Skull base surgery for benign skull base tumors

Predictors of operative ischemic cerebrovascular complications in skull base tumor resections: Experience in low-resource setting

Background

Ischemic cerebrovascular complications following skull base tumor resections remain a significant factor impacting both short-term and long-term patient outcomes. This study aims to improve risk stratification, surgical decision-making, and postoperative care protocols.

Methods

A retrospective cohort study on predictors of ischemic cerebrovascular complications among patients who underwent skull base tumor resection was conducted at 2 high-volume neurosurgical centers in Ethiopia from 2018 to 2023. Binary logistic analysis was performed to see the association of each predictor variable.

Results

The study included 266 patients, with 65.5% being female. The median age and tumor size were 37 (± IQR = 17) years and 4.9 cm (± IQR 1.5), respectively. Ischemic cerebrovascular complications occurred in 19.9% of patients. Middle cranial fossa tumors and tumors spanning both anterior and middle cranial fossa (AOR = 6.75, 95% CI: 1.66-27.54, P < .008), grades 3-5 vascular encasement (AOR = 5.04, 95% CI: 1.79-14.12, P < .002), near-total resection and gross total resection (AOR = 2.89, 95% CI: 1.01-8.24, P < .048), and difficult hemostasis (AOR = 9.37, 95% CI: 3.19-27.52, P < .000) were significantly associated with iatrogenic vascular injury. Subarachnoid hemorrhage had a statistically significant association with vasospasm (AOR = 12.27, 95% CI: 1.99-75.37, P = .007).

Conclusions

Surgery-related ischemic cerebrovascular complications are common. Thorough perioperative risk stratification and proactive treatment planning are crucial to mitigate vascular insults associated with it. In low-resource settings, neurosurgical services are provided without advanced instruments, leading to more complications. Therefore, it is important to focus on improving neurosurgical setup to enhance patient outcomes.

Gruppo Otologico's Experience in Managing the So-Called Inoperable Tympanojugular Paraganglioma

Objective: to identify advanced or "so-called inoperable" cases of tympanojugular paragangliomas (PGLs) and analyze how each case is surgically managed and followed afterward. Study Design: a retrospective case series study. Methods: Out of 262 type C and D TJPs and more than 10 cases of advanced or so-called inoperable cases, files of 6 patients with a diagnosis of advanced tympanojugular PGLs who were referred to an otology and skull-base center between 1996 and 2021 were reviewed to analyze management and surgical outcomes. The criteria for choosing these cases involve having one or more of the following features: (1) a large-sized tumor; (2) a single ipsilateral internal carotid artery (ICA); (3) involvement of the vertebral artery; (4) a considerable involvement of the ICA; (5) an extension to the clivus, foramen magnum, and cavernous sinus; (6) large intradural involvement (IDE); and (7) bilateral or multiple PGLs. Results: The age range at presentation was 25-43 years old, with a mean of 40.5 years: two females and four males. The presenting symptoms were glossal atrophy, hearing loss, pulsatile tinnitus, dysphonia, shoulder weakness, and diplopia. The modified Infratemporal Fossa Approach (ITFA) with a transcondylar-transtubercular extension is the principal approach in most cases, with additional approaches being used accordingly. Conclusions: The contemporary introduction of carotid artery stenting with the direct and indirect embolization of PGLs has made it possible to operate on many cases, which was otherwise considered impossible to treat surgically. Generally, the key is to stage the removal of the tumor in multiple stages during the management of complex PGLs to decrease surgical morbidities. A crucial aspect is to centralize the treatment of PGLs in referral centers with experienced surgeons who are trained to plan the stages and manage possible surgical complications.

Preservation of cranial nerve function in large and giant trigeminal schwannoma resection: a case series

BACKGROUND

Trigeminal schwannomas (TSs) are intracranial tumors that can cause significant brainstem compression. TS resection can be challenging because of the risk of new neurologic and cranial nerve deficits, especially with large (≥ 3 cm) or giant (≥ 4 cm) TSs. As prior surgical series include TSs of all sizes, we herein present our clinical experience treating large and giant TSs via microsurgical resection.

METHODS

This was a retrospective, single-surgeon case series of adult patients with large or giant TSs treated with microsurgery in 2012-2023.

