Bio

Bio


Dr. Corinna Zygourakis specializes in comprehensive surgical care of the adult spine, and focuses on the treatment of complex spinal disorders, including spinal deformity, revision surgery, and spinal tumors. Dr. Zygourakis employs the latest minimally invasive, motion-sparing, and robotic surgical techniques to achieve the best outcomes for her patients. Her philosophy is to take care of patients with respect and compassion, as she would want her own family treated.

Dr. Zygourakis trained at the Johns Hopkins Hospital for her combined neurosurgery and orthopedic surgery complex spine fellowship, where she performed the first surgery internationally with the Globus Excelsius spinal robot. She completed her residency at the top-ranked neurosurgical program at the University of California, San Francisco, and obtained her M.D. degree cum laude from Harvard Medical School. Committed to serving and advocating for spine patients through her clinical, education, and research efforts, Dr. Zygourakis has published more than forty scientific articles and book chapters on healthcare costs, quality of neurosurgical care, and spine surgery.

Clinical Focus


  • Neurosurgery
  • Spinal Deformity Surgery
  • Spine Tumor Surgery
  • Minimally Invasive Spine Surgery
  • Robotic Spine Surgery
  • Spinal Cord Injury

Academic Appointments


Honors & Awards


  • High Impact Manuscript Award, Neurosurgery (2017)
  • Best Senior Resident Clinical Research Presentation, Resident Research Day, University of California, San Francisco (2016)
  • Excellence and Innovation Award in Graduate Medical Education, University of California, San Francisco (2016)
  • Sustainability Award from UCSF Chancellor for Project on OR Waste, University of California, San Francisco (2016)
  • UCSF Health "Great Save Award" from CEO for OR Surgical Cost Reduction Project, University of California, San Francisco (2016)
  • CTSI Catalyst Award, Development of Doctor Mobile App that Decreases Costs, University of California, San Francisco (2015)
  • Naffziger Award for Outstanding Neurosurgical Resident, University of California, San Francisco (2015)
  • UCSF Center for Healthcare Value Research Fellowship, University of California, San Francisco (2015)
  • Caring Wisely Grant, OR SCORE (OR Surgical Cost Reduction Project), University of California, San Francisco (2014)
  • Cum Laude, Harvard Medical School (2011)
  • Seidman Prize for Outstanding Senior HST Medical Student Thesis, Harvard Medical School (2011)
  • Howard Hughes Medical Institute Research Fellowship for Medical Students, Howard Hughes Medical Institute (2008-2009)
  • Paul and Daisy Soros National Fellowship for New Americans, Paul and Daisy Soros Foundation (2006-2008)
  • Mabel Beckman Award, Caltech Commencement Prize to Top Graduating Woman, California Institute of Technology (2006)
  • Jack E. Froehlich Award, Caltech Academic Prize to Top Junior, California Institute of Technology (2005)
  • Axline and Lingle Awards, Caltech Full-Tuition Merit Scholarships, California Institute of Technology (2002-2006)
  • Neuroscience Research Prize, American Academy of Neurology & Child Neurology Society (2002)
  • USA Today All-USA High School Academic First Team, USA Today (2002)
  • United States Presidential Scholar, U.S. Presidential Scholars Program (2002)

Professional Education


  • Fellowship:Johns Hopkins Neurosurgery Spine Fellowship (2018) MD
  • Residency:UCSF Neurological Surgery Residency (2017) CA
  • Medical Education:Harvard Medical School (2011) MA
  • Fellowship, Johns Hopkins Hospital, Complex Spine Fellowship, Depts of Neurosurgery & Orthopedic Surgery (2018)
  • Residency, University of California, San Francisco, Neurological Surgery (2017)
  • M.D., Harvard Medical School, Massachusetts Institute of Technology, Health Sciences and Technology Joint Program, Neuroscience Honors Thesis *Cum laude (2011)
  • Study Abroad, Cambridge University, Physiology (2005)
  • B.S., California Institute of Technology, Biology, English Literature *with honors (2006)

Research & Scholarship

Current Research and Scholarly Interests


My goal is to translate research into real-world action and decision-making so that my work can impact patients and the institutions in which they receive care. With a research focus on healthcare cost and quality of care, I approach neurosurgery in a unique way—one that applies business operations, economics, and healthcare delivery principles to our field. I have pursued formal LEAN business training, and believe in the importance of working together with other departments and administrators, as well as physicians and surgeons on the hospital and national level, to effect change. During my residency, I developed and led a multi-departmental prospective study at UCSF called OR SCORE (OR Surgical Cost Reduction Project) that brought together surgeons from the neurosurgery, orthopedics and ENT departments with nurses and administrators. OR SCORE successfully reduced surgical supply costs by nearly one million dollars in its first year by providing >60 surgeons with price transparency scorecards. This work led to a first-author publication in JAMA Surgery, but more importantly, set the foundation for further quality improvement and cost reduction efforts across the UCSF hospital system.

A volunteer neurosurgical mission trip to Guadalajara, Mexico, where limited resources create an OR environment that is strikingly more frugal than the U.S., inspired me to lead another project aimed at quantifying and reducing operating room waste at UCSF. I have also conducted research looking at the safety and outcomes of overlapping surgery, as well as several projects to define the factors underlying variation in cost for neurosurgical care using UCSF’s hospital data and national databases like the National Inpatient Sample, Vizient (formerly known as University Health Consortium), and Medicare.

As a clinical fellow at Johns Hopkins, I continued and expanded these research efforts. I designed and implemented an Enhanced Recovery after Surgery (ERAS) protocol at the Johns Hopkins Bayview hospital. This protocol standardized care for our spine patients, emphasizing pre-operative rehabilitation, psychiatric and nutritional assessments, and smoking cessation, as well as intra- and post-operative multi-modal pain therapy, early mobilization, and standardized antibiotic and bowel regimens. I also collaborated with engineers in the Johns Hopkins Carnegie Center for Surgical Innovation to develop better algorithms for intra-operative CT imaging, and provided assistance with operations to a basic science study looking at the role of cerebrospinal fluid drainage and duraplasty in a porcine model of spinal cord injury.

At Stanford, I am building a research group focused on: (1) perfecting paradigms for delivery of high-end technology in spinal care, including robotics and navigation, (2) implementing cost and quality strategies in large healthcare systems, and (3) computational analysis of big-data to effect real-time risk stratification and decision making in spine surgery. I'm excited to collaborate with my peers across surgical and medical departments, as well as business and engineering colleagues.

Publications

All Publications


  • Technique: open lumbar decompression and fusion with the Excelsius GPS robot. Neurosurgical focus Zygourakis, C. C., Ahmed, A. K., Kalb, S., Zhu, A. M., Bydon, A., Crawford, N. R., Theodore, N. 2018; 45 (VideoSuppl1): V6

    Abstract

    The Excelsius GPS (Globus Medical, Inc.) was approved by the FDA in 2017. This novel robot allows for real-time intraoperative imaging, registration, and direct screw insertion through a rigid external arm-without the need for interspinous clamps or K-wires. The authors present one of the first operative cases utilizing the Excelsius GPS robotic system in spinal surgery. A 75-year-old man presented with severe lower back pain and left leg radiculopathy. He had previously undergone 3 decompressive surgeries from L3 to L5, with evidence of instability and loss of sagittal balance. Robotic assistance was utilized to perform a revision decompression with instrumented fusion from L3 to S1. The usage of robotic assistance in spinal surgery may be an invaluable resource in minimally invasive cases, minimizing the need for fluoroscopy, or in those with abnormal anatomical landmarks. The video can be found here: https://youtu.be/yVI-sJWf9Iw .

    View details for DOI 10.3171/2018.7.FocusVid.18123

    View details for PubMedID 29963912

  • Association Between Surgeon Scorecard Use and Operating Room Costs. JAMA surgery Zygourakis, C. C., Valencia, V., Moriates, C., Boscardin, C. K., Catschegn, S., Rajkomar, A., Bozic, K. J., Soo Hoo, K., Goldberg, A. N., Pitts, L., Lawton, M. T., Dudley, R. A., Gonzales, R. 2017; 152 (3): 284–91

    Abstract

    Despite the significant contribution of surgical spending to health care costs, most surgeons are unaware of their operating room costs.To examine the association between providing surgeons with individualized cost feedback and surgical supply costs in the operating room.The OR Surgical Cost Reduction (OR SCORE) project was a single-health system, multihospital, multidepartmental prospective controlled study in an urban academic setting. Intervention participants were attending surgeons in orthopedic surgery, otolaryngology-head and neck surgery, and neurological surgery (n = 63). Control participants were attending surgeons in cardiothoracic surgery, general surgery, vascular surgery, pediatric surgery, obstetrics/gynecology, ophthalmology, and urology (n = 186).From January 1 to December 31, 2015, each surgeon in the intervention group received standardized monthly scorecards showing the median surgical supply direct cost for each procedure type performed in the prior month compared with the surgeon's baseline (July 1, 2012, to November 30, 2014) and compared with all surgeons at the institution performing the same procedure at baseline. All surgical departments were eligible for a financial incentive if they met a 5% cost reduction goal.The primary outcome was each group's median surgical supply cost per case. Secondary outcome measures included total departmental surgical supply costs, case mix index-adjusted median surgical supply costs, patient outcomes (30-day readmission, 30-day mortality, and discharge status), and surgeon responses to a postintervention study-specific health care value survey.The median surgical supply direct costs per case decreased 6.54% in the intervention group, from $1398 (interquartile range [IQR], $316-$5181) (10 637 cases) in 2014 to $1307 (IQR, $319-$5037) (11 820 cases) in 2015. In contrast, the median surgical supply direct cost increased 7.42% in the control group, from $712 (IQR, $202-$1602) (16 441 cases) in 2014 to $765 (IQR, $233-$1719) (17 227 cases) in 2015. This decrease represents a total savings of $836 147 in the intervention group during the 1-year study. After controlling for surgeon, department, patient demographics, and clinical indicators in a mixed-effects model, there was a 9.95% (95% CI, 3.55%-15.93%; P = .003) surgical supply cost decrease in the intervention group over 1 year. Patient outcomes were equivalent or improved after the intervention, and surgeons who received scorecards reported higher levels of cost awareness on the health care value survey compared with controls.Cost feedback to surgeons, combined with a small departmental financial incentive, was associated with significantly reduced surgical supply costs, without negatively affecting patient outcomes.

