Endoscopic Endonasal Skull Base Surgery: Advantages,Limitations, and Our Techniques to Overcome Cerebrospinal Fluid Leakage: Technical Note

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

Endoscopic endonasal skull base surgery: Part 1--The midline anterior fossa skull base.

OBJECTIVE: An endonasal endoscopic surgery to the anterior fossa skull base was developed in cadaver dissection as a minimally invasive surgical technique and, subsequently, used in patient treatment. METHODS: Six cadaver head specimens were used. Ideal head positioning and various surgical routes were studied. To estimate the extent of surgical exposure provided by this technique, the width of the exposed anterior cranial fossa was measured between the medial margin of the orbits, the optic nerves and the carotid arteries. Three demonstrative patient cases are presented. RESULTS: Ideal head positioning was discovered to be at 15-degree extension of the forehead-chin line. Paraseptal, middle meatal and middle turbinectomy approaches were developed. The average width between the medial orbits was measured to be 24 mm (range 22-29 mm) at the crista galli level, 27 mm (range 24-30 mm) at the planum sphenoidale, 18 mm (range 15-22 mm) between the optic nerves, and 17 mm (range 13-21 mm) between the rostral carotid siphons. This technique, when it was applied in patient care, proved to be minimally invasive. CONCLUSIONS: This endoscopic endonasal approach provided a direct "short-cut" access to the midline anterior fossa skull base. This technique can be used for the surgical treatment of cerebrospinal fluid (CSF) leak, meningiomas, craniopharyngiomas, pituitary adenomas, and other midline intracranial anterior skull base lesions. This is the first report in the English literature describing endonasal endoscopy for the surgical treatment of primary intracranial anterior fossa skull base lesions.     

Exclusive endoscopic removal of a planum sphenoidale meningioma: a case report.

Midline suprasellar meningiomas have traditionally been removed through transcranial approaches. Endoscopic endonasal approaches have already been described for the removal of tuberculum sellae meningiomas (Cook), but their exclusive use for planum sphenoidale meningiomas has never been reported. A case report of a planum sphenoidale meningioma removed through a transnasal endoscopic approach is presented: the goal of this technique is tumor control with minimal morbidity. The anterior skull base defect has been reconstructed with a pedicled mucosa flap from nasal septum (Hadad-Bassagasteguy flap). The postoperative course was uneventful, and no sign of recurrence was noticed at the MRI control performed after 3 months.     

Combined transcranial and endoscopic nasal resection for esthesioneuroblastoma. Technical note

Esthesioneuroblastoma is a rare malignant neoplasm arising in the nasal cavity. Huge esthesioneuroblastomas, extending into the ethmoid roof and the cribriform plate, or invading the anterior cranial fossa, have traditionally been treated by craniofacial resection. Because of the invasiveness and potentially disfiguring results of a transfacial approach, a new technique has been proposed, combining endoscopic nasal and anterior craniotomy resection. We describe the case of a young male presenting with a large esthesioneuroblastoma involving the nasal cavity and the anterior cranial fossa, causing a huge skull base destruction. A combined transcranial and endoscopic nasal resection resulted in a macroscopically total removal of the tumor. The operative technique is reviewed in detail, along with the method used for the reconstruction of the anterior skull base defect.     

Endoscopic endonasal transsphenoidal surgery: a mentoring surgical model

Background: We report the experience of endoscopic endonasal transsphenoidal surgery (EETS) for resection of pituitary region tumours at Wellington, the central regional referral centre for neurosurgery in New Zealand, and discuss the collaborative mentoring surgical model that enhanced the learning experience. Method: Between January 2007 and June 2009, a total of 47 operations on 46 patients were performed and reviewed retrospectively. All patients had perioperative clinical assessment, hormonal profile and magnetic resonance imaging studies for residual/recurrent disease. The collaborative model utilized two neurosurgeons with experience in the microsurgical resection of pituitary tumours: an endoscopic skull base fellowship trained rhinologist and an endoscopic skull base rhinologist with more experience who visited twice a year from Adelaide, Australia. Results: The pathology results included: 30 non‐functioning pituitary adenomas, 10 secreting pituitary adenomas, 3 meningiomas, 1 chordoma, 1 anterior skull base adenocarcinoma and 1 clival prostate metastasis. Complete tumour resection was intended and achieved in 38 cases. All 10 patients with secreting adenomas achieved improvement of hormonal profile. Nineteen out of 27 cases demonstrated improvement of vision. Perioperative complications included one epistaxis, three cerebrospinal fluid fistulae, one delayed chronic subdural haematoma and one persistent diabetes insipidus. Conclusion: Our results highlight the value of a collaborative mentoring surgical model for a single centre adopting the endoscopic transsphenoidal technique and demonstrate that excellent EETS outcomes can be achieved in a smaller endoscopic skull base unit in Australasia during the learning phase.     

