Trapping and resection of cortical MCA mycotic aneurysm in eloquent area.

BACKGROUND: Mycotic aneurysms, although well recognized, are relatively rare intracranial vascular pathology. These aneurysms are typically located in distal cortical vessels. When these aneurysms are located in eloquent cerebral territories, they may become challenging to treat. Eloquent location may necessitate intraoperative angiographic evaluation to verify complete aneurysmal occlusion/obliteration and preservation of normal adjacent vasculture. Recently, ICG videoangiography has become a widely used intra-operative adjunct and is an important tool used to assess complete occlusion and vessel patency at the conclusion of clip reconstruction. In this report, we outline the comprehensive and concurrent utilization of both vascular imaging modalities to ensure safe and complete occlusion of a mycotic aneurysm. METHODS: We describe our experience with a patient with left M4, Rolandic, enlarging mycotic aneurysm that was treated in a comprehensive fashion with microsurgery and intra-operative angiography (IA). CONCLUSIONS: ICG videoangiography, in combination with concurrent intraoperative angiography in the setting of complex vascular lesions, may support intraoperative decision-making and provide demonstration of complete occlusion in an immediate fashion. A hybrid operative suite allows for high-quality imaging confirming complete resection.

Paradigms for single-patient multimodality treatment for cerebral aneurysms: single-center eleven-year experience.

Endovascular and surgical techniques are conventional options for treating intracranial aneurysms, but criteria for selecting an optimal approach for individual patients remain variable across practitioners and institutions. While endovascular and surgical approaches are generally used alone, both modalities combined in single patients can produce efficacious outcomes. The aim of this study was to evaluate outcomes of combined, concomitant endovascular and surgical modalities in the treatment of multiple and/or complex aneurysms in single patients. Indications, sequencing rationale, and categorization for multimodality treatments are reviewed. All intracranial aneurysms treated at our institution from 2004 to 2014 were reviewed. Single patients who had undergone concomitant endovascular and surgical treatments were eligible for participation in our study. Demographic data and clinical presentation parameters, including location, size, and morphological features of lesions, treatment sequencing, and outcomes were recorded. Our cohort consisted of 27 patients with 57 aneurysms who received concomitant endovascular and surgical treatment of their aneurysm(s). One patient arrived to us after he had an aneurysm clipped at an outside institution and then required treatment for a contralateral ruptured aneurysm. 66.7% of patients were diagnosed with subarachnoid hemorrhage. These were subdivided according to therapeutic approach: clipping and coiling (CL+CO), clipping and stenting (CL+ST), bypass and endovascular parent vessel occlusion (PVO) (BY+PVO), attempted clipping then stenting, and bypass followed by stenting. Glasgow Outcome Scale was as follows: CL-CO-Multiple, 4.17 (five in unruptured patients, 3.75 in ruptured); CO-CL-Multiple, five (all patients had a ruptured aneurysm); CL-CO-Single, three (all patients had a ruptured aneurysm); CO-CL-Single, five (all patients had a ruptured aneurysm). No patients suffered a new neurological deficit as a result of treatment. A total of two mortalities were documented. Concomitant, mutimodality endovascular and surgical therapy may offer a safe and potentially more effective paradigm than single modality approaches for the management of multiple, complex, or "failed" aneurysm treatments in selected patients.

Analysis of superiorly projecting anterior communicating artery aneurysms: anatomy, techniques, and outcome. A proposed classification system.

Superiorly projecting (SP) anterior communicating artery (AComA) aneurysms are typically described as a homogenous group. Clinically and microsurgically, these aneurysms vary in multiple important characteristics. We propose a microsurgical classification system for these complex aneurysms and review its implications regarding presentation, microsurgical techniques, and outcome. This retrospective analysis reviews patients undergoing clipping of SP AComA aneurysms (2005-2013). The classification system is based on the virtual plane created by the A2 segments and its relationship to the aneurysm. Aneurysm type was assessed by intraoperative images and videos. Type 1 is defined by bisection of the dome by the virtual plane. Type 2 is defined by dome projection posterior to this plane. Sagittal rotation of the plane defines type 3. We analyzed clinical presentation, morphology, angiographic characteristics, operative technique, and outcome relative to the classification types. There were 44 SP AComA aneurysms. 3D angiographic images predicted classification type in 83%. Type 1 presented more often with SAH (95.5%, p = 0.0046). There was no statistically significant difference between the types regarding patient demographics or aneurysm characteristics. In type 2, fenestrated clips were used frequently (87.5% p= 0.0016), and there was higher rate of intraoperative rupture (37.5%). Although there was no statistically significant difference between the types in respect to HH grade upon presentation, patients with type 2 aneurysms experienced higher rates of poor GOS (50%). The proposed classification system for SP AComA aneurysms has implications regarding surgical planning, micro-dissection, clipping, and outcome. Type 2 aneurysms carry significant surgical risk.

