Not sure if this was endonasal but it was endoscopic. Have yet to find anyone who has had it successfully or unsuccessfully. Researching more studies but they have not been followed long enough to know real long term outcomes yet.
http://www.ncbi.nlm.nih.gov/pubmed/20819571
Hi...I can tell u why my Drs would not do it for Chiari....they told me they do not use this approach as it is endoscopic, and the space they r working is too small to detect an issue or leak...so they prefer the regular posterior fossa decompression and open the dura in a way to help minimize a leak. as they r better able to close up.....and so they can see the area better. One of the issues is the Drs may not know what all is involved until they get inside...I was even told this with an endoscopic knee surgery, that once inside they may have to revert back to a regular surgery option to be able to correct the problems they find.