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.

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.

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.

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.

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.

Genicular Artery Embolization for the Treatment of Knee Pain Secondary to Osteoarthritis.

PURPOSE: To evaluate the efficacy and safety of embolization of hyperemic synovial tissue for the treatment of knee pain secondary to osteoarthritis (OA). MATERIALS AND METHODS: Twenty patients with radiographic knee OA and moderate-to-severe pain refractory to conservative therapy were enrolled in a prospective, 2-site pilot study. Genicular artery embolization (GAE) was performed with 75- or 100-µm spherical particles. Patients were assessed with magnetic resonance imaging at baseline and at 1 month and with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and at 1, 3, and 6 months. Adverse events were recorded at all timepoints. RESULTS: Embolization of at least 1 genicular artery was achieved in 20/20 (100%) patients. Mean VAS improved from 76 mm ± 14 at baseline to 29 mm ± 27 at 6-month follow-up (P < .01). Mean WOMAC score improved from 61 ± 12 at baseline to 29 ± 27 at 6-month follow-up (P < .01). Self-limiting skin discoloration occurred in 13/20 (65%) patients. Two of 20 (10%) patients developed plantar sensory paresthesia that resolved within 14 days. CONCLUSIONS: GAE to treat knee pain secondary to OA can be performed safely and demonstrates potential efficacy. Further randomized comparative studies are needed to determine true treatment effect versus placebo effect.

CT-Guided Percutaneous Drainage Catheter Placement in the Abdomen and Pelvis: Predictors of Outcome and Protocol for Follow-up.

PURPOSE: To determine predictors of outcomes for patients who undergo computed tomography (CT)-guided percutaneous abdominal or pelvic drainage catheter placement and to identify which patients benefit from fluoroscopic drainage catheter interrogation (abscessogram). MATERIALS AND METHODS: A retrospective review of 383 patients (mean, 52 years old; range 8-89 years old; 158 males: 225 females) who underwent 442 CT-guided procedures and 489 catheter placements for fluid collections in the abdomen or pelvis from January 1, 2015, to December 31, 2016 was performed. Variables including underlying disease, fluid location, number of collections drained, number of catheter exchanges and follow-up abscessograms performed, catheter size, and fistula detection were analyzed to determine factors associated with fistula formation and increased catheter dwell time. RESULTS: A single abscessogram followed by catheter removal was performed for 217 catheters (44%). An increased number of abscessograms was significantly associated with drainage catheter size (P < .001) and presence of a fistula (P < .001). Fistulae were detected in 95 cases (19%) and were significantly associated with an increased number of drain exchanges (P < .001) and an underlying diagnosis of Crohn's disease (P = .02). Based on these data, a clinical algorithm for drain management is presented. CONCLUSIONS: Abscessograms performed after CT-guided percutaneous drainage catheter placement are useful to detect catheter malposition, occluded catheters, and fistulae but are not necessary for all patients. If performed selectively, particularly in patients with an underlying diagnosis of Crohn's disease or those at high risk for developing fistulae, unnecessary examinations can be avoided, reducing cost, extra hospital visits, and radiation dose.

Randomized Comparison of Prostatic Artery Embolization versus Transurethral Resection of the Prostate for Treatment of Benign Prostatic Hyperplasia.

