Real-world evidence of sustained improvement following 60-day peripheral nerve stimulation treatment for pain: a cross-sectional follow-up survey.

Objective: This study presents real-world data from a cross-sectional follow-up survey of patients who previously received 60-day peripheral nerve stimulation (PNS) treatment for pain. Materials & methods: A survey including validated pain and other related outcome measures was distributed to patients who previously underwent implantation of temporary PNS leads for 60-day PNS treatment. Results: Among survey respondents who were at least 3 months from the start of treatment, most reported sustained clinically significant improvements in pain and/or quality of life, with the length of follow-up at the time of survey completion ranging from 3 to 30 months. Conclusion: These real-world data support recent prospective studies indicating that 60-day percutaneous PNS provides significant and sustained relief across a wide range of pain conditions.

This study presents the findings from a survey that was sent to patients who previously received a 60-day peripheral nerve stimulation (PNS) treatment for their chronic pain. Patients were asked about their current pain levels, how their quality of life and physical function have changed since their PNS treatment, and whether they had changed their usage of pain medications. The survey showed that most patients who were at least 3 months from the start of the PNS treatment continued to have meaningful pain relief and/or improvement in their quality of life. This information is consistent with clinical studies that were previously published and supports that the 60-day PNS treatment can provide patients with long-term relief of chronic pain.

Considerations in permanent implantation of peripheral nerve stimulation (PNS) for chronic neuropathic pain: An international cross-sectional survey of implanters.

AIM: Novel minimally invasive short-term and long-term peripheral nerve stimulation (PNS) systems have revolutionized targeted treatment of chronic neuropathic pain. We present an international survey of PNS-implanting pain physicians to assess what factors they consider when offering permanent PNS. METHODS: This cross-sectional study consisted of a survey (Qualtrics) that was distributed to PNS-implanting physicians in a device supplier's entire email database on November 13, 2020, with 3 weeks of response time. Physicians' contact information in the form of their email addresses had been previously collected by the supplier upon device distribution with permission to use survey responses for research. RESULTS: Of 2032 database physicians, 40 physicians representing 37 institutions responded to the survey. The most common application of PNS was mononeuropathic pain (57%). The most frequently targeted nerve was the suprascapular nerve (29%). 14% of physicians reported 81-100% of their implants were dual-lead. The representative physicians ranged broadly in their most frequently targeted nerves. Although mononeuropathic pain was the most common indication for PNS, there was still varied response regarding other indications such as CRPS and post-surgical chronic pain. CONCLUSION: In context of a low response rate, identifying such factors can help update the prevailing treatment algorithm for interventional therapies, assist pain physicians in better identifying which patients are the best candidates for PNS, and inform future clinical trial design on PNS efficacy.

Understanding the role of patient preference in the treatment algorithm for chronic low back pain: results from a survey-based study.

Aims: Interventional pain treatments range from injections to established radiofrequency ablation techniques and finally neuromodulation. In addition to safety, efficacy and cost dominance, patient preference for type of treatment is important. Methods: Chronic pain patients (n = 129) completed a preference scale to determine which interventional pain management procedures they would prefer from among radiofrequency ablation, temporary (60-day) peripheral nerve stimulation (PNS), conventional PNS and spinal cord stimulation/dorsal root ganglion stimulation. A second survey (n = 347) specific to assessing the preference for radiofrequency ablation or temporary PNS treatment was completed by patients with low back pain. Results: On the basis of mean rank, temporary PNS percutaneously implanted for up to 60 days was the most preferred treatment compared with the other options presented (p = 0.002). Conclusions: Patient preference should be unbiased and considered as an independent variable for physician discussion in treatment options and future research.

Patient preference is an important variable for physicians to consider when discussing treatment options for low back pain. A consumer survey study was completed discussing patient preference among various invasive treatments for low back pain. When given scenarios discussing risks and benefits of each procedure (temporary peripheral nerve stimulation for 60 days, heat ablation of small back nerves and permanently implanted back pain devices) temporary peripheral nerve stimulation was considered the preferred option.

