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Background: Traumatic rib fractures are associated with pain lasting weeks to months and a decreased ability to inspire deeply or cough to clear secretions. Ultrasound-guided percutaneous cryoneurolysis involves reversibly ablating peripheral nerve(s) using exceptionally low temperature with a transdermal probe, resulting in a prolonged nerve block with a duration measured in months. We hypothesized that cryoneurolysis would improve analgesia and inspired volume following rib fracture., Methods: Adults with 1-6 traumatic rib fractures were randomized to either active cryoneurolysis and a sham peripheral nerve block (PNB), or sham cryoneurolysis and active PNB in a participant/observer-masked fashion. The primary endpoint was the maximum inspired volume the day after the procedure as measured with an incentive spirometer., Results: The day after the procedure, the unadjusted median [IQR] maximum inspired volume for participants who received cryoneurolysis (n=11) was 2,250 mL [1,500; 2,500] versus 1,300 mL [750; 2,500] for PNB (n=9, mean difference 496; 95%CI -428 to 1420; t-test P=0.269). When adjusted for covariates (e.g., baseline lung volume), the cryoneurolysis group had an estimated 793 mL greater mean volume than PNB (95%CI 273 to 1,312; ANCOVA P=0.005). Improvement from baseline in maximum inspired volume for cryoneurolysis was 1,000 mL [1,000; 1,375] versus 300 mL [0; 1,000] for PNB (t-test P=0.002). This was equivalent to an improvement over baseline of 100% [90%, 188%] for cryoneurolysis versus 30% [0%, 50%] for PNB (t-test P=0.003). Average daily pain scores were generally lower for the cryoneurolysis group throughout the first month. Total cumulative oxycodone equivalents were 5 mg [0, 13] for cryoneurolysis vs 45 mg [43, 135] for PNB (t-test P=0.013)., Conclusions: Ultrasound-guided percutaneous cryoneurolysis improves maximum inspired lung volume while concurrently decreasing pain and opioid consumption after traumatic rib fracture. These results should be considered preliminary, requiring confirmation with a trial including a larger sample size., Competing Interests: Conflicts of Interest: Drs. Finneran and Ilfeld. These authors’ institution has received funding and/or product from Epimed International (Dallas, TX) for other research studies, SPR Therapeutics (Cleveland, OH), Infutronix (Natick, MA), Masimo (Irvine, CA), Varian Medical Systems (Palo Alto, CA), and Avanos Medical (Irvine, CA)., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Anesthesiologists.)

Background: The smallest meaningful improvement in pain scores (minimal clinically important difference [MCID]) after an analgesic intervention is essential information when both interpreting published data and designing a clinical trial. However, limited information is available for patients with chronic pain conditions, and what is published is derived from studies involving pharmacologic and psychological interventions. We here calculate these values based on data collected from 144 participants of a previously published multicenter clinical trial investigating the effects of a single treatment with percutaneous cryoneurolysis., Methods: In the original trial, we enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction. At both baseline and 4 months (primary end point), participants rated their phantom limb pain based on a numeric rating scale (NRS) and their interference of pain on physical and emotional functioning as measured with the Brief Pain Inventory's interference subscale. They subsequently qualitatively defined the change using the 7-point ordinal Patient Global Impression of Change (PGIC). The smallest clinically meaningful improvements in phantom limb pain and Brief Pain Inventory scores were calculated using an anchor-based method based on the PGIC., Results: The median (interquartile range [IQR]) phantom pain NRS (0-10) improvements at 4 months considered small, medium, and large were 1 [1-1], 3 [3-4], and 4 [3-6], respectively. The median improvements in the Brief Pain Inventory interference subscale (0-70) associated with a small, medium, and large analgesic changes were 16 [6-18], 24 [22-31], and 34 [22-46]. The proportions of patients that experienced PGIC ≥5 were 33% and 36% in the active and placebo groups, respectively. The relative risk of a patient experiencing PGIC ≥5 in the active group compared to the sham group with 95% confidence interval was 0.9 (0.6-1.4), P = .667., Conclusions: Amputees with phantom limb pain treated with percutaneous cryoneurolysis rate analgesic improvements as clinically meaningful similar to pharmacologic treatments, although their MCID for the Brief Pain Inventory was somewhat larger than previously published values. This information on patient-defined clinically meaningful improvements will facilitate interpretation of available studies and guide future trial design., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2024 International Anesthesia Research Society.)

