Araştırma Çıktıları | WoS | Scopus | TR-Dizin | PubMed
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Publication Metadata only Gamma knife radiosurgery inhibits angiogenesis of meningiomas: In vivo rat corneal assay(2013) Kiliç, Kaya; Avşar, Timuçin; Akgun, Emel; Ozkan, Abdulkadir; Toktaş, Zafer Orkun; Şeker, Aśkin N.; Kilic, Turker D.; Kiliç, Kaya, Department of Neurosurgery, T. C. Sağlık Bakanlığı, Taksim Eğitim ve Araştirma Hastanesi, Istanbul, Turkey; Avşar, Timuçin, Biotechnology and Genetics Research Center (ITU-MOBGAM), İstanbul Teknik Üniversitesi, Istanbul, Turkey; Akgun, Emel, Laboratory of Molecular Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey; Ozkan, Abdulkadir, Laboratory of Molecular Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Şeker, Aśkin N., Laboratory of Molecular Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey, Department of Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, TurkeyObjective The aim of this study is to reveal inhibitory effect of gamma knife irradiation on angiogenesis of meningiomas using rat corneal angiogenesis assay. Methods A total of 72 rats were divided into three preliminary groups. Each group, consisting of 24 rats, was implanted to World Health Organization (WHO) grade I (typical), grade II (atypical), and grade III (malignant) meningioma. Each of these three preliminary groups of 24 rats, were then divided into four subgroups, each consisting of 6 rats and subsequently irradiated by gamma knife with dose prescriptions of 0, 14, 18, and 22 Gy. The numbers of vessels that developed around the micropockets of the corneas were counted and photographed on days 5, 10, 15, and 20. Results For WHO grade I meningiomas, 18 and 22 Gy doses (P < 0.001), and for grade II meningiomas, the 22-Gy (P = 0.021) dose were found to inhibit tumor-induced angiogenesis compared with the radiation-free control group. For grade III meningiomas, there was no statistical difference with the control group in any of the doses applied. Our findings demonstrate that gamma knife irradiation may suppress the angiogenic activity of WHO grades I and II meningiomas but not of the grade III meningiomas. Conclusions For the first time, this study provides an experimental data to show the antiangiogenic effect of gamma knife irradiation on meningiomas. © 2014 Elsevier B.V., All rights reserved., MEDLINE® is the source for the MeSH terms of this document.Publication Metadata only Isolated metastasis of breast cancer to the pituitary gland(Medknow Publications A-109, Kanara Business Centre, off Link Road, Ghatkopar (E) Mumbai 400 075, 2014) Ekşi̇, Murat Şakir; Hasanov, Teyyub; Yilmaz, Baran; Akakin, Akin In; Bayri, Yasar; Bozkurt, Süheyla Uyar; Kilic, Turker D.; Ekşi̇, Murat Şakir, UCSF School of Medicine, San Francisco, United States; Hasanov, Teyyub, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Yilmaz, Baran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Akakin, Akin In, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Bayri, Yasar, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Bozkurt, Süheyla Uyar, Department of Pathology, Marmara Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey[No abstract available]Publication Metadata only The dentate nucleus and its projection system in the human cerebellum: The dentate nucleus microsurgical anatomical study(Lippincott Williams and Wilkins, 2014) Akakin, Akin In; Peris-Celda, María; Kilic, Turker D.; Şeker, Aśkin N.; Gutiérrez-Martín, Antonio J.; Rhoton, Albert L.; Akakin, Akin In, University of Florida College of Medicine, Gainesville, United States, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Peris-Celda, María, University of Florida College of Medicine, Gainesville, United States, Department of Neurosurgery, Hospital Universitari i Politècnic La Fe, Valencia, Spain; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Şeker, Aśkin N., University of Florida College of Medicine, Gainesville, United States; Gutiérrez-Martín, Antonio J., Department of Neurosurgery, Hospital Universitari i Politècnic La Fe, Valencia, Spain; Rhoton, Albert L., University of Florida College of Medicine, Gainesville, United StatesBackground: Neurosurgical management of cerebellar lesions remains challenging. Thus, it is important to have sound knowledge of the microsurgical anatomy of the cerebellum and dentate nucleus (DN) and to define different types of exposure in a variety of surgical interventions. Objective: To examine the anatomy of the DN from a neurosurgical viewpoint using fiber tracking techniques. Methods: Ten formalin-fixed human hemispheres were dissected with the Ludwig and Klingler fiber dissection