Novel Technique of Head-Mounted Augmented Reality-Assisted Endovascular Neurosurgery: Proof of Concept on a Flow Model.

Augmented reality (AR) is an emerging technology in medicine that is underexplored in the endovascular neurosurgery arena. We describe a novel technique integrating the Hololens 2 head-mounted AR (HMAR) system for navigation of the intracranial circulation and simple coiling of an aneurysm silicone model. Computed tomography angiographies (CTAs) of the silicone models were obtained, simulating the preprocedural CTA obtained for patient treatments. CTA was imported into the 3-dimensional (3D) HMAR system, and a 3D hologram of the circulation was created. Using the right common carotid artery run (performed in the silicon model) as a landmark, the AR hologram was superimposed on the angiography screen (Video 1). A 5-French sheath, intermediate catheter, 0.012-inch microcatheter, and microwire were used for the purely navigational model. The same process was repeated with the aneurysm model, which was navigated with a 0.58 intermediate catheter, 0.17 microcatheter, 0.014 microwire, and 6 × 15 3D-shaped soft coil. The proximal and distal vessels of the flow model were successfully navigated using the AR hologram, which replaced the conventional roadmap. No contrast ¨puffs¨ were needed because the hologram replaced the roadmap from proximal to distal vasculature. The silicon navigational model and aneurysm model were successfully navigated using only the AR 3D model. A coil was deployed in the aneurysm model. Finally, a 3D-360-degree examination of the aneurysmal anatomy was possible during the procedure. The concept of HMAR-assisted cerebral angiography is feasible. We were able to perform the whole intracranial navigation using only the preoperative CTA. Additional refinements and fine-tuning of the registration and alignment of the hologram to the silicon model or anatomy of the patient are needed before this technology can be incorporated into clinical practice. In the meantime, the use of this tool for the training and development of endovascular skills offers valuable educational opportunities. Further advances in this direction aiming to create real 3D roadmaps are needed to decrease contrast use, radiation exposure, and navigation times.

Preoperative assessment of the individual anatomy of the superior petrosal vein complex using balanced fast field echo magnetic resonance imaging.

BACKGROUND: Here, we sought to examine the validity and reproducibility of balanced fast field echo (bFFE) for assessing superior petrosal vein (SPV) complex (SPVC) anatomy. METHODS: Preoperative bFFE or equivalent scans and operative videos were studied and directly compared with regard to the individual anatomical features of SPVCs and their relation to the operative field. The anatomical details of the bFFE findings of the non-operated side (group 2) of all 50 patients were then reviewed, including the presence of petrosal-galenic anastomosis, and finally compared to the operated SPVCs (group 1). RESULTS: A complete correlation between bFFE and intraoperative findings was observed in 62% of cases and had a significant correlation with 3 Tesla magnet strength and higher pixel bandwidth (rbis = - 0.47; p = 0.005). The sensitivity and specificity of bFFE magnetic resonance imaging were 93.7 and 95.2%, respectively, for detecting an SPV disturbing the operative field, and 97.3% and 95% for a disturbing tributary, respectively. Each group had 50 SPVCs, with a total of 70 and 64 SPVs, 10 and 11 general SPVC configurations, as well as 29 and 28 different individual anatomical variations in groups 1 and 2, respectively. Both groups had 1-3 SPVs with a similar distribution of frequencies [Chi-square (4) = 27.56; p = 0.0145 (Fisher's exact test)]. The similarity of the general configurations was not statistically significant. The same four predominant configurations constituted 80% of the SPVCs in each group. The vein of the cerebellopontine fissure was most frequently found in 86% and 88% of cases, and a petrosal-galenic anastomosis was seen in 38% and 40% of groups 1 and 2, respectively. CONCLUSIONS: Individual SPVC variations are extensive. Good quality bFFE or equivalents are feasible for preoperative SPVC assessments. However, methods improving vascular visualization are recommended.

