Are There Racial and Ethnic Health Disparities Among Outcomes After Anterior Cranial Fossa Surgery? A Propensity Score-Matched American College of Surgeons National Surgical Quality Improvement Program Study.

BACKGROUND: Race-based health care outcomes remain to be described in anterior cranial fossa (ACF) surgery. OBJECTIVE: To determine whether race predicts worse outcomes after ACF surgery. METHODS: A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program data for 2005 to 2020. Current Procedural Terminology and International Classification of Diseases-9 codes were used to identify ACF tumor cases. Propensity score matching was performed to compare White and minority patients to assess the robustness of unmatched findings. A subanalysis of pituitary adenoma (PA) resections was also performed. RESULTS: In an unmatched analysis of 1370 patients who underwent ACF surgery (67.9% White, 17.4% Black, 6.6% Asian/Pacific Islander, and 6.3% Hispanic), minority groups had higher rates of comorbidities. Unmatched multivariate analysis found Hispanic patients bore a 1.86 odds ratio (OR) of minor complications, Black and Asian and Pacific Islander patients bore 1.49 and 1.71 ORs, respectively, for extended length of stay, and Black patients bore a 3.78 OR for urinary tract infection (UTI). Matched analysis found that minority patients had higher UTI rates ( P = .02) and a 4.11 OR of UTI. In PA cases specifically, minority groups had higher comorbidities and length of stay in addition to extended length of stay odds (1.84 OR). CONCLUSION: Although most ACF surgery outcomes were unaffected by race, minority groups had more minor postoperative complications than White patients, particularly UTI. Similar disparities were observed among PA cases. Higher rates of comorbidities may also have led to longer hospital stays. Further study is needed to understand what actions might be necessary to address any race-associated health disparities in ACF surgery.

Does the Modified Arrhenius Model Reliably Predict Area of Tissue Ablation After Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Pediatric Lesional Epilepsy?

BACKGROUND: Commercial magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) systems utilize a generalized Arrhenius model to estimate the area of tissue damage based on the power and time of ablation. However, the reliability of these estimates in Vivo remains unclear. OBJECTIVE: To determine the accuracy and precision of the thermal damage estimate (TDE) calculated by commercially available MRgLITT systems using the generalized Arrhenius model. METHODS: A single-center retrospective review of pediatric patients undergoing MRgLITT for lesional epilepsy was performed. The area of each lesion was measured on both TDE and intraoperative postablation, postcontrast T1 magnetic resonance images using ImageJ. Lesions requiring multiple ablations were excluded. The strength of the correlation between TDE and postlesioning measurements was assessed via linear regression. RESULTS: A total of 32 lesions were identified in 19 patients. After exclusion, 13 pairs were available for analysis. Linear regression demonstrated a strong correlation between estimated and actual ablation areas (R2 = .97, P < .00001). The TDE underestimated the area of ablation by an average of 3.92% overall (standard error (SE) = 4.57%), but this varied depending on the type of pathologic tissue involved. TDE accuracy and precision were highest in tubers (n = 3), with average underestimation of 2.33% (SE = 0.33%). TDE underestimated the lesioning of the single hypothalamic hamartoma in our series by 52%. In periventricular nodular heterotopias, TDE overestimated ablation areas by an average of 13% (n = 2). CONCLUSION: TDE reliability is variably consistent across tissue types, particularly in smaller or periventricular lesions. Further investigation is needed to understand the accuracy of this emerging minimally invasive technique.

Vulnerability of the L5 nerve root during anterior lumbar interbody fusion at L5-S1: case series and review of the literature.

OBJECTIVE: Nerve root injuries associated with anterior lumbar interbody fusion (ALIF) are uncommonly reported in the literature. This case series and review aims to describe the etiology of L5 nerve root injury following ALIF at L5-S1. METHODS: The authors performed a single-center retrospective review of prospectively collected data of patients who underwent surgery between 2017 and 2019 who had postoperative L5 nerve root injuries after stand-alone L5-S1 ALIF. They also reviewed the literature with regard to nerve root injuries after ALIF procedures. RESULTS: The authors report on 3 patients with postoperative L5 radiculopathy. All 3 patients had pain that improved. Two of the 3 patients had a neurological deficit, one of which improved. CONCLUSIONS: Stretch neuropraxia from overdistraction is an important cause of postoperative L5 radiculopathy after L5-S1 ALIF. Judicious use of implants and careful preoperative planning to determine optimal implant sizes are paramount.

