Systematic Review of Radiofrequency Ablation for Management of Knee Pain

PURPOSE OF REVIEW

Chronic pain of the lower extremity remains challenging to manage. Radiofrequency ablation procedure applies heat to nerve fibers with the goal of mitigating chronic pain conditions of the knee. However, the clinical efficacy has not yet been adequately established. The goal of this review paper is to report the use of radiofrequency ablations in the treatment of osteoarthritis of the knee.

RECENT FINDINGS

PubMed and the Cochrane Controlled Trials Register were searched (final search 28 February 2018) using the MeSH terms "radiofrequency ablation," "neurolysis," "radiofrequency therapy," "pain syndrome," "analgesia," and "pain" in the English literature. Bibliographies of the published papers were screened for relevance to lower extremity radiofrequency ablation therapies. The quality of selected publications was assessed using the Cochrane risk of bias instrument. Of the 923 papers screened, 317 were further investigated for relevance. Our final search methodology yielded 19 studies that investigated the use of radiofrequency ablation at the knee. Of these 19 studies, there were four randomized control trials, two non-randomized control trials, three prospective studies, two retrospective studies, one case-control study, one technical report, and seven case reports. In summary, the data available suggests radiofrequency ablation as a promising and efficacious with all 19 studies revealing significant short- and long-term pain reductions in patients with knee pain.

Traumatic neuroma of the posterior tibial nerve due to previous surgery presenting as a massive tumor in the midfoot: A case report

A case report of traumatic neuroma, a benign non-neoplastic tumor of the posterior tibial nerve is presented. The soft tissue mass in the midfoot region was likely a sequela of previous nerve decompression surgery that the patient underwent five years previously in the same region and on the same nerve. Physical examination and history taking, along with an MRI, were important steps in reaching a definitive diagnosis of traumatic neuroma based on the findings of an interventional radiologist and histopathological evaluation of the biopsy by a pathologist. The lesion was subsequently surgically removed utilizing a multidisciplinary management approach. The patient recovered uneventfully and no symptom recurrence was noted at the 30-month follow-up. The tumor was the largest reported in the literature at the time. This case was also unique in that the patient was relieved of pronation and regained tactile sensation in the midfoot.

Iatrogenic Injury to the Sciatic Nerve due to Intramuscular Injection: A Case Report

Iatrogenic injuries due to intramuscular (IM) injection, although less frequently reported than before, are still common. The sciatic nerve is the most commonly injured nerve because of an IM injection owing to its large size and the buttock being a common injection site. Iatrogenic injury to the sciatic nerve resulting from a misplaced gluteal IM injection is a persistent problem worldwide affecting patients in economically rich and poor countries alike. The consequences of sciatic nerve injection injury (SNII) are potentially devastating and may result in serious neurological and medico-legal problems. A 68-year-old male presented with intractable neuropathic pain from SNII that occurred during gluteal IM injection of an analgesic for post-appendectomy pain. This chronic SNII pain did not improve despite his gradual recovery from weakness in the left foot. Partial improvement was seen following an external neurolysis, performed three months post-appendectomy. SNII is a preventable complication of gluteal IM injection. While the complete avoidance of gluteal IM injection is desirable, should need arise, the use of an appropriate administrative technique is recommended.

[Clinical analysis of ankle arthroscopy technique for treatment of tarsal tunnel syndrome]

Objective: To explore the effects of ankle arthroscopy technique in treating the tarsal tunnel syndrome. Methods: From May 2014 to May 2016, the ankle arthroscopy technique was used for surgical treatment of tarsal tunnel syndrome in the Department of Hand and Foot Microsurgery in Xuzhou Central Hospital. Twenty-two patients with 24 feet with tarsal tunnel syndrome were hospitalized for treatment, with 10 left feet and 14 right feet, aged 26-57 years. The disease duration ranged from 4 to 15 months (mean 8.3 months). The dual-portals ankle arthroscopic neurolysis and fiber membrane resection were performed. The Pfeiffer scoring system was used to evaluate the post-operative outcomes. Results: Primarily healing of the wound was achieved in all the patients. No postoperative infection was found during the follow-up. The postoperative hospitalization time was 2 to 5 days (mean 3.7 days). All patients were followed up for 12 to 24 months. At the final follow-up, all the patients had significant improvement in numbness and pain. According to the Pfeiffer scoring system, the results were excellent in 16 feet, good in 8 feet, with an excellent and good rate of 100%. Conclusion: The ankle arthroscopic neurolysis is a safe and easy treatment option for the tarsal tunnel syndrome and provides satisfactory results.

