CN-121971200-A - Bracket tectorial membrane cold cutting hole puncher and punching method

CN121971200ACN 121971200 ACN121971200 ACN 121971200ACN-121971200-A

Abstract

A stent tectorial membrane cold cutting hole puncher and a punching method relate to the technical field of medical stent windowing/punching. The bracket tectorial membrane cold cutting hole cutter comprises a body, a handle, a bottom plate and a spring cutting mechanism, wherein an element cavity is formed in the body, one end of the handle is connected with the body, the other end of the handle is connected with the bottom plate, the upper surface of the bottom plate faces a guide hole, a gap between the bottom plate and the guide hole is matched with the thickness of the bracket, the spring cutting mechanism comprises a pressing head, a connecting rod, a spring and a cutter, the pressing head is slidably arranged at the upper end of the element cavity, the connecting rod is connected to the lower end of the pressing head, the cutter is detachably connected to the lower end of the connecting rod, the lower end of the cutter stretches into the guide hole, and the spring forces the pressing head to move to an upper limit position through elasticity. The invention has the advantages that the pure mechanical cold cutting mode is adopted, the round blade is used for one-step stamping forming, the formed hole has accurate geometric shape and smooth and flat edge, and the laminar state of blood flow can be maintained.

Inventors

DENG LIMING
WANG CHUNKE
LIANG KAIRONG
YANG XI
WANG XUAN
ZHOU WEN
Tu Minwen
LIU SHIQI

Assignees

南华大学附属第二医院

Dates

Publication Date: 20260505
Application Date: 20260310

Claims (10)