Expanded Endoscopic Endonasal Approaches to Skull Base Meningiomas

Anterior cranial base meningiomas have traditionally been addressed via frontal or frontolateral approaches. However, with the advances in endoscopic endonasal treatment of pituitary lesions, the transphenoidal approach is being expanded to address lesions of the petrous ridge, anterior clinoid, clivus, sella, parasellar region, tuberculum, planum, olfactory groove, and crista galli regions. The expanded endoscopic endonasal approach (EEEA) has the advantage of limiting brain retraction and resultant brain edema, as well as minimizing manipulation of neural structures. Herein, we describe the techniques of transclival, transphenoidal, transplanum, and transcribiform resections of anterior skull base meningiomas. Selected cases are presented.     

Endoscopic, endonasal extended transsphenoidal, transplanum transtuberculum approach for resection of suprasellar lesions

OBJECT: The extended transsphenoidal approach is a less invasive method for removing purely suprasellar lesions compared with traditional transcranial approaches. Most advocates have used a sublabial incision and a microscope and have reported a significant risk of cerebrospinal fluid (CSF) leakage. The authors report on a series of purely endoscopic endonasal surgeries for resection of suprasellar supradiaphragmatic lesions above a normal-sized sella turcica with a low risk of CSF leakage. METHODS: A purely endoscopic endonasal approach was used to remove suprasellar lesions in a series of 10 patients. Five lesions were prechiasmal (three tuberculum sellae and two planum sphenoidale meningiomas) and five were post-chiasmal (four craniopharyngiomas and one Rathke cleft cyst). The floor of the planum sphenoidale and the sella turcica was reconstructed using a multilayer closure with autologous and synthetic materials. Spinal drainage was performed in only five cases. Complete resection of the lesions was achieved in all but one patient. The pituitary stalk was preserved in all but one patient, whose stalk was invaded by a craniopharyngioma and who had preoperative diabetes insipidus (DI). Vision improved postoperatively in all patients with preoperative impairment. Six patients had temporary DI; in five, the DI became permanent. Four patients with craniopharyngiomas required cortisone and thyroid replacement. After a mean follow up of 10 months, there was only one transient CSF leak when a lumbar drain was clamped prematurely on postoperative Day 5. CONCLUSIONS: A purely endoscopic endonasal approach to suprasellar supradiaphragmatic lesions is a feasible minimally invasive alternative to craniotomy. With a multilayer closure, the risk of CSF leakage is low and lumbar drainage can be avoided. A larger series will be required to validate this approach.     

Endoscopic Surgery of Skull Base Chordomas

Objective To assess our clinical experience in treating midline intracranial pathology using minimally invasive surgical techniques.Design Retrospective chart review of patients undergoing endoscopic endonasal resection of clival chordomas.Setting Two tertiary referral centers in Australia and New Zealand.Main Outcome Measures Patients were assessed by intraoperative findings (macroscopic resection rate, tumor size, and operative complications) and clinical outcomes (residual disease, postoperative complications, recurrence rate, and mortality).Results Fourteen patients underwent endoscopic resection of clival chordomas (seven primary, seven revision) with a mean follow-up of 41.45 months (3 to 104 months). Macroscopic resection rates were 71% and 29%, respectively. Mean operative time was 386 minutes. Overall cerebrospinal fluid (CSF) leak rate was 3/14 (21%) and, using the nasoseptal flap, it was 0/5 (0%). Two patients developed late recurrence; one died of disease and one was treated with intensity modulated radiation therapy. Overall mortality was 2/14 (14%).Conclusion Endoscopic resection of clival chordomas is a safe and viable alternative to the traditional open approach. The nasoseptal flap is an excellent method of obtaining a watertight skull base closure. Furthermore, this series highlighted the fact that the primary attempt at surgery offers the best chance to achieve a total resection.     