Vertebral-Venous fistulas: Single center experience and practical treatment approach.

BACKGROUND: Vertebral-venous fistulas (VVFs) are rare. Scarce literature exists to guide our understanding and management. We report our experience and propose a classification based on flow, feeder number, and involvement of accessible veins. Additionally, we include a practical treatment approach. METHODS: Retrospective chart and imaging review of cerebrovascular arteriovenous fistulas treated in our center between July 2013 and April 2022. We reviewed patient demographics, presentation, imaging, treatment strategies, and outcomes. RESULTS: Nine patients with VVFs were identified, six were females. Ages ranged between 38-83 years. There were six high-flow and three low-flow. Most VVFs originated at the level of V3. Additional feeders from the internal carotid artery, external carotid artery, and/or subclavian artery were present in four cases (two were high-flow). Four cases had multiple arterial feeders. All cases were symptomatic. Origin was spontaneous in eight and iatrogenic in one case. Most common presenting symptoms were pain (7) and pulsatile tinnitus (4). Neurological deficits were present in two cases (1 high- and 1 low-flow). Four cases were treated with vertebral artery segmental sacrifice alone, three required multiple transarterial embolizations with or without VA sacrifice, one case had single transvenous approach, and one was treated with single targeted transarterial embolization. One patient had a minor transient neurological complication. No treatment-related mortality was seen. CONCLUSION: Treatment of high-flow and symptomatic low-flow VVFs is feasible and safe. Our classification and treatment approach might help guide patient selection and choice of endovascular approach. However, our approach warrants further validation with a larger number of patients.

Robotically-assisted neuro-endovascular procedures: Single-Center Experience and a Review of the Literature.

INTRODUCTION: Robotics could expand treatment of rapidly progressive pathologies such as acute ischemic stroke, with the potential to provide populations in need prompt access to neuro-endovascular procedures. METHODS: Robotically-assisted (RA) neuro-endovascular procedures (RANPs) performed at our institution were retrospectively examined (RA-group, RG). A control group of manual neuro-endovascular procedures was selected (manual group, MG). Total operating room (OR) time, procedural time, contrast media use, fluoroscopy time, conversion from RA to manual control, procedural success, and complication rates were compared. A learning curve was identified. RESULTS: Forty-one (41) RANPs were analyzed. Ages ranged from 20-82 y.o. Indications included diagnostic cerebral angiography (37), extracranial carotid artery stenting (3), and transverse sinus stent (1). Total OR time was longer in RG (median 86 vs. 71 min, p < 0.01). Procedural time (median 56 vs. 45 min, p = 0.12), fluoroscopy time (median 12 vs. 12 min, p = 0.69) and contrast media usage (82 vs. 92 ml, p = 0.54) were not significantly different. Patient radiation exposure was similar, considering similar fluoroscopy times. Radiation exposure and lead apron use were virtually absent for the main surgeon in RG. Procedural success was 83% and conversion from RA to manual control was 17% in RG. No treatment-related complications occurred. A learning curve showed that, after the fifth procedure, procedural times reduced and stabilized. CONCLUSIONS: This series may contribute to further demonstrating the safety and feasibility of RANPs. RANPs can potentially reduce radiation exposure and physical burden for health personnel, expand acute cerebrovascular treatment to underserved areas, and enhance telementoring. Prospective studies are necessary for results to be generalized.

Individual variations of the superior petrosal vein complex and their microsurgical relevance in 50 cases of trigeminal microvascular decompression.

