Endoscopic cranial base surgery: classification of operative approaches

Effect of endoscopic endonasal skull base approaches on olfactory function and facial development in children

INTRODUCTION

Endoscopic approaches for skull base pathologies are increasingly being performed, and the subsequent complications, especially in the long term, have also been partially clarified. However, there is no information on the effects of endoscopic endonasal skull base surgeries (EESBS) in children on odor and facial development in parallel with long-term development. We conducted this study to investigate postoperative olfactory function and facial development in pediatric patients who underwent skull base surgery using the endoscopic endonasal method.

METHODS

We evaluated the smell test, sinonasal symptoms, and facial development of pediatric patients who underwent endoscopic endonasal skull base surgery after long-term follow-up. Odor was evaluated using the "Sniffin' Sticks" test kit, which assessed the T (odor threshold), D (odor discrimination), and I (odor identification) parameters. Sinonasal symptoms were evaluated using the SNOT-22 (sinus-nose outcome test) questionnaire. SNA (sella-nasion-A point), SNB (sella-nasion-B point), and ANB (A point-nasion-B point) angles were calculated from maxillofacial tomography and magnetic resonance imaging) to evaluate facial development. Data were compared with those of the healthy control group.

RESULTS

We included 30 patients comprising 19 (63.3%) boys and 11 (36.7%) girls, with no age difference between case and control groups. The mean follow-up period was 7 years. Odor test data, cephalometric measurements, and SNOT-22 analysis results showed no statistically significant differences between the two groups.

CONCLUSION

To our knowledge, this is a comprehensive study with the longest follow-up period in terms of evaluation of facial development after EESBS in children to analyze odor using the Sniffin' Sticks test kit and the quality of life using SNOT-22. Olfactory function, facial development, and quality of life remained unaffected after long-term follow-up after EESBS  in children. Although this surgical approach is minimally invasive, we recommend considering the possibility of complications, and the procedure should be performed by an experienced surgical team with adequate equipment.

Endoscopic transorbital approach for skull base lesions: a report of 16 clinical cases

Due to the deep location, complex anatomy, and adjacent vital neurovascular structures, skull base surgery is challenging and requires specific approaches. The emerging endoscopic transorbital approach (eTOA) technique provides a new approach to the orbital content, spheno-orbital region, lateral cavernous sinus, and Meckel's cave. In this study, the clinical utility and effectiveness of the eTOA are reported. Sixteen cases who underwent the eTOA were included in the current study. The patients were divided into 3 groups according to tumor location: Group A (intraorbital, 6 cases), group B (spheno-orbital, 7 cases), and group C (cavernous sinus, and Meckel's cave, 3 cases). The clinical data and surgical results were analyzed. Eight meningiomas, 2 hemangiomas, 1 low-grade glioma, 1 instance of inflammatory hyperplasia tissue, 1 Langerhans cell histiocytosis, 1 epidermoid cyst, 1 trigeminal schwannoma, and 1 bone fibrosis hyperplasia were observed. The mean tumor diameter was 2.4 cm. A single case in Group A and Group C underwent biopsy (12.5%), and 1 case of fibrous dysplasia in Group B underwent sufficient orbit decompression (6.25%). The remaining 13 cases underwent gross total tumor resection (81.25%). No cerebral-spinal fluid leak or infection occurred. And no cosmetic problems or significant complications were observed during the follow-up. As a minimally invasive technique, the eTOA has unique advantages for carefully selected skull base lesions because of its direct route, short working distance, and distinct attack angle.

[Endonasal repair of spontaneous CSF fistulas of the lateral recess of the sphenoid sinus]

CSF fistulas of the lateral recess of the sphenoid sinus are a rare surgical pathology. Cerebrospinal fluid leak from lateral recess of the sphenoid sinus is observed with a frequency of 7.7% among all leakafe of the skull base. The article presents 3 clinical cases of patients with spontaneous cerebrospinal fluid leak from lateral recess of the sphenoid sinus and surgical treatments by transsphenoidal and transpterygoid (transpterygoid) endoscopic approaches with various postoperative results. The plastic surgery success of CSF fistulas from lateral recess of the sphenoid sinus doesn`t depend on the type of endonasal surgical approach, but on the plastic quality and the preoperative level of CSF pressure.

Surgeon's Eyes on the Relevant Surgical Target

The resolution of the naked eye has been a challenge for the neurosurgical endeavor since the very first attempts of cranial surgery, and advances have been achieved over the centuries, driven by a synergism between the application of emerging technology into the surgical environment and the expansion of the capabilities of neurosurgery. The understanding of the principles of the optical properties of lenses by Abbè (1840-1905) led to the introduction of loupes in the surgical practice, increasing the visual performance during macroscopic procedures. Modern neurosurgery began with the possibility of illumination and magnification of the surgical field as provided by the microscope. Pioneering contributions from Donaghy and Yasargil opened the way to the era of minimalism with reduction of operative corridors and surgical trauma through the adoption of the microsurgical technique. Almost at the same time, engineering mirabilia of Hopkins in terms of optics and lenses allowed for introduction of rigid and flexible endoscopes as a viable tool in neurosurgery. Nowadays, neurosurgeons are aware of and confident using effective and modern tools of visualization in their armamentarium. Herein we present a cogent review of the evolution of visualization tools in neurosurgery, with a special glimpse into the current development and future achievements.

Craniopharyngioma in Pediatrics and Adults

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding β-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

Ultrasound-guided endoscopic endonasal resection of sellar and suprasellar craniopharyngiomas

Introduction

Optimal planning and minimally invasive surgical approach are essential to complete craniopharyngiomas (CP) resection with limited postoperative morbidity. Given the nature of craniopharyngioma recurrence, complete resection of the neoplasm is crucial. Since CP arise from the pituitary stalk and may grow anteriorly or laterally, some cases require an extended endonasal craniotomy. The extension of the craniotomy is crucial to expose the whole tumor and to make its dissection from the surrounding structures feasible. In order to guide the extension of the approach, the intraoperative use of ultrasound is helpful for the surgeons. The objective of this paper is to describe and to demonstrate the applicability of the utilization of intraoperative ultrasound (US) guidance for planning and confirmation of craniopharyngioma resection in EES.

Method

The authors selected one operative video of a sellar-suprassellar craniopharyngioma gross-totally resected by EES. The authors demonstrate the extended sellar craniotomy, the anatomic landmarks that guide bone drilling and dural opening, the aspect of the intraoperative real time US, tumor resection and dissection from the surrounding structures.

Results

The solid component of the tumor was mostly isoechogenic in texture compared to the anterior pituitary gland, with several wide spread hyperechogenic images corresponding to calcifications and hypoechogenic vesicles corresponding to cysts inside the CF ("salt-and-pepper" pattern).

Discussion

The intraoperative endonasal US is a new surgical tool that allows for real-time active imaging for skull base procedures, such as sellar region tumors. Besides tumor evaluation, the intraoperative US helps the neurosurgeon to determine the size of craniotomy, to anticipate the relation between the tumor and vascular structures and to guide the best strategy for gross-total resection of the tumor.

Conclusion

The EES allows a straight access to the craniopharyngiomas located in the sellar region or that grow anteriorly or superiorly. This approach allows the surgeon to dissect the tumor with minimal manipulation of the surrounding structures, when compared to craniotomy approaches. In order to accomplish that, the use of intraoperative endonasal ultrasound helps the neurosurgeon to perform the most suitable strategy, optimizing the rate of success.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Endoscopic transorbital avenue to the skull base: Four-step conceptual analysis of the anatomic journey

Background

In the last decades, skull base surgery had passed through an impressive evolution. The role of neuroanatomic research has been uppermost, and it has played a central role in the development of novel techniques directed to the skull base. Indeed, the deep and comprehensive study of skull base anatomy has been one of the keys of success of the endoscopic endonasal approach to the skull base. In the same way, dedicated efforts expended in the anatomic lab has been a powerful force for the growth of the endoscopic transorbital approach to the lateral skull base.

Therefore, in this conceptual paper, the main steps for the anatomic description of the endoscopic transorbital approach to the skull base have been detailed.

Methods

The anatomic journey for the development of the endoscopic transorbital approach to the skull base has been analyzed, and four “conceptual” steps have been highlighted.

Results

As neurosurgeons, the eyeball has always represented a respectful area: to become familiar with this complex and delicate anatomy, we started by examining the orbital anatomy on a dry skull (step 1). Hence, step 1 is represented by a detailed bone study; step 2 is centered on cadaveric dissection; step 3 consists in 3D quantitative assessment of the novel endoscopic transorbital corridor; and finally, step 4 is the translation of the preclinical data in the real surgical scenario by means of dedicated surgical planning.

Conclusions

The conceptual analysis of the anatomic journey for the description of the endoscopic transorbital approach to the skull base resulted in four main methodological steps that should not be thought strictly consequential but rather interconnected. Indeed, such steps should evolve following the drives that can arise in each specific situation. In conclusion, the four-step anatomic rehearsal can be relevant for the description, diffusion, and development of a novel technique in order to facilitate the application of the endoscopic transorbital approach to the skull base in a real surgical scenario.

