Society of Interventional Radiology Research Reporting Standards for Genicular Artery Embolization.

Genicular artery embolization (GAE) is an emerging, minimally invasive therapy to address the global burden of knee osteoarthritis (OA) and the unmet needs for medically refractory disease. Although total knee arthroplasty has been a standard intervention for severe cases, GAE is developing into a promising alternative, particularly for patients ineligible for or unwilling to undergo surgery. GAE targets the inflammatory cascade underlying OA pathophysiology by arresting neoangiogenesis and preventing pathological neoinnervation, offering potential pain relief. Although early studies have established safety and short-term effectiveness, ensuing studies are needed to validate long-term safety, durability, and comparative effectiveness and to optimize patient selection, embolic agent selection, and administration techniques. Standardized reporting guidelines are therefore essential to enhance transparency and reproducibility across clinical trials, facilitating data aggregation and comparison. This Society of Interventional Radiology (SIR)-endorsed reporting standards consensus document provides a framework to harmonize future research efforts and to improve the interpretation of outcomes.

Multicenter Quantification of Radiation Exposure and Associated Risks for Prostatic Artery Embolization in 1476 Patients.

Background Prostatic artery embolization (PAE) is a safe, minimally invasive angiographic procedure that effectively treats benign prostatic hyperplasia; however, PAE-related patient radiation exposure and associated risks are not completely understood. Purpose To quantify radiation dose and assess radiation-related adverse events in patients who underwent PAE at multiple centers. Materials and Methods This retrospective study included patients undergoing PAE for any indication performed by experienced operators at 10 high-volume international centers from January 2014 to May 2021. Patient characteristics, procedural and radiation dose data, and radiation-related adverse events were collected. Procedural radiation effective doses were calculated by multiplying kerma-area product values by an established conversion factor for abdominopelvic fluoroscopy-guided procedures. Relationships between cumulative air kerma (CAK) or effective dose and patient body mass index (BMI), fluoroscopy time, or radiation field area were assessed with linear regression. Differences in radiation dose stemming from radiopaque prostheses or fluoroscopy unit type were assessed using two-sample t tests and Wilcoxon rank sum tests. Results A total of 1476 patients (mean age, 69.9 years ± 9.0 [SD]) were included, of whom 1345 (91.1%) and 131 (8.9%) underwent the procedure with fixed interventional or mobile fluoroscopy units, respectively. Median procedure effective dose was 17.8 mSv for fixed interventional units and 12.3 mSv for mobile units. CAK and effective dose both correlated positively with BMI (R2 = 0.15 and 0.17; P < .001) and fluoroscopy time (R2 = 0.16 and 0.08; P < .001). No radiation-related 90-day adverse events were reported. Patients with radiopaque implants versus those without implants had higher median CAK (1452 mGy [range, 900-2685 mGy] vs 1177 mGy [range, 700-1959 mGy], respectively; P = .01). Median effective dose was lower for mobile than for fixed interventional systems (12.3 mSv [range, 8.5-22.0 mSv] vs 20.4 mSv [range, 13.8-30.6 mSv], respectively; P < .001). Conclusion Patients who underwent PAE performed with fixed interventional or mobile fluoroscopy units were exposed to a median effective radiation dose of 17.8 mSv or 12.3 mSv, respectively. No radiation-related adverse events at 90 days were reported. © RSNA, 2024 See also the editorial by Mahesh in this issue.

Angiographic Analysis of Anatomical Variants in Adhesive Capsulitis Embolization.

PURPOSE: To analyze the complex shoulder vasculature and identify potential challenges during adhesive capsulitis embolization (ACE). MATERIALS AND METHODS: Two interventional radiologists evaluated angiographic findings from 21 ACE procedures. The suprascapular artery (SSA), thoracoacromial artery (TAA), coracoid branch (CB), circumflex scapular artery (CSA), and anterior/posterior circumflex humeral artery (ACHA/PCHA) were assessed for their presence, course, diameter within 1 cm of origin, angle to the proximal parent vessel, and distance from the clavicle. RESULTS: 83 arteries were embolized: CB (20.5%), TAA (19.3%), PCHA (19.3%), ACHA (16.9%), CSA (14.5%), and SSA (9.6%). The CSA had the largest diameter (4.3 mm), while CB had the smallest diameter (1.0 mm). An acute angle to the parent vessel was noted with the SSA, TAA, ACHA, and PCHA. A common origin for CSA and PCHA was noted in 2 patients. A common origin for TAA and SSA was also noted in one patient. The CB appears perpendicular to the axillary artery and courses vertically toward the coracoid process. The TAA branches off the axillary artery and courses along the medial border of the pectoralis minor. The PCHA and ACHA originate from the axillary artery. The CSA is located on the medial side of axillary artery. The SSA originates from the thyrocervical trunk and courses laterally toward the superior border of the scapula. CONCLUSION: An anatomical-technical guide is provided to help interventional radiologists during ACE to treat adhesive capsulitis.

