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Purpose: Despite significant improvements in the design and performance of continuous flow left ventricular assist devices (CFLVADs), one of the most important reasons hampering further penetration of this technology is the occurrence of adverse events, especially strokes. One of the well-known risk factors for strokes is hypertension which is particularly common in patients undergoing a CFLVAD implant. While the device is implanted in the heart, strokes happen due to pathology in the brain and we hypothesised that modelling the blood flow in the circle of Willis might shed light on the causation of strokes in this situation. The aim of the study was two-fold: 1. What is the reason for hypertension in CFLVADs? Are there physical factors at play, besides neurohumoral mechanisms? 2. Do anatomical factors in the circle of Willis play a role in the causation of strokes in these patients? Methods: The circle of Willis is often incomplete and has a number of anatomical variations, the commonest being the absence of the posterior communicating artery. Hypertension is common after CFLVAD implantation and is also a well-known risk factor for strokes. We examined the blood pressure in the cerebral circulation with pulsatile and non-pulsatile flow for identical conditions and the effect of the absence of the posterior communicating artery on regional cerebral blood flow and pressure. One-dimensional blood flow model was used, taking into account wave propagation and reflections and physiological data obtained from anatomically detailed arterial network (ADAN86) which has data from 86 arteries including detailed cerebral network. Results: The mean arterial pressure was significantly higher in the non-pulsatile blood flow of CFLVADs compared to pulsatile flow, for identical conditions, across all arteries. With increasing imparted pulsatility to CFLVAD flow, the mean arterial pressure progressively decreased. Isolated absence of the posterior communicating artery had no effect on the flow as well as pressure in the middle cerebral artery. However, when combined with the absence of flow in the ipsilateral carotid artery, the flow as well as the pressure decreased very significantly in both continuous and pulsatile flow situations. Conclusions: Physiologically significant pulsatility in CFLVADs can have important clinical advantages in lowering of blood pressure which can lead to lower incidence of strokes, pump thrombosis, gastrointestinal (GI) bleeds, and aortic incompetence. Patient-specific anatomical variations in the circle of Willis, especially the absence of the posterior communicating artery, can have important consequences in regional cerebral perfusion under some circumstances. [ABSTRACT FROM AUTHOR]

Background and objectives: Direct visualization of the aneurysmal neck and its related perforating arteries during microsurgical clipping of posterior communicating artery (PCoA) aneurysms with posterior projection or true PCoA aneurysms through the pterional approach may be difficult and complicated. Methods: From January 2022 to January 2023, the clinical and angiographic information regarding PCoA aneurysms were retrospectively collected. Among them, 10 consecutive patients with PCoA aneurysms treated with microsurgical clipping via the subtemporal approach in our single institution were included. Herein, we analyzed and summarized our experience and clinical outcomes to further evaluate the efficacy, safety and feasibility of this approach as well as the indications. Results: All aneurysms were completely clipped via the subtemporal approach. With respect to procedure-related complications, postoperative oculomotor nerve palsy occurred in one patient (10%), contralateral cerebral infarction in one patient (10%), and intraoperative rupture of the aneurysm in three patients (30%). There were no cases of temporal lobe contusion or venous injury in this group. Overall, Good outcomes were obtained in 9 patients (90%), and poor functional outcome was observed in 1 patient (10%) at the last follow-up. Conclusion: The management of true PCoA aneurysms and PCoA aneurysms projecting posteriorly is more complicated and challenging, and treating these lesions entails considerable risks via the pterional approach. Considering the above problems, we attempted to treat these refractory PCoA aneurysms through the subtemporal approach. Our results suggested that microsurgical clipping of these aneurysms via the subtemporal approach can achieve good clinical outcomes with a high preservation rate of the related branches. Appropriate patient selection, fully grasp of indications, precise understanding of the anatomy and thorough preoperative planning are crucial for successful surgery. The subtemporal approach appears to be a relatively safe and effective procedure in the experienced hands, and may be an alternative method for patients with true PCoA aneurysms or projecting posteriorly PCoA aneurysms which cannot be easily clipped from the pterional approach. It can provide a better lateral view to visualize the neck of the aneurysm, PCoA and its perforating vessels, as well as the other structures. [ABSTRACT FROM AUTHOR]

Variations at the junction of embryonic internal carotid and vertebrobasilar systems are rare and associated with a high incidence of stroke. During cadaver dissection, we demonstrated for the first time a case of hypoplastic right vertebral artery associated with partial duplication of the distal part of the right P1 segment of a partial fetal posterior cerebral artery (FPCA) and bilateral duplication of superior cerebellar arteries (SCAs), of which, the upper right SCA originated from PCA. We hypothesize that the poor development of the right half of the vertebrobasilar system caused the persistence of FPCA with anomalous origin of the right upper SCA as well as partial duplication of P1 segment of PCA as a remnant of the weak anastomosis between the embryonic right PCA and the basilar system. Such complex variations provide a huge challenge in their diagnosis and in choosing the suitable treatment modality for the stroke. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the the measurements of the circle of Willis (CW) arteries diameters in a Romanian population. Material and methods: We performed a retrospective study on a sample of 221 adult patients (≥18 years-old), hospitalized in the Emergency Clinical Hospital “Prof. Dr. N. Oblu” from Iași, Romania, over a period of 12 years, who died during hospitalization and on whom an autopsy was performed. Demographic data (age, gender, residence), causes of death and the outer diameters of CW constituent arteries were collected. There were 221 subjects, who were divided into four groups, according to the association of patient’s cause of death with the presence of anatomical variants of CW. 76.01% of all subjects presented cerebrovascular disease (CVDs) and anatomical variant of the CW, thus representing the great majority. Patients “with CVDs and anatomical variants of CW” were older with about 4 years compared to the other three categories of patients, having an average age of 64.17 ±14.22 years. 56.3% of those “without CVDs and with anatomical variant of CW” and 62.5% of those patients deceased ”with CVDs and anatomical variants of CW” had rural residences. 68.8% of all cases ”without CVDs, but with anatomical variants of CW” were female patients. 37.5% of the patients “with CVDs and anatomical variants of CW” and 43.8% of the patients “without CVDs, but with anatomical variants of CW” lived in the urban environment. Statistically significant differences were observed between the mean outer diameters of the arteries of CW and the patient’s cause of death (p

