior vena cava, ensuring no torsional stress after stent implantation and effectively maintaining hemodynamic stability. The one-piece molded structure further enhances the overall mechanical strength and fatigue durability, making it less prone to deformation or breakage in long-term implantation environments, and significantly reducing the risk of postoperative complications.

[0027] Optionally, the mid-section connecting sleeve 1, the inferior vena cava sleeve 2, and the left iliac vein sleeve 3 are made of silicone rubber. The crosslinking density and flexibility of the silicone rubber are adjusted by changing the content and distribution of vinyl-CH=CH2 in the raw rubber molecular chain of the silicone rubber material.

[0028] In this embodiment, the silicone rubber material possesses excellent flexibility and elasticity, with an elastic modulus close to that of human soft tissue. This effectively buffers and disperses pulsatile pressure from arteries, reducing local stress concentration and preventing damage to the vein wall. Simultaneously, it conforms to the natural pulsation of the blood vessel, maintaining hemodynamic stability. During long-term implantation, this material exhibits good biocompatibility and mechanical stability, effectively supporting the left common iliac vein and its branches, preventing restenosis, and improving the stent's adaptability and durability in complex anatomical structures.

[0029] Meanwhile, the silicone rubber stent forms a dynamic, conformal support outside the vein, avoiding direct stimulation of the intima by the implanted stent and effectively reducing the risk of intimal hyperplasia and thrombosis. Through personalized 3D modeling and 3D printing technology, precise replication of the patient's specific anatomical structure can be achieved, creating a customized stent that perfectly matches the individual's vascular morphology, overcoming the limitations of traditional "approximate matching" and achieving anatomically precise fit. The stent's high consistency with the vascular wall's 3D morphology significantly improves conformation and stability, effectively dispersing local stress and reducing the risk of compressive injury. Personalized design takes into account the course angle and connection relationships of branch vessels, ensuring good compliance and functional integrity even after long-term implantation, further improving treatment safety and clinical efficacy.

[0030] Finally, by further adjusting the vinyl-CH=CH2 content, a gradient change in the material can be achieved, ranging from soft and elastic to moderately tough, thereby precisely matching the required support strength and deformation capacity of blood vessels in different locations. For example, a higher cross-linking density is used in the main stent segment to provide stable radial force, while the degree of cross-linking is reduced at branch connections to enhance flexibility and adapt to the natural movement of blood vessels. This molecular-level regulation technology, combined with personalized three-dimensional structural design, enables the stent to maintain structural integrity and dynamically respond to blood flow pulsation during long-term service, significantly improving post-implantation physiological compatibility and clinical durability.

[0031] A surgical method for external stent placement of the left common iliac vein includes the following steps: S1. Establishing a minimally invasive surgical approach: Using laparoscopic techniques, an observation endoscope is inserted around the umbilicus, and operating channels are established in the left and right lower abdomen, where trocars are inserted. Typically, 3-4 trocar ports are set, located around the umbilicus, in the left lower abdomen, and in the right lower abdomen, respectively.

[0032] S2. Exposure and dissection of the target vessel: Under image guidance, identify the branch from the inferior vena cava to the left common iliac vein, and gently separate the adventitia and surrounding adhesions using a fine dissector to fully expose the main trunk and branches of the left common iliac vein, forming a circular dissection area.

[0033] During the dissection process, adjacent structures (such as arteries or nerves) must be carefully identified and protected. The integrity of the vessel must be maintained during dissection to avoid excessive traction that could damage or perforate the vessel wall. The extent and depth of dissection should be continuously assessed throughout the procedure to ensure no tissue residue or bleeding points remain in the stent placement area. If necessary, temporary vascular clamps can be used to block local blood flow to control bleeding; the procedure should only continue after hemostasis is confirmed.

[0034] S3. Implantation of external vascular stents: By opening the first limiting clamp 4 and the second limiting clamp 6, the inferior vena cava stent 2 and the left iliac vein stent 3 are respectively inserted into the root of the inferior vena cava and the left internal iliac vein. Then the clamps are released to allow them to elastically retract and firmly adhere to the outer wall of the blood vessel.

[0035] The inferior vena cava stent 2 and the left iliac vein stent 3 are precisely delivered to the predetermined positions at the root of the inferior vena cava and the left internal iliac vein through the trocar orifice via the guide device. The insertion action is completed with the help of real-time image monitoring, and the initial fixation is achieved by the elastic retraction of the first limiting clamp 4 and the second limiting clamp 6.

[0036] S4. Adjust the relative position of the mid-segment connecting sleeve 1 to ensure that the mid-segment connecting sleeve 1 is located in the vascular branch area and closely fits the angle area.

[0037] The spatial position of the mid-segment connecting sleeve 1 is adjusted by laparoscopy to precisely align it with the angle region of the left common iliac vein branches. The docking status with the inferior vena cava sleeve 2 and the left iliac vein sleeve 3 is confirmed by image guidance to achieve three-dimensional adaptation and ensure all-round support for the left common iliac vein and its branches.

[0038] After implantation, intraoperative angiography or ultrasound is used to confirm that the stent is well-attached to the vessel wall, without twisting or deformation, and that the blood flow velocity in the target vessel has returned to normal, with no obvious signs of turbulence or stenosis. Once it is confirmed that there are no complications such as bleeding or tissue damage, the trocar puncture sites are closed layer by layer, concluding the procedure.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A left common iliac vein stent, characterized in that: It includes a mid-section connecting sleeve (1), an inferior vena cava sleeve (2) coaxially disposed on the upper side of the mid-section connecting sleeve (1), and two vascular perforations (5) through the other side of the mid-section connecting sleeve (1) for accommodating the branch vessels of the left internal iliac vein and the left external iliac vein. Among them, the vascular perforation (5) located on the left internal iliac vein side is provided with a left iliac vein sleeve (3). A snag groove is opened on the same side of the inferior vena cava sleeve (2) and the left iliac vein sleeve (3). A first limiting clamp (4) is provided on the snag groove of the inferior vena cava sleeve (2), and a second limiting clamp (6) is provided on the snag groove of the left iliac vein sleeve (3).

2. The left common iliac vein stent according to claim 1, characterized in that: The first limiting clamp (4) and the second limiting clamp (6) are both made of elastic silicone material and gradually converge in a direction away from the middle connecting sleeve (1).

3. The left common iliac vein stent according to claim 1, characterized in that: The relative angle between the left iliac vein stent (3) and the inferior vena cava stent (2) is 135 degrees to 145 degrees, and the middle connecting stent (1), the inferior vena cava stent (2), and the left iliac vein stent (3) are integrally formed structures.

4. The left common iliac vein stent according to claim 1, characterized in that: The mid-section connecting sleeve (1), the inferior vena cava sleeve (2), and the left iliac vein sleeve (3) are made of silicone rubber. The crosslinking density and flexibility of the silicone rubber are adjusted by changing the content and distribution of vinyl-CH=CH2 in the raw rubber molecular chain of the silicone rubber material.

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