The effect of a barrier membrane on the incorporation of deproteinized bovine bone mineral (DBBM) in experimental defects at the time of early implant placement. A preclinical study.

OBJECTIVES: This study aimed to assess membrane use with a bone substitute graft for guided bone regeneration (GBR) in experimental dehiscence defects. MATERIALS AND METHODS: Maxillary second incisors (I2) in 9 dogs were extracted. Six weeks later, implants were inserted and experimental dehiscence defects (5 × 3 mm) created on the buccal aspect. The defects and surrounding bone were grafted with deproteinized bovine bone mineral. One side (test) was covered with a resorbable collagen membrane whereas the contralateral side (control) was not. After 6 weeks, histomorphometrical analysis was performed to evaluate: (a) first bone-to-implant contact (fBIC), (b) buccal bone thickness at 1 mm increments from implant shoulder, (c) regenerated area (RA), (d) area and percentages of new bone (B), bone substitute (BS) and mineralized tissue (MT). RESULTS: The histological appearance was similar between test and control sites. At central and lateral sections, there were no differences between groups for fBIC, buccal bone thickness, RA, BS, B, %B, MT and %MT. At central sections, membrane use favoured more %BS and %MT (p = 0.052). There was significantly more B, %B and MT at lateral compared to central sections. CONCLUSIONS: Membrane use tended to retain more bone substitute, but had no effect on new bone ingrowth. Lateral sections showed significantly more bone ingrowth and mineralized tissue compared to central sections, confirming that new bone ingrowth takes place mainly from the lateral walls of the defect. CLINICAL RELEVANCE: Preclinical research to clarify the dynamics of bone regeneration in GBR procedures is relevant in clinical practice.

A Single-Center Experience with a Shear-Thinning Conformable Embolic.

The purpose of this study was to evaluate the technical success, effectiveness, and safety of transarterial embolization for acute bleeding management with a shear-thinning conformable embolic. This single-center retrospective study evaluated outcomes after embolization using Obsidio conformable embolic (OCE). Technical success was defined as performing transarterial embolization within the target vessel to complete stasis of antegrade flow. Treatment effectiveness was defined as cessation of bleeding for patients. Eleven patients underwent 11 embolization procedures. A total of 16 arteries were embolized. Indications for embolization were spontaneous tumor bleeding (6/11), hematuria (2/11), active duodenal bleeding (1/11), portal hypertensive bleeding (1/11), and rectus sheath hematoma (1/11). The technical success rate was 100%. The median vessel diameter was 2 mm (range, 1-3 mm). There were no adverse events or off-target embolization. OCE demonstrated technical success and treatment effectiveness with a short-term safety profile for transarterial embolization interventions.

Current and future directions in interventional neuro-oncology-are we there yet?

Advancements in technology and technical expertise increasingly enable neurointerventionalists to deliver safer and more effective endovascular treatments to cancers of the brain, spine, head, and neck. In addition to established neuro-oncological interventions such as pre-surgical tumor embolization and percutaneous ablation, newer modalities focused on direct arterial infusion of chemotherapy, radioisotopes, and radiosensitizers continue to gain traction as complementary treatment options, while stem cell-mediated delivery of theranostic nanoparticles and oncolytic virus are being explored for even greater specificity in targeting cancers across the blood-brain barrier. This article aims to provide an overview of the current state of the art and future directions for the field of interventional neuro-oncology, as well as opportunities and challenges presented by this emerging treatment modality.

Modified Clavien-Dindo-Sink Classification System for operative complications in adult spine surgery.

OBJECTIVE: Currently there is no standardized mechanism to describe or compare complications in adult spine surgery. Thus, the purpose of the present study was to modify and validate the Clavien-Dindo-Sink complication classification system for applications in spine surgery. METHODS: The Clavien-Dindo-Sink complication classification system was evaluated and modified for spine surgery by four fellowship-trained spine surgeons using a consensus process. A distinct group of three fellowship-trained spine surgeons completed a randomized electronic survey grading 71 real-life clinical case scenarios. The survey was repeated 2 weeks after its initial completion. Fleiss' and Cohen's kappa (κ) statistics were used to evaluate interrater and intrarater reliabilities, respectively. RESULTS: Overall, interobserver reliability during the first and second rounds of grading was excellent with a κ of 0.847 (95% CI 0.785-0.908) and 0.852 (95% CI 0.791-0.913), respectively. In the first round, interrater reliability ranged from good to excellent with a κ of 0.778 for grade I (95% CI 0.644-0.912), 0.698 for grade II (95% CI 0.564-0.832), 0.861 for grade III (95% CI 0.727-0.996), 0.845 for grade IV-A (95% CI 0.711-0.979), 0.962 for grade IV-B (95% CI 0.828-1.097), and 0.960 for grade V (95% CI 0.826-1.094). Intraobserver reliability testing for all three independent observers was excellent with a κ of 0.971 (95% CI 0.944-0.999) for rater 1, 0.963 (95% CI 0.926-1.001) for rater 2, and 0.926 (95% CI 0.869-0.982) for rater 3. CONCLUSIONS: The Modified Clavien-Dindo-Sink Classification System demonstrates excellent interrater and intrarater reliability in adult spine surgery cases. This system provides a useful framework to better communicate the severity of spine-related complications.