Purpose: To describe a case of replaced posterior cerebral artery (PCA) in which all branches of the PCA arose from the anterior choroidal artery (AChA) with an early branching temporal artery. Methods: An 83-year-old man with cerebral infarctions underwent cranial magnetic resonance (MR) imaging and MR angiography using a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique. Results: A large anomalous artery arose from the supraclinoid segment of the right internal carotid artery (ICA) and supplied all branches of the right PCA, mimicking fetal-type PCA. The temporal branch arose from the proximal segment of this artery. In MR angiographic source images, a tiny artery arose from the right ICA proximal to the origin of the anomalous artery, indicating a hypoplastic right posterior communicating artery (PCoA). Thus, we concluded that the anomalous artery was a replaced PCA; all branches of the PCA arose from the AChA. Conclusion: We present a case involving a replaced PCA with an early branching temporal artery, as seen on MR angiography. Careful observation of MR angiographic source images is useful for identifying small arteries. To our knowledge, this is the first report of this combined variation in the relevant English-language literature. [ABSTRACT FROM AUTHOR]

Background and objectivesDirect visualization of the aneurysmal neck and its related perforating arteries during microsurgical clipping of posterior communicating artery (PCoA) aneurysms with posterior projection or true PCoA aneurysms through the pterional approach may be difficult and complicated.MethodsFrom January 2022 to January 2023, the clinical and angiographic information regarding PCoA aneurysms were retrospectively collected. Among them, 10 consecutive patients with PCoA aneurysms treated with microsurgical clipping via the subtemporal approach in our single institution were included. Herein, we analyzed and summarized our experience and clinical outcomes to further evaluate the efficacy, safety and feasibility of this approach as well as the indications.ResultsAll aneurysms were completely clipped via the subtemporal approach. With respect to procedure-related complications, postoperative oculomotor nerve palsy occurred in one patient (10%), contralateral cerebral infarction in one patient (10%), and intraoperative rupture of the aneurysm in three patients (30%). There were no cases of temporal lobe contusion or venous injury in this group. Overall, Good outcomes were obtained in 9 patients (90%), and poor functional outcome was observed in 1 patient (10%) at the last follow-up.ConclusionThe management of true PCoA aneurysms and PCoA aneurysms projecting posteriorly is more complicated and challenging, and treating these lesions entails considerable risks via the pterional approach. Considering the above problems, we attempted to treat these refractory PCoA aneurysms through the subtemporal approach. Our results suggested that microsurgical clipping of these aneurysms via the subtemporal approach can achieve good clinical outcomes with a high preservation rate of the related branches. Appropriate patient selection, fully grasp of indications, precise understanding of the anatomy and thorough preoperative planning are crucial for successful surgery. The subtemporal approach appears to be a relatively safe and effective procedure in the experienced hands, and may be an alternative method for patients with true PCoA aneurysms or projecting posteriorly PCoA aneurysms which cannot be easily clipped from the pterional approach. It can provide a better lateral view to visualize the neck of the aneurysm, PCoA and its perforating vessels, as well as the other structures.

The aim of this study was to evaluate the the measurements of the circle of Willis (CW) arteries diameters in a Romanian population. Material and methods: We performed a retrospective study on a sample of 221 adult patients (≥18 years-old), hospitalized in the Emergency Clinical Hospital "Prof. Dr. N. Oblu" from Iași, Romania, over a period of 12 years, who died during hospitalization and on whom an autopsy was performed. Demographic data (age, gender, residence), causes of death and the outer diameters of CW constituent arteries were collected. There were 221 subjects, who were divided into four groups, according to the association of patient's cause of death with the presence of anatomical variants of CW. 76.01% of all subjects presented cerebrovascular disease (CVDs) and anatomical variant of the CW, thus representing the great majority. Patients "with CVDs and anatomical variants of CW" were older with about 4 years compared to the other three categories of patients, having an average age of 64.17 ±14.22 years. 56.3% of those "without CVDs and with anatomical variant of CW" and 62.5% of those patients deceased ”with CVDs and anatomical variants of CW” had rural residences. 68.8% of all cases ”without CVDs, but with anatomical variants of CW” were female patients. 37.5% of the patients "with CVDs and anatomical variants of CW" and 43.8% of the patients "without CVDs, but with anatomical variants of CW" lived in the urban environment. Statistically significant differences were observed between the mean outer diameters of the arteries of CW and the patient's cause of death (p <.001) in case of anterior communicating artery (AcoA), right anterior cerebral artery (ACA), right and left posterior communicating arteries (PcoAs), and right posterior cerebral artery (PCA). The smallest external diameters of ACoA, right ACA and left PcoA were identified in patients ”with CVDs and anatomical variants of CW”. Our research has provided evidence that a smaller diameter of the right ACA and left PcoA are associated with the occurrence of cerebrovascular diseases. [ABSTRACT FROM AUTHOR]

