Basilar Trunk Research Articles

Impact of intracranial blood-flow redistribution on stroke size during ischemia–reperfusion in 7-day-old rats

We evaluated color-coded pulsed Doppler ultrasound imaging for the assessment of intracranial blood flow in two models of cerebral ischemia in 7-day-old (P7) rats. Blood-flow velocities (BFVs) were measured in the internal carotid arteries and basilar trunk upstream from the circle of Willis, and in the posterior cerebral arteries downstream (1) before, (2) during left middle cerebral artery electrocoagulation and 50 min-transient either one (I/R-1) or both (I/R-2) common carotid (CCA) arteries occlusion, and (3) after release of CCA(s) occlusion. At 48 h after ischemia 41–48% (I/R-1 model) and 24% (I/R-2 model) of rats did not present a lesion. Those rats displayed increased mean BFV in both right internal carotid artery and basilar trunk in I/R-1 model, and increased mean BFV in the basilar trunk (BT) in I/R-2 model. In contrast, no significant changes in mean BFV were observed in lesioned rats. Furthermore, mean BFV in the BT was inversely correlated to the size of the lesion ( r 2 = 0.75, p < 0.0001) in the I/R-2 model. Thus, we demonstrated the protective role of collateral support in P7 rodents. Ultrasound imaging can evidence the establishment or not of the cerebral collateral recruitment, leading to the presence or absence of a lesion. This novel approach should greatly help preclinical studies to reduce animal variability.

Comparison of clinical characteristics and MR angiography appearance in patients with spontaneous intradural vertebral artery dissection with or without subarachnoid hemorrhage

It is well known that spontaneous intradural vertebral artery dissection (siVAD) is an important cause of nontraumatic subarachnoid hemorrhage (SAH). The factors that influence whether SAH develops, however, remain unclear. The aim of this study was to investigate whether clinical characteristics and imaging findings are different in patients with siVAD with SAH compared to those with siVAD without SAH. The authors conducted a retrospective, single-institution study involving patients in whom siVAD developed with or without SAH, between July 2003 and November 2010. Univariate and multivariate analyses were performed to evaluate clinical characteristics and MR angiography findings. The vertebral-union-basilar angle (VUBA) was defined as the most acute angle between line of the basilar artery trunk and line of the vertebral angle (VA) at the vertebral union on 3D MR angiograms. Among 58 patients with siVAD, 21 developed SAH. The presence of siVAD and SAH was significantly associated with higher rates of current smoking (OR 13; 95% CI 3.6-38; p < 0.0001), dissection of the dominant VA (OR 9.2; 95% CI 2.5-19; p = 0.0004), and unruptured supratentorial nondissecting saccular aneurysms (OR 11; 95% CI 2.1-19; p = 0.0025), and the VUBA of the dominant VA was significantly larger (p < 0.0001, univariate analysis). Multivariate analysis showed that these differences were still significant (p < 0.05). A larger VUBA of the dominant VA, the presence of unruptured supratentorial nondissecting saccular aneurysms, and current smoking may be factors that predict which patients with siVAD will develop SAH by dominant VAD.

Endovascular Treatment Using Predominantly Stent-Assisted Coil Embolization and Antiplatelet and Anticoagulation Management of Ruptured Blood Blister–Like Aneurysms

BBA is a rare type of intracranial aneurysm that is difficult to treat both surgically and endovascularly and is often associated with a high degree of morbidity/mortality. The aim of this study was to present clinical and angiographic results, as well as antiplatelet/anticoagulation regimens, of endovascular BBA treatment by using predominantly stent-assisted coil embolization. Thirteen patients (men/women, 6/7; mean age, 49.3 years) with ruptured BBAs were included from 2 different institutions. Angiographic findings, treatment strategies, anticoagulation/antiplatelet protocols, and clinical (mRS) and angiographic outcome were retrospectively analyzed. Eleven BBAs were located in the supraclinoid ICA, and 2 on the basilar artery trunk. Nine of 13 were ≤3 mm in the largest diameter, and 8/13 showed early growth before treatment. Primary stent-assisted coiling was performed in 11/13 patients, double stents and PAO in 1 patient, each. Early complementary treatment was required in 3 patients, including PAO in 2. In stent-placement procedures, altered periprocedural antiplatelet (11/12) and postprocedural heparin (6/12) protocols were used without evidence of thromboembolic events. Two patients had early rehemorrhage, including 1 major fatal SAH. Twelve of 13 BBAs showed complete or progressive occlusion at late angiographic follow-up. Clinical midterm outcome was good (mRS scores, 0-2) in 12/13 patients. Stent-assisted coiling of ruptured BBAs is technically challenging but can be done with good midterm results. Reduced periprocedural and postprocedural antiplatelet/anticoagulation protocols may be used with a low reasonable risk of thromboembolic complications. However, regrowth/rerupture remains a problem underlining the importance of early angiographic follow-up and re-treatment, including PAO if necessary.

