Olfactory Groove Meningioma

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: neurosurgical and otolaryngologic conditions

BACKGROUND

Medical three dimensional (3D) printing is performed for neurosurgical and otolaryngologic conditions, but without evidence-based guidance on clinical appropriateness. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness recommendations for neurologic 3D printing conditions.

METHODS

A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with neurologic and otolaryngologic conditions. Each study was vetted by the authors and strength of evidence was assessed according to published guidelines.

RESULTS

Evidence-based recommendations for when 3D printing is appropriate are provided for diseases of the calvaria and skull base, brain tumors and cerebrovascular disease. Recommendations are provided in accordance with strength of evidence of publications corresponding to each neurologic condition combined with expert opinion from members of the 3D printing SIG.

CONCLUSIONS

This consensus guidance document, created by the members of the 3D printing SIG, provides a reference for clinical standards of 3D printing for neurologic conditions.

Midline Skull Base Meningiomas: Transcranial and Endonasal Perspectives

Simple Summary

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. Over time, several corridors have been proposed, each one carrying its own pros and cons. During the last decades, the endoscopic endonasal route has been asserted among the classic routes for a growing number of midline and paramedian lesions. Therefore, the aim of our paper is to present a comprehensive review of the indications and techniques for the management of skull base meningiomas, emphasizing the ambivalent and complementary role of the low and high routes.

Abstract

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. The state of the art of skull base meningiomas accounts for both transcranial, or high, and endonasal, or low, routes. A comprehensive review of the pertinent literature was performed to address the surgical strategies and outcomes of skull base meningioma patients treated through a transcranial approach, an endoscopic endonasal approach (EEA), or both. Three databases (PubMed, Ovid Medline, and Ovid Embase) have been searched. The review of the literature provided 328 papers reporting the surgical, oncological, and clinical results of different approaches for the treatment of skull base meningiomas. The most suitable surgical corridors for olfactory groove, tuberculum sellae, clival and petroclival and cavernous sinus meningiomas have been analyzed. The EEA was proven to be associated with a lower extent of resection rates and better clinical outcomes compared with transcranial corridors, offering the possibility of achieving the so-called maximal safe resection.

Smell loss as initial symptom of olfactory groove meningioma

Approximately 20% of the general population suffer from olfactory dysfunction (OD). Until today, olfactory function (OF) receives less attention than other human senses despite its significance for quality of life. The main causes of OD are upper respiratory tract infections, traumatic brain injuries and sinonasal diseases. Here, we report the case of a 28-year-old woman, who started to suffer from OD during pregnancy. Smell loss was attributed to pregnancy-induced rhinitis and initiated no further examinations. Nevertheless, OD persisted post partum and undulating headache occurred 1 year later. Only after visual impairment and one more year passing by, diagnosis of olfactory groove meningioma was made using MRI. With this case report, we want to highlight the importance of the symptom of smell loss. Patients reporting OD should undergo thorough anamnesis, endoscopy of the nasal cavity, psychophysical smell testing and radiographic imaging in unclear cases to determine diagnosis.

Stereotactic Radiosurgery for Olfactory Groove Meningiomas: An International, Multicenter Study

BACKGROUND

Stereotactic radiosurgery (SRS) is increasingly considered for selected olfactory groove meningiomas (OGMs).

OBJECTIVE

To investigate the safety and efficacy of SRS for OGMs.

METHODS

From 20 institutions participating in the International Radiosurgery Research Foundation, we pooled patients who underwent SRS for histologically confirmed or radiologically suspected WHO grade I OGMs and were followed for 6 mo or more after the SRS.

RESULTS

In total, 278 (median age 57 yr) patients underwent SRS for histologically confirmed (29%) or radiologically suspected (71%) WHO grade I OGMs Median treatment volume was 4.60 cm3 (range: 0.12-27.3 cm3), median prescription dose was 12 Gy, and median dose to the olfactory nerve was 11.20 Gy. During median post-SRS imaging follow-up of 39 mo (range: 6-240 mo), 43% of patients had partial or marginal response, 54% of patients had stable disease, and 3% of patients experienced progression. During median post-SRS clinical follow-up of 51 mo (range: 6-240 mo), 36 (13%) patients experienced clinical and/or radiological adverse radiation events (AREs). Elevated risk of AREs was associated with larger OGM volume (P = .009) and pre-SRS peritumoral T2/fluid-attenuated inversion-recovery signal abnormalities (P < .001). After the SRS, olfaction remained stable, improved, or deteriorated in 90%, 8%, and 2% of patients, respectively. Complete post-SRS anosmia was predicted by partial/complete anosmia before the SRS (odds ratio [OR] = 83.125; 95% CI [24.589-281.01], P < .001) and prior resection of OGM (OR = 3.919; 95% CI [1.713-8.970], P = .001).

