Electrosurgery and bipolar technology.

A major concern in surgery is the prevention or control of bleeding. The ligature and the clip are the hallmarks of the last century of modern surgery. Therapeutic embolization is not really used to stop hemorrhage but to treat aneurysms and so prevent future rupture and bleeding. Blood clotting within the network of coils of the now widely used Guglielmi detachable coils is now progressively becoming the method of choice whenever possible in aneurysm treatment. Simple external compression at a pressure higher than the intravascular pressure can control bleeding, and if continued long enough, may cause clotting in the bleeding vessels. Unfortunately, there are few areas in the central nervous system where such pressure can be applied, although it is a considerable help in opening muscle layers where self-retaining retractors will be used. Low-pressure venous bleeding may be controlled by application of gelfoam, surgically, or a bit of crushed muscle supported temporarily by a wet cottonoid pledget without occlusion of the venous channel. Historically, hot actual cautery or boiling oil were used to achieve hemostasis by forming a large tissue coagulum, which usually prevented bleeding until the entire dead mass sloughed away.