Outcomes of Hemorrhoidal Artery Embolization from a Multidisciplinary Outpatient Interventional Center.

PURPOSE: To evaluate the safety and efficacy of outpatient transarterial embolization for symptomatic refractory internal hemorrhoids. MATERIALS AND METHODS: Retrospective analysis of 134 patients who underwent hemorrhoidal artery embolization (HAE) for symptomatic internal hemorrhoids between August 2021 and June 2022 (76 men and 58 women) was performed. The mean age was 54.9 years, with a mean Goligher hemorrhoid grade (HG) of 2.1. Branches of the superior rectal artery (SRA) or middle rectal artery supplying the corpus cavernosum recti were embolized with both spherical particles and microcoils. Standard-of-care evaluations were performed at baseline and the 1 month follow-up, which included hemorrhoid-related pain (HRP) (0-10), hemorrhoid symptoms score (HSS) (5-20), quality of life (QoL) (0-4), French bleeding score (FBS) (0-9), and HG (0-4). Clinical success was defined as improvement of symptoms without additional treatment. RESULTS: Embolization of at least 1 hemorrhoidal artery was achieved in 133 (99%) of the 134 patients. The mean number of SRA branches embolized per patient was 2.9 ± 1.0. Clinical success was seen in 93% (124 of 134) of patients at the 1-month follow-up, with 10 patients requiring repeat embolization. There were significant improvements in all mean outcomes at 1 month: HSS (11-7.8; P < .01), HRP (4.1-1.3; P < .01), QoL (2.2-0.8; P < .01), FBS (4.4-2.2; P < .01), and HG (2.3-1.2; P < .05). There were no severe adverse events. CONCLUSIONS: HAE is a safe and effective outpatient treatment for refractory symptomatic internal hemorrhoids in the short term.

Interventional Management of Painful Vertebral Body Metastases.

Management of osseous metastatic disease has advanced over the years with the advent of ablation and interventional technologies. Painful metastatic vertebral body lesions have been particularly studied in the recent years, as open surgery is usually reserved for emergent cord compression. Minimally invasive options in managing these lesions include percutaneous vertebral augmentation, percutaneous ablation, and embolization. This article will include an overview of these procedures including the most recent literature.

Nontarget Radiopaque Embolic Deposition during Prostatic Artery Embolization.

This study evaluated detectable nontarget embolization (NTE) during prostatic artery embolization (PAE) and the safety and efficacy of using radiopaque particles in PAE. Ten patients aged >40 years with prostate glands of >50 mL and refractory lower urinary tract symptoms were analyzed. Unenhanced computed tomography scans at baseline and at 3 months after PAE, using 40-90-µm radiopaque spherical embolic beads, were compared to assess the NTE. Growth models evaluated changes from baseline to 3, 6, and 12 months in International Prostate Symptom Score (IPSS), peak urine flow rate (Qmax), quality of life (QoL), International Index of Erectile Function (IIEF), and postvoid residual (PVR). The IPSS, QoL, and Qmax improved at all time points (P < .05), with no trend in PVR or IIEF. Adverse events that occurred were minor. Radiographic NTE was seen in all patients, correlating at times with postprocedural symptoms (eg, rectal pain). Symptoms were not correlated with the NTE in some patients, whereas other patients remained asymptomatic despite NTE.

Minimally Invasive Treatments for Benign Prostatic Hyperplasia: Systematic Review and Network Meta-Analysis.

PURPOSE: To review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. MATERIALS AND METHODS: A literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect. RESULTS: There was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted. CONCLUSION: Although significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.

