IU Indianapolis ScholarWorks :: Browsing by Author "Cohen-Gadol, Aaron A."

Browsing by Author "Cohen-Gadol, Aaron A."

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A Contemporary Clinico-Anatomical Guide to Craniovertebral Junction Surgery
(Thieme, 2022-09-28) Spiessberger, Alexander; Gruter, Basil; Prashant, Giyarpuram; Haegler, Joshua; Eisenberg, Mark; Cohen-Gadol, Aaron A.; Dehdashti, Amir R.; Neurological Surgery, School of Medicine
Background: Surgical treatment of ventral and ventrolateral lesions of the craniocervical junction are among the most challenging neurosurgical pathologies to treat. Three surgical techniques, the far lateral approach (and its variations), the anterolateral approach, and the endoscopic far medial approach can be used to approach and resect lesions in this area. Objective: The aim of the study is to examine the surgical anatomy of three skull base approaches to the craniocervical junction and review surgical cases to better understand the indications and possible complications for each of these approaches. Methods: Cadaveric dissections with standard microsurgical and endoscopic instruments were performed for each of the three surgical approaches, and key steps and surgically relevant anatomy were documented. Six patients with appropriate pre-, post-, and intraoperative imaging and video documentation are presented and discussed accordingly. Results: Based on our institutional experience, all three approaches can be utilized to safely and effectively approach a wide variety of neoplastic and vascular pathology. Unique anatomical characteristics, lesion morphology and size, and tumor biology should all be considered when determining the optimal approach. Conclusion: Preoperative assessment of surgical corridors with 3D illustrations helps to define the best surgical corridor. 360 degree knowledge of the anatomy of craniovertebral junction allows safe surgical approach and treatment of ventral and ventrolateral located lesions using one of the three approaches.
Acridine Orange as a Novel Photosensitizer for Photodynamic Therapy in Glioblastoma
(Elsevier, 2018) Osman, Hany; Elsahy, Deena; Saadatzadeh, M. Reza; Pollok, Karen E.; Yocom, Steven; Hattab, Eyas; Georges, Joseph; Cohen-Gadol, Aaron A.; Neurological Surgery, School of Medicine
Object Photodynamic therapy is an exciting treatment modality that combines the effects of a chemical agent with the physical energy from light or radiation to result in lysis of cells of interest. Acridine orange is a molecule with fluorescence properties that was demonstrated to possess photosensitizing properties. The objective of this study was to investigate the photodynamic effect of acridine orange on glioblastoma cell viability and growth. Methods Glioblastoma cells (n = 8000 cells/well at 0 hours) were exposed to acridine orange followed by white unfiltered light-emitting diodes (LED) light. Cultures were exposed to either 10 or 30 minutes of light. The cell number per well was determined at 0, 24, 48, and 72 hours after exposure. Results A dramatic cytocidal effect of acridine orange after exposure to as little as 10 minutes of white light was observed. There was almost complete eradication of the glioblastoma cells over a 72-hour period. Although acridine orange or light alone exhibited some effect on cell growth, it was not as pronounced as the combination of acridine orange and light. Conclusions This is the first study to demonstrate the photodynamic effect of acridine orange in glioblastoma cells. This data supports the need for further studies to characterize and evaluate whether this striking cytotoxic effect can be achieved in vivo. The combination of acridine orange and exposure to white unfiltered LED light may have potential future applications in management of glioblastoma.
