Tag: Basilar artery

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Microvascular decompression for trigeminal neuralgia attributable to the vertebrobasilar artery

Acta Neurochirurgica (2021) 163:1037–1043

Separation of the vertebrobasilar artery (VBA) from the trigeminal nerve root in microvascular decompression (MVD) is technically challenging. This study aimed to review the clinical features of VBA involvement in trigeminal neuralgia and evaluate surgical decompression techniques in the long term.

Methods We retrospectively reviewed the surgical outcomes of 26 patients (4.4%) with VBA involvement in 585 consecutive MVDs for TGN using a Teflon roll for repositioning the VBA. The final operative status of the nerve decompression was categorized into two groups: the separation group and the contact group. Separation of the VBA from the nerve root was completed in 13 patients in the separation group, and slight vascular contact remained in the remaining 13 patients of the contact group. The clinical features of VBA-related TGN were investigated and the operative results were analyzed.

Results Multiple arteries are involved in neurovascular compression (NVC) in most cases. The anterior inferior cerebellar artery was the most common concomitant artery (69%). The site of the NVC varies from the root entry zone to the distal portion of the root. All patients were pain-free immediately after surgery and maintained medication-free status during the follow-up period, except for one patient (3.8%) who had recurrent facial pain 8 years after surgery. Postoperative facial numbness was observed in six patients (23%). Of these, one patient showed improvement within 3 months and the other five patients had persistent facial numbness (19.2%). Other neurological deficits include one dry eye, one diplopia due to trochlear nerve palsy, two decreased hearing (< 50 db), two facial weaknesses, and two cerebellar ataxia. Although most of them were transient, one dry eye, two hearing impairments, and one cerebellar ataxia became persistent deficits. Statistical analyses revealed no difference in surgical efficacy or complications in the long term between the two groups.

Conclusions Slightly remaining vascular contact does not affect pain relief in the long term. Our study indicated that once the tense trigeminal nerve is loosened, further attempts to mobilize the VBA are not necessary.

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Tailoring the surgical corridor to the basilar apex in the pretemporal transcavernous approach

Acta Neurochirurgica (2020) 162:2731–2741

The pretemporal transcavernous approach (PTA) provides optimal exposure and access to the basilar artery (BA); however, the PTA can be invasive when vital neurovascular structures are mobilized. The goal of this study was to evaluate mobilization strategies to tailor approaches to the BA.

Methods After an orbitozygomatic craniotomy, 10 sides of 5 cadaveric heads were used to assess the surgical access to the BA via the opticocarotid triangle (OCT), carotid-oculomotor triangle (COT), and oculomotor-tentorial triangle (OTT). Measurements were obtained, and morphometric analyses were performed for natural neurovascular positions and after each stepwise expansion maneuver. An imaginary line connecting the midpoints of the limbus sphenoidale and dorsum sellae was used as a reference to normalize the measurements of BA exposure and to facilitate the clinical applicability of this technique.

Results In the OCT, the exposed BA segment ranged from − 1 ± 3.9 to + 6 ± 2.0 mm in length in its natural position. In the COT, the accessible BA segment ranged from − 4 ± 2.3 to − 2 ± 3.0mmin length in its natural position. Via the OTT, the accessible BA segment ranged from − 7 ± 2.6 to − 5 ± 2.8 mm in length in its natural position. In the OCT, COT, and OTT, a posterior clinoidectomy extended the exposure down to − 6 ± 2.7, − 8 ± 2.5, and − 9 ± 2.9 mm, respectively.

Conclusions This study quantitatively evaluated the need for the expansion maneuvers in the PTA to reach BA aneurysms according to the patient’s anatomical characteristics.

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Flow Diversion for the Treatment of Basilar Apex Aneurysms

Neurosurgery 83:1298–1305, 2018

Flow diversion for basilar apex aneurysms has rarely been reported.

OBJECTIVE: To assess flow diversion for basilar apex aneurysms in a multicenter cohort.

