Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy.

BACKGROUND: Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. MATERIALS AND METHODS: A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient's chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications. RESULTS: Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. CONCLUSION: The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief.

Feasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results.

INTRODUCTION: Spastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system. METHODS: The HIFU ablation of sciatic nerves was performed in swine (n = 5) using a HIFU system integrated with a 3 T MRI scanner. Acute lesions were confirmed using T1-weighted contrast-enhanced (CE) MRI and histopathology using hematoxylin and eosin staining. The animals were euthanized immediately following post-ablation imaging. RESULTS: Reddening and mild thickening of the nerve and pallor of the adjacent muscle were seen in all animals. The HIFU-treated sections of the nerves displayed nuclear pyknosis of Schwann cells, vascular hyperemia, perineural edema, hyalinization of the collagenous stroma of the nerve, myelin sheet swelling, and loss of axons. Ablations were visible on CE MRI. Non-perfused volume of the lesions (5.8-64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7-34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55 to 138 min, and preparation time required 2 h on average. CONCLUSION: The acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology, and histology.

The use of transcutaneous electrical nerve stimulation (TENS) in a major cancer center for the treatment of severe cancer-related pain and associated disability.

BACKGROUND: Cancer pain is difficult to treat, often requiring a multimodal approach. While medication management remains the mainstay for the treatment of cancer pain, medications are often associated with undesired side effects. Transcutaneous electrical nerve stimulation (TENS) provides a potential adjunctive method for treating cancer pain with minimal side effects. OBJECTIVE: Few studies have been performed evaluating the efficacy of TENS on cancer pain. We sought to examine the usefulness of TENS on all cancer patients and to specifically look at the use of TENS as a goal-directed therapy to improve functionality. DESIGN: Retrospective cohort study. METHODS: Since 2008, patients with chronic cancer pain and on multimodal pain regimens were trialed with TENS. Those patients who showed an improvement in pain symptoms or severity were educated about and provided with a TENS unit for use at home. Pain symptoms and scores were monitored with the visual analog scale (VAS), the numerical rating pain (NRP) scale, and Short-Form McGill Questionnaire at the start of TENS treatment and at 2 months follow-up. RESULTS: TENS proved beneficial in 69.7% of patients over the course of 2 months. In TENS responsive patients, VAS scores decreased by 9.8 on a 0-100 mm scale (P < 0.001), and NRP scores decreased by 0.8 on a 1-10 scale (P < 0.001). LIMITATIONS: Lack of placebo and lack of blinding of physician and patient. CONCLUSIONS: TENS provides a beneficial adjunct for the treatment of cancer pain, especially when utilized as a goal-directed therapy.

Novel use of noninvasive high-intensity focused ultrasonography for intercostal nerve neurolysis in a swine model.

BACKGROUND: High-intensity focused ultrasound (HIFU) is a noninvasive thermal ablation technique. High-intensity focused ultrasound has been used in small-animal models to lesion neural tissue selectively. This study aimed to evaluate the efficacy of HIFU in a large-animal model for ablation of nerves similar in size to human nerves. METHODS: Twelve acute magnetic resonance-guided HIFU ablation lesions were created in intercostal nerves in a swine model. In a second pig, as a control, 4 radiofrequency ablation and 4 alcohol lesions were performed on intercostal nerves under ultrasound guidance. Preprocedural and postprocedural magnetic resonance imaging was then performed to evaluate radiologically the lesion size created by HIFU. Animals were euthanized 1 hour postprocedure, and necropsy was performed to collect tissue samples for histopathologic analysis. RESULTS: On gross and histological examination of the intercostal nerve, acute HIFU nerve lesions showed evidence of well-demarcated, acute, focally extensive thermal necrosis. Four intercostal nerves ablated with HIFU were sent for histopathologic analysis, with 2 of 4 lesions showing pathologic damage to the intercostal nerve. Similar results were shown with radiofrequency ablation technique, whereas the intercostal nerves appeared histologically intact with alcohol ablation. CONCLUSIONS: High-intensity focused ultrasound may be used as a noninvasive neurolytic technique in swine. High-intensity focused ultrasound may have potential as a neuroablation technique for patients with chronic and cancer pain.

