Surgical nuances for removal of tuberculum sellae meningiomas with optic canal involvement using the endoscopic endonasal extended transsphenoidal transplanum transtuberculum approach

Cranio-Orbital Approach and Decompression of the Optic Nerves: A 2-Stage, 4-by-4-Step Approach to Improve Vision in Sellar and Parasellar Lesions

BACKGROUND AND OBJECTIVES

Despite advances in cranial base techniques, surgery of the sellar and parasellar regions remains challenging because of complex neurovascular relationships. Lesions within this region frequently present with progressive visual deterioration caused by distortion and compression of the optic chiasm and nerves. In addition to the direct mass effect from mechanical forces acting on the optic apparatus, these lesions alter blood supply and reduce vascular perfusion, prompting surgical treatment to remove the lesion, alleviate compression, and improve blood flow to the optic nerve. We sought to describe a 2-stage, 4-by-4-step approach, broken down and described as a "four-by-four" technique for optic apparatus decompression and a wide approach to different sellar and parasellar lesions.

METHODS

We describe the operative nuances and key anatomic points in the microsurgical removal of sellar and parasellar lesions. The technique is illustrated with examples of different cases with pre- and follow-up MRI imaging and a brief overview of visual outcomes.

RESULTS

The described technique has been demonstrated in various lesions in 5 patients. Patients presented with bilateral visual loss in 4 (80.0%) cases and with unilateral visual loss in 1 (20.0%) case. Improvement in visual function was noted in all cases, confirmed with visual acuity and visual field testing.

DISCUSSION

The transcranial approach ("from above") remains an important surgical option for patients with excellent exposure and visualization of the sellar and parasellar regions. It permits early access to the optic canal for careful microsurgical decompression and relaxation of the optic nerve to preserve and improve its microvascularization and ultimately vision.

CONCLUSION

The authors augmented the 2-stage, 4-by-4-step technique of decompression with elaborate illustrations of diverse sellar and parasellar lesions to demonstrate the versatility of this approach.

Outcomes of Endoscopic Endonasal Surgery for Tuberculum Sellae and Planum Sphenoidale Meningiomas: A Retrospective Study

BACKGROUND

To evaluate clinical outcomes and volumetric changes following endoscopic endonasal approach (EEA) for tuberculum sellae (TS) and planum sphenoidale (PS) meningiomas. Key objectives included evaluating pre- and postoperative tumor volumes, visual assessments and EEA-related complications.

METHODS

A single-center retrospective study was conducted at Foothills Medical Centre, University of Calgary, Canada, from 2009 to 2022 including 24 patients meeting inclusion criteria for midline skull base tumors, confirmed as WHO Grade I or II meningiomas with optic canal extension.

RESULTS

EEA achieved gross total resection in 87.5% of cases, with a mean tumor volume reduction of 92.24%. Postoperatively, 91.67% exhibited visual improvement or stability. Cerebrospinal fluid leaks occurred in 12.5% of cases, necessitating revision surgery in one case. Persistent postoperative endocrine dysfunction affected 4.17%. Preoperative tumor volume did not demonstrate a correlation with complications.

CONCLUSIONS

This study delivers reproducible data for pre- and postoperative tumor volume following the EEA after TS or PS meningiomas. The EEA demonstrated favorable radiographic and clinical outcomes in TS and PS meningiomas, achieving gross total resection with minimal morbidity.

Endoscopic Extended Transsphenoidal Surgery for Transbasal Tuberculum Sellae Meningioma: 2-Dimensional Operative Video

Transbasal meningiomas1 are a rare group of tumors that grow intracranially, invade the skull base, and propagate extracranially; they are usually located at the level of the olfactory cribra and sphenoid wing.1-4 Transbasal tuberculum sellae meningiomas are a subset of these tumors, which extend into the suprasellar and sphenoid regions. The traditional transcranial approach for some transbasal meningiomas has recently evolved toward the transnasal endoscopic approach, which allows the removal of both the intranasal and intracranial components, reducing the manipulation of the optic nerves and neurovascular structures. Nevertheless, specific anatomical criteria must be present; the knowledge of specific anatomy5,6 and the surgeon's experience are fundamental for reaching the most favorable outcome.7-11 In this video, we present the case of a 50-year-old woman with a history of progressive visual impairment and scotoma in the left inferotemporal quadrant. Radiological examinations suggested a transbasal tuberculum meningioma that extended into the suprasellar region, sphenoid sinus, and optic canals. An endoscopic transtuberculum approach with intraoperative visual-evoked potentials12 was performed, allowing an early devascularization with the preservation of the superior hypophyseal arteries and the removal of the component extending in the medial portion of both optic canals. The postoperative MRI documented a gross total resection without complications. The patient reported an immediate improvement of the visual symptoms. Histopathology documented a meningioma (CNS World Health Organization grade 1) with bone invasion. The patient consented to the procedure and to the publication of her image; Institutional Review Board approval was not required for this single case report.

Endonasal versus supraorbital approach for anterior skull base meningiomas: Results and quality of life assessment from a single-surgeon cohort

OBJECTIVE

In this prospective non-randomized study we reported our experience related to planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas in a similar cohort of patients operated via the endonasal or the supraorbital route. A comprehensive quality of life analysis has been performed.

METHODS

Being comparable in general features, between November 2017 to January 2020, a total of 20 patients with anterior skull base meningioma were included. Hence, 10 patients were treated using the supraorbital keyhole procedure (SO) while 10 patients received an endoscopic endonasal approach (EEA). Both surgical techniques were analyzed and compared. Quality of life has been analyzed with the SF-36 questionnaire.

RESULTS

Twenty patients were identified who underwent either EEA (n=10) or SO (n=10). The average extent of resection achieved was not significantly different between the 2 groups. Post-operatively, the EEA group demonstrated a longer hospital stay and bed days compared with SO patients as well as a longer surgical time. There was a significant rate of more CSF leakage after EEA then after SO (20% vs 0%, p=0,0491). The follow-up period resulted shorter in the SO group, with a slight increased recurrence rate. Overall, no differences in visual outcome were detected. There were no differences in terms of quality of life between the two groups in all the explored items.

CONCLUSIONS

In this single-center single-surgeon study of similarly sized and located PS and TS meningiomas, EEA showed longer hospital stays with higher degree of CSF leak compared with the SO group. Supraorbital craniotomy via eyebrow incision reported a comparable quality of life results, even if with a slightly higher percentage of recurrence and less follow-up.

Anatomical variations of foramen of the diaphragma sellae and neighboring structures: a cadaveric study

The aim of our study was to examine the variations and types of foramen of diaphragma sellae (FDS) and their relationship with nearby surgical landmarks on cadavers.Twenty adult (9 male, 11 female) formalin-fixed cadaveric heads were bilaterally used to analyze the anatomical relationships around the supradiaphragmatic region of sella turcica. Lengths and distances of nearby surgical landmarks were measured by a digital microcaliper. SPSS version 25 was used to analyze the comparison between genders and body sides. Dorsum sellae distances to tuberculum sellae and the optic chiasm(OC) were higher in males than females (p < 0.05). Type 8 infundibulum passage was the most common variation with 50%. There was no finding related to types 1-4 of infundibulum passage. Thus, the present study has indicated that the infundibulum passes mostly from the posterior half of the foramen. The shape of the foramen was irregular in 45%, circular in 20%, sagittally oval in 20%, and horizontally oval in 15% of the cases. The OC was noted normal in 60%, prefixed in 35%, and postfixed in 5% of the cases. Comprehensive anatomical knowledge about the types of the FDS and their neighboring structures is crucial for preoperative planning of sellar region diseases in terms of navigating the region when accessing the foramen. Discrimination of variations of FDS, OC, and pituitary stalk, their relationships, and differences between genders is useful to minimize potential surgical complications.

