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

Effect of Optic Canal Opening on Postoperative Visual Acuity in Patients with Tuberculum Sellae Meningiomas

BACKGROUND

 Tuberculum sellae meningiomas (TSMs) account for 5 to 10% of all intracranial meningiomas. They typically invade the optic canal and displace the optic nerve upward and laterally. The transcranial approach has been the standard surgical approach, while the transsphenoidal approach has been proposed for its minimally invasive nature; however, some reservations concerning this approach remain.

METHODS

 From January 2000 to December 2018, a total of 97 patients who were diagnosed with TSM with invasion of the optic canal were enrolled and underwent microsurgery for tumor removal with optic canal opening. A retrospective analysis was performed on the effect of optic canal opening on postoperative visual acuity improvement. The median follow-up was 17.4 months (range: 3-86 months).

RESULTS

 Among the 97 patients with TSM involving the optic canal, optic canal invasion was seen on preoperative imaging in 73 patients and during intraoperative exploration in all patients. In total, 87/97 patients (89.7%) underwent optic canal opening to remove tumors involving the optic canal, and the rate of total macroscopic resection of tumors invading the optic canal was 100%. Among the 10 patients who did not undergo optic canal opening, the rate of total resection of tumors involving the optic canal was 80% (8/10, p < 0.001). There were no deaths or serious complications. The postoperative visual acuity improvement rate was 64.4%, 23.7% maintained the preoperative level, and the visual acuity deteriorated 11.9%.

CONCLUSION

 Intraoperative optic canal opening is the key to total resection of TSMs involving the optic canal and improving postoperative visual acuity.

In-Hospital Cost Comparison for Open Versus Endoscopic Endonasal Approach for Meningioma Resection

Objective

To determine the in-hospital cost implications of an endoscopic expanded endonasal approach (EEEA) for meningioma resection relative to the open transcranial approach.

Methods

All anterior skull base meningioma surgeries performed over a period from January 1st, 2015 to October 31th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using R software. All cost data were converted into August 2021-equivalent dollar amounts using the United States Bureau of Labor Statistics consumer price index.

Results

Thirty-five patients met study criteria, including 27 patients undergoing an open transcranial approach and 8 undergoing an EEEA. Average length of stay for patients undergoing an open approach was 9.3 days compared to 5.6 within the EEEA group ( P = .126). The average total in-hospital cost of patient undergoing an EEEA was $35417.1 compared to $46406.9 among patients undergoing an open transcranial approach ( P = .168). On univariate analysis, the cost of an open transcranial approach relative to the EEEA was $10989.8 ( P = .411).

Conclusions

The open transcranial approach remained the dominant surgical approach to anterior skull base meningiomas over our study time period. However, despite limited patient numbers the EEEA was associated with decreased total in-hospital costs.

Surgical outcomes and longitudinal quality of life after endoscopic endonasal surgery for anterior skull base meningioma

OBJECTIVE

The objective of this study was to establish the effect of endoscopic endonasal surgery on longitudinal quality of life (QOL) in patients with anterior skull base meningioma.

METHODS

A prospectively collected cohort of consecutively operated anterior skull base meningiomas was analyzed. All cases were performed using the endoscopic endonasal approach (EEA). Sinonasal-specific and overall QOL were measured using the 22-Item Sinonasal Outcome Test and the Anterior Skull Base Questionnaire longitudinally (at 3 weeks, 6 weeks, and 3, 6, and 12 months) across the first postoperative year. The relationship between surgical and QOL outcomes to clinical and radiological characteristics was analyzed using multivariate regression.

RESULTS

Fifty cases were available, with a mean age of 61.5 years and female predominance (74.0%). Visual dysfunction and headache were the most common presenting symptoms, and tumors commonly took origin from the planum (46.0%), tuberculum (44.0%), and olfactory groove (24.0%). Median tumor volume was 4.6 cm3. Visual improvement was noted in 73.1% of cases with preoperative field deficits, while nonimprovement was associated with greater tumor height (p = 0.04). Gross-total resection was not possible in patients with 360° vessel encasement and high-grade cavernous sinus extension with ophthalmoplegia. Postoperative diabetes insipidus was observed only in cases with suprasellar extension. Sinonasal-specific QOL worsened transiently after surgery but returned to baseline levels after 3 weeks. Olfaction and taste scores returned to preoperative baseline scores within the year. Overall QOL at presentation was worse in those with larger tumors (p = 0.04) and visual failure (p = 0.04) and better in those presenting with headache (p = 0.04). Transient worsening of QOL was seen in the first 3 weeks, which returned to baseline by 6 weeks, and then improved to above preoperative levels at 6 months and beyond. Worse QOL at baseline (p = 0.01) and visual improvement (p = 0.01) predicted QOL improvement after surgery.

