Endovascular Treatment of Unruptured Intracranial Aneurysms: Occurrence of Thromboembolic Events

Pretreatment with a dual antiplatelet and anticoagulant (APAC) reduces ischemia-reperfusion injury in a mouse model of temporary middle cerebral artery occlusion-implications for neurovascular procedures

BACKGROUND

Several neurovascular procedures require temporary occlusion of cerebral arteries, leading to ischemia of unpredictable length, occasionally causing brain infarction. Experimental models of cerebral ischemia-reperfusion injury have established that platelet adhesion and coagulation play detrimental roles in reperfusion injury following transient cerebral ischemia. Therefore, in a model of cerebral ischemia-reperfusion injury (IRI), we investigated the therapeutic potential of a dual antiplatelet and anticoagulant (APAC) heparin proteoglycan mimetic which is able to bind to vascular injury sites.

METHODS

Brain ischemia was induced in mice by transient occlusion of the right middle cerebral artery for 60 min. APAC, unfractionated heparin (UFH) (both at heparin equivalent doses of 0.5 mg/kg), or vehicle was intravenously administered 10 min before or 60 min after the start of ischemia. At 24 h later, mice were scored for their neurological and motor behavior, and brain damage was quantified.

RESULTS

Both APAC and UFH administered before the onset of ischemia reduced brain injury. APAC and UFH pretreated mice had better neurological and motor functions (p < 0.05 and p < 0.01, respectively) and had significantly reduced cerebral infarct sizes (p < 0.01 and p < 0.001, respectively) at 24 h after transient occlusion compared with vehicle-treated mice. Importantly, no macroscopic bleeding complications were observed in either APAC- or UFH-treated animals. However, when APAC or UFH was administered 60 min after the start of ischemia, the therapeutic effect was lost, but without hemorrhaging either.

CONCLUSIONS

Pretreatment with APAC or UFH was safe and effective in reducing brain injury in a model of cerebral ischemia induced by transient middle cerebral artery occlusion. Further studies on the use of APAC to limit ischemic injury during temporary occlusion in neurovascular procedures are indicated.

DWI-Detected Ischemic Lesions after Endovascular Treatment for Cerebral Aneurysms: An Updated Systematic Review and Meta-analysis

BACKGROUND AND PURPOSE

DWI-detected ischemic lesions are potential complications of endovascular procedures that are performed to treat intracranial aneurysms. We completed a systematic review and meta-analysis to identify the occurrence of DWI-detected ischemic lesions after endovascular treatment for intracranial aneurysms.

MATERIALS AND METHODS

A systematic literature search of PubMed, the Web of Science, EMBASE, and Scopus between January 2000 and June 2022 of post-endovascular procedures for intracranial aneurysm studies was conducted using the Nested Knowledge AutoLit software. The main outcome was DWI-detected ischemic lesions within 5 days of the procedures. Information regarding associated risk factors such as the type of procedure, patient demographics, and aneurysm characteristics was also collected.

RESULTS

Twenty-nine studies with 2686 patients were included. The overall incidence of DWI ischemic lesions was 47.0% (95% CI, 39.6%-55.8%). The highest rate of lesions was seen with flow diversion at 62.4% (95% CI, 48.4%-80.5%), followed by complex procedures at 49.3% (95% CI, 29.5%-82.1%), stent-assisted coiling at 47.5% (95% CI, 34.6%-65.3%), simple coiling at 47.1% (95% CI, 35.7%-62.3%), and balloon-assisted coiling at 37.0% (95% CI, 28.3%-48.4%). The differences among different techniques were not statistically significant; however, there was significant heterogeneity and a significant risk of publication bias among included studies.

CONCLUSIONS

Many patients who undergo endovascular procedures for intracranial aneurysms present with new postprocedural DWI-detected ischemic lesions, regardless of the endovascular procedure used. Future studies and meta-analyses are needed to investigate early and long-term outcomes of such small infarcts.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

Aneurysm treatment within 6 h versus 6-24 h after rupture in patients with subarachnoid hemorrhage

BACKGROUND

The risk of rebleeding after aneurysmal subarachnoid hemorrhage (aSAH) is the highest during the initial hours after rupture. Emergency aneurysm treatment may decrease this risk, but is a logistic challenge and economic burden. We aimed to investigate whether aneurysm treatment <6 h after rupture is associated with a decreased risk of poor functional outcome compared to aneurysm treatment 6-24 h after rupture.

METHODS

We used data of patients included in the ULTRA trial (NCT02684812). All patients in ULTRA were admitted within 24 h after aneurysm rupture. For the current study, we excluded patients in whom the aneurysm was not treated <24 h after rupture. We calculated crude and adjusted risk ratios (aRR) with 95% confidence intervals using Poisson regression analyses for poor functional outcome (death or dependency, assessed by the modified Rankin Scale) after aneurysm treatment <6 h versus 6-24 h after rupture. Adjustments were made for age, sex, clinical condition on admission (WFNS scale), amount of extravasated blood (Fisher score), aneurysm location, tranexamic acid treatment, and aneurysm treatment modality.

RESULTS

We included 497 patients. Poor outcome occurred in 63/110 (57%) patients treated within 6 h compared to 145/387 (37%) patients treated 6-24 h after rupture (crude RR: 1.53, 95% CI: 1.24-1.88; adjusted RR: 1.36, 95% CI: 1.11-1.66).

CONCLUSION

Aneurysm treatment <6 h is not associated with better functional outcome than aneurysm treatment 6-24 h after rupture. Our results do not support a strategy aiming to treat every patient with a ruptured aneurysm <6 h after rupture.

An Updated Review on Glycoprotein IIb/IIIa Inhibitors as Antiplatelet Agents: Basic and Clinical Perspectives

The glycoprotein (GP) IIb/IIIa receptor is found integrin present in platelet aggregations. GP IIb/IIIa antagonists interfere with platelet cross-linking and platelet-derived thrombus formation through the competition with fibrinogen and von Willebrand factor. Currently, three parenteral GP IIb/IIIa competitors (tirofiban, eptifibatide, and abciximab) are approved for clinical use in patients affected by percutaneous coronary interventions (PCI) in the location of acute coronary syndrome (ACS). GP IIb/IIIa antagonists have their mechanism of action in platelet aggregation prevention, distal thromboembolism, and thrombus formation, whereas the initial platelet binding to damage vascular areas is preserved. This work is aimed to provide a comprehensive review of the significance of GP IIb/IIIa inhibitors as a sort of antiplatelet agent. Their mechanism of action is based on factors that affect their efficacy. On the other hand, drugs that inhibit GP IIb/IIIa already approved by the FDA were reviewed in detail. Results from major clinical trials and regulatory practices and guidelines to deal with GP IIb/IIIa inhibitors were deeply investigated. The cardiovascular pathology and neuro-interventional surgical application of GP IIb/IIIa inhibitors as a class of antiplatelet agents were developed in detail. The therapeutic risk/benefit balance of currently available GP IIb/IIa receptor antagonists is not yet well elucidated in patients with ACS who are not clinically evaluated regularly for early cardiovascular revascularization. On the other hand, in patients who have benefited from PCI, the antiplatelet therapy intensification by the addition of a GP IIb/IIIa receptor antagonist (intravenously) may be an appropriate therapeutic strategy in reducing the occurrence of risks of thrombotic complications related to the intervention. Development of GP IIb/IIIa inhibitors with oral administration has the potential to include short-term antiplatelet benefits compared with intravenous GP IIb/IIIa inhibitors for long-term secondary preventive therapy in cardiovascular disease. But studies showed that long-term oral administration of GP IIb/IIIa receptor inhibitors has been ineffective in preventing ischemic events. Paradoxically, they have been linked to a high risk of side effects by producing prothrombotic and pro-inflammatory events.

