Tag: Aneurysm

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A New Aneurysm Occlusion Classification after the Impact of Flow Modification

Classification of angiographic results after endovascular treatment with any technique

AJNR Am J Neuroradiol 37:19 –24

A new classification is proposed for cerebral aneurysms treated with any endovascular technique, for example, coiling with or without adjunctive devices, flow diversion, intrasaccular flow modifiers, or any combination of the above.

Raymond-Roy Occlusion Classification is expanded with novel subgroups such as class 1 represents complete occlusion and is subdivided if a branch is integrated to, or originated from, the aneurysm sac; class 2 represents neck filling; class 3 represents incomplete occlusion with aneurysm filling as in the previous classification; and class 4 describes the immediate postoperative status after extra- or intrasaccular flow modification treatment. A new concept, “stable remodeling,” is included as class 5, which represents filling in the neck region that stays unchanged or reduced, as shown with at least 2 consecutive control angiographies, at least 6 months apart, for not <1 year, or the remodeled appearance of a dilated and/or tortuous vessel in continuation with the parent artery without sac filling.

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Resolution of Oculomotor Nerve Palsy Secondary to Posterior Communicating Artery Aneurysms- Comparison of Clipping and Coiling

Advanced Technical Skills Are Required for Microsurgical Clipping of Posterior Communicating Artery Aneurysms in the Endovascular Era-0

Neurosurgery 77:931–939, 2015

Previous studies have attempted to determine the best treatment for oculomotor nerve palsy (ONP) secondary to posterior communicating artery (PCoA) aneurysms, but have been limited by small sample sizes and limited treatment.

OBJECTIVE: To analyze the treatment of ONP secondary to PCoA with both coiling and clipping in ruptured and unruptured aneurysms.

METHODS: Data from 2 large academic centers was retrospectively collected over 22 years, yielding a total of 93 patients with ONP secondary to PCoA aneurysms. These patients were combined with 321 patients from the literature review for large data analyses. Onset symptoms, recovery, and time to resolution were evaluated with respect to treatment and aneurysm rupture status.

RESULTS: For all patients presenting with ONP (n = 414) 56.6% of those treated with microsurgical clipping made a full recovery vs 41.5% of those treated with endovascular coil embolization (P = .02). Of patients with a complete ONP (n = 229), full recovery occurred in 47.3% of those treated with clipping but in only 20% of those undergoing coiling (P = .01). For patients presenting with ruptured aneurysms (n = 130), full recovery occurred in 70.9% compared with 49.3% coiled patients (P = .01). Additionally, although patients with full ONP recovery had a median time to treatment of 4 days, those without full ONP recovery had a median time to treatment of 7 days (P = .01).

CONCLUSION: Patients with ONP secondary to PCoA aneurysms treated with clipping showed higher rates of full ONP resolution than patients treated with coil embolization. Larger prospective studies are needed to determine the true potential of recovery associated with each treatment.

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In-Pipeline Stenosis: Incidence, Predictors, and Clinical Outcomes

In-Pipeline Stenosis- Incidence, Predictors, and Clinical Outcomes

Neurosurgery 77:875–879, 2015

The Pipeline Embolization Device is a widely utilized flow diverter in the treatment of intracranial aneurysms.

OBJECTIVE: To assess the incidence, clinical significance, predictors, and outcomes of in-Pipeline stenosis (IPS).

METHODS: Angiographic studies in 139 patients treated between 2011 and 2013 were independently reviewed by 2 authors for the presence of IPS. Multivariable logistic regression analysis was conducted to determine predictors of IPS.

RESULTS: A total of 21 (15.8%) patients demonstrated some degree of IPS during the follow-up period at a mean time point of 6.7 months (range, 3-24 months). The stenosis was mild (,50%) in 11 patients, moderate (50%-75%) in 5, and severe (.75%) in 6. None were symptomatic or required further intervention. Sixteen of these 22 patients (73%) had IPS detected within 6 months. IPS was noted in 7.6% (1/13) of patients with posterior circulation aneurysms vs 16.7% (21/126) of those with anterior circulation aneurysms (P = .03). The rate of IPS was 60% (3/5) in patients who did not receive aspirin vs only 14.2% (19/134) in those who received aspirin (P = .02). In multivariable analysis, no aspirin therapy (odds ratio, 10.0; 95% confidence interval, 1.4-67.7; P = .02) and internal carotid artery aneurysm location (odds ratio, 3.1; 95% confidence interval, 1.1-8.8; P = .03) were strong independent predictors of IPS.

