Vertebral augmentation with spinal implants: third-generation vertebroplasty.

This article is to review the different types of vertebral augmentation implants recently becoming available for the treatment of benign and malignant spinal compression fractures. After a detailed description of the augmentation implants, we review the available clinical data. We will conclude with a summary of the advantages and disadvantages of vertebral implants and how they can affect the future treatment options of compression fractures.

Multicenter clinical and imaging evaluation of targeted radiofrequency ablation (t-RFA) and cement augmentation of neoplastic vertebral lesions.

BACKGROUND: Treatment of spinal metastatic lesions by radiofrequency ablation (RFA) before cementation can potentially help in local tumor control and pain relief. This is often limited by access and tumor location. This study reports multicenter clinical and imaging outcomes following targeted RFA (t-RFA) and cement augmentation in neoplastic lesions of the spine. MATERIAL AND METHODS: A retrospective multicenter study of 49 patients with 72 painful vertebral lesions, evaluated for clinical and imaging outcomes following RFA and cement augmentation of spinal metastatic lesions, was undertaken. Visual Analogue Pain score (VAS) and Oswestry Disability Index (ODI) were obtained before and 2-4 weeks after treatment. Pre- and post-procedure imaging examinations including MRI and positron emission tomography (PET) were also evaluated. RESULTS: Mean ablation time was 3.7±2.5 min (range 0.92-15). Mean VAS scores decreased from 7.9±2.5 pre-procedure to 3.5±2.6 post-procedure (p<0.0001). Mean ODI scores improved from 34.9±18.3 to 21.6±13.8 post-procedure (p<0.0001). Post-contrast MRI resulted in a predictable pattern of decreased tumor volume and an enhancing rim. Metabolically active lesions in pre-procedure PET scans (n=10 levels) showed decreased fluorodeoxyglucose activity after ablation. CONCLUSIONS: t-RFA followed by vertebral augmentation in malignant vertebral lesions resulted in significant pain reduction and functional status improvement, with no major complications. t-RFA permitted access to vertebral lesions and real-time accurate monitoring of the ablation zone temperature. Post-procedure MRI and PET examinations correlated with a favorable tumor response and helped to monitor tumor growth and the timing of adjuvant therapy.

Treatment of metastatic spinal lesions with a navigational bipolar radiofrequency ablation device: a multicenter retrospective study.

BACKGROUND: Spinal metastatic lesions are a common occurrence among oncology patients and contribute to significant morbidity. Treatment options have been limited in their effectiveness and scope to this point. OBJECTIVE: This study aims to report the safety and efficacy of radiofrequency ablation (RFA) of malignant spinal lesions using a novel RFA bipolar tumor ablation system which includes a navigational electrode containing 2 active thermocouples. STUDY DESIGN: IRB approved multicenter retrospective review of patients receiving RFA as a treatment of metastatic osseous lesions between March 2012 and March 2013. SETTING: This study consists of patients from 5 large academic centers. METHOD: One hundred twenty-eight metastatic lesions were identified in 92 patients who underwent a total of 96 procedures. Cement augmentation was performed when the vertebral body was at risk or had a pathological fracture. Visual analogue scale (VAS) scores were obtained preoperatively as well as postoperatively at the one week, one month, and 6 month time points. Interval change in the patients' pain medications was recorded. Postoperative imaging was used to assess tumor burden at the treated level when available. RESULTS: RFA was technically successful in all of the lesions without complication or thermal injury. Our study demonstrated significant (P < 0.01) decreases in the VAS scores at one week, one month, and 6 months postoperatively. In our largest center, 54% of our patients experienced a decrease and 30% had no change in their pain medications postoperatively. Sixty-two percent of the spinal lesions in this largest institution were located in the posterior vertebral body. Post-ablation imaging confirmed size of ablation zones consistent with that measured by the thermocouples. LIMITATIONS: The main limitations of this study are the heterogeneous patient population, data set, and potential confounding variable of concurrent cement augmentation. CONCLUSION: The STAR System is an RFA device that was safely and effectively used in the treatment of spine metastatic osseous lesions. This new device allows RFA treatment of previously untreatable lesions with resultant reduction in pain that was not controlled by systemic or radiation therapy.

Spinal cord stimulators in an outpatient interventional neuroradiology practice.

