NCOG-30. AWAKE CRANIOTOMY FOR MENINGIOMA RESECTION: A STUDY ON THE SAFETY AND TOLERABILITY

Resection of intra-axial brain tumors under scalp block improves safety of surgery, permitting preservation of neurological function and early recovery. However, limited data is available on employing this anesthesia technique for extra-axial tumors particularly meningioma, raising concerns that it may not be feasible due to dural attachment of tumor causing intractable pain and discomfort. We retrospectively analyzed 17 patients who underwent AC for resection of meningioma at our hospital during last 5 years, employing non-probability consecutive sampling. Variables for demographics, and details of diagnosis and surgical procedure were recorded. Eleven of these cases had grade I meningioma, and 6 had grade II meningioma. The mean age of these patients was 45.8 ± 10.5 years. Seizures were the most common presenting complain (n = 7; 41.2%). Eleven patients (58.3%) had convexity meningioma, 4 (33.3%) had parasagittal meningioma and 1 each had a parafalcine and anterior skull-base meningioma. The mean duration of surgery was 180.8 ± 36.2 minutes and the median estimated blood loss was 450 ml (IQR: 225 ml – 737.5 ml). The mean length of stay in the hospital was 3.1 ± 1.3 days. Only 1 patient had a prolonged hospital stay of 7 days because of post-operative seizures. Simpson grade I resection was performed in 6 (41.7%) patients, and grade II resection in 10 (50%) patients. Deterioration in pre-operative neurological exam was not seen in any patient, and no one required emergency intubation, conversion of surgery to general anesthesia, or re-operations. We propose that AC does not pose any significant risk of intra-operative or post-operative pain during meningioma resection, particularly convexity and parasagittal meningioma, and can make surgery possible for patients who are high risk for, or are not willing to undergo general anesthesia.

Case report: Rare convexity meningeal chondroma mimicking a meningioma

Background: Intracranial chondromas account for 0.2–0.3% of all intracranial neoplastic lesions and less than a quarter arise in the convexity or falx. Despite its benign nature, exceedingly rare malignant transformations exist. The misdiagnosis with meningiomas is frequent and may be related with chondromas’ similar insidious clinical presentation and imaging features. Standalone surgery is advised and complete resection provides the definitive treatment. Case Description: A 44-year-old female presents with insidious headache, visual disturbances, and papilledema. The imaging studies were compatible with frontal parasagittal meningioma. Surgery revealed a meningeal based mass, mostly avascular and with a well-demarked surgical plane from the brain parenchyma. Complete resection with meningeal margins was achieved and the histopathologic examination revealed a chondroma. The patient symptoms subsided and no surgical complications existed. Conclusion: Intracranial convexity chondromas constitute a rare differential diagnosis for meningiomas. The present case reinforces the current scarce data and serves as reminder for clinicians diagnosing and treating intracranial tumors.

Bilateral central retinal artery occlusion: An exceptional complication after frontal parasagittal meningioma resection

Background: Central retinal artery occlusion (CRAO) is a rare acute disease associated with great morbidity. It is reported as a complication of surgical procedures, but rarely associated with brain surgery and no reports before due to parasagittal meningioma resection. Case Description: We present the case of a 41-year-old female who underwent surgery for a parasagittal meningioma and developed a bilateral CRAO as an acute postoperative complication. Most common causes, such as cardiac embolism, carotid pathology and coagulation problems, were discussed and all clinical and neuroradiological exams performed were reported. Conclusion: Bilateral CRAO as results of brain surgery is extremely rare; however, if it occurs, it should be early recognized and treated to minimize its high morbidity.

Infection of a sylvian Galassi II arachnoid cyst after craniotomy for resection of a parasagittal meningioma

Arachnoid cysts are CSF-containing entities that rarely are symptomatic or warrant neurosurgical intervention. In addition, infection of these lesions is an even rarer event, with only four reports in the literature capturing this. In this report, we present the case of a 79-year-old man presenting with paraparesis, secondary to a right parasagittal meningioma, with an incidental asymptomatic right sylvian arachnoid cyst (Galassi type II). The initially planned surgery was postponed for 3 months, due to COVID-19 restrictions, and he was kept on high dose of steroids. Following tumour resection, the patient developed bilateral subdural empyemas with involvement of the arachnoid cyst, requiring bilateral craniotomies for evacuation of the empyemas and drainage of the arachnoid cyst. Suppuration of central nervous system arachnoid cysts is a very rare complication following cranial surgery with the main working hypotheses including direct inoculation from surrounding inflamed meninges or haematogenous spread secondary to systemic bacteraemia, potentiated by steroid-induced immunosuppression. Even though being a rarity, infection of arachnoid cysts should be considered in immunosuppressed patients in the presence of risk factors such as previous craniotomy.