Histopathologic changes inside the lateral femoral cutaneous nerve obtained from patients with persistent symptoms of meralgia paresthetica

BACKGROUND

In patients with persistent symptoms of meralgia paresthetica, a neurectomy of the lateral femoral cutaneous nerve (LFCN) can be performed to alleviate pain symptoms. The neurectomy procedure can be performed either as a primary procedure or after failure of a previously performed neurolysis or decompression of the LFNC (secondary neurectomy). The goal of the present study was to quantify the histopathologic changes inside the LFCN obtained from patients with persistent symptoms of meralgia paresthetica, and specifically to compare to what extend these changes are present after primary versus secondary neurectomy.

METHODS

A total of 39 consecutive cases were analyzed microscopically: in 29 cases, the neurectomy had been performed as primary procedure, in 10 cases, after failed neurolysis. Intraneural changes were quantified for the (1) thickening of perineurium, (2) deposition of mucoid, and (3) percentage of collagen. Analysis was performed at three levels: proximal to, at, and distal to the previous site of compression. In addition, correlations were investigated for the duration of symptoms and the body mass index (BMI) of the patient.

RESULTS

Intraneural changes were found consistently in all cases. There was no significant difference for the primary and secondary neurectomy groups. There was also no relation with the previous site of compression. There was a weak correlation between the occurrence of intraneural changes and the duration of symptoms, although this difference was not statistically significant.

CONCLUSIONS

Histopathological changes in this study were found in all patients with persistent symptoms of meralgia paresthetica regardless of a previously performed neurolysis procedure. This finding suggests that the intraneural changes that occur in persistent meralgia paresthetica are largely irreversible and support the surgical strategy of neurectomy as an alternative to neurolysis, also for primary surgical treatment and not only after failure of neurolysis.

Neurolysis: A Brief Review for a Fading Art

The key to the successful treatment of patients with spasticity is contingent on choosing appropriate interventions tailored to meet the needs, goals, and specific presentation of each patient. For the clinician attempting to address the focal manifestations of hypertonia without surgical intervention, there have been 2 primary options: neurolysis or chemodenervation. Before the introduction of the botulinum toxins, neurolysis was the only focal spasticity treatment option available to the previous generation of physical medicine and rehabilitation practitioners.

Short- and long-term results of common peroneal nerve injuries treated by neurolysis, direct suture or nerve graft

INTRODUCTION

Damage to the common peroneal nerve is the most frequent nerve injury in lower limb traumas. Our objective was to assess the motor and sensory recovery levels and the functional outcomes after remedial surgery for common peroneal nerve trauma, through either neurolysis, direct suture or nerve graft.

METHODS

This is a transversal, observational study of a monocentric cohort of 20 patients who underwent surgery between January 2004 and June 2016, which included 16 men and 4 women whose median age was 35 ± 11 years. We assessed the level of sensory and motor nerve recovery and the Kitaoka score. Nine patients benefited from neurolysis, 5 had direct sutures, and 6 received a nerve graft.

RESULTS

With 48 months' average follow-up, 7 out of 9 patients underwent neurolysis and 4 out of 5 with direct sutures had good motor recovery (≥ M4), but none for the grafts. Sensory recovery (≥ S3) was satisfactory in 7 out of 9 cases in the neurolysis group, 3 out of 5 in the direct suture group, and 3 out of 6 in the nerve graft group. The average Kitaoka score was 83.7 ± 11.5 for the neurolysis group, 86.8 ± 16 for the direct suture group, and 73 ± 14 for the graft group.

CONCLUSION

Surgical treatment by neurolysis and direct suture yields good results with a motor recovery ratio nearing 80%. When a nerve graft becomes necessary, recovery is poor and resorting to palliative techniques in the shorter run is a strategy which should be evaluated.

