Patient Satisfaction and Radiologic Assessability After Treatment of Complex Skull Defects With a Custom-Made Cranioplasty From a Thin Titanium Sheet.

OBJECTIVE: The cosmetically good coverage of skull defects is a challenge in neurosurgical clinics. In addition, the skull treated with implants and the underlying structures must remain radiologically assessable. In this examination, the postoperative courses of patients after implantation of CranioTop is described. Digital x-ray, computed tomography, and magnetic resonance images after implantation of CranioTop were evaluated with regard to their assessability. MATERIALS AND METHODS: Between 2018 and 2020, 23 titanium cranioplasties (CranioTop) were implanted to 21 patients. The intraoperative handling, the accuracy of fit, the healing process, the cosmetic result and the physical condition of the patients were examined. In addition, digital x-rays, magnetic resonance imaging, and computed tomography scans of the cranium supplied with CranioTop were examined. RESULTS: The evaluation showed good to very good results regarding patients' satisfaction. There were no severe complications; thirteen patients found the cosmetic result very good; 8 patients assessed the cosmetic result as good. Because of the low thickness and density of the CranioTop plastic there was only low formation of radial stripe artifacts (streaking) and susceptibility artifacts. The assessment of digital x-ray, computed tomography, and magnetic resonance imaging images is possible after implantation of CranioTop. CONCLUSION: The patients treated with CranioTop showed a high level of satisfaction with regard to the cosmetic result and their physical condition. Furthermore, the cranium supplied with CranioTop remains well assessable in radiologic imaging with only slight limitations in magnetic resonance imaging.

Rescuing Infected Deep Brain Stimulation Therapies in Severely Affected Patients.

(1) Background: Infections in deep brain stimulation (DBS) hardware, while an undesired complication of DBS surgeries, can be effectively addressed. Minor infections are typically treated with wound revision and IV antibiotics. However, when visible hardware infection occurs, most centers opt for complete removal, leaving the patient in a preoperative state and necessitating post-removal care. To avoid the need for such care, a novel technique was developed. (2) Methods: The electrodes are placed at the exact same spot and then led to the contralateral side. new extensions and a new generator contralateral to the infection as well. Subsequently, the infected system is removed. This case series includes six patients. (3) Results: The average duration of DBS system implantation before the second surgery was 272 days. Only one system had to be removed after 18 months due to reoccurring infection; the others remained unaffected. Laboratory alterations and pathogens were identified in only half of the patients. (4) Conclusions: The described surgical technique proves to be safe, well tolerated, and serves as a viable alternative to complete system removal. Importantly, it effectively prevents the need of post-removal care for patients.

Load-Bearing Capacity and Design Advantages of a Custom-Made, Thin Pure-Titanium Cranioplasty (CranioTop).

BACKGROUND: Adequate and stable coverage of cranial contour and continuity defects of any origin is a common challenge in neurosurgical clinics. This study presents the results of investigations concerning the mechanical load-bearing capacity and design advantages of custom-made implants made from a thin, pure-titanium sheet (CranioTop) (CLinstruments, Attendorn, Germany) for covering complex cranial defects. METHODS: In 9 test series, the stability of three differently shaped and sized thin titanium sheet implants was tested using vertical, uniaxial compression with 3 different compression stamps, to investigate the behaviour of these implants in relation to punctiform as well as planar forces. RESULTS: All 9 model implants showed elastic behavior in the synchronously recorded force/displacement diagrams at an impression of up to 2 mm. The forces at 2 mm deformation were between 170.1 and 702.7 Newton. CONCLUSION: Cranioplasty using CranioTop is a stable procedure for covering skull defects, even those of large dimensions. An added advantage is the significant reduction in effort required to prepare the area of the bone margins compared to other current techniques of cranioplasty.

Cerebral Anatomy Detection and Surgical Planning in Patients with Anterior Skull Base Meningiomas Using a Virtual Reality Technique.

