Randomised Controlled Trial of Particles Used in Uterine fibRoid Embolisation (PURE): Non-Spherical Polyvinyl Alcohol Versus Calibrated Microspheres

Purpose The PURE study is a randomised controlled trial (RCT) comparing the clinical and MRI outcomes of patients treated with non-spherical polyvinyl alcohol, ns-PVA (Contour PVA–Boston Scientific–355–500 & 500–700 microns) versus calibrated hydrogel microspheres (Embozene–Varian Inc–700 & 900 microns) for symptomatic uterine fibroids. Materials and Methods Prospective, ethically approved non-sponsored RCT in 84 patients in a single UK tertiary IR unit, ISRCTN registry trial number ISRCTN18191539 in 2013 and 2014. All patients with symptomatic fibroid disease were eligible. UAE followed a standardised protocol with UFS-QOL and contrast-enhanced MRI before and 6 months post UAE. Outcome measures included: (1) Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL). (2) Percentage total and dominant fibroid infarction. (3) Uterine and dominant fibroid volume reduction. (4) Volume of embolics. Results Sixty-three patients completed the QOL follow-up (33 ns-PVA vs 30 Embozenes), the groups were equivalent at baseline. Patients were followed up for 6 months following UAE. There was no significant difference in symptom scores or HR-QOL between ns-PVA and Embozenes, p = 0.67 and 0.21, respectively. 92.7% of patients treated with ns-PVA achieved > 90% dominant fibroid infarction versus 61.8% treated with Embozenes (p = 0.0016). 66% of patients treated with ns = PVA achieved > 90% total fibroid percentage infarction compared with 35% in the Embozene group (p = 0.011). The mean vials/syringes used were 5.2 with Embozenes versus 4.1 using PVA (p = 0.08). Conclusion The PURE study informs IRs regarding the efficacy of embolic agents in UAE, with superior fibroid infarction on MRI using ns-PVA versus Embozenes however no significant difference in clinical outcomes at 6 months after UAE.

Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistulas. Institutional Series, Systematic Review and Meta-Analysis

Purpose Endovascular treatment represents the first-line therapy for cavernous sinus dural arteriovenous fistulas (CS-dAVF); however, different approaches and embolic agents as well as occlusion rates, complications and clinical outcomes are reported among the published series. In this study we performed a comprehensive meta-analysis to investigate clinical and radiological outcomes after endovascular treatment of CS-dAVFs. Methods PubMed, Ovid Medline, Ovid EMBASE, Scopus, and Web of Science were screened for a comprehensive literature review from 1990 to 2020 regarding series of patients treated for CS-dAVF with endovascular approaches. We performed a proportion meta-analysis estimating the pooled rates of each outcome also including data of patients treated in our center. Results A total of 22 studies reporting 1043 patients and 1066 procedures were included. Chemosis was reported in 559 out of 1043 patients (45.9%), proptosis in 498 (41.5%), and ophthalmoplegia in 344 (23.5%). A transvenous embolization was preferred in 753 cases (63.2%) and coils were used in 712 out of 1066 procedures (57.8%). Overall, 85% (95% confidence interval, CI 69.5–96.1%) of patients had a complete resolution of symptoms, while complications occurred in 7.75% (95% CI 3.82–12.7%) with minimal permanent deficits (0.15%). The mortality rate was 1 out of 1043 patients (< 0.001). Conclusion A transvenous coiling is the most common endovascular approach for CS-dAVF, achieving a high percentage of radiological and clinical resolution and low complication rates. Transvenous approaches show less complications than transarterial ones, and coils appear safer than liquid embolic agents.

Magnetic Nanomaterials for Arterial Embolization and Hyperthermia of Parenchymal Organs Tumors: A Review

Magnetic hyperthermia (MH), proposed by R. K. Gilchrist in the middle of the last century as local hyperthermia, has nowadays become a recognized method for minimally invasive treatment of oncological diseases in combination with chemotherapy (ChT) and radiotherapy (RT). One type of MH is arterial embolization hyperthermia (AEH), intended for the presurgical treatment of primary inoperable and metastasized solid tumors of parenchymal organs. This method is based on hyperthermia after transcatheter arterial embolization of the tumor's vascular system with a mixture of magnetic particles and embolic agents. An important advantage of AEH lies in the double effect of embolotherapy, which blocks blood flow in the tumor, and MH, which eradicates cancer cells. Consequently, only the tumor undergoes thermal destruction. This review introduces the progress in the development of polymeric magnetic materials for application in AEH.

