Middle Cerebral Artery Aneurysm Research Articles

Analysis of the Surgical Efficacy and Risk Factors of a One-stage Unilateral Approach for Clipping Bilateral MCA Mirror Aneurysms.

Numerous microsurgical approaches are available for treating middle cerebral artery (MCA) mirror aneurysms. However, a definitive conclusion regarding which approach yields the best outcome has yet to be reached. Thirty-three patients with MCA aneurysms were categorized into 2 groups: one-stage unilateral approach and other surgical approaches. Prognostic differences were compared using the Modified Rankin Scale (mRS). In addition, the length of hospital stay and costs were also compared. Among the patients with a proposed preoperative one-stage unilateral approach, they were divided into success and failure groups, and these factors were collected, including Hunt-Hess grade, contralateral aneurysm orientation and maximum diameter, contralateral A1+M1 length, and contralateral ICA bifurcation angle. These parameters were analyzed using multivariate logistic regressions to identify the risk factors. The prognosis of patients in the one-stage unilateral approach group did not differ significantly from that of other surgical approaches. However, patients in the one-stage unilateral approach group experienced shorter hospital stays and incurred lower hospital expenses. In the multivariate regressions, the length of the contralateral A1+M1 was identified as an independent risk factor. The one-stage unilateral pterional approach for clipping bilateral aneurysms is an effective method of treating MCA mirror aneurysms. However, in cases where patients have an excessive length of A1+M1 on the contralateral side, this approach may result in surgical failure.

How I do It: High flow EC-IC bypass for complex middle cerebral artery aneurysms using the lateral circumflex femoral artery as interposition graft.

High-flow bypasses with parent vessel occlusion are required for complex aneurysms originating from the ICA or MCA. Traditional graft options are the saphenous vein however, it has a higher rate of thrombus formation than an arterial graft. The radial artery is commonly used, however, tapers in its distal course and is contraindicated in some patients while the lateral circumflex femoral artery is an excellent graft vessel and easy to harvest. We present our technique and experience harvesting the lateral circumflex femoral artery as an alternative graft vessel for high-flow bypasses. The lateral circumflex femoral artery is easy to harvest and is a reliable graft vessel for high-flow bypasses for complex aneurysms.

Clinical Characteristics and Outcomes in Patients with Ruptured Middle Cerebral Artery Aneurysms: A Multicenter Study in Northern China.

The long-term prognosis of ruptured middle cerebral artery aneurysms (MCAAs) in northern China remains unclear. The aim of this study is to analyze the epidemiological characteristics and long-term outcomes of ruptured MCAAs in northern China. We included patients who were consecutively admitted for ruptured MCAAs to 12 tertiary care centers in northern China from January 2017 to December 2020. Kaplan‒Meier curves were used to compare survival in hazard strata. The Cox proportional hazards model was used to analyze risk factors and mortality risk, whereas logistic regression was used to identify factors influencing 2-year survival. Subgroup analyses were performed to verify the robustness of the results. Data on 959 patients with ruptured MCAAs were analyzed; 16.4% of these patients had ruptured intracranial aneurysms (RIAs) and were registered in the Chinese cerebral aneurysm database. The mean follow-up duration was 3.0years (range 0-6.2years). The 3-month and 2-year mortality rates were 15.5% and 18.2%, respectively. The risk factors for mortality were identified via Cox regression and were as follows: age > 70years, previous stroke, combined intracerebral hemorrhage (ICH)/intraventricular hemorrhage (IVH), poor Hunt and Hess grade, multiple aneurysms, and conservative treatment (CT). The positive association between the risk of death and CT was consistent across subgroups. According to logistic regression, hypertension, previous stroke, combined ICH/IVH, Hunt and Hess grade, and WFNS (World Federation of Neurological Surgeons) score were identified as factors negatively influencing 2-year survival. We detail the epidemiologic characteristics and long-term outcomes of MCAAs. The risk factors for mortality included age > 70years, previous stroke, combined ICH/IVH, poor Hunt and Hess grade, and multiple aneurysms. Compared with microsurgical treatment (MST), CT is associated with an increased risk of mortality, while the risk of mortality associated with endovascular treatment (EVT) is not significantly different. Two-year survival was associated with hypertension, previous stroke, ICH/IVH, and poor grades at admission.

