Ramsey Ashour

Preoperative tumor embolization.

In this article, the authors review general principles and technical details of preoperative embolization of various hypervascular head, neck, and spinal tumors encountered in contemporary neuroendovascular practice. Indications, treatment goals, techniques, outcomes, and complications are discussed, and illustrative case examples are presented.

Endovascular management of intracranial blister aneurysms: spectrum and limitations of contemporary techniques

Background Intracranial blister aneurysms are rare lesions that are notoriously more difficult to treat than typical saccular aneurysms. High complication rates associated with surgery have sparked considerable interest in endovascular techniques, though not well-studied, to treat blister aneurysms. Objective To evaluate our experience using various endovascular approaches to treat blister aneurysms. Methods All consecutive blister aneurysms treated using an endovascular approach by the study authors over a 3-year period were retrospectively analyzed. A literature review was also performed. Results Nine patients with blister aneurysms underwent 11 endovascular interventions. In various combinations, stents were used in 8/11, coils in 5/11, and Onyx in 3/11 procedures. At mean angiographic follow-up of 200 days, 8/9 aneurysms were completely occluded by endovascular means alone requiring no further treatment and 1/9 aneurysms required surgical bypass/trapping after one failed surgical and two failed endovascular treatments. At mean clinical follow-up of 416 days, modified Rankin Scale scores were improved in six patients, stable in two, and worsened in one patient. One complication occurred in 11 procedures (9%), resulting in a permanent neurologic deficit. No unintended endovascular parent vessel sacrifice, intraprocedural aneurysmal ruptures, antiplatelet-related complications, post-treatment aneurysmal re-ruptures, or deaths occurred. Conclusion This series highlights both the spectrum and limitations of endovascular techniques currently used to treat blister aneurysms, including a novel application of stent-assisted Onyx embolization. Long-term follow-up and experience in larger studies are required to better define the role of endovascular therapy in the management of these difficult lesions.

Direct continuous measurement of draining vein pressure during Onyx embolization in a swine arteriovenous malformation model

Objective Periprocedural intracranial hemorrhage secondary to intranidal flow redirection may develop after arteriovenous malformation (AVM) embolization. We hypothesized that continuous draining vein pressure monitoring may identify clinically relevant hemodynamic changes during devascularization. Our goal was to characterize the draining vein pressures in a swine rete mirabile AVM model during embolization with Onyx. Methods An acute swine AVM model was constructed in six animals. Baseline, transoperative and final AVM area measurements were used to determine the degree of AVM embolization. Continuous video recordings were captured at 10 s intervals of active embolization. Draining vein pressure, arterial feeder pressure and heart rate were continuously monitored. Results The baseline and post-embolization mean draining vein pressures were 49.8±17.2 and 33.0±11.7 mm Hg (p=0.01), mean arterial pressures were 79.8±19.4 and 79.6±25.2 mm Hg (p=0.94), mean transnidal pressures were 35.8±19.7 and 45.4±33.7 mm Hg (p=0.37) and mean heart rates were 81.1±11.9 and 83.1±12.8 bpm (p=0.38), respectively. The draining vein pressure was averaged according to the degree of AVM embolization and represented as a relative change compared with the baseline draining vein pressure, and the slopes were found to decrease in all cases (p=0.02). In half of the animals the draining vein pressure decreased progressively as the AVM was embolized. In the remaining animals the venous pressure only started to decline after the AVM had been devascularized by > 50%. Conclusions The draining vein pressure response during Onyx embolization in the swine AVM model is heterogeneous. Continuous draining vein pressure monitoring is feasible and may potentially identify clinically relevant hemodynamic changes during AVM embolization.

Lower vertebral-epidural spinal arteriovenous fistulas: a unique subtype of vertebrovertebral arteriovenous fistula, treatable with coil and Penumbra Occlusion Device embolization

A vertebral-epidural spinal arteriovenous fistula (AVF) is an abnormal arteriovenous shunt connecting the vertebral artery to the spinal epidural venous plexus, and may occur spontaneously or secondary to a variety of causes. These unique lesions are uncommon in adults and rarer still in children. Previous reports have grouped together a heterogeneous collection of such arteriovenous lesions, including arterial contributions from the upper and lower vertebral artery, with venous drainage into a variety of spinal and paraspinal collectors. Here, through two cases, we delineate a distinct entity, the lower vertebral-to-epidural AVF. The salient clinical and anatomic features are summarized and contextualized within the broader constellation of vertebrovertebral AVF, the utility of a transarterial intravenous/retrograde intra-arterial endovascular approach is highlighted, and a new use of the Penumbra Occlusion Device (Penumbra Inc) for this purpose is reported.

Ruptured Anterior Spinal Artery Aneurysm Associated with Bilateral Vertebral Artery Occlusion Treated by Surgical Clipping

BACKGROUND Spinal artery aneurysms are rare lesions that can occur in isolation or may be attributed to a variety of secondary causes. Chronic bilateral vertebral artery occlusion is an exceedingly rare cause of anterior spinal artery aneurysm, with only one previous case reported in the literature. Surgical treatment of ventrally located anterior spinal artery aneurysms situated at the craniocervical junction presents particular challenges related to the operative approach, which may entail high cervical anterior exposure, posterolateral complete facetectomy/pediculectomy, or far lateral skull base approaches, among others. CASE DESCRIPTION We present the case of a patient who presented with a ruptured anterior spinal artery aneurysm at the level of C2, associated with a hypertrophied anterior spinal artery due to chronic bilateral vertebral artery occlusion; the second such case reported in the literature. A posterior approach with spinal cord rotation was employed to expose and clip the aneurysm. The patient made an uneventful recovery. CONCLUSION This report highlights an exceedingly rare cause of anterior spinal artery aneurysm and emphasizes the utility and technical aspects of the posterior approach with spinal cord rotation.

