Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Clinical registries are critical for modern surgery and underpin outcomes research, device monitoring, and trial development. However, existing approaches to registry construction are labor-intensive, costly, and prone to manual error. Natural language processing techniques combined with electronic health record (EHR) data sets can theoretically automate the construction and maintenance of registries. Our aim was to automate the generation of a spine surgery registry at an academic medical center using regular expression (regex) classifiers developed by neurosurgeons to combine domain expertise with interpretable algorithms. METHODS:We used a Hadoop data lake consisting of all the information generated by an academic medical center. Using this database and structured query language queries, we retrieved every operative note written in the department of neurosurgery since our transition to EHR. Notes were parsed using regex classifiers and compared with a random subset of 100 manually reviewed notes. RESULTS:A total of 31 502 operative cases were downloaded and processed using regex classifiers. The codebase required 5 days of development, 3 weeks of validation, and less than 1 hour for the software to generate the autoregistry. Regex classifiers had an average accuracy of 98.86% at identifying both spinal procedures and the relevant vertebral levels, and it correctly identified the entire list of defined surgical procedures in 89% of patients. We were able to identify patients who required additional operations within 30 days to monitor outcomes and quality metrics. CONCLUSION/CONCLUSIONS:This study demonstrates the feasibility of automatically generating a spine registry using the EHR and an interpretable, customizable natural language processing algorithm which may reduce pitfalls associated with manual registry development and facilitate rapid clinical research.

Although many frailty tools have been used to predict traumatic spinal injury (TSI) outcomes, identifying predictors of outcomes after TSI in the aged population is difficult. Frailty, age and TSI association are interesting topics of discussion in geriatric literature. However, the association between these variables are yet to be clearly elucidated. We conducted a systematic review to investigate the association between frailty and TSI outcomes. The authors searched Medline, EMBASE, Scopus, and Web of Science for relevant studies. Studies with observational designs that assessed baseline frailty status in individuals suffering from TSI published from inception until 26th March 2023 were included. LoS, AEs, and mortality were the outcomes of interest. Of the 2425 citations, 16 studies involving 37,640 participants were included. The modified frailty index (mFI) was the most common tool used to assess frailty. Meta-analysis was employed only in studies that used mFI for measuring frailty. Frailty was significantly associated with increased in-hospital or 30-day mortality (pooled OR: 1.93 [1.19; 3.11]), non-routine discharge (pooled OR: 2.44 [1.34; 4.44]), and AEs or complications (pooled OR: 2.00 [1.14; 3.50]). However, no significant relationship was found between frailty and LoS (pooled OR: 3.02 [0.86; 10.60]). Heterogeneity was observed across multiple factors, including age, injury level, frailty assessment tool, and spinal cord injury (SCI) characteristics. In conclusion, although there is limited data concerning using frailty scales to predict short-term outcomes after TSI, the results showed that frailty status may be a predictor of in-hospital mortality, AEs and unfavorable discharge destination.

Physicians make critical time-constrained decisions every day. Clinical predictive models can help physicians and administrators make decisions by forecasting clinical and operational events. Existing structured data-based clinical predictive models have limited use in everyday practice owing to complexity in data processing, as well as model development and deployment^1-3. Here we show that unstructured clinical notes from the electronic health record can enable the training of clinical language models, which can be used as all-purpose clinical predictive engines with low-resistance development and deployment. Our approach leverages recent advances in natural language processing^4,5 to train a large language model for medical language (NYUTron) and subsequently fine-tune it across a wide range of clinical and operational predictive tasks. We evaluated our approach within our health system for five such tasks: 30-day all-cause readmission prediction, in-hospital mortality prediction, comorbidity index prediction, length of stay prediction, and insurance denial prediction. We show that NYUTron has an area under the curve (AUC) of 78.7-94.9%, with an improvement of 5.36-14.7% in the AUC compared with traditional models. We additionally demonstrate the benefits of pretraining with clinical text, the potential for increasing generalizability to different sites through fine-tuning and the full deployment of our system in a prospective, single-arm trial. These results show the potential for using clinical language models in medicine to read alongside physicians and provide guidance at the point of care.

