GEL THE NEC: a prospective registry evaluating the safety, ease of use, and efficacy of the HydroSoft coil as a finishing device

Remarkable shrinkage of a thrombosed giant aneurysm by stent-assisted jam-packed coil embolization

Background:

Large and giant aneurysms are known to involve intra-aneurysmal thrombosis and present a poor prognosis because of compression of the surrounding brain tissue with enlargement of the aneurysm. These aneurysms are difficult to cure by endovascular treatment due to involvement of the vasa vasorum in their pathology. We report this technical note to describe stent-assisted jam-packed coil embolization for the treatment of a giant thrombosed aneurysm.

Case Description:

A 62-year-old man presented with right homonymous hemianopsia, and magnetic resonance imaging (MRI) showed a giant thrombosed aneurysm with poor wall contrast enhancement, which indicates little involvement of the vasa vasorum, at the terminal part of the left internal carotid artery. To block blood flow into the aneurysmal dome, stent-assisted “jam-packed” coil embolization was performed. For this, a braided stent was shortened to enhance metal coverage ratio and tight aneurysmal coil packing was performed using a hydrogel coil. Our technique resulted in complete obliteration of the aneurysm, and MRI performed 1 year later showed remarkable shrinkage of the aneurysm dome.

Conclusion:

Stent-assisted jam-packed coil embolization technique might be effective in shrinking the dome of giant thrombosed aneurysms with poor wall contrast enhancement.

The Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): A Randomized Controlled Trial of the Second-Generation Hydrogel Coil

BACKGROUND

Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm.

OBJECTIVE

To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT).

METHODS

HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up.

RESULTS

A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm (P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms.

CONCLUSION

Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms.

VIDEO ABSTRACT

Histological and Transmission Electron Microscopy Results after Embolization with HydroSoft/HydroFrame Coils in Experimental Swine Aneurysm

Coiling and clipping are standard treatment strategies for cerebral aneurysms. Regardless of the strategy used, recanalization may affect the patient's prognosis. The aim of this study was to histologically and morphologically compare the tissue proliferation after coil embolization using bare platinum coils versus second-generation hydrogel coils (HydroSoft/HydroFrame; MicroVention, Inc., Aliso Viejo, CA, USA). Endothelial-like cell proliferation was seen in both groups at 2 weeks after surgery. Macroscopic findings showed a tighter layer at 4 weeks in the hydrogel coil group, and histological and immunohistochemical findings revealed endothelial cell proliferation. This layer became much thicker and tighter at 4 weeks after surgery. Aneurysms treated with second-generation hydrogel coils may be more stable and have a lower incidence of recanalization than those treated with bare platinum coils because of the tight endothelial layer proliferation.

TARGET® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis of Peri-Procedural and Long-Term Safety and Efficacy Results

Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.

Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A secondary analysis investigated the influence of the use of 100% 360-complex coils on clinical and angiographic outcomes.

Results: 148 patients with 157 aneurysms met the inclusion and exclusion criteria. 58 (39.2%) patients with ruptured and 90 (61.8%) with unruptured aneurysms were treated using TARGET 360°, helical Coils, or both. Median age was 58.3 (IQR 48.1–67.4), 73% female, and 71.6% were Caucasian. Median follow-up time was 5.9 (IQR 4.0–6.9) months. The majority were treated with TARGET 360-coils (63.7%), followed by mixed and helical coils only. Peri-procedural morbidity and mortality was seen in 2.7% of patients. A good outcome at discharge (mRS 0–2) was seen in 89.9% of the full cohort, and in 84.5 and 93.3% in the ruptured and unruptured patients, respectively. The median packing density was 28.8% (IQR 20.3–41.1). Long-term complete and near complete occlusion rate was seen in 90.4% of aneurysms and complete obliteration was seen in 66.2% of the aneurysms. No significant difference in clinical and angiographic outcomes were noted between the pure 360-complex coiling vs. mixed 360-complex/Helical coiling strategies. In a multivariate analysis, predictors for long-term aneurysm occlusion were aneurysm location, immediate occlusion grade, and aneurysm size. The long-term independent functional outcome was achieved in 128/135 (94.8%) patients and all-cause mortality was seen in 3/148 (2%) patients.

Conclusion: In the multicenter TARGET Registry, two-thirds of aneurysms achieved long-term complete occlusion and 91.0% achieved complete or near complete occlusion with excellent independent functional outcome.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT01748903

Prospective Registry of Embolization of Intracranial Aneurysms Using HydroSoft Coils: Results of the Japanese HydroSoft Registry

BACKGROUND

The effect of HydroSoft coils on the prevention of recanalization and thrombosis after embolization is unclear. We herein report the results of the single-armed prospective Japanese HydroSoft Registry.