Development of a rabbit human glioblastoma model for testing of endovascular selective intra-arterial infusion (ESIA) of novel stem cell-based therapeutics.

BACKGROUND: Endovascular selective intra-arterial (ESIA) infusion of cellular oncotherapeutics is a rapidly evolving strategy for treating glioblastoma. Evaluation of ESIA infusion requires a unique animal model. Our goal was to create a rabbit human GBM model to test IA infusions of cellular therapies and to test its usefulness by employing clinical-grade microcatheters and infusion methods to deliver mesenchymal stem cells loaded with an oncolytic adenovirus, Delta-24-RGD (MSC-D24). METHODS: Rabbits were immunosuppressed with mycophenolate mofetil, dexamethasone, and tacrolimus. They underwent stereotactic xenoimplantation of human GBM cell lines (U87, MDA-GSC-17, and MDA-GSC-8-11) into the right frontal lobe. Tumor formation was confirmed on magnetic resonance imaging, histologic, and immunohistochemistry analysis. Selective microcatheter infusion of MSC-D24 was performed via the ipsilateral internal carotid artery to assess model utility and the efficacy and safety of this approach. RESULTS: Twenty-five rabbits were implanted (18 with U87, 2 MDA-GSC-17, and 5 MDA-GSC-8-11). Tumors formed in 68% of rabbits (77.8% for U87, 50.0% for MDA-GSC-17, and 40.0% for MDA-GSC-8-11). On MRI, the tumors were hyperintense on T2-weighted image with variable enhancement (evidence of blood brain barrier breakdown). Histologically, tumors showed phenotypic traits of human GBM including varying levels of vascularity. ESIA infusion into the distal internal carotid artery of 2 ml of MSCs-D24 (107 cells) was safe in the model. Examination of post infusion specimens documented that MSCs-D24 homed to the implanted tumor at 24 hours. CONCLUSIONS: The intracranial immunosuppressed rabbit human GBM model allows testing of ESIA infusion of novel therapeutics (eg, MSC-D24) in a clinically relevant fashion.

Image-Guided Deployment and Monitoring of a Novel Tungsten Nanoparticle-Infused Radiopaque Absorbable Inferior Vena Cava Filter in a Swine Model.

PURPOSE: To improve radiopacity of radiolucent absorbable poly-p-dioxanone (PPDO) inferior vena cava filters (IVCFs) and demostrate their effectiveness in clot-trapping ability. MATERIALS AND METHODS: Tungsten nanoparticles (WNPs) were incorporated along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of WNPs. The physicochemical and in vitro and in vivo imaging properties of PPDO IVCFs with WNPs with single-polymer PHB (W-P) were compared with those of WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). RESULTS: In vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physicomechanical properties of the PPDO sutures. W-P- and W-PB-coated IVCFs were deployed successfully into the inferior vena cava of pig models with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at Week 3 for both filters. CONCLUSIONS: The results highlight the utility of nanoparticles (NPs) and polymers for enhancing radiopacity of medical devices. Different methods of incorporating NPs and polymers can still be explored to improve the effectiveness, safety, and quality of absorbable IVCFs.

MicroRNA-29a: a novel target for non-operative management of symptomatic lumbar spinal stenosis.

