Skull Base Tumors Research Articles

THU100 Case Of A Large Suprasellar-clival Mass: Prolactinoma Vs Paraganglioma

Abstract Disclosure: L.N. Madera Marin: None. Y. Rivera-Nieves: None. M.A. Ortiz-Rivera: None. A. Rosado-Burgos: None. L. El Musa Penna: None. W. Medina-Torres: None. L. Sepulveda-Garcia: None. M. Ramirez: None. L.A. Gonzalez-Rodriguez: None. M. Alvarado: None. N. Canales: None. Introduction Prolactin secreting adenomas comprise 30-40% of all pituitary adenomas. Generally, serum prolactin levels correlate with tumor size. Giant prolactinomas measure >4 cm, most have mass related clinical effects. Even large masses respond to cabergoline. Some may require surgical intervention. We present a case of a large pituitary mass associated with elevated prolactin levels, but with an interesting histopathologic analysis. Patient Description 30 y/o male patient with new onset decreased peripheral vision. Retinologist evaluation showed no abnormalities. Laboratories done by PCP found with altered thyroid function tests, but no treatment offered at the time. Two months later, the patient complained of worsening peripheral vision and was found with a left dilated pupil. A head CT scan was performed that showed a large brain mass. Admitted for urgent neurosurgery evaluation and high dose dexamethasone was initiated. ROS was remarkable for weight gain over the past year, and decreased morning erections, although denied decreased libido or erectile dysfunction. MRI showed an infiltrative skull base tumor extending from the clivus to the parasellar area encasing the left cavernous segment of the internal carotid artery with expansion of the sella obliterating the pituitary gland, and extension into the left optic canal. Pre-operative laboratories: Prolactin >877 ng/ml (2-17ng/ml), Cortisol 1.80 mcg/dL (4-22 mcg/dL), TSH 1.45 uIU/ml (0.4-4.0 uIU/ml), Sodium 142mMol/L (135-145mMol/L). Patient underwent left pterional craniotomy. Initial intra-operative pathology: “Positive for Neoplasia”. Post-operative laboratories: Prolactin >877 ng/ml, TSH 0.229 uIU/ml, FSH <0.30 mIU/ml (1.2-7.8 mIU/ml), and LH 0.16 mIU/ml (1.5-9.3 mIU/ml). Case Outcomes/Discussion Central hypothyroidism and hypogonadism confirmed, secondary hypocortisolism could not be assessed due to emergent corticosteroid infusion upon admission. A presumptive diagnosis of a giant prolactinoma was made for which cabergoline therapy was initiated. Final pathologic diagnosis revealed a paraganglioma. Urine fractionated metanephrines and catecholamines were normal. Immunostaining for prolactin requested. Paragangliomas arise from neuroendocrine cells, from either sympathetic or parasympathetic ganglia and can be solitary or multiple. Skull base and neck paragangliomas are usually benign while ∼20% of abdominal paragangliomas (sympathetic) are malignant. Anterior skull base paragangliomas are predominantly located in the sella and are rare but have been described in the literature. Very rare cases of pheochromocytomas or paragangliomas associated to pituitary adenomas have been reported. It has been named as the three P association, thought to be related to succinate dehydrogenase B and D mutations. Moreover, there are no cases in the literature of paragangliomas secreting prolactin. Presentation: Thursday, June 15, 2023

Tumor Location Impacts the Development of Radiation Necrosis in Benign Intracranial Tumors.

Radiation necrosis (RN) is a possible late complication of stereotactic radiosurgery (SRS), but only a few risk factors are known. The aim of this study was to assess tumor location in correlation to the development of radiation necrosis for skull base (SB) and non-skull base tumors. All patients treated with radiosurgery for benign neoplasms (2004-2020) were retrospectively evaluated. The clinical, imaging and medication data were obtained and the largest axial tumor diameter was determined using MRI scans in T1-weighted imaging with gadolinium. The diagnosis of RN was established using imaging parameters. Patients with tumors located at the skull base were compared to patients with tumors in non-skull base locations. 205 patients could be included. Overall, 157 tumors (76.6%) were located at the SB and compared to 48 (23.4%) non-SB tumors. Among SB tumors, the most common were vestibular schwannomas (125 cases) and meningiomas (21 cases). In total, 32 (15.6%) patients developed RN after a median of 10 (IqR 5-12) months. Moreover, 62 patients (30.2%) had already undergone at least one surgical resection. In multivariate Cox regression, SB tumors showed a significantly lower risk of radiation necrosis with a Hazard Ratio (HR) of 0.252, p < 0.001, independently of the applied radiation dose. Furthermore, higher radiation doses had a significant impact on the occurrence of RN (HR 1.372, p = 0.002). The risk for the development of RN for SB tumors appears to be low but should not be underestimated. No difference was found between recurrent tumors and newly diagnosed tumors, which may support the value of radiosurgical treatment for patients with recurrent SB tumors.