Distance from the midline to the aneurysm as simple predictor of ischemic complication with small unruptured middle cerebral artery aneurysm surgery

Distance from the midline to the aneurysm as simple predictor of ischemic complication with small unruptured middle cerebral artery aneurysm surgery

Computational analysis of pulsatile blood flow and heat transport dynamics in middle cerebral artery aneurysms in different body physiologies

This paper presents a comprehensive hemodynamic evaluation of two endovascular techniques for treating cerebral aneurysms. Using the finite volume method, we simulated pulsatile blood flow and heat transport dynamics in two saccular aneurysms of varying sizes and shapes. We assessed hemodynamic factors under two coiling conditions with different porosities and deformation stages to identify the most effective treatment for each case. Our computational analysis reveals that stent and coiling applications are more efficient for aneurysms with low-sac volume. Notably, stent placement proves to be more effective than coiling in treating saccular aneurysms. Our findings indicate that stent-induced deformation sufficiently diverts the main blood flow, thereby reducing the risk of aneurysm rupture near the ostium region.

Microsurgical Clipping of Unruptured Middle Cerebral Artery Bifurcation Aneurysms: A Single-Center Experience

Background/Objectives: Microsurgical clipping has traditionally been considered a standard treatment for middle cerebral artery (MCA) aneurysms. Recently, a caseload reduction related to improved endovascular treatment options has occurred in cerebrovascular neurosurgery. Therefore, studies that report the clinical and radiological outcomes after clipping are highly warranted. Methods: Patients with an unruptured MCA bifurcation aneurysm, who were surgically treated at the Department of Neurosurgery in Linz between 2002 and 2019, were included in this study. Clinical and radiological outcome parameters were evaluated for each patient. Results: Overall, 272 patients were eligible for inclusion. Complete aneurysm occlusion was demonstrated in 266 (99.3%) of the 268 (98.5%) patients who underwent postoperative digital subtraction angiography. In six (2.2%) patients, a permanent new neurological deficit (pNND) persisted after treatment. Intraoperative aneurysm rupture was a significant factor (p = 0.0049) in the logistic regression. At the last follow-up, only two patients (0.7%) had an unfavorable outcome (mRS > 2). More recent surgeries were associated with fewer cases of pNND (p = 0.009). A transient new neurological deficit occurred in 13 patients (4.8%), with aneurysm size being a significant risk factor (p = 0.009). Surgical site infections were reported in four patients (1.5%), with patient age (p = 0.039) and time (p = 0.001) being significant factors. Two patients died (0.7%) perioperatively and two patients (0.7%) needed a retreatment in the long-term follow-up. Conclusions: The findings indicate that microsurgical clipping is a safe procedure with minimal need for retreatment. It achieves a high occlusion rate while maintaining a very low rate of adverse outcomes. Continuous intraoperative enhancements over time have contributed to a progressive improvement in clinical outcomes in recent years. This trend is exemplified by the absence of detectable pNND in the era of ICG angiography. Consequently, these data support the conclusion that microsurgical clipping should still be considered an appropriate treatment option for unruptured MCA bifurcation aneurysms.

Intraoperative visualization of cerebral aneurysms using navigated 3D-ultrasound power-Doppler angiography.

