Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Modeling the Mechanical Microenvironment of Coiled Cerebral Aneurysms.

Successful occlusion of cerebral aneurysms using coil embolization is contingent upon stable thrombus formation, and the quality of the thrombus depends upon the biomechanical environment. The goal of this study was to investigate how coil embolization alters the mechanical micro-environment within the aneurysm dome. Inertialess particles were injected in three-dimensional, computational simulations of flow inside patient aneurysms using patient-specific boundary conditions. Coil embolization was simulated as a homogenous porous medium of known permeability and inertial constant. Lagrangian particle tracking was used to calculate the residence time and shear stress history for particles in the flow before and after treatment. The percentage of particles entering the aneurysm dome correlated with the neck surface area before and after treatment (pretreatment: R2 = 0.831, P < 0.001; post-treatment: R2 = 0.638, P < 0.001). There was an inverse relationship between the change in particles entering the dome and coil packing density (R2 = 0.600, P < 0.001). Following treatment, the particles with the longest residence times tended to remain within the dome even longer while accumulating lower shear stress. A significant correlation was observed between the treatment effect on residence time and the ratio of the neck surface area to porosity (R2 = 0.390, P = 0.007). The results of this study suggest that coil embolization triggers clot formation within the aneurysm dome via a low shear stress-mediated pathway. This hypothesis links independently observed findings from several benchtop and clinical studies, furthering our understanding of this treatment strategy.

Endothelial Responses to Curvature-Induced Flow Patterns in Engineered Cerebral Aneurysms.

Hemodynamic factors have long been associated with clinical outcomes in the treatment of cerebral aneurysms. Computational studies of cerebral aneurysm hemodynamics have provided valuable estimates of the mechanical environment experienced by the endothelium in both the parent vessel and aneurysmal dome walls and have correlated them with disease state. These computational-clinical studies have recently been correlated with the response of endothelial cells (EC) using either idealized or patient-specific models. Here, we present a robust workflow for generating anatomic-scale aneurysm models, establishing luminal cultures of ECs at physiological relevant flow profiles, and comparing EC responses to curvature mediated flow. We show that flow patterns induced by parent vessel curvature produce changes in wall shear stress (WSS) and wall shear stress gradients (WSSG) that are correlated with differences in cell morphology and cellular protein localization. Cells in higher WSS regions align better with the flow and display strong Notch1-extracellular domain (ECD) polarization, while, under low WSS, differences in WSSG due to curvature change were associated with less alignment and attenuation of Notch1-ECD polarization in ECs of the corresponding regions. These proof-of-concept results highlight the use of engineered cellularized aneurysm models for connecting computational fluid dynamics to the underlying endothelial biology that mediates disease.

Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Somatic PDGFRB Activating Variants in Fusiform Cerebral Aneurysms.

The role of somatic genetic variants in the pathogenesis of intracranial-aneurysm formation is unknown. We identified a 23-year-old man with progressive, right-sided intracranial aneurysms, ipsilateral to an impressive cutaneous phenotype. The index individual underwent a series of genetic evaluations for known connective-tissue disorders, but the evaluations were unrevealing. Paired-sample exome sequencing between blood and fibroblasts derived from the diseased areas detected a single novel variant predicted to cause a p.Tyr562Cys (g.149505130T>C [GRCh37/hg19]; c.1685A>G) change within the platelet-derived growth factor receptor ß gene (PDGFRB), a juxtamembrane-coding region. Variant-allele fractions ranged from 18.75% to 53.33% within histologically abnormal tissue, suggesting post-zygotic or somatic mosaicism. In an independent cohort of aneurysm specimens, we detected somatic-activating PDGFRB variants in the juxtamembrane domain or the kinase activation loop in 4/6 fusiform aneurysms (and 0/38 saccular aneurysms; Fisher's exact test, p < 0.001). PDGFRB-variant, but not wild-type, patient cells were found to have overactive auto-phosphorylation with downstream activation of ERK, SRC, and AKT. The expression of discovered variants demonstrated non-ligand-dependent auto-phosphorylation, responsive to the kinase inhibitor sunitinib. Somatic gain-of-function variants in PDGFRB are a novel mechanism in the pathophysiology of fusiform cerebral aneurysms and suggest a potential role for targeted therapy with kinase inhibitors.

