Cerebral Artery Aneurysm Research Articles

Minimally Invasive Lateral Transorbital Approach for Clipping of Right Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

The lateral transorbital approach is a minimally invasive approach that was first described for accessing the cavernous sinus.1 Although other minimally invasive approaches have been broadly applied to aneurysm surgery,2 the use of transorbital keyholes for this is still quite rare.3,4 We present a 72-year-old man with an incidentally discovered 5-mm middle cerebral artery aneurysm. Despite a low rupture risk,5 the patient himself opted for treatment, and because of the complex shape of the aneurysm, he chose surgical clipping as the treatment of choice. Two unique aspects of the patient's anatomy brought forth transorbital approach for consideration. He had a wide fissure, which opened to the orbital wall, and a giant frontal sinus made its avoidance difficult with any anterolateral transcranial approach. The lateral transorbital approach was started with a transpalpebral incision.4,6,7 Both wings of the sphenoid bone were drilled until the frontal and temporal dura was exposed. Opening this through the orbit gained direct access to the large Sylvian fissure. Two specific challenges were specific to this opening: the aneurysm dome pointed straight at the surgeon, and the M1 segment, needed for proximal control, was directly behind the aneurysm. Despite these, the aneurysm was successfully eliminated through the transorbital approach with no residual or normal branch compromise. Given the specific anatomical provisions, the lateral transorbital approach was an effective and safety alternative to the pterional approach for middle cerebral artery aneurysms. No Institutional Review Board approval was sought or necessary as the patient provided consent for the procedure, publication of his image, and this submission.

Microsurgical clipping versus endovascular therapy for treating patients with middle cerebral artery aneurysms presenting with neurological ischemic symptoms.

Studies comparing different treatment methods in patients with middle cerebral artery (MCA) aneurysms in different subgroups of onset symptoms are lacking. It is necessary to explore the safety and efficacy of open surgical treatment and endovascular therapy in patients with MCA aneurysms in a specific population. This study aimed to compare microsurgical clipping versus endovascular therapy regarding complication rates and outcomes in patients with MCA aneurysms presenting with neurological ischemic symptoms. This was a retrospective cohort study in which 9656 patients with intracranial aneurysms were screened between January 2014 and July 2022. Further, 130 eligible patients were enrolled. The primary outcome was the incidence of serious adverse events (SAEs) within 30days of treatment, whereas secondary outcomes included postprocedural target vessel-related stroke, disabling stroke or death, mortality, and aneurysm occlusion rate. Among the 130 included patients, 45 were treated with endovascular therapy and 85 with microsurgical clipping. The primary outcome of the incidence of SAEs within 30days of treatment was significantly higher in the clipping group [clipping: 23.5%(20/85) vs endovascular: 8.9%(4/45), adjusted OR:4.05, 95% CI:1.20-13.70; P = 0.024]. The incidence of any neurological complications related to the treatment was significantly higher in the clipping group [clipping:32.9%(28/85) vs endovascular:15.6%(7/45); adjusted OR:3.49, 95%CI:1.18-10.26; P = 0.023]. Postprocedural target vessel-related stroke, disabling stroke or death, mortality rate, and complete occlusion rate did not differ significantly between the two groups. Endovascular therapy seemed to be safer in treating patients with MCA aneurysms presenting with neurological ischemic symptoms compared with microsurgical clipping, with a significantly lower incidence of SAEs within 30days of treatment and any neurological complications related to the treatment during follow-up.

Evaluating High-Frequency Fluctuations And Its Effect On Hemodynamics At Varying Heart Rates In Intracranial Aneurysms Via 4D PTV

