Association of Menopausal Age with Unruptured Intracranial Aneurysm Morphology.

BACKGROUND: The prevalence of unruptured intracranial aneurysms (UIAs) increases rapidly in aging women compared with younger women. The impact of menopausal age on UIAs and treatment outcomes with endovascular therapy has not been well studied. We hypothesized that premenopausal age may have a protective effect on presentation size and treatment outcomes. OBJECTIVE: To evaluate the association of menopause with UIA size and outcome with endovascular therapy. METHODS: Retrospective analysis of consecutive female patients with UIAs treated with endovascular therapy at our academic tertiary care center. UIA characteristics, complications, and outcomes were recorded and compared. RESULTS: 117 patients were included: 23 patients in the premenopausal age (PRM) group and 94 in the postmenopausal age (POM) group. 93.6% of all aneurysms in the PRM group were in the internal carotid artery (ICA) segments (p < 0.05). Hence only ICA segment aneurysms were further studied. A total of 21 patients in the PRM group and 60 in the POM group were found to have ICA segment aneurysms. Baseline characteristics were similar between the 2 groups. The mean size of the aneurysms in the PRM group was 8.6 ± 3.9 versus 10.8 ± 5.6 mm in the POM group (p = 0.055). There was a trend to higher aneurysm neck size seen in the POM group (4.7 ± 2.5 vs. 3.7 ± 1.7 mm; p = 0.07). The number of aneurysm lobes was higher in the PRM group (1.23 ± 0.54 vs. 1.07 ± 0.31; p = 0.18). In multivariate analysis, the PRM group had a significantly higher number of UIA lobes. Complications and endovascular therapy outcomes were similar between the 2 groups. CONCLUSIONS: A trend to increased UIA maximal diameter and neck size was seen in the POM group compared to the PRM group. The PRM group had a significantly higher number of UIA lobes. Larger prospective trials are needed to confirm these findings.

Association of hypothyroidism with unruptured cerebral aneurysms: a case-control study.

OBJECTIVE Thyroid disorder has been known to affect vascular function and has been associated with aortic aneurysm formation in some cases; however, the connection has not been well studied. The authors hypothesized that hypothyroidism is associated with the formation of cerebral aneurysms. METHODS The authors performed a retrospective case-control study of consecutive patients who had undergone cerebral angiography at an academic, tertiary care medical center in the period from April 2004 through April 2014. Patients with unruptured aneurysms were identified from among those who had undergone 3-vessel catheter angiography. Age-matched controls without cerebral aneurysms on angiography were also identified from the same database. Patients with previous subarachnoid hemorrhage or intracranial hemorrhage were excluded. History of hypothyroidism and other risk factors were recorded. RESULTS Two hundred forty-three patients with unruptured cerebral aneurysms were identified and age matched with 243 controls. Mean aneurysm size was 9.6 ± 0.8 mm. Hypothyroidism was present in 40 patients (16.5%) and 9 matched controls (3.7%; adjusted OR 3.2, 95% CI 1.3-7.8, p = 0.01). Subgroup analysis showed that men with hypothyroidism had higher odds of an unruptured cerebral aneurysm diagnosis than the women with hypothyroidism, with an adjusted OR of 12.7 (95% CI 1.3-121.9) versus an OR of 2.5 (95% CI 1.0-6.4) on multivariate analysis. CONCLUSIONS Hypothyroidism appears to be independently associated with unruptured cerebral aneurysms, with a higher effect seen in men. Given the known pathophysiological associations between hypothyroidism and vascular dysfunction, this finding warrants further exploration.

Combined Use of Intraoperative Indocyanine Green and Dynamic Angiography in Rotational Vertebral Artery Occlusion.

