Embolic Agent Research Articles

Balancing Safety and Efficacy to Determine the Most Suitable Size of Imaging-Visible Embolic Microspheres for Bariatric Arterial Embolization in a Preclinical Model

ObjectivesTo identify the most suitable size of imaging-visible embolic agents with balanced safety and efficacy for bariatric arterial embolization (BAE) in a preclinical model. Materials and MethodsTwenty-seven pigs were divided into 3 cohorts. In Cohort I, 16 pigs were randomized to receive (n = 4 each) 40–100-μm microspheres in 1 or 2 fundal arteries, 70–340-μm radiopaque microspheres in 2 fundal arteries, or saline. In Cohort II, 3 pigs underwent renal arterial embolization with either custom-made 100–200-μm, 200–250-μm, 200–300-μm, or 300–400-μm radiopaque microspheres or Bead Block 300–500 μm with microsphere distribution assessed histologically. In Cohort III, 8 pigs underwent BAE in 2 fundal arteries with tailored 100–200-μm radiopaque microspheres (n = 5) or saline (n = 3). ResultsIn Cohort I, no significant differences in weight or ghrelin expression were observed between BAE and control animals. Moderate-to-severe gastric ulcerations were noted in all BAE animals. In Cohort II, renal embolization with 100–200-μm microspheres occluded vessels with a mean diameter of 139 μm ± 31, which is within the lower range of actual diameters of Bead Block 300–500 μm. In Cohort III, BAE with 100–200-μm microspheres resulted in significantly lower weight gain (42.3% ± 5.7% vs 51.6% ± 2.9% at 8 weeks; P = .04), fundal ghrelin cell density (16.1 ± 6.7 vs 23.6 ± 12.6; P = .045), and plasma ghrelin levels (1,709 pg/mL ± 172 vs 4,343 pg/mL ± 1,555; P < .01) compared with controls and superficial gastric ulcers (5/5). ConclusionsIn this preclinical model, tailored 100–200-μm microspheres were shown to be most suitable for BAE in terms of safety and efficacy.

Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs).

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

Application of temperature-sensitive liquid embolic agent loaded with oxaliplatin in the TACE procedure for rabbit VX2 gastric cancer.

As a promising drug delivery system, the temperature-sensitive liquid embolic agent (TempSLE) has yet to be reported in animal experiments in treating gastric cancer. We observed and compared computed tomography (CT) imaging changes, tumor volume, HE staining, and immunohistochemistry after transcatheter arterial chemoembolization (TACE) treatment in rabbit VX2 gastric cancer models to clarify the effectiveness of TempSLE loaded with oxaliplatin (TempSLE/Oxa) in treating gastric cancer. One milliliter TempSLE can be loaded with 20 mg oxaliplatin. The accumulative drug release rate at 30 min was 38.76%, and after 24 h, it reached more than 90%. CT examination 1 week after TACE revealed that the TempSLE/Oxa group presents unenhanced hypodense necrotic foci, the iodinated oil loaded with oxaliplatin (Ioil/Oxa) group presents shrinking tumors but still visible speckled foci of enhancement, and the normal saline (NS) group presents heterogeneous enhancement with larger tumors than before. In the postoperative autopsy of TACE, the tumor volumes of TempSLE/Oxa, Ioil/Oxa, and NS groups were 0.15 ± 0.06 cm3, 0.37 ± 0.11 cm3, and 1.19 ± 0.16 cm3, respectively, all of which were statistically different. The positive vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA) expression percentages in the TempSLE/Oxa, Ioil/Oxa, and NS groups were statistically different and lowest in the TempSLE/Oxa group. In conclusion, the TempSLE can load a high dose of oxaliplatin to meet the demand of clinical applications. TempSLE/Oxa could effectively inhibit tumor cell proliferation and angiogenesis. This study provides experimental evidence for the further clinical application of the TempSLE/Oxa.

