Are We Paying a High Price for Surgical Sympathectomy? A Systematic Literature Review of Late Complications

Botulinum Toxin for the Treatment of Raynaud's Conditions of the Hand: Clinical Practice Updates and Future Directions

Raynaud's conditions of the hand, referred to commonly as Raynaud's phenomenon, both primary and secondary, represents a spectrum of disorders affecting the digits, characterised by recurrent episodes of vasospasm that result in a triad of symptoms: pain, pallor, and cyanosis. Various therapies, ranging from conservative hand therapy techniques to surgical sympathectomy, have been explored with inconsistent results. Recently, the local administration of botulinum toxin type-A (BTX-A) has re-emerged as a treatment option for this condition. This review delves into the mechanistic pathways of BTX-A therapy, optimal dosing concentrations, administration techniques, and its safety profile. A critical analysis of published studies to date demonstrates varied clinical efficacy of BTX-A in Raynaud's conditions based on patient-reported outcome measures and objective measures of outcomes assessment. Thus, in order to accurately assess the clinical effectiveness of BTX-A in future robust studies, this review emphasises the importance of streamlining patient selection to minimise heterogeneity in disease severity, optimising recruitment to ensure adequate statistical power, and establishing sensitive outcome measures to monitor response and discern treatment efficacy. Additionally, addressing concerns such as minimising antibody resistance, extending the duration of treatment effects on tissues, and exploring new modalities to assess hand perfusion will be focal points for future research and BTX-A drug development.

Sexual effects and long-term outcomes of endoscopic lumbar sympathectomy for plantar hyperhidrosis in men: a cross-sectional study

Background

Plantar hyperhidrosis (PHH) is a disease with high psychosocial impact, and endoscopic lumbar sympathectomy (ELS) has been shown to be the best choice for treatment, but with some concerns such as compensatory sweating (CS) and sexual effects (SE), particularly in men.

Objectives

The aim of this study is to evaluate the long-term effectiveness of ELS for controlling PHH in men, its side effects, and perceived sexual modifications.

Methods

A cross-sectional study including only male patients operated for PHH with ELS between 2014-2022 at a private practice. During remote interviews, patients were asked about symptoms before and after ELS and about the postoperative effects on PHH. They were also objectively asked about any SE during the postoperative period. Validated quality of life for hyperhidrosis and erectile function questionnaires were also administered.

Results

10 male patients averaging 4.26±2.86 years post-ELS were interviewed. Eight of them (80%) achieved complete response (≥80% of sweat reduction) in the first month after surgery and this response was maintained up to the interview date. Two patients had partial response. In six patients, CS occurred, with 5 reporting it as non-troublesome. Six patients reported some type of SE, but none reported erectile dysfunction. Regarding the functional results, all patients rated ELS from good (10%) to very good (30%) or excellent (60%).

Conclusions

Endoscopic lumbar sympathectomy was effective for treatment of plantar hyperhidrosis in these patients, improving their quality of life and providing lasting PHH control, with some transient sexual dysfunctions that did not impair their sexual life.

Toxin for Treating Raynaud Conditions in Hands (The TORCH Study): A Systematic Review and Meta-analysis

Background

Raynaud disease of the hands is a complex disorder resulting in inappropriate constriction and/or insufficient dilation in microcirculation. There is an emerging role for botulinum toxin type A (BTX-A) in the treatment armamentarium for refractory Raynaud disease. The aim of this systematic review was to critically evaluate the management of primary and secondary Raynaud disease treated with BTX-A intervention.

Methods

We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of clinical studies assessing treatment of primary or secondary Raynaud disease with BTX-A by searching Ovid MEDLINE and Embase databases from inception to first August 2023. The review protocol was prospectively registered on the PROSPERO database (CRD42022312253).

Results

Our search strategy identified 288 research articles, of which 18 studies [four randomized controlled trials (RCTs), two non-RCTs, five case series, and seven retrospective cohort studies] were eligible for analysis. Meta-analysis demonstrated that the probability of pain visual analog scale score improvement with BTX-A intervention was 81.95% [95% confidence interval (74.12-87.81) P = 0.19, heterogeneity I 2 = 26%] and probability of digital ulcer healing was 79.37% [95% confidence interval (62.45-89.9) P = 0.02, heterogeneity I 2 = 56%].

Conclusions

Delivery of BTX-A to digital vessels in the hand may be an effective management strategy for primary and secondary Raynaud disease. A definitive, appropriately-powered RCT with objective functional and patient-reported outcome measures is required to accurately assess and quantify the efficacy of BTX-A in Raynaud disease of the hands.

Treatment of Palmar Hyperhidrosis With Radiofrequency Microneedling-Based on Ultrasound Measurements

This study addresses the treatment of palmar hyperhidrosis, which has been difficult to manage. A new treatment has been developed using radiofrequency microneedling to reduce sweating non-surgically by ablating sweat glands. Based on ultrasound measurements of the dermis and precise microneedling damage, effective energy was applied to locate the sweat glands and disabled their function. Radiofrequency microneedling with ultrasound can safely and effectively treat hyperhidrosis in a minimally invasive way.

Efficacy and Safety of Botulinum Toxin B in Focal Hyperhidrosis: A Narrative Review

Botulinum toxin type B (BoNT-B), known as Myobloc® in the United States and as Neurobloc® in Europe, is a new therapeutically available serotype among the botulinum toxin family. During the last years several data have been reported in literature investigating its efficacy and safety, as well as defining the dosing and application regiments of BoNT-B in the treatment of hyperhidrosis. Moreover, recent studies have been examining its safety profile, which may be different from those known about BoNT-A. The aim of this review is to provide information about what is currently known about BoNT-B in regards to the treatment of focal hyperhidrosis.

Interventions for hyperhidrosis in secondary care: a systematic review and value-of-information analysis

BACKGROUND

Hyperhidrosis is uncontrollable excessive sweating that occurs at rest, regardless of temperature. The symptoms of hyperhidrosis can significantly affect quality of life. The management of hyperhidrosis is uncertain and variable.

