Safety and Effectiveness of Stellate Ganglion Cryoablation in Complex Regional Pain Syndrome.

This was a retrospective, observational, descriptive study to evaluate the safety and 6-month effectiveness of percutaneous cryoablation of the stellate ganglion for the treatment of complex regional pain syndrome (CRPS). Eight patients with CRPS diagnosed by Budapest criteria were treated with this procedure. CRPS symptom severity was assessed prior to the procedure and at 3-month intervals after the procedure using a novel CRPS scoring system-the Budapest score-created by the authors. The mean Budapest score prior to and 6 months (187 days, SD ± 43) after stellate ganglion cryoablation was 7.0 (SD ± 2.0) (n = 6) and 3.8 (SD ± 2.3) (n = 6), respectively, showing a decrease of 3.2 (SD ± 1.7) (n = 6; P = .006). There were no major adverse events due to the procedure, and there was only 1 minor adverse event. Stellate ganglion cryoablation is a feasible, safe, and minimally invasive procedure that may represent an efficacious adjunct treatment option for select patients with CRPS.

Percutaneous CT-Guided Cryoneurolysis of the Intercostobrachial Nerve for Management of Postmastectomy Pain Syndrome.

PURPOSE: To evaluate the feasibility, safety, and efficacy of intercostobrachial nerve (ICBN) cryoneurolysis for pain control in patients with postmastectomy pain syndrome (PMPS). MATERIALS AND METHODS: Fourteen patients with PMPS were prospectively enrolled into this clinical trial after a positive response to a diagnostic computed tomography (CT)-guided percutaneous block of the ICBN. Participants subsequently underwent CT-guided percutaneous cryoneurolysis of the same nerve and were observed on postprocedural Days 10, 90, and 180. Pain scores, quality-of-life measurements, and global impression of change values were recorded before the procedure and at each follow-up point using established validated outcome instruments. RESULTS: Cryoneurolysis of the ICBN was technically successful in all 14 patients. The mean pain decreased significantly by 2.1 points at 10 days (P = .0451), by 2.4 points at 90 days (P = .0084), and by 2.9 points at 180 days (P = .0028) after cryoneurolysis. Pain interference with daily activities decreased significantly by 14.4 points after 10 days (P = .0161), by 16.2 points after 90 days (P = .0071), and by 20.7 points after 180 days (P = .0007). There were no procedure-related adverse events. CONCLUSIONS: Cryoneurolysis of the ICBN in patients with PMPS was technically feasible and safe and resulted in a significant decrease in postmastectomy pain for up to 6 months in this small cohort.

Agents Used for Nerve Blocks and Neurolysis.

The recognition of pain and the treatments used for it are vital for all practitioners. Many types of pain can be treated in a locoregional fashion, which has significant implications not just for any individual patient but for society as a whole. These treatments are most effective when performed in a minimally invasive, image-guided fashion. Interventional radiologists should play a central role in providing these lifestyle-limiting treatments. This article describes the medications most typically used for spinal and extra-axial treatments in the management of patients in pain.

Percutaneous Image-guided Cryoneurolysis: Applications and Techniques.

The expansion and dissemination of interventional cryoneurolysis in recent years has been fueled by the integration of advanced imaging guidance, the evolution of our understanding of neuropathologic processes after exposure of nerves to cold, and opportunities for its use beyond pain management. The clinical translation of cryoneurolysis through interventional radiology requires consideration of many factors, including (a) the supply and composition of target nerves, (b) the value of diagnostic injection with imaging guidance for confirmation, (c) the integration of advanced imaging guidance that allows safe ablation, (d) the difference between neoplastic and nonneoplastic causes of pain, (e) the phenomenon of percutaneously induced neuroregeneration, (f) the potential to manage conditions other than pain, (g) the consideration of protocols, (h) the limitations of current technology, and (i) the potential complications and adverse effects. Cryoneurolysis has societal and legislative endorsement as an effective nonopioid option for pain palliation. The Centers for Medicare and Medicaid Services (CMS) approved three new category III Current Procedural Terminology (CPT) codes specifically for the cryoablation of nerves with advanced imaging guidance. Interventional radiologists who are aware of nerve-directed strategies see eligible patients in their daily practice and have opportunities to bundle procedures (eg, celiac plexus block at the time of a biliary drain for pancreatic cancer with low bile duct obstruction), offering an avenue to serve the patient, reduce opioid dependence, allow faster discharge, and establish name recognition of interventional radiologists. Also, the ability to use CT to target deep structures accurately and swiftly, often with only local anesthesia, compared with the usual monitored anesthesia care in a surgical setting, may provide another avenue to build a cryoneurolysis practice. ©RSNA, 2022.

