The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study.

BACKGROUND: COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes. METHODS: Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2, hospitalized and received supplemental O2, admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality. RESULTS: Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity. CONCLUSIONS: Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

Stagnation in quality of next-generation sequencing assays for the diagnosis of hereditary hematopoietic malignancies.

Hereditary hematopoietic malignancies (HHMs) are inherited syndromes that confer the risk of blood cancer development. With the rapid acceleration of next-generation sequencing (NGS) into commercial biotechnology markets, HHMs are increasingly recognized by genetic counselors and clinicians. In 2020, it was demonstrated that most diagnostic test offerings for HHMs were insufficient for accurate diagnosis, failing to sequence the full spectrum of genetic events known to cause HHMs. We hypothesized the number of genes on commercially available HHM assay increased from 2020 to 2022, consistent with a more comprehensive sequencing approach. Here, we analyzed assays from eight commercial laboratories to determine the HHM-related genes sequenced by these assays. We compared these assays with panels from 2020 to determine trends in sequencing quality. Most HHM diagnostic assays did not change and remain insensitive for the detection of all HHM-related variants. Most (75%) HHM assays do not sequence CHEK2, the gene most frequently mutated in HHMs, and 25% of HHM assays does not sequence DDX41, the second most frequent HHM driver. The quality of HHM diagnostic assays stagnated despite the discovery of novel HHM-related genes and prior work demonstrating heterogeneity in the quality of HHM testing. Most commercially available HHM tests remain insufficient.

Role of inflammatory markers in Takayasu arteritis disease monitoring.

BACKGROUND: Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis that can result in significant morbidity and mortality secondary to progressive stenosis and occlusion. Monitoring disease progression is crucial to preventing relapse, but is often complicated by the lack of clinical symptoms in the setting of active disease. Although acute phase reactants such as ESR and CRP are generally used as an indicator of inflammation and disease activity, mounting evidence suggests that these markers cannot reliably distinguish active from inactive TA. CASE PRESENTATION: We report a 24-year-old Hispanic female with a 5-year history of TA who presented with stroke-like symptoms and evidence of left MCA occlusion on imaging, despite a history of decreasing inflammatory markers. CTA revealed complete occlusion of the left common carotid artery, left subclavian, and left MCA from their origins. It also revealed a striking compensatory circulation supplying the left anterior circulation as well as the left subclavian as a response to progressive stenosis. CONCLUSION: Monitoring ESR and CRP levels alone may not be a reliable method to evaluate disease progression in patients with TA, and should be taken in context with both patient's clinical picture and the imaging. We recommend that serial imaging be performed regularly in the setting of active disease to monitor progression and allow for immediate therapy in response to evidence of disease advancement, with a relaxation of the imaging interval once the disease is presumed inactive.

Tension Parameters of Junctional Tethers in Proximal Junction Kyphosis: A Cadaveric Biomechanical Study.

OBJECTIVE: Proximal junctional failure following surgical correction for adult spinal deformity significantly impacts quality of life and increases the economic burden of treating underlying spinal deformity. The objective of this cadaver study was to determine optimal tension parameters in junctional tethers for proximal junctional kyphosis prevention. METHODS: Cadaveric specimens were used to establish the optimal tension range in polyethylene tethering devices, such as the VersaTie (NuVasive) used in this study. Three specimens were instrumented to test tether tensions of 0, 75, and 150 Newtons (N) at L1-L2, T9-T10, and T3-T4. An optical tracking system was used to measure when specimens reached proximal junctional kyphosis, experienced instrumentation or tissue failure, or reached a cap of 2500 cycles. Radiographs were obtained before and after testing. RESULTS: At all levels, use of a tether at tension forces of 75 N and 150 N elicited a protective effect. The only level in which a higher tension on the tether resulted in more protection was at T3-T4. When averaged, the use of a tether at tension forces of 75 N and 150 N showed 1000 cycles of protection at L1-L2, 2000 cycles at T9-T10, and 1426 cycles at T3-T4. Radiographic analysis corroborated these findings. CONCLUSIONS: The use of a tether in a cadaveric model prevents the development of proximal junctional kyphosis across all tested levels and an increased tension force of 150 N is protective at the proximal thoracic spine. These data can be used to develop further models for a tether system that reproducibly applies a fixed tension force above the thoracolumbar rod construct.

