Intradiscal pressure study of percutaneous disc decompression with nucleoplasty in human cadavers

Machine Learning Assisting the Prediction of Clinical Outcomes following Nucleoplasty for Lumbar Degenerative Disc Disease

BACKGROUND

Lumbar degenerative disc disease (LDDD) is a leading cause of chronic lower back pain; however, a lack of clear diagnostic criteria and solid LDDD interventional therapies have made predicting the benefits of therapeutic strategies challenging. Our goal is to develop machine learning (ML)-based radiomic models based on pre-treatment imaging for predicting the outcomes of lumbar nucleoplasty (LNP), which is one of the interventional therapies for LDDD.

METHODS

The input data included general patient characteristics, perioperative medical and surgical details, and pre-operative magnetic resonance imaging (MRI) results from 181 LDDD patients receiving lumbar nucleoplasty. Post-treatment pain improvements were categorized as clinically significant (defined as a ≥80% decrease in the visual analog scale) or non-significant. To develop the ML models, T2-weighted MRI images were subjected to radiomic feature extraction, which was combined with physiological clinical parameters. After data processing, we developed five ML models: support vector machine, light gradient boosting machine, extreme gradient boosting, extreme gradient boosting random forest, and improved random forest. Model performance was measured by evaluating indicators, such as the confusion matrix, accuracy, sensitivity, specificity, F1 score, and area under the receiver operating characteristic curve (AUC), which were acquired using an 8:2 allocation of training to testing sequences.

RESULTS

Among the five ML models, the improved random forest algorithm had the best performance, with an accuracy of 0.76, a sensitivity of 0.69, a specificity of 0.83, an F1 score of 0.73, and an AUC of 0.77. The most influential clinical features included in the ML models were pre-operative VAS and age. In contrast, the most influential radiomic features had the correlation coefficient and gray-scale co-occurrence matrix.

CONCLUSIONS

We developed an ML-based model for predicting pain improvement after LNP for patients with LDDD. We hope this tool will provide both doctors and patients with better information for therapeutic planning and decision-making.

Analysis of the clinical and radiological outcomes of percutaneous cervical nucleoplasty: A case-control study

BACKGROUND

Percutaneous cervical nucleoplasty (PCN) is a simple, safe, and effective treatment for contained cervical herniated intervertebral disc (CHIVD). However, few studies have compared the actual benefits of PCN against conservative treatment (CT), either clinically or radiographically.

PURPOSE

The present study sought to analyze and to compare the outcomes of symptomatic contained CHIVD treated with PCN or CT.

METHODS

The present study was designed as a case-control comparative study. Patients who indicated for PCN after a failed CT for more than 6 months were recruited. After the exclusion of some patients who did not meet the selection criteria of the study, we finally enrolled 71 patients treated with PCN. In addition, another 21 patients who indicated for PCN but finally chose to receive CT continuously were also enrolled and categorized as the control group. All patients completed the 6-month follow-up. Pain levels and functional outcomes were evaluated pre- and post-operatively by assessing the visual analog scale (VAS), Oswestry Disability Index (ODI), and Neck Disability Index (NDI). Radiographic images of 72 of 104 intervened segments were collected to measure disc height and other cervical spinal alignments, such as range of motion, C2-7 Cobb's angle, and C2-7 sagittal vertical axis.

RESULTS

Compared with the CT group, the PCN group showed significantly better outcomes on VAS, ODI, and NDI at the 1-month post-operative follow-up, which continued through at least the 6-month follow-up (P < 0.01 for VAS and P < 0.05 for ODI and NDI). The mean disc height significantly decreased, from 6.04 ± 0.85 mm to 5.76 ± 1.02 mm, 3 months after PCN treatment (P = 0.003). However, the degree of disc height decrease did not correlate with the changes of the substantial VAS improvement.

CONCLUSIONS

To provide therapeutic benefits for symptomatic contained CHIVD patients after an invalid CT for 6 months, PCN seems to be a better option than CT. The reduced disc heights did not alter the clinical outcomes of PCN.

A New Role for Epidurography: A Simple Method for Assessing the Adequacy of Decompression during Percutaneous Plasma Disc Decompression

Percutaneous plasma disc decompression (PPDD) is a minimally invasive treatment for discogenic low back pain and herniated disc-related symptoms. However, there are no known outcome predictive variables during the procedure. The purpose of this study was to evaluate and validate epidurography as an intra-procedure outcome predictor. We retrospectively enrolled 60 consecutive patients who did not respond to conventional treatments. In the next stage of treatment, PPDD was performed, and the epidurography was conducted before and after the PPDD. We analyzed the relationship between epidurographic improvement and the success rate. The Numerical Rating Scale and the Oswestry Disability Index were used to assess pain and functional capacity, respectively, before the procedure and 1 month after the procedure. The pain reduction and the success rate in the epidurographic improvement group were significantly higher than in the epidurographic non-improvement group. Both the Numerical Rating Scale and the Oswestry Disability Index scores were significantly reduced in both groups, but there was no significant difference in Oswestry Disability Index scores. This study's results showed that PPDD is an effective treatment method. We also suggested that epidurography may be a potential outcome predictor for ensuring successful outcomes and determining the endpoint of the procedure.

Percutaneous discectomy under CT and fluoroscopy guidance: an international multicentric study

PURPOSE

To evaluate the technical efficacy, safety, and reproducibility of automated percutaneous lumbar discectomy (APLD) under CT and fluoroscopic guidance, for treating radiculopathy caused by lumbar disc herniation in patients impervious to conservative treatment.

METHODS

A total of 77 patients with symptomatic lumbar disc herniation were treated with APLD in a prospective multicentric study performed in four centers across three countries. Magnetic resonance imaging and/or computed tomography was used to evaluate the disc herniation before and after the procedure. Only local anesthesia was used during these procedures. Clinical outcomes were measured with the visual analog scale (VAS) for pain at one and 6 months after the procedure.

RESULTS

Technical success rate was 100% with a mean intervention duration of 30 min (15-45 min). No complications occurred during the procedure. Post-lumbar puncture syndrome occurred in three patients who were successfully treated with blood patches. VAS decreased from a mean of 8 before the intervention to 3 1 month after (p value = 0.001). The requirement for analgesia decreased from 100 to 27%. No statistically significant differences in outcomes were found between the centers.

CONCLUSION

APLD with dual imaging guidance under local anesthesia is a safe, feasible, and reproducible technique to treat symptomatic lumbar disc herniation.

Percutaneous cervical coblation as therapeutic technique in the treatment of algo-dysfunctional pain of discal herniation

OBJECTIVE

To confirm the validity of coblation nucleoplasty in reduction of cervical discogenic nature.

STUDY DESIGN

In a monocentric prospective clinical observational study recruiting 20 patients, treated with percutaneous coblation for cervical discogenic pain in 16 months in our hospital, we have clinically evaluated 18 patients. The pain was scored with the Visual Analogic Scale (VAS) in a pre-procedural questionary, 3/4 monthly follow-up from treatment and, finally, in a long-term follow-up 2 years after procedure.

