scholarly journals Asymmetrical middle cerebral artery bifurcations are more vulnerable to aneurysm formation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xue-Jing Zhang ◽  
Wei-Li Hao ◽  
Dong-Hai Zhang ◽  
Bu-Lang Gao

Abstract The objective of this study was to elucidate possible relationship between middle cerebral artery (MCA) bifurcation aneurysms and bifurcation morphology. In the present study, 799 patients with three-dimensional angiography were enrolled, including 115 patients with MCA bifurcation aneurysms and 684 subjects without aneurysms. The MCA bifurcation geometry, including angles formed between two M2 segments (φ1) and between M1 and M2 segments, vessel diameters and aneurysm sizes were measured. DA ratio (larger/smaller M2 in diameter) and LA ratio (larger/smaller lateral angle) were also analyzed. The LA and DA ratios and angle φ1 were significantly (P < 0.0001) greater in patients harboring MCA bifurcation aneurysms than in the control, whereas lateral angles and bifurcation branch diameters were significantly smaller (P < 0.01) in patients with than without bifurcation aneurysms. Angle φ1 was significantly increased (P < 0.0001) while both lateral angles significantly decreased (P < 0.0001 and P = 0.0005, respectively) with increase of patients’ age. The size of MCA bifurcation aneurysms was significantly (P < 0.05) positively correlated with the bifurcation vascular diameter and aneurysm neck at the MCA bifurcation. A significantly positive correlation existed between aneurysm neck and DA ratio (P = 0.0075), whereas an inverse correlation between aneurysm neck and LA ratio (P = 0.0219). MCA bifurcation aneurysms were mostly deviated toward the smaller lateral angles and smaller M2 branch. In conclusion, aneurysmal MCA bifurcations have asymmetrical bifurcation structures with widened bifurcation angles, narrowed lateral angles, decreased M1 diameter, imbalanced lateral angles and M2 segments, with the cutoff bifurcation angle of 125.0° and cutoff lateral angle ratio of 1.57 for predicting MCA bifurcation aneurysms, whereas normal MCA bifurcations show close to symmetrical structures in the lateral angles and M2 branches.

2016 ◽  
Vol 18 (4) ◽  
pp. 463-470 ◽  
Author(s):  
Vijay M. Ravindra ◽  
Michael Karsy ◽  
Richard H. Schmidt ◽  
Philipp Taussky ◽  
Min S. Park ◽  
...  

The authors report the case of a previously healthy 6-month-old girl who presented with right arm and leg stiffening consistent with seizure activity. An initial CT scan of the head demonstrated acute subarachnoid hemorrhage in the basal cisterns extending into the left sylvian fissure. Computed tomography angiography demonstrated a 7 × 6 × 5–mm saccular aneurysm of the inferior M2 division of the left middle cerebral artery. The patient underwent left craniotomy and microsurgical clip ligation with wrapping of the aneurysm neck because the vessel appeared circumferentially dysplastic in the region of the aneurysm. Postoperative angiography demonstrated a small remnant, sluggish distal flow, but no significant cerebral vasospasm. Fifty-five days after the initial aneurysm rupture, the patient presented again with an acute intraparenchymal hemorrhage of the left anterior temporal lobe. Angiogram revealed a circumferentially dysplastic superior division of the M2 branch, with a new 5 × 4–mm saccular aneurysm distinct from the first, with 2 smaller aneurysms distal to the new ruptured aneurysm. Endovascular parent vessel occlusion with Onyx was performed. Genetic testing revealed a mutation of the MYH11. To the authors' knowledge, this is the first report of rapid de novo aneurysm formation in an infant with an MYH11 mutation. The authors review the patient's clinical presentation and management and comprehensively review the literature on this topic.


Author(s):  
Abhishek Miryala ◽  
Mahendra Javali ◽  
Anish Mehta ◽  
Pradeep R. ◽  
Purushottam Acharya ◽  
...  

Abstract Background The precise timings of evoked potentials in evaluating the functional outcome of stroke have remained indistinct. Few studies in the Indian context have studied the outcome of early prognosis of stroke utilizing evoked potentials. Objective The aim of this study was to determine somatosensory evoked potentials (SSEPs) and brain stem auditory evoked potentials (BAEPs), their timing and abnormalities in acute ischemic stroke involving the middle cerebral artery (MCA) territory and to correlate SSEP and BAEP with the functional outcome (National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS) and Barthel’s index) at 3 months. Methods MCA territory involved acute ischemic stroke patients (n = 30) presenting consecutively to the hospital within 3 days of symptoms onset were included. Details about clinical symptoms, neurological examination, treatment, NIHSS score, mRS scores were collected at the time of admission. All patients underwent imaging of the brain and were subjected to SSEP and BAEP on two occasions, first at 1 to 3 days and second at 4 to 7 days from the onset of stroke. At 3 months of follow-up, NIHSS, mRS, and Barthel’s index were recorded. Results P37 and N20 amplitude had a strong negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a significant positive correlation with Barthel’s index (p < 0.0001). BAEP wave V had a negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a positive correlation with Barthel’s index (p < 0.0001). Conclusion SSEP abnormalities recorded on days 4 to 7 from onset of stroke are more significant than those recorded within 1 to 3 days of onset of stroke; hence, the timing of 4 to 7 days after stroke onset can be considered as better for predicting functional outcome.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mikołaj Zimny ◽  
Edyta Kawlewska ◽  
Anna Hebda ◽  
Wojciech Wolański ◽  
Piotr Ładziński ◽  
...  

