12 results on '"Chakravarthy, Vikram"'
Search Results
2. Novel Intrafraction Motion Tracking During Postoperative Spine Stereotactic Irradiation for a Patient With Carbon Fiber Fixation Hardware.
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Lee-Poprocki, Hyeri, Ritter, Alex R., Upadhyay, Rituraj, Perlow, Haley K., Ayan, Ahmet S., Cetnar, Ashley J., Degnan, Michael, Scharschmidt, Thomas J., Mendel, Ehud, Blakaj, Dukagjin M., Thomas, Evan M., Chakravarthy, Vikram B., Elder, James B., and Palmer, Joshua D.
- Abstract
Carbon-fiber reinforced (CFR) polyetheretherketone hardware is an alternative to traditional metal hardware used for spinal fixation surgeries before postoperative radiation therapy for patients with spinal metastases. CFR hardware's radiolucency decreases metal artifact, improving visualization and accuracy of treatment planning. We present the first clinical use and proof of principle of CFR spinal hardware with tantalum markers used for successful tracking of intrafraction motion (IM) using Varian TrueBeam IMR (Intrafraction Motion Review) software module during postoperative spine stereotactic radiation. A 63-year-old woman with history of endometrial cancer presented with acute back pain. Imaging demonstrated pathologic T12 vertebral fracture with cord compression. She underwent T12 vertebrectomy with circumferential decompression and posterior instrumented T10-L2 fusion at our facility using CFR-polyetheretherketone hardware with tantalum screw markers followed by postoperative stereotactic body radiation therapy to 3000 cGy in 5 fractions delivered to T11-T12. Tantalum screw markers were used for IMR tracking. During irradiation, 260 kV images were acquired, and IMR software was able to identify and track markers. During the entire treatment, the IM motions were less than 3 mm. This is the first presented case of CFR spinal hardware with tantalum markers used for successful IMR tracking of IM during daily spine stereotactic treatment. Future work will be needed to improve workflow and create a spine-specific IMR protocol. [ABSTRACT FROM AUTHOR]
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- 2023
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3. Long-Term Clinical Outcomes of Patients with Colorectal Cancer with Metastatic Epidural Spinal Cord Compression Treated with Hybrid Therapy (Surgery Followed by Stereotactic Body Radiation Therapy).
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Chakravarthy, Vikram B., Schachner, Ben, Amin, Anubhav, Reiner, Anne S., Yamada, Yoshiya, Schmitt, Adam, Higginson, Daniel S., Laufer, Ilya, Bilsky, Mark H., and Barzilai, Ori
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STEREOTACTIC radiotherapy , *RADIOTHERAPY , *COMPRESSION therapy , *SPINAL cord compression , *CANCER prognosis , *STEREOTAXIC techniques , *SPINAL nerve roots - Abstract
Hybrid therapy, consisting of separation surgery followed by stereotactic body radiation therapy, 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 was to evaluate clinical outcomes for patients treated with hybrid therapy for spinal metastases from CRC. This retrospective study was 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 to 2020 were included. Outcome variables evaluated included patient demographics, overall survival and progression-free survival, surgical and radiation complications, and clinical-genomic correlations. Inclusion criteria were met by 50 patients. 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. 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 other spinal levels. Hybrid therapy in patients with CRC resulted in 86.7% local control at 2 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. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Treatment of IgG4-related pachymeningitis in a patient with steroid intolerance: The role of early use of rituximab
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Gospodarev, Vadim, Câmara, Justin, Chakravarthy, Vikram, Perry, Arie, Wood, Matthew, Dietz, Robin, Wang, Jun, De Los Reyes, Kenneth, and Raghavan, Ravi
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- 2016
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5. Surgical Outcomes in Patients with Congenital Cervical Spinal Stenosis.
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Atli, Karam, Chakravarthy, Vikram, Khan, Aleem I., Moore, Don, Steinmetz, Michael P., and Mroz, Thomas E.