OBJECTIVE

To establish the expected value of undertaking additional research to determine the most effective interventions for the management of refractory primary hyperhidrosis in secondary care.

METHODS

A systematic review and economic model, including a value-of-information (VOI) analysis. Treatments to be prescribed by dermatologists and minor surgical treatments for hyperhidrosis of the hands, feet and axillae were reviewed; as endoscopic thoracic sympathectomy (ETS) is incontestably an end-of-line treatment, it was not reviewed further. Fifteen databases (e.g. CENTRAL, PubMed and PsycINFO), conference proceedings and trial registers were searched from inception to July 2016. Systematic review methods were followed. Pairwise meta-analyses were conducted for comparisons between botulinum toxin (BTX) injections and placebo for axillary hyperhidrosis, but otherwise, owing to evidence limitations, data were synthesised narratively. A decision-analytic model assessed the cost-effectiveness and VOI of five treatments (iontophoresis, medication, BTX, curettage, ETS) in 64 different sequences for axillary hyperhidrosis only.

RESULTS AND CONCLUSIONS

Fifty studies were included in the effectiveness review: 32 randomised controlled trials (RCTs), 17 non-RCTs and one large prospective case series. Most studies were small, rated as having a high risk of bias and poorly reported. The interventions assessed in the review were iontophoresis, BTX, anticholinergic medications, curettage and newer energy-based technologies that damage the sweat gland (e.g. laser, microwave). There is moderate-quality evidence of a large statistically significant effect of BTX on axillary hyperhidrosis symptoms, compared with placebo. There was weak but consistent evidence for iontophoresis for palmar hyperhidrosis. Evidence for other interventions was of low or very low quality. For axillary hyperhidrosis cost-effectiveness results indicated that iontophoresis, BTX, medication, curettage and ETS was the most cost-effective sequence (probability 0.8), with an incremental cost-effectiveness ratio of £9304 per quality-adjusted life-year. Uncertainty associated with study bias was not reflected in the economic results. Patients and clinicians attending an end-of-project workshop were satisfied with the sequence of treatments for axillary hyperhidrosis identified as being cost-effective. All patient advisors considered that the Hyperhidrosis Quality of Life Index was superior to other tools commonly used in hyperhidrosis research for assessing quality of life.

LIMITATIONS

The evidence for the clinical effectiveness and safety of second-line treatments for primary hyperhidrosis is limited. This meant that there was insufficient evidence to draw conclusions for most interventions assessed and the cost-effectiveness analysis was restricted to hyperhidrosis of the axilla.

FUTURE WORK

Based on anecdotal evidence and inference from evidence for the axillae, participants agreed that a trial of BTX (with anaesthesia) compared with iontophoresis for palmar hyperhidrosis would be most useful. The VOI analysis indicates that further research into the effectiveness of existing medications might be worthwhile, but it is unclear that such trials are of clinical importance. Research that established a robust estimate of the annual incidence of axillary hyperhidrosis in the UK population would reduce the uncertainty in future VOI analyses.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015027803.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Usefulness of stellate ganglion block for refractory angina pectoris

Chronic refractory angina pectoris (AP) affects 600,000 to 1,800,000 Americans, with approximately 50,000 new cases annually. A recent study revealed long-term mortality of refractory AP to be lower than previously reported, with >70% of patients living >9 years. Treating AP can improve quality of life. We describe a patient with refractory AP who underwent a successful stellate ganglion block for symptom control.

Comparison of Intrapleural with Paravertebral Levobupivacaine Analgesia for Thoracoscopic Sympathectomy: A Randomized Controlled Study

Background:

Palmar hyperhidrosis is a benign disease of excessive sweating in the palm that exceeds the physiological state. Thoracoscopic sympathectomy is an effective surgical treatment for localized hyperhidrosis.

Aims:

The aim of this study was to compare paravertebral block (PVB) with intrapleural analgesia in thoracoscopic sympathectomy.

Settings and Design:

A total of 90 patients physical status American Society of Anesthesiologists Classes I or II scheduled for arthroscopic thoracoscopic sympathectomy were enrolled in this study.

Subjects and Methods:

Patients were randomly allocated into three groups; in the controlled (C) group, no regional block was performed. In the intrapleural (I) group or paravertebral (P) group using a volume of 20 ml of levobupivacaine 0.5%. The first request for analgesia postoperatively was our primary concern. Secondary outcomes included pain scores, the cumulative consumption of fentanyl during the 1^st postoperative day, pulmonary functions, blood gases, and complications.

Statistical Analysis Used:

Statistical analysis was done using Statistical Package for Social Sciences (SPSS 19.0, Chicago, IL, USA).

Results:

First request of analgesia in paravertebral group was statistically significantly longer when compared with either control or intrapleural group. In addition, total fentanyl dose was significantly higher in control group when compared with the other groups. Groups I and P showed statistically significant less pain scores, better pulmonary function, and blood gases when compared with control group.

Conclusion:

We concluded that either intrapleural or paravertebral analgesia compared with control group in thoracoscopic sympathectomy resulted in later request of analgesia, improved pain control, reduced analgesic requirements postoperatively, preservation of lung function and acid-base balance. The PVB, compared to intrapleural, had an advantage of longer and effective analgesia.

[Ganglion block. When and how?]

CLINICAL ISSUE

Increasing understanding of the anatomy and physiology of neural structures has led to the development of surgical and percutaneous neurodestructive methods in order to target and destroy various components of afferent nociceptive pathways. The dorsal root ganglia and in particular the ganglia of the autonomous nervous system are targets for radiological interventions. The autonomous nervous system is responsible for the regulation of organ functions, sweating, visceral and blood vessel-associated pain.

STANDARD RADIOLOGICAL METHODS

Ganglia of the sympathetic chain and non-myelinized autonomous nerves can be irreversibly destroyed by chemical and thermal ablation.

PERFORMANCE

Computed tomography (CT)-guided sympathetic nerve blocks are well established interventional radiological procedures which lead to vasodilatation, reduction of sweating and reduction of pain associated with the autonomous nervous system.