Acute frame coil migration during filling coil retrieval in a cerebral aneurysm embolization case: A possible result of a venturi effect?

Coil migration is a known complication of endovascular coiling of cerebral aneurysms. We report an acute coil migration occurring during coiling of an unruptured anterior choroidal aneurysm, while a separate coil was retrieved into the microcatheter concomitantly without direct contact between the coils. The “pulling” of a previously deployed stable coil is presented as an adverse effect that should be noted. This case exemplifies that not only direct entanglement or erroneous malposition can generate acute migration, but possibly, also alteration of physical forces during coil retrieval. A potential mechanism, similar to a venturi effect, caused by a quick suction within the microcatheter at its distal end, is suggested, and the clinical relevance of the case is discussed.

Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage

Unruptured intracranial aneurysms (UIAs) are commonly acquired vascular lesions that form an outpouching of the arterial wall due to wall thinning. The prevalence of UIAs in the general population is 3.2%. In contrast, an intracranial aneurysm may be manifested after rupture with classic presentation of a thunderclap headache suggesting aneurysmal subarachnoid hemorrhage (SAH). Previous consensus suggests that although small intracranial aneurysms (<7 mm) are less susceptible to rupture, aneurysms larger than 7 mm should be treated on a case-by-case basis with consideration of additional risk factors of aneurysmal growth and rupture. However, this distinction is outdated. The PHASES score, which comprises data pooled from several prospective studies, provides precise estimates by considering not only the aneurysm size but also other variables, such as the aneurysm location. The International Study of Unruptured Intracranial Aneurysms is the largest observational study on the natural history of UIAs, providing the foundation to the current guidelines for the management of UIAs. Although SAH accounts for only 3% of all stroke subtypes, it is associated with considerable burden of morbidity and mortality. The initial management is focused on stabilizing the patient in the intensive care unit with close hemodynamic and serial neurologic monitoring with endovascular or open surgical aneurysm treatment to prevent rebleeding. Since the results of the International Subarachnoid Aneurysm Trial, treatment of aneurysmal SAH has shifted from surgical clipping to endovascular coiling, which demonstrated higher odds of survival free of disability at 1 year after SAH. Nonetheless, aneurysmal SAH remains a public health hazard and is associated with high rates of disability and death.

Use of pCONUS HPC for the treatment of unruptured wide-necked bifurcation aneurysms: early clinical experience using single antiplatelet therapy

BACKGROUND

In recent years, a growing number of stents and stent-like devices have become available to facilitate the treatment of challenging aneurysms. However, the need for dual antiplatelet therapy can limit their use, especially in ruptured aneurysms. The hydrophilic polymer coating (pHPC, phenox) is a novel glycan-based multilayer polymer that reduces platelet adhesion. This study aims to report our initial experience using the pCONUS HPC device for the treatment of unruptured wide-necked bifurcation aneurysms (WNBA) using acetylsalicylic acid (ASA) as single antiplatelet therapy (SAPT).

METHODS

We retrospectively identified all patients who were treated with the pCONUS HPC for unruptured WNBA in a multi-staged procedure using ASA as SAPT. Records were made of periprocedural complications, clinical outcome and angiographic and clinical follow-up.

RESULTS

We identified 15 patients with 15 WNBA. The average age was 69 years old (range, 41-76). Seven aneurysms were located in the middle cerebral artery, five in the anterior communicating artery, two at the basilar tip and one in the posterior communicating artery. Immediate post-treatment angiography showed five aneurysms with modified Raymond-Roy classification (mRRC) grade I and four aneurysms with mRRC grade II. There were no haemorrhagic complications. Four patients developed thrombus formation during the second treatment session, all of them completely resolving after administration of glycoprotein IIb/IIIa antagonists. Angiographic follow-up data were available for 10 patients and showed adequate occlusion (mRRC I or II) in eight aneurysms (80%). In-stent stenosis was observed in one patient whereas two patients showed de novo stenosis in one of the efferent branches.

CONCLUSIONS

This early experience on the use of the pCONUS HPC device suggests that it can be useful for treating unruptured WNBA under ASA as SAPT. Further investigation with a randomised treatment registry and larger cohort is needed.

Intravenous cangrelor and oral ticagrelor as an alternative to clopidogrel in acute intervention

BACKGROUND

Dual antiplatelet therapy (DAP) is necessary to prevent thromboembolic events during carotid stenting, stent-assisted coil embolization, and implant of flow diverters (FD). However, DAP in the acute phase may be challenging. An intravenous alternative, cangrelor, has rapid onset, short plasma half-life, and more reliable antiplatelet action for acute interventions. The study objective was to evaluate feasibility and safety of IV cangrelor during acute neuroendovascular surgery procedures.

METHODS

We performed a retrospective analysis of our database of patients treated with stent-assisted coil embolization, FD placement for aneurysmal subarachnoid hemorrhage (aSAH), or stenting for acute internal carotid artery (ICA) occlusion where IV cangrelor was used. Morbidity, mortality, incidence of thromboembolic events, hemorrhages, and 90-day outcomes were reported.

RESULTS

Ten patients were found in our database from June 2018 through January 2019. Four patients had aSAH, four had middle cerebral artery strokes with tandem lesions, one had an ICA occlusion, and one had a vertebral artery aneurysm. One of the ten patients experienced a thrombotic event. One patient developed new post-procedural bleeding and two had worsening intracranial hemorrhage. Five patients were discharged home in stable condition, two to acute rehabilitation, one to a nursing facility, and two others expired (likely the result of the severe and evolving strokes). Of the eight who were discharged, six (75%) had a good 90-day functional outcome (modified Rankin Scale 0-2).

CONCLUSION

Acute administration of IV cangrelor with or without oral ticagrelor is a feasible antiplatelet treatment option for acute neuroendovascular procedures.

Timing of Thrombosis in Embolization of Unruptured Intracranial Aneurysms : Tirofiban as Rescue Treatment

PURPOSE

Thrombosis is one of the main complications of endovascular treatment for unruptured intracranial aneurysms (UIA). This article reports the timing and initial location of thrombosis and prognosis after the use of tirofiban for performing coil embolization for UIA.

METHODS

This study retrospectively collected 1686 cases of intracranial aneurysms treated with coil embolization from January 2013 to February 2018. Ruptured cases were excluded. The presumed causes and timing of thrombosis, the response after tirofiban administration and the modified Rankin scale (mRS) score at 3 months were reviewed.

RESULTS

Of the 26 patients 76% were female and middle cerebral artery and basilar artery aneurysms accounted for 7 cases. The initial location of thrombosis was related to the stent (n = 14, 53.8%) or coil (n = 12, 46.2%). Of the patients 19 (73.1%) developed thrombosis during the procedure, and 5 patients (19.2%) developed it within 1 day of the procedure. Median duration between the thrombotic procedure and initial thrombosis was 38.5 min, 12 patients were symptomatic but more than half completely recovered after using tirofiban. Good clinical outcome (mRS 0-2) was seen in 92.3%. In the subgroup analysis, median time from the first thrombotic procedure to initial thrombosis within 1 day was 38.0 min (stent-related group) and 35.0 min (coil-related group, p = 0.651).

CONCLUSION

In most cases of embolization for UIA, thrombosis requiring the use of tirofiban occurs intraprocedurally or on the first day after the procedure. Careful observation of thrombosis during the procedure is important and tirofiban should be used for a better outcome even if the infarction progresses.

Impact of Reducing the Procedure Time on Thromboembolism After Coil Embolization of Cerebral Aneurysms

Background: There is still controversy regarding which procedure-related factors affect the occurrence of periprocedural thromboembolism. This study aimed to investigate which procedure-related risk factors can be modified to prevent adverse thromboembolic events after coil embolization of intracranial aneurysm.

