The role of transsphenoidal microsurgery in the management of sellar and parasellar meningioma

Management of cavernous sinus meningiomas: Consensus statement on behalf of the EANS skull base section

Introduction

The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs.

Research question

To determine the best overall management of CSMs, depending on their clinical presentation, size, and evolution as well as patient characteristics.

Material and methods

Using the PRISMA 2020 guidelines, we included literature from January 2000 to December 2020. A total of 400 abstracts and 77 titles were kept for full-paper screening.

Results

The task force formulated 8 recommendations (Level C evidence). CSMs should be managed by a highly specialized multidisciplinary team. The initial evaluation of patients includes clinical, ophthalmological, endocrinological and radiological assessment. Treatment of CSM should involve experienced skull-base neurosurgeons or neuro-radiosurgeons, radiation oncologists, radiologists, ophthalmologists, and endocrinologists.

Discussion and conclusion

Radiosurgery is preferred as first-line treatment in small, enclosed, pauci-symptomatic lesions/in elderly patients, while large CSMs not amenable to resection or WHO grade II-III are candidates for radiotherapy. Microsurgery is an option in aggressive/rapidly progressing lesions in young patients presenting with oculomotor/visual/endocrinological impairment. Whenever surgery is offered, open cranial approaches are the current standard. There is limited experience reported about endoscopic endonasal approach for CSMs and the main indication is decompression of the cavernous sinus to improve symptoms. Whenever surgery is indicated, the current trend is to offer decompression followed by radiosurgery.

•

A thorough evaluation of cavernous sinus meningiomas by a multidisciplinary team is mandatory.

•

Microsurgery should be considered for aggressive lesions in young patients.

•

Extended endoscopic approaches can be effective when combined with radiotherapy.

•

Stereotaxic radiotherapy and stereotaxic radiosurgery offer excellent tumour control in small/asymptomatic lesions .

[Operative skull base approaches]

CLINICAL ISSUE

Knowledge of skull base anatomy is essential for recognizing the pathological conditions affecting the skull base structures (including cranial nerves and cerebral vasculature), for correct interpretation of their presentation on imaging studies, and finally for proper planning of surgical skull base approaches.

PURPOSE OF THE ARTICLE

The main goal of the following work is to present a brief recapitulation of the regular skull base anatomy (with a focus on the bony structures) and based on this, to provide an overview of the most commonly used neurosurgical skull base approaches (illustrated using radiological case presentations).

DIAGNOSTIC WORK-UP

Already at the step of the preoperative workup, the suitable radiological technique and proper choice of technical parameters for image acquisition lays the foundation for a successful surgical procedure and for the reliable assessment of operative results.

CONCLUSION

Each radiologist should be familiar with basic principles of neurosurgical approaches and operative techniques used in skull base surgery and with their appearance in postoperative images.

Optic nerve mobilization to enhance the exposure of the pituitary stalk during craniopharyngioma resection: early experience

OBJECT Preservation of the pituitary stalk and its vasculature is a key step in good postoperative endocrinological outcome in patients with craniopharyngiomas. In this article, the authors describe the surgical technique of medial optic nerve mobilization for better inspection and preservation of the pituitary stalk. METHODS This operative technique has been applied in 3 patients. Following tumor exposure via a frontolateral approach, the pituitary stalk could be seen partially hidden under the optic nerve and the optic chiasm. The subchiasmatic and opticocarotid spaces were narrow, and tumor dissection from the pituitary stalk under direct vision was not possible. The optic canal was therefore unroofed, the falciform ligament was incised, and the lateral part of the tuberculum sellae was drilled medial to the optic nerve. The optic nerve could be mobilized medially to widen the opticocarotid triangle, which enhanced visualization of and access to the pituitary stalk. RESULTS By using the optic nerve mobilization technique, the tumor could be removed completely, and the pituitary stalk and its vasculature were preserved in all patients. In 2 patients, vision improved after surgery, while in 1 patient it remained normal, as it was before surgery. The hormonal status remained normal after surgery in 2 patients. In the patient with preoperative hormonal deficiencies, improvement occurred early after surgery and hormonal levels were normal after 3 months. No approach-related complications occurred. CONCLUSIONS This early experience shows that this technique is safe and could be used as a complementary step during microsurgery of craniopharyngiomas. It allows for tumor dissection from the pituitary stalk under direct vision. The pituitary stalk can thus be preserved without jeopardizing the optic nerve.