Purpose: To report an unusual case of combined Lie's types A and D of internal carotid artery (ICA) agenesis, diagnosed by magnetic resonance angiography (MRA). Methods: A 60-year-old woman with dizziness underwent cranial magnetic resonance imaging (MRI) and MRA of the intracranial region for the evaluation of brain and vascular lesions. The magnetic resonance machine was a 3.0-T scanner. Results: MRI showed no abnormalities, except for multiple small white matter lesions. MRA showed that the left ICA was absent, except for the supraclinoid segment, and an anastomotic vessel was present between the paraclinoid segments of the bilateral ICAs, indicating Lie's type D ICA agenesis. The left posterior communicating artery (PCoA) was also present. Thus, there were also features of type A ICA agenesis. The anastomotic vessels between the bilateral ICAs and ipsilateral PCoA were relatively small in caliber. Conclusion: Lie's type D ICA agenesis usually does not communicate with the anterior and posterior circulations. We encountered a case of combined type D and type A ICA agenesis. To our knowledge, no similar case has been reported in the English literature. This is the second case of type D ICA agenesis with patent ipsilateral PCoA. We speculate that in case of type A ICA agenesis, when the development of the PCoA is insufficient to support collateral blood flow, an anastomotic vessel between bilateral ICAs may develop. [ABSTRACT FROM AUTHOR]

Isolated posterior communicating artery (PCoA) aneurysms are rare, predominantly fusiform in morphology, and rarely present with subarachnoid hemorrhage. Endovascular management of this pathology is technically challenging due to extreme tortuosity, the artery course in the subarachnoid space, sharp angulations at PCoA junctions with the parent artery, and, at times, associations with either internal carotid artery or basilar artery occlusions. We present a case of a ruptured fusiform PCoA at the junction of middle and distal third with concomitant proximal basilar artery occlusion. The PCoA reforms the posterior circulation, making it a vital artery. Stent-assisted coiling was performed with extreme difficulty in achieving distal positioning of the stents in the basilar artery/posterior cerebral artery/distal PCoA due to artery tortuosity. There was technical difficulty in the stent deployment. After changing strategies to a larger diameter laser-cut stent, endovascular treatment could be performed. There were good angiographic and clinical outcomes with stable occlusion at 6-month-follow-up.

Isolated posterior communicating artery (PCoA) aneurysms are rare, predominantly fusiform in morphology, and rarely present with subarachnoid hemorrhage. Endovascular management of this pathology is technically challenging due to extreme tortuosity, the artery course in the subarachnoid space, sharp angulations at PCoA junctions with the parent artery, and, at times, associations with either internal carotid artery or basilar artery occlusions. We present a case of a ruptured fusiform PCoA at the junction of middle and distal third with concomitant proximal basilar artery occlusion. The PCoA reforms the posterior circulation, making it a vital artery. Stent-assisted coiling was performed with extreme difficulty in achieving distal positioning of the stents in the basilar artery/posterior cerebral artery/distal PCoA due to artery tortuosity. There was technical difficulty in the stent deployment. After changing strategies to a larger diameter laser-cut stent, endovascular treatment could be performed. There were good angiographic and clinical outcomes with stable occlusion at 6-month-follow-up. [ABSTRACT FROM AUTHOR]

A 46-year-old female came to neurosurgery outpatient department with sudden onset of drooping of RE upper eyelid and restriction of movements in adduction, depression and elevation in right eye. Patient was a known case of diabetes mellitus whose blood sugar levels were deranged. On examination, patient was diagnosed pituitary macroadenoma. Patient was treated for her uncontrolled diabetes mellitus following which she had underwent transsphenoidal pituitary macroadenoma removal. On treatment, patient's ptosis had subsided and restriction of movement has resolved. [ABSTRACT FROM AUTHOR]

Copyright of Rechtsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Cranial nerve palsy (CNP) in patients with intracranial aneurysms (IAs) can impose significant burdens on a patient's quality of life. The literature has a paucity of reviews addressing patterns of overall reported cranial nerve (CN) involvement and outcomes in patients with IA. Methods: The literature systematically reviewed CNP at presentation in the setting of IA using PubMed, Web-of-Science, and Scopus according to the PRISMA guidelines. Results: Fifty-two studies reported a total of 513 patients with IA and 630 CNPs observed at presentation: oculomotor (58.25%), abducent (15.87%), optic (12.06%), trochlear (8.7%), and trigeminal (1.9%). Most common aneurysms are located in a posterior communicating artery (46%) and cavernous internal carotid artery (29.2%). Trends of CNP based on the rupture status of IAs showed that 80% were associated with unruptured IAs and 20% with ruptured IAs. Post-treatment of IA, 55% of patients had complete resolution of CNP, with most (89%; n = 134) resolving within the first 6 months. Stratified by CNP type: Complete resolution rate is 100% in CN VII-IX, 60% in CN VI, 59% in CN IV, 54% in CN III, 45% in CN V, and 43% in CN II. Conclusion: In patients with cranial nerve palsies attributed to IAs, the location and rupture status of the aneurysm could determine the type and severity of the nerve palsy. Most patients experienced favorable outcomes in terms of their resolution and long-term function of the CNP after treatment of the IA. [ABSTRACT FROM AUTHOR]

