Endovascular Embolization Of Intracranial Aneurysms Research Articles

Initial Experience with a New Self-Expanding Open-Cell Stent System with Antithrombotic Hydrophilic Polymer Coating (pEGASUS Stent) in the Treatment of Wide-Necked Intracranial Aneurysms.

We report our initial experience with endovascular embolization of intracranial aneurysms using this new self-expanding open-cell stent system (pEGASUS stent system) with the antithrombogenic hydrophilic polymer coating. We retrospectively reviewed all patients treated with stent-assisted coiling or the Woven EndoBridge device using the pEGASUS stent system between September 2022 and June 2023. Demographic, clinical, and angiographic data were analyzed as well as short-term follow-up, including procedural complication rates and aneurysmal occlusion rates using the Raymond-Roy occlusion classification (RROC). Twelve patients with 12 wide-necked intracranial aneurysms were treated with the pEGASUS stent system, including 2 acutely ruptured aneurysms embolized in an emergency setting. The treated aneurysms were located at the anterior communicating artery (25.0%), the basilar artery (50.0%), the middle cerebral artery (16.7%), and the internal carotid artery (8.3%). All stents were deployed successfully. Immediate complete aneurysmal occlusion (RROC class I) was achieved in 83.3% (10/12) and near-complete occlusion (RROC II) in 16.7% (2/12). No periprocedural complications occurred in patients treated in the elective setting. A single case of intraoperative in-stent thrombus formation occurred during the treatment of an acutely ruptured basilar aneurysm and was resolved with intravenous Tirofiban. No other periprocedural complications occurred. Eleven out of 12 patients were available for follow up (mean 7.4 months). Complete aneurysmal occlusion without in-stent stenosis (ISS) was seen in 10 patients (90.9%). One patient (9.1%) showed aneurysmal reperfusion (RROC IIIb) with asymptomatic moderate ISS. Our initial results demonstrate that the pEGASUS stent system appears to be a safe and effective device for stent assisted embolization of wide-necked intracranial aneurysms. More data is necessary to evaluate long-term follow-up.

Single Component Polymers, Polymer Blends, and Polymer Composites for Interventional Endovascular Embolization of Intracranial Aneurysms.

Intracranial aneurysm is the abnormal focal dilation in brain arteries. When untreated, it can enlarge to rupture points and account for subarachnoid hemorrhage cases. Intracranial aneurysms can be treated by blocking the flow of blood to the aneurysm sac with clipping of the aneurysm neck or endovascular embolization with embolics to promote the formation of the thrombus. Coils or an embolic device are inserted endovascularly into the aneurysm via a micro-catheter to fill the aneurysm. Many embolization materials have been developed. An embolization coil made of soft and thin platinum wire called the "Guglielmi detachable coil" (GDC) enables safer treatment for brain aneurysms. However, patients may experience aneurysm recurrence because of incomplete coil filling or compaction over time. Unsatisfactory recanalization rates and incomplete occlusion are the drawbacks of endovascular embolization. So, the fabrication of new medical devices with less invasive surgical techniques is mandatory to enhance the long-term therapeutic performance of existing endovascular procedures. For this aim, the current article reviews polymeric materials including blends and composites employed for embolization of intracranial aneurysms. Polymeric materials used in embolic agents, their advantages and challenges, results of the strategies used to overcome treatment, and results of clinical experiences are summarized and discussed.

Shape Memory Polymer-Based Endovascular Devices: Design Criteria and Future Perspective

Devices for the endovascular embolization of intracranial aneurysms (ICAs) face limitations related to suboptimal rates of lasting complete occlusion. Incomplete occlusion frequently leads to residual flow within the aneurysm sac, which subsequently causes aneurysm recurrence needing surgical re-operation. An emerging method for improving the rates of complete occlusion both immediately after implant and in the longer run can be the fabrication of patient-specific materials for ICA embolization. Shape memory polymers (SMPs) are materials with great potential for this application, owing to their versatile and tunable shape memory properties that can be tailored to a patient’s aneurysm geometry and flow condition. In this review, we first present the state-of-the-art endovascular devices and their limitations in providing long-term complete occlusion. Then, we present methods for the fabrication of SMPs, the most prominent actuation methods for their shape recovery, and the potential of SMPs as endovascular devices for ICA embolization. Although SMPs are a promising alternative for the patient-specific treatment of ICAs, there are still limitations that need to be addressed for their application as an effective coil-free endovascular therapy.

