Nonspherical Polyvinyl Alcohol Particles versus Tris-Acryl Microspheres: Randomized Controlled Trial Comparing Pain after Uterine Artery Embolization for Symptomatic Fibroids

Resorbable Microspheres versus Trisacryl Gelatin Microspheres for Uterine Artery Embolization: A Randomized Controlled Trial

Background There are insufficient data comparing resorbable microspheres (RMs) with permanent trisacryl gelatin microspheres (TAGMs) for uterine artery embolization (UAE). Purpose To compare therapeutic efficacy and clinical outcomes in participants with symptomatic fibroids after UAE with RMs or TAGMs. Materials and Methods This randomized controlled trial included participants undergoing UAE for symptomatic fibroids at a single institution (from May 2021 to May 2023). Participants were randomized one-to-one to undergo UAE with either RMs or TAGMs. Numeric rating scale pain scores and cumulative fentanyl consumption were assessed for 24 hours after undergoing UAE. Anti-Mullerian hormone was measured to assess effects of UAE on ovarian function. MRI was performed before and 3 months after UAE to evaluate fibroid necrosis and uterine artery recanalization. Repeated variables such as pain were analyzed using Mann-Whitney U test with post hoc Bonferroni correction. Results Sixty female participants (mean age, 45.7 years ± 3.6 [SD]) completed the study, with 30 in each group. No evidence of a difference in pain scores was observed between groups (P > .99). Moreover, there was no evidence of a difference in the total fentanyl consumption at 24 hours after UAE between groups (median: RMs, 423 [IQR, 330-530] vs TAGMs, 562 [IQR, 437-780]; P = .15). Serum anti-Mullerian hormone 3 months after UAE showed no evidence of a difference between groups (RMs vs TAGMs, 0.71 ng/mL ± 0.73 vs 0.49 ng/mL ± 0.45, respectively; P = .09). No evidence of a difference in the rate of complete necrosis of the dominant fibroid was observed between groups (97% [29 of 30] for both groups; P > .99). The rate of uterine artery recanalization was higher in RM versus TAGM groups (70% [21 of 30] vs 17% [five of 30], respectively; P < .001). Conclusion UAE with RMs, compared with UAE with TAGMs, showed no evidence of a difference in terms of therapeutic effectiveness or postprocedural pain scores in participants with symptomatic fibroids. Clinical trial registration no. NCT05086770 © RSNA, 2024 See also the editorial by Spies in this issue.

Development and Validation of a Nomogram to Predict the Risk of Special Uterine Leiomyoma Pathological Types or Leiomyosarcoma in Postmenopausal Women: A Retrospective Study

Purpose

The aim of this study was to investigate the risk factors of postmenopausal special uterine leiomyoma pathological types or leiomyosarcoma and to develop a nomogram for clinical risk assessment, ultimately to reduce unnecessary surgical interventions and corresponding economic expenses.

Methods

A total of 707 patients with complete information were enrolled from 1 August 2012 to 1 August 2022. Univariate and multivariate logistic regression models were used to analyse the association between variables and special uterine leiomyoma pathological types or leiomyosarcoma in postmenopausal patients. A nomogram for special uterine leiomyoma pathological types or leiomyosarcoma in postmenopausal patients was developed and validated by bootstrap resampling. The calibration curve was used to assess the accuracy of the model and receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were compared with the clinical experience model.

Results

The increasing trend after menopause, the diameter of the largest uterine fibroid, serum carcinoembryonic antigen 125 concentration, Serum neutrophil to lymphocyte ratio, and Serum phosphorus ion concentration were independent risk factors for special uterine leiomyoma pathological types or leiomyosarcoma in postmenopausal patients. We developed a user-friendly nomogram which showed good diagnostic performance (AUC=0.724). The model was consistent and the calibration curve of our cohort was close to the ideal diagonal line. DCA indicated that the model has potential value for clinical application. Furthermore, our model was superior to the previous clinical experience model in terms of ROC and DCA.

Conclusion

We have developed a prediction nomogram for special uterine leiomyoma pathological types or leiomyosarcoma in postmenopausal patients. This nomogram could serve as an important warning signal and evaluation method for special uterine leiomyoma pathological types or leiomyosarcoma in postmenopausal patients.

