Balloon catheter for surgical enlargement of the aortic annulus

Abstract

The balloon catheter is widely used in interventional cardiology. The device named "balloon catheter for aortic annulus enlargement", was modified and adapted for use in open heart surgery, where the aortic annulus is too small. The catheter consists of a polytetrafluoroethylene (PTFE) body, coupled to a polyethylene terephthalate polymer (PET) inflation balloon and a one-way valve. During the procedure, the balloon is inflated inside the aortic ring, allowing it to dilate to facilitate the implantation of adequate prostheses. The balloons have pre-determined sizes, corresponding to those of the prostheses available. This method avoids the need for adjuvant techniques, such as sectioning and reconstitution using biological or inorganic materials. The use of the catheter balloon simplifying the procedure and significantly reduces the costs and risks associated with this complex surgery. The implantation of properly sized prostheses provides numerous benefits to the patient, both in the short and long term.

Description

[0001] DESCRIPTIVE REPORT - UTILITY MODEL

[0002] TITLE: Balloon catheter for surgical enlargement of the aortic annulus.

[0003] Field of the Invention

[0004] The present invention relates to a medical device, more specifically a “balloon catheter” to be used during aortic valve replacement surgery, with the purpose of enlarging the aortic annulus in patients who require a larger prosthesis to prevent high transvalvular gradients and the associated complications.

[0005] Technical sector

[0006] This invention falls within the technical sector of “medical devices”, particularly in the field of “interventional cardiology” and “cardiac surgery”, with direct applications in procedures involving the dilation and replacement of heart valves, such as aortic valve replacement surgeries.

[0007] Basics of the Invention

[0008] The “balloon catheter” described in this patent has a structure made up of a stem or catheter which, at one end, has an “inflatable balloon”, and at the other, a “one-way valve”. This device is already widely used in various areas of medicine, both in diagnostics and interventional treatments, including its application in coronary angioplasties and the implantation of stents.

[0009] In cases of severe aortic stenosis, where the valve is calcified and obstructed, the surgical risk of open valve replacement surgery can be high. For these patients, less invasive techniques such as “transcatheter aortic prosthesis implantation” (TAVI) have been developed and often make use of balloon catheters to expand the prosthesis.

[0010] Technical problem

[0011] In traditional open surgeries for aortic valve replacement, when the aortic annulus is too small, it is necessary to enlarge it in order to implant an appropriately sized prosthesis. The implantation of very small prostheses can result in high transvalvular gradients, leading to various complications, such as heart failure, myocardial hypertrophy and increased mortality. Currently, the surgical techniques available for enlarging the annulus are complex and involve longer operating times, as well as greater risks of complications, such as bleeding. Proposed Solution

[0012] The present invention offers an innovative solution through the use of a “balloon catheter for aortic annulus enlargement” during open aortic valve replacement surgery. By dilating the tissue annulus directly, after removing the cusps of the original valve, the balloon is used to enlarge the annulus, allowing the implantation of a prosthesis of a more suitable size, in a simpler, faster and more reproducible way. This technique reduces the risks associated with complex annulus enlargement procedures and improves clinical results, with lower transvalvular gradients and greater ease of future prosthesis implantation.

[0013] Advantages

[0014] The main advantages of the present invention include:

[0015] - “Reduction of complications”: the technique reduces the risks of bleeding and other postoperative complications associated with aortic annulus enlargement by traditional methods.

[0016] - “Speed and simplicity”: the use of the balloon catheter makes the procedure faster and more reproducible.

[0017] - “Better prognosis”: adequately sized prostheses result in lower transvalvular gradients, reduce the risk of early deterioration and increase long-term survival.

[0018] - “Possibility of new implants”: the use of this technique facilitates future transfemoral prosthesis implant procedures.

[0019] Documents

[0020] The state of the art is corroborated by the manuscript awaiting publication: “Dealing with the aortic annulus: Surgical aortic annulus enlargement with a balloon catheter”. AL Tyszka, AJ Jorge, HE Ghoz. Innovations, 2024. DOI: 10.1177 / 515569845241288550.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The attached drawings show the details and dimensions of the balloon catheter and a schematic representation of its application.

[0023] - Figure 1 shows a detailed view of the balloon catheter and its dimensions,

[0024] - Figure 2 shows the details of the dimensions of the inflated balloon catheter (front view), and

[0025] - Figure 3 illustrates the detail and schematic representation of the balloon catheter inflated in the aortic annulus. DESCRIPTION OF THE INVENTION

[0026] The present invention relates to a “Balloon Catheter for Surgical Enlargement of the Aortic Ring”, developed for use in open heart surgery, specifically in aortic valve replacement. The device allows the aortic annulus to be enlarged without the need for sutures or additional materials, simplifying the procedure and reducing surgical risks.

[0027] Technical features

[0028] The balloon catheter (1) consists of the following elements:

[0029] - Stem or Catheter: The catheter is flexible, made of “polytetrafluoroethylene (PTFE)”, a biocompatible material that offers chemical resistance and low friction. It has a diameter of 3 mm and a length of 50 cm. It is a “single lumen” catheter, known as “Rapid Exchange”. This means that the catheter does not need an additional lumen to pass the guide wire through, making it easier to insert and handle in the surgical field.

[0030] - Inflatable balloon: Located at the distal end of the catheter, the balloon is made of “PET (polyethylene terephthalate polyester) polymer”, a material that withstands “high pressures” of up to 10 atmospheres (ATM), providing resistance during inflation. The balloon is designed to withstand nominal and burst pressures (NBP and RBP) without damaging the surrounding tissue or the vessel in 99.9% of cases, with a 95% confidence level.

