Endovascular treatment of intracranial aneurysms with bioactive Cerecyte coils: effects on treatment stability

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.

Long-Term Results and Follow-Up Examinations after Endovascular Embolization for Unruptured Cerebral Aneurysms

BACKGROUND AND PURPOSE

The appropriate period of follow-up examinations after endovascular embolization for cerebral aneurysms using time-of-flight MR angiography is not well-known. We retrospectively investigated long-term results after endovascular embolization for unruptured cerebral aneurysms and evaluated the periods from embolization to recanalization and retreatment.

MATERIALS AND METHODS

Between April 2006 and March 2011, one hundred forty-eight unruptured aneurysms were treated with endovascular coil embolization. Among them, we investigated 116 unruptured aneurysms, which were followed up for >5 years. Time-of-flight MR angiography was performed at 1 day, 3-6 months, 1 year after the procedure, and every year thereafter.

RESULTS

The mean follow-up period was 7.0 ± 1.4 years. Recanalization was observed in 19 (16.3%) aneurysms within 2 years. Among them, retreatment for recanalization was performed in 8 (6.8%) aneurysms. No recanalization was detected in any aneurysms that had been stable in the first 2 years after embolization. A larger maximum aneurysm size was significantly correlated with recanalization (P = .019).

CONCLUSIONS

Aneurysms in which recanalization was not observed within 2 years after endovascular coil embolization were stable during a mean follow-up of 7 years. This result may be helpful in considering the appropriate span or frequency of follow-up imaging for embolized cerebral aneurysms.

Mechanisms of endothelial cell attachment, proliferation, and differentiation on 4 types of platinum-based endovascular coils

OBJECTIVE

A subarachnoid hemorrhage is neurologically devastating, with 50% of patients becoming disabled or deceased. Advent of Guglielmi detachable coils in 1995 permitted endovascular treatment of cerebral aneurysms. Coiling is efficacious and safe, but durability needs improvement, as nearly 20% of patients require further invasive intervention secondary to aneurysm recurrence. The aim of this study is to develop an in vitro model of endothelial cell (EC) proliferation and differentiation on four types of platinum-based coils, using gene expression profiling to understand EC biology as they colonize and differentiate on coils.

METHODS

Human umbilical vein ECs were grown in vitro on platinum coil segments. Growth patterns were assessed as a function of coil type. Gene expression profiles for coil attached versus coil unattached ECs were determined using immunohistochemistry and gene array analysis.

RESULTS

ECs showed rapid, robust attachment to all coil types. Some detachment occurred within 24-48 hours. Significant growth of remaining attached cells occurred during the next week, creating a confluence on coils and within coil grooves. Similar growth curve results were obtained with human brain ECs on platinum-based coil surfaces. Differentiation markers in attached cells (α(1), α(2), β(1) integrins) were expressed on immunostaining, whereas microarray gene expression revealed 48 up-regulated and 68 down-regulated genes after 24-hour growth on coils. Major pathways affected as a function of time of colonization on coils and coil type included those involved in regulation of cell cycle and cell signaling.

CONCLUSIONS

We developed an in vitro model for evaluating endothelialization of platinum coils to optimize coil design to support robust EC colonization and differentiation.

Coil type does not affect angiographic follow-up outcomes of cerebral aneurysm coiling: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Previous studies varied in their conclusions about the superiority of second-generation coils compared with bare platinum. In this systematic review and meta-analysis, we assessed differences in reported unfavorable angiographic outcomes of cerebral aneurysms treated with coil embolization as a function of coil type.

MATERIALS AND METHODS

This systematic review covered 1999-2011 through the use of Ovid MEDLINE and EMBASE. Search terms were "subarachnoid hemorrhage," "intracranial aneurysms," "endovascular treatment," and "coiling." Inclusion criteria were studies reporting >50 aneurysms with imaging follow-up. We defined "unfavorable angiographic outcome" as either "recanalization," <90% occlusion, or "incomplete occlusion" at follow-up. Rates of unfavorable outcomes were pooled through the use of random effects models and compared across various coil types. Multivariate random effects meta-regression models were used to further explore the differences in outcomes related to coil type.

RESULTS

We included 82 studies, comprising 90 patient cohorts, among which, 65 (72%) used bare platinum coils, 8 (8.9%) used Matrix, 11 (12%) used HydroCoil, and 6 (6.7%) used Cerecyte. The overall unfavorable outcome rate was 19% (95% CI: 17%,21%). Unfavorable outcome rates were 20% (95% CI: 17%, 22%) for bare platinum coils, 23% (95% CI: 16%, 29%) for Matrix, 15% (95% CI: 9%, 21%) for HydroCoil, and 15% (95% CI: 7%, 23%) for Cerecyte, respectively. The difference in unfavorable outcome rates among the various coil types was not statistically significant after adjusting for baseline characteristics, including aneurysm size, rupture status, and follow-up duration.