Surgical approaches to central skull base and postsurgical imaging

The close proximity to or intricate involvement of critical neurovascular structures in the central skull base region or both present unique surgical challenges. Varied surgical approaches may be used to remove tumors in this region, including open craniotomies and minimally invasive transnasal or transfacial endoscopic approaches. The ideal surgical technique is chosen based on multiple factors including the aggressiveness, histopathology, and location of the tumor with respect to regional neurovascular elements. Postsurgical image analysis of the central skull base requires an intimate understanding of preoperative and expected postoperative appearance in relation to the nature of the excision and surgical materials used.

Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients

OBJECT

Following the introduction of the neurosurgical microscope, the outcomes in suprasellar meningioma surgery were dramatically improved. More recently, the neurosurgical endoscope has been introduced as a visualization option during removal of skull base tumors, both transcranially and endonasally. The authors retrospectively reviewed the effectiveness of endoscopic endonasal surgery (EES) in the management of suprasellar meningiomas.

METHODS

Between 2002 and 2011, 75 patients (81.3% female) with suprasellar meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, visual outcome, and complications.

RESULTS

Seventy-one patients presented with primary tumors, whereas 4 were previously treated elsewhere. Their mean age was 57.3 years (range 36-88 years), and most patients presented with visual loss (81.3%). Tumors occupied the tuberculum sellae (86.7%) and planum sphenoidale (50.7%), with extension into the optic canals in 26.7% (unilateral in 21.3% and bilateral in 5.3%) and the pituitary fossa (9.3%). Gross-total tumor resection (Simpson Grade I) was achieved in 76% of the cases in the whole cohort and in 81.4% of the patients in whom it was the goal of surgery. Tumor location and extension into the optic canals was not a limitation for total resection. Tumor size, configuration, and vascular encasement were significant factors that influenced the degree of resection (p < 0.0001). Vision was improved or normalized in 85.7% of the cases. Visual deterioration following EES occurred in 2 patients (3.6%). Complications included postoperative CSF leaks (25.3% overall, 16.1% in recent years) resulting in meningitis in 4 cases. One patient had an intraoperative injury of the artery of Heubner resulting in associated neurological deficit. Another elderly patient died within 1 month after EES due to cerebral vasospasm and multisystem impairment. No patient developed postoperative cerebral contusions, hemorrhage, or seizures. During a mean follow-up period of 29 months (range 1-98 months), 4 patients have shown recurrence, but only 1 required repeat EES.

CONCLUSIONS

With the goal of gross-total tumor resection and visual improvement, EES can achieve very good results, (comparable to microscopic approaches) for the treatment of suprasellar meningiomas. Avoidance of brain and optic nerve retraction, preservation of the vascularization of the optic apparatus, and wide decompression of the optic canals are the main advantages of EES for the treatment of suprasellar meningiomas, while CSF leaks remain a disadvantage.

[Modern surgery of meningiomas affecting anterior visual pathways]

Meningiomas are the most common form of primary intracranial tumors. If the anterior visual pathways are affected clinical visual compromise, visual field defects, oculomotor nerve disturbances or propotosis are predominant. Meningiomas of the anterior visual pathway remain therapeutically challenging due to the direct anatomical relationship to the circulus arteriosus cerebri, the cavernous sinus and cranial nerves. The therapy of choice is microsurgical resection. In many cases a curative approach can be achieved with modern surgical techniques and simultaneously maintaining patient quality of life. Problematic are cases in which resection would be associated with the risk of clinical impairment and in these cases radiotherapy is an important therapeutic option. In cases involving complex invasiveness an interdisciplinary treatment to control local clinical symptoms is favored.

Endoscopic endonasal transsphenoidal approach: an additional reason in support of surgery in the management of pituitary lesions