Review of Extraosseous Applications of Thermal Ablation in the Treatment of Moderate to Severe Large Joint Osteoarthritis.

Osteoarthritis (OA) is the most common joint disease worldwide, leading to significant pain, restricted range of motion, and disability. A gap exists between short- and long-term symptom-relieving therapies. Although arthroplasty is an effective treatment for symptomatic end-stage disease, most patients ultimately do not receive a joint replacement due to suboptimal surgical qualifications, comorbidities, or an aversion to surgery. The lack of additional treatment options in this setting makes opioid agonists a commonly used pharmacologic agent, contributing to the addiction epidemic that greatly afflicts our communities. Cooled radiofrequency ablation (CRFA) has arisen as a treatment modality in the setting of moderate to severe OA among patients refractory to conservative management, generally showing greater efficacy compared with other existing strategies. This review focuses on the benefits of CRFA and its technical feasibility as a management option among patients experiencing debilitating large joint OA with limited clinical options.

Cryoablation for Palliation of Painful Bone Metastases: The MOTION Multicenter Study.

Purpose: To assess the clinical effectiveness of cryoablation for palliation of painful bone metastases. Materials and Methods: MOTION (Multicenter Study of Cryoablation for Palliation of Painful Bone Metastases) (ClinicalTrials.gov NCT02511678) was a multicenter, prospective, single-arm study of adults with metastatic bone disease who were not candidates for or had not benefited from standard therapy, that took place from February 2016 to March 2018. At baseline, participants rated their pain using the Brief Pain Inventory-Short Form (reference range from 0 to 10 points); those with moderate to severe pain, who had at least one metastatic candidate tumor for ablation, were included. The primary effectiveness endpoint was change in pain score from baseline to week 8. Participants were followed for 24 weeks after treatment. Statistical analyses included descriptive statistics and logistic regression to evaluate changes in pain score over the postprocedure follow-up period. Results: A total of 66 participants (mean age, 60.8 years ± 14.3 [standard deviation]; 35 [53.0%] men) were enrolled and received cryoablation; 65 completed follow-up. Mean change in pain score from baseline to week 8 was -2.61 points (95% CI: -3.45, -1.78). Mean pain scores improved by 2 points at week 1 and reached clinically meaningful levels (more than a 2-point decrease) after week 8; scores continued to improve throughout follow-up. Quality of life improved, opioid doses were stabilized, and functional status was maintained over 6 months. Serious adverse events occurred in three participants. Conclusion: Cryoablation of metastatic bone tumors provided rapid and durable pain palliation, improved quality of life, and offered an alternative to opioids for pain control.Keywords: Ablation Techniques, Metastases, Pain Management, Radiation Therapy/OncologySupplemental material is available for this article.© RSNA, 2021.

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.

Percutaneous CT-Guided Cryoablation of the Celiac Plexus: A Retrospective Cohort Comparison with Ethanol.

PURPOSE: To retrospectively analyze and compare the incidence of diarrhea in patients who underwent cryoablation of the celiac plexus for intractable abdominal pain versus ethanol therapy over a 5-year period. MATERIALS AND METHODS: From June 2014 to August 2019, 83 patients were identified who underwent neurolysis of the celiac plexus for management of intractable abdominal pain by using either cryoablation (n = 39 [59% female; age range, 36-79 years old [average, 60 ± 11 years old]) or alcohol (n = 44 [48% female; age range, 29-76 years old [average, 60 ± 12 years old]). Pain scores and reports of procedure-related complications or side effects, with special attention to diarrhea and/or other gastrointestinal symptoms, were collected from follow-up visits at 1 week, 1 month, and 3 months post-intervention and were compared between groups. RESULTS: The mean time of follow-up was 17.7 days. Four patients who underwent cryoablation developed gastrointestinal symptoms consisting of 2 cases of nausea and vomiting and 2 cases of diarrhea (5.1%). Twelve patients who underwent ethanol ablation developed gastrointestinal symptoms, including 1 case of nausea, 3 cases of vomiting, and 9 cases of diarrhea (20.5%). There was a significantly higher incidence of both diarrhea (chi-squared likelihood ratio, P = .03) and overall gastrointestinal symptoms (chi-squared likelihood ratio, P = .04) in the ethanol group than in the cryoablation group. CONCLUSIONS: Cryoablation of the celiac plexus may provide a new treatment option for intractable abdominal pain, and it appears to have a lower incidence of diarrhea and fewer gastrointestinal side effects than ablation using ethanol.