CONCLUSIONS

Longitudinal QOL in anterior skull base meningioma has been examined for the first time. Endoscopic endonasal surgery improves overall QOL after a transient 3-week worsening due to the sinonasal morbidity of the approach. Visual function is intimately tied to QOL, with worse vision associated with worse preoperative QOL, and QOL improving in parallel with visual restoration after surgery. The EEA is associated with better visual outcomes and should be the preferred approach in accessible tumors.

Comparison of Anatomic Exposure After Petrosectomy Using Anterior Transpetrosal and Endoscopic Endonasal Approaches: Experimental Cadaveric Study

OBJECTIVE

Transcranial anterior petrosectomy (AP) is a classic approach; however, it is associated with adverse consequences. The endoscopic endonasal approach (EEA) has been developed as an alternative. We describe surgical techniques for AP and EEA and compare the anatomic exposures of each.

METHODS

Ten cadaveric heads (20 sides) were dissected. Specimens were divided into 4 groups: 1) AP, 2) EEA for medial petrosectomy (MP), 3) EEA for inferior petrosectomy (IP), and 4) EEA for inferomedial petrosectomy (IMP). Outcomes were areas of exposure, angles of attack to neurovascular structures, and bone resection volumes.

RESULTS

AP had a greater area of exposure than did MP and IP (P = 0.30, P < 0.01) and had a higher angle of attack to the distal part of the facial nerve-vestibulocochlear nerve (cranial nerve [CN] VII/VIII) complex than did IP and IMP (P < 0.01). MP had a lower angle of attack than IMP to the midpons (P = 0.04) and to the anterior inferior cerebellar artery (P < 0.01). Compared with IMP, IP had a lower angle of attack to the proximal part of the CN VII/VIII complex (P < 0.01) and the flocculus (P < 0.01). The bone resection volume in AP was significantly less than that in MP, IP, and IMP (P < 0.01).

CONCLUSIONS

AP and all EEA techniques had specific advantages for each specific area. We suggest AP for the ventrolateral pons and the anterior superior internal auditory canal, MP for the midline clivus, IP for the ventrolateral brainstem, and IMP to enhance the lateral corridor of the abducens nerve.

Endoscopic endonasal transpetroclival approach for recurrent bilateral petroclival meningioma

The authors performed an endoscopic endonasal transpetroclival approach for recurrent bilateral petroclival meningioma, with the aim of sufficient tumor resection with cranial nerve functional preservation. The tumor was sufficiently removed with excellent postoperative course. Petroclival meningioma, especially located in the medial region with dural attachment of the clivus, is considered a good indication for this approach. Recurrent tumors after radiotherapy often have strong adhesion to the brainstem and basilar artery; therefore, careful assessment of whether or not tumor detachment is possible is essential. The endoscopic endonasal transpetroclival approach is an acceptable, less-invasive treatment for petroclival tumors.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21229

Endoscopic endonasal approach for suprasellar meningiomas: introduction of a new scoring system to predict extent of resection and assist in case selection with long-term outcome data

OBJECTIVE

The endoscopic endonasal approach (EEA) has gained increasing popularity for the resection of suprasellar meningiomas (SSMs). Appropriate case selection is critical in optimizing patient outcome. Long-term outcome data are lacking. The authors systematically identified preoperative factors associated with extent of resection (EOR) and determined the relationship between EOR and long-term recurrence after EEA for SSMs.

METHODS

In this retrospective cohort study, the authors identified preoperative clinical and imaging characteristics associated with EOR and built on the recently published University of California, San Francisco resectability score to propose a score more specific to the EEA. They then examined the relationship between gross-total resection (GTR; 100%), near-total resection (NTR; 95%-99%), and subtotal resection (STR; < 95%) and recurrence or progression with Kaplan-Meier survival analysis.

