PcoA Aneurysms Research Articles

Predictive value of neurophysiological monitoring during posterior communicating artery aneurysm clipping for postoperative neurological deficits.

This 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. All 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. Patients with intraoperative MEP/SSEP changes were more likely to develop short-term and long-term neurological deficits than those without MEP/SSEP changes (P < 0.05). From the ROC curve analysis, the safe time from the initiation of temporary clipping during the operation to the early warning of neurophysiological monitoring was 4.5 min (AUC = 0.735, 95%CI 0.5558-0.912). Taking 4.5 min as the dividing line, the incidence of short-term and long-term neurological dysfunction in patients with temporary clipping >4.5 min was significantly higher than that in patients with temporary clipping ≤4.5 min (P = 0.015, P = 0.018). Intraoperative 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.

Impact of fetal-type posterior cerebral artery on recanalization of posterior communicating artery aneurysms after coil embolization: matched-pair case–control study

BackgroundIt is well known that hemodynamic stress may impact the recanalization of coiled aneurysms. One of the most common sites for aneurysms to develop is the posterior communicating artery (PcoA),...

Comparative analysis of coil embolization in posterior and anterior communicating artery aneurysms

BackgroundRecanalization rates after coil embolization are known to be higher in cerebral aneurysms of the posterior (vs anterior) circulation. Although often grouped with anterior lesions, aneurysms of the posterior communicating...

Selective compromise of hypoplastic posterior communicating artery variants with aneurysms treatable by coil embolization: clinical and radiologic outcomes

BackgroundPosterior communicating artery (PcoA) compromise may serve as adjunctive treatment in patients with hypoplastic variants of PcoA who undergo coil embolization of PcoA aneurysms. However, procedural safety and the propensity...

Hemodynamic alterations after stent implantation in 15 cases of intracranial aneurysm.

Stent-assisted coiling technology has been widely used in the treatment of intracranial aneurysms. In the current study, we investigated the intra-aneurysmal hemodynamic alterations after stent implantation and their association with the aneurysm location. We first retrospectively studied 15 aneurysm cases [8 internal carotid artery-ophthalmic artery (ICA-OphA) aneurysms and 7 posterior communicating artery (PcoA) aneurysms] treated with Enterprise stents and coils. Then, based on the patient-specific geometries before and after stenting, we built virtual stenting computational fluid dynamics (CFD) simulation models. Before and after the stent deployment, the average wall shear stress (WSS) on the aneurysmal sac at systolic peak changed from 7.04Pa (4.14Pa, 15.77Pa) to 6.04Pa (3.86Pa, 11.13Pa), P = 0.001; the spatially averaged flow velocity in the perpendicular plane of the aneurysm dropped from 0.5m/s (0.28m/s, 0.7m/s) to 0.33m/s (0.25m/s, 0.49m/s), P = 0.001, respectively. Post stent implantation, the WSS in ICA-OphA aneurysms and PcoA aneurysms decreased by 14.4% (P = 0.012) and 16.6% (P = 0.018), respectively, and the flow velocity also reduced by 10.3% (P = 0.029) and 10.5% (P = 0.013), respectively. Changes in the WSS, flow velocity, and pressure were not significantly different between ICA-OphA and PcoA aneurysms (P > 0.05). Stent implantation did not significantly change the peak systolic pressure in either aneurysm type. After the stent implantation, both the intra-aneurysmal flow velocity and WSS decreased independently of aneurysm type (ICA-OphA and PcoA). Little change was observed in peak systolic pressure.

Acute Aneurismal Bilateral Subdural Haematoma without Subarachnoid Haemorrhage: A Case Report and Review of the Literature.

Spontaneous pure acute bilateral subdural haematoma (ASDH) without intraparenchymal or subarachnoid haemorrhage caused by a ruptured cerebral aneurysm is extremely rare. It can follow rupture of different aneurysms specially located in anterior incisural space; the most frequently encountered location is the PcoA aneurysms as demonstrated in the present case. We present a case report of a PcoA aneurysm presenting as pure bilateral ASDH. A high level of suspicion for bleeding of arterial origin should be maintained in all cases of acute subdural haematoma without history of trauma. The neurological status on admission dictates the appropriate timing and methodology of the neuroradiological investigations.