Single Versus Double Hadad-Bassagasteguy Flap in Expanded Endoscopic Skull-Base Surgery

The reconstruction of dural defects, after endoscopic removal of skull-base lesions, remains challenging when a large defect or a high flow intraoperative cerebrospinal fluid (CSF) leak is observed. The aim of this study is to describe our preliminary experience with a double Hadad-Bassagasteguy (H-B) flap technique for skull-base repair, comparing its efficacy with the use of a single H-B flap in our series. A retrospective chart review was conducted on patients who underwent exclusive endoscopic endonasal skull-base surgery at our Referral Skull Base Center from December 2014 to January 2018. Data on patient demographics, pathology, preoperative and postoperative imaging, intraoperative findings, surgical route, defect size, reconstruction techniques and repair materials, were analyzed. Patients were divided into double and single H-B flap groups. In the single and double H-B groups, the postoperative CSF leak rates were 37.5% (6 of 16 patients) and 4.5% (1 of 22 patients), respectively. The difference between the two groups was statistically significant (p = 0.0470). In patients with defects > 4 cm or high-flow intraoperative CSF leakage related to the opening of the third ventricle, the double H-B flap was successfully placed with no occurrence of postoperative CSF leakage. The double H-B flap significantly reduced the postoperative CSF leakage rate after expanded transnasal skull-base surgery. Particularly in challenging cases, where a large skull-base defect or a high-flow intraoperative CSF leak was observed, this reconstructive method proved to be very effective, with no evidence of postoperative CSF fistulas.

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.

Outcomes and surgical nuances in management of giant pituitary adenomas: a review of 108 cases in the endoscopic era

OBJECTIVE

Giant (maximum diameter ≥ 4 cm) pituitary macroadenomas are complex tumors that require resection for decompression of optic nerves, relief of mass effect, and symptom improvement. Given the lack of surgical accessibility, the lateral extent of the lesions, and the invasion of the cavernous sinus, management presents a significant challenge. Transsphenoidal, transcranial, and combined approaches have been viable options for resection. The authors present their findings from a large series of patients to characterize giant pituitary adenomas, document outcomes, and outline surgical nuances in resection of these tumors.

METHODS

The authors reviewed 887 consecutive patients who underwent resection of pituitary adenomas at a single institution. From this group, 108 patients with giant pituitary adenomas who underwent resection between January 1, 2002, and December 31, 2020, were identified for inclusion in the study. The patient demographics, clinical presentation, tumor imaging characteristics, surgical approaches, and postoperative outcomes were analyzed using descriptive statistics.

RESULTS

The mean preoperative tumor diameter in this cohort was 4.6 ± 0.8 cm, with a mean volume of 25.9 ± 19.2 cm3. Ninety-seven patients underwent transsphenoidal approaches only, 3 underwent transcranial resection, and 8 patients underwent a combined approach. Gross-total resection was achieved in 42 patients. Tumor stability without a need for additional therapy was achieved in 77 patients, with 26 patients undergoing subsequent adjuvant radiotherapy. Among 100 patients with sufficient follow-up, 14 underwent adjuvant therapy-repeat operation and/or adjuvant radiation therapy-because of recurrence or tumor progression. Six patients with recurrence were observed without additional treatment. Overall, the morbidity associated with removal of these lesions was 11.1%; the most common morbidities were cerebrospinal fluid leak (5 patients, 4.6%) and hydrocephalus (4 patients, 3.7%). One death due to postoperative pituitary apoplexy of the residual tumor and malignant cerebral edema occurred in this cohort.

CONCLUSIONS

Giant pituitary tumors still represent a surgical challenge, with significant morbidity. Gross-total resection occurs in a minority of patients. Surgical goals for removal of giant pituitary tumors should include attempts at removal of most tumor tissue to minimize the risk of residual tumor apoplexy by tailoring the approach along the major axis of the tumor. Experience with both transsphenoidal and multiple transcranial techniques is necessary for minimizing complications and improving outcomes.

[Endoscopic endonasal reconstruction of skull base defects in the lateral recess of the sphenoid sinus: evaluation of computed tomograms for planning operations]

OBJECTIVE

Determine the influence of the anatomical features and sizes of the lateral pocket with a defect on the choice of surgical access and the quality of the performed plastics.

MATERIAL AND METHODS

A retrospective analysis of computed tomograms of 38 patients who underwent surgical treatment at the Burdenko National Medical Research Center for Neurosurgery of the Ministry of Health of Russia about defects of the skull base in the area of the lateral pocket of the sphenoid sinus. The patients were divided into three groups depending on the approach used (the 1st group), the recurrence rate (the 2nd group), and the characteristics of intraoperative visualization of the defect (the 3rd group).

RESULTS

There were no statistically significant differences in anatomical features in patients who underwent trans-pterygoid and transsphenoidal approaches, as well as in patients of the 2nd group. Patients of the 3rd group (with visualization features) showed statistically significant differences between the distance from the defect to the VR line (p=0.007). In patients with good visualization of the defect using direct optics, this distance was shorter than in patients in whom the defect was visualized with an angled endoscope. No other anatomical differences were noted.

CONCLUSIONS

The anatomical features of the lateral pocket structure (type of pneumatization, size and volume) did not affect the choice of access to the defect and the frequency of recurrence. When comparing the approaches, it was noted that the trans-pterygoid access, providing direct visualization of defects, minimizes the risk of recurrence in the postoperative period. An objective anatomical indicator for choosing an access to the defects of the lateral pocket can be the distance from the defect to the VR line: at a distance of more than 0.7 cm, it is advisable to perform a trans-pterygoid approach; at a distance of less than 0.7 cm, it is possible to achieve direct visualization of the defect and perform high-quality plastic surgery with a transsphenoidal access.

Carotid Artery-Cavernous Segment Injury during an Endoscopic Endonasal Surgery: A Case Report and Literature Review of the Overlooked Option for Surgical Trapping in the Hyperacute Phase

Internal carotid artery (ICA) injury is a catastrophic complication of endoscopic endonasal surgery (EES). However, its standard management, emergent endovascular treatment, may not always be available, and the transnasal approach may be insufficient to achieve hemostasis. A 44-year-old woman with pituitary adenoma underwent EES complicated with the ICA cavernous segment injury (CSI). In urgent intraoperative angiogram, a good collateral flow from the contralateral carotid circulation was observed. Due to the unavailability of intraoperative embolization, emergent surgical trapping was performed by combined transcranial and cervical approach. The patient recovered but later developed a giant cavernous pseudoaneurysm. During the pseudoaneurysm embolization, ICA was directly accessed via a 1.7-F puncture hole using a bare microcatheter technique. Then, both the aneurysm and parent artery were obliterated with coils. At the 4-year follow-up, the patient was asymptomatic without a residual tumor. To our knowledge, this is the first case of ICA-CSI during EES successfully treated with ICA trapping as a lifesaving urgent surgery that achieved a complete recovery after a pseudoaneurysm embolization. Although several studies reported that EES-related ICA-CSIs with percutaneous carotid artery access, neither our surgical salvage technique nor our carotid access and tract embolization techniques were previously described.

Transcranial approaches for pituitary adenomas: current indications and clinical and radiological outcomes

Background

The indications of transcranial approaches for pituitary adenomas have declined in the last decades with the widespread performance of endoscopic transsphenoidal approaches.

The aim of the study was to review the current indications of transcranial approaches for pituitary adenomas and to evaluate the clinical and radiological outcome following these approaches.

Patients and methods

This study included 16 patients with fresh, residual, or recurrent pituitary adenomas operated upon by transcranial approaches alone or in combination with transsphenoidal approaches. The indication to perform a transcranial approach was reviewed for each patient. Postoperative clinical outcome and the extent of tumor resection were assessed.

Results

The indications of transcranial approaches were significant parasellar and/or anterior fossa extensions in 6 patients, failed previous transsphenoidal surgery in 3 patients, giant adenoma extending into the third ventricle in 3 patients, dumbbell-shaped adenoma in 2 patients, and doubtful diagnosis in 2 patients. Two patients with invasive giant adenomas were operated upon by a combined approach. There was a single mortality. Permanent complications included visual loss in one patient, third nerve palsy in one patient, hypopituitarism in two patients, and permanent diabetes insipidus in two patients. Gross total resection was achieved in one patient, subtotal resection in seven patients, and partial resection in eight patients.

Conclusion

Transcranial approaches are still needed for some complex pituitary adenomas particularly giant tumors with significant lateral, anterior, or superior extensions, tumors with fibrous consistency particularly after failure of transsphenoidal approach, and dumbbell-shaped tumors with severe constriction at the diaphragm.