Clinical considerations at the intersection of hematopoietic cell transplantation and hereditary hematopoietic malignancy.

In recent years, advances in genetics and the integration of clinical-grade next-generation sequencing (NGS) assays into patient care have facilitated broader recognition of hereditary hematopoietic malignancy (HHM) among clinicians, in addition to the identification and characterization of novel HHM syndromes. Studies on genetic risk distribution within affected families and unique considerations of HHM biology represent exciting areas of translational research. More recently, data are now emerging pertaining to unique aspects of clinical management of malignancies arising in the context of pathogenic germline mutations, with particular emphasis on chemotherapy responsiveness. In this article, we explore considerations surrounding allogeneic transplantation in the context of HHMs. We review pre- and post-transplant patient implications, including genetic testing donor selection and donor-derived malignancies. Additionally, we consider the limited data that exist regarding the use of transplantation in HHMs and safeguards that might be pursued to mitigate transplant-related toxicities.

A Review of Finite Element Modeling for Anterior Cervical Discectomy and Fusion.

The cervical spine poses many complex challenges that require complex solutions. Anterior cervical discectomy and fusion (ACDF) has been one such technique often employed to address such issues. In order to address the problems with ACDF and assess the modifications that have been made to the technique over time, finite element analyses (FEA) have proven to be an effective tool. The variations of cervical spine FEA models that have been produced over the past couple of decades, particularly more recent representations of more complex geometries, have not yet been identified and characterized in any literature. Our objective was to present material property models and cervical spine models for various simulation purposes. The outlining and refinement of the FEA process will yield more reliable outcomes and provide a stable basis for the modeling protocols of the cervical spine.

Anatomical and Technical Considerations of Robot-Assisted Cervical Pedicle Screw Placement: A Cadaveric Study.

STUDY DESIGN: Cadaver study. OBJECTIVES: Assess the feasibility of robot-assisted cervical pedicle screw (RA-CPS) placement and understand the anatomical considerations of this technique. METHODS: Four cadaver specimens free from bony pathology were acquired. Anatomical considerations, such as pedicle width (PW) and height (PH), transverse pedicle angle (TPA), and maximal screw length (MSL), were recorded from preoperative computational tomography (CT) scans. Intraoperative cone-beam CT was acquired and registered to the robotic system. After cervical levels were segmented, screw sizes and trajectories were planned, and RA-CPS were placed. Accuracy was assessed using Gertzbein and Robbin's classification on postoperative CT scans. RESULTS: Thirty-five RA-CPS were placed. Major breaches (≥Grade C) occurred in 28.57% screws. Grade A or B accuracy was found in 71.43% of screws, with the most common direction of breach being medial (81.3%). The greatest proportion of breach per level occurred in the upper subaxial levels, (C3:71.4%, C4 66.6%, C5:50%) which had the smallest PW (C3: 4.34 ± .96 mm, C4: 4.48 ± .60, C5: 5.76 ± 1.11). PH was greatest at C2 (8.14 ± 1.89 mm) and ranged subaxial from 6.36 mm (C3) to 7.48 mm (C7). The mean PW was 5.37 mm and increased caudally from 4.34 mm (C3) to 6.31 mm (C7). The mean TPA was 39.9° and decreased moving caudally 46.9°) to C7 (34.4°). The MSL was 37.1 mm and increased from C2 (26.3 mm) to C7 (41.0 mm). CONCLUSION: RA-CPS has the potential to be feasible, but technological and instrument modifications are necessary to increase the accuracy in the cervical region.

Multicenter analysis of immunosuppressive medications on the risk of malignancy following adult solid organ transplantation.

