Successful Thrombectomy of the Posterior Cerebral Artery P2 Segment in a 61-Year-Old Man with Acute Ischaemic Stroke: A Case Report.

BACKGROUND Acute ischemic stroke in the posterior cerebral artery (PCA) territory can lead to persistent disabling deficits. The PCA is divided into 4 segments. The P2 segment begins at the posterior communicating artery and curves around the midbrain and above the tentorium cerebelli. This report is of a 61-year-old man with acute ischemic stroke involving the left hippocampus treated with direct thrombectomy of the P2 segment of the PCA. CASE REPORT A 61-year-old white man presented with transient amnesia, aphasia, right-sided hemianopia, dizziness, and persistent acute memory deficits. Magnetic resonance imaging (MRI) showed a left hippocampal acute ischemic stroke with left PCA occlusion in the P2 segment. Despite a low National Institutes of Health Stroke Scale (NIHSS) score and the already-formed lesion in the hippocampus, successful stent retriever thrombectomy was performed due to a considerable perfusion-diffusion mismatch and a persistent potentially disabling neurocognitive deficit. Due to partial thrombus dislocation, occlusion of the common origin of the right posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA) occurred and was immediately treated by thrombectomy to prevent severe cerebellar infarction. His clinical symptoms completely resolved and a neuropsychological exam showed no residual deficits. CONCLUSIONS Thrombectomy of the P2 segment of the PCA is feasible and can be considered to treat patients with acute occlusion at risk for persistent disabling deficits, based on clinical estimation of the impact of such deficits and the presence of potentially salvageable brain tissue. Potential procedural complications should be sought out and immediately treated, if technically feasible.

Aneurysms Located beyond the Origin of the Major Branches in the Posterior Circulation.

AIM: To evaluate the clinical and radiological features, treatment modalities, and outcomes of unusual aneurysms located beyond the origin of the major branches in the posterior circulation, and to introduce changes in the recent treatment trends due to rapid innovations in endovascular technology. MATERIAL AND METHODS: This was a retrospective study of patients who underwent treatment for these unusual aneurysms, including those that were identified in regular follow-up after treatment, between March 2009 and April 2023. Medical information including the radiological features of the aneurysms, incidences of rebleeding, associated vascular diseases, treatment modalities, and outcomes, was documented. RESULTS: A total of 22 cases consisting of two unruptured and 20 ruptured aneurysms were included. Their locations were the posterior cerebral artery in four cases, the superior cerebellar artery in three, the anterior inferior cerebellar artery in two, and the posterior inferior cerebellar artery in 13. Sixteen were saccular, five fusiform, and one blister-like. Eight were pseudo-aneurysms and pre- or intra-operative rebleeding occurred in 13 (65%) of 20 cases with ruptured aneurysms. Five aneurysms coexisted with causative vascular diseases such as arteriovenous malformation, moyamoya disease, or dolichoectasia. Four cases were treated by microsurgical operations and 18 by endovascular operations. In one of the microsurgical cases and five of the endovascular cases, parent arteries were sacrificed. Stents were used in six cases, including low-profile stents in four. Intermediate guiding catheters were used in seven cases for distal access. Full recoveries were seen in 17 cases and death occurred in three. CONCLUSION: Treatments for these aneurysms are technically demanding due to the high rate of rebleeding, difficult accessibility, and inevitable necessity of sacrifice of the parent artery in some cases. However, advancing endovascular techniques and devices enable distal access to the lesion and help preserve the parent artery.

Endovascular Treatment in Precommunicating Segment Aneurysms of Posterior Cerebral Artery.