360 Degrees Endoscopic Access to and Through the Orbit

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Visual Outcomes and Surgical Approach Selection Focusing on Active Optic Canal Decompression and Maximum Safe Resection for Suprasellar Meningiomas

The goal of treating patients with suprasellar meningioma is improving or preserving visual function while achieving long-term tumor control. We retrospectively examined patient and tumor characteristics and surgical and visual outcomes in 30 patients with a suprasellar meningioma who underwent resection via an endoscopic endonasal (15 patients), sub-frontal (8 patients), or anterior interhemispheric (7 patients) approach. Approach selection was based on the presence of optic canal invasion, vascular encasement, and tumor extension. Optic canal decompression and exploration were performed as key surgical procedures. Simpson grade 1 to 3 resection was achieved in 80% of cases. Among the 26 patients with pre-existing visual dysfunction, vision at discharge improved in 18 patients (69.2%), remained unchanged in six (23.1%), and deteriorated in two (7.7%). Further gradual visual recovery and/or maintenance of useful vision were also observed during follow-up. We propose an algorithm for selecting the appropriate surgical approach to a suprasellar meningioma based on preoperative radiologic tumor characteristics. The algorithm focuses on effective optic canal decompression and maximum safe resection, possibly contributing to favorable visual outcomes.

Surgical management of tuberculum sellae meningioma: Transcranial approach or endoscopic endonasal approach?

Background

Tuberculum sellae meningioma (TSM), a common benign tumor in the sellae region, usually causes neurological deficits, such as vision impairment, by squeezing the peripheral neurovascular structures. Surgical management is recommended as the optimal strategy for TSM treatment and vision restoration. However, it remains challenging to resect TSM in the traditional transcranial approach (TCA). Recently, the endoscopic endonasal approach (EEA) has emerged as an effective option in skull base surgeries. Besides the effectivity, the advantages and limitations of EEA in TSM surgery remain controversial.

Object

We compared the surgical outcomes and complications between TCA and EEA surgeries to identify the principles in TSM surgical management.

Methods

Retrospective analysis was performed on the patients, who underwent TSM surgery in Wuhan Union Hospital between January 2017 and December 2021. The patients were assigned to TCA or EEA group according to the surgery they experienced. All patients were analyzed with the extent of tumor resection, vision outcome, postoperative complications, and follow-up results.

Results

A total of 112 patients were enrolled in this study, including 78 in TCA group and 34 in EEA group. The mean follow-up was 20.5 months (range 3–36 months). There were no statistically significant differences in patient demographic data, preoperative symptoms, and tumor characteristics between TCA and EEA groups. Both TCA and EEA surgeries are effective in TSM resection with relatively high gross total resection rates (85.9% in TCA vs. 91.2% in EEA, p > .05). Meanwhile, EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery (74.6% in TCA vs. 93.1% in EEA, p < .05). Whereas EEA surgery causes more occurrences of cerebrospinal fluid (CSF) leakage than TCA surgery (0% in TCA vs. 11.8% in EEA, p < .05).

Conclusion

Both TCA and EEA surgeries are effective in TSM resection. EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery, but induces higher risk of CSF leakage. As each approach has unique advantages and limitations, we must take all aspects into consideration, including approach feathers, tumor characteristics, and clinical requirements, to make the optimal choice in TSM surgical management.

Anterior Skull Base Meningioma: Surgical Approach and Complication Avoidance

Introduction  Endoscopic endonasal approach (EEA) and keyhole transcranial approaches (TCAs) are being increasingly used in anterior skull base meningioma (ASBM) surgery. Objective  We compare tumor resection rates and complication profiles of EEA and supraorbital keyhole approach (SOKHA) with conventional TCAs. Methods  Fifty-four patients with ASBM (olfactory groove meningioma [OGM], n  = 19 and planum sphenoidale/tuberculum sellae meningioma [PSM/TSM], n  = 35) operated at a single center over 7 years were retrospectively analyzed. Results  The overall rate of gross total resection (GTR) was higher in OGM (15/19, 78.9%) than PSM-TSM group (23/35, 65.7%, p  = 0.37). GTR rate with OGM was 90% and 75% with TCA and EEA. Death ( n  = 1) following medical complication (TCA) and cerebrospinal fluid leak requiring re-exploration ( n  = 2, one each in TCA and EEA) accounted for the major complications in OGM. For the PSM/TSM group, the GTR rates were 73.3% ( n  = 11/15), 53.8% ( n  = 7/13), and 71.4% ( n  = 5/7) with TCA, EEA, and SOKHA, respectively. Seven patients (20%) of PSM-TSM developed major postoperative complications including four deaths (one each in TCA and SOKHA, and two in EEA groups) and three visual deteriorations. Direct and indirect vascular complications were common in lesser invasive approaches to PSM-TSM especially if the tumor has encased intracranial arteries. Conclusion  No single approach is applicable to all ASBMs. TCA is still the best approach to obtain GTR but has tissue trauma-related problems. SOKHA may be a good alternative to TCA in selected PSM-TSMs, while EEA may be an alternate option in some OGMs. A meticulous patient selection is needed to derive reported results of EEA for PSM-TSM.

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

Ipsilateral vs controlateral approach in tuberculum sellae meningiomas surgery: a retrospective comparative study

Most of tuberculum sellae meningiomas (TSM) show asymmetric growth. They are usually resected through ipsilateral approaches. The access of the inferior-medial side of the ipsilateral optic nerve might be challenging, which result in increased manipulation of the compromised optic nerve. The contralateral approach has been described to avoid these technical difficulties. Assessing the long-term visual and olfactory outcome, as well as recurrence rate in patients operated for TSM through ipsilateral or contralateral approaches. Single center retrospective cohort study about 94 patients operated on between March 2000 and April 2018. Seventy percent of the preoperative visual acuity loss totally resolved (44%) or showed varying degrees of improvement (26%) after surgery. Seventy-two percent of the preoperative visual field defects evolved favorably (44% recovery, 28% improvement). Eight patients showed aggravated visual disturbances (9%). A contralateral approach seemed to be predictive of visual field defects improvement after surgery (OR = 0.4), with borderline significant results (p = .08). There was a higher rate of postoperative olfactory nerve impairment after a contralateral approach (37% vs 17%, p = .03). Total removal of the tumor fragment entering the optic canal was accomplished in 96% in the contralateral vs 75% in the ipsilateral group (p = .04). The 2-, 5-, and 7-year tumor progression-free survival were 100% in the Simpson grade 2 group, and 85% (n = 17), 74% (n = 11), and 67% (n = 5) in the Simpson grade 4 group, respectively (p = .00). Resection of tuberculum sellae meningiomas through a contralateral approach seems to provide better visual outcome and tumor control at the cost of increased olfactory nerve disorders.

The expanded endoscopic endonasal approach for treatment of tuberculum sellae meningiomas in a series of 40 consecutive cases

Compared with traditional craniotomy, the expanded endoscopic endonasal approach (EEEA) may have some advantages for tuberculum sellae meningioma (TSM) treatment. We described our experience of the therapeutic effect of endoscopic TSM treatment. From August 2015 to December 2019, 40 patients with a TSM were treated by the EEEA in our institution. EEEA outcome in TSM treatment was analyzed. Among 39 patients with visual impairment, 38 (97.4%) improved their visual function to some extent after the EEEA, and one case had no significant change in visual acuity. Among all patients, 38 (95.0%) achieved gross total resection (GTR) and 2 (5.0%) achieved near-total resection (NTR). Cerebrospinal fluid (CSF) leakage occurred in three patients (7.5%) and meningitis (post-CSF leakage) in two patients (5.0%). Eight patients (20.0%) suffered postoperative hyposmia, three of whom developed long-term hyposmia. One patient (2.5%) suffered from bleeding of the branch of the anterior cerebral artery intraoperatively leading to postoperative acute cerebral infarction. The EEEA is a safe and reliable minimally invasive method for TSM removal. Compared with traditional craniotomy, the EEEA may have better visual outcomes and a higher prevalence of GTR, but carries the risk of CSF leakage.

The endoscope-assisted supraorbital "keyhole" approach for anterior skull base meningiomas: an updated meta-analysis

INTRODUCTION

The gold-standard treatment for symptomatic anterior skull base meningiomas is surgical resection. The endoscope-assisted supraorbital "keyhole" approach (eSKA) is a promising technique for surgical resection of olfactory groove (OGM) and tuberculum sellae meningioma (TSM) but has yet to be compared with the microscopic transcranial (mTCA) and the expanded endoscopic endonasal approach (EEA) in the context of existing literature.

METHODS

An updated study-level meta-analysis on surgical outcomes and complications of OGM and TSM operated with the eSKA, mTCA, and EEA was conducted using random-effect models.