Natural History of Mixed and Motor Nerve Cryoablation in Humans-A Cohort Analysis.

Eight patients who underwent percutaneous cryoablation of mixed and/or motor nerves over a period of 5 years were identified. Distances from the ablation sites to origins of distal musculature were measured, and times to initial clinical recovery were collected. Strength progression over time following muscle activation was also collected and analyzed. All patients demonstrated activation of all muscles distal to the ablation, and the calculated mean rate of nerve regeneration based on distance to the origin of the assessed musculature and time to muscle activation for the group was 1.5 mm/day ± 1.1.

Percutaneous CT-Guided Cryovagotomy in Patients with Class I or Class II Obesity: A Pilot Trial.

OBJECTIVE: This study evaluated the safety of percutaneous CT-guided cryoablation of the vagus nerve (percutaneous cryovagotomy) in participants with class I or class II obesity. METHODS: The study was an open-label, single-group, prospective pilot investigation designed around safety-related stopping criteria. Twenty participants with 30 > BMI > 37 underwent percutaneous cryovagotomy with follow-up visits at day 7, 45, 90, and 180. Data related to adverse events, technical success, weight loss, quality of life, dietary intake, global impressions of hunger change, activity, and body composition were analyzed. RESULTS: The procedural technical success rate was 100%. There were no adverse events in 19 participants who completed the trial. Ninety-five percent of patients reported decreased appetite following the procedure, and reductions in mean absolute weight and BMI were observed at all time points. The mean quality of life and activity scores improved from baseline to 6 months post procedure, and mean caloric intake and overall body fat decreased over the same period. CONCLUSIONS: Percutaneous CT-guided cryovagotomy is feasible and was tolerated without complications or adverse events in this cohort. Quantitative preliminary data from this pilot investigation inform the design of a larger prospective randomized clinical trial.

Image-Guided Transarterial Directed Delivery of Human Mesenchymal Stem Cells for Targeted Gastrointestinal Therapies in a Swine Model.

PURPOSE: To evaluate the feasibility of catheter-directed intra-arterial stem cell delivery of human mesenchymal stem cells (MSCs) to the small bowel in a porcine model. MATERIALS AND METHODS: The cranial mesenteric artery of 6 Yucatan minipigs was selectively catheterized under fluoroscopic guidance following cut-down and carotid artery access. A proximal jejunal branch artery was selectively catheterized for directed delivery of embolic microspheres (100-300 µm) or MSCs (0.1-10 million cells). The pigs were euthanized after 4 hours and specimens collected from the proximal duodenum and the targeted segment of the jejunum. The Chiu/Park system for scoring intestinal ischemia was used to compare hematoxylin and eosin-stained sections of jejunum and duodenum. RESULTS: Successful delivery of microspheres or MSCs in a proximal jejunal branch artery of the cranial mesenteric artery was achieved in all subjects. Radiopaque microspheres and post-delivery angiographic evidence of stasis in the targeted vessels were observed on fluoroscopy after delivery of embolics. Preserved blood flow was observed after MSC delivery in the targeted vessel. The Chiu/Park score for intestinal ischemia in the targeted proximal jejunal segments were similar for microspheres (4, 4; n = 2) and MSCs (4, 4, 4, 3; n = 4), indicating moderate ischemic effects that were greater than for control duodenal tissue (3, 1; 0, 0, 3, 3). CONCLUSIONS: Selective arteriographic deployment of MSCs in swine is feasible for study of directed intestinal stem cell delivery. In this study, directed therapy resulted in intestinal ischemia.