Treatment of Clival Chordomas: A 20-Year Experience and Systematic Literature Review.

Clival chordomas are rare but aggressive skull base tumors that pose significant treatment challenges and portend dismal prognosis. The aim of this study was to highlight the advantages and limitations of available treatments, to furnish prognostic indicators, and to shed light on novel therapeutic strategies. We conducted a retrospective study of clival chordomas that were surgically treated at our institution from 2003 to 2022; for comparison purposes, we provided a systematic review of published surgical series and, finally, we reviewed the most recent advancements in molecular research. A total of 42 patients underwent 85 surgeries; median follow-up was 15.8 years, overall survival rate was 49.9% at 10 years; meanwhile, progression-free survival was 26.6% at 10 years. A significantly improved survival was observed in younger patients (<50 years), in tumors with Ki67 ≤ 5% and when adjuvant radiotherapy was performed. To conclude, clival chordomas are aggressive tumors in which surgery and radiotherapy play a fundamental role while molecular targeted drugs still have an ancillary position. Recognizing risk factors for recurrence and performing a molecular characterization of more aggressive lesions may be the key to future effective treatment.

305 Facial Nerve Outcomes Following Malignant Lateral Skull Base Surgery at a Tertiary Centre

Abstract Background Although a rare malignancy, lateral skull base tumours often present a challenge to head and neck surgeons due to complex neurovascular anatomy. Patients also tend to present late with advanced disease. With lateral skull base tumours being a rare occurrence, there is limited knowledge on facial nerve outcomes following surgery. Method Data from 44 patients were collected and analysed. The main outcome collected in this study was facial nerve function at presentation and post op (both immediately and long-term) according to the House-Brackmann scale. Results 90% of patients presented without signs and symptoms of facial nerve involvement. Patients who had no facial pain or paralysis at presentation are more likely to maintain normal facial functions after surgery (20 out of 26 that scored House-Brackmann 1 pre-op maintain a score of 1 in long term post-op review). 80% of those who presented with signs and symptoms of facial nerve involvement required intraoperative nerve sacrifice. Conclusions Patients who presented with facial pain or paralysis tend to have more advanced disease. The majority (80%) of those presenting with facial deficits pre-operatively underwent nerve sacrifice. The purpose of this study is to offer insight into facial nerve outcomes of patients who underwent lateral skull base surgery at a tertiary centre. We collected and analysed the outcomes of surgery for 44 patients, with main outcome measures including facial nerve functions based on the House-Brackmann scale, as well as any postoperative complications, recurrences, types of adjuvant therapy required and survival after the operation.

Delayed cerebral vasospasm following craniopharyngioma surgery: The impact of the electrolytes imbalance

Cerebral vasospasm is a well-known phenomenon following aneurysmal subarachnoid hemorrhage and trauma. While cerebral vasospasm is observed following skull base tumor surgery, it remains a rare phenomenon and is a major cause of neurologic morbidity and mortality [1,2].

Low-Grade Chondrosarcoma Mimicking Chondroid Chordoma: A Case Report

Chondrosarcomas and Chordomas account for the majority of primary skull base tumors, which are slow growing and locally aggressive. These tumors cause severe cranial nerve neuropathies. Both these tumors have similar clinical, radiological, and histological resemblances. Histopathology, along with immunohistochemistry, helps to differentiate these tumors. We are presenting a case of 39year old female who came with double vision, squint, headache, and tingling sensation over the right side of the face. Examination and investigations concluded a skull base tumor near the cavernous sinus. Surgical resection of the lesion was done and sent for histopathology. Microscopy showed hyaline cartilaginous islands, myxoid matrix, and individual cells with vacuolated cytoplasm and ovoid nucleus. Immunohistochemistry showed positive for S100. Final diagnosis of low-grade Chondrosarcoma was made. Keywords: Chondrosarcoma, Skull base tumors, Chordoma, S100

Evaluation of endocrinological sequelae following particle therapy performed on anterior skull base lesions in the adult population.