The outcome of endoscopic endonasal transsphenoidal surgery in 10 patients with pituitary adenomas was compared with that of traditional transnasal transsphenoidal approach (TTA) in 20 subjects. Among the 10 individuals subjected to "pure endoscopy," 2 had a microadenoma, 1 an intrasellar macroadenoma, 4 had a macroadenoma with suprasellar expansion, 2 had a macroadenoma with supra-parasellar expansion, and 1 a residual tumor; 5 had acromegaly and 5 had a nonfunctioning adenoma (NFA). Among the patients subjected to TTA, 4 had a microadenoma, 2 had an intrasellar macroadenoma, 6 had a macroadenoma with suprasellar expansion, 4 had a macroadenoma with supra-parasellar expansion, and 4 had a residual tumor; 9 patients had acromegaly, 1 hyperprolactinemia, 1 Cushing's disease, and 9 a NFA. At the macroscopic evaluation, tumor removal was total (100%) after endoscopy in 9 patients and after TTA in 14 patients. Six months after surgery, magnetic resonance imaging (MRI) confirmed the total tumor removal in 21 of 23 patients (91.3%). Circulating growth hormone (GH) and insulin-like growth factor-I (IGF-I) significantly decreased 6 months after surgery in all 14 acromegalic patients: normalization of plasma IGF-I levels was obtained in 4 of 5 patients after the endoscopic procedure and in 4 of 9 patients after TTA. Before surgery, pituitary hormone deficiency was present in 14 out of 30 patients: pituitary function improved in 4 patients, remaining unchanged in the other 10 patients. Visual field defects were present before surgery in 4 patients, and improved in all. Early surgical results in the group of 10 patients who underwent endoscopic pituitary tumor removal were at least equivalent to those of standard TTA, with excellent postoperative course. Postsurgical hospital stay was significantly shorter (3.1 +/- 0.4 vs. 6.2 +/- 0.3 days, p < 0.001) after endoscopy as compared to TTA.

Further data favouring hormonal dependency of cerebral meningiomas: evidence from a patient treated with cabergoline

OBJECTIVE

To explore the role of cabergoline, a dopamine agonist, in the progression of meningiomas.

DESIGN

Case report.

SETTING

Teaching hospital in Barcelona, Spain (Gynecology, Obstetrics and Neonatology Clinical Institute, Hospital Clínic).

PATIENT(S)

Women with a history of meningioma underwent surgery via right pterional craniotomy. During the follow-up, at 18 months after the operation the patient developed a progressive hyperprolactinemia with amenorrhea and galactorrhea. An MR examination revealed a recurrence of the neoplasm.

INTERVENTION(S)

Cabergoline treatment.

MAIN OUTCOME MEASURE(S)

Progression of meningioma.

RESULT(S)

Long-standing cabergoline treatment in this patient with meningioma relapse early after surgery and subsequent hyperprolactinemia resulted in absence of progression of the neoplasm many years after the dopamine agonist initiation.

CONCLUSION(S)

These data suggest that cabergoline, a dopamine agonist, had an antiproliferative effect on the growth of meningiomas. Thus, one can hypothesise that the proliferation of cerebral meningiomas may be under dopaminergic control and that dopamine agonists such cabergoline may have a potential role in the medical treatment of patients with meningiomas.

Factors affecting outcome following treatment of patients with cavernous sinus meningiomas

Object

Although there is a considerable volume of literature available on the treatment of patients with cavernous sinus meningiomas (CSMs), most of the data regarding tumor control and survival come from case studies or single-institution series. The authors performed a meta-analysis of reported tumor control and survival rates of patients described in the published literature, with an emphasis on specific prognostic factors.

Methods

The authors systematically analyzed the published literature and found more than 3000 patients treated for CSMs. Separate meta-analyses were performed to calculate pooled rates of recurrence and cranial neuropathy after 1) gross-total resection, 2) subtotal resection without adjuvant postoperative radiotherapy or radiosurgery, and 3) stereotactic radiosurgery (SRS) alone. Results were expressed as pooled proportions, and random-effects models were used to incorporate any heterogeneity present to generate a pooled proportion. Individual studies were weighted using the inverse variance method, and 95% CIs for each group were calculated from the pooled proportions.

Results

A total of 2065 nonduplicated patients treated for CSM met inclusion criteria for the analysis. Comparisons of the 95% CIs for recurrence of these 3 cohorts revealed that SRS-treated patients experienced improved rates of recurrence (3.2% [95% CI 1.9–4.5%]) compared with either gross-total resection (11.8% [95% CI 7.4–16.1%]) or subtotal resection alone (11.1% [95% CI 6.6–15.7%]) (p < 0.01). The authors found that the pooled mixed-effects rate of cranial neuropathy was markedly higher in patients undergoing resection (59.6% [95% CI 50.3–67.5%]) than for those undergoing SRS alone (25.7% [95% CI 11.5–38.9%]) (p < 0.05).

Conclusions

Radiosurgery provided improved rates of tumor control compared with surgery alone, regardless of the subjective extent of resection.