Abstract 1122‐000164: Peri‐embolization Use of Stent Retrievers as a Rescue Tool in Patients with Subarachnoid Hemorrhage

Introduction : Coil migration after endovascular embolization of intracranial aneurysms is one of the periprocedural complications in 2–6% of patients. Stent retriever use is well‐established in treatment of ischemic stroke but has not been well established to address coil retrieval as rescue therapy. We describe three cases with successful removal of migrated coils using stent retrievers. Methods : A retrospective review at a single center university hospital was performed for all Neuro‐endovascular case log from December 2018 to November 2020. Cases of coil migration were reviewed and coil retraction with Stent Retriever with successful coil mass extraction was considered an endpoint. Number of attempts, types of stent retrievers used and time taken for extraction were noted. Results : Case 1: 56‐year‐old female presented with ruptured tri‐lobed 4 × 3 mm Anterior communicating artery aneurysm. Hunt and Hess (H&H) Grade 2. Modified Fisher scale (MFS) 4. Underwent primary coil embolization. Two 2mmx2cm Galaxy Orbit coils were deployed within aneurysm. During deployment of third coil the first two coils displaced out of the aneurysm migrating into left A2 segment. Stryker’s Trevo 3 × 20 mm stent retriever was used for retrieval of coils however they dislodged at the left internal carotid artery (ICA) terminus and migrated distally into the left middle cerebral artery (MCA) M2 superior division. Subsequently, Medtronic’s Solitaire 4 × 40 mm stent retriever was successfully deployed retrieving the migrated coils with full recanalization. Case 2: 64‐year‐old female presented with ruptured 3 × 5.3 mm right posterior communicating artery (Pcom) aneurysm. H&H 5 and MFS 4. Underwent primary coil embolization with placement of Galaxy Orbit 2.5mmx3.5cm coil. On follow up run, coil mass had migrated into the origin of right fetal Pcom. Migrated coil was successfully retrieved using Stryker’s 4 × 40 mm stent retriever with complete recanalization. Case 3: 65‐year‐old female with presented ruptured 8.5 × 6.8 mm right supraclinoid ICA irregular aneurysm. H&H Grade 1. MFS 3. Underwent primary coil embolization with one Galaxy coil (5mm x 10cm) with plan for future flow diversion. Two weeks later, patient experienced acute neurological worsening with new left sided hemiparesis and right gaze deviation. Imaging revealed acute occlusion of right middle cerebral artery M1 segment occlusion with thrombosed migrated coil. Patient underwent retrieval of the coil and superimposed thrombus utilizing Stryker’s Trevo (4*30 mm) stent retriever with resultant full recanalization. Conclusions : These cases demonstrate successful endovascular mechanical removal of migrated coils using stent retrievers. They add to the limited experience of stent retrievers utilization as effective tools for dealing with such complications.

Control Release and Diffusion-Reaction Kinetics of Genipin-Eluting Fibers Using an in Vitro Aneurysm Flow Model.

The minimally invasive treatment of intracranial aneurysms by endovascular coiling is attractive yet faces challenges related to the degradation of fibrin clots in the aneurysm sac over time. Fibrin gels cross-linked with genipin exhibit enhanced mechanical and chemical stability, but there are many unknowns related to best practices for delivery from endovascular devices and subsequent integration of cross-linkers with the nascent clot. Here, we describe the in vitro characterization of genipin-eluting polymer fibers prepared by coextrusion with poly(ethylene-co-vinyl acetate). Genipin incorporation and release from these fibers are characterized by various gravimetric and spectroscopic techniques. Genipin release adheres to Higuchi kinetics with Higuchi constants varying between (2.44 ± 0.83) × 10-7 and (8.41 ± 0.82) × 10-7 mol·h-0.5 depending on genipin loading and vinyl acetate concentration in the polymer matrix. The diffusion-reaction kinetics of genipin released from polymeric fibers within fibrin hydrogels was investigated using an in vitro aneurysm flow model. Spatiotemporal maps of genipin cross-linking density in fibrin gels produced by absorbance measurements suggest that genipin cross-link concentrations up to 9,993.87 ± 909.01 μM can be achieved. This work describes relevant diffusion-reaction parameters of genipin in fibrin gels and establishes the viability of genipin-eluting fibers as a platform for improving endovascular embolization of intracranial aneurysms.