METHODS: Retrospective review of prospectively maintained databases at 8 academic institutions was performed from 2009 to 2016 to identify patients with basilar apex aneurysms treated with flow diversion. Clinical and radiographic data were analyzed.

RESULTS: Sixteen consecutive patients (median age 54.5 yr) underwent 18 procedures to treat 16 basilar apex aneurysms with either the Pipeline Embolization Device (Medtronic Inc, Dublin, Ireland) or Flow Redirection Endoluminal Device (Microvention, Tustin, California). Five aneurysms (31.3%) were treated in the setting of subarachnoid hemorrhage. Seven aneurysms (43.8%) were treated with flow diversion alone, while 9 (56.2%) underwent flowdiversion and adjunctive coiling. At a median follow-up of 6 mo, complete (100%) and near-complete (90%-99%) occlusion was noted in 11 (68.8%) aneurysms. Incomplete occlusion occurred more commonly in patients treated with flow diversion alone compared to those with adjunctive coiling. Patients with partial occlusion were significantly younger. Retreatment with an additional flow diverter and adjunctive coiling occurred in 2 aneurysms with wide necks. There was 1 mortality in a patient (6.3%) who experienced posterior cerebral artery and cerebellar strokes as well as subarachnoid hemorrhage after the placement of a flow diverter. Minor complications occurred in 2 patients (12.5%).

CONCLUSION: Flow diversion for the treatment of basilar apex aneurysms results in acceptable occlusion rates in highly selected cases. Both primary flowdiversion and rescue after failed clipping or coiling resulted in a modified Rankin Scale score that was either equal or better than at presentation and the technology represents a viable alternative or adjunctive option.

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The Superior Cerebellar Artery Aneurysm: A Posterior Circulation Aneurysm with Favorable Microsurgical Outcomes

Neurosurgery 80:908–916, 2017

Superior cerebellar artery (SCA) aneurysms are usually grouped with aneurysms that arise from the upper basilar artery or more broadly, the posterior circulation. However, the SCA aneurysm has distinctive anatomy that facilitates safe surgical management, notably few associated perforating arteries, and excellent exposure in the carotid-oculomotor triangle.

OBJECTIVE: To demonstrate the outcomes of patients treated with microsurgery in a continuous surgical series.

METHODS: Sixty-two patients harboring 63 SCA aneurysmswere retrospectively reviewed from a prospectively maintained database, focusing on clinical characteristics, surgical techniques, and clinical outcomes.

RESULTS: Of 31 patients (49%) presenting with subarachnoid hemorrhage, the SCA aneurysm was the source in 16 (25%). Thirty-three aneurysms were complex (52%) and 43 patients (59%) had multiple aneurysms. Fifty-seven SCA aneurysms (90.5%) were clipped and 5 were bypassed/trapped or wrapped. Complete angiographic occlusion was achieved in 91.7%. Permanent neurological morbidity occurred in 3 patients and 3 patients that presented in coma after subarachnoid hemorrhage died. All patients with “simple” aneurysms and without subarachnoid hemorrhage had improved or unchangedmodified Rankin scale scores. Overall, outcomes were stable or improved in 82.5% of patients.

CONCLUSION: SCA aneurysms are favorable for microsurgical clipping with low rates of permanent morbidity and mortality. Microsurgery should be considered alongside endovascular techniques as a treatment option in many patients.

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Suprasellar Arachnoid Cysts: Toward a New Simple Classification Based on Prognosis and Treatment Modality

Suprasellar Arachnoid Cysts- Toward a New Simple Classification Based on Prognosis and Treatment Modality

Neurosurgery 78:370–380, 2016

Suprasellar arachnoid cysts (SAC) represent between 9% and 21% of pediatric arachnoid cysts. Recent improvements in magnetic resonance imaging, as well as increasing prenatal diagnosis, have allowed more precise knowledge and follow-up.

OBJECTIVE: To describe a novel classification of SAC.