Transcranial duplex sonography for monitoring circle of Willis artery occlusion in a rat embolic stroke model

BackgroundHemodynamic monitoring of circle of Willis arteries during clot embolization in experimental embolic stroke models (ES) is of major importance to assess their reproducibility and to test new recanalization strategies. We sought to assess the potential of transcranial duplex sonography (TDS) in comparison with laser Doppler flowmetry (LDF) to monitor the time of recanalization after occlusion of the right distal intracranial internal carotid artery (rICA) and to predict infarct volume at 24h after ischemia. MethodsTwenty nine male Sprague–Dawley rats were submitted to ES. Right and left ICA, posterior cerebral arteries, and basilar trunk (BT) were monitored by TDS and regional cerebral blood flow was monitored by LDF at baseline, 1, 4 and 24h after the ES onset. Infarct volume was measured at 24h after stroke. ResultsAmong the 25 rats, 3 died during surgery, 5 did not show any significant brain infarct (failure of the stroke model) and absence of occlusion of the rICA was detected in all 5 rats by TDS at 1h whereas only 4 of 5 were detected by LDF. Among the remaining 17 rats, the recanalization time of the occluded rICA assessed by TDS correlated with the infarct volume at 24h, r=0.70, P=0.0013 by contrast to results with LDF, r=0.11, P=0.55. ConclusionAlthough both TDS and LDF can be used for in vivo assessment of occlusion in a rat ES model, TDS was more reliable as it allowed more accurate monitoring of arterial recanalization, and prediction of infarct volume.

A Rapid and Computationally Inexpensive Method to Virtually Implant Current and Next-Generation Stents into Subject-Specific Computational Fluid Dynamics Models

Computational modeling is often used to quantify hemodynamic alterations induced by stenting, but frequently uses simplified device or vascular representations. Based on a series of Boolean operations, we developed an efficient and robust method for assessing the influence of current and next-generation stents on local hemodynamics and vascular biomechanics quantified by computational fluid dynamics. Stent designs were parameterized to allow easy control over design features including the number, width and circumferential or longitudinal spacing of struts, as well as the implantation diameter and overall length. The approach allowed stents to be automatically regenerated for rapid analysis of the contribution of design features to resulting hemodynamic alterations. The applicability of the method was demonstrated with patient-specific models of a stented coronary artery bifurcation and basilar trunk aneurysm constructed from medical imaging data. In the coronary bifurcation, we analyzed the hemodynamic difference between closed-cell and open-cell stent geometries. We investigated the impact of decreased strut size in stents with a constant porosity for increasing flow stasis within the stented basilar aneurysm model. These examples demonstrate the current method can be used to investigate differences in stent performance in complex vascular beds for a variety of stenting procedures and clinical scenarios.

Endovascular Treatment of Aneurysms Arising from the Basilar Artery Trunk and Branches

This study reports our experience with the endovascular treatment of basilar artery (BA) trunk and branch aneurysms. Subjects included 16 patients with BA trunk and branch aneurysms who underwent endovascular treatment in our hospital from October 2000 to October 2009, including four patients with associated arteriovenous malformation (AVM), two with associated moyamoya disease, one with multiple aneurysms at adjacent sites, and one with a distant aneurysm. Endovascular coil embolization, together with stent or balloon assistance when necessary, or while occluding the parent artery was performed. Associated diseases were managed intraoperatively or in the second stage, or treated with gamma knife radiotherapy, or followed up. Two patients with unsuccessful embolization died of re-rupture at the fourth month and fifth month follow-up. The remaining 14 patients reported good outcomes and experienced no re-rupture of either the aneurysm or associated disease. Angiographic follow-ups were conducted for the 14 patients for six to 12 months. Digital subtraction angiography (DSA) examination at the last follow-up showed no recurrence of the BA trunk and branch aneurysms. Together, BA trunk and branch aneurysms should be actively managed via endovascular techniques to prevent serious consequences due to aneurysm rupture and bleeding. Favorable outcomes can be obtained by the proper selection of endovascular treatment regimens.

