Management of lower limb complex regional pain syndrome type 1: an evaluation of percutaneous radiofrequency thermal lumbar sympathectomy versus phenol lumbar sympathetic neurolysis--a pilot study

Effect duration of lumbar sympathetic ganglion neurolysis in patients with complex regional pain syndrome: a prospective observational study

Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7-16.3) at the maximum pain site and 12 weeks (95% CI 9.4-14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.

Spinal cord stimulation-induced gastroparesis: A case report

BACKGROUND

Spinal cord stimulation (SCS) involves the utilization of an implantable neurostimulation device, stereotypically used in the treatment of patients with chronic neuropathic pain. While these devices have been shown to have significant clinical benefits, there have also been documented potential complications, including the risk of infection, fractured electrodes, electrode migration, and lack of symptom improvement. In addition, there has been minimal documentation on gastrointestinal (GI) side effects after SCS implantation.

CASE DESCRIPTION

A 42-year-old patient with chronic axial and radicular neuropathic pain in her back and left leg status post multiple lumbar surgeries underwent implantation of an open paddle lead in the T8-T9 region. After the procedure, the patient endorsed a 50% decrease in pain at the 6-week follow-up with no further concerns. However, at the 18 months follow-up, the patient endorsed severe constipation when the SCS was turned on, leading to subsequent evaluation by gastroenterology, motility studies, and a thorough bowel regimen. Symptoms persisted, and the patient ultimately opted for the removal of the SCS implant at 21 months after the initial surgery.

CONCLUSION

While the exact mechanism behind the GI side effects endorsed in this patient is unknown, current literature postulates a variety of theories, including a SCS-induced parasympathetic blockade of the GI tract. Further, investigation is needed to determine the exact effects of SCS on the GI tract.

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.

AUTHORS' CONCLUSIONS

Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

Agents Used for Nerve Blocks and Neurolysis

The recognition of pain and the treatments used for it are vital for all practitioners. Many types of pain can be treated in a locoregional fashion, which has significant implications not just for any individual patient but for society as a whole. These treatments are most effective when performed in a minimally invasive, image-guided fashion. Interventional radiologists should play a central role in providing these lifestyle-limiting treatments. This article describes the medications most typically used for spinal and extra-axial treatments in the management of patients in pain.

Stellate ganglion intervention for chronic pain: A review

Stellate ganglion (SG) intervention is currently widely being studied in many kinds of chronic pain. As one of the convenient ways to treat the sympathetic nervous system, the indications for stellate ganglion intervention (SGI) include complex regional pain syndrome, postherpetic neuralgia, cancer pain of different origins, orofacial pain, and so forth. SGI refers to the reversible or irreversible blocking of the cervical sympathetic trunk, cervical sympathetic ganglion, and their innervation range through noninvasive or minimally invasive treatment. Current treatment options include stellate ganglion block (SGB), SG pulsed radiofrequency, continuous radiofrequency treatment, and noninvasive SGB. In particular, SGB continues to be one of the most studied methods in chronic pain management. However, a single SGB usually provides only short-term effects; repeated SGB may result in complications such as hoarseness, light-headedness, and vessel or nerve injury. Meanwhile, the mechanism of SGI is still unclear. This review discusses the research progress of SGI methods, effectiveness, complications, and possible mechanisms in the management of chronic pain.

Botulinum Toxin Type A for Lumbar Sympathetic Ganglion Block in Complex Regional Pain Syndrome: A Randomized Trial

BACKGROUND

The present study was designed to test the hypothesis that botulinum toxin would prolong the duration of a lumbar sympathetic block measured through a sustained increase in skin temperature. The authors performed a randomized, double-blind, controlled trial to investigate the clinical outcome of botulinum toxin type A for lumbar sympathetic ganglion block in patients with complex regional pain syndrome.

METHODS

Lumbar sympathetic ganglion block was conducted in patients with lower-extremity complex regional pain syndrome using 75 IU of botulinum toxin type A (botulinum toxin group) and local anesthetic (control group). The primary outcome was the change in the relative temperature difference on the blocked sole compared with the contralateral sole at 1 postoperative month. The secondary outcomes were the 3-month changes in relative temperature differences, as well as the pain intensity changes.

