Expanded Endoscopic Endonasal Approach Research Articles

Outcomes of the Endoscopic Endonasal Approach for the Treatment of Clival Chordomas: A Single-Center Experience

Abstract Objective Chordoma is a low-grade malignant tumor that originates from the remnant tissue of the embryonic notochord. Postoperative or definitive radiotherapy (RT) has been used to enhance local control. This study aims to assess the outcomes of the expanded endoscopic endonasal approach (EEA) for maximal removal of clival chordomas followed by RT for visualized residual or tumor recurrence. Materials and Methods A retrospective review was performed on consecutive patients with clival chordoma who underwent endoscopic endonasal resection in the otorhinolaryngology and neurosurgery departments, between 2016 and 2021. We included all patients with pathologically confirmed clival chordoma who were treated using the EEA. Patients who underwent combined external and endoscopic approaches or transcranial surgery were excluded. Results Seventeen patients were included in this study. Most of them had tumors located in the middle clivus. Regarding RT, the majority of patients underwent postoperative RT. Almost half of them underwent CyberKnife (CK) RT. None of them had severe toxicities (grade 3 or higher). Three patients died, resulting in a mortality rate of 17.6% none of them related to radiation side effect. The 2-year overall survival was 82.4% (mean standard error [SE] = 1.765, 95% confidence interval [CI] = 1.505–2.024), and the progression-free survival (PFS) was 76.5% (mean SE = 3.403, 95% CI = 2.791–4.016). No distal metastasis was reported in our series. Conclusion This series demonstrates that expanded endoscopic endonasal approach (EEA) for the resection of skull base chordomas, followed by CyberKnife radiosurgery, presents a viable alternative to proton beam therapy; however, further research is necessary to directly compare these modalities.

Transorbital transposition of the temporoparietal fascia flap to reconstruct the skull base defects: A preclinical study with comparison to the transpterygoid transposition.

Transpterygoid transposition of the temporoparietal fascia flap (TPFF) is a feasible selection for ventral skull base defect (VSBD) reconstruction, but not anterior skull base defect (ASBD) reconstruction, after expanded endoscopic endonasal approach (EEEA). The goal of this study is to introduce the transorbital transposition of the TPFF for skull base defects reconstruction after EEEA, and make quantitative comparison between the transpterygoid transposition and transorbital transposition. Cadaveric dissections were performed in five adult cadaveric heads with creating three transporting corridors bilaterally, encompassing superior transorbital corridor, inferior transorbital corridor, and transpterygoid corridor. For each transporting corridor, the minimum necessary length of the TPFF for skull base defects reconstruction was measured. The areas of ASBD and VSBD were 1019.63 ± 176.32 mm2 and 572.99 ± 126.21 mm2 . The length of the harvested TPFF was 149.38 ± 6.21 mm. In contrast to the transpterygoid transposition with incomplete coverage, transorbital transposition of the TPFF allowed full coverage of ASBD with a minimum necessary length of 109.75 ± 8.31 mm. For VSBD reconstruction, transorbital transposition of the TPFF needs shorter minimum necessary length (123.88 ± 4.49 mm) than transpterygoid transposition (138.00 ± 6.28 mm). Transorbital corridor is a novel pathway for transporting the TPFF into the sinonasal cavity for skull base defects reconstruction after EEEA. In comparison with transpterygoid transposition, transorbital transposition provides wider coverage of skull base defects with a fixed length of the TPFF.

Tension Pneumocephalus: A Potentially Fatal Complication of Expanded Endoscopic Endonasal Approach.

While some volume of pneumocephalus occurs following any surgery entailing dural breach, tension pneumocephalus (TP) is a rare complication of endoscopic endonasal surgery described in less than 1% cases including expanded endoscopic endonasal approaches (EEEA). It is a neurosurgical emergency warranting urgent decompression. Two cases, who developed TP following EEEA are presented. One had sinonasal malignancy (adenoid cystic carcinoma) eroding the anterior skull-base (T4N0M0) and the other was a large olfactory groove meningioma. TP was heralded in both by sudden deterioration in neurological status. Both cases underwent bifrontal craniotomy for decompression with simultaneous skull-base repair incorporating a vascularised pericranial flap. Brief literature review regarding the pathophysiology, contributing factors, diagnosis, management, and prevention of TP following EEEA is presented. TP, a life-threatening neurosurgical emergency, warrants meticulous precautions for its prevention, and vigilant postoperative monitoring for early detection. Urgent decompression with thorough skull-base repair is imperative to prevent complications.

