Neuromodulation for chronic pain.

Neuromodulation is an expanding area of pain medicine that incorporates an array of non-invasive, minimally invasive, and surgical electrical therapies. In this Series paper, we focus on spinal cord stimulation (SCS) therapies discussed within the framework of other invasive, minimally invasive, and non-invasive neuromodulation therapies. These therapies include deep brain and motor cortex stimulation, peripheral nerve stimulation, and the non-invasive treatments of repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and transcutaneous electrical nerve stimulation. SCS methods with electrical variables that differ from traditional SCS have been approved. Although methods devoid of paraesthesias (eg, high frequency) should theoretically allow for placebo-controlled trials, few have been done. There is low-to-moderate quality evidence that SCS is superior to reoperation or conventional medical management for failed back surgery syndrome, and conflicting evidence as to the superiority of traditional SCS over sham stimulation or between different SCS modalities. Peripheral nerve stimulation technologies have also undergone rapid development and become less invasive, including many that are placed percutaneously. There is low-to-moderate quality evidence that peripheral nerve stimulation is effective for neuropathic pain in an extremity, low quality evidence that it is effective for back pain with or without leg pain, and conflicting evidence that it can prevent migraines. In the USA and many areas in Europe, deep brain and motor cortex stimulation are not approved for chronic pain, but are used off-label for refractory cases. Overall, there is mixed evidence supporting brain stimulation, with most sham-controlled trials yielding negative findings. Regarding non-invasive modalities, there is moderate quality evidence that repetitive transcranial magnetic stimulation does not provide meaningful benefit for chronic pain in general, but conflicting evidence regarding pain relief for neuropathic pain and headaches. For transcranial direct current stimulation, there is low-quality evidence supporting its benefit for chronic pain, but conflicting evidence regarding a small treatment effect for neuropathic pain and headaches. For transcutaneous electrical nerve stimulation, there is low-quality evidence that it is superior to sham or no treatment for neuropathic pain, but conflicting evidence for non-neuropathic pain. Future research should focus on better evaluating the short-term and long-term effectiveness of all neuromodulation modalities and whether they decrease health-care use, and on refining selection criteria and treatment variables.

Metformin attenuates post-epidural fibrosis by inhibiting the TGF-ß1/Smad3 and HMGB1/TLR4 signaling pathways.

Excessive post-epidural fibrosis is a common cause of recurrent back pain after spinal surgery. Though various treatment methods have been conducted, the safe and effective drug for alleviating post-epidural fibrosis remains largely unknown. Metformin, a medicine used in the treatment of type 2 diabetes, has been noted to relieve fibrosis in various organs. In the present study, we aimed to explore the roles and mechanisms of metformin in scar formation in a mouse model of laminectomy. Post-epidural fibrosis developed in a mouse model of laminectomy by spinous process and the T12-L2 vertebral plate with a rongeur. With the administration of metformin, post-epidural fibrosis was reduced, accompanied with decreased collagen and fibronectin in the scar tissues. Mechanistically, metformin decreased fibronectin and collagen deposition in fibroblast cells, and this effect was dependent on the HMGB1/TLR4 and TGF-ß1/Smad3 signalling pathways. In addition, metformin influenced the metabolomics of the fibroblast cells. Taken together, our study suggests that metformin may be a potential option to mitigate epidural fibrosis after laminectomy.

Celecoxib-Loaded Electrospun Fibrous Antiadhesion Membranes Reduce COX-2/PGE2 Induced Inflammation and Epidural Fibrosis in a Rat Failed Back Surgery Syndrome Model.

To date, failed back surgery syndrome (FBSS) remains a therapy-refractory clinical condition after spinal surgery. The antiadhesion membrane is applied to prevent FBSS by isolating fibrosis; however, the inflammation stimulated by the foreign body and surgical trauma needs to be further resolved simultaneously. Therefore, we developed new electrospun polycaprolactone (PCL) fibrous membranes loaded with celecoxib (CEL) to prevent fibrosis and inflammation associated with FBSS. The CEL-loaded PCL fibers were randomly distributed, and the drug was released over two weeks. Fluorescence micrographs revealed that the fibroblasts proliferated less on the PCL-CEL fibrous membranes than in the PCL group and the blank control. In the rat laminectomy model after 4 weeks, magnetic resonance imaging of epidural fibrosis was least in the PCL-CEL group. Expression of COX-2 and PGE2 was lower in the PCL-CEL group. It concluded that the CEL-loaded PCL membrane could reduce fibrosis and inflammation in a rat model of FBSS via COX-2/PGE2 signaling pathways.

