Tej D Azad

Johns Hopkins Medicine | JHUSOM · Department of Neurosurgery

Augmented reality (AR) has emerged as a potential surgical adjunct in spine surgery. We review key developments in surgical AR and detail the technological milestones foundational for AR applications in spine surgery. We evaluate the studies that have analyzed AR systems in spine surgery and discuss the quality of these investigations. Finally, we...

Background and objectives: Despite the extensive amount of research aimed at comparing patient outcomes between microscopic transsphenoidal surgery (MTSS) and endoscopic transsphenoidal surgery (ETSS) approaches, there has been relatively little recent investigation into the nationwide utilization and reimbursement trends of both techniques. This...

OBJECTIVE Brain metastases (BMs) are the most common CNS tumors, yet their prevalence is difficult to determine. Most studies only report synchronous metastases, which make up a fraction of all BMs. The authors report the incidence and prognosis of patients with synchronous and metachronous BMs over a decade. METHODS Study data were obtained from...

It is often challenging to distinguish cancerous from non-cancerous lesions in the brain using conventional diagnostic approaches. We introduce an analytic technique called Real-CSF (repetitive element aneuploidy sequencing in CSF) to detect cancers of the central nervous system from evaluation of DNA in the cerebrospinal fluid (CSF). Short intersp...

Objective: Prior research has not investigated the uncertainty in the relationship between patient frailty and postoperative outcomes after brain tumor surgery. The present study used Bayesian methods to quantify the statistical uncertainty between the 5-factor modified frailty index (mFI-5) and postoperative outcomes in patients undergoing brain...

Introduction: Targeted temperature management (TTM) has been associated with greater likelihood of neurological recovery among comatose survivors of cardiac arrest. However, the efficacy of TTM is not consistently observed, possibly due to heterogeneity of therapeutic response. The aim of this study is to determine if models leveraging multi-modal...

Background and objectives: Sacroiliac (SI) joint dysfunction constitutes a leading cause of pain and disability. Although surgical arthrodesis is traditionally performed under open approaches, the past decade has seen a rise in minimally invasive surgical (MIS) techniques and new federally approved devices for MIS approaches. In addition to neuros...

OBJECTIVE In recent years, machine learning models for clinical prediction have become increasingly prevalent in the neurosurgical literature. However, little is known about the quality of these models, and their translation to clinical care has been limited. The aim of this systematic review was to empirically determine the adherence of machine le...

Background: Given the clinical heterogeneity of COVID-19 infection, we hypothesize the existence of subphenotypes based on early inflammatory responses that are associated with mortality and additional complications. Methods: For this cross-sectional study, we extracted electronic health data from adults hospitalized patients between March 1, 2020...

Background: Stereoelectroencephalography (SEEG) is a critical tool used in the identification of epileptogenic zones. While stereotactic frame-based SEEG procedures have been performed traditionally, newer robotic assisted SEEG procedures have become increasingly common. Objective: To evaluate the accuracy, efficacy, and safety of the ExcelsiusG...

Background: Patients undergoing surgical procedures for spinal tumors are vulnerable to major adverse events (AEs) and death in the postoperative period. Shared decision making and preoperative optimization of outcomes require accurate risk estimation. Objective: To develop and validate a risk index to predict short-term major AEs after spinal t...

Background

Background Brain metastases (BM) constitute a significant cause of oncological mortality. Statistics on the incidence of BM are limited because of the lack of systematic nationwide reporting. We report the incidence of synchronous brain metastases (sBM), defined as BM identified at the time of primary cancer diagnosis from 2015 to 2019 using Nation...

We report the case of a 14-year-old boy who presented with extensive cerebellar and brainstem hemorrhage. Our presumptive diagnosis was a ruptured arteriovenous malformation (AVM), but two cerebral angiograms showed no significant vascular abnormalities. The patient underwent posterior fossa craniotomy and microsurgical evacuation of the hematoma....

