Introduction to Coronary Balloons Angioplasty

Basic Information of Coronary Balloon Angioplasty

Overview:

Coronary balloons angioplasty is an interventional treatment method for coronary artery stenosis, which uses a balloon catheter to deliver and inflate the balloon at the target lesion site in the coronary artery, to expand narrowed coronary arteries. It is also the basis for all interventional treatments for coronary heart disease.

Balloon catheters (referred to as balloons) have gradually evolved from simple balloon angioplasty (POBA) to having many functions such as lesion predilation, assisting in stent delivery and deployment, post-dilation, and drug-coated balloons (DCB) treatment.

Balloons can be classified based on their design as compliant, semi-compliant, and non-compliant balloons. Based on their operational features, they can be divided into rapid exchange and over-the-wire (OTW) balloons. Based on special functions, they have developed from perfusion balloons before the creation of stents to now commonly used cutting balloons, scoring balloons, double wire balloons, and DCBs.

Technical characteristics:

Basic components: The structure of a coronary balloons catheter includes a distal tip, balloon, transition segment, and push rod, which are closely related to the passage of the balloon.

Compliance: Compliance refers to the ability of the balloon diameter to change with pressure.

Pushability: Pushability refers to the ability of the balloon catheter to push the balloon forward, which mainly depends on the design of the balloon head and transition zone, as well as the material of the push rod.

Flexibility: Flexibility refers to the ability of the catheter to navigate and move through tortuous blood vessels.

Indications and contraindications:

Applicable situations:

POBA is the earliest interventional treatment method, but the restenosis rate is as high as 30% to 60%;

Balloon predilation is suitable for most lesion pretreatments before stent implantation, and can also assist in determining the vessel diameter, evaluating the length of the lesion, and to a certain extent, understanding the nature of the lesion.

Post-dilation is mainly used for high-pressure dilation inside the stent after stent implantation, to ensure complete dilation and apposition of the stent.

DCB, also known as drug-coated balloons, delivers anti-proliferative drugs to the vessel wall while dilating the balloon, achieving the effect of inhibiting neointima formation.

Inapplicable situations:

Coronary artery stenosis less than 50%, and no objective evidence of myocardial ischemia;
Severe diffuse multivessel disease, poor results of balloon angioplasty or stent implantation, and coronary artery bypass grafting surgery is safer with a better prognosis.

Operation procedures and technical essentials:

Single-track balloons are currently the most widely used balloons, using this as an example, the operation procedures and technical essentials for balloon dilation are as follows:

(1) Select an appropriate coronary balloons catheter.

(2) Insert the balloon catheter along the wire guide.

(3) Avoid repeatedly using forceful imaging after pre-dilation to avoid further damage to blood vessels.

(4) For severe and complicated narrowings or anticipated difficult stent passage, routine full dilation is necessary.

(5) Post-dilation balloons for stent implantation should be selected based on intracavity imaging guidance, with a similar diameter to the stent for high-pressure dilation, while avoiding exceeding the edge of the stent.

Complications and Treatment

Coronary artery spasm
Coronary artery dissection and intramural hematoma
Branch occlusion
Coronary artery rupture or perforation
Balloon rupture or entrapment
No reflow or slow flow

The semi-compliant balloon for coronary balloons angioplasty

Overview

Mainly used for pre-dilation of lesions before stent implantation, with nominal pressure of 6-8 atm and burst pressure of 14-16 atm. When the inflation pressure in the working range increases by 1 atm, the balloon diameter increases by about 8%-10%.

Device Characteristics

Semi-compliant balloons with diameters of 1.0-3.0mm and lengths of 8-20mm are commonly used.

Indications and Contraindications

Applicable situations:

Pre-dilation of routine lesions;
Balloon dilation for simple PTCA treatment;
Crossing the stent struts and expanding the stent mesh in the treatment of bifurcation lesions;
Used for branch dilation when expanding the kissing balloon in the treatment of bifurcation lesions;
Used as an anchor balloon;
Used as a confinement balloon.

Situations where the effect is poor or not applicable: