Spinal cord stimulation in diabetic lower limb critical ischaemia: transcutaneous oxygen measurement as predictor for treatment success

Disease applications of spinal cord stimulation: Chronic nonmalignant pain

Neuropathic pain is a chronic condition representing a significant burden for society. It is estimated 1 out of 10 people over the age of 30 that in the US have been diagnosed with neuropathic pain. Most of the available treatments for neuropathic pain have moderate efficacy over time which limit their use; therefore, other therapeutic approaches are needed for patients. Spinal cord stimulation is an established and cost-effective modality for treating severe chronic pain. In this article we will review the current approved indications for the use of spinal cord stimulation in the US and the novel therapeutic options which are now available using this therapy.

Analyses of transcutaneous oxygen pressure values stratified for foot angiosomes to predict diabetic foot ulcer healing

AIMS

Previous research suggested that diabetic foot ulcer (DFU) location could affect transcutaneous oxygen pressure (TcPO2) values following the angiosome concept. Up to our knowledge no studies have yet analyzed if the location of a diabetic foot ulcer can be a confounding factor that modifies TcPO2 values. The primary aim of this study was to compare the potential healing prognosis of TcPO2 differentiated for diabetic foot ulcers in different angiosome locations.

METHODS

a 2-years observational cohort prospective study was performed in 81 patients with diabetic foot ulcers. Transcutaneous oxygen pressure measurements were performed at baseline by placing the electrode on two different angiosomes: dorsal zone of the foot (dorsalis pedis angiosome) and between the navicular bone and the tibial malleolus (posterior tibial angiosome). The main outcome was establishing the effectiveness of TcPO2 measurements (dorsalis pedis angiosome and posterior tibial angiosome) for predicting DFU healing.

RESULTS

Transcutaneous oxygen pressure probe placed in the dorsum of the foot (dorsalis pedis angiosome) yielded a sensitivity (S) of 95 % and specificity (SP) of 73 %, and an area under the curve (AUC) of 0.902 (p < 0.001 [0.84-0.96]) for ulcers located in the forefoot and toes; while TcPO2 placed in the posterior tibial angiosome yielded an S of 100 % and SP of 85 % and an AUC of 0.894 (p < 0.001 [0-822-0.966]) for DFU located in the midfoot and heel.

CONCLUSION

This study suggests that angiosome-guided TcPO2 contributes to a prognosis of successful foot ulcer healing.

Quantitative assessment of painful diabetic peripheral neuropathy after high-frequency spinal cord stimulation: a pilot study

OBJECTIVE

Randomized trials have demonstrated efficacy of spinal cord stimulation (SCS) for treatment of painful diabetic neuropathy (PDN). Preliminary data suggested that treatment of PDN with high-frequency SCS resulted in improvements on neurological examination. The purpose of the present study was to explore whether patients with PDN treated with high-frequency SCS would have improvements in lower-extremity peripheral nerve function.

DESIGN

Prospective cohort study in an outpatient clinical practice at a tertiary care center.

METHODS

Patients with PDN were treated with high-frequency SCS and followed up for 12 months after SCS implantation with clinical outcomes assessments of pain intensity, neuropathic symptoms, and neurological function. Small-fiber sudomotor function was assessed with the quantitative sudomotor axon reflex test (QSART), and large-fiber function was assessed with nerve conduction studies (NCS). Lower-extremity perfusion was assessed with laser Doppler flowmetry.

RESULTS

Nine patients completed 12-month follow-up visits and were observed to have improvements in lower-extremity pain, weakness, and positive sensory symptoms. Neuropathy impairment scores were improved, and 2 patients had recovery of sensory responses on NCS. A reduction in sweat volume on QSART was observed in the proximal leg but not at other sites. No significant differences were noted in lower-extremity perfusion or NCS as compared with baseline.

CONCLUSIONS

The improvement in pain relief was concordant with improvement in neuropathy symptoms. The findings from this study provide encouraging preliminary data in support of the hypothesis of a positive effect of SCS on peripheral neuropathy, but the findings are based on small numbers and require further evaluation.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT03769675.