CONCLUSION

SRS is associated with durable local control of the majority of OGM patients with acceptable safety profile. SRS allows preservation or improvement of olfactory function in the majority of OGM patients.

Cognitive Changes in a Commercial Pilot Secondary to an Olfactory Meningioma

BACKGROUND: Olfactory meningiomas are typically benign, slow-growing intracranial tumors with subtle presentations that result in delayed diagnosis. To date, only a few published reports describe meningiomas in airmen. None specifically mention olfactory meningiomas or detail the associated presence of cognitive impairment.CASE REPORT: This was a 55-yr-old commercial pilot with over 20 yr of flight experience who presented for a fitness-for-duty evaluation due to alarming performance at work and neurocognitive concerns. On examination, the patient had an odd affect and anosmia. Imaging showed a large, frontal, midline intracranial mass consistent with an olfactory meningioma.DISCUSSION: Fitness-for-duty cases are often challenging and even more so when neurocognition is called into question. Symptoms may be subtle and gradual in onset, making recognition and diagnosis difficult. Dementia, alcohol or substance misuse/abuse, and psychiatric diagnoses are often the first conditions considered when evaluating new cognitive impairment in a pilot. This case highlights the importance of keeping a broad differential, including intracranial masses, conducting a thorough neurological examination, and the judicious use of brain imaging.Hong M, Kreykes AJ. Cognitive changes in a commercial pilot secondary to an olfactory meningioma. Aerosp Med Hum Perform. 2020; 91(12):966969.

Indications, feasibility, safety, and efficacy of CyberKnife radiotherapy for the treatment of olfactory groove meningiomas: a single institutional retrospective series

Purpose

To assess the safety and efficacy of CyberKnife® radiotherapy (CKRT) for the treatment of olfactory groove meningiomas (OGMs).

Methods

A retrospective review was performed of 13 patients with OGM treated with CKRT from September 2005 to May 2018 at our institution. Nine patients were treated primarily with CKRT, 3 for residual disease following resection, and 1 for disease recurrence.

Results

Five patients were treated with stereotactic radiosurgery (SRS), 6 with hypofractionated stereotactic radiotherapy (HSRT), and 2 with fractionated stereotactic radiotherapy (FSRT). The median tumor volume was 8.12 cm³. The median prescribed dose was 14.8 Gy for SRS, 27.3 Gy for HSRT, and 50.2 Gy for FSRT. The median maximal dose delivered was 32.27 Gy. Median post treatment follow-up was 48 months. Twelve of 13 patients yielded a 100% regional control rate with a median tumor volume reduction of 31.7%. Six of the 12 patients had reduced tumor volumes while the other 6 had no changes. The thirteenth patient had significant radiation-induced edema requiring surgical decompression. Twelve patients were alive and neurologically stable at the time of the review. One patient died from pneumonia unrelated to his CKRT treatment.

Conclusions

CKRT appears to be safe and effective for the treatment of OGMs.

Near-Infrared Optical Contrast of Skull Base Tumors During Endoscopic Endonasal Surgery

BACKGROUND

Near-infrared (NIR) tumor contrast is achieved through the "second-window ICG" technique, which relies on passive accumulation of high doses of indocyanine green (ICG) in neoplasms via the enhanced permeability and retention effect.

OBJECTIVE

To report early results and potential challenges associated with the application of second-window ICG technique in endonasal endoscopic, ventral skull-base surgery, and to determine potential predictors of NIR signal-to-background ratio (SBR) using endoscopic techniques.

METHODS

Pituitary adenoma (n = 8), craniopharyngioma (n = 3), and chordoma (n = 4) patients received systemic infusions of ICG (5 mg/kg) approximately 24 h before surgery. Dual-channel endoscopy with visible light and NIR overlay were photodocumented and analyzed post hoc.

