Treatment
Treatment depends on the severity of the ischaemia and the underlying cause. In cases of trauma an angiogram is needed to define the exact problem and then surgery. I will discuss treatment of embolism or thrombosis here:
Once the patient has been seen and assessed, basic treatment involves the administration of fluids via a drip, pain killing medication and heparin to thin the blood.
If the ischaemia is not too severe and the patient can feel and move the limb, an angiogram will provide useful information and the catheters inserted into the artery can be used to deliver clot dissolving medicines (streptokinase, urokinase and tissue plasminogen activator) to dissolve the blood clot. The progress of the patient is monitored closely (bleeding is the main complication) and repeat angiograms will show how effectively the treatment is working.
If the ischaemia is severe and immediate treatment is needed, the patient must be taken to theatre and an attempt made to remove the blood clot with a balloon ('Fogarty'). The picture below shows such a device and the clots retrieved:
If the cause is not due to embolus but due to thrombosis at a site of previous narrowing (see atherosclerosis) then an angiogram and bypass may be needed (see critical ischaemia).
If the leg has been deprived of blood for some time before flow is restored, compartment syndrome may arise. The muscles of the lower leg are encased in tough fibrous tissue called fascia. There are 4 muscles compartments in the lower leg. As blood flow is restored, the muscles will expand because of leakage of tissue fluid. The fascia does not stretch and the pressure in the compartments will increase. Eventually the pressure will become greater than the pressure forcing blood into the tissues. At this point the tissues will become ischaemic again (compartment syndrome) unless the tissue pressure is released by dividing the fascia - this is called a fasciotomy:
The picture shows a fasciotomy on the inner calf. The muscles are visible. If the swelling subsides, the skin may be closed. If not the defect may need a skin graft.
If the leg is profoundly ischaemic and has been for some time, a primary amputation may be the best way forward.
Sometimes the patient is so frail that an acutely ischaemic leg is merely a presentation of the last few hours or days of life. In this case an operation should be avoided and the patient kept as comfortable as possible with strong painkillers and allowed to die with dignity.