Applications of Cryoneurolysis in Chronic Pain Management: a Review of the Current Literature

PURPOSE OF REVIEW

The purpose of this review is to evaluate and summarize the literature investigating cryoneurolysis in the treatment of various chronic pain pathologies.

RECENT FINDINGS

There is an increasing amount of interest in the use of cryoneurolysis in chronic pain, and various studies have investigated its use in lumbar facet joint pain, SI joint pain, post-thoracotomy syndrome, temporomandibular joint pain, chronic knee pain, phantom limb pain, neuropathic pain, and abdominal pain. Numerous retrospective studies and a more limited number of prospective, sham-controlled prospective studies suggest the efficacy of cryoneurolysis in managing these chronic pain pathologies with a low complication rate. However, more blinded, controlled, prospective studies comparing cryoneurolysis to other techniques are needed to clarify its relative risks and advantages.

The role of high-resolution ultrasound and MRI in the evaluation of peripheral nerves in the lower extremity

Lower extremity peripheral neuropathy is a commonly encountered neurologic disorder, which can lead to chronic pain, functional disability, and decreased quality of life for a patient. As diagnostic imaging modalities have improved, imaging has started to play an integral role in the detection and characterization of peripheral nerve abnormalities by non-invasively and accurately identifying abnormal nerves as well as potential causes of neuropathy, which ultimately leads to precise and timely treatment. Ultrasound, which has high spatial resolution and can quickly and comfortably characterize peripheral nerves in real time along with associated denervation muscle atrophy, and magnetic resonance neurography, which provides excellent contrast resolution between nerves and other tissues and between pathologic and normal segments of peripheral nerves, in addition to assessing reversible and irreversible muscle denervation changes, are the two mainstay imaging modalities used in peripheral nerve assessment. These two modalities are complimentary, and one may be more useful than the other depending on the nerve and location of pathology. Imaging must be interpreted in the context of available clinical information and other diagnostic studies, such as electrodiagnostic tests. Here, we offer a comprehensive overview of the role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of the peripheral nerves of the lower extremity and their associated neuropathies.

Introduction to interventional radiology's role in palliative care for children with cancer: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

As palliative care continues to be an area of increasing emphasis in pediatric oncology programs, it is important to raise awareness about minimally invasive, image-guided procedures that can supplement more conventional palliative interventions, such as systemic analgesics, external beam radiation, and locoregional anesthesia. These procedures, when performed for appropriately selected patients, can often facilitate discharge from an inpatient facility, and help patients meet their end-of-life goals. This article specifically discusses three palliative procedures performed by interventional radiologists that can assist pediatric palliative care teams in: (a) percutaneous thermal ablation of painful bone metastases, (b) cryoneurolysis, and (c) tunneled drainage catheter placement for malignant pleural effusions and ascites.

Role of interventional radiology in pain management in oncology patients

This article reviews the current evidence of interventional radiology procedures for patients suffering with debilitating cancer pain, refractory to conventional therapies. Cancer pain is notoriously difficult to treat. Up to 90% of cancer patients experience pain with 56-82% of cancer pain controlled inadequately. Cancer pain influences a patient's ability to perform normal daily activities, causes higher risk of depression, and reduces quality of life. Pain-free status has been universally voted as a "good death". Alternative minimally invasive options include nerve blocks, neurolysis, bone ablation, spine and peripheral musculoskeletal augmentation techniques, embolisation, and cordotomy with evidence highlighting improved pain control, reduced analgesic requirements, and improved quality of life. Unfortunately, awareness and availability of these procedures is limited, potentially leaving patients suffering during their remaining life. The purpose of this review is to describe the basic concepts of interventional radiology techniques for pain palliation in oncology patients. In addition, emphasis will be given upon the need for an individually tailored approach aiming to augment efficacy and safety.

Preoperative Cryoneurolysis for Total Knee Arthroplasty: A Case Series

PURPOSE

The purpose of this pilot project case series is to describe the use of preoperative cryoneurolysis for 10 patients presenting for total knee arthroplasty (TKA).