CONCLUSION: IPS is a common, early, and mostly benign complication. Patients with internal carotid artery aneurysms are more likely to develop IPS. Aspirin plays a key role in preventing IPS. The results of this study further support the safety of flow diverters.

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Extended endoscopic endonasal transclival clipping of posterior circulation aneurysms

Extended endoscopic endonasal transclival clipping of posterior circulation aneurysms

Acta Neurochir (2015) 157:2077–2085

Transcranial clipping of most posterior circulation aneurysms is one of the most difficult procedures, with high morbidity, and endovascular coiling is an alternative with less risk, but is not devoid of complications and not suitable for all aneurysms. Here we describe four cases of posterior circulation aneurysms clipped via the extended endoscopic endonasal transclival route. To the best of our knowledge, this is the first report of basilar top and posterior cerebral artery aneurysms being clipped endonasally.

Methods and results Four patients with posterior circulation aneurysms underwent extended endoscopic endonasal transclival clipping of the aneurysm. The age range was 35– 70 years. There were two males and two females. Three of the four patients presented after the rupture of aneurysms, and the other patient presented with sudden-onset left hemiparesis probably due to thromboembolism from a large unruptured left posterior cerebral artery (PCA) aneurysm. On evaluation with four-vessel digital subtraction angiography (DSA), two patients had a basilar apex aneurysm, one had a basilar trunk aneurysm, and the other had a PCA (P1) aneurysm. Postoperatively, two patients had good recovery. One patient with a PCA aneurysm and another with a basilar apex aneurysm had fresh postoperative deficits. One patient developed postoperative CSF rhinorrhea.

Conclusion Endoscopic extended transnasal surgery is an expanding field in neurosurgery with a steep learning curve. With improvement in techniques and instrumentation the use of this approach for clipping posterior circulation aneurysms can become an effective alternative in the treatment of aneurysms.

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Adenosine-induced transient asystole during intracranial aneurysm surgery

Adenosine-induced transient asystole

Acta Neurochir (2015) 157:1879–1886

Several flow-arrest techniques have been introduced for the treatment of complex aneurysms that cannot be treated with conventional clipping or endovascular coil embolization. Adenosine-induced transient asystole is an alternative method of flow arrest. However, given the limited number of studies that have reported on this topic, there is no consensus regarding the dose, regimen, efficacy, and potential risks of adenosine.

Method A total of 22 aneurysms in 22 different patients that underwent adenosine-induced transient asystole during aneurismal neck clipping within the past 4 years were retrospectively reviewed. Adenosine was administrated intravenously in a test-incremental manner (starting with 6–12 mg and then giving additional doses as needed) in 11 patients and in an estimated manner (pre-calculated as 0.3–0.4 mg/kg) in 11 patients.

Results Overall, the study consisted of 18 unruptured saccular aneurysms, three ruptured saccular aneurysms, and a ruptured pseudoaneurysm. Adenosine-induced transient asystole was used in cases of temporary clipping inability, wide necked aneurysm, deep-seated aneurysm, or a thin aneurysm wall. The number of administrations, dose (mg/kg in ideal body weight) and duration of asystole were 1–4 (mean, 2.3) times, 0.08–1.27 (mean, 0.36) mg/kg and 0–30 (mean 13) seconds in the test-incremental manner and 1–2 (mean, 1.09) times, 0.24–0.42 (mean, 0.34) mg/kg and 13–41 (mean, 24) seconds in the estimated manner, respectively. There was a linear relationship between the dose and the duration of asystole. Twenty out of 22 aneurysms were clipped successfully with adenosine-induced transient asystole. However, in the other two cases, additional suction decompression was required for the final clipping. Adenosine-related cardiologic complications occurred in two cases of self-limited atrial fibrillation during restoration of the cardiac rhythm.

