Posterior Transdural Approach for Thoracic Corpectomies in the Setting of Complex Spine Deformity Reconstruction.

BACKGROUND AND OBJECTIVE: There are many surgical approaches for execution of a thoracic corpectomy. In cases of challenging deformity, traditional posterior approaches might not be sufficient to complete the resection of the vertebral body. In this technical note, we describe indications and technique for a transdural multilevel high thoracic corpectomy. METHODS: A 25-year-old man with a history of neurofibromatosis type 1 presented with instrumentation failure after a previous T1-T12 posterior spinal fusion, extensive laminectomy, and tumor resection. The patient presented with progressive back pain, had broad dural ectasia, and a progressive kyphotic rotational and anteriorly translated spinal deformity. To resect the medial-most aspect of the vertebral body, a bilateral extracavitary approach was attempted, but was found insufficient. A transdural approach was subsequently performed. A left paramedian durotomy was made, followed by generous arachnoid dissection, bilateral dentate ligament division, and T4 rootlet sacrifice to mobilize the spinal cord. A ventral durotomy was then made and the ventral dura was reflected over the spinal cord to protect it while drilling. The corpectomy was then completed. The ventral and dorsal durotomies were closed primarily and reinforced with fibrin glue and fibrin sealant patch. The corpectomy defect was filled with nonstructural autograft. RESULTS: The focal kyphosis was corrected with a combination of rod contouring, compression, and in situ bending. During the surgery, the patient had stable neuromonitoring data, and postoperatively had no neurological deficits. On follow-up until 1 year, the patient presented with no signs of cerebrospinal spinal leaks, no motor or sensory deficits, minimal incisional pain, and significantly improved posture. CONCLUSION: Complex high thoracic (T3-5) ventral pathology inaccessible via a bilateral extracavitary approach may be accessed via a transdural approach as opposed to an anterior/lateral transthoracic approach that requires mobilization of cardiovascular structures or scapula.

Utilization of Augmented Reality Head-Mounted Display for the Surgical Management of Thoracolumbar Spinal Trauma.

Background and Objectives: Augmented reality head-mounted display (AR-HMD) is a novel technology that provides surgeons with a real-time CT-guided 3-dimensional recapitulation of a patient's spinal anatomy. In this case series, we explore the use of AR-HMD alongside more traditional robotic assistance in surgical spine trauma cases to determine their effect on operative costs and perioperative outcomes. Materials and Methods: We retrospectively reviewed trauma patients who underwent pedicle screw placement surgery guided by AR-HMD or robotic-assisted platforms at an academic tertiary care center between 1 January 2021 and 31 December 2022. Outcome distributions were compared using the Mann-Whitney U test. Results: The AR cohort (n = 9) had a mean age of 66 years, BMI of 29.4 kg/m2, Charlson Comorbidity Index (CCI) of 4.1, and Surgical Invasiveness Index (SII) of 8.8. In total, 77 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 378 mL, 0.78 units transfused, 398 min spent in the operating room, and a 20-day LOS. The robotic cohort (n = 13) had a mean age of 56 years, BMI of 27.1 kg/m2, CCI of 3.8, and SII of 14.2. In total, 128 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 432 mL, 0.46 units transfused units used, 331 min spent in the operating room, and a 10.4-day LOS. No significant difference was found between the two cohorts in any outcome metrics. Conclusions: Although the need to address urgent spinal conditions poses a significant challenge to the implementation of innovative technologies in spine surgery, this study represents an initial effort to show that AR-HMD can yield comparable outcomes to traditional robotic surgical techniques. Moreover, it highlights the potential for AR-HMD to be readily integrated into Level 1 trauma centers without requiring extensive modifications or adjustments.

Virtual, Augmented, and Mixed Reality Applications for Surgical Rehearsal, Operative Execution, and Patient Education in Spine Surgery: A Scoping Review.

Background and Objectives: Advances in virtual reality (VR), augmented reality (AR), and mixed reality (MR) technologies have resulted in their increased application across many medical specialties. VR's main application has been for teaching and preparatory roles, while AR has been mostly used as a surgical adjunct. The objective of this study is to discuss the various applications and prospects for VR, AR, and MR specifically as they relate to spine surgery. Materials and Methods: A systematic review was conducted to examine the current applications of VR, AR, and MR with a focus on spine surgery. A literature search of two electronic databases (PubMed and Scopus) was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The study quality was assessed using the MERSQI score for educational research studies, QUACS for cadaveric studies, and the JBI critical appraisal tools for clinical studies. Results: A total of 228 articles were identified in the primary literature review. Following title/abstract screening and full-text review, 46 articles were included in the review. These articles comprised nine studies performed in artificial models, nine cadaveric studies, four clinical case studies, nineteen clinical case series, one clinical case-control study, and four clinical parallel control studies. Teaching applications utilizing holographic overlays are the most intensively studied aspect of AR/VR; the most simulated surgical procedure is pedicle screw placement. Conclusions: VR provides a reproducible and robust medium for surgical training through surgical simulations and for patient education through various platforms. Existing AR/MR platforms enhance the accuracy and precision of spine surgeries and show promise as a surgical adjunct.

Translational regulation of cyclin D1 by 15-deoxy-delta(12,14)-prostaglandin J(2).

The D-group cyclins play a key role in the progression of cells through the G(1) phase of the cell cycle. Treatment of MCF-7 breast cancer cells with the cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) results in rapid down-regulation of cyclin D1 protein expression and growth arrest in the G(0)/G(1) phase of the cell cycle. 15d-PGJ(2) also down-regulates the expression of cyclin D1 mRNA; however, this effect is delayed relative to the effect on cyclin D1 protein levels, suggesting that the regulation of cyclin D1 occurs at least partly at the level of translation or protein turnover. Treatment of MCF-7 cells with 15d-PGJ(2) leads to a rapid increase in the phosphorylation of protein synthesis initiation factor eukaryotic initiation factor 2alpha (eIF-2alpha) and a shift of cyclin D1 mRNA from the polysome-associated to free mRNA fraction, indicating that 15d-PGJ(2) inhibits the initiation of cyclin D1 mRNA translation. The selective rapid decrease in cyclin D1 protein accumulation is facilitated by its rapid turnover (t(1/2) = 34 min) after inhibition of cyclin D1 protein synthesis. The half-life of cyclin D1 protein is not significantly altered in cells treated with 15d-PGJ(2). Treatment of cells with 15d-PGJ(2) results in strong induction of heat shock protein 70 (HSP70) gene expression, suggesting that 15d-PGJ(2) might activate protein kinase R (PKR), an eIF-2alpha kinase shown previously to be responsive to agents that induce stress. 15d-PGJ(2) strongly stimulates eIF-2alpha phosphorylation and down-regulates cyclin D1 expression in a cell line derived from wild-type mouse embryo fibroblasts but has an attenuated effect in PKR-null cells, providing evidence that PKR is involved in mediating the effect of 15d-PGJ(2) on eIF-2alpha phosphorylation and cyclin D1 expression. In summary, treatment of MCF-7 cells with 15d-PGJ(2) results in increased phosphorylation of eIF-2alpha and inhibition of cyclin D1 mRNA translation initiation. At later time points, repression of cyclin D1 mRNA expression may also contribute to the decrease in cyclin D1 protein.