RESULTS

The mean pre-procedural VAS score was 7.9 ± 1.6 (95%-Confidence Interval 7.198-8.634), while the mean post-procedural score after 3-4 months has been 2.5 ± 3.1 (95%-Confidence Interval 1.089-3.965) and 2.5 ± 2.5 (95%-Confidence Interval 1.367-3.687) after 2 years. Among 18 patients, in the shortly post-treatment follow-up, nine had a complete pain relief, four had a > 50% VAS reduction, two hada < 50% VAS reduction, three did not have any variation of VAS; after 2 years, six patients had a total pain resolution, eight had a > 50% VAS reduction, two hada < 50% VAS reduction, two did not have any benefit. No peri- and post-procedural complication has been observed.

CONCLUSIONS

In a spite of a little sample, our results showed coblation as a valid therapeutic option to reduce cervical discogenic pain in medicine-refractory patients, as an alternative or a previous choice before a more invasive surgical treatment.

The Percutaneous Endoscopic Lumbar Interbody Fusion (PELIF): An Advanced and Innovation Technique

The degenerative spine changes, and its costs, have increased with high rates of work absenteeism and difficult clinical management. The search for minimally invasive treatments, with better results and early patients recover, with rapid hospital discharge are alternatives for these problems. The percutaneous endoscopic lumbar interbody fusion (PELIF) is a new and advanced option.

Comparison the Postoperation Results of Discectomy with Nucleoplasty in Single Cervical Disc Herniation

BACKGROUND

The standard treatment for cervical disc herniation is open discectomy surgery but some of techniques, such as nucleoplasty were applied by neurosurgeons in recent decade. The aim of this study was to compare the postoperation results of open discectomy and nucleoplasty methods in people suffering from single cervical disc herniation.

MATERIALS AND METHODS

In a clinical trial study that performed during 2012-2013, 70 patients who candidate for neck surgery were selected and randomly divided into two groups. The first group was operated with standard discectomia and the second group was operated with nucleoplasty method. All patients were followed neck pain, upper limb pain and common complications included discitis, infection and hematoma in 2 weak, 1, 2, 3, and 6 months after operation. All data were analyzed using SPSS software.

RESULTS

Cervical pain mean from before the operation to 6 months after operation had no significant difference between two groups, but radicular pain had significant difference in 2 and 3 months after operation (P < 0.05). It is notable that after operation it is not observed any discitis, infection and hematoma of operated place.

CONCLUSION

Doing nucleoplasty surgery in patients suffering from single cervical disc herniation causes decrease in cervical and radicular pain, at least as the same as discectomy method. Since now it is possible in our country to apply this method and on the other hand, in this method, time of surgery, postoperation complications, hospital costs, and period of convalescence is low, it is preferred in patients suffering from cervical disc and its application is advised.

Comparison of coblation annuloplasty and radiofrequency thermocoagulation for treatment of lumbar discogenic pain

This study aimed to compare the effectiveness and safety of coblation annuloplasty and radiofrequency thermocoagulation for lumbar discogenic pain.Patients who suffered from lumbar discogenic pain and underwent coblation annuloplasty and radiofrequency thermocoagulation surgery were included. A questionnaire, including the visual analo scale (VAS), MacNab criteria, pain relief rate, and any complications due to surgery, was completed by the patients with the help of a trained volunteer who was blinded to the study. Data were collected at 1 week, and 1, 3, 6, and 12 months after surgery. Significant pain relief was defined as postoperative pain relief ≥50% compared with the preoperative state. Any complications during or after surgery were also recorded.A total of 122 patients were included; 37 patients were lost in the follow-up and 85 were evaluated. Among these, 45 patients underwent coblation annuloplasty (CA group, n = 45) and 40 underwent radiofrequency thermocoagulation procedures (RF group, n = 40).VAS pain scores were decreased at 1 week and 1, 3, 6, and 12 months postoperatively compared with preoperation in both groups (P < .05). The CA group had significantly lower VAS scores at 6 and 12 months of follow-up than did the RF group (P < .05). According to the modified MacNab criteria, the proportions of patients with excellent and/or good results at 3, 6, and 12 months of follow-up were significantly higher in the CA group compared with the RF group (P < .05).Only 2 patients reported soreness at the needle insertion site in the CA group. However, 3 patients had soreness at the needle insertion site, 3 had increased intensity of low back pain, 1 had intracranial hypotension, and 2 had new numbness in the leg and foot in the RF group. At the 1-year follow-up, this numbness was present all of the time. No major complications occurred in the CA group.Our study suggests that CA is a more effective and safe minimally invasive procedure than RF for treating lumbar discogenic pain.

Percutaneous Treatment of Herniated Lumbar Discs with Ozone: Investigation of the Mechanisms of Action

PURPOSE

To elucidate the mechanism of action of intradiscal oxygen-ozone therapy for herniated intervertebral disc therapy.

METHODS

Ozone's mechanism of action was investigated using 3 approaches: mathematical models of intervertebral disc space to explore the relationship between disc pressure and volume; ozonolysis experiments using glycosaminoglycans (GAGs) from a Chinese hamster ovary cell line that were similar in composition to GAGs found in human nucleus pulposus; and experiments in which live Yucatan miniature pigs received various concentrations of percutaneous, image-guided intradiscal oxygen-ozone treatment and were examined (after sacrifice) with histology and semiquantitative analysis of disc cytokine concentrations.

RESULTS

Engineering calculations support observations that a small (6%) disc volume reduction can result in considerable (9.84%) intradiscal pressure reduction. Porcine disc histology and Chinese hamster ovary GAG ozonolysis results showed that administered ozone reacted with and fragmented disc proteoglycans, reducing disc volume through disc dehydration. Cytokine analysis of porcine discs found that each of 4 cytokines measured (interleukin [IL]-1β, IL-6, IL-8, and tumor necrosis factor α) increased in concentration after 2 wt% ozone treatment.

CONCLUSIONS

Oxygen-ozone therapy breaks down proteoglycan GAGs that maintain disc osmotic pressure, dehydrating the nucleus pulposus and reducing intervertebral disc volume. This is likely a primary mechanism by which ozone relieves nerve root compression and alleviates herniated disc-related pain. Additionally, 2 wt% ozone appears to interact with intradiscal cytokines, generating an antiinflammatory response that may contribute to symptom improvement.

Cervical intervertebral disc herniation treatment via radiofrequency combined with low-dose collagenase injection into the disc interior using an anterior cervical approach

This study aimed to determine the therapeutic effect of radiofrequency combined with low-dose collagenase injected into the disc interior via an anterior cervical approach for cervical intervertebral disc herniation.Forty-three patients (26-62-year old; male/female ratio: 31/12) with cervical intervertebral disc herniation received radiofrequency combined with 60 to 100 U of collagenase, injected via an anterior cervical approach. The degree of nerve function was assessed using the current Japanese Orthopaedic Association (JOA) scoring system at 3 and 12 months postoperation. A visual analogue scale (VAS) was used to evaluate the degree of pain preoperation and 7 days postoperation. The preoperative and 3 month postoperative protrusion areas were measured and compared via magnetic resonance imaging (MRI) and picture archiving and communication systems (PACS).Compared with the preoperative pain scores, the 7-day postoperative pain was significantly reduced (P <0.01). The excellent and good rates of nerve function amelioration were 93.0% and 90.7% at 3 and 12 months postoperation, respectively, which was not significantly different. Twenty-seven cases exhibited a significantly reduced protrusion area (P <0.01) at 3 months postoperation. No serious side effects were noted.To our knowledge, this is the first study to demonstrate that the use of radiofrequency combined with low-dose collagenase injection into the disc interior via an anterior cervical approach is effective and safe for the treatment of cervical intervertebral disc herniation.

