Carotid-ophthalmic Aneurysm Research Articles

Commentary: Treatment of Carotid Ophthalmic Aneurysm With Woven EndoBridge (WEB SL): 2-Dimensional Operative Video.

Commentary: Treatment of Carotid Ophthalmic Aneurysm With Woven EndoBridge (WEB SL): 2-Dimensional Operative Video.

In Reply: Occlusion Rate and Visual Complications With Flow-Diverter Stent Placed Across the Ophthalmic Artery's Origin for Carotid-Ophthalmic Aneurysms: A Meta-Analysis

BACKGROUND Flow-diverter stents (FDSs) have recently gained acceptance for the treatment of intracranial aneurysms, especially for carotid-ophthalmic aneurysms (COAs). However, complications have been reported after coverage of side branches, especially the ophthalmic artery (OA). OBJECTIVE To evaluate, through a meta-analysis, the occlusion rate, and the ophthalmic complications after treatment of COA by FDS. METHODS We reviewed on MEDLINE via PubMed, Embase via Ovid, and Cochrane central database via CENTRAL. We included all case series with at least 15 patients and clinical trials about flow diversion of aneurysms close to the OA's origin. Among these studies, we only included articles with aneurysm occlusion rate and rate of new ophthalmic symptoms. RESULTS We included 16 studies with 913 COA treated by FDSs and covering the OA with a mean follow-up of 16.4 mo. The random-effect modeling analysis concerning the overall rate of new ophthalmic complications, after FDS deployment covering the OA, was 3.0% (CI95% 1.0-6.0). There was medium-high heterogeneity in the study reports P < .01, I2 = 70.2% [50.4%; 82.1%]. We were not able to statistically explain this heterogeneity with the performed analysis, which could be related to the design of the included studies. We found an overall aneurysm occlusion rate of 85.0% (95% CI 80.0-89.0). CONCLUSION Our meta-analysis found a high aneurysm occlusion rate (85%) and low rate of iatrogenic visual complications, with only 3.0% of new visual symptoms, after treatment of COA by FDS.

Occlusion Rate and Visual Complications With Flow-Diverter Stent Placed Across the Ophthalmic Artery's Origin for Carotid-Ophthalmic Aneurysms: A Meta-Analysis.

Flow-diverter stents (FDSs) have recently gained acceptance for the treatment of intracranial aneurysms, especially for carotid-ophthalmic aneurysms (COAs). However, complications have been reported after coverage of side branches, especially the ophthalmic artery (OA). To evaluate, through a meta-analysis, the occlusion rate, and the ophthalmic complications after treatment of COA by FDS. We reviewed on MEDLINE via PubMed, Embase via Ovid, and Cochrane central database via CENTRAL. We included all case series with at least 15 patients and clinical trials about flow diversion of aneurysms close to the OA's origin. Among these studies, we only included articles with aneurysm occlusion rate and rate of new ophthalmic symptoms. We included 16 studies with 913 COA treated by FDSs and covering the OA with a mean follow-up of 16.4 mo. The random-effect modeling analysis concerning the overall rate of new ophthalmic complications, after FDS deployment covering the OA, was 3.0% (CI95% 1.0-6.0). There was medium-high heterogeneity in the study reports P<.01, I2=70.2% [50.4%; 82.1%]. We were not able to statistically explain this heterogeneity with the performed analysis, which could be related to the design of the included studies. We found an overall aneurysm occlusion rate of 85.0% (95% CI 80.0-89.0). Our meta-analysis found a high aneurysm occlusion rate (85%) and low rate of iatrogenic visual complications, with only 3.0% of new visual symptoms, after treatment of COA by FDS.

Extent of anterior clinoidectomy for clipping of carotid-ophthalmic aneurysms predicted on three-dimensional computerised tomography angiography.