RESULTS

A total of 48 participants (N = 24/group) were randomly assigned. The change in relative temperature increase was higher in the botulinum toxin group than in the control group (1.0°C ± 1.3 vs. 0.1°C ± 0.8, respectively; difference: 0.9°C [95% CI, 0.3 to 1.5]; P = 0.006), which was maintained at 3 months (1.1°C ± 0.8 vs. -0.2°C ± 1.2, respectively; P = 0.009). Moreover, pain intensity was greatly reduced in the botulinum toxin group compared with the control group at 1 month (-2.2 ± 1.0 vs. -1.0 ± 1.6, respectively; P = 0.003) and 3 months (-2.0 ± 1.0 vs. -0.6 ± 1.6, respectively; P = 0.003). There were no severe adverse events pertinent to botulinum toxin injection.

CONCLUSIONS

In patients with complex regional pain syndrome, lumbar sympathetic ganglion block using botulinum toxin type A increased the temperature of the affected foot for 3 months and also reduced the pain.

EDITOR’S PERSPECTIVE

CT-Guided Lumbar Sympathectomy as a Last Option for Chronic Limb-Threatening Ischemia of the Lower Limbs: Evaluation of Technical Factors and Long-Term Outcomes

OBJECTIVE. The purpose of this study was to assess the effects of anatomic and technical factors on the long-term outcome of CT-guided lumbar sympathectomy in patients with chronic limb-threatening ischemia. SUBJECTS AND METHODS. Thirty patients (28 men, two women; mean age, 45.8 years) with chronic limb-threatening ischemia and diffuse tibial arterial disease not amenable to revascularization were included. CT-guided lumbar sympathectomy was performed at the L2-L3 level with a 22-gauge Chiba needle and absolute alcohol. Any periprocedural complication was noted. Numeric pain score (1-10 scale) and skin ulcers were assessed before the procedure and 3 weeks, 3 months, and 1 and 2 years after the procedure. According to spread of alcohol, patients were categorized into those with medial spread and those without medial spread (lateral spread group) with the lateral edge of the vertebral body as the reference point. Treatment results were categorized as improved, unchanged, or worsened on the basis of clinical response. RESULTS. There were 22 (73.3%) patients in the medial spread group and eight (26.7%) in the lateral spread group. The mean volumes of alcohol injected per side were not significantly different (p = .50). One major complication occurred in the group with medial spread. Mean numeric pain scores before the procedure and 3 weeks, 3 months, and 1 and 2 years afterward were 7.31, 2.95, 2.47, 2.10, and 2.04 in the medial spread group and 6.25, 4.13, 4.50, 4.35 and 4.32 in the lateral spread group (p < .001). At 2 years, 16 patients in the medial spread group and two patients in the lateral spread group showed clinical improvement (p < .001), and the limb salvage rates were 100% and 87.5%, respectively. Multivariate analysis showed a trend in improvement with smoking cessation, but the difference was not statistically significant (p = .15). The direction of spread of the neurolytic agent, however, was a major determinant of outcome. CONCLUSION. CT-guided lumbar sympathectomy is a simple, safe, and effective procedure. Ensuring medial spread of the neurolytic agent significantly improves long-term results.

Interventional Radiofrequency Treatment for the Sympathetic Nervous System: A Review Article

Introduction

Interventional techniques such as radiofrequency (RF) treatment can be used to interrupt pain signals transmitted through the sympathetic nervous system (SNS). RF treatments including the pulsed (PRF) and continuous (CRF) modalities show enhanced control over lesion size and enhanced ability to confirm accurate positioning compared to other interventional methods. PRF also acts to reduce the area of the lesion. In this article, we characterize the currently available evidence supporting the use and efficacy of RF treatments in sympathetically mediated pain (SMP) conditions.

Study Design

A comprehensive literature review.

Methods

A PubMed and Cochrane Library database search was performed for human studies applying RF treatment at sympathetic sites (sphenopalatine ganglion, stellate ganglion, cervical, thoracic, or lumbar sympathetic ganglia, celiac plexus, splanchnic nerves, superior hypogastric plexus, and ganglion impar) between January 1970 to May 2020. Data were extracted, summarized into tables, and qualitatively analyzed.

Results

PRF and CRF both show promise in relieving SMP conditions, such as complex regional pain syndrome (CRPS), pain in the perineal region, headache and facial pain, and oncologic and non-oncologic abdominal pain, in addition to other types of pain, with minimal complications. Furthermore, in most comparative studies, outcomes using RF treatments exceeded other interventional techniques, such as anesthetic block and chemical neurolysis.

