P2portal

Balloon

An angioplasty balloon is a medical device that is attached at the end of a special balloon catheter, the balloon is at one end and can be inflated/deflated from the other end outside the body.
The balloon catheter will send over a guidewire into a a narrow or blocked artery with a fatty substance (plaque).
An interventional cardiologist inflated and deflated the balloon several times to restore blood flow in the artery by pushing the plaque aside.
The other option of the balloon is to open up the stent when it is positioned in the desired place.
Another kind of balloon called cutting balloon is a special balloon containing small blades that are activated when it is inflated. The small blades cut slits in the plaque that is resistant to a traditional balloon, and then pushes the fatty substance into the wall of the artery.

The most commonly used PCI equipment consists of four basic elements: a guiding catheter, a balloon catheter, a coronary guidewire, and a stent.

Definition: the degree of increase in balloon diameter as the inflation pressure increases.

Compliant:

Diameter increases in ratio with the increase in inflation force
Can increase their diameter 10-15% above their nominals when the inflation pressure reaches bursting pressure (which is usually low)
Size of balloon may grow beyond the ceiling of clinical safety

Non-compliant:

Reach and maintain specified size regardless of inflation pressure
Little to no flexibility in vessel sizing
The non-compliant balloons can only reach less than 5% above their nominal sizes at their burst pressure (which is usually high)

Semi-compliant:

There are three types of PCI balloon catheters:

Classical balloon catheters which have two lumens running through the entire course of balloon catheter.
- One lumen is for passage of guidewire
- Other lumen for connecting with an indeflator (for balloon inflation/deflation)

Advantages

Disadvantages

Specific Uses:

Treatment of complex lesions where the following may be required:
- Added wire support
- Easy exchange of wires
- Extra catheter pushability
- Intracoronary injections

Rapid-exchange (RX) or monorail balloon catheters have become the current standard for percutaneous coronary interventions (PCI).
This balloon catheter also contain two lumens, but guidewire lumen does not extend along the entire course of the balloon.
It starts from distal end but finishes well before the proximal end of the balloon catheter.

Advantages

Disadvantages

Specific Uses:

This type of system is ideal for simpler cases, where the extra wire support is not needed.

It has the inelastic balloon wrapped around a central hollow wire(guidewire) with a distal flexible steering tip.
The proximal end of the catheter consists of a single port connected to a thin metal tube (hypotube) used to inflate the balloon. A core wire extends from the hypotube to the end of the distal steerable tip.
The guidewire attached to the balloon can be rotated freely, but it cannot advance independently of the balloon.
This assembly is coated with a thin plastic shaft that enhances flexibility. Fixed-wire balloons have only one enclosed lumen for balloon inflation.
This system is generally not considered for first-line use due to the lack of pushability, trackability, and steerability. However, because of its extremely low profile, it may occasionally cross tight narrowing when over-the-wire balloons fail.