    View details for DOI 10.1001/jamasurg.2016.4674

    View details for PubMedID 27926758

  • Analysis of National Rates, Cost, and Sources of Cost Variation in Adult Spinal Deformity NEUROSURGERY Zygourakis, C. C., Liu, C. Y., Keefe, M., Moriates, C., Ratliff, J., Dudley, R., Gonzales, R., Mummaneni, P. V., Ames, C. P. 2018; 82 (3): 378–87

    Abstract

    Several studies suggest significant variation in cost for spine surgery, but there has been little research in this area for spinal deformity.To determine the utilization, cost, and factors contributing to cost for spinal deformity surgery.The cohort comprised 55 599 adults who underwent spinal deformity fusion in the 2001 to 2013 National Inpatient Sample database. Patient variables included age, gender, insurance, median income of zip code, county population, severity of illness, mortality risk, number of comorbidities, length of stay, elective vs nonelective case. Hospital variables included bed size, wage index, hospital type (rural, urban nonteaching, urban teaching), and geographical region. The outcome was total hospital cost for deformity surgery. Statistics included univariate and multivariate regression analyses.The number of spinal deformity cases increased from 1803 in 2001 (rate: 4.16 per 100 000 adults) to 6728 in 2013 (rate: 13.9 per 100 000). Utilization of interbody fusion devices increased steadily during this time period, while bone morphogenic protein usage peaked in 2010 and declined thereafter. The mean inflation-adjusted case cost rose from $32 671 to $43 433 over the same time period. Multivariate analyses showed the following patient factors were associated with cost: age, race, insurance, severity of illness, length of stay, and elective admission (P < .01). Hospitals in the western United States and those with higher wage indices or smaller bed sizes were significantly more expensive (P < .05).The rate of adult spinal deformity surgery and the mean case cost increased from 2001 to 2013, exceeding the rate of inflation. Both patient and hospital factors are important contributors to cost variation for spinal deformity surgery.

    View details for DOI 10.1093/neuros/nyx218

    View details for Web of Science ID 000439685800042

    View details for PubMedID 28486687

  • Implementation and Impact of a Hospital-Wide Instrument Set Review: Early Experiences at a Multisite Tertiary Care Academic Institution. American journal of medical quality : the official journal of the American College of Medical Quality Yoon, S., Zygourakis, C. C., Seaman, J., Zhu, M., Ahmed, A. K., Kliot, T., Antrum, S., Goldberg, A. N. 2018: 1062860618783261

    Abstract

    A multidisciplinary team of nurses, sterile processing technicians, and surgeons reviewed 609 otolaryngology-head and neck surgery (OHNS) surgical instrument sets at the study institution's 3 hospitals. Implementation of the 4-phase instrument review resulted in decreased OHNS surgical instrument set types from 261 to 234 sets, and a decreased number of instruments in these sets from 18 952 to 17 084. The instrument set review resulted in an estimated savings of $35 665 in sterile processing costs for the OHNS department. Instrument review applied to all 10 surgical specialties at the institution would result in an estimated annual savings of $425 378. Through effective leadership, multidisciplinary participation of all key stakeholders, and a systematic approach, this study demonstrates that a hospital-wide quality improvement intervention for instrument set optimization can be successfully performed in a large, multisite tertiary care academic hospital.

    View details for DOI 10.1177/1062860618783261

    View details for PubMedID 29936862

  • The Safety and Efficacy of CT-Guided, Fluoroscopy-Free Vertebroplasty in Adult Spinal Deformity Surgery. World neurosurgery Zygourakis, C. C., DiGiorgio, A. M., Crutcher, C. L., Safaee, M., Nicholls, F. H., Dalle Ore, C., Ahmed, A. K., Deviren, V., Ames, C. P. 2018; 116: e944–e950

    Abstract

    The goal of this study is to analyze the safety and efficacy of a novel technique of computed tomography-guided, fluoroscopy-free vertebroplasty as an adjunct to help prevent proximal junction kyphosis (PJK) in long-segment posterior spinal fusions.We performed a retrospective analysis of 118 consecutive patients with adult spinal deformity who underwent long-segment fusion with vertebroplasty augmentation from 2013-2016 at a single institution. For each patient, we collected demographics, surgical information, length of stay, discharge disposition, and complications, including reoperation, PJK, and PJK requiring reoperation. We reviewed all postoperative radiographs to assess for cement leakage from vertebroplasty. These patients were compared to a historical control of 253 patients who underwent adult spinal deformity surgery without vertebroplasty augmentation.The PJK rate of 14% and the PJK requiring reoperation rate of 3% in the cohort of 118 patients who underwent vertebroplasty-augmented fusion was significantly lower than that of the 253 historical controls at our institution who did not undergo vertebroplasty (40% PJK rate, 17% PJK-rate requiring reoperation; both P < 0.001). After controlling for patient and other surgical factors in multivariate analyses, vertebroplasty was significantly associated with lower rates of PJK and PJK requiring reoperation (P < 0.001 and P = 0.003).Our novel vertebroplasty technique is safe, and it eliminates the need for additional fluoroscopy in cases already using the O-arm to verify screw placement. In addition, it is an effective technique for reducing PJK in adult spinal deformity surgery compared with historical institutional controls.

    View details for DOI 10.1016/j.wneu.2018.05.139

    View details for PubMedID 29857213

  • Immediate improvement of intraoperative monitoring signals following CSF release for cervical spine stenosis: Case report. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Pennington, Z., Zygourakis, C., Ahmed, A. K., Kalb, S., Zhu, A., Theodore, N. 2018; 53: 235–37

    Abstract

    Cervical spondylotic myelopathy (CSM) is a degenerative pathology characterized by partial or complete conduction block on intraoperative neuromonitoring. We describe a case treated using osseoligamentous decompression and durotomy for cerebrospinal fluid (CSF) release. Intraoperative monitoring demonstrated immediate signal improvement with CSF release, suggesting that clinical improvement in CSM may result from resolution of CSF flow anomalies.

    View details for DOI 10.1016/j.jocn.2018.04.023

    View details for PubMedID 29716808

  • The unreimbursed costs of preventing revision surgery in adult spinal deformity: analysis of cost-effectiveness of proximal junctional failure prevention with ligament augmentation. Neurosurgical focus Safaee, M. M., Dalle Ore, C. L., Zygourakis, C. C., Deviren, V., Ames, C. P. 2018; 44 (5): E13

    Abstract

    OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized complication of surgery for adult spinal deformity and is characterized by increased kyphosis at the upper instrumented vertebra (UIV). PJK prevention strategies have the potential to decrease morbidity and cost by reducing rates of proximal junctional failure (PJF), which the authors define as radiographic PJK plus clinical sequelae requiring revision surgery. METHODS The authors performed an analysis of 195 consecutive patients with adult spinal deformity. Age, sex, levels fused, upper instrumented vertebra (UIV), use of 3-column osteotomy, pelvic fixation, and mean time to follow-up were collected. The authors also reviewed operative reports to assess for the use of surgical adjuncts targeted toward PJK prevention, including ligament augmentation, hook fixation, and vertebroplasty. The cost of surgery, including direct and total costs, was also assessed at index surgery and revision surgery. Only revision surgery for PJF was included. RESULTS The mean age of the cohort was 64 years (range 25-84 years); 135 (69%) patients were female. The mean number of levels fused was 10 (range 2-18) with the UIV as follows: 2 cervical (1%), 73 upper thoracic (37%), 108 lower thoracic (55%), and 12 lumbar (6%). Ligament augmentation was used in 99 cases (51%), hook fixation in 60 cases (31%), and vertebroplasty in 71 cases (36%). PJF occurred in 18 cases (9%). Univariate analysis found that ligament augmentation and hook fixation were associated with decreased rates of PJF. However, in a multivariate model that also incorporated age, sex, and UIV, only ligament augmentation maintained a significant association with PJF reduction (OR 0.196, 95% CI 0.050-0.774; p = 0.020). Patients with ligament augmentation, compared with those without, had a higher cost of index surgery, but ligament augmentation was overall cost effective and produced significant cost savings. In sensitivity analyses in which we independently varied the reduction in PJF, cost of ligament augmentation, and cost of reoperation by ± 50%, ligament augmentation remained a cost-effective strategy for PJF prevention. CONCLUSIONS Prevention strategies for PJK/PJF are limited, and their cost-effectiveness has yet to be established. The authors present the results of 195 patients with adult spinal deformity and show that ligament augmentation is associated with significant reductions in PJF in both univariate and multivariate analyses, and that this intervention is cost-effective. Future studies will need to determine if these clinical results are reproducible, but for high-risk cases, these data suggest an important role of ligament augmentation for PJF prevention and cost savings.