BACKGROUND: Precommunicating (P1) segment aneurysms of the posterior cerebral artery are rare, with few studies reported to date. Herein, we address the clinical and radiologic outcomes of their endovascular treatment. METHODS: For this study, we retrieved prospectively collected data on 35 consecutive patients with 37 P1 aneurysms, analyzing the clinical ramifications and morphologic outcomes of treatment. All subjects received endovascular interventions between January 2001 and October 2021. RESULTS: There were 16 aneurysms (43.2%) of P1 segment sidewalls and 21 (56.8%) at P1/posterior communicating artery junctions. Five (13.5%) were fusiform, and 14 (37.8%) were ruptured. In 14 patients (40%), 16 aneurysms (43%) were associated with intracranial arterial occlusive disease of the anterior circulation. Selective coiling was undertaken in 34 aneurysms (91.9%), using single (n = 24) or double (n = 4) microcatheters, microcatheter protection (n = 2), or stents (n = 4); and trapping was done in 3 (8.1%). No procedure-related morbidity or mortality resulted. Excluding the trapped lesions, angiographic follow-up of 29 aneurysms obtained >6 months after embolization (mean, 12.4 month) revealed stable occlusion in 21 (72.4%), with some recanalization in the other 8 (minor: 3/29, 10.4%; major: 5/29, 17.2%). CONCLUSIONS: Aneurysms of P1 segment (vs. other locations) are strongly associated with intracranial arterial occlusive disease of the anterior circulation and thus are likely flow related. Endovascular treatment of such lesions seems safe and efficacious, despite the array of technical strategies that their distinctive anatomic configurations impose.

Half-and-Half Approach for Multiple Aneurysms at the Superior Cerebellar and Middle Cerebral Arteries.

Aneurysms at the superior cerebellar artery (SCA) are commonly treated endovascularly because of their location around the basilar artery,1,2 but they are not intimately related with thalamoperforators. Therefore in younger patients, those with wide-necked aneurysms, or those with multiple ipsilateral aneurysms, surgery remains a treatment option.3 We present a 52-year-old woman with dizziness in whom multiple, unruptured intracranial aneurysms were identified. Imaging demonstrated a 9-mm right-sided SCA aneurysm and 5-mm right and mirror 3-mm left M1 segment middle cerebral artery aneurysms. The patient gave consent to undergo surgery after counseling regarding her treatment options. A pterional and temporal craniotomy was performed to allow for half-and-half subtemporal and transsylvian approaches (Video 1). Here, we discuss the nuances of the approach related to the anatomy of SCA aneurysms. The challenges of the surgery can be mediated with techniques including division of the tentorium for enhanced exposure and early proximal control with temporary clinping or the use of adenosine (cardiac arrest). Our patient remained neurologically stable postoperatively and in 1-year follow-up. SCA aneurysms are easily visualized by the subtemporal and transsylvian approaches; they are frequently located adjacent to the posterior cerebral artery above and the SCA below. A modified transcavernous approach using the orbitozygomatic craniotomy has been described for access to basilar tip aneurysms.4 While comparable, this case demonstrates the efficient workflow to clip multiple aneurysms using a single, combined approach. In patients with multiple aneurysms presenting ipsilaterally or with comorbid conditions that complicate endovascular embolization, surgery should be considered as a definitive and safe treatment strategy. The patient consented to publication.

Dissecting Aneurysm of the Posterior Cerebral Artery.

Posterior circulation aneurysms are more likely to rupture than those in the anterior circulation but also pose more of a challenge for endovascular treatment or neurosurgical clipping. Aneurysms arising from the posterior cerebral artery are rare; dissecting aneurysms are even rarer. Dissecting posterior cerebral artery aneurysms can be spontaneous or post traumatic. Our case depicts a patient with acute subarachnoid hemorrhage due to a ruptured, dissecting posterior cerebral artery aneurysm who underwent successful endovascular treatment by means of flow diversion.

How I do it? Preoperative Microsoft HoloLens 2 planning-assisted surgical clipping of a fetal posterior cerebral artery aneurysm.

BACKGROUND: The treatment of intracranial aneurysms has predominantly shifted towards endovascular strategies, but complex cases still necessitate microsurgery. Preoperative stimulation can be beneficial for inexperienced young neurosurgeons in preparing for safe microsurgery. METHOD: A 72-year-old female with a left irregular fetal posterior cerebral artery (PCA) aneurysm underwent clipping repair. Microsoft HoloLens 2, utilizing mixed reality technology, was employed for preoperative stimulation and anatomical study. During the operation, we successfully identified the planned relationship between the aneurysm and the fetal PCA. The patient was cured without any complications. CONCLUSION: We hope that this report will highlight the significance of Microsoft HoloLens 2 in microsurgical planning and education.

Aberrant Arterial Anatomy at the Floor of the Third Ventricle: Video Case Report.