Best Practices for Dorsal Root Ganglion Stimulation for Chronic Pain: Guidelines from the American Society of Pain and Neuroscience

With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion stimulation (DRG-S) has significantly improved the treatment of complex regional pain syndrome (CRPS), and it has broad applicability across a wide range of other conditions. Through funding and organizational leadership by the American Society for Pain and Neuroscience (ASPN), this best practices consensus document has been developed for the selection, implantation, and use of DRG stimulation for the treatment of chronic pain syndromes. This document is composed of a comprehensive narrative literature review that has been performed regarding the role of the DRG in chronic pain and the clinical evidence for DRG-S as a treatment for multiple pain etiologies. Best practice recommendations encompass safety management, implantation techniques, and mitigation of the potential complications reported in the literature. Looking to the future of neuromodulation, DRG-S holds promise as a robust intervention for otherwise intractable pain.

Objective Improvements in Peripheral Arterial Disease from Dorsal Root Ganglion Stimulation: A Case Series

BACKGROUND

The sympathetic nervous system (SNS) is important in the regulation of perfusion. Dorsal root ganglion stimulation (DRG-S) modulates sympathetic tone and is approved to treat complex regional pain syndrome, a disorder related to SNS dysfunction. We herein present 3 cases of DRG-S therapy to improve blood flow and symptoms of ischemia in peripheral arterial disease (PAD).

METHODS

Patient 1 is a 44-year-old female with dry gangrene of the third and fourth digits of her right hand due to Raynaud's syndrome who was scheduled for amputation of the affected digits. DRG-S leads were placed at the right C6, 7, and 8 DRG. Pulse volume recordings (PVR) were measured at baseline and after DRG-S. Patient 2 is a 55-year-old female with a non-healing ulcer of her left foot secondary to PAD scheduled for a below the knee amputation who underwent a DRG-S trial with leads placed at the left L4 and L5 DRG followed by a spinal cord stimulation trial with leads placed at the T9-T10 spinal levels for comparison. Transcutaneous oximetry (TcPO2) was measured at baseline and after 3 days of each therapy. Patient 3 is a 69-year-old female with persistent left foot pain at rest secondary to PAD with DRG-S leads placed at the left L4 and S1 levels.

RESULTS

All 3 patients experienced a significant reduction in pain with DRG-S, along with improvements in blood flow of the involved extremities, avoiding or limiting amputation. PVR improved dramatically with DRG-S in patient 1. A greater improvement in TcPO2 was seen with the DRG-S trial compared to spinal cord stimulation trial in patient 2. Patient 3 experienced an increase in walking distance and demonstrated long term efficacy and limb salvage at 32 months postimplantation.

CONCLUSIONS

Modulation of SNS output from DRG-S through orthodromic and antidromic autonomic pathways is likely responsible for improving blood flow. DRG-S may be a treatment option for PAD.

Appropriate referral and selection of patients with chronic pain for spinal cord stimulation: European consensus recommendations and e-health tool

Background

Spinal cord stimulation (SCS) is an established treatment for chronic neuropathic, neuropathic‐like and ischaemic pain. However, the heterogeneity of patients in daily clinical practice makes it often challenging to determine which patients are eligible for this treatment, resulting in undesirable practice variations. This study aimed to establish patient‐specific recommendations for referral and selection of SCS in chronic pain.

Methods

A multidisciplinary European panel used the RAND/UCLA Appropriateness Method (RUAM) to assess the appropriateness of (referral for) SCS for 386 clinical scenarios in four pain areas: chronic low back pain and/or leg pain, complex regional pain syndrome, neuropathic pain syndromes and ischaemic pain syndromes. In addition, the panel identified a set of psychosocial factors that are relevant to the decision for SCS treatment.

Results

Appropriateness of SCS was strongly determined by the neuropathic or neuropathic‐like pain component, location and spread of pain, anatomic abnormalities and previous response to therapies targeting pain processing (e.g. nerve block). Psychosocial factors considered relevant for SCS selection were as follows: lack of engagement, dysfunctional coping, unrealistic expectations, inadequate daily activity level, problematic social support, secondary gain, psychological distress and unwillingness to reduce high‐dose opioids. An educational e‐health tool was developed that combines clinical and psychosocial factors into an advice on referral/selection for SCS.

Conclusions

The RUAM was useful to establish a consensus on patient‐specific criteria for referral/selection for SCS in chronic pain. The e‐health tool may help physicians learn to apply an integrated approach of clinical and psychosocial factors.

