Comparative Efficacy of Transsphenoidal and Transcranial Approaches for Treating Tuberculum Sellae Meningiomas: A Systematic Review and Meta-Analysis

Background/Objectives: Tuberculum sellae meningiomas (TSMs) constitute 5-10% of intracranial meningiomas, often causing visual impairment. Traditional microsurgical transcranial approaches (MTAs) have been effective, but the emergence of innovative surgical trajectories, such as endoscopic endonasal approaches (EEAs), has sparked debate. While EEAs offer advantages like reduced brain retraction, they are linked to higher cerebrospinal fluid leak (CSF leak) risk. This meta-analysis aims to comprehensively compare the efficacy and safety of EEAs and MTAs for the resection of TSMs, offering insights into their respective outcomes and complications. Methods: A comprehensive literature review of the databases PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted for articles published on TSMs treated with either EEA or MTA until 2024. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analysis was performed to estimate pooled event rates and assess heterogeneity. Fixed- and random-effects were used to assess 95% confidential intervals (CIs) of presenting symptoms, outcomes, and complications. Results: A total of 291 papers were initially identified, of which 18 studies spanning from 2000 to 2024 met the inclusion criteria. The exclusion of 180 articles was due to reasons such as irrelevance, non-reporting of selected results, systematic literature review or meta-analysis, and a lack of details on method/results. The 18 studies comprised a total sample of 1093 patients: 444 patients who underwent EEAs and 649 patients who underwent MTAs for TSMs. Gross total resection (GTR) rates ranged from 80.9% for EEAs to 79.8% for MTAs. The rate of visual improvement was 86.6% in the EEA group and 65.4% in the MTA group. The recurrence rate in the EEA group was 6.9%, while it was 5.1% in MTA group. The postoperative complications analyzed were CSF leak, infections, dysosmia, intracranial hemorrhage (ICH), and endocrine disorders. The rate of CSF leak was 9.8% in the EEA group and 2.1% in MTA group. The rate of infections in the EEA group was 5.7%, while it was 3.7% in the MTA group. The rate of dysosmia ranged from 10.3% for MTAs to 12.9% for EEAs. The rate of ICH in the EEA group was 0.9%, while that in the MTA group was 3.8%. The rate of endocrine disorders in the EEA group was 10.8%, while that in the MTA group was 10.2%. No significant difference was detected in the rate of GTR between the EEA and MTA groups (OR 1.15, 95% CI 0.7-0.95; p = 0.53), while a significant benefit in visual outcomes was shown in EEAs (OR 3.54, 95% CI 2.2-5.72; p < 0.01). There was no significant variation in the recurrence rate between EEA and MTA groups (OR 0.92, 95% CI 0.19-4.46; p = 0.89). While a considerably increased chance of CSF leak from EEAs was shown (OR 4.47, 95% CI 2.52-7.92; p < 0.01), no significant difference between EEA and MTA groups was detected in the rate of infections (OR 1.92, 95% CI 0.73-5.06; p = 0.15), the rate of dysosmia (OR 1.25, 95% CI 0.31-4.99; p = 0.71), the rate of ICH (OR 0.61, 95% CI 0.20-1.87; p = 0.33), and the rate of endocrine disorders (OR 1.16, 95% CI 0.69-1.95; p = 0.53). Conclusions: This meta-analysis suggests that both EEAs and MTAs are viable options for TSM resection, with distinct advantages and drawbacks. The EEAs demonstrate superior visual outcomes in selected cases while GTR and recurrence rates support the overall effectiveness of MTAs and EEAs. Endoscopic endonasal approaches had a higher chance of CSF leaks, but there are no appreciable variations in other complications. These results provide additional insights regarding patient outcomes in the intricate clinical setting of TSMs.

Endoscopic precaruncular medial transorbital and endonasal multiport approaches to the contralateral skull base: a clinicoanatomical study

OBJECTIVE

Minimally invasive endoscopic endonasal multiport approaches create additional visualization angles to treat skull base pathologies. The sublabial contralateral transmaxillary (CTM) approach and superior eyelid lateral transorbital approach, frequently used nowadays, have been referred to as the "third port" when used alongside the endoscopic endonasal approach (EEA). The endoscopic precaruncular contralateral medial transorbital (cMTO) corridor, on the other hand, is an underrecognized but unique port that has been used to repair CSF rhinorrhea originating from the lateral sphenoid sinus recess. However, no anatomical feasibility studies or clinical experience exists to assess its benefits and demonstrate its potential role in multiport endoscopic access to the other contralateral skull base areas. In this study, the authors explored the application and potential utility of multiport EEA combined with the endoscopic cMTO approach (EEA/cMTO) to three target areas of the contralateral skull base: lateral recess of sphenoid sinus (LRSS), petrous apex (PA) and petroclival region, and retrocarotid clinoidocavernous space (CCS).

METHODS

Ten cadaveric specimens (20 sides) were dissected bilaterally under stereotactic navigation guidance to access contralateral LRSS via EEA/cMTO. The PA and petroclival region and retrocarotid CCS were exposed via EEA alone, EEA/cMTO, and EEA combined with the sublabial CTM approach (EEA/CTM). Qualitative and quantitative assessments, including working distance and visualization angle to the PA, were recorded. Clinical application of EEA/cMTO is demonstrated in a lateral sphenoid sinus CSF leak repair.

RESULTS

During the qualitative assessment, multiport EEA/cMTO provides superior visualization from a high vantage point and better instrument maneuverability than multiport EEA/CTM for the PA and retrocarotid CCS, while maintaining a similar lateral trajectory. The cMTO approach has significantly shorter working distances to all three target areas compared with the CTM approach and EEA. The mean distances to the LRSS, PA, and retrocarotid CCS were 50.69 ± 4.28 mm (p < 0.05), 67.11 ± 5.05 mm (p < 0.001), and 50.32 ± 3.6 mm (p < 0.001), respectively. The mean visualization angles to the PA obtained by multiport EEA/cMTO and EEA/CTM were 28.4° ± 3.27° and 24.42° ± 5.02° (p < 0.005), respectively.

CONCLUSIONS

Multiport EEA/cMTO to the contralateral LRSS offers the advantage of preserving the pterygopalatine fossa contents and the vidian nerve, which are frequently sacrificed during a transpterygoid approach. This approach also offers superior visualization and better instrument maneuverability compared with EEA/CTM for targeting the petroclival region and retrocarotid CCS.

Predictors and Complications of Cerebrospinal Fluid Leak after Endoscopic Endonasal Surgery: A Single Institution Retrospective Review

Background  The endoscopic endonasal approach (EEA) is a commonly used technique for resection of sellar, suprasellar, and anterior fossa masses. One of the most troublesome complications of this technique is cerebrospinal fluid (CSF) leak. In this study, we evaluate the risk factors and consequences of CSF leak on surgical outcomes. Methods  The current study is a retrospective single-institution cohort study evaluating patients who underwent EEA for sellar and/or suprasellar masses from July 2017 to March of 2020. Risk factors for intraoperative and postoperative CSF leak were evaluated, including sellar defect size, tumor volume and pathology, age, body mass index, prior endoscopic endonasal surgery, lumbar drain placement, nasoseptal and mucosal graft use, year of surgery, and cavernous sinus invasion. Postoperative infection, perioperative antibiotic use, and length of stay were also evaluated. Results  Our study included 175 patients. Sellar defect size ( p  = 0.015) and intraoperative CSF leak ( p  < 0.001) were significantly associated with an increased risk of postoperative CSF leak. Patients with nasoseptal flaps were more likely to have a postoperative CSF leak than those with free mucosal grafts ( p  = 0.025). Intraoperative CSF leak, Cushing's disease, and lumbar drain placement were associated with an increased length of stay. Conclusion  Sellar defect size, intraoperative CSF leak, and nasoseptal flap use were associated with an increased risk of postoperative CSF leak. Intraoperative CSF leak, Cushing's disease, and lumbar drain placement are all associated with an increased length of stay.

Excision of Greater Superficial Petrosal Nerve Schwannoma Via a Pure Endoscopic Endonasal Approach

Greater superficial petrosal nerve (GSPN) schwannomas are an exceedingly rare nerve sheath tumor. The current literature search was conducted using Medline and Embase database by key search terms. Only 31 cases have been reported in the literature so far. Facial palsy, hearing loss, and xerophthalmia accounted for 48.4% (15), 41.9% (13), and 29% (9) of all cases, respectively. The middle cranial fossa approach was used in all previous reports. A retrospective review of 2 GSPN schwannomas patients treated by endoscopic endonasal approach (EEA) in our center was collected. Clinical records, including clinical features, pre- and postoperative images, surgery, and follow-up information, were reviewed. In all cases, clinical features including facial numbness and headache were found, with tinnitus in case 1, hearing loss, xerophthalmia in case 2. Imaging studies showed a solid mass that originated in the anterior of the petrous bone. Two patients were treated by EEA. Furthermore, no recurrence was found during the follow-up period (15-29 months) in both of the 2 cases after the operation. Complete resection of GSPN schwannomas can be achieved via the pure EEA. Endoscopic endonasal approach for radical removal of tumors is safe and feasible.

Exoscopic supraorbital approach for a suprasellar craniopharyngioma

The authors present an operative video of a supraorbital craniotomy for resection of a suprasellar, supradiaphragmatic craniopharyngioma. The patient is a 62-year-old female who presented with 3 months of blurry vision secondary to a 2.5-cm suprasellar mass causing compression on the optic nerve. Supraorbital craniotomy was selected due to the supradiaphragmatic location of the tumor and the subsequent disadvantages, including CSF leakage, of other approaches such as the endoscopic endonasal approach. The operative video emphasizes optimizing operating room (OR) setup to improve surgeon ergonomics and comfort. The patient underwent an uncomplicated gross-total resection with subsequent discharge home the day after surgery. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23140.

Systematic review of transcranial and endoscopic endonasal approaches for craniopharyngiomas in children: is there an evolution?

OBJECTIVE

The optimal surgical approach for pediatric craniopharyngiomas (CPs) remains a matter of debate, with selection bias classically precluding a fair comparison of outcomes between the transcranial approach (TCA) and endoscopic endonasal approach (EEA). The purpose of this systematic review was to analyze the current role of EEA in the treatment of pediatric CPs and to determine whether, upon expansion of its indications, a comparison with TCA is valid.