A 65-year-old woman presented with a 2-month progressive history of forgetfulness, headaches, and decline in mobility. Imaging showed a large, enhancing pineal region tumor with triventricular hydrocephalus. She underwent an endoscopic third ventriculostomy and biopsy after appropriate consent was gained. Video 1 demonstrates the endoscopic procedure during which 2 aberrant arteries were identified at the floor of the third ventricle. The endoscopic third ventriculostomy was performed between these 2 arteries with great care to preserve them. The patient improved postoperatively with resolution of the hydrocephalus. Histology showed a metastatic malignant melanoma. To the best of our knowledge, no similar anatomy has been shown in an endoscopic procedure. We speculate that these are perforating arteries from the posterior communicating artery (premamillary artery) or a branch from the first part of the posterior cerebral artery P1 (thalamoperforators). Other options include perforators from the ophthalmic segment of the internal carotid artery, the communicating segment of the internal carotid artery, the superior hypophyseal artery, or a branch of the medial posterior choroidal arteries. We look at each in turn.

Hemorrhage Risk in Moyamoya Disease with Fetal-Type Posterior Cerebral Artery: A Propensity Score-Matched Analysis.

OBJECTIVE: Patients with moyamoya disease (MMD) and fetal-type posterior cerebral arteries have not been thoroughly investigated as yet. We focused on the risk of intracranial hemorrhage in patients with MMD and fetal-type posterior cerebral arteries. METHODS: We reviewed 2422 patients with MMD diagnosed at the Neurosurgical Department of Beijing Tiantan Hospital between May 2009 and December 2020. We classified patients into 2 groups according to whether they had a fetal-type posterior cerebral artery. After 1:1 propensity score matching, hemorrhagic tendency and Suzuki stage were compared between patients with a fetal-type posterior cerebral artery (group I) and patients without a fetal-type posterior cerebral artery (group II). RESULTS: In total, 2415 patients were included in this study; 181 had fetal-type posterior cerebral arteries. Hemorrhagic events were more frequently observed in patients with fetal-type posterior cerebral artery development than in those without it (28.2% vs. 18.8%, P = 0.035). However, Suzuki stages did not differ between the 2 matched groups (4.03 vs. 4.20, P = 0.081). CONCLUSIONS: Hemorrhagic events occurred more frequently in patients with MMD with fetal-type posterior cerebral arteries than in those without.

External carotid artery-radial artery graft-posterior cerebral artery bypass for complex vertebrobasilar aneurysms: efficacy and analysis of outcome in a single center.

The purpose of this research was to demonstrate the effectiveness and clinical outcome of an external carotid artery-radial artery graft-posterior cerebral artery (ECA-RAG-PCA) bypass in the treatment of complex vertebrobasilar artery aneurysms (VBANs) in a single-center retrospective study. An ECA-RAG-PCA bypass may be a last and very important option in the treatment of complex VBANs when conventional surgical clipping or endovascular interventions fail to achieve the desired outcome. This study retrospectively analyzed the clinical presentation, case characteristics, aneurysm location, size and morphology, choice of surgical strategy, complications, clinical follow-up, and prognosis of the patients enrolled. The data involved were analyzed by the appropriate statistical methods. A total of 24 patients with complex VBANs who met the criteria were included in this study. Eighteen (75.0%) were male and the mean age was 54.1 ± 8.83 years. The aneurysms were located in the vertebral artery, the basilar artery, and in the vertebrobasilar artery with simultaneous involvement. All patients underwent ECA-RAG-PCA bypass surgery via an extended middle cranial fossa approach, with 8 (33.3%) undergoing ECA-RAG-PCA bypass only, 3 (12.5%) undergoing ECA-RAG-PCA bypass combined with aneurysm partial trapping, and 12 (50.0%) undergoing ECA-RAG-PCA bypass combined with proximal occlusion of the parent artery. The average clinical follow-up was 22.0 ± 13.35 months. The patency rate of the high-flow bypass was 100%. At the final follow-up, 15 (62.5%) patients had complete occlusion of the aneurysm, 7 (29.2%) patients had subtotal occlusion of the aneurysm, and 2 (8.3%) patients had stable aneurysms. The rate of complete and subtotal occlusion of the aneurysm at the final follow-up was 91.7%. The clinical prognosis was good in 21 (87.5%) patients and no procedure-related deaths occurred. Analysis of the good and poor prognosis groups revealed a statistically significant difference in aneurysm size (P = 0.034, t-test). Combining the results of this study and the clinical experience of our center, we propose a surgical algorithm and strategy for the treatment of complex VBANs.The technical approach of ECA-RAG-PCA bypass for complex VBANs remains important, even in an era of rapid advances in endovascular intervention. When conventional surgical clipping or endovascular intervention has failed, an ECA-RAG-PCA bypass plays a role that cannot be abandoned and is a very important treatment option of last resort.