Radiotherapy has increasingly assumed a central role in the multidisciplinary treatment of skull base lesions. Unfortunately, it is often burdened by relevant radio-induced damage to the pituitary function and the surrounding structures and systems. Patients who were treated with radiotherapy around the sellar region especially have a high risk of developing radio-induced hypopituitarism. Particle therapy has the potential advantage of delivering a higher radiation dose to the target while potentially sparing the sellar region and pituitary function. The aim of this study is to evaluate the pituitary function in adult patients who have undergone hadron therapy for anterior skull base lesions involving or surrounding the pituitary gland. This is a retrospective, observational, and noncontrolled study. We evaluated pituitary and peripheral hormone levels in all patients referring to National Center for Oncological Hadrontherapy, Pavia, Italy for anterior skull base tumors. Furthermore, we performed a magnetic resonance imaging for every follow-up to evaluate potential tumoral growth. We evaluated 32 patients with different tumoral lesions with a mean follow-up of 27.9 months. The mean hadron therapy (HT) dose was 60 ± 14 Gray, with a mean dose per fraction of 2.3 ± 2.1 Gray. Six patients were treated with carbon ions and 26 with protons. Pituitary hormone alteration of some kind was reported for six patients. No patient experienced unexpected severe adverse events related to particle therapy. Particle radiotherapy performed on anterior skull base lesions has proved to cause limited damage to pituitary function in the adult population.

Update from the 5th Edition of the WHO Classification of Nasal, Paranasal, and Skull Base Tumors: Imaging Overview with Histopathologic and Genetic Correlation.

Sinonasal and skull base tumors are a heterogeneous group of neoplasms with considerable histologic variation and overlapping imaging features. In 2022, the World Health Organization updated the head and neck tumor classification, further emphasizing the importance of molecular data and genetic alterations in sinonasal neoplasms. The changes include the addition of new entities and discussion of emerging entities, as well as changes to the taxonomy and characterization of tumors. The new classification focuses on entities that develop in these sites either exclusively (eg, olfactory neuroblastoma) or most frequently. Another change includes reduction in the number of categories by creating separate category-specific chapters for soft-tissue, hematolymphoid, and neuroectodermal lesions. In this review, we briefly discuss the various categories in the new classification with a more detailed description of the 2 new entities (SWItch/Sucrose Non-Fermentable complex-deficient sinonasal carcinomas and human papillomavirus-related multiphenotypic sinonasal carcinoma). We also highlight the emerging entities including IDH-mutant sinonasal malignancies and DEK-AFF2 carcinoma, presently classified as sinonasal undifferentiated carcinoma and nonkeratinizing squamous cell carcinoma, respectively.

Neuroendoscopy: intraventricular and skull base tumor resection in children.

During the last 30years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

The general trend of surgical treatment of nasal skull base tumors is to construct a multiple disciplinary team including rhinologist and neurosurgeon

The general trend of surgical treatment of nasal skull base tumors is to construct a multiple disciplinary team including rhinologist and neurosurgeon

Variability in the Arterial Supply of Intracranial Meningiomas: An Anatomic Study.

Intracranial meningiomas are a diverse group of tumors, which vary by grade, genetic composition, location, and vasculature. Expanding the understanding of the supply of skull base (SBMs) and non-skull base meningiomas (NSBMs) will serve to further inform resection strategies. We sought to delineate the vascular supply of a series of intracranial meningiomas by tumor location. A retrospective study of intracranial meningiomas that were studied using preoperative digital subtraction angiograms before surgical resection at a tertiary referral center was performed. Patient, tumor, radiologic, and treatment data were collected, and regression models were developed. One hundred sixty-five patients met inclusion criteria. The mean age was 57.1 years (SD: 12.6). The mean tumor diameter was 4.9 cm (SD: 1.5). One hundred twenty-six were World Health Organization Grade I, 37 Grade II, and 2 Grade III. Arterial feeders were tabulated by Al-Mefty's anatomic designations. SBMs were more likely to derive arterial supply from the anterior circulation, whereas NSBMs were supplied by external carotid branches. NSBMs were larger (5.61 cm vs 4.45 cm, P = <.001), were more often presented with seizure (20% vs 8%, P = .03), were higher grade ( P = <.001) had more frequent peritumoral brain edema (84.6% vs 66%, P = .04), and had more bilateral feeders (47.7% vs 28%, P = .01) compared with SBMs. More arterial feeders were significantly associated with lower tumor grade ( P = .023, OR = 0.59). Higher tumor grade (Grade II/III) was associated with fewer arterial feeders ( P = .017, RR = 0.74). Meningioma location is associated with specific vascular supply patterns, grade, and patient outcomes. This information suggests that grade I tumors, especially larger tumors, are more likely to have diverse vascular supply patterns, including internal carotid branches. This study may inform preoperative embolization and surgical considerations, particularly for large skull base tumors.