Conclusions

RF treatments can be effective in carefully selected patients who are refractory to conservative management. However, further randomized controlled studies are needed prior to implementing it into common practice.

Molecular Aspects of Regional Pain Syndrome

The purpose of this review is to summarize the pathophysiology of complex regional pain syndrome (CRPS), the underlying molecular mechanisms, and potential treatment options for its management. CRPS is a multifactorial pain condition. CRPS is characterized by prolonged or excessive pain and changes in skin color and temperature, and/or swelling in the affected area, and is generally caused by stimuli that lead to tissue damage. An inflammatory response involving various cytokines and autoantibodies is generated in response to acute trauma/stress. Chronic phase pathophysiology is more complex, involving the central and peripheral nervous systems. Various genetic factors involved in the chronicity of pain have been identified in CRPS patients. As with other diseases of complex pathology, CRPS is difficult to treat and no single treatment regimen is the same for two patients. Stimulation of the vagus nerve is a promising technique being tested for different gastrointestinal and inflammatory diseases. CRPS is more frequent in individuals of 61–70 years of age with a female to male ratio of 3 : 1. Menopause, migraine, osteoporosis, and asthma all represent risk factors for CRPS and in smokers the prognosis appears to be more severe. The pathophysiological mechanisms underlying CRPS involve both inflammatory and neurological pathways. Understanding the molecular basis of CRPS is important for its diagnosis, management, and treatment. For instance, vagal nerve stimulation might have the potential for treating CRPS through the cholinergic anti-inflammatory pathway.

Lumbar Sympathetic Block with Botulinum Toxin Type A and Type B for the Complex Regional Pain Syndrome

A lumbar sympathetic ganglion block (LSB) is a therapeutic method for complex regional pain syndrome (CRPS) affecting the lower limbs. Recently, LSB with botulinum toxin type A and B was introduced as a novel method to achieve longer duration of analgesia. In this study, we compared the botulinum toxin type A (BTA) with botulinum toxin type B (BTB) in performing LSB on patients with CRPS. LSB was performed with either BTA or BTB on patients with CRPS in their lower extremities. The length of time taken for patients to return to the pre-LSB pain score and the adverse effect of LSB with BTA/BTB were investigated. The median length of time taken for the patients to return to the pre-LSB pain score was 15 days for the BTA group and 69 days for the BTB group (P = 0.002). Scores on a visual analogue scale decreased in the patients of both groups, and no significant adverse effects were experienced. In conclusion, the administration of either BTA or BTB for LSB is a safe method to prolong the sympathetic blocking effect in patients with CRPS. BTB is more effective than BTA to prolong the sympathetic blocking effect in CRPS patients.

Effectiveness of complex regional pain syndrome treatment: A systematic review

Complex regional pain syndrome (CRPS) is a descriptive term for a complex of symptoms and signs typically occurring following trauma of the extremity. Typical symptomatology includes severe pain, swelling, vasomotor instability and functional impairment of the affected limb. At present there is no one, effective method of treatment of the condition. A large number of treatments have been investigated but major multicentre randomized controlled trials are lacking. This study presents the results of a systematic review of the evidence on effectiveness of treatment methods in CRPS. It is a follow-up to earlier reviews of randomized controlled trials on CRPS treatment published between 1966 and 2016.

RESULTS

The review of randomized controlled trials showed that only bisphosphonates were found to give uniformly positive effects, statistically significantly better than placebo. Improvement has been reported with topical dimethyl sulfoxide, systemic steroids, spinal cord stimulation and graded motor imagery/mirror therapy programmes. The available evidence does not support the use of other treatments in CRPS, however they are frequently used in clinical practice.

CONCLUSION

Available evidence, although numerous, does not necessarily reflect what is truly effective and what is sham in the management of CRPS.

