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Objective Precise morphologic evaluation is important for intracranial aneurysm (IA) management. At present, clinicians manually measure the IA size and neck diameter on 2-dimensional (2D) digital subtraction angiographic (DSA) images and categorize the IA shape as regular or irregular on 3-dimensional (3D)-DSA images, which could result in inconsistency and bias. We investigated whether a computer-assisted 3D analytical approach could improve IA morphology assessment. Methods Five neurointerventionists evaluated the size, neck diameter, and shape of 39 IAs using current and computer-assisted 3D approaches. In the computer-assisted 3D approach, the size, neck diameter, and undulation index (UI, a shape irregularity metric) were extracted using semiautomated reconstruction of aneurysm geometry using 3D-DSA, followed by IA neck identification and computerized geometry assessment. Results The size and neck diameter measured using the manual 2D approach were smaller than computer-assisted 3D measurements by 2.01 mm (P < 0.001) and 1.85 mm (P < 0.001), respectively. Applying the definitions of small IAs (<7 mm) and narrow-necked IAs (<4 mm) from the reported data, interrater variation in manual 2D measurements resulted in inconsistent classification of the size of 14 IAs and the necks of 19 IAs. Visual inspection resulted in an inconsistent shape classification for 23 IAs among the raters. Greater consistency was achieved using the computer-assisted 3D approach for size (intraclass correlation coefficient [ICC], 1.00), neck measurements (ICC, 0.96), and shape quantification (UI; ICC, 0.94). Conclusions Computer-assisted 3D morphology analysis can improve accuracy and consistency in measurements compared with manual 2D measurements. It can also more reliably quantify shape irregularity using the UI. Future application of computer-assisted analysis tools could help clinicians standardize morphology evaluations, leading to more consistent IA evaluations. Highlights • Our study shows manual 2D measurements of IA size and neck diameter are smaller than the computer-assisted 3D measurements. • Manual 2D measurement and visual inspection of aneurysm shape are subject to inconsistency. • Variations in measurements and shape evaluation can influence IA morphology assessment. • Computer-assisted 3D morphology can help clinicians standardize morphology assessments. [ABSTRACT FROM AUTHOR]

Background Giant serpentine aneurysms (GSAs) are a subgroup of giant intracranial aneurysms, distinct from saccular and fusiform varieties, that are defined as partially thrombosed giant aneurysms with tortuous internal vascular channel. Clinicopathologic characteristics of middle cerebral artery GSAs have been rarely reported in the literature, with discussion of radiologic characteristics only. We clarify patient clinical and neuroradiologic features and discuss the mechanism of formation and progression. Case Description A 43-year-old woman presented with a GSA arising from the middle cerebral artery. There was a separate inflow and outflow channel of the aneurysm, with the outflow channel feeding the distal branches of the parent artery and supplying normal brain parenchyma. The GSA was treated successfully by aneurysmectomy and superficial temporal artery–middle cerebral artery bypass followed by proximal occlusion and vascular reconstruction. An aneurysm specimen was examined to correlate pathologic findings and morphologic characteristics. Result Pathologic results showed that thickness of the aneurysmal wall was typically increased and varied, and no internal elastic lamina or endothelial lining could be identified. The sac contained thrombi of various ages with recanalizing vessel formation and chronic inflammation infiltration. Intimal hyperplasia and neoangiogenesis in the wall and hyaline degeneration of the media were observed. Vessels coursing in their adventitia showed mucoid changes, which are responsible for the contrast enhancement of the aneurysmal rim on computed tomography scan. Conclusions GSAs are a specific pathologic entity with unique morphologic and pathologic characteristics that can affect intracranial blood vessels. The pathogenic mechanisms are unclear; this report suggests that GSAs may be associated with degeneration of the vascular wall. [ABSTRACT FROM AUTHOR]

Background Pediatric intracranial aneurysms (IAs) are rare. Compared with adult IAs, they are more commonly giant, fusiform, or dissecting. Treatment often proves more complex, and recurrence rate and de novo aneurysmogenesis incidence are higher. A consensus regarding the most appropriate algorithm for following pediatric IAs is lacking. Methods We sought to generate recommendations based on the reported experience in the literature with pediatric IAs through a thorough review of the PubMed database, discussion with experienced neurointerventionalists, and our own experience. Results Digital subtraction angiography (DSA) was utilized immediately post-operatively for microsurgically-clipped and endovascularly-treated IAs, at 6-12 months postoperatively for endovascularly-treated IAs, and in cases of aneurysmal recurrence or de novo aneurysmogenesis discovered by non-invasive imaging modalities. Computed tomographic angiography was the preferred imaging modality for long-term follow-up of microsurgically clipped IAs. Magnetic resonance angiography (MRA) was the preferred modality for following IAs that were untreated, endovascularly-treated, or microsurgically-treated in a manner other than clipping. Conclusions We propose incidental untreated IAs to be followed by magnetic resonance angiography without contrast enhancement. Follow-up modality and interval for treated pediatric IAs is determined by initial aneurysmal complexity, treatment modality, and degree of posttreatment obliteration. Recurrence or de novo aneurysmogenesis requiring treatment should be followed by digital subtraction angiography and appropriate retreatment. Computed tomography angiography is preferred for clipped IAs, whereas contrast-enhanced magnetic resonance angiography is preferred for lesions treated endovascularly with coil embolization and lesions treated microsurgically in a manner other than clipping. [ABSTRACT FROM AUTHOR]

Objective: Population screening for aneurysms in patients with risk factors and preventive surgical treatment are beneficial according to numerous studies. One of the most significant risk factors is heredity, namely, the presence of first-degree relatives (FDR) with aneurysmal subarachnoid hemorrhage (aSAH). Nevertheless, there are still no generally accepted approaches or evidence bases regarding the benefits of the aneurysm screening strategy., Methods: Mathematical modeling of the dynamics of aneurysm development in the population was carried out using an algorithm implementing a discrete Markov's chain. To implement the model, all probabilities of events and distributions are taken from available literature sources. Three-dimensional time of flight noncontrast magnetic resonance angiography was chosen as a screening method. Patients underwent preventive surgical treatment if an aneurysm was detected., Results: Screening and preventive treatment in the general population reduces the prevalence of aneurysms by 1.74% (3.44% in the FDR group) and the prevalence of aSAH by 14.36% (37.48% in the FDR group). Mortality due to aSAH was reduced by 14.44%. The number of disabilities also decreases. The occurrence of deep disability was reduced by 20.2% in the FDR group. Economic analysis of the part of the population consisting of FDRs showed annual savings of ies also decr CONCLUSIONS: The mathematical model demonstrated that screening and preventive treatment of cerebral aneurysms can reduce aSAH-associated morbidity and mortality. In the FDR group, there was decrease in the prevalence of aSAH and decrease in associated mortality. Screening for cerebral aneurysms is