JP-7854898-B2 - Personalized coronary artery stents

JP7854898B2JP 7854898 B2JP7854898 B2JP 7854898B2JP-7854898-B2

Inventors

ムーア、スティーブン、マイケル
ハルプカ、ケリー、ジェイン
ビューレ、ダーシー、ジェームス
ダウントン、マシュー
バルダウフ、ジュリア、ステファニー
シーバー、クリスティーン

Assignees

インターナショナル・ビジネス・マシーンズ・コーポレーション

Dates

Publication Date: 20260507
Application Date: 20220826
Priority Date: 20170717

Claims (8)

A method for manufacturing stents and mandrels , In response to a three-dimensional (3D) model of the actual shape of the blood vessel, a 3D model of the non-stenotic shape of the blood vessel is generated. To establish a parameter description of a stent, wherein the stent includes a plurality of supports, and the stent can be expanded from a predetermined configuration that can be inserted into a blood vessel to a final configuration in which the supports are arranged in a non-stenotic shape by widening the gaps between the plurality of supports, and the parameter description includes parameters that characterize the dimensions of the supports of the stent. The design for the stent is generated by a heuristic design that includes determining, by mechanical stress/strain analysis, whether there is a risk of the support column breaking during the plastic deformation of the stent between the predetermined configuration and the final configuration, and repeating the determination by changing the parameters of the parameter description according to the determination that there is a risk , Establishing the shape of the mandrel supporting the stent of the predetermined configuration, comprising establishing the plurality of columns such that at least one of a plurality of columns, which are more rigid than the membrane and protrude from the flexible membrane of the mandrel, extends to a different distance from the central axis of the mandrel compared to at least one of the other columns, wherein the position and size of the plurality of columns are selected so that the stent expands into the final configuration when the membrane is inflated and uniformly displaced radially , 3D printing the mandrel according to the shape of the mandrel, 3D printing the stent according to the design for the stent, The stent is positioned around the mandrel such that the bridge of the stent aligns with the column of the mandrel, A method that includes this.
The method according to claim 1, wherein establishing the shape of the mandrel includes configuring the columns of the mandrel to support the bridge of the stent of the predetermined configuration.
The method according to claim 2, wherein establishing the shape of the mandrel involves configuring the columns of the mandrel such that the mandrel also supports the bridge of the stent in the final configuration when it is extended to its elongated shape.
The method according to any one of claims 1 to 3, wherein 3D printing of the stent includes 3D printing of the stent around the mandrel.
Establishing the shape of a sleeve having a generally cylindrical body and a plurality of finger portions projecting inward from the body, wherein the length of the finger portions is defined based on the distance between the body and the corresponding bridge of the stent in the final configuration , The method according to any one of claims 1 to 4, further comprising 3D printing the sleeve according to the shape of the sleeve.
The method according to claim 5 , wherein the shape of the sleeve is established such that each of the finger portions uniformly compresses the bridge of the corresponding stent radially from the final configuration to the predetermined configuration.
The method according to claim 5 or 6 , wherein 3D printing the sleeve includes 3D printing the sleeve around the stent.
A computer program stored on a computer-readable medium and loadable into the internal memory of a digital computer, the computer program including a software code portion for carrying out the method according to any one of claims 1 to 7 when the program is run on the computer.

Description

This invention relates to medical technology, and more particularly to interventional cardiology. Cardiovascular disease is one of the biggest health problems in developed countries. One of the more serious conditions is coronary artery disease (CAD), which typically involves the hardening, curettage, and enlargement of the smooth, elastic lining of the coronary arteries due to calcium deposits, fat deposits, and abnormal inflammatory cells, leading to the formation of plaque and atherosclerosis. This plaque creates an obstruction to the normal supply of oxygenated blood to the heart muscle (known as stenosis), which can cause chest pain (angina) and ultimately lead to cardiac arrest. Interventional cardiology is a branch of cardiology that specializes in the catheter-based treatment of structural heart diseases such as CAD. One interventional cardiology procedure is known as percutaneous coronary intervention (PCI). In one mode of PCI, a catheter is inserted into a major systemic artery, either in the groin or arm, and manipulated toward the entrance of the coronary artery branches at the origin of the aorta. This catheter takes the form of a thin tube (known as a Judkins catheter) through which radiopaque dyes can be delivered into the bloodstream, allowing visualization of the coronary arteries using a special type of X-ray called fluoroscopy (known as angiography). Other techniques for imaging the coronary arteries (e.g., intravascular ultrasound) may also be used. If the narrowing (stenosis) is deemed severe enough, a common treatment is to insert a stent to restore the artery to its original (non-stenotic) diameter. To place the stent, another catheter is passed through the first catheter and then advanced further to the narrowed portion of the coronary artery. Once the tip reaches its correct position, the balloon, which has a stent crimped around it, is inflated. The tip of the balloon compresses the plaque, expanding the stent. Once the plaque is compressed and the stent is in its correct position, the balloon is deflated and withdrawn. The stent remains inside, holding the artery open. PCI generally results in beneficial patient outcomes, but long-term complications such as in-stent restenosis (ISR) or stent thrombosis (ST) can occur. ISR occurs when tissue and plaque grow through the stent wall. ST occurs when blood clots adhere to the stent. Both complications will again obstruct the normal blood flow that the stent was supposed to restore. Advances in stent material selection have led to the current generation of stents including drug-eluting stents (coated with drugs that slowly release to inhibit cell proliferation and reduce ISR and ST) and bioreabsorbable stents (designed to dissolve into the bloodstream over time, giving the artery a chance to heal in a non-stenotic state). While material selection significantly impacts patient outcomes, another crucial characteristic is how well the stent fits into the patient's artery. Ideally, the stent should remain in contact with the arterial wall in a "juxtaposed" state when expanded, without being pushed so far as to damage the endothelium (the layer of cells that form the inner lining of the arterial wall). In this case, the endothelium should form a thin layer that grows over the stent as the artery heals, but not to the point of causing ISR or ST. Currently, stents are manufactured in various lengths and diameters, and the appropriate size is selected by examining the narrowed artery using imaging techniques, such as angiography. One problem with this method is that arteries may be tapered or have some complex shape, and a simple cylindrical structure may not be suitable for maintaining contact with the arterial wall in a juxtaposed position. Therefore, the difference between the shape of a ready-made stent and the shape specific to the patient can be quite large, resulting in complications due to incomplete adhesion and inappropriate sizing. These differences range from tens to hundreds of microns, but currently employed techniques cannot achieve a more precise control of tolerances. The lack of contact between the stent and the arterial wall (incomplete adhesion) can lead to complex patterns of low wall shear stress (friction on the arterial wall caused by blood flow), resulting in cell proliferation that can lead to ISR and ST. Therefore, technologies are needed to address the aforementioned problems. U.S. Patent Application No. 15/498,159U.S. Patent Application No. 15/498,185 This figure shows how a desired (non-stenotic) blood vessel shape is created from a 3D model of a stenotic blood vessel, according to an exemplary embodiment of the present invention.This figure shows how an individualized coronary stent design is created from a stent template and a desired vessel shape, according to an exemplary embodiment of the present invention.This figure shows a parameter design for a general-purpose stent template according to an exemplary embodi