1. The bracket is cylindrical and comprises an elastic framework positioned at the inner layer and a covering film wrapped at the outer side of the elastic framework; the bracket tectorial membrane cold cutting hole cutter is characterized by comprising a body, a handle, a bottom plate and a spring cutting mechanism; the body is hollow and cylindrical, an element cavity is arranged in the body, an operation hole communicated with the element cavity is formed in the top of the body, a guide hole communicated with the element cavity is formed in the bottom of the body, and a supporting surface A, a supporting surface B and a supporting surface C are sequentially arranged in the body from the operation hole to the guide hole; The handle is in a U-shaped rod shape, one end of the handle is connected with the outer wall of the body, the other end of the handle is connected with the bottom plate, so that the upper surface of the bottom plate is opposite to the guide hole, and a gap between the upper surface of the bottom plate and the end surface of the guide hole is matched with the thickness of the bracket so as to allow the bracket to pass through; The spring pressing cutting mechanism comprises a pressing head, a connecting rod, a spring and a cutter, wherein the pressing head is slidably arranged at the upper end of an element cavity, the upper end of the pressing head extends out of an operation hole to be pressed, the upper limit position and the lower limit position of the pressing head are limited by a supporting surface A and a supporting surface B respectively, the connecting rod is connected to the lower end of the pressing head, the cutter is detachably connected to the lower end of the connecting rod, the lower end of the cutter extends into a guide hole and is in sliding fit with the guide hole, a circle of circular cutting edge is arranged at the lower end of the cutter, the spring is compressed and sleeved on the connecting rod, the upper end of the spring is abutted against the lower end face of the pressing head, the lower end of the spring is abutted against the supporting surface C, and the spring forces the pressing head to move to the upper limit position through elasticity.
2. The stent graft cold-cut perforator of claim 1, wherein the rounded blade is positioned in the pilot hole when the pusher is in the upper limit position, the rounded blade extends from the pilot hole until it engages the upper surface of the base plate when the pusher is moved from the upper limit position to the lower limit position against the spring force, and the pusher does not reach the lower limit position when the rounded blade engages the upper surface of the base plate.
3. The stent graft cold-cut hole cutter of claim 2, wherein the pressing head and the connecting rod are internally provided with chip removal channels, and the chip removal channels penetrate from the upper end face of the pressing head to the lower end face of the connecting rod. The chip removing push rod is movably inserted in the chip removing channel, the upper end of the chip removing push rod extends out of the upper end of the pressing head, the lower end of the chip removing push rod extends into the cavity of the cutter, and the chip removing push rod is used for pushing out stent coated chips accumulated in the cavity of the cutter to the upper surface of the bottom plate.
4. The stent graft cold-cut perforator of claim 3, wherein the handle is connected to the base plate by means of a post-hole plug.
5. The stent graft cold-cut perforator of claim 4, wherein the body, the pressing head and the connecting rod are all made of transparent plastic materials.
6. The stent graft cold-cut perforator of claim 5, wherein the lower end of the body is provided with a convex column with a length of 5-8mm, and the guiding hole is arranged in the convex column.
7. A method for cold cutting and punching a stent coating, based on the stent coating cold cutting hole cutter as claimed in any one of claims 1 to 3, characterized by comprising the following steps: S01, preparing: A. Three-dimensional planning and positioning, namely three-dimensionally reconstructing a lesion blood vessel segment to be treated and a branch blood vessel thereof in special software based on preoperative medical image data of a patient to obtain a personalized blood vessel anatomical three-dimensional model of the patient, planning a virtual operation on the basis, simulating stent placement, and calculating the position of a window on a stent covering film required for guaranteeing blood flow of the branch blood vessel; B. Mapping the calculated outline of the windowing region onto an unfolded stent covered membrane, expanding the stent in vitro to a working state, temporarily marking the boundary of the windowing region on the surface of the stent covered membrane by adopting a sterile operation marking pen, drawing the outline of each hole in the boundary according to the requirement of hole distance, and marking the hole facing the elastic framework, so that the elastic framework is prevented from being damaged by mistake during subsequent punching; S02, single-point positioning and fine adjustment: A. The clamping and aligning are that one hand is used for perforating the device, the other hand is used for holding the bracket, one end of the bracket is inserted into a gap between the upper surface of the bottom plate and the end face of the guide hole, and as the gap is communicated with the U-shaped area of the handle, the extension length of the U-shaped area of the handle limits the maximum insertion depth of the bracket, and the relative position between the bracket and the end face of the guide hole is preliminarily adjusted based on visual observation, so that the hole position which is currently planned to be cut is positioned under the guide hole; B. Visual fine adjustment, namely, carrying out overlooking view observation on a body, a pressing head and a connecting rod which are made of transparent plastics, and fine adjusting the position of a hole digger or a bracket to ensure that a circular blade at the lower end of a cutter coincides with the contour of a currently selected hole; S03, performing single-hole cold cutting: After the positioning is confirmed, the pressing head is pressed downwards by a finger, the pressing head overcomes the elasticity of a spring, the connecting rod and the cutter are driven to move downwards along a guide path defined by the guide hole, and the cutting edge at the lower end of the cutter punches the support film in a cold cutting mode to form a single hole with a regular shape and a smooth edge; S04, chip removal treatment: A. the chip removal push rod is inserted into the chip removal channel from the upper end surface of the pressing head and is pushed downwards, so that the support film waste accumulated in the pipe cavity of the cutter is pushed downwards to the upper surface of the bottom plate, and then the support film waste on the upper surface of the bottom plate is swept or blown off; B. The quality confirmation comprises observing the body, the pressing head and the connecting rod from the overlook view, confirming that the current hole shape is regular and the elastic framework below is intact; s05, cyclic operation and window forming: A. Finishing windowing, namely adjusting the relative positions of the bracket and the gap to enable a hole site which is planned to be cut next to be opposite to the lower end face of the guide hole, repeatedly executing the step from the step B of the step S02 to the step B of the step S04, and punching a series of adjacent holes in a windowing area, thereby finishing the punching operation of the windowing area; B. And finally cleaning, namely cleaning the stent after the punching operation of all the windowing areas is finished, removing all temporary marks, and then compressing and loading the customized windowed stent into a conveying system according to a conventional operation flow to prepare for the subsequent intravascular implantation operation.
8. The method of claim 7, wherein in step S02, the gap is adapted to the thickness of the stent, so that after the stent is inserted into the gap, the stent is fully attached to the gap, a certain static friction force exists between the stent and the gap, and relative rotation is avoided when no external force is applied, so that deviation of the positions of holes due to relative sliding during subsequent punching is avoided.
9. The method of claim 8, wherein in step S05, if a plurality of windowing areas are planned on the stent, M sub-steps are added between the A sub-step and the B sub-step; And M, repeating the windowing, namely adjusting the relative positions of the bracket and the slot to enable the hole site planned to be cut in the other windowing region to be positioned in the cutting channel, and repeating the steps from the step B in the step S02 to the step B in the step S04 until the punching operation of all the windowing regions is completed.
10. The method for cold cutting and punching a stent-graft according to claim 9, wherein in the step S01, the hole pitch is set to be 2.5mm on the premise of 1.5mm in the hole diameter.

