Atypical meningiomas compared to other WHO Grade 2 meningiomas: Histological features and prognosis.

OBJECTIVES: To study each atypical feature in atypical meningioma versus other grade 2 meningiomas and its possible relation to recurrence. METHODS: This is a retrospective study of patients with WHO grade 2 meningioma operated in our institution between 01/2008 and 12/2020. The rate of recurrence, reoperation and readmission were recorded during the follow-up period. A statistical analysis was done to determine the significance of each pathological feature in regard to recurrence. RESULTS: A total of 74 patients were included as WHO grade 2 meningioma with 60 (81%) patients having an AM and 14 (19%) patients with chordoid or clear cell meningioma. The mean age was 51 years±14. The most common location was meningioma abutting the frontal lobe (convexity). Major atypical features were more noted in the AM, however, there was no significant difference between AM and other types of meningioma. Increased Nuclear cytoplasmic ratio and cellularity were found significantly more in AM. The recurrence rate was 16.2%. No specific pathology feature (major or minor) nor the type of Grade 2 meningioma was significantly related to recurrence. CONCLUSION: The types of WHO grade 2 meningiomas have similar prognosis and recurrence rates. There is no significant difference between the atypical features in indicating a more aggressive nature or risk of recurrence in grade 2 meningiomas.

A New Sarcoma Shortly after Treatment for High-Grade Glioma with Adjuvant Chemoradiation: A Case Report.

Introduction: High-grade gliomas are central nervous system tumors conventionally treated with surgery followed by adjuvant chemoradiotherapy. Secondary cancer due to radiation therapy is a rare yet established phenomenon that typically occurs years after radiation therapy. Case Presentation: In this case, we discuss an early presentation of a second cancer adjacent to the radiation field. This case report is of a 52-year-old male who developed a new scalp sarcoma at the site of primary surgery 8 months after radiation therapy. Genetic testing revealed a heterozygous missense variant in the NF1 gene, a variant of uncertain significance. The report highlights that this case does not conform to the expected criteria for postradiation sarcoma in terms of timing. Conclusion: Secondary cancers may arise earlier than expected, even in phenotypically normal patients, as they may have unmanifested variants of relevant mutations. The question of pre-radiotherapy screening for radiosensitivity syndromes and diseases requires further study, as current data are limited and do not provide enough insight into the significance of different genetic variants.

Early Displacement of Reconstruction Material is a Predictor of Cerebrospinal Fluid Leak Post Endoscopic Skull Base Surgery.

BACKGROUND: The reconstruction technique and materials used for endoscopic skull base surgery (ESBS) are important factors in preventing cerebrospinal fluid (CSF) leak, a notable complication following this surgery. Visualizing the status of reconstruction early in the postoperative course can help determine the risk of postoperative CSF leak. Here, we aimed to determine if the radiological status of reconstruction post endonasal endoscopic surgery can predict postoperative CSF leak. METHODS: This retrospective study included patients who had undergone ESBS between 2015 and 2020. An early computed tomography (CT) scan (obtained within 24 hours of surgery) was utilized to evaluate the reconstruction and postoperative radiological changes, and its findings were correlated with the occurrence of postoperative CSF leaks. RESULTS: Our study included 11 (12.7%) out of 86 patients with CSF leaks. The type of reconstruction, construction material, and type of nasal packing were not identified as significant risk factors for CSF leaks. The location of the fat graft (placed properly vs. displaced out of the surgical cavity) was significantly associated with CSF leak (P = 0.001). All patients with a displaced solid reconstruction (n = 5), displaced septal flap (n = 6), signs of air continuation (n = 2), or significantly increased amount of air (n = 5) presented with a CSF leak (P < 0.001). CONCLUSIONS: Early postoperative CT scan is predictive of CSF leak. Displacement of the fat graft in early postoperative CT was the most important factor in predicting CSF leak. In this patient group, paying attention to radiological predictors of CSF leaks is important, supported by clinical findings.

A Prospective Comparison Between Soft Tissue Dissection Techniques in Pterional Craniotomy: Functional, Radiological, and Aesthetic Outcomes.