Hemodynamics have been shown to affect the growth and rupture of intracranial aneurysms (IA). Studies have increasingly reported the presence of high frequency velocity fluctuations in aneurysms. However, it remains undetermined how transient physiological factors like heart rate and inflow blood waveform amplitude affect the hemodynamic parameters and high frequency fluctuations in and around an IA, as well as the risk of IA progression. In this work, we address this question using a volumetric particle tracking velocimetry (PTV) study where a patient-specific right middle cerebral artery (R MCA) aneurysm model was subjected to two heart rate conditions (60 bpm and 137 bpm). The input waveform amplitude for the 137 bpm case was increased by a factor of 1.6 to be physiologically consistent. Captured PTV images were processed using the Shake-the-Box (STB) workflow. Flow parameters including velocity, vorticity, and turbulent kinetic energy (TKE) were evaluated. To evaluate the presence of high frequency fluctuations, a direct numerical simulation (DNS) using the R MCA geometry and same two heart rate cases was conducted and a method for use with STB particle tracks was proposed. As compared to the 60 bpm case, the 137 bpm case had a more concentrated inflow jet that extended further into the aneurysmal sac and a stronger and larger vortical flow structure in the aneurysmal sac. The 60 bpm case maintained a region of slightly elevated TKE at the main junction point where the aneurysmal sac and all vessels merge. In the 137 bpm case, TKE in this region was dramatically higher. Using probe points, the DNS data revealed high frequency velocity fluctuations in an outflow vessel during the deceleration phase of the cycle. Notably, these fluctuations were only observed for the 137 bpm case. For both the DNS and STB data, high frequency components were more prevalent and stronger outside of the aneurysmal sac as opposed to inside the aneurysmal sac. Overall, these results suggest that changes in heart rate induce changes to the flow structure and can induce significant increases in TKE and high frequency fluctuations. Based on our findings, a higher heart rate would be expected to yield a flow field more akin to IA progression. The specific correlation between the high frequency components computed using our proposed STB-based method and the high frequency fluctuations in the flow field could not be well understood. Thus, additional analysis and development of this method is needed.

Review: Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms.

The invention of flow diverting stents (FDS) is a novel milestone in the field of endovascular aneurysm therapy, promoting physiological healing of the vessel segment contrary to prior deconstructive treatment strategies, such as coiling. The effects of FDS are based on changes in flow patterns, segmental wall stabilization, and the growth of a neointima. Although flow diversion is already well established for cerebral aneurysms in proximal segments, peripheral locations remain challenging. Especially the middle cerebral artery (MCA) with its predominance of non-collateralized perforators and functional end arteries that supply the eloquent areas of the brain is of major concern.The literature was reviewed for flow diversion of the MCA and antiplatelet therapy.Resulting from the special anatomical characteristics of the MCA, FDS implantation in this territory is completely different from the proximal vessel segments. Still, flow diversion represents an effective endovascular strategy, especially in otherwise non-accessible or sufficiently treatable lesions. However, the risk of ischemic adverse events might be increased. Special attention to the individual decision regarding device selection, antiplatelet regimen, and exact definition of the proximal and distal landing zone considering the jailed side branches is essential for a good angiographic and clinical outcome. · MCA aneurysms can be sufficiently treated by FDS.. · The anatomic and hemodynamic characteristics of the MCA result in an increased risk of thromboembolism.. · Individual device selection and antiplatelet regimen are essential for treatment success.. · Schüngel M, Wohlgemuth WA, Elolf E et al. Review: Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms. Fortschr Röntgenstr 2024; DOI 10.1055/a-2343-0046.

Virtual reality guided focused Sylvian approach for clipping unruptured middle cerebral artery aneurysms.

The increasing prevalence of unruptured intracranial aneurysms, detected through advanced brain imaging, necessitates a cautious approach to surgical intervention, with a focus on minimizing associated risks. This retrospective study explores the safety and better aesthetic outcomes of a Virtual Reality (VR) guided Focused Sylvian Approach (FSA) in comparison to the standard Pterional Surgical Approach (SPA) for the clipping of unruptured small-medium-size (<10 mm) Middle Cerebral Artery (MCA) aneurysms. 23 patients with 23 unruptured MCA aneurysms underwent the VR-guided FSA from June 2020 to September 2023, while 22 patients with 23 unruptured MCA aneurysms who underwent SPA were retrospectively recruited from the medical records database from January 2017 to May 2020. The comparative analysis involved surgical duration, postoperative complications, hospital stay, and a three-month follow-up patient's sequela survey. All aneurysms were effectively treated. The FSA procedure demonstrated a shorter surgical duration compared to the SPA group (164 ± 48 min vs. 196 ± 133 min, P = 0.2974). Despite a slightly higher median age in the FSA group (59 vs. 56 years), the median hospital stay was shorter in the FSA group (6 days) compared to the SPA group (7 days). The SPA group exhibited a higher incidence of complications (17/23) including cephalalgia, scar irritation, scar numbness, and temporal muscle dysfunction, compared to the FSA group (1/23), with a statistical significance of P < 0.05. Although FSA cannot demonstrate significant surgical efficiency in surgical duration and hospitalization, its superior aesthetics and preservation of temporalis muscle function compared to the SPA group. The VR-guided FSA offers improved aesthetics and preservation of muscle function compared to the SPA. Our retrospective study underscores the potential benefits of VR-guided, personalized, focused Sylvian approaches for managing unruptured small-medium-size MCA aneurysms.

