Follow-up of cerebral aneurysm embolization with hydrogel embolic system: Systematic review and meta-analysis

Coils embolization use for coronary procedures: Basics, indications, and techniques

The use of coils is fundamental in interventional cardiology and can be lifesaving in selected settings. Coils are classified by their materials into bare metal, fiber coated, and hydrogel coated, or by the deliverability method into, pushable or detachable coils. Coils are delivered through microcatheters and the choice of coil size is important to ensure compatibility with the inner diameter of the delivery catheter, firstly to be able to deliver and secondly to prevent the coil from being stuck and damaged. Clinically, coils are used in either acute or in elective setting. The most important acute indication is typically the sealing coronary perforation. In the elective settings, coils can be used for the treatment of certain congenital cardiac abnormalities, aneurysms, fistulas or in the treatment of arterial side branch steal syndrome after CABG. Coils must always be delivered under fluoroscopy guidance. There are some associated complications with coils that can be acute or chronic, that nictitates regular followed-up. There is a need for education, training and regular workshops with hands-on to build the experience to use coils in situations that are infrequently encountered.

Efficacy and Safety of Different Bioactive Coils in Intracranial Aneurysm Interventional Treatment, a Systematic Review and Bayesian Network Meta-Analysis

Background: Bioactive coils have been used for nearly 20 years to improve aneurysm treatments. Previous studies are inadequate for comparing the efficacy and safety between different coils. The aim of this study was to investigate the safety and efficacy of different coils by comparing the percentage of people with different modified Raymond scale grades, re-rupture rates, and mortality in patients with intracranial aneurysms embolized with different coils. Method: Randomized controlled trials (RCTs) containing coils for aneurysm interventional treatment were collected from Web of Science, PubMed, and the Cochrane Library up to December 2021. Bayesian network meta-analysis with a randomized or fixed model was performed to compare the efficacy and safety among different bioactive coils and bare platinum coils. Results: We pooled 3362 patients from eight RCTs. No significant differences were found between coils in the proportion of patients with a three-grade classification assessed with the modified Raymond scale immediately after surgery. Hydrogel coils did not show a significant difference in the percentage of patients with a modified Raymond scale grade I postoperatively compared with bare platinum coils (OR, −0.1080; 95% CI, −0.4201–0.2423), but at follow-up, the percentage of patients with modified Raymond scale grade I was significantly higher with hydrogel coils than with bare platinum coils (OR, 0.4957; 95% CI, 0.0060–0.9442). There were no statistical differences between these four coils in terms of aneurysm rupture or re-rupture rate and mortality. Conclusion: Though there was no significant difference in the embolization effect between the several coils in the postoperative period, complete embolization was more likely to be achieved with hydrogel coils compared to bare platinum coils at follow-up. There were no significant differences in safety between the several coil materials.

Comparison between second generation HydroSoft coils and bare platinum coils for the treatment of large intracranial aneurysms

BACKGROUND

The development of HydroSoft coils (HSC) aims to reduce the high recurrence and retreatment rates observed in large brain aneurysms by improving primary brain aneurysm filling and thus occlusion efficacy. We compared clinical and angiographic effectiveness of bare platinum coils (BPC) versus second generation HSC for large intracranial aneurysms at our center.

METHODS

We included 61 large aneurysms between 2015 and 2018, 29 embolized primarily using HSC and 32 treated with BPC. The aneurysm occlusion rates were assessed after 3 and 12 months with an MRI scan and at 6 moths with a control digital subtraction angiography (DSA) using the Raymond-Roy occlusion classification (RROC). Clinical outcomes were evaluated using the modified ranking scale (mRS).

RESULTS

The observed immediate occlusion rate was slightly better in the BPC group, however, this group had a significant increase of progressive reperfusion at all imaging follow-up. Contrarily, the rate of complete occlusion increased significantly in the HSC group, starting from the 6 and 12-months follow-up. 7 aneurysms (11.4%) were re-treated (15.6% BPC and 6.9% HSC). The 6 and 12-months clinical data showed mRS score 0-1 in 96.7% of patients.

