Choristoma of the vestibular nerve: Should it influence our management of vestibular Schwannoma- Case report and review of the literature

Background and Importance: Choristomas of the internal auditory canal and cerebellopontine angle are rare, non-neoplastic lesions that mimic vestibular schwannomas and may subsequently be subject to treatment by surgical resection or radiosurgery. Their management is conservative with observation. Surgical intervention has been associated with expected hearing loss that is counter to the goal of surgery. On the other hand, radiosurgery is not indicated in such pathology and will also lead to eventual hearing loss.</p

Direct Repair of Iatrogenic Vertebral Artery Injury Associated With Anterior Cervical Corpectomy: 2-Dimensional Operative Video.

Vertebral artery (VA) injury during anterior cervical spine surgery has potentially devastating neurovascular consequences. Our video highlights the operative nuances of exposing and directly repairing the V2 segment of the VA from an anterior approach. A 67-year-old woman undergoing anterior cervical corpectomy at another hospital began briskly bleeding from a suspected VA injury. Upon emergency transfer of the patient to our facility, angiography confirmed a right VA pseudoaneurysm at the level of the C5 corpectomy. The decision was made to repair the VA directly, thus avoiding vessel sacrifice and stenting. The previous anterior exposure was reopened. The longus colli was mobilized laterally on the right side to expose the C4 and C6 anterior tubercles. A plane was developed in the transverse foramina from C4 to C6, and the foramina were unroofed anteriorly using a high-speed drill and Kerrison rongeurs. The injured segment of the VA was exposed, and the platelet plug over the injured VA was identified. The proximal and distal ends of the injured segment were temporarily clipped, and the platelet plug was removed, revealing a small, ovoid-shaped\u27 full-thickness arterial wall defect. The VA injury was repaired with simple running 10-0 nylon sutures. Indocyanine green angiography confirmed rapid filling of the patent lumen. The corpectomy and anterior fixation were completed. The patient was placed on aspirin therapy postoperatively. The patient remained neurologically intact without neurovascular sequelae at the 1-yr follow-up. The patient consented to surgical treatment (Institutional Review Board review was not necessary). Used with permission from Barrow Neurological Institute

Primary histiocytic sarcoma of the brain mimicking cerebral abscess.

Histiocytic sarcoma is a rare malignancy with only 10 reports confirmed primarily involving the CNS. The diagnosis is dependent on the finding of malignant cells with histiocytic morphology and immunophenotype. The authors report a case of pathologically proven HS of the CNS. A 16-year-old boy presented with headaches, emesis, and altered sensorium. Noncontrast head CT scanning demonstrated a left parietal mass consistent with a tumor. Surgery was undertaken. Intraoperative findings revealed green-yellow exudates consistent with an abscess. Cultures were obtained and broad-spectrum antibiotics were started. The patient subsequently underwent multiple surgical procedures, including drainage and debulking of abscesses and hemicraniectomy. Two months after initial presentation, the patient\u27s diagnosis of histiocytic sarcoma was confirmed. Pathological examination demonstrated necrotizing inflammation with preponderant neutrophil infiltration, variably atypical mononuclear and multinucleate histiocytes, and numerous mitoses. Additional immunohistochemistry studies confirmed immunoreactivity for CD68, CD45, CD45RO, and CD15 and were negative for CD3, CD20, melanoma cocktail, CD30, CD1a, CD34, HMB-45, and melan-A. Once the diagnosis of histiocytic sarcoma was confirmed, antibiotics were stopped and radiation therapy was undertaken. Despite treatment, the patient\u27s neurological status continued to decline and the patient died 126 days after initial presentation. This case represents a rare confirmed example of CNS histiocytic sarcoma. A profound inflammatory infiltrate seen on pathology and green exudates seen intraoperatively make the condition difficult to distinguish from an abscess. Immunohistochemistry showing a histiocytic origin and negative for myeloid, dendritic, or other lymphoid markers is essential for the diagnosis. Further research is needed to establish consensus on treatment

Middle meningeal arteriovenous fistulas: A rare and potentially high-risk dural arteriovenous fistula