Reducing CSF complications by a recycled Hadad's flap combined with autologous mucosa in secondary endoscope transsphenoidal surgery.

Transsphenoidal secondary operations are a minority but not a rare occurrence. How to viably prevent cerebral fluid (CSF)-related complications and confine surgery-caused injury in secondary surgery as minimally as possible is a huge challenge. This article shares our solution of recycling a prior Hadad-Bassagasteguy flap (HBF) along with a using small piece of free autologous mucosa to reconstruct the skull base. Of 69 patients, fitted criteria were assigned into 2 different groups: a recycled HBF incorporated with an autologous free mucosa and a recycled HBF incorporated with an artificial dura to rebuild the skull base in secondary transsphenoidal surgery. The postoperative morbidities of pseudomeningocele, CSF leakage and meningitis were recorded and analyzed. A recycled HBF incorporated with an autologous mucosa is capable of reducing CSF complications compared to that of the matched group, particularly decreasing the morbidity of meningitis in secondary transsphenoidal surgery. Diabetes mellitus, craniopharyngioma, chordoma and the utilization of artificial dura were independent risk factors for CSF complications in secondary transsphenoidal surgery through univariate and multivariate logistic regression. In addition, diabetes mellitus and artificial dura are more likely to induce CSF leakage and meningitis. Patients suffering from craniopharyngioma are more susceptible to meningitis. Chordoma indiscriminately increased the risk of each CSF complication. A recycled HBF incorporated with an autologous mucosa is reliable for reconstructing the skull base in secondary transsphenoidal surgery, especially for patients simultaneously suffering from diabetes mellitus and central skull basetumors.

Surgical Techniques and Functional Reconstruction for Complex Tenosynovial Giant Cell Tumor of Temporal Bone and Middle Skull Base.

Objectives: Temporal tenosynovial giant cell tumors (TGCTs) are often large and have invaded the middle skull base. It is difficult to protect the important neurovascular structures around the tumor and perform functional reconstruction on the basis of complete tumor resection. This study aimed at analyzing the surgical techniques and functional reconstruction during the operation of complex TGCT of temporal bone and middle skull base. Methods: Five patients with pathologically confirmed TGCT of different complex types in the temporal bone and middle skull base were treated in our hospital from December 2020 to February 2023. We collected and retrospectively analyzed their medical records, including medical imaging, surgical procedures, and follow-up data. Results: The tumors invaded beyond the temporal bone and destroyed the middle skull base in all cases, involving the intracranial space and other important neurovascular structures. The internal carotid artery, infratemporal fossa, pterygopalatine fossa, and parapharyngeal space were also involved in 1 case. All the patients' tumors were completely removed, and the operations were performed mainly via modified infratemporal fossa approach, or combined with expanded middle cranial fossa approach. All cases with temporal and skull base destruction were repaired using the temporalis muscle flap with no occurrence of intracranial complications. The dura mater, condyle of temporomandibular joint, facial nerve, and internal carotid artery were fully preserved. Normal maxillofacial morphology was also preserved. The air conductive hearing of 2 patients was preserved. Conclusions: We found and summarized some surgical techniques that can help safeguard the important structures around massive TGCTs of temporal bone and middle skull base, and reconstruct the defects after tumor resection. The techniques are effective and feasible.

Quality of Life in Patients With Benign Lateral Skull Base Neoplasms Following Infratemporal Fossa Approaches.

Objectives: Infratemporal fossa approaches (IFAs) allow the total resection of certain lateral skull base neoplasms. To date, no studies have explored the change of patient-reported quality of life (QoL) after total resection of benign lateral skull base neoplasms through IFA. The present study aimed to give a comprehensive understanding of QoL among patients after IFA through general and disease-specific QoL questionnaires. Methods: Forty-seven patients with benign lateral skull base neoplasms were enrolled. The Short Form 36 (SF-36), World Health Organization Quality of Life-BREF (WHOQOL-BREF), and the University of Washington Head and Neck Quality of Life (UW-QOL) were chosen as tools to assess QoL before and after surgeries through IFA. Results: Patients had significantly lower scores in appearance, chewing, and speech after surgeries through IFA. However, change in health from SF-36 and physical health from WHOQOL-BREF scored higher after surgery. In multivariate linear regression analysis, age, gender, mood, speech, appearance, swallowing, and chewing contributed independently to general QoL. Conclusion: Patients were shown to benefit with regard to overall QoL after gross tumor resection from IFA, despite the impact of appearance, speech, and chewing. Function preservation and restoration are critical since their correlation with postoperative QoL.

