Diagnostic Vascular Angiography
These procedures involve imaging the blood vessels in any part of the body except the heart. Usually only one area is imaged at any one time. The types of areas imaged are the:
- aorta (the main artery in the body)
- iliac arteries (in the pelvis)
- femoral, popliteal and tibial arteries (in the legs)
- renal arteries (for the kidneys)
- carotid arteries (in the neck)
- sub-clavian arteries (in the shoulder area)
- cerebral arteries (in the brain)
- brachial and radial arteries (in the arms)
Although these arteries can be imaged in the CardioVascular Unit the can also be imaged by ultrasound, CT or MRI scans.
If your doctor decides to bring you to the Cardiovascular Unit for imaging the preparation and set up is very similar to coronary angiography. Access is gained through the femoral artery 95% of the time.
During the preparation for the procedure you will move from your bed to the X-ray table which is narrow and a little hard. You will then be connected to an ECG to monitor your heart beat. One of the nurses will then wash your groin area (which will have been shaved) with some antiseptic solution—this feels cold. You will then be covered with a big blue sheet from chin to over your toes. This is sterile to keep any germs from the access site. It is important that you do not touch the top of this sheet. Your arms will be down by your side and supported by some arm boards. Please don’t move them unless told and someone is helping you. If the sterile sheet is “contaminated” we may need to start again.
Your doctor will then numb the groin area with some local anaesthetic. A needle is then used to access the femoral artery which is the easiest point of introduction for the catheter. The only sensation you will feel is a pinprick when the local anaesthetic is injected and a little pushing when a sheath is inserted into the femoral artery.
The catheter is guided to the part of the body to be imaged. When the X-ray images are taken you will be asked to hold your breath and keep very still. If you move or breathe it makes it difficult to get good pictures. When enough pictures have been taken the catheter is then removed and firm pressure is applied to the puncture site for 15 mins to stop any bleeding until the artery puncture is sealed.
Your doctor will then assess your pictures and decide on the next appropriate course of action. The options are:
- continue on medical treatment
- perform an angioplasty procedure
- refer you for surgery.
Your hospital stay will usually be overnight or sometimes your cardiologist may perform the procedure as a same day procedure.
Endovascular Interventional Procedures
Sometimes this procedure follows on immediately after your angiogram. Other times you will come back on another day. If you have to come back the preparation and access of the femoral artery is the same as for an angiogram (see diagnostic vascular angiogram).
This procedure entails the use of devices to fix a blockage in the affected artery and is an alternative (in certain cases) to vascular surgery. The devices used are usually small balloons and stents. A stent is a small metal tube that is used to hold the artery open.
These devices are introduced through the middle of the catheter along a very fine wire that acts like a railroad track for the balloons and stents to run on. Usually a balloon is inserted first, placed across the blockage and inflated to open the blocked area. Secondly, a stent is placed in the artery to keep it open. Sometimes a further balloon is placed inside the stent and inflated to make sure it’s fully open.
If you have more than one blockage this process is repeated in each one. Sometimes only a balloon is required and other times a stent can be placed without the first balloon inflation. Occasionally more than one stent is required to cover the diseased area.
You will be awake but mildly sedated during the procedure.
As with diagnostic vascular procedures, there are different areas that can be treated with balloons and stents. Each area uses an adaptation of the angioplasty technique described above, which is specific to that area. The areas that can be treated are the same as for diagnostic angiography. They include the:
- aorta—the main artery in the body.
This area is often treated with stent grafts which are stents covered with a surgical material that not only hold the artery open but also replace the artery wall. These are used where there is a weakening of the artery wall and it has stretched and swollen to a larger size than normal. This can lead to a possibility of that weakened wall rupturing and causing internal bleeding
- Iliac arteries—in the pelvis
- femoral, popliteal and tibial arteries—in the legs
- renal arteries—for the kidneys
- carotid arteries—in the neck. These procedures usually use filter devices to catch any small blood clots that may be dislodged by the balloons being inflated. The reason to catch them is so they will not float up into the brain and cause a stroke
- sub-clavian arteries—in the shoulder area.
- cerebral arteries—in the brain. In these procedures a technique called embolization is used rather than balloons and stents. The blood vessels in your brain are very fine and the disease process is different from larger vessels in the body. Instead of plaque forming on the inside of the artery and causing a narrowing, here the concern is that the artery wall becomes weakened and bulges like a small balloon—this is called an aneurysm. If this weakened area ruptures you can bleed inside your brain. These aneurysms can be operated on, or can be embolised depending on what your doctor decides that you are suitable for. The embolisation procedure requires fine wires and catheters to be placed in the affected artery. Then small devices called coils and/or a gluey substance is used to block up the swollen part of the artery, while leaving the artery itself intact
- brachial and radial arteries—in the arms.
These procedures use small wire coils and/or a gluey substance to block of blood vessels or parts of blood vessels that are causing problems. Some examples are:
- arteries that are supplying cancer tumours
- small aneurysms (weakened areas of artery walls)
- ovarian veins that have swollen causing pelvic congestion
- arteriovenous malformations (where the artery to capillary to vein structure is not correctly formed).