Epidural adhesiolysis: an evidence-based review.

First described over 25 years ago, epidural lysis of adhesions (LOA) involves the mechanical dissolution of epidural scar tissue, which may directly alleviate pain and facilitate the spread of analgesic substances to area(s) of pain generation. Although it most commonly performed for lumbar failed back surgery syndrome, there is a growing body of evidence that suggests it may be effective for spinal stenosis and radicular pain stemming from a herniated disc. There is weak positive evidence that LOA is more effective than conventional caudal epidural steroid injections for failed back surgery syndrome and spinal stenosis, and that LOA is more effective than sham adhesiolysis and conservative management for lumbosacral radiculopathy. For cervical disc herniation and spinal stenosis, there is only anecdotal evidence suggesting effectiveness and safety. Factors that may contribute to the enhanced efficacy compared to traditional epidural steroid administration include the high volume administered, the use of hypertonic saline, and to a lesser extent the use of hyaluronidase and a navigable catheter to mechanically disrupt scar tissue and guide medication administration. Although LOA is widely considered a safe intervention, the complication rates are higher than for conventional epidural steroid injection.

Alpha-lipoic acid reduces peridural fibrosis after laminectomy of lumbar vertebrae in rabbits.

BACKGROUND: Peridural fibrosis is an inevitable healing process causing failed back surgery syndrome after lumbar spinal operations. In this study, alpha-lipoic acid (ALA), reported to reduce fibrosis in liver, oral mucosa, and peritoneum, investigated as a potential candidate for prevention of peridural fibrosis. METHOD: Twelve adult New Zealand white male rabbits were divided into control (n = 5) and ALA groups (n = 7). Laminectomy of lumbar spine was performed and ALA was applied on the exposed dura mater topically in ALA group. RESULTS: According to histological peridural grading, the ALA group (median grade 1) showed significantly less peridural fibrosis than the control group (median grade 3, p = 0.005). CONCLUSIONS: ALA is a promising substance in the prevention of peridural fibrosis, especially in early preoperative and postoperative period.

Surgical outcome of percutaneous endoscopic interlaminar lumbar diskectomy for recurrent disk herniation after open diskectomy.

STUDY DESIGN: Technical report. OBJECTIVE: To present a detailed surgical technique of percutaneous endoscopic interlaminar diskectomy (PEID) for recurrent lumbar disk herniation and present features of postoperative magnetic resonance images that were unavailable in previous studies. SUMMARY OF BACKGROUND DATA: Revision lumbar diskectomy is troublesome because of the difficulty in dissecting a surgical scar. Endoscopic diskectomy is regarded as an alternative method with comparable clinical outcome and less complication. Technically, a transforaminal approach is similar to a virgin operation, whereas an interlaminar approach is not, because of the scar tissue. There have been only 2 papers describing a PEID surgical procedure. Sharing details of the surgical technique is important in furthering the adoption of this technique, when it is indicated. METHODS: We operated on 10 patients (M:F=6:4; mean age, 61.2±11.6 y) with PEID for recurrent lumbar disk herniation after open diskectomy. The level operated was L5-S1 in 5 cases, L4-5 in 4, and L2-3 in 1. During operation, we dissected the scar tissue from the medial facet joint with a working channel and removed the reherniated disk material after retraction of the scar tissue and the neural tissue together. Dissection of the scar tissue from the neural tissue was not attempted. The follow-up period was 14.4±9.9 months. RESULTS: In all 10 patients, the reherniated disk materials were removed successfully. There was no incidence of dural tear. Postoperative magnetic resonance imaging showed good decompression with thecal sac reexpansion irrespective of the attached scar tissue, except in 1 patient. Excellent or good outcome by Macnab criteria was obtained in 6 of 10 patients, fair outcome in 2, and poor in 2 patients. Rerecurrence occurred in 1 patient 1 year after the surgery. CONCLUSIONS: PEID with dissection of the scar tissue from the medial facet joint rather than from the neural tissue may be an effective alternative surgical method for recurrent disk herniation.