Anterior skull base meningiomas represent a wide cohort of tumors with different locations, extensions, configurations, and anatomical relationships. Diagnosis of these tumors and review of their therapies are inseparably connected with cranial imaging. We analyzed the influence of three-dimensional-virtual reality (3D-VR) reconstructions versus conventional computed tomography (CT) and magnetic resonance imaging (MRI) images (two-dimensional (2D) and screen 3D) on the identification of anatomical structures and on the surgical planning in patients with anterior skull base meningiomas. Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative 2D-CT and 2D-MRI scans were retrospectively reconstructed to 3D-VR images and visualized via VR software to detect the characteristics of tumors. A questionnaire of experienced neurosurgeons evaluated the influence of the VR visualization technique on identification of tumor morphology and relevant anatomy and on surgical strategy. Thirty patients were included and 600 answer sheets were evaluated. The 3D-VR modality significantly influenced the detection of tumor-related anatomical structures (p = 0.002), recommended head positioning (p = 0.005), and surgical approach (p = 0.03). Therefore, the reconstruction of conventional preoperative 2D scans into 3D images and the spatial and anatomical presentation in VR models enabled greater understanding of anatomy and pathology, and thus influenced operation planning and strategy.

Virtual reality-based evaluation of neurovascular conflict for the surgical planning of microvascular decompression in trigeminal neuralgia patients.

OBJECTIVE: Trigeminal neuralgia (TN) is a lightning bolt of violent, electrifying, and stinging pain, often secondary to the neurovascular conflict (NVC). The vessels involved in NVC are mostly arteries and rarely veins. Evaluation of NVC in the deep infratentorial region is inseparably connected with cranial imaging. We retrospectively analyzed the potential influence of three-dimensional (3D) virtual reality (VR) reconstructions compared to conventional magnetic resonance imaging (MRI) scans on the evaluation of NVC for the surgical planning of microvascular decompression in patients with TN. METHODS: Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative MRI scans were retrospectively visualized via VR software to detect the characteristics of NVC. A questionnaire of experienced neurosurgeons evaluated the influence of VR visualization technique on identification of anatomical structures involved in NVC and on surgical strategy. RESULTS: Twenty-four patients were included and 480 answer sheets were evaluated. Compared to conventional MRI, image presentation using 3D-VR modality significantly influenced the identification of the affected trigeminal nerve (p = 0.004), the vascular structure involved in the NVC (p = 0.0002), and the affected side of the trigeminal nerve (p = 0.005). CONCLUSIONS: In patients with TN caused by NVC, the reconstruction of conventional preoperative MRI scans and the spatial and anatomical presentation in 3D-VR models offers the possibility of increased understanding of the anatomy and even more the underlying pathology, and thus influences operation planning and strategy.

Impact of Virtual Reality in Arterial Anatomy Detection and Surgical Planning in Patients with Unruptured Anterior Communicating Artery Aneurysms.

Anterior-communicating artery (ACoA) aneurysms have diverse configurations and anatomical variations. The evaluation and operative treatment of these aneurysms necessitates a perfect surgical strategy based on review of three-dimensional (3D) angioarchitecture using several radiologic imaging methods. We analyzed the influence of 3D virtual reality (VR) reconstructions versus conventional computed tomography angiography (CTA) scans on the identification of vascular anatomy and on surgical planning in patients with unruptured ACoA aneurysms. Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative CTA scans were retrospectively reconstructed to 3D-VR images and visualized via VR software to detect the characteristics of unruptured ACoA aneurysms. A questionnaire was used to evaluate the influence of VR on the identification of aneurysm morphology and relevant arterial anatomy and on surgical strategy. Twenty-six patients were included and 520 answer sheets were evaluated. The 3D-VR modality significantly influenced detection of the aneurysm-related vascular structure (p = 0.0001), the recommended head positioning (p = 0.005), and the surgical approach (p = 0.001) in the planning of microsurgical clipping. Thus, reconstruction of conventional preoperative CTA scans into 3D images and the spatial presentation in VR models enabled greater understanding of the anatomy and pathology, provided realistic haptic feedback for aneurysm surgery, and influenced operation planning and strategy.

Evaluation of Surgical Approaches for Tumor Resection in the Deep Infratentorial Region and Impact of Virtual Reality Technique for the Surgical Planning and Strategy.