METHODS

A systematic review of English-language articles published between February 2010 and June 2022 was performed to identify studies in the MEDLINE (PubMed) and Embase databases reporting on the resection of pediatric CPs. Included were articles reporting on pediatric CPs removed through TCA or EEA. Case reports, review articles, and earlier or less comprehensive series by the same center were excluded. Baseline characteristics and outcomes were analyzed. Prediction intervals (PIs), heterogeneity (Q, I2, and τ2 statistics), and publication bias (funnel plot analysis) were assessed.

RESULTS

A total of 835 patients underwent TCA (18 articles) and 403 patients underwent EEA (19 articles). Preoperatively, the mean patient age (p = 0.055, PI = 5.05-15.11), visual impairment (p = 0.08, PI = 19.1-90.5, I2 = 80%), and hypothalamic syndrome (p = 0.17, PI = 6.5-52.2, I2 = 62%) did not significantly differ between the EEA and TCA groups. Endocrine deficit (anterior pituitary deficit [p < 0.001, PI = 16.5-92.9, I2 = 81%] and diabetes insipidus [p < 0.001, PI = 6.3-60.6, I2 = 43%]) was more frequent in the EEA group. Hydrocephalus and signs/symptoms of raised intracranial pressure were significantly higher (p < 0.001, PI = 5.2-73.3, I2 = 70% vs p < 0.001, PI = 4.6-73, I2 = 62%, respectively) in the TCA group. Recurrent lesions (p = 0.52, PI = 2.7-87.3, I2 = 13%), tumor size (p = 0.25, PI = 22.1-56.8), third ventricle involvement (p = 0.053, PI = 10.9-81.3, I2 = 69%), and hypothalamic involvement (p = 0.06, PI = 8.5-83.6, I2 = 79%) did not differ significantly between the approaches. EEA was preferred (p = 0.006, PI = 26.8-70.8, I2 = 40%) for sellar-suprasellar CPs, whereas TCA was preferred for purely suprasellar CPs (p = 0.007, PI = 13.5-81.1, I2 = 61%). There was no difference between the approaches for purely intrasellar lesions (p = 0.94, PI = 0-62.7, I2 = 26%). The breadth of PIs, I2 values, and analysis of publication bias showed substantial variability among the pooled data, hindering the possibility of outcome meta-analyses.

CONCLUSIONS

With the adoption of extended approaches, the use of EEA became appropriate for a wider spectrum of pediatric CPs, with associated excellent outcomes. Although a fair comparison between outcomes in the EEA and TCA groups was hindered because of the differences in patient populations and tumor subtypes, given the increased versatility of EEA and improved expertise in its use, surgeons can now select the optimal surgical approach based on the unique benefits and drawbacks of each pediatric CP.

Combined subtarsal contralateral transmaxillary retroeustachian and endoscopic endonasal approaches to the infrapetrous region

OBJECTIVE

The eustachian tube (ET) limits endoscopic endonasal access to the infrapetrous region. Transecting or mobilizing the ET may result in morbidities. This study presents a novel approach in which a subtarsal contralateral transmaxillary (ST-CTM) corridor is coupled with the standard endonasal approach to facilitate access behind the intact ET.

METHODS

Eight cadaveric head specimens were dissected. Endoscopic endonasal approaches (EEAs) (i.e., transpterygoid and inferior transclival) were performed on one side, followed by ST-CTM and sublabial contralateral transmaxillary (SL-CTM) approaches on the opposite side, along with different ET mobilization techniques on the original side. Seven comparative groups were generated. The length of the cranial nerves, areas of exposure, and volume of surgical freedom (VSF) in the infrapetrous regions were measured and compared.

RESULTS

Without ET mobilization, the combined ST-CTM/EEA approach provided greater exposure than EEA alone (mean ± SD 288.9 ± 40.66 mm2 vs 91.7 ± 49.9 mm2; p = 0.001). The VSFs at the ventral jugular foramen (JF), entrance to the petrous internal carotid artery (ICA), and lateral to the parapharyngeal ICA were also greater in ST-CTM/EEA than in EEA alone (p = 0.002, p = 0.002, and p < 0.001, respectively). EEA alone, however, provided greater VSF at the hypoglossal canal (HGC) than did ST-CTM/EEA (p = 0.01). The SL-CTM approach did not increase the EEA exposure (p = 0.48). The ST-CTM/EEA approach provided greater exposure than EEA with extended inferolateral (EIL) or anterolateral (AL) ET mobilization (p = 0.001 and p = 0.02, respectively). The ST-CTM/EEA also increased the VSF lateral to the parapharyngeal ICA in comparison with EEA/EIL ET mobilization (p < 0.001) but not with EEA/AL ET mobilization (p = 0.36). Finally, the VSFs at the HGC and JF were greater in EEA/AL ET mobilization than in ST-CTM/EEA without ET mobilization (p = 0.002 and p = 0.004, respectively).

CONCLUSIONS

Combining the EEA with the more laterally and superiorly originating ST-CTM approach allows greater exposure of the infrapetrous and ventral JF regions while obviating the need for mobilizing the ET. The surgical freedom afforded by the combined approaches is greater than that obtained by EEA alone.

Endoscopic Endonasal Transplanum-Transtuberculum Approach for Pituitary Adenomas/PitNET: 25 Years of Experience

The role of the endoscopic transplanum-transtuberculum approach (ETTA) in the treatment of pituitary adenomas/PitNETs (PAs) is sparsely analyzed in the literature, and its use is still debated in the current practice. The aim of this study was to report our experience with this approach. Our institutional registry was retrospectively reviewed, and patients who underwent ETTA for a PA from 1998 to 2022 were included. Fifty-seven cases were enrolled over a time span of 25 years, corresponding to 2.4% of our entire PA caseload. Radical resection was achieved in 57.9% of cases, with re-do surgery (p = 0.033) and vessel encasement/engulfment (p < 0.001) as predictors of partial resection. CSF leak incidence stood at 8.8%, with higher BMI (p = 0.038) as its only significant predictor. Partial or full improvement of the visual field deficits was achieved in 73.5% of cases. No surgical mortality was observed. According to our results, ETTA for the treatment of PAs is characterized by a satisfactory surgical outcome but with greater morbidity than the conventional endoscopic approach. Therefore, it should be reserved for the few selected cases otherwise unsuitable for the endoscopic trans-sphenoidal route, representing a valid alternative and an effective complementary route for the transcranial approach for these challenging PAs.

Endoscopic endonasal approach for acromegaly: surgical outcomes using 2018 consensus criteria for remission

Objective

The primary aim is to analyze the endoscopic endonasal surgical results in short-term and two-year follow-ups according to the 11th Acromegaly Consensus statement (2018). Indeed, prognostic factors and complications were analyzed.

Subjects and methods

40 patients who underwent endoscopic endonasal surgery by acromegaly between 2013 to 2020 was analyzed. Patients were considered in remission if an upper limit of normal (ULN) IGF-1 was less than 1.0 at the six-month and two-year follow-ups. Moreover, we assessed the Knosp grade, tumor volumetry, ULN, T2 signal in MRI, reoperation, and complications.

Results

The mean age of admission was 46.7 years. Thirty-two patients were in remission after six months of surgery (80%), decreasing to 76.32% at the two-year follow-up. All microadenomas presented remission (n = 6). Regarding the complications, three patients had permanent panhypopituitarism (7.5%); postoperative cerebrospinal fluid (CSF) leaks did not occur in this series. The hyperintense signal on the T2 MRI and a higher tumor volumetry were the single predictor's factors of non-emission in a multivariate regression logistic analysis (p < 0.05). Preoperative hormone levels (GH and IGF-1) were not a prognostic factor for remission. The re-operated patients who presented hypersignal already had a high predictor of clinical-operative failure.

Conclusion

The endoscopic endonasal surgery promotes high short-term and two-year remission rates in acromegaly; the tumor's volumetry and the T2 hypersignal were statistically significant prognostic factors in non-remission - the complications presented at similar rates in comparison to the literature. In invasive GH-secreting tumors, we should offer these patients a multi-disciplinary approach to improve acromegalic patients' remission rates.

Current Role of Endoscopic Endonasal Approach for Craniopharyngiomas: A 10-Year Systematic Review and Meta-Analysis Comparison with the Open Transcranial Approach

In recent years, the endoscopic endonasal approach (EEA) for craniopharyngiomas has proven to be a safe option for extensive tumor resection, with minimal or no manipulation of the optic nerves and excellent visualization of the superior hypophyseal branches when compared to the Transcranial Approach (TCA). However, there is an ongoing debate regarding the criteria for selecting different approaches. To explore the current results of EEA and discuss its role in the management of craniopharyngiomas, we performed MEDLINE, Embase, and LILACS searches from 2012 to 2022. Baseline characteristics, the extent of resection, and clinical outcomes were evaluated. Statistical analysis was performed through an X² and Fisher exact test, and a comparison between quantitative variables through a Kruskal-Wallis and verified with post hoc Bonferroni. The tumor volume was similar in both groups (EEA 11.92 cm³, -TCA 13.23 cm³). The mean follow-up in months was 39.9 for EEA and 43.94 for TCA, p = 0.76). The EEA group presented a higher visual improvement rate (41.96% vs. 25% for TCA, p < 0.0001, OR 7.7). Permanent DI was less frequent with EEA (29.20% vs. 67.40% for TCA, p < 0.0001, OR 0.2). CSF Leaks occurred more frequently with EEA (9.94% vs. 0.70% for TCA, p < 0.0001, OR 15.8). Recurrence rates were lower in the EEA group (EEA 15.50% vs. for TCA 21.20%, p = 0.04, OR 0.7). Our results demonstrate that, in selected cases, EEA for resection of craniopharyngiomas is associated with better results regarding visual preservation and extent of tumor resection. Postoperative CSF leak rates associated with EEA have improved compared to the historical series. The decision-making process should consider each person's characteristics; however, it is noticeable that recent data regarding EEA justify its widespread application as a first-line approach in centers of excellence for skull base surgery.

