Abstract

Myocardial infarction and peripheral vascular disease result from the occlusion of arteries that carry blood to the heart and legs. Bypass surgery with autogenous veins (but not synthetic tubes) offers a means of preventing myocardial infarction and of salvaging lower limbs with diseased arteries below the knee. The nonthrombogenic property of veins is attributable to the endothelium; thus, preservation of endothelium during vein harvest is of major importance. Leukocyte adhesion to, and invasion of, veins during harvest produces extensive endothelial damage. This can be prevented by the infusion of lidocaine starting prior to surgery (loading dose of 1.25/mg/kg followed by continuous intravenous infusion of 0.125 mg/kg/min during surgery). Tocainide, a stable derivative of lidocaine, also inhibits leukocyte invasion, thereby protecting venous endothelium.

Hip replacement surgery, which greatly improves the quality of life for the patient, is still complicated by a high incidence of thrombosis (>50%). This is not significantly reduced by low-dose heparin or antiplatelet agents. However, preliminary studies with lidocaine showed a dramatic reduction in the incidence of thrombosis. In a canine model, hip replacement caused a series of roughly parallel tears around 75% of the confluences of side branches with jugular and femoral veins. This was reduced to about 30% by intravenous infusion of lidocaine. It is suggested that lidocaine deserves further study as an agent that could help to reduce the incidence of thrombosis in bypass and hip surgery.