However, the clinical results of both surgical and neurolityc sympathectomy are uncertain. Indeed these procedures lead to a redistribution of the blood flow in the lower limbs from the muscle to the skin, with a concomitant fall of the regional resistance, mainly in undamaged vessels. The blood flow will be diverted into this part of the vascular tree, so that a "stealing" of the blood flow may occur.
Vito A. Peduto, Giancarlo Boero, Antonio Marchi, Riccardo Tani
Bilateral extensive skin necrosis of the lower limbs following prolonged epidural blockade
Anaesthesia 1976; 31: 1068-75.