A drug-coated covered stent

Abstract

The present invention is related to a drug-coated covered stent the drug coated covered stent is a novel medical device designed to address Type III coronary artery perforations during percutaneous coronary intervention (PCI). This system combines a balloon-expandable stent covered with a biocompatible graft material and coated with cytotoxic drugs at its ends to prevent excess tissue growth and promote endothelialization. through a rapid exchange delivery system, the DCCS can be precisely positioned and expanded within the artery, sealing tears and promoting healing. The device's ultrathin profile and high flexibility enable navigation through tortuous vessels. Key components are a blocking balloon (201), second guidewire (203), covered stent (205), proximal and distal shafts of the delivery system (1, 2, 3, 15 4), stent (5), graft material (6), cytotoxic drug coatings (8, 9), and endothelialization (11). This innovative solution offers a promising approach to managing coronary artery perforations, potentially reducing the need for surgical interventions.

Description

TITLE OF THE INVENTIONA DRUG-COATED COVERED STENTDESCRIPTIONField of the Invention

[0001] The present invention is related to the field of bio-medical engineering. More specifically, it relates to a drug-coated covered stent, designed to address Type III coronary artery perforations during percutaneous coronary intervention.Background of the Invention

[0002] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0003] In 2011 Coronary Perforation and Covered Stents by Mohammed Al-Mukhaini, Prashanth Panduranga, Coronary perforation is a rare complication of percutaneous coronary intervention. We present two different types of coronary intervention, but both ending with coronary perforation. However, these perforations were tackled successfully by covered stents. This article reviews the incidence, causes, presentation, and management of coronary perforation in the present era of aggressive interventional cardiology. Coronary perforations are classified as type I (extraluminal crater), II (myocardial or pericardial blushing), and III (contrast streaming or cavity spilling). Types I and II coronary perforations are caused by stiff or hydrophilic guidewires. Type I has a benign prognosis, whereas type II coronary perforations have the potential to progress to tamponade. Type III coronary perforations are caused by balloons, stents, or other intracoronary devices and commonly lead to cardiac tamponade necessitating pericardial drainage. However, type III perforations can be managed with covered stents without need for surgical intervention.

[0004] W02004064911A1 related to a stent for percutaneous coronary intervention, which is coated with a vascular restenosis prevention drug, is provided. The stent includes a plurality of struts. Here, minute wells are formed on the surface of each ofthe struts byscarring a surface of each of the struts, and the entire surface of each of the struts including thewells is coated with a vascular restenosis prevention drug. Since the stent is coated with a vascular restenosis prevention drug and a considerable amount of the vascular restenosis prevention drug is also contained in eachof the drug containing grooves and the drug containing holes, it is possible to provide a brilliant antirestenosiseffect for at least a certain period of time when restenosis is very likely to occur by slowly releasing the vascular restenosis prevention drug into blood vessel wall.

[0005] INA202121057448 describe a stent for renal denervation comprises a composition having a polymer, an active agent and optionally a solvent and an additive. The active agent to polymer ratio is between 5:95 to 70:30. The stent is deployed at the target lesion in a lumen. The stent comes in contact with the inner wall of the lumen, tract or duct, adheres. The active agent transfers from the stent to the tissues through absorption and diffusion due to concentration difference.

[0006] INA202147055886 discloses a degradable drug-loaded stent and a manufacturing method therefor. The degradable drug-loaded stent comprises a stent body, an outer surface of the stent body being provided with a drug-loaded groove, the stent body having a contracted state and an expanded state, the stent body being capable of switching from the contracted state to the expanded state via radial expansion, the stent body being a mesh columnar structure when in the expanded state, the depth of the drug-loaded groove being 10%-60% of the wall thickness of the mesh columnar structure.

[0007] There are various drawbacks to prior art and existing technology. Hence, there was a long-felt need in the art.Objective of the Invention

[0008] The primary objective of the present invention is to provide a drug-coated covered stent.

[0009] Yet another objective of the invention is to provide an effective and minimally invasive solution for managing Type III coronary artery perforations during percutaneous coronary intervention (PCI).

[0010] Yet another objective of the invention is to design a drug-coated covered stent topromote endothelialization and accelerate healing within the treated artery.

[0011] Yet another objective of the invention is to enhance the flexibility and delivery of the stent system, particularly in tortuous and calcified vesselsSummary of the Invention

[0012] The following presents a simplified summary of the disclosure to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure, and it does not identify key / critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description presented later.

[0013] Accordingly, the following invention provides a drug-coated covered stent. The bare metallic stent covered with the graft material is used to seal the tear in the coronary arteries for the Type III Perforation to avoid the need of surgical interventions, by sealing the tear in the artery with a covered stent, the invention aims to prevent life-threatening complications such as pericardial effusion and tamponade.