Contralateral Transmaxillary Approach for Resection of Chondrosarcoma of the Petrous Apex: A Case Report

BACKGROUND

Deep location and neurovascular structures make access to lesions of the petrous apex a significant challenge. A novel approach for these tumors is the contralateral transmaxillary approach.

CLINICAL PRESENTATION

A 31-year-old male was evaluated for left abducens nerve palsy. Magnetic resonance imaging (MRI) and computed tomography revealed an enhancing, lytic lesion of the petrous apex with extension to the cavernous sinus and petroclival junction. The patient underwent a combined endoscopic contralateral transmaxillary and endoscopic endonasal transclival approach for resection of the lesion. No new or worsening neurologic deficits were noted following the procedure. Pathology revealed low-grade chondrosarcoma (grade I). Postoperative MRI revealed gross total resection of the lesion. Patient underwent adjuvant radiation therapy at the discretion of radiation oncology.

CONCLUSION

The contralateral transmaxillary approach to the petrous apex allows for resection of lesions of the petrous apex with the ability to extend the dissection laterally. Excellent results achieved by institutions with advanced extended endoscopic endonasal experience can be reproduced in institutions with less experience. Further characterization of the risks and benefits of this approach is needed.

CSF rhinorrhoea after endonasal intervention to the skull base (CRANIAL): A multicentre prospective observational study

Objective

Despite progress in endonasal skull-base neurosurgery, cerebrospinal fluid (CSF) rhinorrhoea remains common and significant. The CRANIAL study sought to determine 1) the scope of skull-base repair methods used, and 2) corresponding rates of postoperative CSF rhinorrhoea in the endonasal transsphenoidal approach (TSA) and the expanded endonasal approach (EEA) for skull-base tumors.

Methods

A prospective observational cohort study of 30 centres performing endonasal skull-base neurosurgery in the UK and Ireland (representing 91% of adult units). Patients were identified for 6 months and followed up for 6 months. Data collection and analysis was guided by our published protocol and pilot studies. Descriptive statistics, univariate and multivariable logistic regression models were used for analysis.

Results

A total of 866 patients were included - 726 TSA (84%) and 140 EEA (16%). There was significant heterogeneity in repair protocols across centres. In TSA cases, nasal packing (519/726, 72%), tissue glues (474/726, 65%) and hemostatic agents (439/726, 61%) were the most common skull base repair techniques. Comparatively, pedicled flaps (90/140, 64%), CSF diversion (38/140, 27%), buttresses (17/140, 12%) and gasket sealing (11/140, 9%) were more commonly used in EEA cases. CSF rhinorrhoea (biochemically confirmed or requiring re-operation) occurred in 3.9% of TSA (28/726) and 7.1% of EEA (10/140) cases. A significant number of patients with CSF rhinorrhoea (15/38, 39%) occurred when no intraoperative CSF leak was reported. On multivariate analysis, there may be marginal benefits with using tissue glues in TSA (OR: 0.2, CI: 0.1-0.7, p<0.01), but no other technique reached significance. There was evidence that certain characteristics make CSF rhinorrhoea more likely - such as previous endonasal surgery and the presence of intraoperative CSF leak.

Conclusions

There is a wide range of skull base repair techniques used across centres. Overall, CSF rhinorrhoea rates across the UK and Ireland are lower than generally reported in the literature. A large proportion of postoperative leaks occurred in the context of occult intraoperative CSF leaks, and decisions for universal sellar repairs should consider the risks and cost-effectiveness of repair strategies. Future work could include longer-term, higher-volume studies, such as a registry; and high-quality interventional studies.

Machine learning driven prediction of cerebrospinal fluid rhinorrhoea following endonasal skull base surgery: A multicentre prospective observational study

Background

Cerebrospinal fluid rhinorrhoea (CSFR) is a common complication following endonasal skull base surgery, a technique that is fundamental to the treatment of pituitary adenomas and many other skull base tumours. The CRANIAL study explored CSFR incidence and related risk factors, particularly skull base repair techniques, via a multicentre prospective observational study. We sought to use machine learning to leverage this complex multicentre dataset for CSFR prediction and risk factor analysis.

Methods

A dataset of 865 cases - 725 transsphenoidal approach (TSA) and 140 expanded endonasal approach (EEA) - with cerebrospinal fluid rhinorrhoea as the primary outcome, was used. Relevant variables were extracted from the data, and prediction variables were divided into two categories, preoperative risk factors; and repair techniques, with 6 and 11 variables respectively. Three types of machine learning models were developed in order to predict CSFR: logistic regression (LR); decision tree (DT); and neural network (NN). Models were validated using 5-fold cross-validation, compared via their area under the curve (AUC) evaluation metric, and key prediction variables were identified using their Shapley additive explanations (SHAP) score.

Results

CSFR rates were 3.9% (28/725) for the transsphenoidal approach and 7.1% (10/140) for the expanded endonasal approach. NNs outperformed LR and DT for CSFR prediction, with a mean AUC of 0.80 (0.70-0.90) for TSA and 0.78 (0.60-0.96) for EEA, when all risk factor and intraoperative repair data were integrated into the model. The presence of intraoperative CSF leak was the most prominent risk factor for CSFR. Elevated BMI and revision surgery were also associated with CSFR for the transsphenoidal approach. CSF diversion and gasket sealing appear to be strong predictors of the absence of CSFR for both approaches.

Conclusion

Neural networks are effective at predicting CSFR and uncovering key CSFR predictors in patients following endonasal skull base surgery, outperforming traditional statistical methods. These models will be improved further with larger and more granular datasets, improved NN architecture, and external validation. In the future, such predictive models could be used to assist surgical decision-making and support more individualised patient counselling.

Microsurgical anatomy of the cavernous sinus and limitations of surgical approaches: a cadaveric study

BACKGROUND

The endoscopic endonasal approach is common in the treatment of pathologies in and around the cavernous sinus. This cadaveric study aims to examine the anatomy of the cavernous sinus to guide endoscopic studies and determine points to consider during surgical approaches.

MATERIALS AND METHODS

For this study, a total of 7 cadavers, 4 male and 3 female, were injected with coloured silicone and dissections were performed under the microscope. The characteristics of the surgical corridors encountered during the transsphenoidal, transsellar and transcavernous approaches were examined and their images were recorded.

RESULTS

The stages and limitations of surgical approaches to the cavernous sinus in cadavers are presented. The anatomical features of the triangles defined in the cavernous sinus and the structures they contain are explained. It was determined that the surgical field formed by clinoidal and anteromedial triangles could be used effectively to reach cavernous sinus pathologies during endoscopic endonasal interventions. It was also observed that supratrochlear and infratrochlear triangles are dangerous for such surgical interventions.

CONCLUSIONS

The detailed anatomical features related to the cavernous sinus, revealed in our cadaveric study, are valuable in terms of preventing complications that may occur during surgical interventions.

Endoscopic Endonasal Repair of Recurrent Cerebrospinal Fluid Leak With Adipofascial Anterolateral Thigh Free Flap: Case Report and Review of Literature

Background. Cerebrospinal fluid leaks are the most common complication of endoscopic endonasal skull base tumor resection. The workhorse nasoseptal flap or other vascularized intranasal flaps may not be a viable option in patients who have previously undergone surgery or local radiation; in these cases, pericranial flaps may also be unavailable. Free flap reconstruction in patients undergoing endoscopic resection is challenging because of limited exposure. The transmaxillary approach has recently been reported for free flap reconstruction of these defects. This report describes a patient with a pituitary tumor who underwent craniotomy and resection of a pituitary mass via an endoscopic endonasal approach. Postoperatively, the patient developed a high flow cerebrospinal fluid leak that did not resolve with lumbar drain and attempts at endoscopic revision of nasoseptal flap. An adipofascial anterolateral thigh free flap was harvested, based on the descending branch of the lateral circumflex femoral vessels. An upper gingivobuccal sulcus incision was used to access the maxilla. Openings were created in the anterior and medial maxillary sinus to create a passage to the sphenoid sinus. The flap was inset into the defect via this transmaxillary channel. The pedicle was tunneled subcutaneously through the cheek to recipient facial vessels. The procedure resulted in complete resolution of cerebrospinal fluid rhinorrhea and pneumocephalus. Imaging at 18 months showed the flap in good position. This report describes the technique in detail along with a review of the current literature.

Nasoseptal flap and rigid reconstruction in endoscopic endonasal skull base surgeries: The longitudinal experience of a single center

BACKGROUND

Recently, endoscopic endonasal approaches (EEA) have been used for skull base defect reconstruction surgeries. The nasoseptal flap (NSF), a vascular pedicled flap, was introduced to decrease postoperative cerebrospinal fluid (CSF) leakage.

PURPOSES

This study aimed to outline the authors' institutional experience using NSF and rigid implants in anterior skull base defect reconstruction surgeries following EEA.

DESIGN

A retrospective cohort review of patients who underwent NSF reconstruction following EEA in the Otorhinolaryngology and Neurosurgery Departments at King Saud University Medical City, Riyadh, Saudi Arabia, from January 2015 to May 2021, divided into 2 time periods according to the reconstruction technique.

RESULT

Out of the 106 patients who underwent EEA, 77 underwent NSF reconstruction. The majority had expanded EEA (94.8%). The mean age was 40.21 ± 17.7 years, and the female gender represented 61% of the sample. More than half of the sample underwent right NSF (57.1%). Meningioma was the most common diagnosis (45.5%). The clivus was the most frequent site of lesions (23.4%). The overall rate of postoperative CSF leakage and lumbar drainage (LD) insertion was 15.6% and 51.9%, respectively. The duration of LD was a median of four days. The overall failure rate was 13%, declining from 20% in the first period to 5.4% in the second period. Rigid implants were used significantly more in the first period than in the second period (67.5% versus 16.2%, P < 0.001). Meningitis, the highest postoperative complication, was reported in 6 patients (7.8%). One patient died three weeks postoperatively after massive nasal bleeding. No significant difference was found between either side of the NFS regarding the CSF leakage and failure rate.

