Posterior Cerebral Artery Aneurysm Research Articles

A case of posterior cerebral artery aneurysm associated with idiopathic bilateral internal carotid artery occlusion: case report

BACKGROUND Aneurysms of the posterior circulation are challenging lesions to neurosurgeons, despite improvements in microsurgical techniques and advances in skull base approaches. We present a rare case of a posterior cerebral artery (PCA)-posterior communicating artery (PcomA) junction aneurysm associated with bilateral internal carotid artery (ICA) occlusion successfully treated with an endovascular procedure. CASE DESCRIPTION A 57-year-old female presented with sudden onset of severe headache and loss of consciousness. CT scan showed diffuse subarachnoid hemorrhage and acute hydrocephalus. The patient developed severe neurogenic pulmonary edema and shock. Although her neurogenic pulmonary edema did not resolve, she recovered from shock. However, her general condition was so critical and her vital signs so unstable, that direct surgery under general anesthesia was considered too risky. A cerebral angiogram showed complete occlusion of both internal carotid arteries without any Moyamoya vessels. A saccular aneurysm located at the right PCA-PcomA junction was seen. To obliterate the aneurysm and prevent rerupture, the patient underwent coil embolization via an endovascular approach under sedation with local anesthesia. The balloon remodeling technique was useful to prevent occlusion of parent arteries. Finally, four interlocking detachable coils (IDC) with a total length of 44 cm were used to completely obliterate the aneurysm using the balloon remodeling technique. The patient made a full recovery after treatment and the aneurysm remained obliterated 2 years after coil embolization. CONCLUSIONS We emphasize the advantages of the endovascular approach for the patient in critical condition. We believe that this is the first report of a PCA-Pcom junction aneurysm associated with bilateral ICA occlusion without moyamoya disease.

Lumbar puncture in subarachnoid haemorrhage: a necessary evil?

A 70-year-old lady was admitted following the sudden onset of a severe, throbbing headache 7 days previously. The headache was occipital in location, with radiation to the back of the neck and both shoulders. The patient had vomited twice at the onset of the pain but, although initially severe, the headache had gradually resolved without further complication. The patient had a history of hypertension, controlled on bendrofluazide 2.5 mg once daily. A mastectomy had been performed in 1992 for carcinoma of the breast. Clinical examination revealed a sinus tachycardia 120 beats per minute and systolic hypertension 170/80 mmHg. Examination was otherwise unremarkable. Investigations included a normal full blood count, liver function tests, bone profile, random glucose, and electrocardiogram. Computed tomography scan of the head was normal. The only abnormality was the finding of a low sodium 132 mmol/litre, attributed to the diuretic, and serum electrolytes were otherwise unremarkable. The patient was discharged as she was asymptomatic and the sinus tachycardia had settled. Unfortunately, the patient was re-admitted the following day complaining of numbness on the right side of the face, together with low back pain. Clinical examination revealed mild cerebellar ataxia. A lumbar puncture was performed with the isolated finding of xanthochromia. A cell count was not performed on the cerebrospinal fluid (CSF). Subsequent cerebral angiography documented a right posterior communicating artery aneurysm, which was clipped 3 days later. The patient was discharged 10 days later with no neurological deficit. A 37-year-old lady was admitted following the sudden onset of a severe occipital headache 5 days previously. The headache had failed to resolve on simple analgesics. She had vomited twice and had developed mild photophobia. There were no apparent precipitants for the pain and there was no other relevant history. Clinical examination was unremarkable, except for the finding of mild neck stiffness and photophobia. The patient had an elevated white cell count (14.9 × 109/litre) but full blood count, serum electrolytes and glucose were otherwise normal. The initial report of the computed tomography scan of the head was normal, although a later review raised the possibility of hydrocephalus. A lumbar puncture was performed with the finding of xanthochromia, CSF red blood cells 25 000 and CSF white cell count 200 (90% polymorphs). No organisms were seen. CSF opening pressure was 12 cm. The patient was transferred to the tertiary centre and she underwent cerebral angiography which documented a left posterior cerebral artery aneurysm. This was embolized at surgery 5 days later. Postoperative recovery was complicated by communicating hydrocephalus with a CSF pressure of 40 cm, which responded well to lumbar puncture. The patient was discharged 10 days later with no neurological deficit. A 31-year-old lady was admitted following the sudden onset of headache 4 hours before admission. The headache was generalized, sharp in nature and associated with two episodes of vomiting. There was no neck stiffness and no photophobia. There were no other relevant features on the history. Clinical examination revealed a stable pulse rate of 72 beats per minute, blood pressure 130/76 mmHg and mild neck stiffness but no other focal deficit. The patient had an elevated white cell count (16.4 x 109/litre) but full blood count, serum electrolytes, and glucose were otherwise normal. Computed tomography scan of the head was normal. Lumbar puncture was performed, with the finding of 101 000 red cells, 125 white cells (60% polymorphonuclear leucocytes; 40% lymphocytes) but no xanthochromia. The patient was transferred to the tertiary neurosurgical centre, where she underwent cerebral angiography. This documented an aneurysm arising from the left internal carotid artery, with a proximal daughter aneurysm. These were clipped at surgery and the patient was discharged 10 days later with no neurological deficit.