BACKGROUND AND OBJECTIVES: Given the complex anatomy of the operative region and individual surgeon preferences, some techniques for soft tissue dissection before pterional craniotomy have gained more popularity than others. This prospective study used subjective and objective measurements to compare the functional, radiological, and aesthetic outcomes of 3 such dissection techniques. METHODS: This multicenter prospective cohort study included all patients who underwent elective pterional craniotomy between 2018 and 2020 at 3 centers in Riyadh, Saudi Arabia. All patients underwent 1 of 3 soft tissue dissection techniques: myocutaneous flap, interfascial, and subfascial dissection techniques. Clinical and radiological assessments were performed upon discharge and at the 3- and 6-month follow-ups. RESULTS: We included 78 patients, with a mean age of 44.9 ± 16.3 years. Myocutaneous flap, interfascial, and subfascial dissections were performed in 34 (43%), 24 (30%), and 20 patients (25%), respectively. The myocutaneous flap method had the shortest opening ( P = .001) and closure ( P = .005) times; tenderness was more evident in this group than in the others ( P = .05). The frontalis muscle was most affected in the interfascial dissection group ( P = .05). The frontalis nerve function was similar in all groups after 6 months ( P = .54). The incidence of temporomandibular joint dysfunction was highest in the myocutaneous flap group (29%). Decreased temporalis muscle thickness at the 6-month postoperative follow-up was most severe in the subfascial dissection group (12.6%), followed by the myocutaneous flap (11.9%) and interfascial dissection (9.9%) groups, with no significant difference ( P = .85). Temporal hollowing was more prominent in the myocutaneous flap group ( P = .03). Cosmetic satisfaction was highest in the interfascial dissection group, with no significant difference ( P = .4). CONCLUSION: This study provides important information for neurosurgeons in weighing the benefits and risks of each technique for their patients.

Impact of Concurrent Chronic Rhinosinusitis on Complication Rates after Endonasal Endoscopic Skull Base Surgery: A Single-Center Experience.

Objectives Preoperative planning of endoscopic skull base surgery (ESBS) is essential. The safety of performing surgery before managing sinus pathologies including concurrent chronic rhinosinusitis (CRS) in patients undergoing ESBS has been questioned. The current study aimed to evaluate and compare the complication rates between patients with and without CRS undergoing ESBS. Design This is a retrospective study. Setting Present study was conducted at tertiary referral center. Participants We included all patients who underwent ESBS between March 2015 and March 2021. However, patients who had surgical revision for remnant tumor, primary sinonasal tumor excision, and cerebrospinal fluid (CSF) leakage repair were excluded. The presence of concurrent CRS was determined according to the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (EPOS 2020) criteria by reviewing electronic charts about the preoperative clinical assessment and CT scan images of the paranasal sinuses. Then, the incidence rates of postoperative meningitis, CSF leakage, and surgical site infection were compared between patients with and without concurrent CRS undergoing ESBS. Main Outcome Measures Postoperative complication rates in patients underwent ESBS with and without CRS. Results From a total of 130 ESBS cases, 99 patients were included in this study. Among them, 24 had concurrent CRS. One patient presented with postoperative meningitis, one with CSF leakage, and two with surgical site infections. The incidence rate of postoperative meningitis, CSF leakage, and surgical site infection did not significantly differ between patients with and without concurrent CRS. Conclusion Concurrent CRS is not a contraindication for ESBS. Moreover, simultaneous endoscopic sinus surgery can safely be performed without additional morbidity in ESBS.

Outcomes and complications of microscopic transcallosal colloid cyst resection: A single institution experience.