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SPINAL stenosis , *CERVICAL spondylotic myelopathy , *INSTITUTIONAL review boards , *LAMINECTOMY , *SURGICAL decompression - Abstract
To evaluate the differences in surgical outcomes of patients with cervical spondylotic myelopathy with and without congenital cervical spinal stenosis (CCSS). Institutional review board approval was obtained to conduct a retrospective chart review of patients with cervical spondylotic myelopathy who underwent decompression and fusion surgeries from 2010–2016 at a single institution. CCSS was identified using the Torg-Pavlov ratio on lateral cervical radiographs. Pre- and postoperative outcome measures were assessed using the modified Japanese Orthopedic Association (mJOA) and the EuroQol 5-dimension questionnaire (EQ-5D). Of 208 patients, Torg-Pavlov ratio identified 85 patients with CCSS. There were no significant differences between the CCSS patient and control patient groups in EuroQol 5-dimension questionnaire and mJOA scores at all 4 designated time points in the study (preoperative, earliest postoperative, 6 month postoperative, and 1 year postoperative). Although not statistically significantly, there was a notable trend for patients with CCSS to be less likely to have mJOA-defined severe myelopathy at the postoperative (odds ratio [OR], 0.75; P = 0.38), 6 month postoperative (OR, 0.66; P = 0.20), and 1 year postoperative (OR, 0.64; P = 0.14) time points. Postoperatively, compared with non-CCSS patients, patients with congenital cervical stenosis reported equal quality of life for all markers. Our findings suggest that in patients with CCSS and relatively mild symptoms of myelopathy, equal consideration should be given for surgical intervention. The findings of this study warrant further large-scale, multi-institutional investigation to further understand the generalizability of these surgical outcome results. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Ethics of Decision-Making in Metastatic Spinal Disease.
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Chakravarthy, Vikram B., Applewhite, Megan K., and Krishnaney, Ajit A.
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SPINE diseases , *METASTASIS , *ETHICS , *SPINAL cord compression , *DECISION making - Abstract
Autonomy, Ethics, Justice, Metastatic epidural spinal cord compression, Spine oncology, Beneficence, Nonmaleficence. [Extracted from the article]
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- 2021
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7. Computed Tomography Cisternography for Evaluation of Trigeminal Neuralgia When Magnetic Resonance Imaging Is Contraindicated: Case Report and Review of the Literature.
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Gospodarev, Vadim, Chakravarthy, Vikram, Harms, Casey, Myers, Hannah, Kaplan, Brett, Kim, Esther, Pond, Matthew, and De Los Reyes, Kenneth
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TRIGEMINAL neuralgia , *COMPUTED tomography , *CISTERNOGRAPHY , *MAGNETIC resonance imaging , *SURGICAL decompression - Abstract
Background Trigeminal neuralgia (TGN) causes severe unilateral facial pain. The etiology is hypothesized to be segmental demyelination of the trigeminal nerve root via compression by the superior cerebellar artery (SCA). Microvascular decompression (MVD) allows immediate and long-term pain relief. Preoperative evaluation includes magnetic resonance imaging (MRI) and/or magnetic resonance angiography of the brain. Having a pacemaker is a contraindication for MRI. There have been isolated reports of using computed tomography (CT) cisternography scans for radiation planning for TGN. Case Description A 75-year-old male with a permanent pacemaker who had refractory TGN in the V2 (maxillary) distribution of the trigeminal nerve underwent CT cisternography to prepare for MVD. CT angiography with Isovue 370 intravenous contrast injection and 0.625-mm axial images were obtained from the skull base across the posterior fossa. An intrathecal injection of Isovue 180 was performed at the L2/3 level. Imaging revealed the right SCA abutting the medial margin of the proximal right trigeminal nerve. In surgery (K.D.), a standard retrosigmoid suboccipital craniotomy was performed to access the cerebellopontine angle and separate the abutting SCA and trigeminal nerve. The patient had immediate pain relief. Conclusions MRI is the preferred method of evaluating for TGN because it offers excellent visualization of vasculature in relation to the trigeminal nerve without accompanying radiation exposure. However, for patients who have contraindications to MRI, CT cisternography is shown to also be an effective method for visualizing the trigeminal root entry zone and nearby vasculature in preparation for MVD of the trigeminal nerve. [ABSTRACT FROM AUTHOR]
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- 2018
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8. Corrigendum to 'Surgical Outcomes in Patients with Congenital Cervical Spinal Stenosis' [World Neurosurgery 141 (2020) e645-e650].
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Atli, Karam, Chakravarthy, Vikram, Khan, Aleem I., Lee, Bryan S., Moore, Don, Steinmetz, Michael P., and Mroz, Thomas E.
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SPINAL stenosis , *NEUROSURGERY - Published
- 2021
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9. Houdini Tumor: Case Report and Literature Review of Pregnancy-Associated Meningioma.