Description

Bracket tectorial membrane cold cutting hole puncher and punching method Technical Field The invention relates to the technical field of medical stent windowing/punching, in particular to a stent tectorial membrane cold cutting hole puncher and a punching method. Background Abdominal aortic aneurysms are common aortic diseases in vascular surgery, the biggest risk is rupture hemorrhage, and the hemorrhage is an extremely dangerous emergency, and has low rescue success rate and high death rate. In abdominal aortic aneurysm treatment, the complexity of the treatment increases significantly when the aneurysm body involves important branch arteries (e.g. renal arteries, superior mesenteric arteries, dry abdominal arteries, etc.). To ensure the stability of the placement of the stent in the vessel, the stent needs to have a certain length, but this also results in that the stent may cover the junction of the abdominal aorta and the branch vessel after placement, and the blood supply of the branch vessel is hindered. For complex abdominal aortic aneurysms, fenestration stent techniques have evolved. The technology needs to open a corresponding window on the stent covering film, so that the stent does not influence the blood flow of the branch blood vessel while isolating the aortic aneurysm. At present, clinically common stent coating perforation methods comprise an electric knife and laser perforation, and the essence of the two methods is that holes are formed on the stent coating by burning at high temperature. However, both of these methods suffer from the following drawbacks: 1. The open hole shape is irregular, the hole geometry is not good, the local blood flow turbulence is caused, the normal laminar flow is destroyed, and the distribution of the cutting stress of the inner wall surface of the blood vessel is abnormal. This unstable blood flow environment will continue to damage vascular endothelial cells, promote platelet activation, and can significantly promote neothrombosis and neointimal hyperplasia for a long period of time, ultimately leading to restenosis within the stent. 2. The high temperatures generated during the perforation process can cause the coating material (typically polymeric material) to char and carbonize, forming tiny debris that adheres to the edges of the hole and may fall off under the impact of blood flow after stent placement, entering the circulatory system, and causing distal vascular embolism. 3. The high temperature punching mode can form a heat affected zone in the covered material around the holes, and change the physical and chemical properties of the material, so that not only microcrack and chip generation are aggravated, but also biocompatibility of the material in the zone is possibly deteriorated, and stronger foreign body reaction and chronic inflammation of the organism are initiated, and the sustained inflammation stimulus can lead to abnormal repair reaction of the vascular of the stent implantation section, namely intimal hyperplasia and fibrosis taking smooth muscle cells as a main factor. The proliferated fibrous tissue may gradually occupy and even completely block the holes reserved for the branch vessels, resulting in a reduced long-term patency rate of the branch arteries. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a bracket tectorial membrane cold cutting hole puncher and a hole punching method, which solve the problems of irregular hole shape, fragments generated by carbonization of tectorial membrane material due to heat damage, heat affected zone existence, easy damage to bracket framework in operation and the like caused by the existing hot melting hole punching technology. The technical scheme of the invention is that the bracket film-covered cold cutting hole cutter is used for being matched with a bracket, wherein the bracket is cylindrical and comprises an elastic framework positioned on an inner layer and a film covered on the outer side of the elastic framework; The bracket tectorial membrane cold cutting hole cutter comprises a body, a handle, a bottom plate and a spring cutting mechanism; the body is hollow and cylindrical, an element cavity is arranged in the body, an operation hole communicated with the element cavity is formed in the top of the body, a guide hole communicated with the element cavity is formed in the bottom of the body, and a supporting surface A, a supporting surface B and a supporting surface C are sequentially arranged in the body from the operation hole to the guide hole; The handle is in a U-shaped rod shape, one end of the handle is connected with the outer wall of the body, the other end of the handle is connected with the bottom plate, so that the upper surface of the bottom plate is opposite to the guide hole, and a gap between the upper surface of the bottom plate and the end surface of the guide hole is matched with the thickness of the bracket so as to allow