Visualization of injectate spread of intercostal nerve block: a cadaveric study

Introduction

Intercostal nerve block and neurolysis are widely used procedures, but their injectate spread has not been well understood. Previous studies have reported unexpected outcomes (paravertebral or epidural anesthesia) and spinal cord injury after intercostal nerve block and neurolysis. To investigate a possible mechanism for these complications, we aimed to visualize the flow of liquid injected near the intercostal nerve, using cadavers.

Methods

We performed a simulated intercostal nerve block study using two Thiel-embalmed cadavers. Dye was injected into the interfascial plane between the internal and innermost intercostal muscles under ultrasound guidance (blue, 10 ml) or under direct vision (green, 5 ml).

Results

Dye leakage began with injection of only 0.5–2 ml and occurred between the innermost intercostal muscle fibers. The dye injected around the intercostal nerve penetrated into the extrapleural space and reached the paravertebral space.

Conclusions

Injectate placed around the intercostal nerve easily penetrate the extrapleural space and reach the paravertebral space. Intercostal nerve block or neurolysis has a risk of impairing at least the sympathetic chain and conceivably affecting the central nervous system.

Facet joint syndrome: from diagnosis to interventional management

Abstract

Low back pain (LBP) is the most common pain syndrome, and is an enormous burden and cost generator for society. Lumbar facet joints (FJ) constitute a common source of pain, accounting for 15–45% of LBP. Facet joint degenerative osteoarthritis is the most frequent form of facet joint pain. History and physical examination may suggest but not confirm facet joint syndrome. Although imaging (radiographs, MRI, CT, SPECT) for back pain syndrome is very commonly performed, there are no effective correlations between clinical symptoms and degenerative spinal changes. Diagnostic positive facet joint block can indicate facet joints as the source of chronic spinal pain. These patients may benefit from specific interventions to eliminate facet joint pain such as neurolysis, by radiofrequency or cryoablation. The purpose of this review is to describe the anatomy, epidemiology, clinical presentation, and radiologic findings of facet joint syndrome. Specific interventional facet joint management will also be described in detail.

Teaching points

• Lumbar facet joints constitute a common source of pain accounting of 15–45%.

• Facet arthrosis is the most frequent form of facet pathology.

• There are no effective correlations between clinical symptoms, physical examination and degenerative spinal changes.

• Diagnostic positive facet joint block can indicate facet joints as the source of pain.

• After selection processing, patients may benefit from facet joint neurolysis, notably by radiofrequency or cryoablation.

Treatment of Hand Allodynia Resulting from Wrist Cutting with Radial and Ulnar Artery Perforator Adipofascial Flaps

In this article, we report two cases in which recurrent adhesive hand neuropathy with allodynia were successfully treated with radial and ulnar artery adipofascial perforator flap coverage. Treatment of recurrent neuropathy, such as recurrent carpal tunnel syndrome and re-adhesion after neurolysis using free and pedicle flaps to cover the nerves, has been reported to show good results. However, for severe painful nerve disorders, such as complex regional pain syndrome, the efficacy of this treatment was unclear. We present two cases diagnosed with recurrent adhesive hand neuropathy with allodynia, resulting from wrist cutting; these cases were treated with neurolysis and flap coverage with good results and no recurrence. This suggests that neurolysis and flap coverage are effective methods for treating complex regional pain syndrome.

Robot-assisted pudendal neurolysis in the treatment of pudendal nerve entrapment syndrome

INTRODUCTION

Pudendal nerve entrapment syndrome (PNE) is characterised by the presence of neuropathic pain in the pudendal nerve (PN) territory, associated or not with urinary, defecatory and sexual disorders. Surgical PN decompression is an effective and safe alternative for cases when conservative treatment fails. The aim of this study is to describe the first robot-assisted pudendal neurolysis procedure performed in our country.

MATERIAL AND METHODS

We describe step by step the technique of robot-assisted laparoscopic neurolysis of the left PN performed with intraoperative neurophysiological monitoring on a 60-year-old patient diagnosed with left PNE.

RESULTS

The procedure was performed satisfactorily without complications. After 24h, the patient was discharged from the hospital. We observed a 50% reduction in pain measured using the visual analogue scale 2 weeks after the procedure, which remained after 10 weeks of the neurolysis.