Tungsten Coil Disappearance and SAH Recurrence 12 Years After Endovascular Embolisation

A 55-year-old woman presented with a sudden onset of severe headache. Computed tomography (CT) revealed SAH (grade I according to the Hunt and Hess classification), predominantly in the right ambient cistern. digital subtraction angiography (dsA) demonstrated a posterior communicating artery (pCoA) aneurysm (3.2 × 5.1 mm) (Fig. 1c). This patient had suffered sAH because of rupture of a right pCoA 12 years back (Fig. 1a) and had undergone endovascular treatment. Tungsten mechanical detachable coils (MDS; Balt Extrusion, Montmorency, France) were inserted into the aneurysm, and the occlusion was considered to be greater than 90 % (Fig. 1b). she was discharged and returned to normal life without further angiography. After comparing the dsA images of this presentation and the ones 12 years before, the two aneurysms were the same, but the tungsten coils had disappeared. Cranial CT and plain radiographs did not find high radiopacity in other places. On admission, endovascular embolisation was selected. While the patient was under a general anaesthetic, platinum coils (GDC, Boston Scientific, Fremont, CA, USA) were inserted, including two 4 mm × 10 cm coils, a 4 mm × 6 cm coil and a 2 mm × 3 cm coil. The coils were inserted until aneurysmal circulatory exclusion was achieved (Fig. 1d). Whole blood, serum and urine tungsten levels were assayed. The values were 0.00025, 0.00024 and 0.00018 μg/ ml, respectively. The normal serum value is 0.0002 μg/ml. Liver and renal functions were tested, and they were normal. X-ray scan showed no lung fibrosis or dermatitis. Subsequently, she was discharged with no neurological deficit.

True Posterior-Communicating Artery Aneurysm with Superomedial Projection-Case Report and Literature Review-

True posterior-communicating artery (PcoA) aneurysms are rare, and usually have no association with the internal carotid artery (ICA) or the posterior cerebral artery. Here we report the case of an 82-year-old woman with severe subarachnoid hemorrhage due to true PCoA aneurysm rupture. Cerebral angiography revealed an aneurysm of the left PCoA itself with superomedial projection. The patient underwent left pterional craniotomy and neck clipping of the aneurysm. Intra-operatively, the aneurysm was not observed on the lateral side of the ICA, although its origin could be seen on the posterolateral wall of the ICA. The aneurysm was approached via the opticocarotid space after removing the anterior clinoid process and opening the carotid dural ring. The aneurysm was completely obliterated and the PCoA was preserved. True PCoA aneurysms can have a variety of projecting directions, which must be considered when choosing the surgical approach to their treatment.

Impact of anatomical variations of the circle of Willis on the incidence of aneurysms and their recurrence rate following endovascular treatment

To analyse the impact of anatomical variations of the parent arteries on the incidence and recurrence rate following coil embolization of aneurysms of the anterior (AcoA), posterior communicating artery (PcoA) and basilar artery (BA) tip. Two hundred and two (96 AcoA, 67 PcoA, and 29 BA) aneurysms in 200 patients were treated with coil embolization between January 2000 and April 2008. Parent artery variations at each location were classified as: AcoA: A1 aplasia versus hypoplasia versus symmetrical size; PcoA: foetal origin versus medium versus small size, BA: cranial versus caudal versus asymmetrical fusion. The incidence of aneurysms and difference between recurrence rates for each group were recorded on follow-up. AcoA, PcoA, and BA aneurysms were more often associated with embryonically earlier vessel wall dispositions (A1 aplasia, foetal PcoA, asymmetrical fusion). Two of these variations were also associated with aneurysm recurrence following coil embolization: asymmetrical A1 segment (p=0.01), and asymmetrical BA tip (p=0.02). AcoA, PcoA, and BA tip aneurysms tend to occur more often in anatomically variant parent artery dispositions, some of which are related to aneurysm recurrence following coil embolization. This may relate to a more fragile vessel disposition as it is not fully matured or to altered haemodynamics secondary to the anatomical variations.