Uterine Fibroid Embolization Survey in Canada: Challenges, Opportunities, and Differences in Practices Across the Country

Purpose: To assess the current practices surrounding Uterine Fibroid Embolization (UFE) in Canada. Methods: An online survey was sent to Canadian Association for Interventional Radiology (CAIR) members. It included questions on symptoms prompting UFE, patient awareness, investigation, UFE settings, the number of UFE procedures, and post-UFE care. The findings were discussed at CAIR's 2023 annual meeting by an expert panel. Results: Out of 792 surveys sent, 87 were filled (11%). Menorrhagia is the most common indication for UFE (87%). Women's awareness of UFE as a treatment option for fibroids is viewed as poor or average by 94% of our survey respondents. Most respondents see patients in clinics (92%) before the procedure and evaluate fibroids with MRI pre-UFE (76%). There is variability in care post-UFE, with 33% of procedures being performed as day surgery while 67% lead to overnight stay. For pain management, intravenous analgesia (including patient-controlled analgesia) is used in 76% (63/83) of cases while 19% (16/83) of respondents mentioned using epidural analgesia. Finally, there is an even split between embolic agent used; non-spherical polyvinyl alcohol (50%) and spherical particles (50%). Conclusion: Respondents believe patients in Canada still have limited awareness of UFE. Interventional radiologists are increasingly involved in the entire patient care trajectory, overseeing pre-and post-procedure care and hospitalizing patients. For pain management after UFE, it is observed that while epidural analgesia has been demonstrated more effective than alternatives, it is not widely used as the primary method.

Efficacy of intra-arterial lidocaine administration on pain and inflammatory response after uterine artery embolization for symptomatic fibroids

BACKGROUND

There have been conflicting outcomes regarding the use of lidocaine to reduce pain after uterine artery embolization (UAE).

PURPOSE

To investigate the efficacy of intra-arterial lidocaine injection for pain and inflammatory response control within 24 h of UAE for symptomatic uterine fibroids.

MATERIAL AND METHODS

Of 1530 patients who underwent UAE for uterine fibroids in 2007-2021, 5 mL of 1% lidocaine was injected into each uterine artery immediately after UAE in 23 patients. A disease-matched control group (n = 23) who did not receive intra-arterial lidocaine was generated from the same registry. The pain score, white blood cell (WBC) count, C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), and fentanyl consumption were compared before and after UAE. Complete infarction of the dominant fibroid was assessed using magnetic resonance imaging.

RESULTS

Significantly lower WBC count, CRP level, and NLR were noted 24 h after UAE in the lidocaine group. No statistically significant difference was noted in the pain score between groups at 0-24 h. The cumulative fentanyl dose administered during the first 24 h after UAE was not significantly different. After embolization, fibroid-related symptoms resolved in all patients. No significant difference was observed in the rate of complete infarction of the dominant fibroid.

CONCLUSION

Lidocaine administration immediately after UAE resulted in a significant reduction in the inflammatory response. However, such a difference in the inflammatory reaction did not contribute to significant reductions in pain scores or fentanyl consumption.

The Use of Microspheres for Cancer Embolization Therapy: Recent Advancements and Prospective

Embolization therapy involving biomaterials has improved the therapeutic strategy for most liver cancer treatments. Developing biomaterials as embolic agents has significantly improved patients' survival rates. Various embolic agents are present in liquid agents, foam, particulates, and particles. Some of the most applied embolic agents are microparticles, such as microspheres (3D micrometer-sized spherical particles). Microspheres with added functionalities are currently being developed for effective therapeutic embolization. Their excellent properties of high surface area and capacity for being loaded with radionuclides and alternate active or therapeutic agents provide an additional advantage to overcome limitations from traditional cancer treatments. Microspheres (non-radioactive and radioactive) have been widely used and explored for localized cancer treatment. Non-radioactive microspheres exhibit improved clinical performance as drug delivery vehicles in chemotherapy due to their controlled and sustained drug release to the target site. They offer better flow properties and are beneficial for the ease of delivery via injection procedures. In addition, radioactive microspheres have also been exploited for use as an embolic platform in internal radiotherapy as an alternative to cancer treatment. This short review summarizes the progressive development of non-radioactive and radioactive embolic microspheres, emphasizing material characteristics. The use of embolic microspheres for various modalities of therapeutic arterial embolization and their impact on therapeutic performance are also discussed.

In Vitro Characterization of Drug-Loaded Superabsorbent Polymer Microspheres: Absorption and Release Capacity of Contrast Material, Antibiotics and Analgesics

PURPOSE

To examine the characteristics of drug-loaded superabsorbent polymer microspheres (SAP-MS) such as drug absorption, drug release, diameter, and visibility.