Early ambulation after transfemoral diagnostic cerebral angiography: a pilot study.

BACKGROUND: A significant proportion of transfemoral cerebral angiography complications are related to the access site, with no clear consensus concerning the optimal closure technique. In this study, we examined the usefulness of a shortened closure protocol for transfemoral diagnostic cerebral angiography. METHODS: We performed a retrospective review of patients who underwent transfemoral (4Fr sheath) diagnostic cerebral angiography procedures at our institution. We included patients > 18 years old who underwent the shortened closure protocol to achieve hemostasis at the access site. The shortened protocol entailed the use of nonocclusive manual compression for 15 min followed by 2 h of bed rest, with additional 10-15 min of compression for new hematoma. We collected and analyzed the patients' demographics, use of antiplatelet and anticoagulation medications, sheath size, and others. RESULTS: The study cohort comprised 119 patients with a mean age was 54 years with (88%) females. Forty-one patients (34%) were on antiplatelet medications, with 12 (10%) on dual antiplatelet therapy (DAPT). Four patients (3%) (two on DAPT, one on Aspirin alone, and one was not on any antiplatelet medication) had access site hematoma that required additional compression. Subgroup analysis showed that within the DAPT, Aspirin alone, and no antiplatelet medications groups, (17%), (3%), and (1%) of patients developed access site hematoma, respectively. CONCLUSION: This pilot study demonstrates that our closure protocol for transfemoral angiograms is safe and effective. There was a trend toward higher access-site complications in patients on DAPT. Further studies are required to expand on and validate our results.

De novo epilepsy after microsurgical resection of brain arteriovenous malformations.

OBJECTIVE: Seizures are the second most common presenting symptom of brain arteriovenous malformations (bAVMs) after hemorrhage. Risk factors for preoperative seizures and subsequent seizure control outcomes have been well studied. There is a paucity of literature on postoperative, de novo seizures in initially seizure-naïve patients who undergo resection. Whereas this entity has been documented after craniotomy for a wide variety of neurosurgically treated pathologies including tumors, trauma, and aneurysms, de novo seizures after bAVM resection are poorly studied. Given the debilitating nature of epilepsy, the purpose of this study was to elucidate the incidence and risk factors associated with de novo epilepsy after bAVM resection. METHODS: A retrospective review of patients who underwent resection of a bAVM over a 15-year period was performed. Patients who did not present with seizure were included, and the primary outcome was de novo epilepsy (i.e., a seizure disorder that only manifested after surgery). Demographic, clinical, and radiographic characteristics were compared between patients with and without postoperative epilepsy. Subgroup analysis was conducted on the ruptured bAVMs. RESULTS: From a cohort of 198 patients who underwent resection of a bAVM during the study period, 111 supratentorial ruptured and unruptured bAVMs that did not present with seizure were included. Twenty-one patients (19%) developed de novo epilepsy. One-year cumulative rates of developing de novo epilepsy were 9% for the overall cohort and 8.5% for the cohort with ruptured bAVMs. There were no significant differences between the epilepsy and no-epilepsy groups overall; however, the de novo epilepsy group was younger in the cohort with ruptured bAVMs (28.7 ± 11.7 vs 35.1 ± 19.9 years; p = 0.04). The mean time between resection and first seizure was 26.0 ± 40.4 months, with the longest time being 14 years. Subgroup analysis of the ruptured and endovascular embolization cohorts did not reveal any significant differences. Of the patients who developed poorly controlled epilepsy (defined as Engel class III-IV), all had a history of hemorrhage and half had bAVMs located in the temporal lobe. CONCLUSIONS: De novo epilepsy after bAVM resection occurs at an annual cumulative risk of 9%, with potentially long-term onset. Younger age may be a risk factor in patients who present with rupture. The development of poorly controlled epilepsy may be associated with temporal lobe location and a delay between hemorrhage and resection.

Outcome Following Hemorrhage From Cranial Dural Arteriovenous Fistulae: Analysis of the Multicenter International CONDOR Registry.

