Safety and efficacy of endovascular versus microsurgical treatment of unruptured wide-necked middle cerebral artery aneurysms: a propensity score-matched analysis of the NeuroVascular Quality Initiative Quality Outcomes Database Cerebral Aneurysm Registry.

OBJECTIVE: Unruptured, wide-necked middle cerebral artery (WN-MCA) aneurysms have traditionally been considered ideal candidates for microsurgery (MS), although endovascular treatment (EVT) has dramatically increased in popularity with the advent of novel devices such as intrasaccular flow disruptors. The purpose of this study was to evaluate the safety and efficacy of MS versus EVT for unruptured WN-MCA aneurysms. METHODS: The NeuroVascular Quality Initiative Quality Outcomes Database (NVQI-QOD) Cerebral Aneurysm Registry, a multiinstitutional, prospectively collected procedural database, was queried for cases of unruptured WN-MCA aneurysms treated with MS or EVT between 2015 and 2022. A wide neck was defined as an aneurysm neck ≥ 4 mm or a dome/neck ratio ≤ 2. Demographics and aneurysm characteristics were queried. Propensity score matching (PSM) was utilized to match aneurysm size, number of aneurysms treated, patient age, and aneurysm status. Safety outcomes were evaluated including intraoperative and postoperative complication rates. Aneurysm occlusion status and clinical outcomes using the modified Rankin Scale (mRS) score at discharge and the last follow-up were also assessed. RESULTS: Of 671 unruptured MCA aneurysms, 319 were wide necked. Thirty cases were excluded, as the aneurysm had been previously treated. Two hundred eighty-nine operations (203 EVT, 86 MS) in 282 patients satisfied inclusion criteria. After PSM, there were 86 operations in each group for analysis. The mean aneurysm width was 5.0 (EVT) versus 4.9 mm (MS; p = 0.285). Safety data showed similar intraoperative (7.0% EVT vs 3.5% MS, p = 0.496) and postoperative (4.7% vs 7%, p = 0.746) complication rates. The MS patients were more likely to have complete aneurysm occlusion at discharge (90.4% vs 58.8%, p < 0.001). In a limited subset of patients (52.9%) for whom outcome data were available, the EVT patients were more likely to have an mRS score 0 at discharge (50/59 [84.7%] vs 29/54 [53.7%], p < 0.0003] and at the last follow-up (36/55 [65.5%] vs 13/36 [36.1%], p = 0.006). CONCLUSIONS: This study describes a large, modern cohort of propensity score-matched patients who underwent treatment of unruptured WN-MCA aneurysms. Safety data on intraoperative and postoperative complication rates were similar in both treatment groups. MS was more likely to result in complete aneurysm occlusion at discharge. In a subset of patients with available outcome data, EVT was associated with better functional outcomes at discharge and the last follow-up. Given the lack of complete follow-up data and rates of retreatment, these results should be interpreted cautiously.

Training Standards in Neuroendovascular Surgery: Program Accreditation and Practitioner Certification.

BACKGROUND AND PURPOSE: Neuroendovascular surgery is a medical subspecialty that uses minimally invasive catheter-based technology and radiological imaging to diagnose and treat diseases of the central nervous system, head, neck, spine, and their vasculature. To perform these procedures, the practitioner needs an extensive knowledge of the anatomy of the nervous system, vasculature, and pathological conditions that affect their physiology. A working knowledge of radiation biology and safety is essential. Similarly, a sufficient volume of clinical and interventional experience, first as a trainee and then as a practitioner, is required so that these treatments can be delivered safely and effectively. METHODS: This document has been prepared under the aegis of the Society of Neurological Surgeons and its Committee for Advanced Subspecialty Training in conjunction with the Joint Section of Cerebrovascular Surgery for the American Association of Neurological Surgeons and Congress of Neurological Surgeons, the Society of NeuroInterventional Surgery, and the Society of Vascular and Interventional Neurology. RESULTS: The material herein outlines the requirements for institutional accreditation of training programs in neuroendovascular surgery, as well as those needed to obtain individual subspecialty certification, as agreed on by Committee for Advanced Subspecialty Training, the Society of Neurological Surgeons, and the aforementioned Societies. This document also clarifies the pathway to certification through an advanced practice track mechanism for those current practitioners of this subspecialty who trained before Committee for Advanced Subspecialty Training standards were formulated. CONCLUSIONS: Representing neuroendovascular surgery physicians from neurosurgery, neuroradiology, and neurology, the above mentioned societies seek to standardize neuroendovascular surgery training to ensure the highest quality delivery of this subspecialty within the United States.

Dead or alive? New confirmatory test using quantitative analysis of computed tomographic angiography.