Comparing transvenous coiling and transarterial embolization with Onyx/NBCA for cavernous sinus dural arteriovenous fistulas: A retrospective study in a single center

BackgroundEndovascular management is the gold standard for cavernous sinus dural arteriovenous fistulas (CS-dAVFs) in patients with signs of ophthalmoplegia, visual defects, or intolerable clinical symptoms. Although the efficacy of embolization has been confirmed, complications during post-endovascular management have not been compared in a more extensive CS-dAVFs case series. Therefore, we compared the effectiveness and peri-procedural complications of transvenous coiling with those of transarterial embolization (TAE) using liquid embolic agents. MethodsWe reviewed 71 patients with CS-dAVFs in one medical center from 2005/7 to 2016/7. We performed seventy-seven procedures on 71 patients, including six recurrent cases. We compared the efficacy and peri-procedural complications of transvenous coiling and TAE. ResultsThe complete occlusion rate for transvenous coiling was 79.2%, and that for TAE was 75.0%. Findings revealed (1) similar ophthalmoplegia complication rates (p = 0.744); (2) more frequent and permanent CN5 or CN7 neuropathy with liquid embolic agent use (p = 0.031 and 0.028, respectively); and (3) a higher risk of infarction or ICH (p = 0.002 and 0.028, respectively) in response to aggressive TAE. ConclusionTransvenous cavernous sinus coiling resulted in a similar occlusion rate and lower complication risk than transarterial Onyx/n-butyl cyanoacrylate (NBCA). We can access via an occluded inferior petrosal sinus (even contralateral), and direct transorbital puncture was a safe alternative. TAE with Onyx/NBCA was helpful in cases of oligo-feeders, but multidisciplinary treatment and multi-session TAE were usually needed for patients with multiple feeders and complex fistulas.

Drug-eluting beads bronchial arterial chemoembolization/bronchial arterial infusion chemotherapy with and without PD-1 blockade for advanced non-small cell lung cancer: a comparative single-center cohort study.

Drug-eluting beads bronchial arterial chemoembolization (DEB-BACE)/bronchial artery infusion chemotherapy (BAI) have been investigated as treatment options for advanced non-small cell lung cancer (NSCLC), especially for those patients who develop refractoriness to or are intolerant to systemic chemotherapy. This retrospective study aimed to compare the outcomes of DEB-BACE/BAI with and without programmed cell death protein 1 (PD-1) blockade for advanced NSCLC, and to investigate the effectiveness and safety of combination regimens. This retrospective cohort study included advanced NSCLC patients who were intolerant to or were resistant to systemic chemotherapy, radiotherapy, or molecular targeted therapy and underwent DEB-BACE/BAI between October 2016 and October 2021 in Beijing Hospital, National Center of Gerontology. A total of 84 advanced NSCLC patients (DEB-BACE/BAI + PD-1 blockade group: group A, n=27; DEB-BACE/BAI: group B, n=57) were enrolled finally. The embolic agent CalliSpheres (100-300, 300-500, or 500-700 µm) loaded with gemcitabine (800 mg) was administered during the DEB-BACE procedure. The adverse events (AEs) and outcomes were compared. Of these, the median progression-free survival (PFS) and overall survival (OS) were compared via Kaplan-Meier (KM) methods. Univariate and multivariate Cox regression analyses were used to investigate the predictors of PFS and OS. KM methods showed that group A had longer median PFS (12.0 vs. 3.0 months, P<0.001) and OS (27.0 vs. 8.0 months, P<0.001) than group B. The predictors of PFS for DEB-BACE/BAI included tumor diameter (P=0.013), immunotherapy (P<0.001), and DEB-BACE/BAI cycles (P=0.012), whereas the predictors of OS included tumor diameter (P=0.021), extrapulmonary metastases (P=0.041), immunotherapy (P<0.001), and DEB-BACE/BAI cycles (P=0.020). The incidence rates of overall AEs in groups A and B were 40.7% (11/27) and 36.8% (21/57), respectively, and no significant difference was found (P=0.731). Group A had an incidence rate of 11.1% for grade 3 immunotherapy-related AEs (irAEs). There were no incidences of ectopic embolization or spinal artery injury. Compared with DEB-BACE/BAI, PD-1 blockade plus DEB-BACE/BAI could improve the prognosis for advanced NSCLC despite the associated risk of grade 3 irAEs. The combination regimens are promising and safe approaches for advanced NSCLC.

Middle meningeal artery embolization without surgical evacuation for chronic subdural hematoma: a single-center experience of 209 cases.

Middle meningeal artery (MMA) embolization is a minimally invasive treatment option for new and recurrent chronic subdural hematomas (cSDH). To examine the safety and efficacy profile of MMA embolization without surgical evacuation for cSDH patients. A single-center retrospective study of patients with cSDHs treated by MMA embolization was undertaken. Patient demographics, hematoma characteristics, procedural details, and clinical and radiological outcomes were collected. The primary outcome was the need for retreatment, and the secondary outcomes were at least a 50% reduction in the maximum width of cSDH on the last CT imaging, complications, and an improvement in the modified Rankin scale (mRS) score. All results were presented as descriptive statistics. A total of 209 MMA embolizations were successfully performed on 144 patients. Polyvinyl alcohol particles were the primary embolization agent in all procedures. Of the total of 206 cSDH, the median maximum width at pre-intervention and last follow-up were 12 and 3 mm, respectively, and the median reduction percentage was 77.5%, with a >50% improvement observed in 72.8% at the last follow-up imaging. A total of 13.8% of patients needed retreatment for recurrent, refractory, or symptomatic hematomas after embolization. The mRS score improved in 71 (49.3%) patients. Of 144 patients, 4 (2.8%) experienced complications related to the procedure, and 12 (8.4%) died during follow-up due to causes unrelated to the MMA embolization procedures. This study supports the fact that MMA embolization without surgical evacuation is a safe and effective minimally invasive option for the treatment of cSDHs.

Hepatic Hypertrophy in Normal and Cirrhotic Livers Following Portal Vein Embolization: Comparative Assessment of 2 Different Embolic Regimens in a Large Animal Model

PurposeTo compare the mechanistic effects and hypertrophy outcomes using 2 different portal vein embolization (PVE) regimens in normal and cirrhotic livers in a large animal model. Methods and MaterialsThe Institutional Animal Care and Use Committee approved all experiments conducted in this study. Fourteen female Yorkshire pigs were separated into a cirrhotic group (CG, n = 7) and non-cirrhotic group (NCG, n = 7) and further subgrouped into those using microspheres and coils (MC, n = 3) or n-butyl cyanoacrylate (nBCA, n = 3) and their corresponding controls (each n = 1). A 3:1 ethiodized oil and ethanol mixture was administered intra-arterially in the CG to induce cirrhosis 4 weeks before PVE. Animals underwent baseline computed tomography (CT), PVE including pre-PVE and post-PVE pressure measurements, and CT imaging at 2 and 4 weeks after PVE. Immunofluorescence stainings for CD3, CD16, Ki-67, and caspase 3 were performed to assess immune cell infiltration, hepatocyte proliferation, and apoptosis. Statistical significance was tested using the Student’s t test. ResultsFour weeks after PVE, the percentage of future liver remnant (FLR%) increased by 18.8% (standard deviation [SD], 3.6%) vs 10.9% (SD, 0.95%; P < .01) in the NCG vs CG. The baseline percentage of standardized future liver remnant (sFLR%) for the controls were 41.6% for CG vs 43.6% for NCG. Based on the embolic agents used, the sFLR% two weeks after PVE was 58.4% (SD, 3.7%) and 52.2% (SD, 0.9%) (P < .01) for MC and 46.0% (SD, 2.2%) and 47.2% (SD, 0.4%) for nBCA in the NCG and CG, respectively. Meanwhile, the sFLR% 4 weeks after PVE was 60.5% (SD, 3.9%) and 54.9% (SD, 0.8%) (P < .01) and 60.4% (SD, 3.5%) and 54.2% (SD, 0.95%) (P < .01), respectively. Ki-67 signal intensity increased in the embolized lobe in both CG and NCG (P < .01). ConclusionsThis preclinical study demonstrated that MC could be the preferred embolic of choice compared to nBCA when a substantial and rapid FLR increase is needed for resection, in both cirrhotic and non-cirrhotic livers.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Review of Established and Emerging Embolic Agents