Comparative Effectiveness of Therapies in 2665 Elderly Patients with Ruptured Intracranial Aneurysms.

The optimal treatment strategy for elderly patients with ruptured intracranial aneurysms (IAs) remains controversial. We evaluated a national, multihospital database to compare the outcomes of aggressive treatment and medical management for those patients. We performed a retrospective analysis of 2665 elderly patients with ruptured IAs admitted to 11 hospitals in China. Patients were divided into three age groups (60-69, 70-79, and 80 years or older). Multiple logistic regression was used to estimate the odds ratio for favorable and unfavorable outcomes. Patients between 60 and 69 years old undergoing endovascular treatment (EVT) had significantly decreased morbidity (13.7% versus 19.7% and 29.9%), compared to those who underwent clipping and medical management, similar mortality to patients who underwent clipping (3.6% versus 2.6%), and decreased mortality (3.6% versus 8.7%) to patients who underwent medical management. Coiled patients 70 to 79 years old had lower morbidity (21.3% versus 33.8%) and mortality (2.8% versus 11.3%) compared to patients who underwent medical management and similar mortality (21.3% versus 27.2%) and mortality (2.8% versus 4.8%) to patients who underwent clipping. Multivariate logistic regression analysis demonstrated that factors associated with discharge status were age, poor mFisher grade, poor WFNS grade, hypertension, diabetes, smoking, aneurysms 4 mm or larger, and middle cerebral artery aneurysms. Elderly patients treated with EVT had significantly less morbidity and mortality than those treated with clipping and medical management. A comprehensive assessment of the general state of elderly patients and IAs characteristic may help us to predict patients' prognosis.

Peculiarities of angiospasm and ischemic complications in ruptures of cerebral arterial aneurysms against the background of occlusive-stenotic lesions of cerebral arteries

Objective – to determine the effect of occlusive-stenotic lesions of cerebral arteries on angiospasm and ischemic complications in patients with ruptured arterial aneurysms against the background of occlusive-stenotic lesions of cerebral arteries. Materials and methods. A retrospective study of the medical histories of 1,147 patients with cerebral artery aneurysms from 2006 to 2022 was conducted. 63 patients were included in the study group because they met the following criteria: surgical treatment; rupture of saccular aneurysms (SAs); the presence of occlusive-stenotic lesions was proven using instrumental examination methods. Patients of the control group had to meet the following criteria: surgical treatment; rupture of SAs; the absence of occlusive-stenotic lesions was proven by means of instrumental examination methods; the gender and age distribution had to match the study group. Of the 126 patients included in this study, there were 76 men (60.32%) and 50 women (39.68%). The age of the patients varied from 31 to 77 years. The average age of patients- 55.9±0.76 years; men – 54.3±0.94 years, women – 58.3±1.19 years. Results. A percentage predominance of patients with high cerebral blood flow velocity (&gt;200 cm/s, which is equal to the velocity with severe grade III vasospasm of the cerebral arteries) in the study group (32.56%) compared with the control group (24.24%) was revealed. Conclusions. The predominance of men among patients of the study group (60.32%) was established. The average age of men with occlusive-stenotic lesions was younger than that of women (men – 54.3±0.94 years, women – 58.3±1.19 years). The difference in age is the largest in the 2nd subgroup of the study group where the severity of stenosis is 50-75% (men - 48.3 years; women - 62 years). Ruptures of arterial aneurysms of the middle cerebral artery occur more often in the presence of stenoses (study group - 25.4%, control group - 12.7%). The neurological status of patients with a hemorrhagic stroke, as a result of the rupture of an arterial aneurysm, is significantly aggravated by occlusive-stenotic lesions due to the occurrence of chronic brain ischemia. The worst prognosis for life and health was in men with a ruptured arterial aneurysm against the background of a 50-75% stenotic lesion and severe vasospasm of the cerebral arteries.