PURPOSE: Lumbar spinal stenosis (LSS) is the most common reason for spinal surgery in patients over the age of 65, and there are few effective non-surgical treatments. Therefore, the development of novel treatment or preventative modalities to decrease overall cost and morbidity associated with LSS is an urgent matter. The cause of LSS is multifactorial; however, a significant contributor is ligamentum flavum hypertrophy (LFH) which causes mechanical compression of the cauda equina or nerve roots. We assessed the role of a novel target, microRNA-29a (miR-29a), in LFH and investigated the potential for using miR-29a as a therapeutic means to combat LSS. METHODS: Ligamentum flavum (LF) tissue was collected from patients undergoing decompressive surgery for LSS and assessed for levels of miR-29a and pro-fibrotic protein expression. LF cell cultures were then transfected with either miR-29a over-expressor (agonist) or inhibitor (antagonist). The effects of over-expression and under-expression of miR-29a on expression of pro-fibrotic proteins was assessed. RESULTS: We demonstrated that LF at stenotic levels had a loss of miR-29a expression. This was associated with greater LF tissue thickness and higher mRNA levels of collagen I and III. We also demonstrated that miR29-a plays a direct role in the regulation of collagen gene expression in ligamentum flavum. Specifically, agents that increase miR-29a may attenuate LFH, while those that decrease miR-29a promote fibrosis and LFH. CONCLUSION: This study demonstrates that miR-29a may potentially be used to treat LFH and provides groundwork to initiate the development of a therapeutic product for LSS.

Optimizing Ophthalmology Patient Education via ChatBot-Generated Materials: Readability Analysis of AI-Generated Patient Education Materials and The American Society of Ophthalmic Plastic and Reconstructive Surgery Patient Brochures.

PURPOSE: This study aims to compare the readability of patient education materials (PEM) of the American Society of Ophthalmic Plastic and Reconstructive Surgery to that of PEMs generated by the AI-chat bots ChatGPT and Google Bard. METHODS: PEMs on 16 common American Society of Ophthalmic Plastic and Reconstructive Surgery topics were generated by 2 AI models, ChatGPT 4.0 and Google Bard, with and without a 6th-grade reading level prompt modifier. The PEMs were analyzed using 7 readability metrics: Flesch Reading Ease Score, Gunning Fog Index, Flesch-Kincaid Grade Level, Coleman-Liau Index, Simple Measure of Gobbledygook Index Score, Automated Readability Index, and Linsear Write Readability Score. Each AI-generated PEM was compared with the equivalent American Society of Ophthalmic Plastic and Reconstructive Surgery PEM. RESULTS: Across all readability indices, PEM generated by ChatGPT 4.0 consistently had the highest readability scores, indicating that the material generated by this AI chatbot may be most difficult to read in its unprompted form (Flesch Reading Ease Score: 36.5; Simple Measure of Gobbledygook: 14.7). Google's Bard was able to generate content that was easier to read than both the American Society of Ophthalmic Plastic and Reconstructive Surgery and ChatGPT 4.0 (Flesch Reading Ease Score: 52.3; Simple Measure of Gobbledygook: 12.7). When prompted to produce PEM at a 6th-grade reading level, both ChatGPT 4.0 and Bard were able to significantly improve in their readability scores, with prompted ChatGPT 4.0 being able to consistently generate content that was easier to read (Flesch Reading Ease Score: 67.9, Simple Measure of Gobbledygook: 10.2). CONCLUSION: This study suggests that AI tools, when guided by appropriate prompts, can generate accessible and comprehensible PEMs in the field of ophthalmic plastic and reconstructive surgeries, balancing readability with the complexity of the necessary information.

Iris Chafing Syndrome Secondary to Iridociliary Adhesions in a Patient with a Single-Piece Acrylic Intraocular Lens: Case Report.

Introduction: We present a unique case of iris chafing syndrome in a patient with a complex ophthalmologic history after successful placement of a single-piece in-the-bag intraocular lens (IOL) in an eye with healthy zonular support. Case Presentation: A patient with a previous history of multiple retinal surgeries presented with pain and elevated intraocular pressure (IOP) secondary to retained viscoelastic material in the anterior chamber. Following removal of the viscoelastic material in clinic, the patient underwent a combined cataract and glaucoma surgery. Subsequently, the patient developed signs and symptoms of iris chafing syndrome. Anterior segment imaging revealed the cause to be iridociliary adhesion causing an elimination of the sulcus space. Iris chafing syndrome was suspected when the patient presented post-operatively with changes in vision and anterior chamber inflammation. New iris transillumination defects present at the edge of the optic and haptic of the 1-piece lens helped confirm the diagnosis of UGH. Upon further investigation with gonioscopy, ultrasound biomicroscopy and anterior segment optical coherence tomography, it was determined that the patient had iridociliary adhesions. These adhesions eliminated the sulcus space, which resulted in iris chafing. The patient opted for conservative medical management. Best-corrected distance visual acuity remained stable at 20/100 and IOP remained well controlled. Conclusion: A complex ocular history of multiple retinal surgeries and retained viscoelastic material in the anterior chamber resulted in adhesions of the ciliary processes to the iris, leading to UGH syndrome in a patient with an otherwise unremarkable placement of a single-piece in-the-bag IOL.