RESULTS

A total of 2285 articles were screened, yielding 96 studies (2191 TSM and 1510 OGM patients). In terms of effectiveness, gross total resection incidence was highest in mTCA (89.6% TSM, 91.1% OGM), followed by eSKA (85.2% TSM, 84.9% OGM) and EEA (83.9% TSM, 82.8% OGM). Additionally, the EEA group had the highest incidence of visual improvement (81.9% TSM, 54.6% OGM), followed by eSKA (65.9% TSM, 52.9% OGM) and mTCA (63.9% TSM, 45.7% OGM). However, in terms of safety, the EEA possessed the highest cerebrospinal fluid leak incidence (9.2% TSM, 14.5% OGM), compared with eSKA (2.1% TSM, 1.6% OGM) and mTCA (1.6% TSM, 6.5% OGM). Finally, mortality and intraoperative arterial injury were 1% or lower across all subgroups.

CONCLUSIONS

In the context of diverse study populations, the eSKA appeared not to be associated with increased adverse outcomes when compared with mTCA and EEA and offered comparable effectiveness. Case-selection is paramount in establishing a role for the eSKA in anterior skull base tumours.

Accuracy and Interrater Reliability of CISS Versus Contrast-Enhanced T1-Weighted VIBE for the Presence of Optic Canal Invasion in Tuberculum Sellae Meningiomas

BACKGROUND

The magnetic resonance imaging sequence used to assess optic canal invasion by tuberculum sella meningiomas (TSMs) has not been standardized. Both constructive interference in steady state (CISS) and contrast-enhanced T1-weighted volume-interpolated breath-hold examination (VIBE) sequences are frequently used. The aim of the present study was to compare the accuracy and interrater reliability of these sequences in predicting optic canal invasion by TSMs.

METHODS

In the present retrospective study of 27 patients (54 optic canals) who had undergone endoscopic transtuberculum transplanum resection of TSMs, images from preoperative CISS and contrast-enhanced T1-weighted VIBE sequences were assessed by 5 neuroradiologists who were unaware of the operative findings. The readers evaluated the optic canal in 4 quadrants at 2 locations (the posterior tip of the anterior clinoid process and the optic strut). A quadrant was considered positive for tumor invasion if invasion was present at either of these 2 locations. The reference standard was intraoperative observation of gross optic canal invasion.

RESULTS

The interrater agreement was good for the presence or absence of tumor involvement in a particular quadrant (CISS, 0.635; VIBE, 0.643; 95% confidence interval for the difference, -0.086 to 0.010). The mean sensitivity and specificity for optic nerve invasion were 0.643 and 0.438 with CISS and 0.643 and 0.454 with VIBE, respectively. No significant differences were seen between the sequences in terms of reader accuracy when the intraoperative findings were used as the reference standard.

CONCLUSION

CISS and VIBE sequences both have good accuracy in predicting for optic canal tumor invasion by TMEs.

Delayed Postoperative Hyponatremia Following Endoscopic Transsphenoidal Surgery for Non-Adenomatous Parasellar Tumors

Little is known about delayed postoperative hyponatremia (DPH) accompanied with transsphenoidal surgery for non-adenomatous skull base tumors (NASBTs). Consecutive data on 30 patients with parasellar NASBT was retrospectively reviewed with detailed analyses on perioperative serial sodium levels. Serological DPH (sodium ≤ 135 mmol/L) was observed in eight (27%), with four (13%) of them being symptomatic. DPH developed on postoperative day 7-12 where the mean sodium levels were 134 mmol/L (a mean of 7 mmol/L drop from the baseline) in asymptomatic and 125 mmol/L (a mean of 17.5 mmol/L drop from the baseline) in symptomatic DPH. Serological DPH was accompanied with "weight loss and hemoconcentration (cerebral salt wasting type)" in four (50%), "weight gain and hemodilution (syndrome of inappropriate antidiuretic hormone secretion type)" in three (38%), and no significant weight change in one. Intraoperative extradural retraction of the pituitary gland was the only significant factor for serological DPH (p = 0.035; odds ratio, 12.25 (95% confidence interval, 1.27-118.36)). DPH should be recognized as one of the significant postsurgical complications associated with TSS for NASBTs. Although the underlying mechanism is still controversial, intraoperative extradural compression of the pituitary gland and subsequent dysregulation of the hypothalamo-hypophyseal axis may be responsible.

Giant nasofrontal meningioma: endoscopic and transcranial approach followed by microvascularized vastus laterallis flap reconstruction

A 12-year-old girl presented with headache, nasal voice, and anosmia. Magnetic resonance imaging demonstrated a 11 × 9 × 8-cm tumor extending from the nasal cavity to the frontal lobes. Histological analysis was consistent with transitional meningioma WHO grade I. As far as we know, this is the first reported case of a giant olfactory groove meningioma invading the nasal cavity through the anterior cranial base. Complete surgical removal was accomplished with excellent result via a staged endoscopic and transcranial approach. A microvascularized vastus laterallis flap was used for reconstruction. Surgical options and technical details in the management of this lesion are reviewed.

Endoscopic Endonasal Removal of Primary/Recurrent Meningiomas in the Medial Optic Canal: Surgical Technique and Long-Term Visual Outcome

BACKGROUND

Tuberculum sellae meningiomas frequently extend into the optic canals, which leads to a progressive longitudinal visual loss. Therefore, in addition to tumor removal, unroofing and exploration inside the optic canal are important procedures.

OBJECTIVE

To perform endoscopic endonasal tumor removal with optic canal decompression for small primary or recurrent meningiomas associated with a progressive visual loss at the inferior-medial optic canal, which corresponded to a blind corner in the ipsilateral pterional/subfrontal approach.

METHODS

We retrospectively reviewed 2 cases of primary meningiomas that arose in the inferior-medial optic canal and 4 recurrent cases from the remnant inside the medial optic canal that had previously undergone craniotomy for tuberculum sellae meningiomas, and were treated by the endoscopic endonasal approach.

RESULTS

All tumors were detectable and could be removed without manipulation of the affected optic nerve. The average maximum diameter of the tumor was 8.4 mm (range: 5-12 mm). Two patients who had a long history of progressive visual disturbance and papillary atrophy did not recover from severe visual disturbances postoperatively. However, others showed considerable improvement, maintaining postoperative visual function during follow-up. There were no postoperative complications.

CONCLUSION

Endoscopic endonasal approach has several advantages for meningiomas in the medial optic canal and associated with progressive visual disturbance. In surgery of tuberculum sellae meningiomas, optic canal decompression and exploration inside the optic canal are important procedures to avoid symptomatic recurrence, which may be facilitated by the endoscopic endonasal approach. Papillary atrophy and duration of visual deterioration are predictive factors for postoperative visual outcomes.

[Transcranial microsurgical decompression of the optic canal in surgical treatment of meningiomas of the sellar region]

RATIONALE

When removing the meningiomas of the sellar region, there is always a risk of visual impairment for various reasons, in particular, as a result of traction damage to the optic nerve. Decompression of the optic canal increases nerve mobility during tumor manipulation. In cases of meningioma growing into the canal, its decompression often seems necessary.

AIM

Evaluation of the effectiveness and risks of performing decompression of the optic canal.

MATERIALS AND METHODS

The study included patients with meningiomas of the parasellar location, who underwent surgical treatment at the Burdenko Neurosurgical Center for the period from 2001 to 2017. They were divided into two groups - main and control. The main group consisted of 129 patients who underwent decompression of the optic nerve canals when the tumor was removed. The tumor matrix in this group was most often located in the region of the tuberum sellae, supradiaphragmally, in the region of the anterior clinoid process and the optic canal. In 31 cases, decompression was bilateral - during one operation and using one access in 27 patients; in 4 cases, the decompression of the second canal was delayed for 1.5-3 months after the first operation. 160 decompressions were performed by the intradural and 7 - by extradural methods. During intradural decompression, the roof of the optic canal was resected, and during extradural decompression, the lateral wall of the canal was trephined. The control group consisted of 308 patients who did not undergo canal decompression when the tumor was removed. It included meningiomas with a predominant location of the matrix in the area of the tuberclum and diaphragm of the sella. Tumors in both groups were removed according to the same principles (matrix coagulation, mainly the gradual removal of the tumor, the use of ultrasonic aspirator, a situational decision on the radicality of the operation, etc.). The main difference between operations in these two groups was only canal related algorithms (with or without its trepanation), as well as the probable prevalence of significant lateral tumor growth in cases with canal trepanation. Visual functions in the «primary» group were evaluated before and after operations with trepanation of the canal depending on various factors - the initial state of vision and the radicality of the tumor excision, including removal from the canal. The differences in the postoperative dynamics of vision in the main and control groups were studied. The primary data processing was carried out using the program MSExcel. Secondary statistical processing was carried out using the program Statistica. To assess the statistical significance of differences in the results obtained in the compared patient groups, the Chi-square test was used, and in the case of small groups - the exact Fisher test was applied.