Complex aneurysm formation in the proximal segment of the posterior cerebral artery: a report of two cases.

Posterior cerebral artery (PCA) aneurysms are rare and often fusiform. We describe two cases of complex proximal PCA aneurysm in two women in their 60's, which probably resulted from segmental arterial degeneration. Both presented with subarachnoid hemorrhage and had common angiographic and intraoperative findings: tortuous configuration of the affected P1 segment, whitish or yellowish appearance of a portion of the lesion, lesion calcification, and multiple aneurysms in the segment. Interestingly, no significant atherosclerotic changes were noted in other cerebral arteries. The ruptured aneurysm could be successfully trapped, with superficial temporal artery (STA)-PCA bypass in one and without bypass in the other, and both patients recovered well. As complex aneurysm formation in the cases described here are probably related to proximal PCA segmental degeneration, we recommend trapping the lesion, with or without STA-PCA bypass, depending on the size and patency of the posterior communicating artery.

Ictus isquémico agudo por oclusión en tándem de la arteria carótida interna y la arteria cerebral posterior fetal: tratamiento endovascular / Acute tandem occlusion stroke in internal carotid artery and fetal posterior cerebral artery: endovascular management

Introducción: Cuando la arteria cerebral posterior se origina desde la arteria carótida interna con un segmento P1 ausente, se denomina arteria cerebral posterior de origen fetal (ACPF). No está claro si la ACPF aumenta el riesgo de ictus isquémico agudo, y el tratamiento endovascular del ictus isquémico agudo debido a la oclusión aguda de la ACPF no está bien establecido. Caso clínico: Presentamos un caso de ictus isquémico agudo debido a la oclusión en tándem de la arteria carótida interna y la arteria cerebral posterior fetal ipsilateral tratado con éxito mediante la colocación de una endoprótesis en la lesión proximal y trombectomía mecánica de la lesión distal, con excelentes resultados neurológicos y funcionales. Conclusión: Aunque se necesitan más investigaciones para determinar el mejor tratamiento de estos pacientes, el tratamiento endovascular de la oclusión de la arteria cerebral posterior fetal es factible.(AU)

Introduction: When the posterior cerebral artery arises from the internal carotid artery with an absent P1 segment, it is called fetal posterior cerebral artery (FPCA). It is unclear whether FPCA increases the risk of acute ischemic stroke, and the endovascular treatment of acute ischemic stroke due to acute occlusion of FPCA is not well established. Case report: We report a case of acute ischemic stroke due to tandem occlusion of internal carotid artery and ipsilateral fetal posterior cerebral artery treated successfully with acute stenting of proximal lesion and mechanical thrombectomy of distal lesion with excellent neurological and functional outcomes. Conclusion: Although further investigations are needed to determine the best treatment of these patients, endovascular treatment of fetal posterior cerebral artery occlusion is feasible.(AU)

Bihemispheric Right Anterior Cerebral Artery, Fenestrated Origin of the Left Pericallosal Artery, Fenestrated Basilar Artery, Double Right Posterior Cerebral Artery.