An Initial Cost-Effectiveness Analysis of Magnetic Resonance-Guided Laser Interstitial Thermal Therapy in Pediatric Epilepsy Surgery.

INTRODUCTION: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a new technology that provides a clinically efficacious and minimally invasive alternative to conventional microsurgical resection. However, little data exist on how costs compare to traditional open surgery. The goal of this paper is to investigate the cost-effectiveness of MRgLITT in the treatment of pediatric epilepsy. METHODS: We retrospectively analyzed the medical records of pediatric patients who underwent MRgLITT via the Visualase® thermal therapy system (Medtronic, Inc., Minneapolis, MN, USA) between December 2013 and September 2017. Direct costs associated with preoperative, operative, and follow-up care were extracted. Benefit was calculated in quality-adjusted life years (QALYs), and the cost-effectiveness was derived from the discounted total direct costs over QALY. Sensitivity analysis on 4 variables was utilized to assess the validity of our results. RESULTS: Twelve consecutive pediatric patients with medically refractory epilepsy underwent MRgLITT procedures. At the last postoperative follow-up, 8 patients were seizure free (Engel I, 66.7%), 2 demonstrated significant improvement (Engel II, 16.7%), and 2 patients showed worthwhile improvement (Engel III, 16.7%). The average cumulative discounted QALY was 2.11 over the lifetime of a patient. Adjusting for inflation, MRgLITT procedures had a cost-effectiveness of USD 22,211 per QALY. Our sensitivity analysis of cost variables is robust and supports the procedure to be cost--effective. CONCLUSION: Our data suggests that MRgLITT may be a cost-effective alternative to traditional surgical resection in pediatric epilepsy surgery.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for the Treatment of Nonlesional Insular Epilepsy in Pediatric Patients: Technical Considerations.

INTRODUCTION: The insula presents anatomic challenges to surgical exploration and intervention. Open neurosurgical intervention is associated with high rates of complications despite improved seizure control. Minimally invasive techniques using novel energy delivery methods have gained popularity due to their relative safety and ability to overcome access-related barriers. The goal of this paper is to present an operative technical report and methodological considerations on the application of magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) for the treatment of nonlesional, medically refractory, insular epilepsy in pediatric patients. METHODS: Visualase laser probe(s) were implanted using ROSA robotic stereotactic guidance into the insula using a parasagittal trajectory. After confirmation of placement using intraoperative MRI, thermal energy was delivered under real-time MR guidance. Laser wire pullback was performed when the initial dose of thermal energy was insufficient to ablate the target in its entirety. Thermal ablation within the intended target was confirmed using gadolinium-enhanced brain MRI. Following removal of laser wires, a final T1-weighted axial brain MRI was performed to confirm no evidence of hemorrhage. RESULTS: Three patients underwent MRgLITT of nonlesional insular epilepsy over an 11-month period. The epileptogenic focus was localized to the insula using stereoelectroencephalography. The anterior and middle portions of the insula were accessed using a parasagittal trajectory. Laser ablation was performed for up to 3 min using an output of 10.5 W. No complications were encountered, and all patients were discharged within 24 h after the surgery. At the most recent follow-up, all patients had an Engel I outcome without any new neurologic deficits. CONCLUSION: This small cohort shows that insular ablation can be achieved safely with promising seizure outcomes in the short term.

Rigid Cranial Fixation for Robot-Assisted Stereoelectroencephalography in Toddlers: Technical Considerations.

BACKGROUND: Stereoelectroencephalography (sEEG) using depth electrodes has become a mainstay of pediatric epilepsy surgery. This technique relies on rigid cranial fixation using skull pins, which forms the basis for accurate stereotactic navigation. The use of cranial fixation pins poses the threat of traumatic skull injuries in young children because of inadequate cranial bone thickness. OBJECTIVE: To describe a rigid cranial fixation technique involving the integrated Gel Head Ring from the DORO QR3 multipurpose skull clamp set (Pro Med Instruments) with superimposed pin fixation in children below the age of 36 mo undergoing sEEG. METHODS: Patients were placed in the supine position and the head was fixed using a DORO skull clamp with 3 pediatric cranial pins. The head was supported on the integrated Gel Head Ring, and a pin pressure of 20 pounds was applied. The DORO skull clamp set was then attached to the ROSA neurosurgical robot support telescopic arm for stereotactic navigation. RESULTS: We present an illustrative series of 2 patients below the age of 3 yr with medically refractory epilepsy who underwent sEEG using our modified cranial fixation technique. Head position and reference registration were stable throughout the surgeries. Postoperative volumetric computed tomography scans of the head showed accurate placement of sEEG depth electrodes and did not reveal any fractures or epidural hematoma. No other complications related to cranial fixation were noted. CONCLUSION: Concurrent use of rigid and nonrigid cranial fixation using the DORO skull clamp set provides safe and effective cranial fixation in infants and toddlers undergoing sEEG.