CONCLUSIONS

Robot-assisted neurolysis of the PN constitutes a feasible and safe approach, enabling better visualisation and accuracy in the dissection of the PN. Intraoperative neurophysiological monitoring is useful for locating the PN and for detecting intraoperative changes after the release of the nerve.

Pain in pancreatic ductal adenocarcinoma: A multidisciplinary, International guideline for optimized management

Abdominal pain is an important symptom in most patients with pancreatic ductal adenocarcinoma (PDAC). Adequate control of pain is often unsatisfactory due to limited treatment options and significant variation in local practice, emphasizing the need for a multidisciplinary approach. This review contends that improvement in the management of PDAC pain will result from a synthesis of best practice and evidence around the world in a multidisciplinary way. To improve clinical utility and evaluation, the evidence was rated according to the GRADE guidelines by a group of international experts. An algorithm is presented, which brings together all currently available treatment options. Pain is best treated early on with analgesics with most patients requiring opioids, but neurolytic procedures are often required later in the disease course. Celiac plexus neurolysis offers medium term relief in a substantial number of patients, but other procedures such as splanchnicectomy are also available. Palliative chemotherapy also provides pain relief as a collateral benefit. It is stressed that the assessment of pain must take into account the broader context of other physical and psychological symptoms. Adjunctive treatments for pain, depression and anxiety as well as radiotherapy, endoscopic therapy and neuromodulation may be required in selected patients. There are few comparative studies to help define which combination and order of these treatment options should be applied. New pain therapies are emerging and could for example target neural transmitters. However, until better methods are available, management of pain should be individualized in a multidisciplinary setting to ensure optimal care.

The management of dorsal peroneal nerve compression in the midfoot

The foot and ankle specialist will frequently encounter patients with dorsal midfoot pain in clinic. In the presence of midfoot pain and/or paraesthesia, nerve entrapment must be considered. The authors report the outcome of a case series of patients who underwent surgical release of the DPN. Between 2011-2017, a single surgeon operated on seven patients with a diagnosis of DPN entrapment. A retrospective review of the patient's clinical notes was performed, including the operative findings. The average age at presentation was 47 years (range, 31-70 years), and the left foot was affected in four cases. In all cases the patient presented with dorsal midfoot pain, with three cases associated with paraesthesia. The mean follow up was 25 months (range, 4-70 months), with six of the patients discharged with their pre-operative symptoms settled. One patient who had good immediate pain relief following DPN neurolysis, EHB tendon resection and reduction of exostosis developed recurrence of the neuropathic pain at five years. Despite non-operative management the symptoms did not settle and exploration of the DPN was performed. The anatomical position of the DPN, and its site of compression, may vary however it can be localised by a positive Tinel's sign and targeted injection with local anaesthetic. All the patients that underwent surgical exploration and decompression had a good outcome, with one patient requiring further neurolysis for impingement.

Superior and Middle Cluneal Nerve Entrapment as a Cause of Low Back Pain

Low back pain (LBP) is encountered frequently in clinical practice. The superior and the middle cluneal nerves (SCN and MCN) are cutaneous nerves that are purely sensory. They dominate sensation in the lumbar area and the buttocks, and their entrapment around the iliac crest can elicit LBP. The reported incidence of SCN entrapment (SCN-E) in patients with LBP is 1.6%-14%. SCN-E and MCN entrapment (MCN-E) produce leg symptoms in 47%-84% and 82% of LBP patients, respectively. In such patients, pain is exacerbated by lumbar movements, and the symptoms mimic radiculopathy due to lumbar disorder. As patients with failed back surgery or Parkinson disease also report LBP, the differential diagnosis must include those possibilities. The identification of the trigger point at the entrapment site and the disappearance of symptoms after nerve block are diagnostically important. LBP due to SCN-E or MCN-E can be treated less invasively by nerve block and neurolysis. Spinal surgeons treating patients with LBP should consider SCN-E or MCN-E.

Long-Lasting Orthostatic Hypotension and Constipation After Celiac Plexus Block; A Case Report

This case report presents a 55 years old man, presented with abdominal pain and diagnosed with a metastatic pancreatic tumor, who developed long lasting orthostatic hypotension and constipation following a celiac plexus block.

