Eren Yilmaz

Dr. Eren Yilmaz

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 March 2025 in Cancers
Verified
Journal Article
Open access
PDF file
AEAtakan Emengen
Atakan Emengen
EYEren Yilmaz
Eren Yilmaz
AGAykut Gokbel
Aykut Gokbel
AUAyşe Uzuner
Ayşe Uzuner
SBSibel Balci
Sibel Balci
SCSavas Ceylan
Savas Ceylan
Background/Objectives: Giant pituitary adenomas (GPAs) pose significant surgical challenges due to their large size, parasellar/suprasellar extensions, and proximity to critical neurovascular structures. Although the endoscopic endonasal approach (EEA) is preferred for pituitary tumors, achieving gross total resection (GTR) in GPAs remains difficult. Additional transcranial approaches may improve resection rates while minimizing morbidity. This study evaluates the impact of endoscopic and combined surgical approaches on resection outcomes using a classification system previously defined in GPA patients treated over the past year. Methods: Among 517 pituitary adenomas treated in our clinic between September 2023 and September 2024, 49 GPA patients underwent endoscopic endonasal, transcranial, or combined surgery. Their medical records and surgical videos were retrospectively reviewed. Data included demographics, symptoms, imaging, surgical details, and follow-up outcomes. Tumor resection rates were analyzed based on the “landmark-based classification”, considering radiological and pathological features and surgical approach. Results: The mean age was 45.5 years (female/male: 14/35). Zone distribution was 8 (Zone 1), 21 (Zone 2), and 20 (Zone 3). GTR was achieved in 34.6%, near-total resection in 36.7%, and subtotal resection in 28.5%. Endoscopic surgery was performed in 41 patients, combined surgery in 7, and a transcranial approach in 1. Complications included diabetes insipidus (9/49), cerebrospinal fluid leakage (2/49), apoplexy (2/49), hypocortisolism (3/49), epidural hematoma (1/49), and epistaxis (1/49). Conclusions: While EEA is effective for Zone 1 and 2 GPAs, Zone 3 tumors often require combined or transcranial approaches for better resection. A multimodal strategy optimizes tumor removal while minimizing morbidity. Individualized surgical planning based on tumor classification is crucial for improving outcomes.

8 May 2024 in Operative Neurosurgery
Verified
Journal Article
Open access
EYEren Yilmaz
Eren Yilmaz
AUAyse Uzuner
Ayse Uzuner
ECEcem Cemre Ceylan
Ecem Cemre Ceylan
PYPinar Yildirim
Pinar Yildirim
SOSeda Duman Ozturk
Seda Duman Ozturk
SCSavas Ceylan
Savas Ceylan
BACKGROUND AND OBJECTIVES: The widespread use of endoscope and increased surgical experiences in pituitary adenomas (PAs) has raised the expectations for higher resection and cure rates. The subject that will meet this expectation in all types of adenomas is the capsule and its dissection. The purpose of this study was to go beyond the commonly mentioned pseudocapsule definition for small-sized adenomas in previous studies and to describe the capsule structure in different morphologies present in pituitary adenomas of all sizes. This includes detailing the nuances of capsular dissection (CD) and presenting postoperative surgical outcomes through the experiences of a high-volume tertiary center. METHODS: In our center, 534 patients underwent endoscopic trans-sphenoidal surgery because of pituitary adenoma in 2022 by the same surgeon. The data of the patients were examined retrospectively. The surgical techniques applied were grouped as adenoma resection only, capsular resection after internal debulking, and direct extracapsular resection. RESULTS: CD was performed in 275 (51.5%) patients. The gross total resection (GTR) rate in nonsecretory adenomas with and without CD was 90.7% (97/107) and 90.7% (97/107), respectively. The remission rate in secretory adenomas with and without CD was 81.0% (136/168) and 44.0% (67/152), respectively. When the patients were examined in 2 groups as those who underwent CD and those who did not, the application of CD had a positive predictive value in terms of GTR/remission (P: .036). Capsule thickness was not found to be statistically significant depending on tumor subtype, size, and aggressiveness, but capsule thickness was statistically significant in terms of total capsular resection (P: .045). CONCLUSION: The morphology of the capsule, tumor size/subtype/consistency, and patient-specific factors are crucial for the selection of the surgical technique to be applied. It is possible to increase the GTR/remission rates in adenomas of all sizes by capsule dissection. Moreover, performing CD does not contribute significantly to the development of potential complications in such cases.

