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

BackgroundMicrosurgical Transcranial approach (mTCA) is the primary choice for the resection of giant Tuberculum Sellae Meningiomas (TSM). The objective of this study is to explore surgical details of unilateral subfrontal approach.MethodsTen patients with giant TSM treated by unilateral subfrontal approach were included from January 2018 to June 2021. Demographic characteristics, surgical data, post-procedure complications and outcomes of patients have been descriptive analyzed, combined with systematic literature review to explore the surgical details and the prognosis of unilateral subfrontal approach.ResultsTen patients include six male and four females, age range from 35 to 77 years, duration of visual impairment from 1 to 12 months, were all performed unilateral subfrontal approach. Nine patients achieved radical resection (Simpson grades I-II) through post-operative imaging confirmation, and Simpson IV resection was performed in the remaining one due to cavernous sinus invasion. The postoperative visual acuity was improved or maintained in 8 patients. Visual acuity decreased in 2 cases, including 1 case of optic nerve atrophy and the other case of optic canal not opening. Five cases with frontal sinus opened were repaired during the operation and there was no postoperative cerebrospinal fluid leakage or intracranial infection. One patient suffered from postoperative anosmia, one patient developed left limb weakness, but their symptoms have improved in the follow-up.ConclusionSummarize the experience of our center and previous literature, unilateral forehead bottom craniotomy is a feasible surgical approach for giant tuberculum sellae meningioma. Intraoperative application of EC glue and pedicled fascia flap to repair the frontal sinus can prevent complications associated with frontal sinus opening. Optic canal unroofing has huge advantage in visual improvement.

Outcome of Sellar and Suprasellar Brain Tumors with Retractorless Modified Subfrontal Approach

Aim: To determine the outcome of sellar and suprasellar brain tumors with retractorless modified subfrontal approach. Study design: Descriptive/observational study Place and duration of study: Department of Neurosurgery, Liaquat University Hospital Hyderabad/Jamshoro from 1st March 2020 to 28th February 2021. Methodology: Fifty patients of sellar and suprasellar brain tumors age between 15-70 years were enrolled. Patients details demographics age, sex and body mass index were recorded after taking written consent. The inter-hemispheric front-basal technique was used for all patients and the average follow-up time was 6 months. Postoperatively, magnetic resonance imaging (MRI) and computerized tomography (CT) scans in all patients were performed. After 12 hours, the postoperative CT scan was performed to monitor for persistent tumor and hemorrhage cerebral edema following an operation. Results: There were 30 (60%) male patients and 20 (40%) female patients. Mean age of the patients were 28.36±14.88 years with mean BMI 23.16±7.54 kg/m2. Most of the patients 20(40%) were from age group 15-30 years, followed by 31-40 years in 12 (24%) patients. Frequency of pituitary adenoma was found in 22 (44%) cases, craniopharyngioma found in 19 (38.7%) cases, arachnoid cyst found in 4 (8%), keratin flakes in 2 (4%) cases, benign giant cell tumor found in 2 (4%)olfactory groove meningioma in 1 (2%) and epidermoid in 1 (2%) cases. Post operatively 35 (70%) patients were completely recovered, complications found in 13 (26%) patients who were recovered later and frequency of not recovered patients was 2 (4%). According to Karnofsky performance, 16 (32%) patients had scale 30, scale 60 was in 2 (4%) cases, scale 70 in 4 (8%) patients, scale 80 in 19 (38%) and scale 90 in 9 (18%). Conclusion: This retractorless method is very effective and safe in the sellar and suprasellar region for excision of big tumors. This method allows the huge tumor to be removed without serious complication. Keywords: Sub-frontal approach, Sellar, Suprasellar, Brain tumor, Retractorless method

Charles H. Frazier’s craniopharyngioma treatment: the pivotal role of the transfrontal approach

Charles H. Frazier (1870–1936), one of the pioneers of neurosurgery in the US, is known worldwide for devising surgical procedures to relieve trigeminal neuralgia and intractable pain. Less well-known are his substantial contributions to understanding and treating pituitary and parahypophyseal lesions. Along with Bernard Alpers, he defined Rathke’s cleft tumors as a different pathological entity from adenomas and hypophyseal stalk tumors (craniopharyngiomas [CPs]). The surgical challenge posed by CPs piqued Frazier’s interest in these lesions, although he never published a complete account of his CP series. An examination of the Charles Frazier papers at the College of Physicians of Philadelphia allowed the authors to identify 54 CPs that he had treated during his career. In the early 1910s, Frazier developed the subfrontal approach, which would become the primary surgical route to access these lesions, providing better control of the adjacent vital neurovascular structures than the transsphenoidal route hitherto used. Nevertheless, strong adhesions between CPs and the third ventricle floor, the major reason underlying Frazier’s disappointing results, moved him to advocate incomplete tumor removal followed by radiotherapy to reduce both the risk of hypothalamic injury and CP recurrence. This conservative strategy remains a judicious treatment for CPs to this day.