Percutaneous Image-Guided Cryoneurolysis.

OBJECTIVE: The aim of this article is to review the available evidence regarding image-guided percutaneous cryoneurolysis, with a focus on indications, technique, efficacy, and potential complications. CONCLUSION: Percutaneous image-guided cryoneurolysis is safe and effective for the management of several well-described syndromes involving neuropathic pain. Additional rigorous prospective study is warranted to further define the efficacy and specific role of these interventions.

Structured Protocol for Benign Biliary Anastomotic Strictures: Impact on Long-Term Clinical Effectiveness.

OBJECTIVE: The purpose of this study is to compare long-term clinical effectiveness before and after implementation of a structured protocol for percutaneous drainage of benign anastomotic biliary strictures. MATERIALS AND METHODS: Three hundred five adult patients undergoing percutaneous biliary drainage for biliary anastomotic strictures between 1994 and 2015 were identified using Current Procedural Terminology billing codes, with 234 undergoing intervention before implementation of a structured protocol and 71 undergoing intervention after implementation of the protocol. The frequency of surgical anastomotic revision was compared between patients treated before and after the implementation of the structured protocol. Patient characteristics and treatment variables were also analyzed with respect to the frequency of surgical revision. A Kaplan-Meier analysis was performed to determine the long-term probabilities of avoiding surgical revision and patency rates. RESULTS: Overall, 72.8% of patients avoided surgical revision, with 71.1% before and 81.7% after the protocol was implemented (p = 0.1052). A larger maximum drain size was significantly associated with a lower frequency of surgical revision (p = 0.0006). The rates of surgical avoidance 5 years after treatment before and after protocol implementation were 69.1% and 80.8%, respectively. Patency rates 5 years after treatment before and after protocol implementation were 73.8% and 76.8%, respectively. CONCLUSION: Percutaneous drainage and management of benign biliary anastomotic strictures is an effective treatment regardless of the presence of a structured protocol. Although there was no significant benefit in terms of avoidance of surgical revision, the time until surgical revision and patency rates were increased with the protocol. In addition, a larger maximum drain size was associated with a better outcome.

Obstruction of the Biliary and Urinary System.

Biliary and urinary obstructions can be managed endoscopically or cystoscopically, surgically or by percutansous intervention or drainage. If the obtructed system is infected, emergent decompression is needed. Early recognition and treatment is paramount in both conditions. Acute cholangitis can present many different ways, from mild symptoms to fulminant sepsis. It is usually a result of ascending bacterial colonization and biliary obstruction resulting in bacterial overgrowth. Therefore, those patients with recent biliary instrumentation or previous biliary modification are at higher risk. Charcot's triad of fever, right upper quadrant abdominal pain, and jaundice is only seen in 50%-70% of patients. Fever is seen in over 90% of cases, pain is seen in 70% of cases, and jaundice is seen in 60% of cases. Altered mental status and hypotension are associated with severe cases. All 5 symptoms of fever, right upper quadrant abdominal pain, jaundice, altered mental status, and hypotension are referred to as Reynold's Pentad. Acute pyonephrosis can also present many different ways, from minimal symptoms to fulminant sepsis. Fever, chills, and flank pain are the classic symptoms, although some patients may be relatively asymptomatic. Pyonephrosis may present with a classic triad of fever, flank pain, and hydronephrosis, or simply hydronephrosis and sepsis. Pyonephrosis usually occurs as a result of urinary obstruction with either an ascending infection of the urinary tract or hematogenous spread of a bacterial pathogen as the culprit. Up to 75% of cases are related to urinary stone disease. Patients are at increased risk for pyonephrosis when they haven anatomic urinary tract obstruction, certain chronic diseases (diabetes meliitus and AIDS), or are immunosuppressed due to immunodeficiency or medications, (chronic steroid therapy).

Percutaneous Image-Guided Cryoablation for the Treatment of Phantom Limb Pain in Amputees: A Pilot Study.

