[Posterior Communicating Artery / Posterior Cerebral Artery].

Thorough understanding of the vascular anatomy, including embryological development of vessels is important to safely perform endovascular procedures. The posterior cerebral and anterior choroidal arteries are embryologically complementary, which suggests a potential network. Numerous perforators originate from the posterior communicating and posterior cerebral arteries. The tuberothalamic artery arising from the posterior communicating artery and the thalamoperforating artery, which originates from the P1 segment of the posterior cerebral artery are clinically important because occlusion of these vessels can precipitate severe infarction. It is clinically important to be aware that the branching pattern of perforators differs based on the fusion type of the basilar tip. The balloon occlusion and Allcock test are useful to predict ischemic tolerance in cases of intentional artery occlusion. However, accurate prediction remains challenging, and a definitive evaluation method is unavailable. Flow disturbances in the cortical territory and local perforator impairment require close attention in cases of intentional artery occlusion.

Posterior cerebral artery involvement in unilateral moyamoya disease is exclusively ipsilateral and influenced by RNF213 mutation gene dose: The SUPRA Japan study: PCA involvement in unilateral moyamoya.

OBJECTIVES: The characteristics and clinical implications of posterior cerebral artery (PCA) involvement in unilateral moyamoya disease (U-MMD), such as laterality, frequency of the RNF213 p.R4810K mutation, and clinical outcomes, have not been well studied. POPULATION AND METHODS: We analyzed a cohort of 93 patients with U-MMD who participated in the SUPRA Japan study. Clinical characteristics and radiological examinations were collected from medical records. The presence of the p.R4810K mutation was determined using a TaqMan assay. The clinical outcome was assessed using the modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were performed to assess the associations. RESULTS: Among the patients with U-MMD, PCA involvement was observed in 60.0 % (3/5) of patients with homozygous mutation, 11.3 % (7/62) of those with heterozygous mutation, and 3.8 % (1/26) of those with wild type, showing a significant linear trend (p < 0.001 for trend). PCA involvement was observed exclusively on the same side as the affected anterior circulation. Dyslipidemia and cerebral infarction at initial onset were independently associated with mRS ≥1. Hypertension was associated with mRS ≥1 and it was also linked to infarction at initial onset, suggesting a potential confounding effect. Although PCA involvement showed a trend for higher mRS, it was not statistically significant. CONCLUSIONS: Our findings indicate a gene dose effect of the p.R4810K mutation on PCA involvement, with the homozygous state showing the most significant effect. Both genetic and modifiable factors such as dyslipidemia may influence the progression of U-MMD.

Prenatal features of aneurysm of the posterior cerebral artery: a case report.

BACKGROUND: Fetal cerebral aneurysm other than aneurysm of vein of Galen aneurysmal malformation (VGAM) is extremely rare. This report describes prenatal features of aneurysm of the posterior cerebral artery (APCA) with rapid progression and its natural intrauterine course of the disease, which has never been reported. CASE PRESENTATION: This is the first report of prenatal features of APCA, detected at 34-36 weeks of gestation, simulating choroid plexus cyst or arachnoid cyst. The diagnosis was based on color flow ultrasound with tracing along the course of cerebral arteries. Also, rendered 3D color flow ultrasound was helpful in demonstrating course of the vessels feeding the aneurysm and supporting the diagnosis. The aneurysm showed nature of rapidly progressive changes, leading to leakage resulting in intracerebral and intraventricular hemorrhage as well as high output state associated with anemia. Prenatal diagnosis and management are very challenging. This case ended up with planned delivery at 37 weeks, giving birth to a surviving male newborn, weighing 2600 g. The neonatal CT brain scans and CTA confirmed the prenatal findings. The prognosis was relatively poor because of extensive intracerebral hemorrhage with severe hydrocephalus and brain midline shift. The couple opted for neonatal palliative care without neurosurgical correction. CONCLUSION: This study demonstrate that the most important tool for prenatal diagnosis is color Doppler ultrasound, which will demonstrate turbulent blood flow. Three-dimension color Doppler ultrasound is helpful in supporting the diagnosis. The case presented here suggests that the disease has a natural course of rapid progression and massive brain destruction or high output congestive heart failure can be expected.

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.

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 .

The Association between Migraine and Fetal-Type Posterior Cerebral Artery in Patients with Ischemic Stroke.

OBJECTIVE: The aim of the study was to determine if migraine is associated with fetal-type posterior cerebral artery (PCA) in patients with ischemic stroke. METHOD: In this cross-sectional study, patients with acute ischemic stroke were enrolled from two hospitals. The history of migraine headache was evaluated during a face-to-face interview. The variants of fetal-type PCA were assessed with MRA, CTA, or DSA. Patients with and without migraine were compared in terms of fetal-type PCA status and other clinic characteristics. Multivariate logistic regression analyses were performed to adjust for confounders and provide risk estimates for observed associations. RESULT: In 750 patients qualified for analysis, 85 (11.3%) were determined with migraine. Patients with migraine had a higher proportion of female gender (51.8% vs. 31.0%, p < 0.001), hypertension (72.9% vs. 57.7%, p = 0.007), and fetal-type PCA (36.5% vs. 20.1%, p = 0.001), while lower proportion of current smoking (25.9% vs. 38.3%, p = 0.025) than patients without migraine. National Institutes of Health Stroke Scale (NIHSS) score (3 vs. 2, p = 0.016) was also higher in migraineurs than in non-migraineurs. After adjustment for confounders, fetal-type PCA status was independently associated with migraine (odds ratio [OR] = 2.06; 95% confidence interval [CI], 1.25-3.38; p = 0.005). Other factors associated to migraine included female gender (OR = 2.03; 95% CI, 1.13-3.62; p = 0.017), hypertension (OR = 1.97; 95% CI, 1.17-3.34; p = 0.011), and NIHSS score (OR = 1.08; 95% CI, 1.01-1.16; p = 0.018). CONCLUSION: Migraine was associated with fetal-type PCA in patients with ischemic stroke. This finding supported the hypothesis that vascular mechanisms get involved in the migraine-stroke association.

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.

Carotid artery web with fetal posterior cerebral artery variant masquerading as recurrent ipsilateral cryptogenic ischaemic strokes.

A 31-year-old woman was referred to vascular surgeons with the history of recurrent ischaemic strokes in two cerebral artery territories over a span of 1 year. On investigation, she was found to have a right internal carotid artery web, with thrombus and a fetal right posterior cerebral artery (PCA), which explained the ischaemic strokes in right middle cerebral and PCA territory. The rare association of these two infrequent entities makes the case a singular one in the medical literature. Successful surgical excision was done after multidisciplinary teamwork. The carotid web was excised as part of carotid artery endarterectomy and repaired with great saphenous vein patch angioplasty. The patient made a good recovery.

Morphologic Variations in the Circle of Willis as a Risk Factor for Aneurysm Rupture in the Anterior and Posterior Communicating Arteries.

BACKGROUND: Intracranial aneurysms are acquired abnormal vascular dilations. The most dangerous complication of a cerebral aneurysm is its rupture, with a high rate of mortality. This study aimed to determine whether there is an association between anatomic variations in the circle of Willis and ruptured aneurysms in the anterior and posterior communicating arteries. METHODS: A cross-sectional study of adult patients with a diagnosis of intracranial aneurysm was carried out between March 2015 and March 2019. The patients were divided into groups of ruptured or unruptured aneurysm in the anterior and posterior communicating arteries. RESULTS: A total of 132 patients with anterior and posterior communicating artery aneurysms were included. The presence of anatomic variation in the circle of Willis presented a statistically significant association with ruptured aneurysms (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.11-4.65; P = 0.024). There was a statistically significant difference between the presence of nonspherical aneurysm and rupture (OR, 6.9; 95% CI, 3.12-15.48; P < 0.0001). Multivariate logistic regression observed smoking (OR, 2.4; 95% CI, 1.01-5.9; P = 0.4), anterior complex variations (OR, 2.68; 95% CI, 1.01-7.18; P < 0.04), and nonspherical morphology (OR, 4.7; 95% CI, 1.93-11.45; P = 0.001) presented a statistically significant association with the rupture. CONCLUSIONS: Our results suggest that the studied variations of the circle of Willis and nonspherical morphology, in addition to playing a role in the development of cerebral aneurysms, may contribute to their rupture.

Additional Revascularization Using Multiple Burr Holes for PCA Involvement in Moyamoya Disease.

In specific cases of moyamoya disease (MMD), posterior cerebral artery (PCA) stenosis can develop after treatment of the anterior circulation and require additional revascularization. Here, we report two cases that underwent additional posterior indirect revascularization with multiple burr holes for PCA involvement after bilateral revascularization treatment of the anterior circulation. They presented with transient ischemic attack even after bilateral superficial temporal artery-middle cerebral artery bypass, and magnetic resonance angiography (MRA) showed that PCA stenosis had worsened. Indirect revascularization with multiple burr holes using Benz-marked skin incisions was performed. After surgery, the symptoms improved without perioperative complications, and cerebral angiography showed collateral circulation via the burr hole. Indirect revascularization for MMD is often combined with direct revascularization, and there are only a few reports on the use of multiple burr hole surgery alone. In addition, there are few reports of posterior circulation, despite the emphasis on the importance of PCA involvement in MMD. Indirect revascularization with multiple burr holes alone can be performed in multiple areas and applied to patients who cannot undergo direct revascularization using the occipital artery. The procedure is simple and less invasive than traditional direct revascularization procedures. Therefore, it can be effective, especially in pediatric cases of MMD with PCA involvement.

Risk Factors for the Recurrence of Posterior Communicating Artery Aneurysm: The Significance of Fetal-Type Posterior Cerebral artery.

OBJECTIVES: The purpose of this study was to investigate the risk factors associated with recurrence of posterior communicating artery aneurysms after treatment and to evaluate the significance of fetal-type posterior cerebral artery as an independent risk factor for recurrence of posterior communicating artery aneurysms. MATERIALS AND METHODS: The clinical and radiological findings of 220 posterior communicating artery aneurysms treated between January 2009 and December 2016 in a single tertiary institute were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the association between clinical and radiological variables and recurrence. RESULTS: Of 220 posterior communicating artery aneurysms, 148 aneurysms were unruptured and 82 aneurysms were treated with surgery. Forty-six out of 220 aneurysms (20.9%) were associated with fetal-type posterior cerebral artery. Overall recurrence rate was 19% (42 out of 220 aneurysms) during mean 54.6 ± 29.8 months follow-up. Multivariate logistic regression analysis showed that size (OR=1.238; 95% CI, 1.087-1.409, p = 0.001), ruptured status (OR=2.699; 95% CI, 1.179-6.117, p = 0.019), endovascular treatment (OR=3.803; 95% CI, 1.330-10.875, p = 0.013), incomplete occlusion (OR=4.699; 95% CI, 1.999-11.048, p = <0.001) and fetal-type posterior cerebral artery (OR=3.533; 95% CI, 1.373-9.089, p = 0.009) were significantly associated with recurrence after treatment. CONCLUSIONS: The results demonstrated that fetal-type posterior cerebral artery may be an independent risk factor for the recurrence of posterior communicating artery aneurysms. Therefore, fetal-type posterior cerebral artery can be considered as an important risk factor for the recurrence of posterior communicating artery aneurysms, along with other known risk factors such as size, ruptured status, endovascular treatment, and incomplete occlusion.

Ascending pharyngeal artery-posterior inferior cerebellar artery anastomosis via the jugular foramen: a case report and literature review.

The posterior inferior cerebellar artery (PICA) rarely arises from the cavernous segment of the internal carotid artery (ICA) and is called persistent trigeminal artery variant. The PICA also can arise from the cervical segment of the ICA, and it enters the posterior fossa via the hypoglossal canal, where it is called persistent hypoglossal artery variant. Using magnetic resonance angiography (MRA), we diagnosed a 79-year-old man with a PICA arising from the ascending pharyngeal artery and passing through the medial side of the jugular foremen pars vascularis. Only six cases of this variation have been reported previously in the English language literature. To identify this variation on MRA, the careful observation of source images is useful. Recognizing this variation is important in order to avoid ischemic cerebellar complications during neck surgery and endovascular therapy.

Presigmoid Transpetrosal Approach for Superficial Temporal Artery to Distal Posterior Cerebral Artery Bypass and Trapping of Aneurysm.

BACKGROUND AND IMPORTANCE: Aneurysms of the posterior cerebral artery (PCA) are uncommon, estimated at less than 1% of all cerebral aneurysms, and less than half occur distal to the P1/2 junction. Unfortunately, the conventional bypass approach for PCA aneurysms-primarily occipital artery to distal PCA cortical branches-has a history of unsatisfying results. CLINICAL PRESENTATION: A 42-yr-old female presented with Fisher 3 Hunt-Hess 2 subarachnoid hemorrhage secondary to ruptured distal PCA aneurysm. She was initially evaluated by the endovascular service, but due to recent subarachnoid hemorrhage, endovascular treatment with flow diversion and/or vessel sacrifice was felt to be relatively contraindicated and the patient was referred for surgical evaluation for possible bypass. The patient subsequently underwent surgery for trapping of aneurysm and concomitant superficial artery to distal PCA bypass. CONCLUSION: A novel approach for the treatment of a ruptured distal PCA aneurysm is described, consisting of posterior transpetrosal exposure and division of the tentorium with superficial temporal artery to P3 bypass.

Comparison of Clinical Outcomes After Stent-Assisted Coiling with 3 Types of Self-Expanding Laser-Cut Stents in Patients with Wide-Necked Intracranial Aneurysms.

OBJECTIVE: We report the clinical outcomes of stent-assisted coiling for wide-necked intracranial aneurysms using 3 low-profile laser-cut stents and compare the results according to stent type. METHODS: All patients treated with stent-assisted coiling for their intracranial aneurysms at our hospital between July 2010 and September 2019 were reviewed. We selected patients with Enterprise, Neuroform EZ, or Neuroform Atlas stents who underwent imaging follow-up and investigated aneurysm and stent features, stent-related complications, recanalization, and retreatment rates. We compared the retreatment risk among the patients treated with the 3 stent types using Kaplan-Meier survival analysis and Cox regression analysis. RESULTS: We evaluated 364 consecutive cases (103 Enterprise, 105 Neuroform EZ, and 156 Neuroform Atlas stents). Neuroform Atlas was more frequently used in distal vessels: 8 (7.8%) Enterprise, 2 (1.9%) Neuroform EZ, and 41 (26.3%) Neuroform Atlas cases, respectively. The median follow-up durations were 6.49, 4.91, and 1.24 years for the Enterprise, Neuroform EZ, and Neuroform Atlas cases, respectively, and retreatment was performed in 11 (10.1%), 9 (8.6%), and 6 (3.8%) cases. In the first 2 years of follow-up, the estimated retreatment risk ratios for Neuroform EZ and Neuroform Atlas with Enterprise as reference were 0.63 (95% confidence interval, 0.24-1.65; P = 0.35) and 0.54 (95% confidence interval, 0.18-1.59; P = 0.26), respectively. CONCLUSIONS: Neuroform Atlas stents were more frequently deployed in small-caliber vessels compared with the other 2 types of stents. The complication rate and retreatment risk until at least 1 year after the aneurysm treatment appeared to be similar for the 3 stent types.

Right frontotemporal craniotomy for ECA-to-MCA direct and indirect bypass and occipital artery indirect bypass to the posterior circulation: case report.

Moyamoya is an uncommon disease that presents with stenoocclusion of the major vasculature at the base of the brain and associated collateral vessel formation. Many pediatric patients with moyamoya present with transient ischemic attacks or complete occlusions. The authors report the case of a 9-year-old girl who presented with posterior fossa hemorrhage and was treated with an emergency suboccipital craniotomy for evacuation. After emergency surgery, an angiogram was performed, and the patient was diagnosed with moyamoya disease. Six months later, the patient was treated for moyamoya using direct and indirect revascularization; after surgery there was excellent vascularization in both regions of the bypass and no further progression of moyamoya changes. This case illustrates a rare example of intracerebral hemorrhage associated with moyamoya changes in the posterior vascularization in a pediatric patient and subsequent use of direct and indirect revascularization to reduce the risk of future hemorrhage and moyamoya progression.

Comparable blood velocity changes in middle and posterior cerebral arteries during and following acute high-intensity exercise in young fit women.

The cerebral blood flow response to high-intensity interval training (HIIT) remains unclear. HIIT induces surges in mean arterial pressure (MAP), which could be transmitted to the brain, especially early after exercise onset. The aim of this study was to describe regional cerebral blood velocity changes during and following 30 s of high-intensity exercise. Ten women (age: 27 ± 6 years; VO2max : 48.6 ± 3.8 ml·kg·min-1 ) cycled for 30 s at the workload reached at V˙ O2max followed by 3min of passive recovery. Middle (MCAvmean ) and posterior cerebral artery mean blood velocities (PCAvmean ; transcranial Doppler ultrasound), MAP (finger photoplethysmography), and end-tidal carbon dioxide partial pressure (PET CO2 ; gaz analyzer) were measured. MCAvmean (+19 ± 10%) and PCAvmean (+21 ± 14%) increased early after exercise onset, returning toward baseline values afterward. MAP increased throughout exercise (p < .0001). PET CO2 initially decreased by 3 ± 2 mmHg (p < .0001) before returning to baseline values at end-exercise. During recovery, MCAvmean (+43 ± 15%), PCAvmean (+42 ± 15%), and PET CO2 (+11 ± 3 mmHg; p < .0001) increased. In young fit women, cerebral blood velocity quickly increases at the onset of a 30-s exercise performed at maximal workload, before returning to baseline values through the end of the exercise. During recovery, cerebral blood velocity augments in both arteries, along with PET CO2 .

