Luis E. Savastano

Development of a 3D-printed external ventricular drain placement simulator: technical note.

In this paper, the authors present a physical model developed to simulate accurate external ventricular drain (EVD) placement with realistic haptic and visual feedbacks to serve as a platform for complete procedural training. Insertion of an EVD via ventriculostomy is a common neurosurgical procedure used to monitor intracranial pressures and/or drain CSF. Currently, realistic training tools are scarce and mainly limited to virtual reality simulation systems. The use of 3D printing technology enables the development of realistic anatomical structures and customized design for physical simulators. In this study, the authors used the advantages of 3D printing to directly build the model geometry from stealth head CT scans and build a phantom brain mold based on 3D scans of a plastinated human brain. The resultant simulator provides realistic haptic feedback during a procedure, with visualization of catheter trajectory and fluid drainage. A multiinstitutional survey was also used to prove content validity of the simulator. With minor refinement, this simulator is expected to be a cost-effective tool for training neurosurgical residents in EVD placement.

Acute ischemic stroke in a child due to basilar artery occlusion treated successfully with a stent retriever

Ischemic strokes in childhood are rare. Thrombolytic therapy with intravenous (IV) tissue plasminogen activator (tPA) has been the main intervention for the management of pediatric stroke patients, but safety data are lacking and efficacy has been questioned. Recently, successful endovascular treatments for acute ischemic stroke in children have been reported with increasing frequency, suggesting that mechanical thrombectomy can be a safe and effective treatment. We present the case of a 22-month-old child with acute ischemic stroke due to basilar artery occlusion that was successfully treated with a stent retriever.

Multimodal laser-based angioscopy for structural, chemical and biological imaging of atherosclerosis

The complex nature of atherosclerosis demands high-resolution approaches to identify subtle thrombogenic lesions and define the risk of plaque rupture. Here, we report the proof-of-concept use of a multimodal scanning fiber endoscope (SFE) consisting of a single optical fiber scanned by a piezoelectric drive that illuminates tissue with red, blue, and green laser beams, and digitally reconstructs images at 30 Hz with high resolution and large fields-of-view. By combining laser-induced reflectance and fluorescence emission of intrinsic fluorescent constituents in arterial tissues, the SFE allowed us to co-generate endoscopic videos with a label-free biochemical map to derive a morphological and spectral classifier capable of discriminating early, intermediate, advanced, and complicated atherosclerotic plaques. We demonstrate the capability of scanning fiber angioscopy for the molecular imaging of vulnerable atherosclerosis by targeting proteolytic activity with a fluorescent probe activated by matrix metalloproteinases. We also show that the SFE generates high-quality spectral images in vivo in an animal model with medium-sized arteries. Multimodal laser-based angioscopy could become a platform for the diagnosis, prognosis, and image-guided therapy of atherosclerosis.

Stent-assisted coil embolization of a symptomatic middle cerebral artery aneurysm in an infant

Pediatric intracranial aneurysms are rare and challenging to treat. Achieving efficacy and durability of aneurysmal occlusion while maintaining parent vessel patency requires innovative treatment strategies, especially in cases in which aneurysmal location or morphology pose substantial morbidity associated with microsurgical treatment. In the last 3 decades, endovascular treatments have had a remarkable evolution and are currently considered safe and effective therapeutic options for cerebral aneurysms. While endovascular techniques are well described in the English literature, the endovascular management of pediatric aneurysms continues to pose a challenge. In this report, the authors describe the case of a 9-month-old infant who presented with a 1-day history of acute-onset left-sided hemiparesis and left facial droop. Imaging revealed a large symptomatic saccular middle cerebral artery aneurysm. Treatment included successful stent-assisted aneurysm coiling. At follow-up, the patient continued to fare well and MR angiography confirmed complete occlusion of the aneurysm dome. This case features the youngest patient in the English literature to harbor an intracranial aneurysm successfully treated with stent-assisted coiling. Based on this experience, endovascular intervention with vascular reconstruction can be safe and effective for the treatment of infants and could further improve prognosis; however, further studies are necessary to confirm these findings.

Diagnostic and Interventional Optical Angioscopy in Ex Vivo Carotid Arteries

BACKGROUND Angioscopy - or endovascular endoscopy - is a catheter-based technique employing a flexible fiberoptic angioscope to directly visualize arterial lumen. Poor resolution and excessive stiffness of pre-existent angioscopes limited their use clinically. Recent advances resulted in novel fused optical fiber bundle angioscopes with improved flexibility and imaging resolution. Use of these devices in endovascular neurosurgery is still largely unexplored. OBJECTIVE To evaluate image quality and feasibility of optical angioscopes for diagnostic and interventional neuro-angioscopy in carotid arteries of human cadavers. METHODS A 5-F optical angioscope was used in human cadaveric carotid arteries to inspect integrity of arterial walls, identify atherosclerotic plaques and associated lesions prone to thrombogenicity, place intravascular occlusion coils, and deploy endovascular stents with real-time visualization. RESULTS Angioscopy provided key information about endoluminal anatomy such as presence and characteristics of atherosclerotic plaques and thrombogenic lesions not detected by conventional diagnostic methods. Direct real-time visualization of vascular lumen during endovascular interventions provided information on spatial distribution of coils, coil loop herniation, and apposition of stent cells against carotid artery wall complementary to angiography. CONCLUSIONS Fused optical fiber bundle angioscopes provide good-quality endoluminal images in human carotid arteries. Their use can feasibly assist in navigation of extracranial carotid arteries to inspect integrity of the arterial wall and identify atherosclerotic plaques and associated lesions vulnerable to thrombogenicity, allow placement of intravascular occlusion coils, and assess apposition of stents to vessel wall. Further in Vivo validation needs to be conducted along with additional research to improve image quality, flexibility, and size of angioscopes.