Three-dimensional structure of the basal lamella of the middle turbinate

The middle turbinate’s basal lamella (3BL) is a variable landmark which needs to be understood in endoscopic transnasal skull base surgery. It comprises an anterior frontal and a posterior horizontal part and appears in its simplest depiction to be “L”-shaped, when viewed laterally. In this study we analyzed its 3D morphology and variations focusing on a precise and systematic description of the anatomy. CBCTs of 25 adults, 19 cadavers and 6 skulls (total: 100 sides) were investigated with the 3DSlicer software, creating 3D models of the 3BL. We introduced a novel geometrical classification of the 3BL’s shape, based on segments. We analyzed their parameters and relationship to neighboring structures. When viewed laterally, there was no consistent “L”-shaped appearance of the 3BL, as it is frequently quoted. A classification of 9 segment types was used to describe the 3BL. The 3BLs had in average of 2.95 ± 0.70 segments (median: 3), the most frequent was the horizontal plate (23.05% of all segments), next a concave/convex plate (22.71%), then a sigma plate (22.37%). Further types were rare. We identified a horizontal plate in 68% of all lateral views whilst 32% of the 3BLs were vertical. A sigma–concave/convex–horizontal trisegmental 3BL was the most common phenotype (27%). Globally, the sigma–concave/convex pattern was present in 42%. The 3BL adhered the ethmoidal bulla in 87%. The segmenting method is eligible to describe the 3BL’s sophisticated morphology.

Endoscopic transsphenoidal surgery for resection of pituitary macroadenoma: A retrospective study

BACKGROUND

The endoscopic transsphenoidal approach is an efficient minimally invasive procedure for removal of pituitary tumors that can be accomplished through a one-hand or two-hand approach. The one-hand procedure through one nostril is more intuitive for surgeons, but maneuvering the instruments can be restrictive. The two-hand procedure using a one-and-half nostril approach provides more precise manipulation. This study aimed to compare the surgical outcomes of one-hand/mono-nostril and two-hand/one-and-half nostril surgeries for resection of large pituitary tumors by a single neurosurgeon.

MATERIALS AND METHODS

The surgical data of 78 consecutive cases with pituitary macroadenoma (diameter >1 cm) were reviewed retrospectively. Altogether, 30 cases received one-hand/mono-nostril surgery, while 48 cases received two-hand/one-and-half nostril surgery. Postoperative outcomes of the two operations were compared.

RESULTS

The operative time, hospital stay, residual rate of pituitary macroadenoma, visual field, surgical complications, and re-operative rates were slightly improved in the two-hand/one-and-half nostril surgery group compared with that in the one-hand/mono-nostril surgery group (all p>0.05). However, postoperative hypopituitarism was less frequent (1/48; 2.0%) with the two-hand/one-and-half nostril approach than with the mono-nostril approach (p = 0.004). Similar surgical outcomes were found in all patients with either small or large pituitary tumors, except that the difference in postoperative improvement in visual field change reached statistical significance (p = 0.044).

CONCLUSION

A single-surgeon endoscopic endonasal transsphenoidal surgery with two-hand/one-and-half nostril approach is an effective and safe procedure for removal of large pituitary tumors.

Primary Endoscopic Endonasal Management of Giant Pituitary Adenomas: Outcome and Pitfalls from a Large Prospective Multicenter Experience

Simple Summary

Giant pituitary adenomas are highly invasive tumors whose treatment is challenging. Surgery is their management mainstay. However, there is no consensus about the type of approach. Open transcranial, microscopic, and endoscopic trans-sphenoidal approaches have all been employed, alone or in combination. Extended endoscopic endonasal techniques may represent a versatile and safe one-stage approach. Our research aimed at evaluating prospectively their applicability, effectiveness, and safety in a multicenter series, to acquire further evidence toward its use in the treatment of those challenging lesions. Ninety-six patients were recruited and followed-up for 52.4 months on average. Most of them (81.2%) presented with visual deficits and >50% had various degrees of adenohypophysis insufficiency. Resection of at least 75% of initial volume was achieved in all cases, with 98.7% visual improvement, >50% endocrine deficit recovery and a permanent complication rate of 4.2%, indicating extended endoscopic endonasal approaches as a valuable treatment option.

Abstract

Purpose: To evaluate factors influencing clinical and radiological outcome of extended endoscopic endonasal transtuberculum/transplanum approach (EEA-TTP) for giant pituitary adenomas (GPAs). Methods: We recruited prospectively all consecutive GPAs patients undergoing EEA-TTP between 2015 and 2019 in 5 neurosurgical centers. Preoperative clinical and radiologic features, visual and hormonal outcomes, extent of resection (EoR), complications and recurrence rates were recorded and analyzed. Results: Of 1169 patients treated for pituitary adenoma, 96 (8.2%) had GPAs. Seventy-eight (81.2%) patients had visual impairment, 12 (12.5%) had headaches, 3 (3.1%) had drowsiness due to hydrocephalus, and 53 (55.2%) had anterior pituitary insufficiency. EoR was gross or near-total in 46 (47.9%) and subtotal in 50 (52.1%) patients. Incomplete resection was associated with lateral suprasellar, intraventricular and/or cavernous sinus extension and with firm/fibrous consistence. At the last follow-up, all but one patient (77, 98.7%) with visual deficits improved. Headache improved in 8 (88.9%) and anterior pituitary function recovered in 27 (50.9%) patients. Recurrence rate was 16.7%, with 32 months mean recurrence-free survival. Conclusions: EEA-TTP is a valid option for GPAs and seems to provide better outcomes, lower rate of complications and higher EoR compared to one- or multi-stage microscopic, non-extended endoscopic transsphenoidal, and transcranial resections.

Endoscopic Endonasal Transclival Resection of a Pontine Metastasis: Case Report and Operative Video

BACKGROUND AND IMPORTANCE

Brainstem lesions are challenging to manage, and surgical options have been controversial. Stereotactic radiosurgery (SRS) has been used for local control, but life-threatening toxicities from 0% to 9.5% have been reported. Several microsurgical approaches involving safe entry zones have been developed to optimize the exposure and minimize complications in different portions of the brainstem, but require extensive drilling and manipulation of neurovascular structures. With recent advancements, the endoscopic endonasal approach (EEA) can provide direct visualization of ventral brainstem. No case has been reported of EEA to remove a brainstem metastasis.

CLINICAL PRESENTATION

We present an illustrative case of a 68-yr-old female with metastatic colon cancer who presented with 2.8 × 2.7 × 2.1 cm (7.9 cm3) heterogeneously enhancing, right ventral pontine lesion with extensive edema. She underwent endoscopic endonasal transclival approach, and gross total resection of the lesion was achieved.

CONCLUSION

The endoscopic approach may offer certain advantages for removal of ventral brainstem lesions, as it can provide direct visualization of important neurovascular structures, especially, if the lesion displaces the tracts and comes superficial to the pial surface.

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.

Quality of Life and Morbidity after Endoscopic Endonasal Skull Base Surgeries Using the Sinonasal Outcomes Test (SNOT): A Tertiary Hospital Experience

Introduction

Endoscopic endonasal skull base surgery (EESBS) has been associated with a minimally invasive and effective approach for pathology of the anterior skull base and associated with less overall morbidity compared with open approaches. However, it is associated with its own potential morbidity related to surgical manipulation or resection of normal and noninflamed intranasal structures to gain adequate access. The assessment of sinonasal QOL (quality of life) postsurgery is therefore a vital aspect in follow-up of these patients.

Objectives

To assess quality of life and morbidity after endoscopic endonasal skull base surgery using the Sinonasal Outcomes Test (SNOT-22). Methodology. A single-center retrospective cross-sectional review with a sample of 80-100 patients undergoing endoscopic endonasal transsphenoidal surgery was conducted at the ENT and Neurosurgery departments of King Fahad Specialist Hospital-Dammam (KFSH-D) for a period of 10 years from March 2010 to March 2020. Data were collected through hospital records and database, as well as from patients through phone call interviews. Records were reviewed for diagnosis, demographic features, and 22-item Sinonasal Outcomes Test (SNOT-22) scores noted at three points in time: prior to procedure and after, at 3 months and 6 months.

Results

Within the study cohort comprising 96 patients, the mean age of the participants was 39.5 ± 12.1 years, and diagnostic typing before and after histopathological investigations revealed maximum pituitary adenomas (46.9%) closely followed by CSF-related ailments (41.7%). The changes in the mean and standard deviation of the total SNOT-22 scores postoperatively at the 3^rd month (9.5 ± 5.4) and the 6^th month (8.8 ± 5.2) were statistically significant (p < 0.001) when compared to the preoperative score (10.8 ± 5.1).

Conclusion

Although there was a predicted passivity of symptoms in the post-EESBS period, several significant positive outcomes were seen. The increase in discomfort in the sleep domains postsurgery is an issue to pursue and reason out. The overall SNOT-22 scores noted preoperatively and 3 and 6 months postoperatively showed statistically significant improvements in QOL with no long-term effects.

How long is the tail end of the learning curve? Results from 1000 consecutive endoscopic endonasal skull base cases following the initial 200 cases

OBJECTIVE

Endoscopic endonasal approaches (EEAs) to the skull base have evolved over the last 20 years to become an essential component of a comprehensive skull base practice. Many case series show a learning curve from the earliest cases, in which the authors were inexperienced or were not using advanced closure techniques. It is generally accepted that once this learning curve is achieved, a plateau is reached with little incremental improvement. Cases performed during the early steep learning curve were eliminated to examine whether the continued improvement exists over the "tail end" of the curve.