We aimed to verify the value of computerised tomography angiography (CTA) on predicting the extent of anterior clinoidectomy that is optimal for particular carotid-ophthalmic aneurysms (COAs). The anterior clinoid process (ACP) often impedes the complex microsurgery of COA. Complete removal of the ACP ensures safe clipping; however, it also may increase the risk of severe complications. The probability of performing a successful partial anterior clinoidectomy could be evaluated by preoperative CTA. 28 patients with either a ruptured (n=4) or unruptured COA were included in this prospective, single-centre, observational study. One aneurysm was giant, two were large, and the rest were smaller. Successful aneurysm clipping was the aim in all cases. The anterior clinoidectomy was preoperatively planned on multiplanar three-dimensional reconstructions of CTA images (3D-CTA) which resembled the typical view of a frontotemporal craniotomy. Finally, the predicted clinoidectomy was compared to the extent of the actual clinoidectomy. 21 aneurysms (75%) projected superolateral or superior. The ACP was completely and selectively resected in 25% (7 of 28) and 67.9% of patients (19 of 28) respectively. Optic nerve (ON) unroofing was always performed in the case of total anterior clinoidectomy, but accompanied only 8 of 19 selective clinoidectomies (p = 0.03). The extent of the actual clinoidectomy was predicted by the 3D-CTA-based preoperative planning in 17 of 27 cases (63.0%). Particularly, prediction of the osteotomy was correct in 85.7% of complete, 62.5% of selective lateral, and 57.1% of medial clinoidectomy. None of the radiological and clinical factors determined the correlation between the planned and the actual extent of ACP removal. There was one incomplete occlusion among 23 obtained follow-up CTAs. The predictive value of 3D-CTA on the extent of anterior clinoidectomy still remains unsatisfactory; it is limited by the individual variability of COA and its surrounding structures. Currently, the role of 3D-CTA planning is restricted to educational purposes only.

About an Intracranial Aneurysm Rupture During Delivery

AbstractThe rupture of an intracranial aneurysm is rare during pregnancy and exceptional during delivery. When it occurs, the prognosis of two lives is engaged. We are reporting a case of a 41-year-old patient presenting with a subarachnoid hemorrhage during labor. After extraction of healthy baby through cesarian section, radiological investigations permitted to diagnose a ruptured right carotid-ophthalmic aneurysm. The patient benefited from a selective aneurysm’s exclusion by occlusion using Guglielmi detachable coils through an endovascular approach using catheterization. The immediate outcome was favorable.

Are hemodynamics of irregular small carotid-ophthalmic aneurysms different from those of regular ones and large aneurysms based on numerical simulation?

The purpose of this study is to investigate whether hemodynamics of unruptured, irregular small intracranial aneurysms (SIAs) are different from those of regular ones and large intracranial aneurysms (LIAs) in ophthalmic artery segment of internal carotid artery (ICA). Between April 2015 and June 2018, 106 carotid-ophthalmic artery aneurysms were retrospectively analyzed using 3D angiographic images and computational fluid dynamics (CFD). Three categories were stratified: regular SIAs, irregular SIAs and LIAs. Statistical comparisons of the differences in clinical, morphological and hemodynamic parameters among regular SIA, irregular SIA and LIA groups were performed by one-way analysis of variance (ANOVA) or Kruskal-Wallis Test. The median maximal height of regular SIA, irregular SIA and LIA were 3.03 (interquartile range: 2.49-4.22) mm, 4.59 (interquartile range: 3.86-5.32) mm and 11.06 (interquartile range: 9.28-13.69) mm, all P < 0.05). Low shear-stress area percentage (LSA%) and oscillatory shear index (OSI) of irregular SIAs and LIAs were not significantly different (P = 0.72, P = 0.27 respectively), and were significantly higher than those of regular SIAs (all P < 0.01). Wall shear stress (WSS) and normalized wall shear stress (NWSS) of irregular SIAs were significantly higher than those of LIAs (P < 0.01, P < 0.01 respectively), but lower than those of regular SIAs (P < 0.01, P < 0.01 respectively). Special unruptured irregular SIAs share a similarity of hemodynamic characteristics with LIAs in high LSA% and high OSI, and are different from regular SIAs in hemodynamics.