Evaluation of the Efficiency of Ultra-Early Endovascular Embolization of Cerebral Aneurisms in Subarachnoid Hemorrage

The review discusses the effectiveness of endovascular embolization of intracranial aneurysms in subarachnoid hemorrhage (SAH) in the first 24 hours after rupture. The need for this study is dictated by the medical and social significance of the disease, in particular, the high degree of mortality and disability in SAH of aneurysmal origin, including in young patients. The choice of embolization timing for SAH remains a subject of discussion in the professional community since the introduction of the technique into clinical practice. Performing embolization on the first day after the onset of the disease, the so-called “ultra-early embolization” has a potentially positive effect on the outcomes of SAH, reducing the number of deaths and increasing the number of favorable outcomes. The main advantage of this tactic is to prevent repeated rupture of the aneurysm, the probability of which is highest in the first day of the disease, as well as the possibility of starting intensive therapy for SAH at the earliest possible time.

Endovascular treatment of vertebral and basilar artery aneurysms with low-profile visualized intraluminal support device

BackgroundThe Low-profile Visualized Intraluminal Support (LVIS) device is a self-expanding, nitinol, single-braid, closed-cell device that was recently developed for endovascular embolization of intracranial aneurysms. However, current knowledge regarding the use of LVIS devices to treat vertebral and basilar artery aneurysms is limited. We aimed to evaluate the feasibility, efficacy, and safety of the LVIS device for treating vertebral and basilar artery aneurysms.MethodsBetween January 2015 and December 2017, patients with vertebral and basilar artery aneurysms treated using LVIS stents were enrolled in this study. We analyzed patients’ demographic, clinical and aneurysmal characteristics, procedural details, complications, and angiographic and clinical follow-up results.ResultsWe identified 63 patients with 64 vertebral and basilar artery aneurysms who underwent treatment with (n = 59) or without (n = 5) LVIS stenting, including 10 patients with ruptured aneurysms. Forty-one aneurysms were located at the vertebral artery, and 23 at the basilar artery. Intraprocedural-related complications developed in three (4.8%) patients, while none of these patients developed morbidities or died during follow-up. Three patients developed post-procedural complications (4.8%). Two patients experienced ischemic events immediately post-procedure. A minor permanent morbidity developed in one of the two patients (1.6%). The mortality rate was 1.6%, for that the patient died of brainstem hemorrhage after 1 month of follow-up. At a mean follow-up of 12.5 months, 39/43 (90.7%) patients had stable or improved aneurysms, and four (9.3%) had recanalized.ConclusionsLVIS device of vertebral and basilar artery aneurysms may be an acceptable safety profile and may represent a reasonable treatment option in the short-term. Long-term and larger cohort studies are necessary to validate our results.

Treatment of the acute thromboembolic event during endovascular embolization of intracranial aneurysm