Background and Purpose: Dural arteriovenous fistulae can present with hemorrhage, but there remains a paucity of data regarding subsequent outcomes. We sought to use the CONDOR (Consortium for Dural Arteriovenous Fistula Outcomes Research), a multi-institutional registry, to characterize the morbidity and mortality of dural arteriovenous fistula­related hemorrhage. Methods: A retrospective review of patients in CONDOR who presented with dural arteriovenous fistula­related hemorrhage was performed. Patient characteristics, clinical follow-up, and radiographic details were analyzed for associations with poor outcome (defined as modified Rankin Scale score ≥3). Results: The CONDOR dataset yielded 262 patients with incident hemorrhage, with median follow-up of 1.4 years. Poor outcome was observed in 17.0% (95% CI, 12.3%­21.7%) at follow-up, including a 3.6% (95% CI, 1.3%­6.0%) mortality. Age and anticoagulant use were associated with poor outcome on multivariable analysis (odds ratio, 1.04, odds ratio, 5.1 respectively). Subtype of hemorrhage and venous shunting pattern of the lesion did not affect outcome significantly. Conclusions: Within the CONDOR registry, dural arteriovenous fistula­related hemorrhage was associated with a relatively lower morbidity and mortality than published outcomes from other arterialized cerebrovascular lesions but still at clinically consequential rates.

Ultrasonographic cystometry for neurogenic bladder using elastography.

AIM: Ultrasound shear wave elastography (SWE) has been used to measure elasticity (Young's modulus: YM) in solid organs. It was reported to show a better correlation with intravesical pressure (Pves) than with compliance, supporting its potential use in noninvasive cystometry. Contrariwise, conceptually, YM should be more correlated with compliance than with Pves. To optimize the potential use of YM as a noninvasive urodynamic study, the relationship between YM, Pves, and compliance was reassessed in this study. METHOD: YM was serially measured using SWE along with bladder filling. To overcome problems inherent to current compliance measurements, modified dynamic compliance was developed from cystometry by a locally weighted scatter plot smoothing algorithm. Then it was matched with YM from SWE. YM was also correlated with Pves. Furthermore, to understand the nature of YM, which was measured by ultrasound, the bladder wall's modulus, which was the mathematical assessment of YM derived from cystometric data, was also calculated and compared. RESULTS: Thirty-two neurogenic bladder patients were included in this study. YM correlated with Pves (r = .72, p < .0001) better than with modified dynamic compliance (r = -0.43, p < .0001). The correlation of YM with Pves was even higher than that with the calculated bladder wall's modulus (r = .52, p < .0001). CONCLUSION: YM measured by SWE associates with Pves better than with compliance, confirming the results of previous studies. SWE reflects the integration of both the holding capability of the bladder wall and urine rather than either of one, implying its potential utilization in noninvasive cystometry.

Lagrangian Trajectory Simulation of Platelets and Synchrotron Microtomography Augment Hemodynamic Analysis of Intracranial Aneurysms Treated With Embolic Coils.

As frequency of endovascular treatments for intracranial aneurysms increases, there is a growing need to understand the mechanisms for coil embolization failure. Computational fluid dynamics (CFD) modeling often simplifies modeling the endovascular coils as a homogeneous porous medium (PM), and focuses on the vascular wall endothelium, not considering the biomechanical environment of platelets. These assumptions limit the accuracy of computations for treatment predictions. We present a rigorous analysis using X-ray microtomographic imaging of the coils and a combination of Lagrangian (platelet) and Eulerian (endothelium) metrics. Four patient-specific, anatomically accurate in vitro flow phantoms of aneurysms are treated with the same patient-specific endovascular coils. Synchrotron tomography scans of the coil mass morphology are obtained. Aneurysmal hemodynamics are computationally simulated before and after coiling, using patient-specific velocity/pressure measurements. For each patient, we analyze the trajectories of thousands of platelets during several cardiac cycles, and calculate residence times (RTs) and shear exposure, relevant to thrombus formation. We quantify the inconsistencies of the PM approach, comparing them with coil-resolved (CR) simulations, showing the under- or overestimation of key hemodynamic metrics used to predict treatment outcomes. We fully characterize aneurysmal hemodynamics with converged statistics of platelet RT and shear stress history (SH), to augment the traditional wall shear stress (WSS) on the vascular endothelium. Incorporating microtomographic scans of coil morphology into hemodynamic analysis of coiled intracranial aneurysms, and augmenting traditional analysis with Lagrangian platelet metrics improves CFD predictions, and raises the potential for understanding and clinical translation of computational hemodynamics for intracranial aneurysm treatment outcomes.