PURPOSE: To prospectively evaluate percutaneous image-guided nerve cryoablation for treatment of refractory phantom limb pain (PLP) in a pilot cohort for purposes of deriving parameters to design a larger, randomized, parallel-armed, controlled trial. MATERIALS AND METHODS: From January 2015 to January 2016, 21 patients with refractory PLP underwent image-guided percutaneous cryoneurolysis procedures. Visual analog scale scores were documented at baseline and 7, 45, and 180 days after the procedure. Responses to a modified Roland Morris Disability Questionnaire were documented at baseline and 7 and 45 days after the procedure. RESULTS: Technical success rate of the procedures was 100%. There were 6 (29%) minor procedure-related complications. Disability scores decreased from a baseline mean of 11.3 to 3.3 at 45-day follow-up (95% confidence interval 5.8, 10.3; P < .0001). Pain intensity scores decreased from a baseline mean of 6.2 to 2.0 at long-term follow-up (95% confidence interval 2.8, 5.6; P < .0001). CONCLUSIONS: Image-guided percutaneous nerve cryoablation is feasible and safe and may represent a new efficacious therapeutic option for patients with phantom pains related to limb loss.

Cryoablation of Osteoid Osteoma in the Pediatric and Adolescent Population.

PURPOSE: To evaluate the technical feasibility and clinical efficacy of osteoid osteoma (OO) cryoablation in a large, pediatric/adolescent cohort. MATERIALS AND METHODS: An electronic medical record and imaging archive review was performed to identify all cryoablations performed for OOs between 2011 and 2015 at a single tertiary care pediatric hospital. The subsequent analysis included 29 patients with suspected OOs treated by cryoablation (age range, 3-18 y; mean age, 11.3 y; 17 boys; 12 girls). Conventional CT guidance was used in 22 procedures; cone-beam CT guidance was used in 7 procedures. Follow-up data were obtained via a standardized telephone questionnaire (23/29 patients; 79.3%) and clinical notes (5/29 patients; 17.2%). One patient was lost to follow-up. RESULTS: Technical success was achieved in 100% of patients (29/29). Immediate clinical success (cessation of pain and nonsteroidal antiinflammatory drug [NSAID] use within 1 mo after the procedure) was achieved in 27/28 patients (96.4%). Short-term clinical success (cessation of pain and NSAID use for > 3 mo after the procedure) was achieved in 24/25 patients (96%). Long-term clinical success (cessation of pain and NSAID use for > 12 mo after the procedure) was achieved in 19/21 patients (90.5%). Median pain scale score before the procedure was 10 (range, 5-10); median pain scale score after the procedure was 0 (range, 0-8; P < .0001). There were 6 minor complications (21%) and no major complications. CONCLUSION: Image-guided cryoablation is a technically feasible, clinically efficacious therapeutic option for children and adolescents with symptomatic OO.

Inactivation of Bacteria on Explanted Dialysis Catheter Lumens with Fiber Optically Delivered Ultraviolet Light.

PURPOSE: To evaluate the germicidal effect of fiber optically delivered ultraviolet (UV) light on colonized explanted dialysis catheters. MATERIALS AND METHODS: Explanted dialysis catheters were screened for intraluminal colonization by culturing 1 mL of a saline flush. Catheters growing >10 colony-forming units were treated with doses of fiber optically delivered UV light (range, 40-1,300 mJ/cm2). For each UV-treated catheter, an unexposed segment was first cut and set aside as a control sample. A sterile optical fiber was inserted into the catheter hub and advanced to the catheter tip. The fiber was slowly withdrawn at a constant rate while exposing the inner lumen to UV light. A second UV-exposed segment was then removed. The UV-exposed and control segments were split and sonicated to remove the adherent bacteria. The bacteria were counted and identified. RESULTS: There were 14 colonized catheters treated with UV light. The catheters were primarily colonized with coagulase-negative staphylococci (60%) and Staphylococcus aureus (33%). There was a significant reduction in viable bacteria between the UV-treated versus untreated segments of each infected catheter (P = .04). In the seven treated catheters with >100,000 colony-forming units per cm2 of luminal surface area, there was a >99.5% reduction of viable bacteria in all UV-exposed samples, with no residual viable bacteria in four of seven (57%) of the samples. CONCLUSIONS: This study demonstrates the technical feasibility and benchtop efficacy of using fiber optics to deliver UV light into the lumen of a colonized dialysis catheter and inactivating bacteria on the intraluminal surface.