Resection of Giant Invasive Parasagittal Atypical Meningioma With a Venous Graft Reconstruction of the Sagittal Sinus: 2-Dimensional Operative Video

Parasagittal meningioma becomes challenging when it involves the sagittal sinus and frequently invades the skull1; hence, resection of the invasive bone and management of the involved sinus are the two crucial issues in these tumors; notwithstanding the practice of conservative surgical resection coupled with irradiation (radiosurgery or stereotactic radiotherapy),2 radical surgical removal, including the invaded bone and sinus (Simpson grade I), alleviates recurrences. It is more valuable and particularly recommended in grade II meningiomas,3 since radical surgery is the principal factor in a long control of grade II meningioma4 and radiation effectiveness is directly related to gross total removal.5 On the other hand, removal of tumor involving the sinus and sinus reconstruction has been recommended and practiced for years.6-10 When the sinus is occluded, preservation of the collateral venous drainage becomes paramount.11 If the collateral venous drainage included cutaneous and dural channels, as in this patient, reconstructing of the sinus would become preventative of a major venous complication. Sindou et al8 even advocate the routine reconstruction of occluded sinus to minimize morbidity. The patient is 39 yr old with a giant parasagittal meningioma that invaded the skull, occluded the sinus at the mid-third, and had venous collateral through the dura and cutaneous veins. He underwent radical resection with reconstruction of the sinus by saphenous vein graft. Patient consented for the operation and publication of images. Illustrations at 1:51 and 2:15 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997, with permission.

Association between tumor size and peritumoral brain edema in patients with convexity and parasagittal meningiomas

Background and purpose Peritumoral brain edema (PTBE) is a common complication in meningioma and disruption of the tumor-brain barrier in meningioma is crucial for PTBE formation. To evaluate the association between meningioma size and PTBE, we measured meningioma volumes using the 3D slicer in patients with convexity and parasagittal meningiomas. Methods Receiver operating characteristic curve analysis was used to determine the optimal cut-off meningioma volume values for predicting PTBE occurrence. Logistic regressions were used to estimate the odds ratios for PTBE occurrence in patients with convexity and parasagittal meningiomas according to several predictive factors. Results A total of 205 convexity or parasagittal meningioma patients with no other brain disease who underwent one or more contrast-enhanced brain MRIs were enrolled in this 10-year analysis in two hospitals. The optimal cut-off meningioma volume value for prediction of PTBE in all study patients was 13.953 cc (sensitivity = 76.1%; specificity = 92.5%). If a meningioma is assumed to be a complete sphere, 13.953 cc is about 2.987 cm in diameter. Conclusions Our study suggests a cut-off value of 3 cm meningioma diameter for prediction of PTBE in patients with convexity and parasagittal meningiomas. We believe that we have revealed why the meningioma diameter of 3 cm is clinically meaningful.

Reasons for Diagnostic Delay of Foot Drop Caused by Parasagittal Meningioma: Two Case Reports

Foot drop is defined as an impaired ability or inability of dorsiflexion. Peripheral nervous system injuries are commonly considered as the cause of this condition. The central causes including parasagittal meningioma are also described in the literature but very rarely and commonly not recognized early. In this article, we report 2 patients with isolated unilateral foot drop as the first symptom of a parasagittal meningioma and discuss several reasons for delayed diagnosis. Two patients were treated with decompressive craniotomy. The histopathological findings demonstrated a fibroblastic meningioma and a meningothelial meningioma. During postoperative follow-up, the woman patient showed nearly complete recovery and the second case regained total muscle power over a period of 12 months. The rarity of the disease, the absence of upper motor neuron signs, the occurrence of peripheral pathologies and misinterpretation of F wave on nerve conduction study, and motor unit recruitment on electromyography lead to delay in diagnosis and treatment of the central foot drop due to parasagittal meningioma.

A rare appearance of the trigeminocardiac reflex during resection of posterior parasagittal meningioma

Background: Although a well-recognized phenomenon of the tentorium and posterior fossa, the trigeminocardiac reflex (TCR) has been rarely reported during surgery involving the posterior falx cerebri. Case Description: We present the case of a 63-year-old woman who underwent repeat resection of an atypical parasagittal meningioma involving the posterior falx. During resection, TCR was repeatedly elicited during manipulation and coagulation of the falx. Air embolism and cardiac etiologies were initially considered while TCR was not suspected, given the location. Ultimately, TCR was recognized when asystole self-resolved upon cessation of stimulus and due to its reproducibility. Conclusion: Awareness by the anesthesiologist and neurosurgeon of the possibility of TCR during falcine procedures can help with rapid identification to avoid a potentially catastrophic outcome.

Application of Computer-aided Image Reconstruction and Image Guild in Parasagittal Meningioma Resection

BackgroundIn recent years, due to increased cranial imaging more and more small sized (diameter <2.5cm) meningiomas are diagnosed. If symptomatic then most of them need surgical removal. Exact location of the lesion is extremely important to tailor the craniotomy especially if the neuro-navigation system is not available. Many under developed countries cannot afford high costs of neuro-navigation. Hence, is relevant to discover low cost associated and effective methods to exactly locate the lesions for the surgery.MethodsBy using localization markers, we can acquire preoperative CT images of the patients, reconstruct these images into Three Dimensional (3D) virtual graphs using a computer, measure the spatial distance of the tumor from the markers, and in turn calculate the projection location of the tumor on the scalp by the Triangle Pythagorean theorem. Thereby achieving preoperative precise localization of intracranial microlesions.ResultsThe location of the tumor was consistent with that of the preoperative virtual image, and the craniotomy was exact. The patient was discharged 3 days later without any neurological deficits.ConclusionThis method is simple and reliable, inexpensive, and accurate in location of small sized lesion, which can partially compensate lack of neuro-navigationand is suitable for widespread application in hospitals in third world countries.