OBJECTIVE: Tumors in the deep infratentorial region can be accessed via the supracerebellar-infratentorial (SCIT) or suboccipital-transcerebellar (SOTC) approaches in the sitting or prone position. Diagnosis of tumors in this region and review of their therapies are inseparably connected with cranial tomographic imaging. We retrospectively evaluate a cohort of patients who underwent tumor resection in this region and correlate complication rates to the literature, and evaluate the potential influence of a virtual reality (VR) visualization technique on surgery planning and strategy. METHODS: Patient files were retrospectively analyzed regarding operative performance parameters, histopathological findings, surgical outcomes, and complications. Preoperative magnetic resonance imaging scans were visualized via VR software. The influence of 3-dimensional VR images compared to 2-dimensional magnetic resonance imaging scans on surgical planning and surgical strategy was evaluated using a questionnaire. RESULTS: Ninety-three patients were included, 80% placed in a sitting and 20% in a prone position. The SCIT approach was performed in 59% patients and SOTC approach in 41%. Surgical tumor resections were associated with an overall complication rate comparable to the literature. Image presentation using VR had a significant influence on the recommended surgical approach (P = 0.02), but no influence on the recommended patient positioning (P = 0.37) or placement of craniotomy (P = 0.09). CONCLUSION: Tumor resection in the deep infratentorial region, despite frequent use of the sitting position and SCIT approach, was associated with a complication rate comparable to the literature. Preoperative surgical planning using VR technology may increase understanding of the anatomy and pathology, and thus influence operation planning.

Early autologous cranioplasty: complications and identification of risk factors using virtual reality visualisation technique.

Background: Cranioplasty (CP) of autologous bone flap after decompressive craniectomy (DC) is known to be associated with a high complication rate, particularly bone flap resorption (BFR). In a retrospective study, we used a novel virtual reality (VR) visualisation technique to identify and evaluate risk factors associated with CP.Method: Twenty-five patients underwent early autologous CP. All complications were recorded. Cranial computed tomography scans were visualised via the VR software to access the fitting accuracy of the bone flap (bone flap size, gap width at trepanation cutting edge, extent of osteoclastic extension).Results: An overall complication rate of 44% was seen, and BFR was the most common (36%). Only 'osteoclastic extension of trepanation' (p = .04) was a significant risk factor for BFR. The factors 'indication for DC' (p = .09) and 'size of bone flap' (p = .09) had a tendency towards influencing the rate of BFR, while 'age' (p = .68), 'time interval between DC and CP' (p = 1.00), and 'gap width' (p = .50) were not considered to influence the BFR rate.Conclusions: DC and subsequent CP is a complication-prone procedure. Therefore, it is relevant to identify and quantify probable risk factors for the most common complications, such as BFR. Here, we found that the extent of osteoclastic extension may impair the patient's healing process. Our investigation was made considerably easier by using the novel VR visualisation technique, which allows parallax free measurements of distances in 3D space.

Virtual Reality-Based Evaluation of Surgical Planning and Outcome of Monosegmental, Unilateral Cervical Foraminal Stenosis.

BACKGROUND: Foraminal cervical nerve root compression can be caused by lateral disk herniation or osteophyte formation of the vertebrae. Improved diagnosis and evaluation can be achieved using different imaging techniques: radiographs, computed tomography (CT), and magnetic resonance imaging. We retrospectively evaluated the potential influence of a virtual reality (VR) visualization technique on surgery planning and evaluation of postoperative results in patients with monosegmental, unilateral osseous cervical neuroforaminal stenosis. METHODS: Seventy-three patients were included. Ventral decompression of the neuroforamen was performed in 41 patients, dorsal decompression in 32 patients. Patients' files were evaluated. CT scans were visualized via VR software to measure the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region. A questionnaire evaluated the influence of VR technique on surgical planning and strategy. RESULTS: The VR-technique had a moderate influence on the choice of the approach (ventral or dorsal), a significant influence on the ventral approach strategy, and no influence on the positioning of the patient or the dorsal approach strategy. A significant difference was found in the size of the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region between ventral and dorsal approaches, with no correlation to the clinical outcome. CONCLUSIONS: Reconstruction of pre- and postoperative 2D-CT images of the cervical spine into 3D images, and the spatial and anatomical reconstructions in VR models, can be helpful in planning surgical approaches and treatment strategies for patients with cervical foraminal stenoses, and for evaluation of their postoperative results.