Complex Regional Pain Syndrome Type 1: Diagnosis and Management

Diagnosis of Complex regional pain syndrome (CRPS) is made primarily on a clinical basis, and no specific test is known to confirm or exclude CRPS diagnosis. That is, there aren’t specific diagnostic tools and instrumental tests are made only for identifying an etiology at the basis of the CRPS. Numerous therapeutic methods have been introduced, but none have shown definitive results. When symptoms persist, patients experience permanent impairment and disability. Therefore, early recognition of CRPS, along with proper treatment, is important for minimizing permanent loss of function. As there is no gold standard test for CRPS, several clinical diagnostic criteria have been introduced and applied in various studies. However, to date, no formal or standardized diagnostic criteria for CRPS have been widely accepted. However, the Budapest diagnostic criteria have recently increased in popularity and are frequently used in scientific studies. The goal for management of CRPS is the return of normal limb function. No specific technique has been shown to prevent CRPS following surgery, but avoidance of prolonged immobilization may be important. Therefore, initiating early post-surgical rehabilitation, where possible, is important. A multidisciplinary approach would seem to be optimal, above all things objectives of physical and occupational therapy are fulfilled with combination pharmacotherapy due to provide pain relief to facilitate physical rehabilitation. Future research using large randomized controlled trials should focus on collecting strong evidence for the etiology of CRPS, testing pharmacological effects, and determining appropriate combination treatment strategies.

Treatment of complex regional pain syndrome: an updated systematic review and narrative synthesis

PURPOSE

Although multiple treatments have been advocated for complex regional pain syndrome (CRPS), the levels of supportive evidence are variable and sometimes limited. The purpose of this updated review is to provide a critical analysis of the evidence pertaining to the treatment of CRPS derived from recent randomized-controlled trials (RCTs).

SOURCE

The MEDLINE, EMBASE, Psychinfo, and CINAHL databases were searched to identify relevant RCTs conducted on human subjects and published in English between 1 May 2009 and 24 August 2017.

PRINCIPAL FINDINGS

The search yielded 35 RCTs of variable quality pertaining to the treatment of CRPS. Published trials continue to support the use of bisphosphonates and short courses of oral steroids in the setting of CRPS. Although emerging evidence suggests a therapeutic role for ketamine, memantine, intravenous immunoglobulin, epidural clonidine, intrathecal clonidine/baclofen/adenosine, aerobic exercise, mirror therapy, virtual body swapping, and dorsal root ganglion stimulation, further confirmatory RCTs are warranted. Similarly, trials also suggest an expanding role for peripheral sympathetic blockade (i.e., lumbar/thoracic sympathetic, stellate ganglion, and brachial plexus blocks).

CONCLUSIONS

Since our prior systematic review article (published in 2010), 35 RCTs related to CRPS have been reported. Nevertheless, the quality of trials remains variable. Therefore, further research is required to continue investigating possible treatments for CRPS.

Ganglion blocks as a treatment of pain: current perspectives

The inputs from sympathetic ganglia have been known to be involved in the pathophysiology of various painful conditions such as complex regional pain syndrome, cancer pain of different origin, and coccygodynia. Sympathetic ganglia blocks are used to relieve patients who suffer from these conditions for over a century. Many numbers of local anesthetics such as bupivacaine or neurolytic agents such as alcohol can be chosen for a successful block. The agent is selected according to its duration of effect and the purpose of the injection. Most commonly used sympathetic blocks are stellate ganglion block, lumbar sympathetic block, celiac plexus block, superior hypogastric block, and ganglion Impar block. In this review, indications, methods, effectiveness, and complications of these blocks are discussed based on the data from the current literature.

Management of complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a relatively rare, chronic, and debilitating condition that significantly impacts the patient's quality of life. There is an overall paucity of literature addressing the management of CRPS in immunocompromised patients. We define features of CRPS, outline its treatment options, and describe a course of CRPS management for a 35-year-old patient who had heart transplantation requiring immunosuppressive medications.

Does Temperature Increase by Sympathetic Neurolysis Improve Pain in Complex Regional Pain Syndrome? A Retrospective Cohort Study

BACKGROUND

Lumbar sympathetic neurolysis (LSN) is a treatment option for complex regional pain syndrome (CRPS). We examined whether LSN-related temperature changes are associated with clinical outcome and investigated relationships between the outcome of LSN and clinical variables in patients with CRPS-I.

METHODS

We included 95 patients with CRPS-I affecting a single lower extremity, by the Budapest criteria, and who underwent LSN after successful lumbar sympathetic blocks, in this retrospective study. Fluoroscopy-guided LSN was conducted with 1.5 mL of 99% alcohol at L2 and L3 vertebral levels. Positive outcome was defined as a reduction of ≥50% on a numeric rating scale pain score at 6 months after LSN. The relationship between successful outcome and clinical variables was analyzed.