Background: An estimated 50 million Americans receive Medicare health care coverage. Prior studies have established a downward trend in Medicare reimbursement for commonly billed surgical procedures, but it is unclear whether these trends hold true across all neurosurgical procedures. Objective: To assess trends in utilization, charges, and reim...

OBJECTIVE In recent years, frailty indices such as the 11- and 5-factor modified frailty indices (mFI-11 and mFI-5), American Society of Anesthesiologists (ASA) physical status classification, and Charlson Comorbidity Index (CCI) have been shown to be effective predictors of various postoperative outcomes in neurosurgical patients. The Hospital Fra...

Background: Improving neurosurgical quality metrics necessitates the analysis of patient safety indicator (PSI) 04, a measure of failure to rescue (FTR). Objective: To demonstrate that PSI 04 is not an appropriate measure for capturing FTR within neurosurgery. Methods: We conducted a single-center retrospective cohort study. Patients from Janu...

Background Blunt cerebrovascular injury (BCVI), defined as blunt traumatic injury to the carotid or vertebral arteries, is associated with significant risk of stroke and mortality. Cervical spine trauma is a recognized risk factor for BCVI. Objective The objective of this study was to identify significant predictors of BCVI and its sequelae in pat...

OBJECTIVE The post-bypass stroke risk factors and long-term outcomes of moyamoya patients are not well documented. Therefore, the authors studied 30-day stroke risks and patients’ long-term physical, functional, and social well-being. METHODS This was a single-institution combined moyamoya disease (MMD) database interrogation and questionnaire stu...

Background Prompt surgical decompression after traumatic spinal cord injury (TSCI) may be associated with improved sensorimotor outcomes. Delays in presentation may prevent timely decompression after TSCI. Objective To systematically review existing studies investigating delays in presentation after TSCI in low- and middle-income countries (LMICs)...

Background: Management of sporadic schwannomas is often dictated by a patient's clinical presentation and the tumor's behavior. For patients who are managed nonsurgically, there are little data available about the expected natural history. Objective: To evaluate the natural history and growth patterns of extracranial schwannomas including tumors...

BACKGROUND CONTEXT Anterior lumbar interbody fusion (ALIF) is an effective procedure for spondylolisthesis and pseudarthrosis but is not without risks. Surgeons and patients would benefit from an easy to use shared decision-making tool that can accurately predict patients at risk for mortality after ALIF. PURPOSE We developed the ALFA score to pre...

INTRODUCTION: Post-traumatic syringomyelia is an uncommon complication after traumatic spinal cord injury. This case study details our decision-making and surgical approach for a patient with symptomatic post-traumatic syringomyelia after sustaining a gunshot wound. CASE PRESENTATION: A 24-year-old man with past medical history of distant American...

Background Research on the effects of substance use disorders (SUDs) on postoperative outcomes within neurosurgical oncology has been limited. Therefore, the present study sought to quantify the effect of having a SUD on hospital length of stay (LOS), postoperative complication incidence, discharge disposition, hospital charges, 90-day readmission...

Lesions within the brain cavity pose critical challenges for diagnostics, particularly distinction between cancerous and non-cancerous lesions. We here introduce an analytic technique called Real-CSF to detect cancers of the central nervous system from evaluation of DNA in the cerebrospinal fluid (CSF). Short interspersed nuclear elements (SINEs) f...

The ExcelsiusGPS (Globus Medical, Inc., Audubon, PA) robot received clearance from the United States Food and Drug Administration for clinical use in 2017 with the first in human use for lumbar spine instrumentation at Johns Hopkins Hospital the same year. The applications of the robot soon expanded with the first interbody cage placement in 2020 a...

Objective While predictive analytic techniques have been used to analyze meningioma postoperative outcomes, to our knowledge, there have been no studies that have investigated the utility of machine learning (ML) models in prognosticating outcomes among skull base meningioma patients. The present study aimed to develop models for predicting postope...

Diagnosis and longitudinal monitoring of neurological diseases are limited by the poor specificity and limited resolution of currently available techniques. Analysis of circulating cells in cerebrospinal fluid (CSF) has emerged as a promising strategy for the diagnosis, molecular characterization, and monitoring of neurological disease. In comparis...

