Lessons learned in the evolution of endoscopic skull base surgery

Fully endoscopic keyhole approach for intracranial aneurysm clipping: clinical outcomes and technical note

BACKGROUND

Surgical clipping is often utilized to treat intracranial aneurysms. The application of the endoscopy and keyhole approach in neurosurgery is increasing gradually in intracranial aneurysm occlusion. The aim of this study is to evaluate the role of fully endoscopic keyhole approach in clipping of intracranial aneurysms.

METHODS

We retrospectively analyzed four cases of intracranial aneurysms, including three cases of middle cerebral artery bifurcation aneurysms (M1) and one case of anterior communicating aneurysms (ACoA). Among them, the anterior communicating aneurysm underwent fully endoscopic clipping via supraorbital keyhole approach and the middle cerebral aneurysms underwent fully endoscopic clipping via mini-pterional keyhole approach. The clipped aneurysms were evaluated by Digital Subtraction Angiography (DSA).

RESULTS

All patients had satisfactory cerebral aneurysm clipping via the endoscopic keyhole approach. There was no cerebral hemorrhage, cerebral infarction, cerebral vasospasm. One case of intracranial infection was cured by active anti-infection. No recurrence of aneurysms after 6 months of follow-up.

CONCLUSION

With the advantages of the endoscopy and keyhole approach, the excellent visual field of the endoscope can reduce the influence of intracranial aneurysmal neck residual and perforating vessel. However, endoscopic clipping of intracranial aneurysms in narrow corridors requires a learning curve.

Endoscopic-assisted contralateral interhemispheric transfalcine keyhole approach for falcine meningioma: How I do it

BACKGROUND

Although the ipsilateral craniotomy approach has been used for the removal of falcine meningioma (FM), we report a case of FM that was minimally invasively removed using a contralateral interhemispheric approach assisted with endoscopy.

METHODS

We used a contralateral approach with a small craniotomy of the FM. The tumor was detached from the surrounding tissue during internal decompression. It was dissected and coagulated endoscopically in a blind spot under a microscope, and a Simpson Grade I resection was achieved.

CONCLUSION

A small craniotomy with a contralateral interhemispheric approach assisted by endoscopy allowed minimally invasive tumor removal without complications.

Development and Validation of a Novel Human-Fixed Cadaveric Model Reproducing Cerebrospinal Fluid Circulation for Simulation of Endoscopic Endonasal Skull Base Surgery

BACKGROUND AND OBJECTIVES

Endoscopic endonasal surgery is a well-established surgical approach to the skull base. Surgeons need a reusable long-lasting tool to acquire the skills needed for skull base reconstruction. The aim of this study was to elaborate and validate a human formalin-fixed cadaveric model that reproduces a realistic cerebrospinal fluid (CSF) circulation and that adequately renders a CSF leak.

METHODS

An external ventricular drain that connects with a peristaltic pump is placed in the subarachnoid space, which allows a water circulation that reproduces CSF circulation. Intracranial pressure is measured in real time. Endoscopic endonasal skull base approaches are performed, to create different skull base openings and CSF leaks. Participants were tasked with reconstruction of the defects using a standardized multilayered approach, with the goal of obtaining a watertight closure under normal intracranial pressure ranges. Compiled data included time of reconstruction, years of experience of participants, and success/failure to achieve a watertight reconstruction. A Likert questionnaire was also used.

RESULTS

The cadaveric model reproduced CSF circulation in 4 types of dural defects: sellar, suprasellar, transcribriform, and transclival. Intracranial pressures were similar to physiological conditions and were reproducible. Each model was tested multiple times, over several months. Success rates concurred with training levels (r = .8282 and P = .0017). A strong inverse correlation was also found between years of experience and time of reconstruction (r = .4977 and P < .0001). Participants agreed that the model was realistic (median Likert score of 4), and they strongly agreed that it allowed for the improvement of their surgical skills (median Likert score of 5).

CONCLUSION

This novel human-fixed cadaveric model for CSF circulation is efficient and adequately reproduces surgical conditions for skull base approaches. The model is unique, easy to reproduce, and reusable. It can be used as a tool for teaching and for research purposes.

The learning curve and outcomes of 1038 endoscopic endonasal transsphenoidal pituitary tumor surgeries - A single surgical team experience

Background

Pituitary adenomas rank third among adult intracranial tumors, with an incidence of 3.9- 7.4 cases/per 100,000 annually. Transsphenoidal surgery has evolved to include endoscopic endonasal surgery (EEA) in many centers due to technological and surgical advancements over the past two decades. We aim to analyze a 12-year cohort of pituitary adenomas operated through EEA, highlighting the evolution of surgical techniques and outcomes.

Methods

A retrospective review of patients undergoing EEA was conducted. A team of an otolaryngologist and neurosurgeon performed surgeries. The cohort was divided into three groups: Phase 1 (P1, 2012-2015), Phase 2 (P2, 2016-2019), and Phase 3 (P3, 2020-2023). Patient demographics, clinical data, and outcomes were collected from electronic medical records and compared over time.

Results

The mean age was 54.2 years, with 53.5% being female. The gross total resection rate was 75.6%, increasing from 62.3% in P1 to 76.3% in P3 (P = 0.003). The mean operative duration was 274.61 min, with no significant correlation to case number. Complication rates, excluding cerebrospinal fluid (CSF) leaks, were similar between the groups, with no statistically significant differences observed for complications such as visual deficit, cranial nerve palsy, and epistaxis. However, meningitis decreased significantly from 3.8% to 0.3% (P < 0.001). Intraoperative CSF leaks decreased from 65.1% to 55% (P = 0.003). The need for revision surgery was lower in P3 (8.5% vs. 5.4% vs. 2.1, P < 0.001). Length of hospitalization decreased from 5.3 days to 3.9 days (P < 0.001).

Conclusion

Our experience with EEA for pituitary adenomas shows significant improvements in surgical outcomes, reduced complications, and better postoperative management, underscoring the importance of experience, technical refinement, and a multidisciplinary approach.

Skull Base Chordoma and Chondrosarcoma: Neuroradiologist's Guide to Diagnosis, Surgical Management, and Proton Beam Therapy

Skull base chordomas and chondrosarcomas are distinct types of rare, locally aggressive mesenchymal tumors that share key principles of imaging investigation and multidisciplinary care. Maximal safe surgical resection is the treatment choice for each, often via an expanded endoscopic endonasal approach, with or without multilayer skull base repair. Postoperative adjuvant radiation therapy is frequently administered, usually with particle therapy such as proton beam therapy (PBT). Compared with photon therapy, PBT enables dose escalation while limiting damage to dose-limiting neurologic structures, particularly the brainstem and optic apparatus, due to energy deposition being delivered at a high maximum with a rapid decrease at the end of the penetration range (Bragg peak phenomenon). Essential requirements for PBT following gross total or maximal safe resection are tissue diagnosis, minimal residual tumor after resection, and adequate clearance from PBT dose-limiting structures. The radiologist should understand surgical approaches and surgical techniques, including multilayer skull base repair, and be aware of evolution of postsurgical imaging appearances over time. Accurate radiologic review of all relevant preoperative imaging examinations and of intraoperative and postoperative MRI examinations plays a key role in management. The radiology report should reflect what the skull base surgeon and radiation oncologist need to know, including distance between the tumor and PBT dose-limiting structures, tumor sites that may be difficult to access via the endoscopic endonasal route, the relationship between intradural tumor and neurovascular structures, and tumor sites with implications for postresection stability. ©RSNA, 2024 Supplemental material is available for this article.

Prognostic Impact of Hypothalamic Perforation in Adult Patients With Craniopharyngioma: A Cohort Study

CONTEXT

Outcome of craniopharyngioma is related to its locoregional extension, which impacts resectability and the risk of surgical complications. To maximize resection and minimize complications, optic tract localization, temporal lobe extension, and hypothalamic involvement are essential factors for surgical management.

OBJECTIVE

To assess the outcome of craniopharyngiomas depending on their relation to the hypothalamus location.

METHODS

We conducted a retrospective analysis of 79 patients with a craniopharyngioma who underwent surgery from 2007 to 2022. Craniopharyngiomas were classified in 3 groups, depending on the type of hypothalamus involvement assessed by preoperative magnetic resonance imaging: infra-hypothalamic (type A, n = 33); perforating the hypothalamus (type B, n = 40); and supra-hypothalamic (type C, n = 6). Surgical strategy was guided by the type of hypothalamic involvement, favoring endonasal approaches for type A and type B, and transcranial approaches for type C.

