Lower Limb Arterial Bypass Surgery
The principal of bypass surgery is to surgically create a new pipe which takes blood from above the blockage and direct it into a normal vessel below the blockage; effectively bypassing it.
Classically these reconstructions are formed in the leg bypassing the blocked artery in the thigh, however, bypasses can be created in many parts of the body, including the abdomen and pelvis.
The procedures are generally performed in an operating theatre under general anaesthesia. The operation consists of exposing the normal vessel above the blockage and the normal vessel below the blockage as well as harvesting a suitable length of pipe which is generally vein taken from the leg. Intermittently this vein may need to be taken from the other leg or the arm. The vein or bypass graft is then sewn onto the native artery above and below the blockage giving the blood an alternate pathway down to the tissues starved of blood below.
The patient can expect to be in hospital between 4-10 days, generally 6 days. The surgery is relatively painless, as the incision is simply in the skin. Dissolving stitches are used.
Post operatively 40% of patients experience some swelling in the leg which generally resolves in 6-8 weeks, although it can persist for up to 3 months.
Possible Side Effects:
- Wound infection. If this occurs it is generally mild and is treatable with simple antibiotics.
- Bleeding. The joins between the artery and the vein can weep. If this occurs blood can collect under the skin, called a haematoma. If the haematoma is significant it may need surgical evacuation.
- Saphenous nerve neuralgia. The saphenous nerve lies intimately associated with the saphenous vein which is commonly harvested as the graft. If this nerve is stretched or bruised it can cause pins and needles or a burning discomfort in the distribution of the nerve which is felt on the inside aspect of the lower leg. Generally this will resolve within 3 months, although in a percentage of patients it can be persistent. If it is persistent, medications can be used to control symptoms.
Vascular surgery is reconstructive; once performed it is working every second of every day. While the vein is a reasonable graft it is not as good as the original artery and is prone to develop narrowings or stenosis within in it which can result in graft blockage.
Approximately 20% of grafts are lost within 5 years of their creation. It is much easier to prevent a graft from blocking than trying to salvage it after it has blocked. As such, the patient is asked to come back for regular ultrasound scans to monitor the health of the graft. These scans are initially frequent for the first 2 years but then become simply yearly reviews.