Rotational vertebral artery occlusion (RVAO) is a well-documented surgically amenable cause of vertebrobasilar insufficiency. Traditionally, patients have been imaged using dynamic rotational angiography. We report a case of RVAO in which intraoperative indocyanine green angiography (ICGA) was used to confirm adequate surgical decompression of the VA. A 57-year-old female who presented with multiple episodes of syncope provoked by turning her head to the right. Rotational dynamic angiography revealed a dominant right VA that became occluded at the level of C5/6 with head rotation to the right. The patient underwent successful surgical decompression of the VA via an anterior cervical approach. ICGA demonstrated VA patency with head rotation. This was further confirmed by intraoperative dynamic catheter angiography. To the best of our knowledge, we present the first use of ICG combined with intra-operative dynamic rotational angiography to document the adequacy surgical decompression of the VA in a patient with RVAO.

Epidemiology, clinical presentation, diagnostic evaluation, and prognosis of cerebral dural arteriovenous fistulas.

Dural arteriovenous fistulas are abnormal communications, within the dural leaflets, between meningeal arteries and dural venous sinuses and/or subarachnoid veins. Although many fistulas remain clinically silent and do not require treatment, presence of cortical venous reflux, intracranial bleed, and intolerable symptoms are the main indications for treatment. A thorough understanding of the natural history is of prime importance in the decision making and management of these lesions. In this chapter we discuss the epidemiology and natural history of intracranial dural arteriovenous fistulae.

Venous Phase Timing Does Not Predict SPECT Results During Balloon Test Occlusion of the Internal Carotid Artery.

INTRODUCTION: The purpose of this study is to evaluate the role of venous phase timing when compared with technetium-99m Single Photon Emission Computed Tomography (SPECT) during angiographic balloon test occlusion of the internal carotid artery (ICA) and subsequent sacrifice of the ICA. METHODS: Fifty-six patients underwent formal balloon test occlusion from April 2008 to February 2014 at our institution. Venous phase timing was calculated for each patient. SPECT imaging for each patient was interpreted by the nuclear medicine radiologist. Statistical analysis on the 3 groups (No Hypoperfusion, Mild Hypoperfusion, Moderate/Severe Hypoperfusion) was calculated using analysis of variance. RESULTS: Twenty-six patients showed no hypoperfusion during SPECT. The average delay of venous phase for these patients was 0.65 seconds. Eight of the 26 patients went on to have vessel sacrifice, with none showing evidence of infarction at the time of discharge. Six patients showed evidence of mild hypoperfusion on SPECT. None of these patients went on to have vessel sacrifice. The average venous delay was 0.5 seconds. Twenty-four patients were found to have moderate or severe hypoperfusion. The average venous delay was 1.08 seconds. Analysis of variance among the 3 groups demonstrated no significant difference (P = 0.22). CONCLUSION: Our study demonstrated no correlation between venous phase timing and SPECT. Future studies comparing multiple tests with patients who have had vessel occlusion are necessary to determine the best adjunctive measures to predict delayed ischemia following carotid occlusion.

Role of follow-up imaging after resection of brain arteriovenous malformations in pediatric patients: a systematic review of the literature.

OBJECTIVE Pediatric patients are at risk for the recurrence of brain arteriovenous malformation (AVM) after resection. While there is general consensus on the importance of follow-up after surgical removal of an AVM, there is a lack of consistency in the duration of that follow-up. The object of this systematic review was to examine the role of follow-up imaging in detecting AVM recurrence early and preventing AVM rupture. METHODS This systematic review was performed using articles obtained through a search of the literature contained in the MeSH database, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS Search results revealed 1052 articles, 13 of which described 31 cases of AVM recurrence meeting the criteria for inclusion in this study. Detection of AVM occurred significantly earlier (mean ± SD, 3.56 ± 3.67 years) in patients with follow-up imaging than in those without (mean 8.86 ± 5.61 years; p = 0.0169). While 13.34% of patients who underwent follow-up imaging presented with rupture of a recurrent AVM, 57.14% of those without follow-up imaging presented with a ruptured recurrence (p = 0.0377). CONCLUSIONS Follow-up imaging has an integral role after AVM resection and is sometimes not performed for a sufficient period, leading to delayed detection of recurrence and an increased likelihood of a ruptured recurrent AVM.

Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses.

BACKGROUND: Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. OBJECTIVE: We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. METHODS: This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. RESULTS: From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. CONCLUSION: In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign.

Modified Far Lateral Approach for Posterior Circulation Aneurysms: An Institutional Experience.

OBJECTIVE: The modified far lateral approach is a modified version of the far lateral approach without drilling of the condyle. This approach can be used for accessing aneurysms anterior and anterolateral to the brainstem and craniovertebral junction. We describe the surgical outcome and complications of the modified far lateral approach for vertebrobasilar, proximal posterior inferior cerebellar artery, and vertebral artery aneurysms. METHODS: The records of 26 patients with vertebrobasilar aneurysms who underwent surgery using the modified far lateral approach from 1994 to 2015 were retrospectively reviewed to analyze the clinical outcomes. RESULTS: Mean age of patients was 61 years (range, 38-84 years), and 18 patients were women. The most common presenting symptoms were sudden-onset headache (77%) and dizziness (35%). Of patients, 21 (81%) had saccular aneurysms, and 5 (19%) had fusiform aneurysms. The modified far lateral approach was used in 16 patients with posterior inferior cerebellar artery aneurysms, 6 patients with vertebral artery aneurysms, 2 patients with basilar aneurysms, 1 patient with a vertebrobasilar junction aneurysm, and 1 patient with an anterior inferior cerebellar artery aneurysm. All aneurysms were clipped successfully. Follow-up data were available for 25 patients (median duration 67 months). At last follow-up, 22 patients had a good recovery (modified Rankin Scale score 1-3), and 3 patients had a poor outcome (modified Rankin Scale score 4-6). Four patients developed lower cranial nerve palsy, and 7 patients developed new-onset hydrocephalus. CONCLUSIONS: The modified far-lateral approach without condyle resection and vertebral artery mobilization is associated with low procedure-related morbidity and comparable outcomes to the more extensive traditional approach.

Treatment of unruptured intracranial aneurysms: a review.

INTRODUCTION: Unruptured brain aneurysms (UIAs) present a challenge due to the lack of definitive understanding of their natural history and treatment outcomes. As the treatment of UIAs is aimed at preventing the possibility of rupture, the immediate risk of treatment must be weighed against the risk of rupture in the future. As such, treatment for a large proportion of UIAs is currently individualized. AREAS COVERED: In this article, we discuss the important natural history studies of UIAs and discuss the existing scientific evidence and recent advances that help identify the rupture risk guide management of UIAs. We also address the recent advances in pharmacological therapy of UIAs. Expert commentary: In the recent years, there have been great advances in understanding the pathophysiology of UIAs and determining the rupture risk going beyond the traditional parameter of aneurysm size. Aneurysm morphology and hemodynamics play a pivotal role in growth and rupture. A true randomized trial for the management of UIAs is the need of the hour.

Inadvertent Stent Retriever Detachment: A Multicenter Case Series and Review of Device Experience FDA Reports.

Mechanical thrombectomy using retrievable stents or stent retriever devices has become the mainstay of intra-arterial therapy for acute ischemic stroke. The recent publication of a series of positive trials supporting intra-arterial therapy as standard of care for the treatment of large vessel occlusion will likely further increase stent retriever use. Rarely, premature stent detachment during thrombectomy may be encountered. In our multicenter case series, we found a rate of detachment of less than 1% (n = 7/1,067), and all were first-generation Solitaire FR devices. A review of the US Food and Drug Administration database of device experience yielded 90 individual adverse reports of detachment. There were 82, 1 and 7 detachments of Solitaire FR (first generation), Solitaire FR2 (second generation) and Trevo devices, respectively. We conclude with a brief overview of the technical and procedural considerations which may be helpful in avoiding this rare complication.

Combined use of intraoperative indocyanine green and dynamic angiography in rotational vertebral artery occlusion.