Purpose of Review: Cryoneurolysis refers to the process of reversibly ablating peripheral nerves with extremely cold temperatures to provide analgesia for weeks to months. With ultrasound-guidance or landmark-based techniques, it is an effective modality for managing both acute and chronic pain. In this review, we summarize the reported literature behind its potential applications and efficacy., Recent Findings: Here, we summarize several studies (from case reports to clinical trials) describing the use of ultrasound-guided and landmark-based cryoneurolysis for acute and chronic pain. Acute pain indications included pain related to knee arthroplasty, limb amputations, mastectomies, shoulder surgery, rib fractures, and burn. Chronic pain indications included chronic knee pain (due to osteoarthritis), shoulder pain, painful neuropathies, postmastectomy pain syndrome, phantom limb pain, facial pain/headaches, foot/ankle pain, inguinal pain, and sacroiliac joint pain. For both acute and chronic pain indications, more high quality randomized controlled clinical trials are needed to definitively assess the efficacy of cryoneurolysis versus other standard therapies for a multitude of pain conditions., (© 2024. The Author(s).)

Background: Extremity amputations are associated with pain in both the residual limb and the phantom limb. This pain, which is often debilitating, may be prevented by excellent perioperative pain control. Ultrasound-guided percutaneous cryoneurolysis is an analgesic modality offering pain control for weeks or months following surgery. This treatment has not been compared to the sham procedure for large nerves (e.g., femoral and sciatic) to provide preoperative analgesia. We therefore conducted a randomized, controlled pilot study to evaluate the use of this modality for the treatment of pain following amputation to (1) determine the feasibility of and optimize the study protocol for a subsequent definitive clinical trial; and (2) estimate analgesia and opioid reduction within the first postoperative weeks., Methods: A convenience sample of seven patients undergoing lower extremity amputation were randomized to receive either active cryoneurolysis or a sham procedure targeting the sciatic and femoral nerves in a participant-masked fashion. This was a pilot study with a relatively small number of participants, and therefore the resulting data were not analyzed statistically., Results: Compared to the participants who received sham treatment (n=3), those who underwent active cryoneurolysis (n=4) reported lower pain scores and decreased opioid consumption at nearly all time points between days one and 21 following amputation., Conclusions: Ultrasound-guided percutaneous cryoneurolysis of the femoral and sciatic nerves prior to lower extremity amputation appears feasible and potentially effective. The data from this pilot study may be used to power a definitive randomized clinical trial., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2024, Finneran et al.)

Peripheral nerve entrapments can occur anywhere in the head and body and can cause significant pain. Cancer pain can be caused by these entrapments, triggered by a variety of etiologies, including tumor invasion, surgical trauma, chemotherapy, or scarring. Knowing the cause of pain can help the physician treat the problem effectively, and will decrease unnecessary and potentially worsening surgeries and high dose opioid therapies, as well as unnecessary pain. A knowledgeable interventional pain physician can diagnose and treat these nerves entrapments in the most effective manner, providing improved pain relief and quality of life.Key points Nerve entrapments can occur throughout the body in cancer patients due to multiple etiologies such as tumor invasion, surgical trauma, or cancer therapy. The problem of nerve entrapments in cancer pain is under-recognized. Patients with nerve entrapment syndromes frequently complain of a burning tingling sensation and other paresthesias in the nerve distribution which can progress to a complete loss of sensory and motor function. Diagnostic tools include history and physical exam, imaging, nerve conduction studies as well as diagnostic nerve injections/blocks. Treatment of nerve entrapments can range from neuropathic pain medications to nerve blocks and nerve ablations to surgical decompression., (© 2021. Springer Nature Switzerland AG.)