DESIGN

Descriptive research design.

METHODS

Billing codes were used to identify 10 patients who had previously undergone TKA, preoperative cryoneurolysis and physical therapy (PT) at a Midwestern community hospital. Data collected included anesthetic management strategies, multimodal analgesic therapies, postanesthesia care unit pain scores (PACU), pain scores during physical therapy, and achievement of a range of motion during physical therapy.

FINDINGS

Nine of 10 patients who received preoperative cryoneurolysis had PACU pain scores of 0 (0-10 scale) up to 90 minutes postoperatively. Pain scores immediately following cryoneurolysis therapy were reduced in all patients reporting pain greater than 0 (1-10 pain scale) before their treatment. Increased active range of motion trends were noted with reports of decreased pain scores during postoperative physical therapy sessions.

CONCLUSIONS

This pilot project case series demonstrates potential benefits of using preoperative cryoneurolysis to provide postoperative pain control and aid with physical therapy recovery following TKA.

Ultrasound-Guided Percutaneous Cryoneurolysis for Post-Thoracotomy Pain Syndrome: A Case Report

Post-thoracotomy pain syndrome (PTPS) is a post-operative thoracotomy complication that is difficult to treat. We describe the first-time use of ultrasound-guided percutaneous cryoneurolysis of the intercostal nerves to successfully treat PTPS refractory to conventional medications and interventions. We report a case of a 40-year-old male with two years of severe PTPS sustained after undergoing a thoracotomy. Treatment with intercostal cryoneurolysis resulted in an immediate 75% improvement in pain for six weeks followed by sustained 50% pain relief for eight weeks. This highlights the potential of this intervention as a radiation-free, safe, and efficacious therapy for chronic PTPS.

Interventional Palliation of Painful Extraspinal Musculoskeletal Metastases

The musculoskeletal system is commonly involved by metastases, and skeletal-related events such as intractable pain due to direct osseous tumor involvement, pathologic fracture, and neurologic deficits as a result of nerve compression often adversely affect patient's quality of life. There have been substantial advances in percutaneous minimally invasive musculoskeletal oncologic interventions for the management of patients with musculoskeletal metastases including thermal ablations, cementation with or without osseous reinforcement via implants, osteosynthesis, neurolysis, and palliative injections which are progressively incorporated in clinical practice. These interventions are performed, in conjunction with or supplemented by adjuvant radiation therapy, systemic therapy, surgery, or analgesics, to achieve durable pain palliation, local tumor control, or cure. This article reviews minimally invasive percutaneous image-guided musculoskeletal oncologic interventions for the management of patients with extraspinal musculoskeletal metastases.

Intercostal Cryoneurolysis

Chest wall pain affects many patients following chest surgery, fractures, or malignancies, and can be very difficult to manage with normal pharmacologic agents. Intercostal ablation provides one alternative treatment modality for patients suffering from intercostal pain. Intercostal cryoneurolysis involves using extreme cold to cause Wallerian degeneration of the targeted intercostal nerve. This article reviews the patient selection, technique, and complications in the utilization of intercostal neurolysis in the treatment of intractable chest pain.

Celiac Plexus Cryoneurolysis

Intractable, chronic abdominal pain from upper abdominal malignant and benign diseases is a significant challenge for healthcare providers and burden on the healthcare system. While opioid analgesics are commonly used to provide pain relief, the adverse effects of chronic opioid use cannot be overlooked. Celiac plexus neurolysis via chemical or thermal means represents an alternative minimally invasive approach to provide palliative pain relief and increase patients' quality of life. Through the use of computed tomography guidance, celiac plexus neurolysis can be performed by accurately targeting the celiac plexus, while minimizing risks to adjacent structures. Historically, celiac plexus neurolysis was performed via instillation of ethanol or phenol; however, within the past decade cryoablation has gained increasing use with potentially fewer side effects.