CONCLUSIONS

The rate of unfavorable angiographic outcomes was not statistically different across the major approved coil types. The quality of the evidence, however, remains low because of high heterogeneity, small sample size, and potential publication bias.

Bioactive coils cause headache and fever after endovascular treatment of intracranial aneurysms

BACKGROUND

Based on our encounters with patients who have been treated for unruptured intracranial aneurysms by endovascular coil embolization using bioactive coils, we observed that such patients often present with headaches and fever.

OBJECTIVE

The purpose of this study was to evaluate the incidence of headache and fever after coil embolization using bioactive coils.

METHODS

A database of 92 intracranial unruptured aneurysm patients (88 patients who did not have chronic headaches or migraines before treatment) on whom coil embolization had been performed between July 2007 and October 2010 was retrospectively assessed. Forty-five aneurysms (43 patients) were treated using bioactive coils and the other aneurysms were treated using bare coils. We analyzed the incidence and duration of headache, temperature, C-reactive protein, and white blood cell count before and after coil embolization and compared the 2 groups.

RESULTS

Forty-one patients (46.6%) reported onset of headaches just after treatment. Headache incidences were significantly greater in the patients treated with bioactive coils (bioactive coil group: 62.8% [27/43] vs bare coil group: 31.1% [14/45], P = .003), and the duration of headaches was significantly longer in the bioactive coil group (bioactive coil group: 3.44 ± 1.22 days vs bare coil group: 2.40 ± 1.17 days, P = .027). Seventy-one patients (80.7%) had incidences of fever (over 37°C) after treatment (bioactive coil group: 83.7% [36/43] vs bare coil group: 77.8% [35/45], P = .663). The duration of fever was significantly longer in the bioactive coil group (bioactive coil group: 2.9 ± 1.4 days vs bare coil group: 1.9 ± 1.1 days, P = .0017), and temperatures at 1, 2, or 3 days after treatment were significantly higher in the bioactive coil group (respective temperatures at 1, 2, 3 days after treatment: bioactive coil group: 37.42 ± 0.49, 37.19 ± 0.45, 37.00 ± 0.49 vs bare coil group: 37.14 ± 0.38, 36.96 ± 0.41, 36.63 ± 0.51, P = .009, P = .0246, P = .0032). There were no significant differences in C-reactive protein level and white blood cell count 1 and 3 days after treatment between 2 groups.

CONCLUSIONS

Bioactive coils induce headache and fever after coil embolization for intracranial aneurysms due to the inflammatory effects of polyglycolic acid used to accelerate aneurysm fibrosis and neointimal formation.

Incidence of Seizures or Epilepsy After Clipping or Coiling of Ruptured and Unruptured Cerebral Aneurysms in the Nationwide Inpatient Sample Database: 2002-2007

BACKGROUND:

It is not clear whether treatment modality (clipping or coiling) affects the risk of seizures after treatment for cerebral aneurysms.

OBJECTIVE:

To determine whether there is an increased risk of seizures after clipping vs coiling.

METHODS:

Hospitalizations for clipping or coiling of ruptured and unruptured aneurysms were identified in the Nationwide Inpatient Sample Database for 2002 to 2007 by International Classification of Diseases 9th Revision codes for subarachnoid hemorrhage or unruptured cerebral aneurysm and codes for clipping or coiling. Clipping and coiling were compared for the combined primary endpoint of seizures or epilepsy. The analysis was adjusted for patient-specific and hospital-specific factors using generalized linear models with generalized estimated equations.

RESULTS:

There were 10 899 hospitalizations for ruptured aneurysms (6593 clipping, 4306 coiling), and 9686 hospitalizations for unruptured aneurysms (4483 clipping, 5203 coiling). For ruptured aneurysm patients, clipping had a similar incidence of seizures or epilepsy compared with coiling (10.7% vs 11.1%, respectively, adjusted odds ratio: 0.596; 95% confidence interval: 0.158-2.248; P = .445 after adjustment for patient-specific and hospital-specific factors). For unruptured aneurysm patients, clipping was associated with a significantly higher risk of seizures or epilepsy (9.2%) compared with coiling (6.2%) (adjusted odds ratio: 1.362; 95% confidence interval: 0.155-1.606; P &lt; .001 after adjustment for patient-specific and hospital-specific factors). Seizures or epilepsy were significantly associated with longer hospitalizations (P &lt; .01) and higher hospital charges (P &lt; .0001), except in coiled unruptured aneurysm patients, in which seizures or epilepsy were not significantly associated with hospital charges (P = .31).

CONCLUSION:

In unruptured cerebral aneurysm patients, clipping is associated with a higher risk of seizures or epilepsy.