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Chakravarthy, Vikram, Kaplan, Brett, Gospodarev, Vadim, Myers, Hannah, De Los Reyes, Kenneth, and Achiriloaie, Adina
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MENINGIOMA , *PREGNANCY complications , *MAGNETIC resonance imaging , *INTRACRANIAL pressure , *DISEASE progression - Abstract
Background Meningiomas are common intracranial neoplasms of undetermined etiology. Accelerated growth during episodes of elevated serum estrogen and progesterone have been demonstrated in pregnant patients, as exhibited by an overexpression of estrogen or progesterone on immunohistochemical analysis. This case report and literature review describe a case of complete meningioma regression in a postpartum patient. Case Description A 23-year-old female presented at 37 weeks of pregnancy with 1-month history of fluctuating severe left-sided headaches, periodic blurry vision, nausea, and vomiting. She had 2 previous pregnancies without complication. Magnetic resonance imaging revealed a dural-based, heterogeneously enhancing mass along the left tentorium, just posterior to the transverse sinus, with supratentorial extension and surrounding edema. Differential diagnoses included meningioma versus hemangioma versus hemangiopericytoma. The patient followed up with neurosurgery 1 month after delivery. She had continued left-sided headaches but no longer complained of visual changes. A postpartum surgical resection via left occipital and suboccipital craniotomy was planned. Approximately 1 month later (now about 3 months after delivery) a repeat magnetic resonance imaging demonstrated a marked decrease in meningioma size, and the previously seen edema had resolved. In light of the sudden disappearance of the meningioma, no further surgical intervention was pursued. Conclusions Because meningioma shrinkage or disappearance may occur after pregnancy, repeat imaging is advised as part of a preoperative evaluation. In addition, it is possible that an undetermined amount of meningioma removal surgeries may be avoided with further research into monitoring hormone levels connected to meningioma growth. [ABSTRACT FROM AUTHOR]
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- 2018
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10. Interpretable Artificial Swarm Intelligence in Complex Neurosurgical Decision Making: Part 1.
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Habboub, Ghaith, Tish, Shahed, Chakravarthy, Vikram, Mroz, Thomas, Ghogawala, Zoher, and Benzel, Edward
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SWARM intelligence , *ARTIFICIAL intelligence , *DECISION making , *PHYSICIAN-patient relations , *COLLECTIVE representation - Published
- 2020
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11. Trends in Leadership Among Neurosurgical Oncology Fellowships.
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Matichak, David P., Levy, Adam S., Vanderveer-Harris, Nathan, Chang, Henry, Vallejo, Frederic, Schachner, Benjamin, Shah, Ashish H., Komotar, Ricardo J., Chakravarthy, Vikram, and Ivan, Michael E.
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SCHOLARSHIPS , *VOCATIONAL guidance , *ONCOLOGY , *LEADERSHIP , *CORPORATE directors - Abstract
To examine current neurosurgical oncology leadership trends and provide a guide for those interested in obtaining fellowship directorship, we investigated fellowship director (FD) demographic, educational, and leadership characteristics. The American Association of Neurological Surgeons Academic Fellowship Directory and Committee on Advanced Subspecialty Training websites were reviewed for current U.S. program FDs for which data were collected using online resources and surveys. In total, 23 FDs (20 male and 3 female) were represented whose mean age was 52.4 years (standard deviation = 8.7). Our analysis found 65% of current neurosurgical oncology FDs to be singularly trained in neurosurgical oncology, with 8.7% possessing multiple fellowships and 34.8% possessing additional degrees. Fellowship programs producing the most FDs were University of Texas MD Anderson (4), Memorial Sloan Kettering (3), and University of Miami (2). FDs possessed an average of 148 publications, 6423 citations, and an h-index of 33.9. H-index had a high-positive correlation with age and time from residency graduation but not duration of FD appointment. Among survey respondents, 91.7% reported membership and 75% reported leadership positions among national academic societies, whereas 66.7% reported holding journal-editorial positions. The mean age of FD appointment was 46.8 years, with a mean time from fellowship completion to FD appointment of 10.0 years. Through the characterization of current leaders in the field, we provide valuable information with regards to training location trends, research productivity goals, career timelines, and target journal/national academic society involvement worth consideration among young trainees when making career decisions and plans. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Development of a novel in vitro cadaveric model for analysis of biomechanics and surgical treatment of Bertolotti syndrome.
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Golubovsky, Joshua L., Colbrunn, Robb W., Klatte, Ryan S., Nagle, Tara F., Briskin, Isaac N., Chakravarthy, Vikram B., Gillespie, Callan M., Reith, John D., Jasty, Naveen, Benzel, Edward C., and Steinmetz, Michael P.