Expanded endonasal approach, a fully endoscopic transnasal approach for the resection of midline suprasellar craniopharyngiomas: a new classification based on the infundibulum

OBJECT: Craniopharyngiomas are notoriously difficult to treat. Surgeons must weigh the risks of aggressive resection against the long-term challenges of recurrence. Because of their parasellar location, often extending well beyond the sella, these tumors challenge vision and pituitary and hypothalamic function. New techniques are needed to improve outcomes in patients with these tumors while decreasing treatment morbidity. An endoscopic expanded endonasal approach (EEA) is one such technique that warrants understanding and evaluation. The authors explain the techniques and approach used for the endoscopic endonasal resection of suprasellar craniopharyngiomas and introduce a tumor classification scheme. METHODS: The techniques and approach used for the endoscopic, endonasal resection of suprasellar craniopharyngiomas is explained, including the introduction of a tumor classification scheme. This scheme is helpful for understanding both the appropriate expanded approach as well as relevant involved anatomy. RESULTS: The classification scheme divides tumors according to their suprasellar extension: Type I is preinfundibular; Type II is transinfundibular (extending into the stalk); Type III is retroinfundibular, extending behind the gland and stalk, and has 2 subdivisions (IIIa, extending into the third ventricle; and IIIb, extending into the interpeduncular cistern); and Type IV is isolated to the third ventricle and/or optic recess and is not accessible via an endonasal approach. CONCLUSIONS: The endoscopic EEA requires a thorough understanding of both sinus and skull base anatomy. Moreover, in its application for craniopharyngiomas, an understanding of tumor growth and extension with respect to the optic chiasm and infundibulum is critical to safely approach the lesion via an endonasal route.     

Endonasal endoscopic resection of esthesioneuroblastoma: the Johns Hopkins Hospital experience and review of the literature

Esthesioneuroblastoma is an uncommon malignant tumor originating in the upper nasal cavity. The surgical treatment for this tumor has traditionally been via an open craniofacial resection. Over the past decade, there has been tremendous development in endoscopic techniques. In this report, we performed a retrospective analysis of patients with esthesioneuroblastomas treated with a purely endonasal endoscopic approach and resection at the Johns Hopkins Hospital between January 2005 and April 2010. A total of eight patients with esthesioneuroblastoma, five men and three women, were identified. Six patients were treated for primary disease, and two were treated for tumor recurrence. The modified Kadish staging was A in one patient (12.5%), B in two patients (25%), C in four patients (50%), and D in one patient (12.5%). All patients had a complete resection with negative intraoperative margins. One patient had intraoperative hypertension; there were no perioperative complications. With a mean follow-up of over 27 months, all patients are without evidence of disease. In addition, we reviewed the literature and identified several overlapping case series of patients with esthesioneuroblastoma treated via a purely endoscopic technique. Our series adds to the growing experience of expanded endonasal endoscopic surgery in the treatment of skull base tumors including esthesioneuroblastoma. Longer follow-up on a larger number of patients is required to further demonstrate the utility of endoscopic approaches in the management of this malignancy.     

Resection of giant meningiomas of the anterior cranial fossa using orbital osteotomies

AIM: The challenge in large cranial base meningiomas is total resection of the tumor with the least possible mortality and morbidity. During the last two decades the technical approaches for anterior skull base tumors have shown a considerable progress, providing a wide exposure with minimal brain retraction. The purpose of this study is to present our experience with these approaches for treatment of giant anterior cranial fossa meningiomas. METHODS: A retrospective analysis was performed in 20 patients with giant meningiomas (diameter >4.5 cm) of the anterior cranial fossa, which were treated surgically in our department, between January 1992 and January 2002. There were 5 men and 15 women with an average age of 48,3 years. Mental and visual disturbances were the most common presenting symptoms. We used the extended subfrontal approach for 16 patients and the fronto-orbito-zygomatic approach for 4 patients. The follow-up period ranged from 3 to 10 years. RESULTS: In all patients, total resection of the tumor (Simpson grade I, 12 patients, Simpson grade II, 8 patients) was accomplished. Significant improvement occurred by the time of follow-up examination in all but three patients. No evidence of recurrence was observed in 19 of the 20 patients. CONCLUSIONS: The extended anterior skull base approaches, using orbital osteotomies, for giant meningiomas of the anterior cranial fossa have improved the extent of radical tumor removal with minimal neurological morbidity. Furthermore a long term prevention of recurrence was achieved.     