Endoscopic Approaches to the Paramedian Skull Base: An Anatomic Comparison of Contralateral Endonasal and Transmaxillary Strategies.

The expanded endoscopic endonasal approach (EEA) is limited laterally by the internal carotid artery (ICA). The EEA to the paramedian skull base often requires complex maneuvers such as dissection of the Eustachian tube (ET) and foramen lacerum (FL), and ICA manipulation. An endoscopic contralateral transmaxillary approach (CTMA) has the potential to provide adequate exposure of the paramedian skull base while bypassing manipulation of the aforementioned anatomic structures. To quantify and compare the surgical nuances of a CTMA and a contralateral EEA when approaching the paramedian skull base in cadaveric specimens. Five adult cadaveric heads were dissected bilaterally (10 sides) using a contralateral EEA and a CTMA to expose targets of interest at the paramedian skull base. For each target in both approaches, the surgical freedom, angle of attack, the corridor's "perspective angle," and "turning angle" to circumvent the ICA, ET, and FL were obtained. The CTMA achieved superior surgical freedom at all targets ( P < .05) except at the root entry point of cranial nerve XII. The CTMA provided superior vertical and horizontal angles of " attack " to the majority of targets of interest. Except when approaching the root entry point of cranial nerve XII, the CTMA " turning angle " around the ICA, ET, and FL were wider with CTMA for all targets. A CTMA complements the EEA to access the paramedian skull base. A CTMA may limit the need for complex maneuvers such as ICA mobilization and dissection of the ET and FL when approaching the paramedian skull base.

Endoscopic Endonasal Accessibility and Maneuverability Around the Internal Carotid Artery from Distal Dural Ring to Foramen Lacerum: Cadaveric Study

Background: Expanded-endoscopic endonasal approaches (eEEA) to surgical targets around the internal carotid artery (ICA) remain inspiring and necessitate a special learning curve. Methods: Six formalin-fixed heads were dissected to study the 360° accessibility and manoeuvrability around ICAs from the distal dural ring (DDR) to the foramen lacerum (FL) on each side (n=12) via eEEA. The ICA course was divided into three segments: ICA in cavernous sinus (CS-ICA), paraclival-ICA and lacerum-ICA. Following total exposure of each ICA, the three-dimensional (3D= medial/lateral, superficial/deep and above/below) anatomical targets (n= 35) around each ICA were evaluated. The data were collected and analyzed. Results: Distinctively, we included 35 anatomical targets (pertinent to CS-ICA, paraclival-ICA and lacerum-ICA were 16, 10, and 9, respectively) in 360° around every ICA (n=12) from the DDR to FL. Although reasonable visual validation was possible for all targets, micro-dissections were safely achievable for 19 targets (54.3%) through full or limited surgical freedom in 73.7% and 26.3%, respectively. In the remaining 45.7%, the accessibility to targets was abandoned due to hazardous manipulation. The most unreachable targets were around the lacerum-ICA (55.6%) with extremely restricted maneuverability (75%). Though, favorable accessibility (60%) and full surgical freedom (100%) were around the paraclival-ICA. Conclusion: This study delivers a distinctive view to appreciate the degree of complexity and invasiveness in relation to the degree of surgical freedom around ICA via eEEA. Illustrating these details for skull base surgeons can lead them to tailor their approach. It delivers prospective feedback for our operative theatre.

In-Hospital Cost Comparison for Open Versus Endoscopic Endonasal Approach for Meningioma Resection.

To determine the in-hospital cost implications of an endoscopic expanded endonasal approach (EEEA) for meningioma resection relative to the open transcranial approach. All anterior skull base meningioma surgeries performed over a period from January 1st, 2015 to October 31th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using R software. All cost data were converted into August 2021-equivalent dollar amounts using the United States Bureau of Labor Statistics consumer price index. Thirty-five patients met study criteria, including 27 patients undergoing an open transcranial approach and 8 undergoing an EEEA. Average length of stay for patients undergoing an open approach was 9.3 days compared to 5.6 within the EEEA group (P = .126). The average total in-hospital cost of patient undergoing an EEEA was $35417.1 compared to $46406.9 among patients undergoing an open transcranial approach (P = .168). On univariate analysis, the cost of an open transcranial approach relative to the EEEA was $10989.8 (P = .411). The open transcranial approach remained the dominant surgical approach to anterior skull base meningiomas over our study time period. However, despite limited patient numbers the EEEA was associated with decreased total in-hospital costs.

Expanded endoscopic endonasal approach for the resection of midline craniopharyngiomas with hypothalamic involvement.

With relevant surrounding neurological structures and potential involvement of the hypothalamus, the surgical management of craniopharyngiomas is complex. Compared to the transcranial approach, the expanded endoscopic endonasal approach provides direct access to the supradiaphragmatic and retrochiasmatic areas without crossing nerves and arteries. Based on our substantial experience of 68 patients operated on between 2008 and 2022 by endoscopic surgery, our strategy has evolved such that all of our midline infundibular craniopharyngiomas with hypothalamic involvement are currently treated with an expanded endonasal route, except for tumours isolated to the third ventricle. Vascularized mucosal nasoseptal flaps are required for closure. Fine details of the related anatomy and surgical technique are described. Expanded endoscopic endonasal approach is a safe and effective route for resection of midline suprasellar craniopharyngiomas with hypothalamic involvement in centres of expertise.

Expanded endoscopic endonasal transsphenoidal approach to determine morphological characteristics and clinical considerations of the cavernous sinus venous spaces

The study aimed at investigating the morphological characteristics and interconnected regularities of the cavernous sinus (CS) venous spaces using an expanded endoscopic endonasal transsphenoidal approach. Surgical dissections were performed for 15-colored silicon-injected human head specimens. The CS venous spaces were examined for their morphological and clinical characteristics using an expanded endoscopic endonasal transsphenoidal approach. The intracavernous course of the internal carotid artery (ICA) divided the CS venous spaces into four interconnected virtual compartments: medial, anteroinferior, posterosuperior, and lateral. The CS venous spaces had peculiar morphological characteristics; the medial compartment was C-shaped while the anteroinferior compartment resembled a boat's bow. The mean distances from the medial border of the inferior horizontal segment of cavernous ICA to the mid-line of the pituitary gland (PG) were 6.07 ± 1.61 mm (left) and 5.97 ± 1.89 mm (right); the mean distances from the medial border of the subarachnoid segment of cavernous ICA to the mid-line of the PG were 5.77 ± 1.16 mm (left) and 5.63 ± 1.17 mm (right); the mean distances from the medial border of the anterior vertical segment of cavernous ICA to the mid-line of the PG were 10.27 ± 1.74 mm (left) and 10.47 ± 1.90 mm (right). Morphological characteristics and the knowledge of the interconnected regularities of the CS venous spaces may help surgeons accurately locate the neurovascular structure, and thus may contribute to the effective prediction of tumor invasion and extension during endoscopic CS surgery.

Expanded Endonasal Endoscopic Approach for Suprasellar Rathke Cleft Cyst: Treatment Outcome and Surgical Nuances

Rathke cleft cysts (RCCs) are benign lesions originating from remnants of the Rathke pouch. RCCs have been classified into the intrasellar-based or purely suprasellar types. This research aims to study the optimal treatment nuances and evaluate the surgical outcomes of this distinct type of RCCs. This study retrospectively reviewed 36 patients with purely suprasellar RCCs who were treated by expanded endonasal endoscopic approach (EEA) from September 2018 to January 2021. The demographic data, presenting symptoms, endocrine status, imaging findings, operative details, and surgical outcomes were analyzed. According to the relationship with pituitary stalk, the suprasellar RCCs can be divided into 2 different growth patterns: intrastalk cyst (ISC, 52.8%) and extrastalk cyst (ESC, 47.2%). Preoperative endocrine dysfunctions occurred more in patients with ISC than ESC (P= 0.007), which are characterized by hypoadrenalism (P= 0.004) and hypogonadism (P= 0.008). Operation exerted different impacts on endocrine functions between ISC and ESC (P= 0.012). When identifying by single hypothalamic-pituitary axis, 4 patients with normal endocrine function developed a new hormonal deficit, 14 patients with preoperative endocrine dysfunctions benefited from our expanded EEA surgical treatment, and 3 of them completely recovered from the endocrinopathy after surgery. The postoperative endocrinopathy was positively associated with the numbers of preoperative abnormal endocrinal axes. Thirty-four (94.4%) patients had achieved gross total resection. Pituitary stalk was intactly preserved in 23 of 36 patients (63.9%), partly preserved in 10 patients, and not preserved in 3 patients. Purely suprasellar RCCs are a distinct type of RCCs, which originate from the pituitary stalk above the diaphragmatic sellae, and the treatment strategy via expanded EEA is a rational choice. Classification based on growth patterns would be beneficial to reduce endocrine disorders after surgery.