RESULTS

All tumors (adenoma, craniopharyngioma, chordoma) demonstrated NIR positivity and fluoresced with an average SBR of 3.9 ± 0.8, 4.1 ± 1.7, and 2.1 ± 0.6, respectively. Contrast-enhanced T1 signal intensity proved to be the single best predictor of observed SBR (P = .0003). For pituitary adenomas, the sensitivity, specificity, positive predictive value, and negative predictive value of NIR-guided identification of tumor was 100%, 20%, 71%, and 100%, respectively.

CONCLUSION

In this preliminary study of a small set of patients, we demonstrate that second-window ICG can provide NIR optical tumor contrast in 3 types of ventral skull-base tumors. Chordomas demonstrated the weakest NIR signal, suggesting limited utility in those patients. Both nonfunctional and functional pituitary adenomas appear to accumulate ICG, but utility for margin detection for the adenomas is limited by low specificity. Craniopharyngiomas with third ventricular extension appear to be a particularly promising target given the clean brain parenchyma background and strong SBR.

Recurrence of Anterior Skull Base Meningiomas After Endoscopic Endonasal Resection: 10 Years' Experience in a Series of 52 Endoscopic and Transcranial Cases

INTRODUCTION

Although the indication of endoscopic approaches for anterior skull base meningiomas (ASBM) has been progressively refined, there remains a paucity of data on recurrence rates after resection. To analyze and compare recurrence rates of ASBM resected through endoscopic endonasal (EEE) versus transcranial (TCA) approaches.

MATERIAL AND METHODS

We performed a retrospective analysis of patients submitted to the EEE or TCA approach for ASBM resection from May 2006 to January 2016 in our center. Clinical, radiological, and pathology data were retrieved for analysis. Tumor size, location, surgical technique, extent of resection, and tumor grade were assessed. The 2 groups were compared to identify predictors and differences regarding tumor recurrence.

RESULTS

Fifty-two patients (17 olfactory groove meningioma [OGM] and 35 tuberculum sellae meningioma [TSM]) were included; 26 (6 OGM and 20 TSM) underwent EEE and 26 (13 OGM and 13 TSM) TCA, with a mean follow-up of 41 months. Gross total resection was achieved in 38 (73%) patients (18 [69%] in EEE and 20 [77%] in TCA). Eight (15%) patients presented with recurrence: 5 (19%) in the EEE group and 3 (11.5%) in the TCA group without a statistical difference (P = 0.69). Among the recurrences, gross total resection had been achieved in 1 case of each group. In the EEE group, 1 patient underwent TCA for a recurrent tumor and another patient was referred for radiosurgery.

CONCLUSIONS

This study has shown an overall similar recurrence rate of ASBM regardless of the technique used. However, the analysis of larger series with longer follow-up is necessary to clearly define the indications and to fully validate the efficacy of EEE.

Imaging review of the anterior skull base

The anterior skull base (ASB) is intimately associated with the unique soft tissue subtypes of the nasal cavity, paranasal sinuses, orbits, and intracranial compartment. Pathology involving the ASB is rare but the causes are manifold and can be broadly subdivided into those intrinsic to the skull base and processes extending from below or above. Sinonasal pathology is the most commonly encountered and poses significant management challenges that rely heavily on accurate interpretation of the radiological findings. We illustrate the normal anatomy of the ASB and present a cross-sectional imaging review of the pathological entities that may be encountered, focusing on the specific features that will impact on clinical and surgical management.

Limitations of the endonasal endoscopic approach in treating olfactory groove meningiomas. A systematic review

OBJECTIVE

To review current management strategies for olfactory groove meningioma (OGM)s and the recent literature comparing endoscopic endonasal (EEA) with traditional transcranial (TCA) approaches.

METHODS

A PubMed search of the recent literature (2011-2016) was performed to examine outcomes following EEA and TCA for OGM. The extent of resection, visual outcome, postoperative complications and recurrence rates were analyzed using percentages and proportions, the Fischer exact test and the Student's t-test using Graphpad PRISM 7.0Aa (San Diego, CA) software.