RESULTS

In the main group postoperative vision improvement of varying degrees on the side of trepanation was registered in 36.9% (59 out of 160) cases, no vision changes were found in 36.9% (59 out of 160), and in 26,2% (42 out of 160) the eyesight deteriorated. If preserving vision is attributed to a satisfactory result, then in general the results of these operations should be considered good. A comparative study of the results of removal of meningiomas with trepanation of the canals (main group) or without it (control group) was carried out among patients with the most critical vision situation (visual acuity 0.1 and below, up to only light perception). These groups are comparable in the number of observations - 62 and 73 respectively. The predominance of cases with improved vision in the main group compared with the control group (50.0% versus 38.36%) and a lower incidence of vision impairment (22.58% versus 34.25%) were found. However, the revealed differences are statistically unreliable and make it possible for us to talk only about the trend. The complications associated with trepanation of the canal include mechanical damage to the nerve by the drill. In our series of observations, there was only 1 case of abrasion of the nerve surface with the burr, which did not lead to a significant visual impairment. With the intradural method of trepanation in the area of the medial wall of the canal, the sphenoid sinus may open (in our series, in 34 cases out of 160 trepanations). Immediately closure of these defects was performed by various auto- and allomaterials in various combinations (pericranium, fascia, muscle fragment, hemostatic materials, and fibrin-thrombin glue). A true complication - CSF rhinorrhea liquorrhea developed in only one case, which required transnasal plastic surgery of the CSF fistula using a mucoperiostal flap.

CONCLUSIONS

1. Trepanation of the optic canal in cases of meningiomas of parasellar localization is a relatively safe procedure in the hands of a trained neurosurgeon and does not worsen the results of operations compared with the excision of the same tumors without trepanation of the canal. 2. The literature data and the results of our study make it possible to consider the decompression of the optic canal as an optional, but in many cases, useful option that facilitates the transcranial removal of some meningiomas of the sellar region.

Anatomic Nuances of the Ophthalmic Artery Origin from a Ventral Viewpoint: Considerations and Implications for Endoscopic Endonasal Surgery

BACKGROUND

The origin of the ophthalmic artery is within the surgical field of endoscopic endonasal approaches (EEAs) to the suprasellar and parasellar regions. However, its anatomy from the endoscopic point-of-view has not been adequately elucidated.

OBJECTIVE

To highlight the anatomy of the ophthalmic artery origin from an endoscopic endonasal perspective.

METHODS

The origin of the ophthalmic artery was studied bilaterally under endoscopic visualization, after performing transplanum/transtubercular EEAs in 17 cadaveric specimens (34 arteries). Anatomic relationships relevant to surgery were evaluated. To complement the cadaveric findings, the ophthalmic artery origin was reviewed in 200 "normal" angiographic studies.

RESULTS

On the right side, 70.6% of ophthalmic arteries emerged from the superior aspect, while 17.6% and 11.8% emerged from the superomedial and superolateral aspects of the intradural internal carotid artery, respectively. On the left, 76.5%, 17.6%, and 5.9% of ophthalmic arteries emerged from the superior, superomedial, and superolateral aspects of the internal carotid, respectively. Similar findings were observed on angiography. All ophthalmic arteries emerged at the level of the medial opticocarotid recess. Overall, 47%, 26.5%, and 26.5% of ophthalmic arteries (right and left) were inferolateral, inferior, and inferomedial to the intracranial optic nerve segment, respectively. On both sides, the intracranial length of the ophthalmic artery ranged from 1.5 to 4.5 mm (mean: 2.90 ± standard deviation of 0.74 mm).

CONCLUSION

Awareness of the endoscopic nuances of the ophthalmic artery origin is paramount to minimize the risk of sight-threatening neurovascular injury during EEAs to the suprasellar and parasellar regions.

Imaging Analysis of Onodi Cells on Cone-Beam Computed Tomography

Introduction  Onodi cells are the most posterior ethmoid air cells, and extend superolaterally to the sphenoid sinus. The identification of Onodi cells is essential to because they can have some significant anatomic variations and relationships to vital adjacent structures, like the optic canal, the sphenoid sinus, and the internal carotid artery. Objective  The present study aimed to assess the prevalence of Onodi cells and their position with respect to sphenoid sinus. To the authors' best knowledge, this is the first study that uses cone-beam computed tomography (CBCT) to assess the prevalence and position of Onodi cells. Methods  We collected CBCT scan records from November 1st, 2016, to July 31st, 2017; the patients who fulfilled the eligibility criteria were included in the present study. The CBCT scans were reviewed by two independent observers. The descriptive statistics was performed using the Statistical Package for the Social Sciences (SPSS, SPSS, Inc., Chicago IL, US) software, version 17.0. A cross-tabulation of gender with the presence and position of Onodi cells was evaluated using the Chi-squared (χ ² ) test. The inter- and intraobserver agreements were evaluated using Kappa (κ) statistics. Results  Onodi cells were identified in 86 (42.8%) out of 201 patients. A subgroup analysis revealed that Onodi cells were present in 45 (43.3%) female and 41 (42.3%) male patients. The position of the Onodi cells was superior with respect to the sphenoid sinus in 43 (50%) of the patients, superolateral in 36 (41.9%), and lateral to the sphenoid sinus in 7 (8.1%) of the patients. Conclusion  The present study indicated a high prevalence of Onodi cells, with approximately equal distribution among males and females, and mostly superior in position in relation to the sphenoid sinus.

Interdural course of the ophthalmic artery in the optic canal

OBJECTIVE

In the current neurosurgical and anatomical literature, the intracanalicular segment of the ophthalmic artery (OphA) is usually described to be within the optic nerve dural sheath (ONDS), implying direct contact between the nerve and the artery inside the optic canal. In the present study, the authors sought to clarify the exact relationship between the OphA and ONDS.

METHODS

Ten cadaveric heads were subjected to endoscopic endonasal and transcranial exposures of the OphA in the optic canal (5 for each approach). The relationship between the OphA and ONDS was assessed. Histological examination of one specimen of the optic nerve and the accompanying OphA was also performed to confirm the relationship with the ONDS.

RESULTS

In all specimens, the OphA coursed between the two layers of the dura (endosteal and meningeal) and was not in direct contact with the optic nerve, except for the first few millimeters of the proximal optic canal before it pierced the ONDS. Upon reaching the orbit, the two layers of the dura separated and allowed the OphA to literally float within the orbital fat. The meningeal dura continued as the ONDS, whereas the endosteal dura became the periorbita.

CONCLUSIONS

This study clarifies the interdural course of the OphA within the optic canal. This anatomical nuance has important neurosurgical implications regarding safe exposure and manipulation of the OphA.

Relationship between pneumatization of lateral recess in the sphenoid sinus and removal of cavernous sinus invasion in pituitary adenomas by endoscopic endonasal surgery

Background:

Endoscopic endonasal transsphenoidal surgery (EES) is the gold standard for pituitary adenoma (PA) resection. The sphenoid sinus (SS), a highly variable anatomic structure, is located in the center of the cranial base. It has previously been reported that poor pneumatization of the lateral recess of the SS (LRSS) increases the difficulty level of the surgery and the risk of neural and vascular injury. However, to date no studies have evaluated the association between LRSS volume and PAs removal rate by EES.

Methods:

The present study analyzed 23 consecutive patients with new-onset PAs categorized as Knosp Grades 3 and 4 who underwent EES. A retrospective radiographic analysis was conducted on patients undergoing magnetic resonance imaging and high-resolution computed tomography scans.