PURPOSE: To compare clinical and functional outcomes of prostatic artery embolization (PAE) with those of transurethral resection of the prostate (TURP) for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Noninferiority randomized trial was conducted involving men over 60 years of age with LUTS secondary to BPH. From November 2014 to January 2017, 45 patients were randomized to PAE (n = 23) or to TURP (n = 22). PAE was performed with 300- to 500-µm microspheres with the patient under local anesthesia, whereas bipolar TURP was performed with the patients under spinal or general anesthesia. Primary outcomes were changes in peak urinary flow (Qmax) and international prostate symptoms score (IPSS) from baseline to 12 months. Quality of life (QoL), and prostate volume (PV) changes from baseline to 12 month were secondary outcomes. Adverse events were compared using the Clavien classification. RESULTS: Mean Qmax increased from 6.1 mL/s in the PAE group and from 9.6 mL/s in the TURP patients (P = .862 for noninferiority), and mean IPSS reduction was 21.0 points for PAE and 18.2 points for TURP subjects (P = .080) at 12 months. A greater QoL improvement was reported in the PAE group (3.78 points for PAE and 3.09 points for TURP; P = .002). Mean PV reduction was 20.5 cm³ (34.2%) for PAE subjects and 44.7 cm³ (71.2%) for TURP subjects (P < .001). There were fewer adverse events reported in the PAE group than in the TURP group (n = 15 vs n = 47; P < .001). CONCLUSIONS: Reduction of LUTS in the PAE group was similar to that in the TURP group at 12 months, with fewer complications secondary to PAE. Long-term follow-up is needed to compare the durability of the symptomatic improvement from each procedure.

Development of Research Agenda in Prostate Artery Embolization: Summary of Society of Interventional Radiology Consensus Panel.

PURPOSE: To summarize the Society of Interventional Radiology Foundation's Research Consensus Panel development of a research agenda on prostate artery embolization (PAE). MATERIALS AND METHODS: PAE for the treatment of lower urinary tract symptoms has been shown to be safe and effective in decreasing symptoms and prostate size. Lack of randomized controlled trials (RCTs) on PAE in the United States has prevented inclusion in American Urologic Association guideline recommendations for treatment of lower urinary tract symptoms resulting from benign prostatic hyperplasia. Recognizing the need for well-designed trials, the SIR Foundation funded a Research Consensus Panel to prioritize a research agenda. The panel included interventional radiologists, urologists, SIR Foundation leadership, and industry representatives. The goal of the meeting was to discuss weaknesses with current data and study design for development of US trials to report long-term outcomes data. RESULTS: Final consensus on a research design could not be made because the group was split on 3 research designs: (i) RCT of PAE versus sham with crossover of the sham group. (ii) RCT of PAE versus simple prostatectomy. (iii) RCT of PAE versus holmium laser enucleation of the prostate/thulium laser enucleation of the prostate. The panel recommended a nonindustry-funded registry to obtain real-world data. CONCLUSIONS: Level 1 data are required to be included in the American Urologic Association guidelines for treatment of benign prostatic hyperplasia. Because of concerns with all 3 study designs, the panel did not reach a consensus. Further meetings are planned with the panel to select among these research designs.

Predictors of Prostatic Artery Embolization Technical Outcomes: Patient and Procedural Factors.

PURPOSE: To identify technical factors that significantly change prostatic artery embolization (PAE) technical outcomes and to derive and test technical outcome predictive models. MATERIALS AND METHODS: Retrospective analysis of PAEs performed by 2 operators (OPs) was performed: OP1, between April 2014 and May 2017 (n = 150); OP2, between February 2017 and December 2017 (n = 67). Multivariate analysis with mixed-effects modeling was used to test significance and derive predictive models. Mean difference was used to analyze prediction accuracy. RESULTS: Moderate versus none subjective iliac tortuosity grade (SITG) and the presence of internal iliac atherosclerosis (PIIAA) versus none were associated with the following respective technical outcome increases: procedure time (PT): 43% (P < .01), 16% (P < .01); fluoroscopy time (FT): 47% (P < .01), 25% (P < .01); contrast volume (CV): 25.6 mL (P < .001), 13.7 mL (P = .01); and dose area product (DAP) 52% (P < .01), 20% (P = 0.03). Prostatic artery origin left obturator versus left superior vesical was associated with a 24% (P = .01) DAP decrease. For every 1 cc that prostate volume increased, CV decreased on average by 0.1 mL (P = .05). For every 1-cm decrease in patient height and 1-kg increase in weight, DAP increased on average by 0.02% (P < .01) for each. Unilateral versus bilateral versus 3-vessel embolization resulted in a 16.3-mL CV decrease on average for each additional vessel embolized (P = .03). The mean absolute differences between predicted and measured technical outcome values were: PT: 16 minutes, FT: 7 minutes, CV: 25 mL, and DAP: 44 Gy·cm2. CONCLUSIONS: In this study, higher SITGs and PIIAA most likely contributed to higher technical outcomes when controlling for the 2 OPs.

