Overview of Percutaneous Transluminal Angioplasty and Balloon Catheters
Around the world, a disease called atherosclerosis is the most common health problem that causes death and illness. This disease can lead to other health conditions such cardiovascular disease, which affects your heart; carotid artery disease, which affects an artery going to your brain; peripheral vascular disease affects the arteries away from your heart; and renal artery stenosis, which impacts an artery that goes to your kidney.
Angioplasty is a procedure doctors use to make the arteries wider again, removing the blockages caused by atherosclerosis. It’s a low-risk procedure that modifies the plaque (a sticky substance containing fats and cholesterol that blocks your arteries) to reshape it. Thanks to modern technology in the field of interventional radiology (which uses imaging to see inside your body), doctors can now treat almost all areas of blocked arteries. This method has been in use since 1964 when Dr. Charles Dotter used it to open up an artery in the leg of an 82-year-old woman. The techniques and tools have improved a lot since that first procedure, evolving from simple balloon dilation (using a small balloon to open the artery) to the use of stents (small mesh tubes that hold the artery open) and something called atherectomy, which is the removal of plaque.
A variety of stents can be used in this procedure:
1. In a coronary angioplasty (which deals with the arteries of the heart), possible stents include bare metal stents and various types of stents that release drugs to deal with the plaque. These range from early versions with drugs like sirolimus and paclitaxel, to versions made from durable or bioabsorbable polymers carrying drugs like everolimus and zotarolimus. The best choice of stent depends on what is available locally and the expertise of the cardiologist.
2. For a carotid angioplasty (involving the arteries that go to your brain), stents that expand on their own are used. Here, again, the best choice of stent can depend on individual patient’s condition and circumstances.
3. In treating peripheral arteries (the ones that are away from your heart), the choice of stent will depend on where the treatment is taking place, the nature of the plaque, and the exact shape of the patient’s vascular anatomy, as well as what stent types are available and the expertise of the doctor.
Sometimes, doctors use an additional procedure called atherectomy to remove plaque using special equipment. There are several types of atherectomy procedures, some involving mechanical devices and others involving laser technology. The effectiveness of these procedures is still being studied.
Anatomy and Physiology of Percutaneous Transluminal Angioplasty and Balloon Catheters
Atherosclerosis is a condition where fatty substances such as cholesterol build up inside the blood vessels, leading to a blockage. This blockage, also known as a plaque, can interfere with blood flow. Sometimes, these blockages can rapidly increase in size if they rupture or bleed, causing a clot to form and further limiting blood flow. This can cause severe pain and can damage or kill nearby tissues.
a common way to treat Atherosclerosis is by performing a procedure called angioplasty. This involves inserting a balloon or a small tube known as a stent into the blocked artery to reopen it and restore blood flow. However, this procedure can have some complications. One of the main risks is that a clot might form on the stent. To minimize this risk, doctors often prescribe medications known as dual antiplatelet therapy.
Another possible issue after stent placement could be the regrowth of tissue inside the stent, which may lead to a renewed blockage. This issue can be addressed by using special stents coated with drugs that stop cell growth such as sirolimus, tacrolimus, or everolimus.
Despite these advancements, late complications can still occur due to the presence of the metallic structure of the stent. To address this, there are newer stents made from materials that slowly dissolve in the body. However, these aren’t perfect solutions, as they may not be as effective in maintaining the opening of the blood vessel. Therefore, the decision regarding which type of stent to use is specific to each patient, the artery affected, type of blockage, and the local expertise in stent placement.
Why do People Need Percutaneous Transluminal Angioplasty and Balloon Catheters
If you have specific heart problems like unstable chest pain, STEMI (a type of serious heart attack), or NSTEMI (another type of heart attack), you might need a procedure called PCI (Percutaneous Coronary Intervention) – essentially, a type of non-surgical treatment to unblock your heart’s arteries. You might also need it if you’re very active, have certain forms of angina (a type of chest pain) that can’t be controlled by medication, or if you’ve got a specific type of blocked heart vessel. However, if you have a serious type of heart disease that affects multiple vessels or the main heart artery, or if you have diabetes, bypass surgery might be a better option than PCI.
