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Dive into the research topics where Ali Erdem Yildirim is active.

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Featured researches published by Ali Erdem Yildirim.


Turkish Neurosurgery | 2012

Incidence, hormonal distribution and postoperative follow up of atypical pituitary adenomas.

Ali Erdem Yildirim; Denizhan Divanlioglu; Osman Arikan Nacar; Engin Dursun; Mert Sahinoglu; Tuba Unal; Ahmed Deniz Belen

AIM To assess the incidence, hormonal activity and postoperative follow up of the cases that are histopathologically diagnosed as atypical pituitary adenoma (APA) in our series. MATERIAL AND METHODS In this study, 13 atypical pituitary adenoma cases, by the WHO 2004 criteria, among the 146 pituitary adenoma patients operated on in our clinic between January 2009 and May 2012 by endoscopic endonasal transsphenoidal approach were included. RESULTS In histological studies, 133 cases were diagnosed as typical pituitary adenoma (91.1%) and 13 cases were APAs (8.9%) of which 10 were male (76.9%) and 3 were female (23.1%), ranged between 27 and 80 (mean 52.7) ages. Histopathological distribution of APAs was 9 nonsecretory adenomas (69.3%), 3 prolactinomas (23.1%) and 1 somatostatinoma (7.6%). Asymptomatic pituitary apoplexy was diagnosed in 4 cases (30.7%). Eleven cases of typical pituitary adenomas (8.2%) and 5 cases of the atypical pituitary adenomas (38.4%) were re-operated due to tumor recurrences. CONCLUSION Accurate histopathological examination shows that atypical pituitary adenoma is not a rare disease. Although it is not the only determinant, APAs are more prone to recurrence than typical adenomas. In our opinion, if total resection is not possible for the patients with APA, close postoperative follow up and additional curative therapy modalities are needed.


Turkish Neurosurgery | 2014

Endoscopic endonasal transsphenoidal treatment for acromegaly: 2010 consensus criteria for remission and predictors of outcomes.

Ali Erdem Yildirim; Mert Sahinoglu; Denizhan Divanlioglu; Fatih Alagoz; Ahmet Gurhan Gurcay; Ergun Daglioglu; Hilmi Onder Okay; Ahmed Deniz Belen

AIM Acromegaly is a chronic disorder characterized by enhanced growth hormone (GH) secretion and elevated insulin-like growth factor-I (IGF-I) levels, usually caused by pituitary adenomas. In this retrospective study, we reviewed our experience with endoscopic endonasal transsphenoidal surgery (EETS) with in remission rates using the 2010 consensus criteria, predictors of remission and associated complications. MATERIAL AND METHODS The authors retrospectively analyzed data from 56 acromegalic patients who underwent pure EETS. Tumors were classified according to size and suprasellar/parasellar extension. The criteria of remission were GH levels < 1 ng/mL randomly, < 0.4 ng/mL after oral glucose tolerance test and normal IGF-I levels for age and sex within the first 3 and 6 months after surgery. RESULTS Biochemical remission was achieved in 4 of 5 microadenomas (80%) and in 33 of 51 macroadenomas (64.7%). The total remission rate was 66.1% (37 of 56 adenomas). Age, gender and suprasellar extension did not affect the remission rate. However, cavernous sinus invasion, sphenoid sinus invasion and history of prior surgery were associated with lower rates of disease control. CONCLUSION EETS represents an effective and safe option for the treatment of patients with acromegaly. High disease control rates and a small number of complications are some of the most important points related to the technique.


World Neurosurgery | 2016

Nonfunctioning Pituitary Adenomas Are Really Clinically Nonfunctioning? Clinical and Endocrinological Symptoms and Outcomes with Endoscopic Endonasal Treatment.