Multicenter Randomized Sham Controlled Study of Genicular Artery Embolization for Knee Pain Secondary to Osteoarthritis.

PURPOSE: To assess the safety and efficacy of genicular artery embolization (GAE) compared with a sham procedure in the treatment of knee pain secondary to mild to moderate osteoarthritis (OA). MATERIALS AND METHODS: A multicenter, single-blinded, randomized controlled trial was conducted to evaluate knee OA symptom reduction after GAE versus sham procedure. Subjects (n = 21) with mild to moderate OA and intractable knee pain were randomized 2:1 to either GAE or a sham procedure. Subjects who were randomized to the sham procedure and did not report clinical improvement in both the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS) scores were unblinded and able to crossover to treatment at 1 month. Longitudinal data were collected for 12 months, and subjects were excluded if they required additional analgesics at follow-up. Reductions in the VAS and total WOMAC scores were compared using mixed-effects linear regression models. RESULTS: All subjects in the sham group failed to show significant improvements at 1 month and crossed over to the treatment arm. There was a statistically significantly greater pain reduction in the treatment group than in the sham group at 1 month (VAS, 50.1 mm; standard error [SE], 10.6; 95% confidence interval [CI], 29.0, 72.3; P<.01). Disability improvement was also significantly greater in the treatment group (WOMAC, 24.7 points; SE, 10.4; 95% CI, 3.5, 45.9; P=.02). Only minor adverse events were reported. Five subjects were excluded after increased analgesic use. Sensitivity analysis with all excluded patients confirmed significant improvements at 1 and 12 months. CONCLUSION: In patients with mild to moderate knee OA, GAE results in symptomatic improvement greater than the sham procedure with clinically significant reduction in pain and disability.

Results from a United States Investigational Device Study of Adhesive Capsulitis Embolization in the Treatment of Shoulder Pain: The Adhesive Capsulitis Embolization Study.

PURPOSE: To evaluate the safety and efficacy of arterial embolization to relieve shoulder pain secondary to adhesive capsulitis (AC). MATERIALS AND METHODS: In total, 20 patients (18 females, 2 males; mean age, 51 years) with AC resistant to >30 days of conservative treatment were enrolled in a multicenter prospective study. Adhesive capsulitis embolization was performed with 75-µm or 200-µm spherical particles. Subjects were assessed before and after the procedure with magnetic resonance imaging, visual analog scale (VAS; 0-100 mm) scores, Single Assessment Numeric Evaluation (SANE; 0-100) scores, and American Shoulder and Elbow Surgeons (ASES; 0-100) scores. Adverse events were recorded at all follow-up time points. RESULTS: Hypervascularity was identified and embolization was technically successful in all patients, with 83 arteries embolized in 20 patients. Baseline VAS, SANE, and ASES scores before the procedure were 89.2 mm, 27.2, and 30.9, respectively. The 1-month (n = 19), 3-month (n = 18), and 6-month (n = 12) follow-ups demonstrated significant improvements. At the 1-month follow-up, VAS score decreased by 31.8 (P = 1.2E-11), SANE score increased by 22.1 (P = 1.8E-8), and ASES score increased by 14.2 (P = 4.3E-5). At the 6-month follow-up, VAS score decreased by 62.1 (P = 7.0E-11), SANE score increased by 55.4 (P = 4.1E-10), and ASES score increased by 44.5 (P = 1.8E-6). Due to the coronavirus pandemic, the study ended early; 6 patients did not complete the 6-month follow-up. No major adverse events were noted. CONCLUSIONS: Interim findings suggest that arterial embolization is safe and effective for patients with AC refractory to conservative treatment.

Comparison of Minimally Invasive Procedures to Treat Knee Pain Secondary to Osteoarthritis: A Systematic Review and Meta-Analysis.

PURPOSE: To review and indirectly compare the outcomes of genicular artery embolization (GAE), radiofrequency (RF) ablation, and intra-articular (IA) injection for the treatment of knee pain secondary to osteoarthritis (OA). MATERIALS AND METHODS: A literature review of the MEDLINE and Cochrane databases was conducted with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement in June 2020. The visual analog scale (VAS) was recorded at baseline and at all available time points for each therapy. Standard mean differences were calculated at each time point and compared between treatments to assess the magnitude of the treatment effect. RESULTS: All 3 treatments demonstrated significant differences in VAS scores after therapy. RF ablation produced the greatest significant mean reduction in relative VAS score from baseline at 1 year of follow-up (mean, 0.49; 95% confidence interval, 0.4-0.59; P = .03). GAE reported the most significant reductions in VAS scores across all measured time points. Overall, the comparison did not demonstrate a significant difference in VAS scores among patients receiving IA injections, RF ablation, and GAE. CONCLUSIONS: The current evidence does not suggest a significant difference in outcomes among IA injection, RF ablation, and GAE for knee pain secondary to OA.