Anatomical variations of the cerebral vasculature are frequently encountered. The archived magnetic resonance angiogram of a 62-year-old male patient was studied anatomically on planar slices and 3-dimensional volume renderings. Numerous anatomical variants were found in that single case. In the vertebrobasilar system were found: the proximal basilar artery fenestration, with a unilateral origin from that fenestration of an anterior inferior cerebellar artery, and the unilateral origin of the superior cerebellar artery from the P1 segment of the main posterior cerebral artery (PCA). There were also unilateral variants of the right internal carotid artery (ICA): a subvariant of an accessory PCA leaving the ICA as a hyperplastic anterior choroidal artery and united to the main PCA by a short communicating branch, distinctive of the posterior communicating artery in that side (unilateral double PCA); a right bihemispheric anterior cerebral artery (ACA) but with complete agenesis of the contralateral A1 ACA segment; from the right ACA continued an anatomically normal ipsilateral A2 segment and a short transverse contralateral A2 that, in turn, sent off long pericallosal and callosomarginal arteries; and fenestrated origin of the left pericallosal artery. Therefore, an arterial variant in one of the main cerebral circulations could not exclude anatomical variants in the other cerebral circulatory beds.

Encephalo-Duro-Pericranio-Synangiosis for the Treatment of Moyamoya Disease with Posterior Cerebral Artery Lesions.

OBJECTIVE: We describe our experience performing encephalo-duro-pericranio synangiosis for the parieto-occipital region (EDPS-p) as a treatment for moyamoya disease (MMD) with hemodynamic disturbances caused by lesions of the posterior cerebral artery. METHODS: From 2004 to 2020, 60 hemispheres of 50 patients with MMD (38/50 females, age 1-55 years) underwent EDPS-p as a treatment for hemodynamic disturbances in the parieto-occipital region. A skin incision was made on the parieto-occipital area to avoid the major skin arteries, and the pedicle flap was created by attaching the pericranium to the dura mater under the craniotomy with multiple small incisions. The surgical outcome was assessed on the basis of the following points: perioperative complications, postoperative improvement of clinical symptoms, subsequent novel ischemic events, qualitative assessment of the development of collateral vessels by magnetic resonance arteriography, quantitative assessment of postoperative perfusion improvement based on the mean transit time, and cerebral blood volume on dynamic susceptibility contrast imaging. RESULTS: Perioperative infarction occurred in 7/60 hemispheres (11.7%). The transient ischemic symptoms observed preoperatively disappeared in 39/41 hemispheres (95.1%) during the follow-up period (12-187 months), and none of the patients experienced novel ischemic events. Collateral vessels supplied from the occipital arteries, middle meningeal arteries, and posterior auricular arteries developed postoperatively in 56/60 hemispheres (93.3%). Postoperative mean transit time and cerebral blood volume showed significant improvement in the occipital, parietal, and temporal areas (P < 0.001), as well as the frontal area (P = 0.01). CONCLUSIONS: EDPS-p seems to be an effective surgical treatment for patients with MMD who suffer hemodynamic disturbances caused by posterior cerebral artery lesions.

Epidural Pretemporal Transcavernous Approach Double-Barrel Superficial Temporal Artery-Posterior Cerebral Artery/Superior Cerebellar Artery Bypass for a Ruptured Anterior Spinal Artery Aneurysm.

BACKGROUND: Rostral posterior circulation bypass is technically challenging. Pretemporal approach has been reported to facilitate the bypass procedure within the oculomotor-tentorial triangle. However, bridging veins converging into cavernous sinus at the temporal pole usually need to be sacrificed. OBJECTIVE: To report operative nuances of rostral posterior circulation bypass with an emphasis on preserving the Sylvian veins and enlarging surgical space, we use a double-barrel superficial temporal artery-posterior cerebral artery/superior cerebellar artery anastomosis using an epidural pretemporal transcavernous approach. METHODS: A 54-year-old man had a subarachnoid hemorrhage attack 1 month before the admission. A flow-related anterior spinal artery aneurysm with bilateral vertebral artery occlusive diseases was indicated. The aneurysm was difficult to be directly treated, either by the endovascular approach or by the microsurgical clipping. A double-barrel superficial temporal artery-superior cerebellar artery/posterior cerebral artery bypass was performed using an epidural pretemporal transcavernous approach. RESULTS: The anastomoses were successfully accomplished in a large surgical space. The patient recovered well with no events, except a transient right cranial nerve III paralysis. The aneurysm was demonstrated to be completely regressed at the 5-month follow-up. CONCLUSION: An epidural pretemporal transcavernous approach could be an alternative for rostral posterior circulation bypass.

Combined anterior and posterior circulation approach for stent-assisted coiling of a recurrent basilar tip aneurysm.