RESULTS

Long-term disease control was achieved in 33/33 (100%), 37/40 (92%), and 5/6 (83%) patients in type A, B, and C, respectively. In type B, vision was improved in 32/36 (89%) patients, while hypothalamic function was improved, stable, or worsened in 6/40 (15%), 32/40 (80%), and 2/40 (5%) patients, respectively. Papillary craniopharyngiomas were found in 5/33 (15%), 9/40 (22%), and 3/6 (50%) patients in types A, B, and C, respectively. In 4 patients, BRAF/MEK inhibitors were used, with significant tumor shrinkage in all cases.

CONCLUSION

Craniopharyngiomas located below the hypothalamus or perforating it can be safely treated by transsphenoidal surgery. For supra-hypothalamic craniopharyngiomas, postoperative results are less favorable, and documenting a BRAF mutation may improve outcome, if targeted therapy was efficient enough to replace surgical debulking.

Long-term outcomes of neuroendoscopic cyst partial resection combined with stereotactic radiotherapy for craniopharyngioma

PURPOSE

The aim of this study was to evaluate the treatment outcomes of neuroendoscopic cyst partial resection (ECPR) combined with stereotactic radiotherapy (SRT) for cystic craniopharyngiomas.

METHODS

In this retrospective study, 22 craniopharyngioma patients undergoing ECPR combined with SRT were included. This combination therapy was indicated for suprasellar cystic craniopharyngiomas in patients whose pituitary function was preserved but would be difficult to preserve in direct surgery. The outcomes of combination therapy, including tumor control and postoperative visual and pituitary functions, were investigated.

RESULTS

ECPR was safely performed, and cyst shrinkage was accomplished in all cases. After ECPR, visual function improved in 12 of 13 patients (92%) with visual field disturbance and did not deteriorate in any patients. Pituitary function was preserved in 14 patients (64%) and deteriorated in eight patients (36%) after ECPR. As a complication of ECPR, meningitis occurred because of a wound infection in one patient. In 18 of 22 patients (82%), the tumor was controlled without further treatment 19 - 87 months (median, 33 months) after SRT. Hypopituitarism was an adverse event after SRT in two of the 18 patients who achieved tumor control. Four patients (18%) had enlarged cysts after SRT. Postoperative pituitary function was significantly more likely to deteriorate in cases of extensive detachment from the ventricular wall, and retreatment was significantly more common in cases with hypothalamic extension.

CONCLUSION

Although limited to some cases, ECPR combined with SRT is a less invasive and useful therapeutic option for suprasellar cystic craniopharyngiomas. However, its long-term prognosis requires further evaluation.

The Transorbital Approach: A Comprehensive Review of Targets, Surgical Techniques, and Multiportal Variants

The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method.

Interdisciplinary Management of Skull Base Tumors

OBJECTIVE

Endoscopic endonasal skull base surgery has gained acceptance worldwide. Comparative analysis has demonstrated that endoscopic skull base surgery may have advantages for many pathologies of the anterior skull base, e. g., sinonasal malignant tumors; pathologies of the central skull base, e. g., pituitary adenomas, craniopharyngiomas; well-selected cases of planum sphenoidale and tuberculum sellae meningiomas; or for clival lesions, e. g., chordomas, chondrosarcomas, or selected meningiomas. Over the past three decades, interdisciplinary surgical teams, consisting of otolaryngologists and neurosurgeons, have provided detailed anatomical knowledge, suggested new approaches or modifications of established surgical techniques, and offered continued surgical education.

METHOD

A review of pertinent literature was conducted with an emphasis on interdisciplinary endoscopic surgery of skull base lesions.

RESULTS

Based on the authors̓ surgical experience in two different interdisciplinary endoscopic skull base centers, the authors classify approaches for endoscopic endonasal skull base surgery, describe indications, and key anatomic landmarks for common pathologies, and highlight surgical techniques to avoid complications.

CONCLUSION

Interdisciplinary endonasal endoscopic surgery combines surgical expertise, improves resection rates for many pathologies, and minimizes morbidity by reducing the incidence of surgical complications.

Skull-Base Chondrosarcoma: A Systematic Review of the Role of Postoperative Radiotherapy

Surgery and radiotherapy are key elements to the treatment of skull-base chondrosarcomas; however, there is currently no consensus regarding whether or not adjuvant radiotherapy has to be administered. This study searched the EMBASE, Cochrane, and PubMed databases for clinical studies evaluating the long-term prognosis of surgery with or without adjuvant radiotherapy. After reviewing the search results, a total of 22 articles were selected for this review. A total of 1388 patients were included in this cohort, of which 186 received surgery only. With mean follow-up periods ranging from 39.1 to 86 months, surgical treatment provided progression-free survival (PFS) rates ranging from 83.7 to 92.9% at 3 years, 60.0 to 92.9% at 5 years, and 58.2 to 64.0% at 10 years. Postoperative radiotherapy provides PFS rates ranging between 87 and 96.2% at 3 years, 57.1 and 100% at 5 years, and 67 and 100% at 10 years. Recurrence rates varied from 5.3% to 39.0% in the surgery-only approach and between 1.5% and 42.90% for the postoperative radiotherapy group. When considering prognostic variables, higher age, brainstem/optic apparatus compression, and larger tumor volume prior to radiotherapy were found to be significant factors for local recurrence.

Sinonasal Outcomes of the Combined Transseptal/Transnasal Approach with Unilateral Nasoseptal Rescue Flap in Endoscopic Endonasal Transsphenoidal Surgery: A Propensity Score Matching Analysis

Objectives  The authors applied surgical techniques acquired during the use of endoscopic combined transseptal/transnasal approach to reduce approach-related morbidity and improve sinonasal outcomes. Study Design  This is a retrospective cohort study of a prospectively collected database. Setting  The study setting involves a tertiary referral center. Participants  A total of 86 patients who underwent endoscopic endonasal transsphenoidal surgery for newly diagnosed pituitary adenomas from April 2018 to March 2021 were included. Patients treated via the combined transseptal/transnasal approach served as the study group ( n  = 18); those treated via the bilateral transnasal approach comprised the control group ( n  = 68). From the control group, propensity score matching (PSM) analysis was further performed to account for potential confounders and selection bias. Main Outcome Measures  Paired analysis was performed for pre- and 6-month-postoperative time points in study group, control group, and PSM control group. Olfactory function was evaluated by Connecticut Chemosensory Clinical Research Center (CCCRC) test, Cross-Cultural Smell Identification Test (CCSIT), and sinonasal outcomes were assessed by Sino-Nasal Outcome Test-22 (SNOT-22). Results  In the study group, CCCRC ( p  = 0.517) and CCSIT ( p  = 0.497) did not show any significant difference before and after surgery. There was some improvement in the symptom score of SNOT-22, but it was not statistically significant ( p  = 0.115). In the control group adjusted with PSM, a significant decrease in olfaction ( p  = 0.047) was observed using CCCRC. The CCSIT score was also decreased but not significant ( p  = 0.163). Also, there was no difference in the improvement of SNOT-22 ( p  = 0.781). Conclusion  Our new surgical method preserves olfactory function without compromising surgical outcomes.

Full Endoscopic Transcranial Resection of Meningiomas

OBJECTIVE

Tumors of the skull base can be accessed through different routes. Recent advantages in minimally invasive techniques have shown that very different routes can be applied for optimal tumor resection depending on the technical equipment, the surgeon's preference, and the individual anatomy of the pathology. Here, the authors present their technique for pure endoscopic transcranial tumor resection in meningiomas.

METHODS

Out of the cases of the Department of Neurosurgery, Homburg Saar Germany of the last 10 years, all endoscopic procedures for meningiomas were analyzed. Particular attention was given to evaluating the peculiarities of those meningiomas that were treated purely endoscopically.

RESULTS

While the endoscope was used in a large number of skull base meningiomas in endonasal approaches or for endoscopic inspection in transcranial skull base surgery, only a small number of meningiomas was selected for a purely endoscopically performed resection. The characteristics of these cases were rather a small lesion, straight access, and a keyhole position of the craniotomy. A complete resection of the tumor was achieved in all cases. Conversion to the microscope was not necessary in any case. There were no technical issues or complications associated with a fully endoscopic resection.

DISCUSSION

The endoscope is a valuable tool for visualization in meningioma surgery. In most cases, it is applied for an endonasal route or for endoscopic inspection in transcranial microsurgical cases. However, small to medium-sized meningiomas that can be accessed through the keyhole approach are good candidates for pure endoscopic resection. Because of the very high magnification and the minimally invasive nature of this approach, it should be considered more frequently in suitable lesions.