Next up is Carotid Angioplasty, a procedure used to widen the carotid arteries and restore blood flow to the brain. It’s mostly recommended for patients who have severe blockages (around 70-99%) in their carotid arteries, which can lead to stroke. While a more invasive procedure known as carotid endarterectomy usually has lower stroke rates, some people may have better results with carotid stenting – those with prior neck radiation treatments, a high position of the artery divide in the neck, or complete blockage of the main artery on the opposite side of the neck.
As for Peripheral Vascular Disease, which affects blood vessels outside the heart and brain, certain interventions may be needed if lifestyle changes, exercise programs, and medicines aren’t enough to manage the symptoms. Angioplasty with stenting, a procedure to open up the blocked vessels, is generally preferred unless the narrowing is uneven, affects a long part of the vessel or multiple areas.
In cases of Renal Artery Stenosis, a condition causing narrowing of the arteries that carry blood to the kidneys, Angioplasty with stenting is recommended if high blood pressure can’t be controlled using medications. This procedure can help restore normal blood flow, controlling blood pressure and preserving kidney function.
Finally, Angioplasty could be used to treat venous stenosis, a condition where veins narrow, particularly those used for hemodialysis (a procedure to remove waste products from the blood in people with kidney failure). This procedure can help to keep the veins open and functional for effective dialysis treatment.
When a Person Should Avoid Percutaneous Transluminal Angioplasty and Balloon Catheters
There are several reasons why an angioplasty procedure, a surgery to open up blocked blood vessels, may not be suitable for some people. For instance:
If the blood vessels are too small, it can make the procedure more difficult. Problems like the hardening of the backs of blood vessels, known as posterior calcification, or blockages, known as occlusion, can also prevent this procedure. Additionally, if there’s a pool of clotted blood, or a hematoma, in the vessels, an angioplasty might not be possible.
Being unable to take dual antiplatelet therapy, which is medication to prevent blood clots, or having an allergy to the materials in stents (small tubes used to keep the vessel open), can pose problems in this procedure.
Despite its effectiveness, angioplasty is usually not recommended for people over 80 due to the increased risk of stroke.
Certain serious health conditions that can shorten a person’s lifespan might make the procedure too risky, and therefore, could prevent a doctor from recommending an angioplasty.
Equipment used for Percutaneous Transluminal Angioplasty and Balloon Catheters
Here is the list of tools your doctor would use for this procedure:
* Fluoroscopy and X-ray imaging equipment: Special machines used to capture live images of the inside of your body. This includes things like a table for radiographic imaging, two X-ray tubes, and a fluoroscopy screen.
* Micropuncture needle: A small, sharp instrument (18-20G) used to puncture the skin.
* Hydrophilic sheath: A thin, tube-like medical device that slides through blood vessels with minimal friction.
* Contrast material: A type of dye that enhances the images taken during the procedure.
* Guidewire: A slim, flexible wire that helps guide medical instruments to the correct place in the body.
* Balloon catheter: A tiny, flexible tube that can be inflated with air or liquid once inside the body to widen narrow or obstructed areas of blood vessels.
* The stent: This is a small mesh tube that’s used to treat narrow or weak arteries.
* Ultrasound imaging device: Uses sound waves to create pictures and videos of the inside of your body.
* Hemodynamic monitoring system: This system checks your blood pressure and how well your heart is pumping blood.
Preparing for Percutaneous Transluminal Angioplasty and Balloon Catheters
Before any vascular procedures, either an angioplasty or putting in a stent, for instance, a vascular surgeon or cardiologist checks over each patient. This is done to see whether the patient is fit for the procedure and to decide on the best method of treatment. These checks usually don’t need an anaesthetic. Only if the patient has a high Mallampati score, which is a measure of difficulty in intubation or making a breathing tube, will there be a need for an anesthesiologist to assess the situation.