RESULTS

A total of 51 patients were identified. Radiographic GTR was achieved in 40 of 47 (85%) patients in whom it was the surgical goal. Significant independent risk factors for incomplete resection were prior surgery (OR 25.94, 95% CI < 2.00 to 336.49, p = 0.013); tumor lateral to the optic nerve (OR 13.41, 95% CI 1.82-98.99, p = 0.011); and complete internal carotid artery (ICA) encasement (OR 15.12, 95% CI 1.17-194.08, p = 0.037). Tumor size and optic canal invasion were not significant risk factors after adjustment for other variables. A resectability score based on the multivariable model successfully predicted the likelihood of GTR; a score of 0 had a positive predictive value of 97% for GTR, whereas a score of 2 had a negative predictive value of 87.5% for incomplete resection. After a mean follow-up of 40.6 ± 32.4 months (mean ± SD), recurrence was 2.7% after GTR (1 patient with atypical histology), 44.4% after NTR, and 80% after STR (p < 0.0001). Vision was stable or improved in 93.5% and improved in 67.4% of patients with a preoperative deficit. There were 5 (9.8%) postoperative CSF leaks, of which 4 were managed with lumbar drains and 1 required a reoperation.

CONCLUSIONS

The EEA is a safe and effective approach to SSMs, with favorable visual outcomes in well-selected cases. The combination of postoperative MRI-based EOR with direct endoscopic inspection can be used in lieu of Simpson grade to predict recurrence. GTR dramatically reduces recurrence and can be achieved regardless of tumor size, proximity or encasement of the anterior cerebral artery, or medial optic canal invasion. Risk factors for incomplete resection include prior surgery, tumor lateral to the optic nerve, and complete ICA encasement.

Transnasal Endoscopic Surgery for Suprasellar Meningiomas

Aim

Endoscopic trans-nasal surgery has evolved a long way from the days of narrow corridors with high rates of cerebrospinal fluid (CSF) leak to the present state of HD optics with better tissue differentiation, extended approaches, and use of vascularized flaps for defect closure. Trans-nasal approach is an established technique for pituitary tumors practiced worldwide. However, trans-nasal endoscopic excision of suprasellar meningiomas provides a tougher challenge in terms of instrument manipulation, tumor excision with good visual outcome, and a robust defect closure to prevent CSF leaks.

Materials and Methods

Out of 83 cases of midline anterior cranial fossa meningiomas operated over 14 years, our experience in 12 cases of suprasellar meningiomas for radical resection via the trans-nasal endoscopic route is discussed.

Results

Amongst these, six were excised via primary extended endoscopic trans-sphenoidal surgery, four cases had a residual lesion or recurrence after primary transcranial surgery, and two cases involved a combined transcranial and extended endoscopic approach. Visual improvement along with resolution of headache was seen in all patients postoperatively. None of the patients had CSF leak requiring further repair. Syndrome of inappropriate antidiuretic hormone was found in one patient, which was transient and easily corrected.

Conclusion

Trans-nasal endoscopic surgery for suprasellar meningiomas is an effective technique that provides results of tumor excision comparable to the transcranial approach in suitable cases. Visual outcome was found to be superior, and rates of CSF leak were remarkably reduced with vascularized flap. However, each case must be assessed individually and lateral extension beyond the optic canals with internal carotid artery encasement must be considered before planning surgery.

Comparison of Three Surgical Approaches for Frontobasal Meningiomas: Purely Endoscopic Endonasal, Purely Microscopic Bifrontal Transcranial, and Combined Endoscopic and Microscopic Supraorbital Transciliary Approaches