Conclusions In our experience, adenosine-induced transient asystole was safe and helpful for satisfactory clipping of a complicated aneurysm. An estimated dose injection of adenosine was more convenient than the test-incremental method and did not result in serious cardiologic problems.

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Smoking and Intracranial Aneurysm Morphology

Smoking and aneurysms

Neurosurgery 77:59–66, 2015

Smoking is a well-known independent risk factor for both aneurysm formation and rupture. There is mounting evidence that aneurysm morphology beyond size can have a significant role in aneurysm formation and rupture risk by its effects on aneurysmal hemodynamics.

OBJECTIVE: To study the variation in aneurysm morphology between smokers and nonsmokers and delineate how changes in these factors might affect aneurysm formation and rupture.

METHODS: We generated 3-dimensional models of aneurysms and their surrounding vasculature by analyzing preoperative computed tomography angiograms with Slicer software. We then examined the association between smoking status and intrinsic, transitional, and extrinsic aspects of aneurysm morphology in both univariate and multivariate statistical analyses.

RESULTS: From 2005 to 2013, 199 cerebral aneurysms in never smokers and current smokers were evaluated/treated at a single institution with available computed tomography angiograms (102 in never smokers and 97 in current smokers). Multivariate analysis of current smokers vs never smokers demonstrated that aneurysms in current smokers were significantly associated with multiple aneurysms (odds ratio [OR]: 2.15, P = .03), larger daughter vessel diameters (OR: 3.13, P = .01), larger size ratio (OR: 1.78, P = .01), and location at the basilar apex (OR: 6.26, P = .02).

CONCLUSION: The differences in aneurysm morphology between smoking and nonsmoking patient populations may elucidate the effects of smoking on aneurysm formation and eventual rupture. We identified several aspects of aneurysm morphology significantly associated with smoking status that may provide the morphological basis for how smoking leads to increased aneurysm rupture.

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Morphological Parameters Associated With Middle Cerebral Artery Aneurysms

Morphological Parameters Associated With Middle Cerebral Artery Aneurysms

Neurosurgery 76:721–727, 2015

Morphological factors contribute to the hemodynamics of the middle cerebral artery (MCA).

OBJECTIVE: To identify image-based morphological parameters that correlated with the presence of MCA aneurysms.

METHODS: Image-based anatomic parameters obtained from 110 patients with and without MCA bifurcation aneurysms were evaluated with Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vascular architecture. We examined segment lengths, diameters, and vessel-to-vessel angles of the parent and daughter vessels at the MCA bifurcation. In order to reduce confounding by genetic and clinical risk factors, 2 control groups were selected: group A (the unaffected contralateral side of patients with unilateral MCA bifurcation aneurysms) and group B (patients without intracranial aneurysms or other vascular malformations). Univariate and multivariate analyses were performed to determine statistical significance.

RESULTS: One hundred ten patients who were evaluated from 2007 to 2014 were analyzed (73 patients with MCA aneurysms and 37 control patients). Multivariate analysis revealed that a smaller parent artery diameter (group A: odds ratio [OR] 0.20, P < .01, group B: OR 0.23, P < .01) and a larger daughter-to-daughter branch angle (group A: OR 1.01, P = .04, group B: OR 1.02, P = .04) were most strongly associated with MCA aneurysm presence after adjusting for other morphological factors.

CONCLUSION: Smaller parent artery diameter and larger daughter-to-daughter branch angles are associated with the presence of MCA bifurcation aneurysms. These easily measurable parameters may provide objective metrics to assess aneurysm formation and growth risk stratification in high-risk patients.

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Integration of Indocyanine Green Videoangiography With Operative Microscope: Augmented Reality for Interactive Assessment of Vascular Structures and Blood Flow

Integration of Indocyanine Green Videoangiography With Operative Microscope

Operative Neurosurgery 11:252–258, 2015

Preservation of adequate blood flow and exclusion of flow from lesions are key concepts of vascular neurosurgery. Indocyanine green (ICG) fluorescence videoangiography is now widely used for the intraoperative assessment of vessel patency.

OBJECTIVE: Here, we present a proof-of-concept investigation of fluorescence angiography with augmented microscopy enhancement: real-time overlay of fluorescence videoangiography within the white light field of view of conventional operative microscopy.

