A cold test with monitoring of cold-induced changes in peripheral blood flow was used to assess the completeness of the sympathectomy. The preoperative cold test induced a reciprocal response, vasoconstriction in the skin and vasodilation in muscle. DCS with clinical parameters did not produce this reciprocity in the control and sham-operated rats, but induced a vasodilation in both skin and muscle. After complete sympathectomy, defined as postoperative disappearance of the vasomotor responses to cold, the vasodilation in skin and muscle in response to DCS was abolished; however, the vasodilatory response to high-intensity stimulation (approximately 10 times the motor threshold) was not affected. Incomplete sympathetic denervation in some animals resulted in partial preservation of a vasodilatory response to DCS.
http://www.ncbi.nlm.nih.gov/pubmed/1758600