The questions of whether the spatial resolution of navigated 3D-ultrasound (3D-US) power-Doppler angiography imaging rendered by existing 3D-US systems is sufficient for the intraoperative visualization of cerebral aneurysms, and in what percentage of cases, are largely unanswered. A study on this topic is lacking in the literature. From 2015 to 2022, we performed 86 surgeries on 83 aneurysm patients. Navigated 3D-US was used at the discretion of the operating neurosurgeons when available (i.e., not being used during parallel tumor surgeries). Twenty-five aneurysms (15 ruptured) were operated on using 3D-US; 22 aneurysms were located at the middle cerebral artery (MCA). Patient 3D-US power-Doppler angiography images and surgical reports were retrospectively reviewed to assess the intraoperative ultrasound visibility of aneurysms. In 20 patients (80%) the aneurysms were successfully visualized. In five patients (20%), the aneurysms visualization was insufficient or absent. Nineteen of 22 aneurysms (86.4%) were visualized in the MCA aneurysm subgroup. We observed no association between aneurysm visibility and aneurysm size or the presence of subarachnoid hemorrhage. In the subgroup of MCA aneurysms, no association between aneurysm visibility and the presence of subarachnoid hemorrhage was found; a trend toward poor sonographic visibility of smaller aneurysms was observed (p = 0.09). Our initial data show that intraoperative 3D-US power-Doppler angiography, rendered by current navigated 3D-US systems, clearly depicts the majority of aneurysms in the MCA aneurysm subgroup. However, future prospective studies performed on a higher number of aneurysms localized at various anatomic sites are needed to confirm our initial findings and determine their potential clinical relevance.

Defining ideal middle cerebral artery bifurcation aneurysm size for Woven EndoBridge embolization.

The Woven EndoBridge (WEB) device was approved to treat wide-necked bifurcation aneurysms. The device is designed as an intrasaccular flow disruptor covering aneurysm widths up to 10 mm. Although prior studies combined all aneurysm sizes, it is known that aneurysms behave differently in response to endovascular treatment based on their size. Therefore, the authors' objective was to identify ideal middle cerebral artery (MCA) aneurysm width and neck sizes most suitable for WEB treatment. The WorldWideWEB consortium is a large multicenter retrospective database that analyzes intracranial aneurysms treated with the WEB device. In this study, all unruptured MCA bifurcation aneurysms with available measurements were included. Cutoff values based on aneurysm width and neck in relation to aneurysm occlusion status were measured using the receiver operating characteristic (ROC) curve. Propensity score matching (PSM) was then used to compare treatment outcomes between aneurysms smaller and larger than the cutoff value for both width and neck size. The ideal cutoff values for MCA bifurcation aneurysm width and neck were 6.1 mm and 4.6 mm, respectively. On PSM, 87 matched pairs were compared based on width size (≤ 6.1 mm and > 6.1 mm), and 77 matched pairs were compared based on neck size (≤ 4.6 mm and > 4.6 mm). There was a significant difference in adequate aneurysm occlusion between aneurysms smaller and larger than those cutoff values for both widths (93% vs 76%, p = 0.0017) and neck sizes (90% vs 70%, p = 0.0026). The retreatment rate was also significantly higher for larger aneurysms in both parameters. This study shows that MCA bifurcation aneurysms ≤ 6.1 mm in width and ≤ 4.6 mm in neck size are significantly better candidates for WEB treatment, leading to improved occlusion status and reduced retreatment rate, which are important considerations when using WEB devices.

Sex- and Age-Related Variations in Intracranial Aneurysms among Patients with ADPKD: Significance of Middle Cerebral Artery Aneurysms in Elderly Women

Sex- and Age-Related Variations in Intracranial Aneurysms among Patients with ADPKD: Significance of Middle Cerebral Artery Aneurysms in Elderly Women

Characteristics of middle cerebral artery aneurysms treated endovascularly in a clip-favored institution.