Results:

Among PA cases categorized as Knosp 3 and 4, no significant association was found between the whole tumor’s resection rate and LRSS volume (R = 0.08, P = 0.70). However, a significant association was found between cavernous sinus (CS) tumors’ removal rate and LRSS volume (R = 0.52, P = 0.011). The same results were achieved in PAs with a Knosp Grade 4, with a stronger correlation (R = 0.60, P = 0.014).

Conclusion:

The development of LRSS pneumatization affects the removal rate of CS tumors in PAs. Preoperative analysis of LRSS development should be considered when planning EES against PA with CS invasion.

Transsphenoidal versus Transcranial Approach for Treatment of Tuberculum Sellae Meningiomas: A Systematic Review and Meta-analysis of Comparative Studies

There is controversy regarding the surgical route selection for tuberculum sellae meningiomas (TSMs): the transsphenoidal (TS) or transcranial (TC) approach? We conducted a systematic review and meta-analysis to compare clinical outcomes and postoperative complications between two surgical approaches. Literature search was performed. Relevant articles were selected and evaluated. Data were extracted and analyzed. Eight articles comprising 550 patients met the inclusion criteria. Traditionally, the rates of gross total resection, tumor recurrence, visual improvement, and cerebrospinal fluid leakage were the most common outcomes of interest. We demonstrated that the TS approach was significantly associated with better visual outcomes but more frequent cerebrospinal fluid leakage, while the rates of tumor resection and recurrence showed no significant difference between groups. In addition to surgical results that were consistent with previous studies, we further evaluated the impact of approach selection on common postoperative complications, which were closely related to the recovery course and quality of life. We revealed that the risk of dysosmia was significantly higher in the TS group. There was no significant difference between groups regarding infection, intracranial hemorrhage, and endocrine disorders. Because of the relatively low evidence levels of included retrospective studies, it was difficult to reach a categorical conclusion about the optimal surgical approach for TSMs. Finally, we recommended that the TS approach was an alternative option in patients with smaller TSMs (<30 mm) and limited invasion of optic canals in experienced neurosurgical centers.

Defining the lateral limits of the endoscopic endonasal transtuberculum transplanum approach: anatomical study with pertinent quantitative analysis

OBJECTIVE

The extended endoscopic endonasal transtuberculum transplanum approach is currently used for the surgical treatment of selected midline anterior skull base lesions. Nevertheless, the possibility of accessing the lateral aspects of the planum sphenoidale could represent a limitation for such an approach. To the authors' knowledge, a clear definition of the eventual anatomical boundaries has not been delineated. Hence, the present study aimed to detail and quantify the maximum amount of bone removal over the planum sphenoidale required via the endonasal pathway to achieve the most lateral extension of such a corridor and to evaluate the relative surgical freedom.

METHODS

Six human cadaveric heads were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. The laboratory rehearsals were run as follows: 1) preliminary predissection CT scans, 2) the endoscopic endonasal transtuberculum transplanum approach (lateral limit: medial optocarotid recess) followed by postdissection CT scans, 3) maximum lateral extension of the transtuberculum transplanum approach followed by postdissection CT scans, and 4) bone removal and surgical freedom analysis (a nonpaired Student t-test). A conventional subfrontal bilateral approach was used to evaluate, from above, the bone removal from the planum sphenoidale and the lateral limit of the endonasal route.

RESULTS

The endoscopic endonasal transtuberculum transplanum approach was extended at its maximum lateral aspect in the lateral portion of the anterior skull base, removing the bone above the optic prominence, that is, the medial portion of the lesser sphenoid wing, including the anterior clinoid process. As expected, a greater bone removal volume was obtained compared with the approach when bone removal is limited to the medial optocarotid recess (average 533.45 vs 296.07 mm2; p < 0.01). The anteroposterior diameter was an average of 8.1 vs 15.78 mm, and the laterolateral diameter was an average of 18.77 vs 44.54 mm (p < 0.01). The neurovascular contents of this area were exposed up to the insular segment of the middle cerebral artery. The surgical freedom analysis revealed a possible increased lateral maneuverability of instruments inserted in the contralateral nostril compared with a midline target (average 384.11 vs 235.31 mm2; p < 0.05).

CONCLUSIONS

Bone removal from the medial aspect of the lesser sphenoid wing, including the anterior clinoid process, may increase the exposure and surgical freedom of the extended endoscopic endonasal transtuberculum transplanum approach over the lateral segment of the anterior skull base. Although this study represents a preliminary anatomical investigation, it could be useful to refine the indications and limitations of the endoscopic endonasal corridor for the surgical management of skull base lesions involving the lateral portion of the planum sphenoidale.

Cranial nerve monitoring in endoscopic endonasal surgery of skull base tumors (observing of 23 cases)

Background

Preservation of anatomic integrity and function of the cranial nerves during the removal of skull base tumors is one of the most challenging procedures in endoscopic endonasal surgery. It is possible to use intraoperative mapping and identification of the cranial nerves in order to facilitate their preservation.

The purpose of this study was to evaluate the effectiveness of intraoperative trigger electromyography in prevention of iatrogenic damage to the cranial nerves.

Methods

Twenty three patients with various skull base tumors (chordomas, neuromas, pituitary adenomas, meningiomas, cholesteatomas) underwent mapping and identification of cranial nerves during tumor removal using the endoscopic endonasal approach in Department of Neurooncology of Federal State Autonomous Institution “N.N. Burdenko National Medical Research Center of Neurosurgery” of the Ministry of Health of the Russian Federation from 2013 to 2018. During the surgical interventions, mapping and identification of the cranial nerves were carried out using electromyography in triggered mode. The effectiveness of the method was evaluated based on a comparison with a control group (41 patients).

Results

In the main group of patients, 44 nerves were examined during surgery using triggered electromyography. During the study, the III, V, VI, VII, and XII cranial nerves were identified intraoperatively. Postoperative cranial nerve deficiency was observed in 5 patients in the study group and in 13 patients in the control group. The average length of hospitalization was 9 days.

Conclusion

We did not receive statistically significant data supporting the fact that intraoperative identification of cranial nerves using trigger electromyography reduces the incidence of postoperative complications in the form of cranial nerve deficits (p = 0.56), but the odds ratio (0.6) suggests a less frequent occurrence of complications in the study group.

Based on our experience, the trigger electromyography methodology appears quite promising and requires further research.

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.

Contralateral Transcranial Approach to Tuberculum Sellae Meningiomas: Long-Term Visual Outcomes and Recurrence Rates

BACKGROUND

One of the most challenging aspects of the surgical treatment of tuberculum sellae meningioma is to control the involvement of the inferomedial side of the optic nerve, which is not directly visualized by an ipsilateral approach and thus requires optic nerve mobilization.

METHODS

Between 2003 and 2017, 21 consecutive patients were operated on using this approach. The surgical technique is described and the visual outcomes, resection and recurrence rates, and complications are analyzed.

RESULTS

Twenty patients were included, with a median follow-up of 5.6 years. Regarding visual outcomes, among the 19 patients who had a visual impairment before surgery, 14 (74%) improved, 2 were stabilized (10%), and 2 (10%) showed a worsening of the most-compromised optic nerve and 1 (5%) of the less-compromised optic nerve. Gross total resection was achieved in 18 patients (90%) and 1 patient experienced recurrence 10 years after the initial surgery.

CONCLUSIONS

This approach allowed lower mobilization of the compromised optic nerve, better preservation of the vascularization of the visual pathways, and direct access to the inferomedial side of the optic nerve.

[Base of the skull meningioma: Efficacy, clinical tolerance and radiological evaluation after radiotherapy]

Skull base meningioma leads to functional disturbances, which can significantly alter the quality of life. The optimal management of these lesions, whose goals are neurological preservation and tumour local control, is not yet clearly established. It is widely recognized that the goal of a radical excision should be abandoned despite the advances in the field of microsurgery of skull base lesions. Although less morbid, partial tumour excision would be associated with increased risk of local tumour recurrence. Although discussed both exclusive and adjuvant have proven to be highly successful in terms of clinical improvement and local control. Various radiation techniques have demonstrated their efficacy in the management of this pathology. However, high rates of clinical improvement are in contrast with low rates of radiological improvement. The notion of clinical and radiological dissociation appeared. However, in most of these studies, the analysis of the radiological response could be subject of legitimate criticism. This work proposes to review the local control, the efficacy and the clinical tolerance and the radiological response of the various radiation techniques for the meningioma of the base of the skull and to demonstrate the interest of quantitative volumetric analyses in the follow-up of meningioma after radiotherapy.