ObjectiveThe study aimed to discuss the treatment of acute thromboembolic event (TE) during endovascular embolization of intracranial aneurysms. MethodsBetween April 2013 and April 2019, 158 patients with 167 intracranial aneurysms were treated with endovascular embolization in our hospital, in which 9 cases of acute TEs occurred during the embolization procedures. The clinical data, radiological findings and treatments of the 9 patients were reviewed and analyzed. ResultsThe TEs occurred at the aneurysmal neck in 3 patients, at distal part of the parent artery in 3, in the stent in 2, and at the proximal part of the parent artery in 1. Intra-arterial (IA) infusion of tirofiban were performed in 6 patients, mechanical thromboectomy (MT) with a stent in 2 patients, and combined use of the two methods in 1 patients. According to the modified Thrombolysis In Cerebral Infarction (mTICI) score, 7 patients had recanalization of 2b/3a, 1 patients had recanalization of 1, and 1 patients had recanalization of 0. At discharge, the mRS score was 0 in 3 patients, 1 in 3 patients, and 2, 3, 4 in 1 patient each. 6 months after the endovascular treatment, the mRS score was 0 in 5 patients, 1 in 2 patients, and 3 in 1 patient. ConclusionsIA tirofiban and MT are effective remedies for the acute TE during endovascular embolization of intracranial aneurysm, reasonable selection of which may improve the prognosis of patients.

Synthesis and characterization of bio-compatible shape memory polymers with potential applications to endovascular embolization of intracranial aneurysms

Intracranial aneurysms (ICAs) are focal dilations in the brain's arteries. When left untreated, ICAs can grow to the point of rupture, accounting for 50–80% of subarachnoid hemorrhage cases. Current treatments include surgical clipping and endovascular coil embolization to block circulation into the aneurysmal space for preventing aneurysm rupture. As for endovascular embolization, patients could experience aneurysm recurrence due to an incomplete coil filling or compaction over time. The use of shape memory polymers (SMPs) in place of conventional platinum coils could provide more control and predictability for mitigating these complications. This study was focused on characterization of an aliphatic urethane-based SMP to evaluate its potential as a novel biomaterial for endovascular embolization. Twelve compositions of the SMP were synthesized and their thermomechanical properties together with the shape recovery behavior were comprehensively investigated. Our results showed that the SMPs experienced a significant decrease in storage and loss moduli as heated above their glass transition temperatures (32.3–83.2 °C), and that all SMPs were thermally stable up to 265 °C. Moreover, the SMPs exhibited both composition-dependent stress relaxation and a decrease in elastic modulus during cyclic loading. The shape recovery time was less than 11 s for all SMP compositions, which is sufficiently short for shape changing during embolization procedures. Several candidate compositions were identified, which possess a glass transition temperature above body temperature (37 °C) and below the threshold of causing tissue damage (45 °C). They also exhibit high material strength and low stress relaxation behavior, suggesting their potential applicability to endovascular embolization of ICAs.

Glycoprotein IIb/IIIa Inhibitors in Prevention and Rescue Treatment of Thromboembolic Complications During Endovascular Embolization of Intracranial Aneurysms

Thromboembolic complications remain a major risk of endovascular neurosurgery during the treatment of intracranial aneurysms, despite the use of therapeutic heparinization and oral antiplatelet therapy when indicated. Glycoprotein (GP) IIb/IIIa inhibitors target a nonredundant pathway of platelet aggregation following adhesion and activation. Initially established and implemented in the cardiovascular arena, this drug class has provided a new tool in the neurovascular armamentarium as well. Numerous case reports, case series, and retrospective reviews have evaluated the safety and efficacy of abciximab, eptifibatide, and tirofiban in the treatment of acute thromboembolic complications during the endovascular treatment of intracranial aneurysms. The use of this drug class has also been found to be beneficial as a prophylactic agent, providing ischemia protection during the placement of intracranial stents, flow diverters, and thrombogenic coils in the setting of subarachnoid hemorrhage and during elective aneurysmal embolization. While the current published literature clearly establishes efficacy and safety of GP IIb/IIIa inhibitors in the prevention of thromboembolic complications, there does not yet exist an established protocol for their administration in endovascular neurosurgery. This review provides a comprehensive evaluation of the current published literature pertaining to the use of all available GP IIb/IIIa inhibitors for thromboembolic complications, providing recommendations for dosing and administration of abciximab, eptifibatide, and tirofiban based on previously published rates of efficacy and intracranial hemorrhage.

Reliability of dual- vs single-volume reconstruction of three-dimensional digital subtraction angiography for follow-up evaluation of endovascularly treated intracranial aneurysms.

