Assessment of chemical lumbar sympathectomy in critical limb ischaemia using thermal imaging

Objective assessment of chemical lumbar sympathectomy (CLS) is lacking. Its success is usually judged in terms of the patient's clinical improvement. We have thermographically measured the immediate temperature changes of the lower limb following CLS using a thermal imager (SAN-EI Thermotracer 6T61). Seven patients with critical limb ischaemia and one patient with Raynaud's phenomenon underwent unilateral ablation of the lumbar sympathetic chain using 5% phenol. Four patients were diabetic, two of whom had undergone previous sympathectomy on the same side. Within fifteen minutes of injection, all patients showed a rise in skin temperature in parts of the sock distribution of between 0.8 degrees C and 8.5 degrees C. We conclude that the haemodynamic effects of CLS are immediate and can be objectively measured with thermal imaging.