Case Report: Use of novel AR registration system for presurgical planning during vestibular schwannoma resection surgery.

Background and importance: Vestibular schwannomas are benign tumors and are the most common tumor found in the cerebellopontine angle. Surgical management of these lesions involves consideration of various operative approaches, which can have profound effects on procedural course and patient outcomes. Therefore, a comprehensive understanding of the location of the tumor and surrounding anatomical structures is vital for a positive outcome. We present a case of a 47-year-old female patient with vestibular schwannoma. A novel mixed reality (MR) system was used to register patient-specific 3D models onto the patient's head for operative planning and anatomical visualization. Case description: A 47-year-old female presented with a history of left-sided hearing loss, tinnitus, and episodic left facial tingling. Magnetic Resonance Imaging (MRI) demonstrated a 3.3 cm enhancing lesion in the left cerebellopontine angle at the with mass effect on the brachium pontis and medulla. Surgical resection was performed via retrosigmoid craniotomy. Conclusions: In this study, we report the use of Augmented Reality (AR) visualization for planning of vestibular schwannoma resection. This technology allows for efficient and accurate registration of a patient's 3D anatomical model onto their head while positioned in the operating room. This system is a powerful tool for operative planning as it allows the surgeon to visualize critical anatomical structures where they lie on the patient's head. The present case demonstrates the value and use of AR for operative planning of complex cranial lesions.

The Neurosurgeon's Dilemma-Do Antiplatelet/Anticoagulant Medications Increase the Risk of Catheter-Associated Hemorrhage in External Ventricular Drain Placement?

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure that can be performed at bedside. A frequent complication following EVD placement is catheter-associated hemorrhage (CAH). The hemorrhage itself is rarely clinically significant but may be complicated in patients taking anticoagulant or antiplatelet (AC/AP) medications. METHODS: A total of 757 patients were who underwent EVD placement at bedside were included as part of a retrospective study at a large academic medical center. Demographic factors, use of AC/AP therapies, and several other clinical variables were recorded and assessed in univariate and multivariate regression analysis for association with CAH and mortality. RESULTS: One hundred (13.2%) patients experienced CAH within 24 hours of the procedure. After univariate analysis, in 2 tandem-run multivariate regression analyses after stepwise variable selection, use of 2 or more AC/AP agents (odds ratio [OR] = 2.362, P = 0.020) and dual antiplatelet therapy with aspirin and clopidogrel (OR = 3.72, P = 0.009) were significantly associated with CAH. Use of noncoated catheters was a protective factor against CAH compared to use of antibiotic-coated catheters (OR = 0.55, P = 0.019). Multivariate analysis showed age, multiagent therapy, and thrombocytopenia were significantly associated with increased mortality. CONCLUSIONS: There was increased risk of CAH after EVD placement in patients taking more than one AC/AP agent regardless of presenting pathology. In particular, use of aspirin and clopidogrel combined was associated with significantly higher odds of CAH, although it was not associated with higher mortality. In addition, there appears to be an association between use of antibiotic-coated catheters and CAH across univariate and multivariate analysis.

Case report: Use of markerless augmented reality system for ventriculoperitoneal shunt placement.

Background: Ventriculoperitoneal (VP) shunt placement is one of the most commonly performed neurosurgical procedures, yet failure rates remain very high. Surface landmarks are typically used to guide VP shunt placement, but they are not reliable in identifying the target anatomy. Augmented reality (AR) is a promising new technology that has the potential to improve the accuracy and effectiveness of neurosurgical procedures. We describe the use of AR for the surgical planning of a VP shunt. Case Description: A 62-year-old male with a history of subarachnoid hemorrhage presented with delayed hydrocephalus. A computed tomography scan was obtained that confirmed dilated ventricles, requiring a right VP shunt. The patient was brought to the operating room, where the AR system was used for visualization and planning. Conclusion: In this study, we describe the use of AR for VP shunt placement. The AR system consists of a Microsoft HoloLens 2 head-mounted display and a novel markerless registration system, which was used to register patient-specific 3D models onto the patient's head for visualizing target anatomy and planning an operative approach. The AR system was used to plan the VP shunt placement in the operating room. This system is easy to use and provides a visualization of the patient's anatomy, which can be used to plan an optimal trajectory. We believe that this has the potential to improve the accuracy and outcomes of VP shunt placements, and further studies are needed to characterize the system's accuracy and benefits.