An Uncommon Case of Multiple, Recurrent Cerebrospinal Fluid Venous Fistulas.

We present a clinical case to discuss the use of computed tomography (CT) spine myelograms alongside a complete history to diagnose multiple cerebrospinal fluid (CSF) venous fistulas (CVFs). The goal of this study is to familiarize clinicians with this challenging diagnosis and the utility of these studies in localizing leaks. A 63-year-old male patient with a history of cervical spinal stenosis, intermittent double vision, and sinus pressure managed with intermittent steroids presented to the clinic. He provided a detailed timeline of his previous symptoms and previous workups leading to the suspicion of intracranial hypotension due to CSF leak vs. CVF. Our workup, including magnetic resonance imaging (MRI) of the cervical spine and lumbar puncture (LP), was conducted. A CT thoracic spine myelogram was completed to localize the fistula site which was followed by the embolization of the fistula. The patient revealed complete resolution of his symptoms confirmed by imaging done one week postoperatively. This was a difficult case complicated by chronic misdiagnosis and confounding factors. CVFs were first described less than a decade ago; however, they are an extremely important cause of spontaneous intracranial hypotension. CVFs can be challenging to detect on conventional anatomical imaging like MRI. Thus, CT myelogram studies and a thorough history are crucial for accurate diagnosis. It is essential that clinicians, including ophthalmologists, learn to recognize CVFs as a potential cause of intracranial hypotension and become familiar with this diagnosis and its workup in the hopes that, unlike this case, the diagnosis and resolution of patients' life-altering symptoms are not delayed.

Dual Versus Single Plate Fixation of Displaced Midshaft Clavicle Fractures: A Cost-Effectiveness Analysis.

BACKGROUND: Prior studies have highlighted lower rates of reoperation if fixation of a displaced midshaft clavicle fracture is performed with dual plating (DP) compared with single plating (SP). Despite higher initial costs associated with the DP construct, the observed reduction in secondary surgeries compared with the SP construct may make it a more cost-effective treatment option. The objective of this study was to assess the cost-effectiveness of DP compared with SP in patients with operatively indicated displaced midshaft clavicle fractures. METHODS: We developed a decision tree to model the occurrence of postoperative complications (acute hardware complications, wound healing issues, deep infection, nonunion, and symptomatic hardware) associated with secondary surgeries. Complication-specific risk estimates were pooled for both plating techniques using the available literature. The time horizon was 2 years, and the analysis was conducted from the health-care payer's perspective. The costs were estimated using direct medical costs, and the benefits were measured in quality-adjusted life-years (QALYs). We assumed that DP would be $300 more expensive than SP initially. We conducted probabilistic and 1-way sensitivity analyses. RESULTS: The model predicted reoperation in 6% of patients in the DP arm compared with 14% of patients in the SP arm. In the base case analysis, DP increased QALYs by 0.005 and costs by $71 per patient, yielding an incremental cost-effectiveness ratio (ICER) of $13,242 per QALY gained. The sensitivity analysis demonstrated that the cost-effectiveness of DP was driven by the cost of the index surgery, risk of symptomatic hardware, and nonunion complications with SP and DP. At a willingness-to-pay threshold of $100,000 per QALY gained, 95% of simulations suggested that DP was cost-effective compared with SP. CONCLUSIONS: When indicated, operative management of displaced midshaft clavicle fractures using DP was found to be cost-effective compared with SP. Despite its higher initial hardware costs, DP fixation appears to offset its added costs with greater health utility via lower rates of reoperation and improved patient quality of life. LEVEL OF EVIDENCE: Economic and Decision Analysis Level II . See Instructions for Authors for a complete description of levels of evidence.

Dual Mini-Fragment Plate Fixation of Midshaft Clavicle Fractures Reduces Risk of Reoperation Compared With Single-Plate Fixation Techniques.

