Chemical sympathectomy for neuropathic pain: does it work? Case report and systematic literature review.

OBJECTIVE: To determine if chemical sympathectomy successfully reduces limb neuropathic pain. DESIGN: Systematic literature review of the effectiveness of phenol or alcohol sympathectomy for extremity neuropathic pain. PATIENT: A 29-year-old female with complex regional pain syndrome of both lower extremities after back surgery who was submitted to bilateral lumbar chemical sympathectomy. SEARCH STRATEGY: The Cochrane Database of Systematic Reviews, the Cochrane Controlled Trials Register, Medline, and EMBASE were systematically searched. OUTCOME MEASURES: (1) For the patient in question: spontaneous pain, allodynia, pinprick hyperalgesia, pressure evoked pain; (2) For the literature review: meaningful versus nonmeaningful pain relief based on degree and duration (>2 weeks) of pain relief. RESULTS: (1) The case reported experienced partial temporary relief of pain primarily related to selective modulation of allodynia, but not deep pain or pinprick hyperalgesia; (2) 44% of 66 patients in 13 studies that met the authors' inclusion criteria experienced meaningful pain relief. Whereas 19% experienced no meaningful relief, for the remaining 37% of the patients no conclusions regarding duration and degree of relief could be drawn due to poor reporting of outcomes. CONCLUSIONS: Based on the case reported and systematic literature review, chemical sympathectomy seems to have at best a temporary effect, limited to cutaneous allodynia. Despite the popularity of chemical sympatholysis, only few patients and poorly defined outcomes are reported in the literature, substantiating the need for well-designed studies on the effectiveness of the procedure.     

Vom Rollstuhl zur Gehfähigkeit

A 34-year-old woman developed walking disability with wheelchair dependency for more than 2 years due to chronic regional pain syndrome type II (CRPS II) in the feet. After excluding neurological and vascular disease, lumbar sympathectomy was performed on both sides. Surgical treatment was uneventful, and the patient’s symptoms dramatically improved after 2 months. She is now able to walk some 500 m. This case illustrates the fact that surgical lumbar sympathectomy is an effective alternative or adjunct treatment even in fixed CRPS II.     

Continuous lumbar sympathetic block.

A 74-year-old woman with peripheral vascular disease suffered from rest pain in the right big toe and intermittent claudication. Because of concomitant venous congestion, a chemical lumbar sympathectomy was considered to carry an increased risk of leg edema. A continuous lumbar sympathetic block with local anesthetic abolished the pain in the toe without side effects. After this reversible block, a chemical lumbar sympathectomy was performed producing pain relief for 4 weeks when the patient was last seen.     

Regional Lumbar Motion and Patient-Rated Outcomes: A Secondary Analysis of Data From a Randomized Clinical Trial

ObjectiveThe purpose of this study was to examine the relationship in change scores between regional lumbar motion and patient-rated pain of the previous week and back-related function in chronic low back pain patients enrolled in a randomized clinical trial and treated with either exercise therapy or spinal manipulation using 6 different motion parameters.MethodsRegional lumbar motions were sampled using a 6 degrees of freedom instrumented spatial linkage system in 199 participants at baseline and 12-week follow-up. The regional lumbar motion data were analyzed as a total cohort as well as relative to subgroup stratifications; back pain only vs back and leg pain, and treatment modality. For identifying clinically meaningful improvements in the measurements of back pain and back-related function, we used a 30% threshold.ResultsThe relationship between change scores in patient-rated outcomes and objective measures of regional lumbar motion was found to be weak. In contrast, distribution of pain and treatment received affected associations between motion parameters and patient-rated outcomes. Thus, stronger correlation coefficients and significant differences between clinically relevant improved vs no clinical relevant change were found in some motion parameters in the subgroup with back pain only and the treatment group receiving spinal manipulation.ConclusionOverall, changes in regional lumbar motion were poorly associated with patient-rated outcomes measured by back-related function and back pain intensity scores. However, associations between regional lumbar motion vs patient-rated pain and back-related function were different in relative subgroups (back pain only vs back and leg pain and treatment).     