Predicting the development of delayed cerebral ischemia in patients with ruptured arterial aneurysms

Introduction. Vasospasm and delayed cerebral ischemia (DCI), which develop after rupture of cerebral arterial aneurysms and their surgical treatment, are serious complications that worsen the clinical outcome of the disease. The ability to predict the risk of developing these complications is an urgent task allowing to reduce neurological deficits and improve the quality of the patients’ life after aneurysm rupture. Aim – to develop a prognostic model for the development of DCI in patients with ruptured cerebral arterial aneurysms based on the study of a complex of clinical manifestations and a number of laboratory parameters. Material and methods. We examined 91 patients with ruptured arterial aneurysms and the development of subarachnoid hemorrhage in the acute period, identifying the main group with the development of DCI (n=67) and the comparison group without DCI (n=24) in the pre- and postoperative periods. Clinical neurological and neuroimaging studies have been carried out. We studied indicators of blood oxygen transport function, platelet aggregation, coagulogram, concentration of nitrates/nitrites (NOx), angiotensin-converting enzyme (ACE) in venous blood in the pre- and postoperative periods. Results. Based on the logistic regression equation, we determined that predictors influencing the probability of DCI development after aneurysm rupture and clipping include a score on the Glasgow Coma Scale (p=0.001), the p50 value is the partial pressure of oxygen in the blood at which hemoglobin is oxygen saturated by 50% (p=0.001), ACE concentration (p=0.013), NOx/ACE index (p=0.001) and the degree of platelet aggregation according to Traptest (p=0.005). The threshold value of the result of the logistic regression equation was 0.58 with a diagnostic sensitivity of 85.4% and specificity of 69.3%, the area under the ROC of the AUC curve was 0.88±0.015 (p&lt;0.001), which indicates the high quality of the constructed model. Conclusion. The developed predictive model of the probability of DCI development in patients with ruptured arterial cerebral aneurysms with a diagnostic efficiency of 88% allows timely identifying patients for whom it is advisable to begin neuroprotective therapy before surgical treatment.

Virtual Reality vs Phantom Model: Benefits and Drawbacks of Simulation Training in Neurosurgery.

Traditional neurosurgical education has relied heavily on the Halstedian "see one, do one, teach one" approach which is increasingly perceived as inefficient in contemporary settings marked by a steady decline in surgical caseload. In recent years, simulation training has emerged as an effective and accessible training alternative. To date, however, there is no standardized criterion pertaining to the quality and implementation of simulators in neurosurgical education and training. This research aims to compare the efficacy of virtual reality (VR) and Phantom-based simulation training in the context of neurosurgical skill acquisition, with a focus on middle cerebral artery aneurysm clipping. An immersive VR clipping tool and a haptic clipping simulator incorporating 3-dimensional printing, additive manufacturing, and rheological analyses were developed. Twenty-two participants, comprising 12 medical students, 6 neurosurgical residents, and 4 experienced neurosurgeons, tested and evaluated both simulators for face and content validity. Construct and predictive validity of the simulators were assessed using an objective structured assessment scale for aneurysm clipping, measuring participants' performances and progress. Both modalities were deemed highly advantageous for educational purposes. Objective evaluations, however, revealed measurable differences in usability, efficacy, and transferability of the learned skills with VR excelling in procedural planning and visualization while Phantom simulation being noticeably superior in conveying surgical skills. Simulation training can accelerate the neurosurgical learning curve. The results of this study highlight the importance of establishing standardized criteria for the implementation and assessment of simulation modalities, ensuring consistent quality and efficacy in neurosurgical education.

Distribution of rupture sites and blebs on intracranial aneurysm walls suggests distinct rupture patterns in ACom and MCA aneurysms.