RESULTS

Seven patients underwent microsurgical resection for TSs (1 large, 6 giant; 4 males; mean age 39 ± 14 years). Tumors were classified as type M (middle fossa in the interdural space; 1 case, 14%), type ME (middle fossa with extracranial extension; 3 cases, 43%), type MP (middle and posterior fossae; 2 cases, 29%), or type MPE (middle/posterior fossae and extracranial space; 1 case, 14%). Six patients were treated with a frontotemporal approach (combined with transmastoid craniotomy in the same sitting in one patient and a delayed transmaxillary approach in another), and one patient was treated using an orbitofrontotemporal approach. Gross total resection was achieved in 5 cases (2 near-total resections). Five patients had preoperative facial numbness, and 6 had immediate postoperative facial numbness, including two with worsened or new symptoms. Two patients (28%) demonstrated new non-trigeminal cranial nerve deficits over mean follow-up of 22 months. Overall, 80% of patients with preoperative facial numbness and 83% with facial numbness at any point experienced improvement or resolution during their postoperative course. All patients with preoperative or new postoperative non-trigeminal tumor-related cranial nerve deficits (4/4) experienced improvement or resolution on follow-up. One patient experienced tumor recurrence that has been managed conservatively.

CONCLUSIONS

Microsurgical resection of large or giant TSs can be performed with low morbidity and excellent long-term cranial nerve function.

Management principles of cranial base tumor with aneurysm

Skull base tumors are challenging to treat because of their deep location, complex anatomy, and close proximity to important blood vessels and nerves. Furthermore, some patients with cranial tumors are found to have aneurysms, but there is no consensus on how to evaluate the impact of aneurysms on surgery and how to handle the lesions safely and effectively. We retrospectively reviewed our database to identify all patients with a skull base tumor treated in the Department of Neurosurgery of Beijing Tiantan Hospital affiliated with Capital Medical University from 2019 to 2021. The records of patients with skull base tumors associated with aneurysms were analyzed. The operative methods and postoperative follow-up information were collected. We analyzed a total of 481 patients with skull base tumors, comprising 224 males and 257 females with a mean age of 48 ± 14 years. Twenty-four patients (24/481, 5.0%) were diagnosed with aneurysms. For eight patients, it was considered necessary to perform aneurysm treatment before or during the tumor resection surgery. For the other 16 patients, the recommendation was to monitor the aneurysm or perform elective aneurysm treatment after tumor resection. All patients with both skull base tumors and aneurysms benefited from treatment. No severe postoperative complications occurred. We summarized the final treatment plan for all patients with skull base tumors with aneurysms and proposed a protocol to decrease the surgical risk of patients with skull base tumors associated with aneurysms.

Spheno-Orbital Meningiomas: A 16-Year Surgical Experience

OBJECTIVE

To examine the efficacy of spheno-orbital meningioma (SOM) resection aimed at symptomatic improvement, rather than gross total resection, followed by radiation therapy for recurrence.

METHODS

A retrospective review of all patients having undergone resection between 2000 and 2016 was performed. Demographics, operative details, postoperative outcomes, recurrence rates, and radiation treatment plans were analyzed. Statistical analysis was performed to assess for factors affecting recurrence (Fisher exact and Student t test), changes in exophthalmos index (EI) (Student t test), and progression-free survival (Kaplan-Meier and log rank).

RESULTS

Twenty-five patients were included; 92% of participants were women. Mean age was 51 years. World Health Organization grades were I (n = 21) and II (n = 4). Simpson grades were I (n = 14), II (n = 3), and IV (n = 8). Mean follow-up time was 44.8 months. Proptosis was significantly improved at the 3- to 6-month postoperative visit (mean ΔEI, 0.15; P < 0.05) and at last follow-up (mean ΔEI, 0.13; P < 0.05). Visual acuity was either improved or stable in 18 of 19 patients. There were 12 recurrences; mean time to recurrence was 21.8 months. Increased recurrence rate was significantly associated with younger age. Eight patients received fractionated radiation at time of recurrence. To date, all treated patients are progression free.

