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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/6
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Publication Open Access Multi-level anterior cervical decompression in multi-level cervical spondylotic myelopathy without extending the corpus resection: a cadaveric study of a novel surgical technique(Turkish Neurosurgical Society, 2021) Saygı, Tahsin; Özdemir, Ömer; Evran, Şevket; Kayhan, Ahmet; Özbek, Muhammet Arif; Erkan, Buruç; Demirel, Nail; Özdoğan, Selçuk; Baran, Oğuz; Faculty Member; Koç University HospitalAim: to perform three-level decompression with a single-level corpectomy by modifying the fusion with anterior cervical corpectomy (ACC-F) method on a cadaver. Material and methods: the anterior cervical region of four whole-head cadavers was dissected. The corpectomy was performed under a surgical microscope with a MT4-20+ ultrasonic bone dissector (UBD) tip. Superior and inferior decompression were conducted and viewed with a 70 degrees neuroendoscope using two types (vertically and horizontally oriented) of specially designed 23 mm-long, 90 degrees-angled UBD tips. Results: after neck dissection and the removal of the thyroid and cricoid cartilages, C5 corpectomy and adjacent-level discectomies were performed. Following discectomy and corpectomy, superior and inferior decompression were conducted with specially designed UBD tips and viewed with a 70 degrees neuroendoscope. A three-level anterior cervical decompression was provided with a single-level corpectomy. Conclusion: this study demonstrated that two more level decompression is possible with a single-level corpectomy in the cervical region using the new technique.Publication Open Access Outcomes of Norwood procedure with hypoplastic left heart syndrome: our 12-year single-center experience(Bayçınar Tıbbi Yayıncılık ve Reklam Hizmetleri, 2022) Özdemir, Fatih; Korun, Oktay; Dedemoğlu, Mehmet; Çiçek, Murat; Yurdakok, Okan; Altın, Hüsnü Fırat; Yılmaz, Emine Hekim; Yurtseven, Nurgül; Aydemir, Numan Ali; Sasmazel, Ahmet; Biçer, Mehmet; Koç University HospitalBackground: in this study, we aimed to analyze the predictors and risk factors of mortality in patients who underwent Norwood I procedure with the diagnosis of hypoplastic left heart syndrome. Methods: between January 2009 and December 2020, a total of 139 patients (95 males, 44 females) who underwent Norwood I procedure with the diagnosis of hypoplastic left heart syndrome in our center were retrospectively analyzed. Results: the median birth weight was 3,200 (range, 3,000 to 3,350) g and the median age at the time of operation was seven (range, 5 to 10) days. Pulmonary flow was achieved with a Sano shunt in the majority (72%) of patients. Survival rate was 41% after the first stage. Reoperation for bleeding (p=0.017), reoperation for residual lesion (p=0.011), and postoperative peak lactate level (p=0.029), were associated with in-hospital mortality. Nineteen (33%) of 57 patients died before the second stage. Thirty-three (58%) patients underwent second stage, and survival after the second stage was 94%. Thirteen patients underwent third stage, and survival after the third stage was 85%. Estimated probability of survival at six months, and one, two, three, and four years were 33%, 33%, 25%, 25%, and 22% respectively. Conclusion: hospital and inter-stage mortality rates are still high and this seems to be the most challenging period in term of survival efforts of the patients with hypoplastic left heart syndrome. Early recognition and reintervention of anatomical residual defects, close follow-up in the inter-stage period, and the accumulation of multidisciplinary experience may help to improve the results to acceptable limits. / Amaç: bu çalışmada, hipoplastik sol kalp sendromu tanısıyla Norwood I işlemi uygulanan hastalarda mortalitenin öngörücüleri ve risk faktörleri incelendi. Ça¬lış¬ma pla¬nı: Ocak 2009 ve Aralık 2020 tarihleri arasında merkezimizde hipoplastik sol kalp sendromu tanısıyla Norwood I işlemi uygulanan toplam 139 hasta (95 erkek, 44 kadın) retrospektif olarak incelendi. Bulgular: medyan doğum ağırlığı 3200 (dağılım, 3000-3350) g ve ameliyat sırasında medyan yaş yedi (dağılım, 5-10) gün idi. Hastaların büyük kısmında (%72) pulmoner akım, Sano şant ile sağlandı. İlk aşama sonrası sağkalım %41 