BACKGROUND: We investigated the understudied anatomical variations of the superior petrosal vein (SPV) complex (SPVC), which may play some role in dictating the individual complication risk following SPVC injury. METHODS: Microvascular decompressions of the trigeminal nerve between September 2012 and July 2016. All operations utilized an SPVC preserving technique. Preoperative balanced fast field echo (bFFE) magnetic resonance imaging, or equivalent sequences, and operative videos were studied for individual SPVC anatomical features. RESULTS: Applied imaging and operative SPVC anatomy were described for fifty patients (mean age, 67.18 years; female sex and right-sided operations, 58% each). An SPVC component was sacrificed intentionally in 6 and unintentionally in only 7 cases. Twenty-nine different individual variations were observed; 80% of SPVCs had either 2 SPVs with 3 or 1 SPV with 2, 3, or 4 direct tributaries. Most SPVCs had 1 SPV (64%) and 2 SPVs (32%). The SPV drainage point into the superior petrosal sinus was predominantly between the internal auditory meatus and Meckel cave (85.7% of cases). The vein of the cerebellopontine fissure was the most frequent direct tributary (86%), followed by the pontotrigeminal vein in 80% of SPVCs. Petrosal-galenic anastomosis was detected in at least 38% of cases. At least 1 SPV in 54% of the cases and at least 1 direct tributary in 90% disturbed the operative field. The tributaries were more commonly sacrificed. CONCLUSIONS: The extensive anatomical variation of SPVC is depicted. Most SPVCs fall into 4 common general configurations and can usually be preserved. BFFE or equivalent sequences remarkably facilitated the intraoperative understanding of the individual SPVC in most cases.

Epidural Hematoma Treated Conservatively: When to Expect the Worst.

BACKGROUND: The Brain Trauma Foundation's 2006 surgical guidelines have objectively defined the epidural hematoma (EDH) patients who can be treated conservatively. Since then, the literature has not provided adequate clues to identify patients who are at higher risk for EDH progression (EDHP) and conversion to surgical therapy. The goal of our study was to identify those patients. METHODS: We carried a retrospective review over a 5-year period of all EDH who were initially triaged for conservative management. Demographic data, injury severity and history, neurological status, use of anticoagulants or anti-platelets, radiological parameters, conversion to surgery and its timing, and Glasgow Outcome Scale were analyzed. Bivariate association and further logistic regression were used to point out the significant predictors of EDHP and conversion to surgery. RESULTS: 125 patients (75% of all EDH) were included. The mean age was 39.1 years. The brain injury was mild in 62.4% of our sample and severe in 14.4%. Only 11.2% of the patients required surgery. Statistical comparison showed that younger age (p< 0.0001) and coagulopathy (p=0.009) were the only significant factors for conversion to surgery. There was no difference in outcomes between patients who had EDHP and those who did not. CONCLUSIONS: Most traumatic EDH are not surgical at presentation. The rate of conversion to surgery is low. Significant predictors of EDHP are coagulopathy and younger age. These patients need closer observation because of a higher risk of EDHP. Outcome of surgical conversion was similar to successful conservative management.

The use of complementary and alternative therapies in Western Saudi Arabia.

OBJECTIVE: To examine the use of complementary and alternative therapies (CAT) in our region, particularly for children with chronic conditions, and explore contributing factors to their use. METHODS: A prospective random sample of mothers visiting the out patient department of King Abdulaziz University Hospital in Jeddah, Saudi Arabia were identified from the 1st of June, 2006 to the 31st of May, 2008. A survey using a structured 50-item questionnaire was used to examine their demographics, child's medical problem, and the use of CAT. RESULTS: Seventy-nine mothers were interviewed, and their child's condition was acute in 47%, chronic, or recurrent in 53%, and treatable in 84%. Neurological complaints were reported in 25%. Thirty-three (42%) families used CAT in their child, mostly (57%) before seeking medical help. Religious and spiritual healing was used in 82%, oral, or topical preparations or herbs in 30%, and physical interventions in 21%. Factors associated with using CAT included child's age <1 year (p=0.008), less than high school education of the fathers (p=0.01), chronic medical condition (p=0.00008) or neurological disorder (p=0009), and positive family history of using CAT (p<0.0001). CONCLUSION: Many parents refer to CAT typically before seeking medical help. Pediatricians should counsel and caution parents regarding the lack of studies demonstrating efficacy and safety of CAT in young children.