The emergence of flow disruptors has brought a dynamic transition in the selection of treatment for middle cerebral artery (MCA) aneurysms, and the number of MCA aneurysms clipped is acceleratingly decreasing. Still, retreatment after endovascular treatment is still a dilemma, which may necessitate surgical clipping. It is all the more important to elucidate characteristics of MCA aneurysms that make clipping unfavorable. Thus, the practical characteristics of MCA aneurysms treated endovascularly in a clip-favored institution before the usage of flow disruption devices were investigated. This is a retrospective, single-center observational study. The clinical and imaging characteristics of treated MCA aneurysms from January 2012 to May 2022 were analyzed. A total of 83 aneurysms were included; 70 aneurysms (84%) were clipped, and 13 (16%) were treated endovascularly. Eighteen aneurysms (22%) were ruptured (clipping, 12; endovascular, 6). The reasons for an endovascular treatment were as follows: distal (3); subacutely ruptured with burdens of spasm (2); multiple aneurysms (6: another clipped in 3, coiled in 1, and conservatively managed in 2); no access to the operating room due to COVID-19 (1); and retreatment after coiling (1). Endovascular group aneurysms were smaller (maximum diameter 5.2 vs 7.3 mm, p < 0.01, as well as dome, neck, and height) without differences in the dome/neck and aspect (height/neck) ratios. In a subgroup analysis of 78 MCA bifurcation aneurysms, the endovascular group was still smaller (dome 4.4 vs 5.8 mm, p = 0.025; neck 2.8 vs 3.9, p = 0.03). In a limited series from a clip-favored institution before the flow disruption era, factors guided to endovascular treatments on MCA aneurysms were rather anatomical and clinical factors such as distal location, subacutely ruptured, multiple, or retreatment after coiling, than morphological factors such as dome/neck and aspect ratios albeit smaller size.

Letter to Editor, “Giant unruptured middle cerebral artery aneurysm revealed by intracranial hypertension: is a systematic decompressive hemicraniotomy mandatory?

Letter to Editor, “Giant unruptured middle cerebral artery aneurysm revealed by intracranial hypertension: is a systematic decompressive hemicraniotomy mandatory?

Transorbital Approach Clipping of Middle Cerebral Artery Aneurysm: A Virtual Reality Morphometric Anatomic Study

The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of MCA aneurysms remains unclear. This study details the feasibility of clipping unruptured middle cerebral artery (MCA) aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. Virtual reality (VR) models of 25 MCA aneurysms from CT angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these two aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. Given the minimally-invasive, technically-challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA.

Treatment Choice for Ruptured Intracranial Aneurysm in the Hybrid Era

Long-term follow-up results from the International Subarachnoid Aneurysm Trial suggest that coiling is preferable for ruptured aneurysms treatable with both modalities. This finding has led to a growing trend towards coiling for these patients. At our institute, coiling is now the first-line treatment for ruptured aneurysms, with exceptions for middle cerebral artery aneurysms. We also favor direct surgery for small ruptured aneurysms(<3 mm), cases with massive intracerebral hematoma, or situations requiring bypass surgery. While early rebleeding after coiling is uncommon, it carries a certain risk. Therefore, we sometimes choose clipping for ruptured anterior communicating artery or posterior communicating artery aneurysms if clipping poses minimal technical difficulty. To achieve optimal outcomes for ruptured aneurysms, a combined approach is crucial. This involves safe and effective endovascular treatment alongside necessary direct surgical interventions.

Predictors of Neurological Outcomes in Patients with Poor Glasgow Coma Scale Scores 1 Week After Aneurysmal Subarachnoid Hemorrhage

This study assessed neurological outcomes and variables associated with favorable outcomes in aSAH patients with low functional status (Glasgow Coma Scale [GCS] score ≤8) on postbleed day 7 (PBD7). A retrospective analysis was conducted of all patients in the Barrow Ruptured Aneurysm Trial (January 1, 2014-July 31, 2019) treated for a ruptured aneurysm and who had a GCS score ≤8 on PBD7. The primary outcome was a favorable neurological outcome (modified Rankin Scale score ≤2) at last follow-up. Of 312 patients, 63 had low GCS scores at PBD7. These patients had a significantly greater proportion of poor Hunt and Hess scale grades (≥4) (44/63 [70%] vs 49/249 [19.7%], P < 0.001) and poor Fisher grades (grade=4) (58/63 [92%] vs 174/249 [69.9%], P < 0.001) compared to patients who did not have low GCS scores on PBD7, but no differences were found in age, sex, anterior location, aneurysm size, or type of treatment. Of the 63 patients, 7 (11%) experienced a favorable neurological outcome. On univariate analysis, none of the physical examination reflexes predicted a favorable neurological outcome. The middle cerebral artery aneurysm territory was the only significant predictor of a favorable neurological outcome by multivariate analysis (odds ratio, 10.8; 95% confidence interval, 1.16-100], P = 0.04). This study yielded no significant physical examination findings that predict a favorable outcome in patients with GCS score ≤8 on PBD7. This finding may inform the decision of whether to prolong hospital management or arrange for end-of-life care.