Skull base approaches in neurosurgery

The skull base surgery is one of the most demanding surgeries. There are different structures that can be injured easily, by operating in the skull base. It is very important for the neurosurgeon to choose the right approach in order to reach the lesion without harming the other intact structures. Due to the pioneering work of Cushing, Hirsch, Yasargil, Krause, Dandy and other dedicated neurosurgeons, it is possible to address the tumor and other lesions in the anterior, the mid-line and the posterior cranial base. With the transsphenoidal, the frontolateral, the pterional and the lateral suboccipital approach nearly every region of the skull base is exposable.In the current state many different skull base approaches are described for various neurosurgical diseases during the last 20 years. The selection of an approach may differ from country to country, e.g., in the United States orbitozygomaticotomy for special lesions of the anterior skull base or petrosectomy for clivus meningiomas, are found more frequently than in Europe.The reason for writing the review was the question: Are there keyhole approaches with which someone can deal with a vast variety of lesions in the neurosurgical field?In my opinion the different surgical approaches mentioned above cover almost 95% of all skull base tumors and lesions. In the following text these approaches will be described.These approaches are:1) pterional approach2) frontolateral approach3) transsphenoidal approach4) suboccipital lateral approachThese approaches can be extended and combined with each other. In the following we want to enhance this philosophy.

Fronto-basal interhemispheric approach for tuberculum sellae meningiomas; long-term visual outcome

We report our experience with the treatment of tuberculum sellae meningiomas using the fronto-basal interhemispheric approach. A retrospective analysis was performed on a series of 24 patients with tuberculum sellae meningiomas who were operated between March 2000 and January 2007. Patients' presenting symptoms, radiological images, operative reports, and clinical follow-up data were reviewed with special consideration for visual outcome. Visual deterioration was the presenting symptom in all patients, followed by headache in 9 patients (37.5%). The average duration of visual symptoms was 17.6 months. The average tumor diameter was 2.63 cm; encasement of the carotid artery was identified in 7 patients (29%). Complete tumor removal was achieved in 21 patients (87.5%). Mean follow-up period was 52 months. Vision improved in 19 patients (79%), remained stable in 4 (17%) and deteriorated in 1 patient (4%). The degree of tumor removal or visual outcome were both unrelated to the tumor size (p = 0.2 and p = 0.6 respectively). While the degree of preoperative visual deficit did not affect the visual improvement rate in the whole group (p = 0.9), those patients with improvement to good functional vision (>20/40) after the surgery, had a less severe preoperative deficit (p < 0.001). The most common complication was anosmia (29.1%) and there was no mortality. The frontobasal interhemispheric approach is safe and provides a direct anatomical approach to tuberculum sellae meningiomas with relatively low incidence of complications. Patients with improved vision to good functional level had a better preoperative visual status.

Transsphenoidal decompression of the sellar floor for cavernous sinus meningiomas: experience with 21 patients

OBJECTIVE

The aim of this study was to assess the outcome of cranial nerve and endocrine function after transsphenoidal decompression for symptomatic cavernous sinus (CS) meningioma.

METHODS

Between 1991 and 2007, 21 patients (19 women and 2 men; mean age, 51.1 +/- 10.6 years) harboring symptomatic CS meningiomas underwent transsphenoidal decompression. Sufficient bone removal, opening of the inferomedial wall of the CS, and tumor debulking were performed.

RESULTS

Notably, the grading of preoperative optomotoric paresis improved in 15 of the 17 patients who presented with that symptom. Complete recovery could be achieved in 8 patients. Complete recovery rates in patients with preoperative grading of "good," "fair," and "poor" were 77.7%, 20%, and 0%, respectively (P = 0.0088). Improvement of cranial nerve dysfunction was found in 32 of 34 deficits. No worsening of cranial nerve function occurred. Endocrinologically, the prolactin level was normalized in 13 of the 17 patients with preoperative hyperprolactinemia. Recovery of growth hormone deficiency and hypogonadism were found in 3 patients (37.5%) and 1 patient (33.3%), respectively. Seventeen patients were followed for more than 3 years. Of these 17 patients, 12 patients received initial postoperative adjuvant radiotherapy. The overall tumor control rate after surgery with initial adjuvant radiotherapy was 100% (median follow-up, 65 months; range, 36-126 months).

CONCLUSION

Transsphenoidal decompression is a safe and effective treatment to improve cranial nerve and endocrine dysfunction in patients with symptomatic CS meningiomas. The less severe optomotoric nerve palsy before surgery, the better the chance of complete recovery of its function. Combined with adjuvant radiotherapy, this minimally invasive management also provided excellent long-term tumor control.