Background: Colloid cysts have always provoked the interest of neurosurgeons due to their benign histology, wide variety of clinical presentations, and differences in reported surgical outcomes. Although recent studies have reported favorable outcomes with different surgical resection approaches, the transcallosal approach remains the most popular approach to date. In this series, we report the clinical and radiological outcomes of the transcallosal approach for the resection of third ventricle colloid cysts in 12 patients. Methods: We present a case series of 12 patients who were radiologically diagnosed with a third ventricle colloid cyst who underwent transcallosal resection by a single surgeon in one center over a 6-year period. Clinical, radiological, and surgical data were collected, and surgical outcomes and complications were analyzed. Results: Of the 12 patients diagnosed with colloid cysts, 10 (83%) presented with headache, and five (41%) presented with memory disturbance. All 12 patients showed improvement or resolution of their symptoms following resection. Nine patients (75%) presented with hydrocephalus on radiology. All the patients required preoperative or intraoperative external ventricular drain insertion. Four patients (33%) experienced transient postoperative complications. None of the patients required long-term cerebrospinal fluids shunting. One (8%) of 12 patients experienced transient memory loss. No mortality was recorded during the follow-up. Conclusion: Transcallosal resection of colloid cysts has a favorable prognosis. It allows for complete resection of the cyst with minimal transient postoperative complications. Most patients with postoperative complications show complete resolution of symptoms, with no long-term morbidity.

Early Postoperative Computed Tomography Scan Air Distribution Predicts Postoperative CSF Leak in Endoscopic Skull Base Surgery.

BACKGROUND: Cerebrospinal fluid (CSF) leak remains the primary concern of endoscopic skull base surgery (ESBS). Pneumocephalus seen in postoperative images has been linked to CSF leak in some reports; however, few studies have looked at the extent to which it is indicative of CSF leak. In the current study, we aim to examine the size and location of post-ESBS pneumocephalus in the early postoperative period and determine their association with postoperative CSF leak. METHODS: Patients undergoing ESBS in a 5-year period were included. All patients underwent brain computed tomography scan within the first 24 postoperative hours. Computed tomography scans were reviewed by a neurosurgeon and a radiologist and have been classified based on the size and location of pneumocephalus. Patients were followed in the postoperative period for clinical signs of CSF leak and managed accordingly. RESULTS: Out of 120 patients, 86 patients met the inclusion criteria. Thirty-five patients (41%) had no pneumocephalus on day one postoperative imaging, while 51 patients (59%) had pneumocephalus with different sizes and distributions. Eleven of 86 patients developed CSF leak. Of the 11 patients, 5 patients (45%) had grade 4 pneumocephalus (P value = 0.02). Patients with multiple locations of pneumocephalus were more likely to develop CSF leak (P value = 0.01). CONCLUSIONS: In post-ESBS patients, both the volume and location of the pneumocephalus are potentially predictive of CSF leak. In patients with a larger volume of intra-axial air and/or multiple air locations, an impending CSF leak should be anticipated.

Classification of Endoscopic Transnasal Lateral Skull Base Approaches: Anatomical Study.

OBJECTIVE: Endoscopic transnasal approaches (ETAs) to the ventrolateral skull base are commonly classified according to coronal planes or anatomical structures. Our goal is to simplify the description of the ETA to lateral skull base regions in a sequential dissection with correlation to computed tomography, helping in preoperative planning and efficient surgical exposure, and exposing the surgical anatomy limitations. METHODS: Five freshly injected cadaver heads were dissected using an extended ETA to the lateral skull base. Each specimen underwent a high-resolution computed tomography scan. A classification of the lateral skull base based on well-defined zones was proposed. RESULTS: We divided the lateral target into four different zones, in a craniocaudal orientation: zone 1 is the space lying between the orbital floor superior and the level of the sellar floor inferior, zone 2 is on the coronal plane, located between the level of the sellar floor and the vidian canal, zone 3 is the area lateral to the anterior limb of the petro-occipital fissure, located between the vidian canal and the carotid canal, and zone 4 is the space located between the carotid canal and the extracranial opening of the hypoglossal canal, lateral to the anterior part of the posterior limb of petro-occipital fissure. CONCLUSIONS: Multiple previous works have described and classified the coronal plane and its lateral extensions. Our classification system for the proposed lateral zones enables preoperative planning to select a suitable approach. The craniocaudal orientation facilitates the understanding of surgical corridors and tailored exposure.

The 100 Most Cited Articles in Endoscopic Endonasal Skull Base Surgery: A Bibliometric Analysis.