cost-effective., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective The purpose of this study was to compare the efficacy, stability, and safety of stent-assisted coiling (SAC) and balloon-assisted coiling (BAC) in the treatment of ruptured wide-necked aneurysms in the acute period. Methods Consecutive patients including 65 cases treated with SAC and 32 with BAC were reviewed at the authors' institution between November 2011 and December 2014. The efficacy of these 2 approaches and the incidence of periprocedural complications were retrospectively evaluated. Results Morphologic analysis showed a lower fundus/neck ratio (1.2 vs. 1.6) in the aneurysms treated with SAC versus BAC ( P < 0.001). The mean neck width of aneurysms was 4.0 mm in the patients treated with SAC versus 3.4 mm in those treated with BAC ( P < 0.04). Coil protrusion into the parent vessels during embolization was an independent risk factor for cerebral ischemic events (odds ratio [OR], 4.08; 95% confidence interval [CI], 1.03–16.2). Neck width (OR, 0.65; 95% CI, 0.44–0.97) and aneurysm perforation during procedure (OR, 6.24; 95% CI, 1.21–32.3) were independent predictors of complete occlusion (Raymond 1) by immediate postembolization angiography. There was no statistical difference between the 2 techniques regarding the rate of aneurysm occlusion at the end of procedure, periprocedural complications, and favorable outcome at discharge and follow-up. Conclusions These findings suggested that SAC was more appropriate than BAC for ruptured wide-necked aneurysms with lower fundus/neck ratio or wider neck size. However, periprocedural complications, occlusion rates, and favorable outcomes did not differ between the 2 techniques. [ABSTRACT FROM AUTHOR]

Background For the treatment planning of a patient with a middle cerebral artery (MCA) trunk aneurysm, understanding the anatomic relationship among the aneurysm, branching vessels, and lenticulostriate arteries (LSAs) is important. We aimed to demonstrate the branching-vessel anatomy related to an MCA trunk aneurysm using 3-dimensional (3D) angiography. Methods We retrospectively reviewed 3D angiographic findings of 64 cases of MCA trunk aneurysms using a 3D workstation with various postprocessing conditions. We classified the aneurysms into 4 groups (early frontal cortical branch [EFCB], early temporal cortical branch [ETCB], LSA, and nonbranching aneurysms) and analyzed the relationship between the branching vessels and the LSAs. Results There were 30 EFCB aneurysms, 25 ETCB aneurysms, 7 LSA aneurysms, and 2 nonbranching aneurysms. Twenty-six (86.7%) of the 30 EFCB aneurysms shared common origins and were associated with the LSAs, but none of the 25 ETCB aneurysms were. Three of 24 patients who received clipping for an EFCB aneurysm experienced a postoperative infarction in the LSA territory. In these 3 patients, the LSA originated from the EFCB and was closely related with the aneurysm. Conclusions We have identified a clinically important anatomic relationship between the MCA trunk aneurysm and branching vessels, including the LSAs. EFCB aneurysms show a close relationship with the LSAs. Pretreatment identification of the origin of the LSAs is important to obviate any perforator injury in EFCB aneurysms. [ABSTRACT FROM AUTHOR]

Objectives The objective of the study was to determine the clinical utility of 320-detector row volume-computed tomographic angiography (VCTA) in the management of intracranial aneurysms. Methods Between February 2011 and May 2015, 550 patients successfully underwent 320-detector row VCTA for suspected intracranial aneurysms. Three-dimensional (3D) digital subtraction angiography (DSA) was used as the ultimate reference standard, and the sensitivity, specificity, and accuracy of both nonsubtracted and subtracted VCTA in identifying aneurysms were analyzed. Results Nonsubtracted VCTA identified 417 aneurysms (2 false-positive readings, 12 false-negative readings). The diagnostic sensitivity, specificity, and accuracy of non-subtracted VCTA, on a per-aneurysm basis, were 97.2%, 99.0%, and 97.6%, respectively. Subtracted VCTA identified 426 aneurysms (2 false-positive readings, 3 false-negative readings). The sensitivity, specificity, and accuracy of subtracted VCTA, on a per-aneurysm basis, were 99.3%, 99.0%, and 99.2%, respectively. No differences in diagnostic accuracy were found between subtracted VCTA and 3D DSA. Nonsubtracted VCTA, however, was observed to be significantly less sensitive than 3D DSA and subtracted VCTA. Twenty-six aneurysm cases were referred for surgical treatment based on VCTA imaging. All aneurysms were deemed completely occluded during surgical clipping. On the basis of VCTA imaging, 299 aneurysms were found suitable for endovascular coiling, of which 293 aneurysms (98%) were treated successfully. Conclusions The 320-detector row subtracted VCTA technique is an effective, first-line diagnostic imaging modality for surgical and endovascular treatment of aneurysms. The nonsubtracted VCTA was less accurate than the subtracted VCTA, especially for intracranial aneurysms adjoining bone tissue. [ABSTRACT FROM AUTHOR]

Background Perioperative stroke is a known complication in patients undergoing surgical clipping of cerebral aneurysms. Objective To evaluate whether intraoperative changes in somatosensory-evoked potential (SSEP) monitoring during cerebral aneurysm clipping is diagnostic of perioperative stroke. Methods An electronic search of PubMed, Embase, and Web of Science databases was done for studies published through May 2015 on SSEP monitoring in cerebral aneurysm clipping for predicting postoperative outcomes. All titles and abstracts were screened independently on the basis of predetermined criteria. Inclusion criteria included randomized clinical trials and prospective or retrospective cohort reviews; patients with intracranial aneurysms who underwent surgical clipping with intra-operative SSEP monitoring and postoperative neurologic assessment; studies published in English on adult humans ≥18 years with sample size of ≥50; and studies inclusive of an abstract with adequate details on outcomes. Results A total of 14 articles with a sample population of 2015 patients were analyzed. SSEP monitoring demonstrated a strong mean specificity of 84.5% (95% confidence interval [95% CI] −76.3 to 90.3) but weaker sensitivity of 56.8% (95% CI 44.1−68.6) for predicting stroke. A diagnostic odds ratio of 7.772 (95% CI 5.133−11.767) suggested that the odds of observing an SSEP change among those with a postoperative neurologic deficit were 7 times greater than those without a neurologic deficit. Conclusion Intraoperative SSEP monitoring is highly specific for predicting neurologic outcome after cerebral aneurysm clipping. Patients with postoperative neurologic deficits are 7 times more likely to have had intraoperative SSEP changes. SSEP monitoring may help design prevention strategies to reduce stroke rates after cerebral aneurysm clipping. [ABSTRACT FROM AUTHOR]

Aneurysmal subarachnoid hemorrhage (SAH) remains an important health issue in the United States. Despite recent improvements in the diagnosis and treatment of cerebral aneurysms, the mortality rate following aneurysm rupture. In those patients who survive, up to 50% are left severely disabled. The goal of preventing the hemorrhage or re-hemorrhage can only be achieved by successfully excluding the aneurysm from the circulation. This article is a comprehensive review by contemporary vascular neurosurgeons and interventional neuroradiolgists on the modern management of cerebral aneurysms. [ABSTRACT FROM AUTHOR]