Objective: This study aimed to assess the risk of maintenance immunosuppression on the post-transplant risk of malignancy across all solid organ transplant types. Methods: This is a retrospective cohort study from a multicenter hospital system in the United States. The electronic health record was queried from 2000 to 2021 for cases of solid organ transplant, immunosuppressive medications, and post-transplant malignancy. Results: A total of 5,591 patients, 6,142 transplanted organs, and 517 post-transplant malignancies were identified. Skin cancer was the most common type of malignancy at 52.8%, whereas liver cancer was the first malignancy to present at a median time of 351 days post-transplant. Heart and lung transplant recipients had the highest rate of malignancy, but this finding was not significant upon adjusting for immunosuppressive medications (heart HR 0.96, 95% CI 0.72 - 1.3, p = 0.88; lung HR 1.01, 95% CI 0.77 - 1.33, p = 0.94). Random forest variable importance calculations and time-dependent multivariate cox proportional hazard analysis identified an increased risk of cancer in patients receiving immunosuppressive therapy with sirolimus (HR 1.41, 95% CI 1.05 - 1.9, p = 0.04), azathioprine (HR 2.1, 95% CI 1.58 - 2.79, p < 0.001), and cyclosporine (HR 1.59, 95% CI 1.17 - 2.17, p = 0.007), while tacrolimus (HR 0.59, 95% CI 0.44 - 0.81, p < 0.001) was associated with low rates of post-transplant neoplasia. Conclusion: Our results show varying risks of immunosuppressive medications associated with the development of post-transplant malignancy, demonstrating the importance of cancer detection and surveillance strategies in solid organ transplant recipients.

Breakthrough SARS-CoV-2 infections among patients with cancer following two and three doses of COVID-19 mRNA vaccines: a retrospective observational study from the COVID-19 and Cancer Consortium.

Background: Breakthrough SARS-CoV-2 infections following vaccination against COVID-19 are of international concern. Patients with cancer have been observed to have worse outcomes associated with COVID-19 during the pandemic. We sought to evaluate the clinical characteristics and outcomes of patients with cancer who developed breakthrough SARS-CoV-2 infections after 2 or 3 doses of mRNA vaccines. Methods: We evaluated the clinical characteristics of patients with cancer who developed breakthrough infections using data from the multi-institutional COVID-19 and Cancer Consortium (CCC19; NCT04354701). Analysis was restricted to patients with laboratory-confirmed SARS-CoV-2 diagnosed in 2021 or 2022, to allow for a contemporary unvaccinated control population; potential differences were evaluated using a multivariable logistic regression model after inverse probability of treatment weighting to adjust for potential baseline confounding variables. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) are reported. The primary endpoint was 30-day mortality, with key secondary endpoints of hospitalization and ICU and/or mechanical ventilation (ICU/MV). Findings: The analysis included 2486 patients, of which 564 and 385 had received 2 or 3 doses of an mRNA vaccine prior to infection, respectively. Hematologic malignancies and recent receipt of systemic anti-neoplastic therapy were more frequent among vaccinated patients. Vaccination was associated with improved outcomes: in the primary analysis, 2 doses (aOR: 0.62, 95% CI: 0.44-0.88) and 3 doses (aOR: 0.20, 95% CI: 0.11-0.36) were associated with decreased 30-day mortality. There were similar findings for the key secondary endpoints of ICU/MV (aOR: 0.60, 95% CI: 0.45-0.82 and 0.37, 95% CI: 0.24-0.58) and hospitalization (aOR: 0.60, 95% CI: 0.48-0.75 and 0.35, 95% CI: 0.26-0.46) for 2 and 3 doses, respectively. Importantly, Black patients had higher rates of hospitalization (aOR: 1.47, 95% CI: 1.12-1.92), and Hispanic patients presented with higher rates of ICU/MV (aOR: 1.61, 95% CI: 1.06-2.44). Interpretation: Vaccination against COVID-19, especially with additional doses, is a fundamental strategy in the prevention of adverse outcomes including death, among patients with cancer. Funding: This study was partly supported by grants from the National Cancer Institute grant number P30 CA068485 to C-YH, YS, SM, JLW; T32-CA236621 and P30-CA046592 to C.R.F; CTSA 2UL1TR001425-05A1 to TMW-D; ACS/FHI Real-World Data Impact Award, P50 MD017341-01, R21 CA242044-01A1, Susan G. Komen Leadership Grant Hunt to MKA. REDCap is developed and supported by Vanderbilt Institute for Clinical and Translational Research grant support (UL1 TR000445 from NCATS/NIH).