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.

Bilateral vs. unilateral endoscopic ultrasound-guided celiac plexus neurolysis for abdominal pain management in patients with pancreatic malignancy: a systematic review and meta-analysis

CONTEXT

Endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) by bilateral or unilateral approach is widely used in palliative abdominal pain management in pancreatic cancer patients, but the analgesic effect and relative risks of the two different puncture routes remain controversial.

OBJECTIVES

The aim of this systematic review was to evaluate the analgesic efficacy and safety of bilateral EUS-CPN compared with unilateral EUS-CPN.

METHODS

An electronic database search was performed for randomized controlled trials comparing bilateral and unilateral approaches of EUS-CPN using the Pubmed, Cochrane Library, Web of Science, Google Scholar, and CNKI databases. Meta-analysis was performed using RevMan 5.3 after screening and methodological evaluation of the selected studies. Outcomes included pain relief, treatment response, analgesic reduction, complications, and quality of life (QOL).

RESULTS

Six eligible studies involving 437 patients were included. No significant difference was found in short-term pain relief [SMD = 0.31, 95% CI (- 0.20, 0.81), P = 0.23] and response to treatment [RR = 0.99, 95% CI (0.77, 1.41), P = 0.97] between the bilateral and unilateral neurolysis groups. However, only the bilateral approach was associated with a statistically significant reduction in the postoperative use of analgesics [RR = 0.66, 95% CI (0.47, 0.94), P = 0.02] compared to the unilateral approach. A descriptive analysis was performed for complications and QOL.

CONCLUSION

The short-term analgesic effect and general risk of bilateral EUS-CPN are comparable with those of unilateral EUS-CPN, but our evidence supports the conclusion that the bilateral approach significantly reduces postoperative analgesic use.

Dynamic factors involved in common peroneal nerve entrapment neuropathy

BACKGROUND

Common peroneal nerve (CPN) entrapment neuropathy (CPNEN) is the most common peripheral neuropathy of the lower extremities. The pathological mechanisms underlying CPNEN remain unclear. We sought to identify dynamic factors involved in CPNEN by directly measuring the CPN pressure during stepwise CPNEN surgery.

METHODS

We enrolled seven patients whose CPNEN improved significantly after CPN neurolysis. All suffered intermittent claudication, and the repetitive plantar flexion test, used as a CPNEN provocation test, was positive. During decompression surgery we directly measured the CPN pressure during several decompression steps.

RESULTS

Before CPN decompression, plantar flexion elicited a statistically significant increase in the CPN pressure (from 1.8 to 37.3, p < 0.05), as did plantar extension (from 1.8 to 23.1, p < 0.05). The CPN pressure gradually decreased during step-by-step surgery; it was lowest after resection of the peroneus longus muscle (PLM) fascia.

CONCLUSIONS

Dynamic factors affect idiopathic CPNEN. The CPN pressure decreased at each surgical decompression step, and removal of the PLM fascia resulted in adequate decompression of the CPN. Our findings shed light on the etiology of idiopathic CPNEN and recommend adequate CPNEN decompression procedures.

Ablation of the sacroiliac joint using MR-guided high intensity focused ultrasound: a preliminary experiment in a swine model

Background

Dysfunction of the Sacroiliac Joint (SIJ) is one of the key sources of low back pain. For prolonged pain relief, some patients undergo fluoroscopic guided radio-frequency (RF) ablation of SIJ, during which a number of RF probes are inserted to create thermal lesions that disrupt the posterior sacral nerve supply. This procedure is minimally invasive, laborious, time-consuming and costly. To study if High Intensity Focused Ultrasound (HIFU) ablation is a feasible alternative approach to SIJ pain treatment, we performed experiments using HIFU to ablate SIJ in the swine model.

Methods

Three female Yorkshire swine (36, 35.2 and 34 kg) underwent bilateral Magnetic Resonance guided HIFU (MRgHIFU) ablation of the SIJs. Treatment assessment was performed using contrast-enhanced imaging, histopathology and evaluation of pain and changes in ambulation and gait.