ACHIEVEMENTS AND PRACTICAL RECOMMENDATIONS

Sympathetic blocks are applied for the treatment of various vascular diseases including critical limb ischemia. Other indications for thoracic and lumbar sympathectomy include complex regional pain syndrome (CRPS), chronic tumor associated pain and hyperhidrosis. Neurolysis of the celiac plexus is an effective palliative pain treatment particularly in patients suffering from pancreatic cancer. Percutaneous dorsal root ganglion rhizotomy can be performed in selected patients with radicular pain that is resistant to conventional pharmacological and interventional treatment.

Early experience with endoscopic lumbar sympathectomy for plantar hyperhidrosis

OBJECTIVE

We describe our endoscopic lumbar sympathectomy technique and our early experience using it to treat plantar hyperhidrosis.

METHODS

We reviewed 20 lumbar sympathectomies performed in our vascular unit for plantar hyperhidrosis in 10 patients from 2011 and 2014. Demographics and outcomes were analyzed and a review of the literature conducted.

RESULTS

All procedures were carried out endoscopically with no intraoperative or postoperative morbidity. Plantar anhidrosis was achieved in all the patients, although two patients (20%) suffered a relapse. Unwanted side-effects occurred in the form of compensatory sweating in three patients (30%) and post-sympathectomy neuralgia in two patients (20%). None of the patients experienced sexual dysfunction.

CONCLUSION

Management of plantar hyperhidrosis may be based upon a therapeutic ladder starting with conservative measures and working up to surgery depending on the severity of the disease. Minimally invasive (endoscopic) sympathectomy for the thoracic chain is well established, but minimally invasive sympathectomy for the lumbar chain is a relatively new technique. Endoscopic lumbar sympathectomy provides an effective, minimally invasive method of surgical management, but long-term data are lacking.

Thoracic sympathectomy: a review of current indications

BACKGROUND

Thoracic sympathetic ablation was introduced over a century ago. While some of the early indications have become obsolete, new ones have emerged. Sympathetic ablation is being still performed for some odd indications thus prompting the present study, which reviews the evidence base for current practice.

METHODS

The literature was reviewed using the PubMed/Medline Database, and pertinent articles regarding the indications for thoracic sympathectomy were retrieved and evaluated. Old, historical articles were also reviewed as required.

RESULTS AND CONCLUSIONS

Currently, thoracic sympathetic ablation is indicated mainly for primary hyperhidrosis, especially affecting the palm, and to a lesser degree, axilla and face, and for facial blushing. Despite modern pharmaceutical, endovascular and surgical treatments, sympathetic ablation has still a place in the treatment of very selected cases of angina, arrhythmias and cardiomyopathy. Thoracic sympathetic ablation is indicated in several painful conditions: the early stages of complex regional pain syndrome, erythromelalgia, and some pancreatic and other painful abdominal pathologies. Although ischaemia was historically the major indication for sympathetic ablation, its use has declined to a few selected cases of thromboangiitis obliterans (Buerger's disease), microemboli, primary Raynaud's phenomenon and Raynaud's phenomenon secondary to collagen diseases, paraneoplastic syndrome, frostbite and vibration syndrome. Thoracic sympathetic ablation for hypertension is obsolete, and direct endovascular renal sympathectomy still requires adequate clinical trials. There are rare publications of sympathetic ablation for primary phobias, but there is no scientific basis to support sympathetic surgery for any psychiatric indication.

Treatment of compensatory hyperhidrosis after sympathectomy with botulinum toxin and anticholinergics

PURPOSE

Compensatory hyperhidrosis (CH) is the most common adverse complication of sympathectomy. It often has a major negative impact on life quality. No efficient treatment of CH is available. We report nine cases of CH after sympathectomy, which were treated with botulinum toxin A/B (BTX) and anticholinergics.

METHODS

The patients responded to a dermatology life quality index (DLQI) questionnaire before injections with BTX and 3 weeks after treatment. At the follow-up visit, the participants also ranked the effect of the treatment on a five-grade scale. Three patients had residual sweating after BTX treatment, and received additional anticholinergics at the follow-up visit. Those subjects eventually had a third evaluation with the DLQI.

RESULTS

The DLQI score was, on average, 16.4 before treatment and decreased to 4.8 after BTX injections. Eight out of nine patients were satisfied with the treatment. The average DLQI score decreased to 2.2 when the patients with residual sweating (n = 3) received additional anticholinergics. Adverse events from BTX were mild and temporary, but dry mouth was substantial in one patient using anticholinergics.

CONCLUSIONS

A combination of BTX A/B and anticholinergics alleviated the hyperhidrosis with minor side-effects. We consider this treatment safe, effective, and well tolerated.

[Complex regional pain syndrome: A current review]

Complex regional pain syndrome (CRPS) may develop following fractures, limb trauma, or lesions of the peripheral or central nervous system. The clinical picture consists of a triad of symptoms including autonomic, sensory, and motor dysfunction. Diagnosis is based on clinical signs and symptoms according to the Budapest criteria. Therapy is based on an individual and multidisciplinary approach. Distinct methods of physical therapy and pharmacological strategies are the mainstay of therapy. Pharmacotherapy is based on individual symptoms and includes steroids, free radical scavengers, treatment of neuropathic pain, and agents interfering with bone metabolism. In some cases invasive methods may be considered.

Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome

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.

OBJECTIVES

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.

SEARCH 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.

SELECTION CRITERIA

Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible.

MAIN 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.

AUTHORS' 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.