Objective: Although digital subtraction angiography (DSA) remains the standard for intracranial aneurysm diagnosis, computed tomography angiography (CTA) is being increasingly used for this purpose. CTA has sensitivities and specificities reported as high as 97% and 100%, respectively. We analyzed a prospective cohort of 112 patients with 134 unruptured aneurysms who underwent community CTAs and confirmatory DSAs in a tertiary facility. Methods: Patients referred between 2007 and 2010 (mean age 53.2 years) with aneurysms identified by CTA underwent confirmatory DSA. The results were compared to determine accuracy of CTA in diagnosing aneurysms. Aneurysms diagnosed by CTA but ruled out by DSA or aneurysms missed by CTA but diagnosed by DSA were analyzed by size and location. Anatomical variants leading to false CTA positive results were noted. Results: CTA identified 132 aneurysms, of which 27 (20.5%) were false positives. Of these 27 aneurysms, 18 were completely negative but 9 had an anatomical structure that explained the CTA finding, 18 were either small (6–10 mm, 4%) or very small (1–5 mm, 63%), and 16 were located either in the anterior communicating artery (ACoA) region (33%) or at the basilar artery bifurcation (26%). Additionally, DSA identified 29 aneurysms (21.6%) missed by CTA. The most common locations for these were the cavernous segment of the internal carotid artery (24%) and the middle cerebral artery (24%), and all but 1 were very small (1–5 mm). Conclusion: The CTA accuracy rate may be lower than previously reported. CTA is particularly inaccurate in aneurysms 5 mm or smaller and those in the ACoA region. [ABSTRACT FROM AUTHOR]

Objective: Several machine learning algorithms have been increasingly applied to predict the rupture risk of intracranial aneurysms. We performed the present diagnostic meta-analysis to comprehensively evaluate the diagnostic value of machine learning algorithms for assessing the rupture risk of intracranial aneurysms., Methods: We systematically searched 3 electronic databases, including Medline (via PubMed), the Cochrane Register of Controlled Trials (via Ovid), and Embase (via Elsevier), to retrieve eligible studies from the databases' inception through March 2021. The latest update was performed in June 2021. StataMP, version 14, was used to estimate all pooled diagnostic values., Results: A total of 4 studies involving 6 reports were considered to meet the inclusion criteria. Our diagnostic meta-analysis generated the following pooled diagnostic values: sensitivity, 0.84 (95% confidence interval [CI], 0.75-0.90); specificity, 0.78 (95% CI, 0.68-0.85); positive likelihood ratio, 3.8 (95% CI, 2.4-5.9); negative likelihood ratio, 0.21 (95% CI, 0.12-0.35), diagnostic odd ratio, 18 (95% CI, 7-46), and area under the summary receiver operating characteristic curve, 0.88 (95% CI, 0.85-0.90)., Conclusions: Our findings have demonstrated that the diagnostic performance of machine learning algorithms for the rupture risk assessment of AIs is excellent. Considering that the negative effects resulted from the limited number of eligible studies, we suggest developing more well-designed studies with larger sample sizes to validate our findings., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Sixty-four-row multislice computed tomographic angiography (CTA) has great potential for use in vascular studies. The aim of our study was to compare 64-slice CTA with three-dimensional rotational angiography (3DRA) in the detection and characterization of intracranial aneurysms with special attention to smaller (<3-mm) aneurysms. Methods: In a prospective study, a total of 133 patients were included who successively underwent 64-slice CTA and digital subtraction angiography (DSA) examinations for suspected intracranial aneurysms. The 64-slice CTA, conventional DSA, and 3DRA images were independently reviewed by five readers who performed the presence, shape, dimension, and location of aneurysms. The 3DRA results were considered as the ultimate reference standard. Results: The reference standard revealed 111 aneurysms in 93 patients: 27 aneurysms were read as <3 mm, 66 were read as being between 3 and 8 mm, and 18 were read as >8 mm. The sensitivities of 64-slice CTA for aneurysms <3 mm, between 3 and 8 mm, and >8 mm were 96.3%, 98.5%, and 100%, respectively, on a per-aneurysm basis. The sensitivities of conventional DSA for aneurysms <3 mm, between 3 and 8 mm, and >8 mm were 85.2%, 100%, and 100%, respectively, on a per-aneurysm basis. The 64-slice CT angiographic images could clearly show the aneurysmal characteristics and the relationship between aneurysms and adjacent branch vessels. Conclusion: Sixty-four-slice CTA is a highly accurate imaging examination of the first-line imaging technique for detecting and characterizing intracranial aneurysms including <3-mm aneurysms. [ABSTRACT FROM AUTHOR]

Objective: To explore the safe duration of temporary clipping of the parent artery under intraoperative electrophysiological monitoring., Methods: The clinical data of 97 patients who underwent intracranial aneurysm clipping under electrophysiological monitoring in the Department of Neurology, Affiliated Hospital of Qingdao University from June 2019 to June 2020 were retrospectively analyzed. The safety duration of temporary clipping was analyzed using receiver operating characteristic (ROC) curves, and the results were validated in clinical data., Results: Temporary clipping during operation (P < 0.05) and electrophysiological warning during operation (P < 0.05) were related risk factors of a cerebral ischemia event after operation. The ROC curve was drawn for the duration of temporary clipping and the occurrence of intraoperative electrophysiological warning, and the area under the curve was 0.78 (P < 0.05). The optimal cutoff value was 372.5 seconds, the sensitivity was 0.818, and the specificity was 0.762. After reviewing the clinical data, P < 0.05 was statistically significant after a χ 2 test with 372.5 seconds equal to approximately 6 minutes. The ROC curve was drawn for the duration of temporary clipping and the time of postoperative ischemia, and the area under the curve was 0.667 (P < 0.05). The optimal cutoff value was 430.5 seconds, the sensitivity was 0.592, and the specificity was 0.842., Conclusion: Temporary intraoperative block is the risk factor for cerebral ischemia after operation. In this study, the temporary clipping time of the parent artery should not be longer than 6 minutes, and there is approximately 1 minute to adjust the current procedure after the electrophysiological warning to restore the baseline of intraoperative electrophysiological monitoring., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background and Objective: Microsurgical clipping, along with endovascular treatment, has evolved in the treatment of unruptured intracranial aneurysms (UIA), and these developments have resulted in a reduction of the complication rate. We discuss the need for a central venous catheter (CVC) insertion as an anesthetic preparation for microsurgical clipping., Methods: Between January 2019 and September 2019, 722 patients with UIA were treated at our institution. We excluded patients with a history of endovascular treatment or bypass surgery, recurrent aneurysms after coil embolization, brain tumors, or subarachnoid hemorrhages. A total of 272 patients were enrolled. Eighty-four patients underwent CVC insertion, and 188 patients underwent clipping surgery without CVC insertion. Outcome-related factors were compared between the 2 groups. We performed propensity score matching of the 2 groups to increase comparability., Results: There were no significant differences in outcome, sex, aneurysm location, aneurysm multiplicity, aneurysm size, or comorbid disease between the 2 groups. The mean age at the time of surgery was higher in the non-CVC insertion group than in the CVC insertion group. There were no meaningful differences in primary outcomes, including premature rupture and intraoperative motor evoked potential/somatosensory evoked potential change, and secondary outcomes, including estimated blood loss, duration of intensive care unit stay, duration of hospitalization, and Glasgow Outcome Scale score at discharge., Conclusions: CVC insertion for clipping surgery for UIA is not mandatory. Considering