    View details for DOI 10.3171/2018.1.FOCUS17806

    View details for PubMedID 29712521

  • Center variation in episode-of-care costs for adult spinal deformity surgery: results from a prospective, multicenter database. The spine journal : official journal of the North American Spine Society Yeramaneni, S., Ames, C. P., Bess, S., Burton, D., Smith, J. S., Glassman, S., Gum, J. L., Carreon, L., Jain, A., Zygourakis, C., Avramis, I., Hostin, R. 2018; 18 (10): 1829–36

    Abstract

    Adult spinal deformity (ASD) surgery is associated with significant resource utilization, costing more than $958 million in charges for Medicare patients and more than $1.7 billion in charges for managed care population in the last decade. Given the recent move toward bundled payment models, it is important to understand the various care components a patient receives over the course of a defined clinical episode, its associated cost, and the proportion of cost for each component toward the bundled payment.To examine the degree and determinants of variation in inpatient episode-of-care (EOC) cost, resource utilization, and patient-reported outcomes for patients undergoing ASD surgery across four spine deformity centers in the United States.Retrospective analysis of prospective, multicenter database.Consecutive patients enrolled in an ASD database from four spinal deformity centers.Total in-patient EOC costs and Short Form (SF)-6D.The study used a multicenter database of 210 consecutively enrolled operative patients from 2008 to 2013 at four participating centers in the United States. Demographic, surgical, and direct cost data, expressed in 2013 dollars, for the entire inpatient EOC were obtained from administrative databases from the respective hospitals. Mixed models and multivariable linear regression were used to evaluate the impact of center on total costs adjusting for patient characteristics, length of stay (LOS), and surgical factors.A total of 126 patients with complete baseline and 2-year follow-up data were included. The percentages of patients from each center were 36.5%, 7.1%, 24.6%, and 31.7%. Overall, the mean patient age was 58.4±12.6 years, 86% were women, and 94% were Caucasian. The proportion of total cost variation explained by the center at which the patient was treated was 17%. After adjusting for patient, LOS, and surgical factors the cost variation reduced to 4%. In multivariable analysis, each additional level fused increased total cost variation by $2,500, whereas recombinant human bone morphogenetic protein-2 (BMP) use and posterior-only surgical approach lowered total EOC costs by $10,500 and $9,400, respectively. No significant difference was observed in 2-year quality-adjusted life year across centers.Total EOC costs for ASD surgery varied significantly by center. Levels fused, BMP use, and surgical approach were the primary drivers of cost variation across centers. Differences in resource utilization had no impact on 2-year quality-adjusted life year improvement across centers.

    View details for DOI 10.1016/j.spinee.2018.03.012

    View details for PubMedID 29578109

  • Trends in Utilization and Cost of Cervical Spine Surgery Using the National Inpatient Sample Database, 2001 to 2013 SPINE Liu, C. Y., Zygourakis, C. C., Yoon, S., Kliot, T., Moriates, C., Ratliff, J., Dudley, R., Gonzales, R., Mummaneni, P. V., Ames, C. P. 2017; 42 (15): E906–E913

    Abstract

    A retrospective review.The aim of this study was to determine national rates of cervical spine surgery and to examine factors that underlie cost variation.There has been an increase in the rate and cost of spinal surgery over the past decades, but there is little understanding of the drivers of cost variation at the national level.We analyzed 419,830 patients who underwent cervical spine surgery (anterior cervical fusion, posterior cervical fusion, posterior cervical decompression, combined anterior/posterior cervical fusion) for degenerative conditions in the 2001 to 2013 NIS database. We determined the rates of surgery by time and geographic region, and then created univariate and multivariate models to evaluate the effect of these factors on total hospital costs: patient age, gender, race, insurance, income, county of residence, elective versus nonelective case, length of stay, risk of mortality, severity of illness, hospital bed size, wage index, hospital type, and geographic region.The most common type of cervical spine surgery was anterior fusion (80.6% of all surgeries). The national rates of all cervical spine surgery decreased slightly from 2001 to 2013 (75.34 to 72.20 per 100,000 adults), while the mean inflation-adjusted cost increased 64%, from $11,799 to $19,379, during this time period. Multivariate analyses showed that older age, male gender, black/other race, private insurance, greater risk of mortality/severity of illness, and longer length of stay were associated with higher costs. The wage index was positively correlated with cost, and hospitals in the western U.S. were 27% more expensive than those in the Northeast.The rate of cervical spine surgery decreased slightly, while the mean case cost increased at a rate double that of inflation from 2001 to 2013. Even after controlling for patient and hospital factors including wage index, there was significant geographic variation in the cost for cervical spine surgery.3.

    View details for DOI 10.1097/BRS.0000000000001999

    View details for Web of Science ID 000406277300005

    View details for PubMedID 28562473

  • Geographic and Hospital Variation in Cost of Lumbar Laminectomy and Lumbar Fusion for Degenerative Conditions NEUROSURGERY Zygourakis, C. C., Liu, C. Y., Wakam, G., Moriates, C., Boscardin, C., Ames, C. P., Mummaneni, P. V., Ratliff, J., Dudley, R., Gonzales, R. 2017; 81 (2): 331–40

    Abstract

    Spinal surgery costs vary significantly across hospitals and regions, but there is insufficient understanding of what drives this variation.To examine the factors underlying the cost variation for lumbar laminectomy/discectomy and lumbar fusions.We obtained patient information (age, gender, race, severity of illness, risk of mortality, population of county of residence, median zipcode income, insurance status, elective vs nonelective admission, length of stay) and hospital data (region, hospital type, bed size, wage index) for all patients who underwent lumbar laminectomy/discectomy (n = 181 267) or lumbar fusions (n = 433 364) for degenerative conditions in the 2001 to 2013 National Inpatient Sample database. We performed unadjusted and adjusted analyses to determine which factors affect cost.Mean costs for lumbar laminectomy/discectomy and lumbar fusion increased from $8316 and $21 473 in 2001 (in inflation-adjusted 2013 dollars), to $11 405 and $29 438, respectively, in 2013. There was significant regional variation in cost, with the West being the most expensive region across all years and showing the steepest increase in cost over time. After adjusting for patient and hospital factors, the West was 23% more expensive than the Northeast for lumbar laminectomy/discectomy, and 25% more expensive than the Northeast for lumbar fusion ( P < .01). Higher wage index, smaller hospital bed size, and rural/urban nonteaching hospital type were also associated with higher cost for lumbar laminectomy/discectomy and fusion ( P < .01).After adjusting for patient factors and wage index, the Western region, hospitals with smaller bed sizes, and rural/urban nonteaching hospitals were associated with higher costs for lumbar laminectomy/discectomy and lumbar fusion.

    View details for DOI 10.1093/neuros/nyx047

    View details for Web of Science ID 000406145100039

    View details for PubMedID 28327960

  • Analysis of Cost Variation in Craniotomy for Tumor Using 2 National Databases. Neurosurgery Zygourakis, C. C., Liu, C. Y., Yoon, S., Moriates, C., Boscardin, C., Dudley, R. A., Lawton, M. T., Theodosopoulos, P., Berger, M. S., Gonzales, R. 2017; 81 (6): 972–79

    Abstract

    There is a significant increase and large variation in craniotomy costs. However, the causes of cost differences in craniotomies remain poorly understood.To examine the patient and hospital factors that underlie the cost variation in tumor craniotomies using 2 national databases: the National Inpatient Sample (NIS) and Vizient, Inc. (Irving, Texas).For 41 483 patients who underwent primary surgery for supratentorial brain tumors from 2001 to 2013 in the NIS, we created univariate and multivariate models to evaluate the effect of several patient factors and hospital factors on total hospital cost. Similarly, we performed multivariate analysis with 15 087 cases in the Vizient 2012 to 2015 database.In the NIS, the mean inflation-adjusted cost per tumor craniotomy increased 30%, from $23 021 in 2001 to $29 971 in 2013. In 2001, the highest cost region was the Northeast ($24 486 ± $1184), and by 2013 the western United States was the highest cost region ($36 058 ± $1684). Multivariate analyses with NIS data showed that male gender, white race, private insurance, higher mortality risk, higher severity of illness, longer length of stay, elective admissions, higher wage index, urban teaching hospitals, and hospitals in the western United States were associated with higher tumor craniotomy costs (all P < .05). Multivariate analyses with Vizient data confirmed that longer length of stay and the western United States were significantly associated with higher costs (P < .001).After controlling for patient/clinical factors, hospital type, bed size, and wage index, hospitals in the western United States had higher costs than those in other parts of the country, based on analyses from 2 separate national databases.

    View details for DOI 10.1093/neuros/nyx133

    View details for PubMedID 28402457

  • Clinical utility and cost analysis of routine postoperative head CT in elective aneurysm clippings. Journal of neurosurgery Zygourakis, C. C., Winkler, E., Pitts, L., Hannegan, L., Franc, B., Lawton, M. T. 2017; 126 (2): 558–63

    Abstract

    OBJECTIVE Postoperative head CT scanning is performed routinely at the authors' institution on all neurosurgical patients after elective aneurysm clippings. The goal of this study was to determine how often these scans influence medical management and to quantify the associated imaging costs. METHODS The authors reviewed the medical records and accounting database of 304 patients who underwent elective (i.e., nonruptured) aneurysm clipping performed by 1 surgeon (M.T.L.) from 2010 to 2014 at the University of California, San Francisco. Specifically, the total number of postoperative head CT scans, radiographic findings, and the effect of these studies on patient management were determined. The authors obtained the total hospital costs for these patients, including the cost of imaging studies, from the hospital accounting database. RESULTS Overall, postoperative CT findings influenced clinical management in 3.6% of cases; specifically, they led to permissive hypertension in 4 patients for possible ischemia, administration of mannitol for edema and high-flow oxygen for pneumocephalus in 2 patients each, seizure prophylaxis in 1 patient, Plavix readjustment in 1 patient, and return to the operating room for an asymptomatic epidural hematoma evacuation in 1 patient. When patients were stratified on the basis of postoperative neurological examination, findings on CT scans altered management in 1.1%, 4.8%, and 9.0% of patients with no new neurological deficits, a nonfocal examination, and focal deficits, respectively. The mean total hospital cost for treating patients who undergo elective aneurysm clipping was $72,227 (± $53,966) (all values are US dollars), and the cost of obtaining a noncontrast head CT scan was $292. Neurologically intact patients required 99 head CT scans, at a cost of $28,908, to obtain 1 head CT scan that influenced medical management. In contrast, patients with a focal neurological deficit required only 11 head CT scans, at a cost of $3212, to obtain 1 head CT scan that changed clinical management. CONCLUSIONS Although there are no clear guidelines, the large number and high cost of CT scans needed to treat neurologically intact elective aneurysm patients suggest that careful neurological monitoring may be more clinically useful and a better use of hospital resources than routine postoperative CT.

