Renal angiography and renal angioplasty
Angiography is the imaging of blood vessels using contrast media / x-ray dye injected into the blood stream of the arteries so the vessels can be viewed using x-ray (fluoroscopy).
Renal angiography is the study of the blood vessels to the kidneys.
A renal angiogram is an x-ray study of the blood vessels leading to the kidneys and is done to assess the blood flow to the kidneys. X-rays (cine films) are taken as contrast dye is injected into a catheter (a tiny plastic tube) that has been placed into the blood vessels of the kidneys.
The specialist then assesses the cine films for any narrowings or other abnormalities affecting the blood supply to the kidneys. If a narrowing is found, the doctor may treat the affected area with a vascular balloon (PTA or percutaneous transluminal angioplasty) or even place a stent in the affected area.
The images from a renal angioplasty look as follows:
RENAL ANGIOGRAPHY AND RENAL ANGIOPLASTY
If any narrowing of the arteries or other abnormalities affecting the blood supply to the kidneys are found during your renal angiogram, your specialist will proceed to treat the narrowing by passing a balloon catheter along the wire to the diseased area through a tiny incision in your groin. Once in position, the balloon is inflated and the narrowing is gradually widened. This procedure is called angioplasty or nephrostomy ureteric stenting.
In some cases the artery is successfully stretched open, but the narrowed portion of the artery can recoil as the balloon is deflated. If the dilation of the artery is not entirely satisfactory, your specialist may place a stent at the point of the persistent narrowing.
A stent is a mesh tube made of a special metal alloy. On insertion, it is tightly squashed down on a balloon. Once positioned at the point of narrowing, the stent is opened up to a predetermined width and holds the kidney artery open.
You should not have any feeling or sensation while this is happening.
These procedures are carried out in an angiography suite (“cath lab”) at Intra. Your specialist will be assisted by nurses and other highly trained staff.
You will be awake during the procedure but may be lightly sedated. Your groin will be numbed with local anaesthetic before a small incision is made (less than 6mm) and a tiny plastic tube (called a catheter) is introduced. You should not feel pain at the entry site but there still may be some non-painful sensations such as pressure. You cannot feel the catheter moving inside your arteries.
Your specialist watches the catheter on an x-ray screen as he passes the tip of the catheter through your femoral artery guiding it to the left and right kidney (renal) arteries. A special fluid (contrast or dye) is injected in the renal arteries and a movie picture is recorded as the dye flows into the artery and its branches and makes them visible on the fluoroscope's monitor. The contrast makes the renal arteries "light up" in comparison with surrounding structures. Your specialist then carefully studies the recorded images, looking for any disease or narrowing of the vessels. Both renal arteries are studied through one incision in the groin. This portion of the procedure comprises the renal angiogram.
If, during the angiographic study your specialist finds that there is disease or narrowing in the renal arteries, he will proceed to treat the narrowing using a balloon, and possibly put a renal stent into the narrowed vessel, to ensure the vessel remains open and blood flow is restored. This portion of the procedure is the renal angioplasty or intervention and will almost always be performed one after the other, while you are in the the cath lab.
- An intravenous catheter (IV line) for the administration of fluids and medication will be inserted into a vein on the back of your hand or into your arm.
- You will feel a slight pin prick when the needle is inserted into your vein for the intravenous line (IV) and when the local anaesthetic is injected through your groin
- You will be given mild sedation through your IV to make you feel relaxed.
- Devices to monitor your heart rate and blood pressure will be attached to your body.
- You may feel slight pressure when the catheter is inserted, but no serious discomfort.
- As the contrast material passes through your body, you may get a warm feeling.
- While you are in the hospital, your pain will be well-controlled with a medications infused through your IV line.
- The catheter is removed and pressure is applied to your groin to stop bleeding.
- Your specialist will discuss the findings with you or at a follow-up appointment.
- Patients are usually monitored for 4 to 6 hours and must remain flat in bed during that time to reduce the likelihood of bleeding from the groin site.
- You should be able to eat, drink, and take your normal medicines. If an intervention (angioplasty) was required, you may need to stay in hospital overnight.
- Before you leave, a nurse will give you discharge instructions to follow at home.
- Upon discharge you will be explained who to contact in case of an emergency after your procedure.
- A small amount of bruising at the catheter entry point is relatively common. This is not usually clinically important unless it becomes painful.
- For procedures done from the groin sometimes a “false aneurysm” or out-pouching of the artery deep under the skin occurs at the puncture site. This shows up as increasing pain at the puncture site. The diagnosis is made by an ultrasound test and treatment is usually by an injection.
- Also, patients with kidney failure or other kidney problems should notify their specialist of this prior to the procedure as contrast can worsen existing kidney disease.
- Damage to artery or arterial wall, which can lead to blood clots. This is not a frequent occurrence.