Neuroimaging of Brain Tumor Surgery and Epilepsy

To make the best clinical judgements, surgeons need to integrate information acquired via multimodal imaging [...].

Olfactory neuroblastoma: diagnosis, management, and current treatment options

Olfactory neuroblastoma (ONB) is a rare neoplasm originating from the olfactory neuroepithelium representing 3-6% of tumors of the sinonasal tract. ONB require multi-disciplinary care. Historically, the gold standard surgical procedure for ONB has been open craniofacial resection. In the last years, endoscopic endonasal approaches have been largely introduced with lower complication rates, shorter hospital stay, and similar clinical outcome. Radiotherapy plays an important role in the management of ONB, however there are not generally accepted recommendations for its application. Although there is agreement that multimodal therapy is needed, the optimal use of chemotherapy is still unknown. The rarity of the disease, makes difficult to draw definitive conclusions about the role of systemic treatment in induction and concomitant setting.

Endoscopic Ipsilateral Interhemispheric Approach for Middle-Third Falcine Meningioma: A Case Report and Literature Review

Middle-third falcine meningiomas (FMs) are usually hidden deep under the eloquent cortex and abundant bridging veins, which represent the main hindrances to surgical access. The endoscopic approach has the advantages of wide visualization and free visual axis without areas of visual blindness, which allows for the resection of FMs with good visualization in a narrow space, especially in deep operations. Here, we report a case of a middle-third FM treated using the endoscopic ipsilateral interhemispheric approach. A 55-year-old female who had suffered a headache for 6 months without other remarkable symptoms was diagnosed with middle-third FM combined with imaging evaluation. According to the imaging performance and anatomical features, we scheduled the endoscopic ipsilateral interhemispheric approach to access and remove the tumor. Consequently, gross total tumor resection was achieved without surgery-related complications. After the surgery, the patient had an uneventful recovery and was discharged with no neurological deficit. During the 24-month follow-up, the patient's condition remained favorable, with no tumor recurrence. In our opinion, the endoscopic ipsilateral interhemispheric approach is a feasible surgical strategy for FMs, which deserves further exploration as a treatment option.

Endoscope-Assisted Pedicled Maxillary Artery to Middle Cerebral Artery Bypass: An Anatomic Feasibility Study

BACKGROUND

Extracranial to intracranial bypass is used to augment and/or replace the intracranial circulation for various pathologies. The superficial temporal artery is the mainstay donor for pedicled bypasses to the anterior circulation but can be limited by its variable size, low native flow rates, and potential scalp complications. Interposition grafts such as the radial artery or greater saphenous vein are alternatives but are sometimes limited by size mismatch, length needed to reach the extracranial circulation, and loss of inherent vascular elasticity. Interposition grafts between the maxillary artery (IMA) and middle cerebral artery (MCA) address these limitations.

OBJECTIVE

To explore the feasibility of harvesting the IMA through an endoscopic transnasal, transmaxillary approach to perform a direct IMA to MCA bypass.

METHODS

Combined transcranial and endoscopic endonasal dissections were performed in embalmed human cadavers to harvest the IMAs for intracranial transposition and direct anastomosis to the MCA. Donor and recipient vessel calibers were measured and recorded.

RESULTS

A total of 8 procedures were performed using the largest and distal-most branches of the IMA (the sphenopalatine branch and the descending palatine branch) as pedicled conduits to second division of middle cerebral artery (M2) recipients. The mean diameter of the IMA donors was 1.89 mm (SD ± 0.42 mm), and the mean diameter of the recipient M2 vessels was 1.90 mm (SD ± 0.46 mm).

CONCLUSION

Endoscopic harvest of the IMA using a transnasal, transmaxillary approach is a technically feasible option offering an excellent size match to the M2 divisions of the MCA and the advantages of a relatively short, pedicled donor vessel.

The HACKD Score-Predicting Extent of Resection of Pituitary Macroadenomas Through an Endoscopic Endonasal Transsphenoidal Approach

BACKGROUND

Predicting extent of resection before pituitary surgery is imperative for operative planning and patient counseling. In the era of endoscopic endonasal transsphenoidal surgery (EEA), a specific, reliable tool for predicting resection of macroadenomas would have widespread applications.

OBJECTIVE

To identify factors that predict resection of pituitary macroadenomas through the EEA.

METHODS

A prospectively maintained, multicenter database of 277 consecutive macroadenomas resected through the EEA was analyzed. Multivariate logistic regression identified predictors of gross total resection (GTR). A simple scoring system, the Hardy, Age, Clival, Knosp, Depth (HACKD) Score, was developed and tested.

RESULTS

GTR was achieved in 82.3% (228/277) of cases. Older than 50 years (odds ratio [OR] 2.96, P = .01), clival extension (OR 5.87, P < .01), Hardy grade C or D suprasellar extension (OR 3.91, P = .01), Knosp grade 3 or 4 cavernous sinus invasion (OR 7.62, P < .01), and tumor depth >20 mm (OR 5.14, P < .01) were all associated with subtotal resection. The HACKD score, awarding 1 point each for Hardy grade C or D, and older than 50 years, and 2 points each for clival extension, Knosp grades 3 or 4, and tumor depth >20 mm, demonstrated excellent discriminative ability (AUROC 0.887, 95% CI: 0.839-0.934). The rate of GTR progressively decreased with a higher HACKD score. Rates of GTR were 95.8% (182/190) for low (HACKD ≤2), 59.5% (44/74) for moderate (HACKD 3-5), and 15.4% (2/13) for high (HACKD 6+) HACKD scores.

CONCLUSION

The HACKD score is a simple and accurate tool based on the largest study analyzing predictors of GTR in pituitary macroadenomas operated through the EEA.

In-Hospital Costs for Open versus Endoscopic Endonasal Approach for Craniopharyngioma Resection

OBJECTIVE

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

METHODS

All craniopharyngioma surgeries performed at a single institution over a period from January 1st 2001 to October 31th 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate regression analysis was performed using R software.

RESULTS

Thirty-six patients met study criteria, including 22 undergoing an open approach and 14 undergoing an EEEA. There was a significantly longer average length of stay among patients undergoing open resection (21.5 vs. 10.6 days, p = 0.024). The average total in-hospital cost of a patient undergoing an EEEA was $58979.3 compared to $89142.3 for an open approach (p = 0.127). On univariate regression analysis, the total in-hospital cost for a patient undergoing an open approach relative to an EEEA was $30163.0 (p = 0.127). The open approach was exclusively performed from study onset until April 2010 (16 patients). From April 2010 to August 2013, 6 open approaches and 5 EEEA were performed. The EEEA has been exclusively performed from August 2013 until the conclusion of our study period (9 patients).

CONCLUSIONS

There has been a shift toward surgical resection of craniopharyngioma via an EEEA approach for amenable tumors. Our study demonstrates that the EEEA has become the preferred surgical approach at our institution, and shows that the EEEA is associated with shorter postoperative length of stay and lower total in-hospital cost. Laryngoscope, 133:83-87, 2023.

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

Objective

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

Methods

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

Results

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

Conclusions

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

5-Aminolevulinic acid-enhanced fluorescence-guided treatment of high-grade glioma using angled endoscopic blue light visualization: technical case series with preliminary follow-up

OBJECTIVE

5-Aminolevulinic acid (5-ALA)-enhanced fluorescence-guided resection of high-grade glioma (HGG) using microscopic blue light visualization offers the ability to improve extent of resection (EOR); however, few descriptions of HGG resection performed using endoscopic blue light visualization are currently available. In this report, the authors sought to describe their surgical experience and patient outcomes of 5-ALA-enhanced fluorescence-guided resection of HGG using primary or adjunctive endoscopic blue light visualization.

METHODS

The authors performed a retrospective review of prospectively collected data from 30 consecutive patients who underwent 5-ALA-enhanced fluorescence-guided biopsy or resection of newly diagnosed HGG was performed. Patient demographic data, tumor characteristics, surgical technique, EOR, tumor fluorescence patterns, and progression-free survival were recorded.

RESULTS

In total, 30 newly diagnosed HGG patients were included for analysis. The endoscope was utilized for direct 5-ALA-guided port-based biopsy (n = 9), microscopic to endoscopic (M2E; n = 18) resection, or exoscopic to endoscopic (E2E; n = 3) resection. All endoscopic biopsies of fluorescent tissue were diagnostic. 5-ALA-enhanced tumor fluorescence was visible in all glioblastoma cases, but only in 50% of anaplastic astrocytoma cases and no anaplastic oligodendroglioma cases. Gross-total resection (GTR) was achieved in 10 patients in whom complete resection was considered safe, with 11 patients undergoing subtotal resection. In all cases, endoscopic fluorescence was more avid than microscopic fluorescence. The endoscope offered the ability to diagnose and resect additional tumor not visualized by the microscope in 83.3% (n = 10/12) of glioblastoma cases, driven by angled lenses and increased fluorescence facilitated by light source delivery within the cavity. Mean volumetric EOR was 90.7% in all resection patients and 98.8% in patients undergoing planned GTR. No complications were attributable to 5-ALA or blue light endoscopy.