    View details for DOI 10.3171/2016.1.JNS152242

    View details for PubMedID 27128595

  • Operating room waste: disposable supply utilization in neurosurgical procedures. Journal of neurosurgery Zygourakis, C. C., Yoon, S., Valencia, V., Boscardin, C., Moriates, C., Gonzales, R., Lawton, M. T. 2017; 126 (2): 620–25

    Abstract

    OBJECTIVE Disposable supplies constitute a large portion of operating room (OR) costs and are often left over at the end of a surgical case. Despite financial and environmental implications of such waste, there has been little evaluation of OR supply utilization. The goal of this study was to quantify the utilization of disposable supplies and the costs associated with opened but unused items (i.e., "waste") in neurosurgical procedures. METHODS Every disposable supply that was unused at the end of surgery was quantified through direct observation of 58 neurosurgical cases at the University of California, San Francisco, in August 2015. Item costs (in US dollars) were determined from the authors' supply catalog, and statistical analyses were performed. RESULTS Across 58 procedures (36 cranial, 22 spinal), the average cost of unused supplies was $653 (range $89-$3640, median $448, interquartile range $230-$810), or 13.1% of total surgical supply cost. Univariate analyses revealed that case type (cranial versus spinal), case category (vascular, tumor, functional, instrumented, and noninstrumented spine), and surgeon were important predictors of the percentage of unused surgical supply cost. Case length and years of surgical training did not affect the percentage of unused supply cost. Accounting for the different case distribution in the 58 selected cases, the authors estimate approximately $968 of OR waste per case, $242,968 per month, and $2.9 million per year, for their neurosurgical department. CONCLUSIONS This study shows a large variation and significant magnitude of OR waste in neurosurgical procedures. At the authors' institution, they recommend price transparency, education about OR waste to surgeons and nurses, preference card reviews, and clarification of supplies that should be opened versus available as needed to reduce waste.

    View details for DOI 10.3171/2016.2.JNS152442

    View details for PubMedID 27153160

  • Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas. Journal of neurological surgery. Part B, Skull base Zygourakis, C. C., Imber, B. S., Chen, R., Han, S. J., Blevins, L., Molinaro, A., Kahn, J. G., Aghi, M. K. 2017; 78 (2): 125–31

    Abstract

    Background Few studies address the cost of treating prolactinomas. We performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings.

    View details for DOI 10.1055/s-0036-1592193

    View details for PubMedID 28321375

    View details for PubMedCentralID PMC5357228

  • Comparison of Patient Outcomes in 3725 Overlapping vs 3633 Nonoverlapping Neurosurgical Procedures Using a Single Institution's Clinical and Administrative Database. Neurosurgery Zygourakis, C. C., Keefe, M., Lee, J., Barba, J., McDermott, M. W., Mummaneni, P. V., Lawton, M. T. 2017; 80 (2): 257–68

    Abstract

    Overlapping surgery is a common practice to improve surgical efficiency, but there are limited data on its safety.To analyze the patient outcomes of overlapping vs nonoverlapping surgeries performed by multiple neurosurgeons.Retrospective review of 7358 neurosurgical procedures, 2012 to 2015, at an urban academic hospital. Collected variables: patient age, gender, insurance, American Society of Anesthesiologists score, severity of illness, mortality risk, admission type, transfer source, procedure type, surgery date, number of cosurgeons, presence of neurosurgery resident/fellow/another attending, and overlapping vs nonoverlapping surgery. Outcomes: procedure time, length of stay, estimated blood loss, discharge location, 30-day mortality, 30-day readmission, return to operating room, acute respiratory failure, and severe sepsis. Statistics: univariate, then multivariate mixed-effect models.Overlapping surgery patients (n = 3725) were younger and had lower American Society of Anesthesiologists scores, severity of illness, and mortality risk (P < .0001) than nonoverlapping surgery patients (n = 3633). Overlapping surgeries had longer procedure times (214 vs 172 min; P < .0001), but shorter length of stay (7.3 vs 7.9 d; P = .010) and lower estimated blood loss (312 vs 363 mL’s; P = .003). Overlapping surgery patients were more likely to be discharged home (73.6% vs 66.2%; P < .0001), and had lower mortality rates (1.3% vs 2.5%; P = .0005) and acute respiratory failure (1.8% vs 2.6%; P = .021). In multivariate models, there was no significant difference between overlapping and nonoverlapping surgeries for any patient outcomes, except for procedure duration, which was longer in overlapping surgery (estimate = 23.03; P < .001).When planned appropriately, overlapping surgery can be performed safely within the infrastructure at our academic institution.

    View details for DOI 10.1093/neuros/nyw067

    View details for PubMedID 28173545

  • Comparison of Patient Outcomes and Cost of Overlapping Versus Nonoverlapping Spine Surgery. World neurosurgery Zygourakis, C. C., Sizdahkhani, S., Keefe, M., Lee, J., Chou, D., Mummaneni, P. V., Ames, C. P. 2017; 100: 658–64.e8

    Abstract

    Overlapping surgery recently has gained significant media attention, but there are limited data on its safety and efficacy. To date, there has been no analysis of overlapping surgery in the field of spine. Our goal was to compare overlapping versus nonoverlapping spine surgery patient outcomes and cost.A retrospective review was undertaken of 2319 spine surgeries (n = 848 overlapping; 1471 nonoverlapping) performed by 3 neurosurgery attendings from 2012 to 2015 at the University of California San Francisco. Collected variables included patient age, sex, insurance, American Society of Anesthesiology score, severity of illness, risk of mortality, procedure type, surgeon, day of surgery, source of transfer, admission type, overlapping versus nonoverlapping surgery (≥1 minute of overlapping procedure time), Medicare-Severity Diagnosis-Related Group, osteotomy, and presence of another attending/fellow/resident. Univariate, then multivariate mixed-effect models were used to evaluate the effect of the collected variables on the following outcomes: procedure time, estimated blood loss, length of stay, discharge status, 30-day mortality, 30-day unplanned readmission, unplanned return to OR, and total hospital cost.Urgent spine cases were more likely to be done in an overlapping fashion (all P < 0.01). After we adjusted for patient demographics, clinical indicators, and procedure characteristics, overlapping surgeries had longer procedure times (estimate = 26.17; P < 0.001) and lower rates of discharge to home (odds ratio 0.65; P < 0.001), but equivalent rates of 30-day mortality, readmission, return to the operating room, estimated blood loss, length of stay, and total hospital cost (all P = ns).Overlapping spine surgery may be performed safely at our institution, although continued monitoring of patient outcomes is necessary. Overlapping surgery does not lead to greater hospital costs.

    View details for DOI 10.1016/j.wneu.2017.01.064

    View details for PubMedID 28137549

  • Performing concurrent operations in academic vascular neurosurgery does not affect patient outcomes. Journal of neurosurgery Zygourakis, C. C., Lee, J., Barba, J., Lobo, E., Lawton, M. T. 2017; 127 (5): 1089–95

    Abstract

    OBJECTIVE Concurrent surgeries, also known as "running two rooms" or simultaneous/overlapping operations, have recently come under intense scrutiny. The goal of this study was to evaluate the operative time and outcomes of concurrent versus nonconcurrent vascular neurosurgical procedures. METHODS The authors retrospectively reviewed 1219 procedures performed by 1 vascular neurosurgeon from 2012 to 2015 at the University of California, San Francisco. Data were collected on patient age, sex, severity of illness, risk of mortality, American Society of Anesthesiologists (ASA) status, procedure type, admission type, insurance, transfer source, procedure time, presence of resident or fellow in operating room (OR), number of co-surgeons, estimated blood loss (EBL), concurrent vs nonconcurrent case, severe sepsis, acute respiratory failure, postoperative stroke causing neurological deficit, unplanned return to OR, 30-day mortality, and 30-day unplanned readmission. For aneurysm clipping cases, data were also obtained on intraoperative aneurysm rupture and postoperative residual aneurysm. Chi-square and t-tests were performed to compare concurrent versus nonconcurrent cases, and then mixed-effects models were created to adjust for different procedure types, patient demographics, and clinical indicators between the 2 groups. RESULTS There was a significant difference in procedure type for concurrent (n = 828) versus nonconcurrent (n = 391) cases. Concurrent cases were more likely to be routine/elective admissions (53% vs 35%, p < 0.001) and physician referrals (59% vs 38%, p < 0.001). This difference in patient/case type was also reflected in the lower severity of illness, risk of death, and ASA class in the concurrent versus nonconcurrent cases (p < 0.01). Concurrent cases had significantly longer procedural times (243 vs 213 minutes) and more unplanned 30-day readmissions (5.7% vs 3.1%), but shorter mean length of hospital stay (11.2 vs 13.7 days), higher rates of discharge to home (66% vs 51%), lower 30-day mortality rates (3.1% vs 6.1%), lower rates of acute respiratory failure (4.3% vs 8.2%), and decreased 30-day unplanned returns to the OR (3.3% vs 6.9%; all p < 0.05). Rates of severe sepsis, postoperative stroke, intraoperative aneurysm rupture, and postoperative aneurysm residual were equivalent between the concurrent and nonconcurrent groups (all p values nonsignificant). Mixed-effects models showed that after controlling for procedure type, patient demographics, and clinical indicators, there was no significant difference in acute respiratory failure, severe sepsis, 30-day readmission, postoperative stroke, EBL, length of stay, discharge status, or intraoperative aneurysm rupture between concurrent and nonconcurrent cases. Unplanned return to the OR and 30-day mortality were significantly lower in concurrent cases (odds ratio 0.55, 95% confidence interval 0.31-0.98, p = 0.0431, and odds ratio 0.81, p < 0.001, respectively), but concurrent cases had significantly longer procedure durations (odds ratio 21.73; p < 0.001). CONCLUSIONS Overall, there was a significant difference in the types of concurrent versus nonconcurrent cases, with more routine/elective cases for less sick patients scheduled in an overlapping fashion. After adjusting for patient demographics, procedure type, and clinical indicators, concurrent cases had longer procedure times, but equivalent patient outcomes, as compared with nonconcurrent vascular neurosurgical procedures.