Biomechanical Study of Cervical Endplate Removal on Subsidence and Migration in Multilevel Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: This study compares four cervical endplate removal procedures, validated by finite element models. PURPOSE: To characterize the effect of biomechanical strength and increased contact area on the maximum von Mises stress, migration, and subsidence between the cancellous bone, endplate, and implanted cage. OVERVIEW OF LITERATURE: Anterior cervical discectomy and fusion (ACDF) has been widely used for treating patients with degenerative spondylosis. However, no direct correlations have been drawn that incorporate the impact of the contact area between the cage and the vertebra/endplate. METHODS: Model 1 (M1) was an intact C2C6 model with a 0.5 mm endplate. In model 2 (M2), a cage was implanted after removal of the C4-C5 and C5-C6 discs with preservation of the osseous endplate. In model 3 (M3), 1 mm of the osseous endplate was removed at the upper endplate. Model 4 (M4) resembles M3, except that 3 mm of the osseous endplate was removed. RESULTS: The range of motion (ROM) at C2C6 in the M2-M4 models was reduced by at least 9º compared to the M1 model. The von Mises stress results in the C2C3 and C3C4 interbody discs were significantly smaller in the M1 model and slightly increased in the M2-M3 and M3-M4 models. Migration and subsidence decreased from the M2-M3 model, whereas further endplate removal increased the migration and subsidence as shown in the transition from M3 to M4. CONCLUSIONS: The M3 model had the least subsidence and migration. The ROM was higher in the M3 model than the M2 and M4 models. Endplate preparation created small stress differences in the healthy intervertebral discs above the ACDF site. A 1 mm embedding depth created the best balance of mechanical strength and contact area, resulting in the most favorable stability of the construct.

Cerebroprotection by angiotensin-(1-7) in endothelin-1-induced ischaemic stroke.

Activation of angiotensin-converting enzyme 2 (ACE2), production of angiotensin-(1-7) [Ang-(1-7)] and stimulation of the Ang-(1-7) receptor Mas exert beneficial actions in various peripheral cardiovascular diseases, largely through opposition of the deleterious effects of angiotensin II via its type 1 receptor. Here we considered the possibility that Ang-(1-7) may exert beneficial effects against CNS damage and neurological deficits produced by cerebral ischaemic stroke. We determined the effects of central administration of Ang-(1-7) or pharmacological activation of ACE2 on the cerebral damage and behavioural deficits elicited by endothelin-1 (ET-1)-induced middle cerebral artery occlusion (MCAO), a model of cerebral ischaemia. The results of the present study demonstrated that intracerebroventricular infusion of either Ang-(1-7) or an ACE2 activator, diminazine aceturate (DIZE), prior to and following ET-1-induced MCAO significantly attenuated the cerebral infarct size and neurological deficits measured 72 h after the insult. These beneficial actions of Ang-(1-7) and DIZE were reversed by co-intracerebroventricular administration of the Mas receptor inhibitor, A-779. Neither the Ang-(1-7) nor the DIZE treatments altered the reduction in cerebral blood flow elicited by ET-1. Lastly, intracerebroventricular administration of Ang-(1-7) significantly reduced the increase in inducible nitric oxide synthase mRNA expression within the cerebral infarct that occurs following ET-1-induced MCAO. This is the first demonstration of cerebroprotective properties of the ACE2-Ang-(1-7)-Mas axis during ischaemic stroke, and suggests that the mechanism of the Ang-(1-7) protective action includes blunting of inducible nitric oxide synthase expression.

Infundibular hemangioblastoma resection: Video case report.