idi. Kanama nedeniyle tekrar ameliyat (p=0.017), rezidü anatomik lezyon nedeniyle tekrar ameliyat (p=0.011) ve ameliyat sonrası birinci gün pik laktat seviyesi (p=0.029) hastane mortalitesi ile ilişkili idi. Taburcu edilen 57 hastanın 19’u (%33) ikinci aşamaya ulaşamadan kaybedildi. Otuz üç (%58) hastaya ikinci aşama ameliyatı uygulandı ve ikinci aşama sonrası sağkalım %94 idi. On üç hastaya üçüncü aşama ameliyatı uygulandı ve üçüncü aşama sonrası sağkalım %85 idi. Altı ay ve birinci, ikinci, üçüncü ve dördüncü yılda tahmini sağkalım olasılığı sırasıyla %33, %33, %25, %25 ve %22 idi. So¬nuç: hastane ve aşamalar arası mortalite oranları halen yüksek olup, hipoplastik sol kalp sendromu tanılı hastaların sağkalma çabalarındaki en zorlayıcı zaman dilimi olarak görünmektedir. Anatomik rezidü defektlerin erken tanılanması ve erken yeniden girişim yapılması, aşamalar arası dönemde yakın takip ve multidisipliner birikim ve tecrübe sonuçların kabul edilebilir seviyelere ulaşmasına yardım edebilir.Publication Open Access Chitosan channels stuffed with mesenchyme originated stem/progenitor cells for renovate axonal regeneration in complete spinal cord transection(Turkish Neurosurgical Society, 2021) Çakıcı, Nazlı; Bozkurt, Gökhan; Puralı, Nuhan; Denkbaş, Emir Baki; Korkusuz, Petek; Uçkan Çetinkaya, Duygu; Başak, Ahmet Tulgar; Doctor; Koç University HospitalAim: to examine the implantation of chitosan channels stuffed with mesenchyme-originated stem/progenitor cells (MSPCs) derived from adult rats in a spinal cord transection model. The level of axonal regeneration, the effect of chitosan channels on the survival of MSPCs, and the functional recovery results were also evaluated. Material and methods: chitosan channels stuffed with MSPCs were implanted at the level of T8 in a transected rat spinal cord. MSPCs were harvested from the pelvic bone marrow of adult rats, and the MSPC-chitosan channel group was compared with three control groups. The axonal regeneration capacity, the effect of chitosan channels on the survival of MSPCs, and the functional recovery results were compared among four groups. The survival of MSPCs was evaluated using histopathological techniques and electron microscopy, axonal regeneration/germination was evaluated by confocal microscopy, and locomotor function was assessed for 4 weeks using the Basso, Beattie, and Bresnahan locomotor score. Results: the MSPC-chitosan channel group exhibited enhanced survival of transplanted MSPCs compared with MSPCs transplanted directly into the lesion cavity, although no significant difference was detected in locomotor function between the treatment and control groups. The MSPC-chitosan channel group demonstrated thicker myelination of axons than the other groups. Conclusion: chitosan channels promoted the survival of transplanted MSPCs and created a tissue bridge after complete spinal cord transection. They also induced axonal regeneration and germination. No significant improvement in functional recovery was found between the groups.Publication Open Access Tissue thiol concentration in high-grade gliomas: is there any association between IDH1 mutation presence and tumoral cellular antioxidant defense?(Turkish Neurosurgical Society, 2021) Evran, Şevket; Kayhan, Ahmet; Çevik, Serdar; Katar, Salim; Kaya, Mustafa; Sönmez, Derya; Serin, Huriye; Hanımoğlu, Hakan; Kaynar, Mehmet Yaşar; Baran, Oğuz; Faculty Member; Koç University HospitalAim: to assess and compare the antioxidant capacities of high-grade gliomas (HGG) according to their grades and the presence of isocitrate dehydrogenase 1 (IDH1) mutation using tissue thiol level measurement. Material and methods: tissue thiol concentrations were measured in 41 HGG samples and 21 healthy brain tissues obtained from autopsy procedures, which were performed within the first 4 hours of death. All samples were stored at -80 degrees C, and a thiol quantification kit was used in evaluating tissue thiol levels. The Number Cruncher Statistical System was used for statistical analyses to detect the differences between the control group and the HGG group, which was also divided into subgroups according to their grade and IDH1 mutation presence. Results: the tissue thiol levels of HGGs were found to be higher than the control group (p=0.001). Although the median thiol levels of Grade 4 gliomas were higher than those