Circumferential Watertight Dural Repair Using Nitinol U-Clips in Expanded Endonasal and Sublabial Approaches to the Cranial Base

In recent years, significant advances have been made in the field of expanded endonasal approaches that permit treatment of different cranial base intradural lesions. To report our technique of cranial base dural repair by the application of nitinol U-Clips in endoscope-assisted extended endonasal or sublabial approaches. Closure techniques and postoperative cerebrospinal (CSF) leaks are reported. We reviewed 11 patients with different kinds of cranial base tumors or vascular diseases (2 tuberculum sellae meningiomas, 1 planum sphenoidale meningioma, 4 craniopharyngiomas, 1 recurrent clival chordoma, 1 esthesioneuroblastoma, 1 ethmoidal melanoma metastasis, 1 basilar trunk aneurysm) who underwent an endoscope-assisted extended endonasal or sublabial approach. Dural repair was performed using nitinol U-Clips to circumferentially suture AlloDerm or fascia lata directly to the existing dural borders. Lumbar drainage was not used in 9 patients and was used in 2 patients for 5 days. Patients were evaluated for the appearance of CSF leaks. Postoperative CSF leak was observed in 1 patient (9%). This required a second transnasal repair. Circumferential dural closure with U-Clips is a useful adjunct to prevent CSF leaks after expanded endonasal or sublabial approaches to the cranial base for treatment of intracranial pathology.

Preoperative factors affecting the outcome of unruptured posterior circulation aneurysm surgery

We retrospectively investigated preoperative variables contributing to adverse surgical outcome for repair of unruptured posterior circulation aneurysms on data collected prospectively between October 1989 and March 2010. Putative risk factors including age, sex, smoking status, positive family history, modified Rankin Score prior to the surgery, size of the aneurysm, specific site (basilar caput and trunk, vertebral artery and posterior inferior cerebellar artery), midline location, presence of calcium, thrombus or irregularity in the aneurysm on preoperative imaging, associated arteriovenous malformation and preoperative coiling were investigated using regression analyses. In a total of 121 operations, surgical mortality and morbidity was 16.3%. For patients with aneurysms less than 9 mm this rate was 3.2%. Among the investigated variables we found that size, calcification of the aneurysm and age were each predictors of surgical outcome of unruptured posterior circulation aneurysms.

Endovascular Treatment of a Large Aneurysm Arising From a Basilar Trunk Fenestration Using the Waffle-Cone Technique

Endovascular treatment of large intracranial aneurysms arising from a fenestrated parent vessel may prove particularly difficult. We present a case of a large, broad-based aneurysm arising from a proximal basilar artery (BA) fenestration treated with the waffle-cone technique. Technical nuances and indications for this treatment option are reviewed. A 38-year-old man presented with headache, blurred vision, and dizziness. Angiography demonstrated an 11 x 14-mm BA aneurysm associated with the proximal portion of a BA fenestration. A 28 x 4.5-mm Enterprise stent was placed from the right vertebral artery directly into the aneurysm. The stent tines were allowed to flare out in the aneurysm neck creating the "waffle cone." The aneurysm was then coiled with a series of Presidio coils. Use of the waffle-cone technique for stent placement resulted in nearly complete embolization of the aneurysm, retention of the entire coil mass in the dome, and preservation of flow through both vertebral arteries and both limbs of the fenestration.