Shoulder Ablation Approaches.

The shoulder is structurally and functionally complex. Shoulder pain may be refractory to conventional treatments, such as physical therapy, pharmacotherapy, and corticosteroid injections. In such cases, radiofrequency ablation may serve as an alternative treatment plan. Current literature has demonstrated 4 target nerves for ablative therapy: the suprascapular nerve, axillary nerve, lateral pectoral nerve, and subscapular nerve. Special caution is needed when targeting these nerves in order to avoid motor denervation. This article summarizes the current evidence for radiofrequency ablation as a useful treatment option for chronic shoulder pain as well as the described techniques for performing this promising procedure.

Percutaneous Peripheral Nerve Stimulation of the Medial Branch Nerves for the Treatment of Chronic Axial Back Pain in Patients After Radiofrequency Ablation.

OBJECTIVE: Lumbar radiofrequency ablation is a commonly used intervention for chronic back pain. However, the pain typically returns, and though retreatment may be successful, the procedure involves destruction of the medial branch nerves, which denervates the multifidus. Repeated procedures typically have diminishing returns, which can lead to opioid use, surgery, or implantation of permanent neuromodulation systems. The objective of this report is to demonstrate the potential use of percutaneous peripheral nerve stimulation (PNS) as a minimally invasive, nondestructive, motor-sparing alternative to repeat radiofrequency ablation and more invasive surgical procedures. DESIGN: Prospective, multicenter trial. METHODS: Individuals with a return of chronic axial pain after radiofrequency ablation underwent implantation of percutaneous PNS leads targeting the medial branch nerves. Stimulation was delivered for up to 60 days, after which the leads were removed. Participants were followed up to 5 months after the start of PNS. Outcomes included pain intensity, disability, and pain interference. RESULTS: Highly clinically significant (≥50%) reductions in average pain intensity were reported by a majority of participants (67%, n = 10/15) after 2 months with PNS, and a majority experienced clinically significant improvements in functional outcomes, as measured by disability (87%, n = 13/15) and pain interference (80%, n = 12/15). Five months after PNS, 93% (n = 14/15) reported clinically meaningful improvement in one or more outcome measures, and a majority experienced clinically meaningful improvements in all three outcomes (i.e., pain intensity, disability, and pain interference). CONCLUSIONS: Percutaneous PNS has the potential to shift the pain management paradigm by providing an effective, nondestructive, motor-sparing neuromodulation treatment.

Ultrasound-Guided Peripheral Nerve Stimulation for Shoulder Pain: Anatomic Review and Assessment of the Current Clinical Evidence.

BACKGROUND: The shoulder region is a common area for pain. The shoulder has the largest range of motion and the most complex mechanical anatomy. The shoulder girdle and related tendons allow for numerous painful disorders to occur. Also, given the overall use of the shoulder, arthritic deformities are all too common. Finally, pain from more complex states such as poststroke shoulder pain and status post total shoulder arthroplasty pain have always been a difficult diagnosis to treat with effectiveness. The innervation to the shoulder predominantly comes from the suprascapular and axillary nerves. Both nerves relatively follow an expected anatomic course and whereby they can be targeted with ultrasound or fluoroscopy. Recently, there has been an increase in evidence that suggests peripheral nerve stimulation can make a difference in these patients with shoulder pain. OBJECTIVES: To provide a basic overview of peripheral nerve stimulator placement targeting the axillary and suprascapular nerves. Furthermore, to demonstrate the suggested implantation and current evidence of peripheral nerve stimulation for the treatment of shoulder pain. STUDY DESIGN: Anatomic clinical review. METHODS: A comprehensive review was performed regarding the available literature through targeting articles reporting on the use of peripheral nerve stimulation to treat pain of the shoulder region. RESULTS: We compiled and discuss the current evidence available in treating shoulder pain utilizing peripheral stimulation. The strongest evidence currently is for peripheral nerve stimulation targeting either the axillary or suprascapular nerve, as well as placement targeting the motor points of the deltoid. The most common treated pathology is poststroke shoulder pain. LIMITATIONS: Peripheral nerve stimulation has been trialed and is promising for several shoulder pain pathologies; however, there remains a need for large-scale, randomized, placebo-controlled clinical trials to further evaluate the efficacy of most treatments. Much of the current data relies on case reports without randomization or placebo controls. CONCLUSIONS: Overall there is fair to moderate evidence for peripheral nerve stimulation to treat shoulder pain in hemiplegic poststroke patients. There is limited evidence when treating other shoulder pain etiologies. Utilizing ultrasound or fluoroscopic guidance, the procedure has proven to be safe allowing proper placement of the electrodes near the target nerves. Considering the high prevalence of shoulder pain from degenerative conditions and overuse, future studies are undoubtedly warranted to evaluate whether peripheral nerve stimulation can modify our treatment algorithm for management of these conditions.