of Grade 3, no statistically significant difference was noted (p=0.076). When all tumors were compared according to the IDH1 mutation presence, IDH1-negative (IDH1-) HGGs had higher thiol contents than IDH1 mutant (IDH1+) HGGs (p=0.001). The thiol levels of Grade 4 IDH1- gliomas were statistically significantly higher than of Grade 3 gliomas (p=0.023), but no statistically significant difference between the thiol levels of Grade 3 and Grade 4 IDH1+ tumors was noted (p=0.459). Conclusion: we have demonstrated the higher thiol concentrations of HGGs, particularly IDH1- ones. The sulfhydryl contents of gliomas as an indicator of tumoral antioxidant capacity may be responsible for the treatment resistance of IDH1- gliomas, the mechanism of which is not clear. Thiols can be a novel target for treatment, considering the unsatisfactory results of current modalities for HGGs.Publication Open Access How to reduce stress on the pedicle screws in thoracic spine? Importance of screw trajectory: a finite element analysis(Turkish Neurosurgical Society, 2019) Güvenç, Yahya; Erbulut, Deniz; Akyoldaş, Göktuğ; Şentürk, Salim; Yaman, Onur; Özer, Ali Fahir; Faculty Member; Doctor; Doctor; Faculty Member; Koç University Hospital; N/A; N/A; N/A; 1022Aim: to investigate the biomechanical comparison of thoracic transpedicular screw trajectories on the sagittal plane. Material and methods: a three-dimensional, non-linear finite element analysis (FEA) model of T8 through T9 was used. Anatomic trajectory (AT) and Straightforward trajectory (ST) models of the transpedicular screws were used in the intact FEA model. The von-Mises stress and range of motion (ROM) of the transpedicular screws were evaluated. Results: the difference in ROM between both techniques was negligible. In lateral bending and axial rotation, FEA showed decrease in stress by 25% and 8%, respectively, when pedicle screws were placed using AT. Conclusion: AT decreased the von-Mises stress of the pedicle screws, thereby reducing the rates of screw breakage and fatigue risks. In addition, we believe that AT could protect against screw loosening because the von-Mises stress of the internal fixation was scattered.Publication Open Access Kyphoplasty with posterior dynamic stabilization in the surgical treatment of unstable thoracolumbar osteoporotic vertebral compression fractures(Turkish Neurosurgical Society, 2021) Öktenoğlu, Bekir Tunç; Aydın, Ahmet Levent; Sasani, Mehdi; Özer, Ali Fahir; Doctor; Faculty Member; Faculty Member; School of Medicine; Koç University Hospital; 220898; N/A; N/A; 1022; N/A; N/AAim: to evaluate the role of posterior dynamic stabilization (PDS) with kyphoplasty (KP) in the surgical treatment of unstable osteoporotic compression fractures, which are common in the elderly population. Material and methods: this study included 25 patients with osteoporotic compression fractures. KP with PDS was performed on all patients. Radiological evaluation was performed with magnetic resonance imaging, computed tomography, and plain radiographs. The vertebral kyphosis angle (VKA), local kyphosis angle (LKA), and percentage of collapse were calculated. Clinical evaluation was performed with the visual analog scale and the Oswestry Disability Index (ODI). The preoperative and postoperative clinical and radiological data were compared. Results: the clinical and radiological parameters showed significant improvement following surgical treatment. The mean preoperative visual analog scale score of 7.78 decreased to 0.94 after 12 months. The mean preoperative ODI score of 70.33 decreased to 15.65 after 12 months. The mean preoperative VKA of 17.89° decreased to 9.22° after 12 months. The mean preoperative LKA of 9.61° decreased to 5.50° after 12 months. The mean preoperative percentage of collapse of 32.56% decreased to 19.00% after 12 months. There were no major complications. Conclusion: KP with the PDS method offered satisfactory outcomes in the surgical treatment of unstable osteoporotic compression fractures.Publication Open Access Relation between ILAE hippocampal sclerosis classification and clinical findings in temporal lobe epilepsy(Turkish Neurosurgical Society, 2021) Haşimoğlu, O.; Barut, O.; Kapar, M.O.; Kınay, D.; Gül, G.; Dirican, A.C.; Bilgiç, B.; Tuğcu, B.; Hergünsel, Ömer Batu; Faculty Member; Koç University HospitalAim: to investigate