Adenosine-induced cardiac standstill in intracranial aneurysm surgery: A case report

Surgical clipping of complex intracranial aneurysms can pose intraoperative challenges due to difficulty in anatomic exposure and uncontrolled intraoperative rupture, leading to significant morbidities or mortalities. This report presents a case of a 61-year-old Asian male with an unruptured saccular basilar tip aneurysm and an unruptured right middle cerebral artery aneurysm. The patient underwent a left temporal craniotomy and clipping of an unruptured basilar tip aneurysm, successfully achieved through adenosine-induced cardiac standstill. This technique reduces perfusion pressure and decreases the turgor of the aneurysm, thereby facilitating clip ligation. Our experience demonstrated that thorough, careful patient selection, optimal anesthetic management, and proper communication between neurosurgeon and anesthesiologist are important for achieving successful surgical outcomes.

The impact of delivery technique on Woven EndoBridge deployment and detachment in an in vitro aneurysm model.

The Woven EndoBridge (WEB) device is increasingly used for treatment of wide-neck bifurcation aneurysms. With the newer 17 system, WEB deployment has been associated with a phenomenon known as incomplete or "sticky" detachment from the delivery wire, which may lead to imprecise placement. Optimal techniques for WEB manipulation and delivery to avoid this problem are poorly defined. This study aimed to evaluate standard WEB deployment techniques and determine the impact of delivery techniques and WEB stickiness on procedural success. An in vitro study using identical silicone middle cerebral artery aneurysm models (n = 32) assessed WEB (6 × 2 mm) deployment through a VIA 17 microcatheter via three techniques that involved: "loading," "neutral," and "tension" on the pusher wire. Microcatheter position was placed in varied positions from the WEB device. Woven EndoBridge stickiness was graded during detachment attempts. Primary outcomes were detachment stickiness and attempt number, compared between techniques using Fisher's exact test. The tension technique resulted in significantly fewer sticky detachments and detachment attempts compared to forward load or neutral techniques (p < 0.001). Sticky detachment was lower with tension (0% sticky) versus forward load (42% sticky, 8% very sticky) (p < 0.001). Forward load had a 50% rate of stickiness versus 0% with tension and neutral (p < 0.001). Forward load required multiple attempts in 100%, compared to 57% with neutral and 8% with tension (p < 0.001). Higher stickiness grades increased the need for multiple attempts (p < 0.001). The tension technique reduces incomplete WEB detachment and enables precise single-attempt detachment, optimizing delivery precision. In vivo confirmation is needed.

Advancing aneurysm management: the potential of AI and machine learning in enhancing safety and predictive accuracy.

Cerebral aneurysm rupture, the predominant cause of non-traumatic subarachnoid hemorrhage, underscores the need for effective treatment and early detection methods. A study in Neurosurgical Review compared microsurgical clipping to endovascular therapy in 130 patients with middle cerebral artery (MCA) aneurysms, finding significantly fewer serious adverse events (SAEs) and neurological complications in the endovascular group. This suggests endovascular therapy's superiority in safety and reducing complications for MCA aneurysm patients. Furthermore, a systematic review and meta-analysis assessed the diagnostic accuracy of AI algorithms in detecting cerebral aneurysms, revealing a high sensitivity but notable false-positive rates, indicating AI's potential while highlighting the need for further validation. Machine learning algorithms also showed promise in predicting cerebral aneurysm rupture risk, demonstrating reasonable sensitivity and specificity. Additionally, AI-based radiomics models are advancing rapidly, offering enhanced predictive accuracy and personalized treatment planning by analyzing imaging data to identify features indicative of aneurysm conditions. Collectively, these findings emphasize the advantages of endovascular therapy for MCA aneurysms and the emerging role of AI and machine learning in improving early detection and personalized management of cerebral aneurysms.