Background: Hemangioblastomas are benign (World Health Organization Grade I), highly vascular neoplasms commonly associated with Von Hippel-Lindau (VHL) disease.[2] The VHL tumor-suppressor gene, located on chromosome 3, is implicated in sporadic cases and cases associated with VHL disease. Hemangioblastomas most commonly arise in the posterior fossa; however, they may also be found supratentorially or within the spinal cord.[3] Surgical intervention is indicated for symptomatic lesions with a goal of complete resection of the enhancing nodule.[1]. Case Description: We demonstrate the case of a 69-year-old man with a history of multiple hemangioblastomas who had undergone two previous craniotomies and Gamma-Knife radiosurgery (Video https://drive.google.com/file/d/1lUwsb80NLmIW2Enp-DVdtM9_Oqbid3Ih/view?usp=sharing). He presented with progressive imbalance and diplopia and was found to have a new lesion within the suprasellar cistern. Digital subtraction angiography (DSA) and magnetic resonance imaging (MRI) characteristics were typical of hemangioblastoma. Surgery was determined to be indicated, with a goal of vision preservation. Preoperative embolization was not possible because preoperative DSA demonstrated vascular supply by only small perforators directly from the internal carotid artery. Hypopituitarism was identified preoperatively, although diabetes insipidus was not present. The patient underwent a right orbitozygomatic craniotomy and extradural anterior clinoidectomy for access. The tumor was noted to encapsulate the infundibulum, which necessitated its sacrifice. Postoperatively, the patient remained at his neurologic baseline. He had a positive triphasic diabetes insipidus response and was discharged home on maintenance desmopressin. Postoperative MRI demonstrated complete lesion resection.The patient gave informed consent for treatment and video recording. Institutional review board approval was deemed unnecessary. Conclusion: This video highlights a safe and effective surgical technique for suprasellar lesions as well as the complex anatomy observed through an orbitozygomatic approach.

Accuracy and Efficiency of Fusion Robotics™ Versus Mazor-X™ in Single-Level Lumbar Pedicle Screw Placement.

Introduction There has been a surge in robot utilization in spine surgery over the past five years with the rapid development of new spine robotic platforms. This study aimed to compare a new robotic spine platform from Fusion RoboticsTM (Fusion Robotics, Helena, MT) with the widely used Mazor-XTM Stealth Edition robotic platform (Medtronic, Dublin, Ireland) in terms of workflow and lumbar pedicle screw placement accuracy. Methods A cadaver lab was conducted, which included four procedures with single-level lumbar pedicle screw placement using the Fusion RoboticsTM system. These four procedures were compared to four propensity-score matched cases with single-level lumbar pedicle screw placement using the Mazor-XTM Stealth Edition. A single surgeon performed all surgeries. The cases were matched in terms of demographics (age, sex, race, BMI) and comorbidities (Charlson Comorbidity Index score). The primary outcome measure was the operative workflow efficiency (duration as measured with a stopwatch by an independent observer). The secondary outcome measures were pedicle screw accuracy and accuracy to plan. Results After propensity-score matching, there were four cases in each group with no significant between-group differences in terms of sex, race, BMI, or surgical levels; however, there were significant differences in terms of age (p=0.01) and comorbidities (p<0.001). The workflow efficiency measurement showed that the Fusion RoboticsTM platform had a significantly shorter duration in terms of the system set-up time, planning to in-position time, and total procedure time (p<0.05). However, there was no significant difference between the robotic platforms in terms of creating a sterile barrier, scanning and importing images, creating a plan, screw placement, screw accuracy, and screw accuracy to plan. Conclusion Based on our findings, the Fusion RoboticsTM platform had a significantly shorter procedure workflow duration while maintaining the same accuracy as the most commonly used robotic platform (Mazor-XTM). This is the first study to directly compare different spine surgery robotic systems.

Microdiscectomy Under Local Anesthesia and Spinal Block in a Pregnant Female.

