Trans-sinusal frontal approach for olfactory groove meningiomas

Modified Trans-Sinusal Transglabellar Approach for Anterior Cranial Fossa Meningiomas: Technical Note and Literature Review

Introduction  Currently, skull base surgery faces the dilemma of achieving the maximum possible tumor resection through less aggressive approaches and with minimal retraction of brain tissue. The objective of this work is to report a minimally invasive step-by-step approach to anterior cranial fossa tumors and to perform a literature review. Methods  In our work, we describe a step-by-step approach, with images, which is a variation of the transglabellar approach. Results  In all cases, we achieved maximum total resection of the lesion. There were no postoperative complications related to the surgery. In one case, we used the access to remove a foreign body in the frontal lobe. Conclusion  The frontal trans-sinusal transglabellar access allows direct access to anterior cranial fossa tumors and other frontal lobe lesions close to the floor of the anterior fossa, without the need for brain retraction, allowing early devascularization of the tumor. However, this access is not recommended for all types of tumors, and is being improved for more anteriorly located lesions.

Lateral supraorbital approach for resection of large and giant olfactory groove meningiomas: a single center experience

BACKGROUND

The lateral supraorbital approach (LSO) provides an optimal access corridor for various skull bases lesions, including olfactory groove meningiomas (OGMs). The aim of this study is to describe the authors' experience with the management of large and giant OGMs utilizing the LSO approach and describe the technical nuances of the procedure.

METHODS

A retrospective review of seven patients with large and giant OGMs managed with the LSO approach between 2013 and 2019 was performed. Radiographic and clinical data were recorded and analyzed.

RESULTS

Seven patients with large and giant OGMs underwent surgical resection via the LSO approach. Six patients were female, with a median age of 56 years. Patients commonly presented with altered mentation, anosmia, and headaches. The average tumor volume was 120.6 ± 64.7 cm³ with five cases of vascular encasement. Simpson grade II resection was achieved in four patients while Simpson grade IV resection was achieved in three patients. The median length of stay was 2.0 days. The median preoperative Karnofsky Performance Scale (KPS) score was 70, improving to 100 at last postoperative follow-up visit. Two complications were encountered in the form of postoperative cerebrospinal fluid leak in one patient and a transient diplopia in another patient. Tumor recurrence/progression was identified in two patients during a median follow-up time of 65.5 months. Both cases have been managed with adjuvant radiosurgery.

CONCLUSION

The LSO approach is a safe and effective minimally invasive transcranial corridor for the management of OGMs that should be part of the armamentarium of skull base neurosurgeons.

Olfactory Groove Meningiomas: Comprehensive assessment between the different microsurgical transcranial approaches and the Endoscopic Endonasal Approaches, systematic review and metanalysis on behalf of the EANS skull base section

•OGM surgery is much more complex than a simple debate of "from above or from below" (transcranial vs endoscopic).•Lateral Sub-frontal and Superior Interhemispheric seem the most effective, superior and versatile approaches for OGM.•Minimally Invasive Transcranial approaches showed no inferiority in OGM sized <4 ​cm.•Endoscopic Endonasal Approaches showed inferior results in surgical and in functional outcomes for OGM.

Classification of crista galli pneumatization and clinical considerations for anterior skull base surgery

Cerebrospinal fluid (CSF) leakage caused by frontal sinus exposure is a serious complication in the basal interhemispheric approach (BIHA). Crista galli pneumatization (CGP) is often observed on preoperative computed tomography (CT) scan. The aim of this study was to classify and describe variations in anatomical measurements of CGP. We examined CT images of 300 patients with brain tumors to assess the morphology and incidence of CGP. Crista galli were classified according to their location relative to the cribriform plate and the presence of pneumatization. The paranasal sinuses were investigated as the origin of CGP. We assessed 24 patients using the BIHA for skull base tumors; these patients were included as clinical cases to assess the range of skeletonization of the crista galli and determine the route of CSF leakage in the other 276 patients. CGP was found in 28/300 CT scans, including upper, middle, and lower type CGPs. The origin of CGPs was the frontal sinus or ethmoid sinus. All CGPs were localized in the anterior half of the crista galli. In the 24 consecutive clinical cases, there were 13 tuberculum sellae meningiomas, 3 craniopharyngiomas, and 8 with other pathologies. The preoperative crista galli height was 12.3 mm and the distance from the top of the skeletonization to the cribriform plate was 5.2 mm. CGP originating from the paranasal sinuses can lead to CSF leakage. In cases where CGP originates from the ethmoid sinus, care should be taken to seal the exposed crista galli intradurally.

