Renal Artery Stenting
What is a Renal Artery Stenting?
Renal artery disease is a condition caused by the narrowing of the arteries leading to one or both kidneys. This narrowing, or stenosis, is usually caused by a build up of fatty and/or calcium deposits called plaque on the inside of the arteries. Over time, this plaque build up, also called atherosclerosis or hardening of the arteries, can progress to a total blockage (occlusion) of the artery.
When the kidney doesn’t receive enough blood because of a blockage in the artery, it sends a signal to the body to increase the blood pressure. This causes high blood pressure (hypertension) that can be very difficult to control. High blood pressure can increase strain on the heart by speeding the spread of atherosclerosis to other parts of the body, and it can also affect the kidney’s ability to filter the blood and remove waste.
Your kidneys are located on either side of your spine, just below your rib cage. They filter waste materials out of your blood and help keep your blood pressure in the normal range. The arteries that carry blood to your kidneys are called the renal arteries. Renal Artery stenting is a special type of X-Ray using dye to show the narrowing of the renal arteries and allows the cardiologist to insert a stent to open the artery resulting in improved blood flow to the kidneys.
How is it done?
The test is performed in the Cardiac Catheter Laboratory by the Cardiologist, assisted by nurses and technicians. The Cardiac Catheter Laboratory is like a small operating theatre. You will be given a mild sedative for relaxation, but you will be conscious during the test. A small tube called a catheter is inserted into an artery; in the groin (a local anaesthetic is used). The catheter is guided into the major artery of the body (called the aorta) and up to the narrowed section of your renal artery under x-ray control.
What do I do on the day?
Please present yourself to the Admissions Desk at the relevant hospital. You will be directed to the appropriate ward. Do not drive yourself to or from the hospital, as someone must drive you home from hospital when you have had sedative drugs during on the day. Bring full details of Health Cover i.e. Private Health Insurance, Pensioner Health Benefit Card, Health Care Card, Medicare card or Repatriation Card. Bring a bag of personal items in case you need to stay in hospital overnight.
Can I eat and drink before my test?
If your procedure is booked for the morning, do not eat or drink after midnight (morning medication can he taken with a sip of water) If you are booked for the afternoon, fast from 10am.
Do I take my medications on the day of the test?
Yes, and bring all your normal medications to hospital with you.
If you are taking blood thinning tablets (anticoagulants), including Warfarin, Coumadin, Marevan or Dindevan, your doctor will tell you if you are to stop these and when. If you have not been told, ask your cardiologist by ringing The Cardiac Centre on 07 5591 6774.
Please continue taking all other medications including Aspirin. Renal stenting requires patients to take aspirin therapy and another drug called clopidogrel known as Iscover or Plavix, you will be advised by your cardiologist if you need this drug and a script filled out for you in hospital.
If you are diabetic do not take your morning Insulin/diabetic tablets, but bring your medication with you. If you are on Metformin (Diabex, Diaformin) do not take this the day before or the day of the angiogram.
What happens during the test?
In the Cardiac Catheter Laboratory you will be assisted onto a firm table and connected to an ECG machine for monitoring throughout the test. Sterile sheets will be draped over you by nursing staff. The groin area will be prepared with sterile iodine solution, it may be cold. You will be given a mild sedative to make you slightly drowsy, but you will be awake and will not need a general anaesthetic.
A local anaesthetic is injected into the groin to numb the skin, and then a small tube called a catheter is inserted into the artery. This is guided up through the major artery of the body (called the aorta) until it reaches the renal arteries.
Once the catheter is in position the dye (contrast solution) is injected and the x-ray machine takes moving pictures of the renal arteries.
You may experience a warm flushing feeling or an urge to urinate when the x-ray is taken. This lasts for about 5 seconds and then fades, you will be told before this happens and it is of no consequence.
If you have any narrowing in one or more of the arteries requiring urgent treatment, your Cardiologist will discuss this with you at the time. Usually it is possible to repair the narrowing immediately by stretching the wall of the arteries with a small balloon, this is called an Angioplasty. Usually a small metal coil called a Stent is inserted into the artery to help keep it open and to prevent it from re-narrowing. Should you experience any pain or increase in intensity please tell the doctors and you will be given medication to relieve the pain. Your cardiologist will explain the procedure at each step.
How long does the test take?
A routine renal artery stenting takes approximately 30 - 60 minutes depending on the type of blockage.
As with many medical tests there are some risks, although renal artey stenting is generally considered to be quite a safe procedure.
There is a possibility that complications may occur, including, but not limited to, the following:
Bleeding, bruising or leakage of blood at your groin area or catheter
Injury or damage to your artery or wall of the artery requiring emergency surgery or potential loss of the kidney
Major complications included renal infarction in 2.8%, permanently increased serum creatinine level 5.6% that required hemodialysis in 2.8%, blood transfusion in 2.2%, surgical intervention for procedure-related complications in 1.1%, and deep vein thrombosis in 0.6%. The risks will be comprehensively explained by the doctor before the procedure.
What happens after my test?
You will be taken into the Recovery Area where the tube from the groin will be removed and a nurse will press on the artery for 10-15 minutes.
You will need to lie flat for two hours, keeping your leg straight, to minimize bruising in the groin. Or often a collagen plug is inserted under the skin prior to removing the tube. This plug will dissolve over the next 90 days, you will be able to sit up shortly. Next you will need to sit up for a further two hours, and drink plenty of fluids to flush the kidneys. You will be moved from the Recovery Area to the Coronary Care Unit for overnight monitoring. You will usually go home the following day.
Once at home you should rest by lying with your legs slightly elevated for the rest of the day. You can perform light activities the next day, but should avoid heavy physical lifting or strenuous activity for five days.
How will I get my results?
The renal artery stenting will be discussed with you after the test, and with any family or others as you dictate. Ongoing treatment will also be discussed and the need for any further follow up. Your referring doctor and local doctor will often get the results by fax that day and a completed letter sent to arrive for them within 5 working days.
Other discharge instructions
You are advised to rest quietly at home following your procedure.
Your cardiologist will advise you when you may resume your normal activities. Avoid straining and lifting any heavy objects for the first few days following your procedure to avoid the risk of injuring the puncture site before it has had sufficient time to heal. Remove the small plastic dressing over the puncture site the day after the procedure if it has not been removed already. Resume your usual diet and fluid intake. Resume your usual medications. If your groin wound starts to bleed or swell, lie flat and ask the responsible adult with you to press firmly on the site for 10 minutes.
Should this occur, please ring your doctor. Should you have any concerns or require further information immediately following discharge, please contact The Cardiac Centre (07) 5591 6774 between 9:00am and 5:00pm, Monday to Friday. If it is an emergency call 000 for an ambulance.