Musculoskeletal Interventions: A Review on Genicular Artery Embolization.

Symptomatic knee pain is one of the most common joint diseases that affects millions of people worldwide. The treatment for knee pain secondary to osteoarthritis (OA) begins with conservative therapy and progresses to surgical intervention when conservative therapy fails. Genicular artery embolization (GAE) offers an alternative option for patients who are poor surgical candidates. Multiple studies have been conducted worldwide demonstrating the safety and efficacy of GAE in patients with mild to moderate OA. The purpose of this article is to describe the current literature on GAE and highlight the latest findings from a randomized controlled trial comparing GAE versus sham embolization.

A Review of Musculoskeletal Embolization to Treat Pain Outside of the Knee.

Chronic inflammation leading to musculoskeletal pain has garnered interest in the past decade with the success of genicular artery embolization for knee pain secondary to osteoarthritis. Outside the knee joint, musculoskeletal embolization has been applied to other anatomical locations, mainly shoulder pain secondary to adhesive capsulitis and elbow pain secondary to lateral epicondylitis. The success of these early trials and other case reports highlights the efficacy of musculoskeletal embolization and its future potential.

Type II Endoleak Nidus Volume on Arterial and Delayed Phases of Initial CT Angiography after Endovascular Abdominal Aortic Aneurysm Repair Predicts Persistent Endoleak and Aneurysm Sac Enlargement.

PURPOSE: To evaluate type II endoleak nidus volume (ENV) in the arterial phase (ENVAP) and delayed phase (ENVDP) of the first postoperative CT angiography (CTA) as a predictor of persistent endoleak and aneurysm sac enlargement at follow-up CTA in patients with endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm. MATERIALS AND METHODS: Ninety-three patients (mean age ± standard deviation, 72 years ± 8; range, 56-88 years) with EVAR and type II endoleak were included in a single-institution retrospective study conducted between March 1, 2005, and December 31, 2018. ENVAP, ENVDP, change of volume (ENVDP-AP), and percentage of ENVAP and ENVDP in aneurysm sac volume (ASV) (ENVAP/ASV%, ENVDP/ASV%, respectively) were measured on first postoperative CTA images. The mean follow-up was 31.6 months ± 26.6 (range, 6-163.8 months). Patients were divided into two groups (group A, spontaneous resolution of endoleak without intervention [n = 29] and group B, persistent endoleak at follow-up CTA [n = 64]) and compared by using the Mann-Whitney U, Wilcoxon signed rank, and Pearson χ2 tests. Receiver operating characteristic (ROC) analysis was used to compare accuracies of parameters at first postoperative CTA. RESULTS: The accuracy of ENVDP (area under the ROC curve [AUC], 0.78) was superior to the accuracy of ENVDP/ASV% (AUC, 0.76), ENVDP-AP (AUC, 0.74), ENVAP (AUC, 0.71), and ENVAP/ASV% (AUC, 0.69) in indicating persistent endoleak. In group B, 46 patients (72%) showed ASV enlargement and 44 patients (69%) underwent endoleak embolization. ENVAP (1.7 cm3 ± 2.9 vs 3.4 cm3 ± 4.2; P = .001), ENVDP (2.9 cm3 ± 3.8 vs 8.0 cm3 ± 9.6; P < .001), ENVDP-AP (1.1 cm3 ± 1.8 vs 4.5 cm3 ± 7.8; P < .001), ENVAP/ASV% (0.9% ± 1.5 vs 1.7% ± 2.2; P = .003), and ENVDP/ASV% (1.6% ± 2.2 vs 3.7% ± 3.6; P < .001) were smaller in group A than in group B. CONCLUSION: ENVDP of the first postoperative CTA is an accurate predictor of persistent endoleak compared with ENVAP, and persistent endoleak is associated with aneurysm sac enlargement, in which earlier intervention is recommended.© RSNA, 2021.