[0031] The balloon (2) is rectangular in shape, with a length of 4 cm and “variable diameters”: 21 mm, 23 mm, 25 mm, 27 mm and 29 mm, allowing flexibility of choice based on the patient's anatomical characteristics and the size of the aortic annulus, and corresponds to the exact size of existing prostheses.

[0032] - Unidirectional valve: In the proximal portion of the catheter, there is a “unidirectional valve” which allows safe control of the flow of saline solution for balloon inflation.

[0033] The balloon is inflated using an inflation syringe connected to the one-way valve. This disposable syringe has a pressure gauge that measures pressures of up to 10 ATM and a lock that controls the plunger, guaranteeing the correct pressure during the procedure. The entire system is “single use”, guaranteeing safety and preventing contamination. The device can be sterilized by “ethylene oxide”, an effective and commonly used method for medical devices. Application of the Invention

[0034] During cardiac surgery for aortic valve replacement, with the patient on cardiopulmonary bypass, the “balloon catheter” is used after the compromised aortic valve has been removed (3). The procedure follows these steps:

[0035] 1. Aortic valve resection: The surgeon removes the diseased valve in the conventional way, exposing the aortic annulus.

[0036] 2. Positioning the Balloon Catheter: After measuring the diameter of the annulus, an appropriately sized balloon catheter is introduced under direct vision into the aortic annulus. There is no need for a guide wire or introducer, simplifying the procedure.

[0037] 3. Balloon inflation: The balloon is inflated with saline solution using the inflation syringe until it reaches the preset pressure, sufficient to dilate the aortic annulus without the risk of rupture.

[0038] 4. Prosthesis implantation: With the balloon inflated, the aortic prosthesis is positioned and then the balloon is deflated and removed. The prosthesis and balloon have the same diameter, ensuring a precise fit.

[0039] 5. Completion of the procedure: The prosthesis is fixed in place, completing the surgery efficiently and safely.

[0040] Examples of Achievements

[0041] This invention uses the principles of balloon catheters already widely used in interventional cardiology and adapts their application to the field of “open heart surgery”. The introduction of the “Balloon Catheter for Surgical Aortic Ring Enlargement” innovates by simplifying complex aortic ring enlargement procedures, offering advantages such as:

[0042] - “Reduced surgical time” and less need for additional materials, such as sutures or organic and inorganic flaps.

[0043] - “Lower immediate surgical risks”, such as bleeding and complications related to conventional augmentation techniques.

[0044] - “Expanded use” of the device for minimally invasive cardiac surgery, including endoscopic and robotic approaches, expanding the field of application for advanced and innovative techniques.

[0045] This invention represents a significant advance in the surgical approach to aortic valve disease, bringing benefits in terms of “simplicity”, “cost reduction” and “lower risk” for patients.

Claims

The balloon catheter is a medical device used in interventional cardiology percutaneously. This catheter, called the “balloon catheter for aortic annulus enlargement”, has been modified and adapted to be used in open heart surgeries in which it is necessary to enlarge the aortic annulus under direct vision.Independent ClaimA balloon catheter for surgical enlargement of the aortic annulus in open heart surgery, characterized by:- a catheter tubular body 3mm, 50 cm long with one lumen (figure 1), composed of polytetrafluoroethylene (PTFE) polymer, configured for direct insertion into the aortic tissue ring during open-heart surgical procedures surgical procedures, under direct vision and without the need for a guide wire;- an inflation balloon attached to one end of the catheter (figure 1), the balloon is made from polyethylene terephthalate (PET) polymer, with dimensions of length of 4cm and widths of 21 , 23, 25, 27 and 29mm (figure 2), predetermined sizes corresponding to existing biological aortic prostheses, where the balloon is sized to expand the aortic annulus in a controlled manner to facilitate the implantation of larger diameter valve prostheses;- a unidirectional valve located at the opposite end of the catheter (figure 1), adapted to allow precise inflation of the balloon with saline solution and to maintain the internal pressure necessary for dilation of the aortic tissue ring during the procedure;- the balloon catheter is configured to promote enlargement of the aortic annulus without the need for surgical sectioning of the tissue ring or the use of additional materials for reconstruction, reducing the risks and complexity of the surgical procedure.Elements of the Claim Explained- Catheter Body: Clear definition of the material (PTFE), configuration and dimensions for use in the context of open surgery, which is an innovation over traditional balloon catheter that require a double lumen for the passage of the guide wire and longer lengths due to peripheral insertion.- Inflation Balloon: Specified material (PET) and purpose of sizing for to match existing prostheses. The described balloon catheter has been adapted to its new use. The balloonlength of 4 cm corresponds to the thickness of the tissue ring without interfering with neighboring structures and the surgical technique for implanting the prosthesis. As the balloons need to correspond the exact size of the prostheses to be implanted, the final diameter of the balloon should be every 2 mm: 21 , 23, 25, 27 and 29 mm. The material used to make the balloon must be made of PET - polymer (polyethylene polyester terephthalate) capable of withstanding high pressures of up to 10 ATM without the risk of the risk of rupture and reach the predetermined diameter without damaging the vessel in 99.9% with a 95% confidence limit.- Unidirectional valve: Important for safety and functionality during dilation.- Functional differential: Enlargement of the aortic tissue ring without the need for additional surgical techniques, highlighting the advantage of simplicity and reduced risks.

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