Percutaneous CT-guided cryoablation for the treatment of refractory pudendal neuralgia.

PURPOSE: To evaluate the safety and efficacy of percutaneous CT-guided cryoablation of the pudendal nerve for the treatment of refractory pudendal neuralgia. MATERIALS AND METHODS: Eleven patients were selected to undergo percutaneous CT-guided cryoablation of the pudendal nerve based on established diagnostic criteria. Brief Pain Inventory questionnaires were administered prior to the procedure, during the immediate 24 h post procedure, and 45 days and 6 months following the procedure. RESULTS: Prior to treatment, the average level of pain on a scale from 0 (no pain) to 10 (worst pain imaginable) was 7.6, with pain described as "burning" (80%), "pulling" (37.5%), "crushing" (50%), "pressure" (84.5%), "throbbing" (50%), "knife-life" (52%), and "other" (60%). At 24 h, 45 days, and 6 months post-treatment, pain intensity dropped to 2.6, 3.5, and 3.1, respectively (p < 0.005). There were no procedure-related complications. CONCLUSIONS: CT-guided percutaneous cryoablation may represent a safe and efficacious option for selected patients with refractory pudendal neuralgia.

Image-guided cryoablation for the treatment of painful musculoskeletal metastatic disease: a single-center experience.

PURPOSE: The role of image-guided thermal ablation techniques for the nonoperative local management of painful osseous metastatic disease has expanded during recent years, and several advantages of cryoablation in this setting have emerged. The purpose of this study is to retrospectively evaluate and report a single-center experience of CT-guided percutaneous cryoablation in the setting of painful musculoskeletal metastatic disease. METHODS: This study was approved by the institutional review board and is compliant with the Health Insurance Portability and Accountability Act. Electronic medical records of all patients who underwent percutaneous image-guided palliative cryoablation at our institution were reviewed (n = 61). An intent-to-treat analysis was performed. Records were reviewed for demographic data and anatomical data, primary tumor type, procedure details, and outcome-including change in analgesic requirements (expressed as morphine equivalent dosages), pain scores (utilizing the clinically implemented visual analog scale), subsequent therapies (including radiation and/or surgery), and complications during the 24 h following the procedure and at 3 months. Patients were excluded (n = 7) if data were not retrospectively identifiable at the defined time points. RESULTS: Fifty-four tumors were ablated in 50 patients. There were statistically significant decreases in the median VAS score and narcotic usage at both 24 h and 3 months (p < 0.000). Six patients (11%) incurred complications related to their therapy. Two patients had no relief at 24 h, of which both reported worsened pain at 3 months. One patient had initial relief but symptom recurrence at 3 months. Four patients went on to have radiation therapy of the ablation site at some point following the procedure. CONCLUSIONS: CT-guided cryoablation is a safe, effective, reproducible procedural option for the nonoperative local treatment of painful musculoskeletal metastatic disease.

Ablation zones and weight-bearing bones: points of caution for the palliative interventionalist.

PURPOSE: To evaluate and classify underlying mechanisms of adverse outcomes after percutaneous computed tomography (CT)-guided cryoablation for palliation of painful musculoskeletal metastatic disease. MATERIALS AND METHODS: Data were collected for patients who underwent CT-guided percutaneous palliative cryoablation for painful musculoskeletal metastatic disease between January 2010 and December 2012. Cases with adverse outcomes or suboptimal response were identified and classified according to the Society of Interventional Radiology (SIR) classification system for complications by outcome and according to underlying mechanism of the outcome as delineated on follow-up examination. RESULTS: There were 61 patients who received ablation for painful musculoskeletal metastatic disease. Six patients with adverse outcomes were identified. Two were minor complications (A, n = 1; B, n = 1), and four were major complications (C, n = 1; D, n = 3). Four patients incurred sequelae related to damage of ancillary structures included in the ablation zone, and two patients developed complete fractures after ablation of lesions in weight-bearing bones. CONCLUSIONS: Complete cryoablation of a painful musculoskeletal metastatic lesion may lead to ancillary damage of adjacent structures or fracture in weight-bearing bones.