Giant unruptured middle cerebral artery aneurysm revealed by intracranial hypertension: is a systematic decompressive hemicraniotomy mandatory?

Our study aimed to evaluate the postoperative outcome of patients with unruptured giant middle cerebral artery (MCA) aneurysm revealed by intracranial hypertension associated to midline brain shift. From 2012 to 2022, among the 954 patients treated by a microsurgical procedure for an intracranial aneurysm, our study included 9 consecutive patients with giant MCA aneurysm associated to intracranial hypertension with a midline brain shift. Deep hypothermic circulatory flow reduction (DHCFR) with vascular reconstruction was performed in 4 patients and cerebral revascularization with aneurysm trapping was the therapeutic strategy in 5 patients. Early (< 7 days) and long term clinical and radiological monitoring was done. Good functional outcome was considered as mRS score ≤ 2 at 3 months. The mean age at treatment was 44 yo (ranged from 17 to 70 yo). The mean maximal diameter of the aneurysm was 49 mm (ranged from 33 to 70 mm). The mean midline brain shift was 8.6 mm (ranged from 5 to 13 mm). Distal MCA territory hypoperfusion was noted in 6 patients. Diffuse postoperative cerebral edema occurred in the 9 patients with a mean delay of 59 h and conducted to a postoperative neurological deterioration in 7 of them. Postoperative death was noted in 3 patients. Among the 6 survivors, early postoperative decompressive hemicraniotomy was required in 4 patients. Good functional outcome was noted in 4 patients. Complete aneurysm occlusion was noted in each patient at last follow-up. We suggest to discuss a systematic decompressive hemicraniotomy at the end of the surgical procedure and/or a partial temporal lobe resection at its beginning to reduce the consequences of the edema reaction and to improve the postoperative outcome of this specific subgroup of patients. A better intraoperative assessment of the blood flow might also reduce the occurrence of the reperfusion syndrome.

Neurological outcomes of flow-diverter stent placement for middle cerebral artery aneurysms, with reference to the effects of argatroban on ischemic events: patient series.

A systematic review and meta-analysis of flow-diverter stents (FDSs) for the treatment of middle cerebral artery (MCA) aneurysms reported concerns about ischemic complications during treatment. The authors report on the intraoperative and postoperative complications of unruptured MCA aneurysms and their control strategies at their hospital, with detailed information on the aneurysms and a review of the previous literature. Intraoperative and perioperative in-stent thrombus occlusion occurred in 3 (37.5%) of the 8 patients evaluated. In cases with in-stent thrombus formation, rapid administration of 10 mg argatroban led to improvement in blood flow, as seen on angiography. Only 1 patient (12.5%) had a symptomatic stroke postoperatively. This patient was admitted for rehabilitation and drug therapy but was discharged from the hospital 10 days postoperatively with a modified Rankin Scale (mRS) score of 1. The patient had an mRS score of 0 at 90 days after surgery and at the last observation. Ischemic complications require attention during FDS treatment for MCA aneurysms. The use of argatroban in cases of in-stent thrombosis may contribute to a good neurological prognosis. https://thejns.org/doi/10.3171/CASE24237.

Microsurgical clipping of large MCA aneurysm in a 2-month-old child.

Cerebral aneurysms in children have a low incidence and accounts for less than 4% of all cerebral aneurysms. These aneurysms have been linked to various factors. Severe headache, seizures, and motor-sensory deficits are common presentations. We describe the case of a 2-month-old male patient who presented with generalized tonic-clonic seizures for 4days. At the hospital, he was stabilized with ventilatory support, sedation, and antiepileptic drugs. A NCCT (Head) showed intraparenchymal hemorrhage in the left fronto-parieto-temporal lobe and subarachnoid hemorrhage. Subsequently a CT angiogram revealed an aneurysm of the left M3 segment of MCA. Successfully, the patient underwent microsurgical clipping of aneurysm and evacuation of hematoma. Pediatric cerebral aneurysms differ from their adult counterparts, mainly in their etiology and evolution. As per literature, aneurysmal clipping and neurological endovascular therapy have shown similar results.