Methods: Using a single-center database, we retrospectively identified a consecutive series of patients with symptomatic and asymptomatic cerebral aneurysms treated with coil embolization. We evaluated the following procedure-related factors: procedure time, procedure methods (simple coiling, stent-assisted coiling, and use of multiple microcatheters), and number of coils inserted. The primary outcome was the development of thromboembolism before and after coil embolization confirmed by diffusion-weighted imaging (DWI) irrespective of the location of the procedure. Pearson's chi-square, Student's t-test, multivariable logistic regression analysis, and sensitivity analysis with multinomial logistic regression analysis were used in the statistical analyses.

Results: Of 180 cases enrolled, 146 (81.1%) had evidences of thromboembolism confirmed by DWI, and 13 (7.2%) had neurologic symptoms. Among the documented modifiable procedure-related factors, every 10 min increase in the procedure time was independently associated with the risk of thromboembolism, after adjusting the analysis (adjusted odds ratio 1.11; 95% confidence interval 1.01–1.21). The coiling methods, use of multiple catheters, and number of coils inserted did not change the effect of the procedure time on thromboembolic events (p for interactions > 0.05).

Conclusion: This study showed that the procedure time might be the most effective modifiable factor for reducing thromboembolic events irrespective of the procedure methods used during coil embolization of cerebral aneurysms.

Cerebral catheter angiography and its complications

Catheter-based angiography is an important but invasive procedure in vascular neurology. It is used mainly for diagnosis and for planning treatment in patients with a suspected underlying vascular abnormality. It is often performed as a semiurgent, planned investigation or linked to an interventional procedure. Cerebral angiography provides high-resolution, three-dimensional, pathoanatomical data about the cerebral vasculature and also allows real-time analysis of blood flow. Contrast injections can be repeated to identify subtleties. A physical intervention may also follow angiography. For these reasons, angiography remains the gold standard for delineating vascular lesions of the brain (and spine). Permanent neurological complications are rare, approximately 1%, but become increasingly common in patients aged over 55 years. The main complications are embolic stroke, groin haematoma and contrast-induced nephropathy. In the new era of thrombectomy, it may transpire that other specialists including neurologists may learn to perform the procedure and to manage its complications.

Symptomatic periprocedural intracranial hemorrhage unrelated to coil embolization in 1287 patients with intracranial aneurysms

PURPOSE

Periprocedural symptomatic intracranial hemorrhage (sICH) unrelated to coil embolization of intracranial aneurysm has been rarely reported. The incidence and characteristics of this complication remain unclear. This study was designed to elucidate the incidence and characteristics of periprocedural sICH unrelated to coiling of intracranial aneurysm, and to explore the possible mechanisms underlying this complication.

METHODS

Included in this retrospective study were 1287 patients with 1394 aneurysms who were treated with coil embolization (476 patients with stent assistance and 811 patients without stents) between May 2008 and August 2017. All procedure-unrelated sICHs that occurred within 30 days after coiling were selected. The technical details of the procedure, clinical characteristics, and medical therapy were recorded.

RESULTS

A total of 6 patients developed periprocedural sICH unrelated to coil embolization. All these six patients underwent stent-assisted coiling (SAC). Therefore, there was a 1.3% (6/476) procedure-unrelated sICH rate of SAC and 0% (0/811) in patients underwent coiling without stent during the periprocedural period (P = 0.005, RR 0.987; 95% CI, 0.977-0.997). These phenomena occurred more often in patients who received SAC for ruptured aneurysms vs patients underwent this technique for unruptured aneurysms (2.0 vs 0.7%, P = 0.390, RR 2.896; 95% CI, 0.525-15.968). All these phenomena occurred within 7 days after coiling, and resulted in one mortality, one unfavorable outcome (mRS Score 3), and other four favorable outcomes (mRS Scores 0-2) at 90 days after procedure.

CONCLUSION

Our findings suggest that the procedure-unrelated sICH, though less frequent, may exist following stent-assisted coiling of intracranial aneurysm during the periprocedural period. Extra caution may be warranted in patients who were treated with SAC for ruptured aneurysms.

Symptomatic and silent cerebral infarction following surgical clipping of unruptured intracranial aneurysms: incidence, risk factors, and clinical outcome

Cerebral infarction (CI) associated with clipping of unruptured intracranial aneurysms (UIAs) has not been completely studied. The role of individual and operative characteristics is not known, and the risk of silent CI has not been well described. To determine the incidence, risk factors, and clinical outcome of postoperative CI, we retrospectively analyzed 388 consecutive patients undergoing clipping of UIAs between January 2012 and December 2015. We reviewed the pre- and postoperative computed tomography (CT) images of each patient. Postoperative CI was defined as a new parenchymal hypodensity in the vascular territory of treated artery. Patient-specific, aneurysm-specific, and operative variables were analyzed as potential risk factors. Functional outcome at discharge was assessed with the modified Rankin Scale (mRS). Postoperative CI was found in 49 (12.6%) patients, 29 of whom manifested neurological deficits. The incidences of symptomatic stroke and silent CI were 7.5 and 5.2%, respectively. Multivariate analysis showed that larger aneurysm size and history of hypertension were significantly associated with CI. Disability (mRS > 2) rate was 42.9% among patients with CI, which was substantially higher than that among patients without (0.9%). In conclusion, the incidence of CI following clipping of UIAs was not low. Larger aneurysm size and history of hypertension were independent risk factors. Postoperative symptomatic stroke correlated with an extremely high risk of disability. Silent CI was seemingly nondisabling, but the possible cognitive consequence is pending.

Magnetic resonance imaging and brain injury in the chronic phase after aneurysmal subarachnoid hemorrhage: A systematic review

Background Case-fatality rates after aneurysmal subarachnoid hemorrhage have decreased over the past decades. However, many patients who survive an aneurysmal subarachnoid hemorrhage have long-term functional and cognitive impairments. Aims We sought to review all data on conventional brain MRI obtained in the chronic phase after aneurysmal subarachnoid hemorrhage to (1) analyze the proportion of patients with cerebral infarction or brain volume changes; (2) investigate baseline determinants predictive of MRI-detected damage; and (3) assess if brain damage is predictive of patient outcome. Summary of review All original data published between 1 January 2000 and 4 October 2017 was searched using the PUBMED, EMBASE, and Web of Science databases. Based on preset inclusion criteria, 15 from 5200 articles were included with a total of 996 aneurysmal subarachnoid hemorrhage patients. Quality assessment, risk of bias assessment, and level of evidence assessment were performed. The results according to aim, with levels of evidence, were: (1) 25 to 81% of aneurysmal subarachnoid hemorrhage patients show infarcts (strong); there is a higher ratio of cerebrospinal fluid-to-intracranial volume in patients compared to controls (strong); (2) there is a negative relation between age (moderate), DCI (low) and brain volume measurement outcomes; (3) lower brain parenchymal volume (strong) and the presence of infarcts or infarct volumes (moderate) are associated with a worse outcome. Conclusion Patients after aneurysmal subarachnoid hemorrhage may demonstrate brain infarcts and decreased brain parenchyma, which is related to worse outcome. Thereby, both brain infarcts and brain volume measurements could be used as outcome markers in pharmaceutical trials. Systematic Review Registration PROSPERO CRD42016040095.

Early diffusion-weighted MRI lesions after treatment of unruptured intracranial aneurysms: a prospective study

OBJECTIVE

Diffusion-weighted MRI was used to assess periprocedural lesion load after repair of unruptured intracranial aneurysms (UIA) by microsurgical clipping (MC) and endovascular coiling (EC).

METHODS

Patients with UIA were assigned to undergo MC or EC according to interdisciplinary consensus and underwent diffusion-weighted imaging (DWI) 1 day before and 1 day after aneurysm treatment. Newly detected lesions by DWI after treatment were the primary end point of this prospective study. Lesions detected by DWI were categorized as follows: A) 1–3 DWI spots < 10 mm, B) > 3 DWI spots < 10 mm, C) single DWI lesion > 10 mm, or D) DWI lesion related to surgical access.

