Indocyanine Green Fluorescence to Evaluate Nasoseptal Flap Viability in Endoscopic Endonasal Cranial Base Surgery.

 The pedicled nasoseptal flap (NSF) has dramatically reduced postoperative cerebrospinal fluid leakage following endoscopic endonasal approach (EEA) surgery. Although rare, its arterial supply may be damaged during harvest or may be preoperatively damaged for numerous reasons. Early recognition permits harvesting a contralateral flap before sacrificing its pedicle as part of the surgical exposure or use of an alternative flap.

Optic Canal Decompression: Comparison of 2 Surgical Techniques.

Background: The optic canal is a bony channel that connects the anterior cranial fossa and orbit and contains the optic nerve and ophthalmic artery. It can be affected by several pathologies, leading to compression of the nerve nearby or inside the canal, leading to visual impairment. The usual technique to decompress the canal is through a craniotomy, but recently endoscopic endonasal approaches (EEAs) have surfaced as an interesting alternative due to direct access to the canal without the need for manipulation of neurovascular structures.

Role of Leukocyte-Platelet-Rich Fibrin in Endoscopic Endonasal Skull Base Surgery Defect Reconstruction.

 Advancements in endoscopic endonasal approaches have increased the extent and complexity of skull base resections, in turn demanding the development of novel techniques for skull base defect reconstruction. The objective of this pilot study was to investigate the effect of leukocyte-platelet-rich fibrin (L-PRF) on the postoperative healing after endoscopic skull base surgery.  Between January and May of 2015, 47 patients underwent endoscopic endonasal resection of sellar, parasellar, and suprasellar lesions with the application of L-PRF membranes during the skull base reconstruction at two surgical centers.

Sinonasal Carcinomas with Neuroendocrine Features: Histopathological Differentiation and Treatment Outcomes.

 Sinonasal cancers with neuroendocrine features share similar clinical, radiological, and histopathological features; however, these tumors often exhibit varying degrees of aggressive behavior presenting significant treatment challenges. The objective of this study was to report our experience with these rare malignancies and to present a review of current literature.  Following institutional review board approval, the records of all patients with biopsy-proven sinonasal malignancies over a 5-year period were reviewed.

Comparative analysis of the anterior transpetrosal approach with the endoscopic endonasal approach to the petroclival region.

OBJECTIVE The endoscopic endonasal approach (EEA) offers direct access to midline skull base lesions, and the anterior transpetrosal approach (ATPA) stands out as a method for granting entry into the upper and middle clival areas. This study evaluated the feasibility of performing EEA for tumors located in the petroclival region in comparison with ATPA. METHODS On 8 embalmed cadaver heads, EEA to the petroclival region was performed utilizing a 4-mm endoscope with either 0° or 30° lenses, and an ATPA was performed under microscopic visualization.

Effect of Incremental Endoscopic Maxillectomy on Surgical Exposure of the Pterygopalatine and Infratemporal Fossae.

Objective Access to the pterygopalatine and infratemporal fossae presents a significant surgical challenge, owing to their deep-seated location and complex neurovascular anatomy. This study elucidates the benefits of incremental medial maxillectomies to access this region. We compared access to the medial aspect of the infratemporal fossa provided by medial maxillectomy, anteriorly extended medial maxillectomy, endoscopic Denker approach (i.

Endoscopic endonasal study of the cavernous sinus and quadrangular space: Anatomic relationships.

Background: The quadrangular space permits an anterior entry into Meckel's cave while obviating the need for cerebral or cranial nerve retraction. This avenue is intimately associated with the cavernous sinus; thus, from this ventral perspective, it is feasible to visualize the anteromedial, anterolateral, and Parkinson triangles.

Methods: Twenty middle cranial fossae were dissected endonasally under direct endoscopic visualization.

Magnetic resonance imaging fluid-attenuated inversion recovery sequence signal reduction after endoscopic endonasal transcribiform total resection of olfactory groove meningiomas.

Background: Olfactory groove meningiomas grow insidiously and compress adjacent cerebral structures. Achieving complete removal without further damage to frontal lobes can be difficult. Microsurgical removal of large lesions is a challenging procedure and usually involves some brain retraction.

The Endoscopic Endonasal Approach for Removal of Petroclival Chondrosarcomas.

Chondrosarcomas of the skull base are rare, locally invasive tumors that typically arise in the petroclival region, from degenerated chondroid cells located within the synchondrosis. Given their usually slow growth rate, they are capable of reaching sizable dimensions, promoting bone erosion and significant displacement of neurovascular structures before causing symptomatology that will eventually lead to diagnosis; cranial neuropathies and headaches are common complaints. This article discusses the pertinent surgical anatomy, patient selection criteria, technical nuances and complication management of the endonasal resection of skull base chondrosarcomas.

Endoscopic Endonasal Approach for Removal of Tuberculum Sellae Meningiomas.

Tuberculum sellae meningiomas are challenging lesions; their critical location and often insidious growth rate enables significant distortion of the superjacent optic apparatus before the patient notices any visual impairment. This article describes the technical nuances, selection criteria and complication avoidance strategies for the endonasal resection of tuberculum sellae meningiomas. A stepwise description of the surgical technique is presented; indications, adjuvant technologies, pitfalls and the relevant anatomy are also reviewed.

Nuances in the treatment of malignant tumors of the clival and petroclival region.