Very late thrombosis of a pipeline embolization device construct: case report

BACKGROUND

The Pipeline embolization device (PED) is a new endoluminal construct designed to exclude aneurysms from the parent cerebrovasculature. We report the very late (>1 year) thrombosis of a PED construct placed for the treatment of a left vertebral aneurysm.

CLINICAL PRESENTATION

A patient with an occluded right vertebral artery and a large, fusiform intracranial left vertebral artery aneurysm was treated with PED and coil reconstruction. A durable, complete occlusion of the aneurysm was confirmed with control angiography at 1 year. The patient remained neurologically normal for 23 months until he experienced a transient visual disturbance followed weeks later by a minor brainstem stroke.

INTERVENTION

Imaging evaluation showed thrombosis of the PED construct with complete occlusion of the left vertebral artery. After this stroke, he was initially treated with dual antiplatelet therapy and was then converted to warfarin. The patient remained neurologically stable for 5 months until he experienced progressive basilar thrombosis that ultimately resulted in a fatal stroke.

CONCLUSION

The PED represents a promising new endovascular technology for the treatment of cerebral aneurysms; however, as an investigational device, long-term follow-up data are sparse at this point. The etiology of the very late thrombosis of the PED construct in this case remains unknown; however, this report underscores the need for a continued, careful systematic evaluation and close long-term follow-up of treated patients.

Histomorphology of thrombus organization, neointima formation, and foreign body response in retrieved human aneurysms treated with hydrocoil devices

Biological processes, such as thrombus organization, endothelialization, and foreign body response, that occur following embolization of intracranial aneurysms are poorly understood. We examined 13 human aneurysms (retrieved at autopsy 1-74 days postembolization) treated with hybrid hydrogel-platinum coil devices and platinum coils. The specimens were embedded in methyl methacrylate and ground sections were surface stained. Using light microscopy, thrombus organization in the sac, endothelialization of the neck, and foreign body response to the embolic devices were determined. The area percentages of the sac occupied by embolic devices and unorganized thrombus were quantified using image analysis. Thrombus organization increased over time, but was incomplete up to 74 days post-treatment. Neointima formation had started at 5 days upon dense fibrin depositions and progressed to form a new vessel wall at 74 days. The foreign body response to the hydrogel was characterized by mononuclear macrophages, while platinum coils were surrounded by multinuclear foreign body giant cells. Histometric aneurysm occlusion ranged from 89 to 100% and embolic devices occupied 31-64% of the aneurysm sac. These findings showed that the hydrogel-based devices occupied a large percentage of the aneurysm sac, provided a framework for thrombus organization to occur, and elicited less severe foreign body response than platinum coils.

Comparison of bioactive coils and bare platinum coils for treatment of intracranial aneurysms: a matched-pair analysis

Object

The primary goal of this matched-pair analysis was to evaluate the durability of the treatment results with Cerecyte coils in comparison with that of bare platinum coils in terms of angiographic occlusion rates at follow-up.

Methods

Eighty aneurysms treated with Cerecyte coils were included in this study to carry out a matched-pair analysis. Every aneurysm treated with Cerecyte coils was matched with an aneurysm treated with bare platinum coils. Matching of the aneurysms was done according to the aneurysm size, location, neck size, initial occlusion grade, and clinical presentation.

Results

The initial treatment results were similar in both groups as part of a matching protocol. Subgroup analysis revealed a significant difference in the durability of occlusion in aneurysms that showed Raymond Class I obliteration on follow-up angiograms (69 [86.2%] in the Cerecyte group vs 51 [63.8%] in the control group, p = 0.002). Further thrombosis to Raymond Class I occlusions was higher in the Cerecyte group (17 [77.3%] of 22 vs 8 [36.4%] of 22 aneurysms).

Conclusions

Cerecyte coils provide further thrombosis and more durable results than bare platinum coils following coil embolization of cerebral aneurysms.

Clinical experience with Matrix2 360 degrees coils in the treatment of 100 intracranial aneurysms

BACKGROUND

The M2-360 degrees is a recent class of aneurysm coil. This device combines the second generation of bioactive copolymer coating, which is intended to promote aneurysm fibrosis, with the "360 degrees " design, which is meant to improve uniformity and density of packing. This study evaluates the safety and angiographic stability of these devices.

METHODS

This was a retrospective review of 86 consecutive patients with 100 intracranial aneurysms that were treated using M2-360 degrees s. Follow-up was done at 6 and 12 months.

