Vertebrobasilar Junction Research Articles

Endovascular Management of Basilar Artery Aneurysms: A Consecutive Series of 124 Patients

There is currently no established criterion for determining when interventional treatment is necessary and what strategy is appropriate for basilar artery (BA) aneurysms. Through this study, we aimed to propose an algorithm that can effectively determine the optimal endovascular treatment (EVT) option for BA aneurysms. We enrolled patients with BA aneurysms from June 2016 to December 2022 and performed procedures based on the algorithm. The analysis included demographic, clinical, and aneurysmal characteristics, procedural details, complications, angiographic outcomes, and clinical outcomes. This study included 124 patients (mean age 55.0 years) with a BA aneurysm who underwent EVT. Of these, 21 aneurysms were treated in the setting of subarachnoid hemorrhage (SAH). The majority of aneurysms were located at the basilar apex (74), followed by the basilar trunk (30) and vertebrobasilar junction (20). Coiling was used in 18.5% of cases, while stent-assisted coiling embolization was chosen for 58.9%. Overlapping stents were used in 12.9%, flow diverter (FD) implantation in 3.2%, Y/T stent techniques in 4.8%, and stent adjunctive coiling with unilateral vertebral artery (VA) occlusion in only 1.6%. Procedure-related complications occurred in 15 patients (12.1%). Patients had a modified Rankin Scale(mRS) score of 0.74±1.62; 98 (86.7%) had good prognosis with mRS scores ranging from 0 to 2 at the last follow-up. DSA was performed on 105 (84.7%) patients revealing that 101 (81.5%) achieved complete or near-complete occlusion. The endovascular treatment criteria for BA aneurysms depended on the multi-characteristics was safe and effective. However, further evidence is needed from large cohort studies.

Anatomical Variations to the Vertebral Artery and Posterior Inferior Cerebellar Artery are Associated with the Partial Persistence of Primitive Lateral Basirovertebral Anastomosis

The angioarchitecture of the hindbrain is homologous to that of the spinal cord, and its vascular system can be analyzed at the longitudinal and axial structures. During embryonic development, there are two main longitudinal arteries: the longitudinal neural artery and the primitive lateral basilovertebral anastomosis. Commonly observed variations are formed by the fenestration and duplication of either the vertebrobasilar artery, or cerebellar artery, which can be observed when the primitive lateral basilovertebral anastomosis partially persists. Understanding the pattern and development of blood supply to the hindbrain provides useful information of various anomalies in the vertebrobasilar junction and cerebellar arteries.

A Systematic Review and Case Illustrations of Misdiagnosing Intracranial Aneurysms.

Modern neuroimaging methods do not completely rule out false diagnoses of intracranial aneurysms which can lead to an unwarranted operation associated with risks of complications.However,surgical interventions for falsely diagnosed aneurysms are quite rare. The purpose of this study is to demonstrate two clinical cases of false-positive aneurysms and a systematic review of the literature dedicated to the incidence and etiology of false-positive aneurysms, identifying risk factors associated with false-positive aneurysms. A literature search in two databases (PubMed and Web of Science) using keywords "mimicking an intracranial aneurysm", "presenting as an intracranial aneurysm", "false positive intracranial aneurysms", and "neurosurgery" was conducted. A total of 243 papers were found in the initial search in two databases. Sixteen papers (including 20 patients) were included in the final analysis. There were 10 women and 10 men. The most common location of false-positive aneurysms was the bifurcation of the middle cerebral artery (MCA). In the posterior circulation, false-positive aneurysms were identified either on the basilar artery, or at the vertebro-basilar junction. The main causes of false intracranial aneurysm diagnosis included artery occlusion with vascular stump formation, infundibular widening, fenestration, arterial dissection, contrast extravasation, and venous varix.In conclusion, summarizing the results of our analysis, we can say that surgical interventions for false-positive aneurysms are an underestimated problem in vascular neurosurgery. Despite extremely rare published clinical observations, the actual frequency of erroneous surgical interventions for false-positive aneurysms is unknown.

