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.

Objective: To evaluate the policies and procedures to improve the Door to Groin Puncture (Door-to-Groin) time. We hypothesize that by segmenting the process into three phases: (1) Door to Computed Tomography Angiography performed (Door-to-CTA), (2) CTA performed to Interventional Radiology (IR) suite arrival (CTA-to-IR), and (3) IR arrival to Groin Puncture (IR-to-Groin), will enable the Door-to-Groin goal to be achieved under 70 minutes. Background: Tertiary hospitals are reorganizing to provide more efficient and rapid access to endovascular stroke care. Endovascular interventions are time-sensitive and must be initiated immediately. Process map analysis illustrated that delays in Door-to-Groin time were not due to one specific cause. As guidelines changed, we developed a multidisciplinary collaborative process to encourage departments to avoid working in silos. Design/Methods: A prospective data collection was performed between January 2015 to April 2017 (n=68 patients). The multidisciplinary team discussed endovascular intervention times for every patient. Policies streamlining procedure setup, rapid documentation and patient preparation were introduced to all staff. The intervention involved a parallel process approach that resulted in significant time saving. Descriptive statistics were performed. Results: The Door-to-Groin time decreased by 56% from the first quarter of 2015 (156 minutes, n=3) to the first quarter of 2017 (68.4 minutes, n=18). The average Door-to-Groin time progressively decreased with time [2015 (127 minutes, n=20); 2016 (87.9 minutes, n=30); first quarter of 2017 (68.4 minutes, n=18)]. The streamlined processes aimed at reducing the Door-to-CTA, CTA-to-IR, and IR-to-Groin times, collectively reduced the Door-to-Groin time, thereby, reducing revascularization time. Identifying gaps in communication and performance had a positive impact on patient health outcomes and employee engagement. Conclusions: Complex processes, involving multiple stakeholders, can be streamlined when a targeted improvement process is employed. Utilizing evidence-based medicine to identify appropriate communication and performance gaps yields a reduction in preparation time and directly influences revascularization times. Disclosure: Dr. Wright has nothing to disclose. Dr. Katz has nothing to disclose. Dr. Wright has nothing to disclose. Dr. Setton has nothing to disclose. Dr. Thirunavukkarasu has nothing to disclose.

Background Dural arteriovenous fistulas (DAVFs) of the craniocervical junction (CCJ) represent very rare arteriovenous shunts between dural arteries and veins of this area. The classification of these fistulas is based on the draining vein or sinus. Hypoglossal canal, jugular foramen, posterior condylar vein, and marginal sinus fistulas are the commonest types. The clinical presentation of the patients with DAVFs of the CCJ depends on their venous drainage pattern, and thus, the detailed knowledge of the complex venous anatomy and its variations of the CCJ is very important in understanding the pathophysiology, interpreting the clinical symptomatology and establishing their treatment plan. Microsurgical disconnection of the fistulas site using skull base approaches remains a very important consideration for the treatment of these pathologies.

Background The supracerebellar transtentorial approach to the inferior occipital lobe, posterior medial temporal lobe, and tentorial incisura via a suboccipital craniotomy provides an adequate surgical corridor to access lesions in these areas. By using this approach, the need of retraction of the occipital lobe and the transcortical route to deep located lesions is avoided. The sitting position provides a gravitational retraction of the cerebellum and a wider supracerebellar corridor to approach deep located pathologies.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass.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.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.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.

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.

We report our experience with an embolization technique that allows safe, controllable exclusion of pulmonary arteriovenous malformations using detachable coils, a single venous access site, coaxial catheter guidance, and 1 or 2 microcatheters. This technique is particularly useful when treating central lesions with a short feeding artery and when high flow increases the risk of coil migration and nontarget embolization. It affords precise placement and repositioning of coils prior to detachment. The technique facilitates safe and successful endovascular closure of these challenging lesions.

Background and Purpose: “Bridging Therapy” is well described in the literature. However the dose of bridging tissue plasminogen activator (tPA) is a matter of debate given the well-established guideline of 0.9 mg/kg as the standard intravenous dose. Previous and ongoing bridging trials use lower doses of IV-tPA (0.6 mg/kg) with a goal of maximizing safety. Our aim was to explore whether full bridging dose IV-tPA at 0.9 mg/kg can be given safely in combination with intra-arterial (IA)-tPA. Methods: Data were collected prospectively on 47 consecutive patients with acute ischemic stroke who were treated with endovascular stroke therapy (EST, that is IA-tPA +/- mechanical embolectomy (ME)). Patients who were candidates for IV-tPA, who did not clinically improve after receiving full dose IV-tPA (0.9mg/Kg), underwent EST (bridging group, n=23, 15/23 IA-tPA + ME). These patients were compared to patients treated with EST alone because they were not candidates for IV-tPA (control group, n=24, 14/24 IA-tPA + ME). Symptomatic intracranial hemorrhage (ICH) rates were recorded, as defined in the NINDS IV-tPA trial. Death rates were recorded at one month and modified Rankin score was used to measure functional outcome (6 month mean follow-up). Results: Mean age was 62 years in the bridging group and 63 years in the control group. Baseline mean National Institute of Health Stroke Scale was 20 in the bridging group and 21 in the control group (p = 0.188). The mean IA-tPA dose was 14.4 mg in the bridging group and 18.3 mg in the control group (p = 0.371). There was an 8% risk of symptomatic ICH in the control group and no symptomatic ICH in the bridging group (p = 0.155). At 30 days, mortality was 17% in the bridging group and 29% in the control group (p = 0.313). The mean follow-up modified Rankin score was 3 in the bridging group and 4 in the control group (p = 0.20). Conclusion: This non-randomized retrospective cohort study suggests that full dose IV-tPA combined with IA-tPA administered during EST is safe in patients with acute ischemic stroke. Given the possibility that full bridging dose tPA may be more effective than lower dose IV-tPA, a prospective, randomized bridging trial using full dose IV-tPA may be warranted.

Aneurysms of the posterior spinal artery (PSA) are rare lesions. Isolated PSA aneurysms, not in the setting of a high-flow environment, are even more rare. In the few reported cases, these lesions have been predominantly resected or observed. The authors report an isolated pseudoaneurysm of the PSA at the T-11 level presenting with subarachnoid hemorrhage. The patient underwent successful endovascular obliteration. To the authors' knowledge, this is the first report of an endovascular repair of an isolated PSA aneurysm.