Initial experience with HydroPearl microspheres for uterine artery embolization for the treatment of symptomatic uterine fibroids.

BACKGROUND: Uterine Artery Embolization (UAE) is a minimally invasive procedure used to treat symptomatic uterine fibroids. The HydroPearl Microsphere (Terumo Interventional Systems) is an embolic agent approved for UAE and other embolization procedures. The purpose of this article is to describe our initial experience with HydroPearl for UAE in patients with symptomatic uterine fibroids. Twenty-one patients who underwent UAE using HydroPearl Microspheres at a single institution from May 1, 2018 to December 31, 2019 were included in the study. The electronic medical record (EMR) was reviewed for documentation of short- and long-term complications, as well as improvements in menorrhagia and bulk-type symptoms. We also describe unique attributes of the HydroPearl Microsphere that should be considered when utilizing this embolization particle for UAE. RESULTS: Of the 21 patients, 18 had a 3-month or later post-procedure follow-up documented in the EMR and were included in the analysis. The average time between the UAE procedure and the most recent clinical note was 145 days. Sixteen patients reported symptoms of menorrhagia and 13 reported bulk symptoms prior to the UAE procedure. On follow-up, 13/16 patients (81%) and 12/13 patients (92%) experienced improvement in menorrhagia and bulk symptoms, respectively. The only recorded complication was amenorrhea in 4 patients (22%) who had an average age of 51 years. CONCLUSIONS: Several characteristics of HydroPearl Microsphere may prove helpful when considering these embolic particles for use in UAE. Our initial experience with this embolic agent suggest that the reatment response for menorrhagia and bulk symptoms are largely similar to success rates reported in the literature for other embolic agents. Larger studies are needed to evaluate the safety and efficacy of this embolic particle for this indication.

Comparison of Cost and Efficacy of Trufill® vs Histoacryl® n-Butyl Cyanoacrylate for Translumbar Type 2 Endoleak Embolization.

PURPOSE: The study aimed to compare the cost and efficacy of translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl® n-BCA liquid embolic. METHOD AND MATERIALS: This was a retrospective review of patients who had translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl®. Patients were included if they underwent a technically successful type 2 endoleak repair via a translumbar approach with Trufill® or Histoacryl® n-BCA. A multivariable analysis was performed with the primary clinical outcome of percent change in aneurysm diameter per month compared. Procedure cost was calculated based on typical materials used. RESULTS: 20 Trufill® and 14 Histoacryl® patients were included. The mean procedure cost was higher for Trufill® ($5,757.30 vs. $1,586.09, p ≤ 0.001). There was no significant difference between Trufill® or Histoacryl® patients for age at first embolization, gender, total number of embolizations, number of feeding branches, aneurysm sac size prior to embolization, or residual endoleak at first follow-up. Trufill® patients had more coils used (12.0 vs. 4.3, p = 0.0007), less glue used (0.9 vs. 2.1 mL, p < 0.001), longer follow-up duration (33.5 vs. 13.2 months, p = 0.002), more follow-up CT angiograms (CTA) (3.7 vs. 1.9, p = 0.01), and larger excluded aneurysm sac size at most recent CTA (7.1 cm vs. 5.9 cm, p = 0.04). Percent change in sac diameter per month was not significantly different between Trufill® and Histoacryl® (0.21% vs. -0.25%/month, p = 0.06, respectively). There were no complications. CONCLUSION: Use of Histoacryl® over Trufill® n-BCA resulted in significantly less procedural cost while maintaining safety and efficacy.

Ultrasound-Guided Chemical Component Separation with Botulinum Toxin A prior to Surgical Hernia Repair.

US-guided chemical component separation (CCS) of the abdominal musculature using botulinum toxin A can facilitate the surgical repair of large or complex hernias. Eight patients (2 women and 6 men with median age of 54 years [range, 34-78 years]) underwent preoperative US-guided CCS with hydrodissection before planned surgical repair of large or complex ventral (n = 4), inguinal (n = 2), and flank (n = 2) hernias by 2 interventional radiologists. Technical success rate of US-guided CCS procedures was 100%, and all patients achieved surgical closure a mean 34.1 days (range, 14-48 days) after US-guided CCS.