CONCLUSIONS

The blue light endoscope is a viable primary or adjunctive visualization platform for optimization of 5-ALA-enhanced HGG fluorescence. Implementation of the blue light endoscope to guide resection of HGG glioma is feasible and ergonomically favorable, with a potential advantage of enabling increased detection of tumor fluorescence in deep surgical cavities compared to the microscope.

The use of three-dimensional endoscope in transnasal skull base surgery: A single-center experience from China

Objective

The development of skull base surgery in the past decade has been influenced by advances in visualization techniques; recently, due to such improvements, 3D endoscopes have been widely used. Herein, we address its effect for transnasal endoscopic skull base surgery.

Methods

A total of 63 patients who under endoscopic endonasal surgery (EES) with 3-D endoscope were retrospectively reviewed, including pituitary adenomas, craniopharyngiomas, meningiomas, Rathke’s cleft cysts, and chordomas. According to different lesions, transsellar approach (24 cases), transsphenoidal–transtuberculum approach (14 cases), transclival approach (6 cases), and transpterygoid approach (19 cases) were selected.

Results

Total removal of tumors was achieved in 56 patients (88.9%) and subtotal removal in 7 cases (11.1%). Complications included diabetes insipidus in seven patients (11.1%), cerebrospinal fluid (CSF) leakage in two patients (3.2%), major vascular injury occurred in one patient (1.6%), cranial nerve injury in nine patients (14.3%), and meningitis in two patients (3.2%). There was no mortality in the series. All patients recovered and were back to normal daily life, and no tumor recurrence or delayed CSF leakage was detected during the follow-up (2–13 months, mean 7.59 months).

Conclusions

Via 3D EES, it improved depth perception and preserved important neurovascular tissue when tumors were removed, which is important for improving the operative prognosis.

Risk Factors in a Pediatric Population for Postoperative Intracranial Infection Following Endoscopic Endonasal Skull Base Surgery and the Role of Antibiotic Prophylaxis

BACKGROUND

Endoscopic endonasal skull base surgery (EESBS) is performed through a non-sterile corridor. Intracranial infection rates in a pediatric population have not been extensively studied and the exact effect of antibiotic prophylaxis on rates of infection after EESBS in pediatric patients remains unclear.

OBJECTIVE

The purpose of our study is to investigate risk factors for postoperative intracranial infection during EESBS in a pediatric population and help elucidate the role of antibiotic prophylaxis.

METHODS

We conducted a retrospective chart review of 99 consecutive patients under the age of 18 who underwent EESBS at our institution from 2013 to 2021. Centers for Disease Control and Prevention/National Healthcare Safety Network criteria for diagnosis of meningitis were used to identify postoperative intracranial infections.

RESULTS

The average age was 12.3 years (range 1.6-18) with 66 male patients and 33 female patients. 49 patients had an intraoperative cerebrospinal fluid (CSF) leak, of which 4 had a postoperative CSF leak. We identified 3 postoperative intracranial infections (3%), which were all meningitis cases. The infection rate was 6% (3/49) among those with intraoperative CSF leaks. All patients with meningitis had a postoperative CSF leak. All infections were transclival approaches (2 chordoma and 1 neurenteric cyst).

CONCLUSION

This investigation represents one of the largest pediatric endoscopic skull base surgery cohorts. EESBS is safe to perform in pediatric populations, but transclival approaches and postoperative CSF leaks are risk factors for postoperative meningitis.

Endonasal transsphenoidal surgery for planum sphenoidale versus tuberculum sellae meningiomas

OBJECTIVE

The aim of this study was to determine if the distinction between planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas is clinically meaningful and impacts the results of the endoscopic endonasal approach (EEA).

METHODS

A consecutive series of patients who were 18 years of age or older and underwent EEA for newly diagnosed grade I PS meningiomas (PSMs) and TS meningiomas (TSMs) between October 2007 and May 2021 were included. The PS and TS were distinguished by drawing a line passing through the center of the TS and perpendicular to the PS on postcontrast T1-weighted MRI. Probabilistic heatmaps were created to display the actual distribution of tumor volumes. Tumor volume, extent of resection (EOR), visual outcome, and complications were assessed.

RESULTS

The 47 tumors were distributed in a smooth continuum. Using an arbitrary definition, 24 (51%) were PSMs and 23 (49%) were TSMs. The mean volume of PSMs was 5.6 cm3 compared with 4.5 cm3 for TSMs. Canal invasion was present in 87.5% of PSMs and 52% of TSMs. GTR was achieved in 38 (84%) of 45 cases in which it was the goal, slightly less frequently for PSMs (78%) compared with TSMs (91%), although the difference was not significant. Th mean EOR was 99% ± 2% for PSMs and 98% ± 11% for TSMs. Neither the suprasellar notch angle nor the percentage of tumor above the PS impacted the rate of GTR. After a median follow-up of 28.5 months (range 0.1–131 months), there were 2 (5%) recurrences after GTR (n = 38) both of which occurred in patients with PSMs. Forty-two (89%) patients presented with preoperative impaired vision. Postoperative vision was stable or improved in 96% of patients with PSMs and 91% of patients with TSMs. CSF leakage occurred in 4 (16.6%) patients with a PSM, which resolved with only lumbar drainage, and in 1 (4.3%) patient with a TSM, which required reoperation.

CONCLUSIONS

PSM and TSMs arise in a smooth distribution, making the distinction arbitrary. Those classified as PSMs were larger and more likely to invade the optic canals. Surgical outcome for both locations was similar, slightly favoring TSMs. The arbitrary distinction between PSMs and TSMs is less useful at predicting outcome than the lateral extent of the tumor, regardless of the site of origin.

Endoscope-assisted microneurosurgery for intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

In the surgical approach to treat deep-seated intracranial lesions, endoscopes can be used to assist microsurgical operations and improve outcomes. This technique is often called endoscope-assisted microneurosurgery (EAM). This systematic review and meta-analysis aimed to evaluate the feasibility, safety, and effectiveness of EAM.

METHODS

We performed a meta-analysis of relevant articles identified using PubMed, Embase, and the Cochrane Central Register to assess the efficacy of EAM according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Primary outcomes were repositioning of the definitive clip, better surgical field, the overall and endoscope-related complication rates, mortality, and the rate of follow up.

RESULTS

A total of 10 studies of 1,432 patients with 1,717 aneurysms treated with EAM were included. EAM led to repositioning of the definitive clip in 13% (95% CI, 9%-17%; I₂ = 72.61%; p < 0.001); 77% of aneurysms treated with endoscopically assisted vision and information had a better outcome than that with standard surgery (95% CI, 52%-95%; I₂ = 97.63%; p < 0.001). There was an overall complication rate of 6% (95% CI, 1%-13%; I₂ = 91.39%; p < 0.001). The incidence of endoscope-related complications was 0% (95% CI, 0%-1%; I₂ = 64%; p < 0.001). The mortality was 0% (95% CI, 0-1%; I₂ = 0.0%); and 94% of patients had an excellent to good recovery and good outcome (95% CI, 88%-98%; I₂ = 88.42%; p < 0.001).

CONCLUSIONS

Our comprehensive study showed that EAM for intracranial aneurysms is feasible, the safety of the surgery is good, and the patients have a good prognosis, Therefore, we think EAM can be more widely adopted in the future.

Extended endoscopic transorbital approach with superior-lateral orbital rim osteotomy: cadaveric feasibility study and clinical implications (SevEN-007)

OBJECTIVE

The endoscopic transorbital approach (ETOA) has been developed, permitting a new surgical corridor. Due to the vertical limitation of the ETOA, some lesions of the anterior cranial fossa are difficult to access. The ETOA with superior-lateral orbital rim (SLOR) osteotomy can achieve surgical freedom of vertical as well as horizontal movement. The purpose of this study was to confirm the feasibility of the ETOA with SLOR osteotomy.

METHODS

Anatomical dissections were performed in 5 cadaveric heads with a neuroendoscope and neuronavigation system. ETOA with SLOR osteotomy was performed on one side of the head, and ETOA with lateral orbital rim (LOR) osteotomy was performed on the other side. After analysis of the results of the cadaveric study, the ETOA with SLOR osteotomy was applied in 6 clinical cases.

