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Ryan Brewster, Wenya Linda Bi, Timothy R. Smith, William B. Gormley, Ian F. Dunn, and Edward R. Laws Jr.

Baseball maintains one of the highest impact injury rates in all athletics. A principal causative factor is the “beanball,” referring to a pitch thrown directly at a batter’s head. Frequent morbidities elicited demand for the development of protective gear development in the 20th century. In this setting, Dr. Walter Dandy was commissioned to design a “protective cap” in 1941. His invention became widely adopted by professional baseball and inspired subsequent generations of batting helmets. As a baseball aficionado since his youth, Walter Dandy identified a natural partnership between baseball and medical practice for the reduction of beaning-related brain injuries. This history further supports the unique position of neurosurgeons to leverage clinical insights, inform innovation, and expand service to society.

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Panayiotis E. Pelargos, Camille K. Milton, Michael D. Martin, Donald D. Horton, Stanley Pelofsky, Mary K. Gumerlock, Timothy B. Mapstone, and Ian F. Dunn

Neurosurgery at the University of Oklahoma has played a pivotal role in the development of the specialty in the state. Its history spans nearly 90 years, beginning in 1931 when Dr. Harry Wilkins established the first neurosurgical practice in the state at the University of Oklahoma. Together with his first trainee, Dr. Jess Herrmann, Wilkins established the Division of Neurosurgery and its training program in 1946. Through their tireless work, the division and its residency program gained renown for its patient care and teaching, and this tradition was carried forward by its subsequent leaders. The Department of Neurosurgery was established in 1993. From humble beginnings, neurosurgery at the University of Oklahoma has grown a comprehensive residency program with an intensive curriculum, leveraging the clinical and academic breadth afforded by relationships with the College of Medicine, the University of Oklahoma Health Sciences Center, and allied clinical and research partners. Here, the authors recount the history of neurosurgery at the University of Oklahoma, the flagship academic neurosurgical program in the state.

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Hormuzdiyar H. Dasenbrock, Kevin X. Liu, Christopher A. Devine, Vamsidhar Chavakula, Timothy R. Smith, William B. Gormley, and Ian F. Dunn

OBJECT

Although the length of hospital stay is often used as a measure of quality of care, data evaluating the predictors of extended hospital stay after craniotomy for tumor are limited. The goals of this study were to use multivariate regression to examine which preoperative characteristics and postoperative complications predict a prolonged hospital stay and to assess the impact of length of stay on unplanned hospital readmission.

METHODS

Data were extracted from the National Surgical Quality Improvement Program (NSQIP) database from 2007 to 2013. Patients who underwent craniotomy for resection of a brain tumor were included. Stratification was based on length of hospital stay, which was dichotomized by the upper quartile of the interquartile range (IQR) for the entire population. Covariates included patient age, sex, race, tumor histology, comorbidities, American Society of Anesthesiologists (ASA) class, functional status, preoperative laboratory values, preoperative neurological deficits, operative time, and postoperative complications. Multivariate logistic regression with forward prediction was used to evaluate independent predictors of extended hospitalization. Thereafter, hierarchical multivariate logistic regression assessed the impact of length of stay on unplanned readmission.

RESULTS

The study included 11,510 patients. The median hospital stay was 4 days (IQR 3-8 days), and 27.7% (n = 3185) had a hospital stay of at least 8 days. Independent predictors of extended hospital stay included age greater than 70 years (OR 1.53, 95% CI 1.28%-1.83%, p < 0.001); African American (OR 1.75, 95% CI 1.44%-2.14%, p < 0.001) and Hispanic (OR 1.68, 95% CI 1.36%-2.08%) race or ethnicity; ASA class 3 (OR 1.52, 95% CI 1.34%-1.73%) or 4-5 (OR 2.18, 95% CI 1.82%-2.62%) designation; partially (OR 1.94, 95% CI 1.61%-2.35%) or totally dependent (OR 3.30, 95% CI 1.95%-5.55%) functional status; insulin-dependent diabetes mellitus (OR 1.46, 95% CI 1.16%-1.84%); hematological comorbidities (OR 1.68, 95% CI 1.25%-2.24%); and preoperative hypoalbuminemia (OR 1.78, 95% CI 1.51%-2.09%, all p ≤ 0.009). Several postoperative complications were additional independent predictors of prolonged hospitalization including pulmonary emboli (OR 13.75, 95% CI 4.73%-39.99%), pneumonia (OR 5.40, 95% CI 2.89%-10.07%), and urinary tract infections (OR 11.87, 95% CI 7.09%-19.87%, all p < 0.001). The C-statistic of the model based on preoperative characteristics was 0.79, which increased to 0.83 after the addition of postoperative complications. A length of stay after craniotomy for tumor score was created based on preoperative factors significant in regression models, with a moderate correlation with length of stay (p = 0.43, p < 0.001). Extended hospital stay was not associated with differential odds of an unplanned hospital readmission (OR 0.97, 95% CI 0.89%-1.06%, p = 0.55).

