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Öğe Clival dural reconstruction via transnasal approaches:fat graft fixation technique(American Association of Neurological Surgeons, 2025) Luzzi, Sabino; Doğruel, Yücel; Güngör, Abuzer; Gürses, Muhammet Enes; Rahmanov, Serdar; Türe, Hatice; Türe, UğurOBJECTIVE CSF fistulas are the weak spots of transnasal endoscopic and microsurgical skull base approaches. An autologous fat graft is considered the best substrate for clival dural reconstruction via transnasal approaches. However, potential gravitational displacement of the graft may result in CSF leakage. The authors have developed and described herein the fat graft fixation (FGF) technique to secure the fat graft against dislocation after transclival resection of chor- domas invading the dura. METHODS Seventy-five patients with cranial chordomas underwent surgical treatment at the authors’ institution from September 2006 through June 2023. Of these, the authors collected demographic, clinical, radiological, surgical, and outcome data from 34 patients who underwent an endoscope-assisted microsurgical transclival approach via a transna- sal, sublabial, or sublabial transmaxillary extended corridor. The FGF reconstruction technique was progressively imple- mented to improve clival reconstruction, with a focus on the results. With a custom-made 8-mm 3/8 round atraumatic surgical suture needle, a 4/0 Vicryl stitch was placed through the adjacent dural borders. An abdominal autologous fat graft was then placed over the dural defect. One triple knot was tied to secure the graft and prevent its delayed gravita- tional displacement. The primary outcome was to determine if the FGF group had a higher rate of early or late oronasal CSF fistula compared to the unlocked free graft group. Secondary outcomes included tension pneumocephalus, surgical site infection, and meningitis. RESULTS The fat graft was not used in 8 (23.5%) of the 34 patients because the dura was intraoperatively intact. The unlocked free graft and FGF techniques were used in 20 (58.8%) and 6 (17.6%) patients, respectively. Of the 34 patients, no fistulas were observed in the group treated with the FGF technique, while 4 fistulas were found in the unlocked free graft group (p < 0.05), with 2 of these cases involving meningitis. Patients with a CSF fistula underwent a total of 7 surgi- cal procedures: 3 revision surgical procedures, 2 lumboperitoneal shunts, and 2 ventriculoperitoneal shunts. CONCLUSIONS In the authors’ preliminary experience, the FGF technique has shown promise in eliminating the risk of CSF fistula and other related complications after the transclival approach for clival chordomas involving the dura.https://thejns.org/doi/abs/10.3171/2024.11.FOCUS24560 ©AANS 2025, except where prohibited by US copyright law.Öğe Human adapted prosomeric model: a future for brainstem tumor classification(Elsevier, 2024) Munoz-Gualan, Alberth Patricio; Güngör, Abuzer; Cezayirli, Phillip Cem; Rahmanov, Serdar; Gürses, Muhammet Enes; Puelles, Luis; Türe, UğurThis study reevaluates the conventional understanding of midbrain anatomy and neuroanatomical nomenclature in the context of recent genetic and anatomical discoveries. The authors assert that the midbrain should be viewed as an integral part of the forebrain due to shared genetic determinants and evolutionary lineage. The isthmo-mesencephalic boundary is recognized as a significant organizer for both the caudal midbrain and the isthmo-cerebellar area. The article adopts the prosomeric model, redefining the whole brain as neuromeres, offering a more precise depiction of brain development, including processes like proliferation, neurogenesis, cell migration, and differentiation. This shift in understanding challenges traditional definitions of the midbrain based on external brain morphology. The study also delves into the historical context of neuroanatomical models, including the columnar model proposed by Herrick in 1910, which has influenced our understanding of brain structure. Furthermore, the study has clinical implications, affecting neuroanatomy, neurodevelopmental studies, and the diagnosis and treatment of brain disorders. It emphasizes the need to integrate molecular research into human neuroanatomical studies and advocates for updating neuroanatomical terminology to reflect modern genetic and molecular insights. The authors propose two key revisions. First, we suggest reclassifying the isthmo-cerebellar prepontine region as part of the hindbrain, due to its role in cerebellar development and distinct location caudal to the genetically-defined midbrain. Second, we recommend redefining the anterior boundary of the genetically-defined midbrain to align with genetic markers. In conclusion, the authors highlight the importance of harmonizing neuroanatomical nomenclature with current scientific knowledge, promoting a more precise and informed understanding of brain structure, which is crucial for both research and clinical applications related to the human brain.