the possible complications associated with CVCs, we cautiously suggest aneurysm surgery with CVC insertion in patients with serious medical comorbidities, aneurysm sizes >10 mm, and difficult proximal parent artery control., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Scleroderma, or systemic sclerosis, is an autoimmune disorder affecting connective tissues, including blood vessels. Although the exact mechanism is not understood, it results in the production of an abnormal amount of collagen. Cases have been reported in which patients with scleroderma also had intracranial aneurysms. We wish to gain insight into any potential association between the 2 diseases., Case Description: We reviewed the literature of scleroderma cases with cerebral aneurysms and added our own case, focusing on patient and aneurysm characteristics. Including the present case, this paper pertains to 11 cases with 26 aneurysms. Fifty-five percent had multiple aneurysms, of which two thirds had >2. When data were available, 35% of aneurysms were ≥1 cm, 12% of which were giant. Four aneurysms were fusiform (15%). Patients presented with subarachnoid hemorrhage in 45% of cases., Conclusions: Scleroderma may lead to the formation of an aneurysm, and the abnormal growth of collagen may protect it from early rupture, allowing it to reach a large size., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: The repair of unruptured intracranial aneurysms has increased since 2000. In this study, we analyzed the Nationwide Readmission Database (NRD) to determine the rate of 90-day readmission. Our objective is to examine readmission trends after unruptured aneurysm repair., Methods: This study used the 2013 and 2014 NRD. Patient data included standard demographic, comorbidity, and payer information. We selected patients who had undergone microsurgical or endovascular repair for a nonruptured aneurysm. We excluded patients who were under 18 years of age, had a subarachnoid hemorrhage, or were discharged to home the same day. Readmission was calculated by counting the number of days between the end of the index visit and earliest readmission date., Results: A total of 2180 of 29,694 patients (7.34%) were readmitted within 90 days of their initial hospitalization. They were younger (mean, 52.6 years; 95% confidence interval [CI], 51.4-53.8) than patients not readmitted (mean, 57.4 years; 95% CI, 57.1-57.8; P < 0.0001). In total, endovascular repair was more frequent than microsurgery (79.8% vs. 20.2%, respectively). Mean days to readmission was 41.8 (95% CI, 39.7-43.9) and was higher for women (P < 0.0001). The odds ratio for readmission after an endovascular repair was 1.54 (95% CI, 1.27-1.86)., Conclusions: In this study of over 28,000 patients treated for an unruptured aneurysm, the 90-day readmission rate was 7.34%. Endovascular patients had higher odds of readmission than microsurgical patients. Patients with common medical comorbidities (hypertension, obesity, renal failure, and diabetes) were less likely to be readmitted than patients without those conditions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Traumatic vertebral artery dissection (tVAD) is frequently accompanied by cerebellar infarction, but subarachnoid hemorrhage (SAH) is rare., Case Description: We report a unique case of tVAD precipitating SAH, from which the patient fully recovered, most likely because of the protective effects of an anomalously duplicated posterior inferior cerebellar artery (PICA) origin. A 17-year-old Sumo wrestler experienced a brief loss of consciousness after an attack by an opponent to his neck. Head computed tomography imaging demonstrated diffuse posterior fossa SAH; cerebral angiography demonstrated left vertebral artery (VA) occlusion, which was thought to be most likely attributable to tVAD. Angiography revealed distal PICA reconstitution, supplied by collateral arterial flow from the meningeal branch of the proximal ipsilateral VA. An external ventricular drain was placed acutely for treatment of SAH-induced hydrocephalus; however, the patient had an otherwise uneventful course, and remained without clinical evidence of ischemic infarct. A repeat imaging confirming a probable duplicated PICA origin from the VA, distal to the tVAD-associated thrombosis., Conclusions: Of particular interest, the patient's abnormal anatomy may have been a mixed blessing, with a more fragile bifid PICA potentially underlying the unexpected development of SAH, whereas the sister branch simultaneously spared him a potentially catastrophic infarction via arterial collateralization., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Aplastic or twiglike middle cerebral artery (MCA), a congenital anomaly related to the abnormal development of the MCA, is rare. It is usually unilateral; bilateral lesions are extremely rare. An aplastic or twiglike MCA may lead to cerebral ischemic stroke, intracranial hemorrhage, and subarachnoid hemorrhage (SAH). In patients with ischemic stroke due to hemodynamic stress, extracranial-intracranial (EC-IC) bypass surgery is indicated. As hemodynamic stress may also elicit SAH, it is important to select the appropriate treatment. EC-IC bypass surgery was successful in a patient with bilateral aplastic or twiglike MCA who suffered SAH due to hemodynamic stress., Case Description: A 64-year-old female with a history of surgery for tetralogy of Fallot experienced SAH in the left sylvian fissure. As angiography showed a bilateral aplastic or twiglike MCA and single photon emission computed tomography revealed a decrease in the cerebral blood flow in the left MCA territory, we attributed her SAH to hemodynamic stress due to the decreased blood flow in the MCA territory and to the vulnerability of abnormal vessels as are seen in moyamoya disease. We performed EC-IC bypass surgery to reduce hemodynamic stress. A cerebral angiogram obtained 2 weeks postoperatively revealed sufficient blood flow in the MCA territory from the superficial temporal artery used for bypass. In the course of 2-year follow-up she remained stroke free., Conclusions: The presence of aplastic or twiglike MCA may lead to stroke due to hemodynamic stress. EC-IC bypass surgery may help to prevent stroke recurrence and SAH., (Copyright © 2019. Published by Elsevier Inc.)

Background: Machine learning (ML) has been increasingly used in medicine and neurosurgery. We sought to determine whether ML models can distinguish ruptured from unruptured aneurysms and identify features associated with rupture., Methods: We performed a retrospective review of patients with intracranial aneurysms detected on vascular imaging at our institution between 2002 and 2018. The dataset was used to train 3 ML models (random forest, linear support vector machine [SVM], and radial basis function kernel SVM). Relative contributions of individual predictors were derived from the linear SVM model., Results: Complete data were available for 845 aneurysms in 615 patients. Ruptured aneurysms (n = 309, 37%) were larger (mean 6.51 mm vs. 5.73 mm; P = 0.02) and more likely to be in the posterior circulation (20% vs. 11%; P < 0.001) than unruptured aneurysms. Area under the receiver operating curve was 0.77 for the linear SVM, 0.78 for the radial basis function kernel SVM models, and 0.81 for the random forest model. Aneurysm location and size were the 2 features that contributed most significantly to the model. Posterior communicating artery, anterior communicating artery, and posterior inferior cerebellar artery locations were most highly associated with rupture, whereas paraclinoid and middle cerebral artery locations had the strongest association with unruptured status., Conclusions: ML models are capable of accurately distinguishing ruptured from unruptured aneurysms and identifying features associated with rupture. Consistent with prior studies, location and size show the strongest association with aneurysm rupture., (Copyright © 2019. Published by Elsevier Inc.)