Abstract Background Previously published computational fluid dynamics (CFD) studies regarding intracranial aneurysm (IA) formation present conflicting results. Our study analysed the involvement of the combination of high wall shear stress (WSS) and a positive WSS gradient (WSSG) in IA formation. Methods We designed a case-control study with a selection of 38 patients with an unruptured middle cerebral artery (MCA) aneurysm and 39 non-aneurysmal controls to determine the involvement of WSS, oscillatory shear index (OSI), the WSSG and its absolute value (absWSSG) in aneurysm formation based on patient-specific CFD simulations using velocity profiles obtained from transcranial colour-coded sonography. Results Among the analysed parameters, only the WSSG had significantly higher values compared to the controls (11.05 vs − 14.76 [Pa/mm], P = 0.020). The WSS, absWSSG and OSI values were not significantly different between the analysed groups. Logistic regression analysis identified WSS and WSSG as significant co-predictors for MCA aneurysm formation, but only the WSSG turned out to be a significant independent prognosticator (OR: 1.009; 95% CI: 1.001–1.017; P = 0.025). Significantly more patients (23/38) in the case group had haemodynamic regions of high WSS combined with a positive WSSG near the bifurcation apex, while in the control group, high WSS was usually accompanied by a negative WSSG (14/39). From the analysis of the ROC curve for WSSG, the area under the curve (AUC) was 0.654, with the optimal cut-off value −0.37 Pa/mm. The largest AUC was recognised for combined WSS and WSSG (AUC = 0.671). Our data confirmed that aneurysms tend to form near the bifurcation apices in regions of high WSS values accompanied by positive WSSG. Conclusions The development of IAs is determined by an independent effect of haemodynamic factors. High WSS impacts MCA aneurysm formation, while a positive WSSG mainly promotes this process.


2019 ◽  
Vol 10 ◽  
pp. 205
Author(s):  
Seiei Torazawa ◽  
Hideaki Ono ◽  
Tomohiro Inoue ◽  
Takeo Tanishima ◽  
Akira Tamura ◽  
...  

Background: Very large and giant aneurysms (≥20 mm) of the internal carotid artery (ICA) bifurcation (ICAbif) are definitely rare, and optimal treatment is not established. Endovascular treatments are reported as suboptimal due to difficulties of complete occlusion and tendencies to recanalization. Therefore, direct surgery remains an effective strategy if the clipping can be performed safely and reliably, although very difficult. Case Description: Two cases of ICAbif aneurysms (>20 mm) were treated. Prior assistant superficial temporal artery (STA)-middle cerebral artery (MCA) bypass was performed to avoid ischemic complications during prolonged temporary occlusion of the arteries in both cases. In Case 1 (22-mm aneurysm), the dome was inadvertently torn in applying the clip because trapping had resulted in insufficient decompression. Therefore, in Case 2 (28-mm aneurysm), almost complete trapping of the aneurysm and subsequent dome puncture was performed, and the aneurysm was totally deflated by suction from the incision. This complete aneurysm decompression allowed safe dissection and successful clipping. Conclusion: Trapping, deliberate aneurysm dome puncture, and suction decompression from the incision in conjunction with assistant STA-MCA bypass can achieve complete aneurysm deflation, and these techniques enable safe dissection of the aneurysm and direct clipping of the aneurysm neck. Direct clipping with this technique for very large and giant ICAbif aneurysms may be the optimal treatment choice with the acceptable outcome if endovascular treatment remains suboptimal.


2018 ◽  
Vol 10 (12) ◽  
pp. 1174-1178 ◽  
Author(s):  
Yannick de La Torre ◽  
Stéphane Velasco ◽  
Jean-Pierre Tasu ◽  
Cassandre Wanpouille ◽  
Paul Chan ◽  
...  