MATERIALS AND METHODS

SAP-MS (HepaSphere150-200 µm; Merit Medical, South Jordan, UT, USA) were suspended in drug solutions: (a) cefazolin, (b) lidocaine, (c) iopamidol and cefazolin, (d) iopamidol and lidocaine, and (e) iopamidol, cefazolin, and lidocaine. The concentrations of drugs were measured, and the amount of each drug absorbed was calculated. Filtered drug-loaded SAP-MS were mixed with saline, and the drug release rates were calculated. The diameter changes of SAP-MS during absorption were observed. Radiography of drug-loaded SAP-MS was evaluated as radiopacity by contrast-to-noise ratio (CNR).

RESULTS

The drug concentration did not change during absorption. The release rates increased for 10 min and then came to an equilibrium. The mean amounts of drug absorbed at 180 min and mean release rates at 24 h were (a) cefazolin: 265.4 mg, 64.2%; (b) lidocaine: 19.6 mg, 75.6%; (c) iopamidol: 830.2 mg, 22.5%; cefazolin: 137.6 mg, 21.2%; (d) iopamidol: 1620.6 mg, 78.5%; lidocaine: 13.5 mg, 81.4%; and (e) iopamidol: 643.7 mg, 52.9%; cefazolin: 194.0 mg, 51.6%; lidocaine: 5.3 mg, 58.4%. The diameter of SAP-MS increased for approximately 15 min. Finally, the diameters of SAP-MS were (a) 3.9 times, (b) 5.0 times, (c) 2.2 times, (d) 5.5 times, and (e) 3.6 times larger than the original size. Drug-loaded SAP-MS containing iopamidol were visible under X-ray imaging, with CNRs of (c) 3.0, (d) 9.0, and (e) 4.5.

CONCLUSION

SAP-MS can absorb and release iopamidol, cefazolin, and lidocaine.

Our Experience with Hydrogel-Coated Trisacryl Microspheres in Uterine Artery Embolization for the Treatment of Symptomatic Uterine Fibroids and Adenomyosis: A Follow-Up of 11 Years

Uterine artery embolization (UAE) for the treatment of symptomatic uterine fibroids and non-controllable adenomyosis symptoms is a relatively new procedure for organ-preserving therapy. These benign conditions can become symptomatic in about 30% of women between the ages of 35 and 50. The purpose of the UAE either for fibroids or adenomyosis is the elimination of blood loss, the reduction in pain, and bulky or rectal pressure symptoms. The purpose of this study is to present our experience in UAE with the use of hydrogel-coated tris acryl microspheres for the treatment of symptomatic uterine fibroids and adenomyosis.

Current Trends in Gelatin-Based Drug Delivery Systems

Gelatin is a highly versatile natural polymer, which is widely used in healthcare-related sectors due to its advantageous properties, such as biocompatibility, biodegradability, low-cost, and the availability of exposed chemical groups. In the biomedical field, gelatin is used also as a biomaterial for the development of drug delivery systems (DDSs) due to its applicability to several synthesis techniques. In this review, after a brief overview of its chemical and physical properties, the focus is placed on the commonly used techniques for the development of gelatin-based micro- or nano-sized DDSs. We highlight the potential of gelatin as a carrier of many types of bioactive compounds and its ability to tune and control select drugs' release kinetics. The desolvation, nanoprecipitation, coacervation, emulsion, electrospray, and spray drying techniques are described from a methodological and mechanistic point of view, with a careful analysis of the effects of the main variable parameters on the DDSs' properties. Lastly, the outcomes of preclinical and clinical studies involving gelatin-based DDSs are thoroughly discussed.

Comparison of polyvinyl alcohol particles and tris-acryl gelatin microspheres embolic agents used in uterine artery embolization: A systematic review and meta-analysis

Objective

To identify the preferred agent by comparing the therapeutic efficacy, degree of infarction, and side effects of polyvinyl alcohol particles (PVA) and tris-acryl gelatin embolization (TAGM) agents in uterine artery embolization.

Materials and Methods

We included available articles comparing PVA with TAGM embolization agents in the management of fibroids. The primary outcomes included the decrease in uterine volume (%), decrease in dominant tumor volume (%), fibroid infarction rate, complete infarction fibroid, complications, pain score after 24 h, procedure time (minutes), duration of hospital stay, fluoroscopy time (minutes), and the change in symptom severity score.