Small Extended Bifrontal Approach for Midline Anterior Skull Base Meningiomas: Our Experience with 54 Consecutive Patients

OBJECTIVE

To describe the technique of a small extended bifrontal approach and review the clinical outcome of patients with midline anterior skull base (MASB) meningiomas treated using this technique.

METHODS

The small extended bifrontal craniotomy extends inferiorly to the nasofrontal suture without entering the orbit, superiorly 3 cm above the supraorbital rim, and laterally 3 cm to the midline on both sides. A review of a prospectively acquired database was performed of 54 consecutive patients with MASB meningiomas who underwent this craniotomy.

RESULTS

Twenty-nine patients with olfactory groove meningiomas, 2 with planum sphenoidale meningiomas (PSMs), and 23 with tuberculum sellae meningiomas (TSMs) were treated using this technique. Gross total resection was achieved in all patients. Of 29 patients with olfactory groove meningiomas, 12 (41.4%) had normal olfaction at presentation and 8 had preservation of olfaction postoperatively. Of 25 patients with TSMs/PSMs, 23 (92.0%) had preoperative visual impairment, with 13 showing improved vision (56.5%), 8 unchanging (34.8%), and 2 deteriorating (8.7%) after surgery. The most common complications were anosmia and hyposmia, which occurred in 5 patients (20.0%) and 3 patients (12.0%) with TSMs/PSMs, respectively. No mortality was reported. There was no recurrence in all patients after a mean follow-up of 39.5 months (range, 16-64 months).

CONCLUSIONS

The small extended bifrontal approach is a safe and effective technique for resection of MASB meningiomas, which provides adequate surgical exposure with less approach-related morbidity. It is an excellent alternative for surgeons who favor the bifrontal approach and its extended variations.

[Choosing an anterior midline approach to skull base tumors]

The purpose of this review is to analyze used anterior midline approaches to the skull base, identify their advantages and disadvantages, and, after reviewing the literature data, submit a developed algorithm for choosing an optimal approach to the approval of colleagues. We provide brief information on approach techniques, indications and contraindications, and advantages and disadvantages as well as analyze international experience of using the discussed approaches. On the basis of literature data, we have developed a prototype algorithm for choosing an optimal approach to medial tumors of the anterior skull base. The situation of choosing an optimal approach reveals the absence of a clear understanding of the boundaries between capabilities and limitations of approaches. To solve this problem, an original prospective study is required.

Transfrontal-Sinus-Subcranial Approach to Olfactory Groove Meningiomas: Surgical Results and Clinical and Functional Outcome in a Consecutive Series of 21 Patients

BACKGROUND

The transfrontal-sinus-subcranial approach (TFSSA) allows for direct exposure and removal of olfactory groove meningiomas (OGMs), without any brain retraction. Compared with other skull base approaches (e.g., fronto-orbitobasal, transbasal, subcranial, fronto-orbitozygomatic, and one-and-half approach), it could offer the same advantages but is less invasive.

OBJECTIVE

We report the results in a series of 21 consecutive patients with OGMs and operated on through TFSSA, to propose a viable alternative approach.

METHODS

Mean maximum tumor diameter was 45.9 ± 3.4 mm (range, 25-70 mm). The aim of surgery was Simpson grade I removal. Surgical, clinical, and functional outcomes were reported. Mean follow-up was 87 ± 7 months (range, 36-176 months).

RESULTS

In all patients, magnetic resonance imaging after surgery confirmed complete tumor removal. The recurrence-free survival rate was 100% and 85.7% at 5 and 10 years, respectively. Surgery-related mortality and major morbidity were 0% and 4.8%, respectively. Risk of anosmia significantly correlates with meningioma size (P < 0.001) and smell sense was preserved only in patients with tumors less than 4 cm in maximum diameter (4/7; 57.1%). A significant improvement of Mini Mental Standard Examination score was recorded at follow-up (P < 0.001) and no patients worsened their cognitive profile. Visual function improved in 7/8 (87.5%). Karnofsky Performance Scale score after surgery significantly increased (P < 0.001). According to the Glasgow Outcome Score, good outcome was achieved in 20 patients (95.2%).

CONCLUSIONS

Based on reported results, TFSSA allows complete tumor removal with good outcome and low complication rate. It may be proposed as a safe and effective approach to treat large and giant OGMs.

Magnetic resonance imaging fluid-attenuated inversion recovery sequence signal reduction after endoscopic endonasal transcribiform total resection of olfactory groove meningiomas

BACKGROUND

Olfactory groove meningiomas grow insidiously and compress adjacent cerebral structures. Achieving complete removal without further damage to frontal lobes can be difficult. Microsurgical removal of large lesions is a challenging procedure and usually involves some brain retraction. The endoscopic endonasal approaches (EEAs) for tumors arising from the anterior fossa have been well described; however, their effect on the adjacent brain tissue has not. Herein, the authors utilized the magnetic resonance imaging fluid attenuated inversion recovery (FLAIR) sequence signal as a marker for edema and gliosis on pre- and post-operative images of olfactory groove meningiomas, thus presenting an objective parameter for brain injury after surgical manipulation.