OBJECTIVE:By minimizing imaging artifact and particle scatter, carbon fiber-reinforced polyetheretherketone (CF-PEEK) spinal implants are hypothesized to enhance radiotherapy (RT) planning/dosing and improve oncological outcomes. However, robust clinical studies comparing tumor surgery outcomes between CF-PEEK and traditional metallic implants are lacking. In this paper, the authors performed a systematic review of the literature with the aim to describe clinical outcomes in patients with spine tumors who received CF-PEEK implants, focusing on implant-related complications and oncological outcomes. METHODS:A systematic review of the literature published between database inception and May 2022 was performed in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The PubMed database was queried using the terms "carbon fiber" and "spine" or "spinal." The inclusion criteria were articles that described patients with CF-PEEK pedicle screw fixation and had a minimum of 5 patients. Case reports and phantom studies were excluded. RESULTS:This review included 11 articles with 326 patients (237 with CF-PEEK-based implants and 89 with titanium-based implants). The mean follow-up period was 13.5 months, and most tumors were metastatic (67.1%). The rates of implant-related complications in the CF-PEEK and titanium groups were 7.8% and 4.7%, respectively. The rate of pedicle screw fracture was 1.7% in the CF-PEEK group and 2.4% in the titanium group. The rates of reoperation were 5.7% (with 60.0% because of implant failure or junctional kyphosis) and 4.8% (all because of implant failure or junctional kyphosis) in the CF-PEEK and titanium groups, respectively. When reported, 72.5% of patients received postoperative RT (41.0% stereotactic body RT, 30.8% fractionated RT, 25.6% proton, 2.6% carbon ion). Four articles suggested that implant artifact was reduced in the CF-PEEK group. Local recurrence occurred in 14.4% of CF-PEEK and 10.7% of titanium-implanted patients. CONCLUSIONS:While CF-PEEK harbors similar implant failure rates to traditional metallic implants with reduced imaging artifact, it remains unclear whether CF-PEEK implants improve oncological outcomes. This study highlights the need for prospective, direct comparative clinical studies.

OBJECTIVE:The cervicothoracic junction (CTJ) is a challenging region to stabilize after tumor resection for metastatic spine disease. The objective of this study was to describe the outcomes of patients who underwent posterolateral decompression and instrumented fusion (i.e., separation surgery across the CTJ for instability due to metastatic disease). METHODS:The authors performed a single-institution retrospective study of a prospectively collected cohort of patients who underwent single-approach posterior decompression and instrumented fusion across the CTJ for metastatic spine disease between 2011 and 2018. Adult patients (≥ 18 years old) who presented with mechanical instability, myelopathy, and radiculopathy secondary to metastatic epidural spinal cord compression (MESCC) of the CTJ (C7-T1) from 2011 to 2018 were included. RESULTS:Seventy-nine patients were included, with a mean age of 62.1 years. The most common primary malignancies were non-small cell lung (n = 17), renal cell (11), and prostate (8) carcinoma. The median number of levels decompressed and construct length were 3 and 7, respectively. The average operative time, blood loss, and length of stay were 179.2 minutes, 600.5 ml, and 7.7 days, respectively. Overall, 58 patients received adjuvant radiation, and median dose, fractions, and time from surgery were 27 Gy, 3 fractions, and 20 days, respectively. All patients underwent lateral mass and pedicle screw instrumentation. Forty-nine patients had tapered rods (4.0/5.5 mm or 3.5/5.5 mm), 29 had fixed-diameter rods (3.5 mm or 4.0 mm), and 1 had both. Ten patients required anterior reconstruction with poly-methyl-methacrylate. The overall complication rate was 18.8% (6 patients with wound-related complications, 7 with hardware-related complications, 1 with both, and 1 with other). For the 8 patients (10%) with hardware failure, 7 had tapered rods, all 8 had cervical screw pullout, and 1 patient also experienced rod/screw fracture. The average time to hardware failure was 146.8 days. The 2-year cumulative incidence rate of hardware failure was 11.1% (95% CI 3.7%-18.5%). There were 55 deceased patients, and the median (95% CI) overall survival period was 7.97 (5.79-12.60) months. For survivors, the median (range) follow-up was 12.94 (1.94-71.80) months. CONCLUSIONS:Instrumented fusion across the CTJ demonstrated an 18.8% rate of postoperative complications and an 11% overall 2-year rate of hardware failure in patients who underwent metastatic epidural tumor decompression and stabilization.