CONCLUSIONS

Among this cohort, surgery provided a lasting improvement in proptosis and improved or stabilized visual deficits. Surgery followed by radiation at recurrence provided excellent tumor control and lends credence to the growing body of literature demonstrating effective control of subtotally resected skull base meningiomas.

5-Aminolevulinic acid-induced protoporphyrin IX fluorescence in meningioma: qualitative and quantitative measurements in vivo

BACKGROUND

The use of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence has shown promise as a surgical adjunct for maximizing the extent of surgical resection in gliomas. To date, the clinical utility of 5-ALA in meningiomas is not fully understood, with most descriptive studies using qualitative approaches to 5-ALA-PpIX.

OBJECTIVE

To assess the diagnostic performance of 5-ALA-PpIX fluorescence during surgical resection of meningioma.

METHODS

ALA was administered to 15 patients with meningioma undergoing PpIX fluorescence-guided surgery at our institution. At various points during the procedure, the surgeon performed qualitative, visual assessments of fluorescence by using the surgical microscope, followed by a quantitative fluorescence measurement by using an intraoperative probe. Specimens were collected at each point for subsequent neuropathological analysis. Clustered data analysis of variance was used to ascertain a difference between groups, and receiver operating characteristic analyses were performed to assess diagnostic capabilities.

RESULTS

Red-pink fluorescence was observed in 80% (12/15) of patients, with visible fluorescence generally demonstrating a strong, homogenous character. Quantitative fluorescence measured diagnostically significant PpIX concentrations (cPpIx) in both visibly and nonvisibly fluorescent tissues, with significantly higher cPpIx in both visibly fluorescent (P < .001) and tumor tissue (P = .002). Receiver operating characteristic analyses also showed diagnostic accuracies up to 90% for differentiating tumor from normal dura.

CONCLUSION

ALA-induced PpIX fluorescence guidance is a potential and promising adjunct in accurately detecting neoplastic tissue during meningioma resective surgery. These results suggest a broader reach for PpIX as a biomarker for meningiomas than was previously noted in the literature.

Magnetic resonance-guided focused ultrasound: a new technology for clinical neurosciences

Transcranial MRI-guided focused ultrasound (TcMRgFUS) is an old idea but a new technology that may change the entire clinical field of the neurosciences. TcMRgFUS has no cumulative effect, and it is applicable for repeatable treatments, controlled by real-time dosimetry, and capable of immediate tissue destruction. Most importantly, it has extremely accurate targeting and constant monitoring. It is potentially more precise than proton beam therapy and definitely more cost effective. Neuro-oncology may be the most promising area of future TcMRgFUS applications.

Combined cranionasal surgery for spheno-orbital meningiomas invading the paranasal sinuses, pterygopalatine, and infratemporal fossa

OBJECTIVE

To evaluate the efficacy of combining an endonasal endoscopic skull-base approach and repair with a transcranial orbitozygomatic approach for spheno-orbital meningiomas (SOMs).

METHODS

Three patients with recurrent SOMs underwent combined orbitozygomatic and endonasal endoscopic surgery. In 2 patients both procedures were done in 1 operation and in 1 patient the endonasal surgery was done 2.5 months after the craniotomy. Extent of resection, complications, morbidity, and mortality were evaluated.

RESULTS

Gross total resection was achieved in 1 patient and near total resection in the other 2 patients with tumor left in the cavernous sinus and parapharyngeal space. Two patients suffered cranial neuropathy from the transcranial surgery and the other developed a pseudomeningocele. There were no complications from the endonasal surgery. Patients having combined single setting cranionasal surgery were discharged on day 6 and 8, whereas the patient having only the endonasal component on a later date was discharged on day 2.

CONCLUSIONS

A combined cranionasal approach involving transcranial orbitozygomatic and endonasal endoscopic approaches is an effective 2-stage surgery for resecting SOMs invading into the sinuses and paranasal compartments. The ability to perform a multilayer closure involving a vascularized nasoseptal flap additionally decreases the risk of postoperative cerebrospinal fluid leak.