METHODS: We present 35 cases of SAC treated between 1996 and 2014. Patient records and imaging studies were reviewed retrospectively to assess symptomatology, radiological findings, treatment, and long-term follow-up.

RESULTS: Fourteen SAC were diagnosed prenatally (39%). We observed 15 (43%) cases presenting hydrocephalus (SAC-1) removing Liliequist membrane downward. Lower forms (SAC-2) with free third ventricle were observed in 11 (31%) cases. Asymmetrical forms (SAC-3) with Sylvian or temporal extension were seen in the 9 (26%) remaining patients. Twenty-three (66%) patients were treated by ventriculocisternostomy, 3 (8.5%) by shunt surgery, and 3 (8.5%) by craniotomy. Six (17%) patients had no surgery, including 5 cases (14%) that had prenatal diagnosis. Outcomes were initially favorable in 26 cases (87%). Eight (22%) patients had endocrine abnormalities at the end of the follow-up, 3 (8.5%) had developmental delay, and 6 (17%) had minor neuropsychological disturbances.

CONCLUSION: SAC are heterogeneous entities. SAC-1 may come from an expansion of the diencephalic leaf of the Liliequist membrane. SAC-2 show a dilatation of the interpeduncular cistern and correspond to a defect of the mesencephalic leaf of the Liliequist membrane. SAC-3 correspond to the asymmetrical forms expanding to other subarachnoid spaces. Surgical treatment is not always necessary. The recognition of the different subtypes will allow choosing the best treatment option.

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Extended endoscopic endonasal transclival clipping of posterior circulation aneurysms

Extended endoscopic endonasal transclival clipping of posterior circulation aneurysms

Acta Neurochir (2015) 157:2077–2085

Transcranial clipping of most posterior circulation aneurysms is one of the most difficult procedures, with high morbidity, and endovascular coiling is an alternative with less risk, but is not devoid of complications and not suitable for all aneurysms. Here we describe four cases of posterior circulation aneurysms clipped via the extended endoscopic endonasal transclival route. To the best of our knowledge, this is the first report of basilar top and posterior cerebral artery aneurysms being clipped endonasally.

Methods and results Four patients with posterior circulation aneurysms underwent extended endoscopic endonasal transclival clipping of the aneurysm. The age range was 35– 70 years. There were two males and two females. Three of the four patients presented after the rupture of aneurysms, and the other patient presented with sudden-onset left hemiparesis probably due to thromboembolism from a large unruptured left posterior cerebral artery (PCA) aneurysm. On evaluation with four-vessel digital subtraction angiography (DSA), two patients had a basilar apex aneurysm, one had a basilar trunk aneurysm, and the other had a PCA (P1) aneurysm. Postoperatively, two patients had good recovery. One patient with a PCA aneurysm and another with a basilar apex aneurysm had fresh postoperative deficits. One patient developed postoperative CSF rhinorrhea.

Conclusion Endoscopic extended transnasal surgery is an expanding field in neurosurgery with a steep learning curve. With improvement in techniques and instrumentation the use of this approach for clipping posterior circulation aneurysms can become an effective alternative in the treatment of aneurysms.

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Effect of Vascular Anatomy on the Formation of Basilar Tip Aneurysms

Effect of Vascular Anatomy on the Formation of Basilar Tip Aneurysms

Neurosurgery 76:62–66, 2015

The pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. Hemodynamic stress plays a particular role in the formation of intracranial aneurysms, which is conditioned by the geometry and morphology of the vessel trees.

OBJECTIVE: To identify image-based morphological parameters that correlated with the formation of basilar artery tip aneurysms (BTAs) in a location-specific manner.

METHODS: Morphological parameters obtained from computed tomographic angiographies of 33 patients with BTAs and 33 patients with aneurysms at other locations were evaluated with Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vascular architecture. We examined the diameters and vessel-to-vessel angles of the main vessels at the basilar bifurcation in patients with and without BTAs. To control for genetic and other risk factors, only patients with at least 1 aneurysm were included. Univariate and multivariate analyses were performed to determine statistical significance.