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MEDICAL students , *LUMBAR pain , *INTELLECTUAL property , *NEUROLOGICAL disorders , *BONES , *ACOUSTIC radiation force impulse imaging - Abstract
Background Context: Bertolotti syndrome (BS) is caused by pseudoarticulation between an aberrant L5 transverse process and the sacral ala, termed a lumbosacral transitional vertebra (LSTV). BS is thought to cause low back pain and is treated with resection or fusion, both of which have shown success. Acquiring cadavers with BS is challenging. Thus, we combined 3D printing, based on BS patient CT scans, with normal cadaveric spines to create a BS model. We then performed biomechanical testing to determine altered kinematics from LSTV with surgical interventions. Force sensing within the pseudojoint modeled nociception for different trajectories of motion and surgical conditions.Purpose: This study examines alterations in spinal biomechanics with LSTVs and with various surgical treatments for BS in order to learn more about pain and degeneration in this condition, in order to help optimize surgical decision-making. In addition, this study evaluates BS histology in order to better understand the pathology and to help define pain generators-if, indeed, they actually exist.Study Design/setting: Model Development: A retrospective patient review of 25 patients was performed to determine the imaging criteria that defines the classical BS patient. Surgical tissue was extracted from four BS patients for 3D-printing material selection. Biomechanical Analysis. This was a prospective cadaveric biomechanical study of seven spines evaluating spinal motions, and loads, over various surgical conditions (intact, LSTV, and LSTV with various fusions). Additionally, forces at the LSTV joint were measured for the LSTV and LSTV with fusion condition. Histological Analysis: Histologic analysis was performed prospectively on the four surgical specimens from patients undergoing pseudoarthrectomy for BS at our institution to learn more about potential pain generators.Patient Sample: The cadaveric portion of the study involved seven cadaveric spines. Four patients were prospectively recruited to have their surgical specimens assessed histologically and biomechanically for this study. Patients under the age of 18 were excluded.Outcome Measures: Physiological measures recorded in this study were broken down into histologic analysis, tissue biomechanical analysis, and joint biomechanical analysis. Histologic analysis included pathologist interpretation of Hematoxylin and Eosin staining, as well as S-100 staining. Tissue biomechanical analysis included stiffness measurements. Joint biomechanical analysis included range of motion, resultant torques, relative axis angles, and LSTV joint forces.Methods: This study received funding from the American Academy of Neurology Medical Student Research Scholarship. Three authors hold intellectual property rights in the simVITRO robotic testing system. No other authors had relevant conflicts of interest for this study. CT images were segmented for a representative BS patient and cadaver spines. Customized cutting and drilling guides for LSTV attachment were created for individual cadavers. 3D-printed bone and cartilage structural properties were based on surgical specimen stiffness, and specimens underwent histologic analysis via Hematoxylin and Eosin, as well as S-100 staining. Joint biomechanical testing was performed on the robotic testing system for seven specimens. Force sensors detected forces in the LSTV joint. Kruskal-Wallis tests and Dunnett's tests were used for statistical analysis with significance bounded to p<.05.Results: LSTV significantly reduces motion at the L5-S1 level, particularly in lateral bending and axial rotation. Meanwhile, the LSTV increases adjacent segment motion significantly at the L2-L3 level, whereas other levels have nonsignificant trends toward increased motion with LSTV alone. Fusion involving L4-S1 (L4-L5 and L5-S1) to treat adjacent level degeneration associated with an LSTV is associated with a significant increase in adjacent segment motion at all levels other than L5-S1 compared to LSTV alone. Fusion of L5-S1 alone with LSTV significantly increases L3-L4 adjacent segment motion compared to LSTV alone. Last, ipsilateral lateral bending with or without ipsilateral axial rotation produces the greatest force on the LSTV, and these forces are significantly reduced with L5-S1 fusion.Conclusions: BS significantly decreases L5-S1 mobility, and increases some adjacent segment motion, potentially causing patient activity restriction and discomfort. Ipsilateral lateral bending with or without ipsilateral axial rotation may cause the greatest discomfort overall in these patients, and fusion of the L5-S1 or L4-S1 levels may reduce pain associated with these motions. However, due to increased adjacent segment motion with fusions compared to LSTV alone, resection of the joint may be the better treatment option if the superior levels are not unstable preoperatively.Clinical Significance: This study's results indicate that patients with BS have significantly altered spinal biomechanics and may develop pain due to increased loading forces at the LSTV joint with ipsilateral lateral bending and axial rotation. In addition, increased motion at superior levels when an LSTV is present may lead to degeneration over time. Based upon results of LSTV joint force testing, these patients' pain may be effectively treated surgically with LSTV resection or fusion involving the LSTV level if conservative management fails. Further studies are being pursued to evaluate the relationship between in vivo motion of BS patients, spinal and LSTV positioning, and pain generation to gain a better understanding of the exact source of pain in these patients. The methodologies utilized in this study can be extrapolated to recreate other spinal conditions that are poorly understood, and for which few native cadaveric specimens exist. [ABSTRACT FROM AUTHOR]- Published
- 2020
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