    View details for DOI 10.3171/2016.6.JNS16822

    View details for PubMedID 28106498

  • Sexual function after cervical spine surgery: Independent predictors of functional impairment. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Keefe, M. K., Zygourakis, C. C., Theologis, A. A., Canepa, E., Shaw, J. D., Goldman, L. H., Burch, S., Berven, S., Chou, D., Tay, B., Mummaneni, P., Deviren, V., Ames, C. P. 2017; 36: 94–101

    Abstract

    Sexual function (SF) is an important component of patient-focused health related quality of life (HRQoL), but it has not been well studied in spine surgery. This study aims to assess SF after cervical spine surgery and identify predictors of SF. This single-center retrospective study evaluates SF of adults who underwent cervical spine surgery 2007-2012. Predictor variables included demographics, medical/surgical history, operative information, HRQoL measures (Neck Disability Index, SF-12), validated SF surveys [Female Sexual Function Index (FSFI) and Brief Sexual Function Inventory (BSFI) for males], and a study-specific SF questionnaire. 59 patients (31M, 28F; mean age=56±8.4) had significantly lower SF scores compared to age-matched peers: average BSFI = 2.26±1.22 (vs. 06±0.74), average FSFI=13.05±11.42 (<26.55 indicating sexual dysfunction). In men, lower mental SF-12 and higher NDI, back pain, and number of operated levels were associated with lower BSFI scores (all p<0.05). In women, higher total number of medications and pain medications were associated with lower FSFI scores (both p<0.05). 46% of patients reported difficulty performing a sexual position after surgery that they had previously enjoyed. 39% of men had difficulty on top during intercourse, and 32% of participants reported difficulty performing oral sex. 39% of patients reported worse SF, while only 5% reported an improvement in postoperative SF. Men and women who underwent cervical spine surgery had lower SF scores than age-matched peers, likely attributable to general mental health, regional neck disability, back pain, and medications. A large portion of patients reported subjectively worsened SF after surgery.

    View details for DOI 10.1016/j.jocn.2016.10.017

    View details for PubMedID 27825608

  • Developing an algorithm for cost-effective, clinically judicious management of peripheral nerve tumors. Surgical neurology international Birk, H., Zygourakis, C. C., Kliot, M. 2016; 7: 80

    Abstract

    Peripheral nerve tumors such as neurofibromas and schwannomas have become increasingly identified secondary to improved imaging modalities including magnetic resonance neurogram and ultrasound. Given that a majority of these peripheral nerve tumors are benign lesions, it becomes important to determine appropriate management of such asymptomatic masses. We propose a normal cost-effective management paradigm for asymptomatic peripheral nerve neurofibromas and schwannomas that has been paired with economic analyses. Specifically, our management paradigm identifies patients who would benefit from surgery for asymptomatic peripheral nerve tumors, while providing cost-effective recommendations regarding clinical exams and serial imaging for such patients.

    View details for DOI 10.4103/2152-7806.189299

    View details for PubMedID 27625890

    View details for PubMedCentralID PMC5009575

  • Predictors of Variation in Neurosurgical Supply Costs and Outcomes Across 4904 Surgeries at a Single Institution. World neurosurgery Zygourakis, C. C., Valencia, V., Boscardin, C., Nayak, R. U., Moriates, C., Gonzales, R., Theodosopoulos, P., Lawton, M. T. 2016; 96: 177–83

    Abstract

    There is high variability in neurosurgical costs, and surgical supplies constitute a significant portion of cost. Anecdotally, surgeons use different supplies for various reasons, but there is little understanding of how supply choices affect outcomes. Our goal is to evaluate the effect of patient, procedural, and provider factors on supply cost and to determine if supply cost is associated with patient outcomes.We obtained patient information (age, gender, payor, case mix index [CMI], body mass index, admission source), procedural data (procedure type, length, date), provider information (name, case volume), and total surgical supply cost for all inpatient neurosurgical procedures from 2013 to 2014 at our institution (n = 4904). We created mixed-effect models to examine the effect of each factor on surgical supply cost, 30-day readmission, and 30-day mortality.There was significant variation in surgical supply cost between and within procedure types. Older age, female gender, higher CMI, routine/elective admission, longer procedure, and larger surgeon volume were associated with higher surgical supply costs (P < 0.05). Routine/elective admission and higher surgeon volume were associated with lower readmission rates (odds ratio, 0.707, 0.998; P < 0.01). Only patient factors of older age, male gender, private insurance, higher CMI, and emergency admission were associated with higher mortality (odds ratio, 1.029, 1.700, 1.692, 1.080, 2.809). There was no association between surgical supply cost and readmission or mortality (P = 0.307, 0.548).A combination of patient, procedural, and provider factors underlie the significant variation in neurosurgical supply costs at our institution. Surgical supply costs are not correlated with 30-day readmission or mortality.

    View details for DOI 10.1016/j.wneu.2016.08.121

    View details for PubMedID 27613498

  • Economic Impact of Revision Surgery for Proximal Junctional Failure After Adult Spinal Deformity Surgery: A Cost Analysis of 57 Operations in a 10-year Experience at a Major Deformity Center. Spine Theologis, A. A., Miller, L., Callahan, M., Lau, D., Zygourakis, C., Scheer, J. K., Burch, S., Pekmezci, M., Chou, D., Tay, B., Mummaneni, P., Berven, S., Deviren, V., Ames, C. P. 2016; 41 (16): E964–72

    Abstract

    Retrospective cohort analysis.To evaluate the economic impact of revision surgery for proximal junctional failures (PJF) after thoracolumbar fusions for adult spinal deformity (ASD).PJF after fusions for ASD is a major cause of disability. Although clinical sequelae are described, PJF-revision operation costs are incompletely defined.Consecutive adults who underwent thoracolumbar fusions for ASD (August, 2003 to January, 2013) were evaluated. Inclusion criteria include construct from pelvis to L2 or above and minimum 6 months follow-up after the index ASD operation. Direct costs (surgical supplies/implants, room/care, pharmacy, services) were identified from medical billing data and calculated for index ASD operations and subsequent surgeries for PJF. Not included in direct cost data were indirect costs, charges, surgeon fees, or revision operations for indications other than PJF (i.e., pseudarthrosis). Patients were compared based on the construct's upper-instrumented vertebra: upper thoracic (UT: T1-6) versus thoracolumbar junction (TLjxn: T9-L2).Of 501 patients, 382 met inclusion criteria. Fifty-one patients [UT:14; TLjxn: 40 at index; average follow-up 32.6 months (6-92 months)] had revisions for PJF, which summed to $3.2 million total direct cost. Average direct cost of index operations for the cohort ($68,294) was significantly greater than PJF-revisions ($55,547). Compared with TLjxn, UT had a significantly higher average cost for index operations ($79,860 vs. $65,868). However, PJF-revision cases were similar in average cost (UT:$60,103; TLjxn:$53,920; P = 0.09). Costs of PJF amounted to an additional 12.1% of the total index surgical cost in 382 patients.Revision operations for PJF after long thoracolumbar fusions for ASD are associated with an average direct cost of $55,547 per case. Revision costs for PJF are similar based on the index procedure's upper-instrumented vertebra level. At a major tertiary center over a 10-year period, PJF came at a very significant economic expense amounting to $3.2 million for 57 cases.3.

    View details for DOI 10.1097/BRS.0000000000001523

    View details for PubMedID 26909838

  • Preventing Delays in First-Case Starts on the Neurosurgery Service: A Resident-Led Initiative at an Academic Institution. Journal of surgical education Han, S. J., Rolston, J. D., Zygourakis, C. C., Sun, M. Z., McDermott, M. W., Lau, C. Y., Aghi, M. K. 2016; 73 (2): 291–95

    Abstract

    On-time starts for the first case of the day are critical to maintaining efficiency in operating rooms (ORs). We studied whether a resident-led initiative to ensure on-time site marking and documentation of surgical consent could lead to improved first-case start time.In a resident-led initiative at a large 600-bed academic hospital with 25 ORs, we aimed to complete site marking and surgical consents half an hour before the scheduled start time for all first-case neurosurgical patients. We monitored the occurrence of delayed first starts and the length of delay during our initiative, and compared these cases to neurosurgical cases 3 months before the implementation of the initiative and to first-start nonneurosurgical cases.In the year of the initiative, both site marking and surgical consents were completed 30 minutes before the case start in 97% of neurosurgical cases. The average delay across all first-case starts was reduced to 7.17 minutes (N = 1271), compared with 9.67 minutes before the intervention (N = 345). During the study period, non-neurosurgical cases were delayed on average 10.3 minutes (N = 3592). There was a significant difference in latencies between the study period and the period before the initiative (p < 0.001), and also between neurosurgical cases and nonneurosurgical cases (p < 0.001). There was no reduction in delay times seen on the non-neurosurgical services in the study period when compared to the case 3 months before. Considering its effect across 1271 cases, this initiative over 1 year resulted in a total reduction of 52 hours and 57 minutes in delays.Through a resident-led quality improvement program, neurosurgical trainees successfully reduced delays in first-case starts on a surgical service. Engaging physician trainees in quality improvement and enhancing OR efficiency can be successfully achieved and can have a significant clinical and financial effect.