Endonasal versus supraorbital keyhole removal of craniopharyngiomas and tuberculum sellae meningiomas

OBJECTIVE

Endonasal and supraorbital "eyebrow" craniotomies are increasingly being used to remove craniopharyngiomas and tuberculum sellae meningiomas. Herein, we assess the relative advantages, disadvantages, and selection criteria of these 2 keyhole approaches.

METHODS

All consecutive patients who had endonasal or supraorbital removal of a craniopharyngioma or tuberculum sellae meningioma were analyzed.

RESULTS

Of 43 patients, 22 had a craniopharyngioma (18 endonasal, 4 supraorbital), and 21 had a meningioma (12 endonasal, 7 supraorbital, 2 both routes); 33% had prior surgery. Craniopharyngiomas were primarily retrochiasmal in location in 78% of endonasal cases versus 25% of supraorbital cases (P = 0.08). Meningiomas were larger when approached by the supraorbital route versus the endonasal route (33 +/- 10 versus 25 +/- 8 mm, respectively; P = 0.008). Endoscopy was used in 84% of endonasal approaches and in 31% of supraorbital approaches (P = 0.001). Of patients having first-time surgery for a craniopharyngioma (n = 14) or meningioma (n = 15), total/near total removal was achieved in 83% and 80% of patients by the endonasal route and in 50% and 80% of patients by the supraorbital route, respectively. Vision improved in 87% and 70% of patients who had surgery by an endonasal versus supraorbital route, respectively (P = 0.3). Visual deterioration occurred in 2 patients with meningiomas, 1 by endonasal (7%), and 1 by supraorbital (11%) removal. The endonasal approach was associated with a higher rate of postoperative cerebrospinal fluid leaks (16 versus 0%; P = 0.3), 4 of 5 of which occurred in patients with meningioma.

CONCLUSION

The endonasal route is preferred for removal of most retrochiasmal craniopharyngiomas, whereas the supraorbital route is recommended for meningiomas larger than 30 to 35 mm or with growth beyond the supraclinoid carotid arteries. For smaller midline tumors, either approach can be used, depending on surgeon experience and tumor anatomy. Compared with traditional craniotomies, the major limitation of both approaches is a narrow surgical corridor. The endonasal approach has the added challenges of restricted lateral suprasellar access, a greater need for endoscopy, and a more demanding cranial base repair.

Primary intrasellar schwannoma: clinical, aetiopathological and surgical considerations

Schwannomas originating within the sella turcica are extremely rare. We describe the clinical, radiological and intraoperative findings of a patient with an intrasellar and suprasellar schwannoma. Gross total tumour removal was performed by a trans-sphenoidal approach. Perivascular or ectopic Schwann cells, lateral nerve plexus within the cavernous sinus, as well as Schwann cells from small nerve twigs of the dura are some of the current histopathological hypotheses for the origin of these lesions.

Safety and efficacy of the direct endonasal transsphenoidal approach for challenging sellar tumors

INTRODUCTION

The direct endonasal approach to pituitary microadenomas is relatively atraumatic, rapid, and carries a lower complication rate than the sublabial approach. Large macroadenomas (3-4 cm) can still be addressed with this simple, unmodified direct endonasal approach. We present our experience with this unique and challenging patient population.

METHODS

About 64 consecutive patients with large (3-4 cm) pituitary adenomas and craniopharyngiomas were treated by the senior author (SK) using the direct endonasal approach from May 2001 to July 2004. The hospital course, endocrinological function, radiographic imaging, and outpatient follow-up were retrospectively reviewed for each patient.

RESULTS

The mean volume of these lesions was 31.5 cm(3) (range, 10.3-168 cm(3)). Tumor pathologies included 2 craniopharyngiomas, 16 functional, and 46 nonfunctional pituitary adenomas. Suprasellar extension of tumor was evident in all patients and 10 had cavernous sinus invasion. Gross total resection was achieved in 30 patients, near-gross total in 6 patients, and subtotal resection in 26 patients. Eight patients (12.5%) demonstrated postoperative complications, with diabetes insipidus for less than 1 year (n = 4) being the most common. There was no incidence of CSF leak, new panhypopituitarism, or worsened vision. Five patients (7.8%) had tumor residual requiring radiation therapy. Additionally, after a mean clinical follow-up of 24.5 months, 4 patients (6.3%) demonstrated recurrent disease.

CONCLUSIONS

Direct endonasal transsphenoidal surgery enables safe and effective resection of large sellar masses while maintaining a favorable morbidity profile.

