Total Knee Arthroplasty With and Without Schedule II Opioids: A Randomized, Double-Blinded, Placebo-Controlled Trial.

INTRODUCTION: Orthopedic surgeons are the third highest prescribers of narcotics. Previous work demonstrated that surgeons prescribe three times the narcotics required, and most patients do not properly dispose of leftover medication following surgery. This has prompted the creation of multimodal pain regimens to reduce reliance on narcotics. It is unknown if these pathways can effectively eliminate opioids following total knee arthroplasty (TKA). Our purpose was to evaluate a multimodal regimen without schedule II narcotics following TKA, in a randomized, blinded fashion. We hypothesized that there would be no difference in pain scores between groups. METHODS: A total of 43 narcotic-naïve patients participated in a randomized, double-blinded, placebo-controlled trial. Postoperative protocols were identical between cohorts, except for the study medication. The narcotic group received an encapsulated 5 mg oxycodone, whereas the control group received an encapsulated placebo. Perioperative outcomes were compared with routine statistical analysis. RESULTS: Four patients withdrew early secondary to pain: three in the placebo group and one in the narcotic group (p=1.00). We found no difference in hospital length of stay (p=0.09) or pain scores at all time points between cohorts (all p>0.05). There was a higher proportion of patients using a narcotic in the opioid treatment arm at day 30 (40% vs. 21.4%, p=0.29) and day 60 (20% vs. 7.1%, p=0.32), although this was not statistically significant. CONCLUSION: A multimodal regimen without schedule II narcotics demonstrates equivalent pain scores and may reduce the risk of long-term opioid dependence following TKA.

Ultrasound-guided fascial plane blocks for post-breast surgery pain syndrome.

INTRODUCTION: Persistent pain following breast surgery is common and may be challenging to treat. In patients refractory to conservative treatments, ultrasound-guided fascial plane blocks of thoracic nerves can be a useful option. RESULTS: This type of neuro blockade technique provides advantages in terms of safety and efficacy that are convenient for physicians managing refractory and complex cases of post-breast surgery syndrome. CONCLUSION: This technical review aims to present an up-to-date summary of the most common ultrasound-guided fascial plane blocks for chronic pain in post-breast surgery patients, provide a detailed technical description of each intervention, and propose preferred injections based on the anatomical location of the pain.

Ultrasound-guided procedures for the management of chronic thoracic back pain: a technical review.

Pain arising from the thoracic region has been reported to be potentially as debilitating as cervical or lumbar back pain, and may stem from a vast number of spinal sources, including zygapophysial, costovertebral and costotransverse joints, intervertebral discs, ligaments, fascia, muscles, and nerve roots. Over the last two decades, the use of ultrasound in interventional spinal procedures has been rapidly evolving, due to the ultrasound capabilities of visualizing soft tissues, including muscle layers, pleura, nerves, and blood vessels, allowing for real-time needle tracking, while also reducing radiation exposure to both patient and physician, when compared to traditional fluoroscopy guidance. However, its limitations still preclude it from being the imaging modality of choice for some thoracic spinal procedures, notably epidural (interlaminar and transforaminal approaches) and intradiscal injections. In this technical review, we provide an overview of five thoracic spinal injections that are amenable to ultrasound guidance. We start by discussing their clinical utility, followed by the relevant topographic anatomy, and then provide an illustrated technical description of each of the procedures discussed: (1) erector spinae plane block; (2) intra-articular thoracic zygapophyseal (facet) joint injection; (3) thoracic medial branch block; (4) costotransverse joint injection; and (5) costovertebral joint injection.

A Change in the Educational Landscape of Regional Anesthesia: A National Survey of Anesthesiology Residency Programs to Assess the Correlation Between the Frequency of Teaching a Block Technique and Clinical Importance.