Assessment of antiangiogenic effect of imatinib mesylate on vestibular schwannoma tumors using in vivo corneal angiogenesis assay

Object

Angiogenesis and the platelet-derived growth factor (PDGF) pathway are active in the pathogenesis of vestibular schwannomas (VSs). The purpose of this study was to test whether imatinib mesylate (Gleevec), a PDGF receptor (PDGFR) blocker, reduces angiogenic capacity in sporadic VS and in VS associated with neurofibromatosis Type 2 (NF2) using a corneal angiogenesis assay.

Methods

From 121 VS tissue samples stored in the tumor bank at the Marmara University Institute of Neurological Sciences, 10 samples (6 from sporadic cases, 4 from NF2-associated cases) were selected at random for use in this study. Expression of PDGF-A and PDGF-B and their receptors was evaluated in sporadic and NF2-associated VS as well as in glioblastoma (GBM) and normal brain tissue by means of immunohistochemistry and Western blot analysis. Corneal angiogenesis assay was then used to evaluate the angiogenic capacity of tissue specimens from sporadic and NF2-associated VS with and without imatinib treatment as well as positive and negative controls (GBM and normal brain tissue).

Results

The angiogenic potential of the sporadic and NF2-associated VS tumor tissue differed significantly from that of the positive and negative control tissues (p <0.05). Furthermore, NF2-associated VS showed significantly lower angiogenic potential than sporadic VS (p <0.05). Imatinib treatment significantly reduced the angiogenic potential in both the sporadic VS and the NF2-associated VS groups. The level of PDGF-A and PDGFR-α as well as PDGF-B and PDGFR-β expression in sporadic VS and NF2-associated VS also differed significantly (p <0.05) from the levels in controls. Additionally the level of PDGFR-β was significantly higher in sporadic VS than in NF2-associated VS (p <0.05).

Conclusions

The findings of this study indicate that NF2-associated VS has significantly more angiogenic potential than sporadic VS and normal brain tissue. Additionally, imatinib reduces the angiogenic activity of both sporadic and NF2-associated VS. The authors conclude that imatinib may be a potential treatment for VS, especially for NF2-associated lesions that cannot be cured with resection or radiosurgery.

Quantitative and qualitative 5-aminolevulinic acid-induced protoporphyrin IX fluorescence in skull base meningiomas

OBJECT

Complete resection of skull base meningiomas provides patients with the best chance for a cure; however, surgery is frequently difficult given the proximity of lesions to vital structures, such as cranial nerves, major vessels, and venous sinuses. Accurate discrimination between tumor and normal tissue is crucial for optimal tumor resection. Qualitative assessment of protoporphyrin IX (PpIX) fluorescence following the exogenous administration of 5-aminolevulinic acid (ALA) has demonstrated utility in malignant glioma resection but limited use in meningiomas. Here the authors demonstrate the use of ALA-induced PpIX fluorescence guidance in resecting a skull base meningioma and elaborate on the advantages and disadvantages provided by both quantitative and qualitative fluorescence methodologies in skull base meningioma resection.

METHODS

A 52-year-old patient with a sphenoid wing WHO Grade I meningioma underwent tumor resection as part of an institutional review board-approved prospective study of fluorescence-guided resection. A surgical microscope modified for fluorescence imaging was used for the qualitative assessment of visible fluorescence, and an intraoperative probe for in situ fluorescence detection was utilized for quantitative measurements of PpIX. The authors assessed the detection capabilities of both the qualitative and quantitative fluorescence approaches.

RESULTS

The patient harboring a sphenoid wing meningioma with intraorbital extension underwent radical resection of the tumor with both visibly and nonvisibly fluorescent regions. The patient underwent a complete resection without any complications. Some areas of the tumor demonstrated visible fluorescence. The quantitative probe detected neoplastic tissue better than the qualitative modified surgical microscope. The intraoperative probe was particularly useful in areas that did not reveal visible fluorescence, and tissue from these areas was confirmed as tumor following histopathological analysis.

CONCLUSIONS

Fluorescence-guided resection may be a useful adjunct in the resection of skull base meningiomas. The use of a quantitative intraoperative probe to detect PpIX concentration allows more accurate determination of neoplastic tissue in meningiomas than visible fluorescence and is readily applicable in areas, such as the skull base, where complete resection is critical but difficult because of the vital structures surrounding the pathology.