Overcoming Daunting Challenges of Clipping of Paraclinoid Carotid-Ophthalmic and Superior Hypophyseal Artery Aneurysms: 2-Dimensional Operative Video.

This surgical video emphasizes the nuances that needed to overcome daunting challenges of clipping of paraclinoid carotidophthalmic and superior hypophyseal artery (SHA) aneurysms. To avoid hazardous manipulations, scarifying the ipsilateral SHA under visual evoked potential (VEP) guidance can be done without risk of postoperative visual decline. This technique is associated with better visual outcome.1 A 66-yr-old woman presented with gradually enlarging right paraclinoid carotidophthalmic and SHA aneurysms. The relationship between those aneurysms and the critical neurovascular structures made us facing a daunting challenge to preserve the visual function. To preserve the patency of the ophthalmic artery (oph.A), endovascular intervention was abandoned and a direct clipping surgery was selected. Following VEP settings, exposure of the cervical internal carotid artery for proximal control and right frontotemporal craniotomy, a subfrontal approach was used. To get adequate accessibility and safe maneuverability, the anterior clinoidectomy and unroofing of the optic canal were completed, then, the falciform ligament and the distal dural ring were carefully opened. Under VEP guidance, the oph.A and SHAs were temporarily occluded. VEP had been stable under repeated occlusions. The carotidophthalmic aneurysm was clipped with preservation of the oph.A. Besides, 1 ipsilateral SHA was sacrificed to achieve complete clipping of the SHA aneurysm. Final indocyanine green videoangiography confirmed obliteration of the paraclinoid aneurysms and patency of the oph.A, the other SHA and the tiny arterioles around the optic nerve. The postoperative course was uneventful. There was no evidence of postoperative visual disturbances. The patient has consented to the submission of the case report to the journal.

Application of micro-mirror in microsurgical clipping to the intracranial aneurysm

Objective To explore the value and disadvantage of micro-mirror in the intracranial aneurysm surgery. Methods Micro-mirror was used to assist microsurgical clipping to 36 intracranial aneurysms in 31 cases, of which 3 were carotid-ophthalmic artery aneurysms, 3 anterior choroidal artery aneurysm, 11 were posterior communicating artery aneurysms, 7 were middle cerebral artery aneurysms, 10 anterior communicating artery or anterior cerebral artery aneurysms, and the others were a posterior cerebral artery aneurysm and a posterior inferior cerebellar artery aneurysm. The micro-mirror was used before and after clipping to observe the anatomic features of necks hidden behind and medial to aneurysms, to visualize surrounding neurovascular structures, and to verify the optimal clipping position. Intraoperative indocyanine green fluorescein angiography confirmed the success of sufficient clipping. Results All aneurysms were clipped successfully. The parent arteries were occluded temporarily in 26 cases, and 9 aneurysms ruptured during the operation. Postoperative follow-up lasted from 2 weeks to 1 year. After operations digital subtraction angiography (DSA) were repeated in 10 cases, computed tomography angiography(CTA) in 21 cases, and no insufficient clipping or occlusion of parent arteries were revealed. Conclusions Micro-mirror assisting microsurgical clipping to the intracranial aneurysm is conducive to accurate clipping, and is a convenient and practical operation. Key words: Intracranial aneurysm; Microsurgery; Surgical instruments

Predictors for ophthalmic segment aneurysms recanalization after coiling and flow diverter embolization in 6- and 12-month follow-up