Although opioids are potent central acting broad-spectrum analgesics, their effectiveness is diminished by various factors pertaining to their metabolism, drug interactions, genetic issues, adverse/side effects, and potential for abuse. All these factors present potential barriers to effective analgesia requiring specific considerations in clinical practice, which include monitoring and case-based intervention., (© 2021. Springer Nature Switzerland AG.)

Background: Chronic spinal pain is the most prevalent chronic disease with employment of multiple modes of interventional techniques including epidural interventions. Multiple randomized controlled trials (RCTs), observational studies, systematic reviews, and guidelines have been published. The recent review of the utilization patterns and expenditures show that there has been a decline in utilization of epidural injections with decrease in inflation adjusted costs from 2009 to 2018. The American Society of Interventional Pain Physicians (ASIPP) published guidelines for interventional techniques in 2013, and guidelines for facet joint interventions in 2020. Consequently, these guidelines have been prepared to update previously existing guidelines., Objective: To provide evidence-based guidance in performing therapeutic epidural procedures, including caudal, interlaminar in lumbar, cervical, and thoracic spinal regions, transforaminal in lumbar spine, and percutaneous adhesiolysis in the lumbar spine., Methods: The methodology utilized included the development of objective and key questions with utilization of trustworthy standards. The literature pertaining to all aspects of epidural interventions was viewed with best evidence synthesis of available literature and  recommendations were provided., Results: In preparation of the guidelines, extensive literature review was performed. In addition to review of multiple manuscripts in reference to utilization, expenditures, anatomical and pathophysiological considerations, pharmacological and harmful effects of drugs and procedures, for evidence synthesis we have included 47 systematic reviews and 43 RCTs covering all epidural interventions to meet the objectives.The evidence recommendations are as follows: Disc herniation: Based on relevant, high-quality fluoroscopically guided epidural injections, with or without steroids, and results of previous systematic reviews, the evidence is Level I for caudal epidural injections, lumbar interlaminar epidural injections, lumbar transforaminal epidural injections, and cervical interlaminar epidural injections with strong recommendation for long-term effectiveness.The evidence for percutaneous adhesiolysis in managing disc herniation based on one high-quality, placebo-controlled RCT is Level II with moderate to strong recommendation for long-term improvement in patients nonresponsive to conservative management and fluoroscopically guided epidural injections. For thoracic disc herniation, based on one relevant, high-quality RCT of thoracic epidural with fluoroscopic guidance, with or without steroids, the evidence is Level II with moderate to strong recommendation for long-term effectiveness.Spinal stenosis: The evidence based on one high-quality RCT in each category the evidence is Level III to II for fluoroscopically guided caudal epidural injections with moderate to strong recommendation and Level II for fluoroscopically guided lumbar and cervical interlaminar epidural injections with moderate to strong recommendation for long-term effectiveness.The evidence for lumbar transforaminal epidural injections is Level IV to III with moderate recommendation with fluoroscopically guided lumbar transforaminal epidural injections for long-term improvement. The evidence for percutaneous adhesiolysis in lumbar stenosis based on relevant, moderate to high quality RCTs, observational studies, and systematic reviews is Level II with moderate to strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. Axial discogenic pain: The evidence for axial discogenic pain without facet joint pain or sacroiliac joint pain in the lumbar and cervical spine with fluoroscopically guided caudal, lumbar and cervical interlaminar epidural injections, based on one relevant high quality RCT in each category is Level II with moderate to strong recommendation for long-term improvement, with or without steroids. Post-surgery syndrome: The evidence for lumbar and cervical post-surgery syndrome based on one relevant, high-quality RCT with fluoroscopic guidance for caudal and cervical interlaminar epidural injections, with or without steroids, is Level II with moderate to strong recommendation for long-term improvement. For percutaneous adhesiolysis, based on multiple moderate to high-quality RCTs and systematic reviews, the evidence is Level I with strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections., Limitations: The limitations of these guidelines include a continued paucity of high-quality studies for some techniques and various conditions including spinal stenosis, post-surgery syndrome, and discogenic pain., Conclusions: These epidural intervention guidelines including percutaneous adhesiolysis were prepared with a comprehensive review of the literature with methodologic quality assessment and determination of level of evidence with strength of recommendations.