Allergies, particularly to a type of contrast dye used in procedures, and how well the patient follows their medication routine should also be checked. This helps in planning the procedure and helps prevent any complications. The function of the patient’s kidneys should be evaluated as well, since quite a bit of contrast material will be used and should be removed from the body efficiently. Certain medications that might harm the kidneys are stopped before the procedure, including some types of painkillers and drugs for heart disease and diabetes.
Blood-thinning medications are also stopped before any surgical procedure, to prevent excessive bleeding. Instead, aspirin, and any other blood-thinning medications like ticagrelor, prasugrel or clopidogrel would be given. The patient is also asked not to eat or drink anything 8-12 hours before the procedure to prevent complications during anesthesia. Just before the procedure, the patient’s vital signs are checked and monitored throughout to ensure their wellbeing. The skin over the area where the procedure will be performed is shaved, cleaned with an antiseptic solution and covered with sterile drapes.
Most adults getting an angioplasty will have either moderate or deep sedation, which will relax them while keeping them awake. But younger patients might need to be put to sleep completely with general anesthesia.
How is Percutaneous Transluminal Angioplasty and Balloon Catheters performed
For patients with chronic kidney disease (CKD) who may need a treatment known as end-stage renal disease (ESRD) in the near future, it’s best to avoid using the radial artery–the major blood vessel in your wrist–for medical procedures. This is to conserve the radial artery for a procedure called fistula placement which is necessary for a kidney treatment known as hemodialysis.
When a medical procedure called arteriotomy is necessary, the radial artery can be accessed using a small incision made about 2cm above the bony prominences on the thumb side of your wrist. A thin needle is used to puncture the artery and a lubricated sheath is pushed into the artery using a specialized technique known as the modified Selinger technique. To expand the artery and minimize the chances of clotting, medications are injected into your bloodstream.
Access to the femoral artery–a major blood vessel in your thigh–can be secured similarly by feeling the artery’s pulse about 2cm below the grooves of your pelvic bone. A live x-ray known as fluoroscopy can be used to better locate the artery.
Once artery access is obtained, a thin wire is threaded into the artery and guided to the targeted vessel. A catheter, attached with a small balloon, is then moved along the wire to reach the right place. After reaching the target artery, a contrast agent (a special dye) is introduced followed by imaging to visualize that area. The balloon is inflated to widen the blocked artery and squeeze the fatty deposit against the artery walls.
In some cases, a procedure called atherectomy can be planned; an instrument is inserted through the guidewire to break off the plaque.
If the placement of a stent–a small mesh tube–is necessary, the balloon catheter is removed after inflating, and a fit stent is guided over the wire. Once it’s in the right place within the artery, a contrast dye is injected, and the stent is deployed to support the artery’s inner wall. Additional imaging methods like Intravascular Ultrasound or Optic Coherence Tomography may be used to ensure the stent’s proper placement.
Once the satisfactory placement of the stent is achieved, the guidewire is removed. The puncture site is made to stop bleeding by applying pressure manually or with a special band.
Evidence has been increasing to favor the use of radial artery access over femoral artery access in procedures like percutaneous coronary interventions (a non-surgical procedure that improves blood flow to the heart) because it has a lower chance of local bleeding. However, for patients with CKD who may need hemodialysis treatment in the future, radial artery use should be avoided to save it for future use.
Possible Complications of Percutaneous Transluminal Angioplasty and Balloon Catheters
Serious complications like heart attacks, strokes, or even death can occur after angioplasty, a procedure to clear blocked arteries. The chances of these issues are low (less than 1%) in angioplasty of the heart or legs’ arteries but higher for the neck and abdomen arteries. However, everyone has different risks, which doctors will evaluate using scoring scales like the Revised Cardiac Risk Index or American Society of Anesthesiologists score. Higher risks are usually seen in very sick patients or those with liver disease, severe anemia, shock, a recent heart attack, kidney issues, heart disease, heart failure, high blood pressure and unstable chest pain.
