Ozkan Tehli
Military Medical Academy
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Featured researches published by Ozkan Tehli.
Pediatric Neurosurgery | 2011
Ozkan Tehli; Irgen Hodaj; Cahit Kural; Ilker Solmaz; Onder Onguru; Yusuf Izci
Background: The structural changes in filum terminale (FT) may be responsible for tethered cord syndrome (TCS) in children. Although the histological changes in FT related to TCS are well-known, there is no comparative study of the changes which occur in TCS and normal fetal FT samples. The aims of this study are to compare the histological changes which occurred in FT samples of TCS and in fetuses, and to point out these changes. Methods: During the last 2 years, 14 cases of TCS were operated on, the FT was cut and the spinal cord was released. Among them, 6 samples of FT were obtained for histopathological examination. Moreover, 1 FT from an adult cadaver and 4 samples from fetal FT were obtained for the same examination. Results: While adipose tissue, fibrosis, hyalinization, and meningothelial proliferation were observed in FT samples of TCS, none of these findings were observed in fetal samples. Elastic fibers were present in all TCS specimens and the adult cadaver, but were not observed in fetuses. Peripheral nerves, ganglion cells and ependymal cells were observed in fetal FT samples. Conclusion: These changes probably begin at birth.
Turkish Neurosurgery | 2009
Ozkan Tehli; Ramazan Cengiz Celikmez; Baris Birgili; Ilker Solmaz; Ertugrul Celik
Peroneal nerve entrapment is most commonly seen in the popliteal fossa. It is rarely caused by a ganglion. Intraneural ganglia, although uncommon and seldom cause serious complications, are well recognized and most commonly affect the common peroneal (lateral popliteal) nerve. Ganglionic cysts developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. The differential diagnosis should involve L5 root lesions, posttraumatic intraneural hemorrhage, nerve compression near the tendinous arch located at the fibular insertion of the peroneal longus muscle and nerve-sheath tumors. We present a unique case of a pure intraneural ganglion of the common peroneal nerve ascending along the sciatic nerve. This case underscores the importance of consideration of an intraneural ganglion cyst with sciatic nerve involvement.
Turkish Neurosurgery | 2012
Caglar Temiz; Ilker Solmaz; Ozkan Tehli; Serdar Kaya; Onder Onguru; Erhan Arslan; Yusuf Izci
AIM The aim of this study is to investigate the effects of prior splenectomy on oxidative stress and neuronal loss following spinal cord ischemia and reperfusion injury. MATERIAL AND METHODS Twenty-one Sprague Dawley rats were randomly divided into three groups as sham laparatomy (n=7), spinal cord ischemia/reperfusion (SCIR) injury (n=7) and splenectomy+spinal cord ischemia/reperfusion (SSCIR) injury (n=7). In the latter group, splenectomy was performed 3 days before the SCIR injury. The activity of lipid peroxidation in the spinal cord was assessed by malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. The difference between the 3 groups was compared using Kruskal-Wallis test. The histological differences were assessed by counting the viable neurons. RESULTS SCIR injury resulted in a decrease of tissue lipid peroxidation activities. There was statistically significance between the three groups (p < 0.05), but there was not any significance between the SCIR and SSCIR injury groups (p > 0.05). The number of viable neurons was higher in SSCIR group when comparing with SCIR group (p < 0.05). CONCLUSION SCIR injury affects lipid peroxidation in rats. Prior splenectomy does not attenuate lipid peroxidation, but prevents neuronal loss after SCIR injury.
Journal of Neurosurgery | 2014
Cahit Kural; Servet Guresci; Gulcin Guler Simsek; Erhan Arslan; Ozkan Tehli; Ilker Solmaz; Yusuf Izci
OBJECT The structure of the filum terminale (FT) is important in the development of tethered cord syndrome (TCS) in children. Although many studies have been performed on the histological structure of the FT in adults, there has been no detailed investigation for those of fetuses. The aim of this study was to examine the histological structure of the FT in normal human fetuses and to compare the results with those of previous studies. METHODS The histological examination of the FT was performed in 15 normal human fetuses; 11 of them were female and 4 were male. The gestational age of the fetuses ranged between 14 weeks and 35 weeks, and they weighed between 180 g and 1750 g. The FT of each fetus was cut and examined for adipose tissue, fibrous tissue, peripheral nerve, ganglion, ependymal cells, gliosis, elastic fibers, and collagen types (Types I and III). RESULTS Adipose tissue was observed in 2 specimens (13%), whereas fibrous tissue was found in 8 specimens. Peripheral nerve was detected in 11 (73%), ganglion in 6, ependymal cells in 5, and glial tissue in 7 FT samples. Type III collagen was present in 12 specimens (80%) with different concentrations, whereas Type I collagen and elastic fibers were not detected. CONCLUSIONS The normal structure of the FT in fetuses is different from its structure in adults. The FT has no elasticity during intrauterine life because of the lack of elastic fibers. More detailed studies are needed to understand the histological basis of TCS in children.