A vertebrobasilar junction aneurysm successfully treated with a combination of surgical clipping and flow diverter placement based on the results of computational fluid dynamics analysis: illustrative case.

The treatment of vertebrobasilar junction (VBJ) aneurysms is challenging. Although flow diverters (FDs) are a possible treatment option, geometrical conditions hinder intervention. VBJ aneurysms possess dual inflow vessels from the bilateral vertebral arteries (VAs), one of which is ideally occluded prior to FD treatment. However, it remains unclear which VA should be occluded. A 75-year-old male with a growing VBJ complex aneurysm exhibiting invagination toward the brainstem and causing perifocal edema required intervention. Preoperative computational fluid dynamics (CFD) analysis demonstrated that left VA occlusion would result in more stagnant flow and less impingement of flow than right VA occlusion. According to the simulated strategy, surgical clipping of the left VA just proximal to the aneurysm was performed, followed by FD placement from the basilar artery trunk to the right VA. The patient demonstrated tolerance of the VA occlusion, and follow-up computed tomography angiography at 18 months after FD treatment confirmed the disappearance of the aneurysm. Preoperative flow dynamics simulations using CFD analysis can reveal an optimal treatment strategy involving a hybrid surgery that combines FD placement and direct surgical occlusion for a VBJ complex aneurysm.

Endovascular treatment of symptomatic severe intracranial atherosclerotic stenosis with a novel intracranial dedicated drug-eluting stent: a more effective treatment approach.

Endovascular treatment of severe intracranial atherosclerotic stenosis (ICAS) using coronary drug-eluting stents (DESs) significantly reduces the risk of in-stent restenosis (ISR) and stroke recurrence. However, there are few reports regarding the treatment of ICAS with intracranial dedicated DES. Herein, we present our experience with the feasibility, safety, and medium-term follow-up outcomes of a novel intracranial DES, named NOVA stent, in patients with symptomatic severe ICAS (≥70%). From December 2021 to May 2022, patients with symptomatic severe ICAS who underwent implantation of the NOVA stent in our institution were retrospectively analyzed for procedural results, perioperative complications, imaging and clinical follow-up outcomes. Twenty-four patients, 16 (66.7%) with anterior circulation lesions and 8 (33.3%) with posterior circulation lesions, were enrolled. All patients with intracranial ICA (n = 6), middle cerebral artery (n = 10), basilar artery (n = 3), intracranial vertebral artery (n = 3), and the vertebrobasilar junction (n = 2) stenosis were treated successfully using NOVA stents. The severity of stenosis ranged from 75 to 96% (mean 85.9%) before treatment and this was reduced to 0 to 20% (mean 8.6%) immediately after stent placement. Symptomatic distal embolism occurred in one case; however, there were no other perioperative complications. The mean follow-up duration was 12.2 ± 1.06 months. No symptomatic ischemic events occurred during follow-up. Follow-up cerebral angiography was performed in 22 of 24 patients (91.7%), and significant ISR occurred in one patient (4.2%). Our results demonstrate that implantation of the novel intracranial DES NOVA in severe ICAS is feasible, safe, and effective in selected cases, reducing the incidence of ISR, and showing excellent midterm clinical outcomes, providing a promising option for ICAS treatment.

The complete anterior petrosectomy: an expanded extended-middle fossa approach with removal of the infratrigeminal petrous apex and drilling of the lateral clivus.

Intradural exposure in the extended middle fossa anterior transpetrosal approach is traditionally limited to the inferior petrosal sinus inferomedially. Expanding bone removal of the petrous apex around the petrous internal carotid artery (ICA), underneath the trigeminal ganglion/mandibular nerve, and into the lateral component of the clivus can significantly expand the limits of this approach beyond the inferior petrosal sinus and allows for exposure of the midline structures, aspects of the contralateral inferior clival region, and, when high riding, the vertebrobasilar junction. To date, no descriptive techniques for drilling into the lateral clivus in this approach have been published. The authors provide a detailed stepwise description of their complete anterior petrosectomy, in use at their institution, that involves skeletonization of the posteromedial petrous ICA, gentle elevation of the trigeminal ganglion/mandibular nerve, removal of the infratrigeminal petrous apex, and two techniques for drilling into the lateral clivus along the petroclival fissure. These techniques provide a direct and unobstructed corridor to the midpetroclival region and ventral brainstem with greater maneuverability and enhanced control of the midline structures, which is especially useful for resection of petroclival meningiomas, chondrosarcomas, and giant vascular lesions of the mid- and upper basilar artery and its proximal branches.