OBJECTIVE:Frailty has not been clearly defined in the context of spinal metastatic disease (SMD). Given this, the objective of this study was to better understand how members of the international AO Spine community conceptualize, define, and assess frailty in SMD. METHODS:The AO Spine Knowledge Forum Tumor conducted an international cross-sectional survey of the AO Spine community. The survey was developed using a modified Delphi technique and was designed to capture preoperative surrogate markers of frailty and relevant postoperative clinical outcomes in the context of SMD. Responses were ranked using weighted averages. Consensus was defined as ≥ 70% agreement among respondents. RESULTS:Results were analyzed for 359 respondents, with an 87% completion rate. Study participants represented 71 countries. In the clinical setting, most respondents informally assess frailty and cognition in patients with SMD by forming a general perception based on clinical condition and patient history. Consensus was attained among respondents regarding the association between 14 preoperative clinical variables and frailty. Severe comorbidities, extensive systemic disease burden, and poor performance status were most associated with frailty. Severe comorbidities associated with frailty included high-risk cardiopulmonary disease, renal failure, liver failure, and malnutrition. The most clinically relevant outcomes were major complications, neurological recovery, and change in performance status. CONCLUSIONS:The respondents recognized that frailty is important, but they most commonly evaluate it based on general clinical impressions rather than using existing frailty tools. The authors identified numerous preoperative surrogate markers of frailty and postoperative clinical outcomes that spine surgeons perceived as most relevant in this population.

BACKGROUND:In treatment of metastatic epidural spinal cord compression (MESCC), hybrid therapy, consisting of separation surgery, followed by stereotactic body radiation therapy, has become the mainstay of treatment for radioresistant pathologies, such as non-small-cell lung cancer (NSCLC). OBJECTIVE:To evaluate clinical outcomes of MESCC secondary to NSCLC treated with hybrid therapy and to identify clinical and molecular prognostic predictors. METHODS:This is a single-center, retrospective study. Adult patients (≥18 years old) with pathologically confirmed NSCLC and spinal metastasis who were treated with hybrid therapy for high-grade MESCC or nerve root compression from 2012 to 2019 are included. Outcome variables evaluated included overall survival (OS) and progression-free survival, local tumor control in the competing risks setting, surgical and radiation complications, and clinical-genomic correlations. RESULTS:One hundred and three patients met inclusion criteria. The median OS for this cohort was 6.5 months, with progression of disease noted in 5 (5%) patients at the index tumor level requiring reoperation and/or reirradiation at a mean of 802 days after postoperative stereotactic body radiation therapy. The 2-year local control rate was 94.6% (95% CI: 89.8-99.3). Epidermal growth factor receptor (EGFR) treatment-naïve patients who initiated EGFR-targeted therapy after hybrid therapy had significantly longer OS (hazard ratio 0.47, 95% CI 0.23-0.95, P = .04) even after adjusting for smoking status. The presence of EGFR exon 21 mutation was predictive of improved progression-free survival. CONCLUSION/CONCLUSIONS:Hybrid therapy in NSCLC resulted in 95% local control at 2 years after surgery. EGFR treatment-naïve patients initiating therapy after hybrid therapy had significantly improved survival advantage. EGFR-targeted therapy initiated before hybrid therapy did not confer survival benefit.

BACKGROUND:"Hybrid-therapy", consisting of separation-surgery followed by stereotactic body radiation therapy (SBRT) has become the mainstay treatment for radioresistant spinal metastases. Histology-specific outcomes for hybrid therapy are scarce. In clinical practice, colorectal cancer (CRC) is particularly thought to have poor outcomes regarding spinal metastases. The goal of this study is to evaluate clinical outcomes for patients treated with hybrid therapy for spinal metastases from CRC. METHODS:This is a retrospective study performed at a tertiary cancer center. Adult patients with CRC spinal metastasis who were treated with hybrid-therapy for high-grade epidural spinal cord or nerve root compression from 2005-2020 were included. Outcome variables evaluated included patient demographics, overall survival (OS) and progression-free survival (PFS), surgical and radiation complications, and clinical-genomic correlations. RESULTS:Fifty patients met inclusion criteria. Progression of disease occurred in 7 (14%) patients at the index-level requiring reoperation and/or reirradiation at a mean of 400 days after surgery. Postoperative complications occurred in 16% of patients, with 3 (6%) requiring intervention. Adenomatous polyposis coli (APC) exon 14 and 16 mutations were found in 15 of 17 patients tested and in all 3 of 7 local failures tested. Twenty patients (40%) underwent further radiation due to disease progression at another spinal levels. CONCLUSIONS:Hybrid-therapy in CRC patients resulted in 86.7% local control at two years after surgery, with limited complications. APC mutations are commonly present in CRC patients with spine metastases and may suggest worse prognosis. Patients with CRC spinal metastases commonly progress outside the index treatment level.

