Dr. Daniel Kelly delivers a presentation of the endoscopic assisted keyhole craniotomy. Dr. Kelly discusses several approaches to keyhole surgery for removing tumors, the midline skull base approach, endonasal transsphenoidal pituitary adenoma surgery, microinstruments, tentorial meningioma, midbrain cyst, supra-orbital eyebrow craniotomy, metastatic bladder carcinoma, and gravity-assisted trans-dural endoscope.