RESULTS

Positive LSN outcome occurred in 49.5% of patients, and it was suggested that Sympathetically maintained pain may accompany CRPS-I in 28% of patients. The overall temperature in the affected limb was increased after LSN, without contralateral limb temperature changes, but did not differ significantly between the positive and negative outcome groups (P = 0.590). Temperature after LSN in warm-type CRPS was reduced in the affected limb, without contralateral limb temperature changes. The absolute temperature change was significantly greater in cold-type than in warm-type CRPS (P = 0.026). In multivariate analysis, a short duration of pain and concurrent cold intolerance were significant factors predicting a positive outcome after LSN.

CONCLUSIONS

LSN may be effective in some patients with CRPS, irrespective of temperature changes and temperature asymmetry pattern. A short duration of pain and concurrent cold intolerance significantly predict successful LSN.

[Complex regional pain syndrome: A review]

BACKGROUND

Complex regional pain syndrome is characterized by spontaneous or induced pain disproportionate in relation to the initial event and is accompanied by a variety of regional and motor disturbances, leading to a variety of clinical presentations. It is often associated with surgery and minor trauma.

PATHOPHYSIOLOGY

Three mechanisms are postulated: changes secondary to post traumatic inflammation, peripheral vasomotor dysfunction and structural and functional changes of the central nervous system as a result of maladaptation.

DIAGNOSIS

made based on the criteria of Budapest. The patient must have one symptom and sign of each criterion at diagnosis: Continuing pain, disproportionate to any inciting event. A sensory, vasomotor, oedema and motor/trophic change sign and symptoms that are not explained by another diagnosis or cause.

TREATMENT

Multimodal treatment is suggested. There is no gold standard. In early stage NSAIDs or steroids can be used. Drugs used for neuropathic pain treatment have been suggested, but there is not enough evidence for any of these. There is low evidence that bisphosphonates, calcitonin, ketamine and mirror therapy are effective compared to placebo. Interventional treatment should be stepped from epidural block, neurostimulation, intrathecal pump to experimental therapies in case of intractable pain.

DISCUSSION

Although complex regional pain syndrome has been a recognized entity for over 100 years, no clear evidence exists for first-line treatments; however, new technologies that are applicable in complex regional pain syndrome treatment have been developed.

[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.

Minimally invasive procedures for neuropathic pain

Neuropathic pain is "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". The prevalence of neuropathic pain ranges from 7 to 11% of the population and minimally invasive procedures have been used to both diagnose and treat neuropathic pain. Diagnostic procedures consist of nerve blocks aimed to isolate the peripheral nerve implicated, whereas therapeutic interventions either modify or destroy nerve function. Procedures that modify how nerves function include epidural steroid injections, peripheral nerve blocks and sympathetic nerve blocks. Neuroablative procedures include radiofrequency ablation, cryoanalgesia and neurectomies. Currently, neuromodulation with peripheral nerve stimulators and spinal cord stimulators are the most evidence-based treatments of neuropathic pain.

[Image-guided pain therapy. Sympathicolysis]

BACKGROUND

In the autonomic nerve system most sympathetic neurons synapse peripherally in the ganglia of the sympathetic trunk. A reduction in sympathicotonia by partial elimination of these ganglia is a therapeutic approach that has been used for more than 100 years. In the early 1920s the first attempts at percutaneous sympathicolysis (SL) were carried out. Nowadays, minimally invasive image-guided SL has become an integral part of interventional radiology. Established indications for SL are hyperhidrosis, critical limb ischemia and the complex regional pain syndrome.

METHODS

The standard imaging guidance modality in SL is computed tomography (CT) which allows the exact placement of the puncture needle in the target area under visualization of the surrounding structures. Ethanol is normally used for chemical lysis, which predominantly eliminates the unmyelinated autonomic axons. In order to visualize the distribution of the ethanol during application, iodine-containing contrast medium is added.

RESULTS

The sympathetic nervous system (SNS) controls sweat secretion via the efferent neurons; therefore, effective therapy of idiopathic palmar, axillary and plantar hyperhidrosis can be achieved when SL is performed at the corresponding level of the sympathetic trunk. Furthermore, due to the vasomotor innervation of most blood vessels, by reduction of the sympathicotonus an atony of the smooth muscles and therefore vasodilatation occurs, which is used as a palliative therapeutic option in patients with critical limb ischemia. By elimination of the afferent sensory fibers this also results in pain relief. This principle is also used in the SL therapy of the complex regional pain syndrome.