Objectives: The standard-of-care for postoperative care following elective craniotomy has historically been ICU admission. However, recent literature interrogating complications and interventions during this postoperative ICU stay suggests that all patients may not require this level of care. Thus, hospitals began implementing non-ICU postoperativ...

Objective To summarize the clinical characteristics, histo-genomic profiles, management strategies, and survival outcomes of H3K27M-altered adult diffuse midline gliomas (aDMGs). Methods PubMed, Scopus, and Cochrane databases were used to identify relevant articles. Papers including H3K27M-altered aDMGs with sufficient clinical outcome data were i...

Background Context Awake spine surgery is growing in popularity, and may facilitate earlier postoperative recovery, reduced cost, and fewer complications than spine surgery conducted under general anesthesia (GA). However, trends in adoption of awake (ie, non-GA) spine surgery have not been previously studied. Purpose To investigate temporal trend...

Diagnosis of diffuse midline glioma (DMG) portends a grim prognosis, with less than 10% of patients surviving beyond 2 years.¹ Progress in characterizing the genomic and epigenetic landscape of DMG has catalyzed efforts to develop novel therapeutics. Recent work from Cantor et al suggests that blood and cerebrospinal fluid (CSF) liquid biopsy could...

Objective: Within the neurosurgical oncology literature, the effect of structural and socioeconomic factors on postoperative outcomes remains unclear. In this study, the authors quantified the effects of social determinant of health (SDOH) disparities on hospital complications, length of stay (LOS), nonroutine discharge, 90-day readmission, and 90...

Heterogeneity is recognized as a major barrier in efforts to improve the care and outcomes of patients with traumatic brain injury (TBI). Even within the narrower stratum of moderate and severe TBI, current management approaches do not capture the complexity of this condition characterized by manifold clinical, anatomical, and pathophysiologic feat...

This survey study assesses public support for or opposition to transparency measures regarding the US Food and Drug Administration (FDA) drug approval process.

Background: Interest in machine learning (ML)-based predictive modeling has led to the development of models predicting outcomes after aneurysmal subarachnoid hemorrhage (aSAH), including the Nijmegen acute subarachnoid hemorrhage calculator (Nutshell). Generalizability of such models to external data remains unclear. Objective: To externally va...

The use of predictive models within neurosurgery is increasing and many models described in published journal articles are made available to readers in formats such as nomograms and online calculators. The present chapter details a step-by-step methodology with accompanying R code that may be used to implement models both in the form of traditional...

The history of machine learning in neurosurgery spans three decades and continues to develop at a rapid pace. The earliest applications of machine learning within neurosurgery were first published in the 1990s as researchers began developing artificial neural networks to analyze structured datasets and supervised tasks. By the turn of the millenniu...

A host of machine learning algorithms have been used to perform several different tasks in NLP and TSA. Prior to implementing these algorithms, some degree of data preprocessing is required. Deep learning approaches utilizing multilayer perceptrons, recurrent neural networks (RNNs), and convolutional neural networks (CNNs) represent commonly used t...

Background: Intracranial deposits of fat droplets are an unusual presentation of a spinal dermoid cyst after spontaneous rupture and are even more uncommon after trauma. Here, the authors present a case with this rare clinical presentation, along with a systematic review of the literature to guide decision making in these patients. Observations:...

Purpose There is a need to better understanding the prognostic factors that influence high-value care outcomes following meningioma surgery. The goal of this study was to develop predictive models to determine patients at risk for experiencing an extended hospital length of stay (LOS), non-routine discharge disposition, or a 90-day hospital readmis...

BACKGROUND CONTEXT Existing literature demonstrates well-identified racial disparities in spine surgery outcomes. However, previous studies are of significant limitations. PURPOSE To investigate the association of race with 30-day perioperative complication rates of elective posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS)....

