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Background: Caudal pneumatization of the pterygoid process may impact endonasal exposure of the lateral recess of sphenoid sinus (LRSS). Objectives: This study aims to explore the implications of a pneumatized pterygoid process for an endonasal transpterygoid approach to the LRSS and to define strategies regarding the preservation or sacrifice of the vidian nerve. Methods: Dissection of the LRSS (11 sides) was performed on 6 cadaveric specimens, preselected for the radiographic presence of an LRSS. In addition, the dimensions of the LRSS were measured on the deidentified CT images of 120 patients (240 sides). The sphenoid sinus was subdivided into 3 categories: Type 1 (no identifiable LRSS), Type 2 (lateral pneumatization of the greater wing above the vidian canal), and Type 3 (pneumatization of both the greater wing and the pterygoid process). Results: On the cadaveric specimens, a Type 2 pneumatization often allowed access to the LRSS above the level of the vidian canal; thus, sparing the vidian neurovascular bundle. In Type 3 pneumatization, a frontal corridor through the pterygoid base could be created to reach the LRSS with preservation of the vidian nerve. Extreme Type 3 pneumatization, however, required the transposition or sacrifice of the vidian nerve to facilitate a full direct access to the superolateral LRSS. Measurements on CT images revealed that the extent of caudal pneumatization of the pterygoid process had no statistically significant correlation with the superolateral extension of the lateral recess in patients with Type 3 LRSS (P >.05). Conclusion: Pneumatization of the LRSS toward a caudal or superolateral direction may develop independent from each other. Caudal pneumatization of the pterygoid process seems to variably impact the endonasal exposure of the LRSS. [ABSTRACT FROM AUTHOR]

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. Methods Six specimens were dissected. The right optic canal was drilled on the right side via the EEA, and the left optic canal was drilled via frontotemporal craniotomy. The amount of decompression was measured using a 3-dimensional reconstruction on computed tomography scans and compared. Results The EEA generated an average of 267.8 (221–294) degrees of decompression in the anterior portion of the canal versus 258.3 (219–300) degrees of decompression in the posterior portion of the canal, whereas the craniotomy generated an average of 229.3 (101–289) degrees of decompression in the anterior portion of the canal versus 250.3 (76–300) degrees of decompression in the posterior portion of the canal. There was no significant difference statistically. Conclusion The decision for an approach for optic canal decompression should be based on the site of the pathology and localization of canal involvement. Both techniques are equivalent in terms of proportion of nerve decompression. [ABSTRACT FROM AUTHOR]

Background The petroclival region seats many neoplasms. Traditional surgical corridors to the region can result in unacceptable patient morbidity. The combined subtemporal retrolabyrinthine transpetrosal (posterior petrosal) approach provides adequate exposure with hearing preservation; however, the facial nerve and labyrinth are put at risk. Approaching the petroclival region with an endoscopic endonasal approach (EEA) could minimize morbidity. Objective To provide an anatomical and computed tomography (CT) comparison between the posterior petrosal approach and EEA to the petroclival region. Methods The petroclival region was approached transclivally with EEA. Different aspects of dissection were compared with the posterior petrosal approach. The two approaches were also studied using CT analysis. Results A successful corridor medial to the internal auditory canal (IAC) was achieved with EEA. Wide exposure was achieved with no external skin incisions, although significant sinonasal resection was required. The posterior petrosal was comparable in terms of exposure medially; however, the dissection involved more bone removal, greater skill, and a constricting effect upon deeper dissection. Importantly, access lateral to the IAC was obtained, whereas EEA could not reach this area. Conclusion An EEA to the petroclival region is feasible. This approach can be considered in lesions medial to the IAC. [ABSTRACT FROM AUTHOR]

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. Methods Distances between the foramen ovale, foramen rotundum, and fixed anatomical landmarks like the columella and pterygoid process were measured using computed tomography (CT) scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results The mean distances from the foramen ovale to columella and from the foramen rotundum to columella were found to be 9.15 cm and 7.09 cm, respectively. Analysis of radiologic measurements detected no statistically significant differences between sides or gender. Conclusions The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions. [ABSTRACT FROM AUTHOR]

Objective  This study aimed to demonstrate the nuances in preoperative management, surgical technique, and reconstruction for an endoscopic endonasal odontoidectomy. Design  Assembly of an operative video demonstrating technique for endoscopic endonasal odontoidectomy. Setting  this study is a comprehensive skull base team at a tertiary care center. Participant  The patient is a 53-year-old male, with basilar invagination and myelopathy, who underwent cervical fusion, 6 years back, without ventral decompression at an outside hospital. He presented to our clinic with persistent myelopathy and generalized weakness, thus an endoscopic endonasal odontoidectomy for brainstem decompression was recommended. Main Outcome Measures  Preoperative computed tomography (CT) angiography and intraoperative CT navigation demonstrated normal carotid artery anatomic localization. An inverted U -shaped mucosal flap was reflected inferiorly and preserved. The C1 arch was identified and resected with a high speed drill. The resultant diseased soft tissue arising from retropulsion of the odontoid process was then removed and the odontoid process identified. This bone was removed centrally until a thin cap remained. After removal of the cap, the underlying ligamentous tissue was removed until dural pulsations were appreciated and brainstem decompression achieved. Hemostasis was attained and the mucosal flap mobilized into position. Results  Postoperative CT imaging demonstrated resolution of basilar invagination and brainstem decompression (Fig. 1). The patient improved both in arm dexterity and ambulation after surgery and the reconstruction demonstrated appropriate healing on nasal endoscopy 2 months postoperatively. Conclusions  This operative video demonstrates nuances in endoscopic endonasal odontoidectomy. This case also demonstrates that ventral decompression after long-term cervical fusion can improve myelopathy and that fusion in the setting of bony ventral compression, rather than rheumatoid panus, may not reduce over time with fusion only. The link to the video can be found at: https://youtu.be/370FFuBA89Y. [ABSTRACT FROM AUTHOR]