RESULTS

Between 2010 and 2014, 99 cases were included. Sixty-two UIA were treated by MC and 37 by EC. There were no significant differences between groups in age, sex, aneurysm size, occurrence of multiple aneurysms in 1 patient, or presence of lesions detected by DWI before treatment. Aneurysms treated by EC were significantly more often located in the posterior circulation (p < 0.001). Diffusion-weighted MRI detected new lesions in 27 (43.5%) and 20 (54.1%) patients after MC and EC, respectively (not significant). The pattern of lesions detected by DWI varied significantly between groups (p < 0.001). Microembolic lesions (A and B) found on DWI were detected more frequently after EC (A, 14 cases; B, 5 cases) than after MC (A, 5 cases), whereas C and D were rare after EC (C, 1 case) and occurred more often after MC (C, 12 cases and D, 10 cases). No procedure-related unfavorable outcomes were detected.

CONCLUSIONS

According to the specific techniques, lesion patterns differ between MC and EC, whereas the frequency of new lesions found on DWI is similar after occlusion of UIA. In general, the lesion load was low in both groups, and lesions were clinically silent.

Clinical trial registration no.: NCT01490463 (clinicaltrials.gov)

Microembolism after endovascular coiling of unruptured cerebral aneurysms: incidence and risk factors

OBJECTIVE

The incidence and risk factors of microembolic lesions on MR diffusion-weighted imaging (DWI) were analyzed after the endovascular coiling of unruptured intracranial aneurysms (UIAs).

METHODS

Data obtained from 271 consecutive patients (70 men and 201 women; median age 57 years; range 23-79 years) who presented with UIA for coil embolization between July 2011 and June 2013 were analyzed. Two independent reviewers examined the DWI and apparent diffusion coefficient maps obtained the following day for the presence of restrictive diffusion spots and counted the number of spots. Multivariate analysis was then performed to identify independent risk factors for developing microembolism following the coiling of an aneurysm.

RESULTS

Microembolic lesions were noted in 101 of 271 patients (37.3%). The results of the multivariate analysis showed that the following factors significantly influenced the risk for microembolism: age, diabetes, previous history of ischemic stroke, high-signal FLAIR lesions in the white matter, multiple aneurysms, and the insertion of an Enterprise stent (all ORs > 1.0 and all p values < 0.05). Previously known risk factors such as prolonged procedure duration, aneurysm size, and decreased antiplatelet function did not show any significant influence.

CONCLUSIONS

The incidence of microembolism after endovascular coiling of UIA was not low. Lesions occurred more frequently in patients with vascular status associated with old age, diabetes, and previous stroke. Aneurysm multiplicity and the type of stent used for treatment also influenced lesion occurrence.

Microembolism after Endovascular Treatment of Unruptured Cerebral Aneurysms: Reduction of its Incidence by Microcatheter Lumen Aspiration

PURPOSE

Diffusion-weighted MR images (DWI) obtained after endovascular treatment of cerebral aneurysms frequently show multiple high-signal intensity (HSI) dots. The purpose of this study was to see whether we could reduce their incidence after embolization of unruptured cerebral aneurysms by modification of our coiling technique, which involves the deliberate aspiration of the microcatheter lumen right after delivery of each detachable coil into the aneurysm sac.

MATERIALS AND METHODS

From January 2011 to June 2011, all 71 patients with unruptured cerebral aneurysms were treated using various endovascular methods. During the earlier period, 37 patients were treated using our conventional embolization technique (conventional period). Then 34 patients were treated with a modified coiling technique (modified period). DWI was obtained on the following day. We compared the occurrence of any DWI HSI lesions and the presence of the symptomatic lesions during the two time periods.

RESULTS

The incidence of the DWI HSI lesions differed significantly at 89.2% (33/37) during the conventional period and 26.5% (9/34) during the modified period (p < 0.0001). The incidence of symptomatic lesions differed between the two periods (29.7% during the conventional period vs. 2.9% during the modified period, p < 0.003).

CONCLUSION

Aspiration of the inner content of the microcatheter right after detachable coil delivery was helpful for the reduction of the incidence of microembolisms after endovascular coil embolization for the treatment of unruptured cerebral aneurysms.

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms.

METHODS

Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment.

Dual antiplatelet therapy plus postoperative heparin and dextran is safe and effective for reducing risk of embolic stroke during aneurysm coiling

BACKGROUND

Thromboembolic events represent a clinically significant cause of neurological morbidity during the endovascular management of cerebral aneurysms. We have implemented an anti-thromboembolic regimen consisting of pre- and postoperative dual antiplatelet therapy, as well as postoperative anticoagulation using heparin and dextran. The aims of our study were to examine the effect of this regimen on thromboembolic rates during elective aneurysm coiling, and to elucidate risk factors associated with the development of thromboembolic events in this setting.

METHODS

We conducted a retrospective review of patients who underwent elective intracranial aneurysm coiling between January 2005 and February 2012. The primary outcome of interest was the occurrence of a clinically significant peri-procedural thromboembolic event. Secondary outcomes included the occurrence of a central nervous system (CNS) or systemic hemorrhage.

RESULTS

During the study period, 312 patients underwent elective aneurysm coiling and six (2 %) thromboembolic events occurred; three (1 %) occurred in the group that received the anti-thromboembolic regimen (261 patients) and three (6 %) occurred in the group that did not receive the regimen (51 patients), resulting in a statistically significant difference (P = 0.024). Both the presence of a hypercoagulable state (P = 0.014) and the lack of the anti-thromboembolic regimen (P = 0.043) were significantly associated with the occurrence of a thromboembolic event.

CONCLUSIONS

This study provides evidence that the regimen described here is safe and reduces thromboembolic complications during elective aneurysm coiling. Ours is likely the most aggressive regimen in the published literature and significantly reduced the rate of thromboembolism without any significant increase hemorrhagic complications.

Is eptifibatide a safe and effective rescue therapy in thromboembolic events complicating cerebral aneurysm coil embolization? Single-center experience in 42 cases and review of the literature

INTRODUCTION

Thromboembolic complications are the most frequent perioperative complications of endovascular treatment of intracranial aneurysms. Even if the effectiveness of glycoprotein IIb/IIIa inhibitors has been reported, the outcomes in published clinic data are contradictory. This study aims to assess the effectiveness and the safety of eptifibatide in thromboembolic complications during intracranial aneurysm embolization procedure.

METHODS

Between 2006 and 2012, 650 patients with intracranial aneurysm were treated using endovascular coil embolization, and in 62 cases (9.5 %), an intra-arterial thrombus developed. Glycoprotein IIb/IIIa inhibitor was administrated in 45 of them who required a rescue treatment. These 45 patients were treated with an intra-arterial bolus (0.2 mg/kg) of eptifibatide. We respectively reviewed the angiographic and clinical outcomes, and the periprocedural complications of the rescue treatment.

RESULTS

No intra- or early postoperative (48 h) bleeding was observed after treatment. A total recovery of the entire arterial tree (TICI 3) was established in 28 cases (62.2 %), a partial revascularization in 13 cases (28.8 %) (5 TICI 2A and 8 TICI 2B), and no revascularization or reperfusion (TICI 0 or TICI 1) in 4 cases (9 %). Eptifibatide was more effective on proximal obstructions and in-stent occlusions than on peripheral distal thrombus, which were completely disintegrated one time out of three.

CONCLUSION

Intra-operative intra-arterial use of eptifibatide does not imply an increase of hemorrhagic events. Even if eptifibatide allows for a high rate of arterial recanalization, its effectiveness seems to be less important in cases of distal occlusions.