Midline Meningiomas of the Anterior Skull Base: Surgical Outcomes and a Decision-Making Algorithm for Classic Skull Base Approaches

(1) Background: Midline meningiomas such as olfactory groove (OGMs), planum sphenoidale (PSMs), or tuberculum sellae meningiomas (TSMs) are challenging, and determining the appropriate approach is important. We propose a decision algorithm for choosing suitable transcranial approaches. (2) Methods: A retrospective chart review between 06/2007 and 01/2020. Clinical outcomes, radiographic findings, and postoperative complication rates were analyzed with respect to operative approaches. (3) Results: We included 88 patients in the analysis. Of these, 18.2% (16/88) underwent an interhemispheric approach, 72.7% (64/88) underwent a pterional/frontolateral/supraorbital approach, 2.3% (2/88) underwent a unilateral subfrontal approach, and 6.8% (6/88) underwent a bifrontal approach. All OGMs underwent median approaches, along with one PSM. All of the other PSMs and TSMs were resected via lateral approaches. The preoperative tumor volume was ∅20.2 ± 27.1 cm3. Median approaches had significantly higher tumor volume but also higher rates of Simpson I resection (75.0% vs. 34.4%). An improvement of visual deficits was observed in 34.1% (30/88). The adverse event rate was 17.0%. Median follow-up was 15.5 months (range 0–112 months). (4) Conclusions: Median approaches provides satisfying results for OGMs, lateral approaches enable sufficient exposure of the visual apparatus for PSMs and TSMs. In proposing a simple decision-making algorithm, the authors found that satisfactory outcomes can be achieved for midline meningiomas.

A RARE CASE OF NEUROENTERIC CYST INVOLVING THE ANTERIOR FOSSA; REPORT OF A CASE AND REVIEW OF LITERATURE

Neuroenteric cysts, are rare benign endodermal lesions which mostly occur in the central nervous system. We report a case of a neuroenteric cyst in a 30-year-old man who presented with rhinoliquorrhea at the ENT department. After clinical examination, a semisolid mass was revealed in the left nostril. The Computer Tomography Scan revealed a frontal ethmoidal nasal meningoencephalocele with inferior extension into the left nostril. Gadolinium-enhanced T1-weighted MR images showed a well-defined frontal mass with ring-like enhancement and extension into the cribriform plate of the ethmoid bone and into the left nostril. The lesion measured 10/10/20 mm. The tumor was totally resected using a unilateral subfrontal approach. At five months’ follow-up, the patient showed significant amelioration of symptoms and remission of cerebrospinal fluid leakage. Native and Contrast-enhanced Cerebral Computer Tomography, as well as Magnetic Resonance Imaging showed total surgical resection of the cyst. Supratentorial neurenteric cysts involving the anterior fossa are rare. Intracranial neurenteric cysts should be differentiated by any well-demarcated cystic tumors. The gold standard treatment remains complete surgical resection with favorable outcome.

Anatomical Variations in the Location of Veins Draining Into the Anterior Superior Sagittal Sinus: Implications for the Transbasal Approach

BACKGROUND Many approaches are used for midline anterior cranial fossa meningioma resection. In the subfrontal approach, the anterior superior sagittal sinus (SSS) is commonly ligated to release the anterior falx. The transbasal approach allows access to the origin of the anterior SSS, allowing for maximum venous preservation. OBJECTIVE To investigate variations in the first and second veins draining into the SSS. METHODS We performed stepwise dissections for a transbasal level 1 approach on 8 anatomic specimens. We visualized the first and second veins draining into the sinus and measured the distance from the foramen cecum to these veins. We also measured the orbital bar height to determine the length of sagittal sinus that could be preserved with orbital bar removal. RESULTS The distance between the foramen cecum and the first vein ranged from 4 to 36 mm while the distance to the second vein ranged from 6 to 48 mm. The mean orbital bar height was 26.4 mm. Based on these measurements, with a traditional bicoronal craniotomy without orbital bar removal, 81% of first veins and 58% of second veins would be sacrificed. CONCLUSION A supraorbital bar or nasofrontal osteotomy, part of the transbasal skull base approach, is helpful to preserve the first and second veins when ligating the anterior SSS. Based on this study, it may be difficult to preserve these veins without orbital bar removal. Preservation of these veins may be of clinical importance when approaching midline anterior fossa pathologies.

Anatomical Predictors of Transcranial Surgical Access to the Suprasellar Space

Objective The suprasellar space is a common location for intracranial lesions. The position of the optic chiasm (prefixed vs. postfixed) results in variable sizes of operative corridors and is thus important to identify when choosing a surgical approach to this region. In this study, we aim to identify relationships between suprasellar anatomy and external cranial metrics to guide in preoperative planning. Methods T2-weighted magnetic resonance images (MRIs) from 50 patients (25 males and 25 females) were analyzed. Various intracranial and extracranial metrics were measured. Statistical analysis was performed to determine any associations between metrics. Results Interoptic space (IOS) size correlated with interpupillary distance (IPD; a = 7.3, 95% confidence interval [CI] = 4.5–10.0, R 2 = 0.3708, p = 0.0009). IOS size also correlated with fixation of the optic chiasm, for prefixed chiasms (n = 7), the mean IOS is 205.14 mm2, for normal chiasm position (n = 33) the mean IOS is 216.94 mm2 and for postfixed chiasms (n = 10) the mean IOS is 236.20 mm2 (p = 0.002). IPD correlates with optic nerve distance (OND; p = 0.1534). Cranial index does not predict OND, IPD, or IOS. Conclusion This study provides insight into relationships between intracranial structures and extracranial metrics. This is the first study to describe a statistically significant correlation between IPD and IOS. Surgical approach can be guided in part by the size of the IOS and its correlates. Particularly small intraoptic space may guide the surgeon away from a subfrontal approach.