BACKGROUND: When clinical examination is not reliable for brain death (BD) diagnosis, the preferred confirmatory test at our institution is nuclear medicine perfusion test (NMPT). Computed tomographic angiography (CTA) has been described as an alternative for BD confirmation. This study was designed to quantitatively analyze CTA, assess its accuracy compared with NMPT, and define set parameters for BD confirmation. METHODS: This is a prospective clinical study, from 2007 to 2014, evaluating a consecutive series of clinically BD patients (n = 60) and randomly selected control group with normal CTA findings (n = 20). NMPT, used as the reference standard, was performed on all study patients followed immediately by CTA. Assessment of NMPT and quantitative CTA Hounsfield units of the horizontal segment of middle cerebral artery (M1), precommunicating segment of anterior cerebral artery (A1), and basilar artery (BA) was performed. RESULTS: In the study cohort, 88% demonstrated absence of cerebral blood flow (CBF) on NMPT; however, only 50% demonstrated absence on CTA. Together, 50% had no CBF on NMPT and CTA (Group 1), 38% had no CBF on NMPT but persistent CBF on CTA (Group 2), 12% had persistent CBF on both NMPT and CTA (Group 3). Analysis of variance demonstrated that all groups varied significantly for M1, A1, and BA (p < 0.001). We were able to establish criteria that differentiate persistent CBF on CTA as either preserved cerebral perfusion or stasis filling. CONCLUSION: We propose that a CTA Hounsfield units less than 80 in M1, A1, and BA is concordant with no CBF on NMPT, therefore indicative of a lack of physiologic cerebral perfusion, and thus allows the confirmation of BD with 97% sensitivity and 100% specificity. LEVEL OF EVIDENCE: Diagnostic study, level II.

Delayed thrombosis or stenosis following enterprise-assisted stent-coiling: is it safe? Midterm results of the interstate collaboration of enterprise stent coiling.

BACKGROUND: Stent-assisted coiling of intracranial aneurysms with self-expanding stents has widened the applicability of neuroendovascular therapies to those aneurysms previously considered "uncoilable" because of poor morphology. The Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has demonstrated promising initial short-term results. However, the rates of delayed in-stent stenosis or thrombosis are not known. OBJECTIVE: To report midterm results of the Enterprise stent system. METHODS: A 10-center registry was created to provide a large volume of data on the safety and efficacy of the Enterprise stent system. Pooled data were compiled for consecutive patients undergoing Enterprise stent-assisted coiling at each institution. Available follow-up data were evaluated for the incidence of in-stent stenosis, thrombosis, and aneurysm occlusion. RESULTS: In total, 213 patients (176 females) with 219 aneurysms were treated with the Enterprise stent. One hundred ten patients had undergone delayed angiography (≥ 30 days from stent placement, mean follow-up 174.6 days). Forty percent of patients demonstrated total occlusion with 88% having ≥ 90% aneurysm occlusion. Six percent of patients had delayed (>30 days) angiographic findings, of which 3% demonstrated significant (≥ 50%) in-stent stenosis or occlusion. Seven delayed thrombotic events occurred (3%), along with 2 additional immediate periprocedural events. All 7 delayed events were concomitant to cessation of double-antiplatelet therapy. CONCLUSION: Midterm occlusion rates are excellent, and stenosis and thrombosis rates are comparable to other available neurovascular stents. Interruption of antiplatelet therapy appears to be a factor in those developing delayed stenosis or thrombosis.

Brain death confirmation: comparison of computed tomographic angiography with nuclear medicine perfusion scan.

INTRODUCTION: : Brain death is a difficult diagnosis to make, relying primarily on clinical examination. Ancillary tests are used when confounders exist. Nuclear medicine perfusion test (NMPT) is currently the preferred test for confirming brain death. Computed tomographic angiography (CTA) may be an alternative test to confirm brain death. It is readily available 24 hours a day at most level I trauma centers and is easy to perform. METHODS: : Patients with a clinical examination consistent with brain death were selected from the intensive care unit at a 550-bed teaching hospital. The patients underwent NMPT followed immediately by CTA. Both studies were read by radiologists blinded to the results of the alternative study. Absence of brain perfusion confirmed brain death. Multiple independent variables were collected on each patient including demographics, core body temperature, apnea challenge, mechanism of injury, timelines, renal function pre- and posttesting, organ donation, and time to procurement. RESULTS: : There were 25 patients enrolled in the study with multiple injury patterns. No false negative exams were identified on CTA when compared with NMPT. Three patients without flow on NMPT showed minimal flow on CTA. Each of these had open skull defects. Sensitivity of CTA was 0.86 and specificity was 1. There was no induced morbidity with regards to renal failure and organ donation. CONCLUSION: : CTA is a quick and efficient test for brain death confirmation. CTA demonstrated no false negative studies. The resolution of CTA seems to have an increased sensitivity for cerebral blood flow. Further studies with larger sample sizes need to be performed.