Magnetic resonance vessel wall imaging in cerebrovascular diseases

Cerebrovascular diseases manifest as abnormalities of and disruption to the intracranial vasculature and its capacity to carry blood to the brain. However, the pathogenesis of many cerebrovascular diseases begins in the vessel wall. Traditional luminal and perfusion imaging techniques do not provide adequate information regarding the differentiation, onset, or progression of disease. Intracranial high-resolution MR vessel wall imaging (VWI) has emerged as an invaluable technique for understanding and evaluating cerebrovascular diseases. The location and pattern of contrast enhancement in intracranial VWI provides new insight into the inflammatory etiology of cerebrovascular diseases and has potential to permit earlier diagnosis and treatment. In this report, technical considerations of VWI are discussed and current applications of VWI in vascular malformations, blunt cerebrovascular injury/dissection, and steno-occlusive cerebrovascular vasculopathies are reviewed.

International multicentre validation of the arteriovenous malformation-related intracerebral haemorrhage (AVICH) score.

OBJECTIVE: The recently published arteriovenous malformation-related intracerebral haemorrhage (AVICH) score showed better outcome prediction for patients with arteriovenous malformation (AVM)-related intracerebral haemorrhage (ICH) than other AVM or ICH scores. Here we present the results of a multicentre, external validation of the AVICH score. METHODS: All participating centres (n=11) provided anonymous data on 325 patients to form the Spetzler-Martin (SM) grade, the supplemented SM (sSM) grade, the ICH score and the AVICH score. Modified Rankin score (mRS) at last follow-up (mean 25.6 months) was dichotomized into favourable (mRS 0-2, n=210) and unfavourable (mRS 3-6;n=115). Univariate and AUROC analyses were performed to validate the AVICH score. RESULTS: Except nidus structure and AVM size, all single parameters forming the SM, sSM, ICH and AVICH score and the scores itself were significantly different between both outcome groups in the univariate analysis. The AVICH score was confirmed to be the highest predictive outcome score with an AUROC of 0.765 compared with 0.705 for the ICH score and 0.682 for the sSM grade. CONCLUSION: The multicentre-validated AVICH score predicts clinical outcome superior to pre-existing scores. We suggest the routine use of this score for future clinical outcome prediction and in clinical research. TRIAL REGISTRATION NUMBER: NCT02920645.

Intraosseous Hemangioma of the Frontal Bone. Report of a Case and Review of the Literature.

Intraosseous hemangiomas of the maxillofacial region are rare lesions that constitute less than 1% of all osseous tumors. A review of the literature on intraosseous hemangiomas of the skull and facial bones showed a limited number of publications, much of which were largely limited to case reports. This case report summarizes the workup and surgical treatment of a 39-year-old woman with an intraosseous hemangioma of the left frontal bone. The histology, treatment, and literature are reviewed.

Surgery for very large and giant intracranial aneurysms: Results and complications.

BACKGROUND: Results of and the complications encountered during surgery for very large and giant intracranial aneurysms are illustrated. OBJECTIVE: To analyze a consecutive series of patients with very large and giant aneurysms treated with microsurgery. METHODS: This retrospective study included seventy six very large and giant aneurysms which were managed by clipping and bypass technique. Sixty two (82%) aneurysms were located in anterior circulation, and 14 (18%) aneurysms were located in posterior circulation. The bypasses performed included local bypasses, extra-intracranial bypasses, double bypasses and combination techniques of external carotid-internal carotid (EC-IC) bypass and local bypasses. RESULTS: 73 patients with 76 aneurysms were treated over 13 years. There were 44 very large and 32 giant aneurysms. Twenty-four patients presented with subarachnoid hemorrhage [SAH] (32%) while forty nine patients with 52 aneurysms (68%) were unruptured. These 73 patients underwent 63 bypass procedures with aneurysm occlusion and 13 clipping procedures. Out of 62 anterior circulation aneurysms, bypass surgery was performed in 49 patients while 13 underwent clipping. In posterior circulation aneurysms, all patients were treated with bypass procedures with proximal occlusion or trapping. In the ruptured group, 16 (67%) patients had postoperative modified Rankin Scale (mRs) 0-2, six patients (25%) had mRs 3-5, and two patients (8.4%) died. In the unruptured group, 45 patients (87%) had mRs 0-2, 3 patients (6%) had mRs 3-5, and four patients (7.6%) died. CONCLUSIONS: In this large series of very large and giant aneurysms treated with microsurgical clipping and bypasses, excellent results were obtained in the long term, in regards to aneurysm occlusion, functional status, and graft patency. Our experience will be very useful to other neurosurgeons who treat these complex lesions.