BACKGROUND: Recent studies have highlighted dual plating as a method of reducing high rates of postoperative complication after operative management of displaced midshaft clavicular fractures. However, few studies have reliably characterized reoperation rates and magnitude of risk reduction achieved when using dual versus anterior and superior single-plate techniques. HYPOTHESIS: There would be lower rates of reoperation among patients who underwent open reduction and internal fixation (ORIF) of displaced midshaft clavicular fractures via dual plating. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a retrospective analysis of patients who underwent ORIF for a displaced midshaft clavicular fracture between 2010 and 2021 at a level 1 trauma center with a minimum 12-month follow-up. Patients were separated into 3 cohorts based on fixation type: (1) orthogonal dual mini-fragment plate fixation, (2) superior plate fixation, and (3) anterior plate fixation. Data on patient characteristics, fracture pattern, and reoperations were documented. All-cause reoperation rates and hazard ratio (HR) estimates of dual, superior, and anterior plating were calculated using a multivariate multilevel mixed-effects parametric survival model. Significant confounders including high-risk fracture morphology and smoking status were controlled for in the final model. RESULTS: A final cohort of 256 patients was identified with mean follow-up of 4.9 ± 3.8 years. In total, 101 patients underwent superior plating, 92 underwent anterior plating, and 63 underwent dual plating. Overall, 31 reoperations took place (18 in superior, 12 in anterior, 1 in dual plating) among 22 patients. Major contributors to reoperation included symptomatic hardware (n = 11), nonunion (n = 8), deep infection (n = 7), and wound dehiscence (n = 2). Superior plating revealed the highest reoperation rate of 0.031 per person-years, followed by anterior plating with 0.026 per person-years and dual plating with 0.005 per person-years. Overall, single plating (either anterior or superior placement) had a nearly 8-fold greater risk of reoperation than dual plating (HR, 7.62; 95% CI, 1.02-56.82; P = .048). Further broken down by technique, superior plating had an 8-fold greater risk of reoperation than dual plating (HR, 8.36; 95% CI, 1.10-63.86; P = .041), but anterior plating did not demonstrate a statistically significant difference compared with dual plating (HR, 6.79; 95% CI, 0.87-52.90; P = .068). CONCLUSION: Dual-plate fixation represents an excellent treatment for displaced midshaft clavicular fractures, with low rates of nonunion and reoperation. When compared with single locked superior or anterior plate fixation, dual mini-fragment plate fixation has a nearly 8-fold lower risk of reoperation.

Group 5 ITI Consensus Report: Implant placement and loading protocols.

OBJECTIVES: Working Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval. MATERIALS AND METHODS: Two systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary. RESULTS: Five consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research. CONCLUSIONS: Based on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur.

Carotid blowout into the trachea: unusual entity with unexpected management outcome.

We present a case report of a patient with a history of aggressive thyroid cancer managed by surgery, chemotherapy, and radiation to the neck. A year later, he presented with hemoptysis. Endobronchial ultrasound showed a pulsatile vessel; however, a CT scan and conventional angiogram were negative. Three days later, a repeat angiogram revealed a pseudoaneurysm arising from the right common carotid artery. Carotid sacrifice was performed after passing balloon test occlusion. Three years later the patient presented with coil herniation into the trachea. The carotid stump was closed with a vascular plug to prevent rebleeding from coil removal. Four months later the patient experienced an intractable cough and underwent laryngoscopy-assisted removal of the residual coil mass. This case report discusses the rare scenario of a carotid blowout into the trachea and the subsequent course of events.

Imaging in Interventional Radiology: 2043 and Beyond.

Since its inception in the early 20th century, interventional radiology (IR) has evolved tremendously and is now a distinct clinical discipline with its own training pathway. The arsenal of modalities at work in IR includes x-ray radiography and fluoroscopy, CT, MRI, US, and molecular and multimodality imaging within hybrid interventional environments. This article briefly reviews the major developments in imaging technology in IR over the past century, summarizes technologies now representative of the standard of care, and reflects on emerging advances in imaging technology that could shape the field in the century ahead. The role of emergent imaging technologies in enabling high-precision interventions is also briefly reviewed, including image-guided ablative therapies.

The Effects of Cervical Orthoses on Head and Intervertebral Range of Motion.

