Accuracy of Mixed Reality Combined With Surgical Navigation Assisted Oral and Maxillofacial Tumor Resection

ObjectiveTo evaluate the feasibility and accuracy of mixed reality combined with surgical navigation in oral and maxillofacial tumor surgery.MethodsRetrospective analysis of data of seven patients with oral and maxillofacial tumors who underwent surgery between January 2019 and January 2021 using a combination of mixed reality and surgical navigation. Virtual surgical planning and navigation plan were based on preoperative CT datasets. Through IGT-Link port, mixed reality workstation was synchronized with surgical navigation, and surgical planning data were transferred to the mixed reality workstation. Osteotomy lines were marked with the aid of both surgical navigation and mixed reality images visualized through HoloLens. Frozen section examination was used to ensure negative surgical margins. Postoperative CT datasets were obtained 1 week after the surgery, and chromatographic analysis of virtual osteotomies and actual osteotomies was carried out. Patients received standard oncological postoperative follow-up.ResultsOf the seven patients, four had maxillary tumors and three had mandibular tumors. There were total of 13 osteotomy planes. Mean deviation between the planned osteotomy plane and the actual osteotomy plane was 1.68 ± 0.92 mm; the maximum deviation was 3.46 mm. Chromatographic analysis showed error of ≤3 mm for 80.16% of the points. Mean deviations of maxillary and mandibular osteotomy lines were approximate (1.60 ± 0.93 mm vs. 1.86 ± 0.93 mm). While five patients had benign tumors, two had malignant tumors. Mean deviations of osteotomy lines was comparable between patients with benign and malignant tumors (1.48 ± 0.74 mm vs. 2.18 ± 0.77 mm). Intraoperative frozen pathology confirmed negative resection margins in all cases. No tumor recurrence or complications occurred during mean follow-up of 15.7 months (range, 6-26 months).ConclusionThe combination of mixed reality technology and surgical navigation appears to be feasible, safe, and effective for tumor resection in the oral and maxillofacial region.

Towards a First-Person Perspective Mixed Reality Guidance System for Needle Interventions

While ultrasound (US) guidance has been used during central venous catheterization to reduce complications, including the puncturing of arteries, the rate of such problems remains non-negligible. To further reduce complication rates, mixed-reality systems have been proposed as part of the user interface for such procedures. We demonstrate the use of a surgical navigation system that renders a calibrated US image, and the needle and its trajectory, in a common frame of reference. We compare the effectiveness of this system, whereby images are rendered on a planar monitor and within a head-mounted display (HMD), to the standard-of-care US-only approach, via a phantom-based user study that recruited 31 expert clinicians and 20 medical students. These users performed needle-insertions into a phantom under the three modes of visualization. The success rates were significantly improved under HMD-guidance as compared to US-guidance, for both expert clinicians (94% vs. 70%) and medical students (70% vs. 25%). Users more consistently positioned their needle closer to the center of the vessel’s lumen under HMD-guidance compared to US-guidance. The performance of the clinicians when interacting with this monitor system was comparable to using US-only guidance, with no significant difference being observed across any metrics. The results suggest that the use of an HMD to align the clinician’s visual and motor fields promotes successful needle guidance, highlighting the importance of continued HMD-guidance research.

Bio-engineered Nano-vesicles for IR820 Delivery: A Therapy Platform for Cancer by Surgery and Photothermal Therapy

Long-term unsolved health problems from pre-/Intra-/postoperative complications and thermal ablation complications pose threats to liver cancer patients. To reduce the threats, we propose a multimodal-imaging guided surgical navigation system...

Does robot-assisted navigation influence pedicle screw selection and accuracy in minimally invasive spine surgery?

OBJECTIVE The accuracy of percutaneous pedicle screw placement has increased with the advent of robotic and surgical navigation technologies. However, the effect of robotic intraoperative screw size and trajectory templating remains unclear. The purpose of this study was to compare pedicle screw sizes and accuracy of placement using robotic navigation (RN) versus skin-based intraoperative navigation (ION) alone in minimally invasive lumbar fusion procedures. METHODS A retrospective cohort study was conducted using a single-institution registry of spine procedures performed over a 4-year period. Patients who underwent 1- or 2-level primary or revision minimally invasive surgery (MIS)–transforaminal lumbar interbody fusion (TLIF) with pedicle screw placement, via either robotic assistance or surgical navigation alone, were included. Demographic, surgical, and radiographic data were collected. Pedicle screw type, quantity, length, diameter, and the presence of endplate breach or facet joint violation were assessed. Statistical analysis using the Student t-test and chi-square test was performed to evaluate the differences in pedicle screw sizes and the accuracy of placement between both groups. RESULTS Overall, 222 patients were included, of whom 92 underwent RN and 130 underwent ION MIS-TLIF. A total of 403 and 534 pedicle screws were placed with RN and ION, respectively. The mean screw diameters were 7.25 ± 0.81 mm and 6.72 ± 0.49 mm (p < 0.001) for the RN and ION groups, respectively. The mean screw length was 48.4 ± 4.48 mm in the RN group and 45.6 ± 3.46 mm in the ION group (p < 0.001). The rates of “ideal” pedicle screws in the RN and ION groups were comparable at 88.5% and 88.4% (p = 0.969), respectively. The overall screw placement was also similar. The RN cohort had 63.7% screws rated as good and 31.4% as acceptable, while 66.1% of ION-placed screws had good placement and 28.7% had acceptable placement (p = 0.661 and p = 0.595, respectively). There was a significant reduction in high-grade breaches in the RN group (0%, n = 0) compared with the ION group (1.2%, n = 17, p = 0.05). CONCLUSIONS The results of this study suggest that robotic assistance allows for placement of screws with greater screw diameter and length compared with surgical navigation alone, although with similarly high accuracy. These findings have implied that robotic platforms may allow for safe placement of the “optimal screw,” maximizing construct stability and, thus, the ability to obtain a successful fusion.

A virtual platform for real-time performance analysis of electromagnetic tracking systems for surgical navigation

<p class="Abstract">Electromagnetic Tracking Systems (EMTSs) are widely used in surgical navigation, allowing to improve the outcome of diagnosis and surgical interventions, by providing the surgeon with real-time position of surgical instruments during medical procedures. However, particular effort was dedicated to the development of efficient and robust algorithms, to obtain an accurate estimation of the instrument position for distances from the magnetic field generator beyond 0.5 m. Indeed, the main goal is to improve the limited range of current commercial systems, which strongly affects the freedom of movement of the medical team. Studies are currently being conducted to optimize the magnetic field generator configuration (both geometrical arrangements and electrical properties) since it affects tracking accuracy. In this paper, we propose a virtual platform for assessing the performance of EMTSs for surgical navigation, providing real-time results and statistics, and allowing to track instruments both in real and simulated environments. Simulations and experimental tests are performed to validate the proposed virtual platform, by employing it to assess the performance of a real EMTS. The platform offers a real-time tool to analyze EMTS components and field generator configurations, for a deeper understanding of EMTS technology, thus supporting engineers during system design and characterization.</p>