In-Hospital Costs for Open versus Endoscopic Endonasal Approach for Craniopharyngioma Resection.

To determine the in-hospital cost implications of an expanded endoscopic endonasal approach (EEEA) for craniopharyngioma resection relative to the traditional open transcranial approach. All craniopharyngioma surgeries performed at a single institution over a period from January 1st 2001 to October 31th 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate regression analysis was performed using R software. Thirty-six patients met study criteria, including 22 undergoing an open approach and 14 undergoing an EEEA. There was a significantly longer average length of stay among patients undergoing open resection (21.5 vs. 10.6 days, p=0.024). The average total in-hospital cost of a patient undergoing an EEEA was $58979.3 compared to $89142.3 for an open approach (p=0.127). On univariate regression analysis, the total in-hospital cost for a patient undergoing an open approach relative to an EEEA was $30163.0 (p=0.127). The open approach was exclusively performed from study onset until April 2010 (16 patients). From April 2010 to August 2013, 6 open approaches and 5 EEEA were performed. The EEEA has been exclusively performed from August 2013 until the conclusion of our study period (9 patients). There has been a shift toward surgical resection of craniopharyngioma via an EEEA approach for amenable tumors. Our study demonstrates that the EEEA has become the preferred surgical approach at our institution, and shows that the EEEA is associated with shorter postoperative length of stay and lower total in-hospital cost. Laryngoscope, 133:83-87, 2023.

Quality of Life After Endoscopic Skull Base Surgery: Validation and Reliability of the Italian Version of the Sino-Nasal Outcome Test for Neurosurgery (SNOT-NC)

Expanded endonasal approaches (EEA) have become the main approach to the anterior skull base. A specific questionnaire, the Sino-Nasal Outcome Test for Neurosurgery (SNOT-NC), was developed in German to assess quality of life after EEA. The aim of this study was the cross-cultural adaptation and validation of the Italian version of SNOT-NC. Three hundred patients who underwent EEA for anterior skull base diseases were included in the study. An Italian version of SNOT-NC was cross-culturally adapted. Internal consistency, test-retest reliability, construct, and clinical and group validity were analyzed. The Short-Form 36 questionnaire was used for construct validity analysis. The Cronbach α coefficient was 0.862. Only 1 subscale (olfactory disturbance) showed an insufficient internal consistency. The test-retest reliability was excellent (intraclass correlation coefficient between 0.934 and 0.997). The good correlation between SNOT-NC and Short-Form 36 scores (P < 0.05) showed the construct validity of the questionnaire. SNOT-NC was able to distinguish between patients with more or fewer nasal symptoms (P < 0.05). Patients who underwenta transtuberculum/transplanum approach had greater olfactory disturbances compared with other approaches (P < 0.05). The Italian version of SNOT-NC showed good internal consistency, test-retest reliability, construct, and clinical and group validity, as well as original version. It can be considered a good instrument to evaluate the impact of endoscopic EEA to the anterior skull base.

Expanded endoscopic endonasal approach for complex functioning tumours with cavernous sinus, suprasellar and clival invasion: technical nuances for maximising extent of resection and biochemical remission

Expanded endoscopic endonasal approach for complex functioning tumours with cavernous sinus, suprasellar and clival invasion: technical nuances for maximising extent of resection and biochemical remission

Soft Gasket Seal Reconstruction After Endoscopic Endonasal Transtuberculum Resection of Craniopharyngiomas

