Patterns of palmar skin temperature alterations during transthoracic endoscopic T2 sympathectomy for palmar hyperhidrosis

Transthoracic endoscopic T2 sympathectomy has been widely applied to the tr eatment of a variety of sympathetically mediated disorders. Palmar hyperhid rosis is probably the most common indication for thoracic sympathectomy. es pecially in certain subtropical areas. Which sympathetic ganglion is to be ablated and how extensive such ablation is enough to eliminate palm sweatin g are two important issues. Intraoperative monitoring of palmar skin temper ature (PST) is the most frequently used method for assessing the accuracy a s well as adequacy of ablation of the target sympathetic ganglia. With cont inuous monitoring of bilateral PST during the operative course of T2 sympat hectomy, it was possible to depict the alterations of bilateral PST in resp onse to specific surgical procedures in a real-time manner. For each case, a PST graph was obtained, which represented the graphical expression of int raoperatively recorded bilateral PST data plotted against time. The PST gra phs of 93 consecutive cases were analysed. Three types of PST graphs existe d, reflecting different responses of bilateral PST to different surgical pr ocedures during the operation. In Type I PST graph pattern, found in 58 cas es, skin incision and intercostal muscle dissection caused dramatic bilater al PST drop; and unilateral T2 sympathectomy induced synchronous bilateral PST elevation. Twenty-four cases demonstrated Type II PST graph pattern, in which unilateral T2 sympathectomy caused only ipsilateral PST elevation, a lthough the PST-depressing effect of skin incision and muscle dissection wa s as significant as in Type I graph pattern. In the 11 cases who showed Typ e III PST graph pattern, neither skin incision nor T2 sympathectomy induced any apparent changes of PST on either side, giving rise to two rather Rat PST curves on the PST graphs. These findings implicate that reciprocal inte ractions between bilateral sympathetic activities exist in the majority of cases, and that crossover sympathetic modulation may play a role in the neu ral control of the sudomotor and vasomotor activities of the palms. This st udy also provides information regarding how PST would possibly change follo wing specific surgical procedures during transthoracic endoscopic T2 sympat hectomy, which may be of importance to those who use intraoperative PST mon itoring as a guide in determining whether or not the correct sympathetic ga nglia are ablated for adequate sympathetic denervation of the palms. (C) 20 00 Elsevier Science B.V. All rights reserved.