Update on Image-Guided Thermal Lung Ablation: Society Guidelines, Therapeutic Alternatives, and Postablation Imaging Findings

Percutaneous image-guided thermal ablation (IGTA) has been endorsed by multiple societies as a safe and effective lung-preserving treatment for primary lung cancer and metastases involving the lung and chest wall. This article reviews the role of IGTA in the care continuum of patients with thoracic neoplasms and discusses strategies to identify the optimal local therapy considering patient and tumor characteristics. The advantages and disadvantages of percutaneous thermal ablation compared to surgical resection and stereotactic body radiotherapy are summarized. Principles of radiofrequency ablation, microwave ablation, and cryoablation, as well as the emerging use of transbronchial thermal ablation, are described. Specific considerations are presented regarding the role of thermal ablation for early-stage non-small cell lung cancer (NSCLC), multifocal primary NSCLC, pulmonary metastases, salvage of recurrent NSCLC after surgery or radiation, and pain palliation for tumors involving the chest wall. Recent changes to professional society guidelines regarding the role of thermal ablation in the lung, including for treatment of oligometastatic disease, are highlighted. Finally, recommendations are provided for imaging follow-up after thermal ablation of lung tumors, accompanied by examples of expected postoperative findings and patterns of disease recurrence.

Bone Metastases: State of the Art in Minimally Invasive Interventional Oncology

Bone is the third most common site involved by cancer metastases, and skeleton-related events such as intractable pain due to direct osseous tumor involvement, pathologic fracture, and neurologic deficits as a consequence of nerve or spinal cord compression often affect patients' functional independence and quality of life unfavorably. The annual medical-economic burden related to bone metastases is a substantial component of the total direct medical cost estimated by the National Institutes of Health. There have been substantial recent advances in percutaneous image-guided minimally invasive musculoskeletal oncologic interventions for the management of patients with osseous metastatic disease. These advances include thermal ablation, cementation with or without osseous reinforcement with implants, osteosynthesis, thermal and chemical neurolyses, and palliative injections, which are progressively incorporated into the management paradigm for such patients. These interventions are performed in conjunction with or are supplemented by adjuvant radiation therapy, systemic therapy, surgery, or analgesic agents to achieve durable pain palliation, local tumor control, or cure, and they provide a robust armamentarium for interventional radiologists to achieve safe and effective treatment in a multidisciplinary setting. In addition, these procedures are shifting the patient management paradigm in modern-era practice. The authors detail the state of the art in minimally invasive percutaneous image-guided musculoskeletal oncologic interventions and the role of radiologists in managing patients with skeletal metastases. ^©RSNA, 2021.

Feasibility and efficacy of cryoneurolysis analgesia in robotic-assisted thoracoscopic surgery (CARTS): a pilot study

Opioid therapy has been the mainstay therapy of post-operative pain management in thoracic surgery patients. With the high incidence of chronic pain in thoracic surgery patients and adverse effects of opioids, we examined the safety and efficacy of cryoneurolysis as an adjunct for narcotic-free pain management in robotic-assisted thoracoscopic lobectomies. Ten consecutive patients undergoing robotic-assisted (DaVinci) pulmonary resection and cryoneurolysis were compared to ten patients managed without intraoperative cryoneurolysis. All patients received multimodal pain regimen including paravertebral blocks as per our institutional enhanced recovery pathway. Patients with chronic pain and chronic opioid use were excluded. We compared inpatient and outpatient opioid consumption measured in morphine equivalents (mme), incidence of opioid-free outpatient recovery, and adverse events. The two groups did not differ significantly in terms of baseline demographics. Both inpatient (88.13 vs 26.92 mme) and outpatient (118.5 vs 34.5 mme) use of narcotics were significantly lower in the cryoneurolysis group (p < 0.05) with seven of ten patients receiving cryoneurolysis able to recover without the use of opioids in the outpatient setting, compared to two in the control group. One patient reported post-operative neuralgia in each cryoneurolysis and control group. There were no readmissions in either group and mean length of stay was identical at 1.7 days in control group and 1.1 days in experimental group (p = 0.33). The use of intraoperative intercostal cryoneurolysis may safely reduce the utilization of outpatient opioids in patients undergoing robotic-assisted thoracoscopic surgery. A randomized controlled trial is warranted to validate these findings in a larger cohort of patients.