[0014] The covered stent of this invention is coated with drugs at the distal and proximal end of the stent to stop the excess tissue growth promoting or accelerating the endothelialisation and preventing the stent thrombosis by releasing the drug at the implantation site as well as sealing the coronary artery perforations.

[0015] The Proximal and Distal ends of the stents are coated with the drug to prevent excess tissue formation and better healing like Drug Eluting stents which are used to reopen and maintain patent coronary arteries narrowed by arteriosclerosis.

[0016] The drug coated metallic stents covered with the graft material is a balloon-expandable, pre-mounted on a rapid exchange delivery system. The drug coated covered stent is centered in between two radiopaque markers to facilitate fluoroscopic visualization and positioning. The proximal shaft of the delivery system is a hypotube and has a single Luer port for connecting an inflation / deflation device to inflate / deflate the balloon. The catheter has a polymer jacketing on the outer surface of the proximal shaft and a hydrophilic coating on the outer surface of the distal shaft.

[0017] By taking the advantage of this invention the stent length covered with graft protect the leakage of blood by sealing the dissection in the artery and the drug coating promotes the endothelialisation preventing thrombosis by increasing and accelerating endothelial coverage which is the major disadvantage with the covered stents available currently in the market.Brief Description of the Drawings

[0018] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:

[0019] Figure 1 of sheet 1 illustrated the perforations in the coronary artery. Where,101 denotes a main vessel perforation,102 denotes a perforation of epicardial collateral,103 denotes an end branch perforation.

[0020] Figure 2 of sheet 2 illustrated the procedure of advancing the covered stent to treat the coronary artery.Where,201 denotes a blocking balloon,202 denotes a perforation site,203 denotes a second guidewire,204 denotes a main vessel,205 denotes a covered stent.

[0021] Figure 3 of sheet 3 illustrated the type of perforations I, II and III.Where,301 denotes a perforation,302 denotes a coronary artery.

[0022] Figure 4 of sheet 4 illustrated the covered stents coated with drug at the ends pre-mounted on balloon assembled with delivery system.Where,401,405 denotes a marker,402 denotes a coated with drug,403 denotes a graft material,404 denotes a coated with drug,406 denotes a balloon,407 denotes a delivery system,408 denotes a luer.

[0023] Figure 5 of sheet 4 illustrated the stent system with proximal and distal shaft.Where,1 denotes a proximal shaft of the delivery system (hypo tube),2 denotes a single luer port,3 denotes a balloon,4 denotes a distal shaft of the delivery system.

[0024] Figure 6 of sheet 5 illustrated the metallic stents covered with the graft material. Where,5 denotes a Stent,6 denotes a non-textile biocompatible graft material,7 denotes an uncovered end of the stent.

[0025] Figure 7 of sheet 5 illustrated the drug coated at the ends of the stent. Where,8 denotes a cytotoxic drug coating (distal end),9 denotes a cytotoxic drug coating (proximal end).

[0026] Figure 8 of sheet 6 illustrated the less thickness of the covered stent (top view of covered stent)Where,10 denotes a wall thickness of the stent

[0027] Figure 9 of sheet 6 illustrated the cross-sectional view of coronary artery showing endothelialisation after release of drugWhere,11 denotes an endothelialization,12 denotes a slow-release drug coating.

[0028] Figure 10 of sheet 7 illustrated the drug coated stent covered with graft material expanded at perforation site.Where,13 denotes a sealed tear in the artery.

[0029] Figure 11 of sheet 8 illustrated the longitudinal view of the drug coated covered stents.

[0030] Figure 12 of sheet 8 illustrated the side view of the expanded drug coated covered stent.Description of the Invention

[0031] It is to be understood that the present disclosure is not limited in its application to the details of composition set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0032] The use of "including", "comprising" or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Further, the use of terms "first", "second", and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[0033] Reference throughout this specification to "one embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "one embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, different embodiments, or component parts of the same or different illustrated invention.

[0034] Each statement of an embodiment is to be considered independent of any otherstatement of an embodiment despite any use of similar or identical language characterizing each embodiment.

[0035] The wording "one embodiment," or the like, does not appear at the beginning of every sentence in the specification, but is merely a convenience for the reader's clarity. However, it is the intention of this application to incorporate by reference the phrasing "an embodiment," and the like, at the beginning of every sentence herein where logically possible and appropriate.

[0036] The present invention is related to a drug-coated covered stent. The drug coated covered stent is an innovative medical device aimed at effectively treating Type III coronary artery perforations encountered during percutaneous coronary intervention (PCI). This novel solution combines a balloon-expandable stent covered with a biocompatible graft material and coated with cytotoxic drugs at its ends.