BACKGROUND:Metastatic spine tumor surgery consists of palliative operations performed on frail patients with multiple medical comorbidities. Enhanced recovery after surgery (ERAS) programs involve an evidence-based, multidisciplinary approach to improve perioperative outcomes. This study presents clinical outcomes of a metastatic spine tumor ERAS pathway implemented at a tertiary cancer center. METHODS:The metastatic spine tumor ERAS program launched in April 2019, and data from January 2018 to May 2020 were reviewed. Measured outcomes included the following: hospital length of stay (LOS), time to ambulation, urinary catheter duration, time to resumption of diet, intraoperative fluid intake, estimated blood loss (EBL), and intraoperative and postoperative day 0-5 cumulative opioid use (morphine milligram equivalent [MME]). RESULTS:A total of 390 patients were included in the final analysis: 177 consecutive patients undergoing metastatic spine tumor surgery enrolled in the ERAS program and 213 consecutive pre-ERAS patients. Although the mean case durations were similar in the ERAS and pre-ERAS cohorts (265 vs. 274 min; p = .22), the ERAS cohort had decreased EBL (157 vs. 215 ml; p = .003), decreased postoperative day 0-5 cumulative mean opioid use (178 vs. 396 MME; p < .0001), earlier ambulation (mean, 34 vs. 57 h; p = .0001), earlier discontinuation of urinary catheters (mean, 36 vs. 56 h; p < .001), and shorter LOS (5.4 vs. 7.5 days; p < .0001). CONCLUSIONS:The implementation of a multidisciplinary ERAS program designed for metastatic spine tumor surgery led to improved clinical quality metrics, including shorter hospitalizations and significant reductions in opioid consumption.

BACKGROUND CONTEXT/BACKGROUND:Historically, spine surgeons used expected postoperative survival of 3-months to help select candidates for operative intervention in spinal metastasis. However, this cutoff has been challenged by the development of minimally invasive techniques, novel biologics, and advanced radiotherapy. Recent studies have suggested that life expectancy of 6 weeks may be enough to achieve significant improvements in postoperative health-related quality of life. PURPOSE/OBJECTIVE:The purpose of this study was to develop a model capable of predicting 6-week mortality in patients with spinal metastases treated with radiation or surgery. STUDY DESIGN/SETTING/METHODS:Retrospective review was conducted at five large tertiary centers in the United States and Taiwan. PATIENT SAMPLE/METHODS:The development cohort consisted of 3,001 patients undergoing radiotherapy and/or surgery for spinal metastases from one institution. The validation institutional cohort consisted of 1,303 patients from four independent, external institutions. OUTCOME MEASURES/METHODS:The primary outcome was six-week mortality METHODS: Five models were considered to predict six-week mortality, and the model with the best performance across discrimination, calibration, decision-curve analysis, and overall performance was integrated into an open access web-based application. RESULTS:The most important variables for prediction of 6-week mortality were albumin, primary tumor histology, absolute lymphocyte, three or more spine metastasis, and ECOG score. The elastic-net penalized logistic model was chosen as the best performing model with AUC 0.84 on evaluation in the independent testing set. On external validation in the 1,303 patients from the four independent institutions, the model retained good discriminative ability with an area under the curve of 0.81. The model is available here: https://sorg-apps.shinyapps.io/spinemetssurvival/. CONCLUSIONS:While this study does not advocate for the use of 6-week life expectancy as a criteria for considering operative management, the algorithm developed and externally validated in this study may be helpful for preoperative planning, multidisciplinary management, and shared decision making in spinal metastasis patients with shorter life expectancy.