METHODS

Aneurysms with a diameter of <10 mm that were treated with a ≥50% length of HydroSoft coils were registered. We evaluated the safety and recanalization rate and analyzed the factors related to their recanalization and thrombosis 1 year later.

RESULTS

In total, 122 aneurysms were registered. Their mean maximum diameter and neck length were 6.4 and 3.9 mm, respectively. The mean length of the HydroSoft coils was 84.3%. No intracranial hemorrhage occurred, but 2 patients developed minor ischemic strokes. Angiographic examination immediately after the procedure showed complete obliteration, neck remnant (NR), and body filling (BF) in 20 (16.4%), 32 (26.2%), and 67 (54.9%) cases, respectively. One-year follow-up angiography showed complete obliteration, NR, and BF in 68 (55.7%), 15 (12.3%), and 15 (12.3%) cases, respectively, and 5 aneurysms (4.1%) were recanalized (4 and 1 with BF and NR as their initial angiographic result, respectively). Another 11 aneurysms still showed BF, although their thrombosis was promoted. No significant factors related to recanalization were identified. A high volume embolization ratio and small neck were significantly associated with thrombosis 1 year after embolization with HydroSoft coils.

CONCLUSIONS

The safety and prevention of recanalization 1 year after the treatment appeared acceptable. The high volume embolization ratio associated with HydroSoft coils could induce progression of thrombosis for aneurysms characterized by NR and BF during the follow-up period.

Application of PHASES and ELAPSS scores to ruptured cerebral aneurysms: how many would have been conservatively managed?

BACKGROUND

We calculated the PHASES and ELAPSS scores for a large cohort of ruptured intracranial aneurysms (RIA) in order to determine whether these RIA would have been pre-emptively treated or closely followed-up should they have been detected prior to rupture.

METHODS

We retrospectively reviewed a consecutive series of RIA over a 20-year period. The primary outcome of this study was the PHASES score of each ruptured aneurysm included. Secondary outcomes were ELAPSS score and other risk factors for aneurysmal subarachnoid hemorrhage including aneurysm location, aneurysm size, aneurysm morphology, smoking and hypertension history, personal and family history of subarachnoid hemorrhage. Multiplicity of cerebral aneurysms was recorded. Descriptive statistics are reported.

RESULTS

700 consecutive ruptured aneurysms were included. Mean age at rupture was 56 (+/-13.5) years. Mean aneurysm size was 5.9 (+/-2.5) mm. Most common locations of ruptured aneurysms were the anterior cerebral/communicating artery (39%), posterior communicating artery (21%), middle cerebral artery (16%) and basilar terminus (7%). Mean PHASES score was 5.3 (+/-2.5) and 17% of the RIA had a PHASES score of 3 or less. Mean ELAPSS score was 13.89 (+/-7.05) and over half of the RIA included had a low risk of future growth.

CONCLUSIONS

A reasonable percentage of ruptured aneurysms have a low calculated PHASES score and these aneurysms may have been managed conservatively should they have presented incidentally prior to rupture. Most ruptured aneurysms also had a low ELAPSS score and were at low risk of future growth. The use PHASES score and ELAPSS score alone when making treatment decisions could result in many aneurysms being treated conservatively or undergoing remote surveillance despite rupture potential.

Angiographic and clinical outcomes of balloon remodeling versus unassisted coil embolization in the ruptured aneurysm cohort of the GEL THE NEC study

BACKGROUND AND PURPOSE

GEL THE NEC (GTN) was a multicenter prospective registry developed to assess the safety and efficacy of HydroSoft coils in treating intracranial aneurysms. We compared the angiographic and clinical outcomes of aneurysms treated with balloon assisted coil embolization (BACE) versus unassisted coil embolization (CE) in the ruptured aneurysm cohort.

MATERIALS AND METHODS

GTN was performed at 27 centers in five countries. Patients aged 21-90 years with a ruptured aneurysm 3-15 mm in size were eligible for enrollment. We analyzed demographics/comorbidities, aneurysm location, and geometry, including maximum diameter, neck size, and dome to neck ratio, immediate and long term angiographic outcomes (graded by an independent core laboratory using the modified Raymond Scale), and procedure related adverse events. Angiographic and clinical outcomes were studied using χ²and t tests.

RESULTS

Of the 599 patients in the GTN, 194 met the inclusion criteria. 84 were treated with BACE and 110 with CE. There were more prior smokers in the BACE group (p=0.01). The BACE group also had more vertebrobasilar aneurysms (p=0.006) and a larger mean neck size (p=0.02). More aneurysms were immediately completely occluded in the BACE group (p=0.02) Procedure- related major morbidity and mortality were no different between the techniques (p=0.4 and p=1, respectively).

CONCLUSIONS

In this prospective ruptured aneurysm cohort from the GTN, BACE resulted in greater occlusion rates compared with unassisted CE with similar morbi-mortality.