The Beauty and Bane of Pressure-Directed Embolotherapy: Hemodynamic Principles and Preliminary Clinical Evidence.

OBJECTIVE: Particulate emboli are passive agents that follow blood flow. Deployed antireflux devices obstruct blood flow. CONCLUSION: The aim of this review is to describe the complex hemodynamic alterations to blood flow caused by the deployment of antireflux devices and the resulting changes to embolic distribution. The therapeutic goal is optimization of embolization safety and efficacy.

Prostatic Artery Embolization for Benign Prostatic Hyperplasia: Patient Evaluation, Anatomy, and Technique for Successful Treatment.

Symptomatic benign prostatic hyperplasia is a common condition in the aging population that results in bothersome lower urinary tract symptoms and decreased quality of life. Patients often are treated with medication and offered surgery for persistent symptoms. Transurethral resection of the prostate is considered the traditional standard of care, but several minimally invasive surgical treatments also are offered. Prostatic artery embolization (PAE) is emerging as an effective treatment option with few reported adverse effects, minimal blood loss, and infrequent overnight hospitalization. The procedure is offered to patients with moderate to severe lower urinary tract symptoms and depressed urinary flow due to bladder outlet obstruction. Proper patient selection and meticulous embolization are critical to optimize results. To perform PAE safely and avoid nontarget embolization, interventional radiologists must have a detailed understanding of the pelvic arterial anatomy. Although the prostatic arteries often arise from the internal pudendal arteries, several anatomic variants and pelvic anastomoses are encountered. Prospective cohort studies, small randomized controlled trials, and meta-analyses have shown improved symptoms after treatment, with serious adverse effects occurring rarely. This article reviews the basic principles of PAE that must be understood to develop a thriving PAE practice. These principles include patient evaluation, review of surgical therapies, details of pelvic arterial anatomy, basic principles of embolization, and an overview of published results. Online supplemental material is available for this article. ©RSNA, 2019.

Initial Experience with Balloon-Occlusion Prostatic Artery Embolization.

Twelve patients underwent balloon-occlusion prostatic artery embolization (PAE) at a single center. Bilateral prostatic artery catheterization was achieved in all patients, but unilateral embolization was performed in 1 patient as a result of the presence of a prostatic arteriovenous fistula. Mean International Prostate Symptom Score and quality-of-life score decreased by 15 ± 7 (P < .01) and 4 ± 1 (P < .01) points, respectively, over a mean follow-up period of 22 weeks ± 8. Only self-limiting minor complications were encountered. The initial experience with balloon-occlusion PAE suggests that it is technically feasible and can be performed safely.

Comparative Analysis of Cone-Beam CT Angiogram and Conventional CT Angiogram for Prostatic Artery Identification Prior to Embolization.

Pre-prostatic artery embolization (PAE) cone-beam computed tomography (CT) angiograms (n = 31; mean age: 62.4 ± 9.75 years) and conventional CT angiograms (n = 32; mean age: 62.5 ± 7.2 years) were retrospectively compared. Mean signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), radiation exposure, and prostatic artery (PA) identification scores (0-4) for cone-beam CT angiogram and conventional CT angiogram were 33.19 (± 14.31) and 18.13 (± 5.38) (P < .01); 27.42 (± 13.39) and 14.78 (± 4.92) (P < .01); 14.57 mSv (±2.5) and 19.25 mSv (±3.7) (P < .01); 3.36 (± 0.89) and 3.16 (± 0.95) (P = .08), respectively. Pre-PAE cone-beam CT angiogram allows for PA identification with improved SNR and CNR and less radiation dose compared to conventional CT angiogram.