Results

Contiguous lesions along the right and left SIJs were achieved in all animals. In one out of three animals, excessive heating of the muscle and skin tissue in the near-field resulted in unwanted muscle necrosis. No changes in animal behavior, ambulation or gait were detected.

Conclusions

The initial experiments with MRgHIFU ablation of SIJs in sub-acute swine model show promise for this ablation modality as a non invasive and more precise alternative to the currently used fluoroscopically - guided RF ablations and injections.

Results of Operative Treatment of Brachial Plexus Injury Resulting from Shoulder Dislocation: A Study with A Long-Term Follow-Up

BACKGROUND

Injury to the infraclavicular brachial plexus is an uncommon but serious complication of shoulder dislocation. This work aims to determine the effectiveness of operative treatment in patients with this type of injury.

METHODS

Thirty-three patients (26 men and 7 women; mean age, 45 years and 3 months) treated operatively for brachial plexus injury resulting from shoulder dislocation between the years 2000 and 2013 were included in this retrospective case series. Motor function of affected limbs was assessed pre- and postoperatively with the use of the British Medical Research Council (BMRC) scale. Sensory function in the areas innervated by ulnar and median nerves was evaluated with the BMRC scale modified by Omer and Dellon and in the remaining areas with the Highet classification. Follow-up lasted 2-10 years (mean, 5.1 years).

RESULTS

Good postoperative recovery of nerve function was observed in 100% of musculocutaneous, 93.3% of radial, 66.7% of median, 64% of axillary, and 50% of ulnar nerve injuries. No recovery was observed in 5.6% of median, 6.7% of radial, 10% of ulnar, and 20% of axillary nerve injuries. Injury to a single nerve was associated with worse treatment outcome than multiple nerve injury.

CONCLUSIONS

Obtaining improvement in peripheral nerve function after injury resulting from shoulder dislocation may require operative intervention. The type of surgical procedure depends on intraoperative findings: sural nerve grafting in cases of neural elements' disruption, internal neurolysis when intraneural fibrosis is observed, and external neurolysis in the remaining cases. The outcomes of surgical treatment are good, and the risk of intra- and postoperative complications is low.

Evaluating the evidence: is neurolysis or neurectomy a better treatment for meralgia paresthetica?

BACKGROUND

Meralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve (LCFN). Surgical treatment involves transection or decompression of the LCFN. There is no clear consensus on the superiority of one technique over the other. We performed a systematic review of the literature to answer this question.

METHODS

Eligible studies included those that compared neurolysis versus neurectomy for the treatment of meralgia paresthetica after failure of conservative therapy. Our outcome of interest was resolution of symptoms. We performed a computerized search of MEDLINE (PubMed; all years) and of the Cochrane Central Register of Controlled Trials. Eligible studies had to include the words "meralgia paresthetica" and "surgery." All patients regardless of age were included, and there was no language restriction. We then reviewed the articles' titles and abstracts. All studies that compared neurolysis to neurectomy were included in the analysis.

RESULTS

Of the studies identified, none were randomized controlled trials. There were two German language articles that were translated by a third researcher. Each study was evaluated by two independent researchers who assigned a level of evidence according to American Association of Neurologist algorithm and also performed data extraction (neurolysis vs. neurectomy and resolution of pain symptoms). Each study was found to be level four evidence.

CONCLUSION

After reviewing the data, there was insufficient evidence to recommended one method of treatment over the other. This highlights the importance of keeping a national registry in order to compare outcomes between the two methods of treatment.

Interventional Treatments of Cancer Pain

Pain is a significant burden for patients with cancer and is particularly prevalent among those with advanced cancer. Appropriate interventional cancer pain therapies complement conventional pain management by reducing the need for systemic opioid therapy and its associated toxicity; however, these therapies are often underutilized. This article reviews techniques, indications, complications, and outcomes of the most common interventional approaches for the management of cancer-related pain. These approaches include intrathecal drug delivery, vertebral augmentation, neurolysis of the celiac, superior hypogastric and ganglion impar plexus', image-guided tumor ablation, and other less commonly performed but potentially beneficial interventions.