Bilateral posterior communicating (pComm) artery aneurysms represent only 2% of mirror intracranial aneurysms. Usually, these are surgically approached through bilateral craniotomies for clipping. We present the case of a 50-year-old female presenting with headache and horizontal diplopia. Neurological examination revealed a left oculomotor palsy, with no other neurological deficits. Imaging studies revealed bilateral aneurysmatic lesions in both internal carotid arteries (ICA). A conventional left pterional approach was planned in order to treat the symptomatic aneurysm, and, if deemed feasible, a contralateral clipping through the same approach. The procedure was performed in a hybrid operating room (HOR), performing an intraoperative digital subtraction angiography (DSA) and roadmapping assistance during dissection and clipping. Transoperatively, a post-fixed optic chiasm was identified, with a wide interoptic space, which allowed us to perform the contralateral clipping through a unilateral approach. This technique for clipping bilateral pComm aneurysms can be performed when the proper anatomical features are met. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of Gümüshane Üniversitesi Saglik Bilimleri Dergisi is the property of Gumushane University, Faculty of Health Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective : Deciphering the anatomy of posterior communicating artery (PCoA) aneurysms in relation to surrounding structures is essential to determine adjuvant surgical procedures. However, it is difficult to predict surgical structures through preoperative imaging studies. We aimed to present anatomical structures using preoperative high-resolution three-dimensional proton densityweighted turbo spin-echo magnetic resonance (PDMR) imaging with simple classification. Methods : From January 2020 to April 2022, 30 patients underwent PDMR before microsurgical clipping for unruptured PCoA aneurysms in a single tertiary institute. We retrospectively reviewed the radiographic images and operative data of these patients. The structural relationship described by PDMR and intraoperative findings were compared. Subsequently, we classified aneurysms into two groups and analyzed the rate of adjuvant surgical procedures and contact with the surrounding structures. Results : Correlations between preoperative PDMR predictions and actual intraoperative findings for PCoA aneurysm contact to the oculomotor nerve, temporal uncus, and anterior petroclinoid fold (APCF) reported a diagnostic accuracy of 0.90, 0.87, and 0.90, respectively. In 12 patients (40.0%), an aneurysm dome was located on the plane of the oculomotor triangle and was classified as the infratentorial type. Compared to the supratentorial type PCoA aneurysm, adjuvant procedures were required more frequently (66.7% vs. 22.2%, p=0.024) for infratentorial type PCoA aneurysm clipping. Conclusion : Preoperative PCoA aneurysm categorization using PDMR can be helpful for predicting surgical complexity and planning of microsurgical clipping. [ABSTRACT FROM AUTHOR]

The Mongolian gerbil has historically been useful for brain ischemia experiments, owing to the gerbil's uniquely underdeveloped circle of Willis (CoW). This led to a gerbil model of cochlear ischemia being generated in our unit. However, we have found that the usual severe hearing loss seen in this model was not being induced consistently in recent experiments using the MON/Jms/GbsSlc gerbil (the sole commercially available gerbil in Japan). We set out to evaluate the posterior communicating artery (PcomA) in MON/Jms/GbsSlc, to re-establish whether this strain is appropriate for ischemia models. Having found that this unique feature is often lost, we then attempted to breed for the characteristic absent PcomA. India-ink perfusion revealed that the percentage of intact bilateral PcomA ("communicating type") in the MON/Jms/GbsSlc gerbil was 57%; unilateral only ("unilateral communicating type") was 39%; and completely absent PcomA ("non-communicating type") was 4%. We were able to obtain few examples of the indigenous old aged Japanese UNG/Mz gerbil strain (at University of Miyazaki). Unfortunately, the pure UNG/Mz female was too elderly for mating. Therefore, selective breeding crosses between MON/Jms/GbsSlc and male UNG/Mz were carried out. After five generations of selective breeding, the percentage of non-communicating type gerbils was significantly higher in the newly generated strain, MON/Jms/SlcMz (F6 generation; 63%) than in the MON/Jms/GbsSlc gerbil. Bilateral common carotid artery occlusion surgery demonstrated that the cerebral blood flow was significantly reduced in MON/Jms/SlcMz compared with MON/Jms/GbsSlc (p < 0.0001) and induced more hippocampal injuries in MON/Jms/SlcMz than in MON/Jms/GbsSlc (p < 0.01). In conclusion, the commercially available MON/Jms/GbsSlc gerbil can easily regain PcomA, and we established a new gerbil strain (MON/Jms/SlcMz) displaying non-PcomA. [ABSTRACT FROM AUTHOR]

Oculomotor nerve palsies are typically associated with posterior communicating artery (PcommA) aneurysms. We report a rare case of an oculomotor nerve palsy caused by a PcommA infundibular dilatation. Although there are cases of infundibular dilatations causing cranial nerve palsies, only reports of three involving the PcommA exists. We review these reported cases in the literature and discuss their treatments as well as other non-aneurysmal compressive etiologies that may cause oculomotor nerve palsies. We present the case of a 53-year-old female with transient oculomotor nerve palsy that was initially diagnosed with a PcommA aneurysm. She underwent a craniotomy with plans of microsurgical clipping; however, the dilatation was identified correctly as an infundibulum intraoperatively. The operation was completed as a microvascular decompression and her oculomotor nerve palsy has not returned at the 1-year follow-up. We provide a detailed microsurgical report and video detailing the operative technique and relevant anatomy for this operation. Although rare and not as life-threatening as aneurysms, infundibular dilatations as a cause of oculomotor nerve palsy should remain as a differential diagnosis. Given the difference in natural history and treatment of these two entities, it is important to diagnose and treat them appropriately. Multimodal imaging such as thin-sliced computed tomography angiogram (CTA) and 3-dimensional (3D) rotational angiography can aid in diagnosis. [ABSTRACT FROM AUTHOR]