CONCLUSIONS

In this NSQIP analysis that evaluated patients who underwent craniotomy for tumor, much of the variance in hospital stay was attributable to baseline patient characteristics, suggesting length of stay may be an imperfect proxy for quality. Additionally, longer hospitalizations were not found to be associated with differential rates of unplanned readmission.

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Elayna P. Kirsch, Alexander Suarez, Katherine E. McDaniel, Rajeev Dharmapurikar, Timothy Dunn, Shivanand P. Lad, and Michael M. Haglund

OBJECTIVE

There is no standard way in which physicians teach or evaluate surgical residents intraoperatively, and residents are proving to not be fully competent at core surgical procedures upon graduating. The Surgical Autonomy Program (SAP) is a novel educational model that combines a modified version of the Zwisch scale with Vygotsky’s social learning theory. The objective of this study was to establish preliminary validity evidence that SAP is a reliable measure of autonomy and a useful tool for tracking competency over time.

METHODS

The SAP breaks each surgical case into 4 parts, or zones of proximal development (ZPDs). Residents are evaluated on a 4-tier autonomy scale (TAGS scale) for each ZPD in every surgical case. Attendings were provided with a teaching session about SAP and identified appropriate ZPDs for surgical cases under their area of expertise. All neurosurgery residents at Duke University Hospital from July 2017 to July 2021 participated in this study. Chi-square tests and ordinal logistic regression were used for the analyses.

RESULTS

Between 2017 and 2021, there were 4885 cases logged by 27 residents. There were 30 attendings who evaluated residents using SAP. Faculty completed evaluations on 91% of cases. The ZPD of focus directly correlated with year of residency (postgraduate year) (χ2 = 1221.1, df = 15, p < 0.001). The autonomy level increased with year of residency (χ2 = 3553.5, df = 15, p < 0.001). An ordinal regression analysis showed that for every year increase in postgraduate year, the odds of operating at a higher level of independence was 2.16 times greater (95% CI 2.11–2.21, p < 0.001). The odds of residents performing with greater autonomy was lowest for the most complex portion of the case (ZPD3) (OR 0.18, 95% CI 0.17–0.20, p < 0.001). Residents have less autonomy with increased case complexity (χ2 = 160.28, df = 6, p < 0.001). Compared with average cases, residents were more likely to operate with greater autonomy on easy cases (OR 1.44, 95% CI 1.29–1.61, p < 0.001) and less likely to do so on difficult cases (OR 0.72, 95% CI 0.67–0.77, p < 0.001).

CONCLUSIONS

This study demonstrates preliminary evidence supporting the construct validity of the SAP. This tool successfully tracks resident autonomy and progress over time. The authors’ smartphone application was widely used among surgical faculty and residents, supporting integration into the perioperative workflow. Wide implementation of SAP across multiple surgical centers will aid in the movement toward a competency-based residency education system.

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Panayiotis E. Pelargos, Camille K. Milton, Michael D. Martin, Donald D. Horton, Stanley Pelofsky, Mary K. Gumerlock, Timothy B. Mapstone, and Ian F. Dunn

Neurosurgery at the University of Oklahoma has played a pivotal role in the development of the specialty in the state. Its history spans nearly 90 years, beginning in 1931 when Dr. Harry Wilkins established the first neurosurgical practice in the state at the University of Oklahoma. Together with his first trainee, Dr. Jess Herrmann, Wilkins established the Division of Neurosurgery and its training program in 1946. Through their tireless work, the division and its residency program gained renown for its patient care and teaching, and this tradition was carried forward by its subsequent leaders. The Department of Neurosurgery was established in 1993. From humble beginnings, neurosurgery at the University of Oklahoma has grown a comprehensive residency program with an intensive curriculum, leveraging the clinical and academic breadth afforded by relationships with the College of Medicine, the University of Oklahoma Health Sciences Center, and allied clinical and research partners. Here, the authors recount the history of neurosurgery at the University of Oklahoma, the flagship academic neurosurgical program in the state.

