| BACKGROUND:Meningioma that originated from the arachnoid cells mostly, may also come from the dura mater and pia mater fibroblast cells. Thus meningioma may occur in any part of brain containing the arachnoid. The annual incidence rate of meningioma is 2/10 million. According to the literature, the incidence rate of meningioma is second to intracranial glioma, which accounted for 21% of primary brain tumors. The incidence ratio of male to female is about 1:2. The average age was 59±15 years old, and the peak age of onset is 45 years old.Most meningiomas are benign, slow growth tumors. The boundaries of meningiomas and brain tissues are often obvious. Depending on the difference of tumor site, the local symptoms of meningiomas may be difference. The first local symptoms of meningiomas are often epilepsy and headache. Other symptoms also include hemiparesis, vision disorder, deafness or smell disorder. Due to the development of Computer Tomography in recent years, the chance of the discovery for the asymptomatic meningiomas is gradually increasing.Generally, meningiomas accept intracranial and extracranial double blood supply. Thus the blood supplies of meningiomas are often rich, which lead to surgical field unclear and cause difficulties for surgical procedures. These difficulties would increase the incidence of postoperative neurological deficits. Preoperative embolizations of meningiomas can effectively block or reduce tumor blood supply before the resection of tumors, and help to induce meningioma necrosis and softening. As a result, the surrounding normal tissue boundaries become clearer. By this way, it can decrease the surgical blood loss, reduce the operation time and complications, and make surgery easier.Many different embolic materials have been proven to be successful in the embolization of meningiomas. These embolic agents, either permanent or temporary, include gelfoam, polyvinyl alcohol particles, GDCs, Glubran, NBCA and Onxy. Polyvinyl alcohol particles (300-500μ m) are most likely the most common embolic agents. However, there were several limitations in PVA particles. Firstly, the high coefficient of friction in PVA particles requires a high injection pressure that can either cause a hemorrhage of the weak pial arteries or result in the particles clumping and aggregating within the microcatheter. Secondly, PVA is a radiolucent particle. Even if it is mixed with contrast medium, we cannot directly observe it in real time during an injection. Thus, there are risks of inadequate reflux or migration of the PVA into the normal cerebral arteries. Thus PVA particles only administered through ECA branches.As a result of mixing two monomers, N-butyl cyanoacrylate (NBCA) and metacryloxysulpholane (MS, a monomer owned by GEM Srl), Glubran is introduced as a non-absorbable liquid embolic agent. Studies have suggested that liquid embolic agents, such as Glubran, may have more operational and efficacious advantages over other particle agents. The advantages of Glubran can be listed as follows:fast and deep penetration into the tumor vasculature, permanent occlusion effect, low infusion pressure delivery and radiopacity. Furthermore, administered with various microcatheters, Glubran ensures superior distal navigation compared with PVA particles. However, foundings regarding Glubran preoperative embolization of meningiomas are limited. For the skull base meningiomas and the meningiomas which receive blood supply form deep sites, the use of Glubran preoperative embolization is particularly meaningful.This study retrospectively analyzed the data of meningioma patients who received preoperative embolization to assess the efficacy and safety of Glubran glue, and further looked into the factors related to the degree of preoperative embolization and complications of preoperative embolization. The basic information, imaging characteristics, treatments and prognosis were statistically analyzed. Therefore, we could summarize the experience of preoperative embolization to provide theoretical reference for clinical treatments.Part1 Embolization of Meningiomas:A Comparison of the EffectBetween Glubran and Polyvinyl-alcohol Particles As Embolic Agents OBJECTIVE:Glubran is a non-absorbable liquid embolic agent that is used for the presurgical embolization of meningiomas. The purpose of this study was to estimate its safety and efficacy compared with polyvinyl alcohol (PVA) particles.METHODS:From January 2006 to June 2015,157 consecutive patients (96 females; mean age=48.3 years) who suffered from meningiomas and were preoperatively referred for embolization were retrospectively analyzed. Glubran (n=40) and PVA (n=55) were used to devascularize tumors. Embolizations were performed through the transfemoral route under general anesthesia for all patients. After the diagnostic angiography and the selection of the appropriate vessels for embolization, a microcatheter system was placed in the feeding branches as close to the tumor as possible under road-mapping guidance, and then, embolization was performed. Embolization materials included the mixture of PVA 300 to 500μm particles and contrast agent,5-10% mixture of Glubran and lipiodol. Afterwards, a postembolization angiogram of the target vessel was immediately performed to examine the extent of tumor devascularization. For most patients, the period between embolization and surgery was around two to four days. Intraoperative blood loss, intraoperative time, degree of angiographic devascularization and embolization-related complications were retrospectively analyzed.RESULT:Preoperative embolization was performed on 84 patients. One intraventricular and intratumoral hemorrhage occurred immediately after embolization of a large flax meningioma through the anterior cerebral artery branches feeding vessels. Emergent surgical removal of the tumor and a ventricular drain were performed, and the patient received good clinical