Hyperhidrosis: anatomy, pathophysiology and treatment with emphasis on the role of botulinum toxins

Clinical features, anatomy and physiology of hyperhidrosis are presented with a review of the world literature on treatment. Level of drug efficacy is defined according to the guidelines of the American Academy of Neurology. Topical agents (glycopyrrolate and methylsulfate) are evidence level B (probably effective). Oral agents (oxybutynin and methantheline bromide) are also level B. In a total of 831 patients, 1 class I and 2 class II blinded studies showed level B efficacy of OnabotulinumtoxinA (A/Ona), while 1 class I and 1 class II study also demonstrated level B efficacy of AbobotulinumtoxinA (A/Abo) in axillary hyperhidrosis (AH), collectively depicting Level A evidence (established) for botulinumtoxinA (BoNT-A). In a comparator study, A/Ona and A/Inco toxins demonstrated comparable efficacy in AH. For IncobotulinumtoxinA (A/Inco) no placebo controlled studies exist; thus, efficacy is Level C (possibly effective) based solely on the aforementioned class II comparator study. For RimabotulinumtoxinB (B/Rima), one class III study has suggested Level U efficacy (insufficient data). In palmar hyperhidrosis (PH), there are 3 class II studies for A/Ona and 2 for A/Abo (individually and collectively level B for BoNT-A) and no blinded study for A/Inco (level U). For B/Rima the level of evidence is C (possibly effective) based on 1 class II study. Botulinum toxins (BoNT) provide a long lasting effect of 3–9 months after one injection session. Studies on BoNT-A iontophoresis are emerging (2 class II studies; level B); however, data on duration and frequency of application is inconsistent.

Cutaneous noradrenaline measured by microdialysis in complex regional pain syndrome during whole-body cooling and heating

Complex regional pain syndrome (CRPS) is characterised by autonomic, sensory, and motor disturbances. The underlying mechanisms of the autonomic changes in CPRS are unknown. However, it has been postulated that sympathetic inhibition in the acute phase with locally reduced levels of noradrenaline is followed by an up-regulation of alpha-adrenoceptors in chronic CRPS leading to denervation supersensitivity to catecholamines. This exploratory study examined the effect of cutaneous sympathetic activation and inhibition on cutaneous noradrenaline release, vascular reactivity, and pain in CRPS patients and in healthy volunteers. Seven patients and nine controls completed whole-body cooling (sympathetic activation) and heating (sympathetic inhibition) induced by a whole-body thermal suit with simultaneous measurement of the skin temperature, skin blood flow, and release of dermal noradrenaline. CRPS pain and the perceived skin temperature were measured every 5 min during thermal exposure, while noradrenaline was determined from cutaneous microdialysate collected every 20 min throughout the study period. Cooling induced peripheral sympathetic activation in patients and controls with significant increases in dermal noradrenaline, vasoconstriction, and reduction in skin temperature. The main findings were that the noradrenaline response did not differ between patients and controls or between the CRPS hand and the contralateral unaffected hand, suggesting that the evoked noradrenaline release from the cutaneous sympathetic postganglionic fibres is preserved in chronic CRPS patients.

Robotic selective postganglionic thoracic sympathectomy for the treatment of hyperhidrosis

BACKGROUND

The surgical management of hyperhidrosis is controversial. Robotic surgical systems with their high-definition magnified 3-dimensional view and increased maneuverability in a confined space may facilitate the technique of selective sympathectomy (ramicotomy). We present a case series of patients undergoing selective postganglionic thoracic sympathectomy using robotic technology.

METHODS

This study is a case series analysis of patients who underwent selective postganglionic thoracic sympathectomy from July 2006 to November 2011. The operation was performed on a video-assisted thoracoscopic surgery (VATS) platform. The robot was used for pleural dissection and division of the postganglionic sympathetic fibers and the communicating rami. The success of sympathectomy was assessed by intraoperative temperature measurement of the ipsilateral upper extremity, patient interviews, and scoring of the symptomatic nature of hyperhidrosis based on the Hyperhidrosis Disease Severity Scale.

RESULTS

There were 110 sympathectomies performed in 55 patients (25 men, 30 women). Simultaneous bilateral sympathectomy was performed in all patients. Median age was 28 years (range, 16 to 65 years). There was no conversion to thoracotomy. Complications were minor and were seen in 5 of 55 patients (9%). There were no deaths. Median hospital stay was 1 day (range, 1 to 4 days). Of the 55 patients, 53 (96%) had sustained relief of their hyperhidrosis at a median follow-up of 24 months (range, 3 to 36 months), and compensatory sweating was seen in 4 patients (7.2%).

CONCLUSIONS

Robotic thoracoscopic selective sympathectomy is an effective, feasible, and safe procedure with excellent relief of hyperhidrosis and low rates of compensatory sweating and complications.

Intrapleural analgesia after endoscopic thoracic sympathectomy

PURPOSE

To compare analgesia traditionally used for thoracic sympathectomy to intrapleural ropivacaine injection in two different doses.

METHODS

Twenty-four patients were divided into three similar groups, and all of them received intravenous dipyrone. Group A received intravenous tramadol and intrapleural injection of saline solution. Group B received intrapleural injection of 0.33% ropivacaine, and Group C 0.5% ropivacaine. The following aspects were analyzed: inspiratory capacity, respiratory rate and pain. Pain was evaluated in the immediate postoperative period by means of the visual analog scale and over a one-week period.

RESULTS

In Groups A and B, reduced inspiratory capacity was observed in the postoperative period. In the first postoperative 12 hours, only 12.5% of the patients in Groups B and C showed intense pain as compared to 25% in Group A. In the subsequent week, only one patient in Group A showed mild pain while the remainder reported intense pain. In Group B, half of the patients showed intense pain, and in Group C, only one presented intense pain.

CONCLUSION

Intrapleural analgesia with ropivacaine resulted in less pain in the late postoperative period with better analgesic outcomes in higher doses, providing a better ventilatory pattern.

Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome

BACKGROUND

This review is an update on 'Sympathectomy for neuropathic pain' originally published in Issue 2, 2003. 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 minimally invasive procedures using thermal or laser interruption.

OBJECTIVES

To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain. Sympathectomy could be compared with placebo (sham) or other active treatment.

SEARCH STRATEGY

We searched MEDLINE, EMBASE and The Cochrane Library to May 2010. We screened references in the retrieved articles and literature reviews, and contacted experts in the field of neuropathic pain.