Spinal anesthesia and minimal invasive laminotomy for paddle electrode placement in spinal cord stimulation: technical report and clinical results at long-term followup.

OBJECT: We arranged a mini-invasive surgical approach for implantation of paddle electrodes for SCS under spinal anesthesia obtaining the best paddle electrode placement and minimizing patients' discomfort. We describe our technique supported by neurophysiological intraoperative monitoring and clinical results. METHODS: 16 patients, affected by neuropathic pain underwent the implantation of paddle electrodes for spinal cord stimulation in lateral decubitus under spinal anesthesia. The paddle was introduced after flavectomy and each patient confirmed the correct distribution of paresthesias induced by intraoperative test stimulation. VAS and patients' satisfaction rate were recorded during the followup and compared to preoperative values. RESULTS: No patients reported discomfort during the procedure. In all cases, paresthesias coverage of the total painful region was achieved, allowing the best final electrode positioning. At the last followup (mean 36.7 months), 87.5% of the implanted patients had a good rate of satisfaction with a mean VAS score improvement of 70.5%. CONCLUSIONS: Spinal cord stimulation under spinal anesthesia allows an optimal positioning of the paddle electrodes without any discomfort for patients or neurosurgeons. The best intraoperative positioning allows a better postoperative control of pain, avoiding the risk of blind placements of the paddle or further surgery for their replacement.

Prevention of scar tissue formation in spinal surgery: state of the art and review of the literature.

Recurrent radicular pain after lumbar micro-discectomy may lead to reduced quality of life of the patient. Lumbar epidural fibrosis is believed to be one of the mechanisms involved in the genesis of the pain. The use of absorbable gel temporarily separating disc remnants, muscle or bone structures from the nerve roots could reduce the amount of scar tissue surrounding the nerve, reduce tethering and therefore pain, improve outcomes and facilitate revision surgery. The author reviews the literature on prevention techniques for lumbar epidural fibrosis. The most recent studies on new compounds are encouraging in terms of safety and clinical efficacy.

L5-S1 disc replacement after two previous fusion surgeries for scoliosis.

Following scoliosis surgery, lumbar motion segment degeneration below the level of fusion is not uncommon. Especially long fusions extending to the mid and lower lumbar spine increase the likelihood of degeneration of the remaining motion segments. The management for these patients is controversial and depends on the clinical presentation and level of degeneration. The increasing confidence in motion-preserving technology leads to a dilemma on whether to fuse the remaining lumbar levels or risk utilising disc arthroplasty to preserve the remaining motion segments and facilitate coronal balance in patients with previous long fusion for scoliosis. We present an interesting case of a 44-year-old lady, who underwent two-stage corrective surgery for progressive idiopathic scoliosis at the age of 22 years. In the first stage, she had T11-L3 anterior fusion, whilst in the second stage posterior fusion was done from T5 to L3. At 22 years after the initial surgery, she presented with worsening low back pain and bilateral L4 radicular symptoms. MRI scan confirmed severe disc degeneration at L3-4 and L5-S1 levels with preserved L4-5 disc. She initially underwent L3-L4 decompression and posterolateral fusion at that level, which relieved her radicular symptoms. However, she had persistent pain at the lumbosacral junction with Modic I changes. The options of an anterior L5-S1 fusion or disc replacement were considered and discussed with the patient. The disc replacement option was decided upon with the patient, as anterior fusion was judged to increase the risk of coronal imbalance. At the 1-year follow-up, she reported significant improvement in the back pain. The radiographs at 1 year showed satisfactory position and function of the artificial disc replacement. The disc was flexed laterally, accommodating the coronal balance of the spine. We conclude that L5-S1 motion segment can be preserved with artificial disc replacement in patients with previous long fusion for scoliosis surgery. The real difficulty arises when choosing between disc replacement and extension of fusion. In our patient, the disc replacement has worked well so far. However, the disc is clearly at a mechanical disadvantage, and loss of function in the mid- or long term would not be surprising.

The Correlation of Epidural Fibrosis with Epiduroscopic and Radiologic Imaging for Chronic Pain after Back Surgery.

