The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention

Objective@#: The fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs. @*Methods@#: We retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed. @*Results@#: The initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018). @*Conclusion@#: Complete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention

Objective@#: The fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs. @*Methods@#: We retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed. @*Results@#: The initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018). @*Conclusion@#: Complete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

Healing of Aneurysm after Treatment Using Flow Diverter Stent : Histopathological Study in Experimental Canine Carotid Side Wall Aneurysm

Objective@#: Despite widespread use of flow diverters (FDs) to treat aneurysms, the exact healing mechanism associated with FDs remains poorly understood. We aim to describe the healing process of aneurysms treated using FDs by demonstrating the histopathologic progression in a canine aneurysm model. @*Methods@#: Twenty-one side wall aneurysms were created in common carotid artery of eight dogs and treated with two different FDs. Angiographic follow-ups were done immediately after placement of the device, 4 weeks and 12 weeks. At last follow-up, the aneurysm and the device-implanted parent artery were harvested. @*Results@#: Histopathologic findings of aneurysms at 4 weeks follow-up showed intra-aneurysm thrombus formation in laminating fashion, and neointimal thickening at the mid-segment of aneurysm. However, there are inhomogenous findings in aneurysms treated with the same type of FD showing same angiographic outcomes. At 12 weeks, aneurysms of complete and near-complete occlusion revealed markedly shrunken aneurysm filled with organized connective tissues with thin neointima. Aneurysms of incomplete occlusion at 12 weeks showed small amount of organized thrombus around fringe neck and large empty space with thick neointmal formation. Neointimal thickness and diameter stenosis was not significantly different between the groups of FD specification and follow-up period. @*Conclusion@#: Intra-aneurysmal thrombus formation and organization seem to be an important factor for the complete occlusion of aneurysms treated using the FD. Neointimal formation could occur along the struts of the FD independently of intra-aneurysmal thrombus formation. However, neointimal formation could not solely lead to complete aneurysm healing.

De Novo Intracranial Aneurysms Detected on Imaging Follow-Up of Coiled Aneurysms in a Korean Population

OBJECTIVE: Coiled aneurysms are known to recanalize over time, making follow-up evaluations mandatory. Although de novo intracranial aneurysms (DNIAs) are occasionally detected during routine patient monitoring, such events have not been thoroughly investigated to date. Herein, we generated estimates of DNIA development during long-term observation of coiled cerebral aneurysms, focusing on incidence and the risk factors involved. MATERIALS AND METHODS: In total, 773 patients undergoing coil embolization of intracranial aneurysms between 2008 and 2010 were reviewed retrospectively. Their medical records and radiologic data accrued over the extended period (mean, 52.7 ± 29.7 months) were analyzed. For the detection of DNIA, follow-up magnetic resonance angiography and/or conventional angiography were used. The incidence of DNIAs and related risk factors were analyzed using Cox proportional hazards regression and Kaplan-Meier product-limit estimator. RESULTS: In 19 (2.5%) of the 773 patients with coiled aneurysms, DNIAs (0.56% per patient-year) developed during continued long-term monitoring (3395.3 patient-years). Of these, 9 DNIAs (47.4%) were detected within 60 months, with 10 (52.6%) emerging thereafter. The most common site involved was the posterior communicating artery (n = 6), followed by the middle cerebral artery (n = 5) and the basilar top (n = 4). Multivariate analysis indicated that younger age ( 60 years; p < 0.001) and in the absence of post-coiling aneurysm recurrence (p = 0.006). CONCLUSION: In most patients with coiled aneurysms, development of DNIAs during long-term monitoring is rare. However, younger patients (< 50 years) or patients with recurring aneurysms appear to be predisposed to DNIAs.