Introduction Variability regarding which blocks are performed most often can be quite high among anesthesiology residency training programs. Which techniques are viewed by residency programs as "critical" for their graduates to know can also be inconsistent. We administered a national survey to investigate correlations between the cited importance of techniques and the relative frequency with which they are being taught. Materials and methods A three-round modified Delphi method was used to develop the survey. The final survey was sent to 143 training programs across the United States. The surveys collected information on the frequency with which thoracic epidural blocks, truncal blocks, and peripheral blocks were taught. The respondents were also asked to rate how critical each technique is to learn during residency. A correlation between the relative frequency of block teaching and cited importance to education was calculated using Kendall's Tau statistic. Results Among truncal procedures, transversus abdominis plane (TAP) block and thoracic epidural blocks were frequently viewed as "indispensable for daily practice." Among peripheral nerve blocks, interscalene, supraclavicular, adductor, and popliteal blocks were frequently viewed as indispensable. All truncal blocks showed a strong correlation between the relative frequency of block teaching and cited importance to education. However, the frequency of teaching interscalene, supraclavicular, femoral, and popliteal blocks failed to correlate with their reported importance ranking. Conclusions Perceived importance was significantly associated with the reported frequency of block teaching for all truncal and peripheral blocks except for interscalene, supraclavicular, femoral, and popliteal. The lack of correlation between the frequency of teaching and perceived importance is reflective of a changing educational landscape.

Transvenous embolization of cerebrospinal fluid-venous fistulas: Independent validation and feasibility of upper-extremity approach and using dual-microcatheter and balloon pressure cooker technique.

BACKGROUND: Transvenous embolization is emerging as a promising treatment for cerebrospinal fluid-venous fistulas (CVF) associated with spontaneous intracranial hypotension (SIH). OBJECTIVE: To perform an independent validation of the efficacy and safety of the procedure and describe the procedural techniques used at our institution. METHODS: A retrospective review was performed including consecutive patients with SIH who had undergone CVF embolization with 3-month clinical and imaging follow-up. Clinical evaluation included the Patient Global Impression of Change (PGIC) Scale and six-item Headache Impact Test (HIT-6). Bern SIH score was used for imaging evaluation on brain MRI. Post-treatment changes in scores were assessed by Wilcoxon signed rank test. Procedural technical details, including use of upper-extremity access and dual-microcatheter pressure cooker technique, were recorded. RESULTS: 18 patients (13 female, median age 60 years) were included. 17 (94%) procedures were performed with upper-extremity access and 12 (67%) using dual-microcatheter pressure cooker technique. After embolization, 16 (89%) patients reported much or very much improved at follow-up PGIC; median (IQR) HIT-6 score improved from 68 (62-72) to 36 (36-38) and Bern SIH score improved from 8 (6-8) to 3 (1.5-3.5), p values <0.001. Side effects were transient embolization site back pain in 15 (83%) and rebound intracranial hypertension requiring medical management in 9 (50%) patients. HIT-6 and Bern SIH score changes were similar between conventional and pressure cooker techniques (p values >0.05). CONCLUSION: Transvenous embolization is independently validated as a highly effective and safe treatment for CVF and is feasible using upper-extremity venous access. Dual-microcatheter and balloon/coil pressure cooker techniques may be used to optimize distribution of embolic material and potentially, treatment efficacy.

Ultrasound-guided percutaneous peripheral nerve stimulation for chronic refractory neuropathic pain: a unique series.

During the last two decades, with the advent of recent technology, peripheral nerve stimulation has become an appealing modality at the forefront of pain management. In this case series, we document the clinical rationale and technical considerations on three of the most challenging cases, refractory to previous interventions, that were treated by our team with an ultrasound-guided percutaneous peripheral nerve stimulator targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. At the 6-month follow-up, all patients experienced greater than 50% relief of baseline pain, with a near-complete resolution of pain exacerbations. Furthermore, to our knowledge, this is the first report of an ultrasound-guided percutaneous technique of a peripheral nerve stimulator targeting the musculocutaneous and subcostal nerves.