Significance

Determining the eligibility of SCS in patients with chronic pain requires careful consideration of a variety of clinical and psychosocial factors. Using a systematic approach to combine evidence from clinical studies and expert opinion, a multidisciplinary European expert panel developed detailed recommendations to support appropriate referral and selection for SCS in chronic pain. These recommendations are available as an educational e‐health tool (https://www.scstool.org/).

Applicability of Transcutaneous Oxygen Tension Measurement in the Assessment of Chronic Limb-Threatening Ischemia

Transcutaneous oxygen tension measurement (TcPO2) is widely applied for the evaluation of chronic limb-threatening ischemia (CLTI). Nevertheless, studies that focused on the clinical value of TcPO2 have shown varying results. We identified factors that potentially play a role in TcPO2 measurement variation such as probe placement, probe temperature, and the use of a reference probe. In this review of the current literature, we assessed the application of these factors. A systematic search was conducted. Parameters that were assessed were probe placement, probe temperature, and mentioning and/or use of a reference probe. In total, 36 articles were eligible for analysis. In 24 (67%) studies, probes were placed on specific anatomical locations. Seven (19%) studies placed probes, regardless of the location of the ulcer, adjacent to an ischemic lesion or ulcer (perilesion). Selected temperature setting of the probe differed; in 18 (50%), a default probe temperature of 44°C was selected, and in 13 (36%), a different temperature was selected. In 31 (84%) studies, the use of a reference probe was not reported. Transcutaneous oxygen tension measurement is applied diversely in patients with CLTI. Homogeneity in TcPO2 protocols is warranted for reliable clinical application and to compare future TcPO2 research.

Spinal cord stimulation in experimental chronic painful diabetic polyneuropathy: Delayed effect of High-frequency stimulation

Background

Spinal cord stimulation (SCS) has been shown to provide pain relief in painful diabetic polyneuropathy (PDPN). As the vasculature system plays a great role in the pathophysiology of PDPN, a potential beneficial side‐effect of SCS is peripheral vasodilation, with high frequency (HF) SCS in particular. We hypothesize that HF‐SCS (500 Hz), compared with conventional (CON) or low frequency (LF)‐SCS will result in increased alleviation of mechanical hypersensitivity in chronic experimental PDPN.

Methods

Diabetes was induced in 8‐week‐old female Sprague–Dawley rats with an intraperitoneal injection of 65 mg/kg of streptozotocin (n = 44). Rats with a significant decrease in mechanical withdrawal response to von Frey filaments over a period of 20 weeks were implanted with SCS electrodes (n = 18). Rats were assigned to a cross‐over design with a random order of LF‐, CON‐, HF‐ and sham SCS and mechanical withdrawal thresholds were assessed with von Frey testing.

Results

Compared with sham treatment, the average 50% WT score for 5 Hz was 4.88 g higher during stimulation (p = 0.156), and 1.77 g higher post‐stimulation (p = 0.008). CON‐SCS resulted in 50% WT scores 5.7 g, and 2.51 g higher during (p = 0.064) and after stimulation (p < 0.004), respectively. HF‐SCS started out with an average difference in 50% WT score compared with sham of 1.87 g during stimulation (p = 0.279), and subsequently the steepest rise to a difference of 5.47 g post‐stimulation (p < 0.001).

Conclusions

We demonstrated a delayed effect of HF‐SCS on mechanical hypersensitivity in chronic PDPN animals compared with LF‐, or CON‐SCS.

Significance

This study evaluates the effect of SCS frequency (5–500 Hz) on mechanical hypersensitivity in the chronic phase of experimental PDPN. High frequency (500 Hz) – SCS resulted in a delayed effect‐ on pain‐related behavioural outcome in chronic PDPN.