SELECTION CRITERIA

Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible.

MAIN 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 postsympathectomy neuralgia, while two in the radiofrequency group and one in the phenol group complained of paresthaesia during needle positioning. All participants had soreness at the injection site.

AUTHORS' 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.

Validation of proposed diagnostic criteria (the "Budapest Criteria") for Complex Regional Pain Syndrome

Current IASP diagnostic criteria for CRPS have low specificity, potentially leading to overdiagnosis. This validation study compared current IASP diagnostic criteria for CRPS to proposed new diagnostic criteria (the "Budapest Criteria") regarding diagnostic accuracy. Structured evaluations of CRPS-related signs and symptoms were conducted in 113 CRPS-I and 47 non-CRPS neuropathic pain patients. Discriminating between diagnostic groups based on presence of signs or symptoms meeting IASP criteria showed high diagnostic sensitivity (1.00), but poor specificity (0.41), replicating prior work. In comparison, the Budapest clinical criteria retained the exceptional sensitivity of the IASP criteria (0.99), but greatly improved upon the specificity (0.68). As designed, the Budapest research criteria resulted in the highest specificity (0.79), again replicating prior work. Analyses indicated that inclusion of four distinct CRPS components in the Budapest Criteria contributed to enhanced specificity. Overall, results corroborate the validity of the Budapest Criteria and suggest they improve upon existing IASP diagnostic criteria for CRPS.

Complex regional pain syndromes: new pathophysiological concepts and therapies

Complex regional pain syndrome (CRPS), formerly known as Sudeck's dystrophy and causalgia, is a disabling and distressing pain syndrome. We here provide a review based on the current literature concerning the epidemiology, etiology, pathophysiology, diagnosis, and therapy of CRPS. CRPS may develop following fractures, limb trauma or lesions of the peripheral or CNS. The clinical picture comprises a characteristic clinical triad of symptoms including autonomic (disturbances of skin temperature, color, presence of sweating abnormalities), sensory (pain and hyperalgesia), and motor (paresis, tremor, dystonia) disturbances. Diagnosis is mainly based on clinical signs. Several pathophysiological concepts have been proposed to explain the complex symptoms of CRPS: (i) facilitated neurogenic inflammation; (ii) pathological sympatho-afferent coupling; and (iii) neuroplastic changes within the CNS. Furthermore, there is accumulating evidence that genetic factors may predispose for CRPS. Therapy is based on a multidisciplinary approach. Non-pharmacological approaches include physiotherapy and occupational therapy. Pharmacotherapy is based on individual symptoms and includes steroids, free radical scavengers, treatment of neuropathic pain, and finally agents interfering with bone metabolism (calcitonin, biphosphonates). Invasive therapeutic concepts include implantation of spinal cord stimulators. This review covers new aspects of pathophysiology and therapy of CRPS.

Botulinum toxin for hyperhidrosis: a review

Primary focal hyperhidrosis is a disorder of idiopathic excessive sweating that typically affects the axillae, palms, soles, and face. The disorder, which affects up to 2.8% of the US population, is associated with considerable physical, psychosocial, and occupational impairments. Current therapeutic strategies include topical aluminum salts, tap-water iontophoresis, oral anticholinergic agents, local surgical approaches, and sympathectomies. These treatments, however, have been limited by a relatively high incidence of adverse effects and complications. Non-surgical treatment complications are typically transient, whereas those of surgical therapies may be permanent and significant. Recently, considerable evidence suggests that botulinum toxin type A (BTX-A) injections into hyperhidrotic areas can considerably reduce focal sweating in multiple areas without major adverse effects. BTX-A has therefore shown promise as a potential replacement for more invasive treatments after topical aluminum salts have failed. This article reviews the epidemiology, diagnosis, and management of primary focal hyperhidrosis, with an emphasis on recent research evidence supporting the use of BTX-A injections for this indication.

Botulinum toxin: a treatment for compensatory hyperhidrosis in the trunk

BACKGROUND

Severe compensatory hyperhidrosis (CH) in the trunk occurs after sympathectomy in some patients. Limited treatment options for these cases have been proposed, and the overall results have been disappointing, but injection of botulinum toxin-A (BTX-A) is an emerging, reliable treatment method for focal hyperhidrosis.

OBJECTIVE

To demonstrate the efficacy, longevity, and safety of BTX-A injection for severe truncal sweating in CH patients who were refractory to conventional treatment.

METHODS

Seventeen patients were injected with 100 to 500 U of BTX-A in the truncal area. After the follow-up period, the Hyperhidrosis Disease Severity Scale (HDSS) for efficacy and the Dermatology Life Quality Index (DLQI) were measured for improvement in patients' quality of life.

RESULTS

The baseline mean HDSS score+/-standard deviation was 3.6+/-0.5, and the sweating resolved within 5 days. The effect was sustained for 2 to 8 months (4.1+/-1.5 months) and the baseline DLQI score of 9.4+/-2.0 fell to 2.8+/-1.0. No serious side effects or adverse events resulted from the treatment.

CONCLUSIONS

BTX-A injection was a well-tolerated, effective, and safe method for treating severe truncal CH, although the considerable cost and limited duration of the treatment effects were major disadvantages.

Phantom sweating: a novel autonomic paresthesia

OBJECTIVE

To describe the biology of phantom sweating, a novel autonomic neuropathy symptom, based on a description of a patient with a small fiber and autonomic neuropathy.

METHODS

Clinical and laboratory assessments.

RESULTS

Evidence of a generalized small fiber and autonomic neuropathy.

INTERPRETATION

Phantom sweating occurs frequently after sympathectomy but has not been reported previously in patients with a somatosensory or autonomic neuropathy. We suggest that this symptom is an autonomic paresthesia.

Patients with hyperhidrosis have changed grip force, coefficient of friction and safety margin

OBJECTIVE

To evaluate whether subjects with palmar hyperhidrosis have functional problems with the handgrip caused by the wet slippery surface of palm and fingertips. We used two different dosages of botulinum toxin to explore its impact on sweating and on muscle strength in the hand.