CONCLUSION

In the authors' experience, there has been an overt decline in failure rates and complications of EEA over the last three years due to increased experience among surgeons and a standardization of reconstruction techniques. Minimal reconstruction may provide satisfactory results by decreasing the use of rigid implants. An endoscopic endonasal approach with an NSF for anterior skull base defect reconstruction is considered a safe procedure with no significant difference between the sides of the flap.

Cerebrospinal fluid leak management in anterior basal skull fractures secondary to head trauma

OBJECTIVE

To summarize the presentation, diagnosis, and management of cerebrospinal fluid (CSF) leaks in the setting of traumatic anterior skull base fracture.

METHODS

Wide literature research has been performed as well as the authors' own clinical experience has been summarized.

RESULTS

Articles from the most recent 30 years have been reviewed and a typical case of our own has been presented. Based on the most updated evidence, a treatment algorithm for CSF leaks has been proposed.

CONCLUSION

Anterior skull base fracture accounts for about 4% of all head injuries and CSF leaks is a complication that commonly presents with clear fluid emanating from the nasal passage. A positive beta-2-transferrin study is highly specific for diagnosis, while thin-slice CT scanning and MRI cisternography are also useful tools. The majority of the CSF leaks tend to be resolved spontaneously, and conservative management is attempted first with or without the augmentation of a lumbar drain. Surgical management mainly includes open surgery and endoscopic surgery, which have their own pros and cons.

Anterior Skull Base Meningioma: Surgical Approach and Complication Avoidance

Introduction  Endoscopic endonasal approach (EEA) and keyhole transcranial approaches (TCAs) are being increasingly used in anterior skull base meningioma (ASBM) surgery. Objective  We compare tumor resection rates and complication profiles of EEA and supraorbital keyhole approach (SOKHA) with conventional TCAs. Methods  Fifty-four patients with ASBM (olfactory groove meningioma [OGM], n  = 19 and planum sphenoidale/tuberculum sellae meningioma [PSM/TSM], n  = 35) operated at a single center over 7 years were retrospectively analyzed. Results  The overall rate of gross total resection (GTR) was higher in OGM (15/19, 78.9%) than PSM-TSM group (23/35, 65.7%, p  = 0.37). GTR rate with OGM was 90% and 75% with TCA and EEA. Death ( n  = 1) following medical complication (TCA) and cerebrospinal fluid leak requiring re-exploration ( n  = 2, one each in TCA and EEA) accounted for the major complications in OGM. For the PSM/TSM group, the GTR rates were 73.3% ( n  = 11/15), 53.8% ( n  = 7/13), and 71.4% ( n  = 5/7) with TCA, EEA, and SOKHA, respectively. Seven patients (20%) of PSM-TSM developed major postoperative complications including four deaths (one each in TCA and SOKHA, and two in EEA groups) and three visual deteriorations. Direct and indirect vascular complications were common in lesser invasive approaches to PSM-TSM especially if the tumor has encased intracranial arteries. Conclusion  No single approach is applicable to all ASBMs. TCA is still the best approach to obtain GTR but has tissue trauma-related problems. SOKHA may be a good alternative to TCA in selected PSM-TSMs, while EEA may be an alternate option in some OGMs. A meticulous patient selection is needed to derive reported results of EEA for PSM-TSM.

Use of surgical video-based automated performance metrics to predict blood loss and success of simulated vascular injury control in neurosurgery: a pilot study

OBJECTIVE

Experts can assess surgeon skill using surgical video, but a limited number of expert surgeons are available. Automated performance metrics (APMs) are a promising alternative but have not been created from operative videos in neurosurgery to date. The authors aimed to evaluate whether video-based APMs can predict task success and blood loss during endonasal endoscopic surgery in a validated cadaveric simulator of vascular injury of the internal carotid artery.

METHODS

Videos of cadaveric simulation trials by 73 neurosurgeons and otorhinolaryngologists were analyzed and manually annotated with bounding boxes to identify the surgical instruments in the frame. APMs in five domains were defined-instrument usage, time-to-phase, instrument disappearance, instrument movement, and instrument interactions-on the basis of expert analysis and task-specific surgical progressions. Bounding-box data of instrument position were then used to generate APMs for each trial. Multivariate linear regression was used to test for the associations between APMs and blood loss and task success (hemorrhage control in less than 5 minutes). The APMs of 93 successful trials were compared with the APMs of 49 unsuccessful trials.

RESULTS

In total, 29,151 frames of surgical video were annotated. Successful simulation trials had superior APMs in each domain, including proportionately more time spent with the key instruments in view (p < 0.001) and less time without hemorrhage control (p = 0.002). APMs in all domains improved in subsequent trials after the participants received personalized expert instruction. Attending surgeons had superior instrument usage, time-to-phase, and instrument disappearance metrics compared with resident surgeons (p < 0.01). APMs predicted surgeon performance better than surgeon training level or prior experience. A regression model that included APMs predicted blood loss with an R2 value of 0.87 (p < 0.001).

CONCLUSIONS

Video-based APMs were superior predictors of simulation trial success and blood loss than surgeon characteristics such as case volume and attending status. Surgeon educators can use APMs to assess competency, quantify performance, and provide actionable, structured feedback in order to improve patient outcomes. Validation of APMs provides a benchmark for further development of fully automated video assessment pipelines that utilize machine learning and computer vision.

Combined Pipeline Embolization Device with Endoscopic Endonasal Fascia Lata/Muscle Graft Repair as a Salvage Technique for Treatment of Iatrogenic Carotid Artery Pseudoaneurysm

The incidence of internal carotid artery (ICA) injury associated with endoscopic endonasal approaches to the pituitary is less than 1%. While parent vessel sacrifice has historically been the choice of treatment, vessel-preserving endovascular techniques have been reported. Although flow diversion offers endoluminal reconstruction, its major limitation is the delay in obtaining complete occlusion. We describe the use of a combined Pipeline embolization device (PED) with endoscopic endonasal repair using a fascia lata/muscle graft to treat an iatrogenic ICA pseudoaneurysm and report long-term radiographic follow-up. Further investigation into the utility of directed endoscopic endonasal repair of iatrogenic pseudoaneurysms initially treated with PED is necessary, especially given the need of post-PED anticoagulation and the rate of permanent neurological deficit after ICA sacrifice.

Suction mask device: a simple, inexpensive, and effective method of reducing spread of aerosolized particles during endoscopic endonasal surgery in the era of COVID-19

OBJECTIVE

Aerosol-generating procedures, including endoscopic endonasal surgery (EES), are a major risk for physicians during the COVID-19 pandemic. Techniques for reducing aerosolization and risk of transmission of COVID-19 during these procedures would be valuable to the neurosurgical community. The authors aimed to simulate the generation of small-particle aerosols during EES and craniectomy in order to develop methods to reduce the spread of aerosolized particles, and to test the effectiveness of these methods.

METHODS

This study was performed at the Anatomical Laboratory for Visuospatial Innovations in Otolaryngology and Neurosurgery at The Ohio State University. The following two scenarios were used to measure three different particle sizes (0.3, 2.5, and 10 µm) generated: 1) drilling frontotemporal bone, simulating a craniectomy; and 2) drilling sphenoid bone, simulating an endonasal approach. A suction mask device was created with the aim of reducing particle release. The presence of particles was measured without suction, with a single Frazier tip suction in the field, and with the suction mask device in addition to the Frazier suction tip. Particles were measured 12 cm from the craniectomy or endonasal drilling region.

RESULTS

In the absence of any aerosol-reducing devices, the number of particles measured during craniectomy was significantly higher than that generated by endonasal drilling. This was true regardless of the particle size measured (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001). The suction mask device reduced the release of particles of all sizes measured in the craniectomy simulation (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.031; and 2.5 µm, p = 0.026). The suction mask device further reduced the release of particles of all sizes during EES simulation (0.3 µm, p < 0.001; and 2.5 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.033; and 2.5 µm, p = 0.048). Large particles (10 µm) were not detected during EES.

CONCLUSIONS

The suction mask device is a simple and effective means of reducing aerosol release during EES, and it could potentially be used during mastoidectomies. This could be a valuable tool to reduce the risk of procedure-associated viral transmission during the COVID-19 pandemic.

Improved surgeon performance following cadaveric simulation of internal carotid artery injury during endoscopic endonasal surgery: training outcomes of a nationwide prospective educational intervention

OBJECTIVE

Internal carotid artery injury (ICAI) is a rare, life-threatening complication of endoscopic endonasal approaches that will be encountered by most skull base neurosurgeons and otolaryngologists. Rates of surgical proficiency for managing ICAI are not known, and the role of simulation to improve performance has not been studied on a nationwide scale.

METHODS

Attending and resident neurosurgery and otorhinolaryngology surgeons (n = 177) were recruited from multicenter regional and national training courses to assess training outcomes and validity at scale of a prospective educational intervention to improve surgeon technical skills using a previously validated, perfused human cadaveric simulator. Participants attempted an initial trial (T1) of simulated ICAI control using their preferred technique. An educational intervention including personalized instruction was performed. Participants attempted a second trial (T2). Task success (dichotomous), time to hemostasis (TTH), estimated blood loss (EBL), and surgeon heart rate were measured.

RESULTS

Participant rating scales confirmed that the simulation retained face and construct validity across eight instructional settings. Trial success (ICAI control) improved from 56% in T1 to 90% in T2 (p < 0.0001). EBL and TTH decreased by 37% and 38%, respectively (p < 0.0001). Postintervention resident surgeon performance (TTH, EBL, and success rate) was superior to preintervention attending surgeon performance. The most improved quartile of participants achieved 62% improvement in TTH and 73% improvement in EBL, with trial success improvement from 25.6% in T1 to 100% in T2 (p < 0.0001). Baseline surgeon confidence was uncorrelated with T1 success, while posttraining confidence correlated with T2 success. Tachycardia was measured in 57% of surgeon participants, but was attenuated during T2, consistent with development of resiliency.

CONCLUSIONS

Prior to training, many attending and most resident surgeons could not manage the rare, life-threatening intraoperative complication of ICAI. A simulated educational intervention significantly improved surgeon performance and remained valid when deployed at scale. Simulation also promoted the development of favorable cognitive skills (accurate perception of skill and resiliency). Rare, life-threatening intraoperative complications may be optimal targets for educational interventions using surgical simulation.