the relationship between clinical features and prognosis of the hippocampal sclerosis (HS) cases and International League Against Epilepsy (ILAE) histopathology classification. Material and methods: a hundred patients with refractory epilepsy who were operated with the diagnosis of the Mesial Temporal Lobe Epilepsy were included in the study. Socio-demographic characteristics, clinical and family histories, post-operative ILAE and Engel epilepsy scores and diagnostic tests were recorded. At the same time, all of the pathological specimens were classified according to the new semi-quantitative ILAE classification. A significant statistical relationship was investigated between clinical data and HS-ILAE groups. RESULTS: There were 36 male 64 female patients. The mean follow-up period was 6.5 years. 75% of the cases were HS-ILAE type 1, 19% HS-ILAE type 2, 6% were unidentifiable. FCD3A was detected in 3 patients. The HS-ILAE Type 2 ratio was high on the right-sided cases. In addition, HS-ILAE Type 1 ratio was high in patients with early seizure onset and long duration of epilepsy. There was no significant relationship between long-term ILAE and Engel epilepsy outcome scores and HS-ILAE types. Conclusion: resection of mesiotemporal structures in hippocampal sclerosis provides seizure control in at least two-thirds of cases. Histopathological findings may help us understand the epileptogenicity-prognosis of HS. The relationship between ILAE histopathology classification and clinical factors will become more obvious in the future. According to our study, there was a relationship between onset age of epilepsy, epilepsy duration, lesion side and HS-ILAE types. The reinforcement of these relationships with larger series will benefit clinicians.Publication Open Access The prognostic effect of lymph node dissection in secondary lung tumor metastasectomies(Bayçınar Tıbbi Yayıncılık ve Reklam Hizmetleri, 2022) Duman, Salih; Çimenoğlu, Berk; Ülker, Melike; Ağkoç, Melek; Özkan, Berker; Kara, Murat; Toker, Alper; Erus, Suat; Faculty Member; School of Medicine; 175565Background: in this study, we aimed to investigate the prognostic effect of lymph node dissection in secondary lung tumor metastasectomies. Methods: between January 2001 and December 2015, a total of 201 patients (122 males, 79 females; mean age: of 41.4±19.2 years; range, 3 to 79 years) who had pulmonary metastasectomy due to colorectal carcinoma, renal cell carcinoma, and soft tissue - skeletal sarcomas were retrospectively analyzed. The clinicopathological features of the patients, overall survival, and complication rates according to the presence of lymph node dissection were evaluated. Results: the most common histopathological subtype was a sarcoma in 118 (58.7%) patients, followed by colorectal carcinoma in 63 (31.3%) patients, and renal cell carcinoma in 20 (10%) patients. A total of 88 (43.7%) patients underwent systematic lymph node dissection with pulmonary metastasectomy. The mean overall survival of patients with and without lymph node dissection were 49±5.9 (95% confidence interval 37.3-60.6) and 26±4.4 (95% confidence interval 17.2-34.7) months, respectively (p=0.003). The five-year survival rates in colorectal carcinoma, renal cell carcinoma, and sarcoma were 52%, 30%, and 23%, respectively (p=0.002). Locoregional recurrences occurred in 15 (35.7%) patients in the lymph node dissection group and in 23 (60.5%) patients in the non-lymph node dissection group (p=0.026). Lymph node dissection did not show a significant relationship regarding to postoperative complications (p=0.09). Conclusion: lymph node dissection following pulmonary metastasectomy may improve the overall survival and reduce locoregional recurrence, without any increase in morbidity and mortality. / Amaç: bu çalışmada sekonder akciğer tümör metastazektomilerinde lenf nodu diseksiyonunun prognoz üzerine etkisi araştırıldı. Çalışma planı: Ocak 2001 - Aralık 2015 tarihleri arasında kolorektal karsinom, renal hücreli karsinom ve yumuşak doku-iskelet sarkomları nedeniyle pulmoner metastazektomi yapılan toplam 201 hasta (122 erkek, 79 kadın; ort. yaş: 41.4±19.2 yıl; dağılım 3-79 yıl) retrospektif olarak incelendi. Hastaların lenf nodu diseksiyonu varlığına göre klinikopatolojik özellikleri, genel sağkalım ve komplikasyon oranları değerlendirildi. Bulgular: en sık