CONCLUSIONS

In our single-center experience, the second generation HydroSoft coils were shown to be safe and effective for endovascular treatment of large intracranial aneurysms with encouraging clinical and angiographic results, also for ruptured aneurysms. Even if the validity is limited due to our small cohort size, HSC showed a significantly lower rate of recurrence at mid-term follow-up when compared to BPC.

Embolization of Vascular Malformations via In Situ Photocrosslinking of Mechanically Reinforced Alginate Microfibers using an Optical-Fiber-Integrated Microfluidic Device

Embolization, which is a minimally invasive endovascular treatment, is a safe and effective procedure for treating vascular malformations (e.g., aneurysms). Hydrogel microfibers obtained via spatiotemporally controllable in situ photocrosslinking exhibit great potential for embolizing aneurysms. However, this process is challenging because of the absence of biocompatible and morphologically stable hydrogels and the difficulty in continuously spinning the microfibers via in situ photocrosslinking in extreme endovascular environments such as those involving a tortuous geometry and high absorbance. A double-crosslinked alginate-based hydrogel with tantalum nanopowder (DAT) that exploits the synergistic effect of covalent crosslinking by visible-light irradiation and ionic crosslinking using Ca²⁺ , which is present in the blood, is developed in this study. Furthermore, an effective strategy to design and produce an optical-fiber-integrated microfluidic device (OFI-MD) that can continuously spin hydrogel microfibers via in situ photocrosslinking in extreme endovascular environments is proposed. As an embolic material, DAT exhibits promising characteristics such as radiopacity, nondissociation, nonswelling, and constant mechanical strength in blood, in addition to excellent cyto- and hemo-compatibilities. Using OFI-MD to spin DAT microfibers continuously can help fill aneurysms safely, uniformly, and completely within the endovascular simulator without generating microscopic fragments, which demonstrates its potential as an effective embolization strategy.

Advances in Biomaterials and Technologies for Vascular Embolization

Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape-memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.

Hydrogel coils versus bare platinum coils for the endovascular treatment of intracranial aneurysms: a meta-analysis of randomized controlled trials

Background

Recent studies have shown conflicting results regarding the effect of hydrogel coils for treating intracranial aneurysm compared to bare platinum coils. We implemented a meta-analysis to assess the value of hydrogel coils in intracranial aneurysm treatment.

Methods

The MEDLINE, EMBASE, and Cochrane Library databases were searched for randomized controlled trials (RCTs) which had evaluated hydrogel coils versus bare platinum coils for intracranial aneurysms.

Results

We pooled 1526 patients from 4 RCTs with the mean follow-up time of more than 16 months. Hydrogel coils had reductions on mid-term recurrence (RR 0.78, 95% CI 0.65 to 0.94, P = 0.008) and residual aneurysm (RR 0.71, 95% CI 0.57 to 0.88, P = 0.002), but didn’t show any significant differences in other favorable outcomes such as functional recovery, mortality and so on. In the subgroup analysis, we found that second-generation hydrogel coils might exhibit potential impacts on increasing mid-term complete occlusion (RR 1.26, 95% CI 1.07 to 1.48, P = 0.005) and decreasing residual aneurysm neck. (RR 0.54, 95% CI 0.34 to 0.86, P = 0.010).

Conclusions

Hydrogel coils showed no significant efficacy on functional recovery but exhibited a lower rate of recurrences and residual aneurysms in patients with intracranial aneurysms.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1171-8) contains supplementary material, which is available to authorized users.

Synthesis and characterization of bacterial cellulose and gelatin-based hydrogel composites for drug-delivery systems

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Gelatin and bacterial cellulose based hydrogel composite was successfully prepared as drug delivery system.

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Utilization of glutaraldehyde was employed as crosslinking agent for hydrogel formation.

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Green hydrogel presented the excellent swelling ratio.

