Nitinol stent

Types of nitinol stents

A nitinol stent is a tiny tube that doctors insert into a blocked artery or duct to keep it open. It is made from nitinol, a nickel-titanium alloy. The nitinol stent types include:

• Coronary Stents: These are inserted into coronary arteries, which supply blood to the heart. They open narrowed or blocked arteries caused by plaque buildup to restore blood flow and prevent heart damage. Nitinol coronary stents are flexible and expand easily to fit artery shapes.
• Peripheral Stents: These are used in arteries outside the heart, such as those in the legs, arms, or pelvis. They treat peripheral artery disease by opening narrowed arteries from plaque or blood clots. Nitinol peripheral stents are designed to withstand blood vessel movements.
• Carotid Stents: These are placed in the carotid arteries in the neck, which supply blood to the brain. They open narrowed carotid arteries from plaque to prevent strokes or brain damage. Nitinol carotid stents are small and expand to fit artery shapes.
• Aortic Aneurysm Stents: These are inserted into the aorta, the main artery from the heart. They strengthen and open enlarged sections of the aorta from plaque or high blood pressure. Nitinol aortic aneurysm stents are flexible and withstand blood vessel movements.
• Biliary and Pancreatic Stents: These are used in the bile ducts and pancreatic ducts. They treat strictures or blockages from gallstones, tumors, or inflammation. Nitinol biliary and pancreatic stents keep the ducts open to allow bile and digestive fluid to flow.

How to choose nitinol stents

While many nitinol stents are available, choosing the right one is vital to patient care and treatment. Here are some factors to consider when choosing a nitinol stent:

• Type of lesion

  Lesion type refers to its size, shape, and location. Complex lesions with curvatures or small diameter require specialized stents. Some stents have features that make them suitable for difficult lesions, such as higher flexibility and better radial force.

• Stent delivery system

  A good stent delivery system ensures accurate stent placement. Look for stents offering excellent trackability, pushability, and deliverability through the lesion. An effective delivery system will reduce procedure duration and improve patient outcomes.

• Clinical evidence

  Look for stents with clinical trials supporting their safety and effectiveness. Check the sample size, population characteristics, and outcome measures. Clinical evidence provides assurance of the stent's performance in real patient settings.

• Regulatory approval

  Ensure the stents are CE-marked and approved by relevant regulatory bodies. CE marking indicates that the product meets European safety and health requirements.

• Cost-effectiveness

  Consider the cost of the stent and the overall value it provides. Some stents may be expensive but offer better clinical outcomes.

How to use, install, and product safety nitinol stents

How to use nitinol stents

Nitinol stents are tubes inserted into arteries or other body passages to keep them open. Here's how they are generally used:

• Diagnosis: Doctors use tests like angiograms to see blockages in arteries, often from plaque or narrowing.
• Access: When blockage is located, doctors make a small incision in the groin or wrist to insert a thin catheter. They use this catheter to reach the blocked artery in the heart.
• Delivery of Stent: At the blockage site, doctors use a tiny balloon catheter to open the narrowed area. They then slide a stent over the balloon. The balloon expands the stent and props the artery open.
• Types of Stents: Nitinol stents are flexible and expand well. Bare-metal stents are just metal to support the artery. Drug-eluting stents have special drugs to prevent scar tissue from growing.
• Recovery: After the balloon and stent are removed, the artery stays open. Blood can flow freely again. Doctors monitor heart function and may prescribe medications.

Installation

• Minimally Invasive Procedure: Stent placement is typically done through a small incision in the groin or wrist, where catheters are guided to the coronary arteries.
• Balloon Catheter: A balloon catheter is used to open blocked arteries, and the stent is deployed simultaneously.
• Medical Team: A skilled team of doctors called interventional cardiologists places the stent while monitoring the heart's blood vessels with X-ray images.
• Recovery: After placement, patients usually stay in the hospital for one or two nights for recovery and monitoring.