METHOD

Using an object equipped with force sensors we measured the muscle strength and calculated the coefficients of friction and safety margin (SM) in the precision grip before and 2, 4, 6, 8 10-12 weeks and 6 months after treatment of 13 patients with two different doses of botulinum toxin. Sweat evaporation was measured simultaneously.

RESULTS

A significant decrease in evaporation and a parallel reduction of grip force in the dominant hand of the patients were observed. The SM used by the patients was significantly lower after the treatment, and increased gradually when sweating reappeared.

CONCLUSION

These measurements showed, for the first time, that hyperhidrosis of the palms may cause an objective perturbation of the hand function which may be partially corrected by botulinum toxin treatment.

Incidência de pneumotórax residual após simpatectomia torácica videotoracoscópica com e sem drenagem pleural e sua possível influência na dor pós-operatória

OBJETIVO: Avaliar se o pneumotórax residual após simpatectomia torácica videotoracoscópica tem incidência diferente quando utilizada a drenagem pleural pós-operatória ou não e se este pneumotórax residual, quando presente, pode influenciar a dor pós-operatória até o 28º dia. MÉTODOS: Foram incluídos todos os pacientes com queixa de hiperidrose palmoplantar primária atendidos no Ambulatório de Cirurgia Torácica do Hospital Estadual Sumaré, de julho a dezembro de 2006. Todos foram submetidos à simpatectomia do terceiro gânglio torácico por videotoracoscopia e aleatorizados para receber ou não drenagem pleural pós-operatória por 3 h. Todos foram avaliados no pós-operatório imediato com radiogramas de tórax e tomografia computadorizada de tórax de baixa emissão de energia para detecção de pneumotórax residual. Foram avaliados quanto à dor pós-operatória em diferentes momentos até o 28º dia de pós-operatório, por meio de escala numérica visual e dosagem requerida de analgésicos opióides. RESULTADOS: Foram incluídos 56 pacientes neste estudo, 27 com drenagem pleural bilateral e 29 sem drenagem pleural. Não houve diferença estatística entre a incidência de pneumotórax residual após simpatectomia com e sem drenagem pleural. O pneumotórax residual, quando presente e diagnosticado por qualquer um dos métodos, não influenciou a dor pós-operatória até o 28º dia. CONCLUSÃO: Concluiu-se que a drenagem pleural tubular fechada, por um período de 3 h, no pós-operatório imediato de simpatectomia torácica videotoracoscópica, foi tão eficiente quanto a não drenagem, em relação à reexpansão pulmonar e à presença de pneumotórax residual. O pneumotórax residual, quando presente, não interferiu na dor pós-operatória até o 28º dia.

Horner syndrome after sympathectomy in the thoracoscopic era

OBJECTIVE

Horner syndrome after sympathectomy has significantly decreased in current surgical practice. This is predominantly due to refinements in operative techniques, and an improved understanding of the patterns of sympathetic outflow pathways. We present a review of our experience with this disconcerting complication of sympathectomy when undertaken for palmar hyperhidrosis.

METHODS AND TECHNIQUE

Over a 12-year period (1992 to 2004), patients undergoing sympathectomy for palmar hyperhidrosis were prospectively evaluated. In all patients the thoracoscopic approach was attempted bilaterally. The technique entailed the accurate identification of the second thoracic ganglion, followed by its dissection and resection. Excessive manipulation and cautery on the sympathetic chain was avoided.

RESULTS

A total of 1137 procedures were undertaken in 567 patients. In 1 patient (during the early part of the technical experience) a unilateral Horner syndrome was noted on the first postoperative day; this effect was noted to have resolved spontaneously within 6 months. Review at 3 months was possible in 382 patients, either directly or telephonically. In these patients no further case of Horner syndrome was documented.

CONCLUSIONS

The key to avoiding the development of a Horner syndrome after sympathectomy entails a thorough appreciation of the appropriate surgical anatomy, avoidance of violent manipulation and traction of the sympathetic chain, and the avoidance of diathermy on the sympathetic chain. The adherence to these principles has consigned Horner syndrome after sympathectomy as an entity of historical interest.

Current diagnosis and therapy of complex regional pain syndrome: refining diagnostic criteria and therapeutic options

Complex regional pain syndrome is a clinically challenging entity both in terms of accurate diagnosis and effective treatment. Complex regional pain syndrome is a post-traumatic painful neurologic syndrome involving the somatosensory, sympathetic and often the somatomotor systems. This complex condition consists of local neurogenic inflammation out of proportion to injury; severe pain in the skin, subcutaneous tissues and joints; and a central hyperexcitability that is often compounded with a sympathetic component. The syndrome is multifaceted manifesting both central and peripheral neurologic pathophysiology, frequently including a prominent psychosocial component. The wide array of possible patient presentations and antecedent pathologies also complicate successful treatment. To further add to the clinical challenges of complex regional pain syndrome, the epidemiology and natural history of complex regional pain syndrome are only partially known; evidence concerning complex regional pain syndrome treatment has grown slowly, due in large part to the vagaries of diagnosis; and research data--when they are available--are difficult to interpret. Thus, in spite of our evolving understanding of this neurologic disorder, in many cases complex regional pain syndrome remains difficult to diagnose and treat successfully.

Endoscopic Thoracic Sympathectomy for Severe Hyperhidrosis: Impact of Restrictive Denervation on Compensatory Sweating

BACKGROUND

Compensatory sweating is noted frequently after sympathectomy and may be difficult to control in some patients. This prospective trial was projected to measure the impact of limited denervation on compensatory sweating while performing endoscopic thoracic sympathectomy.

METHODS

One hundred seventy-eight patients (127 female and 51 male) with severe primary hyperhidrosis unsuccessfully treated by conservative means entered the study. Group A was treated with sympathectomy from T2 to T4. In group B sympathectomy was performed from T3 to T5. Physical condition was measured after 1, 6, and 24 months by means of the SF-36 Health Survey Test.

