Control of vasospasm following trauma and microvascular surgery.

Vasospasm may result in marked reduction of blood flow through injured or revascularized tissues. Neurogenic vasoconstriction is mediated through sympathetic pathways which may be blocked by long-acting local anesthetics resulting in optimal intravascular pressures and elevated flow. An experimental study performed on normal human volunteers has shown that distal sympathetic blockade using Bupivacaine protects the digital circulation against vasospasm elicited by a strong stimulus for a minimum of 7 to 8 hours. A catheter, placed adjacent to the median or ulnar nerve at the wrist level after digital microvascular reconstruction, facilitates continuous Bupivacaine sympathetic blockade. This technique has been used clinically and appears to improve the circulation of replanted or revascularized tissues and protects against vasospasm caused by a variety of stimuli.