The mechanisms behind intracranial aneurysm formation and rupture are not fully understood, with factors such as location, patient demographics, and hemodynamics playing a role. Additionally, the significance of anatomical features like blebs in ruptures is debated. This highlights the necessity for comprehensive research that combines patient-specific risk factors with a detailed analysis of local hemodynamic characteristics at bleb and rupture sites. Our study analyzed 359 intracranial aneurysms from 268 patients, reconstructing patient-specific models for hemodynamic simulations based on 3D rotational angiographic images and intraoperative videos. We identified aneurysm subregions and delineated rupture sites, characterizing blebs and their regional overlap, employing statistical comparisons across demographics, and other risk factors. This work identifies patterns in aneurysm rupture sites, predominantly at the dome, with variations across patient demographics. Hypertensive and anterior communicating artery (ACom) aneurysms showed specific rupture patterns and bleb associations, indicating two pathways: high-flow in ACom with thin blebs at impingement sites and low-flow, oscillatory conditions in middle cerebral artery (MCA) aneurysms fostering thick blebs. Bleb characteristics varied with gender, age, and smoking, linking rupture risks to hemodynamic factors and patient profiles. These insights enhance understanding of the hemodynamic mechanisms leading to rupture events. This analysis elucidates the role of localized hemodynamics in intracranial aneurysm rupture, challenging the emphasis on location by revealing how flow variations influence stability and risk. We identify two pathways to wall failure-high-flow and low-flow conditions-highlighting the complexity of aneurysm behavior. Additionally, this research advances our knowledge of how inherent patient-specific characteristics impact these processes, which need further investigation.

Neurologic and Neuropsychological Outcomes for Treatment of Unruptured Middle Cerebral Artery Aneurysms: Standard Pterional Versus Minipterional Approach in a Retrospective Single-Center Analysis

BackgroundIn accordance with technique advancement and minimal invasiveness surgical approaches, the mini-pterional has progressively replaced the standard pterional approach for the treatment of unruptured middle cerebral artery (MCA) aneurysms. Multimodal intraoperative resources, including microdoppler and micro-flow probes, indocyanine green video-angiography, and neurophysiological monitoring nowadays constitute a fundamental prerequisite for increasing the safeness of the clipping procedure. ObjectiveOur study aims investigate and compare in a single-center experience the effect of the evolution of minimally invasive and multimodal approach in unruptured MCA aneurysms surgery by measuring post-operative complications rate, recovery time, long-term neuropsychological and functional outcomes. Materials and MethodsOne hundred thirty-one patients who underwent surgical treatment for unruptured MCA aneurysms at our Institution were retrospective evaluated. Patients’ clinical, radiological and surgical reports were collected. Cognitive evaluation and quality-of-life were assessed through validated test through telephone interviews. Patients who met the inclusion criteria were divided into two groups: the “PT (pterional) group” and the “MPT (mini-pterional) group”. ResultsNinety-two patients were included in the present analysis. A significant reduction of postoperative complication rate and of new onset postoperative seizures was recorded in the MPT group (p-value 0.006). Severe cognitive deficits were lower in the MPT group although without a clear statistical correlation. ConclusionDecreasing in complication rates, faster recovery time, and trend towards better cognitive and functional performances were documented for the MPT group of patients. In our experience, the mini-pterional approach with multimodality-assisted microsurgery reduced neurological complications and recovery time, and improved long-term cognitive outcome and quality of life.

Turning the operating room into a mixed-reality environment: a prospective clinical investigation for cerebral aneurysm clipping.