Full access

Hormuzdiyar H. Dasenbrock, Kevin X. Liu, Vamsidhar Chavakula, Christopher A. Devine, William B. Gormley, Elizabeth B. Claus, Timothy R. Smith, and Ian F. Dunn

OBJECTIVE

Although there is a growing body of research highlighting the negative impact of obesity and malnutrition on surgical outcomes, few studies have evaluated these parameters in patients undergoing intracranial surgery. The goal of this study was to use a national registry to evaluate the association of body mass index (BMI) and hypoalbuminemia with 30-day outcomes after craniotomy for tumor.

METHODS

Adult patients who underwent craniotomy for tumor were extracted from the prospective National Surgical Quality Improvement Program registry. Patients were stratified by body habitus according to the WHO classification, as well as by preoperative hypoalbuminemia (< 3.5 g/dl). Multivariable logistic regression evaluated the association of body habitus and hypoalbuminemia with 30-day mortality, complications, and discharge disposition. Covariates included patient age, sex, race or ethnicity, tumor histology, American Society of Anesthesiology class, preoperative functional status, comorbidities (including hypertension and diabetes mellitus), and additional preoperative laboratory values.

RESULTS

Among the 11,510 patients included, 28.7% were classified as normal weight (BMI 18.5–24.9 kg/m2), 1.9% as underweight (BMI < 18.5 kg/m2), 33.4% as overweight (BMI 25.0–29.9 kg/m2), 19.1% as Class I obese (BMI 30.0–34.9 kg/m2), 8.3% as Class II obese (BMI 35.0–39.9 kg/m2), 5.5% as Class III obese (BMI ≥ 40.0 kg/m2), and 3.1% had missing BMI data. In multivariable regression models, body habitus was not associated with differential odds of mortality, postoperative stroke or coma, or a nonroutine hospital discharge. However, the adjusted odds of a major complication were significantly higher for Class I obese (OR 1.28, 99% CI 1.01–1.62; p = 0.008), Class II obese (OR 1.53, 99% CI 1.13–2.07; p < 0.001), and Class III obese (OR 1.67, 99% CI 1.19–2.36; p < 0.001) patients compared with those of normal weight; a dose-dependent effect was seen, with increased effect size with greater adiposity. The higher odds of major complications was primarily due to significantly increased odds of a venous thromboembolism in overweight and obese patients, as well as of a surgical site infection in those with Class II or III obesity. Additionally, 41.0% of patients had an albumin level ≥ 3.5 g/dl, 9.6% had hypoalbuminemia, and 49.4% had a missing albumin value. Hypoalbuminemia was associated with significantly higher odds of mortality (OR 1.91, 95% CI 1.41–2.60; p < 0.001) or a nonroutine hospital discharge (OR 1.46, 95% CI 1.21–1.76; p < 0.001).

CONCLUSIONS

In this National Surgical Quality Improvement Program analysis evaluating patients who underwent craniotomy for tumor, body habitus was not associated with differential mortality or neurological complications. However, obese patients had increased odds of a major perioperative complication, primarily due to higher rates of venous thromboembolic events and surgical site infections. Preoperative hypoalbuminemia was associated with increased odds of mortality and a nonroutine hospital discharge, suggesting that serum albumin may have utility in stratifying risk preoperatively in patients undergoing craniotomy.

Free access

Charis A. Spears, Syed M. Adil, Brad J. Kolls, Michael E. Muhumza, Michael M. Haglund, Anthony T. Fuller, and Timothy W. Dunn

OBJECTIVE

The purpose of this study was to investigate whether neurosurgical intervention for traumatic brain injury (TBI) is associated with reduced risks of death and clinical deterioration in a low-income country with a relatively high neurosurgical capacity. The authors further aimed to assess whether the association between surgical intervention and acute poor outcomes differs according to TBI severity and various patient factors.

METHODS

Using TBI registry data collected from a national referral hospital in Uganda between July 2016 and April 2020, the authors performed Cox regression analyses of poor outcomes in admitted patients who did and did not undergo surgery for TBI, with surgery as a time-varying treatment variable. Patients were further stratified by TBI severity using the admission Glasgow Coma Scale (GCS) score: mild TBI (mTBI; GCS scores 13–15), moderate TBI (moTBI; GCS scores 9–12), and severe TBI (sTBI; GCS scores 3–8). Poor outcomes constituted Glasgow Outcome Scale scores 2–3, deterioration in TBI severity between admission and discharge (e.g., mTBI to sTBI), and death. Several clinical and demographic variables were included as covariates. Patients were observed for outcomes from admission through hospital day 10.