Improving Function in Cavernous Sinus Meningiomas: A Modern Treatment Algorithm

Background: The efficacy and safety of radiosurgery led to paradigm shift in the management of cavernous sinus meningiomas. Nevertheless, patients are still significantly affected by cranial nerve deficits related to the mass effect of these tumors. Our management strategy involves the combination of a functional surgical decompression followed by radiation therapy. Methods: We reviewed a single institution's cohort of patients who underwent endoscopic endonasal decompression (EED) for symptomatic meningiomas primarily involving the cavernous sinus (CS) from 2010 to 2016. The preoperative neuro-ophthalmological exam was compared to the 1- and 6-month postoperative exams. The patient's length of hospital stay, complications, and radiological and clinical follow-up were noted. Results: A total of 17 patients underwent EED for CS meningiomas that fit our radiological criteria. The final outcome at the 6-month visit showed five patients (62.5%) with normalization of deficit and three patients (37.5%) with partial improvement of the CNII deficit. Out of the 12 patients who had cavernous sinus cranial nerves (CSCN) deficits, the final outcome at the 6-month visit showed four patients (33.33%) with normalization of deficit, seven patients (58.3%) with partial improvement, and one patient (8.33%) with no improvement. There were no intraoperative complications. Conclusion: The EED for CS meningiomas is a valuable technique when addressing acute/subacute CNII and CSCN deficits. This conservative surgical approach showed good functional outcomes, low morbidity, and low complication rates. However, it does not exempt the need for radiosurgery/radiation therapy for control of tumor growth.

Combined and simultaneous endoscopic endonasal and transorbital surgery for a Meckel's cave schwannoma: technical nuances of a mini-invasive, multiportal approach

OBJECTIVE

Over the years, Meckel's cave pathologies have been judged off-limits because of high rates of morbidity. Even though several studies have defined various surgical routes with tolerable morbidity and mortality rates, controversies related to the optimal avenue to treat different categories of Meckel's cave and cavernous sinus neoplasms persist.With unceasing energy to cultivate minimally invasive neurosurgical approaches, the endoscopic endonasal route has been tested, and the approach effectively performed, to provide a valid surgical window to these areas. In this dynamic and challenging scenario, another ventral endoscopic minimally invasive route-that is, the superior eyelid endoscopic transorbital approach-has been very recently proposed, and used in selected cases, to access the cavernous sinus and Meckel's cave regions.

METHODS

The authors report the technical nuances of a combined and simultaneous endoscopic endonasal and transorbital surgical treatment of a patient with a Meckel's cave schwannoma. The operation involved collaboration among neurosurgery, otorhinolaryngology, and ophthalmology (oculoplastic surgery). The patient recovered well, had no neurological deficits, and was discharged to home 3 days after surgery.

RESULTS

The multiportal combined route was proposed for the following reasons. The endonasal approach, considered to be more familiar to our skull base team, could allow control of possible damage of the internal carotid artery. From the endonasal perspective, the most inferior and medial portion of the tumor could be properly managed. Finally, the transorbital route, by means of opening the lateral wall of the cavernous sinus via the meningoorbital band, could allow control of the superolateral part of the tumor and, most importantly, could permit removal of the portion entering the posterior cranial fossa via the trigeminal pore. Simultaneous surgery with two surgical teams working together was planned in order to reduce operative time, hospital stay, and patient stress and discomfort, and to ensure "one-shot" complete tumor removal, with minimal or no complications.

CONCLUSIONS

This study represents the translation into the real surgical setting of recent anatomical contributions related to the novel endoscopic transorbital approach and its simultaneous integration with the endoscopic endonasal pathway. Accordingly, it may pave the way for future applications related to minimally invasive, multiportal endoscopic surgery for skull base tumors.

A Rare Presentation of Ameloblastic Carcinoma of the Sinus Cavity and Skull Base

Ameloblastic carcinoma (AC) is an exceedingly rare odontogenic cancer about which there is limited information in the literature. We present a case of AC originating in the sinus cavity and extending to the skull base in a patient in the first trimester of pregnancy. Diagnostic work up was complicated by this pregnancy, which delayed radiation exposure with imaging. Once scans were obtained, diagnosis was further complicated by the radiographic similarities between possible lung metastases and previously undiagnosed sarcoid nodules. After thorough work up to rule out metastatic disease, the patient was successfully treated with primary surgical resection followed by adjuvant chemoradiation. The patient remained disease free at one year after therapy. This case demonstrates the importance of thorough work up in the diagnosis of AC, and is an opportunity to review the literature and discuss therapeutic methods to treat this rare, aggressive neoplasm.

Clival Chordoma: Endoscopic Bilateral Transmaxillary Approach

We present a case of a large clival chordoma in a 54-year-old female with a past medical history of Turner's syndrome and a 1.5-year history of nasal congestion. The tumor was extending in the nasopharynx to both pterygopalatine fossae. An expanded endoscopic endonasal approach was selected. Stereotactic navigation was utilized. Bilateral transmaxillary approach with ethmoidectomy was performed, and a transclival corridor to the deepest portion of the tumor was created. The tumor was successfully dissected off the medial walls of the cavernous sinuses. Gross-macroscopic resection was achieved. Surgical reconstruction of the skull base comprised of a fat graft, fascia lata overlay, and dural sealant. Given the extensive nasal involvement by the tumor, a vascularized nasoseptal flap was not feasible. The patient had an unremarkable postoperative course. She underwent intensity-modulated radiation therapy (IMRT) radiotherapy 6 weeks later, and was seen in follow-up 6 months later, with no issues.

The link to the video can be found at: https://youtu.be/4bnsEUtieAw .

Radial Forearm Free Tissue Transfer to Clival Defect

Introduction  Reconstruction of craniocervical junction (CCJ) defects after endoscopic endonasal skull base surgery (ESBS) remains challenging, despite advancements in vascularized intranasal and regional flaps. Microvascular free tissue transfers have revolutionized reconstruction in open skull base surgery but have been utilized rarely in ESBS. We describe the use of a radial forearm free flap (RFFF) for reconstruction of a recalcitrant CCJ defect after resection of a clival chordoma.

Case Report  A 54-year-old female who underwent ESBS for a clival chordoma complicated by a C1–C2 epidural abscess after proton beam therapy presented with pneumocephalus 4 years after her resection ( Fig. 1 ). At the CCJ, she developed a 1-cm skull-base defect. An occult cerebrospinal fluid (CSF) leak persisted despite an extracranial pericranial flap and a lateral nasal wall flap. Her definite reconstruction was a RFFF inset through a transmaxillary approach. Using a maxillary vestibular incision, anterior, lateral, and medial maxillotomies allowed the introduction of the flap into the nasal cavity and the passage of the RFFF pedicle across the posterior maxillary wall, into the premassateric space and to the facial vessels at the mandible. An endonasal inset supplemented with transoral suturing of the distal end of the flap to the posterior oropharynx halted further CSF egress. Vascularization of the flap was confirmed with intraoperative indocyanine green angiography and postoperative computed tomography (CT) angiography and magnetic resonance imaging (MRI).

Conclusion  A RFFF inset through a transmaxillary approach to the facial vessels has an adequate reconstructive surface and pedicle to cover the central and posterior fossa skull base after ESBS ( Fig. 2 ).

The link to the video can be found at: https://youtu.be/rQ5vJKyD5qg .

Endoscopic Transsphenoidal Surgery for Cushing's Disease: A Review

Ever since the 1960s, transsphenoidal surgery has been the modality of choice for treating Cushing's disease. Subsequent visualization of the pituitary fossa and sphenoid sinus may be done either with the operating microscope or with the relatively new endoscope. The endoscope due to its panoramic view allows greater visualization as compared to the operating microscope. It confers greater access to the cavernous sinus, sella, suprasellar, and parasellar regions and accommodates higher magnifications. It is bi-dimensional, however as opposed to the operating microscope that provides a three-dimensional view and allows greater depth perception. This article provides a comprehensive review of the advantages and disadvantages of the endoscope and compares it to the operating microscope. We hope this article will prove useful to both clinicians and academicians alike in their approach and management of Cushing's disease.

Surgical implementation and efficacy of endoscopic endonasal extradural posterior clinoidectomy

OBJECTIVEThe endoscopic endonasal approach (EEA) for skull base tumors has become an important topic in recent years, but its use, merits, and demerits are still being debated. Herein, the authors describe the nuances and efficacy of the endoscopic endonasal extradural posterior clinoidectomy for maximal tumor exposure.METHODSThe surgical technique included extradural posterior clinoidectomy following lateral retraction of the paraclival internal carotid artery and extradural pituitary transposition. In cases with prominent posterior clinoid process, a midline sellar dura cut was added to facilitate extradural exposure. Forty-four consecutive patients, in whom this technique was performed between 2016 and 2018 at Osaka City University Hospital, were reviewed. The pathology included 19 craniopharyngiomas, 7 chordomas, 6 meningiomas, 6 pituitary adenomas, 4 chondrosarcomas, and 2 miscellaneous. Utilization and effectiveness of this approach were further demonstrated with neuroimaging.RESULTSExtradural posterior clinoidectomies were successfully applied in all patients without permanent neurovascular injury and with better maneuverability and greater resection rate of the tumors. Four patients experienced transient postoperative abducens nerve paresis, and 1 patient experienced transient postoperative oculomotor nerve paresis; however, the patients with deficits recovered within 3 months. On radiological examination, the surgical field was 2.2 times wider in cases with bilateral posterior clinoidectomy than in cases without posterior clinoidectomy.CONCLUSIONSThe extended EEA with extradural posterior clinoidectomy creates an extra working space and allows adequate accessibility with safe surgical maneuverability to remove tumors that extend behind the posterior clinoid and dorsum sellae.

Lower-dose perioperative steroid protocol during endoscopic endonasal pituitary adenoma resection

Background:

Perioperative steroid management for pituitary adenoma resections is multifaceted due to possible hypothalamic–pituitary–adrenal (HPA) axis disruption. Although many different strategies have been proposed, there is no standard protocol for prophylaxis of potential hypocortisolemia.