The overall aim of this study was to demonstrate the potential benefit of a novel mixed-reality-head-mounted display (MR-HMD) on the spatial orientation of surgeons. In a prospective clinical investigation, the authors applied for the first time a new multicamera navigation technology in an operating room setting that allowed them to directly compare MR-HMD navigation to standard monitor navigation. In the study, which included 14 patients with nonruptured middle cerebral artery aneurysms, the authors investigated how intuitively and effectively surgical instruments could be guided in 5 different visual navigation conditions. The authors demonstrate that multicamera tracking can be reliably integrated in a clinical setting (usability score 1.12 ± 0.31). Moreover, the technology captures large volumes of the operating room, allowing the team to track and integrate different devices and instruments, including MR-HMDs. Directly comparing mixed-reality navigation to standard monitor navigation revealed a significantly improved intuition in mixed reality, leading to navigation times that were twice as fast (2.1×, p ≤ 0.01). Despite the enhanced speed, the same targeting accuracy (approximately 2.5 mm, freehand tool use) in comparison to monitor navigation could be observed. Intraoperative planning strategies with mixed reality clearly outperformed classic preoperative planning: surgeons scored the mixed-reality plan as the best trajectory in 63% of the cases (chance level 33%). The incorporation of mixed reality in neurosurgical operations marks a significant advancement in the field. The use of mixed reality in brain surgery enhances the spatial awareness of surgeons, enabling more instinctive and precise surgical interventions. This technological integration promises to refine the execution of complex procedures without compromising accuracy.

Quantitative Analysis of Hemodynamic Changes in Branch Arteries Covered by Flow Diverters.

Understanding post-treatment hemodynamic alterations and their association with the patency of covered branch arteries is limited. This study aims to identify hemodynamic changes after flow diverter stenting and investigate their correlation with the patency status of covered branch arteries. All patients treated with pipeline embolization device for anterior cerebral artery aneurysms at our center between 2016 and 2020 were screened for inclusion. Quantitative digital subtraction angiography was used to analyze changes in hemodynamic parameters pre- and post-stenting. The patency status of covered branch arteries after stenting was categorized as either patent or flow impairment (defined as artery stenosis or occlusion). A total of 71 patients, encompassing 89 covered branch arteries, were enrolled. Flow impairment was observed in 11.2% (10/89) of the branches. The mean transit time and full width at half maximum (FWHM) in covered branches were significantly prolonged post-stenting (P = .004 and .023, respectively). Flow-impaired branch arteries exhibited hemodynamic shifts contrary to those in patent branch arteries. Specifically, flow-impaired branches showed marked reductions in time to peak, FWHM, and mean transit time (decreases of 32.8%, 32.6%, and 29%, respectively; P = .006, .002, and .002, respectively). Further multivariate analysis revealed that reductions in FWHM in the branches (odds ratio = 0.97, 95% CI: 0.95-0.99, P = .007) and smoking (odds ratio = 14.5, 95% CI: 1.39-151.76, P = .026) were independent predictors of flow impairment of covered branches. Pipeline embolization device stenting can cause a reduction in blood flow in branch arteries. Compared with patent branches, flow-impaired branches exhibit an increase in blood flow velocity after stenting. Smoking and ΔFWHM in the covered branches indicate flow impairment.

WHEN CLINICAL FINDINGS TAKE YOU DOWN THE WRONG PATH: PERSISTENT FEVER IN A PATIENT WITH PREVIOUS CARDIAC SURGERY

Abstract Introduction In a patient who underwent previous cardiac surgery, persistent fever may be related to endocarditis. Symptoms and cardiovascular imaging, such as echocardiogram and PET/CT, may guide clinicians and surgeons to the correct diagnosis. Discussion A 43–years–old man came to our attention because of persistent fever (lasting several months) associated with cough and asthenia. When he was 5 years old, he underwent cardiac surgery for partial atrioventricular canal defect (atrial septal defect was about 4 cm) and mitral valve cleft. 14 years ago he undertook chemotherapy due to Hodgkin‘s lymphoma. Recently a cerebral artery aneurysm, radiologically defined as mycotic but proved to be fusiform, was diagnosed and treated with neurosurgery. During a recent hospitalization, blood culture positive for Streptococcus Mitis and brachial rash were reported and antibiotic therapy was started. Suspecting endocarditis, he was referred to our department. Echocardiogram revealed anterior mitral leaflet fissure, resulting in severe mitral regurgitation. Moreover a periannular cavity of doubtful interpretation (seemingly an abscess) was described. Subsequent 18FDG–PET/CT did not detect any abnormal cardiac metabolic activity. Due to severe valve regurgitation, cardiac surgery was performed: myxomatous degenerative mitral valve leaflets, failure of mitral valve cleft closure and anomalous coronary sinus communication to the left atrium (mimicking echocardiogram findings of suspected empty abscess cavity) were observed. Thus mitral valve replacement using a biological valve prosthesis was performed. Macroscopically there was no evidence of endocarditis, confirming PET/CT scan results. During the post–surgery period, third–degree atrioventricular block episodes were noted. Therefore a bicameral pacemaker was implanted. Conclusions This case report demonstrates the importance of not stopping at the first impression, as failure of previous mitral valve repair in a patient presented with persistent fever can mimic endocarditis. Therefore, the results of diagnostic tests should be compared to patients’ medical history and their clinical presentation.

