Evaluation of cardiac sympathetic nerve function by myocardial 123I-metaiodobenzylguanidine scintigraphy before and after endoscopic sympathectomy

Abstract

Object. The purpose of this study was to analyze the change in cardiac sympathetic function by performing a 123I-metaiodobenzylguanidine (MIBG) imaging study after endoscopic upper thoracic sympathectomy (EUTS) in patients with palmar hyperhidrosis before and after surgery. Methods. Between February 1999 and February 2002, 135 patients underwent bilateral EUTS to treat palmar hyperhidrosis. Between September 2001 and February 2002, 12 of these consecutively enrolled patients were also included in a 123I-MIBG imaging study. These patients underwent cardiac 123I-MIBG imaging 1 day before and 7 days after they had undergone EUTS. The heart/mediastinum (H/M) ratio and the washout rate were calculated for both early and late phases, and single-photon emission computerized tomography (SPECT) imaging of the early phase was performed. Excessive perspiration from the palms disappeared immediately after EUTS in all patients, and they showed no symptoms of a circulatory condition following the procedure. On the 123I-MIBG imaging studies, the early H/M ratio before EUTS was 2.35 ± 0.26 and postoperatively it was 2.29 ± 0.23. The delayed H/M ratio before EUTS was 2.59 ± 0.3 and after the procedure it was 2.66 ± 0.27. There was no significant difference between the H/M ratio before and after EUTS. The washout rate after EUTS (14.27 ± 4.71%) was significantly lower than that measured before EUTS (18.36 ± 5.13%; p < 0.01). No apparent local defects of accumulation of MIBG were found on SPECT images obtained post-EUTS. Conclusions. Endoscopic upper thoracic sympathectomy is a minimally invasive procedure; no local denervation was found after EUTS. Findings on 123I-MIBG imaging studies indicate that EUTS suppresses the activation of the sympathetic nervous system slightly, similar to beta-blocker therapy.