Bacterial cellulose and gelatin were successfully used to develop a hydrogel composite material. Hydrogel was synthesized by copolymerization between bacterial cellulose and gelatin. Scanning electron microscopy (SEM) images showed that the bacterial cellulose chain was uniform in size and shape. Glutaraldehyde was employed as a crosslinking agent. H-bonds were formed via the reaction between the amine and hydroxyl groups, which were the functional groups of the gelatin and bacterial cellulose, respectively. The hydrogel composite presented excellent properties in terms of its thermal stability, chemical resistance, and mechanical properties. Moreover, the swelling ratio of the hydrogel network, in water, was estimated to be 400–600%. Importantly, the hydrogel composite developed during this study is considered a good candidate for drug-delivery systems.

Evaluation of Endovascular Embolization of Cerebral Aneurysms by Hydrogel Coils

BACKGROUND

Hydrogel coils were created to improve the chances of an effective endovascular treatment of cerebral aneurysms. Achieving a high packing density of coils in the lumen of aneurysms can decrease the risk of recurrence. The aim of the present study is to report our initial experience on the effectiveness and safety of endovascular treatment of intracranial aneurysms with the use hydrogel coils.

MATERIAL/METHODS

Sixty patients (age: 28-72 years) (45 women, 15 men) were treated. In 18 patients (30%), subarachnoid hemorrhage was present. Digital subtraction angiography (DSA) of cerebral vessels with rotational scanning was performed. Image analysis was performed by the Philips Integris 3D RA device,which is a specialized workstation (Three-Dimensional Rotational Angiography). 3D reconstructions of cerebral arteries were created based on the data. Sixty-six cerebral aneurysms were embolized with hydrogel coils, which expand in contact with blood. reaching the maximum diameter in about 20 minutes. In 29 aneurysms (43.9%), the effect of the procedure was confirmed on a follow-up DSA after 8.0±4.1 months from the initial treatment.

RESULTS

A complete embolization was performed in 55 aneurysms (83.3%), and partial embolization in 11 aneurysms (16.7%). In 6 aneurysms (9.1%), re-embolization was necessary and it resulted in a complete embolization of 5 aneurysms. On a follow-up DSA, complete embolization was present in 25 aneurysms (86.2%), and partial embolization in 4 aneurysms (13.8%), respectively.

CONCLUSIONS

Endovascular embolization with hydrogel coils is an effective and safe treatment method for cerebral aneurysms, although it carries the risk of some complications.

Safety, immediate and mid-term results of the newer generation of hydrogel coils in the treatment of ruptured aneurysms: a multicenter study

OBJECTIVE

To assess the 'real-world' performance of the newer generation of hydrogel coils in ruptured aneurysms.

METHODS

A multicenter retrospective study was carried out of angiographic and clinical outcome data on consecutive patients with ruptured aneurysms treated with at least 70% of the newer generation of hydrogel coils. Demographics and data on clinical grade, smoking, use of statins, aneurysm size, location, technique used, packing density, immediate angiographic result, angiographic follow-up, rebleeding and clinical outcome were obtained and analyzed.

RESULTS

Eighty patients (54F; 26M) with an average age of 55.1 years were entered in the study. Forty-four presented good clinical grade (Hunt and Hess 1 or 2). Forty-two (52.5%) aneurysms were ≤5 mm. 56.7% of the aneurysms were treated with simple coil embolization and 39.6% with balloon-assisted coil. The packing density ranged from 9.3% to 92.6% (mean 48.5%). Immediate occlusion rates (Raymond-Roy Scale) were: complete occlusion (class I) in 57.5%, residual neck (class II) in 32.5% and residual aneurysm (class III) in 10%. Intraoperative rupture occurred in 3 cases (3.75%). Clinical follow-up, available in 73 patients, showed a good outcome (modified Rankin Scale 0-2) in 76.3%. Preliminary data on imaging follow-up were available in 54 patients (average 6.8 months) with complete occlusion in 77.8%, residual neck in 20.3% and residual aneurysm in 1.9%. There was no re-hemorrhage.

CONCLUSIONS

Our data show that the use of the newer-generation hydrogel coils in the treatment of ruptured aneurysms is feasible, safe and effective with high immediate and mid-term occlusion rates and low morbidity.