histopatolojik tanı 118 (%58.7) hastada sarkom, 63 (%31.3) hastada kolorektal karsinom ve 20 (%10) hastada renal hücreli karsinom idi. Toplam 88 (%43.7) hastaya pulmoner metastazektomi ile birlikte sistematik lenf nodu diseksiyonu uygulandı. Lenf nodu diseksiyonu yapılan ve yapılmayan hastalarda ortalama genel sağkalım sırasıyla 49±5.9 (%95 güven aralığı 37.3-60.6) ve 26±4.4 (%95 güven aralığı 17.2-34.7) ay idi (p=0.003). Beş yıllık sağkalım kolorektal karsinomlu hastalarda %52, renal hücreli karsinomlu hastalarda %30 ve sarkomlu hastalarda %23 idi (p=0.002). Lokorejyonel nüks, lenf nodu diseksiyonu uygulanan toplam 15 (%35.7) hastada ve lenf nodu diseksiyonu uygulanmayan grupta 23 (%60.5) hastada görüldü (p=0.026). Lenf nodu diseksiyonu ile ameliyat sonrası komplikasyon oranları arasında anlamlı bir ilişki saptanmadı (p=0.09). Sonuç: pulmoner metastazektomiyi takiben yapılan lenf nodu diseksiyonu genel sağkalımı uzatmakla birlikte, morbidite ve mortaliteyi artırmadan lokorejyonel nüks oranını azaltabilir.Publication Open Access Behavioral functioning of school-aged children with non-syndromic craniosynostosis(Springer, 2020) Zeytinoğlu Saydam, Senem; Özek, M. Memet; Crerand, Canice; Department of Business Administration; Marcus, Justin; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 124653Purpose: this study investigated the risk for children with non-syndromic craniosynostosis to develop behavioral problems during school age determined by the type of craniosynostisis, age at first surgery, and number of surgeries. Method: final sample consisted of 43 children aged between 6 years and 8 months and 17 years and 1 month (M = 10 years and 5 months). Behavioral problems were assessed with Child Behavioral Checklist (CBCL). Results: our sample had higher scores on the CBCL than the general population; specific elevations were observed including somatic complaints, aggressive behavior, social problems, attention problems, and thought problems and rule-breaking behavior. Behavioral functioning varied by number of surgical procedures, type of craniosynostosis, and age at first surgery. Conclusion: for school-aged NSC children's behavioral functioning, diagnosis specific patterns especially impacted by the first age of the surgery and number of surgeries.Publication Open Access An investigation into the correlation of scalp electrophysiological findings with preoperative clinical and imaging findings in patients with focal cortical dysplasia(Turkish Neurosurgical Society, 2022) Gürkan, Zahide Mail; Kapar, Özge; Yeni, Seher Naz; Bilgiç, Bilge; Gürses, Rabia Candan; Faculty Member; School of Medicine; 110149Aim: to evaluate the patients who had epilepsy surgery and pathologically proven focal cortical dysplasia (FCD) in order to further classify and discuss electroencephalography (EEG) findings in different pathological subtypes. Material and methods: this study included 19 refractory epilepsy patients who underwent surgery between 1999 and 2017 in the Istanbul Faculty of Medicine. Demographic data, preoperative examinations, scalp video EEGs, and postoperative outcomes were evaluated retrospectively. Results: In this study, 36.8% of the patients were female. The mean age was 21.89 ± 14.64 years. Rhythmic epileptiform discharges (RED) were observed in 31.6%. 37.5% of the patients with isolated intermittent spike/sharp waves were type I, 50% were type II, and 12.5% were type III. 100% of the patients with normal background activity were FCD type II. 67% of the patients with asymmetric slowing were FCD type I, 22% was FCD type II, 11% were FCD type III. 71% of the patients with symmetrical slowing were FCD type I, 29% were FCD type II. One patient had Frontal Intermittent Rhythmic Activity, one patient had Electrical Status Epilepticus in Slow Sleep, two patients had “burst suppression,” and one patient had a “switch of” sign. The frequency of focal epileptogenic activity was higher when there was an FCD lesion on magnetic resonance imaging. Conclusion: the findings obtained in this study did not reveal any distinctive electrophysiological features in FCD and subgroups of FCD. The incidence of REDs did not differ between types. The frequency of isolated intermittent sharp/spike waves was higher in type II than I. Intermittent and continuous EEG slowing was more commonly seen among FCD Type I patients.