Operative Nuances of Capsular Dissection Techniques and Capsule Morphology in Pituitary Adenomas: Past 1-Year Case Experiences of a Tertiary Center.

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.

Rarely Used Endoscopic Transnasal Transdiaphragmatic Technique in Patients with Suprasellar Extension: A Tertiary Center's Experience with Eleven Patient Cases.

OBJECTIVE: As surgical techniques become less invasive, the use of endoscopy in brain surgery supports this trend. Numerous endoscopic surgical approaches have been defined, especially for skull base diseases. The current study summarizes our experience of using the rarely reported endoscopic transnasal transdiaphragmatic approach through the existing hole in the diaphragma sella to access lesions extending into the suprasellar region. METHODS: Our surgical team performed 4876 endoscopic endonasal surgeries between August 1997 and December 2022 at the Department of Neurosurgery, Pituitary Research Center, Faculty of Medicine, Kocaeli University. The study retrospectively analyzed data from 11 patients who had undergone endoscopic transnasal transdiaphragmatic surgery since January 2020. Preoperative and postoperative magnetic resonance imaging, pituitary function examination, and clinical observation were carried out. RESULTS: The mean age of the patients was 31.1 ± 10.7 years and the female/male ratio was 6:5. Pathologic subtypes observed included breast cancer metastasis (n = 1), adrenocorticotropic hormone-secreting adenoma (n = 4), growth hormone-secreting adenoma (n = 3), craniopharyngioma (n = 2), and Rathke cleft cyst (n = 1). The mean postoperative hospital stay was 4.7 ± 1.1 days and none of the patients showed cerebrospinal fluid leakage during this period. CONCLUSIONS: The endoscopic transnasal transdiaphragmatic approach may be considered an alternative to the conventional extended endoscopic transnasal approach in patients with lesions extending into the suprasellar region. The main strength of this method is that it facilitates suprasellar region access through a small dural incision and bone defect in the base of the skull. As a result, it also reduces the risk of postoperative cerebrospinal fluid leakage and associated complications.

Investigation of Demyelination and Remyelination Processes of the Compressed Optic Chiasm: An Experimental Model.

AIM: To demonstrated demyelination and remyelination of the optic nerve histologically by electron microscopy in an experimental model similar to the compression of pituitary adenomas on the optic chiasm. MATERIAL AND METHODS: The rats were fixed to a stereotaxic device under deep anesthesia, and a balloon catheter was placed under the optic chiasm through a burr hole which was in front of the bregma in accordance with the brain atlas of rats. The animals were divided into five groups (n=8): control, mild compression demyelination, severe compression demyelination, mild compression remyelination, severe compression remyelination. The fine structures of the tissues obtained were evaluated using electron microscopy. RESULTS: We found a significant difference in the severity of degeneration when comparing group 1 with group 5 (p < 0.001); there was no degeneration in group 1 rats and severe degeneration in all of the group 5 rats. Oligodendrocytes were found in all rats in group 1 and none of the rats in no group 2. The nuclei were preserved in the group 1 rats but damaged in all of the group 5 rats. There were no lymphocytes or erythrocytes in group 1 and all positives in group 5. CONCLUSION: This technique, which induced degeneration without causing damage to the optic nerve with toxic or chemical agents, revealed Wallerian degeneration similar to tumoral compression. After compression relief, the optic nerve remyelination process can be better understood, particularly for sellar lesions. In our opinion, this model may guide future experiments to identify protocols to induce and accelerate remyelination.

Endoscopic Endonasal Approach Limitations and Evolutions for Tuberculum Sellae Meningiomas: Data from Single-Center Experience of Sixty Patients.

AIM: To determine the limits, to show the effect of tumor consistency on resection rates and to present the sinonasal morbidity rate in patients with tuberculum sellae meningiomas who underwent endoscopic endonasal approach. MATERIAL AND METHODS: We reviewed the medical data, radiological images, and surgical videos of the patients with pathologically confirmed meningiomas originating from the tuberculum sellae and they were operated via endoscopic endonasal approach between August 1997 and December 2020. We used our endoscopic classification based on infrachiasmatic corridor. In this classification, tumors were divided into those within the infrachiasmatic corridor and proximity of the optic nerve, internal carotid artery, and anterior artery complex and those outside the infrachiasmatic corridor. RESULTS: Gross total resection was achieved in 45/60 (75%) patients. We found that tumor consistency was statistically significant on resection rates. Simultaneously, tumor median diameters on the anteroposterior (≤21.15 mm), transverse (≤19.75 mm), and superoinferior (≤15 mm) axes were statistically significant on resection rates. CONCLUSION: In summary, the most important factor in selecting the surgical technique is the tumor size. Infrachiasmatic corridor boundaries are the limitations of endoscopic approach. These limitations can change based on surgeon's experience. Also, tumor consistency is a factor that affecting degree of tumor resection rates.