Bilateral Vein of Trolard Thrombosis.

Isolated cortical vein thrombosis without dural sinus involvement is not common. The vein of Trolard is an important cortical vein as it drains eloquent cortex. We report 2 cases of bilateral vein of Trolard thrombosis; one with and the other without dural sinus involvement. To our knowledge, there have been no cases of bilateral vein of Trolard thrombosis reported in literature. The clinical presentation of cerebral venous thrombosis is variable; patients can present with isolated intracranial hypertension, focal neurological abnormalities, seizures, or encephalopathy.

Anterior petroclinoid fold fenestration: an adjunct to clipping of postero-laterally projecting posterior communicating aneurysms.

Proximally located posterior communicating artery (PCoA) aneurysms, projecting postero-laterally in proximity to the tentorium, may pose a technical challenge for microsurgical clipping due to obscuration of the proximal aneurysmal neck by the anterior petroclinoid fold. We describe an efficacious technique utilizing fenestration of the anterior petroclinoid fold to facilitate visualization and clipping of PCoA aneurysms abutting this aspect of the tentorium. Of 86 cases of PCoA aneurysms treated between 2003 and 2013, the technique was used in nine (10.5 %) patients to allow for adequate clipping. A 3 mm fenestration in the anterior petroclinoid ligament is created adjacent and lateral to the anterior clinoid process. This fenestration is then widened into a small wedge corridor by bipolar coagulation. In all cases, the proximal aneurysm neck was visualized after the wedge fenestration. Additionally, an adequate corridor for placement of the proximal clip blade was uniformly established. All cases were adequately clipped, with complete occlusion of the aneurysm neck and fundus with preservation of the PCoA. There were two intraoperative ruptures not related to creation of the wedge fenestration. One patient experienced post-operative partial third nerve palsy, which resolved during follow-up. We describe a technique of fenestration of the anterior petroclinoid fold to establish a critical and safe corridor for both visualization and clipping of PCoA aneurysms.

Iatrogenic dural arteriovenous fistula and aneurysmal subarachnoid hemorrhage.

The authors present the case of a patient who presented acutely with aneurysmal subarachnoid hemorrhage (SAH) and a contralateral iatrogenic dural arteriovenous fistula (DAVF). Diagnostic angiography was performed, revealing a right-sided middle cerebral artery (MCA) aneurysm and a left-sided DAVF immediately adjacent to the entry of the ventriculostomy and bur hole site. A craniotomy was performed for clipping of the ruptured MCA aneurysm, and the patient subsequently underwent endovascular obliteration of the DAVF 3 days later. The authors present their treatment of an iatrogenic DAVF in a patient with an aneurysmal SAH, considerations in management options, and a literature review on the development of iatrogenic DAVFs.

Unilateral Venous Approach to Contralateral or Bilateral Carotid Cavernous Shunts.

BACKGROUND: Cavernous carotid fistulas (CCF) are anatomically complex vascular lesions. Treatment via the venous approach has been previously described and is highly dependent on the patency of the drainage pathways. The use of a unilateral approach to contralateral or bilateral shunts is technically challenging and not commonly described. We present our experience with the unilateral across-the-midline approach to both cavernous sinuses to treat shunts according to anatomic compartments to achieve anatomic cure. METHODS: Patients included in this study presented with either bilateral or unilateral shunts with unilateral venous drainage. We used a transarterial guiding catheter for road mapping and control angiography. A venous triaxial system was used to achieve support for distal navigation across the midline via the coronary sinus to the contralateral cavernous sinus. Coils were favored for embolization, with occasional complementary liquid embolic material. RESULTS: Five patients underwent complete occlusion in a single session. One patient required additional complementary transarterial embolization. Despite a successful unilateral approach to bilateral cavernous sinuses, 1 patient needed an additional ipsilateral transophthalmic venous approach to obliterate the anterior compartment of the cavernous sinus. No complications were encountered. Complete angiographic cure was observed in all patients by the end of the final procedures, with persistent occlusion in their follow-up imaging. CONCLUSIONS: Careful inspection of the venous anatomy and fistulization sites is critical when treating unilateral or bilateral carotid cavernous shunts. The contralateral venous route can serve as a safe approach when visualized. Crossing the midline via the anterior or posterior coronary sinuses is feasible and efficacious.