Öğe In Reply: Opening the Parieto-Occipital Fissure for Periatrial Metastasis: 2-Dimensional Operative Video(Lippincott Williams & Wilkins, 2024) Dogruel, Yucel; Rahmanov, Serdar; Gungor, Abuzer; Ture, Ugur[Abstract Not Available]Öğe Microsurgical Resection of a Parachiasmatic Craniopharyngioma via a Left-Sided Pterional Transsylvian Approach(Elsevier Science Inc, 2024) Dogruel, Yucel; Rahmanov, Serdar; Gungor, Abuzer; Ture, UgurCraniopharyngiomas are histologically benign tumors that originate from squamous rests along the pituitary stalk. They make up approximately 1.2% to 4.6% of all intracranial tumors and do not show significant differences in occurrence based on sex. Adamantinomatous craniopharyngiomas have 2 peaks of incidence, commonly observed in patients from ages 5 to 15 years and again from 45 to 60 years. In contrast, papillary craniopharyngiomas mainly affect adults in their fifth and sixth decades of life.1 The malignancy of craniopharyngiomas is attributed to their location and the challenges associated with achieving complete removal because they can manifest in the sellar, parachiasmatic, and intraventricular regions or a combination of these.2,3 Various approaches have been used to resect these tumors.4,5 Radical resection offers the most promising option for disease control, potential cure, and the ability to transform the disease from lethal to survivable in children, allowing for a functional adult life.2,3 Meticulous evaluation is crucial to determine the appropriate approach and side, with particular emphasis on closely examining the relationship between the tumor and optic pathways (nerve, chiasm, tract), which are frequently involved. This assessment should also include the tumor's relationship with other crucial structures, such as the hypothalamus and adjacent arteries, to ensure that the strategy is adjusted accordingly to further minimize the risk of postoperative morbidity. Video 1 demonstrates a left -sided pterional transsylvian approach to remove a parachiasmatic craniopharyngioma involving the left optic chiasm and tract.Öğe Microsurgical Resection of a PediatricTegmentum Tumor Through the Paramedian Supracerebellar Transtentorial Approach with the Tentorial Cut Technique: 2-Dimensional Operative Video(Lippincott Williams and Wilkins, 2024) Rahmanov, Serdar; Doǧruel, Yücel; Güngör, Abuzer; Türe, UǧurThe brainstem contains a highly complex group of nuclei and major white matter tracts within a small volume.1 The complex nature of its anatomy creates challenges for surgery in this area, impeding the standardization of approaches. Therefore, the concept of the "safe entry zone" should be considered with caution, and the strategy for each patient should be tailored based on the relevant subunit of the brainstem and individual patient characteristics. The critical parameter to target in patients is achieving the highest possible extent of resection while preserving function.1 The paramedian supracerebellar transtentorial approach is usually suitable for midbrain lesions. This approach allows for targeting tegmental tumors through the posterolateral midbrain surface.1 It is typically performed through a paramedian suboccipital craniotomy, ideally with the patient in the semisitting position, and is now considered a standard and safe approach.2 In patients with a spontaneous atrial right-to-left shunt, lateral or semilateral positions are viable alternatives, with the semilateral preferred for intraoperative magnetic resonance imaging.1 The cerebellar hemispheric tentorial bridging veins are usually located in the surgical route, narrowing the surgical corridor.3 Sacrifice or unintended rupture of these veins can sometimes lead to unexpected serious complications. Therefore, it is essential to preserve these veins during supracerebellar approaches.3 In this study, we demonstrate the resection of a pediatric tegmentum tumor through the left-sided paramedian supracerebellar transtentorial approach. In addition, we show the tentorial cut technique used to preserve the cerebellar hemispheric tentorial bridging veins. The patient's parents consented to the procedure and to the publication of his image. © 2024 Lippincott Williams and Wilkins. All rights reserved.