Endoscopic endonasal anterior clinoidectomy: surgical anatomy, technique nuance, and case series

Advances in endoscopic technique allow for resection of the anterior clinoid process (ACP) via an endoscopic endonasal approach. The authors discuss the endoscopic endonasal anterior clinoidectomy (EEAC) and demonstrate the relevant surgical anatomy and technical nuances. The approach was simulated in 6 cadaveric heads. From a technical point of view, the lateral optic carotid recess was used as the landmark in the proposed technique. The superomedial, superolateral, and inferior vertices of this recess are the main operative points. The EEAC approach was achieved by disconnecting the ACP tip from the base by drilling the 3 vertices. The proposed approach was successfully performed in all cadaveric specimens. Then, in a case series involving 6 patients in whom the EEAC approach was used, there were no vascular injuries; 2 patients had postoperative oculomotor nerve palsy, which improved in one and resolved in the other by 1 month.The EEAC approach for tumors and vascular lesions in the parasellar region is technically feasible. The surgical corridor is increased by ACP resection, although to a lesser extent than the transcranial anterior clinoidectomy. Based on the authors’ initial anatomical and surgical results, resection of the ACP via the endonasal endoscopic approach is a novel technique worth exploring in suitable cases.

Download Full-text

Endoscopic endonasal transoculomotor triangle approach for adenomas invading the parapeduncular space: surgical anatomy, technical nuances, and case series

Journal of Neurosurgery ◽

10.3171/2017.10.jns17779 ◽

2019 ◽

Vol 130 (4) ◽

pp. 1304-1314 ◽

Cited By ~ 7

Author(s):

Cristian Ferrareze Nunes ◽

Stefan Lieber ◽

Huy Q. Truong ◽

Georgios Zenonos ◽

Eric W. Wang ◽

...

Keyword(s):

Cavernous Sinus ◽

Case Series ◽

Surgical Anatomy ◽

Oculomotor Nerve ◽

Oculomotor Nerve Palsy ◽

Tumor Extension ◽

Endoscopic Endonasal ◽

Transcranial Approach ◽

Surgical Corridor ◽

Dural Opening

OBJECTIVEPituitary adenomas may extend into the parapeduncular space by invading through the roof of the cavernous sinus. Currently, a transcranial approach is the preferred choice, with or without the combination of an endonasal approach. In this paper the authors present a novel surgical approach that takes advantage of the natural corridor provided by the tumor to further open the oculomotor triangle and resect tumor extension into the parapeduncular space.METHODSSix injected specimens were used to demonstrate in detail the surgical anatomy related to the approach. Four cases in which the proposed approach was used were retrospectively reviewed.RESULTSFrom a technical perspective, the first step involves accessing the superior compartment of the cavernous sinus. The interclinoid ligament should be identified and the dura forming the oculomotor triangle exposed. The oculomotor dural opening may be then extended posteriorly toward the posterior petroclinoidal ligament and inferolaterally toward the anterior petroclinoidal ligament. The oculomotor nerve should then be identified; in this series it was displaced superomedially in all 4 cases. The posterior communicating artery should also be identified to avoid its injury. In all 4 cases, the tumor invading the parapeduncular space was completely removed. There were no vascular injuries and only 1 patient had a partial oculomotor nerve palsy that completely resolved in 2 weeks.CONCLUSIONSThe endoscopic endonasal transoculomotor approach is an original alternative for removal of tumor extension into the parapeduncular space in a single procedure. The surgical corridor is increased by opening the dura of the oculomotor triangle and by working below and lateral to the cisternal segment of the oculomotor nerve.

Download Full-text

Endoscopic Endonasal Supraoptic and Infraoptic Approaches for Complex “Parasuprasellar” Lesions: Surgical Anatomy, Technique Nuances, and Case Series

10.21203/rs.3.rs-622199/v2 ◽

2021 ◽

Author(s):

You Yuan Bao ◽

You Qing Yang ◽

Lin Zhou ◽

Shen Hao Xie ◽

Xiao Wu ◽

...

Keyword(s):

Surgical Simulation ◽

Tumor Resection ◽

Case Series ◽

Surgical Anatomy ◽

Anterior Clinoid Process ◽

Endoscopic Endonasal ◽

Multiple Aneurysms ◽

Suprasellar Region ◽

Midline Approach ◽

Planum Sphenoidale

Abstract Surgical management of lesions involving the lateral area of the suprasellar region, including the lateral aspect of the planum sphenoidale and a tight junction region of the optic canal (OC), the anterior clinoid process (ACP), and the internal carotid artery (ICA) and its dural rings, is extremely challenging. Here, the authors introduce two novels endoscopic endonasal supraoptic (EESO) and endoscopic endonasal infraoptic (EEIO) approaches to access these regions, namely, “parasuprasellar” area. Surgical simulation of the EESO and EEIO approaches to the parasuprasellar area was conducted in 5 silicon-injected specimens. The same techniques were applied in 12 patients involving the parasuprasellar area.The EESO and EEIO approaches can be used independently or in combination, but are more often employed as a complement to the endoscopic endonasal midline approach and transcavernous approach. In clinical application, the EESO and EEIO approaches were successfully performed in 12 patients harboring tumors and multiple aneurysms involving the parasuprasellar area. Gross total and subtotal tumor resection were achieved in 9 patients and 1 patient, respectively. For two patients with multiple aneurysms, the lesions were clipped selectively according to location and size. Visual acuity improved in 7 patients, remained stable in 4, and deteriorated in only 1. No postoperative intracranial infection or ICA injury occurred in this series. The EESO and EEIO approaches can be combined with the current endoscopic endonasal midline approach and transcavernous approach to remove extensive pathologies involving the intrasellar, suprasellar, sphenoid, and cavernous sinuses and even bifurcation of the ICA.

Download Full-text

Endoscopic Endonasal Supraoptic and Infraoptic Approaches for Complex “Parasuprasellar” Lesions: Surgical Anatomy, Technique Nuances, and Case Series

10.21203/rs.3.rs-622199/v1 ◽

2021 ◽

Author(s):

YouYuan Bao ◽

YouQing Yang ◽

Lin Zhou ◽

ShenHao Xie ◽

Xiao Wu ◽

...

Keyword(s):

Surgical Simulation ◽

Tumor Resection ◽

Case Series ◽

Surgical Anatomy ◽

Anterior Clinoid Process ◽

Endoscopic Endonasal ◽

Multiple Aneurysms ◽

Suprasellar Region ◽

Midline Approach ◽

Planum Sphenoidale

Abstract Purpose: Surgical management of lesions involving the lateral area of the suprasellar region, including the lateral aspect of the planum sphenoidale and a tight junction region of the optic canal (OC), the anterior clinoid process (ACP), and the internal carotid artery (ICA) and its dural rings, is extremely challenging. Here, the authors introduce two novel endoscopic endonasal supraoptic (EESO) and endoscopic endonasal infraoptic (EEIO) approaches to access these regions, namely, “parasuprasellar” area.Methods: Surgical simulation of the EESO and EEIO approaches to the parasuprasellar area was conducted in 5 silicon-injected specimens. The same techniques were applied in 12 patients involving the parasuprasellar area.Results: The EESO and EEIO approaches can be used independently or in combination, but are more often employed as a complement to the endoscopic endonasal midline approach and transcavernous approach. In clinical application, the EESO and EEIO approaches were successfully performed in 12 patients harboring tumors and multiple aneurysms involving the parasuprasellar area. Gross total and subtotal tumor resection was achieved in 9 patients and 1 patient, respectively. For two patients with multiple aneurysms, the lesions were clipped selectively according to location and size. Visual acuity improved in 7 patients, remained stable in 4, and deteriorated in only 1. No postoperative intracranial infection or ICA injury occurred in this series.Conclusion: The EESO and EEIO approaches can be combined with the current endoscopic endonasal midline approach and transcavernous approach to remove extensive pathologies involving the intrasellar, suprasellar, sphenoid, and cavernous sinuses and even bifurcation of the ICA.

Download Full-text

A morphometric survey of the parasellar region in more than 2700 skulls: emphasis on the middle clinoid process variants and implications in endoscopic and microsurgical approaches

Journal of Neurosurgery ◽

10.3171/2017.2.jns162114 ◽

2018 ◽

Vol 129 (1) ◽

pp. 60-70 ◽

Cited By ~ 8

Author(s):

Akshay Sharma ◽

Gabrielle E. Rieth ◽

Joseph E. Tanenbaum ◽

James S. Williams ◽

Nakao Ota ◽

...

Keyword(s):

Sella Turcica ◽

Significant Risk ◽

Surgical Anatomy ◽

Ct Scans ◽

Anterior Clinoid Process ◽

White Race ◽

Explanatory Variables ◽

Optic Strut ◽

Parasellar Region ◽

Data Points

OBJECTIVEThe middle clinoid process (MCP) is a bony projection that extends from the sphenoid bone near the lateral margin of the sella turcica. The varied prevalence and morphological features of the MCP in populations stratified by age, race, and sex are unknown; however, the knowledge of its anatomy and preoperative recognition on CT scans can aid greatly in complication avoidance and management. The aim of this study was to further illustrate the surgical anatomy of the parasellar region and to quantify the incidence of MCP and caroticoclinoid rings (CCRs) in dried preserved human anatomical specimens.METHODSThe presence, dimensions, morphological classification (incomplete, contact, and CCR), and intracranial relations of the MCP were measured in 2726 dried skull specimens at the Hamann-Todd Osteological Collection at the Cleveland Museum of Natural History. Specific morphometric data points were recorded from each of these hemiskulls, and categorized based on age, sex, and ethnicity. Linear and logistic regressions were used to determine associations between explanatory variables and MCP morphology. Computed tomography scans of the skull specimens were obtained to explore radiological landmarks for different types of MCPs. Illustrative intraoperative videos were also analyzed in the light of these crucial surgical landmarks.RESULTSThe sample included 2250 specimens from males and 476 from females. Specimens were classified as either “white” (60.5%) or “black” (39.2%). An MCP was found in 42% of specimens, with 60% of those specimens presenting bilaterally. Fully ossified CCR comprised 27% of all MCPs, and contact (defined as contact without ossification between MCP and anterior clinoid process) comprised 4% of all MCPs. White race (relative to black race) and increasing age were significant predictors of MCP presence (p < 0.001). White race was significantly associated with greater average MCP height (p < 0.001). Among skulls with CCR, both male sex and older age (> 70 years relative to < 50 years) were associated with increased CCR diameter (p < 0.001). No other significant predictors or associations were observed. The CT scans of skulls replicated and validated the authors’ morphometric observations on incomplete, contact, and CCR patterns adequately. The surgical strategies of clinoid bone removal are validated, with appropriate video illustrations.CONCLUSIONSVariations in the patterns of bony MCPs can pose a significant risk for injury to the internal carotid artery during parasellar procedures, especially those involving clinoidectomy and optic strut drilling. Understanding parasellar anatomy, especially on skull-base CT imaging, may be integral to surgical planning and preoperative risk counseling in both transcranial and extended endonasal procedures, as well as to preparing for complications management perioperatively.

Download Full-text

Endoscopic Endonasal Transclival Transcondylar Approach for Foramen Magnum Meningiomas

Operative Neurosurgery ◽

10.1227/neu.0000000000001102 ◽

2015 ◽

Vol 12 (2) ◽

pp. 153-162 ◽

Cited By ~ 9

Author(s):

Wei-Hsin Wang ◽

Kumar Abhinav ◽

Eric Wang ◽

Carl Snyderman ◽

Paul A Gardner ◽

...

Keyword(s):

Odontoid Process ◽

Human Head ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Occipital Condyle ◽

Anatomical Landmarks ◽

Endoscopic Endonasal ◽

Medial Condyle ◽

Anterior Arch ◽

Surgical Corridor

Abstract BACKGROUND The endoscopic endonasal approach provides a direct route to ventral foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection. OBJECTIVE We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM. METHODS Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from foramen lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis. RESULTS The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room. CONCLUSION Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

Download Full-text

Extradural clinoidectomy for resection of clinoidal meningioma

Neurosurgical FOCUS ◽

10.3171/2017.10.focusvid.17363 ◽

2017 ◽

Vol 43 (videosuppl2) ◽

pp. V10 ◽

Cited By ~ 1

Author(s):

Simon Buttrick ◽

Jacques J. Morcos ◽

Mohamed S. Elhammady ◽

Anthony C. Wang

Keyword(s):

Optic Nerve ◽

Optic Canal ◽

Superior Orbital Fissure ◽

Anterior Clinoid Process ◽

Anterior Clinoidectomy ◽

Link Type ◽

Optic Strut ◽

Parasellar Region ◽

Versatile Technique

Extradural anterior clinoidectomy is a versatile technique to increase exposure of the sellar and parasellar region. It is of particular use in the resection of clinoidal meningiomas, as sphenoidal and clinoidal hyperostosis can cause compression of the optic nerve. Extradural clinoidectomy follows a series of steps, consisting of (1) unroofing of the superior orbital fissure, (2) unroofing of the optic canal, (3) removal of the optic strut, and (4) removal of the anterior clinoid process. The authors show these steps in detail, as well as their application to the resection of a large clinoidal meningioma.The video can be found here: https://youtu.be/O1Fcef29ETg.

Download Full-text

Endoscopic Endonasal Intraconal Approach for Orbital Tumor Resection: Case Series and Systematic Review

Frontiers in Oncology ◽

10.3389/fonc.2021.780551 ◽

2022 ◽

Vol 11 ◽

Author(s):

Xin Zhang ◽

Wei Hua ◽

Kai Quan ◽

Guo Yu ◽

Zunguo Du ◽

...