Chronic pain management techniques have evolved in recent years. With regard to this, ultrasound (US) technology has become a standard for most acute pain procedures and essential for postsurgical pain relief and enhanced recovery after surgery protocols. This manuscript summarizes clinical studies evaluating US use for chronic pain management and compares efficacy with standard techniques including fluoroscopy (FL). US possesses several unique benefits when compared with FL, including elimination of radiation exposure while providing similar clinical outcomes. In summary, US use for chronic pain procedures is emerging as a viable, safe, and effective modality. Additional studies are needed to best appreciate US and its role in chronic pain management., (Published by Elsevier Ltd.)

Pain after limb amputation is frequently challenging to adequately treat with local anesthetic-based regional anesthesia techniques due to its relatively long duration. Furthermore, uncontrolled pain in the immediate postoperative period is associated with persistent postsurgical pain, and frequently phantom limb pain. Cryoneurolysis is an alternative regional analgesic method to local anesthesia-based techniques. We report 3 cases in which ultrasound-guided percutaneous cryoneurolysis was performed in the perioperative period of limb amputation. All reported profound analgesia in the postoperative period without persistent postsurgical residual limb or phantom pain in the following months. No adverse events associated with the cryoneurolysis procedure occurred.

Background: Temple headaches are common, yet the anatomic etiology of headaches in this region is often confusing. One possible cause of temple headaches is dysfunction of the auriculotemporal nerve (ATN), a branch of the third division of the trigeminal nerve. However, the site of pain is often anterior to the described path of the ATN, and corresponds more closely to a portion of the path of a small branch of the second division of the trigeminal nerve called the zygomaticotemporal nerve (ZTN)., Objectives: We present the anatomic and clinical differences between these 2 nerves and describe treatment approaches. Diagnosis is made by physical examination of the temporal fossa and the temporomandibular joint, and injection of local anesthetic over the tenderest nerve., Results: In general, treatments of headaches that generated from the peripheral nerve attempt to neutralize the pain origin using surgical or interventional pain techniques to reduce nerve irritation and subsequently deactivate stimulated migraine centers., Conclusions: Treatment of temporal nerve entrapment includes medications, nerve injections, dental appliances, cryoneuroablation, chemical neurolysis, neuromodulation, and surgical decompression., Key Words: Headache, migraine, trigeminal nerve, Frey's syndrome, zygomaticotemporal nerve, auriculotemporal nerve, temple pain, jaw pain, ear pain, tooth pain.

We report 3 different cases in which ultrasound-guided percutaneous cryoneurolysis was performed to treat acute pain: 1 patient with refractory incisional pain after percutaneous nephrolithotomy; 1 patient with burns to the foot; and 1 patient with pain from iliac crest grafting. Acute pain associated with surgery or injury is a challenge to treat with local anesthetic-based regional anesthesia techniques when the anticipated pain duration exceeds a few days. Cryoneurolysis is an alternative analgesic method that utilizes extremely cold temperatures to reversibly ablate peripheral nerves and is potentially a novel method for acute pain management.