    View details for DOI 10.1016/j.jsurg.2015.09.018

    View details for PubMedID 26774935

  • The impact of a patient education bundle on neurosurgery patient satisfaction. Surgical neurology international Kliot, T., Zygourakis, C. C., Imershein, S., Lau, C., Kliot, M. 2015; 6 (Suppl 22): S567–72

    Abstract

    As reimbursements and hospital/physician performance become ever more reliant on Hospital Consumer Assessment of Health Care Providers and Systems (HCAHPS) and other quality metrics, physicians are increasingly incentivized to improve patient satisfaction.A faculty and resident team at the University of California, San Francisco (UCSF) Department of Neurological Surgery developed and implemented a Patient Education Bundle. This consisted of two parts: The first was preoperative expectation letters (designed to inform patients of what to expect before, during, and after their hospitalization for a neurosurgical procedure); the second was a trifold brochure with names, photographs, and specialty/training information about the attending surgeons, resident physicians, and nurse practitioners on the neurosurgical service. We assessed patient satisfaction, as measured by HCAHPS scores and a brief survey tailored to our specific intervention, both before and after our Patient Education Bundle intervention.Prior to our intervention, 74.6% of patients responded that the MD always explained information in a way that was easy to understand. After our intervention, 78.7% of patients responded that the MD always explained information in a way that was easy to understand. "Neurosurgery Patient Satisfaction survey" results showed that 83% remembered receiving the preoperative letter; of those received the letter, 93% found the letter helpful; and 100% thought that the letter should be continued.Although effects were modest, we believe that patient education strategies, as modeled in our bundle, can improve patients' hospital experiences and have a positive impact on physician performance scores and hospital ratings.

    View details for DOI 10.4103/2152-7806.169538

    View details for PubMedID 26664909

    View details for PubMedCentralID PMC4653328

  • Pituicytomas and spindle cell oncocytomas: modern case series from the University of California, San Francisco. Pituitary Zygourakis, C. C., Rolston, J. D., Lee, H. S., Partow, C., Kunwar, S., Aghi, M. K. 2015; 18 (1): 150–58

    Abstract

    Pituicytomas and spindle cell oncocytomas (SCOs) are extremely rare neoplasms of the sellar and suprasellar region that can often mimic pituitary adenomas. To date, there are relatively few cases of pituicytomas and SCOs reported; and most of these are small case series.In this paper, we provide a retrospective review of the treatment, imaging characteristics, post-operative course, and histopathology of five cases of pituicytomas and two SCOs treated at the University of California, San Francisco (UCSF) over a 10-year period from 2003 to 2013.We find that pituicytomas and SCOs present similarly to pituitary adenomas, and look identical on CT or MR imaging. We histopathologically confirmed all pituicytomas with a combination of hematoxylin and eosin morphology and immunohistochemical positivity for vimentin and S100; SCOs stain for anti-mitochondrial antigen and endothelial membrane antigen. We observe positive thyroid transcription factor 1 (TTF1) immunohistochemistry in both cases of SCO, as well as in both of the cases of pituicytoma in which TTF1 staining was available.This represents the largest single-institution case series of pituicytomas and SCOs to date, and also includes the first description of the management of a pregnant female with SCO. Our findings are consistent with the idea of common histogenesis for pituicytomas and SCOs, and also raise the possibility of more aggressive growth in SCOs as compared to pituicytomas.

    View details for DOI 10.1007/s11102-014-0568-7

    View details for PubMedID 24823438

  • Management of central nervous system teratoma. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Davis, J. L., Kaur, G., Ames, C. P., Gupta, N., Auguste, K. I., Parsa, A. T. 2015; 22 (1): 98–104

    Abstract

    Central nervous system (CNS) teratomas are very rare neoplasms that contain tissues derived from all three germ cell layers (endoderm, mesoderm, and ectoderm). Patients with teratomas usually have a good prognosis. Given the paucity of cases in the literature, we present a retrospective review of 15 CNS teratomas treated over a 25 year period at the University of California, San Francisco. We describe the presentation, location, treatment, and adjuvant therapy for these patients, and highlight three unique cases that emphasize the diverse presentation and treatment of these rare tumors.

    View details for DOI 10.1016/j.jocn.2014.03.039

    View details for PubMedID 25150764

  • Transient pupillary dilation following local papaverine application in intracranial aneurysm surgery. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Vasudeva, V., Lai, P. M., Kim, A. H., Wang, H., Du, R. 2015; 22 (4): 676–79

    Abstract

    Isolated cases of transient pupillary changes after local intracisternal papaverine administration during aneurysm surgery have been reported. This study aimed to determine the prevalence and factors associated with this phenomenon. We assessed a total of 103 consecutive patients who underwent craniotomy for cerebral aneurysm clipping for the presence of postoperative pupillary dilation (mydriasis) after intracisternal papaverine administration. Univariate and multivariate logistic regression were conducted to evaluate the association of mydriasis with patient age, sex, duration of surgery, and aneurysm location. We observed either ipsilateral or bilateral pupillary dilation in the immediate postoperative period in nine out of 103 patients (8.7%). This phenomenon was not associated with patient age or sex. There was a trend towards positive correlation with aneurysms located at the anterior communicating artery (odds ratio 3.76, p=0.10), and a negative correlation with the duration of surgery (odds ratio 0.57, p=0.08). All pupillary dilation resolved within several hours, and the onset and resolution were consistent with the half-life of papaverine. To our knowledge, this represents the largest study of posteropative pupillary changes due to papaverine. The current findings are consistent with the small number of prior case reports of transient pupillary changes after papaverine administration and appear to reflect the local anesthetic action of papaverine on the oculomotor nerve.

    View details for DOI 10.1016/j.jocn.2014.10.016

    View details for PubMedID 25564265

  • Cost-effectiveness research in neurosurgery. Neurosurgery clinics of North America Zygourakis, C. C., Kahn, J. G. 2015; 26 (2): 189–96, viii

    Abstract

    Cost and value are increasingly important components of health care discussions. Despite a plethora of cost and cost-effectiveness analyses in many areas of medicine, there has been little of this type of research for neurosurgical procedures. This scarcity is vexing because this specialty represents one of the most expensive areas in medicine. This article discusses the general principles of cost-effectiveness analyses and reviews the cost- and cost-effectiveness-related research to date in neurosurgical subspecialties. The need for standardization of cost and cost-effectiveness measurement and reporting within neurosurgery is highlighted and a set of metrics for this purpose is defined.

    View details for DOI 10.1016/j.nec.2014.11.008

    View details for PubMedID 25771274

  • Cervical Fracture Stabilization within 72 Hours of Injury is Associated with Decreased Hospitalization Costs with Comparable Perioperative Outcomes in a Propensity Score-Matched Cohort. Cureus Medress, Z., Arrigo, R. T., Hayden Gephart, M., Zygourakis, C. C., Boakye, M. 2015; 7 (1)

    Abstract

    Prior studies have indicated that early decompression of traumatic cervical fractures can be performed safely and is associated with improved outcomes, though the economic impact of the timing of surgery in the American population has not been studied. After adjusting for patient, hospital, and injury confounders, we performed propensity score modeling (PSM) on a large clinical administrative database to determine associated costs depending upon timing of surgery for acute cervical fracture.A total of 3,348 patients with surgically treated, traumatic, cervical fractures were identified. Patients were sorted into early (within 72 hours of admission) and late (beyond 72 hours) surgery groups. PSM was able to match 2,132 early and late surgery patients on age, comorbidity, expected payer, trauma severity, hospital type, urgent admission, and surgical approach. Perioperative complications, mortality, and resource utilization were assessed.Late surgery was more frequently associated with increased age, more comorbidities, higher ICISS score, and non-private insurance. Following PSM matching, there were no significant, preoperative differences between early and late surgery groups. Surgery performed after 72 hours was associated with an increase in in-hospital complications (OR=1.3). The early surgery group was associated with decreased length of stay (11 days vs. 16 days, p <0.0001) and hospital charges ($237,786 v. $282,727, p <0.0001).After controlling for potential confounding differences through PSM matching and multivariate analyses, we found late surgery independently associated with increased in-hospital complications, length of stay, and hospital resource utilization. These data suggest surgery within 72 hours may decrease resource utilization without a corresponding increase in postoperative morbidity.

    View details for DOI 10.7759/cureus.244

    View details for PubMedID 26180668

    View details for PubMedCentralID PMC4494543

  • Surgery is cost-effective treatment for young patients with vestibular schwannomas: decision tree modeling of surgery, radiation, and observation. Neurosurgical focus Zygourakis, C. C., Oh, T., Sun, M. Z., Barani, I., Kahn, J. G., Parsa, A. T. 2014; 37 (5): E8

    Abstract

    Vestibular schwannomas (VSs) are managed in 3 ways: observation ("wait and scan"); Gamma Knife surgery (GKS); or microsurgery. Whereas there is considerable literature regarding which management approach is superior, there are only a few studies addressing the cost of treating VSs, and there are no cost-utility analyses in the US to date.In this study, the authors used the University of California at San Francisco medical record and hospital accounting databases to determine total hospital charges and costs for 33 patients who underwent open surgery, 42 patients who had GKS, and 12 patients who were observed between 2010 and 2013. The authors then performed decision-tree analysis to determine which treatment paradigm produces the highest quality-adjusted life years and to calculate the incremental cost-effectiveness ratio, depending on the patient's age at VS diagnosis.The average total hospital cost over a 3-year period for surgically treated patients was $80,074 (± $49,678) versus $9737 (± $5522) for patients receiving radiosurgery and $1746 (± $2792) for patients who were observed. When modeling the most debilitating symptoms and worst outcomes of VSs (vertigo and death) at different ages at diagnosis, radiation is dominant to observation at all ages up to 70 years. Surgery is cost-effective when compared with radiation (incremental cost-effectiveness ratio < $150,000) at younger ages at diagnosis (< 45 years old).In this model, surgery is a cost-effective alternative to radiation when VS is diagnosed in patients at < 45 years. For patients ≥ 45 years, radiation is the most cost-effective treatment option.