RESULTS

The horizontal and vertical movement range through ETOA with SLOR osteotomy (43.8° ± 7.49° and 36.1° ± 3.32°, respectively) was improved over ETOA with LOR osteotomy (31.8° ± 5.49° and 23.3° ± 1.34°, respectively) (p < 0.01). Surgical freedom through ETOA with SLOR osteotomy (6025.1 ± 220.1 mm3) was increased relative to ETOA with LOR osteotomy (4191.3 ± 57.2 mm3) (p < 0.01); these values are expressed as the mean ± SD. Access levels of ETOA with SLOR osteotomy were comfortable, including anterior skull base lesion and superior orbital area. The view range of the endoscope for anterior skull base lesions was increased through ETOA with SLOR osteotomy. After SLOR osteotomy, the space for moving surgical instruments and the endoscope was widened. Anterior clinoidectomy could be achieved successfully using ETOA with SLOR osteotomy. The authors performed ETOA with SLOR osteotomy in 6 cases of brain tumor. In all 6 cases, complete removal of the tumor was successfully accomplished. In the 3 cases of anterior clinoidal meningioma, anterior clinoidectomy was performed easily and safely, and manipulation of the extended dural margin and origin dura mater was possible. There was no complication related to this approach.

CONCLUSIONS

The authors evaluated the clinical feasibility of ETOA with SLOR osteotomy based on a cadaveric study. ETOA with SLOR osteotomy could be applied to more diverse disease groups that do not permit conventional ETOA or to cases in which surgical application is challenging. ETOA with SLOR osteotomy might serve as an opportunity to broaden the indication for the ETOA.

Visualization of Resected Area in Endonasal Endoscopic Approach versus Transcranial Approach for Skull Base Meningiomas by Voxel-Based-Lesion Mapping

Background: We aimed to evaluate the resected area of endonasal endoscopic approach (EEA) and transcranial approach (TCA) for skull base meningiomas (SBMs) using voxel-based-lesion mapping and visualized the appropriate tumor location in each approach. Methods: We retrospectively examined 182 patients with SBMs who underwent tumor resection in our hospital between 2014 and 2019. Pre- and post-operative SBMs were manually delineated on MRI to create the voxels-of-interest (VOIpre and VOIpost) and were registered onto the normalized brain (normalized VOIpre and normalized VOIpost). The resected map was created by subtracting normalized VOIpost from the normalized VOIpre divided by the number of cases. The resected maps of TCA and EEA were compared by subtracting them. Results: Twenty patients underwent EEA and 135 patients underwent TCA. The tumor resected map demonstrated that the resected area of EEA frequently accumulated on the central skull base, while that of TCA accumulated near the central skull base. The border of both approaches matched the circle that connects neural foramens at the skull base. Conclusions: The resected area of SBMs by EEA and TCA was well visualized by voxel-based-lesion mapping. The circle connecting the neural foramens was the border of EEA and TCA.

Predictors of the Size and Surgical Freedom of the Trans-Cribriform and Trans-Clival Corridors, a Radiographic Analysis

Introduction The transcribriform and transclival corridors are endoscopic endonasal approaches used to treat pathologies of the skull base. We present a predictive model that uses the clival length and ethmoidal width to predict the size and surgical freedom (SF) of these corridors.

Methods Adult facial computed tomography scans were reviewed. Exclusion criteria included patients <18 years of age or radiographic evidence of trauma, neoplasm, or congenital deformities of the skull base. The images were analyzed using OsiriX MD (Bernex, Switzerland). Patients' demographics, clival length, ethmoidal width, surface area, and others were collected. Linear regression was used to create prediction models for the size and SF of the transclival and transcribriform corridors.

Results A total of 103 patients were included with an average age of 44.9 years and 47% males. Females had a smaller clival surface area (8 vs. 9.2 cm2, p = 0.001). For transclival corridor, clival length correlated positively with SF in the sagittal plane (rho = 0.44, p < 0.05) and negatively with SF in the coronal plane (rho = − 0.2, p < 0.05). For transcribriform corridor, ethmoidal width correlated positively with SF in the coronal plane (rho = 0.74, p < 0.05), and negatively with SF in the sagittal plane (rho = − 0.2, p < 0.05).

Conclusion A significant variability of the bony anatomy of the anterior and central skull base was found. The use of clival length and ethmoidal width as part of preoperative surgical planning might help to overcome the anatomical variability which could affect the adequacy of surgical corridors.

Clinical Application of Augmented Reality in Computerized Skull Base Surgery

Cranial base tactics comprise the regulation of tiny and complicated structures in the domains of otology, rhinology, neurosurgery, and maxillofacial medical procedure. Basic nerves and veins are in the nearness of these buildings. Increased the truth is a coming innovation that may reform the cerebral basis approach by supplying vital physical and navigational facts brought together in a solitary presentation. In any case, the awareness and acknowledgment of prospective results of expanding reality frameworks in the cerebral base region are really poor. This article targets examining the handiness of expanded reality frameworks in cranial foundation medical procedures and emphasizes the obstacles that present innovation encounters and their prospective adjustments. A specialized perspective on distinct strategies used being produced of an improved realty framework is furthermore offered. The newest item offers an expansion in interest in expanded reality frameworks that may motivate more secure and practical procedures. In any case, a couple of concerns have to be cared to before that can be for the vast part fused into normal practice.

Long-term tumor control after endoscopic endonasal resection of craniopharyngiomas: comparison of gross-total resection versus subtotal resection with radiation therapy

OBJECTIVE

Surgical management of craniopharyngiomas (CPAs) is challenging. Controversy exists regarding the optimal goals of surgery. The purpose of this study was to compare the long-term outcomes of patients who underwent gross-total resection with the outcomes of those who underwent subtotal resection of their CPA via an endoscopic endonasal approach.

METHODS

From a prospectively maintained database of all endoscopic endonasal approaches performed at Weill Cornell Medicine, only patients with CPAs with > 3 years of follow-up after surgery were included. The primary endpoint was radiographic progression. Data were collected on baseline demographics, imaging, endocrine function, visual function, and extent of resection.

RESULTS

A total of 44 patients with a mean follow-up of 5.7 ± 2.6 years were included. Of these patients, 14 (31.8%) had prior surgery. GTR was achieved in 77.3% (34/44) of all patients and 89.5% (34/38) of patients in whom it was the goal of surgery. Preoperative tumor volume < 10 cm3 was highly predictive of GTR (p < 0.001). Radiation therapy was administered within the first 3 months after surgery in 1 (2.9%) of 34 patients with GTR and 7 (70%) of 10 patients with STR (p < 0.001). The 5-year recurrence-free/progression-free survival rate was 75.0% after GTR and 25.0% after STR (45% in subgroup with STR plus radiotherapy; p < 0.001). The time to recurrence after GTR was 30.2 months versus 13 months after STR (5.8 months in subgroup with STR plus radiotherapy; p < 0.001). Patients with GTR had a lower rate of visual deterioration and higher rate of return to work or school compared with those with STR (p = 0.02). Patients with GTR compared to STR had a lower rate of CSF leakage (0.0% vs 30%, p = 0.001) but a higher rate of diabetes insipidus (85.3% vs 50%, p = 0.02).

CONCLUSIONS

GTR, which is possible to achieve in smaller tumors, resulted in improved tumor control, better visual outcome, and better functional recovery but a higher rate of diabetes insipidus compared with STR, even when the latter was supplemented with postoperative radiation therapy. GTR should be the goal of craniopharyngioma surgery, when achievable with minimal morbidity.

Combined endoscopic endonasal and transorbital multiportal approach for complex skull base lesions involving multiple compartments

PURPOSE

This study defines the specific areas that connect the surgical corridors of the endoscopic endonasal (EEA) and transorbital approach (TOA) to identify adequate clinical applications and perspectives of this combined multiportal approach.

METHODS

Consecutive patients who underwent combined EEA and TOA procedures for various pathologies involving multiple compartments of the skull base were enrolled.

RESULTS

A total of eight patients (2 chondrosarcomas, 2 meningiomas, 2 schwannomas, 1 glioma, and 1 traumatic optic neuropathy) were included between August 2016 and April 2021. The cavernous sinus (CS) was targeted as the connection area of the combined approach in four patients with tumors infiltrating the middle cranial fossa (MCF) and central skull base through the CS. For two patients with MCF tumors extending into the infratemporal fossa (ITF), the horizontal portion of the greater sphenoid wing and the foramen ovale were utilized as the connection area. In the remaining 2 patients, connection was achieved through the optic canal (OC). Gross total and near total resection was achieved in 5 patients with tumors, and circumferential removal of bone composing the OC was performed in one patient with traumatic compressive optic neuropathy. Postoperative complications included one cardiac arrest due to underlying cardiovascular disease and one case of oculomotor nerve palsy.