Introduction: Cryoneurolysis is the direct application of low temperatures to reversibly ablate peripheral nerves to provide pain relief. Recent development of a handheld cryoneurolysis device with small gauge probes and an integrated skin warmer broadens the clinical applications to include treatment of superficial nerves, further enabling treatments for pre-operative pain, post-surgical pain, chronic pain, and muscle movement disorders., Areas Covered: Cryoneurolysis is the direct application of cold temperatures to a peripheral nerve, resulting in reversible ablation due to Wallerian degeneration and nerve regeneration. Use over the last 50 years attests to a very low incidence of complications and adverse effects. Cryoprobes have traditionally been applied through a surgical incision; but, recent technical advances allow percutaneous administration. A new hand-held device is now approved for use within the United States. Cryoneurolysis has been used to treat postoperative and chronic pain states as well as spasticity. Expert commentary: Changes in the US healthcare system such as a push for the reduction of opioid use and the incorporation of Diagnostic Related Group codes, as well as recent technological advances including a handheld unit that allows for treatment of superficial nerves while protecting the skin from damage, may contribute to the resurgence of cryoneurolysis for the treatment of peripheral nerves.

Background: Human Immunodeficiency Virus (HIV) patients have an increased rate of chronic pain, particularly peripheral neuropathy. This disease burden causes considerable disability and negatively affects quality of life. Pain is undertreated and more complex to manage in these patients for a number of reasons, including complex anti-retroviral drug regimens, higher risks of side effects, and higher rates of comorbid psychiatric illness and substance abuse. Pain management must take these factors into account and use all available modalities, including nonopioid pain relievers, adjuvant medications, and psychosocial therapies in addition to opioid analgesics. Here we review recent recommendations regarding acute and chronic opioid treatment of pain and the treatment of opioid dependence in HIV-infected patients, and provide suggestions regarding aberrant behavior in pain treatment., Objectives: The objective of this comprehensive review is to assess and summarize the complicating factors involved in treating HIV patients' pain with opioid analgesics., Study Design: This is a narrative review without a systematic quality assessment of the literature discussion., Methods: A comprehensive review of the literature relating to pain and pain treatment in HIV patients. The literature was collected from electronic databases, textbooks, and other sources. The scientific literature reviewed includes randomized trials, observational studies, systematic reviews, guidelines, and government reports., Results: This patient population is heterogeneous and diverse in their medical issues and comorbidities, but a systematic, stepwise approach to assessing and managing pain in HIV patients is described. Chronic opioid treatment has proven to be problematic and considerations and alternatives to this treatment are described. Management of pain in patients with opioid addiction, a frequent comorbidity of HIV infection, requires special awareness and different prescribing practices. Screening and identifying patients who are at special risk for developing medical or behavior complications of pain treatment is essential, and approaches to this, and common forms of aberrant behavior, are described., Limitations: The scientific literature on opioid treatment in this population is limited. The population of HIV patients is heterogeneous and differs in significant ways based on ethnicity, national origin, and mode of transmission, making it difficult to generalize about pain treatment in such a diverse group., Conclusions: Pain management in HIV patients must take these factors into account and use all available modalities for treatment, including nonopioid analgesics, adjuvant medications, and psychosocial therapies. Opioid analgesics should be prescribed with caution in accordance with current guidelines and after careful risk assessment.

Background: Percutaneous epidural adhesiolysis and spinal endoscopic adhesiolysis are interventional pain management techniques used to treat patients with refractory low back pain due to epidural scarring. Standard epidural steroid injections are often ineffective, especially in patients with prior back surgery. Adhesions in the epidural space can prevent the flow of medicine to the target area; lysis of these adhesions can improve the delivery of medication to the affected areas, potentially improving the therapeutic efficacy of the injected medications., Study Design: A systematic review utilizing the methodologic quality criteria of the Cochrane Musculoskeletal Review Group for randomized trials and the criteria established by the Agency for Healthcare Research and Quality (AHRQ) for evaluation of randomized and non-randomized trials., Objective: To evaluate and update the effectiveness of percutaneous adhesiolysis and spinal endoscopic adhesiolysis in managing chronic low back and lower extremity pain due to radiculopathy, with or without prior lumbar surgery, since the 2005 systematic review., Methods: Basic search identified the relevant literature, in the MEDLINE, EMBASE, and BioMed databases (November 2004 to September 2006). Manual searches of bibliographies of known primary and review articles, and abstracts from scientific meetings within the last 2 years were reviewed. Randomized and non-randomized studies are included in the review based on criteria established. Percutaneous adhesiolysis and endoscopic adhesiolysis are analyzed separately., Outcome Measures: The primary outcome measure was significant pain relief (50% or greater). Other outcome measures were functional improvement, improvement of psychological status, and return to work. Short-term relief was defined as less than 3 months, and long-term relief was defined as 3 months or longer., Results: Studies regarding the treatment of epidural adhesions for the treatment of low back and lower extremity pain were sought and reviewed. The evidence from the previous systematic review was combined with new studies since November 2004. There is strong evidence for short term and moderate evidence for long term effectiveness of percutaneous adhesiolysis and spinal endoscopy., Conclusion: Percutaneous adhesiolysis and spinal endoscopy may be effective interventions to treat low back and lower extremity pain caused by epidural adhesions.

The incidence of inadequate analgesia despite technically well performed injections led our clinic to prospectively test patients for response to a variety of local aesthetics. Skin testing was performed on the skin of the forearm away from the site of pathology. Patients were asked to identify "which is the most numb" of the skin wheals. Although most were equally numb to all three local anesthetics (lidocaine, bupivicaine, and mepivicaine), 7.5% of the patients consistently chose mepivicaine as the local anesthetic resulting in the most hypoesthesia. For patients who had previously undergone an unsuccessful procedure with bupivicaine (the standard local anesthetic used in our practice), the same procedure with mepivicaine provided good relief. Patients are now questioned on their initial evaluation about a history of difficulty getting numb, for instance at the dentist, and preemptively skin tested prior to any invasive procedure.

Cryoneuroablation, also known as cryoanalgesia or cryoneurolysis, is a specialized technique for providing long-term pain relief in interventional pain management settings. Modern cryoanalgesia traces its roots to Cooper et al who developed in 1961, a device that used liquid nitrogen in a hollow tube that was insulated at the tip and achieved a temperature of - 190 degrees C. Lloyd et al proposed that cryoanalgesia was superior to other methods of peripheral nerve destruction, including alcohol neurolysis, phenol neurolysis, or surgical lesions. The application of cold to tissues creates a conduction block, similar to the effect of local anesthetics. Long-term pain relief from nerve freezing occurs because ice crystals create vascular damage to the vasonervorum, which produces severe endoneural edema. Cryoanalgesia disrupts the nerve structure and creates wallerian degeneration, but leaves the myelin sheath and endoneurium intact. Clinical applications of cryoanalgesia extend from its use in craniofacial pain secondary to trigeminal neuralgia, posterior auricular neuralgia, and glossopharyngeal neuralgia; chest wall pain with multiple conditions including post-thoracotomy neuromas, persistent pain after rib fractures, and post herpetic neuralgia in thoracic distribution; abdominal and pelvic pain secondary to ilioinguinal, iliohypogastric, genitofemoral, subgastric neuralgia; pudendal neuralgia; low back pain and lower extremity pain secondary to lumbar facet joint pathology, pseudosciatica, pain involving intraspinous ligament or supragluteal nerve, sacroiliac joint pain, cluneal neuralgia, obturator neuritis, and various types of peripheral neuropathy; and upper extremity pain secondary to suprascapular neuritis and other conditions of peripheral neuritis. This review describes historical concepts, physics and equipment, various clinical aspects, along with technical features, indications and contraindications, with clinical description of multiple conditions amenable to cryoanalgesia in interventional pain management settings.