technique under × 6 to × 40 magnification. Anatomic images were created with 3-dimensional diffusion tensor imaging. The relationships of the DN to tentorium and suboccipital and lateral surfaces of the cerebellum and its spatial positioning relative to different surgical approaches in the cerebellum and fourth ventricle were examined. The fiber tracts terminating at and surrounding the DN were defined. Results: The DN is at greater risk of being injured in the transvermian and supratonsillar approaches to the cerebellum and fourth ventricle, with lesser risk in the telovelar and subtonsillar approaches. Superior approaches are safer compared with other approaches. Conclusion: The DN represents an important anatomic structure in surgical interventions involving the posterior fossa, particularly in the elderly because of the common occurrence of atrophy-related problems in this age group. Functionally and anatomically, the DN is closely related to the superior and middle cerebellar peduncles. The inferior cerebellar peduncle poses positional risks because it follows an anterior and superior course relative to the DN. The telovelar approach is a safer procedure for interventions involving the pathological lesions of the fourth ventricle floor. © 2023 Elsevier B.V., All rights reserved.Publication Metadata only Hypersexuality after bilateral deep brain stimulation of the subthalamic nucleus for Parkinson's disease(Medknow Publications B9, Kanara Business Centre, off Link Road, Ghatkopar (E) Mumbai 400 075, 2014) Akakin, Akin In; Yilmaz, Baran; Urgun, Kamran; Ekşi̇, Murat Şakir; Afşar, Nazire; Kilic, Turker D.; Akakin, Akin In, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Yilmaz, Baran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Urgun, Kamran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Ekşi̇, Murat Şakir, UCSF School of Medicine, San Francisco, United States; Afşar, Nazire, Department of Neurology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey[No abstract available]Publication Metadata only Giant dilations of perivascular spaces in deep brain locations: A cause for Parkinsonism?(Medknow Publications B9, Kanara Business Centre, off Link Road, Ghatkopar (E) Mumbai 400 075, 2014) Yilmaz, Baran; Toktaş, Zafer Orkun; Ekşi̇, Murat Şakir; Toktaş, Hayal Ergin; Mayda-Domaç, Füsun; Kilic, Turker D.; Yilmaz, Baran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Ekşi̇, Murat Şakir, Department of Neurology, Erenkoy Mental Research and Training Hospital, Istanbul, Turkey; Toktaş, Hayal Ergin, Department of Orthopedic Surgery-Spine Center, University of California, San Francisco, San Francisco, United States; Mayda-Domaç, Füsun, Department of Orthopedic Surgery-Spine Center, University of California, San Francisco, San Francisco, United States; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey[No abstract available]Publication Metadata only Anterior transpedicular screw fixation of cervical spine: Is it safe? Morphological feasibility, technical properties, and accuracy of manual insertion(American Association of Neurological Surgeons, 2015) Köktekir, Ender; Toktaş, Zafer Orkun; Şeker, Aśkin N.; Akakin, Akin In; Konya, Deniz; Kilic, Turker D.; Köktekir, Ender, Department of Neurosurgery, Selçuk Üniversitesi, Selçuklu, Turkey; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Şeker, Aśkin N., Department of Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey; Akakin, Akin In, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Konya, Deniz, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, TurkeyOBJECT: Due to lack of construct stability of the current anterior cervical approaches, supplemental posterior cervical approaches are frequently employed. The use of an anterior-only approach with anterior transpedicular screws (ATPSs) has been proposed as a means of providing 3-column fixation. This study was designed to investigate the feasibility of anterior transpedicular screw (ATPS) fixation of cervical spine, to obtain the morphological measurements for technical prerequisites, and to evaluate the accuracy of the ATPS using fluoroscopy. METHODS: The study included both radiological and anatomical investigations. The radiological investigations were based on data from cervical spine CT scans performed in 65 patients. Technical prerequisites of ATPS were calculated using OsiriX for Mac OS. In the anatomical part of the study, 30 pedicles (C3-7) from 6 formalin-preserved cadavers were manually instrumented. Measurements obtained included pedicle width (PW), pedicle height (PH), pedicle transverse angle (PTA), distance of the entry point from the midline (DEPM), and distance of the entry