CONCLUSION

After the introduction of CT guidance, major complications have become rare events. In addition to the usual risks of percutaneous interventions there are, however, a number of specific complications, such as syncope caused by irritation of cardiac sympathetic nerves in thoracic SL and ureteral injury in lumbar SL.

Lumbar sympathetic treatment in the management of lower limb pain

The sympathetic system has been a target for interventional treatment since the early half of the 20th century. One area targeted for treatment has been the lumbar sympathetics for lower limb pain. Physicians have treated various neuropathic and ischemic conditions employing the use of sympathetic procedures as a mode of treatment, yet the studies strongly supporting the utility of the procedure have been lacking. Anatomic studies have brought to light the complexity and variation that exists with identifying the locations of the ganglion. Studies have investigated the different methods to determine the highest yield and less risky approaches in performing the technique. Many studies have reported positive results with blockade and neurolysis, but review of the literature reveals poor strength quality and small sample population. These reports should be viewed as building blocks for more robust investigation. Interpretation of the results should be performed with caution, and translation into common practice implemented on a case by case basis.

Successful treatment of severe sympathetically maintained pain following anterior spine surgery

Sympathetic dysfunction is one of the possible complications of anterior spine surgery; however, it has been underestimated as a cause of complications. We report two successful experiences of treating severe dysesthetic pain occurring after anterior spine surgery, by performing a sympathetic block. The first patient experienced a burning and stabbing pain in the contralateral upper extremity of approach side used in anterior cervical discectomy and fusion, and underwent a stellate ganglion block with a significant relief of his pain. The second patient complained of a cold sensation and severe unexpected pain in the lower extremity of the contralateral side after anterior lumbar interbody fusion and was treated with lumbar sympathetic block. We aimed to describe sympathetically maintained pain as one of the important causes of early postoperative pain and the treatment option chosen for these cases in detail.

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.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Is section of the sympathetic rami communicantes by laparoscopy in patients with refractory low back pain efficient?

OBJECTIVE

The objective of this prospective innovative treatment is to section the pain pathways carried by sympathetic lumbar rami communicantes to achieve lasting pain relief of refractory low back pain.

METHODS

From December 2005 to September 2008, nine patients were operated by bilateral section of rami communicantes for a refractory low back pain. As a diagnostic and predictive test, all patients had, before surgery, a local anaesthetic infiltration of the sympathetic trunk at L2 performed with computed tomography guidance. Surgery is indicated if the tests lead to a reduction in pain of at least 50 %. The procedure, using a retroperitoneal laparoscopic approach, consisted to identify the sympathetic trunk and to section all lumbar rami communicantes from L1 to L2.

RESULTS

No intraoperative complications were observed. The mean postoperative follow-up was 29 ± 15 months. At the last follow-up, only 22 % (2/9) patients had an improvement of their low back pain with this surgery but with a minimal effect (30 and 50 % reduction of pain). An improvement of quality of life was observed in 33 % (3/9) of cases. Due to persistent pain, four patients had a spinal cord stimulation after this surgery.

CONCLUSIONS

Section the pain pathways carried by sympathetic lumbar rami communicantes for refractory low back pain improved 22 % of patients at the last follow-up of 29 months.

Stellate ganglion blockade (SGB) for refractory index finger pain - a case report

OBJECTIVE

To identify through case study the presentation and possible pathophysiological cause of complex regional pain syndrome and its preferential response to stellate ganglion blockade.

SETTING

Complex regional pain syndrome can occur in an extremity after minor injury, fracture, surgery, peripheral nerve insult or spontaneously and is characterised by spontaneous pain, changes in skin temperature and colour, oedema, and motor disturbances. Pathophysiology is likely to involve peripheral and central components and neurological and inflammatory elements. There is no consistent approach to treatment with a wide variety of specialists involved. Diagnosis can be difficult, with over-diagnosis resulting from undue emphasis placed upon pain disproportionate to an inciting event despite the absence of other symptoms or under-diagnosed when subtle symptoms are not recognised. The International Association for the Study of Pain supports the use of sympathetic blocks to reduce sympathetic nervous system overactivity and relieve complex regional pain symptoms. Educational reviews promote stellate ganglion blockade as beneficial. Three blocks were given at 8, 10 and 13 months after the initial injury under local anaesthesia and sterile conditions. Physiotherapeutic input was delivered under block conditions to maximise joint and tissue mobility and facilitate restoration of function.