BACKGROUND: Chronic low back pain is observed frequently after lumbar spinal surgery. Epidural fibrosis has been implicated in the etiology of persistent pain after back surgery. The incidence of epidural fibrosis increases as the number and extent of spinal surgery increases. Epidural fibrosis can be detected by conventional radiologic methods [e.g., lumbosacral magnetic resonance imaging (MRI) with gadolinium], but these methods are insufficient to reveal the presence of epidural adhesions. Imaging of the epidural cavity using an epiduroscope is one of the best methods for visualizing the spinal cavity without damaging anatomic structures. OBJECTIVES: To evaluate the correlation between the type and number of surgery and the degree of epidural fibrosis and to compare epidural fibrosis in epiduroscopic and MRI findings in patients with failed back surgery syndrome (FBSS). STUDY DESIGN: A prospective trial. SETTING: A university hospital. METHODS: This study included 61 patients with persistent low back pain and/or radicular pain for at least 6 months, despite lumbar surgery and conservative treatment, and who accepted epiduroscopic imaging. All patients were evaluated in a physical examination using a visual analog scale (VAS) per the elapsed time after surgery. The patients were divided into 3 groups according to the number and type of surgeries. Epidural fibrosis was rated using MRI with gadolinium and epiduroscopy. RESULTS: When the relationship between admission symptoms and epidural fibrosis was evaluated, MRI findings of fibrosis were found to be significantly higher in all patients with both lumbar and radicular pain symptoms at the confidence level of 95% (P = 0.001). The degree of fibrosis detected using epiduroscopy was grade 1 and 2 in almost all patients who presented with low back pain only, only radicular pain, or only distal paresthesia (P = 0.001). In the correlation analysis between the duration of the postoperative period (4.13 ± 2.97 years) and the degree of fibrosis detected using MRI and epiduroscopy, a statistically significant relationship was found at the confidence level of 95% (P < 0.05). As the number and extent of spinal surgeries increased, the incidence of MRI fibrosis increased, which is compatible with the literature (P = 0.001) There was a statistically significant relationship between the degree of fibrosis as detected using MRI and epiduroscopy at the confidence level of 95% (P < 0.05). Differently, we observed that 6 patients had grade 1 fibrosis as diagnosed using epiduroscopy, whereas none had fibrosis on MRI. LIMITATIONS: We did not have a control group. Further studies are required to demonstrate the relevance of these 2 imaging techniques (epiduroscopy and MRI) in terms of detecting epidural fibrosis in patients with FBSS.  CONCLUSIONS: Epiduroscopic imaging seems to be more sensitive than MRI in detecting grade I epidural fibrosis in patients with FBSS. Thus, the possibility of low-grade epidural fibrosis as a source of pain after back surgery, should be kept in mind in normally reported MRIs. Treatment should be planned accordingly.

Comparison of the effects of an adhesion barrier and chitin on experimental epidural fibrosis.

AIM: Epidural fibrosis is an important factor for postoperative failed back syndrome development and causes clinical complaints in 6-25% of cases. An effective treatment modality has not been found yet. The aim of this study is to investigate the anti-adhesive effects of a novel agent chitin and compare these effects with a popular adhesion barrier collagen matrix. MATERIAL AND METHODS: 21 rabbits were allocated into three groups including 7 rabbits each. L5 total laminectomy was performed to all groups. No treatment was given to Group 1 (Control group). Collagen matrix was used in Group 2 and chitin was used in Group 3. Six weeks later all rabbits were sacrificed and the laminectomy areas were entirely resected and investigated histopathologically. RESULTS: He and Revel grade III epidural fibrosis was detected in the control group. Statistically significant reduction of epidural fibrosis was achieved with both of the anti-adhesive agents, collagen matrix and chitin, when compared with the control group (p < 0.05). The results were not different between treatment groups (p > 0.05). CONCLUSION: The novel agent chitin was found effective for preventing epidural fibrosis and this effect was not significantly different from the collagen matrix. In light of our findings we suggest that chitin is an effective alternative for adhesion barriers.

An Evidence Based Review of Epidurolysis for the Management of Epidural Adhesions.