Percutaneous Nucleoplasty Using Coblation Technique for the Treatment of Chronic Nonspecific Low Back Pain: 5-year Follow-up Results

BACKGROUND

This study evaluated the efficacy of percutaneous nucleoplasty using coblation technique for the treatment of chronic nonspecific low back pain (LBP), after 5 years of follow-up.

METHODS

From September 2004 to November 2006, 172 patients underwent percutaneous nucleoplasty for chronic LBP in our department. Forty-one of these patients were followed up for a mean period of 67 months. Nucleoplasty was performed at L3/4 in 1 patient; L4/5 in 25 patients; L5/S1 in 2 patients; L3/4 and L4/5 in 2 patients; L4/5 and L5/S1 in 7 patients; and L3/4, L4/5, and L5/S1 in 4 patients. Patients were assessed preoperatively and at 1 week, 1 year, 3 years, and 5 years postoperatively. Pain was graded using a 10-cm Visual Analogue Scale (VAS) and the percentage reduction in pain score was calculated at each postoperative time point. The Oswestry Disability Index (ODI) was used to assess disability-related to lumbar spine degeneration, and patient satisfaction was assessed using the modified MacNab criteria.

RESULTS

There were significant differences among the preoperative, 1-week postoperative, and 3-year postoperative VAS and ODI scores, but not between the 3- and 5-year postoperative scores. There were no significant differences in age, sex, or preoperative symptoms between patients with effective and ineffective treatment, but there were significant differences in the number of levels treated, Pfirrmann grade of intervertebral disc degeneration, and provocative discography findings between these two groups. Excellent or good patient satisfaction was achieved in 87.9% of patients after 1 week, 72.4% after 1 year, 67.7% after 3 years, and 63.4% at the last follow-up.

CONCLUSIONS

Although previously published short- and medium-term outcomes after percutaneous nucleoplasty appeared to be satisfactory, our long-term follow-up results show a significant decline in patient satisfaction over time. Percutaneous nucleoplasty is a safe and simple technique, with therapeutic effectiveness for the treatment of chronic LBP in selected patients. The technique is minimally invasive and can be used as part of a stepwise treatment plan for chronic LBP.

Comparison of open surgical discectomy versus plasma-laser nucleoplasty in patients with single lumbar disc herniation

Background:

Intervertebral disc herniation is a major cause of low back pain. Several treatment methods are available for lumbar disc herniation including Chemonucleolysis, open surgery, nucleoplasty, laser disc decompression, and intradiscal electrothermal therapy. The high prevalence of lumbar disc herniation necessitates a minimally invasive yet effective treatment method. In this study, we compared the outcomes of open surgery and nucleoplasty method in patients with single lumbar disc herniation.

Materials and Methods:

This study was a noninferiority randomized clinical trial conducted in one of the University Hospitals of Isfahan Medical University; The Alzahra Hospital. About 200 patients with the diagnosis of lumbar disc herniation were recruited and were assigned to either the treatment or control groups using block randomization. One group received open surgery and the other group received nucleoplasty as the method of treatment. Patients were revisited at 14 days, 1, 2, 3 months, and 1-year after surgery and were assessed for the following variables: Lower back pain, lower limb pain, common complications of surgery (e.g., discitis, infection and hematoma) and recurrence of herniation.

Results:

The mean (standard deviation) severity of low back pain was reduced from 6.92 (2.5) to 3.43 (2.3) in the nucleoplasty group (P = 0.04) and from 7.5 (2.2) to 3.04 (1.61) in the discectomy group (P = 0.73). Between group difference was not statistically significant (P = 0.44), however, time and treatment interaction was significant (P = 0.001). The level of radicular pain evaluated 1 year after treatment was reduced from 8.1 (1.2) to 2.9 (1.2) (P = 0.004) and from 7.89 (2.1) to 3.6 (2.5) (P =0.04) in the discectomy and the nucleoplasty groups respectively, significant interaction between time and treatment options was observed (P < 0.001) while there was no significant difference between two treatment groups (P = 0.82).

Conclusion:

Our results show that while nucleoplasty is as effective as open discectomy in the treatment of lumbar disc herniation, it is also less invasive with higher patient compliance. Taking factor such as decreased cost and duration of the surgery, as well as faster recovery in patients into account; we suggest considering nucleoplasty as an effective method of treatment in patients with single-level disc herniation.

CT-guided nucleoplasty with radiofrequency energy for the treatment of lumbar disk herniation

STUDY DESIGN

A clinical randomized controlled trial.

OBJECTIVE

This study sought to compare the clinical effectiveness of CT-guided nucleoplasty, CT-guided nucleoplasty combined with nerve root injection, and CT-guided transforaminal lumbar epidural injections in treating patients with contained lumbar disk herniation and leg pain, which are caused by radicular encroachment.

SUMMARY OF BACKGROUND DATA

Lumbar disk herniation is the most common cause of nerve root pain. The conservative treatment is proved to be effective for the majority of these patients, and the remaining patients are not ideal surgical candidates. Studies have found that minimally invasive percutaneous disk procedures may be preferable to open surgery in certain clinical situations. However, nucleoplasty in treating contained lumbar disk herniation and leg pain caused by radicular encroachment is still a controversy.

DESIGN

A total of 97 patients with leg pain and MRI evidence of small-sized or medium-sized herniated disks correlating with the symptoms participated in the study. The patients were randomly allocated into 3 groups: the CT-guided nucleoplasty group (N=33), the CT-guided nucleoplasty with nerve root injection group (N=35), and CT-guided transforaminal lumbar epidural injections group (N=29). Numeric Rating Scale (NRS) pain score and Oswestry Disability Index (ODI) values were applied at pretreatment and 1 week, 1 month, 3 months, and 12 months at posttreatment.

RESULTS

There were statistically significant decreases (P=0.000) in the NRS and ODI scores for all posttreatment time points when compared with the pretreatment values in all the 3 groups. The average NRS and ODI results for the transforaminal lumbar epidural injections group were significantly higher than those for the other 2 groups at 3 and 12 months posttreatment (P<0.05). The combination of nucleoplasty with nerve root injection produced a significantly greater reduction in the NRS and ODI scores when compared with nucleoplasty at 1 week (P=0.000 for NRS and P=0.004 for ODI) and 1 month (P=0.000 for NRS and P=0.007 for ODI) after the treatment.

CONCLUSIONS

The results of this study suggest that CT-guided nucleoplasty with radiofrequency energy is a relative effective and safe technique for treating leg pain caused by radicular encroachment. Furthermore, nucleoplasty combined with nerve root injection had achieved a significant greater improvement in pain management and functional level in short term (within 1 mo) after treatment than nucleoplasty alone.