RESULTS

Evaluation rate was 94.9%. Horner's syndrome was not detected, recurrence rate was 0.6%, and rate of persistent pneumothorax was 2.3%. Compensatory sweating was reported with 17.1% in group A and diminished to 4.9% in group B. Gustatory sweating was comparable in both groups (4.3% versus 4.9%). Satisfaction rate was 97% in patients with palmar hyperhidrosis, 95% for axillary hyperhidrosis, and 87% for facial hyperhidrosis. Discomfort originating from compensatory sweating was less than symptoms from primary hyperhidrosis 24 months after endoscopic thoracic sympathectomy in more than 90%. Only 7.1% of the entire group was not satisfied.

CONCLUSIONS

Our study demonstrates that limiting denervation beyond T2 ganglion offers good clinical results in axillary as well as palmar hyperhidrosis and may reduce the risk for compensatory sweating. In women, reduction was as high as 75% and in men, near 50%. Our impression is that severe compensatory sweating and the majority of stellate ganglion lesions occur as a result of starting sympathectomy at level T2.

Neural Modulation by Blocks and Infusions

Neural blockade is widely used in clinical practice to alleviate acute or chronic pain, including neuropathic pain. However, to date there is little controlled evidence to confirm the efficacy of nerve blocks in neuropathic pain. The most common indication for nerve blocks, especially sympathetic blockade, is complex regional pain syndrome, in which success rates of up to 38% have been achieved, depending on the type of the block used. Greater efficacy has been achieved by combining a nerve block with patient-controlled analgesia. Sympathectomy is recommended for the treatment of neuropathic pain only after careful consideration of its usefulness, effectiveness, and risk of adverse effects. Current evidence and clinical experience suggest that neural blockade could be a useful adjunct in the management of refractory neuropathic pain, but further well-controlled studies would be of great benefit to support this type of therapy.

Computed tomography guided lumbar sympathetic block for complex regional pain syndrome in a child: a case report and review

The aim of this paper is to describe the first reported use of computed tomography (CT) guided lumbar sympathetic block as treatment of a case of complex regional pain syndrome (CRPS) in a child. The potential aetiology of CRPS is discussed in relation to the mechanism of action of local anaesthetics used in the block. Based on the successful treatment of this child and the documented success of its use in adults, we conclude that despite the minimal dose of radiation given, CT guided lumbar sympathetic block is an important treatment option in CRPS in children.

[Therapeutic application of botulogenic toxin]

Botulogenic toxin infiltration for the treatment of idiopathic local hyperhidrosis is a safe and well tolerated procedure, with minimum side effects and with an effectiveness demonstrated throughout the years, especially in axillary hyperhidrosis; in the majority of patients with this condition is an effective alternative to surgery. In other locations, the results are more modest and the clinical experience more limited, which forces us to advise the surgery as alternative with an incidence far from desirable.

No compensatory sweating after botulinum toxin treatment of palmar hyperhidrosis

BACKGROUND

Primary focal hyperhidrosis is caused by excessive secretion by eccrine sweat glands, usually at the palms, soles and axillae. The underlying mechanism is unclear. In recent years botulinum toxin A has emerged as a useful treatment. Compensatory sweating, which is a major problem in many patients who have undergone transthoracic endoscopic sympathectomy for hyperhidrosis, has only rarely been reported after botulinum toxin. However, this potential side-effect of botulinum toxin treatment has not been systematically examined.

OBJECTIVES

To investigate if treatment with botulinum toxin A in hyperhidrotic hands may cause compensatory sweating at other skin locations.

METHODS

In 17 patients with a history of palmar hyperhidrosis repeated measurements of evaporation were made before and up to 6 months after treatment of the hands with botulinum toxin A. Recordings were made at 16 skin areas and compared with subjective estimates of sweating.

RESULTS

Following treatment, palmar evaporation decreased markedly and then returned slowly towards pretreatment values, but was still significantly reduced 6 months after treatment. No significant increase of sweating was found after treatment in any nontreated skin area.

CONCLUSIONS

Successful treatment of palmar hyperhidrosis with botulinum toxin does not evoke compensatory hyperhidrosis in nontreated skin territories.

The place of botulinum toxin type A in the treatment of focal hyperhidrosis

BACKGROUND

Hyperhidrosis (primary or secondary) is excessive sweating beyond that required to return body temperature to normal. It can be localized or generalized, commonly affecting the axillae, palms, soles or face, and can have a substantial negative effect on a patient's quality of life.

IMPACT OF DISEASE

Objective evaluation comprising quantitative assessment (gravimetric and Minor's iodine starch test) and subjective evaluation (Dermatology Quality of Life Index and Hyperhidrosis Impact Questionnaire) allow accurate assessment of the impact of hyperhidrosis on patients.

BOTULINUM TOXIN TYPE A

Botulinum toxin type A acts by inhibiting the release of acetylcholine at the presynaptic membrane of cholinergic neurones. It has proved useful in treating a number of diseases relating to muscular dystonia and is now proving beneficial in treating hyperhidrosis. Clinical trials investigating botulinum toxin type A use in axillary and palmar hyperhidrosis show significant benefits with few side-effects reported, with a favourable impact also being seen on patient quality of life. Botulinum toxin type A injections are generally well-tolerated with beneficial results lasting from 4 to 16 months.

CONCLUSIONS

Botulinum toxin type A injections are an effective and well-tolerated treatment for hyperhidrosis. This paper proposes a positioning of this treatment along with current established treatments, and highlights the role of botulinum toxin type A as a valuable therapy for the treatment of hyperhidrosis.

Evaluation of objective methods to diagnose palmar hyperhidrosis and monitor effects of botulinum toxin treatment

OBJECTIVE

To evaluate (1) if laboratory tests may be a useful complement in diagnosing palmar hyperhidrosis and (2) if such tests can be used in the follow up examination of treatment effects.

METHODS

Repeated measurements of evaporation and conductance were made in glabrous skin on hands and compared with subjective estimates of the degree of sweating in 20 control subjects and 20 patients with a history of palmar hyperhidrosis. In addition, 17 patients were monitored for up to 6 months after treatment of the hands with botulinum toxin A.