Local complications: Problems with blood vessels can happen in about 6% of all angioplasty procedures. One such issue is the puncture of an artery, although it happens rarely.
Bleeding: If the blood doesn’t clot properly after the procedure, this can cause blood to gather under the skin, a bulging blood vessel, or bleeding in the abdominal area. Bleeding issues are seen more often in women than men and are more common when the procedure is done through the leg rather than the arm. Signs of bleeding can range from a simple bruise at the site to changes in blood pressure due to significant bleeding. Early detection and restoring fluid balance with solutions are critical. Whether to stop giving antiplatelet drugs depends on the specific case. Severe bleeding may need the help of a vascular surgeon and special methods.
Blood clot: This is less common than bleeding, but it happens more when the procedure is done through the arm rather than the leg. Risk factors for this include a small blood vessel, diabetes, being a woman, using a large tube for the procedure, or blocked arteries in the legs. Symptoms include pain or tingling in the affected arm or leg with reduced or no pulse. It’s important to have this evaluated urgently to prevent any limb damage.
Systemic complications
Atheroembolism: This happens if there is local damage to the arteries’ walls leading to fat deposits breaking off from the artery into the bloodstream. Symptoms include blotchy, red-blue discoloration of the skin, digit ischemia, kidney issues and signs in the eyes’ retina. Treatment is primarily for reducing risk and managing large lesions. The overall impact depends on the existing state of artery health.
Acute Kidney Injury: This can occur for various reasons, including exposure to contrast media used in the procedure, fat deposits breaking off into the bloodstream, or poor blood flow. To prevent this, it’s advisable to hydrate patients well before the procedure and manage their risk factors.
Arrhythmia: Angioplasty can lead to different types of abnormal heart rhythms due to the catheter’s irritation. The management depends on the specific type of arrhythmia according to standard algorithms.
Infection: Strict sterile methods are required to prevent infections. A potential infection can lead to severe bloodstream infection or even sepsis. All personnel is required to wear masks, gowns, gloves, and eyewear and wash their hands thoroughly. They must also be vaccinated for Hepatitis B.
Radiation Exposure: The imaging required during angioplasty can expose patients to substantial radiation, which could theoretically increase the risk of certain types of cancer. But actual association with specific cancers needs more research.
Hypersensitivity reactions: These are more common after stent placements, with the overall chances being low. The cause of allergic reactions can be local anesthetic, iodine-containing contrast media, certain medications used in the procedure. Careful evaluation before the procedure, avoiding the suspected agent or pre-treatment can reduce the severity of the reaction. If a severe allergic reaction develops, a medicine called epinephrine may be needed.
What Else Should I Know About Percutaneous Transluminal Angioplasty and Balloon Catheters?
Angioplasty is a procedure that doctors use to open up clogged arteries. It’s less invasive than open surgery which means that it’s less risky and doesn’t require as long a hospital stay or recovery time. The procedure does, however, carry some risk of the artery becoming narrowed again.
This method has dramatically changed the way heart attacks and unstable chest pain are treated and is now considered the standard approach. It also works well as an alternative treatment for diseases of the peripheral blood vessels, which are the vessels that carry blood away from the heart to the limbs and organs. It allows for a smoother recovery, despite a somewhat lower success rate in improving blood flow compared to other methods.
However, when it comes to the carotid arteries, which supply blood to the brain, angioplasty carries more risk than the benefits it offers. It’s usually only recommended for certain patients.
The success of these types of treatments can be increased if patients commit to a healthier lifestyle. This includes changes such as following a balanced diet, regular exercise, quitting smoking, taking prescribed medications properly, and managing any other health conditions properly.