[0037] The Drug coated Covered stent system of the Current Invention is the single stent with less wall thickness and low crossing profile, the graft material possesses very high ultimate elongation making suitable for expanding the stent radially after implantation.

[0038] The graft material acts as physical barrier to seal the tear inside the coronary artery.

[0039] The covered stent of this invention is coated with drugs at the distal and proximal end of the stent to stop the excess tissue growth promoting or accelerating the endothelialisation and preventing the stent thrombosis by releasing the drug at the implantation site as well as sealing the coronary artery perforations.

[0040] Procedure: The Covered stents in the invention is used to seal the perforation artery as well as to prevent the excess cell growth as the drug will be released slowly after implantation.

[0041] Perforations in the artery is very uncommon, but physicians need to be fully prepared for this emergency event.

[0042] As shown in the Figure: 2 the blocking balloon (201) is temporarily deflated to allow advancement of a second guidewire (203) into main Vessel (204).

[0043] The blocking balloon (201) is re inflated to stop pericardial bleeding. The goal is to stop bleeding from the Perforation site (202) into the pericardium reducing the risk for tamponade.

[0044] The covered stent (205) is then advanced over the second guide wire (203) proximal to the blocking balloon. The second guide wire allows for delivery of a covered stent (205), maintaining hemostasis by the inflated balloon.

[0045] The blocking balloon (201) provides extra support to the second guidewire, facilitating delivery of the covered stent (205). The blocking balloon is deflated and the covered stent is advanced across the ostium of the perforated vessel. The blocking balloon and its guidewire are not removed until after the covered stent has reached the perforation site. The drug coated covered stent of this invention is deployed successfully sealing the dissection and slowly eluting the drug to prevent the excess tissue formation and accelerating endothelialisation.

[0046] The Percutaneous Coronary Intervention (PCI) is a non-surgical procedure that uses a catheter to place a small structure called stent to open up blood vessels in the heart that have been narrowed by plaque build-up, a condition known as atherosclerosis.

[0047] During this procedure, perforation occurs as a consequence of guide wire advancement, balloon or Stent advancement, balloon or Stent inflation, over sizing or ruptured balloon or ruptured stent or from sub intimal passage of balloon or stent into a vessel with severe dissection.

[0048] Coronary perforations as per Figure 1 are rare PCI complication leading to pericardial effusion with or without tamponade and if left untreated it is life-threatening.

[0049] As shown in Figure 3 Coronary Perforations are classified as type I (extra luminal crater), II (myocardial or pericardial blushing), and III (contrast streaming or cavity spilling). Type I has a benign prognosis, Type II have the potential to progress totamponade, type III coronary perforations are caused by balloon, stents or other intracoronary devices may lead to cardiac tamponade.

[0050] Type III perforations can be managed with covered stents avoiding the need for surgical intervention.

[0051] The deep tears of type III perforation in coronary arteries can occur on rare occasions during percutaneous interventions.

[0052] To stop blood from leaking out to the area surrounding the heart, the covered stents system of the present invention with ultrathin thickness is inserted in a similar procedure. It provides a physical barrier with a graft membrane that seals the tear from inside the artery, avoiding the open- heart surgery and also eluting the drug slowly for better healing and accelerating endothelial coverage.

[0053] The drug coated metallic stents covered with the graft is balloon-expandable, premounted on a rapid exchange delivery system. The covered stent is centred in between two radiopaque markers to facilitate fluoroscopic visualization and positioning as shown in Figure 4

[0054] As shown in Figure 5, the proximal shaft 1 of the delivery system is a hypo tube and has a single Luer port 2 for connecting an inflation / deflation device to inflate / deflate theballoon 3. The catheter has a polymer jacketing on the outer surface of the proximal shaft and a hydrophilic coating on the outer surface of the distal shaft 4.

[0055] In some embodiment as shown in Figure 6 the stent 5 is covered with the non-textile biocompatible graft material 6, leaving the distal and proximal end of the stent without covering with graft material at both sides 7.

[0056] In other embodiment as per Figure 7, both the distal and proximal ends of the stent is coated with the cytotoxic drug 8 & 9.

[0057] The currently available stents in the market cannot be used in the tortuous and calcified vessels due its bulkiness and lack of flexibility.

[0058] One embodiment of the Covered stent of current invention is ultrathin as shown in Figure 8 with high tensile strength and flexibility of graft material 6 and high radial strength of the stent material, designed with less wall thickness 10 making it suitable to advance in the tortuous and calcified vessels.