RESULTS: Sixty-six patients (33 with BTAs, 33 with other aneurysms) who were evaluated from 2008 to 2013 were analyzed. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (odds ratio, 1.04; P = 1.42 · 1023) and a smaller basilar artery diameter (odds ratio, 0.23; P = .02) were most strongly associated with BTA formation after adjustment for other morphological and clinical variables.

CONCLUSION: Larger posterior cerebral artery angles and smaller basilar artery diameters are associated with the formation of basilar tip aneurysms. These parameters are easily measurable by the clinician and will aid in screening strategies in high-risk patients.

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Extended Subtemporal Transtentorial Approach to the Anterior Incisural Space and Upper Clival Region: Experience With Posterior Circulation Aneurysms

Extended Subtemporal Transtentorial Approach to the Anterior Incisural Space and Upper Clival Region- Experience With Posterior Circulation Aneurysms

Neurosurgery 10:15–24, 2014

Although most posterior circulation aneurysms are currently treated by endovascular means, some are not amenable to this treatment modality. The narrow working window afforded by the anterolateral and lateral surgical approaches often translates into suboptimal visualization and limited maneuverability.

OBJECTIVE: We present a modified technique of tentorial incision and reflection that optimizes the exposure achieved with the traditional subtemporal approach and report our clinical experience in a series of posterior circulation aneurysms.

METHODS: Retrospective review of patients operated via an extended subtemporal transtentorial approach for posterior circulation aneurysms. The modified tentorial incision implies dissection of the trochlear nerve along its dural canal up to its entrance into the cavernous sinus and incision of a tentorial flap that extends up to Meckel cave, which is then reflected far anterolaterally. Clinical and radiological data were reviewed.

RESULTS: This series comprises 18 patients (21 procedures). Ten patients presented (56%) with a subarachnoid hemorrhage. Aneurysms most frequently arose from the basilar tip (61%) and were of small size (50%) and saccular morphology (72%). Two patients underwent surgery following unsuccessful endovascular treatment. Aneurysm treatment was successful on the first attempt in 90% (19/21) and after a second attempt in 10% (2/21). Documented postoperative palsies of the oculomotor (n = 3) and trochlear (n = 1) nerves were all transient. No procedure-related mortality occurred.

CONCLUSION: This modified technique of tentorial incision and reflection optimizes visibility, anatomic orientation, and maneuverability by increasing the rostrocaudal and anterolateral exposure obtained via the extended subtemporal transtentorial route without permanent postoperative trochlear nerve deficit.

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Combined endovascular and surgical treatment of fusiform aneurysms of the basilar artery

Combined endovascular and surgical treatment of fusiform aneurysms of the basilar artery- technical note

Acta Neurochir (2014) 156:53–61

To present the combined treatment of fusiform basilar artery aneurysms consisting of a surgical posterior fossa decompressive craniectomy and ventriculoperitoneal (VP) shunt operation at the same sitting, before the endovascular procedure with telescopic stenting of the aneurysmatic vessel segment in four cases.

Methods Combined treatment involving surgical procedure consisting of ventriculoperitoneal shunt placement for hydrocephalus and an occipital bone craniectomy and C1 vertebrae posterior laminectomy to decompress the posterior fossa in the same session. After surgery, the patients were loaded with acetylsalicylic acid and clopidogrel, and then the endovascular treatment was performed.

Results All of the procedures were performed successfully without technical difficulty. The patients tolerated the procedures well and all cases showed remodelling with the overlapping stent technique. The patients were discharged home with baseline neurological situation and computed tomography (CT) angiography was performed at the 3rd month.

Conclusion This technique is a safer endovascular approach to treating symptomatic fusiform basilar artery aneurysms by protecting patients from both the haemorrhagic complications of anticoagulant therapy and thrombotic complications due to the interruption of anticoagulant therapy, while treating the hydrocephalus and compression by surgical means.

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