Peripheral nerve stimulation is a new tool used in the treatment of peripheral nerve pain. In this study, we share our experience using this technology in three unusual, difficult-to-treat chronic nerve pain presentations, targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. All patients were asked about how pain levels had changed since the peripheral nerve stimulation device had been implanted. In every case, patients reported a decline in their pain level from day one. After 6 months of peripheral nerve stimulator use, all patients reported a greater than 50% pain relief.

A case for ultrasound-guided peripheral nerve stimulation in intractable anterior cutaneous nerve entrapment syndrome.

Aim: This case report documents the use of peripheral nerve stimulation in the setting of entrapment of the anterior cutaneous branches of the intercostal nerves, with pain rated by the patient as severe during exacerbation episodes. Materials & methods: Under ultrasound guidance, two permanent leads were implanted caudad to cephalad, along and superficial to the lateral aspect of the rectus abdominis, distal to the umbilicus (1 lead per side). Results: At the 6 month follow-up, the patient reported near complete resolution of baseline pain, as well as fewer, sporadic pain exacerbation episodes, rated as mild-to-moderate. Conclusion: This case report suggests that peripheral nerve stimulation might be a valuable treatment option for previously intractable abdominal pain due to entrapment of the anterior cutaneous branches.

Anterior cutaneous nerve entrapment syndrome is a peculiar, a largely disregarded pain condition. Current management algorithms rely mostly on local injections followed by surgical anterior neurectomy. This case report presents a case of longstanding, anterior cutaneous nerve entrapment syndrome, unresponsive to first-line treatment, that was successfully treated with peripheral nerve stimulation technology targeting the anterior cutaneous branches.

A retrospective case series of prophylactic neurectomy during total knee arthroplasty.

INTRODUCTION: Total knee arthroplasty is a common operation performed to relieve pain and restore functional activity. While overall widely successful, a subset of patients has continued pain postoperatively with no identifiable cause. Neuroma formation has been identified as a possible contributor to this unexplained pain, often necessitating an additional procedure for neuroma removal. The purpose of our study was to evaluate if prophylactic neurectomy could reduce the occurrence of postoperative pain. METHODS: A total of 112 patients were compared, 44 control patients and 68 neurectomy patients. Demographic information, Numerical rating pain scale (NRS) and Knee Society Scores (KSS) were collected pre- and post-operatively. Patients were additional asked if they were overall satisfied with the operation. RESULTS: There were no differences between groups with respect to age (Median: 71 vs 69 years, p = 0.28), male sex (41% vs 44%, p = 0.85), or body mass index (Median: 32.2 vs 31.3, p = 0.80). When comparing the degree of change following surgery there were no statistically significant differences observed in NRS pain scores (Median change: -7 vs -6, p = 0.89) or KSS scores (Median change: +44 vs +40, p = 0.14). Similarly, there was no statistically significant difference in overall patient-reported satisfaction with the knee replacement (82.5% vs 86.6%, p = 0.59). CONCLUSION: We did not find a statistically significant difference in NRS, KSS, or overall patient satisfaction between the prophylactic neurectomy and control patient groups. Larger studies with evaluation of the nerve diameter will be needed to determine which patients are at risk for symptomatic neuroma development following total knee arthroplasty.

Ultrasound-Guided Gluteal Fascial Plane Block for the Treatment of Chronic Refractory Greater Trochanteric Pain Syndrome - Technique Description and Anatomical Correlation Study.

INTRODUCTION: Greater trochanteric pain syndrome may often mimic pain generated from other sources. However, it is most commonly caused by gluteus medius and gluteus minimus tendinopathy or tear. The purpose of this technical report was to: 1) describe the ultrasound-guided fascial plane block technique targeting the superior gluteal nerve in the plane between gluteus medius/gluteus minimus to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome; 2) anatomically correlate the procedure with cadaveric dissections demonstrating the structures being imaged and the tissues along the needle trajectory; 3) demonstrate the feasibility of the technique with serial dissection of one cadaveric specimen following injection with color dye. TECHNIQUE DESCRIPTION: The ultrasound-guided fascial plane block targeting the superior gluteal nerve to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome has been outlined with supporting ultrasound scans and anatomical dissections. The cadaveric dissections are correlated to the ultrasound scans of a healthy volunteer and provide visualization of the tissues in the needle trajectory. The feasibility study in a cadaveric specimen showed adequate stain of the superior gluteal nerve without spread to the piriformis muscle belly, the sciatic nerve, or the inferior gluteal nerve. CONCLUSIONS: This ultrasound-guided fascial plane block is a feasible option for blocking the superior gluteal nerve without inadvertent involvement of the sciatic and inferior gluteal nerves. Further randomized controlled clinical trials are necessary to assess the clinical efficacy of the gluteus medius/gluteus minimus fascial plane block to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome.