[0059] The major disadvantage of available covered stents includes thrombogenicity and occlusion of coronary branches.

[0060] In some embodiments of current invention covered stent prevents thrombus formation by promoting or accelerating the endothelialisation 11 as it is coated with the slow-release drug 12 at distal and proximal ends of the stent as shown in Figure 9.

[0061] In the Current invention the stent 5 covered with graft material 6 protect the leakage of blood by sealing the tear in the artery 13 and the drug coated at the ends 8 & 9 promotes the endothelialisation 11 preventing thrombosis by increasing and accelerating endothelial coverage and preventing the excess growth of cells as per Figure 10.

[0062] Construction of the present invention: The Covered Stent System of present invention is balloon expandable that is pre mounted on a rapid exchange delivery system.

[0063] The Proximal shaft of the delivery system is made of hypo tube and has a single Luer port for connecting an inflation / Deflation device to inflate / deflate the balloon.

[0064] The Hypo tube of proximal shaft is made of biocompatible material like Stainless Steel of grade 304V, 304L, and 316 LVM mild steel or the like.

[0065] The Distal shaft of the delivery system is made of polymer with the polymeric balloon attached, some examples of suitable polymers may include elastomeric polyamides, block polyamide / ethers, polyether block amide (PEBA, for example available under the trade name PEBAX, ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon- 12 (such as GRILAMID® available from EMS American Grilon), perfluoro (propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and / or SIBS 50A), polycarbonates, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer / metal composites, and the like.

[0066] The Distal shaft of the present invention can also incorporate various coatings, such as hydrophilic or hydrophobic coatings, anti-thrombogenic coatings, or a combination thereof. An example coating may include BAYER CL- 100, BIOSLIDE, NG-HPC, SLIP COAT, MDX, or the like. These are just examples. Other materials are contemplated including those disclosed herein.

[0067] In other embodiment of the Present Invention the Stent is made of biocompatible material, designed with less thickness of the struts to have the low crossing profile for ease in advancement of the stent to the perforation site, some example of material which helps in less thickness of the struts without compromising the radial strength and providing the exceptional bending stiffness are Co Cr L605 alloy, Co Cr MP35N alloy,Stainless steel 316 L , stainless steel 316 L, Nitinol Super elastic alloy, Platinum Chromium alloys.

[0068] The Invention consist of a single stent design covered with the graft material the covering can be done with different methods like lamination techniques, suturing techniques and electro spinning techniques.

[0069] In some embodiment of the present invention the stent is covered with the non-textile biocompatible graft material leaving the distal and proximal end of the stent without covering with graft material at both sides

[0070] The graft material should possess highly elastic properties, tensile strength and should not impair the stent expansion.

[0071] Some of the graft materials suitable for these applications are (Non-Textile Materials) like PTFE, ePTFE, Polyurethane, Polyethylene terephthalate or the like.

[0072] In other embodiment, the distal and proximal ends of the stents are coated with the drug to prevent the excess cell growth and better healing like drug eluting stents, promoting endothelialisation and further preventing stent thrombosis.

[0073] Some examples of cytotoxic drugs like Sirolimus, Everolimus, paclitaxel, Zotarolimus and the like.

[0074] While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

Claims

CLAIMS:I / We claim:

1. A drug-coated covered stent, comprising of; a. a balloon-expandable stent (5) covered with a biocompatible graft material (6), leaving the distal and proximal ends of the stent uncovered (7); wherein said stent is configured to seal a tear in a coronary artery (13); b. cytotoxic drug coatings (8, 9) applied to the distal and proximal ends of the stent to prevent excess tissue growth and promote endothelialization; wherein said coatings facilitate arterial healing; c. a rapid exchange delivery system including a proximal shaft (1) made of hypo tube and a distal shaft (4) made of polymer; wherein said delivery system enables precise positioning and deployment of the stent within the coronary artery; d. a single luer port (2) for connecting an inflation / deflation device to inflate / deflate the stent;2. The drug-coated covered stent as claimed in claim 1, wherein the biocompatible graft material comprises materials selected from the group consisting of PTFE, ePTFE, Polyurethane, and Polyethylene terephthalate, providing a physical barrier to seal the coronary artery tear (13) while maintaining stent flexibility and radial strength.

3. A method for treating coronary artery perforations using the proposed drug-coated covered stent, comprising the steps of; a. a blocking balloon (201) to temporarily stop pericardial bleeding; b. introducing a second guidewire (203) to facilitate delivery of the covered stent (205) proximal to the perforation site (202), while maintaining hemostasis with the inflated balloon; c. deploying the drug-coated covered stent to seal the tear within the artery and promote endothelialization, thereby preventing thrombosis and facilitating arterial healing.

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