Adenoid Cystic Carcinoma (ACC) Infiltrating the Skull Base: A Systematic Review of Clinical Characteristics and Management Strategies
(International Institute of Anticancer Research, 2022-09-03) Bin-Alamer, Othman; Haider, Ali S.; Chaudhary, Adhiraj; Balasubramanian, Kishore; Breeding, Tessa; Palmisciano, Paolo; Haider, Maryam; Cohen-Gadol, Aaron A.; El Ahmadieh, Tarek Y.; Yu, Kenny; Neurological Surgery, School of Medicine
Background/aim: To systematically review the patient characteristics and management approaches of adenoid cystic carcinoma (ACC) infiltrating the skull base. Materials and methods: According to PRISMA guidelines, PubMed, Scopus, and Cochrane were searched to retrieve studies reporting management protocols and survival outcomes of patients with skull base ACCs. Patient characteristics, management strategies, and outcomes were investigated. Results: The review encompassed 17 studies involving 171 patients, with a female predominance (57.9%) and a mean age of 49±7.12 years. ACCs mostly infiltrated the paranasal sinus (22.2%), cavernous sinus (8.8%), and nasopharynx (7.1%). Perineural invasion was reported in 6.4% of cases. Facial pain, nasal obstruction, and facial paresthesia were the most common symptoms. Surgical resection (45.6%) was favored over biopsy (12.2%). Employing the free flap technique (4.7%), surgical reconstruction of the bony defect after resection was performed using abdominal and anterior thigh muscle grafts in 1.8% of patients each. As adjuvant management, 22.8% of cases had radiotherapy and 14.6% received chemotherapy. Recurrence of skull base ACCs occurred in 26.9% of cases during a mean follow up-time of 30.8±1.8 months. Conclusion: Skull base ACCs pose a surgical challenge mainly due to their proximity to critical neurovascular structures and aggressive behavior. Surgical resection and radiotherapy are shown to be safe and effective treatment modalities. The dismal prognosis and limited data on non-surgical strategies highlight the need for further evaluation of the current management paradigm and upraising innovative therapies to improve patient mortality and quality of life.
Adenoid Cystic Carcinoma (ACC) Infiltrating the Skull Base: A Systematic Review of Clinical Characteristics and Management Strategies
(IIAR, 2022-09-03) Bin-Alamer, Othman; Haider, Ali S.; Chaudhary, Adhiraj; Balasubramanian, Kishore; Breeding, Tessa; Palmisciano, Paolo; Haider, Maryam; Cohen-Gadol, Aaron A.; El Ahmadieh, Tarek Y.; Yu, Kenny; Neurological Surgery, School of Medicine
Background/Aim: To systematically review the patient characteristics and management approaches of adenoid cystic carcinoma (ACC) infiltrating the skull base. Materials and Methods: According to PRISMA guidelines, PubMed, Scopus, and Cochrane were searched to retrieve studies reporting management protocols and survival outcomes of patients with skull base ACCs. Patient characteristics, management strategies, and outcomes were investigated. Results: The review encompassed 17 studies involving 171 patients, with a female predominance (57.9%) and a mean age of 49±7.12 years. ACCs mostly infiltrated the paranasal sinus (22.2%), cavernous sinus (8.8%), and nasopharynx (7.1%). Perineural invasion was reported in 6.4% of cases. Facial pain, nasal obstruction, and facial paresthesia were the most common symptoms. Surgical resection (45.6%) was favored over biopsy (12.2%). Employing the free flap technique (4.7%), surgical reconstruction of the bony defect after resection was performed using abdominal and anterior thigh muscle grafts in 1.8% of patients each. As adjuvant management, 22.8% of cases had radiotherapy and 14.6% received chemotherapy. Recurrence of skull base ACCs occurred in 26.9% of cases during a mean follow up-time of 30.8±1.8 months. Conclusion: Skull base ACCs pose a surgical challenge mainly due to their proximity to critical neurovascular structures and aggressive behavior. Surgical resection and radiotherapy are shown to be safe and effective treatment modalities. The dismal prognosis and limited data on non-surgical strategies highlight the need for further evaluation of the current management paradigm and upraising innovative therapies to improve patient mortality and quality of life.