Filum Terminale Needle Placement During Caudal Epidural Steroid Injection.

OBJECTIVE: Caudal epidural steroid injections (ESIs) are commonly used to treat lumbar radicular pain. Touhy needles are placed under live fluoroscopic guidance to ensure epidural administration of medication. This is a case report of direct needle and catheter placements into and through the filum terminale during a caudal approach to the epidural space. DESIGN: Single case report. SETTING: Beth Israel Deaconess Medical Center. PATIENT: A 69-year-old woman who suffered from chronic low back and leg pain from lumbosacral radiculopathy, failed back surgery syndrome, and lumbar facet arthropathy. INTERVENTIONS: Caudal epidural steroid injection. OUTCOME MEASURES: Patient safety. RESULTS: The needle and catheter placement were confirmed via intrathecal contrast spread to be in the filum terminale, which prompted abortion of the procedure. CONCLUSIONS: Although caudal ESI is a relatively safe and routine intervention, care must be taken to ensure proper placement of needle, catheter, and injectate. While contrast is injected to ensure appropriate epidural spread, it serves also to reveal unexpected and unwanted spread. We present the first report of a needle being inserted directly into the filum terminale during a caudal ESI.

Percutaneous Translaminar Facet Cyst Rupture and Epidural Access-Description of a Novel Technique.

Synovial cysts of the lumbar zygapophysial joints can be treated by percutaneous injection of corticosteroids, with distension and rupture of the cyst. Some cysts can be difficult to access, particularly when they lie deep in relation to the lamina. This technical report describes a fluoroscopy-guided technique for accessing sublaminar pathology. Crucial to the safety of the technique is visualization of the ventral margin of the lamina using a contralateral oblique view, and controlling and limiting the insertion of the needle such that only its tip passes the lamina.

Ultrasound-Guided Cryoablation of a Traumatic Hip Disarticulation Neuroma.

OBJECTIVE: Traumatic amputation at the pelvic level is a rare procedure with few studies addressing long-term complications. Painful neuroma formation may form at the site of nerve transection and cause significant impairments in daily living. Ultrasound-guided cryoablation therapy has grown in popularity and should be considered in patients with painful neuromas. This is a case report of complete pain relief in a patient with rare traumatic hip disarticulation with neuroma formation, treated with ultrasound-guided cryoablation. The patient gave consent for publication. DESIGN: Single case report. SETTING: Mount Sinai Medical Center. PATIENT: A 57-year-old man with traumatic hip disarticulation over 30 years ago with a 10-year history of severe residual limb pain from neuroma formation. INTERVENTIONS: Ultrasound-guided cryoablative injection therapy. OUTCOME MEASURES: Pain reduction. RESULTS: Ultrasound-guided cryoablation of a traumatic hip disarticulation neuroma resulting in complete pain relief and improved functionality and independence. CONCLUSIONS: This case illustrates a rare incidence of painful neuroma formation in a patient with traumatic hip disarticulation. Cryoablation with ultrasound guidance resulted in resolution of all pain. We report, to the best of our knowledge, the first occasion of an ultrasound-guided cryoablation resulting in complete pain relief in a traumatic hip disarticulation neuroma.