Rotational vertebral artery occlusion, also known as bow hunter's syndrome, is a well-documented surgically amenable cause of vertebrobasilar insufficiency. Traditionally, patients have been imaged using dynamic rotational angiography. The authors sought to determine whether intraoperative indocyanine green (ICG) angiography could reliably assess the adequacy of surgical decompression of the vertebral artery (VA). The authors report two patients who presented with multiple transient episodes of syncope provoked by turning their head to the right. Rotational dynamic angiography revealed a dominant VA that became occluded with head rotation to the right side. The patients underwent successful surgical decompression of the VA via an anterior cervical approach. Intraoperative ICG angiography demonstrated patency of the VA with head rotation. This was further confirmed by intraoperative dynamic catheter angiography. To our knowledge, we present the first two cases of the use of ICG combined with intraoperative dynamic rotational angiography to document the adequacy of surgical decompression of the VA in a patient with rotational vertebral artery occlusion. Intraoperative ICG angiography is a useful adjunct and may potentially supplant the need for intraoperative catheter angiography.

Cerebral aneurysm treatment in India: Results of a national survey regarding practice patterns in India.

BACKGROUND: The management of intracranial aneurysms (IAs) varies widely depending upon a number of factors. OBJECTIVE: To understand the variations in practice patterns in the treatment of IAs in India. METHODS: The survey consisted of 23 questions. Two group emails were sent to members of the Neurological Society of India and the Neurological Surgeons Society of India. Uni- and multivariate analysis was performed where appropriate. RESULTS: The response rate was 10.13% (150/1480). Fifty percent of the respondents used steroids in subarachnoid hemorrhage and 64% initiated triple-H therapy prophylactically. There was no significant difference in the use of steroids, antifibrinolytics, mannitol, or hypertonic saline and the choice of therapeutic intervention (clipping or endovascular therapy [EVT]) for anterior circulation aneurysms between physicians working at teaching and nonteaching hospitals. However, physicians in teaching and government hospitals were less likely to choose EVT for middle cerebral artery aneurysms as the first line of treatment (odds ratio [OR] 0.6 and 0.1, respectively). Physicians working at private hospitals were more likely to have EVT facilities than those working in government-owned hospitals. On multivariate analysis, physicians working in teaching hospitals preferred surgical clipping to EVT for posterior circulation aneurysms (OR = 0.7) and physicians at teaching hospitals performed >50 cases/year. CONCLUSION: Our study demonstrates the prevailing practice patterns in the management of IAs in India. Surgical clipping is the preferred treatment of choice for anterior circulation aneurysms and EVT for aneurysms along the posterior circulation. Corticosteroids and prophylactic "triple-H" therapy are still used by a large proportion of physicians.

Stem Cells as a Potential Adjunctive Therapy in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Despite advances in the management of subarachnoid hemorrhage, a considerable proportion of patients are still left with severe and disabling long-term consequences. Unfortunately, there are limited therapeutic options to counteract the sequelae following the initial insult. The role of stem cells has been studied in the treatment of various diseases. The goal of this study was to provide a literature review regarding the potential advantages of stem-cell therapy to counteract or minimize the sequelae of aneurysmal subarachnoid hemorrhage. METHODS: PubMed, Google Scholar, and ClinicalTrials.gov searches were conducted to incorporate pertinent studies that discussed stem cell use in the management of subarachnoid hemorrhage. Included articles were subjected to data extraction for the synthesis of the efficacy of stem-cell therapy. RESULTS: Four preclinical studies with 181 animal model subjects (44 mice, 137 rats) were incorporated in our review. Endovascular punctures (65%) and blood injections in subarachnoid spaces (17%) were used to induce hemorrhage models. Stem cells were administered intravenously (3.0 × 10(6) cells) or intranasally (1.5 × 10(6) cells). According to literature, mesenchymal cell therapy significantly (p<0.05) induces stem-cell migration to lesion sites, decreases associated neural apoptosis and inflammation, improves ultrastructural integrity of cerebral tissue, and aids in improving sensorimotor function post subarachnoid hemorrhage. CONCLUSION: Stem cells, particularly mesenchymal stem cells, have shown promising cellular, morphological, and functional benefits in animal models suffering from induced subarachnoid hemorrhages. However, further studies are warranted to elucidate the full effects of stem-cell therapy for aneurysmal subarachnoid hemorrhage.