Purpose of Review: This review presents epidurolysis as a procedure to alleviate pain and disability from epidural adhesions. It reviews novel and groundbreaking evidence, describing the background, indications, benefits and adverse events from this procedure in an effort to provide healthcare experts with the data required to decide on an intervention for their patients. Recent Findings: Epidural adhesions (EA) or epidural fibrosis (EF) is defined as non-physiologic scar formation secondary to a local inflammatory reaction provoked by tissue trauma in the epidural space. Often, it is a sequelae of surgical spine intervention or instrumentation. The cost associated with chronic post-operative back pain has been reported to be up to nearly $12,500 dollars per year; this, coupled with the increasing prevalence of chronic lower back pain and the subsequent increase in surgical management of back pain, renders EF a significant cost and morbidity in the U.S. Though risk factors leading to the development of EA are not well established, epidural fibrosis has been reported to be the culprit in up to 46% of cases of Failed Back Surgery Syndrome (FBSS), a chronic pain condition found in up to 20-54% of patients who receive back surgery. Moreover, EF has also been associated with lumbar radiculopathy after lumbar disc surgery. Epidurolysis is defined as the mechanical dissolution of epidural fibrotic scar tissue for persistent axial spine or radicular pain due to epidural fibrosis that is refractory to conservative therapy Endoscopic lysis of adhesions is a procedural technique which has been shown to improve chronic back pain in one-third to one-half of patients with clinically symptomatic fibrous adhesions. Here we review some of the novel evidence that supports this procedure in EA and FBSS. Summary: The literature concerning epidurolysis in the management of epidural adhesions is insufficient. Prospective studies, including randomized controlled trials and observational studies, have suggested epidurolysis to be effective in terms of pain reduction, functional improvement, and patient satisfaction scores. Observational studies report epidurolysis as a well-tolerated, safe procedure. Current evidence suggests that epidurolysis may be used as an effective treatment modality for epidural adhesions. Nonetheless, further high quality randomized controlled studies assessing the safety and efficacy of epidurolysis in the management of epidural adhesions is needed.

Non-Union After Multiple Lumbar Fusion Surgeries in a Patient With Facioscapulohumeral Muscular Dystrophy: A Case Report and Review of the Literature.

BACKGROUND: Facioscapulohumeral muscular dystrophy (FSHD) is a rare condition affecting 1/20,000 persons and the third most common muscular dystrophy condition, with an autosomal dominant pattern of inheritance characterized by progressive muscular weakness primarily involving the face, shoulder girdle, and upper arm. The condition is associated with atrophic musculature of the trunk and core leading to difficulties with gait, posture, and function. FSHD leaves as many as 20% of patients wheelchair-bound and most commonly presents with low back, neck, and shoulder pain. CASE DESCRIPTION: We present the case of a patient with FSHD who underwent multiple spinal fusion surgeries without relief in her back pain. Imaging studies serve to highlight the extent of paraspinal muscle atrophy and provides the basis for a discussion on the preoperative factors that may predict patients most likely to benefit from surgery. We then provide a brief review of the literature on the role of paraspinal muscle atrophy in back pain. CONCLUSIONS: This case adds to our understanding of the surgical management of patients with FSHD and patients with atrophic core musculature as a whole.

Minimally invasive interbody fusion for revision lumbar surgery: technical feasibility and safety.

STUDY DESIGN: Retrospective chart review of one surgeon's practice. OBJECTIVE: We evaluate the perioperative morbidity of 43 patients undergoing minimally invasive lumbar interbody fusion to differentiate risks between primary and revision surgery candidates. SUMMARY OF BACKGROUND DATA: Minimally invasive approaches to the lumbar spine have rapidly evolved and the technical feasibility and safety of minimally invasive interbody fusion is well established. Revision surgery is technically more challenging and may cause avoidance of such approaches because of altered anatomy and absent bony landmarks. Description of minimally invasive surgery approaches among revision patients and the feasibility of such techniques demands clarification. METHODS: Forty-three consecutive minimally invasive transforaminal lumbar interbody fusions (TLIFs) and posterior lumbar interbody fusions (PLIFs) were reviewed. Estimated blood loss, operative time, and complication rates were compared between primary and revision patients using Student t tests. RESULTS: Seventeen revision surgery cases (40%) were compared with 26 primary surgeries (60%) to elucidate differences in operative time, estimated blood loss, and complications. Demographic variables were similar in both groups. Estimated blood loss trended higher among the PLIF group and among revision cases, though no statistical significance was observed. A higher rate of complications, most notably incidental durotomy, was observed among revision cases in both PLIF and TLIF patients. One patient undergoing primary surgery had an intraoperative pedicle fracture, and 1 patient undergoing revision surgery had an asymptomatic screw malposition. No patients had a major complication, nerve injury, infection, or conversion to an open procedure. CONCLUSIONS: Minimally invasive lumbar interbody fusion by revision surgery is technically feasible and is not associated with more blood loss or neurologic morbidity. However, revision surgery has a higher minor perioperative complication rate, particularly of incidental durotomy. These outcomes demand significant experience before attempting minimally invasive revision surgery in the lumbar spine.