CONCLUSION

This case demonstrates the need for practitioners from all disciplines to be able to identify the clinical characteristics of complex regional pain syndrome to instigate immediate treatment and supports the notion that stellate ganglion blockade is preferable to upper limb intravenous regional anaesthetic block for refractory index finger pain associated with complex regional pain syndrome.

Minimal access is not maximal safety: pelviureteric necrosis following percutaneous chemical lumbar sympathectomy

Lumbar sympathectomy remains popular in the treatment of a variety of painful and circulatory conditions of the lower extremities. Although percutaneous chemical lumbar sympathectomy (PCLS) under radiographic guidance is minimally invasive and has decreased the need for open surgical sympathectomy, inadvertent damage to neighbouring structures is a matter for concern. We report the case of a 38-year-old man with thromboangiitis obliterans who had PCLS under radiographic guidance for relief of ischaemic rest pain that was complicated by necrotic disruption of the left pelviureteric region. The kidney was salvaged with an ureterocalycostomy and he remains well 4 years later. Such complications point to imprecise and unpredictable spread of the injected chemical too far beyond the needle tip. It is possible that such complications are often under reported and, therefore, not taken into consideration during informed consent. Precise neurolysis with laser and radiofrequency may be a safer alternative.

Evidence-based interventional pain medicine according to clinical diagnoses. 16. Complex regional pain syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A-). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).

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.

Approach-related lesions of the sympathetic chain in anterior correction and instrumentation of idiopathic scoliosis

During anterior scoliosis instrumentation with a dual-rod system, the vertebrae are dissected anterolaterally. After surgery, some patients report a change in temperature perception and perspiration in the lower extremities. Sympathetic lesions might be an explanation for this. The aim of this clinical study was to investigate sympathetic function after anterior scoliosis instrumentation. A total of 24 female patients with idiopathic scoliosis (mean age at follow-up, 23.8 years) who had undergone anterior instrumentation on average 6.6 years earlier were included. Due to the suspected relevance of the sympathetic L2 ganglion, two groups were created: a T12 group, in which instrumentation down to T12 was carried out (n = 12), and an L3 group, in which instrumentation down to L3 was done (n = 12). Sympathetic function was assessed by measuring skin temperature at the back of the foot, a plantar ninhydrin sweat test and sympathetic skin responses (SSRs) following electrical stimulation. The side on which the surgical approach was carried out was compared with the contralateral, control side. Health-related quality of life was investigated using the Scoliosis Research Society SRS-22 patient questionnaire. In the T12 group, mean temperatures of 29.6 degrees C on the side of the approach versus 29.5 degrees C on the control side were measured (P > 0.05); in the L3 group, the mean temperatures were 33.2 degrees C on the approach side versus 30.5 degrees C on the control side (P = 0.001). A significant difference between the T12 group and the L3 group (P < 0.001) was observed on the approach side, but not on the control side (P = 0.15). The ninhydrin sweat test showed reduced perspiration in 11 of 12 patients in the L3 group on the approach side in comparison with the control side (P = 0.002). In the T12 group, no significant differences were noted between the left and right feet. SSRs differed significantly between the two groups (P = 0.005). They were detected in all nine analyzable patients in the T12 group on both sides. In the L3 group, they were found on the approach side only in 4 of 11 analyzable patients versus 11 patients on the control side. The results of the SRS-22 questionnaire did not show any significant differences between the two groups. In conclusion, anterior scoliosis instrumentation with a dual-rod system including vertebrae down to L3 regularly leads to lesions in the sympathetic trunk. These are detectable with an increase in temperature, reduced perspiration and reduced SSRs. The caudal level of instrumentation (T12 vs. L3) has an impact on the extent of impairment, supporting the suspected importance of the L2 ganglion. The clinical outcome does not seem to be significantly limited by sympathetic trunk lesions.

Treatment of complex regional pain syndrome: a review of the evidence

PURPOSE

This narrative review summarizes the evidence derived from randomized controlled trials pertaining to the treatment of complex regional pain syndrome (CRPS).

SOURCE

Using the MEDLINE (January 1950 to April 2009) and EMBASE (January 1980 to April 2009) databases, the following medical subject headings (MeSH) were searched: "Complex Regional Pain Syndrome", "Reflex Sympathetic Dystrophy", and "causalgia" as well as the key words "algodystrophy", "Sudeck's atrophy", "shoulder hand syndrome", "neurodystrophy", "neuroalgodystrophy", "reflex neuromuscular dystrophy", and "posttraumatic dystrophy". Results were limited to randomized controlled trials (RCTs) conducted on human subjects, written in English, published in peer-reviewed journals, and pertinent to treatment.