Single-volume reconstruction of three-dimensional (3D) digital subtraction angiography (DSA) can be effectively used for aneurysm assessment and planning of endovascular embolization. Unfortunately, post-embolization follow-up angiographic images can be obscured by artifact. The dual-volume reconstruction technique was developed in order to reduce artifact and enhance the visualization of the aneurysm, the parent vessel and side branches, and endovascular devices. The purpose of this study was to compare the reliability of dual- vs single-volume reconstruction of 3D DSA in evaluation of follow-up images after endovascular embolization of intracranial aneurysms. Four cerebrovascular neurosurgeons independently and blindly reviewed 20 randomly selected dual-and single-volume reconstructions of 3D DSAs demonstrating cerebral aneurysms treated with primary coil embolization, stent-assisted coil embolization, or Pipeline embolization. Five images were repeated for each modality (single and dual volume) in order to assess intra-rater reliability. The intraclass correlation coefficient was calculated as a measure of the overall inter-rater agreement. Cohen's kappa value was used to assess repeat measurement consistency for each rater. Overall inter-rater agreement using dual- and single-volume reconstruction was 0.81 and 0.75, respectively. Dual-volume reconstruction resulted in superior agreement in assessing location, occlusion status, position of aneurysm recanalization or residual, status of nearby branches, presence of coil migration and presence of intravascular devices (stent or Pipeline). Three-dimensional reconstruction is an important complementary imaging technique in evaluating the angioarchitecture of aneurysms and recanalization after endovascular embolization. Dual-volume reconstruction imaging was associated with superior inter- and intra-rater reliability.

Frequency and Factors Associated With Unsuccessful Lead (First) Coil Placement in Patients Undergoing Coil Embolization of Intracranial Aneurysms

There is limited knowledge about associated rates, aneurysm characteristics, technical factors, and immediate impact of unsuccessful placement of the lead (first) coil during endovascular embolization of intracranial aneurysms. To determine the rates, associated risk factors, and consequences of lead coil placement failure in consecutive embolization procedures. We reviewed clinical and procedural aspects of all endovascular coil embolizations performed at our 2 academic centers over a period of 3.5 years (2006-2010). Morphologic characteristics of the aneurysm and technical aspects of the treatment were recorded. We also performed a flow model analysis to assess the relationship between aneurysm dimensions, length of coil, packing density with first coil, and occurrence of lead coil placement failure. There were 24 (14%) lead coil placement failure procedures in 172 aneurysm embolization procedures; in 23 of 24 (96%) patients with lead coil placement failure, the failure occurred in aneurysms less than 10 mm in size. The main technical factors associated with lead coil placement failure were related to the coil (length, diameter, and type) followed by microcatheter support failure. Among these patients, 21 (87.5%) required change in the coil length, 17 (70.8%) change in coil diameter, and 10 (41.7%) change in coil type (brand and/or configuration) for successful placement of the lead coil. A total of 4 (16.7%) patients required change in microcatheter, and 6 (24.9%) patients had balloon/stent assistance for successful lead coil placement. Two of 24 (8.3%) patients had rupture of their aneurysms during the attempt to reposition the lead coil. In our flow model, these clinical observations were reproduced with higher risk of lead coil failure in smaller aneurysms. Lead coil placement failure is not infrequent during embolization of intracranial aneurysms and may increase the risk of complications. Appropriate coil selection, particularly coil length in small aneurysms, may reduce the rate of lead coil placement failure and associated complications.