CONCLUSIONS

The combined EEA and TOA procedure is a useful strategy for complex lesions involving multiple compartments of the skull base. Herein, we identified the specific areas connecting the two surgical approaches, allowing a common path for EEA and TOA procedures.

Visual deterioration after endonasal endoscopic skull base surgery: causes, treatments, and outcomes

OBJECTIVE

Visual deterioration after endoscopic endonasal transsphenoidal surgery (EETS) for sellar and parasellar masses is a rare but serious complication caused by either compressive or ischemic mechanisms. Timely diagnosis and intervention may restore vision if instituted appropriately. The associated risk factors and their relation to the success of intervention are not well understood.

METHODS

The authors examined a series of 1200 consecutive EETS cases performed by the senior author at Weill Cornell/NewYork-Presbyterian Hospital from 2010 to 2020. Cases with postoperative visual deterioration were identified. Pre- and postoperative clinical data, mechanism of visual decline, latency to intervention, and long-term visual outcome were retrospectively collected and analyzed with appropriate statistical methods.

RESULTS

Twenty-one patients (1.75%) complained of early postoperative visual deterioration. The most common pathology associated with postoperative visual loss was craniopharyngioma (7.69%), followed by meningioma (5.43%) and then pituitary adenoma (1.94%). Timely intervention restored vision in 81% of patients for a 0.33% rate of permanent visual deterioration. Average time to visual deterioration was 28.8 hours, and over 70% of patients experienced vision loss within the first 13 hours. Compressive etiology (n = 11), consisting of either hematoma (n = 8) or graft displacement (n = 3), occurred 7.3 hours and 70.3 hours after surgery, respectively, and was more common in adenomas. Acute postoperative visual deterioration was more common in firm closures (4.78%) compared with soft closures (1.03%; p = 0.0006). Ischemic etiology (n = 10) occurred 10.3 hours after surgery and was more common with craniopharyngiomas and meningiomas (p = 0.08). Sixteen patients (76.2%) underwent early reoperation to explore and decompress the optic apparatus. Vision was restored to baseline after reoperation in all 11 compressive cases, whereas 6/10 ischemic cases improved with supplemental oxygen and hypervolemic hypertensive therapy (p = 0.02). Fluid expansion from 8 to 16 hours (p = 0.034) and systolic blood pressure elevation from 32 to 48 hours (p = 0.05) after surgery were significantly higher in those ischemic patients who recovered some vision compared with those with persistent visual deficits.

CONCLUSIONS

Visual deterioration after EETS is a rare event but can be effectively treated if acted upon appropriately and in a timely fashion. Compressive etiology is reversible with early reoperation. Ischemic etiology can be successfully treated in roughly half of cases with supplemental oxygen and hypertensive hypervolemic therapy but may result in permanent visual deterioration if not instituted appropriately or if delayed with unnecessary exploratory surgery.

Post-operative vision loss: analysis of 587 patients undergoing endoscopic surgery for pituitary macroadenoma

PURPOSE

Vision loss following surgery for pituitary adenoma is poorly described in the literature and cannot be reliably predicted with current prognostic models. Detailed characterization of this population is warranted to further understand the factors that predispose a minority of patients to post-operative vision loss.

MATERIALS AND METHODS

The medical records of 587 patients who underwent endoscopic transsphenoidal surgery at the Mount Sinai Medical Centre between January 2013 and August 2018 were reviewed. Patients who experienced post-operative vision deterioration, defined by reduced visual acuity, worsened VFDs, or new onset of blurry vision, were identified and analysed.

RESULTS

Eleven out of 587 patients who received endoscopic surgery for pituitary adenoma exhibited post-operative vision deterioration. All eleven patients presented with preoperative visual impairment (average duration of 13.1 months) and pre-operative optic chiasm compression. Seven patients experienced visual deterioration within 24 h of surgery. The remaining four patients experienced delayed vision loss within one month of surgery. Six patients had complete blindness in at least one eye, one patient had complete bilateral blindness. Four patients had reduced visual acuity compared with preoperative testing, and four patients reported new-onset blurriness that was not present before surgery. High rates of graft placement (10/11 patients) and opening of the diaphragma sellae (9/11 patients) were found in this series. Four patients had hematomas and four patients had another significant post-operative complication.

CONCLUSIONS

While most patients with pituitary adenoma experience favourable ophthalmological outcomes following endoscopic transsphenoidal surgery, a subset of patients exhibit post-operative vision deterioration. The present study reports surgical and disease features of this population to further our understanding of factors that may underlie vision loss following pituitary adenoma surgery. Graft placement and opening of the diaphragma sellae may be important risk factors in vision loss following ETS and should be an area of future investigation.

Perspective review on applications of optics in skull base surgery

The use of optic technology in skull base surgeries has the potential to revolutionize the field of medicine, particularly neurosurgery and neurology. Here, we briefly present the past, present, and future of skull-base surgery, with an emphasis on the applications of optical topography techniques. We discuss optical topography techniques such as functional near-infrared spectroscopy, optical diffusion tomography, and optical topographical imaging. Optical topography techniques are particularly advantageous when combined with other imaging methods. For instance, optical topography can be combined with techniques such as functional magnetic resonance imaging (fMRI) to combine the temporal resolution of optical topography with the spatial resolution of fMRI. Multimodal approaches will be critical to advance brain-related research as well as medicine. Structured light imaging techniques are also writing the future of 3-dimensional imaging. In short, optical topography can allow for non-invasive, high-resolution imaging that will provide real-time visualizations of the brain that are ideal for neurosurgery. From the limitations of traditional skull base surgeries to the newest developments in optical neuroimaging, here we will discuss the potential applications of optics in skull base procedures.

Multivariate Analysis and Validation of the Prognostic Factors for Skull Base Chordoma

Background: Skull base chordoma is a rare tumor with low-grade malignancy and a high recurrence rate, the factors affecting the prognosis of patients need to be further studied. For that, we investigated prognostic factors of skull base chordoma through the database of the Surveillance, Epidemiology, and End Results (SEER) program, and validated in an independent data set from the Xiangya Hospital.

Methods: Six hundred and forty-three patients diagnosed with skull base chordoma were obtained from the SEER database (606 patients) and the Xiangya Hospital (37 patients). Categorical variables were selected by Chi-square test with a statistical difference. Survival curves were constructed by Kaplan–Meier analysis and compared by log-rank test. Univariate and multivariate Cox regression analyses were used to explore the prognostic factors. Propensity score matching (PSM) analysis was undertaken to reduce the substantial bias between gross total resection (GTR) and subtotal resection (STR) groups. Furthermore, clinical data of 37 patients from the Xiangya Hospital were used as validation cohorts to check the survival impacts of the extent of resection and adjuvant radiotherapy on prognosis.

Results: We found that age at diagnosis, primary site, disease stage, surgical treatment, and tumor size was significantly associated with the prognosis of skull base chordoma. PSM analysis revealed that there was no significant difference in the OS between GTR and STR (p = 0.157). Independent data set from the Xiangya Hospital proved no statistical difference in OS between GTR and STR groups (p = 0.16), but the GTR group was superior to the STR group for progression-free survival (PFS) (p = 0.048). Postoperative radiotherapy does not improve OS (p = 0.28), but it can prolong PFS (p = 0.0037). Nomograms predicting 5- and 10-year OS and DSS were constructed based on statistically significant factors identified by multivariate Cox analysis. Age, primary site, tumor size, surgical treatment, and disease stage were included as prognostic predictors in the nomograms with good performance.

Conclusions: We identified age, tumor size, surgery, primary site, and tumor stage as main factors affecting the prognosis of the skull base chordoma. Resection of the tumor as much as possible while ensuring safety, combined with postoperative radiotherapy may be the optimum treatment for skull base chordoma.

Update on management of craniopharyngiomas

PURPOSE/INTRODUCTION

Craniopharyngiomas are locally-aggressive tumors arising along the hypothalamic-pituitary axis. Treatment is nuanced as a result of their proximity and adherence to vital neurovascular structures and responsiveness to surgery, radiation and, in some cases, chemotherapy.

METHODS

We reviewed the literature discussing the current state of knowledge regarding craniopharyngioma biology and therapy.

