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Background
Loss of olfaction has been considered inevitable in endoscopic endonasal resection of olfactory groove meningiomas. Olfaction preservation may be feasible through an endonasal unilateral transcribriform approach, with the option for expansion using septal transposition and contralateral preservation of the olfactory apparatus. Methods
An...
Citations
... Moreover, olfaction preservation is rarely possible with the extended endonasal approach used for ACF meningioma though recently, few authors have reported some degree of olfaction preservation with the endoscopic approach. 18,19 The study has some limitations. The sample size is not large enough and there is no control group to assess the superiority of this approach over others. ...
Numerous surgical approaches have been described for the resection of anterior cranial fossa meningioma. The common problems associated with these approaches are excessive brain retraction, injury to neurovascular structures, transection of superior sagittal sinus (SSS), and a higher risk of new-onset anosmia. The authors describe a unilateral extended frontal approach with the aim to minimize brain handling without the need for SSS transection and possibly better olfaction preservation. Methods: Thirteen patients with anterior cranial fossa meningioma were operated on using the novel technique of unilateral extended frontal skull base approach. The clinical presentation, radiological studies, intraoperative findings, and outcome at follow-up were recorded. Results: Gross total tumor resection could be achieved in 12 out of 13 patients. At least one of the olfactory tracts could be anatomically preserved in all patients, and superior sagittal sinus was preserved in all patients. Functional olfaction preservation was achieved in 8 patients. No patient developed new-onset anosmia. Conclusions: The extended unilateral frontal approach is a viable and reliable alternative for extended bifrontal technique for the resection of large midline anterior cranial fossa meningiomas with avoidance of SSS ligation, decreased brain handling with better olfaction preservation while achieving comparable tumor resection and acceptable cosmetic outcomes.
... As mentioned previously, loss of olfaction (if not present pre-operatively) is virtually guaranteed with the transcribriform approach due to disruption of the olfactory fibers. This sensory loss has been shown to have a significant impact on quality of life [52,63] . While a unilateral transcribriform approach has been described to preserve contralateral olfaction, the indications for this technique are highly specific and thus not applicable to the vast majority of patients with olfactory groove meningiomas [64] . ...
Meningiomas of the tuberculum sellae, planum sphenoidale and olfactory groove region are relatively common. Traditionally these meningiomas have been approached through several transcranial approaches. More recently, keyhole approaches have been utilized with success even for large tumors. Endoscopic approaches are an extension of this philosophy, which, in carefully selected patients, may be an excellent alternative, offering a direct line of site from an endonasal approach without brain retraction. Furthermore, bilateral optic canal decompression can be safely and effectively accomplished. We propose that a majority of tuberculum sellae and posterior planum meningiomas may be removed via an endonasal approach, particularly those that are 3 cm or smaller in maximal diameter with minimal lateral extension beyond the supraclinoid carotid arteries and with medial optic canal invasion. A deepened sella is also a favorable factor for endonasal removal. In contrast, we propose that a minority of olfactory groove meningiomas are ideal candidates for endoscopic trans-cribriform removal given the higher risk of anosmia and cerebrospinal fluid leak via the nasal corridor. Instead, a majority of these tumors can be safely and effectively removed via a transcranial keyhole approach, such as the supraorbital “eyebrow” craniotomy or traditional pterional craniotomy with a higher rate of olfaction preservation.
To review the effects of endoscopic sinus surgery and endonasal approaches to the skull base on olfaction.
Advancements in endonasal endoscopic approaches to the sinuses and skull base allow for direct treatment of a variety of sinonasal and skull base diseases. However, these extended approaches will often require manipulation of normal anatomical structures and the olfactory neuroepithelium. Depending on the planned procedure and extent of disease, the prognosis of olfactory perception can vary significantly among patients.
Endoscopic sinonasal surgical procedures may impact olfaction. Optimizing olfactory function requires proper surgical techniques, gentle handling of tissue, and perioperative care. Surgeons must discuss objectives and manage patient expectations. Routine olfactory assessment is crucial in surgical work-up and follow-up. Preserving anatomical structures while addressing the obstruction of the olfactory cleft helps to prevent decreased olfactory threshold. However, smell identification and discrimination do not always correlate with sinonasal anatomy.
OBJECTIVE
Management of olfactory groove meningiomas (OGMs) has changed significantly with the advances in extended endoscopic endonasal approaches (EEAs), which is an excellent approach for patients with anosmia since it allows early devascularization and minimizes retraction on the frontal lobes. Craniotomy is best suited for preservation of olfaction. However, not infrequently, a tumor presents after extending outside the reach of an EEA and a solely transcranial approach would require manipulation and retraction of the frontal lobes. These OGMs may best be treated by a staged EEA-craniotomy approach. In this study the authors’ goal was to present their case series of patients with OGMs treated with their surgical approach algorithm.