Aging- and Tumor-Mediated Increase in CD8+CD28- T Cells Might Impose a Strong Barrier to Success of Immunotherapy in Glioblastoma
(American Association of Immunologists, 2021-06-08) Huff, Wei X.; Bam, Marpe; Shireman, Jack M.; Kwon, Jae Hyun; Song, Leo; Newman, Sharlé; Cohen-Gadol, Aaron A.; Shapiro, Scott; Jones, Tamara; Fulton, Kelsey; Liu, Sheng; Tanaka, Hiromi; Liu, Yunlong; Wan, Jun; Dey, Mahua; Neurological Surgery, School of Medicine
Clinical use of various forms of immunotherapeutic drugs in glioblastoma (GBM), has highlighted severe T-cell dysfunction such as exhaustion in GBM patients. However, reversing T-cell exhaustion using immune checkpoint inhibitors in GBM clinical trials has not shown significant overall survival benefit. Phenotypically, CD8+ T cells with downregulated CD28 co-receptors, low CD27 expression, increased CD57 expression, and telomere shortening, are classified as senescent T cells. These senescent T cells are normally seen as part of aging and also in many forms of solid cancers. Absence of CD28 on T-cells leads to several functional irregularities including reduced TCR diversity, incomplete activation of T cells, and defects in antigen induced proliferation. In the context of GBM, presence and/or function of these CD8+CD28− T-cells is unknown. In this clinical correlative study, we investigated the effect of aging as well as tumor microenvironment on CD8+ T-cell phenotype as an indicator of its function in GBM patients. We systematically analyzed and describe a large population of CD8+CD28− T-cells in both the blood and tumor infiltrating lymphocytes of GBM patients. We found that phenotypically these CD8+CD28− T-cells represent a distinct population compared to exhausted T-cells. Comparative transcriptomic and pathway analysis of CD8+CD28− T cell populations in GBM patients revealed that tumor microenvironment might be influencing several immune related pathways and thus further exaggerating the age associated immune dysfunction in this patient population.
Analysis of human gliomas by swab touch spray-mass spectrometry: applications to intraoperative assessment of surgical margins and presence of oncometabolites
(Royal Society of Chemistry, 2017-10-23) Pirro, Valentina; Llor, Raquel Sero; Jarmusch, Alan K.; Alfaro, Clint M.; Cohen-Gadol, Aaron A.; Hattab, Eyas M.; Cooks, R. Graham; Neurological Surgery, School of Medicine
Touch spray mass spectrometry using medical swabs is an ambient ionization technique (ionization of unprocessed sample in the open air) that has potential intraoperative application in quickly identifying the disease state of tissue and in better characterizing the resection margin. To explore this potential, we studied 29 human brain tumor specimens and obtained evidence that this technique can provide diagnostic molecular information that is relevant to brain cancer. Touch spray using medical swabs involves the physical sampling of tissue using a medical swab on a spatial scale of a few mm2 with subsequent ionization occurring directly from the swab tip upon addition of solvent and application of a high voltage. Using a tertiary mixture of acetonitrile, N,N-dimethylformamide, and ethanol, membrane-derived phospholipids and oncometabolites are extracted from the tissue, incorporated into the sprayed microdroplets, vacuumed into the mass spectrometer, and characterized in the resulting mass spectra. The tumor cell load was assessed from the complex phospholipid pattern in the mass spectra and also separately by measurement of N-acetylaspartate. Mutation status of the isocitrate dehydrogenase gene was determined via detection of the oncometabolite 2-hydroxyglutarate. The lack of sample pretreatment makes touch spray mass spectrometry using medical swabs a feasible intraoperative strategy for rapid surgical assessment.
Anterior communicating artery complex aneurysms: anatomic characteristics as predictors of surgical outcome in 300 cases
(Elsevier, 2018) Bohnstedt, Bradley N.; Conger, Andrew R.; Edwards, John; Ziemba-Davis, Mary; Edwards, Gary; Brom, Jacqueline; Shah, Kushal; Cohen-Gadol, Aaron A.; Neurological Surgery, School of Medicine
OBJECTIVE Anterior communicating artery (ACoA) complex aneurysms are challenging to treat microsurgically. The authors report their experience with microsurgical treatment of ACoA aneurysms and examine the anatomic characteristics of these aneurysms as predictors of outcome. METHODS The authors queried their institution’s aneurysm database for records of consecutive patients treated for ACoA aneurysms via microsurgical clip ligation. Data included patient demographics and clinical/radiographic presentation characteristics as well as operative techniques. Glasgow outcome scores (GOS) at hospital discharge and 6-month as well as 1-year follow-up were analyzed. RESULTS Of 319 ACoA aneurysms that underwent treatment, 259 were ruptured and 60 were unruptured. Average GOS at 1-year follow-up for all patients was 4.6. Average GOS for patients with ruptured aneurysms correlated with Hunt and Hess grade at presentation, presence of frontal hemorrhages, and need for multiple clips during surgery. Notably, 142 (44.5%) of aneurysms originated mainly from the ACoA artery; 12 (3.8%) primarily from the A1 branch; 3 (0.9%) from the A2 branch; and 162 (50.8%) from the A1/A2 junction. Aneurysm projection was superior in 118 (37%), inferior in 106 (33.2%), anterior in 88 (27.6%), and posterior in 7 (2.2%). Patients with aneurysms originating from the A1 segment had worse outcomes. Posteriorly-projecting aneurysms were more likely to be unruptured and larger than other aneurysm configurations. CONCLUSIONS The aneurysm’s exact location in relation to the adjacent neurovascular structures is potentially predictive of outcomes in the microsurgical treatment of ACoA aneurysms.