Postoperative improvement in visual function in patients with tuberculum sellae meningiomas: results of the extended transsphenoidal and transcranial approaches

Object

Recently, extended transsphenoidal surgery (ETSS) has become an alternative to transcranial surgery (TCS) for suprasellar meningiomas, although the relative benefits of ETSS have yet to be established. To evaluate the effectiveness of ETSS, the authors analyzed surgical outcomes of TCS and ETSS.

Methods

During a 12-year period, 28 patients with meningiomas arising from the tuberculum sellae underwent tumor removal at Kinki University Hospital. The first 12 patients underwent TCS, and the remaining 16 underwent ETSS. In the TCS group, the optic canal on the approach side was unroofed in all cases. In the ETSS group bilateral optic canals were opened, and the dural and bone defects of the skull base were repaired using abdominal fascia and hydroxyapatite cement. In half of the cases, lumbar drainage of cerebrospinal fluid (CSF) was also performed.

Results

In a retrospective analysis of this consecutive series of patients, improvement in visual acuity and intraoperative blood loss were significantly better in the ETSS group (p = 0.010 and p = 0.011, respectively), whereas improvement in visual field defects, operative times, and the tumor removal rate were not significantly different between the two groups. Nonvisual surgical complications such as CSF leakage (one patient) and infarction of a perforating artery (three patients) were observed in the TCS group. In the ETSS group, CSF leakage (two patients), anosmia (two patients), and infarction of a perforating artery (two patients) were observed.

Conclusions

Given the encouraging results in improvement in visual acuity, ETSS may be acceptable for the treatment of tuberculum sellae meningiomas.

Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations

Object

The midline skull base is an anatomical area that extends from the anterior limit of the cranial fossa down to the anterior border of the foramen magnum. Resection of lesions involving this area requires a variety of innovative skull base approaches. These include anterior, anterolateral, and posterolateral routes, performed either alone or in combination, and resection via these routes often requires extensive neurovascular manipulation. The goals in this study were to define the application of the endoscopic endonasal approach and to become more familiar with the views and skills associated with the technique by using cadaveric specimens.

Methods

To assess the feasibility of the endonasal route for the surgical management of lesions in the midline skull base, five fresh cadaver heads injected with colored latex were dissected using a modified endoscopic endonasal approach.

Full access to the skull base and the cisternal space around it is possible with this route. From the crista galli to the spinomedullary junction, with incision of the dura mater, a complete visualization of the carotid and vertebrobasilar arterial systems and of all 12 of the cranial nerves is obtainable.

Conclusions

The major potential advantage of the endoscopic endonasal approach to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, obviating brain retraction. Many tumors grow in a medial-to-lateral direction, displacing structures laterally as they expand, creating natural corridors for their resection via an anteromedial approach.

Potential disadvantages of this procedure include the relatively restricted working space and the danger of an inadequate dural repair with cerebrospinal fluid (CSF) leakage and potential for meningitis resulting. These approaches often require a large opening of the dura mater over the tuberculum sellae and posterior planum sphenoidale, or retroclival space. In addition, they typically involve large intraoperative CSF leaks, which necessitate precise and effective dural closure.

The extended direct endonasal transsphenoidal approach for nonadenomatous suprasellar tumors

Object. The extended transsphenoidal approach, which requires a bone and dural opening through the tuberculum sellae and posterior planum sphenoidale, is increasingly used for the treatment of nonadenomatous suprasellar tumors. The authors present their experiences in using the direct endonasal approach in patients with nonadenomatous suprasellar tumors.

Methods. Surgery was performed with the aid of an operating microscope and angled endoscopes were used to assess the completeness of resection. Bone and dural defects were repaired using abdominal fat, collagen sponge, titanium mesh, and, in most cases, lumbar drainage of cerebrospinal fluid (CSF).

Twenty-six procedures for tumor removal were performed in 24 patients (ages 9–79 years), including two repeated operations for residual tumor. Gross-total removal could be accomplished in only 46% of patients, with near-gross-total removal or better in 74% of 23 patients (five of eight with craniopharyngiomas, six of seven with meningiomas, five of six with Rathke cleft cysts, and one of two with a dermoid or epidermoid cyst); a patient with a lymphoma only underwent biopsy. Of 13 patients with tumor-related visual loss, 85% improved postoperatively. The complications that occurred included five patients (21%) with postoperative CSF leaks, one patient (4%) with bacterial meningitis; five patients (21%) with new endocrinopathy; and two patients (8%) who needed to undergo repeated operations to downsize suprasellar fat grafts. The only permanent neurological deficit was anosmia in one patient; there were no intracranial vascular injuries.