Carotid-ophthalmic aneurysms are indication for endovascular treatment. Coil embolization is associated with a high recanalization rate and thus usage of flow diverter (FD) could constitute the treatment of choice. Although implementation of FD is very effective, it carries a significant risk of complications. The goal of our study was to find a radiological recanalization marker in order to facilitate decision process which would result in fewer treatment-related complications and in this way, to personalize endovascular therapy.We made a retrospective analysis of seventy-five patients with saccular carotid-ophthalmic aneurysms treated endovascularly. Morphometric measurements were performed in CTA 3D aneurysm models. The aneurysm size and volume were measured on the base of digital subtraction angiography (DSA) images. The treatment effectiveness was determined visually using the modified Raymond Roy classification after embolization and on the 6- and 12-month follow-up DSA. Statistica 13.1 software was used. Multivariate analyses showed that the aneurysm neck size (OR 2.51; 95%CI: 1.20–5.26), aspect ratio (OR 2.60; 95%CI: 1.27–5.21) and neck to parent artery ratio (OR 2.68; 95%CI: 1.26–5.70) were risk factors for carotid-ophthalmic aneurysms recanalization after 6 months. Of those factors, aneurysm neck size remained the only significant risk factor for carotid-ophthalmic aneurysms recanalization after 12 months (OR 5.23, 95%CI: 1.71–15.93).Various factors seem to influence recanalization. Preoperatively, if the above-mentioned predictors of recanalization are present, coiling is burdened with a high recanalization rate. In those cases, FD embolization should be considered.

Application and reliability of the superselective balloon occlusion test in the treatment of complex cerebral artery aneurysms: A report of 12 cases

Although the general balloon occlusion test (BOT) is commonly used, there is limited information on the evaluation standards and methodological protocols for the superselective BOT, which may be required in some special aneurysm cases. We performed the superselective BOT in 12 patients with specific complex aneurysms and report our experiences herein. We retrospectively analyzed the angiographic results and test outcomes of 12 patients (8 men and 4 women) who underwent the superselective BOT to evaluate their collateral flow before treatment. Eight patients had middle cerebral artery complex aneurysms; 2 patients had carotid-ophthalmic aneurysms; and 2 patients had posterior cerebral artery aneurysms. Collaterals were categorized as none (grade 0), poor (grades 1 or 2), or good (grades 3 or 4) based on the collateral flow grade on angiography. The test results were negative in 10 patients and positive in 2 patients. The delay time of the cortical capillary phase after temporary occlusion of the parent artery was between 0.5 and 2.5 s. The collateral flow was graded as poor in 3 patients and good in 9 patients. There were no technical complications related to the superselective BOT. The superselective BOT can be applied for the evaluation of some complex aneurysms prior to treatment. The right method of occlusion can be selected on the basis of the results of this test.

Computational Fluid Dynamics Analysis of Carotid–Ophthalmic Aneurysms with Concomitant Ophthalmic Artery Infundibulum in a Patient-Specific Model

Although previous studies have reported cases of coexistence of carotid-ophthalmic aneurysm and ophthalmic artery (OA) infundibulum, the hemodynamic characteristics of this complicated structure and its damaging effects on vision remain to be elucidated. The aim of the present study was to analyze this artery structure using computational fluid dynamics (CFD) techniques. We have presented the case of a patient with a diagnosis of carotid-ophthalmic aneurysm, who had been experiencing blurred vision. A transient analysis was performed to investigate the blood flowing in the parent artery. Hemodynamic parameters such as streamline, wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time were obtained. When the inlet velocity of the parent artery was at the second peak, the flow rate and intensity of the vortex reached their maximum. In the aneurysm neck, a region of high time-averaged WSS (TAWSS) and a region of low TAWSS with a high OSI coexisted. In addition, a relaxation area was found. In the aneurysm dome, the minimum TAWSS was 2.5 Pa, the maximum OSI was 0.48, and the 2 regions did not overlap. In the OA infundibulum, the maximum OSI and relative residence time were 0.47 and 39.2, respectively; the minimum TAWSS was 0.59 Pa. We detected aneurysm regions that were susceptible to further expansion and assessed the rupture risk of each region. The relaxation area could promote aneurysm progression. In addition, the location of the vortex shear force center varied with time. Finally, double vortex streamlines influenced the blood supply through the OA, impairing the vision. Infundibulum might promote thrombus formation and, hence, retard OA blood flow.