Ali Erdem Yildirim; Mert Sahinoglu; Ibrahim Ekici; Emin Cagil; Derya Karaoglu; Haydar Celik; Osman Arikan Nacar; Ahmed Deniz Belen

BACKGROUND Nonfunctioning pituitary adenomas are the most common pituitary adenomas in adults and cause significant morbidity unless adequately treated. METHODS This study retrospectively assessed the medical records of 160 patients operated via pure endonasal endoscopy. The presenting symptoms, results of neurologic and visual examinations, levels of pituitary hormones, results of radiologic examinations, size of the adenoma, rates of resection, results of postoperative visual examination, and pituitary hormone levels at follow-up were recorded to establish the appropriate approach, operative criteria, and outcomes of patients with nonfunctioning pituitary adenoma. RESULTS Headache was the presenting symptom in 87.5% of the patients. Thirty-three percent had visual loss, and visual examinations on the whole study population revealed a visual field defect in 47.5% of the patients. Only 16.25% of the patients presented with endocrinological symptoms; 52.5% had abnormal anterior pituitary hormone levels. Regarding adenoma size, 56 patients had macroadenoma (35%), 84 (52.5%) had mesoadenoma, and 20 patients had giant adenoma. Gross total resection was achieved in 90% of the patients; subtotal resection was achieved in the remainder. The rate of total resection was lower for giant adenomas and recurrences. Visual symptoms and anterior pituitary hormone levels improved in 27 and 42 patients, respectively, after the operation. CONCLUSIONS Nonfunctioning pituitary adenomas present frequently as mesoademonas and giant adenomas. Patients with these tumors may have subclinical visual or hormonal deficits at the time of diagnosis. Early and effective surgical treatment is essential for rapid recovery of visual and/or hormonal deficits, particularly in symptomatic cases.


Journal of Craniofacial Surgery | 2015

Pure Endoscopic Endonasal Clipping of an Incidental Anterior Communicating Artery Aneurysm.

Ali Erdem Yildirim; Denizhan Divanlioglu; Derya Karaoglu; Nuri Eralp Çetinalp; Ahmed Deniz Belen

AbstractAnterior communicating artery (AcoA) aneurysm is the most common form of intracranial aneurysm. It occurs rarely together with other intracranial lesion. Today, microsurgical techniques and endovascular methods are used in the treatment of these aneurysms. Endoscopic endonasal approach is a useful technique for midline lesions of the skull base and is underpinned with extensive experience. In this article, we present a 72-year-old female patient who underwent endoscopic endonasal transplanum-transtubercular surgery for tuberculum sellae meningioma followed by clipping of the incidental AcoA aneurysm. After complete removal of a tuberculum sellae meningioma via an endoscopic endonasal approach, an anterior and superior projected saccular AcoA aneurysm in the gyrus rectus area was totally clipped successfully via pure endoscopic endonasal transplanum-transtubercular approach, without any damage to parent arteries. The patient was discharged from the hospital within a short period of time without any postoperative complication. Endoscopic endonasal approach is a new paradigm in the treatment of aneurysm. Although this technique cannot be routinely used due to lack of experience, it is an effective and safe method in selected and anatomically appropriate cases. We believe that increased knowledge and experience will create successful results in this approach, and it can offer an alternative method for selected aneurysm cases.


Asian Spine Journal | 2014

An Uncommon Intramedullary Tumor: Primary Spinal Cord Melanoma

Nuri Eralp Çetinalp; Ali Erdem Yildirim; Denizhan Divanlioglu; Deniz Belen

A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities and pain in the back and left leg. Thoracic magnetic resonance imaging (MRI) revealed a spinal intramedullary tumor between the T9 and L1 levels, which were iso- to hypointense on T2 and slightly hyperintense on T1-weighted images. The tumor was resected as total, and the diagnosis was malignant melanoma confirmed with histopathology. Neurological findings improved at the postoperative period and no residual or recurrence was noted on postoperative MRI at the 9-month follow-up. Primary melanoma of the spinal cord, particularly intramedullar localization, is seldomly reported in the literature. We report a primary malignant melanoma of the spinal cord and emphasize the diagnostic and prognostic challenges.