Abstract Objection This study aimed to compare the incidence of cerebral ischemia and outcomes between surgical clipping and endovascular coiling in patients with posterior communicating artery (PCoA) aneurysms. Methods Clinical and imaging data of patients with at least one PCoA aneurysm who underwent surgical clipping or endovascular coiling in our institution from January 2017 to December 2019 were analyzed. Results Three hundred sixty-three aneurysms in 353 patients were included for analysis, 257 in the clipping group, and 106 in the coiling group. The groups did not differ in terms of baseline characteristics. The incidence of postoperative cerebral ischemia (23.35% vs. 11.32%, p = 0.029) was higher in the clipping group. The proportion of patients with a modified Rankin Scale score ≥ 2 was significantly higher in the clipping group at discharge (35.80% vs. 15.09%; p 0.05). In the clipping group, the mean age was significantly higher in patients who developed cerebral ischemia than in those who did not. In the coiling group, modified Fisher grade and incidence of fetal PCoA were significantly higher in patients who developed ischemia. Conclusion The incidence of postoperative cerebral ischemia was higher after PCoA aneurysm clipping than after coiling. The causes and characteristics of postoperative cerebral ischemia after PCoA clipping and coiling are different; therefore, treatment should be selected accordingly.

AIM: To explore the risk factors of oculomotor nerve palsy (ONP) in patients with intracranial aneurysm (IA) and develop a nomogram model for predicting ONP of IA patients. METHODS: A total of 329 IA patients were included. Logistic regression analysis was applied to identify independent factors, which were then integrated into the nomogram model. The performance of the nomogram model was evaluated by calibration curve, receiver operating curve (ROC), and decision curve analysis. RESULTS: Univariate and multivariate logistic regression analysis indicated posterior communicating artery (PCoA) aneurysm [hazard ratio (HR)=17.13, P

ABSTRACT: A 72-year-old man with vertigo underwent cranial magnetic resonance (MR) imaging and MR angiography using a 3.0-Tesla scanner. MR angiography showed an aneurysm-like lateral protrusion from the left supraclinoid internal carotid artery (ICA) and infundibular dilatation of the left posterior communicating artery at its origin. After creating both partial maximum-intensity-projection images and partial volume-rendering images, a fenestration of the supraclinoid ICA was found. The posterior communicating artery arose from the fenestrated segment, and its origin was dilated triangularly, indicating infundibular dilatation. Cerebral arterial fenestration is not so rare, but it is rarely found at the ICA. The majority of recently reported cases had an associated aneurysm at the proximal end of the fenestration diagnosed using three-dimensional rotational angiography (3DRA). MR angiography is noninvasive and widely used for the screening of cerebral arterial lesions. Even though 3.0-Tesla scanner, special resolution of MR angiography is much lower than that of the 3DRA. For the diagnosis and confirmation of this rare variation, partial maximum-intensity-projection images and/or partial volume-rendering images are useful.

Blood blister−like aneurysms (BBAs) usually arise from the anterior walls of the internal carotid artery, and such lesions at the junction of the internal carotid artery and posterior communicating artery (PCoA) have not been reported to date. Here, we report our experiences of BBAs at PCoA. We studied their clinical and angiographical characteristics including the internal carotid−PCoA angle, an indicator of hemodynamic stress at the bifurcation. Three patients with BBAs located at the origin of PCoA were studied. Wrap-clipping was adopted as the first-line therapy, but direct clipping was conducted when difficult. All patients were elderly females (mean age 81.3 years), and BBAs were small in size (mean maximum diameter 1.5 mm), which arose at the origins of wide-angled fetal-type PCoAs (mean internal carotid−PCoA angle 37.8 degrees). All the lesions were treated by surgery (direct clipping 2, wrap-clipping 1), and severe atherosclerotic changes were observed at adjacent arterial walls in all cases. Ordinary wrap-clipping using a polytetrafluoroethylene membrane via the transsylvian approach was difficult because of the limited working space, requiring some special techniques such as usage of fenestrated clips, polyglycolic acid sheets, and combined approach with subtemporal craniotomy. Good clinical outcomes were achieved in 2 patients. BBAs at PCoA were predominantly occurred as the small bulges at the origins of wide-angled fetal-type PCoAs in elderly females. Hemodynamic stress and atherosclerosis would contribute to the aneurysmal formation. Wrap-clipping or direct clipping with additional techniques would be useful for this rare condition. [ABSTRACT FROM AUTHOR]

Infundibular aneurysms are rare lesions that present unique challenges for both surgical and endovascular approaches. We present a case of a 58-year old man with an incidental 7.5 × 3 mm infundibular aneurysm that incorporated the origin of the posterior communicating artery (PCoA). The fusiform aneurysm incorporated the supraclinoid ICA to the terminus. An attempt at surgical clip reconstruction of the aneurysm to preserve the PCoA was not technically possible due to atherosclerosis at the aneurysm neck. The aneurysm was treated with disconnection of the PCoA origin, induced flow reversal and placement of a flow diverter, after confirmation of adequate collateral flow to the PCoA perforators from the posterior circulation. The case illustrates important concepts in the evaluation and management of infundibular aneurysms, including both reconstructive and deconstructive strategies. [ABSTRACT FROM AUTHOR]