Cryoanalgesia of the anterior femoral cutaneous nerve (AFCN) for the treatment of neuropathy-mediated anterior thigh pain: anatomy and technical description

OBJECTIVE

To describe and illustrate the magnetic resonance imaging (MRI) anatomy of the anterior femoral cutaneous nerve (AFCN) and a new technique for cryoanalgesia of the AFCN for long-term analgesic treatment of recalcitrant AFCN-mediated neuropathic pain.

MATERIALS AND METHODS

Using a procedural high-resolution MRI technique, we describe the MRI anatomy of the AFCN. Three patients (mean age, 48 years; range, 41-67 years) with selective nerve block-verified recalcitrant AFCN-mediated anterior thigh pain were enrolled to undergo cryoanalgesia of the AFCN. Procedures were performed under MRI guidance using clinical wide-bore MR imaging systems and commercially available cryoablation system with MR-conditional probes. Outcome variables included technical success, clinical effectiveness including symptom relief measured on an 11-point visual analog scale, frequency of complications, and procedure time.

RESULTS

Procedural MRI allowed to successfully demonstrate the course of the AFCN, accurate cryoprobe placement, and monitoring of the ice ball, which resulted in technically successful iceball growth around the AFCN in all cases. All procedures were clinically effective, with median pain intensity decreasing from 8 (7-9) before the procedure to 1 (0-2) after the procedure. The cryoanalgesia effect persisted during a 12-month follow-up period in all three patients. No major complications occurred. The average total procedure time was 98 min (range, 85-125 min).

CONCLUSION

We describe the MRI anatomy of the AFCN and a new technique for cryoanalgesia of the AFCN using MRI guidance, which permits identification of the AFCN, selective targeting, and iceball monitoring to achieve long-term AFCN-mediated neuropathic pain relief.

Percutaneous cryoneurolysis for acute pain management: current status and future prospects

Introduction: Conventional nerve blocks utilize local anesthetic drugs to provide pain relief for hours or days following surgery or trauma. However, postoperative and trauma pain can last weeks or months. Ultrasound-guided percutaneous cryoneurolysis is an anesthetic modality that offers substantially longer pain relief compared to local anesthetic-based nerve blocks.Areas covered: In this review, we discuss the history, mechanism of action, and use of ultrasound-guided percutaneous cryoneurolysis by anesthesiologists in the setting of acute pain management.Expert opinion: Ultrasound-guided percutaneous cryoneurolysis offers the potential to provide weeks or months of pain relief following surgery or trauma. Compared to continuous local anesthetic-based peripheral nerve blocks, currently the gold standard for providing long duration postoperative analgesia, cryoneurolysis has benefits that include: 1) longer duration measured in weeks or months rather than days; 2) no external reservoir of local anesthetic to be carried by the patient; 3) no risk of infection; and 4) no risk of catheter dislodgement. However, cryoneurolysis can induce a prolonged motor block in addition to the sensory block, decreasing the appropriate indications to those in which potential sensory and motor deficits are acceptable. Additionally, cryoneurolysis of multiple nerves can have a substantial time requirement relative to conventional nerve blocks.

A Technical Report on the Performance of Percutaneous Cryoneurolysis of Splanchnic Nerves for the Treatment of Refractory Abdominal Pain in Patients with Pancreatic Cancer: Initial Experience

PURPOSE

To report our preliminary results upon feasibility, efficacy and safety of percutaneous splanchnic nerves cryoneurolysis for the treatment of abdominal pain refractory to conservative medication in patients with pancreatic cancer MATERIALS METHODS: Institutional database research (retrospective review of prospectively collected data from April 2019 till August 2020) identified 5 patients with pancreatic cancer and pain refractory to conservative medication who underwent percutaneous cryoneurolysis of splanchnic nerves. In all patients, percutaneous cryoneurolysis was performed with posterolateral paravertebral approach using a 17 Gauge cryoprobe under computed tomography guidance and local anesthesia. Self-reported pain scores were assessed before and at the last follow-up using a pain inventory with visual analog scale (VAS) units.