Treatment of intracranial aneurysms with the Enterprise stent: a multicenter registry.

OBJECT: The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms that would otherwise have been untreatable by endovascular techniques. Recent Food and Drug Administration approval of the Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has added a new option for self-expanding stent-assisted intracranial aneurysm coiling. METHODS: The authors established a collaborative registry across multiple institutions to rapidly provide largevolume results regarding initial experience in using the Enterprise in real-world practice. Ten institutions (University at Buffalo, Thomas Jefferson University, University of Florida, Cleveland Clinic, Northwestern University, West Virginia University, University of Puerto Rico, Albany Medical Center Hospital, the Neurological Institute of Savannah, and the Barrow Neurological Institute) have provided consecutive data regarding their initial experience with the Enterprise. RESULTS: In total, 141 patients (119 women) with 142 aneurysms underwent 143 attempted stent deployments. The use of Enterprise assistance with aneurysm coiling was associated with a 76% rate of > or = 90% occlusion. An inability to navigate or deploy the stent was experienced in 3% of cases, as well as a 2% occurrence of inaccurate deployment. Procedural data demonstrated a 6% temporary morbidity, 2.8% permanent morbidity, and 2% mortality (0.8% unruptured, 12% ruptured). CONCLUSIONS: The authors report initial results of the largest series to date in using the Enterprise for intracranial aneurysm treatment. The Enterprise is associated with a high rate of successful navigation and low occurrence of inaccurate stent deployment. The overall morbidity and mortality rates were low; however, caution should be exercised when considering Enterprise deployment in patients with subarachnoid hemorrhage as the authors' experience demonstrated a high rate of associated hemorrhagic complications leading to death.

Submaximal angioplasty and staged stenting for severe posterior circulation intracranial stenosis: a technique in evolution.

INTRODUCTION: Severe medically refractory intracranial stenosis portends a grave prognosis. Recent advances in stent technology have enabled clinicians to treat these lesions. Evidence in the coronary literature suggests that stenting without predilation angioplasty is as safe and effective as stenting immediately preceded by predilation angioplasty for the treatment of severely stenotic lesions. Because of marked differences in vessel histology and differences in the sensitivity of the cerebral and coronary vascular beds to embolic insult, direct stenting of severe intracranial stenoses may be more prone to neurological complications than a conventional or staged stenting procedure. METHODS: We reviewed our clinical experience with conventional, direct, and staged stenting for high-grade stenoses involving the posterior intracranial circulation. We also reviewed the literature and experimental data supporting the rationale for staged stenting. RESULTS: In our experience, no permanent neurological morbidity was identified in four patients treated with a staged approach. In contrast, one of three patients with conventional stenting of the basilar artery and two of four patients treated with direct basilar stenting had permanent neurological sequelae. CONCLUSION: For patients with high-grade posterior circulation intracranial stenoses involving the perforator-rich zones of the basilar artery, staged stenting may reduce procedure-related morbidity. A staged approach allows for plaque stabilization resulting from post-angioplasty fibrosis, which may protect patients from "snow-plowing," embolic shower of debris, or dissection. Further clinical, in vivo, and histological investigation is warranted.

Patient selection for revascularization in cervical carotid artery disease: angioplasty and stenting vs. endarterectomy.

Cervical carotid stenosis is a major cause of stroke and disability. Although carotid endarterectomy is an established and effective treatment for some patients with carotid artery stenosis, angioplasty and stenting has emerged in recent years as a viable alternative, particularly for patients who may be less suited for surgery. This article reviews patient selection for the two alternative approaches. The authors review the findings of the major clinical trials of carotid endarterectomy, summarize the development of carotid angioplasty and stenting, and identify patient characteristics that may guide selection of surgical or endovascular treatment.

Sirolimus-eluting stents in the canine cerebral vasculature: a prospective, randomized, blinded assessment of safety and vessel response.