A single centre study of coil embolization of intracranial aneurysms comparing bare platinum and PGLA-coated coils

There is no robust consensus on the efficacy of polyglycolic/polylactic acid (PGLA)-coated coils used in the endovascular embolization of intracranial aneurysms. We present a comparative study of bare platinum coils and PGLA-coated Gugliemi Detachable Coils (GDC) in the treatment of intracranial aneurysms at a single centre, using target aneurysm recurrence and angiographic recanalization as the primary endpoints. We included all patients treated between 1998 and 2009 who had undergone at least one angiographic post-procedural follow-up. Patient demographics, clinical presentation, operative notes, and all relevant imaging were collected. Of the 441 aneurysms with follow-up, 290 were treated with at least one PGLA coil and 151 aneurysms were treated exclusively with bare platinum coils. At follow-up, 26.5% of platinum controls demonstrated angiographic recanalization, compared to 31.4% of PGLA-treated aneurysms ( p = 0.002). PGLA-treated aneurysms were more likely to have an angiographic remnant at follow-up (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.26–3.04, p = 0.003). The post-operative Raymond score was the only predictor of retreatment (OR = 1.6, 95% CI = 1.08–2.24, p = 0.020), and was the second strongest predictor of a complete angiographic result at follow-up (OR = 1.67, 95% CI = 1.22–2.27, p = 0.001). We concluded that PGLA-coated coils demonstrated poorer post-operative and long-term angiographic occlusion in the treatment of intracranial aneurysms, compared to bare platinum coils.

Endovascular Embolization of Intracranial Aneurysms Using Bare Platinum Axium™ Detachable Coils: Immediate and Short - Term Follow-up Results from a Multicenter Registry

PurposeAxium™ coils were developed to improve the durability of coil-embolized cerebral aneurysms by increasing packing density. The purpose of this prospective multicenter registry was to evaluate the safety and durability of Axium™ coils.Materials and MethodsOne hundred twenty-six patients with 135 aneurysms of ≤ 15 mm in size underwent coil embolization using bare platinum coils, with Axium™ coils constituting over 50% of the total coil length. Immediate and short-term follow-up results were prospectively registered and retrospectively evaluated.ResultsOf the 135 aneurysms (83 unruptured and 52 ruptured), immediate post-embolization angiography revealed complete occlusion in 80 aneurysms (59.3%), neck remnants in 47 (34.8%), and incomplete occlusion in 8 (5.9%). The mean packing density was 42.8% (range, 9.5 - 90%) with Axium™ coil length constituting a mean of 87.9% of total coil length. The rate of procedure-related complications was 16.3%. Procedure-related permanent morbidity and mortality rates were 3.2% and 0.8%, respectively. Follow-up catheter or MR angiography, which was available in 101 aneurysms at 6 - 15 months (mean, 7.7 months), revealed stable or improved occlusion in 95 aneurysms and worsening in 6 aneurysms (5.9%). Lower packing density (< 30%) remained the only predictor for anatomical worsening on multivariable logistic regression analysis (P < 0.05).ConclusionIn this registry, Axium™ coils showed a relatively low rate of anatomical worsening on short-term follow-up imaging with an acceptable periprocedural safety profile compared to reports of other platinum coils. These results may warrant further study of long-term durability with Axium™ coils in larger populations.

P-021 Safety and efficacy of balloon-assisted coil embolization of intracranial aneurysms: a single institution experience

PurposeThe safety of the balloon remodeling technique remains a matter of debate. In this report we analyze the safety of the balloon remodeling technique compared with coil embolization alone for...

Endovascular Treatment of Intracranial Aneurysms Associated with Moyamoya Disease or Moyamoya Syndrome

Direct surgical clipping proves to be difficult and dangerous for intracranial aneurysms associated with moyamoya disease (MMD) or moyamoya syndrome (MMS). This study presents our clinical experience of endovascular embolization of intracranial aneurysms associated with these diseases. A total of 13 cases of intracranial aneurysms associated with MMD or MMS were treated by endovascular embolization between January 2001 and January 2009. Patients were divided into two groups: a saccular aneurysm group (n=10) and a pseudoaneurysm group (n=3). Different endovascular therapeutic strategies were employed for each type of case. Of the 13 cases, 11 received successful endovascular embolization and had an uneventful postoperative course during one to two years of follow-up. However, endovascular embolization failed in the other two cases, of whom one died from rebleeding after the five-month follow-up, while the other was conservatively treated and experienced no rebleeding during the two-year follow-up. A favorable prognosis may be secured through careful selection of endovascular treatment regimens for patients with intracranial aneurysms associated with MMD or MMS according to the site of intracranial aneurysms.