METHODS

A prospectively acquired database of all EEA cases performed by the senior authors at Weill Cornell Medicine/NewYork-Presbyterian Hospital was reviewed. The first 200 cases were eliminated and the next 1000 consecutive cases were examined to avoid the bias created by the early learning curve.

RESULTS

Of the 1000 cases, the most common pathologies included pituitary adenoma (51%), meningoencephalocele or CSF leak repair (8.6%), meningioma (8.4%), craniopharyngioma (7.3%), basilar invagination (3.1%), Rathke's cleft cyst (2.8%), and chordoma (2.4%). Use of lumbar drains decreased from the first half to the second half of our series (p <0.05) as did the authors' use of fat alone (p <0.005) or gasket alone (p <0.005) for dural closure, while the use of a nasoseptal flap increased (p <0.005). Although mean tumor diameter was constant (on average), gross-total resection (GTR) increased from 60% in the first half to 73% in the second half (p <0.005). GTR increased for all pathologies but most significantly for chordoma (56% vs 100%, p <0.05), craniopharyngioma (47% vs 0.71%, p <0.05) and pituitary adenoma (67% vs 75%, p <0.05). Hormonal cure for secreting adenomas also increased from 83% in the first half to 89% in the second half (p <0.05). The rate of any complication was unchanged at 6.4% in the first half and 6.2% in the latter half of cases, and vascular injury occurred in only 0.6% of cases. Postoperative CSF leak occurred in 2% of cases and was unchanged between the first and second half of the series.

CONCLUSIONS

This study demonstrates that contrary to popular belief, the surgical learning curve does not plateau but can continue for several years depending on the complexity of the endpoints considered. These findings may have implications for clinical trial design, surgical education, and patient safety measures.

Management of anterior fossa cephaloceles

Skull base cephaloceles (SBCs) are defined as herniation of intracranial content through the skull base and are classified based on composition, etiology, and topographic location. Anterior SBCs frequently protrude in the sinonasal cavity, and consequently are at potential risk of infection. Therefore, the current recommendation is to treat SBCs with the primary intent of preventing meningitis, and surgery represents the mainstay of treatment. Anterior SBCs may display a wide spectrum of severity and complexity, and in each case the risks and benefits of surgical approaches are to be carefully weighted based on thorough assessment of symptoms, age, general conditions, location and size of the lesion, as well as expertise of the surgeon. In the last 30 years, the evolution and diffusion of transnasal endoscopic surgery have substantially changed the surgical management of the majority of SBC. In the past, they were treated exclusively with open transcranial approaches that may be burdened by relevant morbidity and risk for severe complications. The transnasal endoscopic corridor now provides easy access to the lesion and different reconstructive strategies using endonasal pedicled flaps, without any external incision, cranioplasty or brain manipulation. However, there are still scenarios in which an exclusive transnasal endoscopic route is contraindicated. The aim of the present review was to provide an overview on the comprehensive management of anterior SBC, with a particular focus on lesions suitable for endoscopic surgery. Furthermore, special aspects of SBC management in children and adults will be highlighted.

Cavernous Sinus Meningioma with Orbital Involvement: Algorithmic Decision-Making and Treatment Strategy

Cavernous sinus meningioma (CSM) with orbital involvement presents a unique challenge to modern-day neurosurgeons. In the modern era of preventive medicine with enhanced screening tools, physicians encounter CSM more frequently. An indolent natural history, late clinical presentation, close proximity to vital neurovascular structures, poor tumor-to-normal tissue interface, and high risk of iatrogenic morbidity and mortality with aggressive resection add to the complexity of decision-making and optimal management of these lesions. The clinical dilemma of deciding whether to observe or intervene first for asymptomatic lesions remains an enigma in current practice. The concepts of management for CSM with orbital involvement have gradually evolved from radical resection to a more conservative surgical approach with maximal safe resection, with the specific goals of preserving function and reducing proptosis. This change in surgical attitude has enabled better long-term functional outcomes with conservative approaches as compared with functionally disabled outcomes resulting from the pursuit of anatomical cure from disease with radical resection. The advent of stereotactic radiosurgery as an adjunct tool to treat residual CSM has greatly shaped our resection principles and planning. Interdisciplinary collaboration for multimodality management is key to successful management of these difficult to treat lesions and tailor management as per individual's requirement.

Readmission after endoscopic transsphenoidal pituitary surgery: analysis of 584 consecutive cases

OBJECTIVE

Hospital readmission is a key component in value-based healthcare models but there are limited data about the 30-day readmission rate after endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma. The objective of this study was to determine the incidence and identify factors associated with 30-day readmission after EETS for pituitary adenoma.

METHODS

The authors analyzed a prospectively acquired database of patients who underwent EETS for pituitary adenoma from 2005 to 2018 at NewYork-Presbyterian Hospital, Weill Cornell Medicine. Clinical, socioeconomic, and radiographic data were reviewed for cases of unplanned readmission within 30 days of surgery and, as a control group, for all other patients in the series who were not readmitted. Statistical significance was determined with an alpha < 0.05 using Pearson's chi-square and Fisher's exact tests for categorical variables and the independent-samples t-test for continuous variables.

RESULTS

Of 584 patients undergoing EETS for pituitary adenoma, 27 (4.6%) had unplanned readmission within 30 days. Most readmissions occurred within the first week after surgery, with a mean time to readmission of 6.6 ± 3.9 days. The majority of readmissions (59%) were for hyponatremia. These patients had a mean sodium level of 120.6 ± 4.6 mEq/L at presentation. Other causes of readmission were epistaxis (11%), spinal headache (11%), sellar hematoma (7.4%), CSF leak (3.7%), nonspecific headache (3.7%), and pulmonary embolism (3.7%). The postoperative length of stay was significantly shorter for patients who were readmitted than for the controls (2.7 ± 1.0 days vs 3.9 ± 3.2 days; p < 0.05). Patients readmitted for hyponatremia had an initial length of stay of 2.6 ± 0.9 days, the shortest of any cause for readmission. The mean BMI was significantly lower for readmitted patients than for the controls (26.4 ± 3.9 kg/m2 vs 29.3 ± 6.1 kg/m2; p < 0.05).

CONCLUSIONS

Readmission after EETS for pituitary adenoma is a relatively rare phenomenon, with delayed hyponatremia being the primary cause. The study results demonstrate that shorter postoperative length of stay and lower BMI were associated with 30-day readmission.

Surgical approaches to the petrous apex

The petrous apex is a difficult to reach surgical area due to its deep position in the skull base and many vital surrounding structures. Petrous apex pathology ranges from extradural cholesterol granulomas, cholesteatomas, asymmetric pneumatization, and osteomyelitis to intradural meningiomas and schwannomas. Certain lesions, such as cholesterol granulomas, can be managed with drainage while neoplastic lesions must be completely resected. Surgical options use open, endoscopic, and combined techniques and are categorized into anterior, lateral, and posterior approaches. The choice of approach is determined by the nature of the pathology and location relative to vital structures and extension into surrounding structures and requires thorough preoperative evaluation and discussion of surgical goals with the patient. The purpose of this state-of-the-art review is to discuss the most commonly used surgical approaches to the petrous apex, and the anatomy on which these approaches are based.

Machine-Learning Classifiers in Discrimination of Lesions Located in the Anterior Skull Base

Purpose: The aim of this study was to investigate the diagnostic value of machine-learning models with radiomic features and clinical features in preoperative differentiation of common lesions located in the anterior skull base.

Methods: A total of 235 patients diagnosed with pituitary adenoma, meningioma, craniopharyngioma, or Rathke cleft cyst were enrolled in the current study. The discrimination was divided into three groups: pituitary adenoma vs. craniopharyngioma, meningioma vs. craniopharyngioma, and pituitary adenoma vs. Rathke cleft cyst. In each group, five selection methods were adopted to select suitable features for the classifier, and nine machine-learning classifiers were employed to build discriminative models. The diagnostic performance of each combination was evaluated with area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity calculated for both the training group and the testing group.

Results: In each group, several classifiers combined with suitable selection methods represented feasible diagnostic performance with AUC of more than 0.80. Moreover, the combination of least absolute shrinkage and selection operator as the feature-selection method and linear discriminant analysis as the classification algorithm represented the best comprehensive discriminative ability.

Conclusion: Radiomics-based machine learning could potentially serve as a novel method to assist in discriminating common lesions in the anterior skull base prior to operation.

Endonasal endoscopic surgery for pediatric anterior cranial fossa encephaloceles: A systematic review

BACKGROUND

Endoscopic endonasal skull base surgery (ESBS) is a well-established management strategy for anterior cranial fossa (ACF) encephaloceles in adults. However, its application to the pediatric population has not been evaluated in large-scale studies. This study systematically reviews the safety of ESBS for pediatric ACF encephaloceles.

METHODS

Articles reporting on pediatric patients undergoing purely ESBS for encephaloceles were reviewed from three databases (PubMed, Scopus, and Cochrane Library). Main outcomes were post-operative cerebrospinal fluid (CSF) leak and other surgical complications.