Early Migration of a Self Expanding Intracranial Stent

Abstract OBJECTIVE With the development of support devices such as stents, an increasing number of aneurysms are meeting the criteria for endovascular treatment. A range of intracranial stents currently are available with an array of characteristics. It is essential to understand the properties of these stents to determine their role and implications in endovascular treatment of cerebral aneurysms. CLINICAL PRESENTATION A 45-year-old man presented to our institution with subarachnoid hemorrhage secondary to a small distal basilar trunk aneurysm. INTERVENTION An Enterprise stent (4.5 × 14 mm) was deployed in the parent vessel across the neck of the aneurysm. Repeat angiography 2 days later demonstrated significant proximal stent migration. A second, longer overlapping Enterprise stent (4.5 × 22 mm) was deployed from the left P1 segment into the basilar artery. Complete occlusion of the basilar trunk aneurysm was noted on subsequent angiography. CONCLUSION This is an unequivocal case of early spontaneous migration of a self-expanding intracranial stent. We suggest caution when there is significant discrepancy in luminal diameter and suboptimal wall apposition. Early imaging following stent deployment may be indicated in these cases.

Potential advantages and limitations of the Leo stent in endovascular treatment of complex cerebral aneurysms

Objective The Leo self-expandable stent is a new retractable stent that is delivered via a conventional catheter. The aim of this study was to evaluate the use of this stent for endovascular treatment of complex aneurysms. Methods Twenty-eight complex cerebral aneurysms (27 saccular and 1 fusiform) in 28 patients were treated electively. They were located at the internal carotid artery (17), basilar trunk (3), anterior cerebral artery (1), anterior communicating artery (3), vertebral artery (2) and middle cerebral artery (2). One aneurysm exhibited recanalization after primary endovascular treatment without stent. Clinical outcome was assessed with the modified Glasgow Outcome Scale. Results Deployment of Leo stent was successful in 26 lesions, and difficulties in stent positioning due to tortuous cerebral circulation in 2 cases, which were treated with Neuroform stent. Additional coil embolization was performed in 26 lesions. No permanent neurological deficits were encountered consequent to endovascular procedure. Complete or partial occlusion immediately after stent deployment was achieved in all aneurysms. There was no immediate coil embolization was chosen in 3 cases because of subsequent reduced filling of the aneurysms with contrast agent on angiograms. There were 3 asymptomatic parent artery occlusion related to the deployment of the Leo stent, one stent migration. Follow-up revealed patent stents in the remaining cases. No angiographic recurrences arose. Conclusion The Leo stent is very useful for endovascular treatment of complex cerebral aneurysms because it is easy to navigate and place precisely. A drawback is that in-stent thrombosis caused by stent placement and stiffer delivery catheters to place larger stents.

P-020 The transcirculation treatment of cerebral aneurysms

IntroductionUnfavorable anatomy can preclude embolization of intracranial aneurysms. Transcirculation techniques, in which a catheter is navigated from one side of the brain to the other or from the anterior to...

Clipping of a Mycotic Basilar Trunk Aneurysm under Cardiac Arrest in a Pregnant AIDS Patient

We present the first case of a coccidioidomycosis mycotic anterior inferior cerebellar artery (AICA) aneurysm that was clipped under hypothermic cardiac standstill in a pregnant acquired immunodeficiency syndrome (AIDS) patient. A 24-year-old pregnant AIDS patient presented with intraventricular hemorrhage and hydrocephalus. Angiography revealed an 8-mm basilar trunk aneurysm with the right AICA protruding from the side wall of the aneurysm. The patient underwent a retrosigmoid craniotomy and direct clipping of the aneurysm under hypothermic cardiac standstill. At presentation, the patient had a poor grade due to subarachnoid and intraventricular hemorrhage. Despite her large posterior circulation aneurysm in the setting of AIDS with extensive coccidioidomycosis meningitis, the lesion was clipped successfully. To do so required the full range of neurosurgical repertoire, including a skull base approach and hypothermic cardiac standstill.