STUDY DESIGN: Prospective Cohort. OBJECTIVE: Quantify and compare the effectiveness of cervical orthoses in restricting intervertebral kinematics during multiplanar motions. SUMMARY OF BACKGROUND DATA: Previous studies evaluating the efficacy of cervical orthoses measured global head motion and did not evaluate individual cervical motion segment mobility. Prior studies focused only on the flexion/extension motion. METHODS: Twenty adults without neck pain participated. Vertebral motion from the occiput through T1 was imaged using dynamic biplane radiography. Intervertebral motion was measured using an automated registration process with validated accuracy better than 1 degree. Participants performed independent trials of maximal flexion/extension, axial rotation, and lateral bending in a randomized order of unbraced, soft collar (foam), hard collar (Aspen), and cervical thoracic orthosis (CTO) (Aspen) conditions. Repeated-measures ANOVA was used to identify differences in the range of motion (ROM) among brace conditions for each motion. RESULTS: Compared with no collar, the soft collar reduced flexion/extension ROM from occiput/C1 through C4/C5, and reduced axial rotation ROM at C1/C2 and from C3/C4 through C5/C6. The soft collar did not reduce motion at any motion segment during lateral bending. Compared with the soft collar, the hard collar reduced intervertebral motion at every motion segment during all motions, except for occiput/C1 during axial rotation and C1/C2 during lateral bending. The CTO reduced motion compared with the hard collar only at C6/C7 during flexion/extension and lateral bending. CONCLUSIONS: The soft collar was ineffective as a restraint to intervertebral motion during lateral bending, but it did reduce intervertebral motion during flexion/extension and axial rotation. The hard collar reduced intervertebral motion compared with the soft collar across all motion directions. The CTO provided a minimal reduction in intervertebral motion compared with the hard collar. The utility in using a CTO rather than a hard collar is questionable, given the cost and little or no additional motion restriction.

Super-Resolution Ultrasound Localization Microscopy Using High-Frequency Ultrasound to Measure Ocular Perfusion Velocity in the Rat Eye.

Imaging of the ocular vasculature can provide new insights into the pathophysiology of ocular diseases. This study proposes a novel high-frequency super-resolution ultrasound localization microscopy (SRULM) technique and evaluates its ability to measure in vivo perfusion changes in the rat eye at elevated intraocular pressure (IOP). A 38.4 MHz center frequency linear array transducer on a VisualSonics Vevo F2 imaging platform was used to collect high frame rate (1 kHz) radiofrequency data of the posterior rat eye following systemic microbubble contrast injection. Following clutter and spatiotemporal non-local means filtering, individual microbubbles were localized and tracked. The microbubble tracks were accumulated over 10,000 frames to generate vascular images quantifying perfusion velocity and direction. Experiments were performed using physiologic relevant controlled flow states for algorithm validation and subsequently performed in vivo on the rat eye at 10 mm Hg IOP increments from 10 to 60 mm Hg. The posterior vasculature of the rat eye, including the ophthalmic artery, long posterior ciliary arteries and their branches, central retinal artery and retinal arterioles and venules were successfully visualized, and velocities quantified at each IOP level. Significant reductions in arterial flow were measured as IOP was elevated. High-frequency SRULM can be used to visualize and quantify the perfusion velocity of the rat eye in both the retrobulbar and intraocular vasculature simultaneously. The ability to detect ocular perfusion changes throughout the depth of the eye may help elucidate the role ischemia has in the pathophysiology of ocular diseases such as glaucoma.

Association Between Industry Sponsorship of Spine-Related Clinical Trials, Publication Status, and Research Outcomes.

STUDY DESIGN: Observational Database Study. OBJECTIVES: Prospective clinical trials in spinal surgery are expensive to conduct, especially when randomized, appropriately powered, and/or multicentered. Industry collaborations generate symbiotic relationships promoting technological advancement; however, they also allow for bias. To the authors' knowledge, there is no known analysis of correlations between industry sponsorship and publication rates of spine-related clinical trials. This observational work evaluates such potential associations. METHODS: The ClinicalTrials.gov database was queried with terms spine, spinal, spondylosis, spondylolysis, cervical, lumbar, and compression fracture over an 11-year period. Design characteristics and outcomes were recorded from 822 spine surgery-related trials. Trials were stratified based on funding source and intervention class. Groups were compared via two-tailed chi-square test of independence or Fisher's exact test (α = .05), based on completion status and publication rates of positive vs negative results. RESULTS: Industry-sponsored spine-related clinical trials were more likely to be terminated than their non-industry-sponsored counterparts (P < .001). Of the trials achieving publication, industry-sponsored trials reported positive results at a higher rate than did trials without industry funding (P = .037). Clinical trials examining devices were more likely to be terminated than those studying other intervention classes (P = .001). CONCLUSIONS: High termination rates and positive result publication rates among industry-sponsored clinical trials in spinal surgery likely reflect industry's influence on the research community. Such partnership alleviates financial burden and provides accessibility to cutting-edge innovation. It is essential that all parties remain mindful of the significant bias that funding source may impart on study outcome.