Middle meningeal artery embolization is an increasingly common procedure involved in the treatment of chronic subdural hematoma (cSDH) that can be an adjuvant intervention or an alternative to traditional medical or surgical therapies. Our review aims to summarize the mechanism, properties, and available clinical data for current and investigative embolic agents used for the treatment of cSDH. Pubmed, Scopus, and clinicaltrials.gov were searched for relevant studies and ongoing trials that examine middle meningeal artery embolization for cSDH. Particle agents, liquid embolic agents, and coil embolization are the common classes of embolic materials used in clinical practice and in ongoing trials. These embolic agents are not only mechanical occlusive materials; they have unique properties that address the angiogenic and proinflammatory mechanisms that propagate and sustain cSDH. Particle agents, such as polyvinyl alcohol and Embosphere (tris‐acryl gelatin microspheres) have been the most commonly used embolic agents given the long‐term evidence base regarding efficacy and established safety record. Liquid embolic agents such as cyanoacrylate glues and copolymer agents such as Onyx, Squid, and PHIL are increasingly common in clinical settings due to improved visualization on imaging, durable embolization, and better control of distal embolization. Coil embolization is used in conjunction with other embolic agents or as monotherapy in the setting of dangerous middle meningeal artery anastomoses. There are several ongoing randomized clinical trials and prospective cohort studies that will clarify the safety, efficacy, and use cases of particle agents, liquid embolic agents, and coil embolization for the treatment of cSDH.

Gonadal Veins Embolization for the Management of Pelvic Varices in Females

Background Solid evidence suggests that the treatment of choice for pelvic varicose veins is embolization. The embolization procedure is a simple technique with high success rates in all cases. Recently many series have been published over the past decade regarding the use of various embolic agents namely; coils, N2 Butyl Cyano Acrylate (Medical glue), sclerosing agents namely Polydecanol as well as combination of the previously mentioned agents with a technical success rate close to 100% and clinical success rate for symptoms control of more than 90%. Our study shows the technical and clinical success rates in Ain Shams University Hospitals with the use of all known embolic agents. Patients and Methods 18 patients were included in a prospective cohort study, Foam used as embolic substance in 7 of the included patients, coils used in 2 of them, combined foam and coils used in 8 patients and combined foam and glue used in one patient, follow up done using the Visual analogue scale (VAS) and trans-vaginal ultra-sound (TVUS) 2 weeks and 6months after the embolization. Results Catherization and embolization were successful in all patients. No major complications were observed during the procedure. With significant decline of the preprocedure VAS from 8.67±1.33 to 1.67±0.59 post-procedure revealing significant improvement in the degree of pain (p value= -3.740), technical success rate was 100%, two weeks after embolization TVUS in all the patients showed complete thrombosis of uteroovarian varices, 6 months after embolization 4 patients showed recurrence of the findings with presence of recanalized pelvic varices, with a recurrence rate of 22%, in all the recurrent cases, the embolic substance used was foam, among 7 patients were embolized by foam, 4 of them experienced recurrence 6 months after the procedure, so the recurrence rate using foam only is 57%, with no recurrence in the patients that were embolized using coils, combined foam and coil, or combined foam and glue. Conclusion Gonadal veins embolization in the management of pelvic congestion syndrome is a safe and effective procedure with no significant difference between the different used embolic substances as regard the technical success rate and pain improvement, however the recurrence rate is higher with foam only compared to no recurrence rate using combined embolic substances or coils.

Silk fibroin-based embolic agent for transhepatic artery embolization with multiple therapeutic potentials