Methods:

We performed a retrospective analysis of consecutive endoscopic endonasal pituitary adenoma resections. Before March 2016, patients received ≥100 mg of hydrocortisone intraoperatively followed by 2 mg of dexamethasone immediately postoperatively in most of the patients. Subsequently, patients received only 50 mg of hydrocortisone intraoperatively. A morning cortisol level was checked on postoperative day (POD) 2, and if it was <10 mcg/dL, patients remained on maintenance hydrocortisone. At 6 weeks, serum cortisol was redrawn and low-dose therapy was weaned when indicated.

Results:

Of those who received ≥100 mg of hydrocortisone, 8 of 24 (33.3%) were discharged on hydrocortisone compared to 1 of 14 (7.1%) who received 50 mg. 18 of 24 (75%) of ≥100 mg group received dexamethasone on POD 1, and of those, 8 (44.4%) were discharged on hydrocortisone. Of those who received ≥100 mg and were on outpatient steroid therapy initially, 3 of 8 (37.5%) required continuation after 6 weeks compared to none who received 50 mg. There was an association between patient’s intraoperative/immediate postoperative steroid use and steroid continuation at discharge.

Conclusion:

Through our experience, we hypothesize that ≥100 mg of hydrocortisone intraoperatively followed by postoperative dexamethasone may be overly suppressive in patients with otherwise normally functioning HPA. A 50 mg intraoperative dose alone may be considered to lower rates of unnecessary steroid regimens postoperatively.

Endoscopic endonasal pituitary gland hemi-transposition for resection of a dorsum sellae meningioma

A 69-year-old female with incidental diagnosis of a dorsum sellae meningioma had shown significant tumor growth after initial conservative management. The procedure started with a microscopic sublabial transsphenoidal approach to the sella and the suprasellar space. Due to limitations to a safe dissection and removal of the retrosellar component, the surgery was converted to a purely endoscopic endonasal approach with left hemi-transposition of the pituitary gland, followed by drilling of the dorsum sellae and removal of the left posterior clinoid process. A complete tumor resection was achieved, and a multilayer skull base reconstruction was performed without complications. The video can be found here: https://youtu.be/BEolyK-To_A .

Endoscopic Endonasal Transoculomotor Triangle Approach for the Resection of a Pituitary Adenoma with Ambient Cistern Extension

Objectives  The current video presents the nuances of the endoscopic endonasal transoculomotor triangle approach for the resection of a pituitary adenoma with extension into the ambient cistern.

Design  The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging.

Setting  The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon at a teaching academic institution.

Participants  The case refers to a 62-year-old female who presented with vision loss and headaches, and was found to have a pituitary adenoma with extension into the ambient cistern.

Main Outcome Measures  The main outcome measures consist of the reversal of the patient symptoms (headaches), the recurrence-free survival based on imaging, as well as the absence of any complications.

Results  The patient's headaches improved. There was no evidence of recurrence.

Conclusions  The endoscopic endonasal transoculomotor triangle approach is safe and effective for addressing pituitary tumors which extend into the ambient cistern.

The link to the video can be found at: https://youtu.be/EBLwEWhohxY .

Endoscopic Endonasal Approach for a Suprasellar Craniopharyngioma

Objectives  The current video presents the nuances of an endoscopic endonasal approach to a suprasellar craniopharyngioma.

Design  The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging.

Setting  The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon, at a teaching academic institution.

Participants  The case refers to a 67-year-old man who presented with vision loss and headaches, and was found to have a suprasellar mass, with imaging characteristics consistent with a craniopharyngioma.

Main Outcome Measures  The main outcome measures consistent of the reversal of the patient symptoms (vision loss and headaches), the recurrence-free survival based on imaging, as well as the absence of any complications.

Results  The patient's vision improved after the surgery; at his last follow-up there was no evidence of recurrence on imaging.

Conclusions  The endoscopic endonasal approach is safe and effective in treating suprasellar craniopharyngiomas.

The link to the video can be found at: https://youtu.be/p1VXbwnAWCo .

Endoscopic Endonasal Resection of a Suprasellar Pituitary Adenoma Mimicking Tuberculum Sellae Meningioma in a Patient with an Intrasellar Persistent Trigeminal Artery

A 50-year-old female with an incidentally diagnosed suprasellar lesion was initially managed conservatively due to the presence of an intrasellar persistent trigeminal artery going through the dorsum sellae and fundamentally forming the blood supply of the entire posterior circulation. Serial follow-up brain magnetic resonance imaging (MRI) revealed progressive enlargement of the suprasellar lesion over 4 years period. Surgery was indicated after the initial tumor growth; however, the patient refused surgery for fear of complications related to the persistent trigeminal artery. Two-and-a-half years later, she presented with deterioration of vision. Formal visual field testing revealed a right temporal field defect. Brain MRI demonstrated significantly enlarged suprasellar lesion, most consistent with tuberculum sellae meningioma, exerting mass effect on the optic apparatus. The patient underwent endoscopic endonasal resection of the lesion through a transplanum/transtuberculum approach. Intraoperatively, absence of hypertrophic McConnel arteries, hyperostosis, and the fact that the dura was soft and not under tension was against the diagnosis of tuberculum sellae meningioma. Additionally, the tumor consistency was similar to a pituitary adenoma. A complete resection was accomplished and multilayer skull base reconstruction was performed with no complications. On postoperative day 1 (POD 1), she was operated upon for the evacuation of small suprasellar hematoma associated with vision deterioration. Histopathological examination confirmed the diagnosis of atypical pituitary adenoma with K_i -67 labeling index of 4 to 5%. The patient ultimately recovered well with improved vision, and was discharged on POD 4 with no new neurological deficits. At 4 years follow-up, her vision was normalized and brain MRI showed no residual or recurrent lesion. The link to the video can be found at: https://youtu.be/QZmzctjAEbw .

Endoscopic Endonasal Transtuberculum Sellae Approach for the Resection of Suprasellar Intrainfundibular Epidermoid Cyst

A 49-year-old female presented with intense headaches of 3 months duration. Brain magnetic resonance imaging (MRI) was performed and showed a sellar–suprasellar lesion extending into the third ventricle. A presumptive diagnosis of a craniopharyngioma was made. Since the patient did not have any visual deficits, she opted for conservative management. Four months later, she started to have progressive deterioration of vision; thus, surgery was indicated.

The patient underwent endoscopic endonasal resection of the lesion through a transtuberculum sellae approach. The patient was positioned supine with the head slightly extended and the face turned to the right side. Following the essence of a binostril four-hand technique, a total gross resection of the lesion was achieved and multilayer skull base reconstruction was performed utilizing collagen matrix and nasoseptal flap; with no intraoperative complications.

The patient's postoperative course was uneventful with the improvement in her vision, and she was discharged on postoperative day 4 with no new neurological deficits. Histopathological examination confirmed the diagnosis of an epidermoid cyst. Postoperative pituitary gland function was within normal limits except for mild diabetes insipidus for which she is on DDAVP 0.1 mg twice daily. At 4 years follow-up, the patient was doing well, her vision was normalized, and brain MRI revealed no evidence of residual or recurrent lesion.

The link to the video can be found at: https://youtu.be/OqDFpa_Xq78 .

Endoscopic Endonasal Resection of Tuberculum Sellae Meningioma with Utilization of Indocyanine Green

We present the case of a 67-year-old female with an incidental finding of a left-sided tuberculum sellae meningioma on a brain magnetic resonance imaging (MRI) for an unrelated complaint. Formal visual field testing showed a small defect in the inferior nasal and temporal fields of the left eye, compatible with mass effect on the optic nerve by the tumor. An endoscopic endonasal transtuberculum approach with decompression of the left optic nerve was performed using a standard binostril four-hand technique, with the patient positioned supine with the head turned to the right side and tilted to the left, fixed in a three-pin head clamp, under imaging guidance. After exposure, we drilled the tuberculum sellae and the floor of the sella and after opening the dura, the tumor and optic nerve came into view. The tumor was completely removed and we confirmed the patency of all perforating vessels using indocyanine green. Reconstruction was done in a multilayered fashion, using collagen matrix and a nasoseptal flap. Patient had an uneventful postoperative stay and was discharged on postoperative day 3, neurologically stable with no new hormonal deficits. Pathology report confirmed a WHO Grade I meningioma with K_i -67 of 1% and 3-month postoperative MRI confirmed a gross total resection and visual fields exam showed a complete recovery. The link to the video can be found at: https://youtu.be/zRmt2aIvX5c .

Nasoseptal flap necrosis: a rare complication of endoscopic endonasal surgery

OBJECTIVE The vascularized nasoseptal flap (NSF) has become the workhorse for skull base reconstruction during endoscopic endonasal surgery (EES) of the ventral skull base. Although infrequently reported, as with any vascularized flap the NSF may undergo ischemic necrosis and become a nidus for infection. The University of Pittsburgh Medical Center's experience with NSF was reviewed to determine the incidence of necrotic NSF in patients following EES and describe the clinical presentation, imaging characteristics, and risk factors associated with this complication. METHODS The electronic medical records of 1285 consecutive patients who underwent EES at the University of Pittsburgh Medical Center between January 2010 and December 2014 were retrospectively reviewed. From this first group, a list of all patients in whom NSF was used for reconstruction was generated and further refined to determine if the patient returned to the operating room and the cause of this reexploration. Patients were included in the final analysis if they underwent endoscopic reexploration for suspected CSF leak or meningitis. Those patients who returned to the operating room for staged surgery or hematoma were excluded. Two neurosurgeons and a neuroradiologist, who were blinded to each other's results, assessed the MRI characteristics of the included patients. RESULTS In total, 601 patients underwent NSF reconstruction during the study period, and 49 patients met the criteria for inclusion in the final analysis. On endoscopic exploration, 8 patients had a necrotic, nonviable NSF, while 41 patients had a viable NSF with a CSF leak. The group of patients with a necrotic, nonviable NSF was then compared with the group with viable NSF. All 8 patients with a necrotic NSF had clinical and laboratory evidence indicative of meningitis compared with 9 of 41 patients with a viable NSF (p < 0.001). Four patients with necrotic flaps developed epidural empyema compared with 2 of 41 patients in the viable NSF group (p = 0.02). The lack of NSF enhancement on MR (p < 0.001), prior surgery (p = 0.043), and the use of a fat graft (p = 0.004) were associated with necrotic NSF. CONCLUSIONS The signs of meningitis after EES in the absence of a clear CSF leak with the lack of NSF enhancement on MRI should raise the suspicion of necrotic NSF. These patients should undergo prompt exploration and debridement of nonviable tissue with revision of skull base reconstruction.