Clinical Anatomy | 2014
Soner Yasar; Serdar Kaya; Çağlar Temiz; Ozkan Tehli; Cahit Kural; Yusuf Izci
The objective of this study is to study the anatomy of lumbar plexus on human fetuses and to establish its morphometric characteristics and differences compared with adults. Twenty lumbar plexus of 10 human fetal cadavers in different gestational ages and genders were dissected. Lumbar spinal nerves, ganglions, and peripheral nerves were exposed. Normal anatomical structure and variations of lumbar plexus were investigated and morphometric analyses were performed. The diameters of lumbar spinal nerves increased from L1 to L4. The thickest nerve forming the plexus was femoral nerve, the thinnest was ilioinguinal nerve, the longest nerve through posterior abdominal wall was iliohypogastric nerve, and the shortest nerve was femoral nerve. Each plexus had a single furcal nerve and this arose from L4 nerve in all fetuses. No prefix or postfix plexus variation was observed. In two plexuses, L1 nerve was in the form of a single branch. Also, in two plexuses, genitofemoral nerve arose only from L2 nerve. Accessory obturator nerve was observed in four plexuses. According to these findings, the morphological pattern of the lumbar plexus in the fetus was found to be very similar to the lumbar plexus in adults. Clin. Anat. 27:383–388, 2014.
Turkish Neurosurgery | 2010
Ilker Solmaz; Ozkan Tehli; Serdar Kaya; Ersin Erdogan; Yusuf Izci
Pneumothorax is a very rare complication of ventriculoperitoneal shunting in children. We report a case of an iatrogenic bilateral tension pneumothorax during the placement of a subdural-peritoneal shunting. After the placement of peritoneal catheter, oxygen saturation of the patient quickly decreased, hypotension and bradycardia occurred. Intraoperative x-rays showed the pneumothorax. A thoracostomy tube was inserted and attached to an underwater seal. Vital signs improved in a short time period. The radiological improvement had been achieved in four days. Early diagnosis and prompt intervention are life-saving for this complication. To avoid this complication, the tip of the shunt tunneler should be always palpable during the placement of the peritoneal catheter, especially in childrens shunt surgery.
Journal of Korean Neurosurgical Society | 2013
Burak Kazanci; Ozkan Tehli; Erhan Turkoglu; Bulent Guclu
Ganglion cysts usually arise from the tissues around the facet joints. It is usually associated with degenerative cahanges in facet joints. Bilateral thoracic ganglion cysts are very rare and there is no previous case that located in bilateral intervertebral foramen compressing the L1 nerve root associated with severe radiculopathy. We report a 53 years old woman who presented with bilateral groin pain and severe numbness. Magnetic resonance imaging revealed bilateral cystic mass in the intervertebral foramen between 12th thoracal and 1st lumbar vertebrae. The cystic lesions were removed after bilateral exposure of Th12-L1 foramens. The result of hystopathology confirmed the diagnosis as ganglion cyst. The ganglion cyst may compromise lumbar dorsal ganglion when it located in the intervertebral foramen. The surgeon should keep this rare entity in their mind for differential diagnosis.