The surgical plan and the anesthetic approach are vital in determining the proper treatment of lumbar disc herniation in pregnancy. The diagnostic tools available, as well as the anesthetic agents and methods of delivery, vary in pregnant patients due to factors such as radiation exposure and hemodynamics in the patient and fetus. The gestational age also plays an important role in determining treatment options. When possible, surgery should be avoided during the first trimester, especially during the period of organogenesis, as general anesthesia can interfere with this process. However, when focal neurological deficits are present, urgent surgical decompression may be necessary. In such cases, the selection of anesthesia must be guided by maternal indications and the nature of the surgery. Maternal safety and avoidance of fetal hypoxia and subsequent preterm labor are crucial when pregnant patients receive anesthesia. As a result, local anesthesia is often preferred when possible due to the decreased risk of systemic toxicity. Decompression surgery in pregnant females with lumbar disc herniation, using a multidisciplinary approach among the surgeon, obstetrician, and anesthesiologist, is an effective and safe procedure for both the mother and the fetus. We present the case of a pregnant female at four weeks of gestation who presented with lower back pain radiating down her right leg. MRI of the lumbar spine showed large L4-5 disc herniation. She underwent a successful right L4-5 microdiscectomy under local anesthesia and spinal block using bupivacaine and was completely awake throughout the procedure. Postoperatively, she experienced immediate improvement of symptoms.

Lateral Temporal Approach for Image-Guided Stereotactic Biopsy of Pineal Region Tumors.

BACKGROUND: Biopsy of pineal region neoplasms is frequently accomplished by way of endoscopic transventricular access or using an image-guided, computer-assisted stereotactic approach. METHODS: We evaluated a nonorthogonal lateral temporal approach for stereotactic biopsy of pineal region tumors as a variation of previously described stereotactic methods. Magnetic resonance imaging-guided frameless stereotaxy was used to plan and perform biopsies of pineal region tumors using a nonorthogonal trajectory extending from the superior or middle temporal gyri through the temporal stem, anterior to the atrium of the lateral ventricle, and posterior to the corticospinal tract. RESULTS: All patients had an uncomplicated postoperative course and remained at neurologic baseline. No parenchymal or ventricular hemorrhage was present on postoperative scans. A tissue diagnosis was obtained in all patients. CONCLUSIONS: This method appears to be a safe alternative to stereotactic biopsy using other trajectories and provides adequate tissue for definitive diagnosis.

Drainage, Irrigation, and Fibrinolytic Therapy (DRIFT) for Adult Intraventricular Hemorrhage Using IRRAflow® Self-Irrigating Catheter.

Intraventricular hemorrhage (IVH) is a devastating neurosurgical condition associated with high rates of morbidity and mortality. It can occur as the result of several pathologies and typically presents with mental status changes, neurologic deficits, seizures, headaches, and decreased Glasgow Coma Scale score. These patients are often treated with placement of an external ventricular drain, which helps decrease the clot burden; however, they commonly clot off leading to multiple exchanges. We present a case in which drainage, irrigation, and fibrinolytic (DRIFT) therapy using IRRAflow® (IRRAS) irrigating catheter was used to treat a patient with severe IVH secondary to aneurysmal subarachnoid hemorrhage.

Mazor X Stealth Robotic Technology: A Technical Note.