Symptomatic Retinal Artery Occlusion after Angioplasty and Stenting of the Carotid Artery: Incidence and Related Risk Factors

OBJECTIVE: Retinal artery occlusion (RAO) is rarely seen as a complication in patients undergoing carotid artery stenting (CAS); hence, its characteristics have not been documented in detail. This study aimed to investigate the incidence of this complication and the related risk factors, focusing on differences in ophthalmic artery (OA) supply (whether by the external or internal carotid artery [ECA or ICA]) prior to CAS procedures. MATERIALS AND METHODS: We retrospectively examined 342 patients who underwent CAS for severe and/or symptomatic carotid artery stenosis between January 2009 and December 2017. Cumulative medical records and radiologic data were assessed. RAO was confirmed by photography and fluorescent angiography of the fundus, which were performed by an ophthalmologist. In all patients, distal filter systems of various types were applied as cerebral protection devices (CPDs) during procedures. Univariate and multivariate analyses were conducted to identify the risk factors for RAO after CAS. RESULTS: Symptomatic RAO was observed in six patients (1.8%), of which five (6.8%) were ECA-dominant group members (n = 74). In a binary logistic regression analysis, OA supply by the ECA (odds ratio [OR], 9.705; 95% confidence interval [CI], 1.519–62.017; p = 0.016) and older age (OR, 1.159; 95% CI, 1.005–1.336; p = 0.041) were identified as significant risk factors in patients with RAO after CAS. ECA-supplied OA was also associated with the severity of ipsilateral ICA stenosis (p = 0.001) and ulcerative plaque (p = 0.021). CONCLUSION: In procedures performed using ICA distal filtering CPD systems, RAO as a complication of CAS (performed for severe stenosis) showed a relationship to ECA-supplied OA. For older patients, simultaneous use of ICA-ECA CPDs might help prevent such complications.

Protected versus Unprotected Carotid Artery Stenting : Meta-Analysis of the Current Literature

OBJECTIVE: To compare peri-operative any symptomatic stroke after carotid angioplasty and stenting (CAS), based on the application or absence of a cerebral protection device. METHODS: A systematic literature review using PubMed, Embase, and the Cochrane Central was done across an online data base from January 1995 to October 2016. Procedures which were performed due to carotid dissection or aneurysm, procedures using covered stents or conducted in an emergency, were excluded. The primary endpoint was perioperative any symptomatic stroke within 30 days after the procedure. A fixed effect model was used in cases of heterogeneity less than 50%.

Intracranial Mirror Aneurysms: Anatomic Characteristics and Treatment Options

OBJECTIVE: Mirror aneurysms are generally considered as a subset of multiple aneurysms, defined as aneurysms occurring bilaterally and symmetrically on the same-named vessels. Although not infrequent, the characteristics of mirror aneurysms are not well studied. This investigation was conducted to elucidate the anatomic features of such lesions and examine treatment options. MATERIALS AND METHODS: A retrospective review was conducted, aimed at 172 patients treated for 344 mirror aneurysms between January 2007 and December 2015. Aneurysms of similar nature but in asymmetric locations on the same-named vessels were excluded. All available records were examined and lesion characteristics, as well as treatment outcomes were assessed. RESULTS: In study subjects (n = 172), mirror aneurysms most often involved middle cerebral artery bifurcation (n = 83), followed by a paraclinoid internal carotid artery (n = 50) and posterior communicating artery (n = 21). Most of the lesions (95.3%) measured ≤ 10 mm, and in 126 patients (74.6%), the size ratios were > 50%. Of the 344 aneurysms studied, coil embolization was undertaken in 217, surgical clipping in 62, and observation alone (no treatment) in 65. Coil embolization and surgical clipping were done bilaterally in 83 and 12 patients, respectively. In 12 patients, combined coiling and clipping were implemented on each side. Single-stage coil embolization of both the aneurysms was performed in 73 patients, with excellent post-procedural (85.6%) and follow-up (86.8%) occlusive results. There was no procedure-related morbidity or mortality. CONCLUSION: By adopting different treatment strategies to different configurations and vascular sources, mirror aneurysms can be safely and effectively treated. If feasible, single-stage coil embolization should be considered as a reasonable treatment option for mirror aneurysms.

Protected versus Unprotected Carotid Artery Stenting : Meta-Analysis of the Current Literature

OBJECTIVE: To compare peri-operative any symptomatic stroke after carotid angioplasty and stenting (CAS), based on the application or absence of a cerebral protection device.METHODS: A systematic literature review using PubMed, Embase, and the Cochrane Central was done across an online data base from January 1995 to October 2016. Procedures which were performed due to carotid dissection or aneurysm, procedures using covered stents or conducted in an emergency, were excluded. The primary endpoint was perioperative any symptomatic stroke within 30 days after the procedure. A fixed effect model was used in cases of heterogeneity less than 50%.RESULTS: In the 25 articles included in this study, the number of stroke events was 326 (2.0%) in protected CAS and 142 (3.4%) in unprotected CAS. The use of cerebral protection device significantly decreased stroke after CAS (odds ratio [OR] 0.633, 95% confidence interval [CI] 0.479–0.837, p=0.001). In the publication bias analysis, Egger’s regression test disclosed that the intercept was -0.317 (95% CI -1.015–0.382, p=0.358). Regarding symptomatic patients (four studies, 539 CAS procedures), the number of stroke was six (1.7%) in protected CAS and 11 (5.7%) in unprotected CAS. The protective effect against stroke events by cerebral protection device did not have a statistical significance (OR 0.455, 95% CI 0.151–1.366, p=0.160).CONCLUSION: The use of protection device significantly decreased stroke after CAS. However, its efficacy was not demonstrated in symptomatic patients. Routine use of protection device during CAS should be critically assessed before mandatory use.

Endovascular Treatment of Bilateral Cavernous Sinus Dural Arteriovenous Fistula: Therapeutic Strategy and Follow-Up Outcomes

OBJECTIVE: Bilateral cavernous sinus dural arteriovenous fistula (CSdAVF) is very rare, even in Asian countries. The research intended to present clinical and radiologic outcomes of treating such fistulas through endovascular embolization. MATERIALS AND METHODS: Data was obtained from 220 consecutive patients, with CSdAVF, who were treated from January 2004 to December 2015. Bilateral CSdAVF was identified in 17 patients (7.7%). The clinical and radiologic outcomes of the fistulas were assessed with an emphasis on the technical aspects of treatment. RESULTS: At the time of treatment, 7 and 10 patients presented with bilateral and unilateral symptoms, respectively. In the former cases, 4 patients had progressed from unilateral to bilateral symptoms. Bilateral fistulas were treated with a single-stage transvenous embolization (TVE) in 15 patients, via bilateral inferior petrosal sinuses (IPS) (n = 9) and unilateral IPS (n = 6). In the other 2 patients with one-sided dominance of shunting, only dominant fistula was treated. Two untreated lesions were found on follow-up to have spontaneously resolved after treatment of the dominant contralateral fistula. Of the 34 CSdAVF lesions, complete occlusion was achieved in 32 lesions after TVE. Seven patients (41.2%) developed worsening of cranial nerve palsy after TVE. During the follow-up period, 4 patients obtained complete recovery, whereas the other 3 remained with deficits. CONCLUSION: With adjustments of endovascular procedures to accommodate distinct anatomical configurations, endovascular treatment for bilateral CSdAVF can achieve excellent angiographic occlusion results. However, aggravation of symptoms after TVE may occur frequently in bilateral CSdAVF. In the patients with one-sided dominance of shunt, treatment of only dominant fistula might be an alternative option.

Microguidewire Looping to Traverse Stented Parent Arteries of Intracranial Aneurysms

OBJECTIVE: Stents are widely used in coil embolization of intracranial aneurysms, but on occasion, a microcatheter must traverse a stented segment of artery (so-called trans-cell technique) to select an aneurysm, or double stenting may necessary. In such situations, microguidewire passage and microcatheter delivery through a tortuous stented parent artery may pose a technical challenge. Described herein is a microguidewire looping technique to facilitate endovascular navigation in these circumstances. METHODS: To apply this technique, the microguidewire tip is looped before entering the stented parent artery and then advanced distally past the stented segment, with the loop intact. Rounding of the tip prevents interference from stent struts during passage. A microcatheter is subsequently passed into the stented artery for positioning near the neck of aneurysm, with microguidewire assistance. The aneurysm is then selected, steering the microcatheter tip (via inner microguidewire) into the dome. RESULTS: This technique proved successful during coil embolization of nine saccular intracranial aneurysms (internal carotid artery [ICA], 6; middle cerebral artery, 2; basilar tip, 1), performing eight trans-cell deliveries and one additional stenting. Selective endovascular embolization was enabled in all patients, resulting in excellent clinical and radiologic outcomes, with no morbidity or mortality directly attributable to microguidewire looping. CONCLUSION: Microguidewire looping is a reasonable alternative if passage through a stented artery is not feasible by traditional means, especially at paraclinoid ICA sites.

Prediction of Prolonged Hemodynamic Instability During Carotid Angioplasty and Stenting / 신경중재치료의학

PURPOSE: The aim of this study was to assess the risk factors of prolonged hemodynamic instability (HDI) after carotid angioplasty and stenting (CAS). Herein, a simplified predictive scoring system for prolonged HDI is proposed. MATERIALS AND METHODS: Sixty-six patients who had CAS from 2011 to 2016 at a single institution were evaluated. Prolonged HDI was defined as systolic blood pressure >160 mm Hg or <90 mm Hg or heart rate <50 beats/min, lasting over 30 minutes despite medical treatments. For the study, clinical data and radiologic data, including plaque morphology and stenosis were analyzed. RESULTS: Prolonged HDI was observed in 21 patients (31.8%). Multivariable analysis revealed that calcification (OR, 6.726; p=0.006), eccentric stenosis (OR, 3.645; p=0.047) and extensive plaque distribution (OR, 7.169; p=0.006) were related to prolonged HDI. According to these results, a simplified scoring scale was proposed based on the summation of points: 2 points for calcified plaque, 2 points for extensive plaque distribution, and 1 point for eccentric stenosis. The percentages of prolonged HDI according to the total score were as follows: score 0, 8.7%; score 1, 20.0%; score 2, 38.5%; score 3, 72.7%; score 4, 66.7%; score 5, 100%. From the analysis, the total score in patients with prolonged HDI was significantly higher than those without prolonged HDI (p<0.001). CONCLUSION: Prolonged HDI can be associated with calcification of plaque, eccentric stenosis and extensive plaque distribution, and a simplified scoring system enables prediction of prolonged HDI according to our cohort.

Stent-Assisted Coil Embolization of Vertebrobasilar Dissecting Aneurysms: Procedural Outcomes and Factors for Recanalization

OBJECTIVE: Outcomes of stent-assisted coil embolization (SACE) have not been well established in the setting of vertebrobasilar dissecting aneurysms (VBDAs) due to the low percentage of cases that need treatment and the array of available therapeutic options. Herein, we presented clinical and radiographic results of SACE in patients with VBDAs. MATERIALS AND METHODS: A total of 47 patients (M:F, 30:17; mean age ± SD, 53.7 ± 12.6 years), with a VBDA who underwent SACE between 2008 and 2014 at two institutions were evaluated retrospectively. Medical records and radiologic data were analyzed to assess the outcome of SACE procedures. Cox proportional hazards regression analysis was conducted to determine the factors that were associated with aneurysmal recanalization after SACE. RESULTS: Stent-assisted coil embolization technically succeeded in all patients. Three cerebellar infarctions occurred on postembolization day 1, week 2, and month 2, but no other procedure-related complications developed. Immediately following SACE, 25 aneurysms (53.2%) showed no contrast filling into the aneurysmal sac. During a mean follow-up of 20.2 months, 37 lesions (78.7%) appeared completely occluded, whereas 10 lesions showed recanalization, 5 of which required additional embolization. Overall recanalization rate was 12.64% per lesion-year, and mean postoperative time to recanalization was 18 months (range, 3-36 months). In multivariable analysis, major branch involvement (hazard ratio [HR]: 7.28; p = 0.013) and the presence of residual sac filling (HR: 8.49, p = 0.044) were identified as statistically significant independent predictors of recanalization. No bleeding was encountered in follow-up monitoring. CONCLUSION: Stent-assisted coil embolization appears feasible and safe for treatment of VBDAs. Long-term results were acceptable in a majority of patients studied, despite a relatively high rate of incomplete occlusion immediately after SACE. Major branch involvement and coiled aneurysms with residual sac filling may predispose to recanalization.