Efficacy of coblation annuloplasty in discogenic low back pain: a prospective observational study

In degenerative disc, the innervated outer annulus is confirmed to the major origin resulted in discogenic pain. To alleviate the discogenic pain, annuloplasty with electrothermal technology was proved to be effective, which mainly involves the thermal heating of the annulus to denature collagen fibers and denervate posterior annular nerve fibers. However, little is known that efficacy of annuloplasty with coblation technology in treating discogenic pain through directly interrupting nerves in outer annulus.The purpose of this study was to evaluate the clinical outcomes of coblation annuloplasty for the treatment of discogenic low back pain.In a clinical prospective observational study, 17 consecutive patients with discogenic low back pain underwent coblation annuloplasty under local anesthesia. Pain visual analogue scale (VAS) scores, patient responses stating significant (≥50%) pain relief, and modified MacNab criteria were adopted to evaluate the pain intensity, degree of pain relief, and functional status after 6 months of follow-up.The preoperative pain VAS score was 6.5 ± 0.8(95% confidence interval [CI] 6.1-6.9) and the pain VAS score decreased to 2.9 ± 1.6 (95% CI 2.1-3.8), 2.9 ± 1.7 (95% CI 2.1-3.8), 3.2 ± 1.6 (95% CI 2.4-4.1), 3.2 ± 1.7 (95% CI 2.4-4.2) at 1 week and 1, 3 and 6 month postoperatively, respectively. 12 (70.6%), 11 (64.7%), 10 (58.8%) and 10 (58.8%) of patients reported significant pain relief at 1 week and 1, 3 and 6 months postoperatively. At 1, 3, and 6 months postoperatively, the numbers of patients with "excellent" or "good" ratings were 13 (76.5%), 11 (64.7%), and 10 (58.8%) according to the modified MacNab criteria. No serious complications were observed.The finds show that coblation annuloplasty is an effective, safe, and less uncomfortable procedure in managing discogenic low back pain.

A quantitative study of intervertebral disc morphologic changes following plasma-mediated percutaneous discectomy

OBJECTIVE

To quantitatively evaluate interval magnetic resonance imaging (MRI) changes in disc morphology following plasma-mediated percutaneous discectomy.

DESIGN/SETTING

A retrospective comparison of pretreatment and posttreatment MRIs at a single university spine clinic.

SUBJECTS

From a group of 60 consecutively treated patients, 15 met the study inclusion and exclusion criteria. All had either failed treatment or had other clinical reasons for a posttreatment MRI.

METHODS

Two independent physicians electronically measured disc protrusion size and disc height at the treatment discs and adjacent discs on pre- and posttreatment MRI scans. Additionally, images were compared for gross anatomic changes including disc degeneration by Pfirrman classification, new disc herniations, high intensity zone (HIZ), vertebral endplate changes, post-contrast enhancement, and changes in segmental alignment. Pearson r correlation was used to determine interobserver reliability between the two physicians' MRI measurements. Paired t-tests were calculated for comparisons of pre- and posttreatment MRI measurements, and an ANOVA was performed for comparison of pre- to posttreatment changes in disc height measurements at treatment levels relative to adjacent levels.

RESULTS

Correlation was high for measurement of disc height change (r = 0.89; P < 0.0001) and good for anteroposterior protrusion size change (r = 0.51; P = 0.0512). Disc height at treated discs demonstrated a small but statistically significant mean interval reduction of 0.48 mm (P = 0.0018). This remained significant when compared with the adjacent control discs (P < 0.0001). Pretreatment mean disc protrusion size (4.74 mm; range 3.75-6.55 mm) did not differ significantly (P = 0.1145) from posttreatment protrusion size (4.42 mm; range 2.55-7.95 mm). Gross anatomic changes at treatment levels included reduced disc protrusion size (N = 6), enlarged protrusion (N = 3), resolution of HIZ (N = 3), and improvement in endplate signal changes (N = 1). Also, 11/15 posttreatment MRIs included post-contrast images that showed epidural fibrosis (N = 1), rim enhancement (N = 2), and enhancement of the posterior annulus (N = 4).

CONCLUSIONS

Based on MRI examinations, subtle anatomic changes may occur following plasma-mediated percutaneous discectomy. Further study is required to determine the clinical relevance of these changes.

Preliminary Report of Combined Microscopic Fragmentectomy and Nucleoplasty for Sequestrated Lumbar Disc Herniation

OBJECTIVE

This retrospective study was undertaken to evaluate the efficacy of combined microscopic fragmentectomy and intraoperative nucleoplasty for sequestrated lumbar disc herniation.

METHODS

Twenty-four patients with magnetic resonance imaging proven sequestrated lumbar disc herniation with small annular leak treated by microscopic fragmentectomy and nucleoplasty were included. Patients were followed for at least one year. The Oswestry Disability Index (ODI; version 2.0) was used to assess preoperative and postoperative functional statuses in three age groups (20-40, 41-60, and >60 years). Visual analog scale and modified MacNab's criteria were used to assess the clinical outcomes for spinal surgery.

RESULTS

Mean age at operation was 41.2 years (range 20-72 years). ODIs improved significantly regardless of age group. Significant pain relief was achieved at 1 year after surgery. Most patients (92%) had an excellent or good result according to modified MacNab's criteria, and all patients showed symptomatic improvement after surgery. There were two postoperative wound-related complications, and both responded to antibiotics. No patient underwent further additional surgery because of disc re-herniation during follow-up.

CONCLUSION

This study shows that combined microscopic fragmentectomy and intraoperative nucleoplasty without additional discectomy provides a safe operative option for the treatment of sequestrated lumbar disc herniation with small annular leak.

Nucleoplasty as a therapeutic option for lumbar disc degeneration related pain: a retrospective study of 396 cases

OBJECTIVES

To make a retrospective analysis and evaluate a clinical response to the control of disc degeneration related pain of 396 patients submitted to percutaneous lumbar nucleoplasty; and to make a record of visual analogical scale (VAS) up to a three-year follow-up after the surgical procedure.

METHODS

Analysis of VAS score in 396 patients with lumbar disc degeneration related pain, according to anamnesis, clinical examination and magnetic resonance imaging (MRI), without improvement of previous clinical treatment, submitted to percutaneous nucleoplasty.

RESULTS

A total of 26% of the patients presented 100% remission of pain or paresthesia, of whom 75% showed at least 50% of pain improvement. The median VAS pain improvement was about 67%.

CONCLUSIONS

The median VAS improvement in inferior disc levels was higher than four points. The VAS showed improvement of the pain and paresthesia up to a three-year follow up after the surgical procedure.

Disc volume reduction with percutaneous nucleoplasty in an animal model

Study Design

We assessed volume following nucleoplasty disc decompression in lower lumbar spines from cadaveric pigs using 7.1Tesla magnetic resonance imaging (MRI).

Purpose

To investigate coblation-induced volume reductions as a possible mechanism underlying nucleoplasty.