point from the superior endplate (DEPSEP). The authors also analyzed screw position in the manually instrumented vertebrae. RESULTS: The mean PW and PH values showed a tendency to increase from C-3 to C-7 in both males and females. The means were significantly larger for both PW and PH in males than in females at all levels (p = 0.001). The overall mean PTA value was significantly lower at C-7 (p < 0.0001). The mean value for the distance of entry point from the midline (DEPM) represented a point at the contralateral side of the pedicle for every level except C-7. The mean DEPSEP values showed significant differences between all levels (p < 0.0001). Seven of the 30 screws were identified as breaching the pedicle (23.3%), these screw malplacements were seen at C-3 (3 screws), C-4 (2 screws), and C-5 (2 screws). CONCLUSIONS: The morphological measurements of this study demonstrated that ATPS fixation is feasible in selected cases. They indicate that ATPS insertion using a fluoroscopy-assisted pedicle axis view is safe at the C-6 and C-7 levels, but the results at the other levels did not prove the safety of this technique. © 2018 Elsevier B.V., All rights reserved.Publication Metadata only The supraorbital keyhole approach(Lippincott Williams and Wilkins kathiest.clai@apta.org, 2015) Tatarlı, Necati; Ceylan, Davut; Şeker, Aśkin N.; Solmaz, Bilgehan; Çavdar, Safiye; Kilic, Turker D.; Tatarlı, Necati, Department of Neurosurgery, Kartal Education and Research Hospital, Istanbul, Turkey; Ceylan, Davut, Department of Neurosurgery, Sakarya Üniversitesi, Serdivan, Turkey; Şeker, Aśkin N., Department of Neurosurgery, Marmara Üniversitesi, Istanbul, Turkey; Solmaz, Bilgehan,; Çavdar, Safiye, Department of Anatomy, Koç Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, TurkeyAim: The major aim of the present anatomical study was to demonstrate the anatomical structures that can be visualized using the supraorbital keyhole approach, both endoscopically and microscopically, from an eyebrow incision to intracranial structures. Furthermore, it defines an optimal craniotomy for surgery. Methods: Fine dissection was performed on each side of 5 formalinfixed adult cadavers according to the surgical procedures of the supraorbital keyhole approach, and each step was documented both endoscopically and microscopically. Furthermore, the distance between the superior temporal line and the supraorbital notch/foramen was measured from the 10 total sides of the 5 cadavers and from the 118 sides of the 59 autopsies. Results: Tumors and aneurysms of the anterior cranial fossa can be visualized during the supraorbital keyhole approach. The average distance between the superior temporal line and the supraorbital notch/foramen was measured. The distance obtained from the autopsies on the 25 females was 31.56 ±4.03 mm on the right side and 31.04 ±5.40mm on the left side. The average distance obtained from the autopsies on the 34 males was 34.00 ±4.59 mm on the right side and 33.59 ±5.41 mm on the left side. There was no statistically significant difference between right and left in the female and male autopsies or between sexes. Conclusions: This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size. © 2016 Elsevier B.V., All rights reserved.Publication Metadata only Association of collagen I, IX and vitamin D receptor gene polymorphisms with radiological severity of intervertebral disc degeneration in Southern European Ancestor(Springer Verlag service@springer.de, 2015) Toktaş, Zafer Orkun; Ekşi̇, Murat Şakir; Yilmaz, Baran; Demir, Mustafa Kemal; Özgen, Serdar; Kilic, Turker D.; Konya, Deniz; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Ekşi̇, Murat Şakir, UCSF School of Medicine, San Francisco, United States; Yilmaz, Baran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Demir, Mustafa Kemal, Department of Radiology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Özgen, Serdar, Department of Neurosurgery, Acıbadem Mehmet Ali Aydınlar Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Konya, Deniz, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, TurkeyPurpose: Several genomic loci have been previously found to be associated with intervertebral disc degeneration, so far. Data are mostly derived from northern European countries whereas data derived from Southern European Ancestor are limited. This study aimed to evaluate the association between radiological disease severity of lumbar disc degeneration and certain genetic loci in a sample of participants from Southern Europe. Methods: Seventy-five patients with mild to severe lumbar disc degeneration and 25 healthy controls were enrolled into the study. In each