Impact of preaneurysmal M1 length in unruptured middle cerebral artery aneurysm: mid-term outcome and single-center experience

ObjectiveThis study was design to investigate the surgical and functional outcome based on the preaneurysmal M1 length for unruptured MCA aneurysm. MethodsAmong 250 consecutive patients with unruptured aneurysms operated in our institution between 2015 and 2017, 72 were MCA aneurysms. Risk factors for IR (i.e., intraoperative rupture) were investigated including age, sex, preaneurysmal M1 length, maximal MCA aneurysm diameter, neck size, aneurysm shape, sphenoid ridge proximation sign. Outcome was measured at discharge, 1 yr and last follow-up. Outcome was compared according to the preaneurysmal M1 length. ResultsAmong 68 patients included, five patients (7.3%) suffered IR. Mean maximal diameter of MCA aneurysm (7.9 mm ± 3.4 vs. 4.5 ± 1.8; p = 0.01) was significantly associated with IR risk. Mean M1 length seemed to be shorter in the IR group although not statistically significant (16.2 mm ± 5.1 vs. 11.5 mm ± 4.8; p = 0.053). Mid-term outcome was favorable for all patients at last follow-up but was worsen in case of short preaneurysmal M1 segment (10.7 mm ± 4.8 vs. 16.4 mm ± 5.3, p = 0.02). Complete aneurysm occlusion was achieved for sixty-nine patients (95.5%) with 6.9% of early postoperative complications. ConclusionsThe microsurgical treatment of unruptured MCA aneurysm was associated with favorable mid-term outcome in all patients and high rates of complete occlusion. Aneurysm size was significantly associated with the intraoperative rupture risk for unruptured MCA aneurysm and patients with a short preaneurysmal M1 segment seemed to have a greater risk of intraoperative rupture although not statistically significant. Short preaneurysmal M1 patients had worsen mid-term outcome.

Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development.

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal.

Treating a Challenging Giant Aneurysm of Middle Cerebral Artery (MCA) with a Staged Procedure of Endovascular Coiling and Flow Diverter (FD): Case Report

Background: Giant intracranial aneurysms pose significant challenges in treatment due to a high risk of postoperative complications, including delayed rupture, cerebral edema, and aggravation of mass effect. Endovascular approaches, such as adjunctive coiling and flow diverter (FD) procedures, have become increasingly recommended for wide-necked, large, and giant aneurysms. Case Description: In this report, we present a challenging case of a staged coiling and FD procedure in a giant unruptured middle cerebral artery (MCA) aneurysm. The patient, a 26-year-old adult female, was admitted to our hospital with a history of convulsions. Digital Subtraction Angiography (DSA) revealed a massive aneurysm measuring 40 mm × 27 mm in the M1 segment of the MCA. To mitigate the risk of mass effect aggravation, we performed a two-staged procedure with a seven-day interval between the interventions. The first step involved partial endovascular coiling to shrink the aneurysm, followed by successful flow diversion. The patient did not experience further convulsions or neurologic deficits, and the follow-up angiogram showed no residual flow to the aneurysm. Conclusion: We report one of the very first cases of adjunctive coiling and FD in ‘unruptured’ giant aneurysms. Our neurovascular intervention provides valuable insights into the approach and treatment of unruptured giant aneurysms in cerebral arteries. By employing a staged procedure, effective flow diversion can be achieved even in giant unruptured aneurysms. Although further research is necessary to confirm its superiority and address critical issues, our findings may contribute to the future management of giant aneurysms and inspire avenues for research in the neurosurgical community. Bang. J Neurosurgery 2023; 12(2): 129-136

One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms

BackgroundAneurysms located in the distal middle cerebral artery (MCA) are relatively rare and lack an established treatment strategy. For distal MCA (DMCA) aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. MethodsCases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients’ and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. ResultsSix patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all six cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in one case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass were confirmed in all cases. ConclusionsThe one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Endovascular treatment of wide-neck bifurcation aneurysms using pCONUS2 HPC bridging device with single antiplatelet: A Case Series.