Effectiveness of spinal endoscopic adhesiolysis in post lumbar surgery syndrome: a systematic review.

BACKGROUND: Post lumbar surgery syndrome with persistent chronic low back and lower extremity pain is common in the United States. Epidural fibrosis may account for as much as 20% to 36% of all cases of failed back surgery syndrome (FBSS). Percutaneous adhesiolysis with a catheter or direct visualization of the spinal canal and the contents with an endoscope are techniques employed in resistant cases when patients fail to respond to conservative modalities of treatment, including fluoroscopically directed epidural injections. Some patients failing to respond to percutaneous adhesiolysis are candidates for spinal endoscopic adhesiolysis. However, literature evaluating the effectiveness of spinal endoscopic adhesiolysis is sparse and discussions continue about its effectiveness, utility, and complications. STUDY DESIGN: A systematic review of the available literature. OBJECTIVE: To evaluate the effectiveness and safety of spinal endoscopic adhesiolysis in the management of chronic low back and lower extremity pain in post surgical patients with chronic recalcitrant pain, non-responsive to conservative modalities of management and fluoroscopically directed epidural injections. METHODS: A search of relevant resources (PubMed, EMBASE, and the Cochrane database) was accomplished and the resulting publications were examined based on the inclusion/exclusion criteria set forth. Randomized controlled trials and observational studies were included in the search. Two reviewers assessed the studies' methodologies and outcomes. Randomized clinical trials were assessed and scored based on the criteria established by the Cochrane methodological assessment criteria of randomized clinical trials and the observational studies were assessed and scored based on the Agency for Healthcare Research and Quality (AHRQ) criteria. Clinical relevance was evaluated utilizing Cochrane review criteria. Analysis was conducted using 5 levels of evidence, ranging from Level I to III, with 3 subcategories in Level II. OUTCOME MEASURES: The primary outcome measure was pain relief (> or = 50%) in follow-up for at least 6 months. Pain relief for longer than 6 months was considered long-term and 6 months or less was considered short-term. The secondary outcome measures were functional and psychological status, return to work, patient satisfaction, and opioid intake. RESULTS: Of the 13 studies considered for inclusion, one randomized trial and 5 observational studies met inclusion criteria for evidence synthesis based on the inclusion criteria and methodologic quality scores of 50 or more. The indicated level of evidence for endoscopic adhesiolysis is Level II-1 or II-2 evidence for short- and long-term relief based on the U.S. Preventive Services Task Force (USPSTF) criteria. LIMITATIONS: There was a paucity of literature for randomized trials. CONCLUSION: Spinal endoscopic adhesiolysis may be used as an effective treatment modality for chronic refractory low back pain and radiculopathy that is related to epidural adhesions.

Cell types obtained from the epidural space of patients with low back pain/radiculopathy.

