Citations

AbstractBackgroundTraditional management of olfactory neuroblastoma (ONB) includes margin‐negative resection with removal of cribriform plate, dura, and olfactory bulb, regardless of intracranial disease. This approach may be overtreating certain patients. Our investigation examines risk factors associated with occult intracranial disease to optimize therapeutic outcomes.MethodsThis retrospective, multi‐institutional cohort study examined clinical covariates associated with occult intracranial involvement. Patient demographics, staging, Hyam's grade, and pathologic involvement of dura, olfactory bulb/tract, and brain were collected. Diagnostic imaging was reviewed. Positive and negative predictive value (NPV) were estimated along with effect size estimates. Cox hazard regression examined associations with overall survival (OS) and disease‐free survival (DFS).ResultsA total of 224 subjects with new diagnoses of ONB (2005–2021) were identified. Skull base bone involvement on computed tomography (CT) had the highest NPV for pathologic dura (88.0%), olfactory bulb (88%), and brain involvement (97.3%). Hyam's grade category was significantly associated with dural involvement (φC = 0.26; 95% confidence interval [CI]: 0.16, 0.42). Subjects without radiologic skull base involvement (n = 66) had pathologic positivity of 12.1%. Within this subgroup, Hyam's grade was clinically significant for dural positivity (φ = 0.34; 95% CI: −0.12, 0.71) with 28.6% involvement in high grade tumors. Neither clinical nor pathologic positivity of intracranial structures were associated with significantly different OS or DFS.ConclusionsBoth CT and magnetic resonance imaging (MRI) had reasonably good NPV for involvement of dura and olfactory bulb. Higher Hyam's grade was associated with dural involvement. Patients with low‐grade tumors not involving the skull base may be suitable for avoiding skull base resection; however, further investigation is warranted.

Abstract Introduction The endoscopic endonasal transpterygoid approach (EETPA) with or without the addition of the endoscopic-assisted sublabial anterior transmaxillary approach (ESTA) has become increasingly utilized for lesions posterior to the pterygopalatine fossa (PPF), including infratemporal fossa (ITF), lateral recess of the sphenoid sinus, Meckel's cave, petrous apex, and parapharyngeal space. The main goal of this study is to develop an educational resource to learn the steps of the EETPA for trainees. Methods EETPA and ESTA were performed in 12 specimens by neurosurgery trainees, under supervision from the senior authors. One EETPA and one ESTA were performed on each specimen on opposite sides. Dissections were supplemented with representative cases. Results After a wide unilateral sphenoidotomy, ethmoidectomy, and partial medial maxillectomy, the anteromedial bone limits of the PPF were identified and drilled out. The pterygoid progress was modularly removed. By enlarging the opening of the posterior and lateral walls of the maxillary sinus through EETPA and ESTA, respectively, the neurovascular and muscular compartments of the PPF and ITF were better identified. The EETPA opens direct corridors to the PPF, medial ITF, middle cranial fossa, cavernous sinus, Meckel's cave, petrous apex, and internal carotid artery. If a more lateral exposure of the ITF is needed, the ESTA is an appropriate addition. Conclusion Despite the steep learning curve of the EETPA, granular knowledge of its surgical anatomy and basic surgical steps are vital for those advancing their learning in complex endoscopic approaches to the ventral skull base when expanding the approach laterally in the coronal plane.

Objectives The previously described S‐point, corresponds to the medial projection of the middle turbinate axilla in the superior nasal septum and has been identified as a common source of severe epistaxis. The objective is to define the anatomical patterns of vascularization of the S‐point area that could explain its clinical relevance. Methods Thirty‐three nasal septums of latex‐injected formalin‐embalmed and fresh human cadaveric heads were dissected to analyze the arterial arrangement of the S‐point area. Measurements and patterns of vascularization were described. Results The S‐point area, was consistently surrounded by a single or multiple arterial anastomotic arches consistently formed superiorly by the anterior ethmoidal and posterior ethmoidal artery branches, and inferiorly by the posterior septal artery. The caliber of the arterial arches was typically larger than the caliber of the arterial branches supplying them. A single arch was present in 36.3% of septums, and multiple arches in 63.6%. The mean distance from the S‐point to the anterior limit of the arch was 9 mm, to the posterior arch when the present was 3 mm, to the superior limit 6 mm, to the inferior limit 6 mm, and to the nasal roof was 10 mm. Conclusion This study demonstrates the dense arterial configuration of the S point area, which is characterized by a single or multiple vascular arches of greater caliber than the branches of origin. This finding could explain why the S‐point area is a frequent source of epistaxis, and guide its surgical cauterization when an obvious vascular ectasia is not visualized. Level of Evidence N/A Laryngoscope , 133:2075–2080, 2023