Spinal cord stimulation: a 20-year retrospective analysis in 260 patients

Introduction. Spinal cord stimulation (SCS) is used clinically by many pain physicians and neurosurgeons alike without regard to their own outcome data. Methods. We reviewed our 20-year experience retrospectively of patients receiving SCS implants and analyzed our data by pain type and group. Results. We present 260 patients, 140 men and 120 women. The most frequent type of pain in our series was neuropathic pain in 44.25% and the most frequent diagnosis was peripheral vascular disease (PVD) with 98 cases. The second was failed back surgery syndrome (FBSS) with 65 cases and the third was complex regional pain syndrome type I (CRPS I), with 40 cases. In CRPS group, the mean visual analog scale (VAS) of this group was 77.89 ± 13.38. In total, 5% had no pain relief, 40% had poor pain relief, 47.5% had good pain relief, and 7.5% had excellent pain relief. In FBSS group, the mean VAS was 79.62 ± 11.69 mm. A total of 13.80% had no pain relief at all, 35.39% had poor pain relief, 50.76% had good pain relief, and there were no patients in this group who had complete pain relief. A total of 98 patients, 78 men and 20 women, were diagnosed with PVD. The mean VAS of this group was 69.75 ± 14.36 mm. A total of 11.22% had poor pain relief, 87.75% had good pain relief. One patient had complete pain relief and all patients in this group perceived at least some improvement in their symptoms. The rate of complications was close to 28% in our overall sample. Conclusions. In conclusion, we demonstrated the utility over time of this type of treatment is comparable with other series of efficacy of SCS. The analgesic efficacy was close to 65% in the overall group. The therapy was not free of complications. The preponderance of our patients was patients with the diagnosis of PVD and our results in this group of patients were excellent. These excellent results of more than 90% improvement suggest to us that SCS be considered as a first-line approach to the clinical management of patients with pain and ulcer of PVD.

What is the evidence on efficacy of spinal cord stimulation in (subgroups of) patients with critical limb ischemia?

The use of spinal cord stimulation (SCS) has been advocated for the management of ischemic pain and the prevention of amputations in patients with inoperable critical limb ischemia (CLI), although data on benefit are conflicting. Several reports described apparently differential treatment effects in subgroups. The purpose of this study was to analyze the data on the efficacy of SCS and to clarify preselection issues. Five randomized trials have been performed with a total number of 332 patients. Primary outcome measures were mortality and limb survival. In the largest multicenter randomized trial (n = 120), which compared SCS treatment and best medical treatment alone in patients with inoperable CLI, we determined the incidence of amputation and its relation to various predefined risk factors. We used Kaplan-Meier and Cox regression analyses to quantify prognostic effects and differential treatment effects. Meta-analysis yielded a relative risk for amputation of 0.79 and a risk difference of -0.07 (p = 0.15). The risk factor analysis clearly showed that patients with ischemic skin lesions (ulcerations or gangrene) had a worse prognosis (i.e., higher risk of amputation) (relative risk 2.30, p = 0.01). We did not observe significant interactions between this prognostic factor (or any other) and the effect of SCS. The analysis did not indicate a subgroup of patients who might specifically be helped by SCS. Meta-analysis including all randomized data shows insufficient evidence for higher efficacy of SCS treatment compared with best medical treatment alone. Although some factors provide prognostic information as to the risk of amputation in patients with CLI, there are no data supporting a more favorable treatment effect in any group.

Effect and safety of spinal cord stimulation for treatment of chronic pain caused by diabetic neuropathy

AIM

Spinal cord stimulation (SCS) has been shown effective as a therapy for different chronic painful conditions, but the effectiveness of this treatment for pain as a result of peripheral diabetic neuropathy is not well established. The primary objectives of this study were to evaluate the effect and safety of SCS for treatment of pain and the effects on microcirculatory blood flow in the affected areas in patients with refractory peripheral diabetic neuropathy.

METHOD

The study was designed as a prospective, open-label study. Data were collected during screening, at implant and at regular intervals, after initiation of therapy. Eleven diabetic patients with chronic pain in their lower limbs and no response to conventional treatment were studied. The SCS electrode was implanted in the thoracic epidural space. Neuropathic pain relief was assessed by Visual Analogue Scale (VAS) and microcirculatory skin perfusion was measured with Laser Doppler flowmetry.

RESULTS

Nine subjects had significant pain relief with the percutaneous electrical stimulator. Average pain score for all nine patients was 77 at baseline and 34 at 6 months after implantation. At the end of the study, eight of nine patients continued to experience significant pain relief and have been able to significantly reduce their pain medication. For six of them, the stimulator was the sole treatment for their neuropathic pain. No significant changes in microcirculatory perfusion were recorded.

CONCLUSION

Spinal cord stimulation offers an effective and safe therapy for chronic diabetic neuropathic pain.