Background and Objectives: Anatomical variations of the arterial circle of Willis (cW) are common. A posterior cerebral artery (PCA) fed mostly or exclusively from the internal carotid artery is a fetal PCA (FPCA), partial (p-FPCA), or full/complete (f-FPCA), respectively. Because FPCA occurs in different anatomical configurations of the cW sides, we aimed to document in detail these morphological possibilities of FPCA within the cW. Materials and Methods: FPCAs were documented on a retrospective set of 139 computed tomography angiograms. Results: FPCAs were found in thirteen cases, nine males and four females. In 7/13 cases there were two modified sides of the cW. In 5/13 cases there were three altered sides of the cW. Another case with FPCA showed four altered sides of the cW. In 10/13 cases, FPCA was unilateral and in the other three cases it was bilateral. Compared to the overall group, unilateral p-FPCAs were found in 1.43%, while unilateral f-FPCAs were found in 5.75%. A bilateral p-FPCA-f-FPCA combination was found in 0.71% and a bilateral f-FPCA-f-FPCA combination occurred in 1.43%. An anatomically isolated ICA was found in just one case with bilateral f-FPCA (0.71%). In 7/13 FPCA cases there were arterial variants exclusively in the posterior cW. In the other 6/13 FPCA cases, there were variants in both anterior and posterior circulation. There were no statistically significant associations of FPCA with sex or age. The higher prevalence of right-sided FPCA was not statistically significant. Conclusions: Anatomical assessments of cW should be performed on a case-by-case basis, as they may correspond to different cW morphologies. [ABSTRACT FROM AUTHOR]

Background: The anterior (AcomA) and posterior communicating arteries (PcomA) are two of the most frequent sites for intracranial aneurysms. Anatomical variations in the Circle of Willis (COW) are frequently observed in patients with AcomA and PcomA aneurysms. Strong evidence is needed to determine the pooled estimate of the eect of COW variations on the formation and rupture of these aneurysms. Aim: This systematic review and meta-analysis aimed to establish the eect of COW variations on the formation and rupture of AcomA and PcomA aneurysms using available studies. Summary of review: PubMed, Embase, and Web of Science databases were systematically searched for studies published in English before September 21, 2022. Studies investigating AcomA aneurysms and the hypoplastic/aplastic A1 segment of the anterior cerebral artery and PcomA aneurysms and hypoplastic/aplastic PcomA or fetal-type posterior cerebral artery (FTP) were included. The heterogeneity of the studies was assessed using Cochran Q-test and I2 statistic. Pooled estimate was assessed using either a random- or fixed-eects model based on the heterogeneity of the studies. Among the 4,932 studies, 21 were eligible and included in the analysis. The presence of hypoplastic/aplastic A1 was significantly correlated with the formation [OR (95% confidence interval [CI]) = 7.97 (5.58, 11.39), P < 0.001] and rupture [OR (95%CI) = 1.87 (1.29, 2.72), P < 0.001] of AcomA aneurysms. Significant associations between FTP and both the formation [OR (95%CI) = 2.15 (1.41, 3.30), P < 0.001] and rupture [OR (95%CI) = 1.72 (1.26, 2.36), P < 0.001] of PcomA aneurysms were observed. Conclusions: Significant associations were observed between COW variations and both the formation and rupture of AcomA and PcomA aneurysms. This can help in determining interventions for patients with aneurysms. [ABSTRACT FROM AUTHOR]

Background: Microsurgical clipping and endovascular coiling are viable treatment options for posterior communicating artery (PComA) aneurysms, but there are still major limitations to evidence-based decisions regarding standard-of-care treatment. In this study, we aimed at assessing potential selection biases that may influence our ability to extract conclusions about the comparative effectiveness or efficacy of the aneurysm treatment. Objective: To study the patient/aneurysm characteristics as possible biases in the option for endovascular or neurosurgical treatment of PComA aneurysms. Methods: A single-center, retrospective cohort study was performed, including all patients with treated PComA aneurysms with neurosurgical clipping or endovascular coiling between January 2010 and January 2021. Clinical and morphological data were collected from electronic records, and statistical analysis was performed. Results: A total of 64 patients was eligible for inclusion; 24 (37.5%) patients were proposed for neurosurgical treatment, while 40 (62.5%) for endovascular treatment; 10 patients (25%) crossed over to the clipping group whereas none crossed over to the coiling side. Actual treatment analysis showed significantly higher diameters of mother vessel (t-test, p = 0.034) and aneurysm neck (Mann–Whitney, p = 0.029) in the clipping group and higher aspect and dome-to-neck ratios in the endovascular group (Mann–Whitney, p = 0.008). A significantly higher vasospasm frequency was found in the clipping group but only in the intention-to-treat analysis (Chi-square, p = 0.032). Conclusion: Significant morphological differences between effective endovascular and surgical groups and differences in intention-to-treat analysis may limit the validity of a direct comparison between treatment options and suggest the presence of a possible selection bias. [ABSTRACT FROM AUTHOR]

Abstract Background The relationship between anatomical variations in circle of Willis and brain infarction is controversial. The purpose of this study was to evaluate the relationship between anatomical variations in posterior portion of the circle of Willis assessed by MR angiography (MRA) and ischemic infarction in different brain territories. Methods This cross-sectional study was conducted on consecutive patients who underwent brain MRI and MRA for suspected cerebrovascular accident. The frequency of anatomical variations including persistent fetal origin of posterior cerebral artery (fPCA) and hypoplastic/aplastic posterior communicating artery (PCoA) and their association with infarction in different intracranial vascular territories was assessed. Results In total, 298 patients (155 male/143 female with mean age ± SD of 57 ± 15) were enrolled in the study and categorized into two groups with infarction (n = 142) and without infarction (n = 156). Sixty-three patients (21/1%) had fPCA and 231 (77.5%) had PCoA hypoplasia/aplasia. No significant correlation was identified between fPCA or PCoA hypoplasia/aplasia and presence of infarction. However, regarding the territories involved by infarction, the frequency of thalamus infarction was higher in subgroup with PCoA hypoplasia/aplasia, 17/101 (16.8%) compared to 1/41(2.4%) in the subgroup without ipsilateral PCoA hypoplasia/aplasia (p = 0.024). In two subgroups with and without ipsilateral fPCA variation, frequency of infarction in brain territories was not different significantly. Conclusions In patients with brain infarction, aplastic/hypoplastic ipsilateral PCoA is associated with higher incidence of thalamic territory infarction.