Patient Selection and Technical Nuances for Microsurgical Clipping of Carotid-Ophthalmic Aneurysms: 2-Dimensional Operative Video.

Patient Selection and Technical Nuances for Microsurgical Clipping of Carotid-Ophthalmic Aneurysms: 2-Dimensional Operative Video.

Application of Micromirror in Microsurgical Clipping to the Intracranial Aneurysms.

The aim of the study was to explore the values and disadvantages of micromirror in the intracranial aneurysm clipping surgery. Micromirror was used to assist microsurgical clipping to 36 intracranial aneurysms in 31 patients, of which 3 were carotid-ophthalmic artery aneurysms, 3 were anterior choroidal artery aneurysms, 11 were posterior communicating artery aneurysms, 7 were middle cerebral artery aneurysms, 10 were anterior communicating artery or anterior cerebral artery aneurysms, and the rest were a posterior cerebral artery aneurysm and a posterior inferior cerebellar artery aneurysm. The micromirror was used before and after clipping to observe the anatomic features of necks hidden behind and medial to aneurysms, to visualize surrounding neurovascular structures, and to verify the optimal clipping position. Intraoperative indocyanine green fluorescein angiography, postoperative computerized tomography angiography, and digital subtraction angiography confirmed the success of sufficient clipping. Intraoperative indocyanine green angiography, postoperative computerized tomography angiography , or digital subtraction angiography were performed and showed no case of wrong or insufficient clipping of aneurysm. Micromirror-assisted microsurgical clipping to the intracranial aneurysm is safe, sufficient, convenient, and practical.

Aneurysms with persistent filling after failed treatment with the Pipeline embolization device.

The Pipeline embolization device (PED) has become a valuable tool in the treatment of cerebral aneurysms. Although failures with PED treatment have been reported, the characteristics and course of these aneurysms remain a topic of uncertainty. Electronic medical records and imaging studies were reviewed for all patients treated with the PED between July 2010 and March 2015 to identify characteristics of patients and aneurysms with residual filling after PED treatment. Of 316 cases treated at a single institution, 281 patients had a long-term follow-up. A total of 52 (16.4%) aneurysms with residual filling were identified and constituted the study population. The mean patient age in this population was 58.8 years. The mean aneurysm size was 10.1 mm ± 7.15 mm. Twelve aneurysms were fusiform (23%). Of the aneurysms with residual filling, there were 20 carotid ophthalmic (CO) aneurysms (20% of all CO aneurysms treated), 10 other paraclinoid aneurysms (16.4% of all paraclinoid aneurysms), 7 posterior communicating artery (PCoA) aneurysms (21.9% of all PCoA aneurysms), 7 cavernous internal carotid artery (ICA) aneurysms (14.9% of all cavernous ICA aneurysms), 4 vertebrobasilar (VB) junction aneurysms (14.8% of all VB junction aneurysms), and 3 middle cerebral artery (MCA) aneurysms (25% of all MCA aneurysms). Eleven patients underwent placement of more than one PED (21.2%), with a mean number of devices of 1.28 per case. Eight of 12 aneurysms were previously treated with a stent (15.4%). Nineteen patients underwent re-treatment (36.5%); the 33 patients who did not undergo re-treatment (63.5%) were monitored by angiography or noninvasive imaging. In multivariate analysis, age older than 65 years (OR 2.65, 95% CI 1.33-5.28; p = 0.05), prior stent placement across the target aneurysm (OR 2.94, 95% CI 1.15-7.51; p = 0.02), aneurysm location in the distal anterior circulation (MCA, PCoA, and anterior choroidal artery: OR 2.72, 95% CI 1.19-6.18; p = 0.017), and longer follow-up duration (OR 1.06, 95% CI 1.03-1.09; p < 0.001) were associated with incomplete aneurysm occlusion. While the PED can allow for treatment of large, broad-necked aneurysms with high efficacy, treatment failures do occur (16.4%). Aneurysm size, shape, and previous treatment may influence treatment outcome.