Ultrasound-guided hydrodissection of the superficial peroneal nerve for chronic neuropathic pain: a war veteran's story.

Aim: This case report presents the application of ultrasound-guided hydrodissection of the superficial peroneal nerve to treat chronic refractory neuropathic pain, rated by the patient with an average intensity of 6/10 on the numerical rating scale. Materials & methods: Under ultrasound guidance, the nerve was identified compressed by a herniation of the peroneus brevis. An in-plane hydrodissection was performed using a solution of 10 ml of ropivacaine and methylprednisolone until the epineurium was entirely separated from the surrounding tissue. Results: At the 2-month follow-up, the patient reported a decrease of pain, which he rated a 2/10 on the numerical rating scale. At this point, night-time episodes of moderate pain persisted. The procedure was repeated and at the 6-month follow-up, the patient remained pain free. Conclusion: This case report suggests that consecutive ultrasound-guided hydrodissection techniques might be a valuable option in the treatment of superficial peroneal nerve entrapment neuropathy.

Peripheral neuropathic pain is a debilitating pain condition. Management can be challenging and clinicians often rely on oral medications and surgical options. This case report presents the treatment of a case of longstanding, moderate-to-severe superficial peroneal nerve entrapment neuropathy due to a grenade explosion, with consecutive nerve hydrodissection using a solution containing an anesthetic and a corticosteroid. Immediately after the second procedure and at the 6-month follow-up the patient reported near-total relief.

Intraoperative Epicardial Ultra-High Frequency Ultrasound in Coronary Artery Bypass Grafting Surgery.

The use of intraoperative epicardial ultrasound in order to aid physicians and surgeons in open cardiac surgery has been established for quite some time. Recently, the development of ultra-high frequency ultrasound (UFHUS), 50-70 megahertz (MHz) technology has resulted in high-resolution imaging capabilities previously unavailable for clinical use. This report is the first to describe the use of intraoperative UFHUS epicoronary scanning to assess coronary anatomy and visualize cardioplegia flow within native coronary vessels.

Autologous Platelet-Rich Plasma Applications in Chronic Pain Medicine: Establishing a Framework for Future Research - A Narrative Review.

BACKGROUND: During the last decades, platelet-rich plasma has been studied for the treatment of multiple chronic pain conditions, in addition to being employed in the enhancement of healing after tissue injury. OBJECTIVE: To establish a framework for future research regarding the utilization of platelet-rich plasma in the treatment of chronic tissue injuries. METHODS: Preclinical and clinical studies from 2000-2020 relevant to applications of platelet-rich plasma for the treatment of chronic pain conditions were extracted from PubMed and Medline databases. The studies were analyzed on the basis of the study population, type of intervention, method of platelet-rich plasma preparation, the number of treatments administered, the timeframe of injections, and clinical outcomes. RESULTS: Although several preclinical studies and double-blind, randomized trials have shown promising results in the application of platelet-rich plasma for the treatment of multiple chronic pain conditions, various studies have also reported controversial results. Additionally, the methods employed for obtaining the platelet-rich plasma have not been standardized between studies, resulting in different concentrations of blood components between the preparations utilized. Moreover, differences between studies were also found regarding the number of injections administered per treatment. CONCLUSIONS: Future research addressing the utilization of platelet-rich plasma in the treatment of chronic pain conditions should focus on shedding light on the following major questions: a) Is there a dose-effect relation between the platelet count and the clinical efficacy of the preparation?; b) What pathology determinants should be considered when selecting between leukocyte-enriched and leukocyte-depleted concentrates?; c) What is the role of platelet activation methods on the clinical efficacy of platelet-rich plasma?; d) Is there an optimal number of injections and time frame for application of multiple injection treatment cycles?; e) Does the addition of local anesthetics affect the clinical efficacy of platelet-rich plasma?; and f) Is there potential for future platelet-rich plasma applications for the treatment of neuropathic pain of peripheral origin?