The expanded endoscopic endonasal approach (EEA) is currently well accepted for a variety of ventral skull base tumors. Such an approach often results in a transdural defect and intraoperative cerebrospinal fluid (CSF) leak, and adequate reconstruction is necessary to prevent postoperative CSF leak and its complications. Reconstruction is usually performed using a variety of materials along with the nasoseptal flap. This work's aim is to describe a new reconstructive technique called the "soft gasket seal" (SGS) in detail and compare it with the standard reconstructive technique at our institution for craniopharyngiomas operated via transtuberculum EEA. A retrospective chart review was achieved to identify patients who underwent transtubercular EEA for craniopharyngioma between 2010 and 2018, by the same neurosurgical and otolaryngology team using either the SGS or standard reconstructive technique. Of 36 patients who met criteria and were considered for analysis, 15 of them underwent SGS reconstruction and 21 had standard reconstruction. There were 16 female (44%) and 20 male (56%) patients. The median age was 42.2 ± 20.9 years. The rate of postoperative CSF leak in the group of patients treated with the standard technique was 14.2% and 6.6% in the SGS group (odds ratio 0.43 [confidence interval 95% 0.007-6.15], P= 0.62). The SGS technique provides a simple reconstructive technique in conjunction with the nasoseptal flap, showing a tendency of lower complications when compared with our standard technique while avoiding donor site morbidity. Such results are encouraging, but further studies are necessary to confirm these findings.

The expanded endoscopic endonasal approach for treatment of tuberculum sellae meningiomas in a series of 40 consecutive cases

Compared with traditional craniotomy, the expanded endoscopic endonasal approach (EEEA) may have some advantages for tuberculum sellae meningioma (TSM) treatment. We described our experience of the therapeutic effect of endoscopic TSM treatment. From August 2015 to December 2019, 40 patients with a TSM were treated by the EEEA in our institution. EEEA outcome in TSM treatment was analyzed. Among 39 patients with visual impairment, 38 (97.4%) improved their visual function to some extent after the EEEA, and one case had no significant change in visual acuity. Among all patients, 38 (95.0%) achieved gross total resection (GTR) and 2 (5.0%) achieved near-total resection (NTR). Cerebrospinal fluid (CSF) leakage occurred in three patients (7.5%) and meningitis (post-CSF leakage) in two patients (5.0%). Eight patients (20.0%) suffered postoperative hyposmia, three of whom developed long-term hyposmia. One patient (2.5%) suffered from bleeding of the branch of the anterior cerebral artery intraoperatively leading to postoperative acute cerebral infarction. The EEEA is a safe and reliable minimally invasive method for TSM removal. Compared with traditional craniotomy, the EEEA may have better visual outcomes and a higher prevalence of GTR, but carries the risk of CSF leakage.

Expanded Endoscopic Endonasal Approach and Adjuvant Radiotherapy for the Treatment of Locally Advanced Sinonasal and Skull Base Adenoid Cystic Carcinoma: Case Report and Literature Review

Expanded Endoscopic Endonasal Approach and Adjuvant Radiotherapy for the Treatment of Locally Advanced Sinonasal and Skull Base Adenoid Cystic Carcinoma: Case Report and Literature Review

The endoscope-assisted supraorbital \u201ckeyhole\u201d approach for anterior skull base meningiomas: an updated meta-analysis

IntroductionThe gold-standard treatment for symptomatic anterior skull base meningiomas is surgical resection. The endoscope-assisted supraorbital “keyhole” approach (eSKA) is a promising technique for surgical resection of olfactory groove (OGM) and tuberculum sellae meningioma (TSM) but has yet to be compared with the microscopic transcranial (mTCA) and the expanded endoscopic endonasal approach (EEA) in the context of existing literature.MethodsAn updated study-level meta-analysis on surgical outcomes and complications of OGM and TSM operated with the eSKA, mTCA, and EEA was conducted using random-effect models.ResultsA total of 2285 articles were screened, yielding 96 studies (2191 TSM and 1510 OGM patients). In terms of effectiveness, gross total resection incidence was highest in mTCA (89.6% TSM, 91.1% OGM), followed by eSKA (85.2% TSM, 84.9% OGM) and EEA (83.9% TSM, 82.8% OGM). Additionally, the EEA group had the highest incidence of visual improvement (81.9% TSM, 54.6% OGM), followed by eSKA (65.9% TSM, 52.9% OGM) and mTCA (63.9% TSM, 45.7% OGM). However, in terms of safety, the EEA possessed the highest cerebrospinal fluid leak incidence (9.2% TSM, 14.5% OGM), compared with eSKA (2.1% TSM, 1.6% OGM) and mTCA (1.6% TSM, 6.5% OGM). Finally, mortality and intraoperative arterial injury were 1% or lower across all subgroups.ConclusionsIn the context of diverse study populations, the eSKA appeared not to be associated with increased adverse outcomes when compared with mTCA and EEA and offered comparable effectiveness. Case-selection is paramount in establishing a role for the eSKA in anterior skull base tumours.