Long-term visual outcome in patients treated by flow diversion for carotid-ophthalmic aneurysms

BackgroundFlow-diverter stents (FDSs) are an upgrade in the treatment of intracranial aneurysms. However, complications concerning covered branches have been reported, especially the ophthalmic artery (OA). The purpose of our study...

Surgical management of ophthalmic artery aneurysms via minimally invasive frontolateral approach

Objective: To explore the minimally invasive techniques and outcome of carotid ophthalmic artery aneurysms clipping via a frontolateral approach. Methods: The clinical data of 95 patients with carotid ophthalmic artery aneurysms treated via frontolateral approach in the last 1.5 years in Beijing Tiantan Hospital and Beijing Anzhen Hospital were analyzed retrospectively.Before the operation, digital subtraction angiogram (DSA) was performed among all patients.The patients were divided into two groups by the lateral approach.According to preoperative classification, surgical characteristics and prognosis were summarized. Results: Ninety-five cases of ophthalmic aneurysms were divided into type Ⅰ of 44 cases (46.3%), type Ⅱ of 34 cases (35.7%) and type Ⅲ of 17cases (17.9%), according to the results of DSA.The diameter of aneurysm was <10 mm (35 cases), 10-25 mm (34 cases), and >25 mm (26 cases). In the 17 cases of subarachnoid hemorrhage (SAH), 8 cases were ruptured carotid-ophthalmic artery aneurysms.Among those 95 patients, 93 were clipped successfully, 2 was trapped.Multiple aneurysms in 5 cases were treated in one surgical session through the same approach.No aneurysm residual was found after postoperative CTA review.Ipsilateral vision of 3 cases were decline.Cerebral infarction was appeared in 9 cases.All the others had a good recovery. Conclusions: The carotid-ophthalmic artery aneurysms could be well exposed. Microsurgery through frontolateral approach has the advantages such as minimal invasion, less effect on the patients' look and simple procedure.The frontolateral approach is safe and effective in surgery for ophthalmic segment of the internal carotid artery aneurysms.

Ruptured carotid-ophthalmic aneurysm treatment: a non-inferiority meta-analysis comparing endovascular coiling and surgical clipping

Introduction: Aneurysms of the carotid-ophthalmic segment are relatively rare, comprising only five percent of all intracranial aneurysms. There is no consensus regarding the optimal management for ruptured carotid-ophthalmic aneurysms, whether endovascular coiling or surgical clipping provide the most favourable patient outcome. The aim of this meta-analysis is to analyse these two treatment modalities for ruptured carotid-ophthalmic aneurysms with respect to independent clinical outcome.Methods: We performed a systematic literature search in PubMed, Cochrane Central Registry of Controlled Trials and Clinicaltrials.gov for treatment of ruptured carotid-ophthalmic aneurysms, comparing endovascular coiling and surgical clipping. Primary outcome in the study was independent clinical patient outcome at follow up (defined as Glasgow Outcome Scale four–five). Secondary outcomes were poor clinical patient outcome, mortality and total angiographic occlusion. The meta-analysis was performed using the Mantel–Haenszel method for dichotomous outcome.Results: Four studies met the inclusion criteria and were included in the meta-analysis. In total, 152 patients were included. Sixty-seven of these patients were treated with endovascular coiling and 85 patients were treated with microsurgical clipping. The proportion of patients with an independent clinical outcome after coiling and clipping was comparable, OR 1.04 (95% CI: 0.40, 2.71). The proportion of patients with an independent outcome in the endovascular group was 76% and in the surgical group 71%. Mortality between the two treatment arms was equal.Conclusion: Clinical outcome after endovascular coiling and surgical clipping for ruptured carotid-ophthalmic aneurysms was comparable between surgical clipping and endovascular coiling. There was no proven difference in clinical outcome after endovascular coiling and surgical clipping for ruptured carotid-ophthalmic aneurysms but the evidence was based on few studies of moderate to low quality and we cannot rule out the possibility of a difference in clinical outcome between the two treatment modalities.