Application of Color Doppler Ultrasound to Identify and Repair Postoperative Cerebrospinal Fluid Leak: A Technical Note.

BACKGROUND: Incidental durotomy is a known complication of spinal surgery. Persistent cerebrospinal fluid (CSF) leak after unrecognized durotomy may lead to prolonged hospitalization and significant morbidity. If initial bed rest fails, the surgeon must choose between nontargeted methods such as oversewing the wound and lumbar drain placement or return to the operating room. OBJECTIVE: To report the novel use of color flow doppler (CFD) in conjunction with ultrasound (US) to localize the point of CSF leak, assist with aspiration of the pseudomeningocele, and direct the application of fibrin sealant or epidural blood patch. METHODS: This article includes a description of the technique as a technical note. RESULTS: A 72-year-old man underwent L2-5 laminectomies for spinal stenosis. During the index operation, a durotomy occurred and was repaired primarily. The patient subsequently developed leg weakness, back pain, and bulging of the incision. Using CFD, the site of durotomy was determined. Under direct visualization, 34 mL of CSF was aspirated from the pseudomeningocele and 20 mL of fibrin sealant was placed opposing the durotomy. At 2-month follow-up, CFD confirmed absent flow and MRI demonstrated pseudomeningocele resolution. CONCLUSION: This article represents the first report highlighting the utility of CFD US to guide epidural patch placement for postsurgical CSF leaks. CFD allows localization of the durotomy and direct application of blood or fibrin sealant, potentially increasing the success rate of epidural blood patch in postoperative patients. This approach is less invasive than revision surgery and does not require the prolonged hospitalization of lumbar drainage or other nontargeted interventions.

Ultrasound-guided diagnostic IPACK as a valuable tool in the management of a patient with soleal sling syndrome: a doubly rare case report.

This article describes the use of an infiltration between the popliteal artery and capsule of the knee joint (IPACK) to diagnose an entrapment neuropathy of the tibial nerve (TN) in a patient presenting with chronic neuropathic pain in the medial posterior compartment of the left knee, with a previous electromyography showing no evidence of tibial or common peroneal nerve neuropathy. After a positive sciatic nerve block, the patient was evaluated for a TN block, cancelled due to the presence of an abnormal leash of vessels wrapping around the nerve. For this reason, the patient was submitted to a diagnostic IPACK. A negative IPACK suggested that a compression of the TN at the popliteal fossa was the most likely source of the symptoms. After surgical decompression of the TN nerve at the popliteal fossa, the patient's symptoms decreased substantially.

Lay abstract This case report describes the use of an infiltration between the popliteal artery and capsule of the knee joint (IPACK), a technique in which local anesthetic is injected between the popliteal artery and the back side of the knee joint, to diagnose a compression of the tibial nerve (TN) in a patient with chronic knee pain. A female adult patient presented for further evaluation of chronic pain in the inner side of the back of her left knee. A previous electromyography showed no evidence of tibial or common peroneal nerve disease. After a positive diagnostic block of the left sciatic nerve, the patient was evaluated for a left TN block, so as to ascertain whether a compression of this nerve at the back side of the knee could be the origin of the patient's symptoms. During the ultrasound scanning of the TN, a group of abnormal vessels was found wrapping around the nerve, which made it impossible to inject the TN in a safe manner, even with the guidance of ultrasound. For this reason, the patient was instead submitted to a diagnostic left IPACK. A negative IPACK suggested that a compression of the TN at the popliteal fossa, the region behind the knee joint, was the most likely source of the patient's symptoms. After surgical decompression of the TN at the popliteal fossa, the patient's symptoms decreased substantially.