RESULTS

Recent advances in endoscopic endonasal surgery (EEA) have made surgery a safer and more effective option. While cure may be achieved with gross total resection (GTR), when felt to be too risky, a subtotal resection followed by radiation is often a more prudent strategy, particularly in children with hypothalamic invasion. Data on long-term outcome are mostly derived from older studies in which a craniotomy, rather than EEA, was performed. Long-term EEA outcome studies are lacking. Enhanced knowledge of the biological basis of papillary CPs has led to novel medical treatments for BRAFv^600E variants that appear to be effective.

CONCLUSION

Endoscopic technology has improved surgical results for craniopharyngiomas and expanded the indications for the transsphenoidal approach. The goal of CP surgery goal is maximal safe resection to achieve cure, but subtotal resection and radiation may be equally effective. Early diagnosis of specific variants will facilitate enrollment in promising medical trials.

The Suprasellar Meningioma Patient-Reported Outcome Survey: a disease-specific patient-reported outcome measure for resection of suprasellar meningioma

OBJECTIVE

Suprasellar meningioma resection via either the transcranial approach (TCA) or the endoscopic endonasal approach (EEA) is an area of controversy and active evaluation. Skull base surgeons increasingly consider patient-reported outcomes (PROs) when choosing an approach. No PRO measure currently exists to assess quality of life for suprasellar meningiomas.

METHODS

Adult patients undergoing suprasellar meningioma resection between 2013 and 2019 via EEA (n = 14) or TCA (n = 14) underwent semistructured interviews. Transcripts were coded using a grounded theory approach to identify themes as the basis for a PRO measure that includes all uniquely reported symptoms. To assess content validity, 32 patients and 15 surgeons used a Likert scale to rate the relevance of items on the resulting questionnaire and the general Patient-Reported Outcomes Measurement Information System-29 (PROMIS29). The mean scores were calculated for all items and compared for TCA versus EEA patient cohorts by using unpaired t-tests. Items on either questionnaire with mean scores ≥ 2.0 from patients were considered meaningful and were aggregated to form the novel Suprasellar Meningioma Patient-Reported Outcome Survey (SMPRO) instrument.

RESULTS

Qualitative analyses resulted in 55 candidate items. Relative to patients who underwent the EEA, those who underwent the TCA reported significantly worse future outlook before surgery (p = 0.01), tiredness from medications 2 weeks after surgery (p = 0.001), and word-finding and memory difficulties 3 months after surgery (p = 0.05 and < 0.001, respectively). The items that patients who received a TCA were most concerned about included medication-induced lethargy after surgery (2.9 ± 1.3), blurry vision before surgery (2.7 ± 1.5), and difficulty reading due to blurry vision before surgery (2.7 ± 2.7). Items that patients who received an EEA were most concerned about included blurry vision before surgery (3.5 ± 1.3), difficulty reading due to blurry vision before surgery (2.4 ± 1.3), and problems with smell postsurgery (2.9 ± 1.3). Although surgeons overall overestimated how concerned patients were about questionnaire items (p < 0.0005), the greatest discrepancies between patient and surgeon relevance scores were for blurry vision pre- and postoperatively (p < 0.001 and < 0.001, respectively) and problems with taste postoperatively (p < 0.001). Seventeen meningioma-specific items were considered meaningful, supplementing 8 significant PROMIS29 items to create the novel 25-item SMPRO.

CONCLUSIONS

The authors developed a disease- and approach-specific measure for suprasellar meningiomas to compare quality of life by operative approach. If demonstrated to be reliable and valid in future studies, this instrument may assist patients and providers in choosing a personalized surgical approach.

ABBREVIATIONS

EEA = endoscopic endonasal approach; GTR = gross-total resection; PRO = patient-reported outcome; PROMIS29 = Patient-Reported Outcomes Measurement Information System-29; QOL = quality of life; SMPRO = Suprasellar Meningioma Patient-Reported Outcome Survey; TCA = transcranial approach.

Unilateral Subfrontal Approach for Giant Tuberculum Sellae Meningioma: Single Center Experience and Review of the Literature

Background

Microsurgical Transcranial approach (mTCA) is the primary choice for the resection of giant Tuberculum Sellae Meningiomas (TSM). The objective of this study is to explore surgical details of unilateral subfrontal approach.

Methods

Ten patients with giant TSM treated by unilateral subfrontal approach were included from January 2018 to June 2021. Demographic characteristics, surgical data, post-procedure complications and outcomes of patients have been descriptive analyzed, combined with systematic literature review to explore the surgical details and the prognosis of unilateral subfrontal approach.

Results

Ten patients include six male and four females, age range from 35 to 77 years, duration of visual impairment from 1 to 12 months, were all performed unilateral subfrontal approach. Nine patients achieved radical resection (Simpson grades I-II) through post-operative imaging confirmation, and Simpson IV resection was performed in the remaining one due to cavernous sinus invasion. The postoperative visual acuity was improved or maintained in 8 patients. Visual acuity decreased in 2 cases, including 1 case of optic nerve atrophy and the other case of optic canal not opening. Five cases with frontal sinus opened were repaired during the operation and there was no postoperative cerebrospinal fluid leakage or intracranial infection. One patient suffered from postoperative anosmia, one patient developed left limb weakness, but their symptoms have improved in the follow-up.

Conclusion

Summarize the experience of our center and previous literature, unilateral forehead bottom craniotomy is a feasible surgical approach for giant tuberculum sellae meningioma. Intraoperative application of EC glue and pedicled fascia flap to repair the frontal sinus can prevent complications associated with frontal sinus opening. Optic canal unroofing has huge advantage in visual improvement.

Surgeon education through a surgical cost feedback system reduces supply cost in endoscopic skull base surgery

OBJECTIVE

A large proportion of healthcare expense is operating room (OR) costs. As a means of cost mitigation, several institutions have implemented surgeon education programs to bring awareness about supply costs. This study evaluates the impact of a surgical cost feedback system (surgical receipt) on the supply costs of endoscopic skull base surgery (ESBS) procedures.

METHODS

The supply costs of each ESBS surgical case were prospectively collected and analyzed before and after the implementation of a nonincentivized, automated, and itemized weekly surgical receipt system between January 2017 and December 2019. Supply cost data collected 15 months prior to intervention were compared with cost data 21 months after implementation of the surgical receipt system. Demographics, surgical details, and OR time were collected retrospectively.

RESULTS

Of 105 ESBS procedures analyzed, 36 preceded and 69 followed implementation of cost feedback. There were no significant differences in patient age (p = 0.064), sex (p = 0.489), surgical indication (p = 0.389), or OR anesthesia time (p = 0.51) for patients treated before and after implementation. The mean surgical supply cost decreased from $3824.41 to $3010.35 (p = 0.002) after implementation of receipt feedback. Usage of dural sealants (p = 0.043), microfibrillar collagen hemostat (p = 0.007), and oxidized regenerated cellulose hemostat (p < 0.0001) and reconstructive technique (p = 0.031) significantly affected cost. Mediation analysis confirmed that the overall cost reduction was predominantly driven by reduced use of dural sealant; this cost saving exceeded the incremental cost of greater use of packing materials such as microfibrillar collagen hemostat.

CONCLUSIONS

Education of surgeons regarding surgical supply costs by a surgical receipt feedback system can reduce the supply cost per case of ESBS operations.

Operative nuances and surgical limits of the endoscopic approach to clival chordomas and chondrosarcomas: A single-center experience of 72 patients

OBJECTIVE

Gross total resection (GTR) is the mainstay therapy for chordomas and chondrosarcomas to have the best prognosis. The aims of this study were to specify the limits of EEA, emphasize the need for additional combined approaches for tumors beyond these limitations for high resection rates, discuss the prognostic factors and operative nuances that affect GTR, and present the causes and characteristics of early and late recurrences.

METHODS

We retrospectively analyzed the endoscopic endonasal surgeries in the Pituitary Research Center and Neurosurgery Department of the Kocaeli University Faculty of Medicine, Turkey between January 2004 and December 2019. We retrospectively reviewed the medical data, radiological images, and surgical videos of patients, and 72 patients with chordoma and chondrosarcoma were included in the study.

RESULTS

Based on pathology reports, 72 patients (seven pediatric) were identified, to whom 91 endoscopic operations were performed. We determined the surgical limitations for each clival segment as superior, middle, and inferior. Then, we divided these into three subgroups according to whether the tumor shows dural invasion (extradural chordoma, large extradural - minimal intradural component, and minimal extradural - large intradural component). The tumors of 19 (26.4%), 25 (26.4%), and nine (12.5%) patients originated from the superior, middle, and inferior clivus, respectively. Nineteen (26.4%) patients had panclival involvement. GTR was performed in 47 (65.3%) the patients. The GTR rate in patients with panclival tumors was 47.3% (9/19). The experience, lateralization, dural involvement, and origin of the clivus affecting GTR were analyzed. Extradural - intradural extensions were verified as negative predictor factors for GTR, whereas tumors located in the superior (OR: 16.710, p=0.030) and middle (OR: 11.154, p=0.023) segments were positive predictive factors for GTR.