    View details for DOI 10.3171/2014.8.FOCUS14435

    View details for PubMedID 26218621

  • Medical errors in neurosurgery. Surgical neurology international Rolston, J. D., Zygourakis, C. C., Han, S. J., Lau, C. Y., Berger, M. S., Parsa, A. T. 2014; 5 (Suppl 10): S435–40

    Abstract

    Medical errors cause nearly 100,000 deaths per year and cost billions of dollars annually. In order to rationally develop and institute programs to mitigate errors, the relative frequency and costs of different errors must be documented. This analysis will permit the judicious allocation of scarce healthcare resources to address the most costly errors as they are identified.Here, we provide a systematic review of the neurosurgical literature describing medical errors at the departmental level. Eligible articles were identified from the PubMed database, and restricted to reports of recognizable errors across neurosurgical practices. We limited this analysis to cross-sectional studies of errors in order to better match systems-level concerns, rather than reviewing the literature for individually selected errors like wrong-sided or wrong-level surgery.Only a small number of articles met these criteria, highlighting the paucity of data on this topic. From these studies, errors were documented in anywhere from 12% to 88.7% of cases. These errors had many sources, of which only 23.7-27.8% were technical, related to the execution of the surgery itself, highlighting the importance of systems-level approaches to protecting patients and reducing errors.Overall, the magnitude of medical errors in neurosurgery and the lack of focused research emphasize the need for prospective categorization of morbidity with judicious attribution. Ultimately, we must raise awareness of the impact of medical errors in neurosurgery, reduce the occurrence of medical errors, and mitigate their detrimental effects.

    View details for DOI 10.4103/2152-7806.142777

    View details for PubMedID 25371849

    View details for PubMedCentralID PMC4209704

  • Management of planum/olfactory meningiomas: predicting symptoms and postoperative complications. World neurosurgery Zygourakis, C. C., Sughrue, M. E., Benet, A., Parsa, A. T., Berger, M. S., McDermott, M. W. 2014; 82 (6): 1216–23

    Abstract

    Given their location and slow growth, olfactory groove and planum sphenoidale meningiomas often grow to large sizes before they present with clinical symptoms and pose significant surgical challenges. The goal of our study is to identify which preoperative symptoms and findings on magnetic resonance imaging are correlated with specific postoperative outcomes in order to better counsel patients preoperatively.We retrospectively identified 44 patients with planum/olfactory meningiomas treated at our institution from 1996 to 2006. We used univariate and multivariate regression models to analyze the effect of several magnetic resonance imaging characteristics (tumor volume, distance to optic chiasm, anterior cerebral artery encasement, paranasal sinus invasion, and sellar invasion) on preoperative symptoms and postoperative outcomes, including complication rate and tumor recurrence.Only brain tumor volume (>42 cm(3)), but not distance to the optic chiasm, is independently associated with an increased likelihood of preoperative visual symptoms. Tumors with nasal sinus invasion are significantly more likely to cause postoperative surgical complications, and tumors with anterior cerebral artery encasement are associated with a greater likelihood of both postoperative complications and tumor recurrence.We conclude that tumors larger than 3.4 cm in diameter and those whose posterior edge is within 6-8 mm of the optic chiasm should be recommended for early surgical intervention. In terms of predicting surgical complications, nasal sinus invasion and anterior cerebral artery encasement are associated with greater-risk profiles when surgery becomes necessary. Thus, it is prudent to take these specific variables into consideration when advising patients about the risks of observation and surgery for olfactory/planum meningiomas.

    View details for DOI 10.1016/j.wneu.2014.08.007

    View details for PubMedID 25108294

  • Modern treatment of 84 newly diagnosed craniopharyngiomas. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Kaur, G., Kunwar, S., McDermott, M. W., Madden, M., Oh, T., Parsa, A. T. 2014; 21 (9): 1558–66

    Abstract

    There is debate regarding the appropriate treatment for craniopharyngiomas, which often present symptomatically given their proximity to critical brain structures, and pose significant surgical challenges. The goal of this study is to identify which patient and tumor characteristics are associated with specific preoperative symptoms, surgical complications, patient outcomes, and tumor recurrence in order to guide craniopharyngioma treatment. We retrospectively identified 84 patients with newly diagnosed craniopharyngiomas treated at our institution from 1986-2010. We used binary logistic regression and survival analysis to determine the effect of several variables (including sex, age, tumor size, location, surgical approach, and extent of resection) on preoperative symptoms and postoperative outcomes, including complication rates and tumor recurrence. Age and tumor location were associated with increased rates of preoperative symptoms, with children being more likely than adults to present with endocrine dysfunction, and intraventricular tumors being more likely than extraventricular tumors to present with headaches and hydrocephalus. A transcranial surgical approach was associated with 1.5 times higher rate of surgical complications than transsphenoidal surgery, while only intraventricular tumor location was associated with a poorer patient outcome. The main factor significantly associated with tumor recurrence was extent of resection. We conclude that intraventricular tumor location is most highly correlated with preoperative symptoms. If feasible, transsphenoidal approaches are preferred, as they result in fewer surgical complications, and gross total resections are optimal because they lead to lower rates of recurrence. When gross total resection is not possible, we favor multimodal treatment approaches.

    View details for DOI 10.1016/j.jocn.2014.03.005

    View details for PubMedID 24908374

  • Morbidity of repeat transsphenoidal surgery assessed in more than 1000 operations. Journal of neurosurgery Jahangiri, A., Wagner, J., Han, S. W., Zygourakis, C. C., Han, S. J., Tran, M. T., Miller, L. M., Tom, M. W., Kunwar, S., Blevins, L. S., Aghi, M. K. 2014; 121 (1): 67–74

    Abstract

    OBJECT.: While transsphenoidal surgery is associated with low morbidity, the degree to which morbidity increases after reoperation remains unclear. The authors determined the morbidity associated with repeat versus initial transsphenoidal surgery after 1015 consecutive operations.The authors conducted a 5-year retrospective review of the first 916 patients undergoing transsphenoidal surgery at their institution after a pituitary center of expertise was established, and they analyzed morbidities.The authors analyzed 907 initial and 108 repeat transsphenoidal surgeries performed in 916 patients (9 initial surgeries performed outside the authors' center were excluded). The most common diagnoses were endocrine inactive (30%) or active (36%) adenomas, Rathke's cleft cysts (10%), and craniopharyngioma (3%). Morbidity of initial surgery versus reoperation included diabetes insipidus ([DI] 16% vs 26%; p = 0.03), postoperative hyponatremia (20% vs 16%; p = 0.3), new postoperative hypopituitarism (5% vs 8%; p = 0.3), CSF leak requiring repair (1% vs 4%; p = 0.04), meningitis (0.4% vs 3%; p = 0.02), and length of stay ([LOS] 2.8 vs 4.5 days; p = 0.006). Of intraoperative parameters and postoperative morbidities, 1) some (use of lumbar drain and new postoperative hypopituitarism) did not increase with second or subsequent reoperations (p = 0.3-0.9); 2) some (DI and meningitis) increased upon second surgery (p = 0.02-0.04) but did not continue to increase for subsequent reoperations (p = 0.3-0.9); 3) some (LOS) increased upon second surgery and increased again for subsequent reoperations (p < 0.001); and 4) some (postoperative hyponatremia and CSF leak requiring repair) did not increase upon second surgery (p = 0.3) but went on to increase upon subsequent reoperations (p = 0.001-0.02). Multivariate analysis revealed that operation number, but not sex, age, pathology, radiation therapy, or lesion size, increased the risk of CSF leak, meningitis, and increased LOS. Separate analysis of initial versus repeat transsphenoidal surgery on the 2 most common benign pituitary lesions, pituitary adenomas and Rathke's cleft cysts, revealed that the increased incidence of DI and CSF leak requiring repair seen when all pathologies were combined remained significant when analyzing only pituitary adenomas and Rathke's cleft cysts (DI, 13% vs 35% [p = 0.001]; and CSF leak, 0.3% vs 9% [p = 0.0009]).Repeat transsphenoidal surgery was associated with somewhat more frequent postoperative DI, meningitis, CSF leak requiring repair, and greater LOS than the low morbidity characterizing initial transsphenoidal surgery. These results provide a framework for neurosurgeons in discussing reoperation for pituitary disease with their patients.

    View details for DOI 10.3171/2014.3.JNS131532

    View details for PubMedID 24834943

  • What do hotels and hospitals have in common? How we can learn from the hotel industry to take better care of patients. Surgical neurology international Zygourakis, C. C., Rolston, J. D., Treadway, J., Chang, S., Kliot, M. 2014; 5 (Suppl 2): S49–53

    Abstract

    Despite widely divergent public perceptions and goals, hotels and hospitals share many core characteristics. Both serve demanding and increasingly well-informed clienteles, both employ a large hierarchy of workers with varying levels of responsibility, and both have payments that are increasingly tied to customer/patient evaluations. In the hotel industry, decades of management experience and market research have led to widespread improvements and innovations that improve customer satisfaction. But there has been incredibly little cross-fertilization between the hotel and hospital industries. In this paper, we first consider the changes in the healthcare system that are forcing hospitals to become more concerned with patient satisfaction. We discuss the similarities and differences between the hotel and hospital industries, and then outline several of the unique challenges that neurosurgeons face in taking care of patients and increasing their comfort. We cite specific lessons from the hotel industry that can be applied to patients' preadmission, check-in, hospital stay, discharge planning, and poststay experiences. We believe that hospitals can and should leverage the successful advances within the hotel industry to improve patient satisfaction, without having to repeat identical research or market experimentation. We hope this will lead to rapid improvements in patient experiences and overall wellbeing.

