Search

Object: Bone invasion is a major concern in meningioma surgery, since it is predictive of the recurrence of cranial involvement, morbidity, and mortality. Bone invasion has been reported in 20%-68% of studies with histopathologically confirmed data. Unfortunately, radical resection of bone invasion remains challenging. The aim of this study was to assess the role of 5-aminolevulinic acid (5-ALA) fluorescence in guiding the resection of bone-invading meningiomas. To this purpose, the sensitivity, specificity, and positive and negative predictive values of 5-ALA in detecting meningioma bone invasion were evaluated., Methods: Data from 12 patients affected by bone-invading meningiomas (7 with skull base and 5 with convexity meningiomas) who had undergone surgery with the assistance of 5-ALA fluorescence and neuronavigation between July 2012 and March 2013 at the Department of Neurosurgery of Padua were retrospectively analyzed. To evaluate the sensitivity and specificity of 5-ALA fluorescence in detecting meningioma tissue, a pathologist analyzed 98 surgical bone samples under blue light, according to different fluorescence patterns. Magnetic resonance images and CT scans were obtained pre- and postoperatively to determine the extent of bone invasion resection., Results: The rate of 5-ALA-induced fluorescence of both tumor and bone invasion was 100%. Based on the pathological examination of bone specimens, 5-ALA presented a sensitivity of 89.06% (95% CI 81.41%-96.71%) and a specificity of 100% in detecting meningioma bone invasion, while the positive and negative predictive values were 100% and 82.93% (95% CI 71.41%-94.45%), respectively. At the postoperative stage, MRI did not detect cases of meningioma bone invasion, whereas CT scans revealed residual hyperostosis in 2 cases., Conclusions: In summary, 5-ALA fluorescence represents a suitable and reliable technique for identifying and removing bone infiltration by meningiomas. However, further studies are needed to prove the clinical consequences of this promising technique in a larger population.

Object: There are no doubts about the role that indocyanine green video angiography (ICGVA) can play in current vascular neurosurgery. Conversely, in brain tumor surgery, and particularly in meningioma surgery, this role is still unclear. Vein management is pivotal for approaching parasagittal meningiomas, because venous preservation is strictly connected to both extent of resection and clinical outcome. The authors present the technical traits and the postoperative outcome of the application of ICGVA in patients undergoing parasagittal meningioma surgery., Methods: The authors retrospectively collected demographic, radiological, intraoperative, and follow-up data in 43 patients with parasagittal meningiomas who underwent surgery with the assistance of ICGVA at Padua Neurosurgical Department between October 2010 and July 2013. Intraoperative ICGVA findings at different stages (before dural opening, after dural opening, during resection, after resection) were reviewed. Additional data on functional monitoring, temporary venous clipping, and flow measurements were also recorded. The overall postoperative outcome was evaluated by assessing both the extent of resection and the clinical outcome data., Results: The ICGVA studies were performed 125 times in 43 patients, providing helpful data for vein management and tumor resection in all stages of surgery. In 16% of meningiomas completely occluding the superior sagittal sinus, the ICGVA data differed from radiological findings and changed the surgical approach. In 20% of cases the intraoperative ICGVA findings directly guided the surgical strategy: venous sacrifice was necessary in 7 cases, without postoperative consequences; temporary clipping with neurophysiological monitoring proved to be predictive of safe venous sacrifice. In 7% of cases the ICGVA data needed to be supplemented with flow measurements. Simpson Grade I-II and Grade III resections were achieved in 86% and 14% of cases, respectively, with a 4.6% rate of overall morbidity., Conclusions: This study shows that ICGVA can assist the different stages of parasagittal meningiomas surgery, guiding the vein management and tumor resection strategies with a favorable final clinical outcome. However, in the authors' experience the use of other complementary tools was mandatory in selected cases to preserve functional areas. Further studies are needed to confirm that the application of ICGVA in parasagittal meningioma surgery may improve the morbidity rate, as reported in this study.