Classification and surgical approaches for transnasal endoscopic skull base chordoma resection: a 6-year experience with 161 cases

The aim of this study is to retrospectively analyze 161 cases of surgically treated skull base chordoma, so as to summarize the clinical classification of this tumor and the surgical approaches for its treatment via transnasal endoscopic surgery. Between August 2007 and October 2013, a total of 161 patients (92 males and 69 females) undergoing surgical treatment of skull base chordoma were evaluated with regard to the clinical classification, surgical approach, and surgical efficacy. The tumor was located in the midline region of the skull base in 134 cases, and in the midline and paramedian regions in 27 cases (extensive type). Resection was performed via the transnasal endoscopic approach in 124 cases (77 %), via the open cranial base approach in 11 cases (6.8 %), and via staged resection combined with the transnasal endoscopic approach and open cranial base approach in 26 cases (16.2 %). Total resection was achieved in 38 cases (23.6 %); subtotal resection, 86 cases (53.4 %); partial resection of 80–95 %, 29 cases (18 %); and partial resection <80 %, 8 cases (5 %). The clinical classification method used in this study seems suitable for selection of transnasal endoscopic surgical approach which may improve the resection degree and surgical efficacy of skull base chordoma. Gross total resection of skull base chordoma via endoscopic endonasal surgery (with addition of an open approach as needed) is a safe and viable alternative to the traditional open approach.     

Combined simultaneous endoscopic transsphenoidal and endoscopic transventricular resection of a giant pituitary macroadenoma

Intrasellar and sellar-suprasellar adenomas are generally removed through a transsphenoidal approach. Giant adenomas with significant suprasellar extension often require a craniotomy or combined "above and below" approach. The use of endoscopes has increased the visualization capacity of the transsphenoidal route and made these surgeries less invasive. In this report, we describe a novel combination of the endoscopic transsphenoidal approach with the endoscopic transventricular approach to remove a giant pituitary macroadenoma extending into the third and lateral ventricles. The tumor was initially removed via an endoscopic transnasal transsphenoidal, transtuberculum, transplanum approach. A second endoscope was then advanced into the lateral ventricle through a pre-coronal burr hole to assist in mobilizing the tumor and assure a complete resection. Multilayer closure and a ventriculo-peritoneal shunt were performed to insure a watertight seal of the skull base. Giant pituitary adenomas have traditionally been removed with staged or combined transsphenoidal and transcranial approaches. We describe the successful implementation of a minimal access endoscopic combined extended transsphenoidal and transventricular approach that avoids craniotomy and brain retraction.     

Anatomical study of the pterygopalatine fossa using an endoscopic endonasal approach: spatial relations and distances between surgical landmarks

OBJECT: The pterygopalatine fossa is an area that lies deep within the skull base. The recent extensive use of the endoscopic endonasal approach has provided neurosurgeons with a method to reach various areas of the skull base through a less invasive approach than traditional transcranial or transfacial approaches. This study aims to provide neurosurgeons with new data concerning direct endoscopic measurements and precise anatomical topography features of the pterygopalatine fossa. METHODS: An anatomical dissection of six fixed cadaver heads (12 pterygopalatine fossae) was performed to analyze spatial relationships and distances between the most important neurovascular structures in this region, and to estimate the size of the endoscopic surgical field for operations in this area. The endoscopic endonasal approach offers direct access to the pterygopalatine fossa through its anteromedial walls. CONCLUSIONS: Using an endoscopic endonasal approach makes it possible to identify all of the anatomical landmarks of the pterygopalatine fossa and almost all of the contiguous skull base areas.     

Quality of life and olfactory function after suprasellar craniopharyngioma surgery—a single-center experience comparing transcranial and endoscopic endonasal approaches

Neurosurgical Review - The endoscopic endonasal approach to suprasellar craniopharyngiomas has become popular as alternative to transcranial approaches. However, the literature lacks data regarding...     

One-Piece Modified Gasket Seal Technique

Objectives Review the effectiveness of a modified gasket seal technique utilizing a porous high-density polyethylene plate/rectus sheath fascia construct without fat grafting for primary closure of anterior defects following endoscopic skull base surgery.Design Retrospective review (2011-2012).Setting Single academic medical center.Methods A retrospective review of five patients who underwent expanded endoscopic endonasal surgery for various pathologies (two craniopharyngiomas, two tuberculum meningiomas, and one planum meningioma) was performed. Skull base closure was performed using a one-piece modified gasket seal technique. Primary outcome measures included postoperative cerebrospinal fluid (CSF) leaks and donor site morbidity.Results There were no postoperative CSF leaks. Two patients experienced aseptic meningitis treated with a 14-day course of steroids. Two patients experienced new postoperative chronic/recurrent sinusitis treated with oral antibiotics and topical nasal therapy. There was no donor site morbidity such as infection, hematoma, or hernias.Conclusions The one-piece modified gasket-seal closure is a safe and effective method for reconstruction of endonasal defects of the anterior skull base. Rectus sheath fascia is an appropriate dural substitute for free tissue grafting with low donor site morbidity. The construction of the one-piece graft significantly decreases operative time and lowers the learning curve for multilayered closure.     

