|Christchurch Vascular Surgery||
Ischaemia (Is-keem-E-a) is the term used in medicine when tissues do not have enough oxygen. Without oxygen tissues cannot function properly. In cases where there is a critical shortage of oxygen, the tissues begin to die.
In some circumstances one or several arteries can become suddenly blocked, preventing the flow of blood and oxygen to tissues. The blockage can be the result of a clot getting wedged in an artery or it can be because a clot has developed on an area of narrowing in an artery caused by arterial disease. The symptoms are often sudden whichever the cause. There is a sudden acheing pain in the affected limb. It often goes pale, even white, and cold. As time progresses, without treatment, the limb may loose movement and sensation. These are the indications of an acute limb ischaemia. It needs urgent treatment.
The treatment depends on the severity of the ischaemia, and how it progresses over a period of observation. If possible, the patient is started on a blood thinning drug (heparin) administered directly into the vein. This prevents the clot from getting bigger, and makes it easier for blood to travel around the clot and through other small vessels to supply the ischaemic tissues with oxygen. Often this is enough to enable the vascular team time to perform investigations and to plan surgery if required. Sometimes the limb will recover fully without any further intervention. The source of the clot should be treated within a short timeframe however.
Most frequently the clot needs to be removed to restore blood flow back to normal. This is usually done by an operation on the artery where a collapsed balloon is inserted into the artery, inflated beyond the blockage, and pulled back to pull out the clot. This is called an embolectomy. Xray pictures of the arteries (angiograms) are frequently taken in the operating theatre to help decide whether further procedures are required. If blood flow is not restored by this procedure a bypass might be required. Investigations performed before the operation should enable the vascular team to advise you on the likelihood of this.
Occasionally the clot can be sucked out after being dissolved by clot-busting drugs delivered directly into the clot through small catheters introduced into the artery under xray guidance. This procedure is called suction embolectomy and thrombolysis. Although it does not require an operation, thrombolysis does require careful monitoring. It has the advantage of being able to treat pre-existing disease by angioplasty if possible. It can also give good xray images of the disease if surgery is required.
Acute ischaemia caused when a clot get wedged in the artery and blocks blood flow
Acute ischaemia caused when a clot forms on a diseased artery