BACKGROUND: Middle meningeal arteriovenous fistulas (MMAVFs) are rare lesions with a poorly established natural history. We report our experience with patients with MMAVFs who presented with intracranial hemorrhage. METHODS: We reviewed our prospectively maintained endovascular database for patients with MMAVFs, who were treated by embolization during a 15-year period. Hospital and outpatient medical records and imaging studies were reviewed. RESULTS: Nine patients with MMAVFs, who presented with intracranial hemorrhage, underwent embolization (mean age 60.3 years, range 21-76; four male and five female). Four patients presented after trauma and five after spontaneous hemorrhage. All nine patients were angiographically cured after embolization of the fistula with liquid embolic agents (n = 8) or coils (n = 1). There were no procedure-related complications. CONCLUSION: MMAVFs represent a rarely reported class of vascular lesions. They are typically associated with trauma, but also develop spontaneously, and may be associated with intracranial hemorrhage, which warrants classification of these lesions as high risk. Endovascular treatment is safe and effective and should be considered for these patients, particularly for those who have lesions with intracranial venous drainage

Low-Flow and High-Flow Neurosurgical Bypass and Anastomosis Training Models Using Human and Bovine Placental Vessels: A Histological Analysis and Validation Study

Objective: Microvascular anastomosis is a basic neurosurgical technique that should be mastered in the laboratory. Human and bovine placentas have been proposed as convenient surgical practice models; however, the histologic characteristics of these tissues have not been compared with human cerebral vessels, and the models have not been validated as simulation training models. In this study, the authors assessed the construct, face, and content validities of microvascular bypass simulation models that used human and bovine placental vessels. Methods: The characteristics of vessel segments from 30 human and 10 bovine placentas were assessed anatomically and histologically. Microvascular bypasses were performed on the placenta models according to a delineated training module by \ trained\ participants (10 practicing neurosurgeons and 7 residents with microsurgical experience) and \ untrained\ participants (10 medical students and 3 residents without experience). Anastomosis performance and impressions of the model were assessed using the Northwestern Objective Microanastomosis Assessment Tool (NOMAT) scale and a posttraining survey. Results: Human placental arteries were found to approximate the M 2 -M 4 cerebral and superficial temporal arteries, and bovine placental veins were found to approximate the internal carotid and radial arteries. The mean NOMAT performance score was 37.2 ± 7.0 in the untrained group versus 62.7 ± 6.1 in the trained group (p \u3c 0.01; construct validity). A 50% probability of allocation to either group corresponded to 50 NOMAT points. In the posttraining survey, 16 of 17 of the trained participants (94%) scored the model\u27s replication of real bypass surgery as high, and 16 of 17 (94%) scored the difficulty as \ the same\ (face validity). All participants, 30 of 30 (100%), answered positively to questions regarding the ability of the model to improve microsurgical technique (content validity). Conclusions Human placental arteries and bovine placental veins are convenient, anatomically relevant, and beneficial models for microneurosurgical training. Microanastomosis simulation using these models has high face, content, and construct validities. A NOMAT score of more than 50 indicated successful performance of the microanastomosis tasks

Treatment of Ruptured Anterior Communicating Artery Aneurysms: Equipoise in the Endovascular Era?

BACKGROUND: Ruptured anterior communicating artery (ACoA) aneurysms are heterogeneous intracranial aneurysms whose diverse morphological features influence treatment modality. OBJECTIVE: To compare clinical outcomes and complications of all ruptured ACoA aneurysms treated by clipping or coiling in a modern institutional trial. METHODS: All patients with ruptured ACoA aneurysms in the Barrow Ruptured Aneurysm Trial were included. Clinical follow-up at 1 and 3 years was analyzed; charts were reviewed for patient demographics, aneurysm characteristics, and in-hospital complications. RESULTS: This cohort included 130 patients (mean age, 52.5 years). Mean aneurysm size was 5.8 mm. Most aneurysm domes projected anteriorly (n 52). After randomization and crossover, 91 ACoA aneurysms (70%) were clipped and 39 (30%) were coiled. Twenty-two patients (16.9%) initially randomized to coiling crossed over to clipping after evaluation. No patients crossed over from clipping to coiling. Characteristics precluding aneurysms from coiling included unfavorable dome-to-neck ratio, lesions difficult to access by catheter, and branch vessel involvement. Aneurysm size and dome projection were not significantly associated with treatment group, clinical outcome, or retreatment. No significant difference existed in clinical outcome (modified Rankin Scale scores) between groups at discharge or at 1-year or 3-year follow-up using as-treated and intention-to-treat analyses. Retreatment was performed in 3 clipped patients (2.3%) and 3 coiled patients (2.3%). CONCLUSION: Ruptured ACoA aneurysms, regardless of size and projection, were safely treated by both treatment modalities in a large-scale randomized clinical trial. Clinical outcomes and stroke rates did not differ significantly in as-treated or intention-to-treat analyses. ABBREVIATIONS: ACoA, anterior communicating artery BRAT, Barrow Ruptured Aneurysm Trial ITT, intention-to-treat mRS, modified Rankin Scal