20 February 2025 in Operative Neurosurgery
Verified
Journal Article
Open access
AEAtakan Emengen
Atakan Emengen
EYEren Yilmaz
Eren Yilmaz
AGAykut Gokbel
Aykut Gokbel
AUAyşe Uzuner
Ayşe Uzuner
ÖÇÖZGÜR ÇAKIR
ÖZGÜR ÇAKIR
SCSavas Ceylan
Savas Ceylan
BACKGROUND AND OBJECTIVES: Endoscopic endonasal surgery (EES) is the preferred approach for treating sellar and parasellar lesions due to its panoramic view and detailed anatomical definition. This study aims to review major arterial injuries during EES, a rare but critical complication associated with high mortality and morbidity rates. METHODS: A retrospective analysis was conducted, including 15 patients from 5640 EES procedures performed between August 1997 and February 2024 at in our center/Department of Neurosurgery. The study focuses on perioperative and postoperative management strategies, highlighting the use of oxidized regenerated cellulose (Surgicel®)/gelatin-thrombin matrix (Floseal®) and multidisciplinary collaboration to achieve hemostasis. RESULTS: The incidence of major arterial injury was 0.2%, with a mean patient age of 38.4 years and a female-to-male ratio of 10:5. The most common tumors were adenomas (n = 7) and chordomas (n = 5). The most commonly bleeding arteries in 6 patients each are the cavernous segment of the internal carotid artery and the paraclival carotid artery. Low-flow bleeding was observed in 10 of our patients, while high-flow bleeding was seen in 5 patients, 4 of whom were recurrent cases (P < .05). In 3 patients with high-flow bleeding from segments of the carotid artery, digital subtraction angiography was performed for stent placement or coil embolization, while in 1 patient with high-flow bleeding, digital subtraction angiography was used for monitoring cerebral blood flow. One of our patients died of a myocardial infarction at the 14th month of follow-up and 1 of our patients developed left-hemiparesis. CONCLUSION: The study underscores the importance of preoperative planning, surgical expertise, and multidisciplinary teamwork in managing major arterial injuries during EES. The authors advocate for the development of standardized treatment algorithms to improve outcomes in these patients. The findings contribute to the limited literature on managing internal carotid artery injuries in EES, emphasizing the need for ongoing research and algorithm development.

9 June 2017 in Turkish Archives of Otorhinolaryngology
Verified
Journal Article
Open access
EOErkan Ozturk
Erkan Ozturk
EYEren Yilmaz
Eren Yilmaz
IOIlker Erdinc Ozturk
Ilker Erdinc Ozturk
BPBeldan Polat
Beldan Polat
KOKadir Serkan Orhan
Kadir Serkan Orhan
Türk Otorinolarengoloji Arşivi

21 August 2025 in Journal of Clinical Neuroscience
Verified
Journal Article
Open access
EYEren Yilmaz
Eren Yilmaz
AEAtakan Emengen
Atakan Emengen
AUAyşe Uzuner
Ayşe Uzuner
BOBedrettin Ozsoy
Bedrettin Ozsoy
AGAykut Gokbel
Aykut Gokbel
SCSavas Ceylan
Savas Ceylan
Trigeminal schwannomas (TSs) are uncommon, benign tumors that arise from the trigeminal nerve. They can spread to the middle cranial fossa, posterior fossa, and extracranially (pterygopalatine fossa (PPF), infratemporal fossa, orbita). Among these, extracranial involvement is the least frequent. Before the advent of endoscopic techniques, these tumors were primarily removed using conventional microsurgical approaches. Due to both the rarity of extracranial localization and the increasing use of endoscopic techniques in suitable cases, reports of TSs with extracranial involvement treated via a purely endoscopic endonasal approach (EEA) remain limited, typically appearing as case reports or a small subset within larger case series. This study systematically reviews the literature on extracranial TSs managed exclusively with EEA and presents two illustrative cases from our institution. A systematic search of the PubMed database was performed in accordance with PRISMA guidelines to identify studies that utilized a purely EEA for extracranial TS cases. Additionally, a retrospective review of 6118 EEA procedures conducted at our institution identified two patients with histopathologically confirmed extracranial TSs. Clinical presentation, surgical approach, outcomes, and complications were analyzed. A total of 147 records were identified through database searches and reference lists. After removing duplicate records, 144 full-text articles were assessed for eligibility. Of these, 124 studies were excluded with justification, resulting in 23 studies being included in the review. When combined with our institutional cases, data from a total of 52 patients were analyzed. Facial numbness was the most common presenting symptom (70.5 %). The mean tumor diameter was 38.6 ± 13.3 mm, and the gross total resection rate was 93.1 %. In our cases, both patients successfully underwent tumor resection via EEA without postoperative neurological deficits. EEA provides a direct, minimally invasive route for managing extracranial TSs while reducing the morbidity associated with transcranial approaches. Although optimal for purely extracranial tumors, lesions extending into the middle or posterior fossa may require a combined approach. Therefore, individualized surgical planning is essential for achieving optimal outcomes in TS management.

9 February 2024 in World Neurosurgery
Verified
Journal Article
Closed access
AEAtakan Emengen
Atakan Emengen
EYEren Yilmaz
Eren Yilmaz
AGAykut Gökbel
Aykut Gökbel
AUAyşe Uzuner
Ayşe Uzuner
BCBurak Cabuk
Burak Cabuk
SCSavas Ceylan
Savas Ceylan