Methods

We assessed volume following nucleoplastic disc decompression in pig spines using 7.1-Tesla MRI. Volumetry was performed in lumbar discs of 21 postmortem pigs. A preoperative image data set was obtained, volume was determined, and either disc decompression or placebo therapy was performed in a randomized manner. Group 1 (nucleoplasty group) was treated according to the usual nucleoplasty protocol with coblation current applied to 6 channels for 10 seconds each in an application field of 360°; in group 2 (placebo group) the same procedure was performed but without coblation current. After the procedure, a second data set was generated and volumes calculated and matched with the preoperative measurements in a blinded manner. To analyze the effectiveness of nucleoplasty, volumes between treatment and placebo groups were compared.

Results

The average preoperative nucleus volume was 0.994 ml (SD: 0.298 ml). In the nucleoplasty group (n = 21) volume was reduced by an average of 0.087 ml (SD: 0.110 ml) or 7.14%. In the placebo group (n = 21) volume was increased by an average of 0.075 ml (SD: 0.075 ml) or 8.94%. The average nucleoplasty-induced volume reduction was 0.162 ml (SD: 0.124 ml) or 16.08%. Volume reduction in lumbar discs was significant in favor of the nucleoplasty group (p<0.0001).

Conclusions

Our study demonstrates that nucleoplasty has a volume-reducing effect on the lumbar nucleus pulposus in an animal model. Furthermore, we show the volume reduction to be a coblation effect of nucleoplasty in porcine discs.

Percutaneous Disc Coagulation Therapy (PDCT) comparing with Automated Percutaneous Lumbar Discectomy (APLD) in Patients of Herniated Lumbar Disc Disease: Preliminary Report

OBJECTIVE

Percutaneous techniques are rapidly replacing traditional open surgery. This is a randomized controlled trial study of clinical outcomes of Percutaneous Plasma Disc Coagulation Therapy (PDCT) in patients with HLD(herniated lumbar disc) as a new percutaneous access in comparison with Automated Percutaneous Lumbar Discectomy (APLD) in its clinical application and usefulness as a reliable alternative method.

METHODS

The authors analyzed 25 patients who underwent PDCT randomized 1:1 to 25 who underwent APLD between June, 2010 and October, 2011. All patients had herniated lumbar disc diseases. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria.

RESULTS

The age of the patients who underwent PDCT ranged from 29 to 88 years with a mean age of 51.8 years. The age of the APLD undergone patients' population ranged from 30 to 66 with a mean age of 46.0 years. The average preoperative VAS score in PDCT was 7.60 and 1.94 at 7months post-operatively, and in APLD was 7.32, and 3.53 at 7 months post-operatively (p<0.001). In Macnab's criteria, 20 patients (80%) had achieved favorable improvement (excellent and good) in PDCT group. In Macnab's criteria, 16 patients (64%) had achieved favorable improvement in APLD group (p<0.001).

CONCLUSION

PDCT can be considered a viable option as a new percutaneous access to herniated lumbar disc. PDCT showed to be more effective than APLD in this study, allowing stable decompression and safe minimally invasive operation to an area desired by the operator in lumbar disc herniation patients, although further long term clinical evaluations are still necessary.

Percutaneous disc decompression with nucleoplasty-volumetry of the nucleus pulposus using ultrahigh-field MRI

PURPOSE

To evaluate changes in nucleus pulposus volume as a potential parameter for the effects of disc decompression.

METHODS

Fifty-two discs (T8 to L1) were extracted from 26 pigs and separated into thoracic (T8 to T11) and thoracolumbar discs (T12 to L1). The discs were imaged using 7.1 Tesla ultrahigh-field magnetic resonance imaging (MRI) with acquisition of axial T2-weighted turbo spin-echo sequences for determination of baseline and postinterventional nucleus pulposus volumes. Volumes were calculated using OsiriX® (http://www.osirix-viewer.com). After randomization, one group was treated with nucleoplasty, while the placebo group was treated with an identical procedure but without coblation current. The readers analyzing the MR images were blinded to the kind of procedure performed. Baseline and postinterventional volumes were compared between the nucleoplasty and placebo group.

RESULTS

Average preinterventional nucleus volume was 0.799 (SD: 0.212) ml. Postinterventional volume reduction in the nucleoplasty group was significant at 0.052 (SD: 0.035) ml or 6.30% (p<0.0001) (thoracic discs) and 0.082 (SD: 0.042) ml or 7.25% (p = 0.0078) (thoracolumbar discs). Nucleoplasty achieved volume reductions of 0.114 (SD: 0.054) ml or 14.72% (thoracic) and 0.093 (SD: 0.081) ml or 11.61% (thoracolumbar) compared with the placebo group.

CONCLUSIONS

Nucleoplasty significantly reduces thoracic and thoracolumbar nucleus pulposus volumes in porcine discs.

Clinical outcomes of percutaneous plasma disc coagulation therapy for lumbar herniated disc diseases

OBJECTIVE

This is prospective study of clinical outcomes of percutaneous plasma disc coagulation Therapy (PDCT) in patients with herniated lumbar disc disease (HLD) to evaluate the safety and efficacy in its clinical application and usefulness as a reliable alternative to microscopic discectomy.

METHODS

Forty-six patients were enrolled in this study from April 2006 to June 2010. All patients had one-level HLD. Disc degeneration was graded on routine T2-weighted magnetic resonance Image (MRI) using the Pfirrmann's grading system and all index levels were grade 3 and grade 4. Indications for surgery were radiculopathy caused by disc protrusion with soft consistency. MRI was done at one month after the procedure in all patients to check post-PDCT change. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria.

RESULTS

This study was approved by the Institutional Review Board of our institution. The age of the study population ranged from 16 to 59 years with a mean age of 37.2 years. There were 29 males and 17 females in this study. The mean period of clinical follow-up was 21 months. The average preoperative VAS score for radiculopathy was 7.4±1.4, while the final follow-up VAS score was 1.4±0.7 (p<0.001). In MacNab's criteria, 41 patients (89.1%) had achieved favorable improvement (excellent and good) until later follow-up. There were one patient from infection and two patients who needed to convert to open discectomy.

CONCLUSION

PDCT is a safe and efficient treatment modality in a selective patient with HLD.

Percutaneous treatment of intervertebral disc herniation

Interventional radiology plays a major role in the management of symptomatic intervertebral disc herniations. In the absence of significant pain relief with conservative treatment including oral pain killers and anti-inflammatory drugs, selective image-guided periradicular infiltrations are generally indicated. The precise control of needle positioning allows optimal distribution of steroids along the painful nerve root. After 6 weeks of failure of conservative treatment including periradicular infiltration, treatment aiming to decompress or remove the herniation is considered. Conventional open surgery offers suboptimal results and is associated with significant morbidity. To achieve minimally invasive discal decompression, different percutaneous techniques have been developed. Their principle is to remove a small volume of nucleus, which results in an important reduction of intradiscal pressure and subsequently reduction of pressure inside the disc herniation. However, only contained disc herniations determined by computed tomography or magnetic resonance are indicated for these techniques. Thermal techniques such as radiofrequency or laser nucleotomy seem to be more effective than purely mechanical nucleotomy; indeed, they achieve discal decompression but also thermal destruction of intradiscal nociceptors, which may play a major role in the physiopathology of discal pain. The techniques of image-guided spinal periradicular infiltration and percutaneous nucleotomy with laser and radiofrequency are presented with emphasis on their best indications.