Background: The aneurysmal bone cyst (ABC) is a rare osteolytic lesion that is often associated with osseous disease such as fibrous dysplasia (FD)., Case Description: A 66-year-old woman previously diagnosed with FD presented with suddenly reduced visual acuity. Computed tomography and magnetic resonance imaging revealed a large osteolytic lesion in the middle cranial fossa that had invaded the left orbit. Although its radiological findings were compatible with an ABC, rotational digital subtraction angiography revealed that this osteolytic lesion was a large middle meningeal artery (MMA) aneurysm. To release the compression force on the optic nerve and confirm the diagnosis, we performed endovascular embolization, followed by surgical removal of the lesion. Histologic examination revealed that the resected lesion met the requirements of a thrombosed aneurysm. No new neurologic deficits appeared after the surgery, and no symptomatic recurrence have been noted during the 6-month follow-up., Conclusions: This is the first case report to show that ABC-like lesions in patients with FD could be thrombosed MMA aneurysms. It is thus possible that some lesions previously diagnosed as ABCs were thrombosed MMA aneurysms or included a thrombosed MMA aneurysm. It is therefore important to rule out the presence of a MMA aneurysm when we encounter what appears to be an ABC in the presence of FD., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Cerebral aneurysms (CAs) are characterized by a pathological wall structure with internal elastic lamina and media disruption, which leads to focal weakened pouches of the arterial wall. The prevalence of unruptured CAs has been estimated to be 2%-5% in the general population. During the past few decades, the pathophysiological mechanisms behind the formation, growth, and rupture of CAs have been the focus of numerous research studies. In the present review, we have summarized the inflammatory pathways, genetics, and risk factors for the formation, growth, and rupture of CAs. In addition, we have discussed the concepts of geometric indexes, flow patterns, and fluid dynamics that govern CA development., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The Woven EndoBridge (WEB) device, an intrasaccular flow-diverter that does not require long-term antiplatelet use, has recently emerged as an alternative to embolize complex intracranial aneurysms; however, there are limitations to the WEB device. First, it does not immediately secure the aneurysm in most subarachnoid hemorrhage cases. Second, it may not be suitable for embolization of wide-neck aneurysms with an unfavorable aspect ratio. To overcome these limitations, we have used the WEB device in conjunction with stenting and/or coiling. Here, we present a technical note with an illustrated case series and provide a detailed step-by-step description on how the WEB device can be used in adjunct to coiling and/or stenting to achieve successful angiographic results. Accurate sizing of the WEB device before deployment is critical. Larger case series are required to further assess the safety and success of these combined techniques., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To study clinical significance of augmentation of intraoperative motor evoked potentials (MEPs) during direct open surgery for middle cerebral artery (MCA) aneurysms., Methods: Between 2009 and 2017, 134 MCA aneurysm surgeries were performed with intraoperative MEP monitoring. The frequency and cause of augmentation with >50% increase of MEP amplitude from baseline were studied. Factors associated with MEP augmentation were investigated., Results: MEP augmentation was demonstrated in 9 patients. All 9 events were observed just after application of the temporary clip to the parent artery. The ratio of the maximum amplitude to baseline was 2.6 ± 1.1 at an mean of 2.4 ± 1.1 minutes after parent artery occlusion. Ten patients who did not show MEP augmentation after parent artery occlusion were compared with the patients showing MEP augmentation. The distance of the temporary clip point from the midline was smaller in patients with MEP augmentation compared with patients without MEP augmentation (P = 0.033)., Conclusions: MEP augmentation was thought to be an early ischemic sign preceding a significant decrease in MEPs during MCA aneurysm surgery. Transient augmentation of MEPs was more frequently observed in cases with a temporary clip applied to the more proximal part of the MCA., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Hydrocephalus secondary to spinal cord tumors is rare., Case Description: We present a 39-year-old male with gradual-onset headache whose initial diagnosis was cerebral aneurysm and communicating hydrocephalus. The correct diagnosis was primary intradural extramedullary malignant melanoma of the spinal cord. Initial brain magnetic resonance imaging demonstrated slight dilation of cerebral ventricles and a 3-mm unruptured anterior communicating artery aneurysm. He was placed under observation therapy. Two months later he was seen again due to severe headache. There was no intracranial hemorrhage on brain computed tomography scans. As we suspected rupture of the aneurysm, we operated on him for surgical clipping; however, there was no aneurysmal rupture. We found no lesions responsible for hydrocephalus, so we placed a ventriculoperitoneal shunt. His headache subsequently resolved. Nine months later he developed gait disturbance; a large volume of ascites was observed. Gadolinium-enhanced lumbar magnetic resonance imaging revealed an intradural extramedullary mass at the L-1 to S-5 level. Cytology and immunohistochemistry of the cerebrospinal fluid and ascites identified a few atypical cells positive for HMB-45, S-100 protein, and Melan-A. Whole-body examinations detected no primary lesions outside the central nervous system. Our final diagnosis was primary intradural extramedullary malignant melanoma of the spinal cord with cerebrospinal fluid dissemination., Conclusions: Our findings indicate that communicating hydrocephalus may be due to primary malignant melanoma of the spinal cord., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Aneurysmal subarachnoid hemorrhage (aSAH) requires complex multidisciplinary care. After initial treatment (index hospital), readmission to a different hospital (nonindex) can compromise quality of care, resulting in increased morbidity. We aimed to evaluate factors associated with nonindex readmission and evaluate association of nonindex hospital readmission on outcomes in patients with ruptured aneurysm., Methods: Readmissions within 90 days after aSAH treatment were identified in the 2010-2014 Nationwide Readmissions Database. Multivariable logistic regression identified patient and hospital characteristics associated with nonindex readmission. Separate multivariable models determined increased morbidity or risk of second readmission for nonindex readmissions., Results: A total of 9254 patients who underwent treatment of ruptured aneurysms from 2010 to 2014 were identified. Of these, 1985 (21.5%) were readmitted within 90 days. Three hundred and fifty-five of these readmissions (17.9%) occurred to nonindex hospitals. Patients that were discharged to a skilled nursing or other facility (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.27-2.28]) had higher odds of nonindex readmission, whereas patients with private insurance were associated with lower odds of nonindex readmission (OR, 0.65; 95% CI, 0.46-0.92). Patients readmitted to a nonindex (vs. index) hospital were associated with increased likelihood of major complications (OR, 1.71; 95% CI, 1.18-2.48) and second readmissions (OR, 1.51; 95% CI, 1.17-1.96)., Conclusions: After treatment of a ruptured cerebral aneurysm, 17.9% of readmissions occurred at a nonindex hospital. These patients were at increased risk for major complications or subsequent readmissions, which may be because of care fragmentation. Interventions aimed at improving continuity of care may reduce higher morbidity associated with nonindex readmission., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Spontaneous thrombosis of an intracranial aneurysm is rare but is common in fusiform or large cystic aneurysms, which result in subarachnoid hemorrhage after rupture. This case reports a 47-year-old woman with subarachnoid hemorrhage who developed spontaneous thrombosis of an aneurysm due to rupture of the posterior inferior cerebellar aneurysm., Case Description: The patient was admitted to the hospital with history of sudden headache and vomiting for 3 days. According to early imaging findings, she was initially diagnosed as having a cavernous hemangioma with hemorrhage in the left cerebellum, but according to the intraoperative pictures and postoperative pathologic results, the diagnosis was an aneurysm with thrombosis., Conclusions: This case represents a rare but important complication of ruptured intracranial aneurysm, which can be easily misdiagnosed or ignored. It should be given great attention and considered in patients with subarachnoid hemorrhage who are negative for imaging examinations., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Epistaxis is a rare presentation of the ruptured cavernous carotid aneurysm, especially the nontraumatic type. Both endovascular therapies and open surgeries have a role in the treatment with various outcomes, but the standard procedure is not well established. We report a successful high-flow bypass with cervical internal carotid artery ligation for aneurysm repair and review the related literature., Case Description: An 81-year-old man presented with massive epistaxis from the left nostril. The epistaxis was controlled by nasal packing. A saccular aneurysm of the cavernous segment of the left internal carotid artery projecting into the sphenoid sinus was revealed using computed tomography angiography. We treated this patient with high-flow bypass with ligation of the cervical internal carotid artery. Immediate postoperative computed tomography angiography showed complete disappearance of the aneurysm. Nasal packing was removed without further bleeding. No neurological deficit or complications were detected in the postoperative period., Conclusions: In cases of massive or recurrent epistaxis without coagulopathy or nasal pathology, a cavernous carotid aneurysm should be considered. Immediate cessation of the bleeding is necessary. Flow-preservation bypass with proximal ligation of the parent artery is 1 of the effective procedures for the treatment of this condition with low morbidity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Pial arteriovenous fistulas are abnormal vascular connections between arteries and the cranial venous system on the surface of the brain in the pia mater. In contrast to vein of Galen aneurysmal malformations, they lack a true vascular nidus and may only indirectly involve the vein of Galen., Case Description: An 18-month-old boy was referred to us with a history of seizures, drowsiness, bulging cephalic veins, and cranial nerves