Parent vessel occlusion for traumatic pseudoaneurysm of P3 segment of posterior cerebral artery:A case report and review of literatures

Traumatic intracranial pseudoaneurysms （TIPA） are rare and pseudoaneurysm of P3 segment of the posterior cerebral artery （PCA） is extremely rarely reported. A 27-year-old man suffered from blunt head injury and underwent diagnostic procedure with head CT scans, cerebral CT angiograms （CTA） and digital subtraction angiograms （DSA）. An abnormal high-density lesion was detected at the left side of quadrigeminal cistern and a pseudoaneurysm showed at the P3 segment of PCA. The pseudoaneurysm was successfully treated with parent artery occlusion （PAO）. Making an exact preoperative diagnosis of traumatic intracranial pseudoaneurysms is of great importance. Endovascular techniques allow a safe approach to complex intracranial lesion, so endovascular management of PCA pseudoaneurysms becomes safe and effective. However, the pseudoaneurysm may not be amenable to coil placement under some conditions, thus, occlusion of the parent vessel may be a preferable treatment.

Microvascular decompression for a patient with oculomotor palsy caused by posterior cerebral artery compression:A case report and literature review

BACKGROUND Aneurysm compression,diabetes,and traumatic brain injury are well-known causative factors of oculomotor nerve palsy(ONP),while cases of ONP induced by neurovascular conflicts have rarely been reported in the medical community.Here,we report a typical case of ONP caused by right posterior cerebral artery(PCA)compression to increase neurosurgeons’awareness of the disease and reduce misdiagnosis and recurrence.CASE SUMMARY A 54-year-old man without a known medical history presented with right ONP for the past 5 years.The patient presented to the hospital with right ptosis,diplopia,anisocoria(rt 5 mm,lt 2.5 mm),loss of duction in all directions,abduction,and light impaired pupillary reflexes.Magnetic resonance angiography and computed tomography venography examinations showed no phlebangioma,aneurysm,or intracranial lesion.After conducting oral glucose tolerance and prostigmin tests,diabetes and myasthenia gravis were excluded.Cranial nerve magnetic resonance imaging showed that the right PCA loop was in direct contact with the cisternal segment of the right oculomotor nerve(ON).Microvascular decompression(MVD)of the culprit vessel from the ON through a right subtemporal craniotomy was carried out,and the ONP symptoms were significantly relieved after 3 mo.CONCLUSION Vascular compression of the ON is a rare pathogeny of ONP that may be refractory to drug therapy and ophthalmic strabismus surgery.MVD is an effective treatment for ONP induced by neurovascular compression.

Clinical Analysis of Embryonic Posterior Cerebral Artery

Objective:To understand the clinical characteristics of patients with embryonic posterior cerebral artery and its correlation with abnormal vascular development.Methods:The clinical data of 396 patients with embryonic posterior cerebral artery confirmed by magnetic resonance angiography(MRA)and computed tomography angiography(CTA)were analyzed.Results:Two-hundred patients had clinical manifestations of posterior circulation ischemia,including recurrent dizziness,vertigo,and tinnitus;45 had headaches,97 had limb weakness,and 16 patients had syncope or impaired consciousness.Seventy-six patients with circulatory infarction were admitted to the hospital.There were 251 patients with history of hypertension,74 with diabetes,113 with hyperlipidemia,13 with dominant vertebral artery,10 with intracranial aneurysm,and 19 with absence of A1 segment of the anterior cerebral artery(considering developmental variation).Conclusion:Embryonic posterior cerebral artery develops abnormally during the embryonic period,often accompanied by abnormal vascular access.Due to abnormal hemodynamics,the incidence of posterior circulation ischemia,aneurysm,and infarction increases in such patients.

Regional dynamic cerebral autoregulation across anterior and posterior circulatory territories:A detailed exploration and its clinical implications

Cerebral autoregulation(CA)is the mechanism that maintains stable cerebral blood flow(CBF)despite fluctuations in systemic blood pressure,crucial for brain homeostasis.Recent evidence highlights distinct regional variations in CA between the anterior(carotid)and posterior(vertebrobasilar)circulations.Noninvasive neuromonitoring techniques,such as transcranial Doppler,transfer function analysis,and near-infrared spectroscopy,facilitate the dynamic assessment of CBF and autoregulation.Studies indicate a robust autoregulatory capacity in the anterior circulation,characterized by rapid adjustments in vascular resistance.On the contrary,the posterior circulation,mainly supplied by the vertebral arteries,may have a lower autoregulatory capacity.in acute brain injuries such as intracerebral and subarachnoid hemorrhage,and traumatic brain injuries,dynamic CA can be significantly altered in the posterior circulation.Proposed physiological mechanisms of impaired CA in the posterior circulation include:(1)Decreased sympathetic innervation of the vasculature impairing compensatory vasoreactivity;(2)Endothelial dysfunction;(3)Increased cerebral metabolic rate of oxygen consumption within the visual cortex causing CBFmetabolism(i.e.,neurovascular)uncoupling;and(4)Impaired blood-brain barrier integrity leading to impaired astrocytic mediated release of vasoactive substances(e.g.nitric oxide,potassium,and calcium ions).Furthermore,more research is needed on the effects of collateral circulation,as well as the circle of Willis variants,such as the fetal-type posterior cerebral artery,on dynamic CA.Improving our understanding of these mechanisms is crucial to improving the diagnosis,prognosis,and management of various cerebrovascular disorders.

Dissecting aneurysms of the distal segment of the posterior cerebral artery: clinical presentation and endovascular management

Backgroud:We aimed to evaluate the clinical presentations and report the acceptable clinical and angiographic outcome of the distal posterior cerebral artery (PCA) dissecting aneurysms with parent artery occlusion (PAO).Methods:From June 2006 to July 2013,26 patients with PCA dissecting aneurysms were planned to be treated via endovascular PAO in our institution.Fourteen patients had ruptured aneurysms,and twelve patients had unruptured aneurysms.The endovascular modalities were the following:1) PAO (n =19),2) palliative embolization (n =5),and 3) proximal PAO (n =2).Glasgow Outcome Scale (GOS) was used to assess the clinical outcome.Results:The procedure was technically successful in all cases.In the PAO and proximal PAO group,all of the immediate angiography showed occlusion of the parent vessel,and follow-up imaging showed no recurrence of the aneurysms.In the palliative embolization group,one of five patients was died of rebleeding after the procedure,and follow-up digital subtraction angiography (DSA) showed the other four aneurysms recurred.Five procedure related complications occurred totally:rebleeding (n =1),hemiparesis (n =2),and hemianopsia (n =2).Conclusion:Dissecting aneurysms are dynamic lesions with variable and unpredictable evolution and a thorough treatment is warranted.Sacrificing the parent artery appears to be well tolerated for distal segment of PCA.We propose that this technique could be the first treatment option in treating dissecting aneurysms in this location.However,palliative occlusion of distal PCA dissecting aneurysms is not an advisable treatment option.

Clinical features and outcomes of PComA aneurysms originating from fetal posterior communicating arteries in a single institution

Background:The aim of this study was to retrospectively analyze our experience with the patients who underwent surgical treatment of posterior communicating artery(PComA)aneurysms originating from fetal posterior cerebral artery(fPCA)and analyze the risk factors for the postoperative radiological infarction and outcome.Methods:From 2011 to 2020,we retrospectively reviewed 74 PComA aneurysms originating from fPCA in terms of the clinical and radiological features and obtained the follow-up data from the Department of Neurosurgery,Beijing Tiantan Hospital,Capital Medical University.The relationships between these features and follow-up data were assessed with the univariate and multivariate analysis.Results:In this series,74 aneurysms were occurring at the origin of fPCAs.All the patients showed complete obliteration of their aneurysms.Full fPCA type tends to be a predictive factor for radiological infarction(univariateχ^(2)=5.873,P=0.027;multivariate OR=0.264,P=0.060).Postoperative radiological infarction(univariateχ^(2)=12.611,P=0.001;multivariate OR=6.033,P=0.043),rupture(univariateχ^(2)=4.514,P=0.047;multivariate OR=57.966,P=0.044),and hypertension(univariateχ^(2)=5.301,P=0.024;multivariate OR=24.462,P=0.029)tend to be the independent predictive factors for poor prognosis at 3 months after discharge.Conclusions:In conclusion,we report a series of patients harboring aneurysms originating from the fPCA.Surgical clipping is a reliable strategy.Full fPCA type is related to postsurgical infarction.Postoperative radiological infarction,rupture,and hypertension tend to be the independent predictive factor for poor prognosis at 3months after discharge.