Hemodynamic measurements were used to establish predictive criteria for determining success of lumbar sympathectomy. Blood flow was measured by strain-gauge plethysmography before and after α-blockade and after sympathectomy in 40 patients. Ankle systolic pressure and ankle-brachial pressure index were determined in these and in an additional 44 cases. Results: α-blockade offers no predictive value to the effect of sympathectomy; 60% of patients had either false-positive or false-negative results. Level of ankle systolic pressure and pressure index correlated significantly with effect of sympathetic ablation. Twenty-six of 27 patients with a pressure index <0.205 required subsequent amputation. All patients with a pressure index >0.35 responded well to lumbar sympathectomy. Conclusion: Response to sympathetic ablation depends upon adequacy of collateral circulation, which is easily assessed by the Doppler ultrasound method.
Yao JST, Bergan JJ. Predictability of Vascular Reactivity Relative to Sympathetic Ablation. Arch Surg. 1973;107(5):676-680. doi:10.1001/archsurg.1973.01350230034008