Percutaneous thoracic intervertebral disc nucleoplasty: technical notes from 3 patients with painful thoracic disc herniations

Symptomatic thoracic disc herniation is an uncommon condition and early surgical approaches were associated with significant morbidity and even mortality. We are the first to describe the technique of percutaneous thoracic nucleoplasty in three patients with severe radicular pain due to thoracic disc herniation. Two of the patients experienced more than 75% pain relief and one patient experienced more than 50% pain relief. Post-procedural pain relief was maintained up to an average of 10 months after nucleoplasty. One patient with preoperative neurological signs improved postoperatively. There were no reported complications in all three patients. In view of the reduced morbidity and shorter operating time, thoracic intervertebral disc nucleoplasty can be considered in patients with pain due to thoracic disc herniation, with no calcification of the herniated disc, and in patients who may be otherwise be unfit for conventional surgery.

The results of cervical nucleoplasty in patients with cervical disc disorder: a retrospective clinical study of 22 patients

BACKGROUND

Nucleoplasty is a minimally invasive spinal surgery using a Coblation® technique that creates small voids within the disc. The purpose of this study was to evaluate the efficacy of cervical nucleoplasty in patients with cervical disc disorder.

METHODS

Between March 2008 and December 2009, 22 patients with cervical disc disorders were treated with cervical nucleoplasty after failed conservative treatment. All procedures were performed under local anesthesia, and fluoroscopic guidance and voids were created in the disc with the Perc™ DC Spine Wand™. Clinical outcomes were evaluated by the Modified Macnab criteria and VAS score at preprocedure, postprocedure 1 month, and 6 months.

RESULTS

Six patients had one, eight patients had two and eight patients had three discs treated; a total of 46 procedures was performed. Mean VAS reduced from 9.3 at preprocedure to 3.7 at postprocedure 1 month and to 3.4 at postprocedure 6 months. There was no significant complication related to the procedure within the first month. Outcomes were good or excellent in 17/22 (77.3%) cases. Postprocedure magnetic resonance imaging was acquired in two patients after two months showing morphologic evidence of volume reduction of protruded disc material in one patient but not in the other.

CONCLUSIONS

Percutaneous decompression with a nucleoplasty using a Coblation® technique in the treatment of cervical disc disorder is a safe, minimally-invasive and less uncomfortable procedure, with an excellent short-term clinical outcome.

The efficacy of coblation nucleoplasty for protrusion of lumbar intervertebral disc at a two-year follow-up

PURPOSE

The purpose of this study was to evaluate longer-term efficacy over a two-year follow-up of coblation nucleoplasty treatment for protruded lumbar intervertebral disc.

METHODS

Forty-two cases of protruded lumbar intervertebral disc treated by coblation nucleoplasty followed-up for two years were analysed. Relief of low back pain, leg pain and numbness after the operation were assessed by visual analogue pain scale (VAS). Function of lower limb and daily living of patients were evaluated by the Oswestry Disability Index (ODI).

RESULTS

Operations were performed successfully in all cases. Three patients had recurrence within a week of the procedure. Evaluation of the 42 patients demonstrated significant improvement rate of VAS: defined as 66.2% in back pain, 68.1% in leg pain, and 85.7% in numbness at one-week after the operation; 53.2%, 58.4%, 81.0% at one-year; and 45.5%, 50.7%, 75.0% at two-year follow-up. One week after the operation, obvious amelioration occurred in all the patients, but the tendency decreased. Before operation, the mean value of ODI was 68.2 ± 10.9%. The value at one week was 28.6 ± 8.2%; one-year at 35.8 ± 6.5%; and two-years at 39.4 ± 5.8%.

CONCLUSION

Coblation nucleoplasty may have satisfactory clinical outcomes for treatment of protruded lumbar intervertebral disc for as long as two-year follow-up, but longer-term benefit still needs verification.

Exogenous crosslinking recovers the functional integrity of intervertebral disc secondary to a stab injury

Exogenous crosslinking was proved to improve the fatigue resistance of anulus fibrosus and the stability of motion segment. The effect of crosslinking on the recovery of stab-injured discs, however, was less studied. The purpose of this study is to find if the exogenous crosslinking can increase the mechanical function of injured discs. Fresh healthy porcine discs (T2/T9) from 6-month-old swine were obtained immediately following death. Anular puncture using 16 and 18 G spinal needle were used to create medium and large disc stab injury models. Three treatments were designed for each injury model. The first one is the injured discs without treatment. The second one is the injured discs soaked with phosphate buffered solution for 2 days. The third one is the injured discs soaked with 0.33% genipin solution for 2 days. The disc integrity was evaluated using quantitative discomanometry (QD) apparatus. Four QD parameters, that is, the leakage pressure and volume, and the saturate pressure and volume, were analyzed to find the efficacy of treatment. We found that soaking of genipin solution recovered the disc leakage pressure from 1.3 to 1.8 MPa in 16 G-injury-model and from 2.3 to 3.2 MPa in 18 G-injury-model, and recovered the saturate pressure from 1.6 to 2.0 MPa in 16 G-injury-model and from 2.7 to 3.7 MPa in 18 G-injury-model. The improvement of disc integrity by soaking with genipin solution indicate that the exogenous crosslinking may help the biomechanical performance of an injured disc.

Computed Tomography Fluoroscopic-guided Percutaneous Spinal Interventions in the Management of Spinal Pain

Local back pain and radiculopathy can be debilitating for sufferers of these conditions. There are a multitude of treatment modalities, ranging from conservative approaches such as bed rest, physical therapy and chiropractic manipulation, to more invasive options such as percutane- ous spinal intervention (PSI) and surgery. We present here the techniques employed in the use of minimally invasive, image-guided percutaneous techniques under computed tomography fluoroscopy in our institutions. The inherent high spatial and tissue contrast resolution not only allows ease of trajectory planning in avoiding critical structures, but also allows precision needle placement. Cervical, lumbosacral, and sacroiliac pain can therefore be evaluated and treated both safely and effectively. Key words: Back pain, Fluoroscopy, Spinal injections

Percutaneous cervical disc decompression

BACKGROUND

Cervical disc nucleoplasty is a significant and clinically demonstrated innovation in percutaneous disc decompression in case of non-herniated disc protrusions or prolpase. It allows a percutaneous decompression via a 19-gauge needle under utilization of the Coblation technique and under C-arm control. Until now the patients suffering of a cervicobrachialgia in cause of a disc prolapse had only the therapeutical solution between conservative treatment and monosegmental spondylodesis or disc prosthesis of the mentioned motion segment.