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

The purpose of this article was to systematically review the literature in order to assess (1) the current indications for surgical sympathectomy and (2) the incidence of late complications collectively and per indication. All types of upper or lower limb surgical sympathectomies are included. An extensive search strategy looked for controlled trials and observational studies or case series with an english abstract. Out of 1,024 abstracts from MEDLINE and 221 from EMBASE, 135 articles reporting on 22,458 patients and 42,061 procedures (up to april 1998) fulfilled the inclusion criteria. Weighted means were used to control for heterogeneity of data. No controlled trials were found. The main indication was primary hyperhidrosis in 84.3% of the patients. Compensatory hyperhidrosis occurred in 52.3%, gustatory sweating in 32.3%, phantom sweating in 38.6%, and horner's syndrome in 2.4% of patients, respectively, with cervicodorsal sympathectomy, more often after open approach. Neuropathic complications (after cervicodorsal and lumbar sympathectomy) occurred in 11.9% of all patients. Compensatory hyperhidrosis occurred 3 times more often if the indication was palmar hyperhidrosis instead of neuropathic pain (52.3% versus 18.2%), whereas neuropathic complications occurred 3 times more often if the treatment was for neuropathic pain instead of palmar hyperhidrosis (25.2% versus 9.8%). Surgical sympathectomy, irrespective of approach, is accompanied by several potentially disabling complications. Detailed informed consent is recommended when surgical sympathectomy is contemplated.     

Sympathectomy does not abolish bradykinin-induced cutaneous hyperalgesia in man.

Bradykinin is an endogenous peptide that is thought to be a chemical mediator of the hyperalgesia following inflammation. In rat, bradykinin has been postulated to cause hyperalgesia to mechanical stimuli by releasing prostaglandin from sympathetic post-ganglionic terminals. The aim of this study was to determine whether bradykinin-induced cutaneous hyperalgesia in humans requires post-ganglionic sympathetic terminals. In humans, intradermal injection of bradykinin produces dramatic hyperalgesia to heat but not mechanical stimuli. Therefore, we measured the magnitude and duration of pain and hyperalgesia to heat stimuli following intradermal injection of bradykinin into the leg of a woman before and 6 months after an ipsilateral, surgical, lumbar sympathectomy. The pain and hyperalgesia to heat following bradykinin was found to be unaffected by the sympathectomy. These results suggest that the algesic effects of cutaneous bradykinin in human are independent of the sympathetic nervous system.     

Lumbar Sympathectomy Attenuates Cold Allodynia But Not Mechanical Allodynia and Hyperalgesia in Rats With Spared Nerve Injury

In certain patients with neuropathic pain, the pain is dependent on activity in the sympathetic nervous system. To investigate whether the spared nerve injury model (SNI) produced by injury to the tibial and common peroneal nerves and leaving the sural nerve intact is a model for sympathetically maintained pain, we measured the effects of surgical sympathectomy on the resulting mechanical allodynia, mechanical hyperalgesia, and cold allodynia. Decreases of paw withdrawal thresholds to von Frey filament stimuli and increases in duration of paw withdrawal to pinprick or acetone stimuli were observed in the ipsilateral paw after SNI, compared with their pre-SNI baselines. Compared with sham surgery, surgical lumbar sympathectomy had no effect on the mechanical allodynia and mechanical hyperalgesia induced by SNI. However, the sympathectomy significantly attenuated the cold allodynia induced by SNI. These results suggest that the allodynia and hyperalgesia to mechanical stimuli in the SNI model is not sympathetically maintained. However, the sympathetic nervous system may be involved, in part, in the mechanisms of cold allodynia in the SNI model. PERSPECTIVE: The results of our study suggest that the SNI model is not an appropriate model of sympathetically maintained mechanical allodynia and hyperalgesia but may be useful to study the mechanisms of cold allodynia associated with sympathetically maintained pain states.     

The effect of lumbar sympathectomy in the spinal nerve ligation model of neuropathic pain.

To evaluate the sympathetic dependency of pain behaviors in an animal model of neuropathic pain, the effect of surgical sympathectomy on the mechanical sensitivity of the hindpaw was examined in rats with L5 spinal nerve ligation. Mechanical sensitivity was determined by measuring foot withdrawal thresholds to mechanical stimulation with von Frey filaments applied to the base of the third or fourth toe. Tight ligation of the segmental L5 spinal nerve led to the development of mechanical hypersensitivity in the hindpaw. The effects of 2 different procedures of surgical lumbar sympathectomy on mechanical hypersensitivity were compared, limited (resection of sympathetic chain/ganglia L2 to L4 segments) and extensive (resection of L2 to L6 segments) sympathectomies. Mechanical hypersensitivity produced by L5 spinal nerve ligation was partially but significantly reduced by both sympathectomy procedures. In a separate group of rats, the L5 spinal nerve was ligated while irritating the neighboring L4 spinal nerve. This procedure produced a lesser degree of mechanical hypersensitivity, and subsequent sympathectomy had no effect on these animals. These data suggest that sympathectomy is effective in this model only when the animals show severe mechanical hypersensitivity.     