Risk factors associated with postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery

OBJECTIVE The aim in this paper was to determine risk factors for the development of a postoperative CSF leak after an endoscopic endonasal approach (EEA) for resection of skull base tumors. METHODS A retrospective review of patients who underwent EEA for the resection of intradural pathology between January 1997 and June 2012 was performed. Basic demographic data were collected, along with patient body mass index (BMI), tumor pathology, reconstruction technique, lumbar drainage, and outcomes. RESULTS Of the 615 patients studied, 103 developed a postoperative CSF leak (16.7%). Sex and perioperative lumbar drainage did not affect CSF leakage rates. Posterior fossa tumors had the highest rate of CSF leakage (32.6%), followed by anterior skull base lesions (21.0%) and sellar/suprasellar lesions (9.9%) (p < 0.0001). There was a higher leakage rate for overweight and obese patients (BMI > 25 kg/m²) than for those with a healthy-weight BMI (18.7% vs 11.5%; p = 0.04). Patients in whom a pedicled vascularized flap was used for reconstruction had a lower leakage rate than those in whom a free graft was used (13.5% vs 27.8%; p = 0.0015). In patients with a BMI > 25 kg/m², the use of a pedicled flap reduced the rate of CSF leakage from 29.5% to 15.0% (p = 0.001); in patients of normal weight, this reduction did not reach statistical significance (21.9% [pedicled flap] vs 9.2% [free graft]; p = 0.09). CONCLUSIONS Preoperative BMI > 25 kg/m² and tumor location in the posterior fossa were associated with higher rates of postoperative CSF leak. Use of a pedicled vascularized flap may be associated with reduced risk of a CSF leak, particularly in overweight patients.

Indocyanine Green Fluorescence to Evaluate Nasoseptal Flap Viability in Endoscopic Endonasal Cranial Base Surgery

Objectives  The pedicled nasoseptal flap (NSF) has dramatically reduced postoperative cerebrospinal fluid leakage following endoscopic endonasal approach (EEA) surgery. Although rare, its arterial supply may be damaged during harvest or may be preoperatively damaged for numerous reasons. Early recognition permits harvesting a contralateral flap before sacrificing its pedicle as part of the surgical exposure or use of an alternative flap. Design  Technical feasibility study and case series. Setting  Tertiary care university-associated medical center. Participants  Five patients requiring an EEA with NSF reconstruction. Main Outcome Measures  During NSF harvest, intravenous indocyanine green (IVICG) was administered, and a customized endoscopic system was used to visualize the emerging fluorescence. At the end of each case, just before final positioning of the NSF, additional IVICG was administered, and the custom endoscope was again introduced to evaluate fluorescence. Results  In four patients, the entire NSF fluoresced brightly with IVICG on initial harvest and before final positioning. One patient showed heterogeneous fluorescence of the pedicle and distal parts of the NSF at both stages. All NSFs healed well without complication. Conclusion  IVICG facilitates real-time evaluation NSF's arterial supply. This may provide early recognition of arterial compromise, allowing the harvest of alternate flaps or modification of surgery.

Endoscopic endonasal resection of the odontoid process: clinical outcomes in 34 adults

OBJECTIVE Treatment of odontoid disease from a ventral corridor has consisted of a transoral approach. More recently, the endoscopic endonasal approach (EEA) has been used to access odontoid pathology. METHODS A retrospective review was conducted of patients who underwent an EEA for odontoid pathology from 2004 to 2013. During our analysis, the mean follow-up duration was 42.6 months (range 1-80 months). Patient outcomes, complications, and postoperative swallowing function were assessed either by clinic visit or phone contact. RESULTS Thirty-four patients underwent an EEA for symptomatic odontoid pathology. The most common pathology treated was basilar invagination (n = 17). Other pathologies included odontoid fractures, os odontoideum, and metastatic carcinoma. The mean patient age was 71.5 years. Thirty-one patients underwent a posterior fusion. All 34 patients experienced stability or improvement in symptoms and all had successful radiographic decompression. The overall complication rate was 76%. Nearly all of these complications were transient (86%) and the overall complication rate excluding mild transient dysphagia was only 44%. Twenty-one patients (62%) suffered from transient postoperative dysphagia: 15 cases were mild, transient subjective dysphagia (6 of whom had documented preoperative dysphagia), whereas 6 other patients required tube feedings for decreased oral intake, malnutrition, and dysphagia in the perioperative setting (5 of these patients had documented preoperative dysphagia). Sixteen patients had documented preoperative dysphagia and 6 of these had lower cranial nerve dysfunction. Postoperatively, 6 (37.5%) of 16 patients with preoperative dysphagia and 4 (67%) of 6 with lower cranial nerve dysfunction had significant dysphagia/respiratory complications. Eighteen patients had no documented preoperative dysphagia and only 2 had significant postoperative dysphagia/respiratory complications (11%). The rates of these complications in patients without preoperative dysphagia were lower than in those with any preoperative dysphagia (p = 0.07) and especially those with preexisting lower cranial neuropathies (p = 0.007). Dysphagia was also significantly more common in patients who underwent occipitocervical fixation (19/26, 73%) than in patients who underwent cervical fusion alone or no fusion (2/8, 25%; p = 0.02). All patients with perioperative dysphagia had improved at follow-up and all patients were tolerating oral diets. No patient suffered from velopalatal insufficiency. Two patients had intraoperative CSF leaks. One of these patients underwent a negative exploratory surgery for a questionable postoperative CSF leak. One patient developed infection in the resection bed requiring debridement and antibiotics. One patient died 8 days following surgery from an unknown cause. The 90-day perioperative mortality rate was 2.9%. CONCLUSIONS A completely EEA can be performed for compressive odontoid disease in all cases of neoplastic, degenerative, or invaginative atlantoaxial disease with satisfactory outcomes and low morbidity. Transient perioperative dysphagia and respiratory complications are common, usually as an exacerbation and reflection of underlying disease or occipitocervical fusion rather than the EEA, emphasizing the importance of avoiding transoral surgery.

Complete endoscopic resection of a pituitary stalk epidermoid cyst using a combined infrasellar interpituitary and suprasellar endonasal approach: case report

Intracranial epidermoid cysts are benign lesions of epithelial origin that most frequently present with symptoms of mass effect. Although they are often associated with a high rate of residual tumor and recurrence, maximal safe resection usually leads to good outcomes. The authors report a complete resection of an uncommon pituitary stalk epidermoid cyst with intrasellar extension using a combined suprasellar and infrasellar interpituitary, endoscopic endonasal transsphenoidal approach. The patient, a 54-year-old woman, presented with headache, visual disturbance, and diabetes insipidus. Postoperatively, she reported improvement in her visual symptoms and well-controlled diabetes insipidus using 0.1 mg of desmopressin at bedtime and normal anterior pituitary gland function. One year later, she continues to receive the same dosage of desmopressin and is also taking 50 mcg of levothyroxine daily after developing primary hypothyroidism unrelated to the surgical procedure. A combined infrasellar interpituitary and suprasellar approach to this rare location for an epidermoid cyst can lead to a safe and complete resection with good clinical outcomes.

Surgical Resection of an Optic Nerve Sheath Meningioma: Relevance of Endoscopic Endonasal Approaches to the Optic Canal

Optic nerve sheath meningiomas (ONSMs) account for less than 2% of meningiomas and 1.7% of orbital tumors. Although rare, the management of these tumors is important as unilateral blindness often results in untreated cases. Radiotherapy has emerged as the preferred treatment. However, therapies for ONSMs are controversial due to the variable natural history of the disease and limitations of surgical and radiotherapy options. A 60-year-old woman presented with monocular left diminished color perception and blurred vision. Magnetic resonance imaging demonstrated a homogenously enhancing 5-mm left optic nerve mass with evidence of nerve compression. Conservative management was advised. However, 1 month after diagnosis her visual acuity deteriorated further. Because of the small focal location of the tumor within the optic canal, surgery was considered. Given the tumor's location inferomedial to the optic nerve, an endoscopic endonasal approach to the optic canal was performed. This patient recovered fully with resolution of visual symptoms immediately following surgery. Postoperative imaging 24 hours after surgery demonstrated gross total resection of the tumor; 1 year postoperatively the patient has a normal ophthalmologic examination. This report highlights the value of endoscopic endonasal approaches in the management of select optic canal pathology, otherwise inaccessible via transcranial approaches.

Hemi-transseptal Approach for Pituitary Surgery: A Follow-Up Study

Objectives The hemi-transseptal (Hemi-T) approach was developed to overcome the potential drawbacks of the nasoseptal flap (NSF) in endoscopic endonasal transsphenoidal skull base surgery. In this study, we describe further refinements on the Hemi-T approach, and report long-term outcomes as compared with traditional methods of skull base reconstruction. Design A retrospective case-control study. Setting Montreal Neurological Institute and Jewish General Hospital, Montreal, Canada. Participants Patients who underwent endoscopic endonasal transsphenoidal approach to skull base pathology. Main Outcome Measures Operative time, CSF rhinorrhea, and postoperative nasal morbidity. Results A total of 105 patients underwent the Hemi-T approach versus 40 controls. Operative time was shorter using the Hemi-T technique (180.51 ± 56.9 vs. 202.9 ± 62 minutes; p = 0.048). The rates of nasal morbidity (septal perforation [5/102 vs. 6/37; p = 0.029] and mucosal adhesion [11/102 vs. 10/39 p = 0.027]), fascia lata harvest (21/100 vs. 18/39; p = 0.0028), and postoperative CSF leak rates (7/100 vs. 9/38; p = 0.006) were lower in the Hemi-T group. Conclusion Advantages of the Hemi-T approach over traditional exposure techniques include preservation of the nasal vascular pedicle, shorter operative time, reduced fascia lata harvest rates, and decreased nasal morbidity.