RESULTS

Twenty-three articles provided data on 110 eligible patients with a mean age of 4.3 years (range birth - 18 years). Intraoperative CSF leaks occurred in 18.5% of children while post-operative CSF leaks developed in 6.0% of cases. Rates of meningitis and hydrocephalus were each 3.7%. Other complications included alar collapse, nasal stenosis, transient diabetes insipidus, pneumonia, and neurologic injury, collectively occurring in 7.0% of cases. The rate of death was 4.8%. The average duration of follow-up was 25.3 months. Encephaloceles recurred in 5.2% of patients.

CONCLUSIONS

ESBS for pediatric ACF encephaloceles provides a relatively favorable risk-benefit profile, with a low rate of post-operative CSF leak, other surgical complications, and disease recurrence.

Endonasal Endoscopic Surgery for Pediatric Sellar and Suprasellar Lesions: A Systematic Review and Meta-analysis

OBJECTIVES

The advent of endonasal endoscopic skull base surgery (ESBS) has redefined the management of pediatric sellar and suprasellar lesions. To date, the outcomes of these procedures have not been systematically reviewed. This study performed a systematic review with meta-analysis of surgical outcomes for pediatric patients undergoing ESBS for sellar and suprasellar lesions.

DATA SOURCES

PubMed (National Library of Medicine, National Institutes of Health), Scopus (Elsevier), and Cochrane Library (Wiley).

REVIEW METHODS

Articles reporting on pediatric patients undergoing ESBS for craniopharyngiomas, pituitary adenomas, and Rathke's cleft cysts were reviewed. The primary outcome was postoperative cerebrospinal fluid (CSF) leak. Secondary outcomes included endocrine, visual, and other complications.

RESULTS

Twenty-five articles reporting on 554 patients were included. Overall postoperative CSF leak rate was 8.6%, with tumor-specific rates of 10.6% in craniopharyngiomas, 6.5% in pituitary adenomas, and 7.2% in Rathke's cleft cysts (P > .05). Older studies demonstrate higher postoperative CSF leak rates as compared with more recent studies (12.5% vs 6.1%, P = .0082). Younger children (8.9-12.6 years old) experienced a higher rate of postoperative CSF leaks as compared with older children (13.0-16.6 years old; 12.9% vs 4.9%, P = .0016). Additional postoperative complications included diabetes insipidus (26.7%), hypopituitarism (46.6%), visual deficits (2.6%), meningitis (3.4%), and weight gain (3.4%).

CONCLUSION

ESBS for pediatric sellar and suprasellar lesions is overall an effective management approach with an increasingly favorable risk-benefit profile. Younger children may be more susceptible to postoperative CSF leak as compared with older pediatric patients. Tumor type does not appear to be an independent risk factor for postoperative CSF leak in this population.

Endoscopic Endonasal Transsphenoidal Surgery: History and Evolution

In previous decades, extensive and disfiguring transfacial and/or transcranial approaches were used to reach the sellar and parasellar areas. However, these surgical routes were burdened by severe complications and high mortality rates. Recently, the development of endoscopic endonasal techniques has revolutionized the surgical strategies for approaching the sella and adjacent areas and increased the development of transsphenoidal surgery. With these techniques, surgeons have been able to overcome the visual limitations of the open surgical approaches and access areas previously hidden from view. After the contributions of the Pittsburgh duo, Carrau and Jho, pioneers of pure endoscopic surgery, our school began to implement this technique, introducing technical innovations and variations, describing the anatomical details and defining new routes, and playing a key role in its widespread clinical application.

[Modern aspects of surgical treatment of nasal liquorrhea with localization of defect in frontal sinus]

Defects localized in the frontal sinus are difficult for surgical treatment, since there is a large number of anatomical variations in the structure of the naso-frontal canal and the sinus itself. With the development of endoscopic technology and paying attention to the modern tendency of minimal invasive surgery, new invasive approaches to reach frontal sinus, such as endoscopic approach according to Draf I-III and combined approaches were developed and put into practice.

OBJECTIVE

To summarize and to analyze the results of treatment of nasal liquorrhea with localization of the defect in the frontal sinus using endoscopic endonasal and combined intra-extranasal approaches.

MATERIAL AND METHODS

A retrospective analysis of a series of 43 cases of nasal liquorrhea with a frontal sinus defect being treated at the NMRCN Burdenko during the period from 2001 to 2017. To select access, a classification of frontal sinus defects according to their localization was developed. The analysis of demographic and clinical data of patients, as well as intraoperative and postoperative data analysis were done.

RESULTS

In the series of 43 patients, endoscopic endonasal approach was performed in 28 (65%) cases. Combined approach was performed at 15 (35%) patients. The success rate of plastic surgery with endoscopic endonasal approach was 86% (24 of 28), with combined approach - 93% (14 of 15).

CONCLUSION

Endoscopic endonasal and combined approaches are the methods of choice for plastic surgery of defects of the skull base in the frontal sinus as they are effective and safe. The choice of approach depends on anatomical features of the frontal sinus and on the localization of defect.

Long-Term Sinonasal Function Following Transnasal Pituitary Surgery: A Comparison of Surgical Approach

Background

Surgical approaches to the pituitary have undergone significant changes from transcranial, sublabial, direct transnasal microscopic, and now endoscopic. This study compares sinonasal outcomes from patients from these techniques.

Methods

A cross-sectional study of patients who underwent pituitary surgery in a tertiary setting was conducted. Patients were recruited via phone, mail, e-mail, and in person. Surveys with questions on nasal function, subsequent nasal treatment, the Nasal Symptom Score (NSS), Sinonasal Outcome Test-22 (SNOT-22), Chronic Sinusitis Survey (CSS), and Short Form 36 version 2 (SF-36v2) were obtained.

Results

A total of 252 surveys were sent, of which 165 were returned (65.48% response rate) and 16 were excluded (3 records destroyed, 13 transcranial approach). A total of 149 patients (age 60.10 ± 13.99 years, 47.83% female) were assessed with the following breakdown: sublabial (n = 69), transnasal microscopic (n = 28), and endoscopic (n = 52) approaches. Sublabial and transnasal microscopic, compared to endoscopic, had more sinus treatment (30.43%, 39.29%, and 15.38%; P = .05), medication use (28.99%, 32.14%, and 11.54%; P = .04), and new allergy symptoms (21.74%, 7.14%, and 1.92%; P < .01). Compared to sublabial and transnasal microscopic, endoscopic patients had superior NSSs (0.40 [1.00], 0.60 [1.75], and 0.20 [0.60]; P = .05), SNOT-22 total scores (1.02 ± 0.58, 1.40 ± 0.78, and 1.00 ± 0.59; P < .01), and CSS medication subscores (100.00 [8.33], 100.00 [8.33], and 100.00 [0.00]; P = .03). Endoscopic patients also reported superior SF-36v2 physical subscores (44.02 ± 11.14, 41.13 ± 9.86, and 47.60 ± 10.12; P = .03).

Conclusion

Nasal function was superior, and further sinus therapy and medication use was lower in patients with endoscopic approaches. Disease-specific quality of life was superior and the endoscopic approach resulted in reduced long-term sinonasal morbidity.

Cavernous sinus meningioma

Cavernous sinus meningioma (CSM) presents a management challenge to present-day neurosurgeons. Lack of adequate understanding of the natural history of these lesions, the early involvement of vital neurovascular structures, the absence of clear tissue planes with normal surrounding structures, and a high rate of aggressive surgery-related morbidity each pose management dilemmas for neurosurgeons. Over the past few decades, the enthusiasm of the neurosurgical community has shifted from aggressive microsurgical resection to maximal safe resection and institution of adjuvant radiotherapy, if necessary. This paradigm shift has ensured better functional outcome in treated patients. This chapter has been designed to discuss the current treatment algorithm and the importance of multimodality management for optimal outcome in patients with CSM. The technical aspects of this approach to management are presented, and the various treatment options are compared.

Three-Hand Endoscopic Endonasal Transsphenoidal Surgery: Experience With an Anatomy-Preserving Mononostril Approach Technique

BACKGROUND

Variations on the endoscopic transsphenoidal approach present unique surgical techniques that have unique effects on surgical outcomes, extent of resection (EOR), and anatomical complications.

OBJECTIVE

To analyze the learning curve and perioperative outcomes of the 3-hand endoscopic endonasal mononostril transsphenoidal technique.

METHODS

Prospective case series and retrospective data analysis of patients who were treated with the 3-hand transsphenoidal technique between January 2007 and May 2015 by a single neurosurgeon. Patient characteristics, preoperative presentation, tumor characteristics, operative times, learning curve, and postoperative outcomes were analyzed. Volumetric EOR was evaluated, and a logistic regression analysis was used to assess predictors of EOR.