The Role of radiofrequency in the management of complex regional pain syndrome

The nomenclature, pathophysiology, and treatment modalities of complex regional pain syndrome (CRPS) are controversial. Thus far there are no specific, scientifically valid treatments for the management of CRPS. The numerous modalities of treatment range from sympathetic ganglion blocks, intravenous regional blocks, administration of a multitude of pharmacologic agents and behavioral interventions, to surgical sympathectomy. Minimally invasive radiofrequency lesioning for managing CRPS is a modality in its developmental stages. This article describes radiofrequency lesioning techniques in managing CRPS.     

Renal protective function in surgical treatment for chronic infrarenal aortic aneurysms

The authors analyzed different modes of prevention of acute renal failure (ARF) in the planned surgical treatment of abdominal aortic aneurysms. A hundred patients randomly divided into 4 groups were examined. In patients from a control group, prevention of renal failure included no use of aminoglycosides, prevention of hyperglycemia, and provision of steady-state hemodynamics. In Group 2 patients, the reperfusion syndrome was prevented through a preventive load and early administration of antioxidants, for which they were enterally fed with Berlamine-modular for 5 days before surgery and in the postoperative period. The authors made efforts for Group 3 patients to have high oxygen supply values at all stages of surgical treatment. For this, they optimized infusion therapy and compensated for intraoperative blood loss by preoperatively prepared autoblood and through reinfusion of the blood collected from an operation wound with "Cell saver" apparatus. In Group 4 patients, the prevention of ischemia and reperfusion were simultaneously made and blood oxygen-transporting function was optimized. Renal function was evaluated from the activity of urinary enzymes and from nitrogen metabolic parameters. The studies have indicated that activation of free radical lipid peroxidation in the presence of ischemia/reperfusion and blood oxygen-transporting dysfunction plays an important role in the genesis of renal failure during surgical treatment for infrarenal aortic aneurysms. According to the data on changes occurring in urinary enzymatic activities, the preventive load with antioxidants and their early postoperative use ameliorate renal lesion. The similar effect is achieved by the provision of high tissue oxygen supply and uptake at all the stages of surgical treatment. The best effect shown, in addition to enzymuria diminution, by a clinical reduction in the frequency of renal dysfunction is achieved by applying a comprehensive approach to preventing ARF.     

Our Experience with Spinal Cord Stimulation (SCS) In Peripheral Vascular Disease

Spinal cord stimulation (SCS) by epidural electrodes is being used more often in the treatment of patients with severe intractable ischemic pain. The promising clinical results and the objective increase in lower extremity blood flow (plethysmography, thelethermography, etc.), suggests that spinal cord stimulation may have an important role in the management of advanced arterial disease when other forms of treatment have failed. The selection criteria for implantation of SCS are very important. Our indications in patients with peripheral vascular disease are: 1. Peripheral vascular disease with severe, intractable symptoms that are untreatable by medical or surgical therapy. 2. Inflammatory or diabetic arterial disease resistant to medical treatment and/or sympathectomy. 3. Persistent and severe ischemic pain and/or ulcers in patients with patent grafts. 4. Patients for lumbar sympathectomy who have a high myocardial risk. Contraindications to implantation of SCS are claudication intermittent, large necrotic lesions (gan-grene) and patients who have undergone prolonged narcotic therapy.     

Feasability of a back school assessment programme]