RESULTS

Seventy-eight aneurysms were coiled solely with M2-360 degrees s, and 22 aneurysms were treated with a combination of coils. In mixed-coil cases, the average percentage of coil volume consisting of M2-360 degrees coils was 78%. Procedure-related neurologic complications occurred in 6 patients (7%). Initial complete occlusion was obtained in 80 aneurysms. Of 76 aneurysms with 6-month angiographic follow-up, 4 (5.3%) revealed further occlusion, 54 (71.1%) were unchanged, and 18 (23.7%) showed recanalization. Of 38 aneurysms with 12-month follow-up, 1 (2.6%) revealed further occlusion, 23 (60.5%) were unchanged, and 14 (36.8%) showed recanalization. Six- and 12-month angiograms showed major recanalization (requiring further coiling) in 3.9% and 15.8% of cases, respectively.

CONCLUSIONS

The risk of complications with M2-360 degrees -treated aneurysms is comparable with reports of other coils, indicating that M2-360 degrees s are relatively safe. Although the initial occlusion rate is higher than that in other coiling series, recanalization rates were similar to those obtained with other coil designs. This study does not demonstrate an advantage with M2-360 degrees s.

Treatment of giant intracranial aneurysms

We report on report the clinical outcome obtained in treatment of giant intracranial aneurysms (GAs). Between 2005 and 2007, 51 patients with 51 GAs presented at our hospital. Twentynine were treated with primary parent vessel occlusion without distal bypass and ten underwent treatment preserving the parent artery. Twelve patients could not be treated endovascularly. Selective embolization (including two remodeling techniques and two stent-coil mbolizations) resulted in only one cure. Two patients died as a result of subarachnoid hemorrhage periprocedurely. Twenty-nine patients treated primarily with parent vessel occlusion and three patients treated with covered stent were considered cured after their treatments. Only one patient treated with parent vessel occlusion experienced ischemia during follow-up, which resulted in a mild neurological deficit. Of the twelve patients who could not be treated endovascularly, one succumbed to surgery, four died while being treated conservatively, and three were lost to follow-up. Parent artery occlusion, covered stent and coil occlusion provide effective protection against bleeding. In treatment of paraclinoid GAs of the internal carotid rtery, the use of a stent, and stent-assisted coil embolization may be a pitfall.

Coiling of intracranial aneurysms: a systematic review on initial occlusion and reopening and retreatment rates

BACKGROUND AND PURPOSE

The proportion of incompletely occluded aneurysms after coiling varies widely between studies. To assess overall outcome of coiling, we systematically reviewed the literature to determine initial occlusion, reopening, and retreatment rates of coiled aneurysms according to predefined criteria and subgroups.

METHODS

We searched PubMed and EMBASE (January 1999 to September 2008) for studies of >50 coiled aneurysms. Two reviewers independently extracted data. We grouped studies reporting on only ruptured aneurysms, posterior circulation aneurysms, and studies with large proportions of aneurysms >10 mm to assess possible determinants for incomplete occlusion, reopening, and retreatment.

RESULTS

Forty-six studies totalling 8161 coiled aneurysms met inclusion criteria. Immediately after coiling, 91.2% (95% CI, 90.6% to 91.9%) of the aneurysms were adequately occluded. Aneurysm reopening occurred in 20.8% (95% CI, 19.8% to 21.9%) and retreatment was performed in 10.3% (95% CI, 9.5% to 11.0%). Reopening rate was lower in studies reporting on ruptured aneurysms only compared with all studies (11.4% versus 20.8%; relative risk, 0.55; 95% CI, 0.47 to 0.64) and higher in studies focusing on posterior circulation aneurysms compared with studies with >85% anterior circulation aneurysms (22.5% versus 15.5%; relative risk, 1.5; 95% CI,1.2 to 1.7). Regression analysis showed higher retreatment rates with increasing proportion of aneurysms >10 mm (beta=0.252; 95% CI, 0.073 to 0.432). We could not find a relation between reopening and type of coils used.

CONCLUSIONS

At follow-up, one fifth of all coiled intracranial aneurysms shows reopening of which half is retreated. Possible risk factors for aneurysm reopening are location in the posterior circulation and size >10 mm. To confirm our findings, a meta-analysis on individual well-reported patient data is desirable.

Advances in Interventional Neuroradiology

In 2008 we witnessed a rapid advancement in stent technology, which is reflected in the high number of case reports, publications of case series, and randomized trials. Stents not only served for a combined intrasaccular and extrasaccular treatment of challenging aneurysms but also assisted the revascularization in acute and chronic ischemic conditions of the neurovascular system. Although a self-expanding nitinol semiopen cell stent is currently used for intracranial occlusive disease, a new retrievable closed-cell designed stent is widely used for aneurysms because of its easy delivery through a microcatheter in frequently tortuous head and neck as well as cerebrovascular circulation ( Figure 1 ). However, despite numerous publications in the field, the widespread acceptance of the use of stents to routinely treat carotid stenosis awaits the results of the multicenter randomized clinical trials that should be available in 2009. The role of interventional neuroradiology in the treatment of acute ischemic stroke continues to expand and excite interest.