Endoscopic transnasal surgery in optic pathway gliomas located in the chiasma-hypothalamic region: case series of ten patients in a single-center experience and endoscopic literature review.

OBJECTIVE: Optic pathway gliomas (OPGs) constitute approximately 3-5% of childhood intracranial tumors. In this study, the authors presented their experience of using the endoscopic endonasal approach to treat patients with OPG located in the chiasma-hypothalamic region and aimed to use the infrachiasmatic corridor in the endoscopic endonasal approach as an alternative to the transcranial approach in the surgical necessity of OPGs. METHODS: We retrospectively analyzed the data of ten patients diagnosed with OPG histopathologically among 3757 cases who underwent endoscopic endonasal surgery between August 1997 and March 2021 at Kocaeli University Faculty of Medicine Pituitary Research Center and Department of Neurosurgery. Mean follow-up period 48.5 months. During the postoperative follow-up period, 3 of these 10 patients underwent reoperation due to tumor recurrence. Combined (endoscopic endonasal approach + transcranial approach) approach was applied to 2 patients in the same session. Surgical and clinical outcomes were evaluated in detail. RESULTS: Ten patients with a mean patient age of 20.6 ± 11.4 were included in this study. The most common complaint was visual impairment. After surgery, improvement in visual impairment was observed in five patients. No increase in postoperative visual impairment was observed in any of the patients. Postoperative panhypopituitarism was not observed in any of the patients. STR resection was performed in 5 patients and NTR resection in 5 patients. No additional treatment was required during follow-up in 4 of 5 patients who underwent NTR. A total of 6 patients received postoperative radiotherapy treatment. CONCLUSIONS: In gliomas located in the chiasma-hypothalamic region, appropriate patient selection and endoscopic endonasal surgical treatment may contribute to the elimination of symptoms due to the mass effect of the tumor. It may also contribute to keeping the disease under control with targeted adjuvant therapies by clarifying the pathological diagnosis of the lesion.

A single-center experience with giant cell tumors of sphenoid bone and clivus.

OBJECTIVE: To present pathologic, clinical, and treatment findings for giant cell tumors (GCTs) of sphenoid bone and clivus. METHODS: We describe the optimal treatment algorithm in patients with a histopathologic diagnosis of bone GCT by presenting the effects of denosumab treatment in both pediatric and adult patients with GCT undergoing endoscopic transnasal surgery. Clinicopathologic correlation is crucial for the differential diagnosis of GCT and the choice of treatment modality. CONCLUSION: GCT of bone is a local aggressive tumor that accounts for about 3%-7% of all bone tumors. GCTs located in the cranium are extremely uncommon neoplasms. There are no defined guidelines for the treatment of GCTs in skull base. Following surgical resection of the tumor, the addition of denosumab treatments to radiotherapy has a significant role in preventing the recurrence of GCT and in promoting regression of residual tumor size.

Operative nuances and surgical limits of the endoscopic approach to clival chordomas and chondrosarcomas: A single-center experience of 72 patients.

OBJECTIVE: Gross total resection (GTR) is the mainstay therapy for chordomas and chondrosarcomas to have the best prognosis. The aims of this study were to specify the limits of EEA, emphasize the need for additional combined approaches for tumors beyond these limitations for high resection rates, discuss the prognostic factors and operative nuances that affect GTR, and present the causes and characteristics of early and late recurrences. METHODS: We retrospectively analyzed the endoscopic endonasal surgeries in the Pituitary Research Center and Neurosurgery Department of the Kocaeli University Faculty of Medicine, Turkey between January 2004 and December 2019. We retrospectively reviewed the medical data, radiological images, and surgical videos of patients, and 72 patients with chordoma and chondrosarcoma were included in the study. RESULTS: Based on pathology reports, 72 patients (seven pediatric) were identified, to whom 91 endoscopic operations were performed. We determined the surgical limitations for each clival segment as superior, middle, and inferior. Then, we divided these into three subgroups according to whether the tumor shows dural invasion (extradural chordoma, large extradural - minimal intradural component, and minimal extradural - large intradural component). The tumors of 19 (26.4%), 25 (26.4%), and nine (12.5%) patients originated from the superior, middle, and inferior clivus, respectively. Nineteen (26.4%) patients had panclival involvement. GTR was performed in 47 (65.3%) the patients. The GTR rate in patients with panclival tumors was 47.3% (9/19). The experience, lateralization, dural involvement, and origin of the clivus affecting GTR were analyzed. Extradural - intradural extensions were verified as negative predictor factors for GTR, whereas tumors located in the superior (OR: 16.710, p=0.030) and middle (OR: 11.154, p=0.023) segments were positive predictive factors for GTR. CONCLUSION: An increasing experience in endoscopic surgery significantly increases the GTR rates by widening the surgical limitations. Due to dense bone infiltration and adhesion to critical neurovascular structures, recurrence rates are high despite performing GTR. Although surgery and adjuvant treatments improve the 5-year survival of patients, the mortality rates remain high. Therefore, surgery of these tumors should be performed by experienced centers. In addition to surgical and adjuvant therapies, targeted molecular and translational biological therapies are also needed for chordomas and chondrosarcomas in the future.