Background and purposeIntracranial aneurysm recanalization after endovascular treatment (EVT) remains a major problem. The goal of this study was to find new predictive factors of recanalization after EVT of middle cerebral artery (MCA) bifurcation aneurysms.Methods96 MCA bifurcationaneurysms, ruptured or unruptured, treated by EVT between Septembre 2009 and December 2014, were retrospectively included. Clinical parameters and aneurysm characteristics were recorded. From the initial three-dimensional DSA, spatial coordinates found on parent and daughter arteries of MCA bifurcations gave four different flow angle values; inflow, outflows 1 and 2, and the global outflow angle (the sum of the two outflow angles). Inter- and intra-observer reproducibilities of three-dimensional angle value measurements were performed.ResultsRecanalization occurred in 25 cases (26%) and retreatment was performed in 11 cases (11%). Only 1 patient (1%) had rebleeding. Univariate analysis established the following as predictive factors of recanalization: high blood pressure (P=0.014), aneurysm height (P<0.001), aneurysm width (P<0.001), neck size (P<0.001), postoperative occlusion class (P=0.040), percentage of packing volume (P<0.001), as well as the two outflow angles (P=0.006 and 0.045), and the global outflow angle (P<0.001). Multivariate analysis revealed two independent risk factors for recanalization: the global outflow angle (OR=1.05; 95% CI 1.02 to 1.08; P<0.002) and aneurysm width (OR=0.67; 95% CI 0.46 to 0.96; P=0.031). A global outflow angle threshold <192° was found to be a risk factor for recanalization (OR=13.75; 95% CI 4.46 to 42.44), with a sensitivity of 80% and specificity of 77%.ConclusionsThis study emphasizes that a new parameter, the global outflow angle, can be predictive of recanalization for MCA bifurcation aneurysms treated by EVT.


1993 ◽  
Vol 75 (6) ◽  
pp. 2805-2810 ◽  
Author(s):  
L. L. Thomsen ◽  
H. K. Iversen

A new transcranial Doppler system (3-D Transscan, Eden Medizinische Elektronik) was evaluated in relation to sex, age, intersubject, interobserver, side-to-side, and day-to-day variation. Fifty-eight healthy volunteers participated (aged 18–80 yr). Mean velocity was higher in females than in males and decreased with age. The coefficient of variation in the middle cerebral artery was 26% between subjects, 20% between sides, 16% between days, 13% between observers, and 7% during 5 min. The coefficient of variation was higher in the anterior and posterior cerebral arteries. Bruits were heard in 35 subjects, 24 females and 11 males (P = 0.002). When middle cerebral artery velocity was monitored, high- and low-frequency oscillations were found, with a mean frequency of 5 and 1.6/min, respectively. These variations underline the necessity of standardized conditions and very carefully matched control groups in studies using transcranial Doppler. This is especially important when expected changes are small and easy to overlook, as in studies of normal physiological responses and migraine.


2008 ◽  
Vol 62 (suppl_5) ◽  
pp. ONS344-ONS353 ◽  
Author(s):  
Arthur J. Ulm ◽  
Gregory L. Fautheree ◽  
Necmettin Tanriover ◽  
Antonino Russo ◽  
Erminia Albanese ◽  
...  

Abstract Objective: To determine the prevalence of early branch aneurysms, characterize these lesions angiographically and anatomically, and determine their clinical significance. Methods: The authors conducted a retrospective review of 125 consecutive patients with a diagnosis of middle cerebral artery (MCA) aneurysm. Eighty-four patients harboring 100 MCA aneurysms were studied; 41 patients were excluded for lack of adequate imaging or for fusiform morphology of the aneurysm. Demographic characteristics including age, side, sex, subarachnoid hemorrhage, intracerebral hematoma, multiple aneurysms, and type of treatment were obtained. Results: The average patient age was 57.3 years (range, 29–79 yr); 69 were women and 15 were men. Fifty-eight were right MCA aneurysms and 42 were left aneurysms. Fourteen patients had multiple MCA aneurysms. Thirty-nine of 100 aneurysms were associated with subarachnoid hemorrhage. Twelve of 100 aneurysms were associated with an intracerebral hematoma. The average aneurysm sizes were 9.1 mm overall (range, 2.0–27.0 mm), 12.3 mm for ruptured aneurysms, and 7.5 mm for unruptured. There were 36 M1 bifurcation aneurysms, 39 early frontal branch aneurysms, 18 early temporal branch aneurysms, four lenticulostriate artery aneurysms, and three trifurcation aneurysms. Conclusion: In our retrospective review, the majority of MCA aneurysms arose along the M1 segment proximal to the M1 bifurcation. Early frontal branch aneurysms were more common than typical M1 segment bifurcation aneurysms. M1 segment aneurysms arising from early frontal and early temporal branches have distinct anatomic features that impact surgical management and outcome. Understanding the relationship between the recurrent lenticulostriate arteries arising from the proximal segments of these early branches and the aneurysm neck should allow surgeons to avoid many postoperative ischemic complications when dealing with these challenging lesions.


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