Recent evidence suggests that this increase in total blood flow represents, in the main, arteriovenous shunting with little, if any, effect on the nutritive blood flow at the tissue level. Studies aimed at investigating the effect of lumbar sympathectomy on regional tissue circulation have utilized the local clearance of radioactive isotopes. No significant change in the clearance of these substances in muscle have been noted following lumbar sympathectomy in man. However, the data on skin clearance remains conflicting.
Vascular and Endovascular Surgery, Vol. 6, No. 5, 227-238 (1972)
http://ves.sagepub.com/cgi/pdf_extract/6/5/227