ObjectiveThis study aimed to evaluate the diagnostic effect of intraoperative neurophysiological monitoring in identifying intraoperative ischemic events and predicting postoperative neurological dysfunction during PCoA aneurysm clipping, as well as to explore the safe duration of intraoperative temporary clipping of the parent artery.MethodsAll 71 patients with PCoA aneurysm underwent craniotomy and aneurysm clipping. MEP and SSEP were used for monitoring during operation to evaluate the influence of MEP/SSEP changes on postoperative neurological function. Receiver operating characteristic (ROC) curve analysis was used to calculate optimal duration of intraoperative temporary clipping.ResultsPatients with intraoperative MEP/SSEP changes were more likely to develop short-term and long-term neurological deficits than those without MEP/SSEP changes (P 4.5 min was significantly higher than that in patients with temporary clipping ≤4.5 min (P = 0.015, P = 0.018).ConclusionIntraoperative MEP/SSEP changes are significantly associated with postoperative neurological dysfunction in patients with PCoA aneurysms. The optimal duration of temporary clipping of the parent artery during posterior communicating aneurysm clipping was 4.5 min under neurophysiological monitoring.

Introduction: The top of the basilar artery is a five-branched junction, consisting of two superior cerebellar arteries (SCAs), two posterior cerebellar arteries (PCAs), and the basilar artery itself. This study aimed to investigate prognostic factors in patients with selective acute basilar top occlusion managed with mechanical thrombectomy, focusing on occlusion type and posterior communicating artery (PCoA) patency. Methods: Eligible patients who underwent endovascular treatment (EVT) for acute basilar top occlusion were reviewed. Patterns of basilar top occlusion were categorized as types I-III according to whether the SCA and PCA were visible on angiography. The PCoA was categorized as hypoplastic or non-visible (type I), normal patency but non-visible PCA through PCoA flow (type II), and fetal type (type III). Results: Good outcomes were observed in 50% (21/42) and mortality in 11.9% (5/42) of the cases at 90 days. Patients with good outcomes showed lower baselineNational Institutes of Health Stroke Scale (NIHSS) score (P=0.001) and a higher proportion of type III basilar top occlusion (P=0.004) and type III PCoA (P = 0.001). Multivariable logistic analysis showed that baseline NIHSS score [odds ratio (OR), 0.84; 95% confidence interval (CI), 0.73-0.97; P = 0.017) and type III PCoA (OR, 21.54, 95% CI, 1.33-347.97; P = 0.031) were independent predictors of good functional outcomes. Conclusion: A low initial NIHSS score and good PCoA patency were independent predictors of favorable clinical outcomes after EVT in patients with acute basilar top occlusion. Furthermore, the favorable outcome group showed a high proportion of type III basilar top occlusions. [ABSTRACT FROM AUTHOR]

Background: Ruptured posterior communicating artery (PCoA) aneurysms are common; they usually present with subarachnoid haemorrhage (SAH) and oculomotor nerve palsy. The aneurysmal dome projection may influence the safety access and aneurysmal neck clipping. Here, we discuss additional intraoperative steps that may be required to widen the surgical field to ensure safe surgical clipping of a rupture pure posteriorly directed PCoA aneurysm. Case description: A previously healthy 38-year-old male reported sudden severe headache and disturbed level of consciousness with a Glasgow coma scale (GCS) of 13. His initial computed tomography (CT) scan of the head showed SAH in the basal cistern. 3D-constructed CT angiography (CTA) revealed a left pure posteriorly directed PCoA aneurysm. In the surgery, through the left pterional approach, all intraoperative steps were carried out. Additional steps were performed as well. Three additional intraoperative steps were contemplated because a pure posteriorly directed PCoA aneurysm is not well appreciated and is often hidden behind the supra cliniold internal carotid artery (ICA). First, the extension of Sylvian fissure dissection to include the distal part and the proximal. Second, temporal pole mobilization is performed by cutting small anterior temporal veins. Third, a brain retractor is placed on the temporal lobe to gently tract the superficial part of the lobe. All these steps widened the surgical corridor to ensure the aneurysm's safe clipping. Conclusion: Surgical clipping is influenced by the aneurysmal dome projection. In a ruptured pure posteriorly directed PCoA aneurysm, further intraoperative steps may facilitate complete access and safe clipping of the aneurysm. [ABSTRACT FROM AUTHOR]