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Distal Posterior Cerebral Artery Revascularization in Multimodality Management of Complex Peripheral Posterior Cerebral Artery Aneurysms: Technical Case Report

Abstracts of Literature

Abstracts of Literature

Giant Multilocular Fusiform Aneurysm of the Posterior Cerebral Artery

A 60-year-old woman presented with a giant posterior cerebral artery aneurysm. Her visual field examination revealed right upper quadrantanopia. Because of the difficulty of the neck clipping, we performed parent artery occlusion using the Guglielmi detachable coils following balloon Matas test monitored with single photon emission computed tomography (SPECT) with 99mTc-d, I hexamethyl-propylene-amine oxime. Postoperative left internal angiography showed the left occipital region was supplied by a leptomenigeal collateral via left the middle cerebral artery. Six months after embolisation the aneurysm was completely thrombosed on MR imaging. Her visual field deficits had also improved six months after embolisation. A combination of the balloon Matas test with SPECT followed by parent artery occlusion is an excellent method to treat such giant aneurysms.

Intra-Aneurysmal Pressure Changes During Angiography in Coil Embolization

Background Although elevation of blood pressure in aneurysms induced by injection of contrast medium has been postulated as a major cause of rerupture of ruptured cerebral aneurysms during angiography, no study has proved the elevation of intra-aneurysmal pressure because of difficulty in measuring the intra-aneurysmal pressure during angiography. The present study demonstrated intra-aneurysmal pressure to be raised by injection of contrast medium, using a microcatheter introduced into aneurysms. Methods To confirm the accuracy of pressure measurement through a microcatheter, we measured intra-aneurysmal pressure in a plastic model of an artery and an aneurysm during and after injection of contrast medium through a microcatheter and a needle inserted into the aneurysm. In a clinical study, intra-aneurysmal pressures were measured through the microcatheter in nine cerebral aneurysms of seven patients. Results In the model experiment, changes in the pressure measured through the microcatheter correlated well with those observed through the needle. In the clinical study, intra-aneurysmal systolic pressures increased by 5–23 mm Hg immediately after injection of contrast medium for 1–3 s in four basilar tip, three internal carotid-ophthalmic, and one middle cerebral artery aneurysm, whereas no pressure change was observed in a posterior cerebral artery aneurysm. Systemic blood pressure during angiography remained unchanged in all cases. Conclusions This abruptly elevated intra-aneurysmal pressure by injection of contrast medium might cause rerupture of an aneurysm soon after rupture of the aneurysm, especially when the rupture site is fragile.

Intracranial aneurysms in Marfan's syndrome: an autopsy study.

Marfan's syndrome is a heritable connective tissue disorder that has been associated with intracranial aneurysms. However, the prevalence of intracranial aneurysms in Marfan's syndrome is unknown and pathological studies of affected vessels have not been reported. We therefore examined the neuropathological findings in a group of patients with Marfan's syndrome. We identified all patients with Marfan's syndrome in whom postmortem examination had been performed at the Mayo Clinic between 1969 and 1993. Autopsy included examination of the brain in seven patients with Marfan's syndrome (five men and two women with a mean age of 28 yr). Each of two patients had one or more intracranial aneurysms. The first patient, a 32-year-old man who died as a result of aortic dissection, was observed to have an incidental saccular supraclinoid carotid artery aneurysm (7 mm). Microscopic examination of the remainder of the cerebral arteries revealed duplication and fragmentation of the internal elastic lamina. The second patient, a 20-year-old man who died as a result of a subarachnoid hemorrhage, had ruptured saccular supraclinoid carotid artery (3 mm) and anterior cerebral artery (20 mm) aneurysms as well as unruptured fusiform middle cerebral artery (18 mm) and posterior cerebral artery (13 mm) aneurysms. Microscopic examination of the cerebral arteries revealed widespread changes consisting of intimal proliferation, medial degeneration, and fragmentation of the internal elastic lamina. These findings confirm an association between Marfan's syndrome and intracranial aneurysms. Microscopic involvement of cerebral arteries in Marfan's syndrome may be variable, even among those with intracranial aneurysms.

Management strategies for posterior cerebral artery aneurysms: a proposed new surgical classification.