BackgroundThe excellent physicochemical and biomedical properties make silk fibroin (SF) suitable for the development of biomedical materials. In this research, the silk fibroin microspheres (SFMS) were customized in two size ranges, and then carried gold nanoparticles or doxorubicin to evaluate the performance of drug loading and releasing. Embolization efficiency was evaluated in rat caudal artery and rabbit auricular artery, and the in vivo distribution of iodinated SFMS (125I/131I-SFMS) after embolization of rat hepatic artery was dynamically recorded by SPECT. Transhepatic arterial radioembolization (TARE) with 131I-SFMS was performed on rat models with liver cancer. The whole procedure of selective internal radiation was recorded with SPECT/CT, and the therapeutic effects were evaluated with 18 F-FDG PET/CT. Lastly, the enzymatic degradation was recorded and followed with the evaluation of particle size on clearance of sub-micron silk fibroin.ResultsSFMS were of smooth surface and regular shape with pervasive pores on the surface and inside the microspheres, and of suitable size range for TAE. Drug-loading functionalized SFMS with chemotherapy or radio-sensitization, and the enhanced therapeutic effects were proved in treating HUH-7 cells as lasting doxorubicin release or more lethal radiation. For artery embolization, SFMS effectively blocked the blood supply; when 131I-SFMS serving as the embolic agent, the good labeling stability and embolization performance guaranteed the favorable therapeutic effects in treating in situ liver tumor. At the 5th day post TARE with 37 MBq/3 mg 131I-SFMS per mice, tumor activity was quickly inhibited to a comparable glucose metabolism level with surrounding normal liver. More importantly, for the fragments of biodegradable SFMS, smaller sized SF (< 800 nm) metabolized in gastrointestinal tract and excreted by the urinary system, while SF (> 800 nm) entered the liver within 72 h for further metabolism.ConclusionThe feasibility of SFMS as degradable TARE agent for liver cancer was primarily proved as providing multiple therapeutic potentials.Graphical abstract

Long-Term Outcomes of Endovascular Embolization in a Vein of Galen Aneurysmal Malformation: A Single-Center Experience.

A vein of Galen aneurysmal malformation (VGAM) is a rare congenital cerebral vascular condition with a high mortality rate if left untreated. This study describes the long-term outcomes of patients with VGAM, who were treated with endovascular embolization. This retrospective analysis focused on VGAM patients who underwent one or more endovascular embolization sessions between January 2008 and December 2022. The study included newborns and children under 18 years. Data encompassed clinical and demographic characteristics, types of endovascular embolization, treatment complications, mortality rates, and long-term outcomes. Out of 22 VGAM cases, the majority were boys (86.36%), and the average age of the participants was 38 months, ranging from 25 days to 17 years. Endovascular embolization using liquid embolizing agents was the most common intervention (50%), and around 73% of patients underwent multiple sessions. Some patients underwent ventriculoperitoneal shunting (VPS) due to persistent hydrocephalus. In long-term outcomes, four patients (18.2%) showed developmental delays, and 16 patients (72.7%) had a positive outcome. Combining endovascular therapy with a comprehensive management strategy significantly reduces mortality rates and improves the possibility of normal neurological development in patients.

Endovascular treatment of traumatic penile arteriospongious fistula in a patient with erectile dysfunction: a case report and literature review

BackgroundAn arteriovenous fistula is an abnormal communication between an artery and a vein. Traumatic penile arteriospongious fistula is a rare complication and has been described as a cause of erectile dysfunction. Clinical evaluation of patients with erectile dysfunction after penile trauma includes a thorough history, physical examination, vascular assessment, and other complementary exams. Treatment consists of endovascular embolization, surgical ligation, or a combination of both techniques.Case presentationA 40-year-old man presented with erectile dysfunction that had persisted since suffering blunt trauma a few months ago. He reported problems with short duration of erection and insufficient penile tumescence. Due to high suspicion of an arteriovenous fistula, he was referred to angiography, which confirmed the diagnosis of an abnormal connection between the pudendal vessels. The patient was treated with the coil embolization technique and the symptoms were successfully resolved after endovascular treatment.ConclusionsThe appearance of a post-traumatic arteriospongious fistula is a rare complication with almost non-existent literature reported. Rapid development in endovascular techniques, in which we use embolic agents to block anomalous blood flow, has allowed safe, effective and less invasive alternative to surgery. Our case demonstrates that endovascular approach is a successful treatment for post-traumatic arteriospongious fistula since the symptoms were resolved, and normal erectile function was regained after the intervention.

Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

AbstractEndovascular embolization can selectively deploy embolic agents into diseased or injured blood vessels to complete the treatment. However, traditional embolic agents still face challenges, such as poor intravascular diffusivity, non‐biodegradable, unstable mechanical properties, radiolucency, and recanalization. Herein, we report a poly (lipoic acid‐tannic acid)/tromethamine/Galinstan (PLTTG) dimethyl sulfoxide (DMSO) solution‐derived hydrogel liquid embolic agent. By injecting PLTTG DMSO solution into body fluids, a PLTTG hydrogel can be formed in situ owing to the solvent exchange induced intra‐ and inter‐polymer hydrogen bonding and electrostatic interactions. Moreover, the gelation time and injection forces of the solution as well as the mechanical properties and embolic pressure of the obtained hydrogels can be adjusted by changing the concentration of PLTTG. The PLTTG hydrogel can effectively embolize the renal artery and femoral vein without recanalization and displacement in rabbit models. Furthermore, the hydrogel can embolize the ruptured femoral artery to arrest active bleeding. Owing to the advantages of the hydrogel, including adjustable gelation time, mechanical properties, viscosities, injection forces, and embolic pressure, as well as good biocompatibility and biodegradability, radiopacity, excellent embolization performance and intravascular diffusivity, easy usage, low cost, allowing it to be a potential embolic agent to treat multiple vascular diseases in clinic.

Embolisation Using Microvascular Plugs for Peripheral Applications: Technical Results and Mid-Term Outcomes.

The Micro Vascular Plug® (MVP, Medtronic) is a mechanical embolic agent available in small sizes that allows for distal embolisation. The objective of this retrospective observational single-centre study was to assess MVP embolisation procedures performed at a university hospital. The 33 patients who underwent MVP embolisation in 2021 were included (mean age, 64; 24 males and 9 females). The primary endpoint was technical success, which was defined as a full first-attempt occlusion with one or more MVPs, as documented on the end-of-procedure angiogram. In all patients, 51 MVPs were used overall, with other embolic agents in 23 of the 33 cases (usually coils and/or glue); 22 of the 33 procedures were emergent for bleeding and 11 were planned for other indications. Of the three technical failures, two were due to an angled target artery configuration precluding microcatheterisation and one to failure of the device to release from its wire. The technical success rate was thus 90.9%. No patient experienced MVP migration or other major complications. Five patients had recurrent clinical symptoms; in four cases, the cause was collateral development, and in one case, the cause was incomplete initial embolisation. No instances of recanalisation were documented during the short follow-up of 12 months, for a 100% secondary clinical success rate. At our tertiary-level centre, the MVP was both effective and safe for peripheral applications. Interventional radiologists should be conversant with the techniques and indications of MVP embolisation.

Preparation of a modified silk-based gel/microsphere composite as a potential hepatic arterial embolization agent

Transcatheter arterial chemoembolization (TACE) is an effective method for treating hepatocellular carcinoma (HCC). In this study, chitosan (CS), sodium glycerophosphate (GP), and sodium alginate (SA) were used as the main raw materials to develop clinically non-degradable embolization microspheres (Ms). Chitosan/sodium alginate embolization Ms. were generated using an emulsification cross-linking method. The Ms. were then uniformly dispersed in CS/GP temperature-sensitive gels to produce Gel/Ms. composite embolic agents. The results showed that Gel/Ms. had good morphology and a neatly arranged three-dimensional structure, and the Ms. dispersed in the Gel as evidenced by SEM. Furthermore, Gel/Ms. has good blood compatibility, with a hemolysis rate of ≤5 %. The cytotoxicity experiments have also proven its excellent cell compatibility. The degradation rate of Gel/Ms. was 58.869 ± 1.754 % within 4 weeks, indicating that Gel/Ms. had good degradation performance matching its drug release purpose. The Gel/Ms. adheres better at the target site than Ms. alone and releases the drug steadily over a long period, and the maximum release rate of Gel/Ms. within 8 h was 38.33 ± 1.528 %, and within 168 h was 81.266 ± 1.193 %. Overall, Gel/Ms. demonstrate better slow drug release, reduced sudden drug release, prolonged drug action time at the target site, and reduced toxic side effects on the body compared to Gel alone.