Surgical management of petroclival chordomas: report of eight cases.

In the management of skull base chordomas, surgical treatment is essential to achieve long-term control. A petroclival chordoma growing laterally in the skull base is one of the most challenging tumors for neurosurgeons. We have treated petroclival chordomas based on the principle of maximal surgical resection of the tumor with minimal morbidity. Lateral skull base approaches were used to approach petroclival chordomas in eight patients. The surgical procedure involved removal of soft tumor tissue and extensive drilling of adjacent bony structures. Gross total resection of the tumor was achieved in six patients. Subtotal resection in the remaining two patients was associated with acceptable morbidity. In cases of petroclival chordomas, lateral skull base approaches can be used as a primary procedure, although those approaches may be associated with high rates of morbidity and mortality.     

Combined Transcranial-endonasal Reconstructive Surgery for Cerebrospinal Fluid Leakage Resulting from Traumatic Anterior Skull Base Fractures Involving the Parasellar Region

Extensive traumatic anterior skull base fractures from the frontal sinus to the parasellar region are frequently accompanied by multiple dural defects that cause persistent cerebrospinal fluid (CSF) leakage. Conventional transcranial reconstruction using a frontal periosteal flap is frequently insufficient, and parasellar dural defects are often deep, complex, and difficult to identify. In this report, we describe a combined transcranial–endonasal reconstructive technique and report our experience. Simultaneous combined transcranial and endoscopic surgery was performed in three patients with CSF leakage resulting from traumatic anterior skull base fractures. Dural defects were thoroughly identified from the transcranial and endonasal surgical fields, and covered using a multilayer sealing technique. The anterior regions of the anterior skull base were reconstructed using a free fascial flap and frontal periosteal flap; posterior and parasellar regions were reconstructed using a fat graft, vascularized nasoseptal flap, and endonasal balloon. Suturing the transcranial grafts to the parasellar dura mater was performed collaboratively by the transcranial and endonasal surgeons. In our cases, complete cessation of CSF leakage was achieved without perioperative lumbar drainage in all patients. Mean time to postoperative ambulation was 7 days (range, 3–11). No surgical complications occurred. Simultaneous transcranial and endonasal procedures were helpful to detect all sites of CSF leakage and secure reconstructive grafts. The combined transcranial and endonasal reconstructive technique achieved secure skull base reconstruction without recurrence of CSF leakage, and allowed early postoperative ambulation. This technique can be a reliable surgical option to repair CSF leakage resulting from extensive anterior skull base fractures.     

Frontal skull base surgery combined with endonasal endoscopic sinus surgery

BACKGROUND: Postoperative infection remains a serious complication after radical resection of anterior skull base lesions because intracranial, nasal, and paranasal cavities are opened during surgery. To prevent complications from postoperative infection, we combined endonasal endoscopic sinus surgery (ESS) with the frontal transbasal approach in patients with skull base lesions. METHODS: Patients (n = 16) with anterior skull base lesions extending to the paranasal or nasal cavity underwent surgical resection via the frontal transbasal approach. After removal of the lesion via the transcranial approach, enlargement of the ostium or sinusotomy was performed bilaterally using our endonasal ESS procedure. The main purpose of ESS is the establishment of a wide drainage route to avoid dead space and postoperative infection. Furthermore, we confirmed the absence of residual lesion and leakage of cerebrospinal fluid (CSF), endoscopically. RESULTS: The frontal transbasal approach combined with endonasal ESS was performed in 16 patients with frontal skull base lesions. There were 8 malignant tumors, 6 benign tumors, and 2 mucoceles. Although 11 patients had preoperative active paranasal sinusitis, most frequently at the ethmoid sinus, none experienced postoperative infection. There was no complication related to ESS procedure. Furthermore, leakage of CSF and extracranial residual tumor were not found. CONCLUSION: Endonasal ESS after frontal skull base surgery is a highly useful technique for preventing postoperative infection, especially for the cases with large skull base tumors extending into other regions involving the paranasal sinuses or nasal cavity and with active paranasal sinusitis.