The rate of morbidity reported in the literature for lumbar sympathectomy is low. However, post-operative neuralgia is a severe complication since pain can be permanent, severe, and incapacitating. Relief of pain by traditional means is ofter hazardous and symptoms may persist.
Between March and October 1986, 33 consecutive patients underwent unilateral lumbar sympahtectomy in the Thoracic and Cardiovascular Surgical Unit of the Catholic University in Louvain, Belgium. Ten patients experienced post-sympathectomy neuralgia.
Doppler studies and thermography were used to assess the efficacy of the operation in improving arterial supply to the lower limb on the side of sympathectomy. In all ten cases, neuralgia appeared between the ninth and 30th postoperative days, with mean of 16 days.
http://www.springerlink.com/content/q04711t06j164206/