BACKGROUND: The accelerated growth of endoscopic endonasal skull base surgery has led to an abundance of highly cited works that have helped shape the field into its current state. Highlighting these works can serve as a guide for trainees and facilitate evidence-based clinical decision making and operative techniques. METHODS: Elsevier's Scopus database was used to generate a list of the 100 most cited articles on endoscopic endonasal skull base surgery in September 2022. Results were categorized based on pathology, approach, study design, and study objective. A citation per year analysis was conducted to highlight later publications that may not have had the time to accumulate as many citations as older publications. RESULTS: The average number of citations for the 100 most cited articles was 210 per article (range 104-1285). Publication dates ranged from 1997 to 2019, with the highest number of articles among the 100 most cited being published in 2008 (15 articles). The journal with the greatest number of publications was Neurosurgery (30 articles). Of the 100 most cited articles, 77 were published between 2000 and 2010. Moreover, 40 of the 100 articles reported surgical outcomes and related complications, and the most common pathology was pituitary adenoma (25 articles). CONCLUSIONS: This article provides a list of highly influential articles in the field of endoscopic endonasal skull base surgery, highlighting its rapid evolution over the last 3 decades and demonstrating its leap from small descriptive series confined to certain pathologies to larger cohorts exploring possible boundaries and other pathologies.

Ultrasound Elastography in Neurosurgery: Current Applications and Future Perspectives.

BACKGROUND: Similar to clinical palpation, Ultrasound elastography (USE) helps distinguish between tissues by providing information on their elasticity. While it has been widely explored and has been applied to many body organs, USE has not been studied as extensively for application in neurosurgery. The current systematic review was performed to identify articles related to the use of interoperative USE in neurosurgery. METHODS: Search included MEDLINE(R) database. Only original peer-reviewed full-text articles were included. No language or publication year restrictions were imposed. Two independent reviewers assessed the search results for relevance. The identified articles were screened by title, abstract, and full-text review. RESULTS: Seventeen articles were included in the qualitative analysis and 13 articles were related to oncology, epilepsy (n = 3), and spine (n = 1). In oncology, USE was found useful in defining tumor stiffness, aiding surgical planning, detecting residual tumors, discriminating between tumor and brain tissue, and differentiating between different tumors. In epilepsy, USE could improve the detection of epileptogenic foci, thereby enhancing the prospect of complete and safe resection. The application in spinal surgery was limited to demonstrating that a compressed spinal cord is stiffer than the decompressed one. CONCLUSIONS: USE was found to be a safe, quick, portable, and economic tool that was a useful intraoperative adjunct to provide information corresponding to a variety of neurosurgical diseases, at different stages of surgery. This review describes the current intraoperative neurosurgical applications of USE, the concept of elasticity, and different USE modalities as well as the technical challenges, limitations, and possible future implications.

Graft-Extended Nasoseptal Flap for Endoscopic Anterior Skull Base Reconstruction: A Novel Technique.

Reconstruction of the anterior part of the anterior skull base with a nasoseptal flap (NSF) is technically demanding. This challenge is mainly related to the real possible length of the flap. Herein, we describe a new technique for extending the NSF such that it can sufficiently cover the far anterior part of the anterior skull base. Three cadaveric heads were used for mucosal graft extension of the NSF. The graft was harvested from the other side, sutured to the NSF, then repositioned over the skull base after opening all the paranasal sinuses. Each head was operated by a rhinologist and a skull base surgeon. The study variables were the initial length of the NSF, the length of the graft harvested, the new length of the graft-extended NSF, and the length of the new graft-extended NSF from the nasal spine. The average length of the NSFs was 6.4 cm (± 0.2); that of the harvested grafts was 2.93 cm (± 0.1); that of the graft-extended NSF was 9.33 cm (± 0.4); and that of the graft-extended NSF from the nasal spine was 3.93 cm. The graft-extended NSF is an easy and extremely useful technique for the reconstruction of the far anterior parts of the skull base. However, further prospective studies on the clinical usefulness of this technique and its long-term results are yet to be performed. Level of evidence: IV.

Modified retrosigmoid extended approach to jugular tubercle meningioma: A video abstract.