ABSTRACT

Surgical removal of frontobasal meningiomas (FBMs) can be achieved using different techniques, including endoscopic, transcranial, and combined approaches. The advantages and disadvantages of the outcomes of these approaches should be compared to provide the most convenient surgical treatment to the patient. This study aimed to compare 3 surgical approaches for FBMsin terms of outcomes and determine the superiority of each on the basis of anatomical, surgical, and clinical efficacy. Systematic review was performed to identify studies comparing techniques for the surgical removal of FBMs. Each group included 13 patients; 39 patients with FBMshad undergone surgery. These groups were endoscopic endonasal approach (EEA), microscopic bifrontal transcranial approach (MTA), and endoscopic plus microscopic combined supraorbital transciliary approach (STA) groups. Data on the demographics of patient population, pre- and post-operative neurological examination, tumor properties, imaging studies, and surgical complications were extracted. The mean age at the time of surgery for the patient population was 53.2 years. Among the groups, no statistically significant differences were observed with regard to sex (P = 0.582). The mean follow-up time was 56.7 months. A statistically significant difference was observed in the mean tumor volume among the groups; the MTA group showed the highest mean tumor volume. However, no significant difference was found in the mean tumor volume between EEA and STA groups. Regarding operation duration, the STA group had the shortest operation time (mean = 281.5 minutes), whereas the average surgical duration in MTA group was the longest (mean = 443.8 minutes). The average bleeding volume was highest in the MTA group (mean = 746.2 ml) and lowest in the EEA group (mean = 320.8 ml). Tumor removal was incomplete in three patients (two in the EEA group and one in the MTA group). Recurrence was detected in two cases. One patient with recurrence was operated using the endoscopic surgical approach, whereas the other patient underwent the microscopic bifrontal approach. Post-operative hyposmia/anosmia or decreased olfactory function was the most common complication observed in 5 patients, 2 patients each in the EEA and MTA groups and one in the STA group. The second most common complication was wound infection in one patient in the MTA group and two patients in the STA group (7.7%). Both cerebrospinal fluid (CSF) leakage and meningitis were present in two patients (5.1%), one patient each from the EEA and STA groups. Pre-operative visual disturbances were reported in 13 patients (33.3%), all of which resolved post-operatively No statistical differences were found among the groups. Mortality occurred in a patient in the MTA group (2.6%) caused by cardiac arrest on post-operative day 1. This is the first study comparing the surgical outcomes of three surgical approaches for FBMs. Although recent literature suggests that both endoscopic and transcranial approaches have their own advantages and disadvantages, the authors showed that none of the surgical approaches have obvious superiority over the others with regard to outcomes. Thus, the selection of the ideal surgical approach should be based on surgical experience and tumor characteristics.

Application of endoscopic endonasal approach in skull base surgeries: summary of 1886 cases in a single center for 10 consecutive years

Background

Endonasal endoscopic skull base surgery has undergone rapid technological developments and is now widely performed, but its strengths and weaknesses deserve further investigation and deliberation. This study was performed to investigate the surgical indications, complications, and technical advantages and disadvantages of endonasal endoscopic skull base surgery.

Methods

The clinical data of 1886 endoscopic endonasal skull base surgeries performed in our ward at Beijing Tiantan Hospital from June 2006 to June 2016 were retrospectively analyzed.

Results

One thousand ninety-three (73.4%, 1490) pituitary adenomas, 54 (24.9%, 217) chordomas, 28 (80.0%, 35) craniopharyngiomas, and 15 (83.3%, 18) meningiomas underwent total resection. Two patients died postoperatively, both having pituitary adenomas. Other postoperative complications included olfactory disorders (n = 226, 11.9%), postoperative cerebrospinal fluid leakage (n = 78, 4.1%), hypopituitarism (n = 74, 3.9%), diabetes insipidus (n = 64, 3.4%), intracranial infection (n = 36, 1.9%), epistaxis (n = 24, 1.3%), vascular injury (n = 8, 0.4%), optic nerve injury (n = 8, 0.4%), and oculomotor movement impairment (n = 4, 0.2%). In total, 1517 (80.4%) patients were followed up for 6 to 126 months (average, 42.5 months) postoperatively. A total of 196 (13.2%) pituitary adenomas and 13 (37.1%) craniopharyngiomas recurred but no meningiomas recurred. Chordomas recurred in 97 (44.7%) patients, in whom 5-year survival rate was 65%.

Conclusion

Endoscopic surgery is an innovative surgical technique and the first choice for most midline extradural lesions such as chordomas, and an excellent choice for pituitary adenomas. It probably will be a good technique for many kinds of craniopharyngiomas and a common technique for most of skull base meningiomas, so the surgical indications of these cases should be chosen carefully to make good use of its respective advantages.

Extended endonasal endoscopic approach for anterior midline skull base lesions

AIM

In recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature.

METHOD

The data of 24 patients who were operated using EEEA in our department between 2010-2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented.

RESULTS

Eleven patients were female and 13 were male. Their ages ranged between 18-75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50 %), 7 were in the tuberculum sella (29.1 %), and 5 were in both anatomic sites (20.8 %). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75 % of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis.

CONCLUSION

Although the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.