Use of Triple Microcatheters for Endovascular Treatment of Wide-Necked Intracranial Aneurysms: A Single Center Experience

OBJECTIVE: The dual microcatheter technique is common practice for coil embolization of a wide-necked aneurysm, due to safety and efficacy. However, technical limitations of some complex configurations may necessitate additional microcatheters to bolster coil stability, compact the coil, or for protection. Described herein is a triple microcatheter technique for endovascular management of wide-necked intracranial aneurysms. MATERIALS AND METHODS: Data accruing prospectively between January 2006 and October 2014 on simultaneously executed triple microcatheter coil embolization procedures done in 38 saccular aneurysms were reviewed. Clinical and morphological outcomes were assessed, with emphasis on technical aspects of treatment. RESULTS: The triple microcatheter technique was successfully applied to all 38 saccular aneurysms, involving the posterior communicating artery (n = 13), the middle cerebral artery (n = 10), the basilar tip (n = 7), the anterior cerebral artery (n = 5), and the internal carotid artery (n = 3). Stent protection was added in four patients and balloon remodeling in one. Dual microcatheters (n = 24) were usually deployed to deliver the coil within sacs of aneurysms, with the additional microcatheter used for protection. Otherwise, triple microcatheters were deployed for coil delivery (n = 11) or coils were delivered via a single microcatheter, with dual microcatheters deployed for protection (n = 3). Successful occlusion of aneurysms was achieved in 89.5% of cases, with no procedure-related morbidity or mortality. Stable occlusion was maintained in 72.2% (26/36) of the aneurysms at the final follow-up (mean interval, 30.2 +/- 22.7 months). CONCLUSION: The outcomes of this limited study suggest that the triple microcatheter technique may be an effective and safe therapeutic option for wide-necked aneurysms, using technical strategies tailored to complex angio-anatomic configurations.

Endovascular Treatment of 429 Anterior Communicating Artery Aneurysms Using Bare-Platinum Coils : Clinical and Radiologic Outcomes at the Long-term Follow-up

OBJECTIVE: We reviewed the feasibility, safety and efficacy as well as the clinical outcome and long-term angiographic results of endovascular treatment (EVT) of the anterior communicating artery (ACoA) aneurysms. METHODS: A total of 429 ACoA aneurysms in 426 patients were treated using coil embolization between March 1996 and October 2010 in a single institution. Pretreatment aneurysmal features were checked using angiogram. We had usually used tailored steam shaped microcatheter according to individual angiographic architectures. Immediate postembolization outcomes were evaluated using an angiographic outcome scale and clinical evaluation was performed using the Glasgow Outcome Scale (GOS). RESULTS: Postembolization angiograms demonstrated total occlusion of aneurysm in 290 of 429 (67.6%) aneurysms, neck remnant in 80 (18.6%) and body filling in 59 (13.8%). Dome direction and aneurysm angle was not associated with initial angiographic outcomes. The procedure-related morbidity rate was 0.9% (4 of 429). Clinical and imaging follow-up more than 6 months were available in 382 (89.0%) patients with a mean of 26.2 months. Overall rate of major recanalization was 7.9% (30 of 382) and all of them were retreated without complications. At the last follow-up, 233 (99.2%) of 235 patients had GOS of 5 in unruptured group, and 152 (79.5%) of 191 patients showed good clinical outcomes (GOS of 4 or 5) in ruptured group. CONCLUSION: Tailored steam shaping of the microcatheter is vital to achieve good angiographic outcomes regardless of aneurysmal direction. EVT is feasible and safe for most ACoA aneurysms with acceptable immediate and long-term outcomes.

