In this study, we compared the differences in short-term surgery outcomes between younger (<65 years old) and older patients (>65 of age) patients with middle third parasagittal and falx meningioma. The incidence of meningioma increases with age, with the peak incidence between the 6th and 7th decade of life . Our data suggested that the elderly have more comorbidities, including hypertension, diabetes mellitus, liver disease, renal disease, pulmonary disease, and cardiovascular disease, compared to the younger patients; however, the operative complication rate was similar in the two groups (P=0.97). Simultaneous tumors occurred in 5 younger patients, all females. One of them had uterine fibroid and osteoma on the left tibia, while the other four had uterine fibroid, renal clear cell carcinoma, thyroid carcinoma, and glioblastoma, respectively. Multiple primary brain tumors with different histological types occurring in the same patient are extremely rare, and only a few such cases have been reported thus far [14, 15]. Tunthanathip reported 6 cases of simultaneous multiple, primary brain tumors, predominantly in aging patients. In this study, one patient (a 55-year-old woman) presented with meningioma and glioblastoma.
Large meningiomas (>5 cm) were likely to occur in elderly patients, accounting for nearly 32.56% (14/43) as compared to 20.63% (13/63) in the younger group (P=0.013). Large meningiomas usually arise in an area of maximal brain compliance . Cerebral atrophy facilitates maximal brain compliance in aging patients, and the symptoms do not appear until the lesion oppresses the central cortex. Furthermore, aged Chinese individuals tend to refuse to see the doctor before their health worsens due to the fear of discovering additional health problems. Some studies showed that the size of this neoplasm is indicative of the factors of fear and denial that occur in many patients, thereby delaying detection and therapy [17, 18].
A previous study that investigated 42 patients with primary intracranial meningioma of all locations found preoperative peritumoral edema in 47.6% of patients >65 years old . Our subgroup analyses demonstrated that giant intracranial meningioma invades the vital neurovascular structures and causes severe peritumoral edema. Furthermore, giant meningioma patients revealed severe peritumoral edema incidence rate than patients with medium and tiny meningioma. Severe edema was not detected in patients with tiny meningioma. In a study of 80 giant intracranial meningiomas, only 12.5% (n=10) cases revealed severe peritumoral edema . The 80 lesions were localized at the skull base (n=57), convexity (n=17), and falx/parasagittal (n=6). Thus, we deduced that giant intracranial meningioma located at the middle third parasagittal and falx meningioma in elderly patients would have the highest frequency of severe peritumoral edema than any other subgroup.
Histological subtypes are related to peritumoral edema. Herein, we compared the postoperative peritumoral edema based on histological subtypes. We discovered that peritumoral edema was significantly larger in patients with grade II and III meningiomas than grade I meningiomas. The elderly patients showed severe peritumoral edema base on the histological grade. In a study of 240 cases, Ressel et al reached a similar conclusion . However, the study diagnosed 26.1% (n=29) of the elderly cases as grade II and grade III meningioma at any intracranial site. On the other hand, in the current study, only 13.95% of the aging patients with middle third parasagittal and falx meningioma were diagnosed as grade II and grade III meningioma. This discrepancy indicated that middle third parasagittal and falx are not likely to be involved in grade II and grade III meningioma as compared to other locations.
Rapid advances in neurosurgical techniques and perioperative care have improved safety and reduced tumor resection-related mortality. However, parasagittal and falx meningioma resections remain a challenging task for neurosurgeons worldwide. So far, many different neurosurgical techniques have been applied [6, 21-26]. Karthigeyan et al used a modified unilateral approach to resect mid-third giant bilateral falcine meningiomas . In order to minimize any potential surgery-induced damage, the study chose the side of the non-dominant hemisphere to create a surgical window. Furthermore, the tumors were excised through an oblique anterior or a posterior trajectory instead of directly working over the major draining veins and eloquent brain. In a previous study, we utilized this approach to resect deep and tiny falx meningioma. Neuronavigation has been widely applied in neurosurgery [27, 28]. Bir et al  analyzed 517 cases of meningiomas and concluded that interactive surgical navigation is a useful tool in the operative management of intracranial meningiomas; it can decrease the recurrence rate, blood loss, and length of stay and improve the RFS and performance status. In addition, neuronavigation should be used for small (<2 cm) and deep tumor falx meningioma, or else it would be rather time-consuming to seek out the tumor, thereby causing substantial damage to the brain. All tiny meningiomas were completely resected. In the current study, neuronavigation was applied in most patients as adjuncts to microsurgical tumor resection, and all the tiny meningioma were resected. There was no difference between the two groups according to the neuronavigation application (P=0.775). We proposed that giant parasagittal can be easily identified by the neurosurgeons through anatomical markers rather than the assistance of neuronavigation. Giant meningiomas often have a wide basement on the falcine, increasing the difficulty of radical resection. Despite the large size, the tumors could be successfully removed from the unilateral side .