The use of combined spinal-epidural technique to compare intrathecal ziconotide and epidural opioids for trialing intrathecal drug delivery.

SUMMARY Choosing the initial medications for intrathecal delivery is often confusing and not standardized. We describe a novel way for using a combined spinal-epidural technique to compare two first-line medications for intrathecal delivery; ziconotide and morphine (or hydromorphone). Five patients with intractable chronic or cancer pain were elected to have an intrathecal drug delivery system implanted for pain management. Each patient was given a 3-day inpatient trial with the combined spinal-epidural technique. The Visual Analog Scale, Numerical Rating Scale, short-term McGill questionnaire and opioid consumption were monitored daily. The results were used to develop a paradigm to describe how ziconotide can be used in practice.

Transcutaneous electrical nerve stimulation for treatment of sarcoma cancer pain.

UNLABELLED: SUMMARY  BACKGROUND: Pain is often the initial presenting symptom with sarcomas. Upon resection of a sarcoma, most patients experience a resolution of their pain. However, in those patients with continued pain, treatment often requires multiple medications with moderate benefit. AIMS: The authors present eight patients who suffer from continued sarcoma-related pain following resection of their initial cancer. METHODS: For each patient, we describe the use of transcutaneous electrical nerve stimulation (TENS) for the treatment of sarcoma-related pain. Each patient was brought to the pain clinic for an initial four-lead trial of TENS lasting 30 min to determine the TENS setting that provided greatest pain relief. Patients were educated about the application and use of their TENS unit, which they self-utilized at home. Patients' pain response was monitored prior to the initial TENS trial and after 2 months of TENS use. RESULTS: Seven out of eight patients had a qualitative or quantitative reduction in their sarcoma-related pain. Three out of the seven patients demonstrated clinically significant (>30%) pain relief, while the other four patients demonstrated increased physical functionality and pain relief, during movement and rest. No patients experienced any adverse effects; however, TENS was stopped in one patient who had a beneficial response to TENS as that patient was found to have recurrent, widespread metastases of her sarcoma. CONCLUSION: Initial results indicate that TENS provides an easy-to-use, inexpensive therapeutic tool that can be used an adjunct in the treatment of sarcoma-related cancer pain. Future studies consisting of a large, randomized trial will be necessary to validate the efficacy of TENS in this patient population.

The use of lumbar sympathetic blockade at L4 for management of malignancy-related bladder spasms.

BACKGROUND: Cancer-related bladder spasms may be a rare but severe symptom of bladder or metastatic cancer or its related treatments. Various treatments described in the literature include systemic medications, intravesical or epidural medications, or even sacral neurolectomies. OBJECTIVE: We present 3 patients who have suffered from bladder spasm either from invasion of the bladder wall by tumor (2 patients) or from intravesical chemotherapeutic treatment. DESIGN: Case Report. SETTING: Cancer pain management hospital. METHODS: For each patient, we describe the use of lumbar sympathetic block to successfully treat the bladder spasms. Sympathetic blockade was performed at the left anterolateral border of lumbar vertebra L4. We used 10 mL of local anesthetic (0.25% bupivacaine) delivered in 2 mL aliquots, each given after negative aspiration for heme. Each procedure was performed with fluoroscopic guidance (both AP and lateral views) with the use of iodine contrast (Omnipaque-180) to confirm the location of the medication and its resulting spread. RESULTS: All 3 patients had a reduction in the frequency and intensity of spasms, with 2 out of 3 patients not having a recurrence of the spasms for up to 2 months post procedure and follow up. LIMITATIONS: Case Report. CONCLUSION: Lumbar sympathetic blockade could be a useful treatment for recurrent bladder spasm in the oncologic population. Based on these findings, we feel that the branches of the sympathetic nerve set at L4 may be a good target for neurolytic procedures, such as radiofrequency ablation, for long term treatment of bladder spasms. Further research is necessary to determine the efficacy of this technique for the treatment of bladder spasms in the oncologic population.