Covered Stents for the Endovascular Treatment of a Direct Carotid Cavernous Fistula : Single Center Experiences with 10 Cases

OBJECTIVE: Covered stent has been recently reported as an effective alternative treatment for direct carotid cavernous fistulas (DCCFs). The purpose of this study is to describe our experiences with the treatment of DCCF with covered stents and to evaluate whether a covered stent has a potential to be used as the first choice in selected cases. METHODS: From February 2009 through July 2013, 10 patients underwent covered stent placement for a DCCF occlusion. Clinical and angiographic data were retrospectively reviewed. RESULTS: Covered stent placement was performed for five patients primarily as the first choice and in the other five as an alternative option. Access and deployment of a covered stent was successful in all patients (100%) and total occlusion of the fistula was achieved in nine (90%). Complete occlusion immediately after the procedure was obtained in five patients (50%). Endoleak persisted in five patients and the fistulae were found to be completely occluded by one month control angiography in four. The other patient underwent additional coil embolization by a transvenous approach. Balloon inflation-related arterial dissection during the procedure was noted in two cases; healing was noted at follow-up angiography. One patient suffered an asymptomatic internal carotid artery occlusion noted seven months post-treatment. CONCLUSION: Although endoleak is currently a common roadblock, our experience demonstrates that a covered stent has the potential to be used as the first choice in DCCF; this potential is likely to increase as experience with this device accumulates and the materials continue to improve.

Simultaneous Endovascular Treatment of Ruptured Cerebral Aneurysms and Vasospasm

OBJECTIVE: The management of patients with ruptured cerebral aneurysms and severe vasospasm is subject to considerable controversy. We intended to describe herein an endovascular technique for the simultaneous treatment of aneurysms and vasospasm. MATERIALS AND METHODS: A series of 11 patients undergoing simultaneous endovascular treatment of ruptured aneurysms and vasospasm were reviewed. After placement of a guiding catheter within the proximal internal carotid artery for coil embolization, an infusion line of nimodipine was wired to one hub, and of a microcatheter was advanced through another hub (to select and deliver detachable coils). Nimodipine was then infused continuously during the coil embolization. RESULTS: This technique was applied to 11 ruptured aneurysms accompanied by vasospasm (anterior communicating artery, 6 patients; internal carotid artery, 2 patients; posterior communicating and middle cerebral arteries, 1 patient each). Aneurysmal occlusion by coils and nimodipine-induced angioplasty were simultaneously achieved, resulting in excellent outcomes for all patients, and there were no procedure-related complications. Eight patients required repeated nimodipine infusions. CONCLUSION: Our small series of patients suggests that the simultaneous endovascular management of ruptured cerebral aneurysms and vasospasm is a viable approach in patients presenting with subarachnoid hemorrhage and severe vasospasm.

Microcatheter Looping to Facilitate Aneurysm Selection in Coil Embolization of Paraclinoid Aneurysms

OBJECTIVE: Described herein is a microcatheter looping technique to facilitate aneurysm selection in paraclinoid aneurysms, which remains to be technically challenging due to the inherent complexity of regional anatomy. MATERIALS AND METHODS: This retrospective study was approved by our Institutional Review Board, and informed consent was waived. Microcatheter looping method was employed in 59 patients with paraclinoid aneurysms between January 2012 and December 2013. In the described technique, construction of a microcatheter loop, which is steam-shaped or pre-shaped, based on the direction of aneurysms, is mandatory. The looped tip of microcatheter was advanced into distal internal carotid artery and positioned atop the target aneurysm. By steering the loop (via inner microguidewire) into the dome of aneurysm and easing tension on the microcatheter, the aneurysm was selected. Clinical and morphologic outcomes were assessed with emphasis on technical aspects of the treatment. RESULTS: Through this looping technique, a total of 59 paraclinoid aneurysms were successfully treated. After aneurysm selection as described, single microcatheter technique (n = 25) was most commonly used to facilitate coiling, followed by balloon protection (n = 21), stent protection (n = 7), multiple microcatheters (n = 3), and stent/balloon combination (n = 3). Satisfactory aneurysmal occlusion was achieved through coil embolization in 44 lesions (74.6%). During follow-up of 53 patients (mean interval, 10.9 +/- 5.9 months), only one instance (1.9%) of major recanalization was observed. There were no complications related to microcatheter looping. CONCLUSION: This microcatheter looping method facilitates safe and effective positioning of microcatheter into domes of paraclinoid aneurysms during coil embolization when other traditional microcatheter selection methods otherwise fail.

