Emerging Polymer Materials in Trackable Endovascular Embolization and Cell Delivery: From Hype to Hope

Advanced targeted microsphere embolization for arteriovenous malformations: state-of-the-art and future directions

BACKGROUND

Arteriovenous malformations (AVMs) present a significant therapeutic challenge, as current treatment modalities frequently fail to achieve complete and rapid obliteration and are associated with substantial morbidity in both the short and long term. This underscores the critical need for innovative therapeutic strategies that enable efficient AVM obliteration while minimizing patient risk. The current review aims to comprehensively assess the role of ATME in AVM management, examining its clinical efficacy, associated risks and benefits, and the economic and ethical implications to provide valuable foundation for future studies and guiding development in treatment strategies for AVMs.

RESULTS

Advanced targeted microsphere embolization (ATME) has emerged as a promising therapeutic option, initially developed for the localized treatment of AVMs and unresectable tumors, including liver cancer. By providing targeted delivery, ATME offers potential advantages over conventional approaches in achieving effective local control.

CONCLUSIONS

ATME are safe and effective for vascular disease and cancer. Although evidence for microspheres in AVMs is scarce, results are promising. Future research could refine eligibility criteria, evaluate treatment techniques, and optimize ATME.

Drug-eluting beads transarterial chemoembolization vs conventional transarterial chemoembolization in the treatment of hepatocellular carcinoma in adult patients: a systematic review and update meta-analysis of observational studies

Study design

Systematic review and update meta-analysis.

Purpose

The present systematic review and meta-analysis were conducted to compare the efficacy and safety of the two approaches for HCC in adult patients (DEB-TACE vs cTACE).

Overview of literature

The TACE procedure is indicated for the treatment of HCC with intermediate (BCLC B) and early (BCLC A). Conflicting data obtained from earlier meta-analyses comparing DEB-TACE with cTACE prompted the updated meta-analysis.

Methods

The study included adult patients over the age of 18 with HCC. MEDLINE conducted a literature search using Pubmed and Google Scholar up to May 2024. The following parameters were evaluated: the effectiveness of the tumor response to treatment according to the mRECIST criteria (CR, PR, SD, PD), overall survival, progression-free survival, and complication rate. 32 retro- and prospective studies were analyzed.

Results

The study included 4,367 patients. The radiological response of the tumor in all four CR, PR, SD, and PD parameters in the DEB-TACE group showed the best response. The overall survival rate during the DEB-TACE procedure was higher by 3.54 months (p <0.00001), and progression-free survival (PFS) by 3.07 months (p <0.0001), respectively. The incidence of complications was comparable in both groups.

Conclusions

The results of the meta-analysis revealed clinically significant advantages of DEB-TACE in comparison with cTACE. Being comparable in terms of the frequency of complications, DEB-TACE demonstrated the best result in the radiological response of the tumor to the therapy, in terms of overall survival and progression-free survival.

Whey Protein-Based Hydrogel Microspheres for Endovascular Embolization

Transarterial embolization (TAE) is an image-guided, minimally invasive procedure for treating various clinical conditions by delivering embolic agents to occlude diseased arteries. Conventional embolic agents focus on vessel occlusion but can cause unintended long-term inflammation and ischemia in healthy tissues. Next-generation embolic agents must exhibit biocompatibility, biodegradability, and effective drug delivery, yet some degradable microspheres degrade too quickly, leading to the potential migration of fragments into distal blood vessels causing off-target embolization. This study presents the development of whey protein hydrogel microspheres (WPHMS) made from methacrylated whey protein, which successfully withstood terminal sterilization by autoclaving. In vitro characterization revealed that sterile WPHMS are suspensible in iodine-containing contrast agents, injectable through standard catheters and microcatheters, and can be temporarily compressed by at least 12.8% without permanent deformation. Cytocompatibility was confirmed using NIH/3T3 cells, while enzymatic degradation was assessed with proteinase K. Preliminary drug loading and release studies demonstrated the potential for doxorubicin hydrochloride (Dox-HCl) as a model drug. In vivo assessments in rabbit renal models showed that WPHMS successfully occluded the renal arteries in the acute study and remained in the renal arteries for up to 3 weeks in the chronic study, with signs of early degradation. Fibrous tissue anchored the degraded residues, minimizing the risk of migration. These findings indicate that WPHMS holds significant promise as endovascular embolization agents for minimally invasive therapies.

Preoperative Embolization of Glomus Tumors: Role, Effectiveness, and Complications

Purpose: Paragangliomas represent a surgical challenge due to their hypervascularization. The preoperative selective embolization of these tumors significantly decreases intraoperative blood loss. However, the literature on preoperative embolization in glomus tumors is limited. The aim of this study is to contribute additional evidence regarding the role of preoperative embolization, as well as to evaluate risks and complications in the treatment of glomus tumors. Methods: A retrospective evaluation of all the embolizations of glomus tumors from 2009 to 2023 was conducted. The primary outcome parameter was the rate of devascularization after embolization and the occurrence of significant perioperative hemorrhages. The secondary outcome was embolization-related complications. Results: Twenty-one embolizations in 20 patients were investigated in the study. In 43% of the cases more than 90% devascularization was achieved by embolization, while in the remaining cases, 80 to 90% devascularization was reached. In one case (5%), significant perioperative bleeding after embolization occurred. In one case (5%), a symptomatic complication occurred periinterventionally due to the brief dislocation of the coaxial and microcatheter into the internal carotid artery (ICA), which led to fresh punctate DWI lesions on the subsequent MRI. No patients developed nerve palsy following embolization. Conclusions: The preoperative embolization of glomus tumors can lead to significant tumor devascularization and a reduction in perioperative bleeding, with a low complication rate.

A First-in-Human Trial of a New Aqueous Ionic Liquid Embolic Material in Distal Embolization Applications

PURPOSE

A prospective, single-arm, open-label, multicenter, first-in-human, early feasibility study was completed to evaluate the safety and performance of the GPX Embolic Device (Fluidx, Salt Lake City, Utah), a novel liquid embolic agent, for use in the peripheral vasculature when deep distal embolization is desired.

MATERIALS AND METHODS

The early feasibility study evaluated the use of the device in the peripheral vasculature. Enrollment consisted of 17 patients with diverse embolization needs requiring deep distal vessel/vessel bed occlusion. Technical success, freedom from adverse events (AEs), and handling/performance characteristics were assessed with follow-up at 30 days.

RESULTS

The trial enrolled 17 patients requiring distal vascular penetration of the embolic agent, including 7 with renal angiomyolipomas, 4 with renal cell carcinomas (primary and secondary), 4 with portal veins needing embolization, 1 with pelvic sarcoma, and 1 with polycystic kidney. In all cases (100%), technical success was achieved with target regions fully occluded on the first angiogram (taken immediately after delivery). Furthermore, the material received high usability ratings, as measured by a postprocedural investigator questionnaire. Most patients (15/17, 88.2%) were free from device-related severe AEs, and there were no unanticipated AEs during the study. Each patient completed a 30-day follow-up evaluation, and sites remained fully occluded in each case where imaging was available (6 [35.3%] of 17 patients had follow-up imaging where all sites were deemed occluded [100%] with a mean of 30.2 days after the procedure).

CONCLUSIONS

The results of this first-in-human, early feasibility study demonstrate that the GPX Embolic Device may provide safe and effective embolization for arterial or venous applications where deep distal penetration is desired.