Endovascular Therapy for Asymptomatic Unruptured Intracranial Aneurysms

Background and Purpose—

National registration studies (the Japanese Registry of Neuroendovascular Therapy [JR-NET] and JR-NET2) have determined the current status and outcomes of neuroendovascular therapy (neuro-EVT). We analyzed short-term outcomes of EVT for asymptomatic unruptured intracranial aneurysms (UIAs).

Methods—

We extracted periprocedural information about EVT for 4767 asymptomatic UIAs from 31 968 registered procedural records of all EVT in the JR-NET and JR-NET2 databases. We assessed the features of the aneurysms and procedures, immediate radiographic findings, procedure-related complications, and clinical outcomes at 30 days after the procedures.

Results—

We located 80.0% of UIAs in the anterior circulation, and the most frequent were paraclinoid. The diameter of 2.5%, 32.9%, 51.9%, 12.0%, and 0.7% of the UIAs was <3, 3 to 4, 5 to 9, 10 to 19, and >20 mm, respectively. EVT failed in only 2.1%. Adjunctive techniques were applied in 54.8% of procedures. Pre- and postprocedural antiplatelet agents were prescribed in 85.6% and 84.0%, respectively, of the procedures. The immediate radiographic outcomes of 57.7%, 31.9%, and 10.0% of the UIAs comprised complete occlusion, residual necks, and residual aneurysms, respectively. Complications that were associated with 9.1% of procedures comprised 2.0% hemorrhagic and 4.6% ischemic, and the 30-day morbidity and mortality rates were 2.12% and 0.31%, respectively.

Conclusions—

The radiographic results of EVT for asymptomatic UIAs in Japan were acceptable, with low mortality and morbidity rates.

Silent embolism after stent-assisted coiling of cerebral aneurysms: diffusion-weighted MRI study of 75 cases

PURPOSE

New ischemic brain lesions are common findings after cerebral diagnostic angiography and endovascular therapy. Diffusion-weighted MRI (DWI) can be used for detection of these lesions. The aim of the present study was to investigate the incidence of DWI lesions after stent-assisted coiling and the evaluation of possible risk factors.

METHODS

The study included a total of 75 consecutive patients treated with stent-assisted coiling. Post-procedural DWI of the brain was performed to detect ischemic lesions. Demographic data, aneurysm characteristics and angiographic parameters were correlated with properties of DWI lesions.

RESULTS

In post-procedural DWI, 48 of the 75 patients (64%) had 163 DWI lesions in a pattern consistent with embolic events. The number of patients with DWI lesions was significantly increased in older patients (≥55 years) and longer intervention times (≥120 min). The ischemic brain volume was significantly increased in older patients (≥55 years) as well as in patients who were implanted with a shorter stent (<20 mm).

CONCLUSIONS

Thromboembolic events are common after stent-assisted coiling with an incidence comparable to DWI studies after coiling alone. Despite several devices and low operator experience, stent-assisted coiling for intracranial aneurysms has a very low risk of permanent neurologic disability. Further studies are necessary to improve the safety of stent-assisted coiling for patients in conditions with increased risk potential (age, procedure time, stent length).

Monitoring of the heparinization in the rabbit animal model during endovascular interventions

INTRODUCTION

The purpose of this study was to monitor and to optimize heparinization during endovascular procedures in the New Zealand White Rabbit (NZWR) model.

METHODS

Right common carotid artery aneurysms were surgically created in 43 NZWR, with an average weight of 4,330 g (range 3,500-5,430 g). The activated partial thromboplastin time (aPTT) was measured during different stages of the interventional procedures. Blood samples were taken before and 10 min after administration of heparin and at the end of each endovascular procedure. We compared three different experimental groups: 100 U heparin, 500 U heparin and 100 U heparin plus pretreatment with aspirin and clopidogrel. The individual aPTT values were measured using a ball coagulometer.

RESULTS

The average baseline aPTT in the rabbit is 75.2 ± 18.9 s compared to a mean of 33 s (range 26-40 s) in humans. The dosages of heparin used achieved anticoagulation in all cases. Five hundred units of heparin increased the aPTT significantly more than 100 U. No difference was found between the aPTT obtained from the 100 U and the 100 U plus pretreatment group, as aspirin and clopidogrel do not affect the coagulation cascade.

CONCLUSION

One hundred units of heparin can achieve anticoagulation in a similar magnitude as needed in interventional procedures in humans. This fact enhances suitability of the rabbit animal model for the testing of intravascular devices.

Antiplatelet therapy for prevention of thromboembolic complications associated with coil embolization of unruptured cerebral aneurysms

Background: Antiplatelet agents are used during endovascular treatment of cerebral aneurysms to prevent thromboembolic complications.

Objective: The aim of this study was to investigate the efficacy of clopidogrel for the prevention of thromboembolic complications during elective coil embolization of unruptured cerebral aneurysms.

Methods: Sixty-three patients prospectively received oral clopidogrel 75mg/day from 3 days before and for 1 day after the procedure at our institute (Kohnan Hospital, Sendai, Japan) during 2007.

Results: At 24 hours post-coiling, significantly less high-intensity areas, detected by MRI with diffusion-weighted imaging (MRI-DWI), were observed in clopidogrel-treated patients compared with a historical control cohort of aspirin (acetylsalicylic acid)-treated patients (13/63 [20.6%] vs 27/69 [39.1%]; p = 0.02), primarily due to a statistically significantly lower rate during repair of small (<10mm) lesions (p = 0.008).Also, the rate of periprocedural thromboembolic events was lower in the clopidogrel than the aspirin cohort (2/63 [3.2%] vs 5/69 [7.2%]; p = 0.3).

Conclusions: Clopidogrel was generally well tolerated with no signs of hemorrhagic complications or liver dysfunction.

Heparin dosing is associated with diffusion weighted imaging lesion load following aneurysm coiling

BACKGROUND AND PURPOSE

Diffusion weighted imaging (DWI) may be used to evaluate post-coiling ischemia. Heparinization protocols for cerebral aneurysm coiling procedures differ among operators and centers, with little literature surrounding its effect on DWI lesions. The goal of this study was to determine which factors, including heparinization protocols, may affect DWI lesion load post-coiling.

MATERIALS AND METHODS

A review of 135 coiling procedures over 5 years at our centre was performed. Procedural data including length of procedure, number of coils used, stent or balloon assistance and operators were collected. Procedures were either assigned as using a bolus dose (>2000 U at any one time) or small aliquots of heparin (≤2000 U). Postprocedure DWI was reviewed and lesions were classified as small (< 5mm), medium (5-10 mm) or large (>10 mm). The cases were then classified into group 1 (≤5 small lesions) or group 2 (>5 small lesions or ≥1 medium or large lesion). Multivariate regression of the procedural variables for the two groups was calculated. A p value of <0.05 was considered significant.

RESULTS

There were 78 procedures in group 1 and 57 procedures in group 2. Patients who received small aliquots (n=37) versus boluses of heparin (n=98) intraprocedurally had significantly greater frequency and size of DWI lesions (p=0.03). None of the other procedural variables was found to impact on lesion load.

CONCLUSIONS

More substantial DWI lesions were associated with small aliquots of heparin dosage compared with bolus doses. Heparin boluses should be preferentially administered during aneurysm coiling.

Delayed ipsilateral parenchymal hemorrhage following flow diversion for the treatment of anterior circulation aneurysms

BACKGROUND AND PURPOSE

The PED is a flow-diverting stent designed for the treatment of cerebral aneurysms. We report 4 cases of delayed ipsilateral IPH following the technically successful treatment of anterior circulation aneurysms with the PED.

MATERIALS AND METHODS

Clinical and imaging data from all patients undergoing aneurysm treatment with the PED at 2 institutions were analyzed to assess the incidence of delayed IPH after treatment with the PED.

RESULTS

A total of 66 patients (47 anterior circulation) with cerebral aneurysms underwent treatment with a PED between January 2008 and November 2010. Four patients experienced delayed periprocedural IPH, all after the treatment of anterior circulation aneurysms (8.5%, 4/47). The aneurysm size ranged from 5 to 21 mm. All IPHs occurred within the cerebral hemisphere, ipsilateral to the treated aneurysm, and were anatomically remote from the treated aneurysms. All procedures were uncomplicated, and patients emerged from general anesthesia at neurologic baseline. The hemorrhages became clinically evident between 1 and 6 days after the procedure. Two patients had unfavorable outcomes (mRS scores, 4 and 6).

CONCLUSIONS

Delayed IPH may occur after the treatment of anterior circulation aneurysms with flow diverters. This complication does not seem to be restricted to a specific aneurysm subtype and does not seem to be related to an intraprocedural complication or solely attributable to DAT.

Deep venous thrombosis prophylaxis

Although clinicians are generally advised to use prophylactic therapy to reduce the risk for developing deep venous thrombosis in patients after repair of ruptured aneurysms, limited data are available to guide specific therapeutic decisions. An electronic literature search was conducted to identify English-language articles that addressed prophylactic treatment for deep venous thrombosis after subarachnoid hemorrhage published between 1980 and March 2011. A total of 12 articles were included in this review, including seven original research studies and one meta-analysis. The incidence of deep venous thrombosis varied among studies, with the highest incidence reported with prospective ultrasound screening. Poor-grade patients are at highest risk. Mechanical prophylactic methods appear to be modestly effective as monotherapy, without significant risk for the typical patient with subarachnoid hemorrhage. Unfractionated heparin is moderately effective but carries a small risk of intracranial hemorrhage. Low molecular weight heparin has been linked to an increased risk for intracranial hemorrhage. Limited data are available to direct the timing and duration of prophylactic therapies.

Endovascular treatment of unruptured intracranial aneurysms

We report the clinical and angiographic results of endovascular treatment of unruptured intracranial aneurysms. Over a three-year period, 80 unruptured aneurysms in 74 patients were electively treated with endovascular management. One aneurysm was diagnosed during investigations for a second ruptured aneurysm, 54 aneurysms were incidentally discovered, 18 aneurysms presented with symptoms of mass effect and seven aneurysms presented with symptoms of brain stem ischemia. Mean size of the 80 unruptured aneurysms was 12.5±8.0 mm (range, 2-39 mm). Thirty-six aneurysms (45%) were small (<10 mm), 38 aneurysms (47.5%) were large (10-25 mm), and six aneurysms (7.5%) were giant (25-39 mm). Forty-eight wide-necked aneurysms (60%) were coiled with the aid of a supporting device. The mortality rate was 1.25%, and the overall morbidity was 1.25%. Of these, one of the patients suffered a stroke, leading to severe disability (1.25%). In one patient, the aneurysm ruptured during treatment, resulting in death. Initial aneurysm occlusion was complete (100%) in 76.25% aneurysms, nearly complete (90%-98%) in 10% aneurysms and incomplete (60%-85%) in 13.75% aneurysms. Follow-up angiography was available in 67 patients with 73 treated aneurysms (91.25%) from one to 36 months (mean 9.3 months); partial reopening occurred in 7.5%, mainly large and giant aneurysms (5.5%). Additional coiling was performed in four aneurysms. There were no complications in additional treatments. At 14.1-month clinical follow-up (range, 2 to 36 months), mRS score was 0 in 78.75% patients, 1 in 10% patients, 2 in 8.75% and 3 in 1.25%. There was no aneurysmal rupture during the follow-up period. Endovascular treatment of unruptured intracranial aneurysms has low procedural mortality and morbidity rates.

Crescent sign on magnetic resonance angiography revealing incomplete stent apposition: correlation with diffusion-weighted changes in stent-mediated coil embolization of aneurysms

Object

Few data are available on how closely stents appose the luminal vessel wall in stent-mediated coil embolization of intracranial aneurysms and on the effect of incomplete stent apposition on procedural thromboembolic complications.

Methods

Postprocedural 3-T MR diffusion-weighted imaging and time-of-flight angiography were obtained in 58 patients undergoing stent-mediated coil embolization of aneurysms using the Enterprise closed-cell and Neuroform open-cell self-expanding intracranial microstents.

Results

A distinctive semilunar signal pattern, identified using 3-T MR angiography, represented flow outside the confines of the stent struts in patients in whom Enterprise but not Neuroform devices were used. This pattern, designated as the crescent sign, was confirmed to correspond to incomplete stent apposition by use of high-resolution angiographic flat-panel CT scanning revealing flow ingress into and egress out of the isolated luminal wedge. The presence of the crescent sign was seen in 18 of 33 Enterprise-treated but in 0 of 25 Neuroform-treated cases, and was more likely in stents delivered in the tortuous internal carotid artery (p = 0.034). The crescent sign was strongly predictive of ipsilateral postprocedural lesions seen on diffusion-weighted imaging in the entire population (OR 18, 95% CI 4.33–74.8; p < 0.0001). In the Enterprise stent subset, ipsilateral lesions were detected on diffusion-weighted imaging in 15 (45%) of 33 cases; the crescent sign was seen in 12 (80%) of 15 patients with ipsilateral lesions on diffusion-weighted imaging, but in only 6 of 18 patients without lesions (OR 8, 95% CI 1.61–39.6; p = 0.006).

Conclusions

Incomplete stent apposition is detectable on 3-T MR angiography as a crescent sign, and was found to be highly prevalent in Enterprise closed-cell design stents used to assist coil embolization of aneurysms. Incomplete stent apposition was also associated with periprocedural ipsilateral hyperintense lesions on diffusion-weighted imaging. These results identify an association between incomplete stent apposition and thromboembolic complications in stent-mediated coil embolization of intracranial aneurysms.

Vascular perforation during coil embolization of an intracranial aneurysm: the incidence, mechanism, and clinical outcome

Purpose

The occurrence of a vascular perforation during an endovascular procedure is an unexpected and feared complication which can be fatal. However, the incidence, risk or the mechanism of vascular perforation which can occur in the endovascular management of aneurysms remains unclear. The purpose of the present study was to evaluate the incidence of vascular perforation during endovascular coil embolization of a cerebral aneurysm, and to reveal characteristics and clinical outcomes.

Materials and Methods

We reviewed the endovascular coil embolization procedures performed for the treatment of 459 aneurysms. Incidence and clinical, radiological and technical data of patients concerning the vascular perforation were reviewed from medical records and radiological findings.

Results

The incidence of procedure-related vascular perforation in our patient group was 0.87% (4/459). For all four occurrences, the cause of vascular perforation involved the guidewire or microcatheter. Clinical outcome was poor in 2 cases and favorable in 2 cases.

Conclusion

Although rare, the occurrence of vascular perforation during coil embolization for treatment of an aneurysm may be fatal. Therefore, careful management of the guidewire is suggested for the prevention of vascular rupture during an endovascular procedure.

Cost-effectiveness of magnetic resonance angiography versus intra-arterial digital subtraction angiography to follow-up patients with coiled intracranial aneurysms

BACKGROUND AND PURPOSE

To follow up patients with coiled intracranial aneurysms, magnetic resonance angiography (MRA) is a promising noninvasive alternative to current standard intra-arterial digital subtraction angiography (IA-DSA). MRA test results do not always concord with those of IA-DSA, and the impact of discrepancies on health benefits and costs is unknown. We evaluated the cost-effectiveness of follow-up with MRA vs IA-DSA to assess whether in this setting MRA may replace IA-DSA.

METHODS

We studied aneurysm occlusion on MRA in addition to follow-up IA-DSA in 310 patients with 341 coiled intracranial aneurysms. The observed sensitivity (82%) and specificity (89%) of MRA for detection of reopening with IA-DSA as a reference were used as input for a Markov decision-analytic model. Other determinants were derived from the literature. We compared life expectancy, quality-adjusted life-years (QALY), costs, and expected number of events for the two strategies.

RESULTS

Follow-up with MRA yielded similar life expectancy (MRA, 26.66 years; IA-DSA, 26.63 years; difference, 0.03 years; 95% CI, -0.17-0.23) and QALY (MRA, 10.96; IA-DSA, 10.95; difference, 0.01 QALY; 95% CI, -0.05-0.08) at lower costs (MRA, $7003; IA-DSA, $8241 per patient; difference, -$1238; 95% CI, -2617--36). The expected number of events was comparable except for complications from IA-DSA.

CONCLUSIONS

MRA provided equivalent health benefits as IA-DSA and was cost-saving. MRA dominates and should replace routine IA-DSA to follow-up patients with coiled aneurysms.

Influence of Coil Geometry on Intra-Aneurysmal Packing Density: Evaluation of a New Primary Wind Technology

Introduction: This prospective randomized double-blinded in-vitro study was conducted to determine the relative Packing Density (PD) of the new Deltapaq coil (Micrus Endovascular) as compared to Micrus’s conventional filling CHE (Helipaq) and finishing CFS (Ultipaq) coils. Methods: Two physicians independently deployed the coils under fluoroscopy into a 4mm berry shaped glass aneurysm. Each coil tested was a 4mm × 35cm coil specially made for this study. Physicians and observer were blinded as to the type of coil. Five samples per group, per operator, were deployed. Results: mean PD were 36.6% (Helipaq), 37.9% (Ultipaq) and 40.4% (Deltapaq). Two-sample T-test showed a significantly higher PD of Deltapaq versus Helipaq (p < 0.022). Discussion: Higher coil PD and better neck coverage may provide an increased biomechanical stability and may potentially reduce the recanalization rate of aneurysms. Conclusion: The new Deltapaq coil may have the potential to achieve higher packing densities in the treatment of aneurysms.

Symptomatic and Silent Ischemia Associated With Microsurgical Clipping of Intracranial Aneurysms

Background and Purpose— Silent ischemic events are known to occur during diagnostic and interventional endovascular procedures between 10% and 69% of the time. The occurrence of silent and symptomatic ischemic events in the surgically treated population is not known, although atherosclerotic changes of intracranial vessels or within the aneurysms wall or neck area are seen often during surgery.

Methods— Patients with unruptured and ruptured intracranial aneurysms treated by microsurgical clipping were prospectively evaluated with MRI using diffusion-weighted imaging sequences before and within 24 hours after surgery. Patients were evaluated clinically before and after surgery. During surgery, the overall and maximal time of temporary occlusion as well as the total number of temporary and finally applied clips was noted. Diffusion-weighted images were analyzed with determination and characterization of diffusion-weighted imaging abnormalities.

Results— Thirty-six patients with 51 aneurysms were included. One symptomatic and 5 silent ischemic lesions were found in 5 patients. This represents a risk of silent ischemia of 9.8% per treated aneurysm and a risk of symptomatic stroke of 2%. The most significant risk factor in increasing order was: age ( P <0.05), presence of thrombus ( P <0.05), number of final clips applied ( P <0.05), number of temporary clips used ( P <0.01), total time of temporary clip occlusion ( P <0.001), and maximal time of temporary occlusion ( P <0.001).

Conclusions— The risk of silent and symptomatic ischemic events during microsurgical clipping of intracranial aneurysms seems to be low. Microsurgical clipping is safe and should continue to be strongly considered as a treatment option.

Abciximab for thrombolysis during intracranial aneurysm coiling

INTRODUCTION

Thrombotic events are a common and severe complication of endovascular aneurysm treatment with significant impact on patients' outcome. This study evaluates risk factors for thrombus formation and assesses the efficacy and safety of abciximab for clot dissolution.

MATERIALS AND METHODS

All patients treated with abciximab during (41 patients) or shortly after (22 patients) intracranial aneurysm coil embolisation were retrieved from the institutional database (2000 to 2007, 1,250 patients). Sixty-three patients (mean age, 55.3 years, +/- 12.8) had received either intra-arterial or intravenous abciximab. Risk factors for clot formation were assessed and the angiographic and clinical outcome evaluated.

RESULTS

No aneurysm rupture occurred during or after abciximab application. The intra-procedural rate of total recanalisation was 68.3%. Thromboembolic complications were frequently found in aneurysms of the Acom complex and of the basilar artery, whilst internal carotid artery aneurysms were underrepresented. Two patients died of treatment-related intracranial haemorrhages into preexisting cerebral infarcts. Two patients developed a symptomatic groin haematoma.

CONCLUSIONS

Abciximab is efficacious and safe for thrombolysis during and after endovascular intracranial aneurysm treatment in the absence of preexisting ischaemic stroke.

Immediate clinical outcome of patients harboring unruptured intracranial aneurysms treated by endovascular approach: results of the ATENA study

BACKGROUND AND PURPOSE

The management of unruptured intracranial aneurysms remains controversial and the results of endovascular treatment are not precisely known because no prospective data exist. The first prospective multicenter study (ATENA) was conducted in Canada and France to determine clinical outcome and risks of this treatment.

METHODS

Six hundred forty-nine patients harboring a total of 1100 aneurysms from 27 Canadian and French neurointerventional centers were prospectively and consecutively treated by endovascular coil embolization. Of these, 739 unruptured intracranial aneurysms were treated during 700 procedures. Aneurysms were selectively treated in the great majority of cases (98.4%) with coils alone (54.5%), the balloon remodeling technique (37.3%), or stenting (7.8%).

RESULTS

Endovascular treatment failed in 32 aneurysms (4.3%). Technical adverse events with or without clinical modification were encountered in 15.4% of patients and included thromboembolic complications (7.1% per procedure), intraoperative rupture (2.6% per procedure), and device-related problems (2.9% per procedure). Adverse events associated with transient or permanent neurological deficit or death were encountered in 5.4% of cases. The 1-month morbidity and mortality rates were 1.7% and 1.4%, respectively.

CONCLUSIONS

Endovascular treatment of unruptured intracranial aneurysms is feasible in a high percentage of cases with low morbidity and mortality rates.

Endovascular treatment of intracranial aneurysms in patients 65 years or older: clinical outcomes

BACKGROUND AND PURPOSE

A controversial discussion concerning treatment of aneurysms in elderly patients exists. The aim of this study was to analyze clinical outcome in patients older than 65 years harboring intracranial aneurysms after endovascular treatment.

MATERIALS AND METHODS

A total of 108 patients aged 65 years or older (mean age, 72 years, range, 65-87 years) were selected for endovascular treatment between 1997 and 2005. A total of 85 (78.7%) patients had an acute subarachnoid hemorrhage (SAH). SAH was classified according to Hunt and Hess (HH) grade: I (n = 16), II (n = 11), III (n = 33), IV (n = 19), and V (n = 6). There were 69 aneurysms that were small; 46, medium; 8, large; and 5, giant. Occlusion rate was categorized as complete (100%), subtotal (95% to 99%), and incomplete (<95%) obliteration according to the Raymond scale.

RESULTS

Endovascular treatment was technically feasible in 108 of 113 aneurysms. Complete occlusion could be achieved in 80 patients; basal remnant was seen in 26 patients and a dog ear in 2 patients. Procedural complications included thrombotic vessel occlusion (n = 9), aneurysmal rupture (n = 4), and stenosis of the parent vessel (n = 2). The Glasgow Outcome Scale (GOS) for the patients with SAH after 6 months was good recovery (n = 43), moderate disability (n = 12), severe disability (n = 28), persistent vegetative state (n = 5), and death (n = 18). Outcome for the patients with unruptured aneurysms was good recovery in all 23 patients. On follow-up digital subtraction angiography (DSA) in 69 patients, complete aneurysmal occlusion was confirmed in 81% after 6 months. Five patients with recanalization were re-treated with coiling.

CONCLUSION

Endovascular treatment of ruptured and unruptured intracranial aneurysms in this subgroup was safe and effective.

Long-term results with Matrix coils vs. GDC: an angiographic and histopathological comparison

INTRODUCTION

The aim of the study was to compare standard platinum Guglielmi detachable coils (GDC) with coated platinum coils (Matrix; both Boston Scientific, Fremont, CA) regarding handling, complications, occlusion and recanalization rate after 3 and 6A months.

METHODS

Aneurysms in the right common carotid artery were created in 25 rabbits. The animals were divided into five groups of five animals each. The animals of group 1 (the control group) received no treatment of the induced aneurysms, the animals of groups 2 and 3 (killed at 3 and 6A months) were treated with standard GDC, and the animals of groups 4 and 5 (killed at 3 and 6A months) were treated with Matrix coils.

RESULTS

Histopathological evaluation showed organized thrombus formation and connective tissue with neovascularization around the implanted coils in all the treated groups. The achieved occlusion rates in groups 2 and 3 were identical to those in groups 4 and 5. Thus the long-term results of aneurysm treatment with GDC and Matrix coils show no differences regarding occlusion and recanalization rates. The only noticeable difference was the difference in handling. More force was required to pushing the Matrix coils forward through the microcatheter and there was more friction in coil interaction in the aneurysm.

CONCLUSION

The bioactive coating of the Matrix coil produces no significant benefit in achieving higher occlusion and lower recanalization rates, and the coil is more difficult to handle. Future bioactive coils must be shown to produce significantly better long-term results than GDC and their ease of handling has to be improved.

Dual antiplatelet therapy monitoring for neurointerventional procedures using a point-of-care platelet function test: a single-center experience

BACKGROUND AND PURPOSE

Growing evidence of the relationship between poor antiplatelet response and occurrence of clinical events elicited the need of monitoring the response which has not been part of our daily practice. We present our initial experience with a new point-of-care antiplatelet-function test (VerifyNow assay) in neurointerventional procedures.

MATERIALS AND METHODS

Among the 106 consecutive patients from July 2006 to April 2007, ninety-eight met the inclusion criteria. Our preferred antiplatelet regimen was aspirin (325 mg daily) and clopidogrel (300 mg of loading dose followed by 75 mg daily) starting 5-10 days before the procedure. The test results were reported as aspirin-reaction unit (ARU) for aspirin and P2Y(12) reaction units (PRU), baseline (BASE), and percentage inhibition for the P2Y(12) assay and were summarized as mean +/- SD of the values. We analyzed the effects of several factors of poor clopidogrel response (<40% inhibition). The occurrence of thrombotic events was recorded.

RESULTS

The mean ARU of aspirin assays was 438.3 +/- 47.9 (range, 350-632), and the response was poor in 2 patients (2.1%). For clopidogrel, the mean of the BASE, PRU, and percentage inhibition was 356.8 +/- 56.3 (range, 234-495), 198.9 +/- 104.4 (range, 8-401), and 45.2 +/- 27.1% (range, 0-98), respectively. Forty-two patients (42.9%) showed poor response. Multivariate analysis showed greater body weight (81.9 Kg +/- 19.1 kg versus 69.9 +/- 15 kg) in the poor-response group. All 3 cases of intraprocedural thrombosis (3.1%) were observed only in the poor-response group.

CONCLUSION

We observed a high frequency of poor clopidogrel responses in the neurointerventional setting. Routine monitoring of the drug response would be helpful for the early identification of poor antiplatelet responders so that we may modify the regimen and/or treatment plan.

Feasibility, procedural morbidity and mortality, and long-term follow-up of endovascular treatment of 321 unruptured aneurysms

BACKGROUND AND PURPOSE

The purpose of our study was to evaluate the technical feasibility, morbidity and mortality, and durability of occlusion of unruptured aneurysms treated with Guglielmi detachable coils (GDCs) with a long-term follow-up.

MATERIALS AND METHODS

Between January 1998 and January 2005, we treated 321 unruptured aneurysms with GDCs in 5 neuroradiologic institutions. During this period, 63% of unruptured aneurysms were treated by endovascular technique. Procedural feasibility, technical complications, morbidity and mortality, and acute and long-term angiographic occlusion were assessed.

RESULTS

Overall technical feasibility of coiling treatment was 94%; 302 aneurysms were treated by endovascular technique. At the end of the initial procedure, acute occlusion was classified as complete in 207 cases (70%), subtotal in 84 cases (26.1%), and incomplete in 11 cases (3.9%). Ischemic complications were observed in 28 patients (9%); 8 patients (2.6%) had perforation of their aneurysms. Treatment-related morbidity was 14.4%, and morbidity with clinical complications was evaluated at 7.7% (n = 23 patients). Five patients (1.7%) died as a result of aneurysm perforation. Final follow-up angiograms, after 9 secondary treatments, demonstrated complete occlusion in 193 patients (69.5%), subtotal in 80 aneurysms (28.5%), and incomplete occlusion in 5 (1.8%). Nineteen patients were lost to follow-up (6.3%).

CONCLUSION

Endovascular coiling with detachable coils is an attractive option for treatment of unruptured aneurysms. This method of treatment is safe with a low rate of complications. Prospective studies with longer follow-up periods are needed to assess the long-term durability of occlusion in unruptured aneurysms.

Treatment related morbidity of unruptured intracranial aneurysms: results of a prospective single centre series with an interdisciplinary approach over a 6 year period (1999-2005)

OBJECTIVES

To review the angiographic and clinical outcome of patients with unruptured intracranial aneurysm(s) (UIA) with regard to complications and successful obliteration by surgical clipping or endovascular coiling.

METHODS

Data were derived from a prospective database of intracranial aneurysms from June 1999 to May 2005. All patients were followed-up for 6 months using the modified Rankin Scale (mRS). Favourable outcome was classified as mRS 0-2. From a total of 691 patients included in the database, 173 harboured 206 UIA of whom 118 patients (133 UIA) were treated.

RESULTS

Primary treatment assignment was surgical repair in 91 UIA and endovascular treatment in 42. In 3 UIA (7.1%), endovascular treatment was not feasible and had to be abandoned. Definite treatment was surgery in 94 UIA (81 patients) and endovascular obliteration in 39 UIA (37 patients). There were no deaths related to any treatment. Immediately after treatment, 6.4% of the surgical and 7.7% of the endovascular patients showed new neurological deficits, mainly related to cerebral ischaemia. After 6 months, 3 (2.3%) patients had a treatment related unfavourable outcome, defined as mRS >2, 2 patients after surgical and 1 patient after endovascular aneurysm repair (not statistically different, p = 0.3; Fisher's exact test). This led to an overall satisfactory outcome in 97.9% of surgically and 97.4% of endovasculary treated UIA. After surgical clipping, complete occlusion of the aneurysm was achieved in 88 (93.6%) and near complete (small residual neck) in 4 (4.3%) of 94 UIA. Two small posterior communicating artery aneurysms with a fetal type posterior communicating artery were wrapped. After endovascular treatment, obliteration was complete in 26 (66.7%). Small residual neck was seen in 13 (33.3%), but none of the UIA showed residual aneurysm filling. Five patients in the endovascular group (13.9%) underwent repeated endovascular treatment after aneurysm recanalisation.

CONCLUSIONS

If patients are carefully selected and individually assigned to their optimum treatment modality, UIA can be obliterated by surgery or endovascular treatment in the majority of patients, with a low percentage of unfavourable outcomes. In this series, the outcome was not dependent on treatment. However, the rate of recanalisation of UIA is higher after endovascular obliteration. After diagnosis of an UIA, an individual interdisciplinary decision is essential for each patient to provide the optimum management.