The prominent role of percutaneous transarterial embolization in the treatment of anterior abdominal wall hematomas: the results of three high volume tertiary referral centers

PurposePercutaneous transarterial embolization (PTE) represents a fast, safe and effective option for life-threatening anterior abdominal wall hematomas (AWHs) and those unresponsive to conservative treatment. Our study aims to assess cumulative results of safety, technical and clinical success of PTE performed in three high-volume tertiary referral centers and to evaluate the efficacy of the different embolic materials employed.Materials and methodsA consecutive series of 124 patients (72.8 ± 14.4 years) with AWHs of different etiology submitted to PTE were retrospectively collected and analyzed. Clinical success, defined as absence of recurrent bleeding within 96 h from PTE, was considered as primary endpoint. The results of the comparison of three groups based on embolic agent employed were also analyzed.ResultsSpontaneous AWHs accounted for 62.1%, iatrogenic for 21.8% and post-traumatic for 16.1% of cases. SARS-CoV-19 infection was present in 22.6% of patients. The most commonly embolized vessels were epigastric inferior artery (n = 127) and superior epigastric artery (n = 25). Technical and clinical success were 97.6 and 87.1%, respectively. Angiographic signs of active bleeding were detected in 85.5% of cases. Four (4%) major complications were reported. The comparison of the three groups of embolic agents (mechanical, particulate/fluid and combined) showed no statistically significant differences in terms of clinical success. SARS-CoV-2 infection was found to be an independent factor for recurrent bleeding and poor 30-day survival.ConclusionPTE performed with all the embolic agent employed in our centers is a safe and effective tool in the treatment of life-threatening anterior AWH of each origin.

Catheter-directed hemorrhoidal embolization for rectal bleeding due to hemorrhoids (Goligher grade I-III): prospective outcomes from a Spanish emborrhoid registry.

To evaluate the safety and efficacy of catheter-directed hemorrhoidal embolization (CDHE) by microcoil embolization for rectal bleeding due to hemorrhoids classified as Goligher grade I-III. Eighty patients (62.5% males) with a mean age of 48 ± 9 years were recruited prospectively. All patients had symptomatic bleeding hemorrhoids. All patients were classified according to Goligher classification: grade I (13.7%), grade II (71.1%), grade III (15%), and no grade IV were recruited in this study. In all cases, microcoils were used to embolize the superior rectal artery(SRA), and microspheres if recurrence of bleeding occurred. Follow-up evaluation (1, 3, 6, and 12 months) included clinical examination and anoscopy. A questionnaire was conducted to determine improvement regarding bleeding, quality of life before, and the degree of patient satisfaction of each participant. Technical success was achieved in 100% of the cases. Fifty-five (68.7%) participants had the absence of rectal bleeding after 12 months of embolization. VAS and QL improved 4 points and 1.5 respectively after embolization. A total of 25/80 (31.3%) had a recurrence in rectal bleeding. Seventeen (21.3%) patients underwent a second embolization, and four patients (5%) were treated with open hemorrhoidectomy. No major complications were observed. Sixteen participants had minor complications. Subjective post-treatment symptom and QL surveys showed significant differences from the baseline survey. Likewise, the degree of satisfaction in the telephone survey at 12 months revealed a high degree of patient satisfaction (8.3±1.1). The present study demonstrates that CDHE is a feasible, well-tolerated, ambulatory, anal sphincter-sparing procedure for the treatment of internal hemorrhoids. CDHE is a simple procedure, well tolerated and accepted by patients, that preserves the anal sphincter and presents few complications when metal devices or microspheres are used as embolic agents. • The technical success rate of CDHE, defined as the closure of all the SRA in their distal segment, was achieved 100% of all patients. However, a second embolization treatment was required since 21.25% of the patients experienced rectal bleeding. • Overall, CDHE's safety profile is acceptable. After the procedure and 1 year of follow-up, no significant complications were observed. • Encouraging clinical outcomes have demonstrated CDHE in individuals with hemorrhoids and mild prolapse Goligher grades I-III with persistent rectal bleeding.