Treatment of distal anterior cerebral artery aneurysms with the Pipeline Embolization Device.

Aneurysms of the anterior cerebral artery (ACA) located distal to the anterior communicating artery complex (ACOM) remain challenging to treat with surgical clip reconstruction as well as with endovascular coil-embolization strategies. We have treated five complex geometry distal ACA aneurysms with endoluminal reconstruction using the Pipeline Embolization Device (PED). Two aneurysms were of the dysplastic fusiform type. Three aneurysms were of complex saccular configuration. Three aneurysms were treated electively at the outset with PED. One patient had previously undergone aborted clip reconstruction, and one was treated for recurrent aneurysm growth after coil embolization. The mean diameter of the ACA in this cohort was 1.96mm proximal to the aneurysm and 1.79mm distal to the aneurysmal segment. A single PED of 2.5mm inner diameter was the sole treatment in four cases. Two PEDs, telescopically overlapped across the aneurysm, were used in the remaining case. All devices were deployed successfully. No parent artery occlusion or stenosis was observed. In all cases an associated branch vessel arising from the vicinity of the aneurysm or incorporated into its neck was covered by the endoluminal construct. At follow-up angiography, robust antegrade flow was maintained in the jailed branch. One patient experienced asymptomatic, delayed occlusion of the jailed branch. Complete aneurysm occlusion was seen in all patients. We confirm that PED can be deployed in parent vessels smaller than 2mm diameter, and that endoluminal reconstruction with the PED may be a safe and effective treatment alternative for selected distal ACA aneurysms.

Intraoperative Angiography for Arteriovenous Malformation Resection in the Prone and Lateral Positions, Using Upper Extremity Arterial Access.

BACKGROUND: Intraoperative angiography is routinely utilized for aneurysms and arteriovenous malformations (AVMs) to verify complete occlusion and resection. Surgery for spinal and posterior fossa neurovascular lesions is usually performed in prone position. Intraoperative angiography in the prone position is challenging and there is no standardized protocol for this procedure. OBJECTIVE: To describe our experience with intraoperative angiography in the prone and lateral positions, using upper extremity arterial access. METHODS: We reviewed our experience with intraoperative angiography in the prone position between 2014 and 2015, where vascular access was obtained via the upper extremity arteries. Patients were treated in a hybrid endovascular operating room. High cervical and intracranial lesions were studied via brachial or radial access. All accesses were obtained using ultrasonographic guidance and a small caliber arterial sheath (4F). RESULTS: Five patients were treated in the prone and lateral positions using brachial/radial artery access. Patients harbored cerebellar AVM, lateral medullary AVM, cervical arteriovenous fistula (AVF), tentorial dural AVF, and tentorial-incisural dural AVF. Patients were positioned prone (n = 2), semiprone (n = 2), and lateral (n = 1) for the surgery. Three patients were treated via right brachial artery access. Two patients were treated via radial arteries access. All patients tolerated the procedures without technical or clinical complications. Intraoperative angiography verified complete occlusion and resection in all cases prior to surgical closure. CONCLUSIONS: Intraoperative angiography in the prone and lateral positions using upper extremity access is an important adjunct. Brachial or radial access can be obtained safely and provides comfortable and quick approaches.

Intracranial Bypass of Posterior Inferior Cerebellar Artery Aneurysms: Indications, Technical Aspects, and Clinical Outcomes.