True posterior communicating artery aneurysms: are they more prone to rupture? A biomorphometric analysis

Posterior communicating artery (PCoA) aneurysms can occur at the junction with the internal carotid artery, posterior cerebral artery (PCA), or the proximal PCoA itself. Hemodynamic stressors contribute to aneurysm formation and may be associated with parent vessel size and aneurysm location. This study evaluates the correlation of various biomorphometric characteristics in 2 of the aforementioned types of PCoA aneurysms. Patients with PCoA aneurysms were analyzed using CT angiography. Source images and reconstructions were used to determine which aneurysms originated purely from the PCoA and those that originated from the internal carotid artery/PCoA junction. Morphometric analysis was performed on the aneurysm, the precommunicating segment of the PCA (P(1)), the ambient segment of the PCA (P(2)), and both PCoA arteries and were correlated to clinical presentation. Parametric and nonparametric analyses were performed to test for significance. A total of 77 PCoA aneurysms were analyzed, and 10 were found to be true PCoA aneurysms (13.0%). The ipsilateral PCoA/P(1) ratio (1.77 +/- 0.44 vs 0.82 +/- 0.46, p = 0.0001) and ipsilateral P(2)/P(1) ratio (1.73 +/- 0.40 vs 1.22 +/- 0.41, p = 0.0003) were significantly larger in true PCoA aneurysms. Interestingly, aneurysm size was statistically larger in the junctional aneurysms (0.14 +/- 0.1 vs 0.072 +/- 0.04 cm(3), p = 0.03). The prevalence of ruptured aneurysms was similar in both groups (approximately 80%, p value not significant). These data suggest that true PCoA aneurysms have a larger PCoA relative to the ipsilateral P(1) segment. To the authors' knowledge, this represents the first such biomorphometric comparison of these different types of PCoA aneurysms. Although statistically smaller in size, true PCoA aneurysms also have a similar prevalence of presenting as a ruptured aneurysm, suggesting that they might be more prone to rupture than a junctional aneurysms of similar size. Further analysis will be required to determine the biophysical factors affecting rupture rates.

Microsurgical treatment in aneurysms of anterior circulation

Objective To summarize the method and experience of microsurgical treatment of intracranial aneurysms in anterior circulation. Methods The clinical data, the skills and experience of 171 cases with aneurysmso of anterior circulation within the latest 2 years. Results One hundred and seventy-one patients under surgery, including 67 PCOA aneurysm, 56 ACoA aneurysm, 32 MCA aneurysm, 10 ICA aneurysm, OphA aneurysm and 3 haimess aneurysm. Accoring to Glasgow Prognostic Scale, there were 3 cases of grade Ⅰ, 6 cases of grade Ⅲ, 14 cases of grade Ⅳ and 148 cases of grade Ⅴ. Conclusion The key points to cure intracranial aneurysms successfully is favourable exposure and the skills of microsurgery; the factors of intluent surgery include forcejudgement in surgery, reasonable choice of aneurysm clips, correctly block in arterious. Key words: Cerebral arterial circle; Anterior circulation; Intracranial aneurysms; Mircosurgical operation

Oculomotor Nerve Palsy Associated with Rupture of Middle Cerebral Artery Aneurysm

Oculomotor nerve palsy (ONP) with subarachnoid hemorrhage (SAH) occurs usually when oculomotor nerve is compressed by growing or budding of posterior communicating artery (PcoA) aneurysm. Midbrain injury, increased intracranial pressure (ICP), or uncal herniation may also cause it. We report herein a rare case of ONP associated with SAH which was caused by middle cerebral artery (MCA) bifurcation aneurysm rupture. A 58-year-old woman with clear consciousness suffered from headache and sudden onset of unilateral ONP. Computed tomography showed SAH caused by the rupture of MCA aneurysm. The unilateral ONP was not associated with midbrain injury, increased ICP, or uncal herniation. The patient was treated with coil embolization, and the signs of oculomotor nerve palsy completely resolved after a few days. We suggest that bloody jet flow from the rupture of distant aneurysm other than PcoA aneurysm may also be considered as a cause of sudden unilateral ONP in patients with SAH.

Aberrant regeneration of the oculomotor nerve: implications for neurosurgeons

Aberrant regeneration of cranial nerve III, otherwise known as oculomotor synkinesis, is an uncommon but well-described phenomenon most frequently resulting from trauma, tumors, and aneurysms. Its appearance usually follows an oculomotor palsy, but it can also occur primarily without any preceding nerve dysfunction. It is vital that neurosurgeons recognize this disorder because it may be the only sign of an underlying cavernous tumor or PCoA aneurysm. The tumor most often implicated is a cavernous or parasellar meningioma, but any tumor that causes compression or disruption along the course of the oculomotor nerve may cause primary or secondary misdirection. The most common clinical signs of oculomotor synkinesis consist of elevation of the upper eyelid on attempted downward gaze or adduction, adduction of the eye on attempted upward or downward gaze, and constriction of the pupil on attempted adduction. The authors present the largest series of patients with oculomotor synkinesis, including those in whom it developed after neurosurgical intervention, to illustrate various presentations. In addition, the various mechanisms that contribute to synkinesis are reviewed. Last, the treatment strategies for both oculomotor palsies and synkinesis are discussed.