subject, each lumbar intervertebral disc was separately examined to obtain a total radiological score for disease severity. In addition, single-nucleotide polymorphisms of predefined genetic samples were analyzed in all participants: COL1A1 Sp1, COL9a2 Trp2, COL9a3 Trp3, and VDR TaqI. Results: Degeneration scores were significantly worse in cases with COL1A1 Sp1, COL9a3 Trp3, and VDR TaqI mutations, however, COL9a2 Trp2 mutation was not associated with a difference in the severity of disc degeneration. In addition, subjects with mutation in more than one gene sample (n = 20) had significantly worse degeneration scores than the remaining study participants (n = 80) (17.70 ± 2.72 vs. 21.81 ± 1.81, p < 0.001). Conclusion: Single-nucleotide polymorphisms occurring in COL1A1, COL9a3 and VDR genes seem to be associated with the development of lumbar disc degeneration in this cohort, possibly with even more pronounced association when multiple mutations are present in the same individual. By further prospective twin studies in associated genes and analyses of their relationship with environmental factors in an internationally sampled large cohort will make a more clear-minded conclusion about their association with disc degeneration, which would yield better appreciation and clinical planning of some predisposed people for these pathologies. © 2016 Elsevier B.V., All rights reserved.Publication Metadata only Gamma Knife treatment of low-grade gliomas in children(Springer Verlag service@springer.de, 2015) Ekşi̇, Murat Şakir; Yilmaz, Baran; Akakin, Akin In; Toktaş, Zafer Orkun; Kaur, Ahmet Cemil; Demir, Mustafa Kemal; Kilic, Turker D.; Ekşi̇, Murat Şakir, University of California, San Francisco, San Francisco, United States; Yilmaz, Baran, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Akakin, Akin In, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Kaur, Ahmet Cemil, Department of Pathology, Medical Park Göztepe Hospital, Istanbul, Turkey; Demir, Mustafa Kemal, Department of Radiology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, TurkeyBackground: Low-grade gliomas have good overall survival rates in pediatric patients compared to adults. There are some case series that reported the effectiveness and safety of Gamma Knife radiosurgery, yet they are limited in number of patients. We aimed to review the relevant literature for pediatric low-grade glial tumors treated with stereotactic radiosurgery, specifically Gamma Knife radiosurgery, and to present an exemplary case. Case description: A 6-year-old boy was admitted to clinic due to head trauma. He was alert, cooperative, and had no obvious motor or sensorial deficit. A head CT scan depicted a hypodense zone at the right caudate nucleus. The brain magnetic resonance imaging (MRI) depicted a mass lesion at the same location. A stereotactic biopsy was performed. Histopathological diagnosis was low-grade astrocytoma (grade II, World Health Organization (WHO) classification, 2007). Gamma Knife radiosurgery was applied to the tumor bed. Tumor volume was 21.85 cm3. Fourteen gray was given to 50 % isodose segment of the lesion (maximal dose of 28 Gy). The tumor has disappeared totally in 4 months, and the patient was tumor-free 21 months after the initial treatment. Discussion and conclusion: The presented literature review represents mostly single-center experiences with different patient and treatment characteristics. Accordingly, a mean/median margin dose of 11.3–15 Gy with Gamma Knife radiosurgery (GKRS) is successful in treatment of pediatric and adult low-grade glial tumor patients. However, prospective studies with a large cohort of pediatric patients should be conducted to make a more comprehensive conclusion for effectiveness and safety of GKRS in pediatric low-grade glial tumors. © 2015 Elsevier B.V., All rights reserved.Publication Metadata only Lumbar nerve root hemangioblastoma and iliac bone cyst in a patient with von Hippel-Lindau disease(Elsevier Inc. usjcs@elsevier.com, 2016) Toktaş, Zafer Orkun; Akakin, Akin In; Konya, Deniz; Furuncuoǧlu, Yavuz; Demir, Mustafa Kemal; Kilic, Turker D.; Toktaş, Zafer Orkun, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Akakin, Akin In, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Konya, Deniz, Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey; Furuncuoǧlu, Yavuz, Department of Internal Medicine, Bahçeşehir Üniversitesi, Istanbul, Turkey; Demir, Mustafa Kemal, Department of Radiology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Kilic, Turker D., Department of Neurosurgery, Bahçeşehir Üniversitesi, Istanbul, Turkey[No abstract available]
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