Purpose: Excluding aplasia and hypoplasia of the P1 segment of the posterior cerebral artery (PCA), anatomical variations in the PCA are rare. To our best knowledge, there are few reports of an extremely long P1 segment of the PCA. Methods: Herein, we report a rare case of an extremely long P1 segment of the PCA, which was diagnosed by 1.5-T magnetic resonance angiography (MRA). Results: A 96-year-old woman was transferred by ambulance to our hospital with impaired consciousness. Her symptom improved, and magnetic resonance imaging showed no significant findings. MRA revealed an extremely long P1 segment of the left PCA. The length of the P1 segment of the left PCA was 27.3 mm. The left posterior communicating artery (PCoA) was 20.9 mm, which is not considered long. The left anterior choroidal artery branched from the internal carotid artery distal to the PCoA branching position. Basilar artery fenestration was also incidentally identified. Conclusion: Careful imaging assessment was important for identifying the extremely long P1 segment of the PCA in the present case. This rare anatomical variation can also be confirmed by 1.5-T MRA. [ABSTRACT FROM AUTHOR]

A 20-year-old woman presented with left eye ptosis without any headache and pupillary dysfunctions. After the radiological examination, the oculomotor nerve compression was detected in the interpeduncular space by the posterior communicating artery (PCoA) with normal size and shape. The patient underwent frontotemporal craniotomy, and during the surgery, the nerve was detached from the PCoA. Immediately after surgery, all symptoms disappeared. Although oculomotor nerve palsy (ONP) owing to internal carotid-PCoA aneurysm is common, vascular compression due to a non- aneurysmal PCoA is very rare. To the extent of our knowledge, this is the first case in which a slightly displaced, otherwise normal, PCoA causes ONP without any pupillary involvement. After ruling out an aneurysmal artery, this should be considered as one of the possible causes of the ONP.

Background: Ruptured posterior communicating artery (PCoA) aneurysms are common; they usually present with subarachnoid haemorrhage (SAH) and oculomotor nerve palsy. The aneurysmal dome projection may influence the safety access and aneurysmal neck clipping. Here, we discuss additional intraoperative steps that may be required to widen the surgical field to ensure safe surgical clipping of a rupture pure posteriorly directed PCoA aneurysm. Case description: A previously healthy 38-year-old male reported sudden severe headache and disturbed level of consciousness with a Glasgow coma scale (GCS) of 13. His initial computed tomography (CT) scan of the head showed SAH in the basal cistern. 3D-constructed CT angiography (CTA) revealed a left pure posteriorly directed PCoA aneurysm. In the surgery, through the left pterional approach, all intraoperative steps were carried out. Additional steps were performed as well. Three additional intraoperative steps were contemplated because a pure posteriorly directed PCoA aneurysm is not well appreciated and is often hidden behind the supra cliniold internal carotid artery (ICA). First, the extension of Sylvian fissure dissection to include the distal part and the proximal. Second, temporal pole mobilization is performed by cutting small anterior temporal veins. Third, a brain retractor is placed on the temporal lobe to gently tract the superficial part of the lobe. All these steps widened the surgical corridor to ensure the aneurysm's safe clipping. Conclusion: Surgical clipping is influenced by the aneurysmal dome projection. In a ruptured pure posteriorly directed PCoA aneurysm, further intraoperative steps may facilitate complete access and safe clipping of the aneurysm.

Background: Ruptured cerebral artery aneurysms (RCAA) are devastating diseases with high morbidity and mortality rates if not promptly managed. In Nigeria, access to timely neurosurgical services remains a challenge and aneurysm coiling is still not possible in virtually all centres in Nigeria. The aim of this study is to report on our 9 years' experience with clipping of cerebral aneurysm and on the attendant clinical outcomes. Methodology: A retrospective analysis of all consecutive operated RCAA between March 2012 and June 2021 was conducted. Patients' demographic parameters, World Federation of Neurosurgical Societies (WFNS) grade, Hunt and Hess (HH) grade, aneurysm location, timing of surgery and outcome were analysed. Outcome was measured using Glasgow Outcome Scale (GOS) score. Results: A total 29 were included in the study. The most common age group affected was between 50-59 years. RCAA were mainly in the region of the middle cerebral artery and posterior communicating artery (PComA) territories. All the patients presented after 24 hours of the ictus. Two (6.9%) patients had multiple aneurysms. Early clipping (<72hours after presentation) was possible in 8 (27.6%) patients. At least one episode of a rebleed occurred in 19 (65.5%) patients prior to surgery. Mortality rate was 17.2%. None of the patients with PComA aneurysm died. The patients' pre-operative WFNS and HH grades were significantly associated with GOS. Conclusion: Modifiable factors like under diagnoses, delayed referral, cultural belief and financial challenges may account for the low number of patients presenting for neurosurgical care. The possibility of a sizeable number of patients dying due to these factors is a strong possibility for the low number of patients presenting for neurosurgical care. [ABSTRACT FROM AUTHOR]

Purpose: Variations of the posterior cerebral artery (PCA) are rare, excluding aplasia or hypoplasia of the P1 segment. To the best of our knowledge, there are few reports of complete duplication of the PCA. Methods: Herein, we report a case of complete duplication of the PCA diagnosed by 1.5 T magnetic resonance angiography. Results: A 55-year-old woman visited our hospital for cerebrovascular disease screening. Magnetic resonance angiography revealed two right PCAs with similar diameters. One PCA originated as the P1 segment of the PCA branching from the basilar artery, and the other was the fetal-type posterior communicating artery (PCoA) branching from the internal carotid artery (ICA). Neither PCA supplied the right anterior choroidal artery (AChA) territory. Bilateral PCoAs branched from the same position as each ICA, respectively. The right AChA branched from the ICA distal to the PCoA branching position. Conclusion: Careful imaging assessment is important for identifying complete duplication of the PCA. In addition to the direct findings of AChA identification, the indirect findings of the PCoA branching position and that the PCAs did not supply the AChA territory were also useful for diagnosis in this case. [ABSTRACT FROM AUTHOR]