PURPOSE: Spinal cord stimulation is a known modality for the treatment of chronic back and neck pain. Traditionally, spine surgeons and pain physicians perform the procedures. We report our experience in performing neuromodulation procedures in an outpatient interventional neuroradiology practice. METHODS: A retrospective analysis of medical records of all trial and permanent implantation patients over a period of 4 years was performed. 45 patients (32 men) of median age 47 years were included in the study. The primary diagnoses were 23 cases of failed back or neck surgery syndrome, 12 cases of spinal stenosis, 4 cases of axial pain, 3 cases with reflex sympathetic dystrophy, 1 case of peripheral vascular disease, 1 case of phantom limb and 1 case of post-concussion syndrome. RESULTS: Thirty-four trials were performed in an outpatient clinic while 11 trials were performed in hospital outpatient settings. Trial periods were 3-7 days. 27 patients (60%) who reported ≥50% pain relief underwent a permanent implantation. An interventional neuroradiologist performed 17 implantations, while spine surgeons performed 10 implantations. 23 implants were epidural (19 lumbar and 4 cervical) and four implants were subcutaneous. During the follow-up period, three patients had infections (13%) and required removal of the device and two cases (8%) reported lead migration. CONCLUSIONS: Neuromodulation procedures can be performed safely in an outpatient interventional radiology setting. Although the infection rate was relatively higher in this study population, the other complication rates and trial-to-implant ratio are similar to published data.

Comparison between radiofrequency targeted vertebral augmentation and balloon kyphoplasty in the treatment of vertebral compression fractures: addressing factors that affect cement extravasation and distribution.

BACKGROUND: Both vertebroplasty and balloon kyphoplasty have been described for treatment of vertebral compression fractures. Vertebroplasty is known for its high leakage rate compared with balloon kyphoplasty. In vitro studies have shown that high-viscosity cements significantly decrease the incidence of cement leakage and increase the predictability of cement fill in cancellous bonelike substrates compared with low-viscosity cements. OBJECTIVE: This study compares the incidence and pattern of cement leakage in cases treated with standard balloon kyphoplasty (BKP) and a novel vertebral augmentation procedure, radiofrequency targeted vertebral augmentation (RF-TVA). STUDY DESIGN: Retrospective evaluation of postoperative radiographs. SETTING: Single center inpatient and outpatient population. METHODS: Two methods of vertebral augmentation were utilized. Conventional bipedicular BKP and RF-TVA, a novel unipedicular technique which uses a navigational osteotome to create targeted, bone sparing cavities and RF energy to deliver an ultra-high viscosity cement at a consistent rate via a remote controlled, automated hydraulic delivery system. Postoperative radiographs of patients treated with the 2 techniques were critically analyzed for the incidence and location of cement leakage. Eighty consecutive patients with 106 treated levels were included. Thirty-five patients with 49 levels in the BKP and 45 patients with 57 levels in RF-TVA group were evaluated. RESULTS: Leakages less than 1-2 mm were not reported since they may not represent any clinical significance. In the BKP group, 6 leakages (12%) were reported (3 discal, 2 venous, one paravaertebral, and no epidural). In the RF-TVA group, a total of 3 leakages (5%) were reported, (one discal, 2 venous, no paravaertebral or epidural). Using contingency analysis for leakage per level, there was a statistical difference for leakage between RF-TVA and standard BKP, P < 0.01. LIMITATIONS: Retrospective study, single center. CONCLUSIONS: The RF-TVA technique may provide an approximately 50% reduction in leakage rate when compared to standard BKP. This may be related to the combination of controlled delivery of radiofrequency activated (high viscosity) cement at a fixed, low rate of delivery into site-specific channels created using a navigational osteotome. Additionally, based on the unipedicular access and remotely controlled cement delivery RF-TVA may decrease procedural invasiveness and physician radiation exposure, respectively.INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board.

Feasibility, safety and cement leakage in vertebroplasty of osteoporotic and malignant compression fractures using ultra-viscous cement and hydraulic delivery system.