Surgery for petroclival meningiomas: a comprehensive review of outcomes in the skull base surgery era

Skull base surgery has evolved to a point that its focus is now shifting to outcome analysis. To do so for petroclival meningiomas is difficult. The rarity of the tumor, different treatment philosophies, and variations in reporting complicate the outcome analysis. With this limitation in mind, we analyzed the literature on this disease and report the combined outcomes in a unified fashion in hopes that it will serve as a starting point for further prospective analysis. Data was extracted from all available reports on MEDLINE/PubMed published in English. All studies were retrospective and uncontrolled. The majority of studies represent the experience of a single surgeon at a single institution. Of the 19 studies with detailed demographic and outcome data, no data met criteria for meta-analysis. A total of 1000 patients were reported. The mean age of the patients was 50 years. The male to female ratio is 1:3. GTR (gross total resection) was reported in 49% of patients. Thirty-four percent of patients experienced some neurological deficit in the early postoperative period (<3 months). The most common morbidities reported were cranial nerve deficits (34.4% [range: 20 to 79%]) with facial nerve injury accounting for 19%, followed by motor deficits (14%), infection rates (1.6%), CSF leaks (5%), hemorrhage (1.2%), and hydrocephalus (1%). Death within 1 year of surgery was reported for 1.4% of patients. Once considered untreatable, petroclival meningiomas can now be approached relatively safely. There, however, still remains an ∼34% morbidity with the most common being cranial nerve. Despite this, >75% of patients return to independence at 1 year, many of which will resume employment. The nature of this study limits the conclusions that can be drawn; however, it provides some generalizations that may help guide patient questions regarding treatment outcomes.

Different microsurgical approaches to meningiomas of the anterior cranial base

INTRODUCTION

Meningiomas of the anterior skull base show specific characteristics, which render them difficult to handle. These tumors include olfactory groove, supra- and parasellar, anterior sphenoid ridge, cavernous sinus, and spheno-orbital meningiomas. Tumor localization and size, encasement of important structures as well as the extent of dural attachment may influence the decision for an adequate approach.

DISCUSSION

Various approaches to the anterior cranial fossa exist, each with corresponding advantages and disadvantages. Recently, endoscopic approaches have increasingly been used. In this review, the different approaches to meningiomas of the anterior cranial fossa in respect of anatomical issues, indications, and associated risks are discussed.

Microsurgical management of 53 jugular foramen schwannomas: lessons learned incorporated into a modified grading system

OBJECT

Due to the proximity and involvement of critical neurovascular structures, the resection of jugular foramen schwannomas can pose a formidable challenge. The authors review their experience in the microsurgical management of jugular foramen schwannomas and propose a modified grading scale to guide surgical management.

METHODS

All jugular foramen schwannoma cases treated by the senior author (T.F.) between 1980 and 2004 were retrospectively reviewed. The average age at presentation, surgical approach, tumor characteristics, cranial nerve (CN) deficits, and tumor recurrence rates were assessed. The authors present the following modified grading scale: Type A, intradural tumors; Type B, dumbbell-shaped tumors; and Type C, triple dumbbell tumors with a high cervical extension.

RESULTS

The authors treated jugular foramen tumors in 129 patients during the study period. Of these, 53 patients (41%) had jugular foramen schwannomas. The mean patient age was 52 years (range 14-74 years); there were 12 male and 41 female patients. The mean follow-up period was 8.4 years. Patients presented most commonly with deficits of the vagus nerve, followed by vestibular/cochlear nerve and glossopharyngeal nerve deficits. Gross-total resection of the tumor was achieved in 48 patients (90.5%). New postoperative paresis in a previously normal CN was not seen; however, worsening of preoperative CN deficits was frequently noted. The highest incidence occurred with the glossopharyngeal and vagus nerves (30%), with 26% of the deficits being permanent. There were no deaths related to surgery in this series. Three patients (5.7%) experienced tumor recurrence.

CONCLUSIONS

The microsurgical resection of jugular foramen schwannomas carries a risk of worsening preoperative CN deficits; however, these are often transient. Based on their experience, the authors have formulated a grading scale that predicts the optimal surgical approach to these lesions. Considerable technical training and microneuroanatomical knowledge of the region is required. The modified grading scale presented facilitates preoperative planning.