Initial Results of Precision Treatment of Postoperative Cerebrospinal Fluid Leak with Ultrasound-Guided Epidural Blood Patch.

BACKGROUND: Incidental durotomy, a known complication of spinal surgery, can lead to persistent cerebrospinal fluid leak and pseudomeningocele if unrecognized or incompletely repaired. We describe the use of ultrasound to visualize the site of durotomy, observe the aspiration of the pseudomeningocele, and guide the precise application of an ultrasound-guided epidural blood patch (US-EBP), under direct visualization in real time. METHODS: A retrospective review was performed to determine demographic, procedural, and outcome characteristics for patients who underwent US-EBP for symptomatic postoperative pseudomeningocele. RESULTS: Overall, 48 patients who underwent 49 unique episodes of care were included. The average age and body mass index were 60.5 (±12.6) years and 27.8 (±4.50) kg/m2, respectively. The most frequent index operation was laminectomy (24.5%), and 36.7% of surgeries were revision operations. Durotomy was intended or recognized in 73.4% of cases, and the median time from surgery to symptom development was 7 (interquartile range 4-16) days. A total of 61 US-EBPs were performed, with 51.0% of patients experiencing resolution of their symptoms after the first US-EBP. An additional 20.4% were successful with multiple US-EBP attempts. Complications occurred in 14.3% of cases, and the median clinical follow-up was 4.3 (interquartile range 2.4-14.5) months. CONCLUSIONS: This manuscript represents the largest series in the literature describing US-EBP for the treatment of postoperative pseudomeningocele. The success rate suggests that routine utilization of US-guided EBP may allow for targeted treatment of pseudomeningoceles, without the prolonged hospitalization associated with lumbar drains or the risks of general anesthesia and impaired wound healing associated with surgical revision.

Revisiting the Genicular Nerve Block: An Up-to-Date Guide Utilizing Ultrasound Guidance and Peripheral Nerve Stimulation - Anatomy Description and Technique Standardization.

BACKGROUND: Over the last decade, several authors have reported that percutaneous peripheral nerve stimulation (PNS) can be used to assist in verifying the position of the procedure needle tip in relation to nerve structures, and that the combined technique using both ultrasound (US) guidance and PNS may serve as a reliable method for confirmation of the correct position of the procedure needle tip. It has also been reported that, when combined with US guidance, PNS may increase the success rate of pain management interventions. OBJECTIVES: The aim of this technical report was to standardize an effective and easy to learn illustrated step-by-step technical approach to nerve identification during US-guided genicular nerve blocks, using percutaneous PNS as a verification instrument for procedure needle tip location. STUDY DESIGN: This technical protocol was developed based on the results of the authors' most recent cadaveric study on the innervation of the knee joint capsule. The technique was developed and tested by 4 different interventionists with different levels of expertise in US-guided procedures. SETTING: The cadaveric study of the knee joint capsule innervation was performed at the laboratory of the Division of Anatomy of one institution. The technical protocol using US and PNS was later developed at the medical simulation center of a different institution. METHODS: A team of anatomists from a division of anatomy of one institution performed the cadaveric study on the innervation of the knee joint capsule. A team of physicians then developed the step-by-step approach to this technical protocol at the medical simulation center of  a different institution. Finally, the illustrated step-by-step approach was tested by 4 different interventionists with different levels of expertise in US-guided procedures (1 beginner-level user; 1 intermediate-level user; 2 expert-level users), using a portable percutaneous PNS and 2 different US transducers at 2 different institutions. RESULTS: This technical protocol was successfully developed based on the results of the cadaveric study on the innervation of the knee joint capsule. Additionally, it was later successfully tested by interventionists with various levels of expertise utilizing different US equipment at separate institutions. LIMITATIONS: By combining US and nerve stimulation, this protocol requires the availability of both US equipment and necessary equipment for nerve stimulation that must all be made available in the sterile field. Another potential disadvantage is that nerve stimulation controls and the US image screen are generally located on 2 separate display panels, which could cause difficulty with visualization and simultaneous calibration for 2 individual devices. CONCLUSIONS: Our illustrated step-by-step technical protocol can be effectively and safely utilized as a reliable method of training, by which physicians with little to moderate US experience can improve their skills in accurately identifying the genicular nerves while performing US-guided examinations with the intent of executing a peripheral nerve block.