Öğe Neglected tracts of the brainstem: transverse peduncular tract of Gudden and taenia pontis(American association of neurological surgeons, 2024) Rahmanov, Serdar; Güngör, Abuzer; Gülsuna, Beste; Munoz-Gualan, Alberth PatricioOBJECTIVE The anatomy and function of the brainstem have fascinated scientists for centuries; however, the brain- stem remains one of the least studied regions of the human brain. As the authors delved into studying this structure, they observed a growing tendency to forget or neglect previously identified structures. The aim of this study was to describe two such structures: the transverse peduncular tract, also known as the Gudden tract, and the taenia pontis. The authors analyzed the potential effects of neglecting these structures during brainstem surgery and the implications for clinical practice. METHODS After removal of the arachnoid and vascular structures, 20 human brainstem specimens were frozen and stored at -16 degrees C degrees C for 2 weeks, according to the method described by Klingler. The specimens were then thawed and dissected with microsurgical techniques. The results of microsurgical fiber dissection at each step were photographed. RESULTS This study revealed two previously neglected or forgotten structures within the brainstem. The first is the transverse peduncular tract of Gudden, which arises from the brachium of the superior colliculus. This tract follows an arcuate course along the lateral and ventral surfaces of the midbrain, perpendicular to the cerebral peduncle, and terminates in the nuclei of the transverse peduncular tract within the interpeduncular fossa. The second structure is the taenia pontis, which originates contralaterally in the interpeduncular fossa. It becomes visible at the level of the pontomesencephalic sulcus and extends to the base of the lateral mesencephalic sulcus, where it divides into several thin bundles. Along the interpeduncular sulcus, between the superior and middle cerebellar peduncles, it reaches the parabrachial recess and enters the cerebellum. CONCLUSIONS Recently, with increasing understanding and expertise in brainstem research, surgical approaches to this area have become more common, emphasizing the importance of a detailed knowledge of the brainstem. The two structures mentioned in this paper are described in history books and were widely studied in the 19th century but have not been mentioned in modern literature. The authors propose that a deeper understanding of these structures may prove valuable in neurosurgical practice and help reduce patient comorbidity.Öğe Opening the Parieto-Occipital Fissure for Periatrial Metastasis: 2-Dimensional Operative Video(Lippincott Williams & Wilkins, 2024) Dogruel, Yucel; Rahmanov, Serdar; Gungor, Abuzer; Ture, Ugur[Abstract Not Available]Öğe Posterior Interhemispheric Transtentorial Subsplenial Approach for Posterior Thalamic Tumors: 2-Dimensional Operative Video(Lippincott Williams & Wilkins, 2024) Dogruel, Yuecel; Rahmanov, Serdar; Gungor, Abuzer; Ture, UgurINDICATIONS: CORRIDOR AND LIMITS OF EXPOSURE:The posterior interhemispheric transtentorial subsplenial approach provides a direct corridor to posterior thalamic lesions without a cortical or callosal incision.1 ANATOMIC ESSENTIALS: NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT:This corridor is through the posterior interhemispheric fissure along the medial surface of the cuneus and allows the subsplenial region to be explored. Evaluating the tumor's size and extension is crucial to determining the suitability of this approach. The deep venous system may be displaced from mass effect, requiring preoperative venous examination. ESSENTIALS STEPS OF THE PROCEDURE:A 34-year-old male patient was admitted elsewhere with blurred vision and imbalance. MRI revealed a right-sided posterior thalamic tumor with heterogeneous contrast enhancement. The patient was followed-up after placement of a ventriculoperitoneal shunt. Seven months later, he was admitted to our clinic because the tumor had grown. The patient underwent surgical intervention. The