Spinal cord stimulation for the treatment of chronic non-malignant pain

Over the past four decades, techniques and devices for spinal cord stimulation have undergone considerable refinement. Currently, percutaneous implantable electrodes are placed in the epidural space and a low-frequency electrical current is used to modify the transmission of chronic pain signals in the dorsal columns of the spinal cord. Before permanent implantation, the spinal cord stimulation will be examined during a test phase to determine its analgesic effect and tolerability. We have reviewed our experience in 88 patients with chronic nonmalignant pain. The follow-up of our study ranged from 15 to 75 months, with an average of 60 months. The indication for SCS in these 88 patients was mainly neuropathic pain syndromes. The patients were followed up by the Visual Analog Scale (VAS), level of activity and subjective assessment of the quality of life. On the basis of the patients' self-assessments using the VAS, the degree of pain relief was excellent/good in 72 of 88 patients (82%). At the end of the follow-up period, 50% of the patients were in a better psychological status and 86% of the patients reported an improvement in activities of their daily living and a reduction in the use of analgesic medication. Ninety percent of the patients stated that they would go through the procedure again for the same result. The findings of the present study indicate that spinal cord stimulation is an efficacious therapy for the treatment of chronic non-malignant pain.

Epidural spinal cord stimulation in lower limb ischemia

Epidural spinal cord stimulation (SCS) has been used as a method to improve microcirculatory blood flow, relieve ischemic pain and reduce amputation rate in patients with severe peripheral arterial occlusive disease (PAOD). In this article, the theories attempting to explain the mechanisms of SCS vasoactive action are presented. Our method of patient screening and our surgical technique for SCS implantation are described. In addition, the various published series reporting on the efficacy of SCS in PAOD are critically reviewed. The contemporary reports demonstrate the efficacy of SCS in ischemic pain relief. In the light of these results and our own experience, we conclude with an appraisal of modern techniques for assessing critical limb ischemia.

Roles of peripheral terminals of transient receptor potential vanilloid-1 containing sensory fibers in spinal cord stimulation-induced peripheral vasodilation

BACKGROUND

Spinal cord stimulation (SCS) is used to relieve ischemic pain and improve peripheral blood flow in selected patients with peripheral arterial diseases. Our previous studies show that antidromic activation of transient receptor potential vanilloid-1 (TRPV1) containing sensory fibers importantly contributes to SCS-induced vasodilation.

OBJECTIVES

To determine whether peripheral terminals of TRPV1 containing sensory fibers produces vasodilation that depends upon the release of calcitonin gene-related peptide (CGRP) and nitric oxide (NO) during SCS.

METHODS

A unipolar ball electrode was placed on the left dorsal column at lumbar spinal cord segments 2-3 in sodium pentobarbital anesthetized, paralyzed and ventilated rats. Cutaneous blood flow from left and right hindpaws was recorded with laser Doppler flow perfusion monitors. SCS was applied through a ball electrode at 30%, 60%, 90% and 300% of motor threshold. Resiniferatoxin (RTX; 2 microg/ml, 100 microl), an ultra potent analog of capsaicin, was injected locally into the left hindpaw to functionally inactivate TRPV-1 containing sensory terminals. In another set of experiments, CGRP(8-37), an antagonist of the CGRP-1 receptor, was injected at 0.06, 0.12 or 0.6 mg/100 microl into the left hindpaw to block CGRP responses; N-omega-nitro-l-arginine methyl ester (L-NAME), a nonselective nitric-oxide synthase (NOS) inhibitor, was injected at 0.02 or 0.2 mg/100 microl into the left hindpaw to block nitric oxide synthesis; (4S)-N-(4-Amino-5[aminoethyl]aminopentyl)-N'-nitroguanidine, TFA, a neuronal NOS inhibitor, was injected at 0.02 or 0.1 mg/100 microl into the left hindpaw to block neuronal nitric oxide synthesis.

RESULTS

SCS at all intensities produced vasodilation in the left hindpaw, but not in the right. RTX administration attenuated SCS-induced vasodilation at all intensities in the left hindpaw (P<0.05, n=7) compared with responses before RTX. CGRP(8-37) administration attenuated SCS-induced vasodilation in the left hindpaw in a dose dependent manner (linear regression, P<0.05) compared with responses before CGRP(8-37). In addition, L-NAME at a high dose, but not (4S)-N-(4-Amino-5[aminoethyl]aminopentyl)-N'-nitroguanidine, TFA, decreased SCS-induced vasodilation (P<0.05, n=5).