Direct percutaneous puncture versus transarterial embolization for head and neck paragangliomas: A systematic review and meta-analysis.

Embolization of head and neck paragangliomas (HNPs) is a well-established treatment strategy and adjunctive therapy. However, the optimal mode of intervention, whether by direct percutaneous puncture (DP) or via transarterial embolization (TAE), remains unclear. The aim of this study was to complete a systematic literature review and meta-analysis to compare the safety and efficacy of DP versus TAE for HNP embolization. The Cochrane Library and MEDLINE databases were used to identify studies describing the clinical outcomes of either DP or TAE for HNP embolization. Outcome measures included: complete angiographic devascularization, major complications, and minor complications. Pooled rates were calculated for each variable which were then compared with meta-regression using a random effects model. Thirty-one retrospective studies met inclusion criteria, detailing 394 patients with 411 HNPs. Overall, DP was associated with a higher rate of complete devascularization (91.5%, 95% confidence interval [CI]: 85.6% to 97.4%; I2 = 0%) when compared to TAE technique (40.1%, CI: 27.2% to 58.9%; I2 = 93%). However, there was no difference regarding major complication rates between DP (6%, CI:1.3% to 10.8%; I2 = 0%) and TAE for HNP embolization (3.3%, CI: 1.4% to 5.3%; I2 = 0%) (p = 0.370), nor in minor complications between the techniques (p = 0.211). Subgroup analysis of TAE embolic agents revealed that particle embolics were associated with a significantly lower rate of major complications (2.5%; 0.4% to 4.6%; I2 = 0%) when compared to liquid embolics (10.6%, CI:4% to 17.3%; I2 = 48%; p = 0.022). A DP approach for HNP embolization results in a higher rate of complete devascularization and with a similar complication profile when compared to TAE. These findings also suggest that particle embolics are associated with fewer major complications compared to liquid embolics when TAE is utilized.

Selective Arterial Embolization of Pseudoaneurysms and Arteriovenous Fistulas after Partial Nephrectomy: Safety, Efficacy, and Mid-Term Outcomes.

The primary objective was to evaluate the clinical success rate after endovascular embolization of iatrogenic vascular lesions caused during partial nephrectomy. The secondary objective was to evaluate the technical success and to assess potential effects on renal function. We retrospectively included consecutive patients from our center who underwent selective embolization to treat iatrogenic renal arterial lesions induced during partial nephrectomy between June 2010 and June 2020. The technical and clinical success rates and renal outcomes were collected. We identified 25 patients with 47 pseudoaneurysms and nine arteriovenous fistulas. Among them, eight were treated by coils only, eight by liquid embolization agents only, and nine by both. The technical success rate was 96% after the first attempt and 100% after the second attempt. The median follow-up was 27.1 ± 24.3 months. Clinical success, defined as no need for further hemostatic surgery during follow-up, was also obtained in 96% and 100% of patients with one and two attempts, respectively. Renal function estimated by the modification of diet in renal disease equation did not change significantly despite a mean 13.8% ± 15.1% decrease in kidney functional volume estimated by angiography. No complications were attributable to the endovascular treatment. No significant difference was found across embolization agents; however, the subgroup sizes were small. Endovascular embolization is safe and effective for treating iatrogenic arterial lesions after partial nephrectomy: success rates are high, complications are infrequent, and renal function is maintained. Recommendations by interventional radiology societies are needed to standardize this treatment.

Endovascular and Percutaneous Embolotherapy for the Body and Extremity Arteriovenous Malformations.

Arteriovenous malformations (AVMs) consist of abnormal communications between the arteries and veins. They can involve any part of the body and extremity and grow in proportion to age and in response to hormonal influence or trauma. When symptoms progress from Schöbinger clinical stage II to III, transcatheter and/or direct puncture embolization are less-invasive and repeatable options for symptom palliation. The goal of embolization is to obliterate the AV shunt, and the choice of lesion access and embolic agents is based on the individual anatomy and flow. Embolization can be technically challenging due to complex vascular anatomy and morbidity risks. Therefore, a multidisciplinary management is essential for the diagnosis and therapeutic intervention of AVMs.