palsy identified as vein of Galen aneurysmal malformation according to initial magnetic resonance imaging. Digital subtraction angiography showed a vertebrobasilar junction pial high-flow fistula between the basilar artery and anterior pontomesencephalic vein, causing retrograde flow, dilation, and tortuosity of the lateral and posterior mesencephalic vein as well as the vein of Galen. Endovascular treatment, including coil embolization of fistula site, was done successfully without complication resulting in recovery from previous symptoms and signs., Conclusions: If cerebral venous dilations are encountered, one must keep in mind that the location of the fistula may not be in close proximity to the dilated veins, especially when there is a suspicion for vein of Galen aneurysmal malformation. Other pathologies, such as pial arteriovenous fistula, in a region away from the site of the vein of Galen must be considered., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The presence of an anterior communicating artery blister-like aneurysm in the setting of a craniopharyngioma has never been reported to our knowledge., Case Description: This patient was admitted to our service for an untreated craniopharyngioma resection. An anterior interhemispheric approach with right frontal craniotomy was performed and a blister-like aneurysm of the anterior communicating artery was found during the surgery. After the tumor was completely resected, a suturing technique was used for the aneurysm. In this article, we are going to present this rare case and discuss the potential pathogeny of the aneurysm., Conclusions: We hypothesized that cystic craniopharyngioma may rupture spontaneously. The cystic fluid accumulated in the lower subarachnoid space due to gravity, and it may lead to local vascular cytotoxic and inflammatory reactions which may result in the vascular wall remodeling and lead to the reconstructed vascular wall weakness., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: We tested the hypothesis that low hemoglobin levels are associated with acute seizures after aneurysmal subarachnoid hemorrhage (aSAH)., Methods: Patients with ruptured intracranial aneurysms were enrolled in the observational cohort study that prospectively collected age, sex, symptom onset, history of diabetes and hypertension, history of coronary artery disease, temperature, Hunt-Hess grade, Fisher grade, aneurysm location, hemoglobin, hematocrit, serum potassium, sodium, calcium, phosphorus, iron, and modified Rankin Scale. Acute seizures were determined as seizures within 1 week after aSAH., Results: We included 554 patients with requisite data for analysis in the prospective study. Incidence of acute seizures following aSAH was 3.61%. In the univariate analysis, significant differences were detected in admission Hunt-Hess grade, Fisher grade, hemoglobin, and serum iron between epilepsy and nonepilepsy groups. Furthermore, acute seizures were associated with higher modified Rankin Scale score and poor outcome (P = 0.004). Serum hemoglobin levels were 114.30 ± 20.08 g/L in the epilepsy group, which were lower than those in the nonepilepsy group (128.64 ± 17.94 mmol/L, P = 0.001). Serum iron levels were 8.89 ± 5.03 g/L in the epilepsy group, which were also lower than those in the nonepilepsy group (13.71 ± 6.70 mmol/L, P = 0.002). The hemoglobin level was positively correlated with serum iron on admission (ρ = 0.321, P = 0.000). In the multivariate logistic regression model, lower hemoglobin was considered as an independent risk factor of acute seizures (odds ratio 4.286, 95% confidence interval 1.492-12.315, P = 0.007). The optimal cutoff value for hemoglobin level as a predictor for acute epilepsy after aSAH was determined as 119 g/L in the receiver operating characteristic curve (sensitivity was 75.00%, and specificity was 69.48%)., Conclusions: These data support the hypothesis that hemoglobin was inversely associated with acute seizures following aSAH., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Radiculomedullary arteries aneurysms are rare, with only few cases so far reported., Case Description: We report the case of a 54-year-old woman with sudden onset of upper thoracic back pain. Magnetic resonance imaging/magnetic resonance angiography of the spine showed a cervico-thoraco-lumbar hematoma, with no evidence of underlying vascular malformations. Using Phantom retractors, a unilateral laminectomy was performed at the level of T3, in proximity of the thickest part of the epidural hematoma. No epidural blood was detected. The dura was opened, and subdural and subarachnoid blood was found. After its removal, a fusiform aneurysm of the right radiculomedullary artery was found. The parental vessel was temporarily clipped and the aneurysm removed after ligation of both proximal and distal vessels. No postoperative complications occurred., Conclusions: Rupture of radiculomedullary artery aneurysm always should be considered as differential diagnosis in patients with sudden onset of isolated back pain, headache, and spinal epidural/subdural bleeding. Among different possible treatments, surgery represents a valid option. The use of microsurgical techniques is crucial to achieve a good clinical outcome. A minimally invasive approach can be used to minimize muscle disruption, with minimal blood loss, and faster recovery., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Posterior cerebral artery (PCA) aneurysms are relatively rare, and neck clipping is often difficult due to their fusiform shape. We report a case of a thrombosed aneurysm of the distal PCA for which curative trapping and parent artery reconstruction by in situ bypass were performed through an occipital transtentorial approach (OTA)., Case Description: A 67-year-old woman had been suffering from numbness in the right face and limbs for 4 months. Radiologic imaging demonstrated a thrombosed aneurysm on a distal portion of the left PCA. Curative trapping of the aneurysm and in-situ bypass between the distal PCA and superior cerebellar artery were performed through the OTA. Before surgery, we had evaluated access to the PCA and feasibility of the bypass in a cadaveric simulation. The PCA was well exposed in the posterior half of the ambient cistern, and the proximity of the distal PCA to the superior cerebellar artery through a tentorial incision was confirmed., Conclusions: This OTA could represent a useful option for definitive treatment of distal PCA aneurysms., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: Intracranial-intracranial (IC-IC) bypass with a graft vessel (IBGV) is a straightforward arterial reconstruction technique used for the treatment of complex aneurysms and skull base tumors. We have described the technical characteristics and summarized the clinical results of IBGV in complex cerebrovascular disorders., Methods: We performed a search of the PubMed and Google Scholar online databases. The terms "intracranial-intracranial bypass," "jump graft bypass," "interposition graft bypass," "radial artery graft bypass," "saphenous vein graft bypass," and "superficial temporal artery graft bypass" were searched. Studies involving IBGV combined with other bypass methods were excluded. Illustrations of the technique have been provided to enhance comprehension., Results: We identified 59 cases involving 6 types of graft vessels were identified from 1978 to July 2018. The IBGV technique was divided into the following 4 subtypes: type IA, in situ interposition graft bypass; type IB, Y-shaped double-barrel interposition graft bypass; type IIA, long jump graft bypass; and type IIB, Y-shaped double-barrel jump graft bypass. Grafts from the radial (44.1%; 26 of 59) and superficial temporal (39.3%; 22 of 59) arteries were used most frequently, and the middle cerebral artery territory was the most commonly involved region for IBGV. Of the cases with the specified postoperative characteristics, the graft patency and overall uneventful rates were 96.3% (52 of 54) and 82.2% (37 of 45), respectively. A higher patency rate (100% vs. 90.5%) and a lower complication rate (<20% vs. 60%) were observed with the type II group with an arterial graft., Conclusions: The IBGV method is a technically feasible option for vascular disease or complex cerebral tumors and should be considered by neurosurgeons. Long jump bypass with arterial grafts should be preferred when IC-IC bypass has been considered owing to the high rates of graft patency and favorable clinical outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background A contralateral approach to aneurysm clipping in cases of bilateral middle cerebral artery (MCA) aneurysms reduces surgical time and cost. However, there is a lack of evidence for objective patient selection. In this study, we assessed the change in surgical freedom along the contralateral MCA to provide objective evidence for patient selection. Methods Sixteen cadaveric specimens were studied. Through a pterional approach, the surgical freedom was calculated moving distally along the contralateral MCA in 5-mm increments. In addition, in a series of 19 MCA aneurysms clipped contralaterally by the senior author, the average length of the MCA from its origin to the aneurysm neck was measured on angiography. Results In these patients treated via a contralateral approach, the average length of the MCA segment from its origin to the aneurysm neck was 12.4 mm. Starting at the MCA origin, surgical freedom decreased significantly between all adjacent target points except at 5–10 mm from the MCA origin. Conclusions After the proximal 5 mm, there is no significant decrease in surgical maneuverability within the proximal 10 mm of MCA when approached contralaterally. When compared to the average length of the MCA from its origin to the aneurysm neck in the clinical series, it can be concluded that the first 10 mm (average, 12.4 mm) of the contralateral MCA may be considered a surgical comfort zone for a contralateral approach. This criterion may be useful for patient selection for a contralateral approach in cases of multiple bilateral intracranial aneurysms. [ABSTRACT FROM AUTHOR]

Background: Neoplastic cerebral aneurysms are exceedingly rare. We describe a case of a ruptured, distal middle cerebral artery aneurysm as the presenting symptom leading to the identification of metastatic lung cancer., Case Description: The patient underwent an uncomplicated surgical trapping and ligation of the aneurysm. Histopathologic examination of the aneurysm confirmed the neoplastic cerebral aneurysm was due to a metastatic lung adenocarcinoma with neuroendocrine features. The patient subsequently underwent stereotactic radiosurgery to the resection cavity., Conclusions: Neoplastic cerebral aneurysms are rare, and there are insufficient data to support specific guidelines for management. This case is novel as the patient received adjuvant stereotactic radiosurgery to the operative bed, as well as systemic chemotherapy, and has maintained good functional status as of last follow-up at 6 months., (Published by Elsevier Inc.)