Anomalous External Carotid Artery-Internal Carotid Artery Anastomosis in Two Patients with Proximal Internal Carotid Arterial Remnants

Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

Time-of-Flight Magnetic Resonance Angiography for Follow-Up of Coil Embolization with Enterprise Stent for Intracranial Aneurysm: Usefulness of Source Images

OBJECTIVE: The aim of this study was to determine the interobserver and intermodality agreement in the interpretation of time-of-flight (TOF) MR angiography (MRA) for the follow-up of coiled intracranial aneurysms with the Enterprise stent. MATERIALS AND METHODS: Two experienced neurointerventionists independently reviewed the follow-up MRA studies of 40 consecutive patients with 44 coiled aneurysms. All aneurysms were treated with assistance from the Enterprise stent and the radiologic follow-up intervals were greater than 6 months after the endovascular therapy. Digital subtraction angiography (DSA) served as the reference standard. The degree of aneurysm occlusion was determined by an evaluation of the maximal intensity projection (MIP) and source images (SI) of the TOF MRA. The capability of the TOF MRA to depict the residual flow within the coiled aneurysms and the stented parent arteries was compared with that of the DSA. RESULTS: DSA showed stable occlusions in 25 aneurysms, minor recanalization in 8, and major recanalization in 11. Comparisons between the TOF MRA and conventional angiography showed that the MIP plus SI had almost perfect agreement (kappa = 0.892, range 0.767 to 1.000) and had better agreement than with the MIP images only (kappa = 0.598, range 0.370 to 0.826). In-stent stenosis of more than 33% was observed in 5 cases. Both MIP and SI of the MRA showed poor depiction of in-stent stenosis compared with the DSA. CONCLUSION: TOF MRA seemed to be reliable in screening for aneurysm recurrence after coil embolization with Enterprise stent assistance, especially in the evaluation of the SI, in addition to MIP images in the TOF MRA.

Reappraisal of Anatomic Outcome Scales of Coiled Intracranial Aneurysms in the Prediction of Recanalization

OBJECTIVE: Several scales are currently used to assess occlusion rates of coiled cerebral aneurysms. This study compared these scales as predictors of recanalization. METHODS: Clinical data of 827 patients harboring 901 aneurysms treated by coiling were retrospectively reviewed. Occlusion rates were assessed using angiographic grading scale (AGS), two-dimensional percent occlusion (2DPO), and volumetric packing density (vPD). Every scale had 3 categories. Followed patients were dichotomized into either presence or absence of recanalization. Kaplan-Meier analysis was conducted, and Cox proportional hazards analysis was performed to identify surviving probabilities of recanalization. Lastly, the predictive accuracies of three different scales were measured via Harrell's C index. RESULTS: The cumulative risk of recanalization was 7% at 12-month, 10% at 24-month, and 13% at 36-month of postembolization, and significantly higher for the second and third categories of every scale (p<0.001). Multivariate-adjusted hazard ratios (HRs) of the second and third categories as compared with the first category of AGS (HR : 3.95 and 4.15, p=0.004 and 0.001) and 2DPO (HR : 4.87 and 3.12, p<0.001 and 0.01) were similar. For vPD, there was no association between occlusion rates and recanalization. The validated and optimism-adjusted C-indices were 0.50 [confidence (CI) : -1.09-2.09], 0.47 (CI : -1.10-2.09) and 0.44 (CI : -1.10-2.08) for AGS, 2DPO, and vPD, respectively. CONCLUSION: Total occlusion should be reasonably tried in coiling to maximize the benefit of the treatment. AGS may be the best to predict recanalization, whereas vPD should not be used alone.