OBJECTIVES: Testing the feasability of a back school assessment programme in two populations of people suffering with chronic low back pain. MATERIAL: Twenty-nine patients were randomly included in a chronic low back pain assessment programme (15 patients waiting for back school and 14 patients after back school). METHODS: The programme was made of the measure of the age, the sex, the body mass index, the pain (VAS, St Antoine Hospitals Pain Questionnaire - SAPQ), the anxiety, the depression, the RIII nociceptive reflex, the fingertip-floor distance, the strength of the flexors and of the extensors of the lumbar spine (CybexR 6000 isocinetic dynamometer), the lumbar function (EIFEL, Dougados), the Dallas self-questionnaire. The Back School Education programme was made of five sessions (information, ergonomics, extension exercises). RESULTS: Comparing the two populations we did not observe significant differences concerning the age, the body mass index, the anxiety and depression levels, the pain (VAS, SAPA, RIII nociceptive reflex), the lumbar stiffness, the lumbar disability, the quality of life; the patients who had achieved back school had a peak torque of the flexors and a ratio flexors/extensors significantly lower. Comparing men and women we observed significant differences in the SAPQ and the muscles strength. The SAPQ was correlated with the depression and anxiety levels, the lumbar disability, the peak torque of the flexors. The VAS was correlated with the age, the lumbar stiffness, the depression level, the peak torque of the flexors. The RIII nociceptive reflex was correlated with the ratio flexors/extensors. CONCLUSION: This study present some biases but this objective assessment of chronic low back pain appeared as feasible. The pain must be investigated in term of intensity, expression, alleviation. The impairment of the flexors muscles in women and after back school has to be confirmed. The different tests are relevant to determinate the efficiency of the back school programmes.     

Chronic regional pain syndrome, type 1: Part I

Chronic regional pain syndrome refers to a class of disorders thought to involve common neuropathic and clinical features. These disorders usually are caused by injury, and they manifest in pain and sensory changes that are disproportionate in intensity, distribution, and duration to the underlying pathology. The result of these injuries is significant impairment of motor function over time. This article is divided into two parts. Part I discusses background information such as pain, pathophysiology, diagnosis, clinical stages, and the most common treatment modality, sympathetic nerve blocks. Part II, discusses alternate treatment modalities, such as sympathectomy, physical therapy, stimulators, trigger point injections, acupuncture, tourniquet effects, placebo effects, and amputation.     

胸腔镜下胸部交感神经切断术治疗手掌多汗症

胸腔镜下胸部交感神经切断术治疗手掌多汗症１２８例，其手术创伤小，手术方法简单、安全、手术时间短、术后恢复快，疗效可靠。本方法作为微外科术式对手掌多汗症病人而言是值得提倡的。     

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.     

Neurosurgery (68)

Microinvasive transaxillary thoracoscopic sympathectomy: technical note. (Presbyterian University Hospital, Pittsburgh, PA) Neurosurgery 2000;46:1254–1258. This report describes a two‐port transaxillary thoracoscopic approach for thoracic sympathectomy that maximizes working space, improves manipulative ability, and enhances visualization of the surgical field. Positioning of the patients was optimized to displace the scapula posteriorly, widen the avenue of approach to the sympathetic ganglia, and create a more direct route to the target. The semi‐Fowler position permitted the lung apex to fall away from mediastinal structures, obviating a separate retraction port. A 30‐degree endoscope allowed an unobstructed view of surgical progress, and anatomic relationships were manipulated in a temporal sequence to facilitate dissection. Microinvasive transaxillary sympathectomy was performed successfully in 13 patients, all of whom had a good outcome without complications. Conclude the modifications implemented increase the speed and safety of thoracoscopic sympathectomy while minimizing complications. Comment by R. Ruiz‐López, MD. Thoracic sympathectomy is an accepted means of treating hyperhidrosis, Raynaud's disease, causalgia major and other autonomically mediated syndromes. The authors describe a two‐port transaxillary thoracoscopic approach that maximizes working space, improves manipulative ability, and enhances visualization of the surgical field, advocating a lateral decubitus semi‐Fowler position. A total of 13 patients were treated, 11 with reflex sympathetic dystrophy (complex regional pain syndrome type I (CRPS I)) and 2 with palmar hyperhidrosis. Interestingly, the authors excellent outcomes for CRPS I, not reflecting the experience of most practitioners. Thoracoscopic sympathectomy is evolving quickly since first described by Klux in 1951. From a technical standpoint, the authors describe a useful procedure of endoscopic thoracic sympathectomy that is worthy of further investigation as the series is limited to only 13 patients and in a larger series come complications would be encountered.     