METHODS

We wanted to demonstrate a new and practicable anatomical pathway for reaching the cervical disc prolapse comparable to the technique for discography of the cervical spine. The introducer needle is advanced into the disc under fluoroscopic guidance using a standard anterior-lateral approach. The controller delivers radiofrequency energy to quickly ablate tissue at temperatures between 50 degrees and 60 degrees C. The decompression will be done in ablation mode by rotating the device through 180 degrees for 5 s in the posterior, medial and ventral third of the cervical disc. After failed conservative treatment over an average time period of 3 months we treated 26 patients with a contained herniated prolapse or protrusion with radicular arm pain by percutaneous decompression under utilization of the Coblation technique with a controlled energy plasma-mediated field. A randomized control group of 30 patients was treated alone conservatively with medical and physical therapy in the same period.

RESULTS

The average preoperative VAS was 8.8. With a follow-up time of 2-years we found an average pain reduction with the visual pain score (VAS) of 2.3 who had a further check-up. The VAS was checked 24 h, 1 week, 3, 6, 12 and 24 months postoperatively. No complications with this method were seen. Comparable to the surgically treated group the conservative patients have had a VAS of 8.4. Under using conservative treatment with physical therapy, physiotherapy, analgetics and perineural injections we have had a diminution of the VAS to 5.1 after 2 years.

CONCLUSION

The percutaneous decompression of the cervical disc protrusion with the Perc DC-Spine Wand by using the Coblation mode is a quick and safe procedure. Furthermore, one may state a persistent pain relief in the follow-up time up to 2 years after the percutaneous decompression of the disc.

Percutaneous cervical nucleoplasty in the treatment of cervical disc herniation

Percutaneous disc decompression procedures have been performed in the past. Various percutaneous techniques such as percutaneous discectomy, laser discectomy, and nucleoplasty have been successful. Our prospective study was directly to evaluate the results of percutaneous cervical nucleoplasty (PCN) surgery for cervical disc herniation, and illustrate the effectiveness of PCN in symptomatic patients who had cervical herniated discs. From July of 2002 to June of 2005, 126 consecutive patients with contained cervical disc herniations have presented at the authors' clinic and treated by PCN. The patients' gender distribution for PCN was 65 male, 61 female. The age of patients ranged from 34 to 66 years (mean 51.9 +/- 10.2 years). The levels of involvement were 21 cases at C3-4, 30 cases at C4-5, 40 cases at C5-6, and 35 cases at C6-7. The clinical outcomes, pain reduction and the segment stability were all recorded during this study. A clinical outcome was quantified by the Macnab standard and using VAS. The angular displacement (AD) > or =11 degrees or horizontal displacement (HD) > or =3 mm was considered to be radiographically unstable. In the results of this study, puncture of the needle into the disc space was accurately performed under X-ray guidance in all cases. There was one case where the Perc-D Spine Wand had broken in the disc space during the procedure. The partial Perc-D Spine Wand, which had broken in the disc space could not be removed by the percutaneous cervical discectomy and thus remained there. There were no recurrent cases or complications in our series. Macnab standard results were excellent in 62 cases, good in 41 cases and fair in 23 cases. The rate of excellent and good was 83.73%. The VAS scores demonstrated statistically significant improvement in PCN at the 2-week, 1, 3, 6, and 12-month follow-up visits when compared to preoperational values (P < 0.01). There were no cases of instability following the PCN procedure. There was no significant difference in stability either preoperatively or postoperatively (P > 0.05). Our findings confirm that PCN for the treatment of cervical disc herniation results in a good outcome without any tampering of the stability of the cervical spine. Hence, PCN as a procedure is safe, minimally invasive, less traumatic, requiring less time with an excellent clinical outcome. PCN should be performed for those patients who fail conservative medical management including medication, physical therapy, behavioral management, psychotherapy, and who are unwilling to undergo a more invasive technique such as spinal surgery.

Effects of monopolar radiofrequency heating on intradiscal pressure in sheep

BACKGROUND CONTEXT

No previous study has assessed the effect of monopolar radiofrequency (RF) heating on intradiscal pressure.

PURPOSE

To determine the decrease in lumbar intradiscal pressure after monopolar RF heating.

STUDY DESIGN/SETTING

Intradiscal pressure was measured in sheep lumbar discs treated with monopolar RF heating.

METHODS

Two monopolar RF heat treatments at 90 degrees C were applied for 2 minutes each to lumbar intervertebral discs of sheep. Intradiscal pressure was measured in live sheep at 0, 7, 14, 21, and 28 days posttreatment. Pressure measurements were taken with a microtip pressure transducer. Electrodes were inserted but not activated in separate discs as a sham control. In vitro sheep spine of different age groups, loading conditions, and electrode orientations were similarly heat treated and intradiscal pressures were measured.

RESULTS

Intradiscal pressure was significantly reduced 1 week after monopolar RF heating and remained stable through the 4-week observation period. The RF electrode orientation, the age, and the type of disc loading have significant effects on the amount of initial intradiscal pressure reduction.

CONCLUSIONS

Monopolar RF heating can reduce intradiscal pressure in the lumbar spine of sheep.

The results of nucleoplasty in patients with lumbar herniated disc: a prospective clinical study of 52 consecutive patients

BACKGROUND CONTEXT

Nucleoplasty is a minimally invasive, percutaneous procedure that uses radiofrequency energy to ablate nuclear material and create small channels within the disc.

PURPOSE

To evaluate the efficacy of nucleoplasty technique in patients with leg pain caused by radicular encroachment.

STUDY DESIGN/SETTING

A prospective clinical study of subjects with lumbar disc herniation, and radicular pain resistant to previous medical treatment and physiotherapy for a period of at least 3 months.

PATIENT SAMPLE

Fifty-two consecutive patients with leg pain and magnetic resonance imaging evidence of small and medium-sized herniated discs correlating with the patient's symptoms (contained disc herniation<6 mm, with a disc height>/=50% in comparison to normal adjacent discs) were included.

OUTCOME MEASURES

Visual analogue scale (VAS) was administered and Oswestry disability questionnaires were filled out at preprocedure and postprocedure 2 weeks, 6 months, and 1 year. Reduction of analgesic treatment and the patients' satisfaction were also recorded.

METHODS

All procedures were performed under local anesthesia and fluoroscopic guidance on an outpatient basis. Patients underwent discography to evaluate annular integrity just before nucleoplasty. Channels were created in the nucleus by advancing the radiofrequency probe (ablating) and withdrawing it (coagulation). In all patients six channels were created.

RESULTS

Thirty-four patients had one and 18 had two discs treated; a total of 70 procedures were performed. Mean age of patients was 44.8+/-8.6 years. The mean follow-up period was 12.1+/-1.6 months. Mean VAS reduced from preprocedure 7.5 to 3.1 at postprocedure 6 months and to 2.1 at the latest follow-up. Mean Oswestry index decreased from 42.2 to 24.8 at 6 months and to 20.5 at the latest examination. Analgesic consumption was stopped or reduced in 42 patients (85%) at 6 months and in 46 patients (94%) 1 year after the procedure. Overall patient satisfaction was 81% at 2 weeks, 85% at 6 months, and 88% at the latest follow-up. There were no complications related to the procedures.

CONCLUSIONS

Our results encourage us to use nucleoplasty in carefully selected patients with leg pain caused by radicular encroachment. We recommend applying this minimally invasive technique only in those patients with small (<6 mm) contained disc herniations, with a disc height of>or=50% and with annular integrity.