Endoscopic Transnasal Resection of Solitary Fibrous Tumor in the Optic Canal

BACKGROUND

Tumors extending into the optic canal can cause progressive visual impairment because of optic nerve compression. Prompt surgical resection is often necessary. When the tumor is located medially in the optic canal, endoscopic transnasal surgery provides a safer, less invasive alternative to a transcranial approach.

CASE DESCRIPTION

We recently encountered a case of small solitary fibrous tumor in the optic canal causing rapid visual deterioration. The radiographic findings of preoperative imaging studies were compatible with those of meningioma; however, unlike meningioma, bleeding from the tumor was profuse during the operation. The endoscopic transnasal approach was effective for handling the highly vascularized tumor in this delicate region, and gross total removal was achieved with postoperative gradual improvement in his visual function. Nevertheless, the tumor recurred after 6 months, and re-resection was performed using the same surgical corridor, followed by adjuvant radiotherapy.

CONCLUSIONS

Endoscopic transnasal surgery is a valuable option for aggressive lesions in the optic canal. Although the efficacy of radiotherapy for solitary fibrous tumor remains controversial, it should be considered when the tumor shows progressive features.

Neuro-endoscope for skull base tumors

The endoscope has traditionally been used in neurosurgery to access a lesion within a natural body cavity. The challenge has been to access and resect deep-seated intraparenchymal lesions using a minimally invasive endoscopic technique. Endoscopic endonasal trans-sphenoidal surgery has gained increasing acceptance by otolaryngologists and neurosurgeons. Surgical procedures of the skull base include exposure, resection, and base reconstruction. These approaches start at the sphenoid sinus, which provides a reference point to important vascular and neural structures. The endoscopic endonasal approach is optimal in paramedian ventral skull base tumors, allowing wide access to the ventral skull base regions and allowing early devascularization of the tumor without retraction of the brain. Limited exposure results in limited "injury" to surrounding tissue and consequently reduced post-operative pain, a shorter length of hospital stay, a reduction in the time to return to work, and decreased overall cost.

Extent of Surgery in Endoscopic Transsphenoidal Skull Base Approaches and the Effects on Sinonasal Morbidity

Background

Endoscopic transsphenoidal skull base surgery (ETSS) is now considered the criterion standard approach for resection of pituitary adenomas and other midline anterior skull base lesions. Normal sinonasal structures are resected during ETSS, which raises concerns for nasal morbidity and patient-based outcome.

Objective

To perform a surgical outcome assessment by examining whether the extent of ETSS approaches affected patient-specific sinonasal quality of life as measured by the 22-item Sino-Nasal Outcome Test (SNOT-22).

Methods

A single-center prospective cohort study of patients operated on by the same skull base team between 2012 and 2016. Patients with completed pre- and postoperative SNOT-22 were included. The primary outcome was SNOT-22 scores at preoperative, 0–1 month, 2–4 months, >5 months follow-up. Age, sex, tumor pathology, surgical procedure, and intraoperative cerebral spinal fluid leak repair were also obtained.

Results

Of the 249 ETSS performed, 148 patients (59%) had at least one completed SNOT-22; 45 (18%) met the inclusion criteria. Sinonasal quality of life based on SNOT-22 at the 0–1-month follow-up was significantly worse than the presurgical levels (p < 0.05). However, there was a return of SNOT-22 scores to preoperative levels at 2–4 months (p > 0.05), which was sustained at >5 months (p > 0.05). Factors such as the extent of ETSS, a previous nasal surgery, repair of an intraoperative cerebral spinal fluid leak, and the tumor pathology did not affect SNOT-22 scores at any follow-up intervals (p > 0.05).

Conclusion

Sinonasal quality of life worsened after ETSS at 0–1 month follow-up but returned to preoperative levels at 2–4 months and remained at postoperative levels >5 months. Analysis of these data will allow us to educate our patients that the anticipated nasal morbidity after ETSS is usually only transient and should be expected to recover to preoperative levels.

Outcomes After Transcranial and Endoscopic Endonasal Approach for Tuberculum Meningiomas-A Retrospective Comparison

BACKGROUND

Degree of resection and visual outcome are the main concerns in the surgical resection of tuberculum sellae meningioma (TSM). In addition to the transcranial approach (TCA), the endoscopic endonasal approach (EEA) has been used increasingly. However, the controversy regarding the optimal surgical approach is not clearly resolved.

METHODS

We compared the surgical outcomes of each approach for TSMs from 44 patients receiving EEA and 40 patients receiving TCA in 2 institutions between 2004 and 2015. We analyzed the surgical outcomes and affecting factors for the relapse of tumor and visual outcome.

RESULTS

Gross total resection rates and relapse-free survival were not different between the 2 groups; however, the locations of residual or recurred tumor definitely differed. All recurrences in the TCA group were in the sella turcica, whereas residual tumors in EEA group were mainly located at lateral or superior to the clinoid process. The complete or partial improvement rate of visual function in the EEA group was 97.7%, but 9 patients (23.7%) in the TCA group experienced visual deterioration after surgery. EEA and younger age (<55 years) were associated with favorable visual outcome. Cerebrospinal fluid leakage occurred in only one case in the EEA group.

CONCLUSIONS

Surgical approaches do not affect the gross total resection rates, but the locations of residual tumor or recurrence differ according to surgical approaches. EEA is superior to TCA in visual outcome. At least in pure TSMs, the trend seems to be shifting in favor of EEA, considering the huge difference in visual outcome.

The extended, transnasal, transsphenoidal approach for anterior skull base meningioma: considerations in patient selection

PURPOSE

In this study, we set out to define our institutional criteria for patient eligibility for transsphenoidal resection of parasellar meningiomas, and to report our experience with extended transnasal approaches for these lesions. We aimed to discuss the important considerations of patient selection and risk stratification to optimize outcomes for patients with these difficult lesions, and also include considerations that should be reviewed during surgical approach selection.

METHODS

Medical records from Brigham and Women's Hospital were retrospectively reviewed for all patients who underwent transsphenoidal surgery for pituitary disease with the senior author from April 2008 to March 2017 (938 procedures). Patients undergoing surgery for anterior skull base meningioma were identified and patient data were collected.

RESULTS

Seven patients (four women, three men) underwent transsphenoidal resection (five endoscopic, one microscopic, and one hybrid endoscopic/microscopic) of pathologically-confirmed anterior skull base meningiomas during the study period. Five patients presented with visual field deficits, three presented with headache, two presented with hypopituitarism, and one woman presented with infertility. The median maximum tumor diameter was 1.7 cm (range 1.4-4.2 cm). Six patients underwent subtotal resection, and one underwent gross total resection. The median MIB-1 index was 2.3 (range 1.0-7.6). Complications included two readmissions (one on POD11 for small bowel obstruction, one on POD48 for epistaxis), and the development of new onset thyroid deficiency and transient diabetes insipidus in one patient. Two patients had reoperations by craniotomy for tumor recurrence after 5 and 6 years, respectively.

CONCLUSIONS

Although more commonly treated transcranially, anterior skull base meningiomas are sometimes amenable to resection transphenoidally. Patient selection is critical, and multiple factors, including tumor size, consistency, and location, patient and surgeon preference, and presenting symptoms each affect the optimum surgical approach. We have developed criteria for patient selection so that transsphenoidal surgery can be used to resect or debulk anterior skull base meningiomas safely and with favorable outcomes.

Pituitary Macroadenoma and Visual Impairment: Postoperative Outcome Prediction with Contrast-Enhanced FIESTA

BACKGROUND AND PURPOSE

Contrast-enhanced FIESTA can depict anterior optic pathways in patients with large suprasellar tumors. We assessed whether the degree of kink in the optic nerve at the optic canal orifice on contrast-enhanced FIESTA correlates with the postoperative improvement of visual impairment in patients with pituitary macroadenoma.