Liquid Embolics: A Guide to Currently Available and Pipeline Products

Over the last decade, several publications have reported the safety and efficacy of liquid embolics in a wide range of clinical indications. The expansion of clinical scenarios in which liquid embolics are utilized has been in part driven by some of the advantages these materials hold over other embolic agents. For instance, liquid embolics do not rely on the patient's ability to form clot and can be delivered more distally then coils at times. While several liquid embolics are commercially available, and in some cases have been for decades, there are limitations to these materials as well. The potential benefits of liquid embolics combined with the limitations of available materials have led to the ongoing development of several new agents. This review aims to familiarize the reader with both available liquid embolics and those that are relatively new or in development.

The Common but Complicated Tool: Review of Embolic Materials for the Interventional Radiologist

Embolization is an important and widely utilized technique in interventional radiology. There are a variety of different categories and individual products which can be utilized to perform embolization. Understanding the different classes of embolic agents, the important features of each of these classes including strengths and limitations, and the variation in individual products within the classes is critical for interventional radiologist to practice safely and effectively. This article reviews the different kinds of embolics and relays some of the pertinent physical and chemical properties of individual products which should be considered when determining which embolic to select for a given purpose.

Transcatheter Arterial Embolization in Acute Non-Variceal Gastrointestinal Bleedings: A Ten-Year Single-Center Experience in 91 Patients and Review of the Literature

Objective: To report the safety and efficacy of trans-arterial embolization (TAE) for upper gastrointestinal bleeding (UGIB) and lower gastrointestinal bleeding (LGIB) due to different etiologies in 91 patients for ten years. Methods: A retrospective analysis of GIB treated between January 2010 and December 2020 was performed. TAE was performed using different embolic agents (coils, particles, glue, gelatin sponge, and EVOH-based agents). Technical success, secondary technical success, clinical success, and complications were evaluated. Results: Technical success was achieved in 74/91 (81.32%) patients. Seventeen patients (18.68%) required re-intervention. Secondary technical success was achieved in all cases (100.0%). Clinical success was achieved in 81/91 patients (89.01%). No major complications were recorded; overall, minor complications occurred in 20/91 patients. Conclusions: TAE is a technically feasible and safe therapeutic option for patients with GIB from a known or blind anatomic source where endoscopic therapy has failed or is deemed unfeasible.

Non-Adhesive Liquid Embolic Agents in Extra-Cranial District: State of the Art and Review of the Literature

This review focuses on the use of “new” generation of non-adhesive liquid embolic agents (NALEA). In literature, non-adhesive liquid embolic agents have mainly been used in the cerebral district; however, multiple papers describing the use of NALEA in the extracranial district have been published recently and the aim of this review is to explore and analyze this field of application. There are a few NALEA liquids such as Onyx, Squid, and Phil currently available in the market, and they are used in the following applications: mainly arteriovenous malformations, endoleaks, visceral aneurysm or pseudoaneurysm, presurgical and hypervascular lesions embolization, and a niche of percutaneous approaches. These types of embolizing fluids can be used alone or in combination with other embolizing agents (such as coils or particles) so as to enhance its embolizing effect or improve its possible defects. The primary purpose of this paper is to evaluate the use of NALEAs, predominantly used alone, in elective embolization procedures. We did not attempt a meta-analysis due to the data heterogeneity, high number of case reports, and the lack of a consistent follow-up time period.

Relevant Biological Effects of Varicocele Embolization with N-Butyl Cyanoacrylate Glue on Semen Parameters in Infertile Men

Surgical treatment or varicocele embolization (VE) with sclerosing or mechanical embolic agents have been shown to improve the semen parameters of infertile men. The aim of this study was to evaluate the impact of VE using N-butyl cyanoacrylate (NBCA) glue on semen parameters in infertile men. From January 2014 to June 2018, infertile adult patients with stage 3 varicocele and an initial semen analysis showing at least one abnormal semen parameter, and who were successfully embolized with NBCA Glubran®2 glue, were retrospectively recruited. The availability of a second semen analysis after VE was mandatory for patient inclusion. The primary endpoint was the change in total sperm number (TSN) after VE. The other parameters of interest were progressive and total sperm motilities (Smot) at 1 h (H1), sperm vitality (SV) and morphology (SMor). One hundred and two patients were included. Eight patients presented null TSN before and after VE. Among the remaining 94 patients, a significant improvement in the median TSN after VE was shown (31.79 × 106/ejaculate [IQR:11.10–127.40 × 106/ejaculate] versus 62.24 × 106/ejaculate [IQR:17.90–201.60 × 106/ejaculate], p= 0.0295). Significant improvement in TSN was found for the 60 oligo- or azoospermic patients (p = 0.0007), whereas no significant change was found for the 42 patients with normal initial TSN (p = 0.49). Other parameters, such as progressive and total SMot, SV and SMor, also significantly improved after VE (p = 0.0003, 0.0013, 0.0356 and 0.007, respectively). The use of NBCA glue as an embolic agent for VE in infertile men with stage 3 varicocele significantly improves the semen parameters.