Extensive bone erosion caused by pseudotumoral aneurysm growth

Carotid ophthalmic aneurysms constitute 0.9–6.5% of the aneurysms of the ICA with up to 20% of the cases presenting with visual symptoms. We report a case of an adult woman, presented with chronic headaches and protracted visual alterations progressing to left eye amaurosis. Neuroradiological exams, revealed a giant partially thrombosed carotid ophthalmic aneurysm extending anteriorly, causing pseudotumoral spheno-orbital bone erosion. The patient underwent surgical clipping, evacuation of the thrombotic mass and decompression of the optic pathways with rapid recovery of the vision. This unusual case, contributes to the available body of evidence on aneurysms growth.

Flow Diversion for Ophthalmic Artery Aneurysms.

Endovascular treatments of ophthalmic segment aneurysms are commonly used but visual outcomes remain a concern. We performed a retrospective review of patients with carotid-ophthalmic aneurysms treated with flow diversion from June 2009 to June 2015. The following outcomes were studied through chart review: visual outcomes, complications, postoperative stroke and intraparenchymal hemorrhage, and clinical outcomes. Angiographic outcomes were studied with angiography and MRA at 6 months, 1 year, and 3 years. We evaluated 50 carotid-ophthalmic aneurysms in 48 patients, among whom 44 patients with 46 aneurysms underwent treatment. The mean clinical follow-up was 29 ± 22 months (range, 0-65 months). There were no permanent adverse visual outcomes. There was 1 death because of late intraparenchymal hemorrhage (2.2%). Six-month angiography showed complete occlusion in 24 of 37 patients (64.9%), and 3-year angiography results showed occlusion in 24 of 25 patients (96%). In conclusion, flow diversion is a safe and effective treatment for carotid-ophthalmic aneurysms in carefully selected patients. The risk of adverse visual outcomes is low, and most aneurysms progress to complete occlusion.

Carotid-ophthalmic aneurysms – protective features making them a rare cause of subarachnoid hemorrhage

Abstract Objective: To review the rate of carotid-ophthalmic aneurysm (COA) rupture and to identify protective features that may contribute to their low rupture rate. Methods: We reviewed the records of 790 patients with 773 aneurysms greater than 2 mm treated by endovascular routes between 2002 and 2012 at our institution. Seventy five carotid-ophthalmic aneurysms were identified in 72 patients. Three injected human cadaver heads were studied to evaluate the perianeurysmal environment of the carotid-ophthalmic region. Results: Only 2 (2.8%) of these 72 patients presented with acute SAH due to a ruptured carotid-ophthalmic aneurysm. The average size of ruptured COA was 11.3 mm versus 7 mm for unruptured aneurysms. Most of the aneurysms were discovered in patients who were asymptomatic. The most common presenting symptom was headache. In this study, we also provide cadaveric anatomic illustrations of the perianeurysmal environment in order to investigate the low rate of COA rupture. Additionally, we highlight the existence of a double arachnoid layer consisting of the arachnoid on the inferior aspect of the optic nerve and surrounding the internal carotid artery (ICA), which could further contribute to the low rupture rate of these aneurysms. Conclusions: Carotid-ophthalmic aneurysms are uncommon sources of subarachnoid hemorrhage. The perianeurysmal environment surrounding these aneurysms may provide protection, lending these aneurysms to a relatively benign natural history.