An endoscopic endonasal approach to craniopharyngioma via the infrachiasmatic corridor: a single center experience of 84 patients.

OBJECT: The infrachiasmatic corridor is the most important surgical access route for craniopharyngiomas and was identified and used in clinical series. The aims of this study were to describe the characteristics that assist dissection and resection rates in endoscopic surgery of solid, cystic, and recurrent cases and their importance in the infrachiasmatic corridor in endoscopic surgery. METHODS: One hundred operations on 84 patients with pathologically identified craniopharyngioma were included in the study. The MRI findings were evaluated, and the location of the lesions was classified as (1) infrasellar; (2) sellar; or (3) suprasellar. In the sagittal plane, we measured the longest diameter of cystic and solid components and the height of chiasm-sella. Images were assessed for the extent of resection and were classified as gross total resection. This was deemed as the absence of residual tumor and subtotal resection, which had residual tumor. RESULTS: The infrasellar location was reported in 7/84 (8.3%) patients, the sellar location in 8/84 (9.5%), and the suprasellar location in 69/84 (82.1%) patients. The narrow and high chiasm-sella were observed in 28/69 (40.5%) and 41/69 patients (59.4%), respectively. The mean distance of the chiasm-sella was 9.46± 3.76. Gross total tumor resection was achieved in 60/84 (71.4%) and subtotal tumor resection was performed in 24/84 (28.6%) patients. The results revealed that suprasellar location (OR: 0.068; p = 0.017) and recurrent cases (OR: 0.011; p<0.001) were negative predictive factors on GTR. Increasing the experience (OR: 42,504; p = 0.001) was a positive predictor factor for GTR. CONCLUSION: An EETS approach that uses the infrachiasmatic corridor is required for skull base lesions extending into the suprasellar area. The infrachiasmatic corridor can determine the limitations of endoscopic craniopharyngioma surgery. This corridor is a surgical safety zone for inferior approaches.

Clinicopathologic Characteristics and Endoscopic Surgical Outcomes of Symptomatic Rathke's Cleft Cysts.

BACKGROUND: The purpose of this study was to evaluate the preoperative clinical data and postoperative endocrinologic improvement, recurrence, and complications of Rathke's cleft cysts (RCCs) in a large series of endoscopic transsphenoidal surgery patients, operated in a single center. METHODS: Between 1997 and April 2018, 84 patients underwent endoscopic transsphenoidal surgery for RCCs. The presentation symptoms, endocrinologic results by localization and content of the cysts, surgical resections, postoperative complications, and recurrences were evaluated retrospectively. RESULTS: Chronic headache was reported in 66.6% (56/84), visual field defects were present in 20.2% (17/84), and 23.8% (20/84) of the cases had pituitary dysfunction. Among the endocrinopathies, 17 of 17 patients had hyperprolactinemia, 2 of 7 patients had cortisol deficiency, and 2 of 13 had hypogonadism, which resolved after surgery. Preoperative pituitary hormone deficiency was associated with gelatinous tumor content (P = 0.044). However, there was no significant relationship between tumor localization and preoperative hormone insufficiency. Postoperative hypocortisolemia was seen more frequently in intrasellar RCCs (P = 0.048). Three new pituitary hormonal deficiencies were identified in postoperative patients (1 hypocortisolism, 1 diabetes insipidus, 1 hypogonadism). Gross total resection was achieved in 20 cases (23.8%), 9 of which were performed using an extended approach. Postoperative complications included 3 cerebrospinal fluid leakages and 1 epistaxis. Two patients presented with cyst recurrence at follow-up at 12 and 26 months. CONCLUSIONS: Preoperative hormone deficiency was found to be associated with tumor content, independent of size or localization. The surgical aim for symptomatic RCCs should be decompression and this is effective for endocrinologic improvement. An extended endoscopic approach was adequate for total cyst wall removal in suprasellar cysts. Endoscopic transsphenoidal surgery was successful, with low complication rates, for decompression of intrasellar and suprasellar cysts in both complete cyst wall resection and cyst fenestration.