Endovascular treatment of recurrent basilar aneurysms is challenging due to significant changes in the configuration of the aneurysm and adjacent vessels from prior interventions.1 Coil compaction is a common cause of recurrence and alters the aneurysm morphology significantly.2-4 Stenting of the basilar artery into a posterior cerebral artery modifies the angles between these vessels.5 In this video, we discuss a combined approach via the anterior and posterior circulation for stent-assisted coiling of a recurrent basilar tip aneurysm (Video 1) . A patient in their 40s with a history of ruptured aneurysm underwent multiple endovascular interventions including coiling, stent-assisted coiling, and Woven Endobridge (WEB) device. The patient presented with worsening headaches and underwent treatment with stent-assisted coiling for recurrence. After encountering challenges with direct access from the basilar artery, a combined anterior and posterior circulation approach was used.6 The stent was deployed through the posterior communicating artery and a snare was used to navigate the complex anatomy. neurintsurg;15/5/512/V1F1V1Video 1 .

How I do it: left posterior cerebral artery P1-2 segment dissecting aneurysm distal clipping via an A1-RAG-P2 bypass.

BACKGROUND: Posterior cerebral artery (PCA) P1-2 segment dissecting aneurysms are difficult because regular craniectomy aneurysm clipping or intravascular interventional therapy is not applicable. METHOD: We report distal clipping of a PCA P1-2 segment dissection aneurysm with an anterior cerebral artery (ACA) A1-radial artery graft-PCA P2 bypass. CONCLUSION: This case demonstrates the value of an ACA-RAG-PCA bypass in the therapy of a PCA dissecting aneurysm.

Solitaire AB Stent Deployment for Treatment of Basilar Apex Aneurysm via the Posterior Communicating Artery.

AIM: To report the retrograde technique of horizontal stenting through the PCoA using a Solitaire AB stent. MATERIAL AND METHODS: A self-expandable stent was deployed from one posterior cerebral artery to the opposite, across the neck of a ruptured wide-neck basilar apex aneurysm. RESULTS: The technique allowed successful aneurysm embolization with coils in a 53-year-old woman. CONCLUSION: Differently from clipping, where the fetal posterior communicating arteries may represent an obstacle, in endovascular treatment it provides an alternative way to the aneurysm. The Solitaire AB stent is easy to navigate, fully retrievable and repositionable, which enables accurate deployment.

Superficial Temporal Artery-Posterior Cerebral Artery Bypass Through Zygomatic Anterior Temporal Approach for Complex Posterior Cerebral Artery Aneurysm.

BACKGROUND: Posterior cerebral artery (PCA) aneurysms are rare, and most are giant, dissecting, or fusiform in morphology. Proximal occlusion of the PCA without revascularization causes high risk of ischemic complications. This study aimed to evaluate the safety and validity of using superficial temporal artery (STA)-PCA bypass through zygomatic anterior temporal approach in complex PCA aneurysms. METHODS: Trapping or resecting of aneurysms and reconstruction of distal PCA through a zygomatic anterior temporal approach were performed in 6 patients from June 2017 to August 2020. Postoperative angiography confirmed obliteration of aneurysms and patency of bypass artery. Neurological function was assessed by the modified Rankin Scale (mRS). RESULTS: Patients were 4 men and 2 women with a mean age of 43.8 years (range, 21-58 years). Subarachnoid hemorrhage occurred in 5 patients. Hunt and Hess grade was IV in 3 patients, III in 2 patients, and I in 1 patient. All PCA aneurysms were treated with trapping or resection of the aneurysms and revascularization of distal PCA. Postoperatively, all aneurysms were eliminated, and no new permanent neurological deficit was found. During follow-up, mRS score of all patients improved: 2 patients had mRS score 0, 1 patient had mRS score 1, 1 patient had mRS score 3, and 2 patients had mRS score 4. Long-term graft patency rate was 100%. CONCLUSIONS: STA-PCA bypass appears to be safe and effective for the treatment of complex PCA aneurysms requiring supplementation of blood flow in the area of the PCA. We established a surgical route, allowing the procedure to be done through the zygomatic anterior temporal approach. This approach provides adequate operative field exposure and reduces retraction of temporal lobe.