METHODS: The femoral artery was exposed in 7 anesthetized rats. The dissection microscope was augmented to integrate real-time electronically processed near-infrared filtered images with conventional white light images seen through the standard oculars. This was accomplished by using an integrated organic light-emitting diode display to yield superimposition of white light and processed near-infrared images. ICG solution was injected into the jugular vein, and fluorescent femoral artery flow was observed.

RESULTS: Fluorescence angiography with augmented microscopy enhancement was able to detect ICG fluorescence in a small artery of interest. Fluorescence appeared as a bright-green signal in the ocular overlaid with the anatomic image and limited to the anatomic borders of the femoral artery and its branches. Surrounding anatomic structures were clearly visualized. Observation of ICG within the vessel lumens permitted visualization of the blood flow. Recorded video loops could be reviewed in an offline mode for more detailed assessment of the vasculature.

CONCLUSION: The overlay of fluorescence videoangiography within the field of view of the white light operative microscope allows real-time assessment of the blood flow within vessels during simultaneous surgical manipulation. This technique could improve intraoperative decision making during complex neurovascular procedures.

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A Reverse-Action Clip Applier for Aneurysm Surgery

A Reverse-Action Clip Applier for Aneurysm Surgery

Operative Neurosurgery 11:230–234, 2015

Clipping is an important technique for cerebral aneurysm surgery. Although clip mechanisms and features have been refined, little attention has been paid to clip appliers. Clip closure is traditionally achieved by opening the grip of the clip applier. We reconsidered this motion and identified an important drawback, namely that the standard applier holding power decreased at the moment of clip release, which could lead to unstable clip application.

OBJECTIVE: To develop a forceps to address this clip applier design flaw.

METHODS: The new clip applier has a non–cross-type fulcrum that is closed at the time of clip release, with an action similar to that of a bipolar forceps or scissors. Thus, a surgeon can steadily apply the clip from various angles.

RESULTS: We successfully used our clip applier to treat 103 aneurysms. Although training was required to ensure smooth applier use, no difficulties associated with applier use were noted.

CONCLUSION: This clip applier can improve clipping surgery safety because it offers additional stability during clip release.

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Long-term Functional Outcomes and Predictors of Shunt-Dependent Hydrocephalus After Treatment of Ruptured Intracranial Aneurysms in the BRAT Trial: Revisiting the Clip vs Coil Debate

Hydrocephalus

Neurosurgery 76:608–615, 2015

Acute hydrocephalus is a well-known sequela of aneurysmal subarachnoid hemorrhage (SAH). Controversy exists about whether open microsurgical methods serve to reduce shunt dependency compared with endovascular techniques.

OBJECTIVE: To determine predictors of shunt-dependent hydrocephalus and functional outcomes after aneurysmal SAH.

METHODS: A total of 471 patients who were part of a prospective, randomized, controlled trial from 2003 to 2007 were retrospectively reviewed. All variables including demographic data, medical history, treatment, imaging, and functional outcomes were included as part of the trial. No additional variables were retrospectively collected.

RESULTS: Ultimately, 147 patients (31.2%) required a ventriculoperitoneal shunt (VPS) in our series. Age, dissecting aneurysm type, ruptured vertebrobasilar aneurysm, Fisher grade, Hunt and Hess grade, admission intraventricular hemorrhage, admission intraparenchymal hemorrhage, blood in the fourth ventricle on admission, perioperative ventriculostomy, and hemicraniectomy were significant risk factors (P < .05) associated with shunt-dependent hydrocephalus on univariate analysis. On multivariate analysis, intraventricular hemorrhage and intraparenchymal hemorrhage were independent risk factors for shunt dependency (P< .05). Clipping vs coiling treatment was not statistically associated with VPS after SAH on both univariate and multivariate analyses. Patients who did not receive a VPS at discharge had higher Glasgow Outcome Scale and Barthel Index scores and were more likely to be functionally independent and to return to work 72 months after surgery (P < .05).

CONCLUSION: There is no difference in shunt dependency after SAH among patients treated by endovascular or microsurgical means. Patients in whom shunt-dependent hydrocephalus does not develop after SAH tend to have improved long-term functional outcomes.

