Introduction
Peripheral arterial stenting is a minimally invasive (Keyhole) technique to treat blockages within arteries. It is most commonly used in the legs to treat atherosclerotic peripheral arterial disease (PAD).
PAD is caused by the build-up of atherosclerotic plaque within the arterial wall. This plaque narrows and eventually blocks the channel (lumen) where blood flows resulting in reduced blood flow to the peripheral tissues. This can lead to a critical loss of blood flow that can cause ulcers, poor wound healing and gangrene.
Stenting squash’s the plaque into the wall of the artery, increasing the size of the channel where the blood is flowing. The stent is a metallic scaffold that keeps the artery open to reduce the risk of the narrowing process from re-occurring.
Indications
Peripheral artery stenting is indicated for patients with symptomatic arterial disease. Generally, angioplasty or stenting is the first line treatment in PAD. Bypass surgery is reserved for patients where stenting has not worked or not possible. Stenting is most effective in patients with short blockages or narrowing within arteries. The more extensive the disease the more difficult it can be to use stents successfully.
Preoperative Instructions
In preparation for stenting procedures, review of blood thinning and diabetic medications is required. It is important to bring a list of current medications with you to hospital. Most procedures are performed with Local Anaesthesia and Sedation. Fasting is still a requirement for sedation. The relevant groin will be shaved prior to the procedure. Most patients will be admitted on the same day as the procedure.
Procedure
To facilitate stenting, access to the arterial circulation is required. In most cases this will be through the femoral artery, the main artery in the groin. The femoral artery is used as it is relatively superficial and a large size to allow access for a variety of different stents and balloons. In certain circumstances the arteries in the arm or foot may also be used to help facilitate stenting procedures.
A tube (or sheath) is placed into the artery. Ultrasound is used to help guide the access into the main artery. X-ray dye is then injected to give a map of the vessels. The dye will demonstrate the blood flow and show any disease within the artery. This confirms the area of disease and provides guidance on the best option for treatment.
Once an area of occlusion or narrowing (Stenosis) is identified, a guide wire is manipulated through the lesion. It is important to then position the wire within the normal artery below the diseased segment. A balloon is then used to stretch the artery open. In certain situations, a balloon angioplasty is all that is required. Most vessels are better served with a stent, and this is positioned using X-ray dye. Stents are either self-expanding like a spring or mounted on a balloon. The choice depends on which artery is being treated and the nature of the disease present. The stent acts as a scaffold to keep the artery open. The stent is then re-ballooned to ensure it is fully expanded.
Once the stent has been deployed further angiography (dye injection) is used to check the adequacy of treatment and ensure normal flow is maintained beyond the stent.
The puncture in the groin is treated with a closure device, that places a stitch or clip on the artery. Some vessels are not suitable for a closure device and then compression is used. This will entail lying flat for 4-6 hours post procedure to prevent bleeding from the puncture point.
Postoperative Instructions
Post procedure the circulation to the treated leg will be carefully monitored. The groin puncture site will be checked regularly. Bruising at the puncture site is normal and occasionally a firm lump will develop. Usually this is just a haematoma which will slowly disappear over approximately 7 days.
Depending on the puncture site and whether a closure device was used, the patient will be instructed to lie flat for a period of time. The amount of time will be advised after the procedure.
After the period of lying flat has passed returning to normal mobility is safe. Most patients will be observed overnight and discharged from hospital the following morning. A review after 2-4 weeks will be scheduled, and routine follow-up Ultrasound scans arranged. Avoidance of heavy lifting is advised for 7 days to protect the puncture site from bleeding.
Risks
Angiography and stenting are very safe procedures, however there is a small risk of complications. In certain circumstances complications may require urgent intervention.
Potential complications include:
- Allergic reaction to anaesthetic drugs or the X-ray contrast dye.
- Bleeding from the puncture site – a certain amount of bruising is normal. Occasionally this is excessive and further intervention may be required.
- Inability to access the arteries.
- Inability to cross the diseased segment – whilst rare if the lesion cannot be crossed it is not possible to stent the vessel.
- Inability to deploy the stent or poor stent placement.
- Blockage of the stent – a rare complication that can occur if the artery is damaged. Usually can be managed with further ballooning / stenting but surgery could be required to repair the artery.
- Dislodgment (Embolisation) of plaque from the artery – this can lodge in the smaller arteries further down the leg and can obstruct blood flow. The plaque can usually be aspirated (sucked) out of the artery but may require surgical removal in rare situations.
- Fistula development in the groin – any small veins are associated with the artery in the groin. If a vein is inadvertently damaged by the puncture needle blood can flow from the artery into the vein forming an AV fistula. This will usually resolve on its own but rarely requires surgical correction.
- Femoral artery False Aneurysm (FA) – this is the development of a contained bleed from the puncture site in the groin. Most settle without treatment, but larger FA may require intervention. They can cause a painful pulsatile lump in the groin.
- Re-stenosis – whilst stents are very good at improving blood flow they can slowly narrow down over time due to the buildup of scar tissue within the stent. This may require re-ballooning, re-stenting or bypass surgery in extreme cases.
Treatment Alternatives
Peripheral Arterial Disease (PAD) treatment should involve optimizing other medical conditions including those that increase the development of atherosclerosis. This is particularly important for high blood pressure, high cholesterol, diabetes and smoking.
A regular walking program will also help to control the symptoms of PAD and may reduce the need for intervention.
If symptoms are severe enough then treatment needs to be considered. Endovascular arterial treatment is the first line treatment for symptomatic PAD. This may involve angioplasty or stenting depending on the target vessel involved. A number of adjunctive treatments to endovascular stenting are evolving. These include atherectomy (endovascular removal of plaque), drug coated balloons and stents. The benefit of these in addition to stenting is considered at the time of treatment.
Bypass surgery is the main alternative option. Bypass surgery is a very effective treatment for PAD, however the procedure is much more invasive, with longer hospitalisation and recovery time. Bypass surgery is usually reserved if endovascular treatments are not suitable or have failed.
Related Information
Arterial Bypass Surgery
Peripheral Artery Balloon Angioplasty
Diabetic Foot Ulcers
Peripheral Artery Disease
Femoral Aneurysms
Popliteal Aneurysms