Background: Hemangioblastomas (HBMs) are benign vascular neoplasms that most commonly arise within the cerebellum. Although other vascular lesions should be considered in the differential diagnosis, HBMs rarely resemble aneurysms on neuroimaging and only 1 case of a cerebellar HBM mimicking a posterior fossa aneurysm has been reported. Here we describe a retromedullary HBM that masqueraded as a distal posterior inferior cerebellar artery (PICA) medullary branch aneurysm., Case Description: A 63-year-old asymptomatic male was incidentally diagnosed with an unruptured 3-mm left PICA aneurysm via computed tomography angiography during a workup for carotid stenosis. Two years later, the presumed aneurysm enlarged to 6.5 mm and prompted elective treatment. Endovascular treatment was unsuccessful, and the patient was immediately transitioned to a craniotomy for aneurysm clipping. After microsurgical dissection, the lesion was visualized on the posterior medullary surface with several small arterial feeders extending from the brainstem into the aneurysm dome, but no major parent vessel was observed. Because a clip could not be safely applied to these small vessels, they were instead coagulated and the lesion was completely resected. Final pathology revealed hemangioblastoma (World Health Organization grade I)., Conclusions: To our knowledge, this is the second case of HBM mimicking a PICA aneurysm. Given the rarity of PICA medullary branch aneurysms and their highly symptomatic nature, other etiologies, especially HBM, should be strongly considered when an apparent distal PICA aneurysm is diagnosed in an asymptomatic patient. If the lesion is unamenable to endovascular treatment, there should be high suspicion for HBM and subsequent craniotomy should be pursued., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Crooke cell adenomas (CCAs) are rare and potentially aggressive pituitary tumors that often invade the cavernous sinuses. Although clinical presentations of pituitary tumors may include the development of accompanying intracranial aneurysms, there are no documented cases of coexistent intracranial aneurysms and CCAs to date. Herein we describe an apoplectic silent CCA that presented with adjacent cavernous internal carotid artery (ICA) aneurysms., Case Description: A 45-year old male patient presented for evaluation of headaches and diplopia. Subsequent imaging series revealed a hemorrhagic pituitary macroadenoma that had invaded the left cavernous sinus and circumferentially involved the ICA. Two pseudoaneurysms were visualized along regions of the ICA directly attached to the tumor. A transnasal transsphenoidal endoscopic approach was used for resection of the tumor, which was identified histologically as a CCA. Endocrine evaluations characterized the tumor as nonfunctional. The patient experienced an excellent recovery with resolution of related symptoms. A pseudoaneurysm was treated with a Pipeline embolization device; however, it persisted at last follow-up., Conclusions: CCAs are a poorly characterized and rare pituitary tumor type. In this case, an apoplectic silent CCA invaded the left cavernous sinus and presented with pseudoaneurysms along its involvement of the ICA. Accordingly, the authors speculated that the invasive qualities of this silent corticotroph adenoma may have directly contributed to the development of these aneurysms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Isolated abducens nerve palsy can be the presenting sign of a ruptured PICA aneurysm. Few cases have been reported in the literature. In the majority of cases, cranial nerve VI resolved following microsurgical clipping., Case Description: Here, we report a 56-year-old female who presented with a ruptured 4 mm × 3 mm left PICA aneurysm associated with a left abducens nerve palsy. The patient underwent endovascular coil embolization of the aneurysm and had complete resolution of her abducens nerve palsy., Conclusions: Here, we present the first case of an abducens nerve palsy associated with a ruptured PICA aneurysm to completely resolve following endovascular coil embolization. The direction and amount of subarachnoid hemorrhage extravasation from the ruptured aneurysm are most likely responsible for cranial nerve palsy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: Thin-walled regions (TIWRs) within cerebral aneurysms have a high risk of rupture during surgical manipulation. Previous reports have demonstrated specific changes in the parameters of computational fluid dynamics in TIWRs; however, they have not been fully evaluated. We identified and investigated a novel parameter, wall shear stress vector cycle variation (WSSVV), with user-friendly software that could predict TIWRs., Methods: Twelve unruptured cerebral aneurysms were analyzed. TIWRs were defined as reddish areas compared with the normal-colored parent artery on intraoperative views. The position and orientation of these clinical images were adjusted to match the WSSVV color maps. TIWRs and thick-walled regions (TKWRs) were marked and compared with the corresponding regions on WSSVV maps. The default images obtained from WSSVV imaging required appropriate maximum color bar value (MCBV) adjustment for predicting TIWRs. Sensitivity and specificity analyses were performed by changing the MCBV from 300 to 700 at intervals of 100. With the optimal MCBV, the WSSVV values were quantitatively compared., Results: All of the selected 18 TIWRs and 16 TKWRs corresponded to low- and high-value regions of the WSSVV color maps at the adjusted MCBV, respectively. The mean optimal MCBV was 483.3 ± 167.50 (range, 300-700). According to receiver operating characteristic analysis, the best MCBV for predicting TIWRs was 500 (highest sensitivity, 0.89; specificity, 0.94). Under this condition, the quantitative values of the computational fluid dynamics color maps for TIWRs and TKWRs were significantly different (P < 0.01)., Conclusions: Low WSSVV values may indicate TIWRs within cerebral aneurysms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Although partial thrombosis is common with intracranial aneurysms, complete aneurysmal thrombosis is extremely rare. An even rarer and seldom reported phenomenon is the spontaneous complete occlusion of the parent artery in the presence of a thrombosed aneurysm. Given the unclear natural history of this phenomenon, therapeutic decision making may be rather difficult. Here we report a case of right cavernous carotid artery aneurysm with spontaneous right internal carotid artery (ICA) thrombosis in a 45-year-old man., Case Description: Our patient presented almost 1 month after an episode of sudden-onset severe holocranial headache associated with vomiting that had resolved completely within 2 days. He was neurologically intact at the time of presentation. A computed tomography (CT) scan done at the time of ictus showed a rounded hyperdensity with the epicenter at the right parasellar region along with nonvisualization of the ipsilateral ICA on CT angiography. Magnetic resonance imaging (MRI) suggested a diagnosis of a completely thrombosed right cavernous segment ICA aneurysm. Intra-arterial angiography confirmed a complete ipsilateral ICA thrombosis and a good arterial cross-flow from the left side to the bilateral anterior and middle cerebral artery territories. We started the patient on oral aspirin and a close clinicoradiologic follow-up after having decided against any active intervention., Conclusions: Spontaneous thrombosis of an intracranial aneurysm and the parent artery is rare, with only a few cases reported in the literature. In the absence of symptoms and adequate collateral circulation, these patients are perhaps best managed conservatively., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Microsurgical or endovascular treatment for blood-blister aneurysm remains a technical challenge. This video demonstrates a microsurgical suturing technique for ruptured blood-blister aneurysm of the left middle cerebral artery. The patients experienced favorable clinical outcomes without apparent stenosis of the normal vessel wall., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: In direct aneurysm surgery, tentative clipping is frequently applied to facilitate aneurysm dissection. However, no systemic review on the pros and cons of tentative clipping has been