BACKGROUND: We investigated if correlations exist between medical history, tissue abnormalities, and cell types retrieved from the epidural space of patients with chronic low back pain (LBP) and chronic radicular pain (RP). METHODS: Approval was obtained from the Institutional Review Board for the Protection of Human Subjects to study 191 patients undergoing epiduroscopy. Visual inspection was performed and abnormal areas were identified. A specimen obtained from the area using a cytology brush was processed by the Thin Prep technique. Patients were divided into four groups based on the presence or absence and intensity of LBP and RP. The gender and age of the patients were recorded, as was any history of prior back surgery. Areas of tissue abnormalities were rated according to changes in vascularity and amount of fat, fibrosis, and inflammation. Stenosis was assessed from magnetic resonance imaging or computerized tomography scan images. Cytologic assessments included notations of the presence or absence of erythrocytes, leukocytes, cell groups, lipocytes, spindled cells, and large round cells. RESULTS: There was a significant difference in the number of patients from whom big round cells were obtained who had a high degree of LBP compared with the number of patients who had a high degree of both LBP and RP. CONCLUSIONS: The findings provide a foundation for future studies of cells obtained from similar patients with the goal of furthering the understanding of the pathogenesis of LBP/RP.

Effect of cepea extract-heparin and allantoin mixture on epidural fibrosis in a rat hemilaminectomy model.

AIM: Epidural fibrosis following a laminectomy procedure is a serious problem that results in failed back surgery syndrome. Aserious number of manuscripts have explained its possible mechanism and results but no effective preventive surgical technique or treatment is currently present. MATERIAL AND METHODS: We used a rat hemilaminectomy model at lumbar fourth level. In the treatment group (n:10), the hemilaminectomy sites were filled with cepea extract-allantoin and heparin mixture as sterile cream form. In the second group, the same surgical procedure was performed and the site was filled with physiological saline. All animals were terminated after 6 weeks and laminectomy sites removed en-bloc. Epidural fibrosis was evaluated and compared using semi-quantitative histopathological scoring scales. RESULTS: In the physiological saline group, the fibrosis score was 10.3 points and 90% of the subjects had acute inflammatory reaction, 80% chronic inflammatory reaction and 100% showed bone destruction and reparation process. In the cepea extract group, these values were fibrosis score 4.2 points, 0% acute inflammatory reaction, 33.3% chronic inflammatory reaction and 10% bone destruction and reparation process, respectively. CONCLUSION: This study showed that aloe cepea extract-allantoin and heparin mixture diminished epidural scarring formation effectively with decreased scores of acute and chronic inflammation, compared to the physiological saline solution group.

Transforaminal Epiduroscopy in Patients with Failed Back Surgery Syndrome.

BACKGROUND: Epiduroscopy is a useful diagnostic and therapeutic tool for managing failed back surgery syndrome (FBSS). The conventional approach is via either the sacral hiatus or the interlaminar. Major causes of FBSS include epidural fibrosis, disc herniation, and stenosis. When these problems are located at the intervertebral foramen level, it can be difficult to reach the lateral recess and the foramen with the epiduroscope. Transforaminal epiduroscopy could be a useful alternative approach in patients with FBSS located at the foraminal level. OBJECTIVE: We present a new procedure for lumbar epiduroscopy via a transforaminal approach and its application in patients with FBSS. The technique is described and long-term results are reported. STUDY DESIGN: This study used a single-arm prospective observational design. SETTING: The research took place at the University Hospital in Spain. METHODS: Patients with FBSS suffering severe chronic radicular pain (Numeric Rating Scale [NRS-11] > 7) who had not responded to other treatments were included. Selective root stimulation during a pulsed radiofrequency procedure confirmed the origin of pain by means of an exact reproduction of typical pain. Transforaminal epiduroscopy was performed at the affected level. The severity of fibrosis observed was recorded. The NRS-11 score was reevaluated at 1, 6, and 12 months after the procedure. Any complications related to the treatment were recorded. RESULTS: Twenty-four patients were included. The mean number of back surgeries was 1.66 (range, 1-5). The basal NRS-11 score was 7.83 (0.14); at 1 month, 3.66 (0.38) (P < 0.001); at 6 months, 4.46 (0.48) (P < 0.01); and at 1 year after treatment, 4.17 (0.51) (P < 0.01). Most patients (54%; 95% CI, 34%-74%) obtained > 50% pain reduction on the NRS-11, maintained during a 1-year follow-up period. No major complications were registered. LIMITATIONS: The research was limited by the lack of a control group. CONCLUSIONS: We have described a new procedure for epiduroscopy via the transforaminal approach. It is a useful and safe approach to managing FBSS at the foraminal level and shows better long-term results than other endoscopic procedures. KEY WORDS: Epidural, epiduroscopy, chronic pain, spinal cord, back surgery.