Diagnostic cerebral angiogram injecting from bilateral vertebral arteries at the same time confirmed the giant aneurysm arising immediately distal to the vertebrobasilar junction. There were no intraluminal thrombus or intramural hematoma.

Diagnostic cerebral angiogram injecting from bilateral vertebral arteries at the same time confirmed the giant aneurysm arising immediately distal to the vertebrobasilar junction. There were no intraluminal thrombus or intramural hematoma.

High-Resolution Magnetic Resonance Imaging in Endovascular Treatment of Vertebrobasilar Junction Stenosis.

Vertebrobasilar junction (VBJ) stenosis is a challenge in endovascular treatment due to structural variants and complexities. The role of high-resolution magnetic resonance imaging (HRMRI) in endovascular treatment for patients with severe VBJ stenosis is uncertain. Four patients with symptomatic VBJ stenosis underwent HRMRI of the vessel wall before endovascular treatment. In 3 patients, the VBJ could not be visualized on luminal imaging. One of them had a hypoplastic artery and 2 of them had severe stenotic arteries on HRMRI. HRMRI showed an artery with a negative remodeling in a patient with a hypoplastic vertebral artery. One patient had intraplaque hemorrhage and calcification, and 2 patients had calcification in VBJ lesions. Endovascular treatment was performed utilizing HRMRI findings to guide the decision-making process. HRMRI provides additional information about the structure and angle of the VBJ, the characteristics and vulnerability of the plaques, and the lesion size, thus helping to improve the operation process and reduce the risk of complications.

Abstract 197: Mechanical Thrombectomy Of Basilar Artery Occlusion On A Hypoplastic Vertebrobasilar Circulation

Introduction Basilar artery occlusion (BAO) is one of the most severe acute ischemic strokes which carries high mortality and morbidity risk. Mechanical thrombectomy (MT) has been used as a promising treatment for BAO. However, the vertebral‐basilar anatomy is more challenging for MT compared to the anterior circulation due to several congenital variants such as hypoplastic vertebral artery, fenestration on the vertebrobasilar junction, or chronic asymptomatic occlusions of vertebral arteries, and tortuous subclavian arteries and vertebral arteries (VAs). Here, we described a BAO case with hypoplastic vertebrobasilar arteries, which was successfully treated with thrombectomy using the direct aspiration technique. Methods Electronic Medical Records review of a patient with acute basilar artery occlusion stroke. Results 55‐year‐old healthy gentleman presented to ER with acute onset with confusion, dysarthria, left‐sided weakness, and right facial droop. Initial NIHSS was 12. CT angiography (CTA) head and neck showed basilar artery was occluded in the distal one third segment. Because of the right fetal posterior cerebral artery and prominent left posterior communicating artery, his bilateral VAs and basilar artery were underdeveloped. The left VA appeared to be slightly bigger than the right one. After the patient received IV tPA, he was taken for mechanical thrombectomy. A Ballast catheter was placed in the left subclavian artery near the left VA origin. The conventional angiography showed the left VA was 2.8 mm and proximal basilar was about 2.1 mm. The Zoom 35 aspiration catheter was then used for mechanical thrombectomy. A complete basilar recanalization was achieved on the first pass. The patient improved after the MT. His NIHSS on discharge was 0. Conclusion The benefits of MT on BAO remain unknown despite several clinical trials. One of the reasons is due to more challenged vascular anatomy compared to anterior circulation. Underdevelopment of unilateral VA was commonly seen in posterior circulation ischemic strokes. But the underdevelopment of bilateral VAs with basilar arteries in BAO cases was rare and more difficult to treat. The Zoom 35 aspiration catheter provided a great advantage for this case with its smaller outer diameter, good navigation ability, and great aspiration efficacy. Our experience suggested a direct aspiration first pass technique (ADAPT) has an advantage on BAO, especially in the congenitally underdeveloped vertebrobasilar arteries.