conducted. This study aimed to investigate the efficacy and concerns of tentative clipping., Methods: A total of 867 direct clippings in 737 patients were performed to treat intracranial aneurysms between 1994 and 2015. We retrospectively investigated the frequency, purpose, location, and adequacy of tentative clipping., Results: Tentative clipping was performed in 149 of the 867 aneurysms that were clipped (17.2%). The purpose of tentative clipping was to dissect an aneurysm in 141 (94.6%), separate the vessels from the surface of a sac in 5 (3.4%), and prevent slipping of the final clip in 3 (2.0%) cases. Further dissection revealed that tentative clipping completely excluded the blood flow into the aneurysm in 126 (84.6%) of the 149 cases and incompletely shut it out in 23 (15.4%) cases. Five (21.7%) of the 23 patients with incomplete clipping had intraoperative aneurysm ruptures subsequently., Conclusions: Tentative clipping facilitates dissection of the aneurysm sac from the surrounding structure but can occasionally lead to intraoperative rupture. Before applying tentative clips, surgeons should prepare for temporary clipping or additional tentative clipping in case of a rupture., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Duane syndrome is a congenital eye movement disorder characterized by congenital malformation of the abducens nucleus. Thrombogenic conditions during development may lead to vascular anomalies in Duane syndrome; however, the presence of a giant aneurysm in this patient population is a rarely documented phenomenon., Case Description: We reported a case of a large cerebral aneurysm in a pediatric patient with Duane syndrome and performed a review of the literature to identify other potential cases and associations. The pathophysiologic hallmarks of Duane syndrome that lead to alterations in the fetal cerebral vasculature and that may form the basis for a potential mechanism for aneurysm formation were reviewed in this study. The patient was an 11-year-old female with Duane syndrome who presented with seizures. Computed tomography and magnetic resonance imaging demonstrated a large, heterogeneously enhancing right temporal mass. Intraoperatively, the mass was revealed to be a partially thrombosed giant middle cerebral artery aneurysm. After surgery, the patient had an uneventful postoperative course without residual aneurysm presented on postoperative angiogram. No clinical or radiographic appearance of recurrent aneurysm was evident at her 6-month follow-up., Conclusions: The pathophysiology of vascular anomalies with Duane syndrome may be related to thrombogenic conditions during development leading to alterations in cerebral fetal vasculature. Strong consideration for vascular anomaly should be given when evaluating cerebral masses in patients with Duane syndrome., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: In situ side-to-side (STS) revascularization is an intracranial-intracranial bypass technique that is increasingly used to treat complex aneurysms and cerebral ischemia. This sophisticated technique involves connecting 2 proximal parallel vessels to create an artificial conduit for blood flow. This study aims to provide a detailed description of the configuration of the STS bypass technique and extensive information regarding its technical characteristics, current anastomosis approaches, and surgical significance., Methods: A literature search was performed using the PubMed, Medline, ScienceDirect, Embase, Wiley Online Library, Cambridge Journals, SAGE Journals, Oxford Journals, Research Gate, and Google Scholar databases. The terms "intracranial-intracranial bypass," "in situ bypass," "communicating bypass," and "STS anastomosis" were searched to identify pertinent articles. Articles involving in situ STS anastomosis combined with other bypass methods were excluded. Computer tablet-drawn illustrations of this technique are provided to enhance comprehension., Results: In total, 70 articles that met our search and inclusion criteria were identified. Overall, the radiographic and clinical outcomes of 132 (125 aneurysms and 7 cerebral ischemias) patients who underwent in situ STS revascularization were analyzed., Conclusions: Intracranial-intracranial bypass in the STS fashion can be a safe and effective strategy for the management of complex intracranial aneurysms and cerebral ischemia and is particularly attractive in rescue, anticipated, and troubleshooting cases. Despite its extreme rarity, a de novo aneurysm may be observed after STS anastomosis; thus, long-term follow-up is mandatory. Vascular neurosurgeons should consider including this procedure in their treatment armamentarium., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: There is increasing acknowledgement that surgical care is important in global health initiatives. In particular, neurosurgical care is as limited as 1 per 10 million people in parts of the world. We performed a systematic literature review to examine the worldwide incidence of central nervous system vascular lesions and a meta-analysis of aneurysmal subarachnoid hemorrhage (aSAH) to define the disease burden and inform neurosurgical global health efforts., Methods: A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to estimate the global epidemiology of central nervous system vascular lesions, including unruptured and ruptured aneurysms, arteriovenous malformations, cavernous malformations, dural arteriovenous fistulas, developmental venous anomalies, and vein of Galen malformations. Results were organized by World Health Organization regions. After literature review, because of a lack of data from particular World Health Organization regions, we determined we could only provide an estimate of aSAH. Using data from studies with aSAH and 12 high-quality stroke studies from regions lacking data, we meta-analyzed the yearly crude incidence of aSAH per 100,000 persons. Estimates were generated via random-effects models., Results: From an initial yield of 1492 studies, 46 manuscripts on aSAH incidence were included. The final meta-analysis included 58 studies from 31 different countries. We estimated the global crude incidence for aSAH to be 6.67 per 100,000 persons with a wide variation across WHO regions from 0.71 to 12.38 per 100,000 persons., Conclusions: Worldwide, almost 500,000 individuals will suffer from aSAH each year, with almost two-thirds in low- and middle-income countries., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Nickel is the most common metal allergen and predominantly affects women. It is also the ubiquitous component in the alloys used to manufacture intracranial devices for aneurysm treatments, including aneurysm clips, self-expanding stents, flow-diverting stents, and endosaccular occlusion devices. Adverse events related to nickel allergy after deployment of such devices are uncommon but can be severe, resulting in dilemmas in the choice of treatment strategies and devices in managing nickel-sensitive patients with intracranial aneurysms., Methods: A literature search was performed in accordance with the PRISMA guidelines to identify studies reporting on nickel-related adverse events in patients being treated for cerebral aneurysm. The materials of the culprit devices, clinical presentation, histological features, and treatments were reviewed. Clinical considerations and management options for nickel allergy patients were evaluated., Results: Nickel is a major component of the cobalt alloy used in aneurysm clips and also of nitinol, which is commonly used in flow diverters and intracranial stents. Our literature review identified 9 articles reporting 10 unique cases of nickel-related adverse events after aneurysm treatment. Five of the cases occurred after aneurysm clipping, and the other 5 were attributed to endovascular devices. Two patients presented with dermatologic manifestations and 8 with neurologic manifestations, including cerebral edema and cerebritis., Conclusions: Neurologic complications related to nickel in cerebral aneurysm treatments are rare but remain concern owing to the high prevalence of nickel allergy in the population. Surgeons and interventionists should consider the metal allergy history and its potential clinical significance in managing nickel-allergic patients with aneurysms., (Copyright © 2018 Elsevier Inc. All rights reserved.)