RESULTS

Of 1544 patients included in the cohort, 369 (24%) had undergone surgery. Rates of poor outcomes were 4% (n = 13) for surgical patients and 12% (n = 144) among nonsurgical patients (n = 1175). Surgery was associated with a 59% reduction in the hazard for a poor outcome (HR 0.41, 95% CI 0.23–0.72). Age, pupillary nonreactivity, fall injury, and TBI severity at admission were significant covariates. In models stratifying by TBI severity at admission, patients with mTBI had an 80% reduction in the hazard for a poor outcome with surgery (HR 0.20, 95% CI 0.04–0.90), whereas those with sTBI had a 65% reduction (HR 0.35, 95% CI 0.14–0.89). Patients with moTBI had a statistically nonsignificant 56% reduction in hazard (HR 0.44, 95% CI 0.17–1.17).

CONCLUSIONS

In this setting, the association between surgery and rates of poor outcomes varied with TBI severity and was influenced by several factors. Patients presenting with mTBI had the greatest reduction in the hazard for a poor outcome, followed by those presenting with sTBI. However, patients with moTBI had a nonsignificant reduction in the hazard, indicating greater variability in outcomes and underscoring the need for closer monitoring of this population. These results highlight the importance of accurate, timely clinical evaluation throughout a patient’s admission and can inform decisions about whether and when to perform surgery for TBI when resources are limited.

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William R. Kennedy, Todd A. DeWees, Sahaja Acharya, Mustafaa Mahmood, Nels C. Knutson, S. Murty Goddu, James A. Kavanaugh, Timothy J. Mitchell, Keith M. Rich, Albert H. Kim, Eric C. Leuthardt, Joshua L. Dowling, Gavin P. Dunn, Michael R. Chicoine, Stephanie M. Perkins, Jiayi Huang, Christina I. Tsien, Clifford G. Robinson, and Christopher D. Abraham

OBJECTIVE

The internal high-dose volume varies widely for a given prescribed dose during stereotactic radiosurgery (SRS) to treat brain metastases (BMs). This may be altered during treatment planning, and the authors have previously shown that this improves local control (LC) for non–small cell lung cancer BMs without increasing toxicity. Here, they seek to identify potentially actionable dosimetric predictors of LC after SRS for melanoma BM.

METHODS

The records of patients with unresected melanoma BM treated with single-fraction Gamma Knife RS between 2006 and 2017 were reviewed. LC was assessed on a per-lesion basis, defined as stability or a decrease in lesion size. Outcome-oriented approaches were utilized to determine optimal dichotomization for dosimetric variables relative to LC. Univariable and multivariable Cox regression analysis was implemented to evaluate the impact of collected parameters on LC.

RESULTS

Two hundred eighty-seven melanoma BMs in 79 patients were identified. The median age was 56 years (range 31–86 years). The median follow-up was 7.6 months (range 0.5–81.6 months), and the median survival was 9.3 months (range 1.3–81.6 months). Lesions were optimally stratified by volume receiving at least 30 Gy (V30) greater than or equal to versus less than 25%. V30 was ≥ and < 25% in 147 and 140 lesions, respectively. For all patients, 1-year LC was 83% versus 66% for V30 ≥ and < 25%, respectively (p = 0.001). Stratifying by volume, lesions 2 cm or less (n = 215) had 1-year LC of 82% versus 70% (p = 0.013) for V30 ≥ and < 25%, respectively. Lesions > 2 to 3 cm (n = 32) had 1-year LC of 100% versus 43% (p = 0.214) for V30 ≥ and < 25%, respectively. V30 was still predictive of LC even after controlling for the use of immunotherapy and targeted therapy. Radionecrosis occurred in 2.8% of lesions and was not significantly associated with V30.

CONCLUSIONS

For a given prescription dose, an increased internal high-dose volume, as indicated by measures such as V30 ≥ 25%, is associated with improved LC but not increased toxicity in single-fraction SRS for melanoma BM. Internal dose escalation is an independent predictor of improved LC even in patients receiving immunotherapy and/or targeted therapy. This represents a dosimetric parameter that is actionable at the time of treatment planning and warrants further evaluation.