Reverse Y stenting in the management of vertebrobasilar junction fenestrated aneurysm: A novel technique.

Fenestrated aneurysm at vertebrobasilar junction (VBJ) is very rare and can occur due to non-fusion of longitudinal neural axis forming basilar artery in the early stage of embryonic life. Due to defects in tunica media and weakness in its wall, these fenestrations are more likely to develop an aneurysm. Various treatment strategies are required for the management of these types of aneurysms including simple coiling, stent-assisted coiling, balloon remodeling technique, and more recently kissing flow diverters. Herein, we report the case of ruptured fenestrated VBJ aneurysm which was managed successfully with novel reverse Y stenting with coiling.

The cerebellopontine angle cistern volumetric differences in trigeminal neuralgia patients with and without vertebrobasilar compression: a case-matched study.

Previous studies have indicated that the small cerebellopontine angle (CPA) cistern plays a role in the pathogenesis of trigeminal neuralgia (TN), but they are likely not involved in TN associated with vertebrobasilar artery (VBA) compression because of its rarity. Forty-four patients with VBA-associated TN and 44 age-, sex-, and hypertension-matched TN patients without VBA compression (non-VBA-associated) were included. All patients underwent high-resolution MRI. The CPA cistern volumes were measured bilaterally. The presence of vertebrobasilar dolichoectasia (VBD) and laterality of the vertebrobasilar junction (VBJ) were observed. The CPA cistern volume on the affected side was smaller than the unaffected side (714.4 ± 372.8 vs 890.2 ± 462.2 mm3, p < 0.001) in non-VBA-associated TN patients, while VBA-associated TN patients show a larger CPA cistern on the affected side than the unffected side (1107.0 ± 500.5 vs 845.3 ± 314.8 mm3, p < 0.001). The prevalence of VBD was higher in patients with VBA-associated TN than in matched non-VBA-associated TN patients (90.9% vs 4.5%, p < 0.001). A positive correlation between the laterality of VBJ and the affected side was found in the VBA-associated TN group (p < 0.0001). Large CPA cistern may be a neuroradiological feature of VBA-associated TN, and most of the VBA-associated TN is accompanied by VBD. The presence of VBD and the lateral shift of VBJ may expand the CPA cistern by squeezing the surrounding tissue on the affected side and also increase the chance of VBA compression on the trigeminal nerve, resulting in the genesis of VBA-associated TN.

Ruptured vertebrobasilar junction aneurysm supplied by reversed flow from the anterior spinal artery: Illustrative case report.

In patients with vertebral artery (VA) occlusion, spontaneous flow reversal may occur in the anterior spinal artery (ASA) as a source of compensatory supply to the posterior circulation. Turbulent flow and increased flux through these small arteries may predispose to luminal damage and intracranial aneurysm formation. We report a novel case of a ruptured ASA-VA junction aneurysm in a patient with chronic bilateral VA occlusion, successfully treated with endovascular embolization. A 62-year-old female with uncontrolled hypertension presented with acute-onset headache, emesis, neck stiffness, and decreased level of consciousness. Head computed tomography demonstrated diffuse cisternal subarachnoid hemorrhage with intraventricular extension and ventriculomegaly. Computed tomography angiography showed left VA atresia and chronic right VA occlusion just distal to the posterior inferior cerebellar artery origin, as well as a complex, bilobed aneurysm at the ASA-VA junction. Angiography demonstrated flow reversal from the ASA into the distal stump of the occluded right VA, which in turn filled the aneurysm. Of note, the patient's posterior circulation was predominantly supplied by the dilated ASA, and associated collaterals from ASA and right VA stump. The aneurysm was accessed and embolized using superselective microcatheterization over a soft microguidewire through the right cervical VA perforators supplying retrograde flow into and through the ASA. ASA-VA aneurysms are exceedingly rare, and generally associated with atypical flow dynamics. Dynamic treatment strategies may be needed, especially in the setting of subarachnoid hemorrhage.