Magnetic resonance-guided laser interstitial thermal therapy for the treatment of non-lesional insular epilepsy in pediatric patients: thermal dynamic and volumetric factors influencing seizure outcomes.

PURPOSE: To investigate the safety and efficacy of stereoelectroencephalography (sEEG) directed magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) in medically refractory insular epilepsy in pediatric patients, define the relationship between ablation volumes and seizure control, and analyze the relationship between thermal energy and ablation volumes. METHODS: A single-institution, retrospective review of pediatric patients with insular epilepsy who underwent sEEG directed MRgLITT over a 10-month period was performed. Perioperative, imaging, and outcome data were analyzed. Seizure outcomes were determined based on Engel score (Engel I versus Engel II-IV). Insula and ablation volumes were measured, and the proportion of insula volume ablated was calculated. Thermal energy was calculated in joules. RESULTS: Four patients underwent sEEG directed MRgLITT of insular epileptogenic foci. The ablation volume was higher in patients with Engel I outcome (3.93 cm3) compared to Engel II-IV outcome (1.02 cm3). The proportion of ablation to insula volume was lowest in patients with Engel II-IV outcome (25.09%). The mean energy requirement to create a unit volume of ablation in the insula is 1205.86 J. A linear trend was noted between thermal ablation energy and ablation volume (R2 = 0.884). Over a mean follow-up period of 104 days, three patients were seizure-free (Engel I), and one patient saw significant improvement in seizure frequency (Engel III). CONCLUSIONS: The proportion of insula ablated, as well as the volume of ablation, are related to seizure outcome with increasing ablation volumes corresponding to improved seizure control. Further analysis of insula laser ablation thermal dynamics and volumes is needed.

Tpl2 knockout keratinocytes have increased biomarkers for invasion and metastasis.

Skin cancer is the most common form of cancer in the USA, with an estimated two million cases diagnosed annually. Tumor progression locus 2 (Tpl2), also known as MAP3K8, is a serine/threonine protein kinase in the mitogen-activated protein kinase signal transduction cascade. Tpl2 was identified by our laboratory as having a tumor suppressor function in skin carcinogenesis, with the absence of this gene contributing to heightened inflammation and increased skin carcinogenesis. In this study, we used gene expression profiling to compare expression levels between Tpl2 (+/+) and Tpl2 (-) (/-) keratinocytes. We identified over 2000 genes as being differentially expressed between genotypes. Functional annotation analysis identified cancer, cell growth/proliferation, cell death, cell development, cell movement and cell signaling as the top biological processes to be differentially regulated between genotypes. Further microarray analysis identified several candidate genes, including Mmp1b, Mmp2, Mmp9 and Mmp13, involved in migration and invasion to be upregulated in Tpl2 (-) (/-) keratinocytes. Moreover, Tpl2 (-/-) keratinocytes had a significant downregulation in the matrix metalloproteinase (MMP) inhibitor Timp3. Real-time PCR validated the upregulation of the MMPs in Tpl2 (-/-) keratinocytes and zymography confirmed that MMP2 and MMP9 activity was higher in conditioned media from Tpl2 (-/-) keratinocytes. Immunohistochemistry confirmed higher MMP9 staining in 12-O-tetradecanoylphorbol-13-acetate-treated skin from Tpl2 (-/-) mice and grafted tumors formed from v-ras(Ha) retrovirus-infected Tpl2 (-/-) keratinocytes. Additionally, Tpl2 (-/-) keratinocytes had significantly higher invasion, malignant conversion rates and increased endothelial cell tube formation when compared with Tpl2 (+/+) keratinocytes. In summary, our studies reveal that keratinocytes from Tpl2 (-/-) mice demonstrate a higher potential to be invasive and metastatic.