A Spherical Joint Robotic End-Effector for the Expanded Endoscopic Endonasal Approach

The endonasal transsphenoidal approach allows surgeons to access the pituitary gland through the natural orifice of the nose. Recently, surgeons have also described an Expanded Endoscopic Endonasal Approach (EEEA) for the treatment of other tumours around the base of the brain. However, operating in this way with nonarticulated tools is technically very difficult and not widely adopted. The goal of this study is to develop an articulated end-effector for a novel handheld robotic tool for the EEEA. We present a design and implementation of a 3.6[Formula: see text]mm diameter, three degrees-of-freedom, tendon-driven robotic end-effector that, contrary to rigid instruments which operate under fulcrum, will give the surgeon the ability to reach areas on the surface of the brain that were previously inaccessible. We model the end-effector kinematics in simulation to study the theoretical workspace it can achieve prior to implementing a test-bench device to validate the efficacy of the end-effector. We find promising repeatability of the proposed robotic end-effector of 0.42[Formula: see text]mm with an effective workspace with limits of [Formula: see text], which is greater than conventional neurosurgical tools. Additionally, although the tool’s end-effector has a small enough diameter to operate through the narrow nasal access path and the constrained workspace of EEEA, it showcased promising structural integrity and was able to support approximately a 6N load, despite a large deflection angle the limiting of which is scope of future work. These preliminary results indicate the end-effector is a promising first step towards developing appropriate handheld robotic instrumentation to drive EEEA adoption.

Expanded endoscopic endonasal approach for extending suprasellar and third ventricular lesions.

Expanded endonasal approaches can provide direct access to the midline skull base from the anterior cranial fossa to the ventral foramen magnum. Surgical strategies of bone drilling, dural opening, and intradural dissection can determine the area of surgical exposure and instrument handling, affecting the safety of devascularizing/debulking suprasellar tumors. We describe an expanded endoscopic endonasal approach for suprasellar lesions, with stepwise image-guided dissections highlighting surgical pearls and pitfalls to enhance surgical safety. This article presents transnasal intra-third-ventricular anatomy from trans-tuber cinereum, and trans-lamina terminalis approaches, comparing subchiasmatic and suprachiasmatic trajectories. The rostral extension via endoscopic endonasal transsellar-transtubercular-transplanum approaches can provide a safe and feasible route for suprasellar lesions, in subchiasmatic, suprachiasmatic, and intraventricular regions.

Neuronavigation-Guided Endoscopic Endonasal Drainage of Pediatric Anterior Cranial Base Epidural and Subdural Empyema

In children, epidural and/or subdural intracranial empyema can complicate frontal sinusitis or pansinusitis. The standard transcranial approach used to treat epidural or subdural empyema has many drawbacks, but these can be avoided with an endoscopic expanded endonasal approach (EEA). To support the feasibility and advantages of this approach, we report the successful drainage through endoscopic EEA of a bifrontal empyema caused by an intracranial extension of pansinusitis. Our case and the ones previously reported in the literature establish well that endoscopic EEA offers several advantages over the standard craniotomy. Hence, EEA should be considered as an alternative to the transcranial approach when surgically draining anterior skull base empyema resulting from pansinusitis in children.

Concerns of cerebrospinal fluid leak in aggressive expanded endonasal endoscopic approach for craniopharyngiomas

Cerebrospinal fluid leak represents a frequent complication in Craniopharyngioma´s Endoscopic Endonasal Approach. A descriptive observational investigation was performed in 50 adult patients operated of Craniopharyngiomas by aggressive Expanded Endonasal Endoscopic Approach (EEEA) in “Hermanos Ameijeiras” Hospital since 2010 to 2019 using nasoseptal flap. The 14% of all patients develop CSF leak and 85,7 % of these cases had a great communication into third ventricle creating a cisternoventricular space. Was identified relation with tumor size, hypothalamic invasion and adhesion strength of tumour. Surgical cavity suffered hydrostatic and hydrodynamic pression than lead to CSF leak independent of multilayer reparation.