Prateek Agarwal

Translation of an injectable triple-interpenetrating-network hydrogel for intervertebral disc regeneration in a goat model

Degeneration of the intervertebral discs is a progressive cascade of cellular, compositional and structural changes that is frequently associated with low back pain. As the first signs of disc degeneration typically arise in the discs central nucleus pulposus (NP), augmentation of the NP via hydrogel injection represents a promising strategy to treat early to mid-stage degeneration. The purpose of this study was to establish the translational feasibility of a triple interpenetrating network hydrogel composed of dextran, chitosan, and teleostean (DCT) for augmentation of the degenerative NP in a preclinical goat model. Ex vivo injection of the DCT hydrogel into degenerated goat lumbar motion segments restored range of motion and neutral zone modulus towards physiologic values. To facilitate non-invasive assessment of hydrogel delivery and distribution, zirconia nanoparticles were added to make the hydrogel radiopaque. Importantly, the addition of zirconia did not negatively impact viability or matrix producing capacity of goat mesenchymal stem cells or NP cells seeded within the hydrogel in vitro. In vivo studies demonstrated that the radiopaque DCT hydrogel was successfully delivered to degenerated goat lumbar intervertebral discs, where it was distributed throughout both the NP and annulus fibrosus, and that the hydrogel remained contained within the disc space for two weeks without evidence of extrusion. These results demonstrate the translational potential of this hydrogel for functional regeneration of degenerate intervertebral discs. STATEMENT OF SIGNIFICANCE The results of this work demonstrate that a radiopaque hydrogel is capable of normalizing the mechanical function of the degenerative disc, is supportive of disc cell and mesenchymal stem cell viability and matrix production, and can be maintained in the disc space without extrusion following intradiscal delivery in a preclinical large animal model. These results support evaluation of this hydrogel as a minimally invasive disc therapeutic in long-term preclinical studies as a precursor to future clinical application in patients with disc degeneration and low back pain.

Cost Analysis of Spinal Versus General Anesthesia for Lumbar Diskectomy and Laminectomy Spine Surgery

BACKGROUND Lumbar spine surgery can be performed using various anesthetic modalities, most notably general or spinal anesthesia. Because data comparing the cost of these anesthetic modalities in spine surgery are scarce, this study asks whether spinal anesthesia is less costly than general anesthesia. METHODS A total of 542 patients who underwent elective lumbar diskectomy or laminectomy spine surgery between 2007 and 2011 were retrospectively identified, with 364 having received spinal anesthesia and 178 having received general anesthesia. Mean direct operating cost, indirect cost (general support staff, insurance, taxes, floor space, facility, and administrative costs), and total cost were compared among patients who received general and spinal anesthesia. Linear multiple regression analysis was used to identify the effect of anesthesia type on cost and determine the factors underlying this effect, while controlling for patient and procedure characteristics. RESULTS When controlling for patient and procedure characteristics, use of spinal anesthesia was associated with a 41.1% lower direct operating cost (-

Students to Surgeons: Increasing Matriculation in Surgical Specialties.

3629 ±

324 Neurosurgical Cost Containment Via Improved Physician Awareness.

343, P < 0.001), 36.6% lower indirect cost (-

Schizophrenia and neurosurgery: A dark past with hope of a brighter future

1603 ±

328 A Propensity-Based Analysis of the Use of Prothrombin Complex Concentrate Prior to Emergent Neurosurgical Procedures.

168, P < 0.001), and 39.6% lower total cost (-

Liver disease is an independent predictor of poor 30-day outcomes following surgery for degenerative disease of the cervical spine

5232 ±

A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures

482, P < 0.001) compared with general anesthesia. Shorter hospital stay, shorter duration of anesthesia, shorter duration of operation, and lower estimated blood loss contributed to lower costs for spinal anesthesia, but other factors beyond these were also responsible for lower direct operating and total costs. CONCLUSIONS When comparing the benefits of spinal and general anesthesia, spinal anesthesia is less costly when used in patients undergoing lumbar diskectomy and laminectomy spine surgery.

Reducing Surgical Infections and Implant Costs via a Novel Paradigm of Enhanced Physician Awareness

Introduction. Our nation suffers from a shortage in surgeons. This deficiency must be addressed at the medical student level. Increasing faculty and resident interaction with junior students augments surgical interest. Our surgical interest group has recently redefined its role to address these concerns. Methods. A multifocal approach has been implemented to increase interest in the surgical specialties. Each academic year, senior students recruit first and second year students to our group to establish early exposure. Members receive didactic presentations from surgical faculty, addressing various topics, on a biweekly basis. In addition, scrubbing, knot-tying, and suturing workshops address technical skills throughout the semester. Membership and match data were collated and analyzed. Results. Over the past 5 years, the enrollment in the student interest group increased significantly from 112 to 150. Accordingly, we have observed a parallel increase in the number of students who have successfully matched into surgical residencies. A record number of students (37) from the class of 2013 matched into surgical specialties, representing an 85% increase over the last decade. After creating bylaws and electing societal officers, the group has been recognized by the school’s Student Council and given financial support. At present, the group is fiscally solvent with support from the institution, surgery department, and faculty. Conclusion. As the demand for surgeons increases so too does the need to increase student interest in surgery. Our school has been successful because of our surgical interest group, and we encourage other schools to adopt a similar approach.

Risk-to-Benefit Ratio of Venous Thromboembolism Prophylaxis for Neurosurgical Procedures at a Quaternary Referral Center

INTRODUCTION Several studies in the literature have demonstrated that physicians are often unaware of prescription drug, laboratory, diagnostic, and surgical supply costs. Other studies have suggested that increased physician awareness of supply cost contributes to reduced overall cost. In this study, we investigated the effects of such increased awareness on neurosurgical cost containment. METHODS Within the Department of Neurological Surgery at the University of Pittsburgh Medical Center, physicians were informed of the prices of various ventricular shunt brands, such as the more expensive Medtronic shunts vs the more economic fixed Integra shunt. In addition, the costs of DuraGen vs alternative materials used during craniotomy such as Gelfoam were reviewed with faculty neurosurgeons. RESULTS The total supply cost of ventricular shunts in fiscal year 2015 was