Complications of the Superior Eyelid Endoscopic Transorbital Approach to the Skull Base: Preliminary Experience With Specific Focus on Orbital Outcome.

The endoscopic superior eyelid approach is a relatively novel mini-invasive technique that is currently investigating for skull base cancers. However, questions remain regarding specific approach-related complications when treating different skull base tumors. This study aims to analyze any surgical complications that occurred in our preliminary consecutive experience, with specific focus on orbital outcome. A retrospective and consecutive cohort of patients treated via a superior eyelid endoscopic transorbital approach at the Division of Neurosurgery of the Hospital Clinic in Barcelona was analyzed. Patients features were described in detail. Complications were divided into 2 groups to analyze separately the approach-related complications, and those resulting from tumor removal. The ocular complications were subdivided into early ocular status (<3 weeks), late ocular status (3-8 weeks), and persistent ocular complications. The "Park questionnaire" was used to determine patient's satisfaction related to the transorbital approach. A total of 20 patients (5 spheno-orbital meningiomas, 1 intradiploic Meningioma, 2 intraconal lesions, 1 temporal pole lesion, 2 trigeminal schwannoma, 3 cavernous sinus lesions, and 6 petroclival lesions) were included in the period 2017-2022. Regarding early ocular status, upper eyelid edema was detected in all cases (100%) associated with diplopia in the lateral gaze in 30% of cases, and periorbital edema in 15% of cases. These aspects tend to resolve at late ocular follow-up (3-8 weeks) in most cases. Regarding persistent ocular complications, in one case of intraconal lesion, a limitation of eye abduction was detected (5%). In another patient with intraconal lesion, an ocular neuropathic pain was reported (5%). In 2 cases of petroclival menigioma, who were also treated with a ventriculo-peritoneal shunt, slight enophthalmus was observed as a persistent complication (10%). According to the Park questionnaire, no cosmetic complaints, no head pain, no palpable cranial irregularities, and no limited mouth opening were reported, and an average of 89% of general satisfaction was encountered. The superior eyelid endoscopic transorbital approach is a safe and satisfactory technique for a diversity of skull base tumors. At late follow-up, upper eyelid edema, diplopia, and periorbital edema tend to resolve. Persistent ocular complications are more frequent after treating intraconal lesions. Enophthalmus may occur in patients with associated ventriculo-peritoneal shunt. According to patient's satisfaction, fairly acceptable results are attained.

Cone Beam CT Features and Oral Radiologist's Decision-making of Arrested Pneumatization of the Sphenoid Sinus.

To assess the demographic and radiographic features of arrested pneumatization of the sphenoid sinus (APS) and their influence on the confidence of oral and maxillofacial radiologists (OMFRs) in diagnosing APS. Reports of cone beam computed tomography (CBCT) APS were retrieved, and the demographic and radiographic features were retrospectively analyzed. Five OMFRs assessed the CBCT images and their confidence in diagnosing APS. The OMFRs' experience (years), expertise (skull-base CBCT cases/month) and diagnostic confidence level were analyzed for agreement and associations with demographic or radiographic features. Of 29 APS cases, 17 (58.6%) were females, and the mean age was 29.9±19 years. Twenty cases (69.0%) presented unilaterally, and 27 (93.1%) involved the sphenoid body. The most common accessory site was the pterygoid process (19, 65.5%). The vidian canal and foramen rotundum were involved in 27 (93.1%) and 17 (58.6%) cases, respectively. Most cases (28, 96.6%) were well-defined, corticated, and showed mixed attenuation. APS diagnostic confidence was higher among the expert OMFRs (72.4%-82.8% vs. 58.6%-62.1%). Radiographic features differentiating APS from skull-base tumors were shown on CBCT. The confidence of OMFRs with similar experience in years depended on their frequency of examining CBCT cases involving the skull base.

Quantification of Fat Graft Retention in the Translabyrinthine Approach Using Magnetic Resonance Imaging Volumetric Analysis.