Operative blood loss is a critical parameter for evaluating the surgical effect. Surprisingly, in the current study, the blood loss was substantial in the younger group, which could be attributed to the wide surgical field and fewer vessels destroyed in the elderly as a result of cerebral atrophy. Furthermore, less blood loss in the elderly may be the benefit from stricter indication and consummated preoperative preparation. SSS involvement was the most common reason for massive blood loss. A total of 9 young patients lost more than 800 mL of blood, of whom 7 (77.8%) had SSS involvement, while among the elderly, 2 (40%) patients showed SSS involvement in 5 massive blood loss patients. The closure of the middle and posterior thirds of the superior sagittal sinus carries a significant risk of cortical venous infarction. Surgeons must choose between two operating strategies: to attempt a total meningioma removal, restoring the venous outflow; or to leave residual meningioma and await sinus occlusion by the tumour and the development of collateral flow. In some studies [31, 32], patches, bypasses were recommended to reconstruct the damaged veins but not aneurysm clips as they are known to be susceptible to secondary thromboses [31, 32]. In the current study, if SSS was damaged during the operation, venous reconstruction was performed using patches or bypasses. An aneurysm clip was used on the sinus wall to reconstruct the ruptured SSS in a 65-year-old man who underwent an 1800-mL blood loss during surgery to resect a huge meningioma involving the third middle SSS. Subtotal resection is one of several alternatives when the operation facing great risks.
A significant difference in the postoperative hospitalization duration was found between the two groups. Despite substantial blood loss in the younger group, they recovered faster than the aging patients. Supposedly, the aging physiology and comorbidities increase the duration of recovery in aging patients than younger patients . Elderly patients tended to have more operation complications than younger patients; yet, no significant difference was observed (39.53% vs. 38.09%, P=0.932). The most common operation complications included neurological deficits, operative field bleeding, and subdural hematoma. The present study showed that younger patients have more severe and fatal complications than elderly patients. Four younger patients underwent craniotomy operation to remove the hematoma or abscess as compared to one in the elderly. Neurological deficit is a vital factor in evaluating the surgery outcome of middle third parasagittal and falx meningioma patients. In the current study, 41.9% (n=18) elderly patients experienced hemiparesis at the 1-year follow-up as compared to 27% (n=17) in the younger group without a statistical difference (P=0.11). Nakamura et al compared the surgical treatment of cerebellopontine angle meningiomas between 21 elderly (aged >70 years) and 65 younger patients and found no significant difference in the surgical complication rate . Roser et al  compared 43 elderly (aged >70 years) patients with skull base meningiomas to 89 controls and showed that the surgical morbidity in skull-based meningioma surgery was not related to the age of the patient. However, several studies obtained different results [5, 36, 37]. This discrepancy may construe stringent criteria for selecting appropriate candidates  for surgery in some studies, while other studies might apply loose criteria. Furthermore, in the current study, the heavy blood loss might increase the complication rate in the younger group. In the current study, a 56 year-old-woman died; her primary complaint was repeated seizures for 3 years. Thus, we deduced that this patient died of severe epilepsy, which caused secondary cerebral ischemia and hypoxia. Taken together, it can be inferred that elderly patients are more likely to develop minor postoperative complications than younger ones, but none of those complications are life-threatening events, which is consistent with Poon et al .
The pathological subtypes of 2 recurrent patients in the elderly group were transitional and atypical, respectively, while the 2 cases in the younger group were transitional and anaplastic, respectively. Magill reported 67 recurrent non–skull base meningiomas with 35 (52.2%) lesions locating at middle 3rd sagittal plane. Middle third parasagittal and falx meningioma operation should apply by experienced surgeons with more patience and surgical technique.
Firstly, this study's retrospective nature limits the ability to determine the degree of resident involvement in surgery. Furthermore, this is a single-center study, and the number of patients was not sufficient to deduce a convincing conclusion.