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Introduction Indocyanine green (ICG) is commonly used to visualize cerebral vasculature, particularly in the management of cerebral aneurysms. There have also been attempts to use ICG for visualization of tumors. Injection of ICG followed by immediate fluorescence microscopy is limited by the short time window for imaging and administration and restricted depth of imaging. Second Window Indocyanine Green (SWIG) addresses these issues by allowing for longer contrast times and the imaging of deeper regions of brain tissue. Biopsy of spinal cord lesions is often difficult for a variety of reasons, including the delicate nature of the tissue and differentiating normal from lesional tissue visually, especially in lesions with heterogeneous enhancement. Methods In this case report, we describe the use of second window ICG to facilitate the visualization of a spinal cord lesion and subsequent biopsy of the lesion. Results This patient is a 24-year-old female who had recurrence of a suprasellar germinoma. An MRI of the rest of the neuraxis was performed to assess for the presence of drop metastases. The spinal cord from C2-5 was expanded with areas of patchy enhancement; however, this lesion was asymptomatic. The patient's oncologist requested a biopsy of this lesion to help direct subsequent care of her recurrent germinoma. The day before surgery, the patient had an intravenous injection of ICG dye. She then underwent a C3-5 laminectomy for biopsy of her cervical intramedullary lesion. After opening of the dura, no visible abnormality of the spinal cord could be identified. A Stryker endoscope showed an area of ICG uptake in the cord at approximately the C3-4 level. A midline myelotomy was centered over the ICG demarcated area and several samples were taken for pathology. Final biopsy results determined the lesion to be spinal cord parenchyma with perivascular and intraparenchymal lymphocytes – not consistent with spinal cord tumor or germinoma. Conclusion Second Window ICG is effective in visualizing otherwise visually unremarkable spinal cord lesions. This technology can facilitate biopsy of these lesions and possibly their surgical resection.

Objective. Holographic mixed reality (HMR) allows for the superimposition of computer-generated virtual objects onto the operator’s view of the world. Innovative solutions can be developed to enable the use of this technology during surgery. The authors developed and iteratively optimized a pipeline to construct, visualize, and register intraoperative holographic models of patient landmarks during spinal fusion surgery. Methods. The study was carried out in two phases. In phase 1, the custom intraoperative pipeline to generate patient-specific holographic models was developed over 7 patients. In phase 2, registration accuracy was optimized iteratively for 6 patients in a real-time operative setting. Results. In phase 1, an intraoperative pipeline was successfully employed to generate and deploy patient-specific holographic models. In phase 2, the registration error with the native hand-gesture registration was 20.2 ± 10.8 mm (n = 7 test points). Custom controller-based registration significantly reduced the mean registration error to 4.18 ± 2.83 mm (n = 24 test points, P < .01). Accuracy improved over time (B = −.69, P < .0001) with the final patient achieving a registration error of 2.30 ± .58 mm. Across both phases, the average model generation time was 18.0 ± 6.1 minutes (n = 6) for isolated spinal hardware and 33.8 ± 8.6 minutes (n = 6) for spinal anatomy. Conclusions. A custom pipeline is described for the generation of intraoperative 3D holographic models during spine surgery. Registration accuracy dramatically improved with iterative optimization of the pipeline and technique. While significant improvements and advancements need to be made to enable clinical utility, HMR demonstrates significant potential as the next frontier of intraoperative visualization.

Background The emergence of SARS-CoV-2/2019 novel coronavirus (COVID19) has created a global pandemic with no approved treatments or vaccines. Repurposing existing drugs and rapidly launching clinical trials present the greatest near-term opportunities for mitigating COVID19s impact. Many treatments have already been administered to COVID19 patients but have not been systematically evaluated. We performed a systematic literature review to identify and assess all treatments reported to be administered to COVID19 patients. Methods We searched PubMed, BioRxiv, MedRxiv, and ChinaXiv for articles reporting treatments for COVID19 patients published between Dec 1, 2019 and Mar 27, 2020. All studies reporting treatments were included. Data for each paper were manually extracted by two independent extractors. Outcomes included the duration from drug administration to clinically-meaningful response (complete symptom resolution or hospital discharge). Data were analysed descriptively. Results We identified 2,706 articles from single patient case reports to single-centre interventional studies. Of these, 155 studies met inclusion criteria, comprising 9,152 patients from 14 different countries. The cohort was 45.4% female and 98.3% hospitalised, and mean (SD) age was 44.4 years (SD 21.0). The most frequently administered drug classes were antivirals, antibiotics, and corticosteroids, and of the 115 reported drugs, the most frequently administered was combination lopinavir/ritonavir, which was associated with a response time of 11.7 (1.09) days. Discussion A large number of treatments have been administered to the first 9,152 reported cases of COVID19. Further work is needed to prioritise drugs for investigation in well-controlled clinical trials and treatment protocols. Funding None.