Human Placenta Aneurysm Model for Training Neurosurgeons in Vascular Microsurgery

BACKGROUND: Neurosurgery, a demanding specialty, involves many microsurgical procedures that require complex skills, including open surgical treatment of intracranial aneurysms. Simulation or practice models may be useful for acquiring these skills before trainees perform surgery on human patients. OBJECTIVE: To describe a human placenta model for the creation and clipping of aneurysms. METHODS: Placental vessels from 40 human placentas that were dimensionally comparable to the sizes of appropriate cerebral vessels were isolated to create aneurysms of different shapes. The placentas were then prepared for vascular microsurgery exercises. Sylvian fissure-like dissection technique and clipping of large- and small-necked aneurysms were practiced on human placentas with and without pulsatile flow. A surgical field designed to resemble a real craniotomy was reproduced in the model. RESULTS: The human placenta has a plethora of vessels that are of the proper dimensions to allow the creation of aneurysms with dome and neck dimensions similar to those of human saccular and fusiform cerebral aneurysms. These anatomic scenarios allowed aneurysm inspection, manipulation, and clipping practice. Technical microsurgical procedures include simulation of sylvian fissure dissection, unruptured aneurysm clipping, ruptured aneurysm clipping, and wrapping; all were reproduced with high fidelity to the haptics of live human surgery. Skill-training exercises realistically reproduced aneurysm clipping. CONCLUSION: Human placenta provides an inexpensive, widely available, convenient biological tissue that can be used to create models of cerebral aneurysms of different morphologies. Neurosurgical trainees may benefit from the preoperative use of a realistic model to gain familiarity and practice with critical surgical techniques for treating aneurysms

Onyx embolization of skull base paragangliomas: a single-center experience.

BACKGROUND: Skull base paragangliomas are highly vascular tumors that are often embolized before surgical resection; however, the safety and efficacy of preoperative embolization using an ethylene vinyl alcohol copolymer (Onyx; Medtronic, Dublin, Republic of Ireland) in these tumors is unknown. This retrospective cohort study evaluated patient outcomes after preoperative embolization of skull base paragangliomas using Onyx. METHODS: We retrospectively analyzed data from all patients with skull base paragangliomas who underwent preoperative Onyx embolization at our institution (January 01, 2005-December 31, 2017). Patient, tumor, embolization, and outcomes data were extracted by reviewing inpatient and outpatient clinical and imaging records. RESULTS: Seven patients were studied (5/7 [71%] female), 6 with glomus jugulares and 1 with a glomus vagale. The median age was 52 years, and the most common presenting symptom was cranial neuropathy (6/7 [86%]). The tumor vascular supply was from the ascending pharyngeal artery in all 7 cases (100%) with additional feeders including the occipital artery in 5 (71%); internal carotid artery in 3 (43%); middle meningeal, vertebral, and internal maxillary artery each in 2 (29%); and posterior auricular artery in 1 (14%). The median postembolization tumor devascularization was 80% (range, 64-95%). The only postembolization complication was a facial palsy in 1 patient. CONCLUSION: Preoperative embolization with Onyx affords excellent devascularization for the majority of skull base paragangliomas, and it may facilitate resection of these hypervascular lesions. The advantages provided by Onyx with respect to penetration of intratumoral vessels must be weighed against the risk of cranial neuropathy