RESULTS

There were 444 patients in the TCA group with a mean diameter of 4.61 (±1.17) cm and 101 patients in the EEA group with a mean diameter of 3.55 (± 0.58) cm (p = 0.0589). GTR was achieved in 90.9% (404/444) in the TCA group and 70.2% (71/101) in the EEA group (p < 0.0001). Of the patients with preoperative visual disturbances, 80.7% (21/26) of patients in the EEA cohort had an improvement in vision compared to 12.83%(29/226) in the TCA group (p < 0.0001). Olfaction was lost in 61% of TCA and in 100% of EEA patients. CSF leaks and meningitis occurred in 25.7% and 4.95% of EEA patients and 6.3% and 1.12% of TCA patients, respectively (p < 0.0001; p = 0.023).

CONCLUSIONS

Our updated literature review demonstrates that despite more experience with endoscopic resection and skull base reconstruction, the literature still supports TCA over EEA with respect to the extent of resection and complications. EEA may be an option in selected cases where visual improvement is the main goal of surgery and postoperative anosmia is acceptable to the patient or in medium-sized tumors with existing preoperative anosmia. Nevertheless, based on our results, it seems more prudent at this time to use TCA for the majority of OGMs.

Endoscopic Endonasal Approach for Olfactory Groove Meningiomas: Operative Technique and Nuances

Olfactory groove meningiomas represent approximately 10% of all intracranial meningiomas. Because these tumors originate at the ventral skull base, the endonasal route provides direct access to the tumor blood supply for early devascularization and removal of the underlying hyperostotic bone at the cranial base. In carefully selected patients, these tumors can be totally removed without additional brain retraction or manipulation. In this report, we describe the surgical technique and operative nuances for removal of olfactory groove meningiomas using the endoscopic endonasal approach, and also discuss the indications, limitations, complication avoidance and management, and postoperative care.

Anterior and Posterior Ethmoidal Artery Ligation in Anterior Skull Base Meningiomas: A Review on Microsurgical Approaches

OBJECTIVE

Anterior skull base neoplastic and vascular lesions can receive significant blood supply from the anterior and posterior ethmoidal artery. Although useful in preoperative embolization of middle meningeal artery branches, endovascular techniques for the occlusion of anterior ethmoidal artery expose the parent vessel, the ophthalmic artery, to possible embolic complications, which can cause loss of vision. When dealing with anterior fossa giant meningiomas, moreover, it is not always possible to gain direct intracranial access to anterior ethmoidal arteries because of dimensions and invasiveness of these neoplasms. The aim of this review is to illustrate the anterior and posterior ethmoidal artery anatomy and the microsurgical approaches for extracranial ligation.

METHODS

We performed a literature review of the relevant microsurgical anatomy of these arteries; particular attention is given to anterior cranial fossa and medial orbital wall anatomy.

RESULTS

Our research found two surgical sites of arterial occlusion that can be best exposed with five microsurgical approaches.

CONCLUSIONS

A combination of different surgical and endovascular techniques before resection of hypervascular giant olfactory groove and planum sphenoidale meningiomas should always be considered. Microsurgical extracranial ligation of anterior and sometimes posterior ethmoidal arteries provides a safe and feasible option to limit blood loss during anterior skull base surgery.

Reconstructive challenges in the extended endoscopic transclival approach

OBJECTIVE

We wanted to present our experience with the extended endoscopic approach to clival pathology, focusing on cerebrospinal fluid leak and reconstruction challenges.

METHODS

We examined a consecutive series of 37 patients undergoing the extended endoscopic approach for skull base tumours, 9 patients with clival pathology. Patients were examined for the incidence of post-operative cerebrospinal fluid leak in relation to tumour pathology, location, size, reconstruction and lumbar drain.

RESULTS

The overall incidence of post-operative cerebrospinal fluid leak was 10.8 per cent. Seventy-five per cent of patients who had a post-operative cerebrospinal fluid leak underwent a transclival approach (p < 0.05). All patients with clival pathology who underwent an intradural dissection had a post-operative cerebrospinal fluid leak (p < 0.05).

CONCLUSION

Post-operative cerebrospinal fluid leak rates after the extended endoscopic approach have improved significantly after advancements including the vascularised nasoseptal flap. Despite this, transclival approaches continue to pose much difficulty. Further investigation is necessary to develop technical improvements that can meet the unique challenges associated with this region.