Most circulating tumor DNA (ctDNA) assays are designed to detect recurrent mutations. Pediatric sarcomas share few recurrent mutations but rather are characterized by translocations and copy number changes. We applied CAncer Personalized Profiling by deep Sequencing (CAPP-Seq) for detection of translocations found in the most common pediatric sarco...

Introduction Given the benign nature of extracranial schwannomas and the low rate of conversion to malignancy, management is often dictated by a patient's clinical presentation and the tumor's growth. For patients who are managed expectantly, there remains the question of what is the expected natural history of the lesion. This can help drive decis...

Background Context Despite established guidelines, long-term management of surgically-treated low back pain (LBP) and lower extremity pain (LEP) remains heterogeneous. Understanding care heterogeneity could inform future approaches for standardization of practices. Purpose To describe treatment heterogeneity in surgically-managed LBP and LEP. Stu...

Study design: Systematic review. Objectives: To review the existing literature of prediction models in degenerative spinal surgery. Methods: Review of PubMed/Medline and Embase databases was conducted to identify articles between January 1, 2000 and March 1, 2020 that reported prediction model performance for outcomes following elective degene...

Objectives: To determine if a restrictive visitor policy inadvertently lengthened the decision-making process for dying inpatients without coronavirus disease 2019. Design: Regression discontinuity and time-to-event analysis. Setting: Two large academic hospitals in a unified health system. Patients or subjects: Adult decedents who received...

Craniosynostosis (CS) is a congenital disease that arises due to premature ossification of single or multiple sutures, which results in skull deformities. The surgical management of single-suture CS continues to evolve and is driven by a robust body of clinical research; however, the molecular underpinnings of CS remain poorly understood. Despite l...

Traumatic brain injury patients may be dependent on the decision-making of their families. Restrictive visitation policies implemented during the COVID-19 pandemic disproportionately affect these patients and their families. This narrative aims to illustrate this phenomenon and catalyze discussions regarding the need for careful evaluation of restr...

Introduction: The recent COVID-19 pandemic has revealed important obstacles in our health care systems, including online specialist consultations. Amidst mass lockdowns and social distancing, we observed the importance of developing a consistent method of performing effective neurological examinations that yield accurate results in a time efficient...

Objective To investigate the impact of race on 30-day postoperative complication rates of elective posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS). Methods Patients who underwent (PSF) between 2012-2018 were reviewed from the ACS-NSQIP pediatric database. Propensity score matching was utilized to evaluate whether race (i.e...

OBJECTIVE The objective of this study was to evaluate the characteristics and performance of current prediction models in the fields of spine metastasis and degenerative spine disease to create a scoring system that allows direct comparison of the prediction models. METHODS A systematic search of PubMed and Embase was performed to identify relevan...

As the use of machine learning algorithms in the development of clinical prediction models has increased, researchers are becoming more aware of the deleterious effects that stem from the lack of reporting standards. One of the most obvious consequences is the insufficient reproducibility found in current prediction models. In an attempt to charact...

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BACKGROUND CONTEXT Outpatient postoperative pain management in spine patients, specifically involving the use of opioids, demonstrates significant variability. PURPOSE Using preoperative risk factors and 30-day postoperative opioid prescribing patterns, we developed models for predicting long-term opioid use in patients after elective spine surger...

Radiologic screening of high-risk adults reduces lung-cancer-related mortality1,2; however, a small minority of eligible individuals undergo such screening in the United States3,4. The availability of blood-based tests could increase screening uptake. Here we introduce improvements to cancer personalized profiling by deep sequencing (CAPP-Seq)⁵, a...

Study Design Narrative review. Objectives Robotic systems in spinal surgery may offer potential benefits for both patients and surgeons. In this article, the authors explore the future prospects and current limitations of robotic systems in minimally invasive spine surgery. Methods We describe recent developments in robotic spine surgery and mini...

Background: The setting of a randomized trial can determine whether its findings are generalizable and can therefore apply to different settings. The contribution of low- and middle-income countries (LMICs) to neurosurgical randomized trials has not been systematically described before. Objective: To perform a systematic analysis of design chara...

