Effect of intrasite vancomycin powder on development of epidural fibrosis

Local drug delivery challenges and innovations in spinal neurosurgery

The development of novel therapeutics in the field of spinal neurosurgery faces a litany of translational challenges. Achieving precise drug targeting within the confined spaces associated with the spinal cord, canal and vertebra requires the development of next generation delivery systems and devices. These must be capable of overcoming inherent barriers related to drug diffusion, whilst concurrently ensuring optimal drug distribution and retention. In this review, we provide an overview of the most recent advances in the therapeutic management of diseases and disorders affecting the spine, including systems and devices capable of releasing small molecules and biopharmaceuticals that help eliminate pain and restore the mechanical function and stability of the spine. We highlight material-based approaches and minimally invasive techniques that can be employed to provide control over drug release kinetics and improve retention. We also seek to explore how the newest advancements in nanotechnology, biomaterials, additive manufacturing technologies and imaging modalities can be employed in this translational pursuit. Finally, we discuss the landscape of clinical trials and recently approved products aimed at overcoming the complexities associated with drug delivery to the spine.

Dilation of the superior sagittal sinus detected in rat model of mild traumatic brain injury using 1 T magnetic resonance imaging

Introduction

Mild traumatic brain injury (mTBI) is a common injury that can lead to temporary and, in some cases, life-long disability. Magnetic resonance imaging (MRI) is widely used to diagnose and study brain injuries and diseases, yet mTBI remains notoriously difficult to detect in structural MRI. mTBI is thought to be caused by microstructural or physiological changes in the function of the brain that cannot be adequately captured in structural imaging of the gray and white matter. However, structural MRIs may be useful in detecting significant changes in the cerebral vascular system (e.g., the blood-brain barrier (BBB), major blood vessels, and sinuses) and the ventricular system, and these changes may even be detectable in images taken by low magnetic field strength MRI scanners (<1.5T).

Methods

In this study, we induced a model of mTBI in the anesthetized rat animal model using a commonly used linear acceleration drop-weight technique. Using a 1T MRI scanner, the brain of the rat was imaged, without and with contrast, before and after mTBI on post-injury days 1, 2, 7, and 14 (i.e., P1, P2, P7, and P14).

Results

Voxel-based analyses of MRIs showed time-dependent, statistically significant T2-weighted signal hypointensities in the superior sagittal sinus (SSS) and hyperintensities of the gadolinium-enhanced T1-weighted signal in the superior subarachnoid space (SA) and blood vessels near the dorsal third ventricle. These results showed a widening, or vasodilation, of the SSS on P1 and of the SA on P1-2 on the dorsal surface of the cortex near the site of the drop-weight impact. The results also showed vasodilation of vasculature near the dorsal third ventricle and basal forebrain on P1-7.

Discussion

Vasodilation of the SSS and SA near the site of impact could be explained by the direct mechanical injury resulting in local changes in tissue function, oxygenation, inflammation, and blood flow dynamics. Our results agreed with literature and show that the 1T MRI scanner performs at a level comparable to higher field strength scanners for this type of research.

Is Use of Topical Vancomycin in Pediatric Spine Surgeries a Safe Option in the Prevention of Surgical Site Infections? A Meta-analysis and Systematic Review of the Literature

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To systematically review the available articles on topical vancomycin powder (TVP) use in pediatric spine surgeries exploring the usefulness and safety of such practice.

METHODS

We conducted an independent and duplicate electronic database search in PubMed, EMBASE, and Cochrane Library till March 2020 to identify all relevant literature on the use of TVP for pediatric spine surgeries. Surgical site infection (SSI) rate, specific reported complications, reoperation rate, microbial flora pattern in reported SSIs, and safety profile were the outcomes analyzed. Analysis was performed with the R platform using OpenMeta[Analyst] software.

RESULTS

No prospective studies were available to evaluate the use of TVP in pediatric spine surgeries for the prevention of SSIs. Neither standardized protocol, nor drug dosage, nor safety profile was established for pediatric use. Three retrospective cohort studies including 824 patients (TVP/control: 400/424) were included in the meta-analysis. There was low-quality evidence suggesting no significant difference between the 2 groups in SSI rate (RR = 0.474; 95% CI = [0.106,2.112]; P = .327) with significant heterogeneity (I² = 70.14; P = .035). The TVP group showed a significant benefit on cost analysis in one of the included studies. However, TVP did not prevent gram-negative coinfection on SSI in the TVP group.

CONCLUSION

From the literature available at present, TVP does not qualify to be recommended as a safe and useful option to prevent SSI following pediatric spine surgeries. High-quality prospective interventional studies are needed to arrive at a consensus on its use along with appropriate dosage and method of application.