Saccular aneurysms at middle basilar trunk fenestration

Basilar artery (BA) fenestration is reported in 0.6% of angiograms1 and in about 5% of autopsy series2,3. It may occur anywhere along the BA but it is most frequent in the proximal trunk, close to the junction of the vertebral arteries2-5, and rarer in the middle and distal thirds. In these instances, they may represent therapeutic dilemmas […] Saccular aneurysms at middle basilar trunk fenestration

Stenting and Coil Embolization of a Ruptured Dissecting Basilar Artery Aneurysm Associated with Coil Embolization of a Pericallosal Artery Aneurysm

We describe the case of a 54-year-old woman who underwent endovascular treatment in the setting of a massive subarachnoid haemorrhage due to rupture of a dissecting basilar trunk aneurysm treated with stent implantation and coiling. A further saccular aneurysm in the left pericallosal artery disclosed by four-vessel angiography was treated with coiling during the same procedure. Follow-up DSA performed after six months confirmed complete occlusion of both aneurysms and patency of the stent.

Delayed Thrombosis of the Basilar Artery after Stenting for a Basilar Trunk Dissection Aneurysm

A 30-year-old man was referred in our department for treatment of a midbasilar trunk aneurysm. His presenting symptoms included headache and dizziness. A CT scan at another hospital showed no significant findings whereas a digital subtraction angiogram disclosed a dissecting aneurysm in the midbasilar trunk, and there was severe stenosis in the basilar artery. After discussion, we planned to use stent-assisted-coil embolization technique. During the procedure, a LEO stent (Balt, Montmorency, France) was implanted into the basilar artery across the aneurysm neck, but fearing acute basilar artery occlusion because of stent collapse or thrombus we did not fill coils into the aneurysm. After the procedure, the completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. The patient awoke from general anaesthesia after the procedure and had no additional neurological symptoms, he was discharged three days later and used clopidogrel and aspirin for antiplatelet therapy. Six months later when he was admitted for a recheck, a DSA showed the basilar artery was occluded completely and the aneurysm had disappeared even though the patient remained neurologically normal.

Successful Clipping of a Large Fusiform Aneurysm in the Basilar Artery Using an Endovascular Technique: Report of a Subarachnoid Hemorrhage Case

An 80-year-old male presented with a subarachnoid hemorrhage of Hunt and Kosnik Grade IV. Cerebral angiography revealed a large eccentric fusiform aneurysm arising from the lower portion of the basilar artery just distal to the right anterior inferior cerebellar artery. We decided to surgically treat the ruptured basilar artery aneurysm in the acute stage via a right retromastoid suboccipital approach. Before the operation, we guided a balloon catheter into the left vertebral and right carotid arteries. Intraoperatively, we applied a temporary clip to the right vertebral artery. After exposing the aneurysm, we temporarily inflated the occlusion balloon within the left vertebral and right internal carotid arteries. After suction decompression from the left vertebral artery, we used Sugita’s long clip to clip the neck parallel to the basilar trunk. Bradycardia occurred, but the heart rhythm recovered immediately after the recanalization of these arteries. Intraoperative digital subtraction angiography showed obliteration of the aneurysm and preservation of basilar artery patency. The patient gradually recovered consciousness after being in a comatose state for 10 hours after surgery. It is possible to directly clip a large basilar trunk aneurysm. The clipping tends to be done in the same direction as the operative approach. Therefore, the operative approach should be parallel to and should preserve the basilar artery. The intraoperative endovascular technique (using temporary balloon occlusion) and intraoperative digital subtraction angiography can contribute to gaining proximal artery control and verifying basilar artery patency. Clipping is much easier when using suction decompression. However, temporary balloon occlusion should be done as quickly as possible.

Cerebellar Stroke in Elderly Patient with Basilar Artery Agenesia: A Case Report

We report a case of a 76-year-old woman admitted to our institution with sudden onset of dizziness and vertigo followed by vomiting and blurred vision. Her medical history was remarkable for hypertension, diabetes, and ischemic stroke in the territory of the left cerebral median artery. Her symptoms were suggestive of a cerebellar stroke. Computed tomography brain scan and neck vessel ultrasounds produced normal findings. A 24-hour blood pressure monitoring showed a reverse dipping pattern. Magnetic resonance imaging examination was performed, showing a hyperintense ischemic focus involving pons and left middle cerebellar peduncle, on T2-weighted images. On Time-of-flight (TOF)-3-dimensional magnetic resonance angiography, there was a marked reduction of basilar artery signal. The digital subtraction angiography showed a vertebrobasilar system anomaly. The right vertebral artery was hypoplastic with few thin terminal spinal branches. The left vertebral artery was vicarious to the right one in intracranial tract. V3 to V4 tract showed multiple atherosclerotic wall irregularities. The basilar common trunk was absent. An abnormal posterior inferior cerebellar artery replaced the anterior inferior cerebellar artery and superior cerebellar artery. Right posterior inferior cerebellar artery, anterior inferior cerebellar artery, and superior cerebellar artery arose from ipsilateral V4 tract. This case is the first description of pure basilar agenesia. The symptoms might be related to temporary decrement of the flow in the left vertebral artery. Furthermore, the reverse dipping pattern together with the aging, hypertension, and diabetes had probably contributed to a hemodynamic malfunction of the cerebral vascular system.

Surgical clipping of vertebral and basilar artery aneurysms

Objective To study an effective method for clipping vertebral and basilar artery aneurysms. Method There were 26 patients with 28 aneurysms of vertebral and basilar arteries. Aneurysms ruptured in 9 patients,the aneurysms in 16 patients were located in basilar artery including two aneurysms in one patient,and 10 aneurysms were located in vertebral artery including bilateral vertebral artery aneurysms in one patient and vertebral AVMs in one patient. Pterional approach underwent in 5 patients with basilar tip aneurysms,orhitozygomatic approach in 5 patients with basilar tip aneurysms and 2 patients with the upper basilar aneurysms, combination of presigmoid with far-lateral approach in 4 patients with mid basilar aneurysms. Of 10 patients with aneurysms of vertebral arteries, combination of far lateral with transpetrosal approaches were performed in 4 patients and combination of far lateral with condylar approaches in 6 patients. In 11 patients with bypass grafts because of the likehood of prolonged temporary occlusion or possibility of intraoperative parent artery sacrifice, the internal carotid artery to P2 segment of posterior cerebral artery bypass were performed in 2 patients, the external carotid artery to P2 segment of posterior cerebral artery bypass were performed in 4 patients, cervical vertebral to cranial vertebral artery bypass in 2 patients,and occipital to PICA bypass in 3 patients. Results There were back to normal life without neurological deficits after surgery in 9 patients with basilar tip aneurysms, 5 patients with basilar trunk aneurysms,and 10 patients with vertebral artery aneurysms. Total good outcome reached 24 (92%) patients after surgery. One patient need assistant for his daily life related to severe neurological deficits after surgery, one patient with basilar trunk aneurysm die of brain stem ischemia from the perforating arteries occlusion 20 days after surgery. Conclusions The selection of proper cranial base approaches should be benefit to obtain an adequate operative space for clipping of vertebrobasilar aneurysms. The adjunctive use of graft bypass may be till required to avoid parent and major branch occlusion during protracted temporary clipping of the parent artery and the sacrifice of either the parent vessel or one of the major branches for management of a complex intracranial aneurysm. Key words: Vertebrobasilar artery; Intracranial aneurysm; Surgical procedures,operative

STENT-ASSISTED COIL EMBOLIZATION OF POSTERIOR CIRCULATION ANEURYSMS USING SOLITAIRE AB

To evaluate patients with wide-necked aneurysms of the posterior circulation who underwent Solitaire AB (ev3, Inc., Irvine, CA) stent-assisted coil embolization. Retrospective analysis of 10 patients (age range, 32-76 years; mean age, 59.1 years) with aneurysms of the basilar artery (basilar tip, n = 5; basilar trunk, n = 4; posterior cerebral artery, n = 1). Seven of the patients presented with an acute subarachnoid hemorrhage. Five aneurysms were small, 2 were large, and 3 were giant. All patients were treated by different applications (n = 14) of the Solitaire AB neurovascular remodeling device followed by a standard coiling procedure using bioactive coils. Positioning of all Solitaire AB stents was easy and successful. No stent required retrieving and repositioning after full deployment. There were no thromboembolic complications, and no dissection/rupture or vasospasm occurred during stent placement. In all cases except 3, 100% lesion occlusion was observed after the initial treatment. The initial technical and clinical results of Solitaire AB stent-assisted coiling of different types of wide-necked aneurysms in the posterior circulation are highly encouraging, and this technique may improve the endovascular treatment of these aneurysms.