To characterize the viability and volume of autologous free fat grafts over time, determine clinical/patient factors that may affect free fat graft survival and assess the clinical impact of free fat graft survival on patient outcomes in the translabyrinthine approach for lateral skull base tumor resection. Retrospective chart review. Tertiary neurotologic referral center. Forty-two adult patients who underwent translabyrinthine craniotomy for resection of a lateral skull base tumor with the mastoid defect filled by autologous abdominal fat graft and subsequently underwent more than one postoperative magnetic resonance imaging (MRI) scans of the brain. Mastoid obliteration with abdominal fat after craniotomy, postoperative MRI. Rate of fat graft volume loss, fraction retention of original fat graft volume, initial fat graft volume, time to steady-state fat graft retention, rate of postoperative cerebrospinal fluid (CSF) leak, and/or pseudomeningocele formation. Patients were followed postoperatively with MRI for a mean of 31.6 months with a mean of 3.2 postoperative MRIs per patient. Initial graft size was a mean of 18.7 cm3 with a steady-state fat graft retention of 35.5%. Steady-state graft retention (<5% loss per year) was achieved at a mean of 24.96 months postoperatively. No significant association was found in multivariate regression analysis of clinical factors impact on fat graft retention and CSF leak/pseudomeningocele formation. In the use of autologous abdominal free fat graft for filling mastoid defects after translabyrinthine craniotomy, there is a logarithmic decline in fat graft volume over time, reaching steady state in 2 years. Rates of CSF leak or pseudomeningocele formation were not significantly affected by initial volume of the fat graft, rate of fat graft resorption, nor the fraction of original fat graft volume at steady state. In addition, no analyzed clinical factors significantly influenced fat graft retention over time.

Expanded Endoscopic Endonasal Surgery for Skull Base Tumors

With the development of endoscopic and surgical instruments, expanded endoscopic endonasal surgery for skull base tumors has been widely performed. Compared with conventional microscopic transsphenoidal surgery, endoscopic surgery provides a wider view and clearer images, owing to the introduction of a high-resolution camera. However, for safe and reliable surgery, it is necessary to create an appropriate surgical field and avoid complications. This article discusses the basic knowledge needed for expanded endoscopic endonasal surgery, focusing on surgical anatomy and techniques and how to close the skull base completely.

Dosimetric Comparison of Between Multileaf and Fixed Cone Collimator Plans with Cyberknife-M6 in the Benign Skull Base Tumors

Dosimetric Comparison of Between Multileaf and Fixed Cone Collimator Plans with Cyberknife-M6 in the Benign Skull Base Tumors

Endoscopic Extended Transsphenoidal Surgery Aiming for Radical Resection of Skull Base Tumors Involving Cavernous Sinus: Assessment of Resectability and Risks of Complications.

Surgical resection of tumors invading the cavernous sinus (CS) still shows therapeutic challenges. For "nonadenomatous" skull base tumors invading in CS, there were only a few reports showing the outcomes of radical resection. Therefore, the outcomes of endoscopic transsphenoidal surgery (ETS) aiming for radical resection thus remain largely unknown regarding resectability and functional results of the cranial nerves. We performed ETS aiming for radical resection in 35 skull base tumors involving CS (17 chondrosarcomas, 12 chordomas, 3 meningiomas, and 3 trigeminal schwannomas; median follow-up 36.5 months ranging from 12 to 91 months). Gross total resection (GTR) is attempted in all the cases for real-time findings from electrophysiological monitoring of the cranial nerves. When the tumor was strongly adherent to the cranial nerves or internal carotid artery, maximum volume reduction of the tumor was attempted. GTR was achieved in 28 patients (80.0%), subtotal resection in 3 (8.6%), and partial resection in 4 (11.4%). One patient experienced internal carotid artery injury during surgery. After ETS, 15 patients showed symptom improvement (51.7% in all 29 patients with preoperative cranial nerve symptoms, CNS). Four (11.4%) transiently developed abducens nerve palsy, and one required repair surgery for cerebrospinal leakage. In univariate analyses, extension to the lateral compartment of CS ( P = .04) was significantly associated with reduced achievement of GTR. Previous transcranial surgery was associated with reduced possibility of improvement and worsening in CNS. Eleven patients underwent stereotactic radiosurgery, at a median of 12 months after ETS. 32 patients (91.4%) did not show recurrence at the final follow-up. ETS can achieve sufficient surgical resection in most of the patients, with acceptable neurological complications. For patients with CNS, ETS may offer the opportunity for improving CNS. We should also always prioritize avoidance of critical situations by preventing internal carotid artery injury.