Results

Eight articles that met our inclusion criteria were included in this study. Our analysis yielded an overall superiority of PVA compared to TAGM regarding complete fibroid infarction rate at the first 24 h. However, TAGM was better than PVA concerning <90% infarction rate outcome. While both embolization techniques showed similar effects regarding the change in symptom severity score, the percentage of decrease in uterine volume, percentage of decrease of dominant tumor volume, 90-99% infarction rate, complete infarction rate when assessed after the first 24 h, pain score after the first 24 h, procedure time, fluoroscopy time, minor, and major complications.

Conclusion

Both PVA and TAGM embolization agents are effective and safe modalities in treating patients with fibroids, with no significant variation of both agents in most outcomes.

8Spheres conformal microspheres as embolic agents for symptomatic uterine leiomyoma therapy in uterine artery embolization (UAE): A prospective clinical trial

To evaluate the treatment efficacy of uterine artery embolization (UAE) using 8Spheres conformal microspheres for symptomatic uterine leiomyoma. In this prospective observational study, 15 patients were enrolled and underwent UAE by 2 experienced interventionalists from September 1, 2018, to September 1, 2019. All patients underwent menstrual bleeding scores, the symptom severity domain of the Uterine Fibroid Symptom and Quality of Life questionnaire scores (with lower scores indicating mild symptoms), pelvic contrast-enhanced magnetic resonance imaging, ovarian reserve tests (estradiol, prolactin, testosterone, follicle-stimulating, luteinizing, and progesterone), and other appropriate preoperative examinations within 1 week before UAE. During follow-up, menstrual bleeding scores and the symptom severity domain of the Uterine Fibroid Symptom and Quality of Life questionnaire scores were recorded at 1, 3, 6, and 12 months after UAE to assess the efficacy of symptomatic uterine leiomyoma. Pelvic contrast-enhanced magnetic resonance imaging was performed 6 months after the interventional therapy. Biomarkers of ovarian reserve function were reviewed at 6 and 12 months after treatment. All 15 patients successfully underwent UAE, without severe adverse effects. Six patients experienced abdominal pain, nausea, or vomiting, all of which improved significantly after symptomatic treatment. The menstrual bleeding scores declined from baseline (350.2 ± 61.9 mL) to (131.8 ± 42.7 mL), (140.3 ± 42.4 mL), (68.0 ± 22.8 mL), and (64.43 ± 17.0 mL) at 1, 3, 6, and 12 months, respectively. The symptom severity domain scores at 1, 3, 6, and 12 months postoperatively were significantly lower and statistically significant compared to the preoperative scores. The uterus and dominant leiomyoma volumes decreased from baseline (340.0 ± 35.8 cm3), (100.6 ± 24.3 cm3) to (266.6 ± 30.9 cm3), (56.1 ± 17.3 cm3) at 6 months after UAE, respectively. Moreover, the ratio of leiomyoma volumes and uterus decreased from (27.4 ± 4.5%) to (18.7 ± 3.9%). At the same time, there was no significant effect on changes in the biomarkers of ovarian reserve levels. Only the changes in testosterone levels before and after UAE were statistically significant (P < .05). 8Spheres conformal microspheres are ideal embolic agents for UAE therapy. This study showed that 8Spheres conformal microsphere embolization for symptomatic uterine leiomyoma could effectively relieve heavy menstrual bleeding, improve the symptom severity of patients, reduce the volume of leiomyoma, and have no significant effect on ovarian reserve function.

Long-Term Middle Meningeal Artery Caliber Reduction Following Trisacryl Gelatine Microsphere Embolization for the Treatment of Chronic Subdural Hematoma

PURPOSE

Middle meningeal artery (MMA) particle embolization is a promising treatment of chronic subdural hematomas (CSDH). The main purpose of this study is to measure MMA proximal caliber and assess the visibility of the two main MMA branches as a surrogate for long-term distal arterial patency following MMA CSDH embolization with trisacryl gelatine microspheres (TAGM).

METHODS

This is a single-center retrospective study. All patients having undergone MMA TAGM only embolization for CSDH treatment between 15 March 2018 and 6 June 2020 with an interpretable follow-up magnetic resonance imaging (MRI) examination and no confounding factors were included. Patients were compared with controls matched for age, sex and MRI machine. Two independent readers analyzed the MRI images.