patient was placed in the prone oblique position. After dural opening, the quadrigeminal cistern was opened to release cerebrospinal fluid, allowing significant gravity relaxation of the ipsilateral hemisphere. The tentorium was cut and retracted to achieve the necessary exposure. PITFALLS/AVOIDANCE OF COMPLICATIONS:The most serious complications of this approach occur from vascular injuries. Gravitational retraction of the occipital lobe protects the optic radiation, and anatomic landmarks help the surgeon maintain anatomic orientation. VARIANTS AND INDICATIONS FOR THEIR USE:The perimedian supracerebellar transtentorial approach is an alternative to the posterior interhemispheric transtentorial subsplenial approach for lesions in this area; however, the indications and limits of these approaches have some differences.The patient consented to the procedure and to the publication of his/her image.Images at 0:29 reused from Serra et al,1 with permission from Elsevier. VARIANTS AND INDICATIONS FOR THEIR USE:The perimedian supracerebellar transtentorial approach is an alternative to the posterior interhemispheric transtentorial subsplenial approach for lesions in this area; however, the indications and limits of these approaches have some differences.The patient consented to the procedure and to the publication of his/her image.Images at 0:29 reused from Serra et al,1 with permission from Elsevier. VARIANTS AND INDICATIONS FOR THEIR USE:The perimedian supracerebellar transtentorial approach is an alternative to the posterior interhemispheric transtentorial subsplenial approach for lesions in this area; however, the indications and limits of these approaches have some differences.The patient consented to the procedure and to the publication of his/her image.Images at 0:29 reused from Serra et al,1 with permission from Elsevier.Öğe Selective amygdalohippocampectomy via the paramedian supracerebellar-transtentorial approach for mediobasal temporal epilepsy(American association of neurological surgeons, 2024) Doğruel, Yücel; Rahmanov, Serdar; Güngör, Abuzer; Türe, UğurSelective amygdalohippocampectomy via the pterional transsylvian approach is a feasible option for many patients with mediobasal temporal epilepsy. However, it may be insufficient for patients when the posterior hippocampal region is involved. The paramedian supracerebellar transtentorial approach offers precise anatomical orientation when expos-ing the entire length of the mediobasal temporal region, including the fusiform gyrus. In addition, this approach allows selective amygdalohippocampectomy without any neocortical damage. This video presents the successful treatment of a patient with posterior hippocampal sclerosis and mediobasal temporal epilepsy through the paramedian supracerebellar transtentorial approach.Öğe Thrombosed posterior inferior cerebellar artery aneurysm mimicking a medulla oblongata cavernous malformation: 2-dimensional operative video(Lippincott williams & wilkins, 2024) Doğruel, Yücel; Rahmanov, Serdar; Güngör, Abuzer; Türe, UğurThe incidence of posterior inferior cerebellar artery (PICA) aneurysms is estimated to be between 0.5% and 3% of total aneurysm cases.(1) Most patients with these aneurysms typically present with subarachnoid hemorrhage, although there are instances in which patients may present with symptoms resulting from mass effect exerted on the brain stem or lower cranial nerves.(1,2) Treatment options for PICA aneurysms include endovascular procedures, surgical clipping, or bypass techniques.(2) Surgical treatment is considered more effective for partially thrombosed aneurysms compared with endovascular approaches.(3) In addition, endovascular coiling of these aneurysms carries the potential risk of coilmigration and subsequent reopening of the aneurysm lumen.(4) In certain instances, thrombosed PICA aneurysms have the potential to simulate the radiological characteristics of alternative pathologies, such as cavernous malformations or brainstem tumors.(5-7) This situation can result in misdiagnosis and inappropriate management. We present the case of a patient who exhibited symptoms of imbalance and dysfunction in the lower cranial nerves. Magnetic resonance imaging findings indicated a possible cavernous malformation in the medulla oblongata. However, further investigation revealed that the underlying cause was a thrombosed PICA aneurysm. The patient was successfully treated through surgical clipping.