RESULTS

Mean patient age was 63.81 years (male-female: 3-2). Mean pain score prior to cryoanalgesia of splanchnic nerves was 9.4 VAS units. This score was reduced to a mean value of 2.6, 2.6 and 3 VAS units at 1, 3 and 6 months of follow-up, respectively. All patients reported significantly reduced analgesic usage. No complication was reported according to the CIRSE classification system. The mean procedure time was 44.4 min (range 39-50 min), including local anesthesia, cryoprobe(s) placement, ablation and post-procedural CT evaluation.

CONCLUSION

Percutaneous cryoanalgesia of the splanchnic nerves is a minimally invasive, safe and effective procedure for pancreatic cancer pain relief. A larger, randomized trial is justified to substantiate these findings.

Ultrasound-guided microwave ablation in the treatment of inguinal neuralgia

Chronic groin pain can be due to a variety of causes and is the most common complication of inguinal hernia repair surgery. The etiology of pain after inguinal hernia repair surgery is often multifactorial though injury to or scarring around the nerves in the operative region, namely the ilioinguinal nerve, genital branch of the genitofemoral nerve, and the iliohypogastric nerve, is thought to be a key factor in causing chronic post-operative hernia pain or inguinal neuralgia. Inguinal neuralgia is difficult to treat and requires a multidisciplinary approach. Radiologists play a key role in the management of these patients by providing accurate image-guided injections to alleviate patient symptoms and identify the pain generator. Recently, ultrasound-guided microwave ablation has emerged as a safe technique, capable of providing durable pain relief in the majority of patients with this difficult to treat condition. The objectives of this paper are to review the complex nerve anatomy of the groin, discuss diagnostic ultrasound-guided nerve injection and patient selection for nerve ablation, and illustrate the microwave ablation technique used at our institution.

Percutaneous cryoanalgesia for pain palliation: Current status and future trends

Cryoanalgesia, otherwise termed cryoneurolysis, refers to application of extreme cold upon peripheral nerves for palliation of pain associated to nerve lesions or biomechanical syndromes of neoplastic and non-neoplastic substrate. Application of cryoanalgesia initiates a cascade of pathophysiologic events interrupting nerve conduction of painful stimuli without irreversible nerve damage. Cryoanalgesia is considered a safe procedure with minimal risk of complications when performed with percutaneous approaches under imaging guidance. In the era of an opioid overdose crisis, cryoanalgesia can be proposed as an alternative aiming at controlling pain and improving life quality. Imaging guidance has substituted open surgical and nerve stimulation approaches in nerve identification, significantly contributing to the minimally invasive character of percutaneous approaches. Ultrasound or computed tomography can serve as low cost, ideal guiding techniques due to their abilities for precise anatomic delineation, high spatial resolution and good tissue contrast. The purpose of this review is to become familiar with the most common imaging guided percutaneous cryoanalgesia indications, to learn about different technical considerations during performance providing the current evidence. Controversies concerning products will be addressed.

Cryoneurolysis and Percutaneous Peripheral Nerve Stimulation to Treat Acute Pain

Two regional analgesic modalities currently cleared by the U.S. Food and Drug Administration hold promise to provide postoperative analgesia free of many of the limitations of both opioids and local anesthetic-based techniques. Cryoneurolysis uses exceptionally low temperature to reversibly ablate a peripheral nerve, resulting in temporary analgesia. Where applicable, it offers a unique option given its extended duration of action measured in weeks to months after a single application. Percutaneous peripheral nerve stimulation involves inserting an insulated lead through a needle to lie adjacent to a peripheral nerve. Analgesia is produced by introducing electrical current with an external pulse generator. It is a unique regional analgesic in that it does not induce sensory, motor, or proprioception deficits and is cleared for up to 60 days of use. However, both modalities have limited validation when applied to acute pain, and randomized, controlled trials are required to define both benefits and risks.