Long-term angiographic results of endovascularly "cured" intracranial dural arteriovenous fistulas.

OBJECTIVE: Dural arteriovenous fistulas (DAVFs) are complex lesions consisting of abnormal connections between meningeal arteries and dural venous sinuses and/or cerebral veins. The goal of treatment is surgical or endovascular occlusion of the fistula or fistulous nidus or at least the disconnection of the feeding vessels and the draining veins. Delayed angiographic data on previously embolized dural fistulas is lacking. The authors report their experience and the long-term angiographic results with embolization of intracranial DAVF using Onyx. METHODS: All cases of DAVF treated primarily with Onyx at the authors' institution from 2006 to 2013 were retrospectively reviewed. Patient demographics, fistula characteristics, embolization details, and angiographic follow-up were analyzed. RESULTS: Fifty-eight patients with DAVFs were treated during the study period. Twenty-two patients were treated with open surgery with or without prior embolization. Thirty-six patients were treated with embolization alone, of whom 26 underwent an attempt at curative embolization and are the subject of this review. All but 2 of these patients were treated in a single session. Angiographic "cure" was achieved in all cases following treatment. Follow-up angiography was performed in 21 patients at a mean of 14 months after treatment (range 2-39 months). Asymptomatic angiographic recurrence of the fistula was evident in 3 of the 21 patients (14.3%). On reviewing the procedural angiograms of the cases in which the DAVFs recurred, it was observed that the Onyx cast did not reach the venous portion in 1 case, whereas it did reach the vein in the other 2 cases. CONCLUSIONS: Recurrence following initial angiographic cure of DAVF is not uncommon. Incomplete penetration of the embolic material into the proximal portion of the venous outlet may lead to delayed recurrence. Long-term angiographic follow-up is highly recommended.

Preoperative embolization of intracranial hemangiopericytomas: case series and introduction of the transtumoral embolization technique.

BACKGROUND AND PURPOSE: Hemangiopericytomas (HPCs) are rare dural-based neoplasms. Preoperative embolization of these notoriously hypervascular tumors can be challenging as they often receive their dominant blood supply from pial feeders arising from the internal carotid artery (ICA) or vertebrobasilar (VB) circulation. This study reviews our historical experience with HPC embolization and introduces the transtumoral technique for backfilling pial tumor vasculature by delivering Onyx-18 through diminutive external carotid artery (ECA) feeders. METHODS: A retrospective review of all preoperative HPC embolizations performed at Anonymous University #1 (September 2002-November 2014) and Anonymous University #2 (January 2014-November 2014) is presented. RESULTS: Fifteen patients with pathologically confirmed HPC underwent 17 embolizations. More extensive devascularization percentages were achieved for HPCs with primarily ECA blood supply (76.4±10.7%; n=6) than with HPCs supplied via the ICA/VB circulation (57.9±26.9%; n=8; p=0.046). There was a trend towards greater devascularization of ICA/VB-dominant HPCs embolized with Onyx (70.0±34.6%; n=4) versus polyvinyl alcohol particles (33.3±15.3%; n=3). The extent of angiographic devascularization negatively correlated with intraoperative blood loss (rho=-0.71; p=0.005). There were no embolization-related complications. CONCLUSIONS: The extent of preoperative embolization of HPCs correlates with decreased intraoperative blood loss. However, HPCs with an ICA/VB-dominant blood supply remain challenging embolization targets, demonstrating reduced devascularization percentages compared with ECA-dominant counterparts. The authors favor the use of Onyx for ICA/VB-dominant HPCs, noting a trend towards an improved devascularization rate.