Effects of purinergic and adrenergic antagonists in a rat model of painful peripheral neuropathy

In previous studies, pain behaviors produced in the spinal nerve ligation rat model of neuropathic pain were partly reduced by surgical lumbar sympathectomy. However, systemic injection of phentolamine, an alpha-adrenoceptor blocker, was not effective in reducing pain behaviors, at least in the Sprague-Dawley strain of rats. This suggests that sympathectomy removes not only adrenoceptor function but also other factors that must contribute importantly to the generation of neuropathic pain behaviors. Since the purinergic substance adenosine 5'-triphosphate (ATP) is known to be co-released with norepinephrine (NE) from the sympathetic nerve terminals, we hypothesized that ATP might be involved in the sympathetic dependency of neuropathic pain. The present study tested this hypothesis by examining the effects of systemic injection of an adrenoceptor blocker (phentolamine), a purinoceptor blocker (suramin), and a combination of these two on behavioral signs of mechanical allodynia in the spinal nerve ligation model of neuropathic pain. The results of the present study showed two novel findings. First, the mechanical hypersensitivity (allodynia) resulting from the L5/6 spinal nerve ligation can be reduced either by sympathetic block accomplished by application of a local anesthetic or by surgical sympathectomy of the L2-L6 sympathetic ganglia. Second, suramin (at 100 mg/kg, i.p.) can reduce mechanical hypersensitivity in neuropathic rats when given in combination with 5 mg/kg of phentolamine. This effect was observed in a subset of neuropathic rats, and the drug responses were consistent in repeated treatments within the animal group. Neither phentolamine nor suramin changed the mechanical sensitivity of neuropathic rats when given alone. The data suggest that the purinergic substance ATP is co-released with NE from sympathetic nerve terminals and these two are together involved, at least in part, in the maintenance of the sympathetically dependent component of pain behaviors in some neuropathic rats.     

Multimodale Therapie bei chronischem HWS- und LWS-Schmerz

BACKGROUND: Multimodal therapy has been established for patients with chronic low back pain, but studies reporting results in patients with chronic neck pain are rare. METHODS: This prospective clinical study compared the results in 97 patients with chronic cervical pain and 231 patients with chronic lumbar pain after three weeks of multimodal therapy. The following factors were analyzed in both groups at the beginning and after 6 months: ability to work, pain intensity and functional back capacity. RESULTS: Both groups had improved significantly after 6 months in all outcome parameters. Functional back capacity and ability to work at 6 months were not different between the two groups, but pain intensity was significantly lower in patients with low back pain compared to patients with neck pain. CONCLUSION: Multimodal therapy is also an efficient treatment strategy for patients with chronic cervical pain as has already been shown for patients with chronic lumbar pain.     

MRI-guided treatment of degenerative spinal diseases

Summary

In the treatment of degenerative spinal diseases, CT-guided local injections, RF or ethanol denervation of facet joints and laser decompression of herniated intervertebral disks offer a precisely aimed and effective option in cases of back pain and sciatica. As CT involves significant exposure of the patient to ionising radiation, we evaluated the feasibility of MR-guided therapy. MRI offers a variety of advantages, such as excellent soft-tissue contrast, high flow and temperature sensitivity, and arbitrary slice orientation within a 3D data set. The recently-introduced low-field open magnets, though of compromising imaging capabilities, have considerably facilitated access to the patient. The use of instruments and ancillary equipment, however, is made difficult by the high magnetic field and sensitive RF system of the MRI scanner. The techniques of MR-guided injection and using MR-compatible cannulae were developed and tested with ex vivo specimens of the spine and animal phantoms. 184 patients were treated with periradicular corticoid injections, six patients with laser decompression, 21 patients with neurolysis of facet joints and 16 patients underwent chemical lumbar sympathectomy. MR-guidance is feasible and the early clinical results are promising and comparable to those of CT-guided pain therapy. Further technical improvement of MR technology are required to facilitate the procedures.     

Other Surgical Interventions

Abstract:   Optimal management of patients with chronic neuropathic pain requires a multidisciplinary approach that may include surgery. Yet despite the fact that lumbosacral spinal surgery, for example, is performed in thousands of patients every year, there is very little controlled clinical data to support its use or that of other surgical techniques in the treatment of chronic nonmalignant pain, especially neuropathic pain. Nevertheless, there is evidence of some success for ablative techniques such as dorsal root entry zone lesioning for phantom limb pain and girdle-zone neuropathic pain, and sympathectomy for the treatment of complex regional pain syndrome, and a variety of operations for tic douloureux. However, before considering a surgical procedure, a nonsurgical approach should have been tried and the suitability of the patient must be carefully assessed. To fully establish the role of surgery in the treatment of chronic neuropathic pain, further well-designed, prospective, controlled trials are essential.