MATERIALS AND METHODS

Thirty-one patients with pituitary macroadenoma who underwent preoperative MR imaging and an operation were evaluated. We measured the optic nerve kinking angle on sagittal oblique contrast-enhanced FIESTA parallel to the optic nerve; the optic nerve kinking angle was defined as the angle between a line parallel to the planum sphenoidale and a line parallel to the intracranial optic nerve at the optic canal orifice. We used logistic regression analyses to determine whether the clinical (sex, age, and duration of symptoms) and imaging (tumor height, chiasmal compression severity, hyperintense optic nerve on T2WI, and optic nerve kinking angle) characteristics were associated with the postoperative improvement (good-versus-little improvement) of visual acuity disturbance and visual field defect.

RESULTS

There were 53 impaired sides before the operation: 2 sides with visual acuity disturbance alone, 25 with visual field defect alone, and 26 with both. After the operation, good improvement was found in 17 of the 28 sides with visual acuity disturbance and in 32 of the 51 sides with visual field defects. Only the optic nerve kinking angle was significantly associated with good improvement of the visual acuity disturbance (P = .011) and visual field defect (P = .002).

CONCLUSIONS

The degree of the optic nerve kinking angle was an independent predictor of postoperative improvement, indicating that irreversible damage to the optic nerve may be associated with its kinking at the optic canal orifice.

Prechiasmatic sulcus and optic strut: an anatomic study in dry skulls

BACKGROUND

Although safe surgical access to the cavernous sinus is related to understanding the anatomical and ethnic variants of the prechiasmatic sulcus and the optic strut, there remains a paucity of studies of the morphology and the bony relationships in the region. The present study provides a systematic morphological and morphometric analysis of the sulcal region and the optic strut anatomy and their relations in a Greek population.

METHODS

The interoptic distance, length of planum sphenoidale, sulcal length and sulcal angle was determined in 96 Greek adult dry skulls. The prechiasmatic sulci and optic struts were morphologically classified and association of sulcal region measures according to type of prechiasmatic sulcus and optic strut were examined.

RESULTS

Mean interoptic distance was 1.69 ± 0.25 cm; sulcal length, 0.72 ± 0.18 cm; length of planum sphenoidale, 1.86 ± 0.32 cm; sulcal angle, 24.05 ± 17.17°. The sulcal angle was significantly smaller in female skulls compared to males (14.82 ± 12.43 vs 28.29 ± 15.24; p < 0.05). Type I (narrow, steep) prechiasmatic sulci were the most commonly observed (35.8%), followed by Type IV (wide, flat) (32.1%), Type II (narrow, flat) (18.5%) and, finally, Type III (wide, steep) sulci (13.6%). The optic strut was presulcal in 8.3% of specimens, sulcal in 31%, postsulcal in 41.7% and asymmetric in 19%.

CONCLUSIONS

The present study augments the current knowledge of the morphology of key anatomical landmarks, prechiasmatic sulcus and the optic strut, for cavernous sinus surgery and indicates population and gender differences. We report significant anatomical variations in the prechiasmatic sulcus, optic strut and surrounding structures. In addition to providing a better understanding of the anatomical landmarks, necessary for the safe navigation in transcranial and endoscopic procedures, the present results also suggest that surgeons must consider population differences in determining the anatomical landmarks and navigation points in the sellar region.

A Retrospective Analysis of Vision-Impairing Tumors Among 467 Patients with Neurofibromatosis Type 2

BACKGROUND

Vision is important for patients with hearing loss caused by neurofibromatosis type 2 (NF2). Tumors adjacent to the anterior visual pathway can potentially impair the vision. Only a few case reports and small-series studies have been reported.

OBJECTIVE

To evaluate the clinical features of tumors adjacent to the anterior visual pathway in a large series of patients with NF2.

METHODS

Seventy-three patients with potentially vision-impairing tumors were carefully screened from among 467 patients with NF2.

RESULTS

Among the 73 patients, 31 had intraorbital tumors, 21 had suprasellar meningiomas, and 21 had medial sphenoid ridge meningiomas. Of the 31 patients with intraorbital tumors, 17 had optic nerve sheath meningiomas, 9 had intraorbital schwannomas, 3 had spheno-orbital meningiomas, 1 had an anterior cranial fossa-orbital meningioma, and 1 had a cranio-orbital schwannoma. To the date of the last follow-up, 43 patients (58.9%) experienced visual loss. In most cases, hearing loss tended to occur earlier than visual loss. Six patients underwent early operations, and they recovered well without any further vision damage. Six other patients underwent operations after having no functional visual ability in the affected eyes, and their visual ability was not saved.

CONCLUSIONS

Tumors adjacent to the anterior visual pathway, although uncommon in patients with NF2, can cause progressive visual loss. Early surgical intervention seems to be the primary treatment strategy, except for in patients' optic nerve sheath meningiomas. If patients adopt a wait and see policy, regular visual examination seems to be mandatory.

An Overview of Anterior Skull Base Meningiomas and the Endoscopic Endonasal Approach

Meningiomas represent 30% of all primary brain tumors. Anterior skull base meningiomas represent 8.8% of all meningiomas. Surgical resection is a main treatment option for tumors that are symptomatic and/or growing. Recurrence is directly related to the extent of resection of the tumor, the dural attachment, and pathologic bone. Endoscopic endonasal approaches represent an important addition to the treatment armamentarium for skull base meningiomas. This article provides an overview of meningiomas, with a focus on those of the anterior skull base and their management.

Cerebrospinal fluid leaks in extended endoscopic transsphenoidal surgery: covering all the angles

Following extended endoscopic transsphenoidal approach (EETSA), cerebrospinal fluid (CSF) leak rate has been reported in the range of 5-50 %. Novel closure techniques, such as the nasoseptal flap and other multilayered repairs improved the outcomes significantly but took most of our focus. Little attention, however, was given to other aspects of the equation such as nasal support-to support the heavy weight of such repairs-and lumbar drains. These are important because they diminish the forces acting on both sides of the repair, hence covering all the angles. We reviewed data of 98 consecutive patients who underwent an EETSA between 1999 and 2014. We analyzed the rates of CSF leak throughout the years and with every modification added to our closure technique. Common pathologies encountered were invasive adenomas, meningiomas, chordomas, and craniopharyngiomas. CSF leak occurred overall in five patients (5.1 %). The nasoseptal flap decreased the rate of CSF leak but not significantly (P = 0.112), while placing a nasal trumpet to support our repair resulted in significant decrease in CSF leak rate (P = 0.0013). In the last 2 years of our series, when all modifications took place and all angles were covered, there was one leak in 35 cases (2.8 %). A protocol that covers all the angles by a good multilayered repair (regardless of its type and materials) while diminishing the forces acting on both sides of the repair leads to a minimal rate of CSF leak. No principle alone is effective individually.

Endoscopic transnasal surgery for planum and tuberculum sella meningiomas: decision-making, technique and outcomes

Tuberculum sella and planum sphenoidale meningiomas pose a management challenge given their intimate relationship to surrounding critical neurovascular structures. The development and advancement of expanded endoscopic transnasal surgery has provided a good surgical option that in well-selected cases, may provide several advantages over a transcranial route. These include early devascularization, complete dura and bone removal, elimination of brain retraction and enhanced visualization of the optic apparatus perforating vessels. The authors review the endoscopic transnasal approach to these tumors and discuss surgical decision-making and case selection, surgical technique and outcomes. We also discuss the expanding role of stereotactic radiosurgery and fractionated stereotactic radiotherapy for these challenging lesions.

Endoscopic Endonasal Approach to the Optic Canal: Anatomic Considerations and Surgical Relevance

BACKGROUND

Increasing use of endoscopic endonasal surgery for suprasellar lesions with extension into the optic canal (OC) has necessitated a better endonasal description of the OC.

OBJECTIVE

To identify the osseous OC transcranially and then investigate its anatomic relationship to the key endonasal intrasphenoidal landmarks. We also aimed to determine and describe the technical nuances for safely opening the falciform ligament and intracanalicular dura (surrounding the optic nerve [ON]) endonasally.

METHODS

Ten fresh human head silicon-injected specimens underwent an endoscopic transtuberculum/transplanum approach followed by 2-piece orbitozygomatic craniotomy to allow identification of 20 OCs. After completing up to 270° of endonasal bony decompression of the OC, a dural incision started at the sella and continued superiorly across the superior intercavernous sinus. Subsequently the dural opening was extended anterolaterally across the dura of the prechiasmatic sulcus, limbus sphenoidale, and planum.