Background: Pediatric pineoblastomas are highly aggressive tumors that portend poor outcomes despite multimodal management. Controversy remains regarding optimal disease management. Objective: To evaluate patterns of care and optimal clinical management of pediatric pineoblastoma. Methods: A total of 211 pediatric (age 0-17 yr) histologically...

Background: Idiopathic intracranial hypertension results in increased intracranial pressure leading to headache and visual loss. This disease frequently requires surgical intervention through lumboperitoneal (LP) or ventriculoperitoneal (VP) shunting. Objective: To compare postoperative outcomes between LP and VP shunts, including failure and co...

The optimal surgical management of gliomas requires a balance between surgical cytoreduction and preservation of neurological function. Preoperative functional neuroimaging, such as functional MRI (fMRI) and diffusion tensor imaging (DTI), has emerged as a possible tool to inform patient selection and surgical planning. However, evidence that preop...

Objective: Rising patient demand for minimally invasive surgery and increased payer emphasis on quality-based payment schema have created a need for technologies that provide consistent, high-quality outcomes for patients undergoing spine surgery. Robotic assistance is one such technology. Here we report our early experience with a novel real-time...

Background: Ventriculoperitoneal shunts are used to alleviate elevated intracranial pressure due to either hydrocephalus or idiopathic intracranial hypertension; however, shunt failure is a significant neurosurgical problem. Despite increases in intraoperative stereotactic navigation usage over the past decade, its effect on shunt survival remains...

Diffuse midline glioma (DMG) is a highly malignant childhood tumor with an exceedingly poor prognosis and limited treatment options. The majority of these tumors harbor somatic mutations in genes encoding histone variants. These recurrent mutations correlate with treatment response and are forming the basis for molecularly guided clinical trials. T...

Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms that have limited treatment options and are associated with high rates of morbidity and mortality. To better understand the genetic basis of these tumors we performed whole exome sequencing on 45 tumors and matched germline DNA, including twenty-nine spinal cord ependymomas and sixteen a...

Introduction: Randomized controlled trials (RCTs) have been critical in evaluating the safety and efficacy of functional neurosurgery interventions. Given this, we sought to systematically assess the quality of functional neurosurgery RCTs. Methods: We used a database of neurosurgical RCTs (trials published from 1961 to 2016) to identify studies...

Study Design This was an epidemiological study using national administrative data from the MarketScan database. Objective To investigate the impact of early versus delayed adjuvant radiotherapy (RT) on wound healing following surgical resection for spinal metastatic disease. Methods We queried the MarketScan database (2007-2016), identifying pati...

Background: The morbidity and mortality associated with opioid and benzodiazepine co-prescription is a pressing national concern. Little is known about patterns of opioid and benzodiazepine use in patients with acute low back pain or lower extremity pain. Objective: To characterize patterns of opioid and benzodiazepine prescribing among opioid-n...

Background & aims: Biomarkers are needed to identify patients at risk of tumor progression following chemoradiotherapy for localized esophageal cancer. These could improve identification of patients at risk for cancer progression and selection of therapy. Methods: We performed deep sequencing (CAPP-Seq) analyses of plasma cell-free DNA collected...

Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly; however, users are enthusiast...

Introduction: Rising patient demand for minimally invasive surgery and increased payer emphasis on quality-based payment schema have created a need for technologies capable of providing consistent, high-quality outcomes for spine surgery patients. Robot-assistance is one such technology. Here we report our preliminary experience with a novel real-t...

Background: Although the incidence of spinal fusions has increased significantly in the United States over the last quarter century, national trends of anterior lumbar interbody fusion (ALIF) utilization are not known. Purpose: The objective of this study was to characterize trends, clinical characteristics, risk factors associated with, and out...

INTRODUCTION Intramedullary spinal cord tumors (IMSCTs) are a rare, heterogeneous group of neoplasms with limited treatment options and high rates of morbidity and mortality. Next-generation sequencing has revealed opportunities for targeted therapies of the intracranial counterparts of IMSCT, but little is known about the molecular features of IMS...