BACKGROUND: For some posterior inferior cerebellar artery (PICA) aneurysms, there is no constructive endovascular or direct surgical clipping option. Intracranial bypass is an alternative to a deconstructive technique. OBJECTIVE: To evaluate the clinical features, surgical techniques, and outcome of PICA aneurysms treated with bypass and obliteration of the diseased segment. METHODS: Retrospective review of PICA aneurysms treated via intracranial bypass was performed. Outcome measurements included postoperative stroke, cranial nerve deficits, gastrostomy/tracheostomy requirement, bypass patency, modified Rankin scale (mRS) at discharge, and mRS at 6 mo. RESULTS: Seven patients with PICA aneurysms treated with intracranial bypass were identified. Five had fusiform aneurysms (4 ruptured, 1 unruptured), 1 had a giant partially thrombosed saccular aneurysm (unruptured), and 1 had a dissecting traumatic aneurysm (ruptured). Two aneurysms were at the anteromedullary segment, 4 at the lateral medullary segment, and 1 at the tonsillomedullary segment. Three patients underwent PICA-to-PICA side to side anastomoses, 2 PICA-to-PICA reanastomosis, 1 vertebral artery-to-PICA bypass, and 1 occipital artery-PICA bypass. Six out of 7 aneurysms were obliterated surgically and 1 with additional endovascular occlusion after the bypass. All bypasses were patent intraoperatively; 2 were later demonstrated occluded without radiological signs or symptoms of stroke. No patients had new cranial nerve deficit postoperatively. With the exception of 1 death due to pulmonary emboli 3 mo postoperatively, all others remain at a mRS ≤ 2. CONCLUSION: Constructive bypass and aneurysm obliteration remains a viable alternative for treatment of PICA aneurysms not amenable to direct surgical clipping or to a vessel-preserving endovascular option.

Angiographic Evidence of a Purely Pial Bihemispheric Intracranial Hemangiopericytoma.

Background. Classification of hemangiopericytoma (HPC) has evolved to a mesenchymal, nonmeningothelial grade two or three neoplasm according to the World Health Organization; however its blood supply has always been defined by dual origin, pial and dural contribution. Case Description. We present the case of a patient with an intracranial HPC with only pial vascular supply. Angiography confirmed the lack of dural supply to this bihemispheric intracranial mass. Subsequent histologic examination confirmed the diagnosis of hemangiopericytoma. Angiographic evidence here is atypical of the natural history of hemangiopericytomas with dual vascular supply and was critical in the decision-making towards surgical resection without tumor embolization. Conclusion. Data presented suggests the lack of dural vascular supply alone does not rule out the diagnosis of hemangiopericytoma.

Modifying flow in the ACA-ACoA complex: endovascular treatment option for wide-neck internal carotid artery bifurcation aneurysms.

BACKGROUND: Treatment of selected wide-neck internal carotid artery (ICA) bifurcation aneurysms remains challenging for clip reconstruction and for endovascular options. OBJECTIVE: To describe a new endovascular treatment technique for wide-neck ICA bifurcation (ICAb) aneurysms. METHODS: We have employed a treatment approach that uses both complete proximal occlusion and reversal of flow in the ipsilateral A1 segment, using different endovascular modalities such as coils, stent-assisted coiling, or flow diverters (FDs) plus coiling concomitantly. This endovascular technique may overcome the challenges of current treatments and high recanalization rates for coiled ICAb aneurysms. RESULTS: We treated four patients in whom we redirected the pre-existing flow in the supraclinoid ICA into the ipsilateral A1 and M1 segments, to a new unilateral, linear flow from the supraclinoid ICA solely into the ipsilateral M1 segment. This resulted in the establishment of flow from the contralateral A1 segment into the ipsilateral A1 segment, allowing supply of only demanding perforating arteries on this specific (ipsilateral) segment. This technique was not associated with any new neurological deficits or radiographic ischemia. The four patients reviewed were all treated using coils. One was treated with a standard stent. The other two were treated with a FD. CONCLUSIONS: We found that the proposed technique of flow modification can allow for hemodynamic conversion of ICAb to 'side-wall' aneurysm. In patients with good collateral flow through the anterior communicating complex, this treatment paradigm is safe and effective.

Concurrent use of the Pipeline Embolization Device and coils for intracranial aneurysms: technique, safety, and efficacy.

