The aim of bypass surgery in the lower limbs is to increase the amount of blood flow to the thigh, calf or foot. This may be necessary to improve walking, relieve pain or heal ulcers or other lesions.
Patients having this operation generally fall into one of two groups.
The first group comprises patients who are suffering intermittent claudication or pain, usually in the calf muscle, after walking a particular distance. This pain occurs because blockages or narrowing in the arteries restrict blood flow to the muscles. These patients are unlikely to lose their leg without an operation but after a successful bypass there is improved blood flow to exercising muscles and patients are generally able to walk a lot further.
The other group of patients having this type of operation are those with such severely impaired blood flow in the leg that ulcers or small spots of dry gangrene occur. Chronic pain, usually in foot, is often also a feature. In this group a successful bypass may be the difference between saving and losing a leg.
What happens before my bypass?
Before bypass most patients will undergo ultrasound and angiography. These tests provide a “roadmap” of the arteries and help in the determination of whether bypass is possible or appropriate. Blood tests, chest x-ray and appointments with a specialist physician and anaesthetist are usually organized. Most patients are admitted to hospital the day before operation although some patients may be admitted on the morning of surgery.
What form of anaesthetic is involved?
Lower limb bypass is performed under general or spinal/epidural anaesthesia. You can discuss the advantages and disadvantages of each of these with the anaesthetist before the operation.
What does the operation involve?
The purpose of the operation is to bypass a blocked or narrowed artery usually in the thigh or sometimes in the calf. The best thing to use for the bypass is your own vein. A superficial vein on the inner thigh and calf is often suitable. If this vein has already been used (e.g. for heart bypass) or is unsuitable then a plastic graft (Gore-Tex) can be used. If your vein is used then you can expect an incision from the groin to the knee.
The bypass is stitched to the artery with very fine sutures above and below the blockage. The incision is stitched up at the end of the operation with dissolving sutures. Most operations take about two hours.
Most patients will spend around 7 days in hospital. An epidural is often used for pain relief for the first two days and urinary catheter and an IV are often also present.
Most patients are up and walking within a couple of days. The bypass and the wounds are carefully monitored. It is common for the leg to swell after a successful bypass particularly as more and more walking is done. Swelling can be reduced by wearing the white stocking and by keeping the leg up as much as possible when not walking. Lying on the sofa or bed with the leg up on a pillow is best. Within a few weeks of the bypass most patients are noticing a significant improvement in the leg. Postoperative review is undertaken in about 6 weeks.
What are the possible complications?
Lower limb bypass is not a risk free procedure and many possible complications can occur however the great majority of patients that undergo this form of surgery do not suffer any major problems. The following is a sample of well recognised complications.
Complications can arise as a result of the anaesthetic and these can be discussed with the anaesthetist preoperatively.
With respect to the operation itself it is common to have bruising and stiffness of the leg. Swelling of the leg is also common particularly if it is not kept elevated between walks. Numbness or a dead feeling in the inner lower leg is also common. It is possible that the graft may not be successful. In the majority of these cases this will not make the leg a great deal worse but in some cases an unsuccessful operation may put the leg at risk and ultimately lead to amputation. Other problems with bleeding, blood clots or infections can occur but are not common. Other complications such as heart attacks or pneumonia are possible.