CONCLUSION

While TRPV1, CGRP and NO are known to be localized in the same nerve terminals, our data indicate that SCS-induced vasodilation depends on CGRP release, but not NO release. NO, released from endothelial cells, may be associated with vascular smooth muscle relaxation and peripheral blood flow increase in response to SCS.

Spinal cord stimulation: indications and outcomes

✓Spinal cord stimulation (SCS) is the most commonly used implantable neurostimulation modality for management of pain syndromes. In this paper the authors describe the current indications for SCS and its efficacy in the treatment of those diseases. Specifically, the literature on patient selection and outcomes after SCS for failed–back surgery syndrome (FBSS), refractory angina pectoris, peripheral vascular disease, and complex regional pain syndrome (CRPS) Type I was reviewed. Effective pain relief was obtained in 60 to 80% of patients with FBSS and CRPS Type I. Furthermore, these patients had significant improvements in quality of life (QOL) and a significantly greater chance of returning to work than patients who did not undergo SCS. The use of SCS in patients with inoperable angina (that is, refractory angina pectoris) resulted in significant decreases in chest pain and hospital admissions as well as increased exercise duration, with less morbidity than with open procedures that were performed for pain control only. Patients with inoperable PVD also demonstrated significant improvements in pain relief, QOL, and limb mobility. Reported complications were mostly related to hardware and were relatively minor. Review of randomized controlled studies supports the use of SCS as an effective treatment modality for pain associated with FBSS, refractory angina pectoris, peripheral vascular disease, and CRPS Type I.

Early and five-year amputation and survival rate of diabetic patients with critical limb ischemia: data of a cohort study of 564 patients

OBJECTIVE

To evaluate the early and late major amputation and survival rates and related risk factors in diabetic patients with critical limb ischemia (CLI).

DESIGN

Retrospective study.

METHODS

Revascularization feasibility, major amputation, survival rate and related risk factors were recorded in 564 diabetic patients consecutively hospitalized for CLI from 1999 to 2003 and followed until June 2005.

RESULTS

Peripheral angioplasty (PTA) was carried out in 420 (74.5%), bypass graft (BPG) in 117 (20.7%) patients. In 27 (4.8%) patients both PTA and BPG were not possible. Twenty-three above-the-ankle amputations (4.1%) were performed at 30 days: 6 in PTA patients, 3 in BPG patients, 14 in non revascularized patients. In the follow-up of 558 patients (98.9%), 62 repeated PTAs and 9 new BPGs, 32 new major amputations (16 in PTA patients, 14 in BPG patients and 2 in non-revascularized patients) were performed. Major amputation was associated with absence of revascularization (OR 35.9, p < 0.001, CI 12.9-99.7), occlusion of each of the three crural arteries (OR 8.20, p = 0.022, CI 1.35-49.6), wound infection (OR 2.1, p = 0.004 CI 1.3-3.6), dialysis (OR 4.7, p = 0.001 CI 1.9-11.7) increase in TcPO2 after revascularization (OR 0.80, p < 0.001 CI 0.74-0.87). One hundred seventy three patients died during follow-up and this was associated with age (HR 1.05, p < 0.001 CI 1.03-1.07), history of cardiac disease (HR 2.16, p < 0.001 CI 1.53-3.06), dialysis (HR 3.52, p < 0.001 CI 2.08-5.97), absence of revascularization (HR 1.68, p < 0.001, CI 1.29-2.19) and impaired ejection fraction (HR 1.08, p < 0.001, CI 1.05-1.09).

CONCLUSIONS

In diabetic patients with CLI the revascularization is feasible in most cases and allows a low rate of early major amputation. This rate is higher in the follow-up period. Major amputation is very high in patients where revascularization is not feasible while the high mortality rate is due to the serious comorbidities observed in these patients.

Spinal cord stimulation is not cost-effective for non-surgical management of critical limb ischaemia

OBJECTIVE

To quantify the costs of treatment in critical limb ischaemia (CLI) and to compare costs and effectiveness of two treatment strategies: spinal cord stimulation (SCS) and best medical treatment.