OBJECT: The use of the Pipeline Embolization Device (PED) as a sole endovascular modality has been described for the treatment of brain aneurysms. The benefit of using coils concurrently with a limited number of PEDs is not well documented. The authors describe their experience with this technique as well as their midterm clinical and angiographic results. METHODS: This is a retrospective review of patients treated between 2011 and 2014. The authors placed a minimal number of PEDs with the addition of coils using a "jailed" microcatheter technique. A partially dense coil mass was obtained. Immediate and midterm clinical and angiographic results are reviewed. RESULTS: The authors treated 27 patients harboring 28 aneurysms using this technique. The mean aneurysm size was 11.9 mm, and the mean neck size was 5.4 mm. A mean of 1.48 PEDs were placed per patient, and a mean of 1.33 PEDs per aneurysm were placed. The Raymond score immediately after PED placement was 2 or 3 in 82.1% of the patients. There were no intraprocedural or postprocedural complications. All PEDs were successfully deployed. No clinical or technical adverse effects related to the coil mass were observed. There were no clinical or radiographic signs of ischemia in this group. At follow-up imaging, complete aneurysm occlusion was demonstrated on the first MR angiogram (3-5 months) in all patients who reached this milestone. Follow-up digital subtraction angiography (5-13 months) confirmed complete occlusion in all patients who reached this milestone. All patients maintained their baseline clinical status. CONCLUSIONS: The deployment of PEDs with concurrent partially dense coiling is safe and efficacious. This technique achieved early complete occlusion and endovascular reconstruction of the parent vessel, without inducing mass effect. Favorable midterm clinical results were observed in all patients.

Three-dimensional rotational spinal angiography in the evaluation and treatment of vascular malformations.

BACKGROUND AND PURPOSE: Conventional spinal angiography, although useful in providing angioarchitectural details of spinal vascular disease, has limitations. The advent of 3D angiography has provided a better comprehension of angioarchitectural detail when evaluating the intracranial circulation. The purpose of this study was to evaluate the usefulness of 3D angiography in the diagnosis and treatment of vascular malformations of the spine. METHODS: This retrospective analysis included 17 3D spinal angiograms acquired in 14 consecutive patients examined at our institution for a spinal vascular lesion, which included nine spinal cord arteriovenous malformations (AVMs), one perimedullary arteriovenous fistula (AVF), three spinal dural AVFs, and one nerve root AVM. 3D angiography was obtained with apnea under general anesthesia by using a 14-second acquisition and 200 degrees rotation of the gantry during injection of 300 mg I/mL nonionic contrast material at a rate of 0.5-3.5 mL/s. Multiple reconstructed images were obtained with or without opacification of the surrounding structures. These images were then evaluated by the interventionalists at the time of the procedure and compared with findings obtained by conventional subtraction angiography. RESULTS: 3D angiography was useful in differentiating intramedullary lesions from perimedullary surface lesions; detecting arterial, nidal, or venous aneurysms; and evaluating the 3D structure of the lesion as well as the relationship between the malformation and its draining veins or surrounding bony structures. In specific situations, it obviated the need for contrast-enhanced conventional or 3D CT, as well as for lateral or oblique angiographic views, which are sometimes difficult to obtain with good quality. No 3D angiography-related complications were experienced. Some limitations in the definition of small vessel anatomy in the reconstructed images were noted. CONCLUSION: In this small series of patients, 3D angiography was safe and useful for evaluation of the 3D vascular anatomy of spinal vascular malformations.

Neurophysiologic monitoring and pharmacologic provocative testing for embolization of spinal cord arteriovenous malformations.

BACKGROUND AND PURPOSE: Embolization of a spinal cord arteriovenous malformation (SCAVM) is still considered risky. We evaluated the efficacy and reliability of pharmacologic provocative testing with neurophysiologic monitoring in the embolization of SCAVMs. METHODS: We retrospectively analyzed results of 60 provocative tests during 84 angiographic procedures (in 52 patients) with intended endovascular embolization. Tests included 47 sodium amytal and 56 lidocaine injections. All procedures were performed with general anesthesia and monitoring of cortical somatosensory evoked potentials (SEPs) and transcranial motor evoked potentials (MEPs). For provocative testing, 50 mg of amytal and 40 mg of lidocaine were consecutively injected through a microcatheter placed at the position of intended embolization. If SEPs and MEPs did not change, embolization was performed with N-butyl-cyanoacrylate (NBCA). If SEPs or MEPs changed, NBCA embolization was not performed from that catheter position. RESULTS: One false-negative result occurred, with an increase in spasticity after embolization. Nineteen positive results occurred: four after amytal injection and 15 after lidocaine injections. Seven injections in a posterior spinal artery feeder resulted in loss of SEPs or MEPs. Eleven injections in the anterior spinal artery feeder and one in the posterior inferior cerebellar artery feeder resulted in loss of MEPs. CONCLUSION: Provocative testing with amytal and lidocaine combined with neurophysiologic monitoring had a high negative predictive value and was a useful adjunct for SCAVM embolization. Both amytal and lidocaine should be used as provocative agents, and both SEPs and MEPs should be monitored.