Product Safety

• Biocompatibility: Stents are made from materials that the body accepts without causing inflammation or reactions.
• Corrosion Resistance: Nitinol stents resist corrosion from body fluids, maintaining strength and structure over time.
• Mechanical Properties: Nitinol has excellent flexibility, allowing it to conform to artery shapes without kinking or loss of patency.
• Drug Elution: In drug-eluting stents, the released drugs are safely absorbed or eliminated within therapeutic levels.
• Long-Term Studies: The safety of nitinol stents has been proven through studies that monitor patient outcomes over many years.

Functions, features, and design of nitinol stents

Function

• Vascular Support: Nitinol stents are primarily designed to provide permanent support to blood vessels that have been narrowed or blocked due to conditions like atherosclerosis. By holding the artery open, they facilitate improved blood flow and reduce the risk of heart attacks or other vascular diseases.
• Controllable Release Drugs: Some nitinol stents are designed to release controlled drugs over time to the affected arterial walls. These drugs help prevent restenosis (re-narrowing of the artery) by inhibiting smooth muscle cell proliferation and promoting healing.

Feature

• Superelasticity and Flexibility: Nitinol stents possess remarkable superelastic properties, allowing them to easily expand and contract without losing shape. This flexibility enables the stents to navigate through the complex vascular anatomy during deployment and then securely fit within the artery or the affected area of the artery, ensuring optimal support and patency of the blood vessel.
• Corrosion Resistance: Nitinol stents have a significant advantage in terms of long-term performance and safety, with excellent corrosion resistance. They can withstand the harsh chemical environment inside blood vessels without deteriorating over the years, thus maintaining structural integrity and biocompatibility over time. This property reduces the risk of harmful corrosion products being released into the bloodstream and ensures the stent remains effective in supporting the artery for an extended period, enhancing patient outcomes and the durability of the stented vessel.
• Biocompatibility: Nitinol stents are highly biocompatible, meaning they can co-exist with body tissues and fluids without causing significant inflammatory reactions or rejection phenomena. This property is vital for the long-term safety and effectiveness of the stent in vascular applications, as it minimizes the risk of complications such as thrombosis, infection, or chronic inflammation that could compromise the vascular health of the patient. By integrating well with biological systems, nitinol stents help promote better healing and function within the arterial environment, thereby improving patient prognosis and quality of life after procedures like angioplasty where these stents are deployed.

Design

• Mesh Structure: The characteristic mesh structure of nitinol stents is designed to provide the necessary radial strength for keeping arteries open while also allowing flexibility and conformability to the arterial wall. This design helps prevent the stented segment from collapsing, thus improving blood flow and reducing the risk of restenosis.
• Biodegradable Polymers: Some nitinol stents incorporate a biodegradable polymer coating that gradually disappears over time, leaving only the nitinol framework. This design allows for a temporary controlled drug release while the artery heals, eventually leaving a fully restored vessel without a foreign body.

Q&A

Q1: What are the common uses of a nitinol stent?

A1: Nitinol stents are mainly used in coronary arteries to treat conditions like atherosclerosis, angina, heart attacks, and coronary artery disease. They are also used in peripheral arteries to treat atherosclerosis and other vascular diseases.

Q2: What is the average delivery time?

A2: The average delivery time for nitinol stents is one to three months, depending on the quantity and customization. Delivery may take longer in case of urgent orders and due to other external factors such as bad weather, traffic, and pandemics.

Q3: Can buyers get product samples?

A3: Many manufacturers allow buyers to order product samples. The samples can be free or paid, depending on the manufacturer. Keep in mind that the samples are produced in small quantities and may not reflect the exact product ordered in bulk.

Q4: Do nitinol stents have any side effects?

A4: Nitinol stents are biocompatible and have minimal side effects. However, patients may experience blood clots, stent blockage, and excessive tissue growth, which can lead to heart attacks and chest pain. Stents should be used together with anticoagulant drugs to prevent blood clotting.

Q5: How can one tell if a nitinol stent is original?

A5: Original nitinol stents have a smooth surface with no irregularities. They are also flexible, deliverable, and have excellent radial strength. Original stents are packed in sterile packages with barcodes, expiry dates, and production information. They should also be CE and ISO certified.