Chemical lumbar sympathectomy for ischemic rest pain. A randomized, prospective controlled clinical trial

The results of a randomized, controlled, prospective double-blind trial of phenol chemical sympathectomy against placebo bupivacaine injection in 41 limbs (24 treatment and 17 control) have been presented. Ablation of the skin potential response was used as an indication of successful sympathectomy. Rest pain was relieved in 83.5 percent of patients at 1 week with a placebo response of 23.5 percent (chi-square test, p less than 0.002). Sixty-six percent of patients remained free from rest pain at 6 months (chi-square test, p less than 0.02). The ankle-brachial systolic pressure index and resting and peak (reactive hyperemic) blood flows were measured in the foot; there was no demonstrable improvement in these hemodynamic factors. Chemical sympathectomy in these circumstances is probably acting as a pain-relieving injection but nevertheless produces useful remission of rest pain in these inoperable but otherwise relatively stable patients. It can also be employed while relevant investigations are carried out before direct arterial surgery.