Intra-arterial abciximab for the treatment of thrombus formation during coil embolization of intracranial aneurysms

Background and purposeThrombus formation during endovascular embolization of intracranial aneurysms occurs in 2.9%–6% of patients. Use of IIb/IIIA inhibitors such as abciximab or eptifibatide intravenously has been reported in management...

Intravascular tissue reactions induced by various types of bioabsorbable polymeric materials: correlation between the degradation profiles and corresponding tissue reactions

IntroductionSeveral different bioabsorbable polymeric coil materials are currently used with the goal of improving treatment outcomes of endovascular embolization of intracranial aneurysms. However, little is known about the correlation between polymer degradation profiles and concomitant tissue responses in a blood vessel. The authors describe in vitro degradation characteristics of nine different polymeric materials and their corresponding tissue responses induced in rabbit carotid arteries.Methods Mass loss and molecular weight loss of nine commercially available bioabsorbable sutures were evaluated in vitro up to16 weeks. The same nine materials, as well as platinum coils, were implanted into blind-end carotid arteries (n = 44) in rabbits, and their tissue reactions were evaluated histologically 14 days after the implantation.ResultsFive of the nine polymers elicited moderate to strong tissue reactions relative to the remaining materials. While polymer mass loss did not correlate with their histologic findings, polymers that showed a faster rate of molecular weight loss had a tendency to present more active tissue reactions such as strong fibrocellular response around the implanted material with a moderate inflammatory cell infiltration. Maxon exhibited the fastest rate of molecular weight loss and poly-l-lactic acid the slowest.ConclusionsThe rate of molecular weight loss may be an important factor that is associated with the degree of bioactivity when bioabsorbable polymers are implanted into blood vessels. For further quantitative analysis, additional experiments utilizing established aneurysm models need to be conducted.

Surgical extraction of migrated coils via proximal segment of the anterior cerebral artery: An emergency alternative

Coil migration is a severe complication in endovascular treatment. We report our experience of prompt surgical extraction of migrated coils via excised proximal A1 following endovascular embolization of intracranial aneurysms in two patients. Both patients had to undergo coiling or stent-assisted coiling for cerebral aneurysms, and while operating the coils protruded and migrated to the bifurcation of internal carotid artery and middle cerebral artery. Immediate craniotomy was performed after unsuccessful or unfeasible endovascular retrieval. The migrated coils were removed via excised proximal A1, and the patients recovered well without any neurological deficits. We suggest that this surgical procedure might be an alternative route in selected patients with good cross circulation in emergency. In addition, a rare occasion of coil migration after stent-assisted coiling is also described in one patient, which might have resulted from unsatisfactory wall apposition of the stent due to a curved vessel.

INTRA-ARTERIAL TIROFIBAN INFUSION FOR THROMBOEMBOLISM DURING ENDOVASCULAR TREATMENT OF INTRACRANIAL ANEURYSMS

Thromboembolism is one of the most common and serious complications associated with the endovascular embolization of intracranial aneurysms. We report our clinical experiences with intra-arterial tirofiban infusion during aneurysm embolization. The clinical, radiological, and laboratory data of 24 patients harboring 25 aneurysms (25 procedures) who underwent intra-arterial tirofiban infusion for thromboembolism during the endovascular treatment of intracranial aneurysms were reviewed retrospectively. Thrombi or emboli were resolved by superselective intra-arterial tirofiban infusion via a microcatheter. The study cohort comprised 14 unruptured and 11 ruptured aneurysms. Intra-arterially infused tirofiban doses ranged from 0.2 to 1.0 mg (mean +/- standard deviation, 0.64 +/- 0.25 mg). Thromboemboli were resolved, and arteries were recanalized on all occasions except one: a case of distal middle cerebral artery embolism. No hemorrhagic complications related to intra-arterial tirofiban infusion occurred. Intra-arterial tirofiban delivery appears to be a safe and effective treatment modality when thromboembolism is encountered during the endovascular treatment of intracranial aneurysms.