Regional intravascular sympathetic (RIS) block with guanethidine.

Vasodilatation is a prerequisite in the treatment of a number of circulatory disorders in the extremities of man. The regional intravascular sympathetic (RIS) block with guanethidine (Ismelin) results in an effective sympathetic block, apparently without systemic effects. Based on theoretical considerations as well as on the experience gained in 50 patients, the method is discussed and illustrated with seven case reports.