World Journal of Emergency Surgery | 2014

Analysis and injury paterns of walnut tree falls in central anatolia of turkey.

Suleyman Ersoy; Bedriye Müge Sönmez; Fevzi Yilmaz; Cemil Kavalcı; Derya Öztürk; Ertugrul Altinbilek; Fatih Alagoz; Fatma Cesur; Ali Erdem Yildirim; Ozhan Merzuk Uckun; Tezcan Akin

IntroductionFalls are the second most common cause of injury-associated mortality worldwide. This study aimed to analysis the injuries caused by falls from walnut tree and assess their mortality and morbidity risk.MethodsThis is a retrospective hospital-based study of patients presenting to emergency department (ED) of Ahi Evran Univercity between September and October 2012. For each casualty, we computed the ISS (defined as the sum of the squares of the highest Abbreviated Injury Scale (AIS) score in each of the three most severely injured body regions). Severe injury was defined as ISS ≥ 16. The duration of hospital stay and final outcome were recorded. Statistical comparisons were carried out with Chi-Square test for categorical data and non-parametric spearman correlation tests were used to test the association between variables. A p value less than 0.05 was considered to be statistically significant.ResultsFifty-four patients admitted to our emergency department with fall from walnut tree. Fifty (92.6%) patients were male. The mean age was 48 ± 14 years. Spinal region (44.4%) and particularly lumbar area (25.9%) sustained the most of the injuries among all body parts. Wedge compression fractures ranked first among all spinal injuries. Extremities injuries were the second most common injury. None of the patients died. Morbidity rate was 9.25%.ConclussionFalls from walnut trees are a significant health problem. Preventive measures including education of farmers and agricultural workers and using mechanized methods for harvesting walnut will lead to a dramatic decrease in mortality and morbidity caused by falls from walnut trees.


Turkish Neurosurgery | 2014

Systemic administration of atorvastatin improves locomotor functions and hyperacute-acute response after experimental spinal cord injury: an ultrastructural and biochemical analysis.

Osman Arikan Nacar; Eroglu H; Cetinalp Ne; Menekse G; Ali Erdem Yildirim; Ozhan Merzuk Uckun; Ergun Daglioglu; Turkoglu Of; Ahmet Deniz Belen

AIM Spinal cord injury (SCI) is characterized by posttraumatic inflammatory cascades including excitotoxicity, oxidative stress, and apoptosis. Agents against neuroinflammation are the current scope of studies on experimental SCI with promising results. MATERIAL AND METHODS Thirty-two male Sprague-Dawley rats weighing 250-320 gram were used. They were randomized and divided into four groups with eight animals in each as sham, control, SCI+PEG (polyethylene glycol) and SCI+atorvastatin group. Rats were anesthetized with intraperitoneal ketamine (80 mg/kg) and xylazine (10 mg/kg) and SCI was induced by the weight-drop model. A single level laminectomy was performed at T10 and the spinal column was immobilized with a stereotactic device. Rats in the treatment group received ip atorvastatin at 0.2 mg/kg. Neurological impairments were examined through Modified Tarlovs and inclined angle scores. The SCI section was resected for electron-microscopic analysis, IL-1β and IL-6 level. All data were analyzed using one-way ANOVA and Dunnet T3 test. RESULTS Atorvastatin improved locomotor recovery after rat SCI. The results were further confirmed with a statistically significant decrease of IL-1β, IL-6 and lipid peroxide levels. This finding revealed the anti-inflammatory and beneficial effect of atorvastatin on rat SCI. CONCLUSION The present study focused on both B and T cell mediated immunity and confirmed the beneficial effect of atorvastatin with decreased expressions of IL-1β and IL-6.


Turkish journal of trauma & emergency surgery | 2015

Outcomes and demostration of cranial firearm injuries: A multicenter retrospective study.