    View details for DOI 10.4103/2152-7806.128913

    View details for PubMedID 24818061

    View details for PubMedCentralID PMC4014833

  • Trends in the diagnosis and treatment of pediatric primary spinal cord tumors Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Gephart, M. G., Lober, R. M., Arrigo, R. T., Zygourakis, C. C., Guzman, R., Boakye, M., Edwards, M. S., Fisher, P. G. 2012; 10 (6): 555-559
  • Venous Thromboembolism After Thoracic/Thoracolumbar Spinal Fusion WORLD NEUROSURGERY Gephart, M. G., Zygourakis, C. C., Arrigo, R. T., Kalanithi, P. S., Lad, S. P., Boakye, M. 2012; 78 (5): 545-552

    Abstract

    Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a serious and potentially fatal surgical complication. The goal of our study was to examine preoperative characteristics, incidence, and outcomes of patients with VTE after elective thoracic/thoracolumbar level spine fusion.We identified 430,081 patients from the Nationwide Inpatient Sample database who underwent spinal fusion between 2002 and 2008. Patients undergoing thoracic/thoracolumbar level fusion (n = 8617) were found to have the greatest concurrent rate of VTE. We then performed multivariate analyses on this cohort to identify predictors of and outcomes after VTE in patients undergoing thoracic/thoracolumbar level fusion.The overall VTE rate in spinal fusion surgery was 0.40% (cervical = 0.22%, thoracic/thoracolumbar = 1.90%, lumbar/lumbosacral = 0.49%, re-fusions = 0.64%, and fusions not otherwise specified = 0.84%). On multivariate logistic regression analysis of patients undergoing spinal fusion at the thoracic/thoracolumbar level, increasing age, Medicare insurance coverage (vs. private insurance), urban teaching hospital (vs. urban nonteaching hospital), combined anterior/posterior surgical approach (vs. posterior-only approach), and the presence of congestive heart failure or weight loss (Elixhauser comorbidity groups) were each independently associated with an increased odds ratio of VTE complication. VTE after thoracic/thoracolumbar surgery was significantly associated with longer hospital stays (16.6 vs. 6.74 days), increased total hospital costs ($260,208 vs. $115,474), and increased mortality (4.33% vs. 0.33%).Multivariate logistic regression analysis reveals age, insurance status, hospital type, combined anterior/posterior surgical approach, and the presence of congestive heart failure or weight loss to be independently associated with an increased odds ratio of VTE complication. This complication is associated with increased hospital costs, length of stay, and overall mortality.

    View details for DOI 10.1016/j.wneu.2011.12.089

    View details for Web of Science ID 000311996100038

    View details for PubMedID 22381270

  • Retrospective, Propensity Score-Matched Cohort Study Examining Timing of Fracture Fixation for Traumatic Thoracolumbar Fractures JOURNAL OF NEUROTRAUMA Boakye, M., Arrigo, R. T., Gephart, M. G., Zygourakis, C. C., Lad, S. 2012; 29 (12): 2220-2225

    Abstract

    The timing of surgery in patients with traumatic thoracic/thoracolumbar fractures, with or without spinal cord injury, remains controversial. The objective of this study was to determine the importance of the timing of surgery for complications and resource utilization following fixation of traumatic thoracic/thoracolumbar fractures. In this retrospective cohort study, the 2003-2008 California Inpatient Databases were searched for patients receiving traumatic thoracic/thoracolumbar fracture fixation. Patients were classified as having early (<72 h) or late (>72 h) surgery. Propensity score modeling produced a matched cohort balanced on age, comorbidity, trauma severity, and other factors. Complications, mortality, length of stay, and hospital charges were assessed. Multivariate logistic regression was used to determine the impact of delayed surgery on in-hospital complications after balancing and controlling for other important factors. Early surgery (<72 h) for traumatic thoracic/thoracolumbar fractures was associated with a significantly lower overall complication rate (including cardiac, thromboembolic, and respiratory complications), and decreased hospital stay. In-hospital charges were significantly lower ($38,120 difference) in the early surgery group. Multivariate analysis identified time to surgery as the strongest predictor of in-hospital complications, although age, medical comorbidities, and injury severity score were also independently associated with increased complications. We reinforce the beneficial impact of early spinal surgery (prior to 72 h) in traumatic thoracic/thoracolumbar fractures to reduce in-hospital complications, hospital stay, and resource utilization. These results provide further support to the emerging literature and professional consensus regarding the importance of early thoracic/thoracolumbar spine stabilization of traumatic fractures to improve patient outcomes and limit hospitalization costs.

    View details for DOI 10.1089/neu.2012.2364

    View details for Web of Science ID 000307859900009

    View details for PubMedID 22676801

  • Immunotherapy for glioma: promises and challenges. Neurosurgery clinics of North America Han, S. J., Zygourakis, C., Lim, M., Parsa, A. T. 2012; 23 (3): 357–70

    Abstract

    Novel immunotherapeutic modalities are being pursed in the treatment of high-grade gliomas. This article explains how tumors suppress immune function in the brain. It specifically describes the ways in which tumors limit effective communication with immune cells, secrete immune-inhibitory cytokines and molecules, and express molecules that induce apoptosis of immune cells. It also defines 3 different immunotherapeutic approaches to counteract this tumor-associated immunosuppression: cytokine therapy, passive immunotherapy (either serotherapy or adoptive immunotherapy), and active immunotherapy. Although immunotherapeutic approaches have met with mixed success so far, immunotherapy continues to be actively pursued because of its potential to attack infiltrating high-grade gliomas.

    View details for DOI 10.1016/j.nec.2012.05.001

    View details for PubMedID 22748649

  • Delayed development of os odontoideum after traumatic cervical injury: support for a vascular etiology. Journal of neurosurgery. Pediatrics Zygourakis, C. C., Cahill, K. S., Proctor, M. R. 2011; 7 (2): 201–4

    Abstract

    A previously healthy 2-year-old girl sustained a C1-2 ligamentous injury after a motor vehicle accident and underwent successful halo immobilization, with postimmobilization images showing good cervical alignment. At the time, plain radiography, CT scanning, and MR imaging showed a normal odontoid. Four years later, however, the patient was found to have an os odontoideum, evident on plain radiography and CT imaging. At the 10-year follow-up, the os odontoideum had not been surgically repaired, and the child had mild hypermobility. This is the first documented case in the modern imaging era of delayed os odontoideum formation after definitive CT scanning showed no fracture. As such, this suggests that os odontoideum may result from traumatic vascular interruption in the developing spine, with resulting osseous remodeling leading to an os odontoideum. This case argues against the congenital etiology of os odontoideum, as well as the strict posttraumatic theory whereby a trauma-induced odontoid fracture leads to osseous remodeling and subsequent development of an os odontoideum.

    View details for DOI 10.3171/2010.11.PEDS10289

    View details for PubMedID 21284467

  • Nitric oxide-generating hydrogels inhibit neointima formation. Journal of biomaterials science. Polymer edition Masters, K. S., Lipke, E. A., Rice, E. E., Liel, M. S., Myler, H. A., Zygourakis, C., Tulis, D. A., West, J. L. 2005; 16 (5): 659–72

    Abstract

    This study evaluated the effects of localized delivery of nitric oxide (NO) from hydrogels covalently modified with S-nitrosocysteine (Cys-NO) on neoinitma formation, a key component of restenosis, in a rat balloon-injury model. Soluble Cys-NO was used in preliminary studies to identify dosage ranges that were able to simultaneously inhibit smooth muscle cell proliferation, enhance endothelial cell proliferation, and reduce platelet adhesion. Photo-cross-linked PEG-based hydrogels were formed with covalently immobilized Cys-NO. These materials release NO for approximately 24 h and can be applied to tissues and photo-cross-linked in situ to form local drug-delivery systems. Localized delivery of NO from hydrogels containing Cys-NO inhibited neointima formation in a rat balloon-injury model by approximately 75% at 14 days.

    View details for PubMedID 16001723

  • Quantitative trait loci modulate ventricular size in the mouse brain JOURNAL OF COMPARATIVE NEUROLOGY Zygourakis, C. C., Rosen, G. D. 2003; 461 (3): 362-369

    Abstract

    Cerebral ventricular size in humans varies significantly. Abnormal enlargement of the ventricles has been associated with schizophrenia, and hydrocephalus can lead to serious cognitive and motor deficiencies in humans and animals. In this study, we mapped quantitative trait loci (QTLs) modulating cerebroventricular size in mice. We hypothesized that genes underlying hydrocephalus might also modulate normal variation in ventricular size. By using digital images of mouse brain sections and stereological techniques, we estimated the volume of the combined lateral and third ventricles, as well as the volume of the entire brain, in 228 AXB and BXA recombinant inbred mice and their parent strains (A/J and C57BL/6J). Ventricle size, expressed as percentage of brain volume, is a heritable trait (h(2) = 0.32). We detected a major QTL controlling variance in volume on chromosome (Chr) 8 near the markers D8Mit94 and D8Mit189. We also detected a strong epistatic interaction affecting ventricular volume between loci on Chr 4 (near D4Mit237 and D4Mit214) and on Chr 7 (D7Mit178 and D7Mit191). These three QTLs, labeled Vent8a, Vent4b, and Vent7c, are close to genes that have been previously implicated in hydrocephalus.

    View details for DOI 10.1002/cne.10697

    View details for Web of Science ID 000183172500007

    View details for PubMedID 12746874