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Effect of Vascular Anatomy on the Formation of Basilar Tip Aneurysms

Effect of Vascular Anatomy on the Formation of Basilar Tip Aneurysms

Neurosurgery 76:62–66, 2015

The pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. Hemodynamic stress plays a particular role in the formation of intracranial aneurysms, which is conditioned by the geometry and morphology of the vessel trees.

OBJECTIVE: To identify image-based morphological parameters that correlated with the formation of basilar artery tip aneurysms (BTAs) in a location-specific manner.

METHODS: Morphological parameters obtained from computed tomographic angiographies of 33 patients with BTAs and 33 patients with aneurysms at other locations were evaluated with Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vascular architecture. We examined the diameters and vessel-to-vessel angles of the main vessels at the basilar bifurcation in patients with and without BTAs. To control for genetic and other risk factors, only patients with at least 1 aneurysm were included. Univariate and multivariate analyses were performed to determine statistical significance.

RESULTS: Sixty-six patients (33 with BTAs, 33 with other aneurysms) who were evaluated from 2008 to 2013 were analyzed. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (odds ratio, 1.04; P = 1.42 · 1023) and a smaller basilar artery diameter (odds ratio, 0.23; P = .02) were most strongly associated with BTA formation after adjustment for other morphological and clinical variables.

CONCLUSION: Larger posterior cerebral artery angles and smaller basilar artery diameters are associated with the formation of basilar tip aneurysms. These parameters are easily measurable by the clinician and will aid in screening strategies in high-risk patients.

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Perianeurysmal edema as a predictive sign of aneurysmal rupture

Brain edema in aneurysm

J Neurosurg 121:1112–1114, 2014

Subarachnoid hemorrhage following intracranial aneurysmal rupture is a major cause of morbidity and mortality. Several factors may affect the probability of rupture, such as tobacco and alcohol use; size, shape, and location of the aneurysm; presence of intraluminal thrombus; and even the sex of the patient. However, few data correlate such findings with the timing of aneurysmal rupture.

The authors report 2 cases of middle-age women with headache and MRI findings of incidental aneurysms. Magnetic resonance imaging showed evidence of surrounding parenchymal edema, and in one case there was a clear increase in edema during follow-up, suggesting a progressive inflammatory process that culminated with rupture.

These findings raise the possibility that bleb formation and an enlargement of a cerebral aneurysm might be associated with an inflammatory reaction of the aneurysm wall resulting in perianeurysmal edema and subsequent aneurysmal rupture. There may be a temporal link between higher degree of edema and higher risk for rupture, including risk for immediate rupture.

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Subarachnoid hemorrhage and intracerebral hematoma caused by aneurysms of the anterior circulation

Subarachnoid hemorrhage and intracerebral hematoma caused by aneurysms of the anterior circulation

Neurosurg Rev (2014) 37:653–659

Additional space-occupying intracerebral hematoma (ICH) in patients suffering from subarachnoid hemorrhage (SAH) is a known predictor for poor outcome. Emergent clot evacuation might be mandatory. However, data concerning the influence of ICH location on outcome is scarce. Therefore, we analyzed the influence of ICH location on clinical course and outcome in patients with SAH and additional ICH.

One hundred seventy-four patients were treated with aneurysmal SAH and additional ICH between September 1999 and May 2012. Information including patient characteristics, treatment, and radiological findings were prospectively entered into a database. Patients were stratified according to ICH location and neurological outcome. Neurological outcome was assessed according to modified Rankin Scale (mRS).

ICH location was temporal (58.6 %), frontal (28.7 %), and perisylvian ICH (12.6%); 63.8% presented in poor admission status and favorable outcome was achieved in 35.6 %. In the multivariate analysis, favorable outcome was associated with young age, ICH <50 ml, and good admission status. The location of ICH was not associated with outcome. The current data confirms that a significant number of patients with ICH after aneurysm rupture achieve favorable outcome. Prognostic factor for favorable outcome are “age,” “size of the hematoma,” and “admission status.” The location of the ICH seems not to be associated with outcome.

