What is Drug Elution Balloon Catheter Ultrasonic Spraying?

Introduction to drug eluting balloon catheters:

 

Balloon catheter, also known as balloon dilation catheter, is the main component of coronary intracavitary balloon angioplasty. Under the guidance of the guide wire, the balloon catheter enters the narrow segment along the guide wire, causing the narrow area to expand. The commonly used balloon catheters are generally divided into two types: integral exchange and rapid exchange.

 

In recent decades, percutaneous puncture technology has made significant progress in the treatment of arterial diseases, and the development of each new technology has been improved. Balloon catheter angioplasty is an invasive minimally invasive treatment method. Previous treatment methods often involved repetitive medical processes and had a higher probability of complications, and their own disadvantage was that they could not prevent vascular recoil and endometrial hyperplasia. Within the coronary artery, angioplasty overcomes the acute recoil of the balloon by inserting a bare metal stent (BMS), but cannot prevent in stent restenosis (ISR) and excessive neointimal hyperplasia. The use of drug eluting stents (DES) effectively reduces the occurrence of neointimal hyperplasia and increases or decreases its occurrence, eliminating the time required for subsequent treatment. Anti proliferative drugs and specially designed polymers are controlled for slow release through coatings on the surface of balloon catheters, with controllable dosage and time.

The balloon catheter of the ultrasonic spraying system for spraying drugs is the main body of the entire treatment system. Atherosclerosis is a very popular disease in China, especially for middle-aged and elderly people, coronary artery balloon angioplasty is an effective solution. Ultrasonic atomization technology has been proven to be successful.

The ultrasonic balloon catheter spraying system is used to spray anti restenosis polymers and plasticizers onto implantable balloon catheters, producing a thinner, more uniform, and more effective coating. Some balloon catheters require the use of an automatic inflation device to inflate the balloon catheter before coating.

 

 

The structure of the balloon catheter:

 

The main structural components of a balloon catheter include a pointed tip, a balloon, and a push rod (as shown in the following figure). In addition, the connecting section serves as a link between the push rod and the balloon, which has a significant impact on the pushing and bending resistance of the balloon. Generally, a central steel wire is added to the connecting section of the balloon to enhance support and improve the pushing and bending resistance of the balloon catheter.

1. Sharp tip

The size performance parameters of the tip of the balloon catheter (such as diameter, length, and hardness) can directly affect its ability to pass through occlusive lesions. If the tip adopts a conical design, the diameter of the balloon tip is reduced, thereby enhancing the tracking ability of the catheter. Generally speaking, balloon dilation catheters with short hard heads are suitable for the treatment of severe stenosis lesions, while those with long soft heads are more suitable for handling tortuous lesions.

2. Balloon

The material of the balloon has a significant impact on the compliance ability of the balloon dilation catheter. The PET material has lower balloon compliance, while the POC material has higher balloon compliance. At present, the commonly seen semi compliant balloons in clinical practice are made of nylon materials. The retraction performance of balloon dilation catheter refers to the ability of the balloon diameter to recover after balloon dilation and suction, which can be used as one of the indicators to evaluate the passage of the balloon through the lesion, and this is also related to the balloon material. Nowadays, the surface of the balloon is mostly coated with hydrophilic materials, which improves the ability of the balloon to pass through lesions.

3. Push rod

The well-known materials for balloon catheter push rods in China are polymer materials and metal materials. The use of polymer materials in the balloon push rod will reduce the friction during pushing, while the use of metal materials in the push rod can have good pushing performance. When multiple balloon dilation catheters need to be inserted simultaneously to treat lesions, such as bifurcation lesions, the relationship between the outer diameter of the balloon push rod and the inner diameter of the guide catheter should also be considered.

 

Performance of balloon catheters:

 

Including balloon outer diameter, flexibility, traceability, propulsion, and compliance. The tip of the balloon depends on its shape and material. A long soft head is beneficial for guiding the balloon through twisted blood vessels, while a short hard head is beneficial for passing through severely narrowed blood vessels. The material of the balloon determines its flexibility and ability to pass through the lesion. The materials are usually nylon and special polyethylene, which have ultra-thin thickness, low compliance, and high pressure resistance. Low compliance can prevent excessive dilation of the balloon at both ends, leading to balloon vessel tearing, but the shape of low compliance materials is poor.

Therefore, currently, semi compliant balloons made of nylon materials are mostly used, while non compliant balloons are mainly used for transporting scaffolds. The connecting section mainly reflects the pushability, flexibility, coaxiality, and bending resistance of the balloon. The materials of push rods are divided into two categories: shell polymer material center reinforced steel wire and steel pipe push rods. The former has poor thrust, but due to the hydrophilic coating on the outer layer, the friction force is small. The latter has strong thrust, but is prone to breakage and high friction, currently with two push rods coexisting.

The balloon catheter sprayed by the ultrasonic precision spraying system is the core medical project of surgery. Maintain a small diameter before expansion, making it easy to pass through narrow areas. Its radiographic characteristics ensure accurate positioning and safe and reliable results.

 

The working principle of balloon catheter:

The balloon is inflated before coating (some new catheters in the market no longer require inflation). The rotary motor rotates the catheter and balloon as a whole 360 degrees, while the precision clamping device firmly fixes the tail of the catheter in place. Balloons can also be indexed to the level specified by the user.

Designed to spray anti restenosis solutions containing paclitaxel, rapamycin (sirolimus), zotocin, docetaxel, heparin, or other cell anti proliferative drugs+plasticizer excipient solutions onto catheters containing medical balloons coated with cardiac angioplasty or other drugs. Used to deposit a uniform anti restenosis drug film onto implantable devices such as the heart and peripheral stents. Compared with other spray deposition methods of precision medical equipment, the unique characteristics of ultrasonic spraying can produce thinner, more uniform, and more efficient coatings.

 

Advantages of ultrasound coating for balloon catheters:

 

1. A highly uniform thin film coating on the heart or other balloon catheter can evenly transfer drugs at the lesion site.

Compared to immersion coating, it saves materials.

3. Reliable, repeatable, and controllable balloon catheter coating.

4. Able to atomize common chemical compositions, including hydrophilic carriers and plasticizers, to increase the flexibility of coatings.

5. A durable coating without cracking or peeling ensures correct delivery of drugs at blocked areas.

6. The target area (stripes) can be sprayed on the surface of the balloon instead of covering the entire balloon surface.

7. The medical grade gasket on the balloon of the catheter ensures that it will not damage the catheter component or coil the catheter.