Treatment and Outcome of Hemorrhagic Transformation After Intravenous Alteplase in Acute Ischemic Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association.

PURPOSE: Symptomatic intracranial hemorrhage (sICH) is the most feared complication of intravenous thrombolytic therapy in acute ischemic stroke. Treatment of sICH is based on expert opinion and small case series, with the efficacy of such treatments not well established. This document aims to provide an overview of sICH with a focus on pathophysiology and treatment. METHODS: A literature review was performed for randomized trials, prospective and retrospective studies, opinion papers, case series, and case reports on the definitions, epidemiology, risk factors, pathophysiology, treatment, and outcome of sICH. The document sections were divided among writing group members who performed the literature review, summarized the literature, and provided suggestions on the diagnosis and treatment of patients with sICH caused by systemic thrombolysis with alteplase. Several drafts were circulated among writing group members until a consensus was achieved. RESULTS: sICH is an uncommon but severe complication of systemic thrombolysis in acute ischemic stroke. Prompt diagnosis and early correction of the coagulopathy after alteplase have remained the mainstay of treatment. Further research is required to establish treatments aimed at maintaining integrity of the blood-brain barrier in acute ischemic stroke based on inhibition of the underlying biochemical processes.

Natural History and Management of Blunt Traumatic Pseudoaneurysms of the Internal Carotid Artery: The Harborview Algorithm Based Off a 10-Year Experience.

OBJECTIVE: To define the natural history of, and treatment strategy for, blunt traumatic internal carotid artery (ICA) pseudoaneurysms. BACKGROUND: The natural history and management of traumatic ICA pseudoaneurysms is controversial. METHODS: We retrospectively identified all traumatic ICA pseudoaneurysms diagnosed on head/neck computed tomographic angiography at a high-volume trauma center over a 10-year period. Radiographic and clinical data were recorded, and a treatment algorithm was derived. RESULTS: Forty-three pseudoaneurysms were diagnosed in 39 patients. All patients were treated with daily aspirin unless contraindicated, and 82% underwent daily transcranial Doppler ultrasonography with embolic monitoring. A rate of 8 or more emboli per hour was predictive of embolic stroke (P = 0.0076). Acute ischemic or embolic stroke was seen in 7 patients (16%) with an overall mortality in this subpopulation of 42% (n = 3). Four patients (9%) underwent acute surgical treatment (parent vessel sacrifice and/or arterial bypass) for ongoing ischemia. Long-term radiographic and clinical follow-up was obtained for 36 surviving patients (mean = 8 months; range: 1 week-5 years), all of whom were maintained on daily aspirin. No delayed ischemic or embolic events were reported. For ICA pseudoaneurysms treated with aspirin and observation alone, 9 (28%) increased in size, 17 (53%) decreased or stabilized, and 6 (19%) resolved. Enlargement of 5 mm or more in maximal diameter underwent delayed endovascular treatment with a 100% obliteration rate and no complications. CONCLUSIONS: Traumatic ICA pseudoaneurysms are safely treated with daily aspirin, embolic monitoring, and radiographic surveillance. Acute stroke or hemorrhage, or delayed radiographic progression, are indications for endovascular or surgical treatment.

Endovascular treatment of complex dural arteriovenous fistula using the dual-microcatheter technique.