Subtle clinical signs of a meningioma in an adult: a case report

Background

Meningiomas are the most common brain tumor in the adult population. This case report describes the epidemiology, the clinical presentation as well as the current treatment options for this condition.

Case presentation

A 49 year-old man attended a chiropractic clinic with non-specific chronic low back pain. Upon the history taking and the systems review, he reported a loss of both smell and taste for which investigations conducted by two different otolaryngologists did not yield a specific diagnosis. The patient was referred to a neurologist who ordered a computer tomography scan that eventually revealed a compression brain tumor.

Brain tumors can produce a large variety of clinical presentations, such as upper motor neuron lesion symptoms, altered consciousness or vital functions which are easy to identify. However, subtle signs, such as those presented in this case, can be neglected.

Conclusion

Clinicians should be aware of uncommon clinical presentations including cranial nerve or neurological dysfunction and refer their patient to a specialist when detected.

Personal experience in transnasal endoscopic resection of the olfactory groove meningiomas. What can an otolaryngologist offer to a neurosurgeon?

Olfactory groove meningioma is a demanding therapeutic problem involving two medical specialties, otolaryngology and neurosurgery. The use of transnasal endoscopic (TNE) approach to the tumour has been proved effective in many publications. Three patients with meningiomas localized in olfactory groove were treated in 2011 and 2012 by the otolaryngologist-neurosurgeon team using TNE approach and neuronavigation. The diagnosis was based on MR and CT images. In all patients after tumour removal an endoscopic anterior cranial fossa floor reconstruction was performed using homogeneous cartilage or titanium mesh and Hadad-Bassagasteguy flap. During postoperative period in all patients lumbar drainage was used. There were no cerebrospinal fluid leakage episodes. No recurrence was observed in 22, 12 and 8 months of follow-up, respectively. The authors describe otolaryngological and neurosurgical aspects of TNE approach to anterior cranial fossa with special regard to possible radical resection (according to Simpson) and reconstruction of the bony postoperative defect. TNE is a feasible operative method in olfactory groove meningioma management due to good tumour visibility, lack of brain traction, limited neurovascular structure manipulation and acceptable risk of neurological deficiencies when compared to open approach. Cosmetic aspect and short hospitalization is also of great importance.

Challenges and surgical nuances in reconstruction of large planum sphenoidale tuberculum sellae defects after endoscopic endonasal resection of parasellar skull base tumors

OBJECTIVES/HYPOTHESIS

Endoscopic endonasal transplanum transtuberculum (EETT) resection of parasellar skull base (SB) tumors often results in large SB defects with intraoperative high-flow cerebrospinal fluid (CSF) leaks. Reconstruction of these defects can be challenging because of the large defects size, communication with the suprasellar cistern, and close proximity to the optic nerves and chiasm. Recent studies have postulated that transplanum defects may be associated with increased postoperative CSF leakage. We review our experience with reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Challenges encountered during these repairs and our operative nuances for successful reconstruction are discussed.

METHODS

A retrospective analysis was performed between March 2010 and February 2012 on patients undergoing reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Repair materials, defect sizes, postoperative CSF leakage, postoperative CSF diversion, and demographic data were collected.

RESULTS

Nineteen patients who underwent 22 repairs with a pedicled nasoseptal flap (PNSF) were identified. The mean age was 47.6 years (range, 12-68 years). Average defect size was 5.6 cm(2) (range, 2.2-10.4 cm(2)). Three failed repairs necessitated a revision procedure. All three revisions were successfully reconstructed with the previously used PNSF. The mean follow-up period was 13.5 months (range, 1-26 months). The overall success rate was 86.4% for transplanum defects alone, as compared to 97.0% for our comprehensive PNSF experience in 99 repairs.

CONCLUSION

Repair of large transplanum defects after EETT resection of parasellar SB tumors presents a unique challenge. Using a PNSF along with meticulous multilayer closure may help decrease postoperative CSF leaks.

Endoscopic, endonasal, transclival resection of a pontine cavernoma: case report

BACKGROUND AND IMPORTANCE

Hemorrhagic, symptomatic cavernous malformations in the brainstem are difficult to access. Conventional approaches such as the transpetrosal approach often require significant brain retraction. We present the successful purely endoscopic, endonasal, transclival resection of a symptomatic cavernoma located in the ventromedial pons.