METHODS
The authors conducted an IRB-approved, nonrandomized historic cohort including all consecutive cases of OGMs treated surgically between 2010 and 2020. Patient demographic information, presenting symptoms, operative details, and complications data were collected. Preoperative and postoperative tumor and T2/FLAIR intensity volumes were calculated using Visage Imaging software.
RESULTS
Thirty-one patients with OGMs were treated (14 craniotomy only, 11 EEA only, and 6 staged). There was a significant difference in the distribution of patients presenting with anosmia and visual disturbance by approach. Tumor size was significantly correlated with preoperative vasogenic edema. Gross-total resection was achieved in 90% of cases, with near-total resection occurring twice with EEA and once with a staged approach. T2/FLAIR hyperintensity completely resolved in 90% of cases and rates did not differ by approach. Complication rates were not significantly different by approach and included 4 CSF leaks (p = 0.68).
CONCLUSIONS
A staged approach for the management of large OGMs with associated anosmia and significant lateral extension is a safe and effective option for surgical management. Through utilization of the described algorithm, the authors achieved a high rate of GTR, and this strategy may be considered for large OGMs.
This chapter will consider olfaction in relation to CSF leaks and look at the various skull bases causes for CSF leaks and their bearing on olfaction. In terms of operative intervention, this chapter will examine the effect of skull base reconstruction on olfaction, the effect of different reconstructive materials on olfaction (flaps, grafts, synthetic materials, bone, cartilage, and others and preoperative patient counselling regarding olfaction in skull base reconstruction.KeywordsOlfactionOlfactory disordersCSF rhinorrhoeaSkull base surgeryReconstruction
BACKGROUND
Meningiomas are the most frequent primary tumors in the central nervous system (CNS), but intraorbital location is uncommon and accounts for only 0.2% to 4% of all CNS meningiomas. Lesions in this compartment could be classified as primary, secondary, or ectopic. The close relationship with the optic nerve sheath is a landmark to identify the tumor as primary, whereas secondary tumors commonly come from an extension of an intracranial meningioma, and ectopic meningioma is a concept not yet completely established.
OBSERVATIONS
The authors present a rare case of a secondary intraorbital meningioma operated through an endoscopic endonasal approach. Secondary meningiomas at the medial orbit are very uncommon, given their more common superior and lateral location as an extension of sphenoid meningiomas. The endoscopic endonasal route provides direct access to the medial orbit. The authors present an illustrative case of a meningioma located at the medial orbit and resected through an endoscopic endonasal approach that provided excellent visualization and anatomical exposure. Additionally, the authors review the concept and possible similarities between secondary and ectopic intraorbital meningiomas.
LESSONS
An endoscopic endonasal approach should be considered as a feasible treatment option for intraorbital meningiomas, especially if they are in the medial orbital wall.
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.
There has been a paradigm shift in skull base surgery toward optimizing functional outcomes rather than perfecting radiographic outcomes. Treatment goals evolved into maximum safe resection with functional preservation after radical resection often jeopardized cranial nerve functions and left patients with significant disability. In function-preservation surgery, approach selection is governed by several factors such as patients’ pretreatment condition, goal(s) of treatment, and the complexity of treatment modality/surgery and its possible impact on neurovascular structures. Cranial nerve function is a major determinant of patients’ quality of life post-treatment. In this chapter, we review the basics and surgical tenets of functional preservation in skull base surgery with special emphasis on cranial nerve preservation.
Anterior fossa meningiomas include midline lesions in addition to anterior extension from anterolateral lesions such as sphenoid wing meningiomas. Surgical planning for anterior midline and anterolateral skull base meningiomas should include consideration of the size, shape, vascularity, and adjacent neurovascular structures. Anterior skull base approaches comprise expanded endoscopic endonasal and open approaches. Midline meningiomas are intimately related to the olfactory apparatus and anterolateral meningiomas can involve the circle of Willis, orbit, cavernous sinus, and the cranial nerves. Controversy still exists regarding the optimum approach to anterior skull base meningiomas. For midline tumors, preservation of olfaction should be considered in patients when function and tumor size permit and can be achieved through unilateral tailored surgical approaches. Special surgical considerations exist for small (tumor <2 cm), medium (tumor 2–4 cm), and large (tumors >4 cm), as these lesions can be approached utilizing the transnasal corridor or via tailored unilateral craniotomies. Expanded anterolateral approaches can be tailored according to tumor size and exact type of sphenoid wing meningioma. In this chapter, we share our management strategy of anterior fossa meningiomas including midline lesions and sphenoid wing meningiomas.