Periodic olfactory assessment in patients undergoing skull base surgery with preservation of the olfactory strip

OBJECTIVES/HYPOTHESIS

Others have reported olfactory disturbances following endoscopic approaches to the skull base. However, there is a lack of consensus on the extent and duration of dysfunction. This study aimed to compare our results with previously published work and to validate the olfactory strip-sparing approach.

STUDY DESIGN

Prospective study to assess olfaction in 50 patients scheduled to undergo resection of skull base tumors via extended endoscopic approaches.

METHODS

Patients were divided into two groups. Group I had a nasoseptal flap (NSF), and group II included patients in whom rescue flaps were performed bilaterally. Olfactory outcomes were assessed using repeated University of Pennsylvania Smell Identification Test at baseline, 6 weeks, 3 months, and 6 months following surgery.

RESULTS

Ultimately, 42 patients (seven group I and 35 group II) were available for assessment. Scores for group I were lower than at baseline at 6 weeks postoperatively (30.71 ± 5.5 vs. 24.5 ± 5.4; P = .05). However, by the third postoperative month the scores had improved to a level that was not significantly different from baseline (29.0 ± 3.7; P = .5). At 6 months, the score was 30.0 ± 3.9. Patients in group II showed no difference between their baseline and 6-week scores (31.5 ± 5.3 vs. 29.7 ± 5.9; P = .16). Six months postoperatively, the score was significantly higher (33.78 ± 3.6; P = .04).

CONCLUSIONS

Expanded endoscopic approaches to skull base tumors involving reconstruction with an NSF are associated with a short-term negative impact on olfaction. Olfaction does not seem to be affected by the surgical resection of pituitary adenomas associated with rescue flaps. Identification of the olfactory epithelium and meticulous harvesting of the NSF are critical to preserve olfaction.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1970-1975, 2017.

Transnasal endoscopic partial maxillectomy: Operative nuances and proposal for a comprehensive classification system based on 1378 cases

BACKGROUND

Despite the development of functional endoscopic endonasal surgery, there are still areas of the maxillary sinus that remain technically difficult to access using a standard middle meatal antrostomy as well as deep-seated skull base lesions requiring expanded transmaxillary approaches.

METHODS

All patients who underwent transnasal endoscopic partial maxillectomy (TEPM) in a single institution from 2000 to 2014 were retrospectively reviewed. The TEPM was classified into 5 types according to the anatomic structures progressively removed and to the access provided.

RESULTS

The TEPM was performed in 1378 patients for the management of: inflammatory diseases in 513 cases (37%), benign sinonasal tumors in 425 cases (31%), skull base malignancies in 285 cases (21%), and as a corridor to address deep-seated skull base lesions in 155 cases (11%).

CONCLUSION

The TEPM is a stepwise approach offering increasing access that can be tailored to different maxillary, sinonasal, and skull base pathologies with minimal morbidity for patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 754-766, 2017.

Feasibility Study for Transnasal Endoscopic Repair of Orbital Floor Fracture With Alloplastic Implant

OBJECTIVE

Fractures of the orbital floor are common yet repaired by various techniques, including open periorbital, transantral endoscopic, and endoscopic endonasal approaches. To date, endoscopic endonasal repair of an orbital floor fracture using an alloplastic implant has not been described. We aim to determine the technique and limitations of completely endoscopic endonasal orbital floor repair using an alloplastic implant.

STUDY DESIGN

Cadaveric anatomic study and retrospective case series.

METHODS

Cadaveric study of 12 sides with endoscopic sinonasal dissection followed by the creation and repair of an isolated orbital floor fracture using an alloplastic implant. Four representative patient cases are presented in which the techniques developed in the cadaveric study were employed. Patients were selected for this technique based on the results of the cadaveric study.

RESULTS

Cadaveric study demonstrated feasibility of access and repair for fractures that did not extend lateral to the infraorbital canal or anterior to the nasolacrimal duct. In all cadaveric sides and in all 4 patient cases, successful alloplastic orbital floor reconstruction was achieved.

CONCLUSION

This method of repair is feasible for selected patients and may be considered in cases of favorable fracture anatomy with or without concomitant indication for an ipsilateral sinus procedure.

Endoscopic endonasal control of the paraclival internal carotid artery by Fogarty balloon catheter inflation: an anatomical study

OBJECTIVE Neurosurgical management of many vascular and neoplastic lesions necessitates control of the internal carotid artery (ICA). The aim of this study was to investigate the feasibility of achieving control of the ICA through the endoscopic endonasal approach by temporary occlusion with a Fogarty balloon catheter. METHODS Ten endoscopic endonasal paraseptal approaches were performed on cadaveric specimens. A Fogarty balloon catheter was inserted through a sellar bony opening and pushed laterally and posteriorly extraarterially along the paraclival carotid artery. The balloon was then inflated, thus achieving temporary occlusion of the vessel. The position of the catheter was confirmed with CT scans, and occlusion of the ICA was demonstrated with angiography. The technique was performed in 2 surgical cases of pituitary macroadenoma with cavernous sinus invasion. RESULTS Positioning the Fogarty balloon catheter at the level of the paraclival ICA was achieved in all cadaveric dissections and surgical cases through a minimally invasive, quick, and safe approach. Inflation of the Fogarty balloon caused interruption of blood flow in 100% of cases. CONCLUSIONS Temporary occlusion of the paraclival ICA performed through the endoscopic endonasal route with the aid of a Fogarty balloon catheter may be another maneuver for dealing with intraoperative ICA control. Further clinical studies are required to prove the efficacy of this method.

Endoscopic endonasal study of the cavernous sinus and quadrangular space: Anatomic relationships

BACKGROUND

The quadrangular space permits an anterior entry into Meckel's cave while obviating the need for cerebral or cranial nerve retraction. This avenue is intimately associated with the cavernous sinus; thus, from this ventral perspective, it is feasible to visualize the anteromedial, anterolateral, and Parkinson triangles.

METHODS

Twenty middle cranial fossae were dissected endonasally under direct endoscopic visualization. Measurements of the surface area of the quadrangular space and the ventrally accessible cavernous sinus triangles were performed using 3 coordinates under image-guided navigation.

RESULTS

The surface area of the quadrangular space was 16.36 mm(2) (±2.89 mm(2) ). The anterolateral triangle was the largest (47.27 ± 5.37 mm(2) ), whereas Parkinson's was the smallest (22.46 ± 5.54 mm(2) ); the anteromedial triangle presented an average surface area 36.07 mm(2) (±4.15 mm(2) ).

CONCLUSION

The trajectory of the internal carotid artery (ICA) significantly impacts the quadrangular space area and may be a potential parameter for defining the feasibility of this corridor. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1680-E1687, 2016.

Craniovertebral junction 360°: A combined microscopic and endoscopic anatomical study

Objectives:

Craniovertebral junction (CVJ) can be approached from various corridors depending on the location and extent of disease. A three-dimensional understanding of anatomy of CVJ is paramount for safe surgery in this region. Aim of this cadaveric study is to elucidate combined microscopic and endoscopic anatomy of critical neurovascular structures in this area in relation to bony and muscular landmarks.

Materials and Methods:

Eight fresh-frozen cadaveric heads injected with color silicon were used for this study. A stepwise dissection was done from anterior, posterior, and lateral sides with reference to bony and muscular landmarks. Anterior approach was done endonasal endoscopically. Posterior and lateral approaches were done with a microscope. In two specimens, both anterior and posterior approaches were done to delineate the course of vertebral artery and lower cranial nerves from ventral and dorsal aspects.

Results:

CVJ can be accessed through three corridors, namely, anterior, posterior, and lateral. Access to clivus, foreman magnum, occipital cervical joint, odontoid, and atlantoaxial joint was studied anteriorly with an endoscope. Superior and inferior clival lines, supracondylar groove, hypoglossal canal, arch of atlas and body of axis, and occipitocervical joint act as useful bony landmarks whereas longus capitis and rectus capitis anterior are related muscles to this approach. In posterior approach, spinous process of axis, arch of atlas, C2 ganglion, and transverse process of atlas and axis are bony landmarks. Rectus capitis posterior major, superior oblique, inferior oblique, and rectus capitis lateralis (RCLa) are muscles related to this approach. Occipital condyles, transverse process of atlas, and jugular tubercle are main bony landmarks in lateral corridor whereas RCLa and posterior belly of digastric muscle are the main muscular landmarks.

Conclusion:

With advances in endoscopic and microscopic techniques, access to lesions and bony anomalies around CVJ is becoming easier and straightforward. A combination of microscopic and endoscopic techniques is more useful to understand this anatomy and may aid in the development of future combined approaches.

Endoscopic Endonasal Reconstruction of Skull Base: Repair Protocol

Background Endoscopic endonasal skull base reconstructions have been associated with postoperative cerebrospinal fluid (CSF) leaks. Objective A repair protocol for endoscopic endonasal skull base reconstruction is presented with the objective of decreasing the overall leak rate. Methods A total of 180 endoscopic endonasal skull base reconstructions were reviewed. Reconstructions were classified I to IV according to the reconstruction method, determined by severity of intraoperatively encountered CSF leaks for types I to III, and planned preoperatively for type IVs, which required nasoseptal flap. Results A total of 11 patients(6%) had postoperative leaks: 0 in type I (0%), 2 in type II (5%), 7 in type III (18%), and 2 (4%) in type IV reconstruction. Type III leak rate was higher than all other reconstructions. Total 31 intraoperative and 16 postoperative lumbar drains were placed. More patients had lumbar drains placed postoperatively for type III and intraoperatively for type IV than all other groups. There were significant overall differences in postoperative CSF leaks and lumbar drain placement between the four reconstruction types. No patient with type III reconstruction and intraoperative lumbar drain had postoperative CSF leak. Conclusions A repair protocol for endoscopic endonasal reconstructions determined by intraoperative CSF leak and preoperative planning minimizes unnecessary repair materials and additional morbidity. Our experience leads to a routine prophylactic lumbar drain placement in all type III leak and reconstructions. We also favor the type III reconstruction for minor intraoperative leaks, and a more generous use of type IV reconstructions in expectation of significant intraoperative CSF leak. The option of rescue flap technique in type III leaks should be strongly considered.