Counting ribs and thoracic levels under ultrasound: a systematized technical protocol for both posterior and anterior approaches.

Over the last two decades, the clinical applications of diagnostic and interventional ultrasound have expanded rapidly. When analyzing the chest wall and thoracic region, ultrasound has previously been shown to reliably identify chest wall pathologies like rib fracture and slipping rib syndrome, as well as having fundamentally changed perioperative management and patient outcomes after the emergence of point-of-care ultrasound. In addition, ultrasound guidance has recently become more popular for multiple blocks in the field of regional anesthesia and pain medicine. In this technical report, we systematize an ultrasound-guided protocol for counting ribs and thoracic levels for both posterior and anterior approaches, which does not require level confirmation by fluoroscopy. With this protocol, we hope to create an effective educational resource to support physicians from any specialty background as they engage in point-of-care ultrasound applications in the thoracic region.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation for the Treatment of Chronic Intractable Pain Originating From a Lipofibromatous Hamartoma of the Median Nerve.

This case report presents an application of peripheral nerve stimulation to the median nerve to treat a patient with intractable pain due to a lipofibromatous hamartoma of the left upper extremity. Ultra high-frequency ultrasound was used to determine the boundaries of the hamartoma. The patient then underwent an ultrasound-guided implantation of 2 stimulator electrodes distal to the elbow along the median nerve with stimulation coverage achieved at 1.2 and 1.4 mA, respectively. After an uneventful procedure, the pain score immediately decreased from 9 out of 10 to less than 6 on a numeric rating scale. Two weeks after the procedure, the patient reported substantial pain relief, with an average pain level of 5 to 6 out of 10. Twelve months after implantation, the patient maintained significant pain relief, rating her average pain level as a 4 to 6 out of 10. Placement of a percutaneous peripheral nerve stimulator was safe and effective with no adverse events being reported at the 12-month follow-up.

Ultrasound-Guided Intercostal Peripheral Nerve Stimulator Implantation: Technique Report and Feasibility Study in a Cadaver.

OBJECTIVE: This study aimed to describe and validate a novel ultrasound-guided intercostal peripheral nerve stimulator implantation technique. METHODS: The fifth to tenth ribs on both sides of an unembalmed cadaveric specimen were localized using a 15-6-MHz linear array transducer, counting distally from T-1 bilaterally. A single interventionist then implanted 12 peripheral nerve stimulators on the fifth through tenth ribs, six MicroLeads on the left side and six StimRouters on the right side, using an in-plane lateral to medial approach to the inferior border of the corresponding rib. After all the stimulators were implanted, their location was confirmed using fluoroscopy. Gross anatomic dissection was later performed for each of the stimulators placed, and the distance of the lead from the intercostal nerve and pleura was noted. RESULTS: All leads were noted in an accurate position in the plane between the inner and innermost intercostal muscle, without any intrapleural placement. The distance of the leads from the intercostal nerves was on average 2.3 mm and 1.1 mm for MicroLead and StimRouter, respectively. CONCLUSIONS: To our knowledge, this study is the first to determine the feasibility of ultrasound-guided peripheral nerve stimulator placement in close proximity to the pleura. All the stimulator leads were accurately placed using our ultrasound-guided technique and were within 0.5-3 mm from the intercostal nerve. Although this technique might prove technically challenging, the use of ultrasound for intercostal peripheral nerve stimulator implantation appears feasible and warrants further investigation to establish this as an acceptable technique for patients.