Ultrasound-guided first metatarsophalangeal joint injections: description of an in-plane, gel standoff technique in a cadaveric study.

OBJECTIVE: To describe a longitudinal ultrasound-guided in-plane approach for injection into the first metatarsophalangeal (MTP) joint and assess its accuracy in a cadaveric model. DESIGN: A prospective anatomical cadaver study model was used. A total of 10 first MTP joints using the described technique were injected with 0.5 mL of dye under ultrasound guidance. The joints were later dissected, and accuracy was classified as accurate, accurate with overflow, or inaccurate with no injectate in the target area. RESULTS: Of the injections, 9 were classified as accurate injections, and 1 was classified accurate with overflow. CONCLUSION: This cadaveric study suggests that ultrasound-guided injections of the first MTP joint can be accurately and reproducibly performed with a gel standoff, long-axis in-plane approach. This technique attempts to minimize the collateral damage to the surrounding tissue, specifically the articular cartilage. Clinicians should consider using this technique when performing ultrasound-guided injections to the first MTP joint. LEVEL OF EVIDENCE: Cadaveric, Level V.

Accuracy of ultrasound-guided superficial trigeminal nerve blocks using methylene blue in cadavers.

OBJECTIVE: To describe a technique for and assess accuracy of ultrasound-guided supraorbital, infraorbital, and mental nerve injections in a cadaveric model. Prior studies have shown that peripheral trigeminal nerve injections can be beneficial for a subgroup of patients for whom surgical treatment is not appropriate. Accurate injection is necessary to limit side effects and improve its efficacy. Ultrasound guidance may improve the accuracy of an injection that is typically performed using a blind technique. METHODS: A single operator completed 36 ultrasound-guided injections with methylene blue dye on six embalmed cadavers. Three cadavers were injected using an in-plane approach and three cadavers using an out-of-plane approach. Injections staining the target nerve were considered "accurate," whereas "inaccurate" injections resulted in no nerve staining. RESULTS: The accuracy rate was 100% (18 of 18) for the in-plane approach and 94% (17 of 18) for the out-of-plane approach. Thirty-five injections were considered accurate (97%) with overflow, and one injection was inaccurate. CONCLUSION: This cadaveric investigation suggests that ultrasound guidance can be used to inject the peripheral trigeminal nerve with a high degree of accuracy. Clinicians should consider using ultrasound guidance to inject the trigeminal nerve for diagnostic or therapeutic purposes.

Continuous infusion of intraperitoneal bupivacaine after laparoscopic surgery: a randomized controlled trial.

BACKGROUND: A standard approach for postoperative analgesia in laparoscopic surgery is to infiltrate the incisions with local anesthetic in combination with systemic opioids. The intraperitoneal introduction of local anesthetic in this setting has the potential to provide appropriate analgesia without the side effects of systemic opioids. We performed a randomized clinical trial of the On-Q pump delivery system to determine the safety and efficacy of this device for this novel purpose. METHODS: Thirty patients undergoing laparoscopic adjustable gastric banding were randomly assigned to one of two groups. The treatment group received On-Q pump systems filled with 0.375% bupivacaine, while the control group received pumps filled with 0.9% normal saline. The pump's catheter was introduced intraperitoneally, and bupivacaine or saline was then delivered for the first 48 h after surgery. Patient's subjective pain scores were evaluated at preset intervals. In addition, shoulder pain, morphine requirements, and anti-emetic requirements were tabulated. RESULTS: A statistically significant decrease in patient's subjective reports of pain by visual analog score was noted in the On-Q group 1.8+/-1.93 vs. control 3.5+/-2.4, p<0.046 and remained significant until the end of the study (48 h). No statistical difference was noted in shoulder pain, morphine requirements, or anti-emetic requirements at any time point. CONCLUSION: Our trial was able to provide evidence of significant reduction in postoperative pain as measured by subjective pain scores with the use of continuous intraperitoneal bupivacaine using the On-Q pain pump system. Further investigation is warranted to evaluate the cost effectiveness of this technique.