METHODS

Imaging of 18 olfactory groove meningiomas removed through EEAs was reviewed. Tumor and pre/postoperative FLAIR signal volumes were assessed utilizing the DICOM image viewer OsiriX(®). Inclusion criteria were: (1) No previous treatment; (2) EEA gross total removal; (3) no further treatment.

RESULTS

There were 14 females and 4 males; the average age was 53.8 years (±8.85 years). Average tumor volume was 24.75 cm(3) (±23.26 cm(3), range 2.8-75.7 cm(3)), average preoperative FLAIR volume 31.17 cm(3) (±39.38 cm(3), range 0-127.5 cm(3)) and average postoperative change volume, 4.16 cm(3) (±6.18 cm(3), range 0-22.2 cm(3)). Average time of postoperative scanning was 6 months (range 0.14-20 months). In all cases (100%) gross total tumor removal was achieved. Nine patients (50%) had no postoperative FLAIR changes. In 2 patients (9%) there was minimal increase of changes postoperatively (2.2 cm(3) and 6 cm(3) respectively); all others demonstrated image improvement. The most common complication was postoperative cerebrospinal fluid leakage (27.8%); 1 patient (5.5%) died due to systemic complications and pulmonary sepsis.

CONCLUSIONS

FLAIR signal changes tend to resolve after endonasal tumor resection and do not seem to worsen with this operative technique.

Transfrontal sinus approach for an anterior cranial fossa, ethmoidal, dural arteriovenous fistula

Background:

Ethmoidal dural arteriovenous fistulas (eDAVFs) are usually approached via a pterional or a frontal craniotomy. A more direct route to the fistula is possible through a purely transfrontal sinus approach. The aim of this report is to illustrate the interest of transsinus frontal approach for eDAVFs.

Case Description:

The transfrontal sinus approach is described and illustrated in a case of an ethmoidal arteriovenous fistula. This approach is the most direct when treating an eDAVF surgically, allowing preserving neural structures with minimal to no brain manipulation.

Conclusion:

For eDAVFs, the purely transfrontal sinus approach is highly worth considering in cases of large frontal sinuses.

Bilateral visual loss due to a giant olfactory meningioma

Olfactory groove meningiomas can present as large and insidious masses in the anterior cranial base. Due to their location and minimal clinical symptoms, these tumors can go undetected until they have grown extremely large. We present a clinical case and discuss the surgical management of a 63-year-old man who presented for an initial eye examination with bilateral visual loss for over 2 years due to a giant olfactory meningioma encompassing his entire frontal lobe and compressing on his optic nerves.

Proposed classification for the transbasal approach and its modifications

The transbasal approach offers extradural exposure of the anterior midline skull base transcranially. It can be used to treat a variety of conditions, including trauma, craniofacial deformity, and tumors. This approach has been modified to enhance basal access. This article reviews the principle differences among modifications to the transbasal approach and introduces a new classification scheme. The rationale is to offer a uniform nomenclature to facilitate discussion of these approaches, their indications, and related issues.

Comparative analysis of extensions of transbasal approaches: effect on access to midline and paramedian structures

We sought to quantitate the effect of extensions of transbasal approaches (TBAs) on midline and paramedian targets of the cranial base. Eight silicone-injected cadaveric heads were dissected with extensions of TBA level I removal of the orbital bar. Objective measures were the comparisons of the accessibility of midline and paramedian targets with progressive dissections by level II detachment of the medial canthal ligaments and removal of the nasal bone and by level III removal of the lateral orbital walls with lateral orbital retraction. Mean areas of freedom increased for most targets with progressive bone removal. For midline targets, the most effective freedom increment was at the pituitary gland (level II: 28.8%, p = 0.05; level III: 107.1%, p < 0.001). For paramedian targets, the best freedom increment was for the foramen rotundum (level II: 56.4%; level III: 134.5%, all p < 0.001). Extensions of the TBA can increase the surgical corridor to midline and paramedian structures, especially for pituitary and maxillary regions. Level II exposure offers no clear benefit for most targets except the foramen rotundum. With level III exposure, all targets are effectively exposed compared with levels I and II.