Interventional Cryoneurolysis: An Illustrative Approach

The application of advanced imaging guidance and the interventional radiology skill set has expanded the breadth of nerve and nerve plexus targets in the body for potential cryoneurolysis. Advancement of the basic science supporting cryoneurolysis has further solidified proceduralists' confidence and ability to select and manage patients clinically. As these procedures continue to evolve, a structured approach to the wide variety of indications is necessary.

Image-guided Sports Medicine and Musculoskeletal Tumor Interventions: A Patient-Centered Model

The spectrum of effective musculoskeletal (MSK) interventions is broadening and rapidly evolving. Increasing demands incite a perpetual need to optimize services and interventions by maximizing the diagnostic and therapeutic yield, reducing exposure to ionizing radiation, increasing cost efficiency, as well as identifying and promoting effective procedures to excel in patient satisfaction ratings and outcomes. MSK interventions for the treatment of oncological conditions, and conditions related to sports injury can be performed with different imaging modalities; however, there is usually one optimal image guidance modality for each procedure and individual patient. We describe our patient-centered workflow as a model of care that incorporates state-of-the-art imaging techniques, up-to-date evidence, and value-based practices with the intent of optimizing procedural success and outcomes at a patient-specific level. This model contrasts interventionalist- and imaging modality-centered practices, where procedures are performed based on local preference and selective availability of imaging modality or interventionalists. We discuss rationales, benefits, and limitations of fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging procedure guidance for a broad range of image-guided MSK interventions to diagnose and treat sports and tumor-related conditions.

Percutaneous CT-Guided Cryoablation of the Bilateral Pudendal Nerves for Palliation of Intractable Pain Related to Pelvic Neoplasms

Objectives:

The purpose of this report is to describe the effect of computed tomography–guided bilateral pudendal nerve cryoablations on pain and time to discharge in the setting of acute hospitalizations secondary to refractory pelvic pain from cancer.

Methods:

Investigators queried the medical record for patients who underwent pudendal nerve cryoablation using the Category III Current Procedural Technology code assignment 0442T or Category I code 64640 for cases prior to 2015. The resulting list was reviewed, and procedures performed on inpatients for intractable pelvic pain related to neoplasm were selected. The final cohort was then analyzed with regard to patient demographics, procedure details, technical success, safety, pain scores, and time to discharge.

Results:

Ten patients underwent cryoablation by 3 operators for palliation of painful pelvic neoplasms between June 2014 and January 2019. All probes were satisfactorily positioned and freeze cycles undertaken without difficulty. There were no procedure-related complications or adverse events. The mean difference in pre- and posttreatment worst pain scores was significant (n = 5.20, P = .003). The mean time to discharge following the procedure was 2.3 days.

Conclusion:

Computed tomography–guided percutaneous cryoablation of the bilateral pudendal nerves may represent a viable option in the setting of acute hospitalization secondary to intractable pain in patients with pelvic neoplasms.

Diagnostic and interventional magnetic resonance neurography diagnosis of brachytherapy seed-mediated pudendal nerve injury: a case report

Injury to the pudendal nerve in men presents with pain, paresthesia, or numbness of the perineum, and/or scrotum, and/or penis. There is evidence implicating the brachytherapy seeds used to treat prostate cancer as source of pudendal nerve injury. Compared to surgical prostatectomy, brachytherapy has the advantage of being less invasive, but seeds may not only lead to well-established complications such as urinary, bowel, and erectile dysfunction, but also injury to the sensory branches of the pudendal nerve. We report and document a case of pudendal nerve injury secondary to brachytherapy seeds diagnosed with magnetic resonance (MR) neurography, nerve blocks, and histopathological examination; and successful treatment via sensory branch neurectomy.