RESULTS

Two hundred seventy-five patients underwent an endoscopic transsphenoidal surgery using the 3-hand technique. One hundred eighteen patients in the early group had surgery between 2007 and 2010, while 157 patients in the late group had surgery between 2011 and 2015. Operative time was significantly shorter in the late group (161.6 min) compared to the early group (211.3 min, P = .001). Both cohorts had similar EOR (early group 84.6% vs late group 85.5%, P = .846) and postoperative outcomes. The learning curve showed that it took 54 cases to achieve operative proficiency with the 3-handed technique. Multivariate modeling suggested that prior resections and preoperative tumor size are important predictors for EOR.

CONCLUSION

We describe a 3-hand, mononostril endoscopic transsphenoidal technique performed by a single neurosurgeon that has minimal anatomic distortion and postoperative complications. During the learning curve of this technique, operative time can significantly decrease, while EOR, postoperative outcomes, and complications are not jeopardized.

Outcomes following endoscopic endonasal resection of sellar and supresellar lesions in pediatric patients

PURPOSE

The endoscopic endonasal approach (EEA) is a credible surgical alternative for the resection of sellar and suprasellar lesions such as pituitary adenomas, craniopharyngiomas, and Rathke cleft cysts. However, its application to pediatric patients poses several unique challenges that have not yet been well evaluated. The authors evaluate the safety, efficacy, and outcomes associated with the use of the EEA for treatment of these pathologic entities in pediatric patients.

METHODS

Retrospective review of 30 patients between the ages of two and 24 who underwent endoscopic endonasal resection of sellar or suprasellar lesions between January 2010 and December 2015. Endocrinological and ophthalmological outcomes, as well as extent of resection and complications were all evaluated.

RESULTS

Gross total resection was achieved in eight of the nine pituitary adenomas, nine of the 12 craniopharyngiomas, and six of the nine Rathke cleft cysts. Of the 30 patients, 22 remained disease free at last follow-up. A total of six patients developed hypopituitarism and five developed diabetes insipidus. Eleven patients experienced improved vision, sixteen experienced no change, and one patient experienced visual worsening. Postoperative cerebrospinal fluid leak was seen in a single case and later resolved, vasospasm/stroke was experienced by 10% of patients, and new obesity was recorded in 10% of patients. There were no perioperative deaths.

CONCLUSIONS

Endoscopic endonasal resection is a safe and effective surgical alternative for the management of sellar and suprasellar pathologies in pediatric populations with excellent outcomes, minimal complications, and a low risk of morbidity.

Decision-making algorithm for minimally invasive approaches to anterior skull base meningiomas

OBJECTIVE Anterior skull base meningiomas are benign lesions that cause neurological symptoms through mass effect on adjacent neurovascular structures. While traditional transcranial approaches have proven to be effective at removing these tumors, minimally invasive approaches that involve using an endoscope offer the possibility of reducing brain and nerve retraction, minimizing incision size, and speeding patient recovery; however, appropriate case selection and results in large series are lacking. METHODS The authors developed an algorithm for selecting a supraorbital keyhole minicraniotomy (SKM) for olfactory groove meningiomas or an expanded endoscopic endonasal approach (EEA) for tuberculum sella (TS) or planum sphenoidale (PS) meningiomas based on the presence or absence of olfaction and the anatomical extent of the tumor. Where neither approach is appropriate, a standard transcranial approach is utilized. The authors describe rates of gross-total resection (GTR), olfactory outcomes, and visual outcomes, as well as complications, for 7 subgroups of patients. Exceptions to the algorithm are also discussed. RESULTS The series of 57 patients harbored 57 anterior skull base meningiomas; the mean tumor volume was 14.7 ± 15.4 cm³ (range 2.2-66.1 cm³), and the mean follow-up duration was 42.2 ± 37.1 months (range 2-144 months). Of 19 patients with olfactory groove meningiomas, 10 had preserved olfaction and underwent SKM, and preservation of olfaction in was seen in 60%. Of 9 patients who presented without olfaction, 8 had cribriform plate invasion and underwent combined SKM and EEA (n = 3), bifrontal craniotomy (n = 3), or EEA (n = 2), and one patient without both olfaction and cribriform plate invasion underwent SKM. GTR was achieved in 94.7%. Of 38 TS/PS meningiomas, 36 of the lesions were treated according to the algorithm. Of these 36 meningiomas, 30 were treated by EEA and 6 by craniotomy. GTR was achieved in 97.2%, with no visual deterioration and one CSF leak that resolved by placement of a lumbar drain. Two patients with tumors that, based on the algorithm, were not amenable to an EEA underwent EEA nonetheless: one had GTR and the other had a residual tumor that was followed and removed via craniotomy 9 years later. CONCLUSIONS Utilizing a simple algorithm aimed at preserving olfaction and vision and based on maximizing use of minimally invasive approaches and selective use of transcranial approaches, the authors found that excellent outcomes can be achieved for anterior skull base meningiomas.

Preserve or sacrifice the stalk? Endocrinological outcomes, extent of resection, and recurrence rates following endoscopic endonasal resection of craniopharyngiomas

OBJECTIVE

Gross-total resection (GTR) of craniopharyngiomas (CPs) is potentially curative and is often the goal of surgery, but endocrinopathy generally results if the stalk is sacrificed. In some cases, GTR can be attempted while still preserving the stalk; however, stalk manipulation or devascularization may cause endocrinopathy and this strategy risks leaving behind small tumor remnants that can recur.

METHODS

A retrospective review of a prospective cohort of patients who underwent initial resection of CP using the endoscopic endonasal approach over a period of 12 years at Weill Cornell Medical College, NewYork-Presbyterian Hospital, was performed. Postresection integrity of the stalk was retrospectively assessed using operative notes, videos, and postoperative MRI. Tumors were classified based on location into type I (sellar), type II (sellar-suprasellar), and type III (purely suprasellar). Pre- and postoperative endocrine function, tumor location, body mass index, rate of GTR, radiation therapy, and complications were reviewed.

RESULTS

A total of 54 patients who had undergone endoscopic endonasal procedures for first-time resection of CP were identified. The stalk was preserved in 33 (61%) and sacrificed in 21 (39%) patients. GTR was achieved in 24 patients (73%) with stalk preservation and 21 patients (100%) with stalk sacrifice (p = 0.007). Stalk-preservation surgery achieved GTR and maintained completely normal pituitary function in only 4 (12%) of 33 patients. Permanent postoperative diabetes insipidus was present in 16 patients (49%) with stalk preservation and in 20 patients (95%) following stalk sacrifice (p = 0.002). In the stalk-preservation group, rates of progression and radiation were higher with intentional subtotal resection or near-total resection compared to GTR (67% vs 0%, p < 0.001, and 100% vs 12.5%, p < 0.001, respectively). However, for the subgroup of patients in whom GTR was achieved, stalk preservation did not lead to significantly higher rates of recurrence (12.5%) compared with those in whom it was sacrificed (5%, p = 0.61), and stalk preservation prevented anterior pituitary insufficiency in 33% and diabetes insipidus in 50%.

CONCLUSIONS

While the decision to preserve the stalk reduces the rate of postoperative endocrinopathy by roughly 50%, nevertheless significant dysfunction of the anterior and posterior pituitary often ensues. The decision to preserve the stalk does not guarantee preserved endocrine function and comes with a higher risk of progression and need for adjuvant therapy. Nevertheless, to reduce postoperative endocrinopathy attempts should be made to preserve the stalk if GTR can be achieved.

Quantitative Analysis of Surgical Working Space During Endoscopic Skull Base Surgery

Objectives  Selective dissection of intranasal anatomy may improve visualization and maneuverability at the skull base. We aimed to quantify the dimensions of working space and angles achieved following sequential removal of intranasal structures using an endoscopic transphenoidal approach to the skull base. Methods  Cone beam computed tomography scans of four cadaveric heads were obtained for registration of an optical tracking system. Each head was sequentially dissected: (1) sphenoidotomy and limited posterior septectomy, (2) unilateral partial middle turbinectomy, (3) bilateral partial middle turbinectomy, and (4) wide posterior septectomy. The maximal craniocaudal and mediolateral distance (mm) and angle (degrees) reached were calculated at the sphenoid face and sella. Data were analyzed using descriptive statistics and tests of statistical significance. The significance level was set at p  ≤  0.05. Results  A significant improvement in both dimensions of working space was observed with each stage of dissection at the level of the sphenoid face. Maximal working space was achieved following bilateral middle turbinectomy and wide posterior septectomy with a 38 and 29% increase in working space in the mediolateral and craniocaudal dimensions, respectively. The largest stepwise increase in working space was observed with unilateral middle turbinectomy (mediolateral: 24 ± 3 mm and craniocaudal: 20 ± 3 mm). A trend toward improved degrees of visualization was observed with each stage of dissection but was not statistically significant. Conclusion  Approaches to the skull base can be enhanced by selective unilateral/bilateral partial middle turbinectomy and posterior septectomy being performed to improve visualization and maximize surgical working freedom.

Endoscopic transorbital approach to anterolateral skull base through inferior orbital fissure: a cadaveric study

BACKGROUND

Endoscopic transorbital approach (eTOA) has been announced as an alternative minimally invasive surgery to skull base. Owing to the inferior orbital fissure (IOF) connecting the orbit with surrounding pterygopalatine fossa (PPF), infratemporal fossa (ITF), and temporal fossa, the idea of eTOA to anterolateral skull base through IOF is postulated. The aim of this study is to access its practical feasibility.