Transfrontoethmoidal approach to medial intraconal lesions

Object The standard superior craniotomy approach through the orbital roof is obstructed by numerous muscles, nerves, and vessels. Accessing the medial intraconal space also involves considerable brain retraction. The authors present a modified approach through the frontal sinus that overcomes these limitations. Methods Seven fixed silicone-injected cadaveric specimens were dissected bilaterally. In addition to the superior orbital wall, the ethmoidal sinuses and medial orbital wall were removed. The anatomical relationships between the major neurovascular complexes in the medial intraconal space and the optic nerve were observed. Results Intraconally, working space was created both in a "superior window" between the superior oblique and levator palpebrae muscle and in a "medial window" between the superior oblique and medial rectus muscle. The superior window mainly created an ipsilateral trajectory to the deep target. The medial window, which created a contralateral trajectory, provided a more inferior view of the medial intraconal space. Removal of the medial orbital wall further widened the exposure obtained from the superior window. The combination of these working windows makes the medial surface of the optic nerve available for exploration from multiple angles. Most of the major neurovascular complexes of the posterior orbit can be retracted safely without impinging on the optic nerve. Conclusions This novel extradural transfrontoethmoidal approach affords a direct view to the medial posterior orbit without major conflicts with intraconal neurovascular structures and requires minimal brain manipulation. The approach appears to offer advantages for medially located intraconal lesions.

LATERAL SUPRAORBITAL APPROACH APPLIED TO OLFACTORY GROOVE MENINGIOMAS

OBJECTIVE

The lateral supraorbital approach for safely and completely removing olfactory groove meningiomas was assessed.

METHODS

Between September 1997 and June 2008, a total of 656 meningiomas were operated on by the senior author (JH) at the Department of Neurosurgery, Helsinki University Central Hospital; 66 were olfactory meningiomas. We retrospectively analyze the clinical data, radiological findings, surgical treatment, histology, and outcome of all the olfactory groove meningioma patients and discuss the operative techniques used.

RESULTS

Sixty-six patients were operated on by the lateral supraorbital approach. The median preoperative Karnofsky Performance Scale score was 80 (range, 40–100). Three patients were redo cases in which the primary operation had been performed elsewhere. Seemingly complete tumor removal was achieved in 60 patients (91%); there was no surgical mortality. Postoperatively, 6 patients (9%) had cerebrospinal fluid leakage, 5 (8%) had new visual deficits, 4 (6%) had wound infections, 4 (6%) had cotton granulomas, and 1 (2%) had a postoperative hematoma. The median Karnofsky score at discharge was 80 (range, 40–100). Six patients had recurrent tumors; 3 underwent reoperations after an average of 21 months (range, 1–41 months); 1 was treated with radiosurgery, and 2 were only followed. During the median follow-up time of 45 months (range, 2–128 months), there were 4 recurrences (6%) diagnosed on average 32 months (range, 17–59 months) after surgery.

CONCLUSION

The lateral supraorbital approach can be used safely for olfactory groove meningiomas of all sizes with no mortality and relatively low morbidity. Surgical results and tumor recurrence with this fast and simple approach are similar to those obtained with more extensive, complex, and time-consuming approaches.

The radical transbasal approach for resection of anterior and midline skull base lesions

OBJECT

Craniofacial surgery can be performed to treat midline and anterior skull base lesions by creating a bicoronal scalp incision without the need for an additional transfacial procedure. Originally described as the transbasal approach, several modifications for further exposure of the skull base have been described. The authors present data on the application and outcomes of a modified transbasal approach. The radical transbasal approach consists of a bifrontal craniotomy and a frontoorbitonasal osteotomy.

METHODS

Between 1992 and 2002, 41 patients (28 male and 13 female patients with a mean age of 38.3 years [range 7-77 years]) underwent 44 radical transbasal procedures. Twenty-three malignant and 18 benign lesions involving the midline skull base were treated. These cases were reviewed retrospectively. Gross-total resection of 30 lesions was achieved. Seven lesions were resected subtotally and six partially; one lesion was debulked. Complications occurred in 26 (59.1%) of the 44 operations and mostly consisted of cerebrospinal fluid leakage. The surgery-related mortality rate was 6.8% (three patients). Based on their pre- and postoperative Karnofsky Performance Scale scores, 86.4% of patients improved or remained the same.

CONCLUSIONS

The radical transbasal approach increases the midline craniofacial corridor by allowing the globes to be safely retracted laterally. It also enhances exposure of the maxillary sinus from above. The morbidity and mortality rates associated with this procedure are high but consistent with the known rates for craniofacial surgery. This approach is best suited for the treatment of anterior skull base tumors that extend into the nasal cavity, orbit, ethmoid sinus, nasopharynx, and upper clivus. The approach may allow resection of tumors involving the maxillary sinus area without the need for an additional transfacial approach.