Endovascular treatment outcomes of vertebrobasilar junction aneurysms: Systematic review and meta-analysis.

Vertebrobasilar junction (VBJ) aneurysms represent a relatively rare and often anatomically complex subgroup of saccular aneurysms. This systematic review and meta-analysis aimed to assess the safety and efficacy of endovascular treatment (EVT) of VBJ aneurysms. PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched from inception to 20 December 2022. We included primary studies assessing the long-term clinical and angiographic outcomes for VBJ aneurysms treated with endovascular techniques. We excluded surgically managed studies. All data were analyzed using R software version 4.2.1. We calculated pooled prevalence rates and their corresponding 95% confidence intervals (CI). In this meta-analysis, a total of 76 VBJ aneurysms from seven studies were included for quantitative analysis. The results showed that the rate of adequate occlusion (complete + near complete occlusion) was 94.1% (95% CI = 76.71-98.71), and the rate of complete occlusion was 77.7% (95% CI = 63.07-87.65). A modified Rankin Scale (mRS) score of 0-2 was achieved in 93.9% of patients (95% CI = 67.65-99.14). The mortality rate was found to be 5.9% (95% CI = 0.97-28.55), and the retreatment rate was 4.6% (95% CI = 1.50-13.36). The overall ischemic complication rate was 4.7% (95% CI = 0.73-25.4), while the overall hemorrhagic complication rate was 4.6% (95% CI = 1.5-13.36). The treatment of VBJ aneurysms with EVT is effective in achieving curative treatment and is associated with good clinical outcomes and low mortality rates. These findings provide important insights into the clinical and angiographic outcomes and the complication rates of EVT for VBJ aneurysms.

P.129 Endovascular coiling of ruptured basilar fenestration aneurysm: case report and review of literature

Background: Basilar fenestration is a rare congenital anomaly. When present, it is commonly found at the proximal portion of the artery near the vertebrobasilar junction. Methods: This is a case report of a ruptured basilar fenestration aneurysm in a 47-year-male successfully treated with endovascular coiling. Results: A 47-year-old male presented with sudden onset headache, neck pain, blurry vision, nausea, vomiting, and diaphoresis. Cerebral angiogram revealed a saccular basilar fenestration aneurysm located at the vertebrobasilar junction measuring 3.1 x 2.6 x 3.4 mm with a 2.3 mm neck. Multiple coils were placed including Target 360 Nano 2mm x 4 cm (Stryker, Kalamazoo, MI, US), Target 360 Nano 1.5 mm x 2 cm (Stryker, Kalamazoo, MI, US), and Target Helical Nano 1.5 mm x 1 cm (Stryker, Kalamazoo, MI, US). A repeat angiogram revealed complete exclusion of the aneurysm with preservation of both vertebral arteries. Conclusions: A literature review was conducted on basilar fenestration aneurysms which included 158 patients from 39 studies. Overall, complete exclusion of the aneurysm was achieved in 75.8% of cases, with 22.4% of cases having residual flow and 1.8% of cases with unreported exclusion status.

Association between basilar artery stenosis features, vertebral artery stenosis and perforator stroke after stenting.

We investigated the relationship between basilar artery (BA) atherosclerotic stenosis features and vertebral artery (VA) stenosis and explored whether BA stenosis features are associated with perforator stroke after stenting. Patients with BA stenosis who underwent HRMRI and DSA were recruited. Patients were divided into proximal BA stenosis and middle-or-distal BA stenosis groups, and then subgroup analyses were performed based on whether they had VA stenosis. BA plaque features were evaluated by HRMRI. Artery stenosis was measured by DSA. The incidence of perforator stroke after BA stenting was recorded, and the potential association between BA stenosis features and perforator stroke was analyzed. One hundred and seventy-four patients were consecutively enrolled. Patients with proximal BA stenosis had a higher proportion of severe stenosis than those with middle-or-distal BA stenosis (P = 0.027). In the subgroup analysis, this difference mainly existed in patients complicated with VA stenosis (P = 0.023). Patients with proximal BA stenosis had a higher proportion of strong plaque enhancement than those with middle-or-distal BA stenosis (P < 0.001), especially in those with vertebrobasilar junction (VBJ) stenosis (P < 0.001). Perforator stroke after BA stenting occurred in five patients, of whom four had lateral wall BA plaques, four had plaque enhancement and four had proximal BA stenosis. Patients with proximal BA stenosis had a higher proportion of severe stenosis and strong plaque enhancement, particularly in patients complicated with VA stenosis and VBJ stenosis. Perforator stroke after BA stenting may be related to distribution, burden and characteristics of BA lesions.