Introduction Malignancies of the clivus and petroclival region are mainly chordomas and chondrosarcomas. Although a spectrum of malignancies may present in this area, a finite group of commonly encountered malignant pathologies will be the focus of this review, as they are recognized to be formidable pathologies due to adjacent critical neurovascular structures and challenging surgical approaches. Objectives The objective is to review the literature regarding medical and surgical management of malignant tumors of the clival and petroclival region with a focus on clinical presentation, diagnostic identification, and associated adjuvant therapies.

Endonasal endoscopic approaches to the paramedian skull base.

Objective: To describe the technical and anatomic nuances related to endoscopic endonasal approaches (EEAs) to the paramedian skull base.

Methods: Surgical indications, limitations, and technical aspects pertaining to EEAs designed to access areas oriented in the coronal plane are systematically reviewed with special attention to caveats, pitfalls, and common complications and how to avoid them. Case examples are presented.

Advantages and limitations of endoscopic endonasal approaches to the skull base.

Background: The anatomy of the skull base is extremely complex with an abundance of critical neurovascular bundles and their corresponding foramina as well as the insertions and origins of multiple masticatory and craniocervical muscles. These anatomic intricacies increase the difficulty of surgery within this area.

Methods: Advantages and disadvantages of endoscopic endonasal approaches (EEAs) based on the authors' sequential learning and experience are described.

Clinical correlates of the anatomical relationships of the foramen ovale: a radioanatomical study.

Introduction Endonasal endoscopic transpterygoid approaches are commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomical relationships of the foramen ovale, establishing its distance to other important anatomical landmarks such as the pterygoid process and columella.

Endoscopic endonasal anatomical study of the cavernous sinus segment of the ophthalmic nerve.

Objectives/hypothesis: This cadaveric study analyzes the endoscopic endonasal anatomy of the ophthalmic division of the trigeminal nerve (V1 ), from the middle fossa to its orbital entry via the superior orbital fissure. Anatomical relationships with the surrounding cranial nerves and blood vessels are described, with emphasis on their clinical correlation during surgery in this region. Our objective was to describe the anatomical relationships of the ophthalmic division of the trigeminal nerve.

Endoscopic endonasal cranial base surgery simulation using an artificial cranial base model created by selective laser sintering.

Mastery of the expanded endoscopic endonasal approach (EEA) requires anatomical knowledge and surgical skills; the learning curve for this technique is steep. To a great degree, these skills can be gained by cadaveric dissections; however, ethical, religious, and legal considerations may interfere with this paradigm in different regions of the world. We assessed an artificial cranial base model for the surgical simulation of EEA and compared its usefulness with that of cadaveric specimens.

Immediate complications associated with high-flow cerebrospinal fluid egress during endoscopic endonasal skull base surgery.

Endoscopic expanded endonasal approaches (EEAs) to the skull base are increasingly being used to address a variety of skull base pathologies. Postoperative CSF leakage from the large skull base defects has been well described as one of the most common complications of EEAs. There are reports of associated formation of delayed subdural hematoma and tension pneumocephalus from approximately 1 week to 3 months postoperatively.

Endoscopic endonasal surgical management of chondrosarcomas with cerebellopontine angle extension.

Object: Skull base chondrosarcomas are slow-growing, locally invasive tumors that arise from the petroclival synchondrosis. These characteristics allow them to erode the clivus and petrous bone and slowly compress the contents of the posterior fossa progressively until the patient becomes symptomatic, typically from cranial neuropathies. Given the site of their genesis, surrounded by the petrous apex and the clival recess, these tumors can project to the middle fossa, cervical area, and posteriorly, toward the cerebellopontine angle (CPA).

Anatomic comparison of the endonasal and transpetrosal approaches for interpeduncular fossa access.

Object: The interpeduncular cistern, including the retrochiasmatic area, is one of the most challenging regions to approach surgically. Various conventional approaches to this region have been described; however, only the endoscopic endonasal approach via the dorsum sellae and the transpetrosal approach provide ideal exposure with a caudal-cranial view. The authors compared these 2 approaches to clarify their limitations and intrinsic advantages for access to the interpeduncular cistern.

Retrosigmoid approach for resection of petrous apex meningioma.

We present the case of a 50-year-old female with a 1-year history of right-side facial numbness, as well as an electric shock-like sensation on the right-side of the face and tongue. She was previously diagnosed with vertigo and trigeminal neuralgia. MRI was obtained showing a large right cerebellopontine angle mass.

Side-cutting aspiration device for endoscopic and microscopic tumor removal.

The authors present a unique side-cutting instrument (NICO Myriad, Indianapolis, IN) with variable aspiration designed specifically for tumor resection. The study included retrospective review of data collected from 10/2009 to 01/2011. We detail the use of the Myriad in 31 patients with the following pathologies: meningioma (n=16), chordoma (n = 3), schwannoma (n = 3), pituitary adenoma (n = 2), metastasis (n = 3), hemangioblastoma (n = 1), craniopharyngioma (n = 1), and nasopharyngeal tumors (n = 2).

Supraorbital eyebrow craniotomy for removal of intraaxial frontal brain tumors: a technical note.

Objective: To present the utility and selection criteria for the supraorbital (SO) craniotomy, an approach commonly used to remove extraaxial tumors such as meningiomas and craniopharyngiomas, to resect intraaxial frontal brain lesions.

Methods: All consecutive patients who underwent a SO craniotomy for an intraaxial lesion were retrospectively analyzed for lesion location, pathology, extent of resection, operative times, length of stay, and complications.

Results: During 28 months, 10 patients (mean age, 67.