Side effects and complications after percutaneous disc decompression using coblation technology

OBJECTIVE

To report the short-term side effects and complications after percutaneous disc decompression utilizing coblation technology.

DESIGN

Following institutional review board approval, consecutive patients who were to undergo percutaneous disc decompression using coblation technology (nucleoplasty) were prospectively enrolled. Patients were questioned preoperatively, postoperatively, and 24 hrs, 72 hrs, 1 wk, and 2 wks postprocedure by an independent reviewer regarding 17 possible symptom complications, which included bowel or bladder symptoms, muscle spasm, new pain, numbness/tingling or weakness, fevers/chills, rash/pruritus, headaches, nausea/vomiting, bleeding, and needle insertion site soreness. Statistical analysis was performed using Wilcoxon's signed-rank test.

RESULTS

A total of 53 patients enrolled, of whom four patients dropped out. Two patients had increased symptoms and opted for surgery. Two patients could not be contacted. The most common side effects at 24 hrs postprocedure was soreness at the needle insertion site (76%), new numbness and tingling (26%), increased intensity of preprocedure back pain (15%), and new areas of back pain (15%). At 2 wks, no patient had soreness at the needle insertion site or new areas of back pain; however, new numbness and tingling was present in 15% of patients. Two patients (4%) had increased intensity of preprocedure back pain. There were statistically significant reductions in visual analog scale score for back pain and leg pain (P < 0.05).

CONCLUSIONS

Based on this preliminary data, nucleoplasty seems to be associated with short-term increased pain at the needle insertion site and increased preprocedure back pain and tingling numbness but without other side effects.

Fundamentals of interventional pain medicine

Chronic pain is one of the most common and challenging medical problems facing our society. The specialty of pain medicine has grown steadily in recent years, largely because of the recognition that multiple factors contribute to chronic pain. The practice of pain medicine is multidisciplinary in approach, incorporating modalities from various specialties to ensure the comprehensive evaluation and treatment of the pain patient. The integration of various specialties such as anesthesiology, neurology, neurologic surgery, orthopedic surgery, physical medicine, and psychiatry is essential to treating patients with chronic pain and to establishing continuity of care. Research in the last 30 years has developed a variety of alternatives or adjuncts to opiates for chronic pain, including neuroactive medications, counterstimulation methods, and cognitive-behavioral therapies. Pain medicine specialists have provided leadership in the development of the practice, with the application of a wide verity of central and peripheral nerve blocks, sympathetic and neurolytic blocks, intradiscal procedures, neuromodulation techniques, intrathecal infusion systems, and other technical procedures that are firmly linked to a biomedical model of pain.

Radiofrequency and laser ablation of spinal lesions

Radiofrequency current and laser energy can be delivered locally through electrode-needle or optical fiber inserted in the tissue and allows local ablation of tissues, up to a volume of 4 to 5 cm in diameter with one application or vaporizes tissue. Tumor ablation guided with medical imaging proved a high local efficacy over 90% for tumors less than 25 mm in the liver, lung, and kidney. The spinal applications of the thermal energy of RF and laser are reported in this paper. First, the tumor ablation is reviewed with malignant and benign tumors. In malignant tumors, radiofrequency is very efficient in local tumor control and in pain management. The second part of this paper is devoted to disk diseases where laser and RF techniques increase their applications. The technique, indications and results of these techniques are reported and illustrated.

The effect of uniform heating on the biomechanical properties of the intervertebral disc in a porcine model

BACKGROUND CONTEXT

The use of minimally invasive lumbar intradiscal heating techniques, including intradiscal electro-thermal therapy (IDET), endoscopic radio-frequency annuloplasty, nucleoplasty and laser discectomy, for chronic lumbar discogenic pain and contained disc herniation has recently gained popularity. The purported therapeutic mechanisms of these interventions include subtotal nuclectomy, annular nociceptor ablation, and stabilization of the annular fibers. Basic science data elucidating the biomechanical and histomorphologic alterations of heat treatments on disc remain sparse.

PURPOSE

The purpose of this study is to examine the effects of uniform heating on biomechanical properties and histomorphology of intervertebral disc tissues using a porcine model.

STUDY DESIGN/SETTING

In a laboratory setting, porcine functional spinal units consisting of vertebra-nucleus pulposus-vertebra core and porcine hamstring tendons were harvested. Studies were performed on these tissue samples by uniformly heating the specimens in a constant temperature water bath. Ten porcine lumbar disc core and twenty-five porcine hamstring tendons were utilized as the subjects for this study. The effects of uniform heat treatments on disc core and hamstring tendon were measured for shrinkage, stiffness, and load to failure strength. Histomorphological study was also carried on the same specimen.

METHODS

The porcine vertebra-nucleus pulposus-vertebra segments were cored to a uniform 1-cm diameter. The hamstring tendons were cut to uniform 1.2-inch lengths. The tendon specimens were divided into groups of five each and heated in constant temperature water baths of 60 degrees C, 65 degrees C, 70 degrees C, or 75 degrees C for 10 min. Unheated specimens served as controls. The disc core specimens were divided in two group of five each, and tested at room temperature or after immersion in a 70 degrees C bath. The shrinkage was monitored during immersion in the water bath. Biomechanical testing to failure was carried out using mechanical loading on an MTS servohydraulic testing machine operating under stroke control. Strength and stiffness of the tissue was determined. Histomorphology was studied by staining the specimen with hematoxylin and eosin (H&E), and examined under 200 times magnification. Non-heated controls were used for comparisons.

RESULTS

The porcine hamstring tendons had no measurable shrinkage in specimens heated up to 65 degrees C. At temperatures above 65 degrees C, the shrinkage was concluded within 2 min of immersion and 70 degrees C appeared to be the optimal temperature, as temperatures higher than this did not demonstrate incremental effects. The disc core samples were heated to 70 degrees C (optimum temperature), and there appeared to be gross contraction of the disc core circumference to visual inspection, but no measurable lengthwise shrinkage could be appreciated. Histologically, the specimens demonstrated progressive loss of individual collagen fiber outline as the temperature increased. In the tendons, at 75 degrees C all of the fibers appear to be fused together, and the voids between individual collagen fibers were no longer present. Biomechanical testing revealed that the tendons undergo a substantial reduction in stiffness after heating. The mean tendon stiffness for the unheated specimens was 19,356 psi, while the corresponding value for the heated tendons was 1023 psi. These were significantly different using the paired t-test at p=0.0043. For the disc core samples, there was no significant difference in either stiffness (p=0.182) or failure strength (p=0.998) after heating. All failures occurred in mid-substance of the specimen.

CONCLUSIONS

The application of uniform heating to nucleus pulposus disc core caused visible contraction of its circumference but not lengthwise shrinkage. The same heating shrinks the hamstring tendon and reduces its stiffness. Ultimate failure strength of the disc core specimen remains unchanged. The failure data was not obtainable for the tendon due to premature slippage from the fixation apparatus before failure. The results of this study fail to support a biomechanical justification for the application of uniform heat treatment to the whole intervertebral disc. Heating annulus fibrosus and nucleus pulposus separately to specific temperatures may have potential clinical benefits.