Blood Supply to the Human Spinal Cord. I. Anatomy and Hemodynamics
(Wiley, 2015-01) Bosmia, Anand N.; Hogan, Elizabeth; Loukas, Marios; Tubbs, R. Shane; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, IU School of Medicine
The arterial network that supplies the human spinal cord, which was once thought to be similar to that of the brain, is in fact much different and more extensive. In this article, the authors attempt to provide a comprehensive review of the literature regarding the anatomy and known hemodynamics of the blood supply to the human spinal cord. Additionally, as the medical literature often fails to provide accurate terminology for the arteries that supply the cord, the authors attempt to categorize and clarify this nomenclature. A complete understanding of the morphology of the arterial blood supply to the human spinal cord is important to anatomists and clinicians alike.
Blood Supply to the Human Spinal Cord. II. Imaging and Pathology
(Wiley, 2015-01) Bosmia, Anand N.; Tubbs, R. Shane; Hogan, Elizabeth; Bohnstedt, Bradley N.; DeNardo, Andrew J.; Loukas, Marios; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, IU School of Medicine
The blood supply of the spinal cord is a complex system based on multilevel sources and anastomoses. Diseases often affect this vascular supply and imaging has been developed that better investigates these structures. The authors review the literature regarding pathology and imaging modalities for the blood supply of the spinal cord. Knowledge of the disease processes and imaging modalities used to investigate these arterial lesions of the spinal cord will assist the clinician when treating patients with spinal cord lesions.
Characterization of outcomes and practices utilized in the management of internal carotid artery injury not requiring definitive endovascular management
(Wiley, 2021-07-17) London, Nyall R., Jr.; AlQahtani, Abdulaziz; Barbosa, Siani; Castelnuovo, Paolo; Locatelli, Davide; Stamm, Aldo; Cohen-Gadol, Aaron A.; Elbosraty, Hussam; Casiano, Roy; Morcos, Jacques; Pasquini, Ernesto; Frank, Georgio; Mazzatenta, Diego; Barkhoudarian, Garni; Griffiths, Chester; Kelly, Daniel; Georgalas, Christos; Janakiram, Trichy N.; Nicolai, Piero; Prevedello, Daniel M.; Carrau, Ricardo L.; Neurological Surgery, School of Medicine
Background: After internal carotid artery (ICA) injury during endoscopic skull base surgery, the majority of patients undergo ICA embolization or stenting to treat active extravasation or pseudoaneurysm development. However, management practices when embolization or stenting is not required have not been well described. The objective of this study was to determine how patients with ICA injury but no embolization, stenting, or ligation do long-term and ascertain the reconstruction methods utilized. Methods: Twenty-nine cases of ICA injury were identified in an international multi-institutional retrospective review. Of these, we identified six cases that were not treated with embolization, stenting, or ICA sacrifice. Information was available for five cases. Results: A muscle patch was used in the immediate repair of each case. A nasoseptal flap was used in one case. Prefabricated nasal tampons were used in all cases. Nasal packing was initially left in for a median of 7 days prior to removal. The initial muscle patch was reinforced with a second muscle graft in one case. One case demonstrated ICA bleeding at the time of packing removal and was repacked an additional week. Follow-up for each of these cases was at least 2 years. No cases of subsequent carotid rupture were found and none of these cases ultimately underwent endovascular stenting. Radiation or proton therapy has not been subsequently used in any of these patients. Conclusions: This study details the reconstruction, lessons learned, and long-term follow-up for five cases of ICA injury not treated with embolization, stenting, or ligation.

Browsing by Author "Cohen-Gadol, Aaron A."

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