RESULTS

In this study, 30 patients having undergone embolization procedures using TAGM of 36 MMAs were included. The follow-up MRI scans were performed after a mean delay of 14.8 ± 7.1 months (range 4.9-29.4 months). The mean diameter of TAGM embolized MMAs (1 mm; 95% confidence interval, CI 0.9-1.1) was significantly smaller than the mean diameter of paired control MMAs (1.3 mm; 95% CI 1.3-1.4) (p < 0.001). The mean proximal diameter of the embolized MMAs (0.9 mm; 95% CI 0.7-1.1) was significantly smaller than the mean diameter of the contralateral MMAs in the same patients (1.4 mm; 95% CI 1.3-1.6)(p < 0.001).

CONCLUSION

Long-term follow-up MRI demonstrated a significant impact of TAGM embolization on MMA proximal caliber as well as on the visibility of the two main MMA branches. All comparisons indicated that there was a probable lasting impact of embolization on the patency of distal branches.

An update on uterine artery embolization for uterine leiomyomata and adenomyosis of the uterus

Uterine artery embolization (UAE) is an established technique to treat benign diseases of the uterus such as uterine leiomyomata (fibroids) and adenomyosis. This article reviews the use of UAE in these conditions and summarizes the evidence regarding safety and efficacy of the technique based on the current literature.

Postinterventional Patient Comfort After Uterine Artery Embolization and Superior Hypogastric Nerve Block

PURPOSE

To evaluate the duration and effect of superior hypogastric nerve block (SHNB) with ropivacaine and clonidine on postinterventional pain levels and opioid requirements in patients undergoing uterine artery embolization.

MATERIALS AND METHODS

Postinterventional pain levels (numeric rating scale, NRS 0-10) and opioid doses were retrospectively analyzed in 53 patients undergoing transfemoral uterine artery embolization and intraprocedural superior hypogastric nerve block during 24 h. A mixture of 150 mg of ropivacaine and 150 µg of clonidine was used for the block.

RESULTS

Postinterventional pain averaged between 1.4 and 2.0 during the first 9 h, after which a small but significant increase was observed (NRS 1.7 ± 1.6 vs. NRS 2.6 ± 2.2, p < 0.001). 70% of patients did not exceed a tolerable pain threshold of NRS 4 during the first 9 h after the intervention. Thirty-three patients (62%) did not require any opioid medication. Mean iv morphine dose was 3.1 ± 4.7 mg, whereas 71% of opioid doses were administered after 9 h.

CONCLUSION

Superior hypogastric nerve block using a mixture of ropivacaine and clonidine provides good pain relief for 9 h after uterine artery embolization requiring only very low amounts of additional opioids.

Correlation Between Platelet-Lymphocyte Ratio and Neutrophil-Lymphocyte Ratio in Patients with Uterine Leiomyoma: A Cross-Sectional Study

The inflammatory reaction has been proven to be a key factor in the pathogenesis of uterine leiomyoma. The platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) are inexpensive and reliable inflammatory biomarkers. However, evidence of the relationship between PLR and NLR in patients with uterine leiomyoma is limited. This study aimed to explore the relationship between PLR and NLR in patients with incident uterine leiomyoma. This cross-sectional study included 763 patients with uterine leiomyoma who were first diagnosed in our hospital between January 2016 and December 2016. Patient characteristics were collected for univariate analysis, smooth curve fitting, and multivariate piecewise linear regression. Overall, 722 patients with an average age of 40.16 ± 5.99 years were included. The average PLR was 161.22 ± 65.33. Univariate analysis revealed a significant positive correlation between PLR and NLR (P < 0.0001). In addition, the non-linear relationship between the PLR and NLR was tested using smooth curve fitting after adjusting for potential confounding factors. The multivariate piecewise linear regression model showed that there was a significant positive correlation between PLR and NLR in both PLR <226.45 (β 0.01, 95% CI: 0.01, 0.01;P < 0.0001) and >226.45 (β 0.00, 95% CI: 0.00, 0.00; P=0.0026). In conclusion, PLR and NLR are positively correlated in patients with uterine leiomyoma. This result clarifies the promoting role of inflammation in the occurrence of uterine leiomyoma.

Nononcologic Embolization

The scope of conditions managed by embolization, which was initially used for the treatment of hemorrhage and vascular malformations, is constantly expanding. Apart from oncologic indications, embolization is used to treat a wide range of benign pathology, including uterine fibroids and benign prostatic hyperplasia. While various particulate embolic agents are successfully used for benign embolization, there is growing evidence that unique properties of these may result in different outcomes. This article reviews available evidence comparing various particles used for uterine fibroid embolization and prostate artery embolization. In addition, we provide an overview of periprocedural pharmacology and protocols facilitating same-day discharge for these interventions.