The differential effect of the level of spinal cord stimulation on patients with advanced peripheral vascular disease in the lower limbs

Percutaneous spinal cord stimulation (SCS) (Medtronic model 3487A PISCES-Quad lead) was carried out in 10 patients with rest pain from advanced peripheral vascular disease of the lower limb, who were unsuitable for conventional treatment. Trial stimulation ranged from 1-20 weeks and was associated with pain relief in nine of the patients. Claudication distance was improved in six patients. Trophic lesions improved in one patient with small artery disease. Spinal cord stimulation did not reverse the course of acute gangrenous lesions. The distal arterial pressure measured by Doppler Ankle/Brachial Pressure Index, (ABPI), showed no change. The capillary blood flow and skin temperature of both feet, measured, respectively, by Laser Doppler flowmetry and skin thermistor, showed a tendency to decrease when the stimulation was at the higher level, above T10, compared with an increase when the stimulation was at the lower level T12. Transcutaneous oxygen tension monitoring of the symptomatic foot showed an increase in four out of five patients. Pain relief was not dependent on circulatory changes, but it was more significant when the circulatory changes showed an impressive increase in the blood flow. The mechanism of these circulatory changes is probably by modulation of the sympathetic nervous system. Recognition of the optimal siting of SCS may be critical in the clinical use of this technique, which seems to be a valuable option in the treatment of patients with advanced peripheral vascular disease (PVD).