METHODS

Anatomical dissections were performed in five human cadaveric heads (10 sides) using 0-degree and 30-degree endoscopes. A stepwise description of eTOA to anterolateral skull base through IOF was documented. The anterosuperior corner of the maxillary sinus in the horizontal plane of the upper edge of zygomatic arch was defined as reference point (RP). The distances between the RP to the foramen rotundum (FR), foramen ovale (FO), and Gasserian ganglion (GG) were measured. The exposed area of anterolateral skull base in the coronal plane of the posterior wall of the maxillary sinus was quantified.

RESULTS

The surgical procedure consisted of six steps: (1) lateral canthotomy with cantholysis and preseptal lower eyelid approach with periorbita dissection; (2) drilling of the ocular surface of greater sphenoid wing and lateral orbital rim osteotomy; (3) entry into the maxillary sinus and exposure of PPF and ITF; (4) mobilization of infraorbital nerve with drilling of the infratemporal surface of the greater sphenoid wing and pterygoid process; (5) exposure of middle cranial fossa, Meckel's cave, and lateral wall of cavernous sinus; and (6) reconstruction of orbital floor and lateral orbital rim. The distances measured were as follows: RP-FR = 45.0 ± 1.9 mm, RP-FO = 55.7 ± 0.5 mm, and RP-GG = 61.0 ± 1.6 mm. In comparison with the horizontal portion of greater sphenoid wing, the superior and inferior axes of the exposed area were 22.3 ± 2.1 mm and 20.5 ± 1.8 mm, respectively. With reference to the FR, the medial and lateral axes of the exposed area were 11.6 ± 1.1 mm and 15.8 ± 1.6 mm, respectively.

CONCLUSIONS

The eTOA through IOF can be used as a minimally invasive surgery to access whole anterolateral skull base. It provides a possible resolution to target lesion involving multiple compartments of anterolateral skull base.

Adherus Dural Sealant in Endoscopic Skull Base Surgery: Safety, Imaging Characteristics, and Sinonasal Quality of Life

Objective  This study was aimed to compare the safety profiles, magnetic resonance imaging (MRI) findings, and sinonasal outcome test (SNOT-22) scores of Adherus dural sealant, a novel tissue glue designed for skull base surgery. Design  Present study is a prospective case series. Setting  The research work took place at a tertiary-care academic medical center. Participants  Consecutive series of 26 patients undergoing endoscopic skull base surgery (ESBS) with Adherus was compared with a control group of 24 patients matched for tumor type and size with DuraSeal as a sealant. Main Outcome Measures  Postoperative complication rates, imaging characteristics, and postoperative SNOT-22 scores were measured and compared. Results  No postoperative cerebrospinal fluid (CSF) leaks, intracranial hemorrhages, or mucoceles were observed in either cohort. Adherus was more likely to be identifiable on immediate postoperative MRI (50 vs. 20.8%, p  = 0.032). In patients in whom a nasoseptal flap was utilized, the flap was opposed to the skull base in all cases regardless of sealant selected. Postoperative SNOT-22 total (17.25 [±10.81] vs. 14.85 [±14.22], p  = 0.609) and subdomain scores were similar between the two groups. Conclusions  Adherus dural sealant appears to be a safe alternative to Duraseal in ESBS with comparable quality of life outcomes and imaging findings. These preliminary results are promising but should be examined in a larger population with long-term follow-up.

Sinonasal quality-of-life outcomes after endoscopic endonasal skull base surgery

BACKGROUND

There are substantial gaps in our understanding of the influence of the endoscopic endonasal approach (EEA) for endoscopic skull base surgery on sinonasal-specific quality of life (QOL) as well as the instruments available for assessment. Our primary objective in this study was to characterize postoperative changes in sinonasal QOL, specifically using the 22-item Sino-Nasal Outcome Test (SNOT-22), with a secondary objective of delineating weaknesses in our current understanding of patient symptomatology after EEA for skull base surgery.

METHODS

A comprehensive literature review was conducted using PubMed, CINAHL, Cochrane Library, and SCOPUS for studies reporting SNOT-22 data pre- and postoperatively in patients who underwent EEA for skull base pathologies. Studies were limited to patients ≥18 years of age and excluded patients diagnosed with chronic rhinosinusitis (CRS).

RESULTS

Nineteen unique studies with 27 separate data sets and a total of 1025 patients were used in this meta-analysis. Overall SNOT-22 scores statistically improved at the 6-month (p = 0.0009) and 1-year (p = 0.002) time-points. Patients with preoperative SNOT-22 scores ≥20 achieved postoperative improvements at 12-week (p < 0.00001), 6-month (p < 0.0001), 1-year (p < 0.00001), and long-term follow-up (p < 0.0001). Patients with preoperative SNOT-22 scores <20 remained stable and did not worsen postoperatively.

CONCLUSION

Patients undergoing EEA for skull base pathologies who have impaired sinonasal QOL preoperatively demonstrated significant postoperative QOL improvements. Those patients with relatively normal preoperative sinonasal QOL remained asymptomatic postoperatively. This study supports the need for development of a contemporary disease- and approach-specific, validated QOL instrument for skull base pathologies.

[Experience of treating patients with lateral sphenoid sinus recess CSF leak]

According to various authors, the rate of sphenoid sinus defects ranges from 15 to 26%. In the sphenoid sinus, the most common defect localization is the lateral recess - 35.3%. Regardless of the etiology and pathogenesis of lateral sphenoid sinus recess cerebrospinal fluid (CSF) leak, the treatment approach is aimed at plastic closure of the defect. Surgery in this area is associated with a high rate of recurrences (25%) due to a complex anatomical landscape and inapplicability of a direct approach.

PURPOSE

The study purpose was to analyze our own experience in treating patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess and, based on the obtained results, develop an algorithm for the treatment of this pathology.

MATERIAL AND METHODS

We retrospectively reviewed a series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess who were treated at the Burdenko Neurosurgical Institute in the period between 2001 and 2017. The demographic characteristics of patients, clinical data, and aspects of surgical treatment were analyzed. Treatment outcomes were assessed based on analysis of recurrences and postoperative complications. The obtained data were compared to the literature data.

RESULTS

In the series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess, the mean age was 49 years. Surgery through the transsphenoid approach was performed in 89 (74%) patients. There were 25 (28%) recurrences in this group. Nine (7%) patients underwent repair of a complex skull base defect using the transethmoidal approach; there were 3 (33%) recurrences. The transpterygoid approach was used in 22 (17%) patients; there were 3 (14%) recurrences in this group.

CONCLUSION

Endoscopic endonasal repair is an effective technique for treating complex skull base defects in the lateral sphenoid sinus recess. The choice of an approach to the defect depends on the degree of pneumatization of the sphenoid sinus, surgeon's experience, and availability of the necessary equipment and tools. The endoscopic transpterygoid approach is advisable to use in cases of excessive pneumatisation of the sinus with developed lateral processes and recurrent nasal CSF leak. This enables visualization of the defect edges in this hard-to-reach area and adequate repair.

The Helmet-Visor Pericranial Flap as a Viable Option for Anterior Cranial Base Reconstruction in Complex Oncologic Cases

OBJECTIVE

To describe a novel bilaterally pedicled pericranial flap for anterior cranial base reconstruction after removal of complex frontobasal cancers extending to the frontal region, thus precluding the use of standard reconstructive techniques.

METHODS

In selected oncologic cranial base surgeries, the use of the standard galea frontalis pericranial flap for reconstructive purposes may be precluded by tumor infiltration. In such cases, dura mater reconstruction and exclusion of frontal sinuses from the intracranial space can be performed using a large superficial temporal artery bilaterally pedicled pericranial flap obtained from both temporoparietal regions. Surgical technique, indication, contraindication, complications, and degree of resection are recorded to evaluate the efficacy of this surgical method.

RESULTS

A 48-year-old man affected by a recurrence of frontobasal squamous cell carcinoma was surgically treated by combined transcranial and endoscopic endonasal resection. A large pericranial flap pedicled bilaterally on the parietal branches of the superficial temporal artery was obtained, transposed anteriorly, carefully watertight sutured to the dural defect, and used to exclude cranialized frontal sinuses as well. The reconstruction was successful, and the patient was discharged home on the tenth postoperative day without any complications and/or development of cerebrospinal fluid leak. Contrast-enhanced magnetic resonance imaging 3 months after surgery was clear from disease with consolidated surgical outcomes.

CONCLUSIONS

This novel pericranial flap seems to be easily obtained and effective for anterior cranial base reconstruction when the use of a traditional galea frontalis flap is precluded for oncologic reasons and there are concerns for the possible development of contaminations and cerebrospinal fluid leaks.