Intentional partial coil occlusion followed by delayed clip application to wide-necked middle cerebral artery aneurysms in patients presenting with severe vasospasm. Report of two cases.

The treatment of ruptured cerebral aneurysms in patients presenting with vasospasm remains a particular challenge. The authors treated two patients harboring Hunt and Hess Grade 1 subarachnoid hemorrhages from middle cerebral artery (MCA) aneurysms associated with severe local angiographically demonstrated yet asymptomatic vasospasm on presentation. Because both aneurysms had wide necks and were located at the MCA bifurcation, they were believed to be anatomically suitable for microsurgical clip application. Severe M, vasospasm was believed to be a relative contraindication to open surgery, however. An intentionally staged endovascular and microsurgical treatment strategy was planned in each patient. Partial coil occlusion of the aneurysmal dome was performed to prevent the lesion from rebleeding and was followed by balloon angioplasty of the spastic vessel. Early treatment of the severe spasm appeared to prevent significant delayed neurological ischemic deficit. Following resolution of the vasospasm, definitive clipping of the aneurysms was performed on Day 13 post embolization. One patient had a good clinical recovery and was discharged without neurological deficit. The other patient's hospital course was complicated by the occurrence of a postoperative posterior temporal infarct requiring partial temporal lobectomy, although she eventually had a good recovery with only a small visual field deficit. Based on data obtained in these two patients, one can infer that ruptured wide-necked MCA aneurysms associated with severe local vasospasm may best be treated using a staged combined treatment plan. Delayed clip application might be performed more safely 4 to 6 weeks postocclusion, or later, than at 2 weeks.

Cavernous carotid aneurysms rarely cause subarachnoid hemorrhage or major neurologic morbidity.

GOAL: To determine whether aneurysms of the cavernous internal carotid artery (CCA) cause major neurologic morbidity or death. METHODS: Retrospective analysis of all patients with a spontaneous CCA evaluated by a referral multidisciplinary neurovascular service from 1981 to 2000. All patients had complete clinical neuro-ophthalmologic and neurologic examinations and magnetic resonance imaging (MRI) or computed tomography (CT) with angiographic diagnostic confirmation. Follow-up evaluations were performed by our service in the majority of patients, and the remaining patients' subsequent examinations were obtained from the referring physicians. RESULTS: One hundred seventy-four patients (mean age 60.7 years, median age 63 years, 161 women, 13 men) had 193 CCA. All 19 patients with bilateral CCAs were female. Twenty-eight patients had 1 or more subarachnoid aneurysms. The presentation included 156 aneurysms with pain or cranial neuropathy or both, 13 with a carotid cavernous fistula (CCF), and 24 asymptomatic CCAs. Two patients, both with a coagulopathy, had a cerebral infarct ipsilateral to the CCA, 1 at presentation and the other 2 years after partial third nerve palsy. One patient had a subarachnoid hemorrhage (SAH) 2.3 years after presentation, and no patient had arterial epistaxis or a CCA-related death. Excluding the 15 patients (16 aneurysms) who had no follow-up or died from SAH due to a subarachnoid aneurysm, 177 aneurysms were followed up for a mean duration of 3.10 years (SD = 3.6). One hundred six never-treated aneurysms were followed for 4.5 years (SD = 3.80, range 0.1-17), and 71 ultimately treated aneurysms were followed for 1.56 years (SD = 2.69, range 0.1-15). The overall rate for SAH was 0.19% and for a CCA-associated cerebral infarct was 0.37% per patient year. There were no correlations with cerebral infarct, SAH, or CCF and diabetes mellitus, hypertension, gender, age, cranial neuropathy, or size of the aneurysm, except for the largest diameter of the aneurysm and CCF (r = 0.17, P = .018). However, all of the patients with cerebral infarct or SAH and 12 of the 13 CCF had an aneurysm diameter > or = 1 cm. CONCLUSIONS: CCA is a disorder with strong female gender bias that uncommonly causes major neurologic complications. These data suggest that CCA should not be included in analyses that determine the risk of severe neurologic morbidity, hemorrhage, or death due to intracranial aneurysms.

Internal maxillary artery-middle cerebral artery bypass: infratemporal approach for subcranial-intracranial (SC-IC) bypass.

BACKGROUND: Internal maxillary artery (IMax)-middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a "keyhole" craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis. OBJECTIVE: To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass. METHODS: Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass. RESULTS: There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well. CONCLUSION: IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis.