For the last 15 years over hundred of the posterior midline suboccipital approaches were modified , as seen in this video record, to obtain a bony flap in continuity with posterior rim of the foramen, still attached to the muscles and the ligamentum flavum between the rim and C1 lamina. The most critical part of the procedure is to add further drilling near the rim, so that, when reflecting the bone flap, to get the crack in the weak lines of the posterior rim. This avoid the procedure of possible unplanned fracture with subsequent hazard to the neuro-vascular elements located anterior. The flap is reflected down and temporarly sutured to the muscular alignment of C2 spinous process. By this means, the possible CSF leak despite water-tight closure of the dura is lessened in frequency postoperatively and postoperative normal anatomy is respected. It happened in several cases, that with this flap the posterior lamina of C1 was included and returned back in cases with lesions extending down to upper level of C2 lamina. In case of presence of a lesion more shifted to one side, the same procedure is undertaken with slight expansion of the bony flap to that direction. In rare cases, it was mandatory to remove the flap in case that the case requires postoperative relaxation of the dural covers to eliminate possible pressure toward the medulla. In summary the procedure is an easy one to perform and has several logical advantages.