title: Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome.
abstract: BACKGROUND
  This review is an update of a review first published in Issue 2, 2003, which was substantially updated in Issue 7, 2010. The concept that many neuropathic pain syndromes (traditionally this definition would include complex regional pain syndromes (CRPS)) are "sympathetically maintained pains" has historically led to treatments that interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy ganglia of the sympathetic chain, while surgical ablation is performed by open removal or electrocoagulation of the sympathetic chain or by minimally invasive procedures using thermal or laser interruption.
  
  
  OBJECTIVE
  To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain, including complex regional pain syndrome. Sympathectomy may be compared with placebo (sham) or other active treatment, provided both participants and outcome assessors are blind to treatment group allocation.
  
  
  METHODS
  On 2 July 2013, we searched CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Relief Database. We reviewed the bibliographies of all randomised trials identified and of review articles and also searched two clinical trial databases, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, to identify additional published or unpublished data. We screened references in the retrieved articles and literature reviews and contacted experts in the field of neuropathic pain.
  
  
  METHODS
  Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS.
  
  
  METHODS
  Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible.
  
  
  RESULTS
  Only one study satisfied our inclusion criteria, comparing percutaneous radiofrequency thermal lumbar sympathectomy with lumbar sympathetic neurolysis using phenol in 20 participants with CRPS. There was no comparison of sympathectomy versus sham or placebo. No dichotomous pain outcomes were reported. Average baseline scores of 8-9/10 on several pain scales fell to about 4/10 initially (1 day) and remained at 3-5/10 over four months. There were no significant differences between groups, except for "unpleasant sensation", which was higher with radiofrequency ablation. One participant in the phenol group experienced post sympathectomy neuralgia, while two in the radiofrequency group and one in the phenol group complained of paraesthesia during needle positioning. All participants had soreness at the injection site.
  
  
  CONCLUSIONS
  The practice of surgical and chemical sympathectomy for neuropathic pain and CRPS is based on very little high quality evidence. Sympathectomy should be used cautiously in clinical practice, in carefully selected patients, and probably only after failure of other treatment options. In these circumstances, establishing a clinical register of sympathectomy may help to inform treatment options on an individual patient basis.
authors.affiliation: Institute of Occupational, Social and Environmental Medicine, University Medical Center Göttingen, Waldweg 37 B, Göttingen, Germany, D-37073.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Straube
authors.forename: Sheena
authors.initials: S
authors.lastname: Derry
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Moore
authors.forename: Peter
authors.initials: P
authors.lastname: Cole
mesh_terms: D017115:Catheter Ablation / Q000379:methods*; D020918:Complex Regional Pain Syndromes / Q000628:therapy*; D006801:Humans; D007866:Leg / Q000294:innervation; D009333:Neck; D009437:Neuralgia / Q000628:therapy*; D019800:Phenol; D016032:Randomized Controlled Trials as Topic; D013562:Sympathectomy / Q000379:methods*; D013563:Sympathectomy, Chemical / Q000379:methods; D013565:Sympatholytics; D013909:Thorax
chemical_list: D013565:Sympatholytics; D019800:Phenol