Endoscopic endonasal resection of epidermoid cysts involving the ventral cranial base

OBJECTIVE

Epidermoid cysts (ECs) commonly extend to involve the ventral cisterns of the cranial base. When present, symptoms arise due to progressive mass effect on the brainstem and adjacent cranial nerves. Historically, a variety of open microsurgical approaches have been used for resection of ECs in this intricate region. In recent years, the endoscopic endonasal approach (EEA) has been proposed as an alternative corridor that avoids crossing the plane of the cranial nerves. To date, there is a paucity of data in the literature regarding the safety and efficacy of the EEA in the treatment of ECs of the ventral cranial base.

METHODS

The authors reviewed a prospectively acquired database of EEAs for resection of ECs over 8 years at Weill Cornell, NewYork-Presbyterian Hospital. All procedures were performed by the senior authors. Standardized clinical and radiological parameters were assessed before and after surgery. Statistical tests were used to determine the impact of previous surgery and tumor volume on extent of resection and recurrence as well as the method of closure on rate of CSF leak.

RESULTS

Between January 2009 and February 2017, 7 patients (4 males and 3 females; age range 16-70 years) underwent a total of 8 surgeries for EC resection utilizing the EEA. Transplanum and transclival extensions were performed in 3 and 5 patients, respectively. Methods of closure incorporated a gasket seal in 6 of 8 procedures and a nasoseptal flap in 7 of 8 procedures. Gross-total resection (GTR) was achieved in 43% of patients, and near-total resection (> 95%) was obtained in another 43%. Complications included diabetes insipidus (n = 2), postoperative CSF leak (n = 2), transient third cranial nerve palsy (n = 1), and epistaxis (n = 1). With a mean follow-up of 43.5 months, recurrence has been observed in 2 of 7 patients. In 1 case, reoperation for recurrence was required 71 months following the initial surgery. Use of the gasket-seal technique with nasoseptal flap coverage significantly correlated with the absence of postoperative CSF leakage (p = 0.018). GTR was achieved in 25% of the patients who had prior surgeries and in 50% of patients without previous resections. The mean volume of cysts in which GTR was achieved (4.3 ± 1.8 cm3) was smaller than that in which subtotal or near-total resection was achieved (12.2 ± 11 cm3, p = 0.134).

CONCLUSIONS

The EEA for resection of ECs of the ventral cranial base is a safe and effective operative strategy that avoids crossing the plane of the cranial nerves. In the authors' experience, gasket-seal closure with nasoseptal flap coverage has been associated with a decreased risk of postoperative CSF leakage.

Combined Multiportal Endoscopic Endonasal and Transcranial Approach for Recurrent Tuberculum Sellae Meningioma: Operative Video

Surgery for anterior cranial base lesions is challenging because tumors often spread from their origin to sinuses, orbits, and middle cranial fossa, resulting in risky surgeries.^1,2 To approach such complex diseases, recently combined multiportal approaches have been proposed.^3,4 At the best of our knowledge, operative application of a combined endoscopic endonasal and transcranial surgery for complex anterior cranial base lesions has not been described. Therefore a surgical video of such an approach is presented. A 37-year-old woman affected by a huge recurrence of a tuberculum meningioma extended to right orbit presented to our department, complaining of right ocular bulb dislocation with multidirectional limitations in eye movements (Video 1). Given the complexity and localization of the lesion, a combined endoscopic endonasal-transcranial surgery was performed. Such a combined approach, although demanding in terms of the presence of both otolaryngologist and neurosurgeon during the surgery, also requires strong synergy among them and permits them to control anterior cranial base lesions from both specialists' perspectives, simultaneously. In this case, while an endonasal corridor permitted an accurate excision of ethmoidal and medial orbital wall part of the lesion, a bicoronal approach allowed the aggression of the anterior cranial base portion of the tumor, allowing good control of cranial base neurovascular structures, eventually obtaining a gross total resection, without perioperative complications. Furthermore, a combined multiportal approach allows cooperative strategies among the surgeons involved, leading to safer, quicker, and more effective resections with less brain retraction, given the wide angles of views to the lesion that a multiportal approach can offer.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endoscopic transorbital transtentorial approach to middle incisural space: preclinical cadaveric study

BACKGROUND

Endoscopic transorbital approach is a novel development of minimally invasive skull base surgery. Recently, anatomical studies have started to discuss the expanded utilization of endoscopic transorbital route for intracranial intradural lesions. The goal of this cadaveric study is to assess the feasibility of endoscopic transorbital transtentorial approach for exposure of middle incisural space.

METHODS

Anatomical dissections were performed in four human cadaveric heads (8 sides) using 0- and 30-degree endoscopes. A stepwise description of endoscopic transorbital transtentorial approach to middle incisural space and related anatomy was provided.

RESULTS

Orbital manipulation following superior eyelid crease incision with lateral canthotomy and cantholysis established space for bone drilling. Extradural stage consisted of extensive drilling of orbital roof of frontal bone, lessor, and greater wings of sphenoid bone. Intradural stage was composed of dissection of sphenoidal compartment of Sylvian fissure, lateral mobilization of mesial temporal lobe, and penetration of tentorium. A cross-shaped incision of tentorium provided direct visualization of crural cistern with anterolateral aspect of cerebral peduncle and upper pons. Interpeduncular cistern, prepontine cistern, and anterior portions of ambient and cerebellopontine cisterns were exposed by 30-degree endoscope.

CONCLUSION

The endoscopic transorbital transtentorial approach can be used as a minimally invasive surgery for exposure of middle incisural space. Extensive drilling of sphenoid wing and lateral mobilization of mesial temporal lobe are the main determinants of successful dissection. Further studies are needed to confirm the clinical feasibility of this novel approach.

Validation of training levels in endoscopic endonasal surgery of the skull base

OBJECTIVE

A five-level training program was first proposed 10 years ago for surgeons learning endoscopic endonasal surgery (EES) of the skull base. Levels were based on the complexity of anatomy, risk of neurovascular injury, intradural dissection, technical difficulty and vascularity of tumors.

METHOD

A three-phase validation concept is proposed: 1) face validity (the classification is related to clinically significant elements), 2) construct validity (the classification predicts the outcome), and 3) inter-team validation (the classification applies to other surgical teams). Consecutive cases over a 1-year time span were retrospectively classified. Primary outcome measures included: complication rates (cranial nerve injury, stroke and vascular injury, cerebrospinal fluid [CSF] leak and infection), estimated blood loss and duration of surgery.

RESULTS

Two hundred and nine consecutive cases were analyzed. The distribution of cases for each category was: 63 cases in level II, 70 cases in level III, 66 cases in level IV, and 10 cases in level V. Construct validity demonstrated statistical difference with increasing rate of complications from level II to level III and from level III to level IV; also, specific rates of cranial nerve injury and CSF leak increased between levels III and IV. Face validity identified 162 citations since publication of the original article. Inter-team validation demonstrated no difference between two teams of surgeons.

CONCLUSION

This study provides a three-phase validation of training levels for endoscopic skull base surgery. Adoption of a progressive systematic approach to learning EES from least complex to advanced procedures is expected to minimize the risks while surgical teams gain experience.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:2253-2257, 2019.

Transoral (transvestibular-paramandibular) endoscopic approach for benign tumours in the infratemporal fossa

We describe a minimally invasive transoral approach to the infratemporal fossa, by means of endoscopy, which facilitates examination and resection of lesions in this area. Furthermore, we outline the technique employed and a case treated with this approach, which permits a rapid access with very low patient morbidity, due to the use of endoscopy and of transoral access, instead of traditional transfacial approaches.

Nasal Morbidity and Quality of Life After Endoscopic Transsphenoidal Surgery: A Single-Center Prospective Study

OBJECTIVE

The aim of this study was to assess nasal morbidity of endoscopic transsphenoidal approaches (ETAs) for treatment of sellar and parasellar diseases through evaluation of quality of life (QoL) and nasal function. The impact of different ETAs, according to extent and reconstruction technique, was also studied.

METHODS

Patients undergoing ETA for treatment of sellar or parasellar lesions were prospectively recruited and examined preoperatively and at 6 months after surgery according to the following workup: nasal endoscopy, rhinomanometry, acoustic rhinometry, University of Pennsylvania Smell Identification Test, Anterior Skull Base Nasal Inventory-12, Sino-nasal Outcome Test-22, and Short-Form Health Survey-36 (SF-36).

RESULTS

Of 34 patients initially recruited, 29 completed follow-up examinations. Seven patients (24.14%) developed turbinoseptal synechiae; anterior septal perforations were observed in 3 patients (10.35%). More extended surgical dissection was associated with the presence of postoperative septal perforation and synechiae. No significant difference was noted between preoperative and postoperative results on the University of Pennsylvania Smell Identification Test, acoustic rhinometry, Sino-nasal Outcome Test-22, or Anterior Skull Base Nasal Inventory-12. There was a significant increase in nasal airflow after surgery and improvement of the Short-Form Health Survey-36 score in 4 of 8 domains.

CONCLUSIONS

The modular ETA technique is associated with minimal morbidity and preserves nasal patency, airflow, and olfactory function. Quality of life is not affected and although small septal perforations and synechiae can be observed, nasal physiology is not compromised. Nonetheless, careful manipulation of sinonasal structures is recommended to minimize postoperative sequelae.