Conclusions. The direct endonasal skull-base approach provides an effective minimally invasive means for resecting or debulking nonadenomatous suprasellar tumors that have traditionally been approached through a sublabial or transcranial route. Procedures in the supraglandular space can be performed effectively with excellent visualization of the optic apparatus while preserving pituitary function in most cases. The major challenge remains developing consistently effective techniques to prevent postoperative CSF leaks.

The transsphenoidal approach

Over the last century, the transsphenoidal approach has evolved into the first-line method of treatment for sellar as well as select groups of parasellar and suprasellar lesions. The journey to its current popularity has been marked by controversy and near abandonment in the late 1920s, followed by its renaissance in the late 1960s. Despite the profound skepticism with which this procedure was viewed, several visionary neurosurgeons persevered through its nadir in popularity, preserving this surgical corridor to the skull base. Advances in medical and surgical techniques, paralleling an improved understanding of pituitary pathophysiology, contributed to its resurgence. The transsphenoidal procedures now performed stem from an array of modifications and refinements accumulated through nearly 100 years of medical and surgical evolution. This era's critical innovations and neurosurgical personalities are the topic of this historical overview.

Endonasal transsphenoidal removal of tuberculum sellae meningiomas: technical note

OBJECTIVE

Tuberculum sellae meningiomas traditionally have been removed through a transcranial approach. More recently, the sublabial transsphenoidal approach has been used to remove such tumors. Here, we describe use of the direct endonasal transsphenoidal approach for removal of suprasellar meningiomas.

METHODS

Three women, aged 32, 34, and 55 years, each sought treatment for visual loss and headaches. In each patient, magnetic resonance imaging (MRI) showed a suprasellar mass causing optic chiasmal and optic nerve compression (average size, 2 x 2 cm). All three patients underwent tumor removal via an endonasal approach with the operating microscope. Suprasellar exposure was facilitated by removal of the posterior planum sphenoidale. Ultrasound was used to help define tumor location before dural opening. The extent of tumor removal was verified with angled endoscopes in all patients, and with intraoperative MRI in one patient. The surgical dural and bony defects were repaired in all patients with abdominal fat, titanium mesh, and 2 to 3 days of cerebrospinal fluid lumbar drainage. Nasal packing was not used.

RESULTS

There were no postoperative cerebrospinal fluid leaks or meningitis. One patient required a reoperation 2 weeks after surgery to reduce the size of her fat graft, which was causing optic nerve compression; within 24 hours, her vision rapidly improved. At 3 months after surgery, all three patients had normal vision, no new endocrinopathy, and no residual tumor on MRI. At 10 months after surgery, one patient had a small asymptomatic tumor regrowth seen on MRI.

CONCLUSION

The endonasal approach with the operating microscope appears to be an effective minimally invasive method for removing relatively small midline tuberculum sellae meningiomas. Intraoperative ultrasound, the micro-Doppler probe, and angled endoscopes are useful adjuncts for safely and completely removing such tumors. Longer follow-up is needed to monitor for tumor recurrence in these patients.

Extended transsphenoidal approach with submucosal posterior ethmoidectomy for parasellar tumors. Technical note

The authors have developed an extended transsphenoidal approach with submucosal posterior ethmoidectomy for resection of tumors located in the cavernous sinus or the suprasellar region that are difficult to remove via the conventional transsphenoidal approach. Surgery was performed using this approach in 14 patients with large pituitary adenomas, three patients with craniopharyngiomas, and one patient with a meningioma of the tuberculum sellae. The submucosal dissection of the nasal septum used in the conventional transsphenoidal approach was extended to the superior lateral wall of the nasal cavity to expose the bony surface of the superior turbinate lying under the nasal mucosa. Submucosal posterior ethmoidectomy widened the area visualized through the conventional transsphenoidal approach both superiorly and laterally. This provided a safer and less invasive access to lesions in the cavernous sinus or the suprasellar region through the sphenoid sinus. Using this approach the authors encountered no postoperative complications, such as olfactory disturbance, cranial nerve palsy, or arterial injury. In this article the authors present the surgical methods used in this approach.

Intrasellar meningioma: case report and review of the literature

BACKGROUND

Intrasellar meningioma is a rare clinical entity, and surgical resection may be difficult when it is hypervascularized.

METHODS

A case of subdiaphragmatic hypervascular intrasellar meningioma with attachment to the dura of the anterior wall of the sella turcica is described. Literature review of 18 cases with operatively confirmed intrasellar meningioma discloses unexpected intraoperative bleeding and relatively low resectability of the tumor are also described.

RESULTS

We used preoperative endovascular embolization of feeding arteries, and resected a hypervascular intrasellar meningioma by a combined transsphenoidal-transcranial approach safely and without massive bleeding.

CONCLUSIONS

Preoperative endovascular embolization of feeding arteries and combined transsphenoidal-transcranial approach are useful for the surgical resection of hypervascular intrasellar meningiomas.

Dislocation of the pituitary gland by sphenocavernous meningiomas

BACKGROUND

Dislocation of the pituitary gland from the sella turcia by tumor has only very rarely been described. To date, only two cases have appeared in the neurosurgical literature.

METHODS

After intraoperative identification of pituitary dislocation in five patients with cavernous sinus meningiomas, a review of our most recent 20 patients with cavernous sinus meningiomas was performed. A subgroup of sphenocavernous meningiomas was identified, as were the associations between pituitary dislocation and the patient's endocrinologic status.

RESULTS

Of 20 consecutive patients with cavernous sinus meningiomas, seven tumors could be subclassified as sphenocavernous meningiomas due to the significant amount of tumor extension into the sphenoid sinus. At the time of surgery, dislocation of the pituitary gland from the sella into the suprasellar cistern was observed in five of seven of these patients. Four of the five patients with pituitary dislocation had evidence of hypopituitarism, whereas there was no evidence of this condition in the two patients with sphenocavernous meningiomas without pituitary dislocation.

CONCLUSIONS

Pituitary dislocation in these patients is likely due to the physical dislocation of the pituitary gland from the sella, through an incompetent diaphragma sella, and by the tumorous extension in the sphenoid sinus. The extension of a cavernous sinus meningioma into the sphenoid sinus, and specifically the sella turcica, may be via the intercavernous venous sinuses. The lack of endocrinologic improvement suggests that the hypopituitarism noted in these patients is likely due to disturbance of the pituitary microcirculation with subsequent pituitary ischemia. The possibility of pituitary dislocation in patients with sphenocavernous meningiomas, especially those with panhypopituitarism, should be considered and searched for at the time of surgery.

Endosellar meningiomas: report of 2 cases and review of the literature

Two cases of endosellar meningiomas are presented. The clinical and radiological picture is not always sufficiently specific to distinguish meningiomas from other types of sellar lesions, but pre-operative diagnosis is of fundamental importance in choosing the best surgical approach. In both cases, the transsphenoidal approach was used, and due to the dense consistency of the tumors, only biopsies were performed. One of the two patients was reoperated on using the sub-frontal approach for radical removal of the tumor. In the authors' experience, craniotomy proved to be the more favorable approach than the transsphenoidal route for radical excision of endosellar meningiomas. Literature on the classification of sellar meningiomas for radiological diagnosis and surgical strategy of endosellar meningiomas is reviewed.

Diaphragma sellae meningiomas

Despite their unique clinical, radiological, and surgical considerations, diaphragma sellae meningiomas remain largely undistinguished from tuberculum sellae meningiomas. On the basis of our experience with 12 patients with diaphragma sellae meningiomas and our review of the literature, we classify these tumors into three groups: Type A, originating from the upper leaf of the diaphragma sellae anterior to the pituitary stalk; Type B, originating from the upper leaf of the diaphragma sellae posterior to the pituitary stalk; and Type C, originating from the inferior leaf of the diaphragma sellae. Each type has specific clinical symptoms. Type A mainly presents with unilateral visual disturbances and visual field defects resembling those of tuberculum sellae meningiomas, although preoperative diabetes insipidus occurred in patients with large tumors. Type B causes fewer visual disturbances, but memory disturbance and hypopituitarism occur. Type C closely resembles nonfunctioning pituitary adenomas; bitemporal hemianopsia and hypopituitarism are common. Multiplanar magnetic resonance images can accurately diagnose the tumor and establish its type. Surgical approaches include the cranio-orbital approach for Types A and B and the transcranial-transsphenoidal approach for Type C. Surgery is more difficult than for tuberculum sellae meningiomas because of the deep location and the difficulty of dissecting Types A and B from the pituitary stalk. Repair of the sphenoid sinus to prevent cerebrospinal fluid leakage is mandatory for Type C tumors.