Wide neck bifurcation aneurysms (WNBA) are technically challenging for both surgical and endovascular treatments. Endovascular treatment for WNBA often requires dual antiplatelet therapy (DAPT) post stent insertion. Novel devices such as the pCONUS2 HPC neck bridging device have an HPC coating which reduces the device thrombogenicity. This theoretically allows for use of single antiplatelet therapy (SAPT), which would be advantageous, particularly in treating ruptured aneurysms. This case series aims to evaluate the safety of SAPT regimen only post stent insertion, by presenting our center early clinical experience in using pCONUS2 HPC neck bridging device in patients that are not suitable for DAPT. We report the cases of 3 patients (2 females, 1 male; range: 64-71 years old) who underwent coil embolization for WNBA using the pCONUS2 HPC device (2 unruptured WNBA, and 1 ruptured WNBA). As all 3 patients were allergic to Aspirin, they could only be started on SAPT post endovascular therapy. All 3 patients were diagnosed with WNBA on angiographic studies. Patient 1 had an unruptured left middle cerebral artery aneurysm; Patient 2 had a ruptured basilar tip aneurysm; Patient 3 had an unruptured anterior communicating artery (ACOM) aneurysm. All 3 WNBA were treated with pCONUS2 HPC neck bridging device. There were no immediate complications. The immediate angiographic result of aneurysm treatment in Patient 1 and Patient 2 demonstrated incomplete occlusions, with delayed complete occlusion of aneurysm in Patient 1 and growth of aneurysmal neck in Patient 2 on follow-up angiograms (range: 6-9 months). No major thrombo-embolic or hemorrhagic complications in the first 2 patients. For Patient 3, the immediate angiographic result of the treated aneurysm demonstrated complete occlusion. However, the patient readmitted 11 days post procedure with cerebral infarction, scoring 5 on the modified Rankin scale on discharge. pCONUS2 HPC as a neck bridging device in treating WNBA has yet to be shown superior to traditional techniques and devices. The theoretical advantage of HPC coating reducing its thrombogenicity requiring only SAPT is yet to be proven safe in clinical practice.

Changes in treatment of intracranial aneurysms during the last decade in a large European neurovascular center

ObjectiveTreatment modality for ruptured and unruptured intracranial aneurysms has shifted during the last two decades from microsurgical treatment towards endovascular treatment. We present how this transition happened in a large European neurovascular center.MethodsWe conducted a retrospective observational study consecutive patients treated for an unruptured or ruptured intracranial aneurysm at Helsinki University Hospital during 2012–2022. We used Poisson regression analysis to report age-adjusted treatment trends by aneurysm location and rupture status.ResultsA total of 2491 patients with intracranial aneurysms were treated (44% ruptured, 56% unruptured): 1421 (57%) surgically and 1070 (43%) endovascularly. A general trend towards fewer treated aneurysms was noted. The proportion of patients treated surgically decreased from 90% in 2012 to 20% in 2022. The age-adjusted decrease of surgical versus endovascular treatment was 6.9%/year for all aneurysms, 6.8% for ruptured aneurysms, and 6.8% for unruptured aneurysms. The decrease of surgical treatment was most evident in unruptured vertebrobasilar aneurysms (10.8%/year), unruptured communicating artery aneurysms (10.1%/year), ruptured communicating artery aneurysms (10.0%/year), and ruptured internal carotid aneurysms (9.0%/year). There was no change in treatment modality for middle cerebral artery aneurysms, of which 85% were still surgically treated in 2022. A trend towards an increasing size for treated ruptured aneurysms was found (p = 0.033).ConclusionA significant shift of the treatment modality from surgical to endovascular treatment occurred for all aneurysm locations except for middle cerebral artery aneurysms. Whether this shift has affected long-term safety and patient outcomes should be assessed in the future.