Surgical outcomes in patients with endoscopic versus transcranial approach for skull base malignancies: a 10-year institutional experience

Object: The authors performed an extensive comparison between patients treated with open versus an endoscopic approach for skull base malignancy with emphasis on surgical outcomes.Methods: A single-institution retrospective review of 60 patients who underwent surgery for skull base malignancy between 2009 and 2018 was performed. Disease features, surgical resection, post-operative morbidities, adjuvant treatment, recurrence, and survival rates were compared between 30 patients who received purely open surgery and 30 patients who underwent purely endoscopic resection for a skull base malignancy.Results: Of the 60 patients with skull base malignancy, 30 underwent open resection and 30 underwent endoscopic resection. The most common hisotype for endoscopic resection was squamous cell carcinoma (26.7%), olfactory neuroblastoma (16.7%), and sarcoma (10.0%), and 43.3%, 13.3%, and 10.0% for the open resection cohort, respectively. There were no statistical differences in gross total resection, surgical-associated cranial neuropathy, or ability to achieve negative margins between the groups (p > 0.1, all comparisons). Patients who underwent endoscopic resection had shorter surgeries (320.3 ± 158.5 minutes vs. 495.3 ± 187.6 minutes (p = 0.0003), less intraoperative blood loss (282.2 ± 333.6 ml vs. 696.7 ± 500.2 ml (p < 0.0001), and shorter length of stay (3.5 ± 3.7 days vs. 8.8 ± 6.0 days (p < 0.0001). Additionally, patients treated endoscopically initiated adjuvant radiation treatment more quickly (48.0 ± 20.3 days vs. 72.0 ± 20.5 days (p = 0.01).Conclusions: An endoscopic endonasal approach facilitates a clinically meaningful improvement in surgical outcomes for skull base malignancies.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Endoscopic endo- and extra-orbital corridors for spheno-orbital region: anatomic study with illustrative case

BACKGROUND AND OBJECTIVE

Management of selected spheno-orbital meningiomas via the endoscopic transorbital route has been reported. Surgical maneuverability in a narrow corridor as that offered by the orbit may be challenging. We investigate the additional use of an extra-orbital (EXO) path to be used in combination with the endo-orbital (EO) corridor.

MATERIAL AND METHODS

Three human cadaveric heads (six orbits) were dissected at the Laboratory of Surgical Neuroanatomy at the University of Barcelona. The superior eyelid endoscopic transorbital approach was adopted, introducing surgical instruments via both corridors. Surgical freedom analysis was run to determine directionality of each corridor and to calculate the surgical maneuverability related to three anatomic targets: superior orbital fissure (SOF), foramen rotundum (FR), and foramen ovale (FO). We also reported of a 37-year-old woman with a spheno-orbital meningioma with hyperostosis of the lateral wall of the right orbit, treated with such combined endo-orbital and extra-orbital endoscopic approach.

RESULTS

Combining both endo-orbital and extra-orbital corridors permitted a greater surgical freedom for all the targets compared with the surgical freedom of each corridor alone (EO + EXO to SOF: 3603.8 mm² ± 2452.5 mm²; EO + EXO to FR: 1533.0 mm² ± 892.2 mm²; EO + EXO to FO: 1193.9 mm² ± 782.6 mm²). Analyzing the extra-orbital pathway, our results showed that the greatest surgical freedom was gained in the most medial portion of the considered area, namely the SOF (1180.5 mm² ± 648.3 mm²). Regarding the surgical case, using both pathways, we gained enough maneuverability to nearly achieve total resection with no postoperative complications.

CONCLUSION

An extra-orbital corridor may be useful to increase the instruments' maneuverability, during a pure endoscopic superior eyelid approach, and to reach the most medial portion of the surgical field from a lateral-to-medial trajectory. Further studies are needed to better define the proper indications for such strategy.

Pre- and postoperative headache in patients with meningioma

Background

Meningiomas are generally slowly growing intracranial tumors. They are often incidentally diagnosed, given that symptoms may be absent even in cases of an enormous tumor size. Headache is a frequent but not consistent symptom. Therefore, we examined the association between structural, biochemical and histochemical tumor parameters with preoperative as well as postoperative occurrence of headache.