RESULTS

Endonasally, the length of the osseous OC was approximately 6 mm and equivalent to the length of the lateral opticocarotid recess, as measured anteroposteriorly. The ophthalmic artery arose from the supraclinoidal carotid artery at approximately 2.5 mm from the medial osseous OC entrance. Transcranial correlation of the endonasal dural incision confirmed medial detachment of the falciform ligament and exposure of the preforaminal ON.

CONCLUSION

The lateral opticocarotid recess allows distinction of the preforaminal ON, roofed by the falciform ligament from the intracanalicular segment in the osseous OC. This facilitates the preoperative surgical strategy regarding the extent of OC decompression and dural opening. Extensive endonasal decompression of the OC and division of the falciform ligament is feasible.

Frontobasal Midline Meningiomas: Is It Right To Shed Doubt on the Transcranial Approaches? Updates and Review of the Literature

BACKGROUND

Traditionally, the surgical removal of tuberculum sellae meningioma (TSM) and olfactory groove meningioma (OGM) requires transcranial approaches and microsurgical techniques, but in the last decade endoscopic expanded endonasal approaches have been introduced: transcribriform for OGMs and transtuberculum-transplanum for TSM. A comparative analysis of the literature concerning the two types of surgical treatment of OGMs and TSM is, however, difficult.

METHODS

We conducted a literature search using the PubMed database to compare data for endoscopic and microsurgical techniques in the literature. We also conducted a retrospective analysis of selected cases from our series presenting favorable characteristics for an endoscopic approach, based on the criteria of operability of these lesions as generally accepted in the literature, and we compared the results obtained in these patients with those in the endoscopic literature.

RESULTS

We believe that making the sample more homogeneous, the difference between microsurgical technique and endoscopic technique is no longer so striking. A greater radical removal rate, a reduced incidence of cerebrospinal fluid fistula and, especially, the possibility of removing lesions of any size are advantages of transcranial surgery; a higher percentage of improvement in visual outcome and a lower risk of a worsening of a pre-existing deficit or onset of a new deficit are advantages of the endoscopic technique.

CONCLUSION

At present, the microsurgical technique is still the gold standard for the removal of the anterior cranial fossa meningiomas of all sizes, and the endoscopic technique remains a second option in certain cases.

Current Status of Endoscopic Endonasal Surgery for Skull Base Meningiomas: Review of the Literature

Endoscopic endonasal approach (EEA) is expected to be ideal for the paramedian ventral skull base meningiomas, allowing wide access to the ventral skull base regions and realizing early devascularization of the tumor without retraction of the brain. We searched clinical reports of EEA for skull base meningiomas, written in English language, published before October 2014, using the PubMed literature search on the website. Skull base meningiomas are subdivided by the site of occurrence, olfactory groove (8 articles including 80 cases), tuberculum sellae (14 articles, 153 cases), cavernous sinus (2 articles, 8 cases), petroclival region (4 articles, 10 cases), and craniofacial region (2 articles, 5 cases), and the surgical outcomes of EEA were analyzed. In anterior skull base regions, EEA contributed to effective improvement of the symptoms in small and round-shaped meningiomas, but 25% of the patients had postoperative cerebrospinal fluid rhinorrhea. In cavernous sinus and petroclival regions, successful surgical removal largely depended on tumor consistency, and the extent of the surgical resection proportionally increased the risks of serious complications. Thus, judicious endoscopic resection with adjuvant radiotherapy or radiosurgery remains to be the most reasonable treatment option. To decrease the risks of surgical complications, the surgeons must master the closure techniques of dural defect and meticulous microsurgical procedure under endoscopic vision. Further progress will depend on the progresses of surgical technique in neurosurgeons engaging this potentially “minimally invasive” surgery.

Endoscopic endonasal optic nerve and orbital apex decompression for nontraumatic optic neuropathy: surgical nuances and review of the literature

OBJECT

While several approaches have been described for optic nerve decompression, the endoscopic endonasal route is gaining favor because it provides excellent exposure of the optic canal and the orbital apex in a minimally invasive manner. Very few studies have detailed the experience with nontraumatic optic nerve decompressions, whereas traumatic cases have been widely documented. Herein, the authors describe their preliminary experience with endoscopic endonasal decompression for nontraumatic optic neuropathies (NONs) to determine the procedure's efficacy and delineate its potential indications and limits.

METHODS

The medical reports of patients who had undergone endoscopic endonasal optic nerve and orbital apex decompression for NONs at the Lyon University Neurosurgical Hospital in the period from January 2012 to March 2014 were reviewed. For all cases, clinical and imaging data on the underlying pathology and the patient, including demographics, preoperative and 6-month postoperative ophthalmological assessment results, symptom duration, operative details with video debriefing, as well as the immediate and delayed postoperative course, were collected from the medical records.

RESULTS

Eleven patients underwent endoscopic endonasal decompression for NON in the multidisciplinary skull base surgery unit of the Lyon University Neurosurgical Hospital during the 27-month study period. The mean patient age was 53.4 years, and there was a clear female predominance (8 females and 3 males). Among the underlying pathologies were 4 sphenoorbital meningiomas (36%), 3 optic nerve meningiomas (27%), and 1 each of trigeminal neuroma (9%), orbital apex meningioma (9%), ossifying fibroma (9%), and inflammatory pseudotumor of the orbit (9%). Fifty-four percent of the patients had improved visual acuity at the 6-month follow-up. Only 1 patient whose sphenoorbital meningioma had been treated at the optic nerve atrophy stage continued to worsen despite surgical decompression. The 2 patients presenting with preoperative papilledema totally recovered. One case of postoperative epistaxis was successfully treated using balloon inflation, and 1 case of air swelling of the orbit spontaneously resolved.

CONCLUSIONS

Endoscopic endonasal optic nerve decompression is a safe, effective, and minimally invasive technique affording the restoration of visual function in patients with nontraumatic compressive processes of the orbital apex and optic nerve. The timing of decompression remains crucial, and patients should undergo such a procedure early in the disease course before optic atrophy.

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. Tuberculum sellae meningiomas may be safely and effectively resected through the endonasal route; invasion of the optic canals does not represent a limitation.

Fascia patchwork closure for endoscopic endonasal skull base surgery

With the development of endoscopic technology and surgery, resection of midline skull base tumors has been achieved using endoscopic endonasal skull base (EESB) approaches. EESB approaches reportedly have a greater risk of postoperative cerebrospinal fluid (CSF) leakage. Recently, the introduction of the nasoseptal flap (NSF) decreased dramatically the incidence of CSF leakage, but the use of an NSF increases the risk of disturbing the function of the nose. Here, we report our new technique called "fascia patchwork closure" for closure after EESB surgery and its outcome. All 48 cases involved midline skull base tumors resected via EESB approaches. Of them, 32 cases were closed by the fascia patchwork technique after tumor resection, and there was no incidence of CSF leakage. Moreover, 6 of the 32 cases were closed without the use of an NSF, indicating that the fascia patchwork closure approach is effective as part of a multilayer closure for the prevention of CSF leakage. The establishment and popularization of this technique might result in the further development of EESB surgery and also an improvement of postoperative nasal function.

Endoscopic endonasal skull base surgery: advantages, limitations, and our techniques to overcome cerebrospinal fluid leakage: technical note

In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques.

Meningiomas of the pediatric skull base: a review

Pediatric skull base meningiomas are rare and complex clinical entities. Meningioma is a relatively uncommon brain tumor in children, and only ∼ 27% involve the skull base. Some evidence suggests that these tumors are more likely to be atypical or malignant in children than adults. The absence of female preponderance in pediatric meningiomas is reflected in the skull base subpopulation. Skull base meningiomas in children are most likely to be found in the anterior or middle fossa base, or involving the orbit and optic nerve sheath. Petroclival, suprasellar/parasellar, cerebellopontine angle, cavernous sinus, and foramen magnum tumors are very rare. Meningiomas constitute a small proportion of reported cases of pediatric skull base pathology, and they are entirely absent from many case series. Initial gross total resection is consistently associated with superior outcomes. Surgical approaches to the pediatric skull base must take additional factors into consideration including relatively smaller anatomy, immature dentition, incompletely aerated sinuses and air cells, and altered configurations of structures such as the pterional bony complex. Multidisciplinary expertise is essential to optimizing treatment outcomes.