BACKGROUND: Minimally invasive techniques in spine surgery have continued to advance as robotic technology has evolved over several generations. Although traditional techniques for placing pedicle screws are still widespread in practice, newer technology has increased the reliability of accurately placing instrumentation with smaller incisions and subsequent decreased length of stay. Additionally, advancements in planning software have improved the ability to align posterior instrumentation to assist with rod placement on multilevel constructs. METHODS: This paper describes the surgical techniques and operative workflow for placing pedicle screws with the latest robotic technology. The robotic platform, registration, surgical planning, and placement of instrumentation are discussed in detail. Advantages of the Mazor X Stealth Edition compared with the previous generation robot include obviating the need for K wires and eliminating the need for a percutaneous pin, as navigation is integrated into the robot. RESULTS: Our use of this new technology has been encouraging. Using the techniques described in this paper, the first 90 pedicle screws placed with the Mazor X Stealth Edition robot yielded 100% grade A accuracy on the Gertzbein-Robbins scale confirmed on immediate postoperative CT. There were no complications experienced in any case. CONCLUSIONS: In our experience, this robotic technology has the potential to improve patient outcomes and is associated with advanced surgical planning compared with more traditional techniques.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray. SUMMARY OF BACKGROUND DATA: Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation. METHODS: We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs. RESULTS: Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ±â€Š11.3 years, mean levels operated on were 2.0 ±â€Š0.79, and mean body mass index (BMI) was 30.3 ±â€Š6.9. In those who did not, mean age was 51.8 ±â€Š10.9 years, mean levels operated on were 1.48 ±â€Š0.65, and mean BMI was 29.9 ±â€Š6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ±â€Š948.67, versus those in the control group, $700.26 ±â€Š634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01). CONCLUSION: Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

Assessment of Rod Material Types in Spine Surgery Outcomes: A Systematic Review.

BACKGROUND: Lumbar spine fusion surgery is traditionally performed with rigid fixation. Because the rigidity is often supraphysiologic, semirigid rods were developed. To the best of our knowledge, a comprehensive evaluation of rod material type on surgical outcomes has yet to be conducted. METHODS: A systematic review based on PRISMA guidelines was conducted across 3 electronic databases. After examination for inclusion and exclusion criteria, data were extracted from the studies. RESULTS: Seventeen studies, including 1399 patients, were included in this review. The mean rigid rod fusion rate is 92.2% and 95.5% for semirigid rods (P = 0.129). The mean improvement in back pain was 60.6% in rigid rods and 71.6% in semirigid rods. The improvement in leg pain was 81.9% and 77.2%, respectively. There were no differences in visual analog scale back pain score (P = 0.098), visual analog scale leg pain score (P = 0.136), or in functional improvement between rigid and semirigid rods (P = 0.143). There was no difference (P = 0.209) in the reoperation rate between rigid rods (13.1%) and semirigid rods (6.5%). There was a comparable incidence of adjacent segment disease (3%), screw fracture (1.7%), and wound infection (1.9%) between rod material types. CONCLUSIONS: There is a moderate level of evidence supporting that surgical intervention results in high fusion rates regardless of rod material type. Surgical intervention improves back pain, leg pain, and function, with neither material type showing clear superiority. There are comparable rates of reoperation, development of adjacent segment disease, development of mechanical complications, and incidence of infection in both rigid and semirigid rods. Further studies regarding rod material type are warranted.

Robot-Assisted Cortical Bone Trajectory Insertion of Pedicle Screws: 2-Dimensional Operative Video.

Robot-assisted pedicle screw insertion has been slowly gaining popularity in the spine surgery community. In previous studies, robotics has been shown to increase accuracy and reduce complication rates compared to other navigation technologies, although those studies have been conducted using traditional trajectories for pedicle screw insertion. We present a surgical video in which a robotics system (Mazor X; Mazor Robotics Ltd, Caesarea, Israel) was used to create cortical bone trajectories for the insertion of the screws. The patient in this case is a 52-yr-old woman with severe L4-5 disc herniation requiring a transforaminal interbody fusion with the insertion of pedicle screws. The robotic system's scan-and-plan technique was utilized, in which an intraoperative computed tomography (CT) scan generates a real-time operative plan. Other techniques for inserting pedicle screws using cortical bone trajectories include CT navigation and fluoroscopic guidance. These techniques allow the surgeon to manually direct the screw under precise guidance in multiple planes, although the surgeon is still using all 6 degrees of freedom the human hand provides. With robotic guidance, a pilot hole is drilled, which eliminates 4 of 6 degrees of freedom, which can potentially reduce the risk of misplaced screws. To our knowledge, this is the first video demonstrating pedicle screw insertion through cortical bone trajectories using robotic guidance. Future studies are warranted to compare cortical bone trajectory insertion using different navigation techniques to determine the long-term efficacy of each technique. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary.