Extended endoscopic endonasal transsphenoidal approach to the suprasellar area: anatomic considerations--part 1

Endonasal Route for Tuberculum and Planum Meningiomas

Tuberculum and planum meningiomas are challenging tumors per their critical location and neurovascular relationships. The standard treatment is usually represented by complete tumor removal, being the transcranial approaches the well-established routes. During the last decades, novel surgical routes have been experimented with emphasis on the concept of minimal invasive approaches. The peculiar perspective from below the endoscopic endonasal approach provides a short and direct access avoiding brain and neurovascular structures manipulation, featuring excellent outcomes and a reduced morbidity. Ideal indications are small or medium size midline meningiomas, with wide tuberculum sellae angle and deep sella at the sphenoid sinus, possibly with no optic nerve and/or vessels encasement. Adequate removal of paranasal structures and extended bony opening over the dural attachment provide a wide surgical corridor ensuring safe intradural exposure at the suprasellar area. The main advantage is related to early decompression of the optic apparatus and reduced manipulation of subchiasmatic perforating vessels, with improved visual outcomes. Direct exposure of the inferomedial aspect of the optic canals allows for maximal decompression in cases of tumor extending within. Transcranial approaches tend to be selected for larger tumors with lateral extension beyond optic nerves and supraclinoid carotid arteries, in inaccessible areas from an endonasal corridor.

Midline Skull Base Meningiomas: Transcranial and Endonasal Perspectives

Simple Summary

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

Abstract

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

Endoscopic Endonasal Approach to the Third Ventricle Using the Surgical Corridor of the Reverse Third Ventriculostomy: Anatomo-Surgical Nuances

Objective Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures.

Methods Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle.

Results The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella, and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly.

Conclusion The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and precommissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Endoscopic Endonasal Approach to the Third Ventricle using the Corridor of the Reverse Third Ventriculostomy: anatomo-surgical nuances

Objective: Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures. Methods: Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle. Results: The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly. Conclusion: The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and pre-commissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Extended Neuroendoscopic Endonasal Approach for Resection of Craniopharyngioma in Children

Objective

To explore the surgical approach and technique of neuroendoscopic endonasal resection of pediatric craniopharyngiomas and to further evaluate its safety and effect in children.

Methods

The clinical data of 8 children with craniopharyngiomas who were surgically treated by neuroendoscopy through an extended endonasal approach in our center from 2018 to 2021 were retrospectively analyzed. The related surgical approach and technique were evaluated to improve the surgical results and further reduce the surgical complications when removing craniopharyngioma in children.

Results

All 8 patients achieved a gross-total resection of the tumor under neuroendoscopy. Postoperatively, 2 cases of transient hyperthermia and 4 cases of transient hyper- and/or hyponatremia occurred within the first 2 weeks, all of which were quickly controlled. Seven patients had symptoms of diabetes insipidus to varying degrees after the operation, and 4 of them improved within 1–3 months after surgery, but 3 cases still needed oral pituitrin. There were no cases of coma or death, leakage of cerebrospinal fluid, or severe electrolyte imbalance after surgery. During the postoperative follow-up of 3 months to 2 years, no tumor recurrence was found. Among the 7 patients who suffered postoperative neuroendocrine deficiencies, 3 patients were found to be temporary during the follow-up, but 4 patients still required hormone replacement therapy. Particularly, postoperative visual deterioration and olfactory defect that occurred in patients were all improved during follow-up periods. In addition, 4 cases of obesity were noted at the last follow-up.

Conclusions

Extended neuroendoscopic endonasal resection of craniopharyngiomas may be used as a safe and effective approach for children. Due to the poor pneumatization of the sphenoid sinus and worse compliance of treatment in children, surgical techniques of exposing the sellar region, removing the tumor, and reconstructing the skull base, as well as postoperative management of patients was proposed. However, due to the limited surgical cases in the study, the surgical safety and effects of the extended neuroendoscopic endonasal approach for children with craniopharyngiomas need to be further studied in the future.

The eagle sign: a new preoperative MRI-based tool for predicting topographic correlation between craniopharyngioma and hypothalamus

PURPOSE

Accurate prediction of topographical correlation between craniopharyngiomas (CPs) and hypothalamus is important for treatment. This study sought to develop a predicting tool based on preoperative-MRI through radiological-surgical-pathological-outcome analysis.

MATERIALS AND METHODS

Third ventricle floor (TVF), mammillary bodies and cerebral peduncle were evaluated through preoperative-MRI. An eagle-head-like sign named "eagle sign" was observed. Normal TVF on sagittal-MRI was defined as the baseline. Variants of the sign were analyzed by comparing with the baseline and corresponding correlations of CPs with hypothalamus were verified using intraoperative records, histopathology and outcome evaluation.

RESULTS

A total of 146 CPs patients, who undergone endoscopic endonasal procedure were divided into four groups based on the variants of "eagle sign". Group A: 24 patients with the upward sign; group B: 81 with the downward sign; group C: 21 with the anterior TVF upward sign and group D: 20 with the unidentifiable sign. Surgical-pathological analysis showed significant correlations between 95.8% CPs in group A and 95.2% in group C with tumor topography and tumor adherence to the hypothalamus. These CPs had their origins beneath the hypothalamus. In contrast, groups B and D, with hypothalamic origin, showed hypothalamic infiltration by tumor in 97.5% and 95% of cases in groups B and D, respectively. Outcomes of groups A and C were relatively better than groups B and D. Predictive sensitivity and specificity of "eagle sign" were more than 90%.

CONCLUSION

"Eagle sign" is an accurate tool for predicting topographic correlations between CPs and hypothalamus with high sensitivity and specificity.

Outcomes of the endoscopic endonasal approach for tumors in the third ventricle or invading the third ventricle

We aimed to retrospectively analyze the surgical and clinical outcomes of the endoscopic endonasal approach (EEA) for tumors in the third ventricle or invading the third ventricle. In total, 82 patients who had undergone surgical treatment using the EEA for tumors involving the third ventricle were enrolled in this study. This cohort study comprised 46 male and 36 female patients. The median age was 37 years (range, 5-76), and the median follow-up duration was 56.5 months (range, 6-117). Seventy-six patients had craniopharyngiomas, and 6 had gangliocytomas, gangliogliomas, astrocytomas, diffuse midline gliomas and lymphomas. Gross total removal was performed in 71 (86.5%) of the 82 patients, subtotal tumor removal in 7 patients and partial removal or biopsy in 4 patients. The pituitary stalk was preserved in 20 cases. Visual function improved in 40 (81.6%) of 49 patients. Endocrine function worsened in 41 (50%) of 82 patients. Hypothalamic function improved in 16 (72.7%) of 22 cases. Postoperative obesity occurred in 3 (20.0%) of 15 children and 11 (23.9%) of 46 adult patients. The postoperative cerebrospinal fluid leakage rate was 3.6%. Postoperative meningitis occurred in 18 (21.9%) cases. Permanent diabetes insipidus was identified in 73 (89.0%) of 82 patients. Tumor recurrence was observed in 10 patients (12%). The EEA appears to be a safe and effective treatment modality for tumors in the third ventricle or involving the third ventricle. However, more cases and long-term follow-up outcomes are required to confirm the clinical efficacy of the EEA.

The endoscopic endonasal approach for pediatric craniopharyngiomas: the key lessons learned

PURPOSE

The aim of this study is to highlight the role of the endoscopic endonasal approach (EEA) in pediatric craniopharyngiomas by reviewing our experience and the key lessons learned from the application of this approach in children.

METHODS

Between 1998 and 2017, 12 pediatric craniopharyngiomas were treated via EEA at our institution. Demographic data, preoperative assessment, tumor features, surgical results, complications, and recurrences were analyzed.

RESULTS

Visual defects were the most frequent presenting sign. Seven craniopharyngiomas were infradiaphragmatic, and five were supradiaphragmatic. The EEA was successfully performed in all cases with no complication related to children's sinonasal anatomy. Gross total resection (GTR) rate was of 75%. Endocrinological disturbances improved in one case (20%) and worsened in three (60%). New onset of diabetes insipidus was observed in four (36%) children. Visual defect improved in 91% of cases, with no new postoperative deficit. Postoperative cerebrospinal fluid (CSF) leak occurred in one patient (8%). Three patients (27%) experienced tumor regrowth, and one craniopharyngioma recurred (mean follow-up, 78 months).

CONCLUSIONS

The EEA offers a straight route to the sellar-suprasellar, making it the ideal approach for pediatric infradiaphragmatic craniopharyngiomas. In supradiaphragmatic craniopharyngiomas, the extended EEA provides a clearer and close-up visualization of the tumor-hypothalamus interface, which can grant better results in terms of quality of life. The pediatric skull base anatomy should not represent a contraindication for the endoscopic technique. Larger series encompassing a wider spectrum of pediatric craniopharyngiomas are needed to further support the benefits of this surgical approach.

Endoscopic reconstruction of large anterior skull base defects with opening of the sellar diaphragm. Experience at a tertiary level university hospital

Background

The indications for expanded endoscopic transnasal approaches continue to increase, with more complex skull base defects needing to be repaired. This study reviews the management of large anterior skull base defects with opening of the sellar diaphragm.

Method

A prospective analysis of endonasal endoscopic surgery carried out at Son Espases University Hospital between January 2013 and December 2018 was performed. The analysis included only the cases with a significative intra-operative cerebrospinal fluid leak. In all cases, reconstruction was performed by combining the gasket seal technique with a pedicled mucosal endonasal flap.

Results

Twenty-eight patients were included. The mucoperiosteal nasoseptal flap, the lateral wall flap and the middle turbinate flap were used in 13, 8 and 7 patients, respectively, combined with the gasket seal technique. One case of post-operative cerebrospinal fluid leak was observed (3.57 per cent).

Conclusion

The combination of a gasket seal with an endonasal mucosal flap is an excellent technique for repairing large anterior skull base defects.

Anterior communicating artery division in the endoscopic endonasal translamina terminalis approach to the third ventricle: an anatomical feasibility study

BACKGROUND

Endonasal endoscopic approaches (EEA) to the third ventricle are well described but generally use an infrachiasmatic route since the suprachiasmatic translamina terminalis corridor is blocked by the anterior communicating artery (AComA). The bifrontal basal interhemispheric translamina terminalis approach has been facilitated with transection of the AComA. The aim of the study is to describe the anatomical feasibility and limitations of the EEA translamina terminalis approach to the third ventricle augmented with AComA surgical ligation.

METHODS

Endoscopic dissections were performed on five cadaveric heads injected with colored latex using rod lens endoscopes attached to a high-definition camera and a digital video recorder system. A stepwise anatomical dissection of the endoscopic endonasal transtuberculum, transplanum, translamina terminalis approach to the third ventricle was performed. Measurements were performed before and after AComA elevation and transection using a millimeter flexible caliper.

RESULTS

Multiple comparison statistical analysis revealed a statistically significant difference in vertical exposure between the control condition and after AComA elevation, between the control condition and after AComA division and between the AComA elevation and division (p < 0.05). The mean difference in exposed surgical area was statistically significant between the control and after AComA division and between elevation and AComA division (p < 0.01), whereas it was not statistically significant between the control condition and AComA elevation (NS).

CONCLUSION

The anatomical feasibility of clipping and dividing the AComA through an EEA has been demonstrated in all the cadaveric specimens. The approach facilitates exposure of the suprachiasmatic optic recess within the third ventricle that may be a blind spot during an infrachiasmatic approach.

Preliminary Experience with a New Multidirectional Videoendoscope for Neuroendoscopic Surgical Procedures

Purpose

We assessed the applicability of a new multidirectional videoendoscope (digiCAMeleon, Karl Storz GmbH, Tuttlingen, Germany) in various neuroendoscopic procedures.

Methods

A 4-mm-diameter rigid videoendoscope (digiCAMeleon, Karl Storz GmbH, Tuttlingen, Germany) with 1 sensor and an internal LED light source was tested. The device offers a resolution of 1920 x 1080 pixels and weighs ≈ 215 g. The prototype was tested on three cadaveric heads using three different approaches: a) endoscopic endonasal transsphenoidal; b) frontal transcortical intraventricular; c) supraorbital.

Results

We identified several major benefits of the integrated system as applied to endoscopic endonasal, transcortical intraventricular, and endoscopic supraorbital keyhole approaches. These included improved maneuverability of the scope on account of reduced bulk and integration of the camera and fiberoptic light components, a variable angle of view from 0–70 degrees, and a novel feature that can be activated to maintain orientation of the surgical horizon. Our preliminary report highlights the potential for handling the videoendoscope in one hand, as one would a microsurgical instrument. The videoendoscope harbors all its electronic and lighting data into a unique and thin cable, thus resembling a modern "all-in-one" computer technology. Because of its reduced weight and ergonomic shape, controlling its movements is very easy and comfortable, even in the microsurgical environment. Furthermore, the videoendoscope offers the unique feature of orienting the horizon of vision, thanks to the possibility of offering angled views while working; this helps the surgeons to stay oriented with direct visualization and improved control of the instruments over a specific area of interest.

Conclusions

The videoendoscope prototype represents an HD-image quality versatile tool in a neurosurgical environment, thanks to its reduced weight and dimensions; in these preliminary simulations, we have identified optimized visibility and maneuverability as major benefits of this novel surgical adjunct.

Endoscopic Endonasal Approach in the Management of Rathke's Cleft Cysts

OBJECTIVE

Rathke's cleft cysts (RCCs) are quite uncommon sellar lesions that can extend or even arise in the suprasellar area. The purpose of this study is to evaluate the effectiveness of both standard and extended endoscopic endonasal approaches in the management of different located RCCs.

METHODS

We retrospectively analyzed a series of 29 patients (9 males, 20 females) complaining of a RCC, who underwent a standard or an extended endoscopic transsphenoidal approach at the Division of Neurosurgery, Department of Neurosciences and Reproductive and Odontostomatological Sciences, of the Università degli Studi di Napoli "Federico II". Data regarding patients' demographics, clinical evaluation, cyst characteristics, surgical treatments, complications and outcomes were extracted from our electronic database (Filemaker Pro 11, File Maker Inc., Santa Clara, California, USA).

RESULTS

A standard transsphenoidal approach was used in 19 cases, while the extended variation of the approach in 10 cases (5 purely suprasellar and 5 intra-suprasellar RCC). Cysts contents was fully drained in all the 29 cases, whilst a gross total removal, that accounts on the complete cyst wall removal, was achieved in an overall 55,1% of patients (16/29), specifically 36,8% (7/19) that received standard approach and 90% (9/10) of those that underwent to extended approach. We reported a 56.2% of recovery from headache, 38.5% of complete recovery and 53.8% of improvement from visual field defect and an overall 46.7% of improvement of the endocrine functions. Postoperative permanent DI rate was 10.3%, overall post-operative CSF leak rate 6.9%; recurrence/regrowth occurred in 4 patients (4/29, 13.8%), but only one required a second surgery.

CONCLUSION

The endoscopic transsphenoidal approach for the removal of a symptomatic RCC offers several advantages in terms of visualization of the surgical field during both the exposure and removal of the lesion. The "extended" variation of the endoscopic approach provides a direct access to the supradiaphragmatic space, allowing adequate view and room for the safe removal of selected supradiaphragmatic RCCs, regardless of the sellar size (even a not enlarged sella), and provides a higher likelihood of preserving normal pituitary tissue and functions.

Anatomical partition of the clival region and adjacent structures via extended endoscopic endonasal approach

OBJECTIVES

To explore the anatomy of the ventral clivus and adjacent structure in the endoscopic surgery through the anterior approach, particularly in accurate locating lesions in transnasal endoscopic surgery.

PATIENTS AND METHODS

A total of 9 formalin-fixed adult cadaver heads were injected with red and blue latex to observe the arteries and veins, respectively. The relationships between various parts of internal carotid artery (ICA) and anatomic structures of clivus were investigated, followed by the measurement of the posterior pharyngeal wall, anterior wall and posterior wall of clivus, cerebral dura mater, subdural space and adjacent regions to determine their correlations, as well as the clivus and adjacent structures.

RESULTS

The clivus structure was divided into the bone segment, the ICA segment and subdural segment for anatomic division according to the anatomic landmarks in the anatomic process. The clivus can be classified in a shape of '' with the ICA, including the middle superior region, middle inferior region, bilateral lateral superior and lateral inferior regions.

CONCLUSION

The ICA is closely related to the ventral clivus and adjacent structure, which can be used as the basis of anatomic division via anterior approach.

Expanding indications for the extended endoscopic endonasal approach to hypothalamic gliomas: preliminary report

Object In the last decade the indications for the endoscopic endonasal approach have been progressively expanded to include lesions that have not been traditionally considered amenable to resection through the transsphenoidal route. In this study, the authors analyze their experience with hypothalamic gliomas treated via the endoscopic endonasal approach. Methods Consecutive cases of hypothalamic gliomas treated since 2007 via an endoscopic endonasal approach were reviewed. Preoperative and postoperative neuroimaging as well as endocrinological, neurological, and visual symptoms were analyzed to assess the surgical outcome. Signs and symptoms of hypothalamic dysfunction including body mass index (BMI), memory, sleep-wake rhythm, and polyphagia were prospectively collected pre- and postoperatively to assess hypothalamic function. Quality of life was evaluated using the Katz scale. Results In the initial phase the endoscopic endonasal approach was adopted in 3 cases with a palliative intent, to obtain a biopsy sample or for debulking of the mass followed by radio- or chemotherapy. In 2 later cases it was successfully adopted to achieve gross-total tumor resection. Complications consisted of 2 postoperative CSF leaks, which required an endoscopic endonasal reintervention. Visual deficit improved in 3 cases and normalized in the other 2. Four patients developed diabetes insipidus, and 3 an anterior panhypopituitarism. All patients had a moderate increase in BMI. No patients presented with any other signs of hypothalamic damage, and their quality of life at follow-up is normal. Conclusions Despite the limitations of a short follow-up and small sample, the authors' early experience with the endoscopic endonasal approach has revealed it to be a direct, straightforward, and safe approach to third ventricle astrocytomas. It allowed the authors to perform tumor resection with the same microsurgical technique: dissecting the tumor with 2 hands, performing a central debulking, and controlling the bleeding with bipolar coagulation. The main limitations were represented by some anatomical conditions, such as the position of the chiasm and the anterior communicating artery complex and, finally, by the challenge of watertight plastic repair. To definitively evaluate the role of this approach in hypothalamic gliomas, a comparison with transcranial series would be necessary, but due to the rarity of these cases such a study is still lacking. The authors observed that more aggressive surgery is associated with a worse endocrinological outcome; thus they consider it to be an open question (in particular in prepubertal patients) whether radical removal is an advisable goal for hypothalamic gliomas.

The endonasal approach for treatment of cerebral aneurysms: A critical review of the literature

The last two decades of neurosurgery have seen flourishing use of the endonasal approach for the treatment of skull base tumors. Safe and effective resections of neoplasms requiring intracranial arterial dissection have been performed using this technique. Recently, there have been a growing number of case reports describing the use of the endonasal approach to surgically clip cerebral aneurysms. We review the use of these approaches in intracranial aneurysm clipping and analyze its advantages, limitations, and consider future directions. Three major electronic databases were queried using relevant search terms. Pertinent case studies of unruptured and ruptured aneurysms were considered. Data from included studies were analyzed. 8 case studies describing 9 aneurysms (4 ruptured and 5 unruptured) treated by the endonasal approach met inclusion criteria. All studies note the ability to gain proximal and distal control and successful aneurysm obliteration was obtained for 8 of 9 aneurysms. 1 intraoperative rupture occurred and was controlled, and delayed complications of cerebrospinal fluid leak, vasospasm, and hydrocephalus occurred in 1, 1, and 2 patients, respectively. Described limitations of this technique include aneurysm orientation and location, the need for lower profile technology, and challenges with handling intraoperative rupture. The endonasal approach for clipping of intracranial aneurysms can be an effective approach in only very select cases as demonstrated clinically and through cadaveric exploration. Further investigation with lower profile clip technology and additional studies need to be performed. Options of alternative therapy, limitations of this approach, and team experience must first be considered.

Endoscope-assisted keyhole surgery via an eyebrow incision for removal of large meningiomas of the anterior and middle cranial fossa

BACKGROUND

Conventional open surgery of large meningiomas has proven to be challenging even in experienced hands. Intense retraction and dissection around neurovascular structures increase morbidity and mortality. In the present study, we retrospectively analyzed the surgical technique, and outcome in 40 patients with large anterior cranial fossa meningiomas extending to the middle fossa. All patients were approached via a supraorbital mini craniotomy.

METHODS

It is a retrospective study of 40 patients (12 males, 28 females) who underwent surgery for large anterior cranial fossa meningiomas (diameter >5 cm) extending to the middle fossa in four different neurosurgical centers within 6 years. Depending on the localization of the tumor, the skin incision was between 2.5 and 3 cm long and was made without shaving the patient's eyebrow hair. Subsequently, a keyhole craniotomy was performed of approximately 0.8×1.2-1.4 cm in diameter. Preoperative and postoperative clinical and radiological data were analyzed and discussed.

RESULTS

Headache and psycho-organic syndrome were the most common presenting symptom in all patients. Presenting symptoms were associated with psychological changes in 23 cases, visual impairment in 19 patients, and anosmia in 17 patients. In overall, 36 of 40 patients (90%) showed a good outcome and returned at long-term follow-up to their previous occupations. The elderly patients returned to their daily routine.

CONCLUSION

With the appropriate keyhole approach as a refinement of the classic keyhole craniotomy to a smaller key"burr"hole, and with use of modern and new designed equipment, it is possible to perform complete resection of large anterior and middle fossa meningiomas with the same safety, efficiency and with less complication rates as described in the literature for large meningiomas even performed with classic keyhole craniotomies.

Quantitative analysis of progressive removal of nasal structures during endoscopic suprasellar approach

OBJECTIVES/HYPOTHESIS

Following recent studies measuring working area and surgical freedom of transcranial approaches, we aimed to quantify the gain achieved with progressive removal of nasal structures during the endoscopic endonasal suprasellar approach.

STUDY DESIGN

Human cadaveric anatomic study.

METHODS

The width of the endoscopic endonasal corridor to the suprasellar area was obtained and measured in five cadaver heads using a computerized tracking system with six steps: 1) standard approach with monolateral lateralization of middle turbinate; 2) standard bilateral lateralization of the middle turbinates; 3) monolateral middle turbinectomy; 4) bilateral middle turbinectomy; 5) monolateral ethmoidectomy; 6) bilateral ethmoidectomy.

RESULTS

The progressive removal of nasal structures offers a nonlinear increasing of the working area during the first steps of the procedure. The maximum advantage is offered by bilateral lateralization of the middle turbinates (102.7% increase in exposure), whereas a moderate increase is observed with each following step. Surgical freedom mainly increased during the first part of the approach, that is, with a monolateral right middle turbinectomy (17.9% raise of maneuverability), whereas additional steps did not increase surgical freedom enough to justify an aggressive nasal disruption.

CONCLUSIONS

Monolateral turbinectomy on the side of endoscope docking represents the best solution, optimizing working area and surgical freedom (offering increases of 116.9% and 17.9%, respectively). Bilateral turbinectomy, together with a monolateral anterior and posterior ethmoidectomy, can be reserved for selected cases (increases of 148.5% and 24.7%, respectively). Bilateral ethmoidectomy does not significantly improve surgical freedom (0.81%).

LEVEL OF EVIDENCE

N/A. Laryngoscope 124:2231-2237, 2014.

The endoscopic endonasal approach for the management of craniopharyngiomas: a series of 103 patients

OBJECT

Despite their benign histological appearance, craniopharyngiomas can be considered a challenge for the neurosurgeon and a possible source of poor prognosis for the patient. With the widespread use of the endoscope in endonasal surgery, this route has been proposed over the past decade as an alternative technique for the removal of craniopharyngiomas.

METHODS

The authors retrospectively analyzed data from a series of 103 patients who underwent the endoscopic endonasal approach at two institutions (Division of Neurosurgery of the Università degli Studi di Napoli Federico II, Naples, Italy, and Division of Neurosurgery of the Bellaria Hospital, Bologna, Italy), between January 1997 and December 2012, for the removal of infra- and/or supradiaphragmatic craniopharyngiomas. Twenty-nine patients (28.2%) had previously been surgically treated.

RESULTS

The authors achieved overall gross-total removal in 68.9% of the cases: 78.9% in purely infradiaphragmatic lesions and 66.3% in lesions involving the supradiaphragmatic space. Among lesions previously treated surgically, the gross-total removal rate was 62.1%. The overall improvement rate in visual disturbances was 74.7%, whereas worsening occurred in 2.5%. No new postoperative defect was noted. Worsening of the anterior pituitary function was reported in 46.2% of patients overall, and there were 38 new cases (48.1% of 79) of postoperative diabetes insipidus. The most common complication was postoperative CSF leakage; the overall rate was 14.6%, and it diminished to 4% in the last 25 procedures, thanks to improvement in reconstruction techniques. The mortality rate was 1.9%, with a mean follow-up duration of 48 months (range 3-246 months).

CONCLUSIONS

The endoscopic endonasal approach has become a valid surgical technique for the management of craniopharyngiomas. It provides an excellent corridor to infra- and supradiaphragmatic midline craniopharyngiomas, including the management of lesions extending into the third ventricle chamber. Even though indications for this approach are rigorously lesion based, the data in this study confirm its effectiveness in a large patient series.

Endoscopic endonasal skull base approach for parasellar lesions: Initial experiences, results, efficacy, and complications

BACKGROUND

Endoscopic surgery is suitable for the transsphenoidal approach; it is minimally invasive and provides a well-lit operative field. The endoscopic skull base approach through the large opening of the sphenoid sinus through both nostrils has extended the surgical indication for various skull base lesions. In this study, we describe the efficacy and complications associated with the endoscopic skull base approach for extra- or intradural parasellar lesions based on our experiences.

METHODS

Seventy-four cases were treated by an endoscopic skull base approach. The indications for these procedures included 55 anterior extended approaches, 10 clival approaches, and 9 cavernous approaches. The operations were performed through both the nostrils using a rigid endoscope. After tumor removal, the skull base was reconstructed by a multilayered method using a polyglactin acid (PGA) sheet.

RESULTS

Gross total resection was achieved in 82% of pituitary adenomas, 68.8% of meningiomas, and 60% of craniopharyngiomas in anterior extended approach and in 83.3% of chordomas in clival approach, but only in 50% of the tumors in cavernous approach. Tumor consistency, adhesion, and/or extension were significant limitations. Visual function improvements were achieved in 37 of 41 (90.2%) cases. Cerebrospinal fluid (CSF) leakage (9.5%), infections (5.4%), neural injuries (4.1%), and vascular injuries (2.7%) were the major complications.

CONCLUSIONS

Our experiences show that the endoscopic skull base approach is a safe and effective procedure for various parasellar lesions. Selection of patients who are unlikely to develop complications seems to be an important factor for procedure efficacy and good outcome.

Suprasellar pediatric craniopharyngioma resection via endonasal endoscopic approach

PURPOSE

Purely endoscopic endonasal approaches to surgical resection of pediatric suprasellar craniopharyngiomas are uncommonly performed. The aim of the study is to assess the feasibility and to describe the short-term outcomes of endonasal endoscopic approaches for the gross total resection of suprasellar craniopharyngiomas in the pediatric population.

METHODS

A combined neurosurgical-otolaryngologic team performed gross total resection of craniopharyngiomas in seven pediatric patients (mean age 9.6 years) at The Children's Hospital of Philadelphia over 2011-2012. Short-term outcomes were analyzed over a mean follow-up period of 6.3 months.

RESULTS

All tumors involved the sellar and/or suprasellar space and contained some cystic component. The mean maximal tumor diameter was 31.5 mm (range 18.5-62.0 mm). Using a binostril approach, gross total tumor resection was obtained in all patients (100 %). All patients with preoperative visual dysfunction demonstrated improvement in visual acuity. New or stable panhypopituitarism was observed in all cases. All patients developed postoperative diabetes insipidus, and cerebrospinal fluid leak occurred in one patient (15 %).

CONCLUSIONS

Complete radiographic resection of pediatric craniopharyngioma can be achieved via a purely endoscopic endonasal approach. In particular, this approach can be performed safely using the "two-nostrils-four-hands" technique with intraoperative neuronavigation. This approach should be highly considered in patients with progressive visual dysfunction. Further studies are needed to characterize the long-term surgical and clinical outcome of pediatric patients treated with this surgical approach.

Anatomical variations of the sphenoid sinus and its adjacent structures: a review of existing literature

The sphenoid sinus, one of the posterior groups of sinuses, has long been regarded as a 'neglected sinus' due to the anatomical location, poor understanding and poor accessibility, till the advent of endoscopes and modern imaging techniques. Increasing knowledge and greater understanding of this sinus has permitted an evolution in surgical practices and boundaries. Various literatures of the past report a great variety of rates of pneumatization, rates of optic nerve protrusion and dehiscence, as well as internal carotid artery (ICA) protrusion and dehiscence. One similarity noted among these studies is that the rates vary according to the ethnicity of the patients. Recommendations have also been made along the way with regard to modified surgical techniques. This review aims to describe the pneumatization of sphenoid sinus and the topographical relation of the optic nerve and ICA in different populations.

Endoscopic endonasal transsphenoidal approach to sellar lesions: a detailed account of our mononostril technique

Objective The endonasal endoscopic approach is currently under investigation for perisellar tumor surgery. A higher resection rate is to be expected and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery after 218 procedures. Methods Between October 2000 and September 2011, 210 patients received 218 endoscopic endonasal transsphenoidal procedures for perisellar lesions. Procedures were video recorded. The surgical technique was carefully analyzed. These cases were prospectively followed. Results Standard technique was mononostril approach with 0-degree optics. 30-degree and-after availability-45-degree optics were used for assessment of radicality. On follow-up, magnetic resonance imaging revealed radical tumor resection in 94 out of 104 cases (90.3%). Recurrent tumor growth was observed in five younger patients (2.2%). There was no mortality and a low complication rate. Three patients (1.4%) complained postoperatively of nasal congestion or reduced nasal air flow; however, no complaints were considered to be severe. Conclusion In comparison with other literature reports, the results are comparable or even better with respect to surgical radicality. The very low rate of nasal complaints is particularly remarkable. The technique has been shown to be safe and successful with a high radicality and only minor complications.

Value of anatomical landmarks in single-nostril endonasal transnasal-sphenoidal surgery

The sphenoid sinus occupies a central location in transsphenoidal surgery (TSS). It is important to identify relevant anatomical landmarks to enter the sphenoid sinus and sellar region properly. The aim of this study was to identify anatomical landmarks and their value in single-nostril endonasal TSS. A retrospective study was performed to review 148 cases of single-nostril endonasal TSS for pituitary lesions. The structure of the nasal cavities and sphenoid sinus, the position of apertures of the sphenoid sinus and relevant arteries and the morphological characteristics of the anterior wall of the sphenoid sinus and sellar floor were observed and recorded. The important anatomical landmarks included the mucosal aperture of the sphenoid sinus, a blunt longitudinal prominence on the posterior nasal septum, the osseocartilaginous junction of the nasal septum, the 'bow sign' of the anterior wall of the sphenoid sinus, the osseous aperture and its relationship with the nutrient arteries, the bulge of the sellar floor and the carotid protuberance. These landmarks outlined a clear route to the sella turcica with an optimal view and lesser tissue damage. Although morphological variation may exist, the position of these landmarks was generally consistent. Locating the sphenoid sinus aperture is the gold standard to direct the surgical route of TSS. The 'bow sign' and the sellar bulge are critical landmarks for accurate entry into the sphenoid sinus and sella fossa, respectively.

The endoscopic endonasal approach for the management of craniopharyngiomas involving the third ventricle

The third ventricle has historically represented one of the most challenging areas to access surgically, so that lesions directly harboring into the ventricular chamber or secondarily extending into it from adjacent areas have been approached by means of different transcranial routes. The aim of this work is to report our experience with the endoscopic endonasal approach in the management of a series of patients affected by craniopharyngiomas, extending into or arising from the third ventricle, evaluating pros and cons of this technique, also in regards of the anatomy and the pathology dealt with. During the period between January 2001 and February 2011, 12 patients, 9 male and 3 female (mean age 50.4 years; range 12-68) underwent an endoscopic endonasal approach for the treatment of a craniopharyngioma involving or arising from the third ventricle. According to the grade of involvement of the third ventricle, we identified three main ventricular growth patterns: (1) stalk-infundibulum; (2) infundibulum-ventricular chamber; (3) stalk-infundibulum-ventricular chamber. Though gross total removal was achieved in eight patients (66.7%), in three patients (25%) was possible a near total removal (>95%) and only in one case (8.3%) tumor removal has been partial (<50%). The overall analysis revealed a rate of 77.8% improvement of post-operative visual defects. Concerning the complications, we reported an overall CSF rate of 16.7%; two patients developed a subdural hematoma that has been treated with a surgical drainage. One patient died after the occurrence of a brainstem hemorrhage. The endoscopic endonasal route provides a good exposure, especially of the sub- and retro-chiasmatic areas, as well as of the stalk-infundibulum axis, which represents, when directly involved by a lesion, a gate to access the third ventricle chamber. Despite this study reporting only a preliminary experience, it seems that in properly selected cases--namely tumors growing mostly along the pituitary stem-infundibulum-third ventricle axis--this approach could be advocated as a valid route among the wide kaleidoscope of surgical approaches to the third ventricle.

Anatomical aspects in the transsphenoidal-transethmoidal approach to the optic canal: an anatomic-cadaveric study

BACKGROUND

Determining anatomic landmarks during a transsphenoidal-transethmoidal approach to the optic canal region is of critical importance.

METHODS

Sella-parasella sphenoid bone blocks were extracted from adult cadavers. Anatomic dissections were performed in the optic canal region using a surgical microscope in 30 samples. Quantitative measurements were done using photographic techniques. For histological evaluation, coronal and longitudinal cross-sections were taken from the bilateral optic canal in seven decalcified samples.

RESULTS

Optic protuberance (OP), carotid protuberance (CP), medial opticocarotid recess (MOCR) and lateral opticocarotid recess (LOCR) were defined as lateral landmarks determining the width of the opening in the extended transsphenoidal-transethmoidal approach. Among all anatomic markers, LOCR was the most determinant lateral marker with tubercular recess the most prominent central marker. OPs showing the optic canal direction and inter-recessal sulci had similar distinguishing rates in the sphenoid sinus base. Inter-recessal sulci formed by OPs and CPs were observed between MOCR and LOCR in most samples. In histologic sections, the dural sheath was thicker inferolaterally to the optic nerve compared to superiorly and medially; collagen arrangement was dense and irregular.

CONCLUSION

Although LOCRs and tubercular recesses are safe and prominent markers in extended transsphenoidal-transethmoidal approaches, other anatomic markers should also be taken into consideration to perform an efficient optic canal approach and optic canal decompression. Other factors for safe dissection are the length of the optic canal, bone thickness, adherence of dural structures and the course of the intradural ophthalmic artery.

Nasal symptoms following endoscopic transsphenoidal pituitary surgery: assessment using the General Nasal Patient Inventory

OBJECT

The endoscopic approach for pituitary tumors is a recent innovation and is said to reduce the nasal trauma associated with transnasal transsphenoidal surgery. The authors assessed the temporal changes in the rhinological symptoms following endoscopic transsphenoidal surgery for pituitary lesions, using the General Nasal Patient Inventory (GNPI).

METHODS

The GNPI was administered to 88 consecutive patients undergoing endoscopic transsphenoidal surgery at 3 time points (presurgery, 3-6 months postsurgery, and at final follow-up). The total GNPI score and the scores for the individual GNPI questions were calculated and differences between groups were assessed once before surgery, several months after surgery, and at final follow-up.

RESULTS

Of a maximum possible score of 135, the mean GNPI score at 3-6 months postsurgery was only 12.9 ± 12 and was not significantly different from the preoperative score (10.4 ± 13) or final follow-up score (10.3 ± 10). Patients with functioning tumors had higher GNPI scores than those with nonfunctioning tumors for each of these time points (p < 0.05). Individually, a mild increase in symptom severity was seen for symptoms attributable to the nasal trauma of surgery, with partial recovery (nasal sores and bleeding) or complete recovery (nasal blockage, painful sinuses, and unpleasant nasal smell) by final follow-up (p < 0.05). Progressive improvements in symptom severity were seen for symptoms more attributable to tumor mass preoperatively (for example, headaches and painkiller use [p < 0.05]). In total, by final follow-up 8 patients (9%) required further treatment or advice for ongoing nasal symptoms.

CONCLUSIONS

Endoscopic transsphenoidal surgery is a well-tolerated minimally invasive procedure for pituitary fossa lesions. Overall patient-assessed nasal symptoms do not change, but some individual symptoms may show a mild worsening or overall improvement.

Low-grade CSF leaks in endoscopic trans-sphenoidal pituitary surgery: efficacy of a simple and fully synthetic repair with a hydrogel sealant

BACKGROUND

Intra-operative CSF leak during endoscopic trans-sphenoidal surgery is not uncommon. Surgical repair with a variety of autologous grafts, rigid buttresses and CSF diversion techniques that add time and complexity have been reported.

OBJECTIVE

To describe a simple and purely synthetic closure for low-grade CSF leaks following endoscopic trans-sphenoidal pituitary surgery.

METHODS

A retrospective review of all endoscopic trans-sphenoidal surgery undertaken for pituitary pathology between 2005 and 2010 was carried out. The grade of CSF leak and success of graded repair was noted. Patients with no CSF leak (grade 0) had gelatin sponge placed in the tumour cavity. In those with low-grade CSF leak through small arachnoid defects (grade 1), repair was carried out using gelatin sponge and hydrogel sealant overlay. CSF diversion was not employed for low-grade CSF leaks.

RESULTS

Of the 255 endoscopic trans-sphenoidal surgeries, 158 (62%) had no leak (grade 0) and 74 (29%) had a low-grade leak (grade 1). Repairs in all cases were of grade 0, and all but two cases of grade 1 CSF leak were successful at a mean follow-up of 29 months. The 2 (2.7%) post-operative CSF leaks were seen within 6 weeks of surgery. Both cases were related to bouts of sneezing and were repaired using further trans-sphenoidal surgery and/or lumbar CSF diversion.

CONCLUSIONS

A simple purely synthetic repair of low-grade CSF leaks is described. This repair is safe and comparable in efficacy whilst avoiding the morbidity related to more complex sellar reconstructions previously described.

Minimally invasive surgery (endonasal) for anterior fossa and sellar tumors

The primary goal of any surgical approach is to adequately visualize and treat the pathologic condition with minimal disruption to adjacent normal anatomy. The work of several researchers has revealed the promise of minimally invasive endonasal neurosurgery and paved the way for broader applications of the technology. This article discusses the current state of minimally invasive endonasal techniques to address the pathologic conditions of the anterior cranial fossa and parasellar region.

Endoscopic minimally invasive neurosurgery: emerging techniques and expanding role through an extensive review of the literature and our own experience - part II: extraendoscopic neurosurgery

BACKGROUND/AIMS

The field of minimally invasive neurosurgery has grown dramatically especially in the last decades. This has been possible, in the most part, due to the advancements in technology especially in tools such as the endoscope. The contemporary classification scheme for endoscopic procedures needs to advance as well.

METHODS

The present classification scheme for neuroendoscopic procedures has become confusing because it mainly describes the use of the endoscope as an assisting device to the microscope. The authors propose an update to the current classification that reflects the independence of the endoscope as a tool in minimally invasive neurosurgery.

RESULTS

The proposed classification groups the procedures as 'intraendoscopic' neurosurgery or 'extraendoscopic' neurosurgery (XEN) in relation to the 'axis' of the endoscope. A review of the literature for the XEN group together with exemplary cases is presented.

CONCLUSION

We presented our proposed classification for the endoscope-only surgical procedures. The XEN group is expanded in this article.

Extended endoscopic endonasal approach to the suprasellar parachiasmatic cisterns: anatomic study

OBJECTIVE

The objective of this study is to recognize the available endoscopic routes during approaches to the suprasellar region and the surgical endoscopic anatomy of the related neurovascular structures.

MATERIAL AND METHODS

Extended endoscopic endonasal approach to the suprasellar region (EEASR) through the planum sphenoidale was performed in five fresh adult cadavers. The anatomic characteristics of the suprasellar parachiasmatic cisterns were studied and documented following the resection of the planum sphenoidale and opening the dura to expose the anterior incisural space.

RESULTS

Two separate surgical corridors could be used during EEASR: one above and the other below the chiasm. The suprachiasmatic route exposed the gyrus recti, interhemispheric fissure, anterior cerebral artery complex, the lamina terminalis, and through this structure the anterior recess of the third ventricle. The subchiasmatic route exposed the pituitary stalk, superior hypophyseal artery, supraclinoidal internal carotid artery, origin of the ophthalmic artery, anterior choroidal artery, posterior communicating artery, uncus, optic tract, basilar artery and its bifurcation, pons, posterior cerebral artery, superior cerebellar artery, and oculomotor nerve.

CONCLUSION

The EEASR, a minimally invasive route to suprasellar parachiasmatic area, provided wide exposure of the basal cisterns. The surgical areas that were accessed through the subchiasmatic corridor could be divided into a medial part that included the interpeduncular and prepontine cisterns and a lateral part that contained carotid and sylvian cisterns superiorly and the crural and ambient cisterns inferiorly.

Endoscopic anatomy of the oculomotor nerve: defining the blind spot during endoscopic skull base surgery

OBJECTIVE

The objective of this study is to define the endoscopic anatomy of the oculomotor nerve (CN III) and its neurovascular relations in order to facilitate surgical procedures and avoid injury to this nerve during endoscopic endonasal approach to the skull base.

MATERIALS AND METHODS

Endoscopic anatomy of the cavernous sinus was studied in seven fresh adult cadavers bilaterally and the basal cisterns in five fresh adult cadavers. Extended endoscopic endonasal suprasellar approach was performed to expose the oculomotor nerve in the interpeduncular cistern and the endoscopic endonasal transethmoidopterygoidosphenoidal approach to expose the oculomotor nerve within the cavernous sinus.

RESULTS

The extraorbital part of the oculomotor nerve can be divided into three segments in regard to the cisterns and venous spaces that are being transected: the interpeduncular segment, the cisternal segment, and the intercavernous segment. Of these segments, only the cisternal segment could not be exposed since this segment was located at the initial part of the roof of the cavernous sinus, anterolateral to the posterior clinoid, and posteroinferior to the anterior clinoid processes. Thus, cisternal segment of the oculomotor nerve was considered a blind spot during endoscopic approaches to the skull base.

CONCLUSION

We defined the endoscopic anatomy of the CN III and the related neurovascular structures and proposed a new segmental classification of extraorbital oculomotor nerve. Awareness of the endoscopic anatomy and the new segmental classification of the CN III may prove helpful in avoiding the risk of nerve injury during endoscopic endonasal surgery for skull base pathologies.

Extended endoscopic endonasal transsphenoidal approach to the suprasellar region: anatomic study and clinical considerations

The extended endoscopic endonasal approach to the suprasellar region was performed on 10 fresh adult cadavers to describe the anatomic landmarks and key surgical steps for safe performance of the surgical approach. The anatomic features and relationships of the sphenoidal ostia, sphenoidal sinus, and optic-carotid recess are described, as are four intradural suprasellar neurovascular structural areas, including the suprachiasmatic, subchiasmatic, retrosellar and ventricular regions. Various anatomic conditions may influence the use of the extended endoscopic endonasal approach. This approach provides a straight, midline approach to the suprasellar region and offers a multi-angled and close-up view of the relevant neurovascular structures. For clinical use, the most important surgery-related complications concern the management of operative bleeding and the prevention of postoperative cerebrospinal fluid leakage.

Endoscopic endonasal transsphenoidal approach for pituitary adenomas invading the cavernous sinus

Object

In this report, the authors describe their experience with surgical access to the cavernous sinus via a fully transnasal endoscopic approach in 20 cases. Clinical and endocrinological follow-up are discussed.

Methods

The authors used an endoscopic transsphenoidal approach in 192 patients with pituitary adenomas between September 1997 and January 2008, adding a cavernous sinus approach in 20 patients with invasive tumors during the last 5 years of this period. Parasellar extension of the tumor was measured according to the Knosp Scale. Radical tumor removal was achieved in 13 (65%) of 20 patients, and subtotal removal in 7 (35%). The authors used recently defined cavernous sinus approaches in the first 14 cases, including the paraseptal approach in 6, middle turbinectomy in 7, and contralateral middle turbinectomy in 1 case. Combined approaches rather than defined standard cavernous sinus approaches were used in 4 cases and an extended approach in 2.

Results

The tumors included nonsecretory adenomas in 5 cases (25%), growth hormone–secreting adenomas in 7 (35%), prolactin-secreting adenomas in 4 (20%), and adrenocorticotropic hormone–secreting adenomas in 4 cases (20%). Normal growth hormone and insulin-like growth factor 1 levels were achieved in 4 patients (57%) with growth hormone adenomas, and remission criteria were obtained in 3 patients with prolactinomas and 3 patients with adrenocorticotropic hormone–secreting adenomas.

Conclusions

Compared with transcranial and microscopic transsphenoidal surgery, endoscopic transsphenoidal surgery offers a wide exposure for cavernous sinus medial wall adenomas that enables removal of the adenoma from the medial cavernous sinus wall. Because of the necessity for multidisciplinary treatment to achieve satisfactory results, Gamma Knife surgery and medical therapy should be supplementary treatment options after endoscopic transsphenoidal surgery.

Extended endoscopic endonasal transsphenoidal approach for residual or recurrent craniopharyngiomas

Object

The management of recurrent or residual craniopharyngiomas remains controversial. Although possible, revision surgery is more challenging than primary surgery, and more often results in incomplete resection and an increased risk of death and complications. The extended (also called expanded) endoscopic endonasal transsphenoidal approach through the planum sphenoidale has been proposed over the past decade as an alternative surgical route for removal of various suprasellar tumors including craniopharyngiomas. In this study, the authors describe the feasibility and advantages of this technique in recurrent or symptomatic residual craniopharyngiomas.

Methods

Between January 2004 and June 2008, 22 patients underwent surgery via the extended endoscopic transsphenoidal approach for the treatment of recurrent or residual symptomatic craniopharyngiomas at either the University of Pittsburgh or the Universita degli Studi di Napoli. The lesions included 12 purely suprasellar craniopharyngiomas, 9 with both intra- and suprasellar extensions, and 1 arising from a remnant in the Meckel cave. To better evaluate the features of the extended endonasal approach for recurrent or residual craniopharyngiomas, each patient was assigned to 1 of 3 subgroups depending on the original surgical treatment: transcranial pterional route (13 patients), transphenoidal approach (3 patients; 2 microsurgically and 1 with the standard endoscopic technique), or extended endonasal endoscopic approach (6 patients).

Results

Total removal was achieved in 9 patients (40.9%), and in 8 patients (36.4%) near-total removal (defined as > 95% removal) was possible. Subtotal removal (> 70%) was attained in 4 patients (18.2%), and tumor removal was partial (< 50%) in only 1 case (4.5%). There were no deaths or major complications, including behavior changes. Postoperative CSF leaks developed in 2 patients in the transcranial subgroup, and 1 in the transsphenoidal subgroup (overall rate 13.6%), requiring early successful endoscopic revision surgery for the cranial base defect.

Conclusions

Most of the advantages of the endoscopic endonasal technique were noted during tumor dissection from the inferior aspect of the chiasm, the infundibulum, the third ventricle, and/or the retro- and parasellar areas. These benefits were best appreciated in patients who had originally undergone transcranial surgery, since in such cases the authors' endoscopic endonasal approach was a virgin route. However, the extended endoscopic endonasal technique can also be safely used in patients who originally underwent transsphenoidal surgery. The endoscopic endonasal technique should be considered as a therapeutic option in selected cases of recurrent or symptomatic residual craniopharyngiomas.

Endoscopic transnasal resection of anterior cranial fossa meningiomas

OBJECT

The extended transnasal approach, a recent surgical advancements for the ventral skull base, allows excellent midline access to and visibility of the anterior cranial fossa, which was previously thought to be approachable only via a transcranial route. The extended transnasal approach allows early decompression of the optic canals, obviates the need for brain retraction, and reduces neurovascular manipulation.

METHODS

Between 2004 and 2007, 11 consecutive patients underwent transnasal resection of anterior cranial fossa meningiomas--4 olfactory groove (OGM) and 7 tuberculum sellae (TSM) meningiomas. Age at surgery, sex, symptoms, and imaging studies were reviewed. Tumor size and tumor extension were estimated, and the anteroposterior, vertical, and horizontal diameters were measred on MR images. Medical records, surgical complications, and outcomes of the patients were collected.

RESULTS

A gross-total removal of the lesion was achieved in 10 patients (91%), and in 1 patient with a TSM only a near-total (> 90%) resection was possible. Four patients with preoperative visual function defect had a complete recovery, whereas 3 patients experienced a transient worsening of vision, fully recovered within few days. In 3 patients (2 with TSMs and 1 with an OGM), a postoperative CSF leak occurred, requiring a endoscopic surgery for skull base defect repair. Another patient (a case involving a TSM) developed transient diabetes insipidus. The operative time ranged from 6 to 10 hours in the OGM group and from 4.5 to 9 hours in the TSM group. The mean duration of the hospital stay was 13.5 and 10 days in the OGM and TSM groups, respectively. Six patients (3 with OGMs and 3 with TSMs) required a blood transfusion. Surgery-related death occurred in 1 patient with TSM, in whom the tumor was successfully removed.

CONCLUSIONS

The technique offers a minimally invasive route to the midline anterior skull base, allowing the surgeon to avoid using brain retraction and reducing manipulation of the large vessels and optic apparatus; hastens postoperative recovery; and improves patient compliance. Further assessment and refinement are required, particularly because of the potential risk of CSF leakage. Other studies and longer follow-up periods are necessary to ascertain the benefits of the technique.