Background Oncologic resection of the nasopharynx is challenging due to its complex and deep-seated nature. We aimed to illustrate the anatomic landmarks of endoscopic nasopharyngectomy and design a surgical training model that could facilitate learning of this technique. Methods An endoscopic endonasal dissection of the nasopharynx was completed in fresh cadaveric specimens under conditions similar to those of our operating suite. Digital data from a high-resolution CT scan were imported to an image guidance system to be used during the dissections. Results We expanded the sinonasal corridor, harvested a contralateral nasoseptal flap, and exposed the pterygopalatine and infratemporal fossae. A detailed anatomic dissection of the nasopharynx was correlated to multiplanar images provided by the image guidance system, highlighting appropriate bony, neural, and vascular landmarks. Conclusions Understanding the anatomy-based endoscopic modular approaches facilitates planning and safe execution of an oncologic nasopharyngectomy. Clinical experience remains mandatory because anatomic models fall short of clinical scenarios. © 2012 Wiley Periodicals, Inc. © 2012 Wiley Periodicals, Inc. Head Neck, 2013 [ABSTRACT FROM AUTHOR]

A 50-year-old female with an incidentally diagnosed suprasellar lesion was initially managed conservatively due to the presence of an intrasellar persistent trigeminal artery going through the dorsumsellae and fundamentally forming the blood supply of the entire posterior circulation. Serial follow-up brain magnetic resonance imaging (MRI) revealed progressive enlargement of the suprasellar lesion over 4 years period. Surgery was indicated after the initial tumor growth; however, the patient refused surgery for fear of complications related to the persistent trigeminal artery. Two-and-ahalf years later, she presented with deterioration of vision. Formal visual field testing revealed a right temporal field defect. Brain MRI demonstrated significantly enlarged suprasellar lesion, most consistent with tuberculum sellae meningioma, exerting mass effect on the optic apparatus. The patient underwent endoscopic endonasal resection of the lesion through a transplanum/ transtuberculum approach. Intraoperatively, absence of hypertrophic McConnel arteries, hyperostosis, and the fact that the dura was soft and not under tension was against the diagnosis of tuberculum sellae meningioma. Additionally, the tumor consistency was similar to a pituitary adenoma. A complete resection was accomplished and multilayer skull base reconstruction was performed with no complications. On postoperative day 1 (POD 1), she was operated upon for the evacuation of small suprasellar hematoma associated with vision deterioration. Histopathological examination confirmed the diagnosis of atypical pituitary adenomawith Ki-67 labeling index of 4 to 5%. The patient ultimately recovered well with improved vision, and was discharged on POD 4 with no new neurological deficits. At 4 years follow-up, her vision was normalized and brain MRI showed no residual or recurrent lesion. [ABSTRACT FROM AUTHOR]

We present the case of a 67-year-old female with an incidental finding of a left-sided tuberculum sellae meningioma on a brain magnetic resonance imaging (MRI) for an unrelated complaint. Formal visual field testing showed a small defect in the inferior nasal and temporal fields of the left eye, compatible withmass effect on the optic nerve by the tumor. An endoscopic endonasal transtuberculum approach with decompression of the left optic nerve was performed using a standard binostril four-hand technique, with the patient positioned supine with the head turned to the right side and tilted to the left, fixed in a three-pin head clamp, under imaging guidance. After exposure, we drilled the tuberculum sellae and the floor of the sella and after opening the dura, the tumor and optic nerve came into view. The tumor was completely removed and we confirmed the patency of all perforating vessels using indocyanine green. Reconstruction was done in a multilayered fashion, using collagen matrix and a nasoseptal flap. Patient had an uneventful postoperative stay and was discharged on postoperative day 3, neurologically stable with no new hormonal deficits. Pathology report confirmed a WHO Grade Imeningioma with Ki-67 of 1% and 3-month postoperative MRI confirmed a gross total resection and visual fields exam showed a complete recovery. [ABSTRACT FROM AUTHOR]

Background Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual changes, and seizure combined with brain imaging consistent with cerebral edema without infarction. To the best of our knowledge, we report the first case of PRES after an endoscopic endonasal resection of a pituitary macroadenoma. Case Description A 59-year-old woman was diagnosed with a pituitary macroadenoma, for which she underwent endoscopic endonasal extracapsular resection. After an uneventful initial postoperative recovery, the patient experienced sudden onset of emesis, confusion, vision loss, and severe hypertension. Emergent computed tomography showed normal postoperative changes, with no signs of hematoma or infarction. Magnetic resonance imaging (MRI) showed fluid-attenuated inversion recovery changes in the posterior lobes and thalamus, consistent with PRES. Cerebral angiography showed no vascular abnormalities. Blood pressure control was the primary treatment modality. Within 10 days, the patient was neurologically intact except for right homonymous hemianopsia. Follow-up MRI showed resolution of the PRES with an area of infarction in the left occipital lobe. At 5 years follow-up, the patient reported minimal blurred vision. MRI showed encephalomalacia at the old infarct area, and her visual field testing was unremarkable. Conclusions Although rare in neurosurgical patients, PRES must be considered in patients who develop acute vision loss and mental status changes associated with hypertension after surgery, including endoscopic endonasal surgery. PRES has the potential for significant neurologic morbidity, if not treated in a timely manner. Early recognition and treatment, with blood pressure control mainly, are therefore mandatory after a surgical complication, such as a postoperative hematoma, has been ruled out. [ABSTRACT FROM AUTHOR]