PRINCIPAL FINDINGS

The search criteria yielded 41 RCTs with a mean of 31.7 subjects per study. Blinded assessment and sample size justification were provided in 70.7% and 19.5% of RCTs, respectively. Only biphosphonates appear to offer clear benefits for patients with CRPS. Improvement has been reported with dimethyl sulfoxide, steroids, epidural clonidine, intrathecal baclofen, spinal cord stimulation, and motor imagery programs, but further trials are required. The available evidence does not support the use of calcitonin, vasodilators, or sympatholytic and neuromodulative intravenous regional blockade. Clear benefits have not been reported with stellate/lumbar sympathetic blocks, mannitol, gabapentin, and physical/occupational therapy.

CONCLUSIONS

Published RCTs can only provide limited evidence to formulate recommendations for treatment of CRPS. In this review, no study was excluded based on factors such as sample size justification, statistical power, blinding, definition of intervention allocation, or clinical outcomes. Thus, evidence derived from "weaker" trials may be overemphasized. Further well-designed RCTs are warranted.

Evidence based guidelines for complex regional pain syndrome type 1

Background

Treatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I.

Method

A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according to their strength of evidence, published between 1980 to June 2005. Treatment recommendations based on the literature findings were formulated and formally approved by all Dutch professional associations involved in CRPS-I treatment.

Results

For pain treatment, the WHO analgesic ladder is advised with the exception of strong opioids. For neuropathic pain, anticonvulsants and tricyclic antidepressants may be considered. For inflammatory symptoms, free-radical scavengers (dimethylsulphoxide or acetylcysteine) are advised. To promote peripheral blood flow, vasodilatory medication may be considered. Percutaneous sympathetic blockades may be used to increase blood flow in case vasodilatory medication has insufficient effect. To decrease functional limitations, standardised physiotherapy and occupational therapy are advised. To prevent the occurrence of CRPS-I after wrist fractures, vitamin C is recommended. Adequate perioperative analgesia, limitation of operating time, limited use of tourniquet, and use of regional anaesthetic techniques are recommended for secondary prevention of CRPS-I.

Conclusions

Based on the literature identified and the extent of evidence found for therapeutic interventions for CRPS-I, we conclude that further research is needed into each of the therapeutic modalities discussed in the guidelines.

Endoscopic lumbar sympathectomy for plantar hyperhidrosis

Background

The aim of this study was to evaluate the results of endoscopic lumbar sympathectomy for plantar hyperhidrosis.

Methods

A total of 178 endoscopic resections of the lower sympathetic lumbar trunk were carried out in 90 patients (59 men, 31 women) with severe plantar hyperhidrosis. The clinical results, including morbidity and satisfaction rates, were evaluated. Follow-up examination was carried out for all patients after a mean follow-up of 24 (range 3–45) months.

Results

All procedures were carried out endoscopically. There were no deaths and only three patients had a postoperative complication. All patients had evidence of postoperative sympathetic denervation of the feet. In 87 patients (97 per cent) hyperhidrosis was eliminated, but in three (3 per cent) it recurred. Compensatory sweating occurred in 40 patients (44 per cent), postsympathectomy neuralgia in 38 (42 per cent) and one man suffered temporary loss of ejaculation. A total of 86 patients (96 per cent) were very, or partly, satisfied with the result, and 83 (92 per cent) would have the procedure repeated if required.

Conclusion

Endoscopic lumbar sympathectomy was a safe and effective option for patients with severe plantar hyperhidrosis.

Sympathetic block with botulinum toxin to treat complex regional pain syndrome

Complex regional pain syndrome is a refractory pain condition with few tested therapies. We hypothesized that botulinum toxin A (BTA) would prolong analgesia after sympathetic blocks in patients with complex regional pain syndrome. We compared the duration of standard lumbar sympathetic block (LSB) with bupivacaine to LSB with bupivacaine and BTA in nine patients with refractory complex regional pain syndrome. Median time to analgesic failure was 71 (95% confidence interval, 12-253) days after LSB with BTA compared with fewer than 10 days (95% confidence interval, 0-12) after standard LSB (log-rank, p < 0.02). BTA profoundly prolonged the analgesia from sympathetic block in this preliminary study.