CLINICAL PRESENTATION

A 17-year-old male patient presented with acute onset of headache, facial numbness, and tingling. Magnetic resonance imaging demonstrated an enhancing lesion in the pons consistent with a cavernous malformation. Over the course of the next 3 weeks, the patient had 2 additional episodes of acutely worsening neurological deficits that left him with left-sided hemiparesis, a right sixth nerve palsy, and dysphagia. A purely endoscopic, endonasal, transclival approach was used to resect the cavernoma. Postoperatively, he had a transient worsening of his left-side motor function and restricted horizontal gaze, but at the last follow-up, his hemiparesis had improved and his magnetic resonance imaging demonstrated a radiographic cure. He developed a cerebrospinal fluid (CSF) leak despite prophylactic lumbar CSF drainage for 2 days and the use of bilateral vascularized nasoseptal flaps. The CSF leak was repaired with CSF diversion and a second surgical procedure; at the last follow-up, he had no recurrence of the leak.

CONCLUSION

An endoscopic, endonasal, transclival approach is a novel and effective approach to cavernous malformations presenting to the ventral surface of the pons. Recently developed techniques for closure and repair of the skull base defect have minimized but have not eliminated the risk of CSF leak in these procedures.

Endoscopic versus open resection of tuberculum sellae meningiomas: a decision analysis

BACKGROUND/AIMS

Tuberculum sellae meningiomas (TSMs) are challenging tumors for surgical resection. Endoscopic endonasal (EE) approaches to these lesions have not been directly compared to open craniotomy in a controlled trial.

METHODS

We searched Medline and Embase online databases for English-language articles containing key words related to TSMs. Data were pooled, including 5 of our own patients reported here for the first time. Metaregression was used and a decision-analytical model was constructed to compare outcomes between open microsurgery and EE approaches.

RESULTS

The overall quality of life (QOL) was not significantly different between the approaches (p = 0.410); however, there were large differences in individual complication rates. The Monte Carlo simulation yielded an overall average QOL in craniotomy patients of 0.915 and in endoscopic patients of 0.952. Endoscopy had a higher CSF leak rate (26.8 vs. 3.5%, p < 0.001) but a lower rate of injury to the optic apparatus (1.4 vs. 9.2%, p < 0.001) compared with craniotomy. The 3-year recurrence rates were not statistically different (p = 0.529).

CONCLUSION

EE resection of TSMs appears to be a comparable alternative to traditional open microsurgical resection with respect to overall QOL based on available publications. A meaningful comparison of recurrence rates will require a longer follow-up.

Radiographic enhancement of the nasoseptal flap does not predict postoperative cerebrospinal fluid leaks in endoscopic skull base reconstruction

OBJECTIVES/HYPOTHESIS

Cerebrospinal fluid (CSF) leaks continue to be the most common postoperative complication in expanded endonasal skull base procedures. Currently, a multilayer closure using a vascularized nasoseptal flap is most commonly performed for large ventral skull base defects in an effort to avoid postoperative CSF leaks. We correlated nasoseptal flap enhancement with postoperative CSF leak rates in a group of skull base reconstruction patients. The nasoseptal flap enhancement was determined by immediate postoperative gadolinium-enhanced magnetic resonance imaging (MRI), which allowed for imaging of the flap's vascular pedicle. Our aim was to identify whether nasoseptal flap enhancement contributed to reduction of postoperative CSF leak rates.

STUDY DESIGN

Retrospective cohort study.

METHODS

We reviewed 19 patients who underwent expanded endoscopic resections of skull base lesions of advanced complexity. We calculated the incidence of CSF leaks and measured the presence of nasoseptal flap enhancement.

RESULTS

Of the 19 patients with immediate postoperative MRIs, three developed postoperative CSF leaks. All three CSF leaks were in cases with enhancing vascular pedicles. In contrast, we had three patients without evidence of flap enhancement, none of whom developed a postoperative CSF leak (Fisher exact test, P = 1.0). CSF leak was associated with posterior fossa lesions (P = .25). Nasoseptal flap enhancement was associated with younger age (P = .15).

CONCLUSIONS

This retrospective cohort study demonstrates that although the vascularized pedicled nasoseptal flap is effective for closure of expanded endonasal skull base procedures, our experience found the actual enhancement of the flap itself does not appear to effect postoperative CSF leak rates.