Objective: The aim of this study is to verify if the length of the nasoseptal flap is sufficient to cover the tuberculum sellae and planum sphenoidale of sphenoidal sinuses with varied degrees of pneumatization Methods: Retrospective study of paranasal sinus computed tomography comparing the potential length of the nasoseptal flap and the length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches in conchal, presellar, sellar, incomplete postsellar, and complete postsellar sphenoidal sinuses Results: The length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches was directly related to the degree of pneumatization of the sphenoidal sinus. The nasoseptal flap length was adequate to cover the cranial base after transtuberculum approaches of all cases from the conchal, presellar, and sellar groups and the majority of cases from postsellar pneumatization. For transplanum approaches, the nasosseptal flap was sufficient to reconstruct defects in most cases from conchal, pre-sellar, and sellar type sinuses and in 54,9% and 19,2% in incomplete and complete postsellar, respectively. Conclusions: In well pneumatized sphenoidal sinus, the nasoseptal flap may not be sufficient to cover the cranial base after transtuberculum and transplanum approaches.

BACKGROUND: The lingual process of the sphenoid bone (LP) and the petrolingual ligament (PLL) surround laterally the internal carotid artery within the middle cranial fossa (MCF). OBJECTIVE: To study the LP and the PLL and anatomical variations considering their relationships with different structures and landmarks within the MCF, especially oriented toward the endoscopic endonasal approaches. METHODS: Seventy-two sides of dry skulls and 20 sides of embalmed specimens were studied. The measurements of the LP and the PLL were obtained, considering important landmarks in the MCF. RESULTS: The LP had a mean length and height of 5 mm and 3 mm, respectively. Its distance from the foramen lacerum was 6 mm, from the foramen ovale 10 mm, foramen rotundum 15 mm, and petrous apex 9 mm. In 44 sides (61.11%), the LP partially closed the lateral aspect of the carotid sulcus; in 17 sides (23.61%), it was found as a near-ring; and in 11 sides (15.2%), it was considered rudimentary. Considering the PLL, its length and height were, respectively, 9 mm, and 4 mm. CONCLUSION: The LP and PLL separate the carotid artery at the inferior aspect of Meckel's cave and constitute important landmarks for endoscopic endonasal approaches to Meckel's cave and MCF, and their identification and removal is essential for internal carotid artery mobilization in this area.

Abstract Introduction Endoscopic endonasal approaches (EEAs) are increasingly utilized for intracranial pathology. As opposed to sinonasal tumors, the nasal cavity is being used as a corridor to access these intracranial tumors but is not the site of primary surgical intent. Accordingly, there has been recent interest in preserving intranasal structures not directly involved by tumor and improving postoperative sinonasal quality of life (QOL). Objectives The aim of the study is to highlight recent advances in EEA techniques focused on improving sinonasal QOL including turbinate preservation, reducing the morbidity of reconstructive techniques, and the development of alternative minimally invasive EEA corridors. Methods The method of the study involves contemporary literature review and summary of implications for clinical practice. Results Nasoseptal flap (NSF) harvest is associated with significant morbidity including septal perforation, prolonged nasal crusting, and external nasal deformities. Various grafting and local rotational flaps have demonstrated the ability to significantly limit donor site morbidity. Free mucosal grafts have re-emerged as a reliable reconstructive option for sellar defects with an excellent sinonasal morbidity profile. Middle turbinate preservation is achievable in most EEA cases and has not been shown to cause postoperative obstructive sinusitis. Recently developed minimally invasive EEA techniques such as the superior ethmoidal approach have been described to better preserve intranasal structures while allowing intracranial access to resect skull base tumors and have shown promising sinonasal QOL results. Conclusion This contemporary review discusses balancing effective skull base reconstructive techniques with associated morbidity, the role of turbinate preservation in EEA, and the development of unique EEA techniques that allow for increased nasal structure preservation.