RESULTS

Before treatment, evaporation in the palms was higher in the patients than in the control subjects but skin conductance did not differ between the groups. After treatment both evaporation and skin conductance decreased markedly in the patients and then slowly returned towards pretreatment values.

CONCLUSIONS

Measurements of evaporation, but not skin conductance, may be a useful objective adjunct when diagnosing palmar hyperhidrosis. Both methods can, however, be used to monitor intraindividual changes of sweating over time.

Characteristics and associated features of persistent post-sympathectomy pain

OBJECTIVES

The aim of this study is to describe the incidence and characteristics of pain, sensory abnormalities, abnormal body sweating, and pathologic gustatory sweating in pain patients with persistent post-sympathectomy pain.

METHODS

A retrospective chart review of a series of consecutive pain patients with persistent post-sympathectomy pain was performed. Inclusion criteria were: (1) sympathectomy performed for the indication of neuropathic pain, and (2) persistent pain after the procedure. Demographic data, patterns of pain before and after sympathectomy, patients' pain drawings, and incidence of pain had been collected concurrently at the time of referral. Additional data regarding sensory findings, surgical details of the sympathectomy, sweat patterns, and incidence of abnormal body sweating and pathologic gustatory sweating were extracted from the patients' charts or obtained in follow-up appointments.

RESULTS

Seventeen adults (13 females and 4 males) with a mean age of 37 years (range 25-52) at the time of sympathectomy met the inclusion criteria. Five of the 17 patients experienced temporary pain relief for an average of 4 months (range 2-12 months), 3/17 retained the same pain as before the surgery, 1 patient was cured of her original pain but experienced a new debilitating pain, and 8/17 patients continued to have the same or worse pain in addition to a new or expanded pain. Pathologic gustatory sweating was present in 7/11 patients asked, and abnormal sweating (known as compensatory hyperhidrosis) in 11/13 patients asked.

DISCUSSION

The present study does not allow for conclusions about the effectiveness of surgical sympathectomy for neuropathic pain. However, our findings indicate that if the pain persists after the procedure, the complications may be quite serious and at times worse than the problem for which the surgery was originally performed.

Efficacy and safety of botulinum toxin type a in the treatment of palmar hyperhidrosis: a double-blind, randomized, placebo-controlled study

BACKGROUND

Recent studies demonstrate that botulinum toxin type A (BTX-A) decreases palmar hyperhidrosis.

OBJECTIVE

To evaluate the efficacy and safety of BTX-A for palmar hyperhidrosis.

METHODS

Patients (n = 19) received injections of placebo (normal saline) in one hand and BTX-A in the other. Assessments included gravimetric measurement of sweat production and physician's and patient's rating of severity. Safety evaluations included measuring grip strength. Preliminary 28-day results are reported.

RESULTS

The mean percentage decrease in gravimetric measurement at day 28 was significantly greater with BTX-A versus placebo. One hundred percent of 17 patients rated the treatment as successful, while only 12% (2/17) rated placebo injection successful. Grip and hand strength were unchanged with either treatment. Only 21% (4/19) reported mild adverse events.

CONCLUSION

BTX-A injections produce significant improvements in palmar hyperhidrosis without a concomitant decrease in grip or dexterity, or the occurrence of serious adverse events.

Sympathectomy for neuropathic pain

BACKGROUND

Neuropathic pain is defined as pain initiated or caused by a primary lesion or dysfunction in the nervous system. Some examples of this condition are phantom limb pain, post-stroke pain and complex regional pain syndrome type I (reflex sympathetic dystrophy) and type II (causalgia). Treatment options include drugs, physical treatments, surgery and psychological interventions. The concept that many neuropathic pain syndromes, particularly RSD and causalgia are "sympathetically maintained pains" has historically led to attempts to temporarily or permanently interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy the sympathetic chain, but this effect is temporary until regeneration of the sympathetic chain occurs. Surgical ablation can be performed by open removal or electrocoagulation of the sympathetic chain, or minimally invasive procedures using stereotactic thermal or laser interruption.

OBJECTIVES

The review aimed to assess the effects of both chemical and surgical sympathectomy for neuropathic pain. Secondary objectives were to compare the effects of sympathectomy with no treatment, placebo or conventional treatment, and to evaluate whether the technique of sympathectomy influences the outcomes of the procedure.

SEARCH STRATEGY

We searched MEDLINE and EMBASE up to February 2003 and the latest issue of the Cochrane Library (Issue 1, 2003). We screened references in the retrieved articles, literature reviews and book chapters. We also contacted experts in the field of neuropathic pain.

SELECTION CRITERIA

Clinical trials and observational studies assessing the effects of sympathectomy (surgical or chemical) for neuropathic pain of both central or peripheral origin were included.

DATA COLLECTION AND ANALYSIS

Two reviewers applied the selection criteria to titles and abstracts. Full articles of potentially eligible trials were obtained and the same reviewers applied the inclusion criteria to the studies. The methodological quality of the studies was evaluated. The studies were also evaluated for clinical relevance according to a classification developed by our group. Statistical pooling was not possible due to heterogeneity of data; instead a narrative description of each included study was performed.

MAIN RESULTS

We included four studies. One randomized trial comparing radiofrequency sympatholysis with phenol sympathectomy was rated as low methodological quality and it showed that radiofrequency sympatholysis does not offer advantage over phenol techniques. However, a modified technique produced sympatholysis comparable to that produced by 6% phenol, with less incidence of post-sympathectomy neuralgia.

REVIEWER'S CONCLUSIONS

The practice of surgical and chemical sympathectomy is based on poor quality evidence, uncontrolled studies and personal experience. Furthermore, complications of the procedure may be significant, in terms of both worsening the pain or producing a new pain syndrome; and abnormal forms of sweating (compensatory hyperhidrosis and pathological gustatory sweating). Therefore, more clinical trials of sympathectomy are required to establish the overall effectiveness and potential risks of this procedure.