Kadir Çınar; Mehmet Seçer; Fatih Alagoz; Murat Ulutaş; Ozhan Merzuk Uckun; Ali Erdem Yildirim; Ahmet Gurhan Gurcay; Yahya Guvenc; Haydar Celik; Fırat Narin

BACKGROUND Cranial firearm injuries (CFAI) are associated with significant morbidity and mortality.This study was aimed to determine the factors affecting mortality of CFAI cases managed in our institution by a retrospective analysis of CT scans and clinical data. METHODS This multicenter retrospective study examined two hundred and nineteen patients presenting to neurosurgery clinics after CFAI between January 2012 and November 2014. Age, sex, Glasgow Coma Score (GCS), CT findings, and mortality and morbidity rates of the patients were analyzed to determine the factors affecting mortality. RESULTS Mean age of the study population was 24.19±12.25 years, 85.8% of them were male. The most common CT findings were fracture (100%), intracranial hemorrhage (61.2%), and an intracranially located foreign body (44.3%). A cranial operation was performed in 64.8% of the victims. Mean GCS on admission was 8±3.9, which increased in survivors (p<0.05). CONCLUSION CFAIs are associated with increased mortality and morbidity. We determined that many factors affected morbidity and mortality rates, and patient age, presence of intracranial hemorrhage, GCS, and treatment protocols were significantly associated with mortality.


Journal of Craniofacial Surgery | 2015

Endoscopic endonasal optic nerve decompression in a patient with pseudotumor cerebri.

Ali Erdem Yildirim; Derya Karaoglu; Denizhan Divanlioglu; Ahmed Eren Secen; Ahmet Gurhan Gurcay; Emin Cagil; Ahmed Deniz Belen

AbstractPseudotumor cerebri (idiopathic intracranial hypertension) is a syndrome characterized by intracranial pressure elevation and associated signs and symptoms in the absence of a space-occupying intracranial lesion. The most common symptoms are visual loss and headache. Sometimes, surgical therapy is needed in patients who have no apparent response to medical therapy and exhibit a progressive course. Optic nerve decompression is an effective and recommended treatment approach for patients with pseudotumor cerebri in whom visual loss predominates. With the growing experience with endoscopic skull base approaches, this method has begun to be used as an alternative and effective treatment modality. In this study, we aimed to present the outcome of endoscopic endonasal optic nerve decompression and to review the literature on this treatment modality in 2 patients diagnosed with pseudotumor cerebri that was unresponsive to medical therapy and associated with progressive visual loss.


Turkish Neurosurgery | 2014

Biochemical and histopathological effects of catechin on experimental peripheral nerve injuries.

Ali Erdem Yildirim; Ali Dalgic; Denizhan Divanlioglu; Rifat Akdag; Cetinalp Ne; Fatih Alagoz; Helvacioglu F; Take G; Yahya Guvenc; Koksal I; Ahmet Deniz Belen

AIM Catechin is a type of polyphenol, along with epicatechin, epigallocatechin, and epigallocatechin-gallate (EGCG). This study aims to investigate the effect of EGCG, a major metabolite of catechin, which is the principle bioactive compound in green tea, on rats with peripheral nerve injury. MATERIAL AND METHODS A total of 74 rats were divided into six groups, namely the control, the trauma, the normal saline, a 25mg/kg EGCG, a 50mg/kg EGCG and a daily consumption group (10mg/kg EGCG was given intraperitoneally for 14 days before the trauma). Except the first group, the other groups underwent a 1-minute sciatic nerve compression by clip with 50gr/cm2 pressure. Nerve samples were obtained at 28 day after trauma for the biochemical and histopathological analysis. RESULTS Our study showed that the Daily consumption, 25mg/kg EGCG and 50mg/kg EGCG groups demonstrated statistically significant decreased lipid peroxidation levels and particularly daily consumption, and the 25mg/kg EGCG group showed a favourable reduction of degeneration and edema histologically. CONCLUSION This study shows that Catechin and its derivatives have a protective effect on peripheral nerve injury.

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Engin Dursun

Recep Tayyip Erdoğan University

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Mete Karatay

Yeni Yüzyıl University

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