outcomes without symptoms related to the hemorrhage.There was a significant difference among the three groups in intraoperative blood loss (P=0.014, Kruskal-Wallis test) and operative time (P=0.013, Kruskal-Wallis test). The intraoperative blood loss was significantly lower in the Glubran-embolized group compared with the non-embolized group (P=0.010, Mann-Whitney test), which remained significant following a Bonferroni adjustment. However, there was no significant difference between the Glubran-embolized and PVA-embolized groups (P =0.603, Mann-Whitney test). The intraoperative blood loss was significantly lower in the PVA-embolized group compared with the non-embolized group (P=0.019, Mann-Whitney test). However, there was no significant difference between the PVA-embolized and non-embolized groups when adjusted by Bonferroni post hoc analysis. The operative time was significantly lower in the Glubran-embolized group compared with the non-embolized group (P=0.006, Mann-Whitney test), which remained significant following a Bonferroni adjustment. The operative time was significantly lower in the PVA-embolized group compared with the non-embolized group (P= 0.030, Mann-Whitney test); however, this difference did not remain significant following a Bonferroni adjustment. There was no significant difference between the PVA-embolized and Glubran-embolized groups (P=0.584, Mann-Whitney test). Embolization with Glubran can significantly reduce intraoperative blood loss (P=0.012, Dunnett’s T3 test)and operative time (P=005, Kruskal-Wallis test) for hypervascular meningiomas that received their primary blood supply from the internal carotid artery and/or the vertebral arteries.CONCLUSION:Preoperative embolization of meningiomas with Glubran can decrease intraoperative blood loss and operative time. Additionally, embolization with Glubran is able to produce more effective devascularization of the tumor vascular bed compared with the usage of PVA for hypervascular meningiomas that received their primary blood supply from the internal carotid artery and/or the vertebral arteries.Part2 Preoperative Embolization of Meningiomas:the Predictors of Complete Embolization and ComplicationsOBJECTIVE:To investigate the risk factors for the complications of preoperative embolization of meningiomas and the predict factors for the complete embolization. To summarize the clinical experience Preoperative embolization, the purpose of reducing thrombosis-related complications, provide a theoretical reference for clinical treatment. In order to provide a theoretical basis for clinical treatment of meningiomas, achieve a better devascularization effect and reduce embolization related complication, we summarized the clinical experience of preoperative embolization.METHODS:From January 2006 to June 2015,95 consecutive patients (57females; mean age=48.1 years) who suffered from meningiomas and were preoperatively embolization were retrospectively analyzed. Glubran (n=40) and PVA (n=55) were used to devascularize tumors. Embolizations were performed through the transfemoral route under general anesthesia for all patients. After the diagnostic angiography and the selection of the appropriate vessels for embolization, a microcatheter system was placed in the feeding branches as close to the tumor as possible under road-mapping guidance, and then, embolization was performed. Embolization materials included the mixture of PVA 300 to 500 μm particles and contrast agent,5-10% mixture of Glubran and lipiodol. Afterwards, a postembolization angiogram of the target vessel was immediately performed to examine the extent of tumor devascularization. Patient demographics, tumor size, location, degree of embolization, embolization related complications and the presence of blood supply from pial or cortical branches were recorded. All related variables were entered multivariate logistic regression model to determine whether they were associated with complications and complete embolization. When P<0.05, the difference was considered statistically significant. All the statistics used SPSS 20.0 statistical software for analysis.RESULTS:Preoperative embolization was performed for 95 patients (38 males and 57 females; mean age 48.1 years, range 21-75 years) during the study period. Glubran (n=40) and PVA (n=55) were used to devascularize tumors. Embolization-related complications occurred in 12 patients. Ten patients suffered transient neurological symptoms due to aggravation of brain edema or tumor swelling. One patient who underwent embolization of both superficial temporal feeding vessels experienced scalp necrosis after surgical resection. One intraventricular and intratumoral hemorrhage occurred immediately after the embolization of a large flax meningioma through the anterior cerebral artery branch feeding vessels. An emergency surgical removal of the tumor and a ventricular drain were performed. The patient exhibited good clinical outcomes without hemorrhage-related symptoms. Multivariate analysis revealed that elderly patients (≥60 years; OR 7.10,95% CI 1.42-35.43,P=0.02) and presence of pial supply (OR 6.78,95%CI 1.33-34.46, P=0.02) were independent factors for complications. Various factors for total devascularization were investigated. Multivariate analysis found the following factors were significantly associated with total devascularization:tumor size (≥6 cm; OR 0.13,95% CI 0.04-0.43, P=0.00), deep location (OR 0.19,95%CI 0.05-0.67, P=0.001), and presence of pial supply (OR 0.07,95%CI 0.02-0.31, P=0.00).CONCLUSION:Preoperative embolization for intracranial meningiomas using Glubran gule can attain effective devascularization with a related low complication rate. Elderly patients and presence of pial supply were risk factors for complications. Huge tumor, deep location and presence of pial supply were risk factors for total devascularization. |
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