In a period of 10 years fifteen patients bearing sixteen aneurysms arising at the posterior cerebral artery were operated at our institution. Based on the approaches selected for each location a division of the posterior cerebral artery into three surgical segments is proposed. The first segment (S1), or anterior extends from the basilar artery bifurcation to the point where the artery reaches the level of the most lateral edge of the cerebral peduncle, the second segment (S2), or middle extends from the posterior limit of S1 to a point located just before the most medial extent of the artery in the quadrigeminal cistern (collicular point), and the third segment (S3), or posterior corresponds to the collicular point and to the portions of the posterior cerebral artery distal to it. Utilizing the concept of surgical segments all aneurysms in our series were satisfactorily exposed. Those arising at the S1 segment (8 cases) were operated either through a pterional or a pretemporal approaches; those from the S2 segment (6 cases) were operated either via the subtemporal or the subtemporal transventricular routes; and that arising from the S3 segment (1 case) was managed through the occipital interhemispheric approach. Among the aneurysms eleven were small, one was large, and four were large or giant. Ten of these aneurysms were surgically clipped, two coagulated, three treated by trapping and in one case the aneurysm was resected and the posterior cerebral artery was reconstructed by a termino-terminal anastomosis. The surgical results were considered good in all cases but one, where the patient died due to clinical complications three months after surgery. It is our belief that the use of this classification can provide the means to best select the most appropriate surgical approach to treat aneurysms arising at the posterior cerebral artery.

Imaging of Vestibular Aqueduct, Endolymphatic Duct and Sac and Adenocarcinoma of Probably Endolymphatic Sac Origin

We review four cases of posterior cerebral artery (PCA) aneurysm, of which three showed intolerance of parent artery occlusion. In two, balloon test occlusion (BTO) indicated poor opaci- fication of the PCA branches from the anastomoses, and therefore, permanent occlusion was not attempted.

Skull Base Approaches for Posterior Circulation Aneurysms

With the emergence of skull base surgery, surgical approaches have been developed and redefined, providing surgeons with accessible avenues to difficult lesions of the cranial base. Although the majority of lesions to which these techniques have been applied have been for tumors, we find that these skull base approaches can equally provide access to difficult vascular lesions, especially complex aneurysms of the posterior circulation. In this report three different skull base approaches were used in four patients for the treatment of posterior circulation aneurysms. A cranio-orbital-zygomatic approach was used for the acute stage of a ruptured basilar tip artery anenrysm and for a giant posterior cerebral artery aneurysm. A petrosal approach was used for a ruptured basilar trunk aneurysm, and the transcondylar approach was used for a vertebral artery aneurysm. Each approach provides a wide field and excellent exposure of vital structures with minimal brain retraction. Neck clipping of the aneurysms was successfully achieved in all cases. We believe that our skull base approaches facilitate the surgical treatment of posterior circulation aneurysms.

脚間・迂回槽内および周囲の血管性病変に対するtrans-choroidal fissure approachの手術適応

The microsurgical anatomy of trans-choroidal fissure (CF) approach for vascular lesions in and around the interpeduncular and ambient cisterns was studied using 3 cadavers treated by arterial and venous injection of the mixture of silicon with dye and barium sulfate. The angiographical “plexal point,” which shows the entrance of the anterior choroidal artery (AChA) coming into the inferior horn (IF) of the lateral ventricle, is thought to be the key anatomical landmark in the surgery for the vascular lesions in the ambient and interpeduncular cisterns. The transcortical route into IF through the inferior temporal gyrus is better for avoiding the injury of the optic radiation around IF.After opening CF posterior to the plexal point between the hippocampal formation (fimbria) and the choroid plexus, the posterior cerebral artery (PCA) in the ambient cistern can be seen with minimal retraction of the hippocampal formation (fimbria). When retracting the brain, great care must be taken not to injure the hippocampus, the tail of caudate nucleus, and the lateral geniculate body. Additional partial resection of the uncus permits opening the interpeduncular cistern and can give neurosurgeons a working space large enough for access to the high basilar tip aneurysm and the retrochiasmatic lesions such as parasellar tumors.Patients with PCA aneurysm or arteriovenous malformation (AVM) in and around the ambient cisterns, as well as those with AChA AVM in the medial temporal lobe, are likely to be good surgical candidates for trans-CF approach when their PCA is running nearly as high as the “plexal point” of AChA or higher.For patients, however, whose PCA is running far lower than this point on the lateral angiography, the subtemporal approach is likely to be better than the trans-CF approach. Clinically for a patient with the ruptured PCA aneurysm and one with the AVM in the medial temporal lobe, good surgical results were achieved with this trans-CF approach.

Traumatic posterior cerebral artery aneurysm secondary to an intracranial nail: Case report

We present the case of a traumatic posterior cerebral artery aneurysm from a self-inflicted pneumatic nail-gun missile injury through the roof of the mouth. The patient presented to us in a coma with subarachanoid and intraventricular hemorrhage. Cerebral angiography revealed an aneurysm of the left posterior cerebral artery with no distal filling. The patient died 6 days after admission. At autopsy, a pseudoaneurysm of the posterior cerebral artery was seen. This aneurysm resulted from direct disruption of the arterial wall by the intracranial nail

Perimesencephalic subarachnoid hemorrhage. Additional perspectives from four cases.

Nonaneurysmal perimesencephalic hemorrhage, a distinct form of subarachnoid hemorrhage, is a recently described variant of intracranial hemorrhage. We describe two patients who presented with unusual features of this type of subarachnoid hemorrhage and also two patients who had a perimesencephalic pattern of hemorrhage due to a ruptured posterior circulation aneurysm. The first patient, a 41-year-old woman with perimesencephalic hemorrhage, underwent an exploratory craniotomy because angiography had suggested an anomaly of the basilar tip. No source of hemorrhage could be identified at the time of surgery. The second patient was a 3-year-old boy who presented with opisthotonos and who was found to have a perimesencephalic hemorrhage. Angiography revealed no source for the hemorrhage. The third patient, a 54-year-old man, had a perimesencephalic pattern of subarachnoid hemorrhage from a vertebrobasilar junction aneurysm associated with a fenestration that was missed on the initial angiographic study. The fourth patient, a 43-year-old man, suffered a perimesencephalic pattern of subarachnoid hemorrhage from a small posterior cerebral artery aneurysm, which had not been recognized on two angiograms. These patients elaborate on the clinical spectrum of subarachnoid hemorrhage with a perimesencephalic pattern. First, a negative exploratory craniotomy suggests that the source of nonaneurysmal perimesencephalic hemorrhage may not be arterial. Second, nonaneurysmal perimesencephalic hemorrhage may also occur in children. Finally, the index of suspicion for a posterior circulation aneurysm should remain high in patients who present with a perimesencephalic pattern of subarachnoid hemorrhage, and these aneurysms may rise from unusual locations.

Spontaneous thrombosis of posterior cerebral artery aneurysm with angiographic reappearance

The case is presented of a 23-year-old man suffering ischemic brain infarction from spontaneous thrombosis of a left posterior cerebral artery P1-P2 junction aneurysm. Vasospasm and/or partial parent vessel occlusion were documented by magnetic resonance (MR) imaging and angiography. Repeat cerebral angiography and MR imaging 3 months later revealed patency of the posterior cerebral artery and luminal filling of a 1-cm fusiform aneurysm, which was successfully trapped at surgery.

An Alternative Surgical Approach to Aneurysms of the Posterior Cerebral Artery

The value of a skull base approach (the transzygomatic approach) is assessed in the treatment of patients with posterior cerebral artery aneurysms. The operative approach is outlined, and the advantages and disadvantages of the procedure are discussed.

Frameless isocentric stereotactic laser beam guide for image-directed microsurgery.

We have developed a frameless stereotactic multi-articulated arm suitable for image-directed microsurgery and surgical navigation. The system comprises a frameless isocentric mechanism and a three-dimensional (3 D) digitizer for intra-operative monitoring. Five joints of our multi-articulated arm are equipped with electromagnetic clutches, and the arms are provided with counterbalancing weights to ensure safe, smooth movement. Stereotactic microsurgical procedures were carried out with a laser beam guide mounted at the tip of the isocentric arm. We have used this system in 22 cases to resect tumours or epileptic foci. There were 12 cases of glioma, 5 cases of deep seated benign tumours, 3 cases of multiple metastatic tumours, and 2 cases of temporal lobe epilepsy. Postoperative enhanced CT images indicated total or subtotal resection in all cases. We also have used this system to determine the approach for clipping of a posterior cerebral artery aneurysm in 2 cases. The error of mechanical accuracy of the system was less than 1 mm. We believe that this system will prove useful in image-directed microsurgical procedures.

Aneurysm of the Posterior Cerebral Artery

Eleven cases of an aneurysm of the posterior cerebral artery are reported. All 11 aneurysms were saccular, and 3 were either giant or large. The aneurysms arose from the P1 segment in three patients, the P1-P2 junction in three patients, the P2 segment in three patients, and from the P3 segment in two patients. In all, 10 patients underwent surgery. All P1 and P1-P2 junction aneurysms were treated with the pterional approach. Three P2 and two P3 aneurysms were managed by the subtemporal approach. Two small aneurysms in the series were treated by coating the aneurysmal dome, two by clipping the afferent artery, and all other saccular type aneurysms were treated by clipping the aneurysmal neck. Seven patients had either an excellent or good outcome; two had poor results; and one patient died. The operative approaches and procedures are also discussed in relation to the anatomy of posterior cerebral artery aneurysms.

脳室内出血を伴った破裂後大脳動脈末稍部動脈瘤の1例

脳室内出血を伴った破裂後大脳動脈末稍部動脈瘤の1例