Methods

In our study, we prospectively investigated 69 consecutive patients enrolled for meningioma neurosurgery. Anatomical, histological and biochemical parameters were acquired, and headache parameters were registered from the clinical report and from a questionnaire filled by the patients before neurosurgery. The headache was re-evaluated one year after neurosurgery. The study was designed to exploratively investigate whether there is an association of acquired clinical and biological parameters with the occurrence of preoperative and postoperative headache.

Results

Edema diameter and the proliferation marker MIB-1 were negatively associated with the incidence and intensity of preoperative headache, while the content of prostaglandin E2 in the tumor tissue was positively associated with preoperative headache intensity. Headache was more prevalent when the meningioma was located in the area supplied by the ophthalmic trigeminal branch. Compared to preoperative headache levels, an overall reduction was observed one year postoperative, and patients with a larger tumor had a higher headache remission. In parietal and occipital meningiomas and in those with a larger edema, the percentage of the headache remission rate was higher compared to other locations or smaller edema. Multivariable analyses showed an involvement of substance P and prostaglandin E2 in preoperative headache.

Conclusions

The study demonstrates new associations between meningiomas and headache. The postoperative headache outcome in the presented patient sample is encouraging for the performed neurosurgical intervention. These results should be tested in a prospective study that incorporates all patients with meningiomas.

Reconstruction of Dural Defects in Endoscopic Transnasal Approaches for Intradural Lesions Using Multilayered Fascia with a Pressure-Control Spinal Drainage System

OBJECTIVE

Nasoseptal flap reconstruction is a widely accepted method for reducing cerebrospinal fluid (CSF) leakage after endoscopic transnasal surgeries (ETSs). However, this method is associated with nasal complications and is difficult to apply repeatedly in recurrent cases. Therefore, alternative methods are needed.

METHODS

Layers of autologous fascia lata were placed on the inside and outside of the dural defect to sufficiently cover it, and the grafts were compressed with an inflated balloon. A lumbar drainage system with a pressure-control valve was used for 72 hours postoperatively. We retrospectively analyzed data on patients with skull base lesions showing intracranial extensions that required wide opening of the ventral dura in ETS. Fifty cases (47 skull base tumors and 3 others) were included, 28 of which were recurrent cases.

RESULTS

In 21 cases (42%), the nasal septum was not intact because of the previous ETS. Seventeen patients (34%) had a history of radiotherapy and 9 (18%) had undergone multisession radiotherapies. None of the 50 patients required additional surgery for postoperative CSF rhinorrhea, and 2 had intermittent CSF leakage that resolved with prolonged lumbar drainage placement for a week. Previous multisession radiotherapy was the only significant risk factor for the need of prolonged drainage (P = 0.029).

CONCLUSIONS

The multilayer closure method with a pressure-control spinal drainage system is a simple, safe, and effective method for preventing postoperative CSF leakage, which can be readily applied to dural defects in any parts of the skull base regions and in patients with various conditions.

Endoscopic Endonasal Reconstructive Methods to the Anterior Skull Base

The success of expanded endoscopic endonasal approaches (EEAs) to the anterior skull base, sellar, and parasellar regions has been greatly aided by the advancement in reconstructive techniques. In particular, the pedicled vascularized flaps have been developed and effectively cover skull base defects of varying sizes with a significant reduction in postoperative CSF leaks. There are two aims to this review: (1) We will provide our current, simplified reconstruction algorithm. (2) We will describe, in detail, the relevant anatomy, indications/contraindications, and surgical technique, with a particular emphasis on the nasoseptal flap (NSF). The inferior turbinate flap (ITF), middle turbinate flap (MTF), pericranial flap (PCF), and temporoparietal fascial flap (TPFF) will also be described. The NSF should be the primary option for reconstruction of majority of skull base defects following endonasal endoscopic surgery. In general, for the planum, cribriform, and upper two-thirds of the clivus, the NSF is ideal. For the lower-third of the clivus, the NSF may not be adequate and may require additional reconstructive options. Although limited in reach or more technically challenging, these reconstructive flaps should still be considered and kept in the surgical algorithm.

Imaging of Paranasal Sinuses and Anterior Skull Base and Relevant Anatomic Variations

This article reviews the normal anatomy and variants of the anterior skull base and sinonasal cavities that are relevant to endoscopic sinus and skull base surgery. Radiologists should be aware of sinonasal anatomy that can be impediments to surgical access and increase risk of vascular or cranial nerve injury during surgery. Imaging features of the paranasal sinuses and anterior skull base pathologies are also discussed.