BACKGROUND: The major complications arising from vertebroplasty or kyphoplasty are related to leakage of cement beyond the confines of the collapsed vertebral body. Traditionally, a liquid (low viscosity) cement is used in most vertebroplasty systems available on the market, coupled with mechanical injection devices or one mL syringes. OBJECTIVES: The purpose of this study is to evaluate the feasibility and safety, as well as study cement leakage patterns, in vertebroplasty performed for both osteoporotic and malignant vertebral compression fractures using ultraviscous cement injected by the hydraulic CONFIDENCE Vertebral Augmentation System. STUDY DESIGN: Retrospective evaluation of postoperative images. SETTING: Single center inpatient and outpatient population. METHODS: A retrospective evaluation of clinical charts and postoperative X-ray imaging was performed in 122 cases; a total of 214 levels were treated. The study group comprised a total of 163 levels of benign osteoporotic fractures and 51 levels of various malignant lesions. The degree of leakage, seen in postoperative films, was assessed at each treated level using a strict 4-point scale (none, mild, moderate, severe). RESULTS: For benign lesions, there was no leakage in 82 levels (50%), mild venous leakage in 38 levels (23%), moderate venous leakage in 4 levels (2%), mild disc leakage in 28 levels (17%), moderate disc leakage in 7 levels (4%), mild paravertebral leakage in 2 levels (1%), and moderate paravertebral leakage in 2 levels (1%). No severe leakage or epidural leakage were seen. For malignant lesions, there was no leakage in 25 levels (49%), mild venous leakage in 12 levels (24%), moderate venous leakage in 4 levels (8%), mild disc leakage in 7 levels (14%), moderate disc leakage in one level (2%), mild paravertebral leakage in one level (2%), and one level showed a mild epidural leakage (2%). LIMITATIONS: Retrospective study, single center. CONCLUSION: Percutaneous cement augmentation in osteoporotic and malignant compression fractures using a highly viscous cement that can be safely controlled and injected via a hydraulic system can be performed safely without significant complications. The leakage rate and patterns were similar in both benign and malignant compression fractures. The use of highly viscous cement may decrease the complication rate in malignant lesions that has been traditionally described to exhibit more cement leakage with low viscosity cement.

Vertebroplasty technique in metastatic disease.

The purpose of this article is to review the current state of the art of using vertebral augmentation techniques for treating symptomatic spinal fractures that are associated with malignant lesions and to present potential future trends in treatments for this patient population. Epidemiology and biomechanical ramifications of these lesions are summarized, and treatment regimes, clinical outcomes, complications, and technical issues associated with treatments are presented. Potential future trends and new technologies for performing vertebral body augmentation in patients with metastatic spinal lesions are also discussed in this article.

Spinal cord stimulation: a basic approach.

Chronic back pain and other refractory pain syndromes are a documented burden on our society. They also are a huge cost in quality of life and dollars spent on health care. Neuromodulation and specifically dorsal column stimulation of the spinal cord has been shown to decrease pain with minimal risk to the patient. We describe in this article the basic techniques and methods of both the stimulation trial and the permanent implantation of the leads and generator. With advanced imaging and the minimally invasive approach we further explain how to minimize any risk associated with this percutaneous procedure.

Percutaneous image-guided augmentation for spinal metastatic tumors.

The purpose of this article is to review the current state of the art for treating symptomatic spinal fractures associated with malignant lesions by image-guided interventional techniques. Epidemiology, clinical presentation, and biomechanical ramifications of these lesions are summarized. A suggested treatment algorithm is also presented. The second part of the article deals with how to approach these lesions, explaining the issues that pertain to patient evaluation, preoperative, operative, and postoperative treatment regimes. Tips for certain difficult situations and potential complications are also discussed.

Interventional techniques in managing persistent pain after vertebral augmentation procedures: a retrospective evaluation.

BACKGROUND: Based on systematic reviews, it appears that at least 10% of patients may continue to suffer with residual or persistent pain after successful vertebral or sacral augmentation procedures. OBJECTIVE: To report and evaluate the incidence and prevalence of different spinal injections in patients who received vertebroplasty, kyphoplasty, and sacroplasty procedures for both benign and malignant compression fractures. DESIGN: A retrospective case review. METHODS: Retrospective review of all cases of vertebroplasty, sacroplasty, and kyphoplasty performed in a 12-month period in a single outpatient setting of interventional radiology was conducted. RESULTS: In a 12-month period starting from October 2005 to September 2006, 144 patients underwent cement augmentation procedures. Of the 144, 34 patients required a spinal injection procedure for residual or persistent pain within a 1-year period after the augmentation procedure. Twenty-four patients required epidural steroid injections, 6 patients required intercostal nerve blocks, 5 patients required trigger point injections, 5 patients required sacroiliac joint injections, and 1 patient required facet joint injections. Nine patients who required lumbar epidural steroid injections and all patients who required intercostal nerve blocks and had underwent a thoracic cement augmentation procedure. CONCLUSION: A small proportion of patients undergoing percutaneous cement augmentation for vertebral compression fractures or sacral insufficiency fractures potentially require spinal injections to treat residual pain after the procedure.