METHODS

One hundred and twenty patients with CLI not suitable for vascular reconstruction were randomised to either SCS in addition to best medical treatment or best medical treatment alone. Primary outcomes were mortality, amputation and cost. Cost analysis was based on resources used by patients for 2 years after randomisation. Both medical and non-medical costs were included.

RESULTS

Patient and limb survival were similar in the two treatment groups. Costs of in-hospital-stay and institutional rehabilitation constituted the predominant part (+/-70%) of the total costs of medical care in CLI. Cost of SCS-implantation and complications (7950 euro per patient) exceeded by far cost due to amputation procedures (410 euro per patient). The total costs of treatment were 36,600 euro per patient over 2 years for the SCS-group vs. 28,700 euro for best medical treatment alone (28% higher for SCS-group, p=0.009).

CONCLUSIONS

Total costs of treatment in CLI are high. Major components are hospital and rehabilitation costs. In contrast to recent reviews, there were no long-term benefits of SCS-treatment. Therefore, cost-effectiveness is reduced to cost-minimisation and SCS-treatment is considerably more expensive than best medical treatment.

Management of neuropathic pain following treatment for breast cancer in the absence of recurrence: A challenge for the radiation oncologist

This report reviews various management options for treatment-induced neuropathic pain in breast cancer. First-line options include tricyclic antidepressants and anticonvulsant drugs. Opioids should be prescribed according to published guidelines. Second-line treatments include lignocaine, mexiletine and ketamine. Sympatholytic therapies are available to patients with features of chronic regional pain syndrome. Anti-inflammatory agents are used for neurogenic inflammation. Surgical interventions are considered for refractory neuropathic pain. Interdisciplinary management is appropriate when persisting pain causes physical and psychosocial disabilities.

Systematic review and meta-analysis of controlled trials assessing spinal cord stimulation for inoperable critical leg ischaemia

Background

Spinal cord stimulation (SCS) may have a place in the treatment of patients with inoperable chronic critical leg ischaemia.

Methods

A systematic review and meta-analysis was performed of all controlled studies comparing SCS in addition to any form of conservative treatment for inoperable chronic critical leg ischaemia. Main endpoints were limb salvage, pain relief and clinical situation. Systematic methodological appraisal and data extraction were performed by independent reviewers.

Results

Of the 18 reports found, nine trials, comprising 444 patients, matched the selection criteria. After pooling, limb salvage at 12 months appeared significantly greater in the SCS group (risk difference (RD) − 0·13 (95 per cent confidence interval (c.i.) − 0·04 to − 0·22)). Significant pain relief occurred in both treatment groups, but patients who received SCS required significantly less analgesia and reached Fontaine stage 2 more often than those who did not have SCS (RD 0·33 (95 per cent c.i. 0·19 to 0·47)). Complications of SCS were problems of implantation (8·2 per cent), changes in stimulation requiring reintervention (14·8 per cent) and infection (2·9 per cent).

Conclusion

The addition of SCS to standard conservative treatment improves limb salvage, ischaemic pain and the general clinical situation in patients with inoperable chronic critical leg ischaemia. These benefits should be weighed against the cost and the (minor) complications associated with the technique.

Stimulation methods for neuropathic pain control

Neurostimulation methods for control of chronic neuropathic pain have recently gained in popularity. The reasons for this are multifactorial. As opposed to nerve ablation, these methods are minimally invasive and reversible. The improvements in hardware design simplified implantation techniques and prolonged equipment longevity. Stimulation trials have become less invasive, allowing patients to test its effects before final implantation. Finally, the scientific evidence has shown good outcomes of neurostimulation methods for chronic neuropathic pain control. Recent research efforts have revealed new potential mechanisms of action of neurostimulation. Whereas its action was widely explained by gate control theory in the past, it seems that neuromodulation acts also by modulation of neurotransmitters in the central nervous system. Three neurostimulation methods are currently used in clinical practice: spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), and deep brain stimulation (DBS). The SCS and PNS are excellent treatment choices for certain forms of neuropathic pain. The new indications for SCS are end-stage peripheral vascular disease and ischemic heart disease, whereas PNS is used for the treatment of occipital neuralgia and chronic pelvic pain. DBS is reserved for carefully selected patients in whom the other treatment modalities have failed. In a minority of patients the "tolerance" to neurostimulation develops after long-term use. Further research is needed to establish better outcome predictors to neurostimulation and possibly improve patient selection criteria.