Impact of cortical hemodynamic failure on both subsequent hemorrhagic stroke and effect of bypass surgery in hemorrhagic moyamoya disease: a supplementary analysis of the Japan Adult Moyamoya Trial.

OBJECTIVE: Here, the authors aimed to determine whether the presence of cerebral hemodynamic failure predicts subsequent bleeding attacks and how it correlates with the effect of direct bypass surgery in hemorrhagic moyamoya disease. METHODS: Data from the Japanese Adult Moyamoya (JAM) Trial were used in this study: 158 hemispheres in 79 patients. A newly formed expert panel evaluated the SPECT results submitted at trial enrollment and classified the cortical hemodynamic state of the middle cerebral artery territory of each hemisphere into one of the following three groups: SPECT stage (SS) 0 as normal, SS1 as decreased cerebrovascular reserve (CVR), and SS2 as decreased CVR with decreased baseline blood flow. In the nonsurgical cohort of the JAM Trial, the subsequent hemorrhage rate during the 5-year follow-up was compared between the SS0 (hemodynamic failure negative) and SS1+2 (hemodynamic failure positive) groups. The effect of direct or combined direct/indirect bypass surgery on hemorrhage prevention was examined in each subgroup. RESULTS: The hemodynamic grade was SS0 in 59 (37.3%) hemispheres, SS1 in 87 (55.1%), and SS2 in 12 (7.6%). In the nonsurgical cohort, subsequent hemorrhage rates in the SS0 and SS1+2 groups were 12 cases per 1000 person-years and 67 cases per 1000 person-years, respectively. Kaplan-Meier analysis revealed that hemorrhagic events were significantly more common in the SS1+2 group (p = 0.019, log-rank test). Cox regression analysis showed that hemodynamic failure was an independent risk factor for subsequent hemorrhage (HR 5.37, 95% CI 1.07-27.02). In the SS1+2 subgroup, bypass surgery significantly suppressed hemorrhagic events during 5 years (p = 0.001, HR 0.16, 95% CI 0.04-0.57), with no significant effect in the SS0 group (p = 0.655, HR 1.56, 95% CI 0.22-11.10). Examination of effect modification revealed that the effect of surgery tended to differ nonsignificantly between these two subgroups (p = 0.056). CONCLUSIONS: Hemodynamic failure is an independent risk factor for subsequent hemorrhage in hemorrhagic moyamoya disease. Direct bypass surgery showed a significant preventive effect in the hemodynamically impaired hemispheres. Thus, hemodynamic failure, as well as previously proposed factors such as choroidal anastomosis, should be considered for the surgical indication in hemorrhagic moyamoya disease.Clinical trial registration no.: C000000166 (umin.ac.jp).

Removal of distal fragments of liquid embolic agents during arteriovenous malformation embolization using the TIGERTRIEVER 13: a technical report.

BACKGROUND: Arteriovenous malformations (AVMs) are vascular lesions that may be treated by an endovascular approach using liquid embolic agents but the control of the liquid embolic agent remains poor and a potential complication may be distal migration of embolic material. The TIGERTRIEVER 13 is a new stent retriever designed for stroke thrombectomy and has a version ideal for distal occlusions. We report our experience in the removal of embolic agent which had migrated into the distal vessels using the TIGERTRIEVER during PHIL/Onyx embolization of AVMs. CLINICAL PRESENTATIONS: Three patients with brain and spinal AVMs underwent endovascular embolization. During trans-arterial embolization of the AVM with PHIL/Onyx, retrograde filling of distal arterial feeders was followed by migration into the normal arterial branches (cortical middle cerebral artery, distal posterior cerebral artery, and anterior spinal artery). This resulted in occlusion or sluggish distal flow in these branches with potential significant neurological deficits. In all three cases, a Headway Duo microcatheter was navigated distally in the occluded vessel beyond the embolic material using a Traxcess microwire. The TIGERTRIEVER 13 was deployed with recanalization of the vessel after a single attempt. In all three patients there were no complications related to the retrieval of embolic agent. CONCLUSION: Distal migrated embolic agents such as PHIL or Onyx can be removed from various arterial vascular territories using stent retrievers dedicated to small vessels.