CONCLUSION

An increasing experience in endoscopic surgery significantly increases the GTR rates by widening the surgical limitations. Due to dense bone infiltration and adhesion to critical neurovascular structures, recurrence rates are high despite performing GTR. Although surgery and adjuvant treatments improve the 5-year survival of patients, the mortality rates remain high. Therefore, surgery of these tumors should be performed by experienced centers. In addition to surgical and adjuvant therapies, targeted molecular and translational biological therapies are also needed for chordomas and chondrosarcomas in the future.

Limited utility of 5-ALA optical fluorescence in endoscopic endonasal skull base surgery: a multicenter retrospective study

OBJECTIVE

Incomplete resection of skull base pathology may result in local tumor recurrence. This study investigates the utility of 5-aminolevulinic acid (5-ALA) fluorescence during endoscopic endonasal approaches (EEAs) to increase visibility of pathologic tissue.

METHODS

This retrospective multicenter series comprises patients with planned resection of an anterior skull base lesion who received preoperative 5-ALA at two tertiary care centers. Diagnostic use of a blue light endoscope was performed during EEA for all cases. Demographic and tumor characteristics as well as fluorescence status, quality, and homogeneity were assessed for each skull base pathology.

RESULTS

Twenty-eight skull base pathologies underwent blue-light EEA with preoperative 5-ALA, including 15 pituitary adenomas (54%), 4 meningiomas (14%), 3 craniopharyngiomas (11%), 2 Rathke's cleft cysts (7%), as well as plasmacytoma, esthesioneuroblastoma, and sinonasal squamous cell carcinoma. Of these, 6 (21%) of 28 showed invasive growth into surrounding structures such as dura, bone, or compartments of the cavernous sinus. Tumor fluorescence was detected in 2 cases (7%), with strong fluorescence in 1 tuberculum sellae meningioma and vague fluorescence in 1 pituicytoma. In all other cases fluorescence was absent. Faint fluorescence of the normal pituitary gland was seen in 1 (7%) of 15 cases. A comparison between the particular tumor entities as well as a correlation between invasiveness, WHO grade, Ki-67, and positive fluorescence did not show any significant association.

CONCLUSIONS

With the possible exception of meningiomas, 5-ALA fluorescence has limited utility in the majority of endonasal skull base surgeries, although other pathology may be worth investigating.

Olfactory outcomes after endonasal skull base surgery: a systematic review

For the last two decades, endonasal approach has been regularly applied to treat skull base lesions. However, postoperative olfactory dysfunction remains an unsolved problem. This systematic review aimed to identify factors that might affect postoperative olfactory prognosis of patients undergoing endonasal surgery for resection of sellar/parasellar lesions. The literature search was conducted comprehensively to exhaust studies which focused on patients' olfaction with objective olfactory assessments after endonasal skull base surgery. We sought to characterize the potential factors that might affect postoperative olfactory outcomes. Nineteen articles met inclusion criteria. We found that (1) endoscopic surgery was beneficial to patients' olfactory prognosis than microscopic surgery (incidence of postoperative decreased olfactory function: 18.48% (39/211) for the endoscopic group and 36.88% (52/141) for the microscopic group, P < 0.01); meta-analysis for single rate, 20% (95% CI 9-30%) for the endoscopic group and 35% (95% CI 0-72%) for the microscopic group); (2) harvesting septal flaps was an unfavorable factor for olfactory recovery and the rescue flap technique should be preferred compared with the HB flap; (3) no evidence showed that resection of the middle turbinate was detrimental to recovery of olfaction. Patients undergoing endoscopic endonasal surgery may have better olfactory outcomes than those undergoing microscopic endonasal surgery for resection of sellar/parasellar lesions. Special attention should be paid when using septal flaps is planned and the rescue flap technique should be the preferred choice. After resecting the middle turbinate, patients' olfaction still has a great chance of returning to the baseline. More homogeneous and high-quality studies are needed for further assessment.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The efficacy of function-preservation in treating paranasal sinus and nasal cavity neoplasms

Background

Craniofacial resection (CFR) has been regarded as the gold standard for paranasal sinus and nasal cavity (PNSNC) neoplasms. The improvement of surgical procedures has been ongoing in recent years. We analyzed the clinical curative effects of the function-preservation therapy that was mainly using nasal endoscopic surgery along with appropriate radiotherapy and chemotherapy as applicable.

Methods

We performed a retrospective analysis of factors that influence the survival time of the 28 patients with PNSNC neoplasms who underwent nasal endoscopic surgery. All patients with tumor lesions underwent a complete resection in en bloc or piecemeal resection. Five cases did not undergo radiotherapy or chemotherapy; the remaining 23 patients had multimodality therapy.

Results

The median follow-up time was 41.5 (range = 14-97) months. The overall 3-year survival rate was 78.57% for T3 cancer and 50% for those with T4. T classification (P = 0.031) and multimodality therapy (P = 0.038) were independent prognostic factors for postoperative 3-year survival rate of patients with PNSNC neoplasms.

Conclusion

Function-preservation therapy based on the minimally invasive endoscopic resection (MIER) with appropriate adjuvant therapy not only prolonged the overall survival time but also provided an opportunity to preserve organ function at the same time, which helped to improve the patients' quality of life.

Automated atlas-based segmentation for skull base surgical planning

PURPOSE

Computational surgical planning tools could help develop novel skull base surgical approaches that improve safety and patient outcomes. This defines a need for automated skull base segmentation to improve the usability of surgical planning software. The objective of this work was to design and validate an algorithm for atlas-based automated segmentation of skull base structures in individual image sets for skull base surgical planning.

METHODS

Advanced Normalization Tools software was used to construct a synthetic CT template from 6 subjects, and skull base structures were manually segmented to create a reference atlas. Landmark registration followed by Elastix deformable registration was applied to the template to register it to each of the 30 trusted reference image sets. Dice coefficient, average Hausdorff distance, and clinical usability scoring were used to compare the atlas segmentations to those of the trusted reference image sets.

RESULTS

The mean for average Hausdorff distance for all structures was less than 2 mm (mean for 95th percentile Hausdorff distance was less than 5 mm). For structures greater than 2.5 mL in volume, the average Dice coefficient was 0.73 (range 0.59-0.82), and for structures less than 2.5 mL in volume the Dice coefficient was less than 0.7. The usability scoring survey was completed by three experts, and all structures met the criteria for acceptable effort except for the foramen spinosum, rotundum, and carotid artery, which required more than minor corrections.

CONCLUSION

Currently available open-source algorithms, such as the Elastix deformable algorithm, can be used for automated atlas-based segmentation of skull base structures with acceptable clinical accuracy and minimal corrections with the use of the proposed atlas. The first publicly available CT template and anterior skull base segmentation atlas being released (available at this link: http://hdl.handle.net/1773/46259 ) with this paper will allow for general use of automated atlas-based segmentation of the skull base.

Tailored Anterior Clinoidectomy: Beyond the Intradural and Extradural Concepts

Anterior clinoidectomy (AC) is a key microsurgical step for the safe and successful management of parasellar pathologies that involve the anterior clinoid process (ACP) and the optic canal. Traditionally, extra and intradural ACs are performed separately according to the surgeon's experience or preference. The objective is to present and discuss the tailored AC concept through illustrative cases. We conducted a retrospective record review of three patients who underwent AC as a surgical step for the treatment of parasellar pathologies that involve the ACP and optic canal. A review of the relevant literature on AC was performed in the PubMed, LILACS, and SciELO databases.

In all three cases, the pterional craniotomy was the preferred approach for AC. Case 1, a 47-year-old female patient with type III anterior clinoidal meningioma, underwent a tailored intradural technique (optic canal unroofing) with total tumor resection and complete visual recovery. Case 2, a 63-year-old female patient with a complex type II anterior clinoidal meningioma with extensive hyperostosis of the ACP, underwent a hybrid AC technique with complete removal of the tumor and visual improvement. Case 3, a 62-year-old female, underwent a tailored intradural AC for clipping an incidental carotid-ophthalmic aneurysm.

Tailored AC aims to provide adequate exposure with less risk of neurovascular injury, allowing enough space to safely treat parasellar lesions. The type, size, and location of the lesion, as well as the surgeon’s experience, should always be considered for surgical planning.