Percutaneous imaging-guided techniques for the treatment of benign neuropathic pain

To date, conservative management including physical and/or systemic pharmacologic therapy is considered as the first line approach for the management of neuropathic pain syndromes. In the era of an opioid overdose crisis with an increased concern upon the risks and harms arising from the misuse of medicines for pain management, percutaneous minimally invasive techniques such as nerve infiltrations as well as neurolysis or neuromodulation techniques can be proposed to control pain and improve life quality. Computed tomography can serve as an ideal guiding technique due to its specific characteristics including precise anatomic delineation, high spatial resolution and good tissue contrast. The purpose of this review is to make the reader familiar with the most common indications for minimally invasive imaging-guided techniques in patients with neuralgia and provide current evidence regarding technical considerations.

Ultrasound-guided Therapeutic Injection and Cryoablation of the Medial Plantar Proper Digital Nerve (Joplin's Nerve): Sonographic Findings, Technique, and Clinical Outcomes

RATIONALE AND OBJECTIVES

The medial plantar proper digital nerve, also called Joplin's nerve, arises from the medial plantar nerve, courses along the medial hallux metatarsophalangeal joint, and can be a source of neuropathic pain due to various etiologies, following acute injury including bunion surgery and repetitive microtrauma. We describe our clinical experience with diagnostic ultrasound assessment of Joplin's neuropathy and technique for ultrasound-guided therapeutic intervention including both injection and cryoablation over a 6-year period.

MATERIALS AND METHODS

Retrospective review of all diagnostic studies performed for Joplin's neuropathy and therapeutic Joplin's nerve ultrasound-guided injections and cryoablations between 2012 and 2018 was performed. Indications for therapeutic injection and cryoablation, were recorded. Studies were assessed for sonographic abnormalities related to the nerve and perineural soft tissues. Post-treatment outcomes including immediate pain scores, clinical follow-up, and periprocedural complications were documented.

RESULTS

Twenty-four ultrasound-guided procedures were performed, including 15 perineural injections and nine cryoablations. With respect to sonographic abnormalities, nerve thickening (33%) and perineural hypoechoic scar tissue (27%) were the most common findings. The mean pain severity score prior to the therapeutic injection was 6.4/10 (range 4-10) and 0.25/10 (range 0-2) following the procedure; mean follow-up was 26.2 months (range 3-63 months). All of the cryoablation patients experienced sustained pain relief with a mean length follow-up of 3.75 months (range 0.2-10 months).

CONCLUSION

Therapeutic injection of Joplin's nerve is a safe and easily performed procedure under ultrasound guidance, with high rates of immediate symptom improvement. For those experiencing a relapse or recurrent symptoms, cryoablation offers an effective secondary potential treatment option.

Case Report Of Cryoneurolysis For The Treatment Of Refractory Intercostobrachial Neuralgia With Postherpetic Neuralgia

Postherpetic neuralgia is a common and potentially debilitating neuropathic pain condition. Current pharmacologic therapy can be inadequate and intolerable for patients. We present a case of a gentleman with refractory postherpetic neuralgia in the intercostobrachial nerve distribution that was successfully treated with cryoneurolysis/cryoanalgesia therapy.

Cryoneurotomy as a Percutaneous Mini-invasive Therapy for the Treatment of the Spastic Limb: Case Presentation, Review of the Literature, and Proposed Approach for Use

Objective

To provide a proof-of-concept study demonstrating that the decades old procedure of cryoneurotomy, used traditionally for analgesia, is a safe adjunctive and effective treatment for limb spasticity.

Design

Case series.

Setting

Publicly funded outpatient hospital spasticity clinic and community interventional anesthesia clinic.

Participants

Patients (N=3) who had plateaued with standard of care spasticity treatments including botulinum toxin. Two hemiplegic stroke patients with elbow spasticity and 1 pregnant patient with multiple sclerosis and a spastic equinovarus foot for whom botulinum toxin was now contraindicated.