OBJECT: Use of the sirolimus-eluting stent has led to a reduction of in-stent stenosis following treatment of coronary atherosclerosis, whereas treatment of intracranial atherosclerosis with bare-metal stents results in excessive restenosis rates of approximately 40%. Neurotoxicity effects and vessel injury are unknown in the cerebral vasculature. To assess the safety profile and vascular effects of sirolimus-coated stents, the authors conducted a prospective comparative study in which drug-eluting and bare-metal stents were implanted in the canine basilar artery (BA). METHODS: Sixteen mongrel dogs were randomized (eight animals per group) to receive either bare-metal 1.5 x 8-mm (six-cell) stents or sirolimus-eluting stents of the same dimensions. Interventionists, histopathologists, and histopathology technicians who participated in the study were blinded to the stent characteristics. Stents were implanted in the canine BA. Serial peripheral blood samples were obtained during the 1st week after implantation to determine the time-dependent serum concentration of sirolimus. Follow-up angiographic studies were performed 30 days after stent implantation to assess the effects of stent placement on the BA and brainstem perforating vessels. Explantation of the stent and BA was performed immediately after angiography by using a pressurized formalin fixation procedure. Histological and computer-assisted morphometric analyses of specimens obtained in each animal were performed. Sirolimus could not be detected in peripheral blood samples obtained later than 24 hours posttreatment. On follow-up angiography, all perforating vessels observed on initial angiograms remained patent, and no evidence of parent vessel damage or pseudoaneurysm formation was observed. Explanted vessels and brainstem sections did not demonstrate evidence of histological neurotoxicity, such as gliosis or infarction. No significant differences were found in the time to endothelialization of bare-metal and sirolimus-coated stents. Smooth-muscle cell (SMC) proliferation, the putative agent for restenosis, was lower in animals receiving sirolimus-coated stents (p = 0.003). Additionally, intimal fibrin density was increased in the dogs treated with sirolimus-coated stents (p < 0.0001). Histological evidence of an inflammatory response demonstrated a trend toward a reduced response in the sirolimus group (mean 0.58) compared with the bare-metal group (mean 0.83, p = 0.33). CONCLUSIONS: No neurotoxic effects were observed in the intracranial vessel walls or brainstem tissue in which sirolimus-coated stents were implanted. Compared with bare-metal stents, the sirolimus-coated devices did not impair endothelialization and, furthermore, tended to reduce the proliferation of SMCs. These findings indicate that sirolimus-coated devices may inhibit in-stent stenosis. Further studies with longer-term follow up are required to assess the restenosis rates of sirolimus-coated stents implanted in the intracranial vasculature.

Cocaine use as a predictor of outcome in aneurysmal subarachnoid hemorrhage.

OBJECT: The goal of this study was to analyze the relationship between cocaine use and outcomes of aneurysmal subarachnoid hemorrhage (SAH). METHODS: A retrospective review was performed of the medical records of patients with intracranial aneurysms treated at a single institution between January 1996 and December 2001. Only patients who presented with SAH were included in the study. The covariates chosen for the statistical analysis included the following: patient age, sex, and race; systolic and mean arterial blood pressure measurements on hospital admission; Hunt and Hess and Fisher grades; pre-existent major systemic disease; and history of alcohol, tobacco, or cocaine use. The Glasgow Outcome Scale (GOS) was used to standardize outcome and was dichotomized such that a score between 1 and 3 was considered a poor outcome and a score of 4 or 5 was considered a favorable outcome. The records of 151 patients were reviewed and 108 of these presented with aneurysmal SAH. Of these 108 patients, 36 (33.3%) had used cocaine within 24 hours before presentation. A Hunt and Hess grade of IV or V was assigned to 20 (55.6%) of 36 patients who used cocaine, compared with eight (11.1%) of 72 patients who did not; this difference was found to be statistically significant (p < 0.0001). Twenty-eight patients (77.8%) in the cocaine user group and 20 patients (27.8%) in the non-cocaine user group experienced clinically significant, angiographically confirmed vasospasm during their hospital course (p < 0.0001). Cocaine use was associated with a 2.8-fold greater risk of developing vasospasm (95% confidence interval [CI] 1.86-4.22). A GOS score of 1, 2, or 3 was assigned to 33 patients (91.7%) in the cocaine user group and to 20 patients (27.8%) in the non-cocaine user group (p < 0.0001). Cocaine use was associated with a 3.3-fold greater risk of poor outcome (95% CI 2.24-4.85). This association was found to be independent of Hunt and Hess grade as well as of vasospasm. CONCLUSIONS: Cocaine adversely affects both the presentation of and outcome in patients with aneurysmal SAH who are undergoing treatment for this disease. The vasoactive properties of the drug appear to aggravate the already tenuous situation of SAH and increase both the occurrence and influence of cerebral vasospasm. Statistical analysis demonstrates that cocaine directly affects both presentation and outcome in a significant manner. It is the authors' interpretation of the results of this retrospective review that cocaine use negatively affects outcome to such an extent that it should be considered equal to the presence of a major systemic illness when determining Hunt and Hess grade.

Should interventional cardiologists treat ischemic strokes? A global perspective.

Stroke is the third leading cause of death and the leading cause of severe neurological disability in our nation. The stroke death rate has the potential to reach epidemic proportions as the elderly segment of the population continues to rise. There is an insufficient number of trained physicians to supply the care for this patient population. The logical source for qualified physicians to care for these patients is the interventional cardiologist. We review the recent intraarterial therapy trials and detail the training necessary to allow interventional cardiologists to treat ischemic strokes.