Article--Diagnosis and management of dural carotid–cavernous sinus fistulas

✓Aberrant regeneration of cranial nerve III, otherwise known as oculomotor synkinesis, is an uncommon but well-described phenomenon most frequently resulting from trauma, tumors, and aneurysms. Its appearance usually follows an oculomotor palsy, but it can also occur primarily without any preceding nerve dysfunction. It is vital that neurosurgeons recognize this disorder because it may be the only sign of an underlying cavernous tumor or PCoA aneurysm. The tumor most often implicated is a cavernous or parasellar meningioma, but any tumor that causes compression or disruption along the course of the oculomotor nerve may cause primary or secondary misdirection. The most common clinical signs of oculomotor synkinesis consist of elevation of the upper eyelid on attempted downward gaze or adduction, adduction of the eye on attempted upward or downward gaze, and constriction of the pupil on attempted adduction. The authors present the largest series of patients with oculomotor synkinesis, including those in whom it developed after neurosurgical intervention, to illustrate various presentations. In addition, the various mechanisms that contribute to synkinesis are reviewed. Last, the treatment strategies for both oculomotor palsies and synkinesis are discussed.

Microsurgical experience with keyhole operations on intracranial aneurysms

Background We report our experience with keyhole approaches as favorable treatments for various intracranial aneurysms including multiple aneurysms and giant aneurysms. Methods According to the different locations of 105 aneurysms harbored in 100 patients, different keyhole approaches were designed elaborately, among which a supraorbital keyhole approach was used in 91 cases, a pterional keyhole approach in 5 cases, a subtemporal keyhole approach in 3 cases, a retromastoid keyhole approach in 2 cases, and a unifrontal interhemispheric keyhole approach in 1 case. Results Among those 105 aneurysms, 99 were clipped successfully, including 4 that were resected after clipping. One mini-aneurysm was wrapped. The other aneurysms were trapped, including 1 VA aneurysm, 1 giant ICA aneurysm, 1 giant PCoA aneurysm, and 2 giant aneurysms in the PCAs (P2-P3 segment). Multiple aneurysms in 5 cases were treated in 1 surgical session, including 3 cases via unilateral approaches and 2 cases via bilateral approaches. There were no severe keyhole approach–related complications in this present series. Conclusion The keyhole approaches, based on improvements in diagnostic imaging, advanced surgical instruments, and microsurgical skills, are effective and ideal craniotomy techniques in the hands of experienced neurosurgeons for the treatment of intracranial aneurysms, including multiple and giant aneurysms, in patients without diffuse SAH, severe cerebral vasospasm, and severe brain edema or brain swelling.

Detection of Intracranial Aneurysms Using Multi-detector Row CT 3D-Angiography: Comparison with Operative Findings

Purpose: To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. Materials and Methods: 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms dignosed with 3D-CTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. Results: A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1- 2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysm was the filling of the aneurismal sac by thrombosis. Conclusion: Though there were some limitations in the detection of aneurysms, 3DCTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure.

Neuropsychological outcome of operated cerebral aneurysms: prognostic factors on 148 patients.

To analyse prognostic factors in patients operated upon for cerebral aneurysms. A previous investigation by our group showed that patients operated later than 10 days after bleeding have a worse neuropsychological prognosis, but the number of patients operated upon within 3 days was not sufficient. Here, a new sample of patients with early surgery is included in the analyses. Patients numbered 148 (65 with ACoA, 39 with MCA, and 44 with PCoA aneurysms): 56 were operated within 3 days, 44 within 4-10 days, and 48 after at least 10 days from bleeding. A standardized battery of 13 neuropsychological tests was adopted: we considered both the number of defective scores and the average performance. Patients operated later than 10 days after bleeding had a worse prognosis than the 2 groups with early and intermediate surgery, which were not different. Aneurysm site was not relevant. Old age and low education were associated with a worse prognosis. Hunt and Hess scores at operation and post operation were also predictive of the outcome. On the whole, patients operated upon later than 10 days after bleeding have a less favourable prognosis than those with earlier operation timing.