“…In this case, a multilayer reconstruction was performed, which included a collagen matrix laid against the dura mater as the first layer, bone pile fitted into the bone as the second layer, and a pedicle nasoseptal flap covering the bone as the third layer. Previously, for small defects, only soft reconstruction was performed with fascia or fat and rigid reconstruction was not recommended [7][8][9] . However, since spontaneous CSF leakage is related to chronic intracranial hypertension [2][3][4][5][6] , a strong reconstruction is preferable.…”