Stent deployment protocol for optimized real-time visualization during endovascular neurosurgery

Successful application of endovascular neurosurgery depends on high-quality imaging to define the pathology and the devices as they are being deployed. This is especially challenging in the treatment of complex cases, particularly in proximity to the skull base or in patients who have undergone prior endovascular treatment. The authors sought to optimize real-time image guidance using a simple algorithm that can be applied to any existing fluoroscopy system. Exposure management (exposure level, pulse management) and image post-processing parameters (edge enhancement) were modified from traditional fluoroscopy to improve visualization of device position and material density during deployment. Examples include the deployment of coils in small aneurysms, coils in giant aneurysms, the Pipeline embolization device (PED), the Woven EndoBridge (WEB) device, and carotid artery stents. The authors report on the development of the protocol and their experience using representative cases. The stent deployment protocol is an image capture and post-processing algorithm that can be applied to existing fluoroscopy systems to improve real-time visualization of device deployment without hardware modifications. Improved image guidance facilitates aneurysm coil packing and proper positioning and deployment of carotid artery stents, flow diverters, and the WEB device, especially in the context of complex anatomy and an obscured field of view.

Successful coiling of a giant ophthalmic aneurysm resulting in blindness: case report and critical review.

Giant ophthalmic aneurysms often present with visual loss secondary to mass effect upon the optic pathways and also carry a high risk of subarachnoid hemorrhage. Endovascular coil embolization is used in select cases to occlude these aneurysms, but this approach is less effective than direct surgical obliteration because of the high rate of aneurysm recanalization and the possibility of worsening mass effect.

Refinement of the Hybrid Neuroendovascular Operating Suite: Current and Future Applications

OBJECTIVE In early-generation hybrid biplane endovascular operating rooms, switching from surgical to angiographic position is cumbersome. In this report, we highlight the unique design of a new hybrid neuroendovascular operating suite that allows surgical access to the head while keeping the biplane system over the lower body of the patient. Current and future hybrid neuroendovascular operating suite applications are discussed. METHODS We collaborated with engineers to implement the following modifications to the design of the angiographic system: translation of the bed toward the feet to allow biplane cerebral imaging in the head-side position and the biplane left-side position; translation of the base of the A-plane C-arm away from the feet to allow increased operator space at the head of the bed and to allow cerebral imaging in both the head-side and left-side positions; use of a specialized boom mount for the display panel to increase mobility; and use of a radiolucent tabletop with attachments for the headrest or radiolucent head clamp system. RESULTS The modified hybrid neuroendovascular operating suite allows for seamless transition between surgical and angiographic positions within seconds, improving workflow efficiency and decreasing procedure time as compared with early-generation hybrid rooms. CONCLUSIONS Combined endovascular and surgical applications are facilitated by co-locating their respective technologies and refining the ergonomics of the system to ease transition between both sets of technologies. In so doing, hybrid neuroendovascular operating suites can be anticipated to improve patient outcomes, generate novel treatment paradigms, and improve time and cost efficiency.

Neuromeningeal access for transarterial intravenous carotid-cavernous fistula embolization

While numerous endovascular access routes have been described for carotid-cavernous fistula (CCF) treatment, transarterial embolization via the neuromeningeal trunk of the ascending pharyngeal artery is typically avoided due to the risk of cranial nerve palsy or non-target embolization via external-to-internal carotid anastamoses. We present the case of a dural CCF in which access to the venous side of the fistula was achieved via the neuromeningeal trunk and allowed for curative transarterial intravenous coil/liquid embolic embolization of the lesion. The utility of a transarterial intravenous approach in the face of venous sinus occlusion is highlighted. The neuromeningeal trunk should not be overlooked as a potential access route for transarterial intravenous CCF embolization in cases where traditional endovascular access is limited; this approach does not carry the same risks that are generally associated with pure transarterial embolization along this pathway.

Interventional neuroradiology in children: diagnostics and therapeutics.

Purpose of review To highlight the spectrum of pediatric neurovascular conditions typically referred for diagnostic or interventional neuroangiography, the range of techniques available in contemporary pediatric neurointerventional practice, and the specific considerations relating to radiation and contrast dosing applicable to pediatric neurointerventional procedures. Recent findings Neurointerventional procedures are increasingly utilized in children for a variety of indications, with continuous emphasis on improving safety and treatment effectiveness. Numerous steps can be taken to mitigate the potential risks of pediatric neurointerventional procedures, with recent data from high-volume centers suggesting similar, if not lower, complication rates in children compared with adults. Judicious patient selection and clarity of goals are critically important, however, because children undergoing complex and lengthy neurointerventional procedures are particularly vulnerable to the effects of ionizing radiation, vessel injury, and contrast overload. Summary With continued advances in endovascular technology, neurointerventionalists stand to play an important and expanding role in the multidisciplinary management of pediatric neurovascular disease.