Mandibular Fossa Approach to Petroclival and Anterior Pontine Lesions.

Objective To describe the anatomy related to a novel approach to the petroclival region through the mandibular fossa for the treatment of petroclival and anterior pontine lesions. Design Five dry skulls were examined for surgical approach. Three adult cadaveric heads underwent bilateral dissection. One cadaveric head was evaluated with computed tomography after dissection. Setting This study was performed in an academic medical center. Participants Neurosurgical anatomy researchers performed this study using dry skulls and cadaveric heads. Main Outcome Measurements This was a proof-of-concept anatomical study. Results The mandibular fossa approach uses a vertical preauricular incision above the facial nerve branches. Removal of the temporomandibular joint exposes the mandibular fossa. The anterior boundary is the mandibular nerve at the foramen ovale, and the posterior boundary is the jugular foramen. The chorda tympani, eustachian tube, and tensor tympani muscle are sectioned. The carotid artery is transposed out of the petrous canal, and a petrosectomy is performed from Meckel's cave to the foramen magnum and anterior occipital condyle. Dural opening exposes the anterior pons, vertebrobasilar junction, bilateral vertebral arteries, and the ipsilateral anterior and posterior inferior cerebellar arteries. At completion, the temporomandibular joint is reconstructed with a prosthetic joint utilizing a second incision along the mandible. Conclusions The mandibular fossa approach is a new trajectory to the petroclival region and the anterior pons. It combines the more anterior angle of endoscopic approaches along with the enhanced control of open approaches. Further study is necessary before this approach is used clinically.

New frontiers in intracranial imaging with HF-OCT: Ex vivo human cerebrovasculature evaluation and in vivo intracranial arteries dynamic visualization

Optical coherence tomography (OCT) technology is a well-established diagnostic tool in multiple fields of medicine. Intravascular OCT has been used for more than a decade for the clinical imaging of coronary arteries, however, its use for the imaging of the human cerebrovasculature has been delayed by the challenges posed by the elevated vascular tortuosity. A novel high-frequency OCT (HF-OCT) probe designed for neurovascular use was evaluated in tortuous, ex vivo, human intracranial anatomy and, using an in vivo canine model, for the dynamic imaging of intracranial arteries and the subarachnoid trabecula (SAT). Using four cadavers, we investigated HF-OCT probe navigation and imaging performances in human anterior arterial circulation (from the M4 segment to internal carotid artery), in the posterior arterial circulation (from the P4 segment to vertebrobasilar junction) and in a broad range of venous sinuses. HF-OCT was able to gain distal access through elevated tortuosity and generate high-quality imaging data depicting vessel morphology, the vessel wall pathology (e.g., atherosclerotic disease and dissecting lesions), and the subarachnoid trabecula (SAT). Using an in vivo canine model, the HF-OCT probe was used to record stationary dynamic data in multiple intracranial vascular locations. Data showed the motion of the arteries and the SAT, including collisions between vessels, membranes, and the interaction between the SAT and the blood vessels. HF-OCT data allowed for the quantification of the dynamics of the vessels and the SAT, including vessel lateral motion with respect to the parenchyma, and collisions between large and small arteries. Results showed that the HF-OCT probe can overcome delivery obstacles in tortuous cerebrovascular anatomy and provide high-quality and high-resolution imaging at multiple distal locations, including M4 and P4 segments of the anterior and posterior circulations. HF-OCT has the potential to facilitate a better understanding of fine anatomical details of the cerebrovascular and perivascular environment, neurovascular disease, and collect real time information about the dynamics of the subarachnoid space and arteries and become a valuable diagnostic tool.

Use of flow diverter device in basilar artery for aneurysm treatment: Case series and literature review.

BackgroundFlow diverters (FDs) for the treatment of basilar artery (BA) aneurysms remain controversial. In this study, we report our initial experience of flow diversion for treatment of this pathology.MethodsConsecutive patients with an aneurysm of the BA that was treated by implantation of the FD were included in our retrospective study. Procedural complications, aneurysm occlusion, and a functional outcome were evaluated. FD placement in BA for aneurysm treatment reported in the literature was also reviewed and summarized.ResultsSixteen patients with 16 BA aneurysms were treated by FD implantation with (n = 8) or without (n = 8) adjunctive coiling. The Tubridge was used in 13 (81.3%) and Pipeline in 3 (18.8%) procedures. Average aneurysm size was 15.7 mm. Four aneurysms were located at the basilar apex, six at the basilar trunk, and six at the vertebrobasilar junction. Three patients experienced procedural complications (18.8%), including two ischemic strokes and one hydrocephalus, with resultant mortality in one case (6.3%). Median follow-up was 7.7 months and available for 15 aneurysms. Complete/near-complete occlusion was seen in 13 (86.7%) aneurysms.ConclusionIn our initial experience, flow diversion is feasible and safe in the treatment of BA aneurysms with promising occlusion rates at mid-term follow-up. Larger cohort studies are required to validate these results.

Vertebrobasilar dissecting aneurysms: microsurgical management in 42 patients.

Vertebrobasilar dissecting (VBD) aneurysms are rare, and patients with these aneurysms often present with thromboembolic infarcts or subarachnoid hemorrhage (SAH). The morphological nature of VBD aneurysms often precludes conventional clip reconstruction or coil placement and encourages parent artery exclusion or endovascular stenting. Treatment considerations include aneurysm location along the vertebral artery (VA), the involvement of the posterior inferior cerebellar artery (PICA), and collateral blood flow. Outcomes after endovascular treatment have been well described in the neurosurgical literature, but microsurgical outcomes have not been detailed. Patient outcomes from a large, single-surgeon, consecutive series of microsurgically managed VBD aneurysms are presented, and 3 illustrative case examples are provided. The medical records of patients with dissecting aneurysms affecting the intracranial VA (V4), basilar artery, and PICA that were treated microsurgically over a 19-year period were reviewed. Patient demographics, aneurysm characteristics, surgical procedures, and clinical outcomes (according to modified Rankin Scale [mRS] scores at last follow-up) were analyzed. Forty-two patients with 42 VBD aneurysms were identified. Twenty-six aneurysms (62%) involved the PICA, 14 (33%) were distinct from the PICA origin on the V4 segment of the VA, and 2 (5%) were located at the vertebrobasilar junction. Thirty-four patients (81%) presented with SAH with a mean Hunt and Hess grade of 3.2 at presentation. Six (14%) of the 42 patients had been previously treated using endovascular techniques. Nineteen aneurysms (45%) underwent clip wrapping, 17 (40%) were treated with bypass trapping, and 6 (14%) underwent parent artery sacrifice. The complete aneurysm obliteration rate was 95% (n = 40), and the surgical complication rate was 7% (n = 3). The 8 patients with unruptured VBD aneurysms were significantly more likely to be discharged home (n = 6, 75%) compared with 34 patients with ruptured aneurysms (n = 9, 27%; p = 0.01). Good outcomes (mRS score ≤ 2) were observed in 20 patients (48%). Eight patients (19%) died. These data demonstrate that patients with VBD aneurysms often present after a rupture in poor neurological condition, but favorable results can be achieved with open microsurgical repair in almost half of such cases. Microsurgery remains a viable treatment option, with the choice between bypass trapping and clip wrapping largely dictated by the specific location of the aneurysm and its relationship to the PICA.

Microsurgical Perspective for Uncommon Variations Associated with the Vertebrobasilar Junction: An Anatomical and Radiologic Investigation

Microsurgical Perspective for Uncommon Variations Associated with the Vertebrobasilar Junction: An Anatomical and Radiologic Investigation