Pediatric Emergency Care | 2011
Ozkan Tehli; Burak Kazanci; Erhan Turkoglu; Ilker Solmaz
Objective: We aimed to identify the incidence, clinical features, management, and outcome of subdural hematomas (SHs) in infancy and childhood. Methods: Twenty-one children younger than 11 years with SH were analyzed. Clinical features and possible child abuse were considered in each case. Results: Eight children experienced minor injuries due to hitting of solid items on their head. Five of these children also had coagulation disorders. Three of the children suffered from child abuse, only one of the children had head trauma due to car accident. Nine of the patients experienced SH due to fall down. Nine patients have acute SH, 7 had subacute SH, 4 had chronic SH, and 1 had acute and subacute SH together. Clinical presentation varied greatly. Most of them presented with vomiting and seizure. The outcome patterns were different among the patients. Deep coma on admission was associated with an unfavorable outcome. Conclusions: Subdural hematoma is common in infancy and childhood and carries a poor prognosis. Most of the cases are due to head trauma, coagulation disorders, and child abuse. We believe that clinical investigation of such children should be carried out in a multidisciplinary approach with the collaboration of pediatricians, social workers, and neurosurgeons.
Turkish Neurosurgery | 2015
Murat Kutlay; Cahit Kural; Ilker Solmaz; Ozkan Tehli; Caglar Temiz; Mehmet Daneyemez; Yusuf Izci
AIM To present a new simple disposable tubular retractor which provides fully endoscopic resections of the intraaxial brain lesions. MATERIAL AND METHODS A total of 13 patients underwent surgical resection of an intraaxial brain lesion larger than 3 cm with a fully endoscopic approach using the navigation-guided pediatric anoscope. The anoscope was adapted to serve as a tubular retractor. All lesions were resected under endoscopic visualization and navigation guidance. There were 7 men and 6 women with a mean age of 49.6 years (range, 19-76 years). Lesion location was as follows: frontal (n=4), parietal (n=1), frontoparietal (n=2), temporal (n=2), and intraventricular (n=4). RESULTS With the use of this technique, preoperative goals of surgery were met in all patients. Gross total resection of the lesions was achieved in 7 of 13 patients (53.8%), near-total resection in 3 patients (23.1%) and subtotal resection in 3 (23.1%) patients. The histological diagnosis included 2 metastases, 5 (38.5%) glioblastomas, 3 meningiomas, 2 low grade gliomas and one oligodendroglioma. There were no complications related to the surgical procedure. Duration of surgery ranged from 60 to 110 minutes, with an average 90 minutes. The average postoperative hospital stay was 2.7 days. CONCLUSION Endoscopic resection of deep-seated brain lesions with the neuronavigated tubular retractor is a safe and an effective technique and may be a feasible alternative to conventional microsurgical or endoscope-assisted methods in selected patients. The modified transparent plastic pediatric anoscope can be used as a tubular retractor and it is easy to apply, simple, lightweight, inexpensive and effective.
Neurosurgery | 2015
Ozkan Tehli; Ahmet Murat Dursun; Çağlar Temiz; Ilker Solmaz; Cahit Kural; Murat Kutlay; Yunus Kaçar; Mehmet Can Ezgu; Erbil Oguz; Mehmet Daneyemez; Yusuf Izci
BACKGROUND: The procedure of reconstruction after the removal of cranial fibrous dysplasia (FD) must be precise to achieve good functional and aesthetic results. Intraoperative modeling of implants is difficult and may cause cosmetic disturbances. OBJECTIVE: To present our experience with the treatment of cranial FD using preoperative computer-based surgical planning of tumor removal with reconstruction of the cranium with custom-made titanium implants. METHODS: Four patients underwent surgical treatment for cranial FD over a 2-year period. All patients were male with a mean age of 25.25 years and had monostotic-type FD. Computed tomography (CT) with 0.5-mm slices was obtained preoperatively. Computer-based planning of the tumor removal was performed, and a template was created by the computer to determine the margins of tumor removal. After this procedure, the preoperative computer-based construction of the titanium implant was performed. The patients underwent surgical treatment, and the tumor was removed with the use of this template. Then, the titanium implant was inserted onto the bone defect and fixed with mini-screws. Patients were followed up by periodic CT scans. RESULTS: The histological diagnosis of all patients was FD. No intraoperative or postoperative complications have occurred. Postoperative CT scans showed complete tumor removal and confirmed appropriate cosmetic reconstruction. The mean follow-up period was 15.25 months. CONCLUSION: Computer-based surgical planning associated with the production of custom-made titanium implants is a highly promising method for the treatment of cranial FD. Better radiological and cosmetic outcomes could be obtained by this technique with interdisciplinary work with medical designers. ABBREVIATIONS: DICOM, digital imaging and communications in medicine FD, fibrous dysplasia