Surgical Treatment of Middle Cerebral Artery Aneurysms Without Using Indocyanine Green Videoangiography Assistance: Retrospective Monocentric Study of 263 Clipped Aneurysms.

INTRODUCTION: Middle cerebral artery (MCA) aneurysms represent 20% of intracranial aneurysms. Most (80%) of them are located on the sylvian bifurcation, the seat of hemodynamic turbulence flow. Morbidity and mortality related to surgery of MCA aneurysms are not negligible. MCA vascularization areas are important eloquence functional territorial of Brain tissue. Indocyanine green videoangiography assistance (ICG-VA) is an emergent tool for intraoperative assessment of aneurysmal occlusion and for checking a possible stenosant clip in vascular area. The purposes of this study were to evaluate the safety of clipping procedure in terms of morbidity, mortality, and efficiency of aneurysm occlusion without using ICG-VA, recurrence and bleeding/rebleeding at short and long terms, and angiographic and clinical follow-ups. MATERIAL AND METHODS: This study is a monocentric retrospective study performed at Pitié-Salpêtrière-Charles Foix Hospital Center, reporting clinical and angiographic follow-up of consecutive patients treated for MCA aneurysms (ruptured and unruptured) by clipping procedures. From 2002-2012, 251 consecutive patients were admitted at the author's institution for treatment of 263 MCA aneurysms (163 ruptured and 100 unruptured). Procedure-related death and complications were systematically assessed without video-angiography availability. The degree of aneurysms exclusion was evaluated according to the Raymond-Roy scale after the procedure and at long-term angiographic follow-up (mean delay = 36 months). RESULTS: The death rate related to aneurysmal exclusion procedure was 1.2%. The major complication rate related to surgery was 5.3%. Postprocedure, an aneurysm occlusion rate Raymond-Roy grade A or B was 95.6%. Neither recanalization controlled clipped aneurysms nor re-aneurysmal rupture was observed in the long-term clinical follow-up (mean time = 83.5 months). The institution's series of surgical outcomes reported 95.6% of complete exclusion and 4.5% incomplete procedures without ICG-VA. A clip of repositioning rate was estimated at 15% when ICG-VA was used. CONCLUSION: Surgical management is relatively safe for patients, with an acceptable complication rate in the era when ICG-VA was not yet available. Indeed, the main source of procedural ischemia microsurgery is stenosant clip. To limit the occurrence of malposition, the author's center began using ICG-VA a few months ago and expects to reduce its rate of incomplete occlusion.

TCF12 is mutated in anaplastic oligodendroglioma.

Anaplastic oligodendroglioma (AO) are rare primary brain tumours that are generally incurable, with heterogeneous prognosis and few treatment targets identified. Most oligodendrogliomas have chromosomes 1p/19q co-deletion and an IDH mutation. Here we analysed 51 AO by whole-exome sequencing, identifying previously reported frequent somatic mutations in CIC and FUBP1. We also identified recurrent mutations in TCF12 and in an additional series of 83 AO. Overall, 7.5% of AO are mutated for TCF12, which encodes an oligodendrocyte-related transcription factor. Eighty percent of TCF12 mutations identified were in either the bHLH domain, which is important for TCF12 function as a transcription factor, or were frameshift mutations leading to TCF12 truncated for this domain. We show that these mutations compromise TCF12 transcriptional activity and are associated with a more aggressive tumour type. Our analysis provides further insights into the unique and shared pathways driving AO.