Background: Primary jugular fossa meningiomas are one of the rarest subgroups of meningioma, with an estimated incidence of 0.7-4.3% of all skull base meningiomas. Indeed, only 145 cases of jugular foramen meningiomas have been reported in the literature to date. While meningiomas of this region are typically referred to as "jugular foramen meningiomas," we make a distinction between meningiomas arising directly from the foramen itself, and those arising from the jugular tubercle. Jugular tubercle meningiomas, therefore, represent an even smaller subset of an already uncommon location for meningiomas. The jugular tubercle is the upper surface of the lateral parts of occipital bone presents an oval eminence, which overlies the hypoglossal canal and is sometimes crossed by an oblique groove for the glossopharyngeal, vagus, and accessory nerves. Only eight cases in the anterior foramen magnum lesions excised by a far lateral retrosigmoid approach have been described. The aim of this video article is to describe the surgical approach the senior author used to access lesion involving the jugular tubercle. Case Description: In this surgical video, we present a case of a 56-year-old female presented to our hospital with dizziness, headache, lower cranial nerves deficits, and lower limbs weakness. On exam, she was noted to have a left paraparesis, 9th, 10th, and 11th nerves palsies. An MRI scan demonstrated a mass in the region of the left jugular tubercle. Frozen section was suggestive of meningioma and our patient underwent a successful near total resection with no permanent neurologic sequelae. Conclusion: Jugular tubercle meningiomas are one of the rarest subgroups of meningioma. The described modified retrosigmoid approach provides outstanding access to the entire ventrolateral brainstem and cerebellopontine angle, with reduced approach related morbidity.

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

BACKGROUND: Recently, endoscopic endonasal approaches (EEA) have been used for skull base defect reconstruction surgeries. The nasoseptal flap (NSF), a vascular pedicled flap, was introduced to decrease postoperative cerebrospinal fluid (CSF) leakage. PURPOSES: This study aimed to outline the authors' institutional experience using NSF and rigid implants in anterior skull base defect reconstruction surgeries following EEA. DESIGN: A retrospective cohort review of patients who underwent NSF reconstruction following EEA in the Otorhinolaryngology and Neurosurgery Departments at King Saud University Medical City, Riyadh, Saudi Arabia, from January 2015 to May 2021, divided into 2 time periods according to the reconstruction technique. RESULT: Out of the 106 patients who underwent EEA, 77 underwent NSF reconstruction. The majority had expanded EEA (94.8%). The mean age was 40.21 ± 17.7 years, and the female gender represented 61% of the sample. More than half of the sample underwent right NSF (57.1%). Meningioma was the most common diagnosis (45.5%). The clivus was the most frequent site of lesions (23.4%). The overall rate of postoperative CSF leakage and lumbar drainage (LD) insertion was 15.6% and 51.9%, respectively. The duration of LD was a median of four days. The overall failure rate was 13%, declining from 20% in the first period to 5.4% in the second period. Rigid implants were used significantly more in the first period than in the second period (67.5% versus 16.2%, P < 0.001). Meningitis, the highest postoperative complication, was reported in 6 patients (7.8%). One patient died three weeks postoperatively after massive nasal bleeding. No significant difference was found between either side of the NFS regarding the CSF leakage and failure rate. CONCLUSION: In the authors' experience, there has been an overt decline in failure rates and complications of EEA over the last three years due to increased experience among surgeons and a standardization of reconstruction techniques. Minimal reconstruction may provide satisfactory results by decreasing the use of rigid implants. An endoscopic endonasal approach with an NSF for anterior skull base defect reconstruction is considered a safe procedure with no significant difference between the sides of the flap.

Extent of Nasal Irrigation in Non-operated Sinuses: A Cadaveric Trial.

BACKGROUND: Nasal irrigation is among the most widely used treatment modalities for sinonasal diseases. The extent of irrigation is well studied in operated sinuses but not for non-operated sinuses. Moreover, the preferred head positioning during irrigation is not known. Herein, we studied the extent of nasal irrigation in cadaveric heads with non-operated sinuses. METHODS: Nine cadaveric heads were used. Normal saline solution mixed with radiological contrast material was used to irrigate the nasal cavities with the heads in 2 different positions: standing-leaning-forward (SLF) and Head-down forward (HDF). After each irrigation, computed tomography images of the head were acquired. The extent of irrigation was assessed for each subunit of the sinonasal cavity. RESULTS: Irrigation was performed twice on a total of 18 sides, each time in 1 position. Nine subunits were evaluated: inferior, middle, and superior meati; the olfactory cleft; and the frontal, maxillary, anterior, and posterior ethmoid and sphenoid sinuses. The extent of irrigation was significantly better in the HDF position for the olfactory cleft (100% vs 33%), P-value=.001, frontal sinus (33% vs 11%), P-value=.002, maxillary sinus (78% vs 17%), P-value=.001, and anterior ethmoid sinus (89% vs 17%), P-value=.001. There was no significant difference in the extent of irrigation between the 2 positions for the other evaluated subunits. The overall extent of irrigation was 70.37% of the subunits in HDF position and 45.06% of the subunits for SLF position, P-value= .001. CONCLUSIONS: Nasal irrigation reached the cavities of non-operated paranasal sinuses. However, while the extent of irrigation was limited in the SLF, it was well achieved in the HDF position. Studies on the clinical efficacy of irrigation in this position are recommended.

Otogenic Pneumocephalus After Tegmen Bone Reconstruction: A Case Report.

Pneumocephalus is usually induced by trauma, infections, tumors of the skull base, and surgical interventions. Spontaneous pneumocephalus occurs due to a defect in the temporal bone with no obvious cause. Few cases have been reported with spontaneous otogenic pneumocephalus. However, delayed postoperative pneumocephalus is rarely reported in the literature. Here, we present a case of otogenic pneumocephalus through Eustachian tube (ET) preceded by nose blowing 10 days after surgical treatment of meningoencephalocele of the right middle ear (ME) cleft and reconstruction of tegmen and dural defects. Pneumocephalus was provoked by decreased intracranial pressure (ICP) secondary to placement of lumbar drain, which caused direct communication between unsutured dural defect and the defective posterior wall of external auditory canal skin. A revision surgery of combined transmastoid/middle cranial fossa approach was performed for intracranial decompression followed by appropriate closure by suturing the dura, obliterating the ET and ME.

Alveolar Soft-Part Sarcoma in Olfactory Cleft: A Case Report and Clinicopathological Review.

Sinonasal alveolar soft-part sarcoma (ASPS) is a rare malignant disease that comprises 0.4% to 1.2% of all soft-tissue sarcomas. Alveolar soft-part sarcoma is usually difficult to diagnose because it has many clinical and pathological mimickers. In this case study, ASPS occurred in the olfactory cleft, representing the second case in this location in the literature. This article presents the clinical presentation, radiologic, and histopathological case, and reviews the literature regarding the differentials.

Persistence of communicating hydrocephalus post choroid plexus tumor resection: Case reports and review of literature.

BACKGROUND: Hydrocephalus is the most common presentation of choroid plexus tumors; it is thought to be caused either by mass effect obstructing the cerebrospinal fluid pathways or secretory properties of the tumor. In these case reports, we present two cases of choroid plexus tumors with persistence of communicating hydrocephalus postoperatively and review similar reports in the literature. CASE DESCRIPTION: Case 1: a 2-month-old baby girl presented with bulging fontanelle, sunsetting eyes. Magnetic resonance imaging (MRI) showed large third ventricle mass with communicating hydrocephalus. She underwent complete excision of tumor through transcortical approach with perioperative intraventricular hemorrhage. Hydrocephalus persisted postoperatively and the patient required permanent ventriculoperitoneal (VP) shunt. Case 2: a 16-year-old boy presented decreased visual acuity, papilledema, and morning headaches. MRI showed a tumor in the right ventricle and communicating hydrocephalus. He underwent transparietal resection of the tumor. In both cases, hydrocephalus persisted postoperatively and patients required permanent VP shunt. Review of similar cases showed the majority of cases required permanent shunting. CONCLUSION: Choroid plexus tumor patients can present with communicating hydrocephalus that may persist post tumor resection for different etiologies. Careful follow-up to determine the need for cerebrospinal fluid diversion through a permanent VP shunt is important.