A 71-year-old woman presented with headache and dilated vessels on CTA. Angiography demonstrated a complex dural arteriovenous fistula with retrograde cortical venous hypertension, supplied by branches of internal and external carotids bilaterally into a fistulous pouch paralleling the left transverse and sigmoid sinuses, which was occluded at the jugular bulb. The patient refused treatment and was lost to follow-up, returning with sudden confusion and hemianopsia from left temporo-occipital hemorrhage. Transvenous endovascular embolization was performed using the dual-microcatheter technique with a combination of coiling and Onyx copolymer, completely occluding the sinus and fistula while preserving normal venous drainage. The video can be found here: http://youtu.be/u_4Oc7tSmDM .

Current Indications, Trends, and Long-Term Results of 233 Bypasses to Treat Complex Intracranial Aneurysms: A Location-Specific Analysis.

BACKGROUND AND OBJECTIVES: Advances in endovascular flow diverters have led to a secular shift in the management of brain aneurysms, causing debate on current bypass indications. We therefore sought to investigate the long-term results, current indications, and trends of bypasses for brain aneurysms. METHODS: We retrospectively reviewed bypasses performed between 2005 and 2022 to treat brain aneurysms. Demographic, clinical, and radiological data were collected till the most recent follow-up. Aneurysm occlusion and graft patency was noted on cerebral angiogram in the immediate postoperative, 3-month, and most recent follow-up periods. Clinical outcomes (modified Rankin scores) and complications were assessed at 3 month and most recent follow-up. Trends in bypass volume and graft patency were assessed in 5-year epochs. Results were dichotomized based on aneurysm location to generate location-specific results and trends. RESULTS: Overall, 203 patients (mean age 50 years, 57% female patients) with 207 cerebral aneurysms were treated with 233 cerebral bypasses with a mean follow-up of 2 years. Fusiform morphology was the most common bypass indication. Aneurysm occlusion on immediate postoperative and final follow-up angiogram was 89% (184/207) and 96% (198/207), respectively. Graft patency rate in the immediate postoperative period and most recent follow-up was 95% (222/233) and 92% (215/233), respectively. Of 207 aneurysms, 5 (2%) recurred. Of 203 patients, 81% (165) patients had modified Rankin scores of 0-2 at the 3-month follow-up and 11 patients died (mortality 5%). Although there was a steady decrease in the bypass volume over the study period, the proportion of bypasses for recurrent aneurysms increased serially. Posterior circulation aneurysms had lower rates of aneurysm occlusion and significantly higher incidence of postoperative strokes and deaths (P = .0035), with basilar artery aneurysms having the worst outcomes. CONCLUSION: Bypass indications have evolved with the inception of novel flow diverters. However, they remain relevant in the cerebrovascular surgeon's armamentarium, and long-term results are excellent.

A comparison of computed tomography angiography and digital subtraction angiography for the diagnosis of penetrating cerebrovascular injury: a prospective multicenter study.

OBJECTIVE: In this research, the authors sought to characterize the incidence and extent of cerebrovascular lesions after penetrating brain injury in a civilian population and to compare the diagnostic value of head computed tomography angiography (CTA) and digital subtraction angiography (DSA) in their diagnosis. METHODS: This was a prospective multicenter cohort study of patients with penetrating brain injury due to any mechanism presenting at two academic medical centers over a 3-year period (May 2020 to May 2023). All patients underwent both CTA and DSA. The sensitivity and specificity of CTA was calculated, with DSA considered the gold standard. The number of DSA studies needed to identify a lesion requiring treatment that had not been identified on CTA was also calculated. RESULTS: A total of 73 patients were included in the study, 33 of whom had at least 1 penetrating cerebrovascular injury, for an incidence of 45.2%. The injuries included 13 pseudoaneurysms, 11 major arterial occlusions, 9 dural venous sinus occlusions, 8 dural arteriovenous fistulas, and 6 carotid cavernous fistulas. The sensitivity of CTA was 36.4%, and the specificity was 85.0%. Overall, 5.6 DSA studies were needed to identify a lesion requiring treatment that had not been identified with CTA. CONCLUSIONS: Cerebrovascular injury is common after penetrating brain injury, and CTA alone is insufficient to diagnosis these injuries. Patients with penetrating brain injuries should routinely undergo DSA.