Keyword(s):

Tumor Resection ◽

Case Series ◽

Oculomotor Nerve Palsy ◽

Cerebrospinal Fluid Leakage ◽

Lateral Extension ◽

Total Resection ◽

Endoscopic Endonasal ◽

Pathological Conditions ◽

Surgical Methods

Intraorbital tumor could be approached by numerous surgical methods. The neuroendoscopic endonasal approach could provide a feasible corridor for indicated tumors. Herein we present a series of 6 consecutive intraorbital tumors from April 2018 to October 2020, which received endonasal endoscopic resection. Cadaveric dissection was performed for the intraconal approach, and the literature was also reviewed. Five tumors were located intraconally, while one extraconally. The pathology revealed 1 angioleiomyoma, 1 cavernous hemangioma, 1 pilocytic astrocytoma, 1 meningioma, and 2 schwannomas. Five of the six achieved gross total resection, including 3 tumors with lateral extension beyond the optic nerve. Preoperative visual deterioration was observed in 4 of the 6 patients, and all got improvement postoperatively. Transient oculomotor nerve palsy was presented in one patient postoperatively. No cerebrospinal fluid leakage, enophthalmos, or strabismus was observed. The median follow-up time is 27 months (11~41 months). At the 6-month follow-up, the visual acuity remained unchanged compared with that at discharge. Proptosis was resolved in 2 of the 3 patients; diplopia was improved in one patient. In conclusion, endoscopic endonasal intraconal approach could be suitable for selected pathological conditions, and for both medial or beyond medial extraconal and intraconal orbital tumors.

Download Full-text

The medial wall of the cavernous sinus. Part 1: Surgical anatomy, ligaments, and surgical technique for its mobilization and/or resection

Journal of Neurosurgery ◽

10.3171/2018.3.jns18596 ◽

2019 ◽

Vol 131 (1) ◽

pp. 122-130 ◽

Cited By ~ 6

Author(s):

Huy Q. Truong ◽

Stefan Lieber ◽

Edinson Najera ◽

Joao T. Alves-Belo ◽

Paul A. Gardner ◽

...

Keyword(s):

Cavernous Sinus ◽

Single Layer ◽

Lateral Wall ◽

Anterior Wall ◽

Surgical Anatomy ◽

Medial Wall ◽

Vertical Segment ◽

Anterior Clinoid Process ◽

Endoscopic Endonasal

OBJECTIVEThe medial wall of the cavernous sinus (CS) is often invaded by pituitary adenomas. Surgical mobilization and/or removal of the medial wall remains a challenge.METHODSEndoscopic endonasal dissection was performed in 20 human cadaver heads. The configuration of the medial wall, its relationship to the internal carotid artery (ICA), and the ligamentous connections in between them were investigated in 40 CSs.RESULTSThe medial wall of the CS was confirmed to be an intact single layer of dura that is distinct from the capsule of the pituitary gland and the periosteal layer that forms the anterior wall of the CS. In 32.5% of hemispheres, the medial wall was indented by and/or well adhered to the cavernous ICA. The authors identified multiple ligamentous fibers that anchored the medial wall to other walls of the CS and/or to specific ICA segments. These parasellar ligaments were classified into 4 groups: 1) caroticoclinoid ligament, spanning from the medial wall and the middle clinoid toward the clinoid ICA segment and anterior clinoid process; 2) superior parasellar ligament, connecting the medial wall to the horizontal cavernous ICA and/or lateral wall of the CS; 3) inferior parasellar ligament, bridging the medial wall to the anterior wall of the CS or anterior surface of the short vertical segment of the cavernous ICA; and 4) posterior parasellar ligament, which anchors the medial wall to the short vertical segment of the cavernous ICA and/or the posterior carotid sulcus. The caroticoclinoid ligament and inferior parasellar ligament were present in most CSs (97.7% and 95%, respectively), while the superior and posterior parasellar ligaments were identified in approximately half of the CSs (57.5% and 45%, respectively). The caroticoclinoid ligament was the strongest and largest ligament, and it was typically assembled as a group of ligaments with a fan-like arrangement. The inferior parasellar ligament was the first to be encountered after opening the anterior wall of the CS during an interdural transcavernous approach.CONCLUSIONSThe authors introduce a classification of the parasellar ligaments and their role in anchoring the medial wall of the CS. These ligaments should be identified and transected to safely mobilize the medial wall away from the cavernous ICA during a transcavernous approach and for safe and complete resection of adenomas that selectively invade the medial wall.

Download Full-text