By Ileah Chissick

Introduction

Percutaneous transluminal coronary angioplasty (PTCA) is the dilation of narrowed blood vessels using a balloon catheter, and is one of the most common types of treatment for the heart.

PTCA is important because narrowed veins and arteries, reduces blood circulation, which leads to an increased risk of getting cardiovascular disease, having a stroke and heart attacks.

Balloon Catheter

Balloon catheters are long, flexible tubes with a small diameter.

They also have other useful properties, which makes them ideal for PTCA.

Balloon catheters have an ‘Over the Wire’ tip, which is a hole at the tip of the patient end, which is designed for a guidewire to be threaded through, without letting fluid through.

Guidewires are strong, thin wires placed in the body and used to guide the catheter towards the site of the procedure.

The balloon on the catheter is cylindrical, long and flexible so they can effectively widen the dilated vessels.

Some balloons are covered in serrated edges on the surface, which damages the walls of the blood vessel slightly, which encourages them to widen. This design also requires less pressure within the balloon to widen the vessels.

Tri-Lobe balloon catheters have three balloons, which can be individually inflated and deflated, allowing the blood circulation to be controlled during the procedure. The balloons also act like a tripod for maximum stability during PTCA.

Another property of the balloon catheters is their echogenicity. Being echogenic allows catheters to be visible on x-rays, because the x-rays are absorbed by the catheter instead of passing through. This allows the location of the catheter to be known within the body, and identify when it is in the ideal position for PTCA.

PTCA

PTCA is a minimally invasive procedure, as only a small incision is required to insert the catheter into the body. The catheter carries a stent, which is positioned around the balloon.

Firstly, a guidewire is placed in the narrowed blood vessel, which is then threaded through the catheter, and is used to position the catheter within the narrowed blood cell.

Once in position an x-ray is taken, so that the catheters position within the vessel can be identified. Once the catheter is confirmed to be in position, the balloon is inflated with disinfected water.

Once the balloon inflates, the walls of the blood vessels are pushed, and any atherosclerosis deposits are compressed into the vessel walls. The stent is also pushed into the walls of the vessel and is used to prevent the vessel narrowing after the procedure.

The balloon is deflated and the catheter is removed from the body with the guidewire, leaving the stent in place.

Stents

Stents are small, metal wire mesh tubes that acts like a scaffold, to ensure the blood vessel stays open and allows blood to flow through.

There are two different types of stent:

• Bare metal stents.
• Drug-eluting stents

A bare metal stent is a doesn’t have any coatings or additions, and is the stent on its own.

Drug-eluting stents have a coating on the surface, which releases medicine into the tissue around the stent, which is to prevent the body attacking the stent as part of an immune response. This has caused drug-eluting stents to be more commonly used than the bare metal ones.

There is a downside to the drug-eluting stents, the medicine which prevents the immune response also prevents the tissue healing around the stent. Blood thinners must also be taken to prevent blood clots blocking the stent.

Most stents are permanent, however there are stents which are surgically removed after a certain period of time. Some stents are bioresorbable and does not require surgery to remove, as it will be absorbed into the body after a certain period of time.

Risks of PTCA

The surgery is minimally invasive, however there are risks associated with the surgery.

Infection is a risk, because the catheter used is a long hollow tube that is put within the body. The stents and guidewires used could also cause infection if they are not sterilised effectively.

Another risk is the potential for patients to have an allergic reaction to the equipment used and the drug contained within the stent.

Other risks are caused by damage to the heart or blood vessels during PTCA, which includes;

• Internal bleeding
• Blockages
• Blood clots
• Heart Attack
• Stroke

Although these complications are serious, they aren’t common. Most of the listed complications are more likely to occur if surgery is not performed to dilate the blood vessels.

Procedures Similar to PTCA

Transcatheter Aortic Valve Replacement

Transcatheter Aortic Valve Replacement (TAVR) is the replacement of a damaged heart valve, with a new synthetic one, made from metal and animal tissue that is compatible with human tissue.

Aortic stenosis is a disease which causes the aortic valve to become stiff, narrow and unable to open and close properly. People with this disease can undergo TAVR, to replace the damaged valve.

For this procedure a transcatheter is used, which is similar to balloon catheter, but there is one potential difference. Transcatheters do not always use a balloon, in some cases the new valve will expand by itself when in position.

Before the procedure a temporary pacemaker may be placed in the patient along with a filtration device, used to collect plaque and debris, preventing it from travelling through the bloodstream.

During the procedure, a transcatheter is inserted and directed into the heart.

Once in position an x-ray is taken to confirm its location, then the catheter balloon inflates or the replacement valve expands on its own.

The new valve is positioned inside the old valve, and will regulate blood flow from the heart. The old valve is not removed from the body.

After the procedure, the patients heart rate is checked and the pacemaker and filtration device are removed from the body.

The risks for TAVR includes:

• Bleeding
• Replacement valve slipping
• Replacement valve leakage
• Infection
• Stroke
• Kidney Disease
• Heart Rhythm Problems (arrhythmias)

Eustachian Tube Dysfunction

Eustachian tube dysfunction is when the eustachian tube, in the ear becomes swollen and is blocked by fluid and mucus.

Eustachian tube dysfunction can cause loss of hearing, tinnitus and loss of balance as well as pain. These symptoms can get worse with changes in pressure and altitude.

During the procedure, a Eustachian tube catheter is passed through the nose into the Eustachian tube, where the balloon is inflated.

The fluid and mucus within the ear is removed through the catheter, and the balloon is deflated.

This is not a permanent solution, but it helps to relieve symptoms and prevent infection caused by the fluid build up.

There are risks involved with this procedure, including:

• Damage to the ear
• Infection
• Bleeding

Conclusion

The aim of PTCA and the aforementioned procedures, is to widen a narrowed opening using catheters, which is achieved in different ways, either by placing a stent to keep the vessel open, or by removing the blockage.

The functionality of the catheters is key to being able to effectively carry out these procedures.

These surgeries is important because the risks to the patients health is greater without the surgery, compared to the risks of the surgery itself.

PTCA and TAVR save the lives of patients by allowing blood to circulate around the body as intended.

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By Ileah Chissick