Delayed extrusion of embolic coils into the airway after embolization of an external carotid artery pseudoaneurysm

Carotid blowout syndrome (CBS) is a known devastating complication of head and neck surgery. The risk of developing CBS increases in the setting of radiation therapy, wound breakdown, or tumor recurrence. Traditionally, the treatment of choice for CBS is surgical ligation of the bleeding artery; however, recently, endovascular occlusion has become a more common option. If a pseudoaneurysm is present, treatment consists of trapping with endovascular coils or occlusion with a liquid embolic agent. Delayed migration of embolization coils into the airway causing acute respiratory distress is a rare occurrence. This report presents a case of a 57-year-old woman who presented to her otolaryngologist after experiencing an episode of acute respiratory distress which resolved when she expectorated embolization coil material from her tracheostomy tube. Three months prior to the episode she underwent coil embolization of an external carotid artery pseudoaneurysm for life-threatening hemorrhage.

Microvascular Brainstem Ischemia After Vestibular Schwannoma Surgery: A Clinical and Microanatomic Study

OBJECTIVE To identify a potential microvascular etiology in patients who underwent vestibular schwannoma surgery (VSS) complicated by postoperative microvascular brainstem ischemia. METHODS Charts were retrospectively reviewed of all patients who had an MRI within 14 days of VSS in years 2005-2016. Patient characteristics, preoperative and postoperative imaging features, clinical course and potential predictors of brainstem ischemia were recorded. Cadaveric dissections of 4 cerebellopontine angle (CPA) cisterns with focus on the anterior inferior cerebellar artery (AICA) microvascular were also performed to identify candidate vessels and potential etiology. RESULTS Fifty-four of 258 patients had an MRI within 14 days of VSS. Retrosigmoid approach was used in 61.1% of patients, translabyrinthine approach in 25.9%, and middle fossa approach in 13.0%. Four patients (7.4%) had acute microvascular ischemia involving the middle cerebellar peduncle (MCP) adjacent to the cranial nerve (CN) VII-VIII complex demonstrated on postoperative MRI. A statistically significant association was found between the translabyrinthine approach and acute brainstem ischemia (odds ratio, 10.6; 95% confidence interval, 1.004-112.7). Dissection of CPAs revealed 10-20 perforating arteries per specimen originating from the lateral pontine and the flocculopeduncular segments of the AICA. Most microvessels travelled in retrograde fashion along the anteroinferior surface of the CN VII-VIII complex to perforate the cisternal surface of the MCP. No patient had residual or delayed neurologic deficits related to brainstem ischemia at final follow-up. CONCLUSIONS While effort should be made to preserve perforating vessels, microvascular brainstem ischemia is often asymptomatic and did not lead to permanent neurologic deficits in our series.

Posterior Fossa Craniotomy for Adherent Fourth Ventricle Neurocysticercosis

BACKGROUND AND IMPORTANCE Neurocysticercosis (NCC) is an infectious helminthic disease often presenting in patients who have immigration or travel history from areas where NCC is endemic. Fourth ventricle cysts from NCC pose a unique treatment challenge, as there is little consensus on the best treatment. This case study describes the treatment of a patient with fourth ventricle neurocysticercosis (FVNCC), examines the therapeutic decision-making, and provides a video of a posterior fossa craniotomy (PFC) resection of a degenerative cyst. CLINICAL PRESENTATION The patient presented with headache, dizziness, nausea, and memory difficulties. A fourth ventricle cyst consistent with NCC was found on magnetic resonance imaging, and serum enzyme-linked immunosorbent assay (ELISA) confirmed the diagnosis. The cyst was removed utilizing an open PFC followed by antihelminthic therapy and corticosteroids. There was resolution of symptoms at 9 mo postoperatively. CONCLUSION Several treatment modalities have been proposed for isolated cysts in the fourth ventricle, including medication, ventriculoperitoneal shunt, endoscopic removal, and PFC. The treatment decision is complex, and there is little guidance on the best treatment choices. In this article, we describe treatment via PFC for an adherent FVNCC cyst.

Biology of Cerebral Aneurysm Formation, Growth, and Rupture

Abstract Cerebral aneurysm rupture leads to significant morbidity and mortality. The biological understanding of aneurysmal growth and rupture may lead to opportunities of preventing subarachnoid hemorrhage. This chapter is dedicated to presenting the current understanding of the biochemical and hemodynamic changes that allow aneurysmal growth and rupture. The role of turbulent flow leading to endothelial cellular damage and subsequent changes to the internal elastic lamina leading to myoproliferation is presented. Atherosclerosis has been integral to the development of ischemic stroke and we present its association to aneurysmal growth and rupture. The roles of proinflammatory markers, including matrix metalloproteinases and interleukin-1, are discussed as such markers are more common in patients with ruptured aneurysm as compared to asymptomatic aneurysms. Finally, we present risk factors of aneurysm rupture, including patient- and aneurysm-related factors as well as triggers for aneurysmal rupture.

Primary diffuse leptomeningeal melanomatosis: Description and recommendations

Primary melanocytic disease of the central nervous system is a rarely encountered condition currently without consensus on treatment and lacking major guidelines for management. Understanding the nature of the disease and differentiating primary melanocytic disease from the much more commonly encountered secondary (metastatic) melanoma is important in identifying the condition and pursuing appropriate treatment.