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Impact of Indocyanine Green Videoangiography on Rate of Clip Adjustments Following Intraoperative Angiography

Essentials in intraoperative indocyanine green videoangiography assessment for intracranial aneurysm surgery

Neurosurgery 75:437–444, 2014

Intraoperative angiography (IA) is used to evaluate the adequacy of clip reconstruction of intracranial aneurysms. Alternative imaging such as indocyanine green videoangiography (ICG-VA) has been proposed. The additional benefit of ICG-VA when IA is routinely used has not been previously determined.

OBJECTIVE: To report our experience with the use of ICG-VA in combination with IA vs IA alone.

METHODS: We retrospectively reviewed cases of aneurysm clipping during a 21-month period by a single surgeon in which ICG-VA was performed after clip reconstruction prior to IA, or IA alone was performed to verify optimal clipping. Records were reviewed for age, sex, race, length of stay, rupture status, Hunt and Hess grade, aneurysm size, location, and temporary clipping. Intraoperative decision making was determined for each group.

RESULTS: Ninety-four patients who underwent 97 craniotomies for 128 aneurysms met inclusion criteria for this study. ICG-VA1IA was performed in 37 craniotomies; IA alone was performed for 60 craniotomies. Baseline characteristics were similar with the exception that median aneurysm size was slightly larger in the ICG-VA group (5.6 mm vs 4.3 mm, P = .04). ICG-VA produced 4 false negatives, which required clip adjustments following IA (10.8%), vs 7 patients (11.7%) in the IA-alone group requiring clip adjustments (P = .897).

CONCLUSION: When IA is routinely performed, the additional use of ICG-VA does not eliminate the need for post-IA clip adjustments owing to the possibility of false negatives. When ICG-VA suggests optimal clipping, but is followed by IA, the rate of post-IA modifications in this study did not differ significantly than if ICG-VA had not been performed.

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Morphological predictors of intraprocedural rupture during coil embolization of ruptured cerebral aneurysms

Morphological predictors of intraprocedural rupture for coiling

J Neurosurg 121:605–612, 2014

This study aimed to investigate morphological predictors of intraprocedural rupture (IPR) during coil embolization of ruptured cerebral aneurysms.

Methods. A retrospective analysis was conducted in 322 consecutive patients with ruptured cerebral aneurysms who were treated with coil embolization over an 8-year period from January 2005 to December 2012. The authors analyzed all available data with emphasis on morphological characteristics of the aneurysm as shown on baseline angiography in relation to IPR. Regarding aneurysm morphology, the authors classified patients according to multilobulation, presence of a daughter sac, and presence of a small basal outpouching (SBO).

Results. The incidence of IPR was 4.8% (16 of 332). In terms of aneurysm configuration, the presence of multilobulation (100.0% [16 of 16] in the IPR group vs 89.2% [282 of 316] in the non-IPR group, p = 0.388) and daughter sac (75.0% [12 of 16] in the IPR group vs 59.2% [187 of 316] in the non-IPR group, p = 0.208) were not significantly associated with IPR. However, SBO, found in 9% (30 of 332) of the study population, was significantly associated with IPR (56.3% [9 of 16] in the IPR group vs 6.7% [21 of 316] in the non-IPR group, OR 18.06, p < 0.0001).

Conclusions. Based on the authors’ data, the more general groups of multilobulation and daughter sac were not significantly associated with IPR, although the more specific subgroup with an SBO was. More confirmation studies on these results are required, but they point to the possibility that SBO (with its possible connection to basal rupture) is an important morphological risk factor for IPR during coiling. In addition, future comparison of coiling and clipping treatment for ruptured aneurysms associated with an SBO seems necessary.

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Increasing Flow Diversion for Cerebral Aneurysm Treatment Using a Single Flow Diverter

Increasing Flow Diversion for Cerebral Aneurysm Treatment Using a Single Flow Diverter

Neurosurgery 75:286–294, 2014

A neurovascular flow diverter (FD), aiming at inducing embolic occlusion of cerebral aneurysms through hemodynamic changes, can produce variable mesh densities owing to its flexible mesh structure.

OBJECTIVE: To explore whether the hemodynamic outcome would differ by increasing FD local compaction across the aneurysm orifice.

METHODS: We investigated deployment of a single FD using 2 clinical strategies: no compaction (the standard method) and maximum compaction across the aneurysm orifice (an emerging strategy). Using an advanced modeling technique, we simulated these strategies applied to a patient-specific wide-necked aneurysm model, resulting in a relatively uniform mesh with no compaction (C1) and maximum compaction (C2) at the aneurysm orifice. Pre- and posttreatment aneurysmal hemodynamics were analyzed using pulsatile computational fluid dynamics. Flow-stasis parameters and blood shear stress were calculated to assess the potential for aneurysm embolic occlusion.

RESULTS: Flow streamlines, isovelocity, and wall shear stress distributions demonstrated enhanced aneurysmal flow reduction with C2. The average intra-aneurysmal flow velocity was 29% of pretreatment with C2 compared with 67% with C1. Aneurysmal flow turnover time was 237% and 134% of pretreatment for C2 and C1, respectively. Vortex core lines and oscillatory shear index distributions indicated that C2 decreased the aneurysmal flow complexity more than C1. Ultrahigh blood shear stress was observed near FD struts in inflow region for both C1 and C2.

CONCLUSION: The emerging strategy of maximum FD compaction can double aneurysmal flow reduction, thereby accelerating aneurysm occlusion. Moreover, ultrahigh blood shear stress was observed through FD pores, which could potentially activate platelets as an additional aneurysmal thrombosis mechanism.

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Suboptimal interventional conditions for the occlusion of ruptured intracranial aneurysms do not increase periprocedural complications and poor clinical outcomes


 aneurysms of the middle cerebral artery

Acta Neurochir (2014) 156:1267–1272

Occluding a ruptured intracranial aneurysm as early as possible may entail certain periprocedural conditions that compromise the outcome. The aim of the present study was to evaluate the effectiveness, safety, and clinical outcome of endovascular coiling procedures performed on an emergency basis under potentially suboptimal conditions, and to compare results with those from scheduled procedures under potentially optimal conditions.

Methods Interventions performed on 66 SAH patients were retrospectively analysed by classifying them into two groups: under emergency (within three hours fromdiagnosis or during non–standard working hours) or scheduled conditions. A binary logistic regression analysis was also performed to identify characteristics associated with poor outcomes.

Results No differences in effectiveness, periprocedural complications, or clinical outcomes were found between the two groups. Rebleeding was detected in 4.8 % of the emergency interventions and 2.2 % of the scheduled interventions. Multivariate analysis identified age and Hunt and Hess grade, but no conditions of treatment, as the factors associated to poor outcome.

Conclusion Suboptimal interventional conditions for occluding ruptured intracranial aneurysms, such as performing procedures outside of standard working hours or within three hours of diagnosis, do not result in increased periprocedural complications and poor clinical outcomes compared with scheduled procedures under potentially optimal conditions. These results suggest the need for treatment to be provided as soon as possible.

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Revascularization and Aneurysm Surgery: Techniques, Indications, and Outcomes in the Endovascular Era

Revascularization and Aneurysm Surgery

Neurosurgery 74:482–498, 2014

Given advances in endovascular technique, the indications for revascularization in aneurysm surgery have declined.

OBJECTIVE: We sought to define indications, outline technical strategies, and evaluate the outcomes of patients treated with bypass in the endovascular era.

METHODS: We retrospectively reviewed all aneurysms treated between September 2006 and February 2013.

RESULTS: We identified 54 consecutive patients (16 males and 39 females) with 56 aneurysms. Aneurysms were located along the cervical internal carotid artery (ICA) (n = 1), petrous/cavernous ICA (n = 1), cavernous ICA (n = 16), supraclinoid ICA (n = 7), posterior communicating artery (n = 2), anterior cerebral artery (n = 4), middle cerebral artery (MCA) (n = 13), posterior cerebral artery (PCA) (n = 3), posterior inferior cerebellar artery (n = 4), and vertebrobasilar arteries (n = 5). Revascularization was performed with superficial temporal artery (STA) to MCA bypass (n = 25), STA to superior cerebellar artery (SCA) (n = 3), STA to PCA (n = 1), STA-SCA/STA-PCA (n = 1), occipital artery (OA) to PCA (n = 2), external carotid artery/ICA to MCA (n = 15), OA to MCA (n = 1), OA to posterior inferior cerebellar artery (n = 1), and in situ bypasses (n = 8). At a mean clinical follow-up of 18.5 months, 45 patients (81.8%) had a good outcome (Glasgow Outcome Scale 4 or 5). There were 7 cases of mortality (12.7%) and an additional 9 cases of morbidity (15.8%). At a mean angiographic follow-up of 17.8 months, 14 bypasses were occluded. Excluding the 7 cases of mortality, the majority of aneurysms (n = 42) were obliterated. We identified 7 cases of residual aneurysm and recurrence in 6 patients at follow-up.

CONCLUSION: Given current limitations with existing treatments, cerebral revascularization remains an essential technique for aneurysm surgery.

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Surgical Anatomy of Endoscope-Assisted Approaches to Common Aneurysm Sites

Surgical Anatomy of Endoscope-Assisted Approaches to Common Aneurysm Sites 

Operative Neurosurgery 10:121–144, 2014

The endoscope is being introduced as an adjuvant to improve visualization of certain areas in open cranial surgery.

OBJECTIVE: To describe the endoscopic anatomy of common aneurysm sites and to compare it with the microsurgical anatomy.

METHODS: Pterional, anterior interhemispheric, and subtemporal approaches to the most common aneurysm sites were examined in cadaveric heads under the surgical microscope and with the endoscope.

RESULTS: The endoscopic view, particularly with the angled endoscopes, provides a significant improvement compared with the microscopic view, especially for poorly visualized sites such as the medial aspect of the supraclinoid carotid artery and its branches, the area below the anterior perforated substance and optic tract, and the carotid and basilar bifurcations. The endoscope aided in the early visualization of perforating branches at each aneurysm site except the middle cerebral artery. Small-diameter optics (2.7 mm) provided greater space for dissection and less potential for tissue damage in narrow places, whereas the larger 4-mm diameter optics provided better visualization and less panoramic distortion. The positioning of the endoscope for each aneurysm site is reviewed.

CONCLUSION: The endoscope provides views that complement or improve the microscopic view at each aneurysm site except the middle cerebral artery. Endoscopy training and a thorough knowledge of endoscopic vascular anatomy are essential to safely introduce endoscopic assistance in vascular surgery.

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Surgical Treatment of 127 Anterior Choroidal Artery Aneurysms

Anterior Choroidal Artery Aneurysms

Neurosurgery 73:933–940, 2013

The anterior choroidal artery (AChA) supplies important areas of the nervous system, particularly the posterior limb of the internal capsule and optic radiation. Treatment of AChA aneurysms poses particular challenges because of the complex anatomy of the aneurysm associated with the relatively small diameter of AChAs, making preservation of the parent vessel during clip ligation or endosaccular coiling challenging.

OBJECTIVE: To investigate the incidence and features of ischemia in treatment of AChA aneurysms.

METHODS: A prospectively maintained database of patients who underwent treatment of aneurysms from 1985 to 2011 was queried to find patients with AChA aneurysms. Age, sex, Hunt and Hess grade, treatment modality, and complications were analyzed by use of the unpaired Student t test and Fisher exact test.

RESULTS: One hundred twenty-two patients harbored 127 AChA aneurysms, and 67% (82 of 122) had multiple aneurysms. Treatment included 112 microsurgical clip ligations, 8 endosaccular coil embolizations, 5 aneurysmal wrappings, and 2 surgical explorations. Complications developed in 53% (67 of 127) of AChA aneurysms. Postoperative ischemia occurred in 12% (15 of 127) of treated aneurysms. The number of temporary clip applications was most closely associated with postoperative ischemia. Glasgow Outcome Scale scores of 4 or 5 were obtained by 78% at discharge, 89% at 6 months, and 85% at 1 year.

CONCLUSION: The ischemic complication rate from surgical treatment of AChA aneurysms is most closely associated with higher frequency of temporary clip applications for proximal control and may be lower than previously reported. Supplementary intraoperative tools and limitation of vessel manipulation should be used to improve outcomes.

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