Presentation of Neurolytic Effect of 10% Lidocaine after Perineural Ultrasound Guided Injection of a Canine Sciatic Nerve: A Pilot Study

BACKGROUND

Phenol and alcohol have been used to ablate nerves to treat pain but are not specific for nerves and can damage surrounding soft tissue. Lidocaine at concentrations > 8% injected intrathecal in the animal model has been shown to be neurotoxic. Tests the hypothesis that 10% lidocaine is neurolytic after a peri-neural blockade in an ex vivo experiment on the canine sciatic nerve.

METHODS

Under ultrasound, one canine sciatic nerve was injected peri-neurally with 10 cc saline and another with 10 cc of 10% lidocaine. After 20 minutes, the sciatic nerve was dissected with gross inspection. A 3 cm segment was excised and preserved in 10% buffered formalin fixative solution. Both samples underwent progressive dehydration and infusion of paraffin after which they were placed on paraffin blocks. The sections were cut at 4 µm and stained with hemoxylin and eosin. Microscopic review was performed by a pathologist from Henry Ford Hospital who was blinded to which experimental group each sample was in.

RESULTS

The lidocaine injected nerve demonstrated loss of gross architecture on visual inspection while the saline injected nerve did not. No gross changes were seen in the surrounding soft tissue seen in either group. The lidocaine injected sample showed basophilic degeneration with marked cytoplasmic vacuolation in the nerve fibers with separation of individual fibers and endoneurial edema. The saline injected sample showed normal neural tissue.

CONCLUSIONS

Ten percent lidocaine causes rapid neurolytic changes with ultrasound guided peri-neural injection. The study was limited by only a single nerve being tested with acute exposure.

Surgical outcome of foot drop caused by common peroneal nerve injuries; is the glass half full or half empty?

BACKGROUND

Foot drop is a gait abnormality with various etiologies. The Common Peroneal Nerve (CPN) is one of the most frequently injured peripheral nerves. CPN deficit leads to foot drop. Most CPN injuries recover spontaneously; nonetheless, some require nerve surgery. The present study set out to assess the surgical outcomes of foot drop following CPN injuries.

METHOD

Surgical outcomes were reviewed in 36 subjects with foot drop caused by CPN injuries, undergoing surgical nerve exploration. The CPN injuries were confirmed by physical examination, Magnetic Resonance Imaging (MRI) and electrodiagnostic findings.

RESULTS

Subsequent to surgery, a significant improvement was seen in the motor recovery of the subjects. Interestingly, no significant difference in the recovery was found between neurolysis and nerve repair (direct repair and nerve grafting). There was no significant association between the age and the functional recovery. Gender was not associated with the functional recovery. No significant difference was seen in the recovery between thigh-level and knee-level CPN divisions.

CONCLUSIONS

The findings from the present study suggest that nerve surgery can yield beneficial results in the recovery of foot drop following CPN injuries. In addition, the surgical outcome of neurolysis in the treatment of CPN injuries can be similar to that of the nerve repair (direct repair or nerve grafting). This may show the value of nerve repair, which was comparable to neurolysis in the treatment of CPN injuries.

Technical feasibility of robot-assisted minimally-invasive neurolysis of the lateral cutaneous nerve of thigh: About a case

To limit the risk of iatrogenic neuroma and recurrence after surgical treatment of meralgia paresthetica, some authors have recently developed a technique of endoscopic neurolysis of the lateral cutaneous nerve of thigh (LCNT) below the level of the inguinal ligament. We report the case of a robot-assisted endoscopic technique underneath the inguinal ligament. A 62-year-old patient suffering of idiopathic meralgia paresthetica for the past 18 months received a Da Vinci robot-assisted minimally-invasive 10cm long neurolysis, of which 1/3 was situated above the level of the inguinal ligament and 2/3 below it. The patient was discharged the following day without complications. At 6-months follow-up the pain was rated 0/10 compared to 5/10 pre-operatively. Robot-assisted endoscopic neurolysis of the LCNT retains the advantages of conventional endoscopy and enables to approach the nerve in the most frequently compressed zone underneath the inguinal ligament. The three-dimensional view offered by robotic surgery facilitates the dissection. The superiority of this technique remains to be demonstrated by comparing it to conventional techniques.