Interventions

Selective anesthetic diagnostic motor nerve blocks with ultrasound and e-stimulation with 1cc of 1% lidocaine to the motor nerve to the targeted spastic muscle were performed to either the musculocutaneous nerve to brachialis, radial nerve to the brachioradialis or the tibial nerve. If the benefits included improved active and passive range motion and or decreased clonus, a percutaneous cryoneurotomy was performed.

Main Outcome Measures

Active and passive range of motion were measured using the Modified Tardieu Scale. The change in resistance to passive stretch was measured using the Modified Ashworth Scale (MAS). Videos of the before and after treatment were collected.

Results

Both elbows’ treatments resulted in MAS improving from a 3 to a 1+. Greatly improved active range of motion was noted at 94 and 64 degrees, respectively, as well as improvements in passive range on the Modified Tardieu Scale. The tibial nerve cryoneurotomy resulted in improvements in all parameters with a much improved gait. Results were maintained up to 17 months of follow-up.

Conclusion

Cryoneurotomy as a treatment for spasticity is a novel safe adjuvant treatment. Our initial results suggest patients can achieve significantly increased active and passive range of motion in the upper extremity and decreased clonus, and improved gait after tibial nerve cryoneurotomy.

Adjuvant MRI-guided percutaneous cryoablation treatment for aneurysmal bone cyst

Aneurysmal bone cysts are benign, expansile, lytic bone lesions that behave in a locally aggressive manner. Although radiography and computed tomography (CT) can detect the lesion, magnetic resonance imaging (MRI) is ideal for the demonstration of characteristic fluid-fluid levels, extent, and margins. Treatment typically consists of open surgical curettage with the addition of local adjuvants and bone grafting. Residual or recurring lesions may be treated using percutaneous cryoablation. Although CT guidance is often employed for image guidance, visualization and targeting of smaller clusters can be challenging in young children, secondary to the partially mineralized bone matrix in the immature skeleton. In such cases, the higher contrast resolution of interventional MRI affords direct visualization and targeting of small aneurysmal bone cysts, accurate monitoring of the extent of the growing ice ball beyond the lesion's margin, and avoidance of exposure to ionizing radiation. We report a case of a 5-year-old boy with recurrent or remaining aneurysmal bone cysts of the scapula after surgical excision and embolization, which were successfully treated using MRI-guided cryoablation.

Interventional radiology techniques for pain reduction and mobility improvement in patients with knee osteoarthritis

Osteoarthritis of the knee is the most common cause of chronic knee pain being more prevalent in middle-aged and elderly patients. Symptomatic patients complain of pain and mobility impairment. Therapeutic armamentarium includes physical therapy, oral pharmacologic therapy, intra-articular injections, nerve ablation or modulation, trans-catheter arterial embolization, minimally invasive arthroscopic treatment and partial or total knee arthroplasty. Interventional radiology therapies for knee osteoarthritis include intra-articular injections, neurotomy and neuromodulation techniques as well as transcatheter intra-arterial therapies. These therapies aim to control pain and inflammation, improve mobility and function whilst the novel cell-based therapies have the potential for bone and cartilage regenerative repair facilitating the delay to surgery. The purpose of this review is to illustrate the technical aspects, the indications and the methodology of local therapies for knee osteoarthritis performed by interventional radiologists and provide current evidence.

Current Concepts and Future Directions of Minimally Invasive Treatment for Knee Pain

PURPOSE OF REVIEW

The purpose of this paper is to review the percutaneous interventions available for the treatment of osteoarthrosis of the knee that address pain and prolong the time to arthroplasty.

RECENT FINDINGS

Corticosteroid injection and viscosupplementation have been the most studied, but there is still no consensus about their value. Thermal nerve ablation, including both radiofrequency ablation and cryoneurolysis, is a promising new modality of therapy that may increase in clinical use given current data showing favorable outcomes. Of the future therapies that are currently under investigation, synovial embolization via the geniculate arteries represents an exciting new approach that may soon be available clinically. There are various percutaneous interventions available for the treatment of osteoarthrosis of the knee that address pain and prolong the time to arthroplasty.