Sensitivity, specificity and predictive value of intra-operative elevation of hand temperature to ensure a successful T2-sympathectomy in patients with palmar hyperhidrosis.

To appraise the validity, intra-operative elevation of hand temperature ensuring a successful T2-sympathectomy, we conducted a randomized, self-compared, case-control study on 40 consecutive patients with palmar hyperhidrosis. All patients had a postoperative follow-up of at least 18 months without recurrence. During operation, dynamic temperature changes on their thenar eminence of both the surgically treated and non-surgically treated hands were simultaneously measured just before (baseline) and after completion of T2-sympathectomy, and again 5 and 10 minutes later. An elevation of the temperature by at least 0.5 degree C from the baseline temperature was recognized as an "elevated" temperature. The relationship between sensitivity and specificity of temperature changes was compared using receiver operator characteristic (ROC) analysis. Sensitivity was defined as the proportion of temperature-elevating procedures in the group of operated hands. As a whole, post-sympathectomy elevation of hand temperature is a useful, but not an ideal, indicator for assuring a successful T2-sympathectomy due to its low sensitivity. At the 5-minute point, if the hand temperature was elevated by 1 degree C, its sensitivity, specificity and positive predictive value were 40%, 80% and 66.7%. In comparison, a 2 degrees C elevation at the 10-minute point had a sensitivity, specificity and positive predictive value of 30%, 90% and 75% (p < 0.05). We suggest that correct localization of the T2 ganglion followed by adequate ablation should be the prerequisite for use of this monitoring system.