Endoscopic Transnasal Resection of Midline Skull Base Meningiomas: Tumor Consistency and Surgical Outcomes.

Background The endoscopic transnasal approach (ETA) has proven to be of great value in the resection of midline skull base meningiomas when compared with traditional approaches. Our objective was to assess tumor consistency in relation to surgical outcomes for midline meningiomas (MMs) resected using ETA. Methods Radiological preoperative features, including the tumor to cerebellar peduncle T2-weighted magnetic resonance imaging (MRI) ratio (TCTI), were evaluated. The intraoperative consistency assessment was performed by the surgeon, which determined if the tumor was soft (resectable by suction) or firm (required a cavitation ultrasonic aspirator). Surgical resection and postoperative complications were evaluated in relation to tumor consistency. Results Twenty patients were evaluated; 6 were classified as firm and 14 were classified as soft. The mean TCTI ratio was 1.7 and the median was 1.7 (range: 1.3-2.4). Three firm tumors had a ratio of <1.6. All soft tumors had a ratio of ≥1.6 with three outliers. Additionally, 66.7% of patients with firm tumors had complications compared with 35.7% of patients with soft tumors. Only 33.3% of firm tumors underwent gross total resection (GTR) in comparison to 79.0% of tumors with a soft consistency. Conclusion In our analysis, we found that tumor consistency was significantly related to short-term surgical outcomes in MMs resected using the ETA. The TCTI ratio was found to be the most reliable predictor with a sensitivity of 76.9% and a specificity of 40.0%. Our findings suggest that traditional cranial approaches should be considered as the first surgical option for managing firm MMs.

Effects of compressive lesions on intraoperative human spinal cord elasticity.

OBJECTIVE: Although evaluating tissue elasticity has various clinical applications, spinal cord elasticity (SCE) in humans has never been well documented. In this study, the authors aimed to evaluate the impact of compression on human SCE in vivo. METHODS: The authors prospectively assessed SCE using intraoperative shear wave elastography (SWE). All consecutive patients undergoing spinal cord (SC) decompression (laminectomy or corpectomy) between June 2018 and June 2019 were included. After intraoperative exposure of the patient's dura mater, at least three SWE measurements of the SC and its coverings were performed. Intraoperative neurological monitoring in the form of motor and somatosensory evoked potentials was utilized. Cases were divided into two groups based on the state of SC compression following bone removal (laminectomy or corpectomy): patients with adequate decompression (the decompressed SC group [DCG]) following bone removal and patients with remining compression, e.g., compressing tumor or instability (the compressed SC group [COG]). RESULTS: A total of 25 patients were included (8 females and 17 males) with a mean age of 48.28 ± 21.47 years. Most cases were degenerative diseases (10 cases) followed by tumors (6 cases), and the compression was observed at cervical (n = 14), thoracic (n = 9), and conus medullaris (n = 2) levels. The COG (6 cases) expressed significantly higher elasticity values, i.e., greater stiffness (median 93.84, IQR 75.27-121.75 kPa) than the decompressed SC in DCG (median 9.35, IQR 6.95-11.22 kPa, p < 0.001). Similarly, the compressed dura mater in the COG was significantly stiffer (mean ± SD 121.83 ± 70.63 kPa) than that in the DCG (29.78 ± 18.31 kPa, p = 0.042). Following SC decompression in COG, SCE values were significantly reduced (p = 0.006; adjusted for multiple comparisons). Intraoperative monitoring demonstrated no worsening from the baseline. CONCLUSIONS: The current study is to the authors' knowledge the first to quantitatively demonstrate increased stiffness (i.e., elasticity value) of the human SC and dura mater in response to external compression in vivo. It appears that SCE is a dynamic phenomenon and is reduced following decompression. Moreover, the evaluation of human SCE using the SWE technique is feasible and safe. Information from future studies aiming to further define SCE could be valuable in the early and accurate diagnosis of the compressed SC.