脳動脈瘤に対する低侵襲手術  [in Japanese] Minimally Invasive Neurosurgery of Intracranial Aneurysm for Prevention of Surgical Complications  [in Japanese]

The use of the minimally invasive procedures in neurosurgery significantly reduces peri-operative morbidity. We present some experiences of minimally invasive surgeries for intracranial aneurysms. Interfascial skin flap separation avoided injury of the facial nerve at the pterional approach. The perpendicular from the burr hole behind the frontozygomatic suture points to the anterior clinoid process when the patient's head is rotated to the opposite side by 30 degrees. This burr hole can be defined as the smallest pterional craniotomy. The small craniotomy at the forehead wrinkle allowed the shortest surgical route to Acom aneurysms. The following surgical techniques provided a wide operative view without brain retractor. Insertion of Bemsheets into the sylvian fissure served as a retractor, and head position with vertex down allowed the frontal lobe to fall away. Resection of the meningo-orbital band made it easy to remove the anterior clinoid process, which provided a wide working space to avoid optic nerve injury and excessive brain retraction. Combined surgery of bypass and endovascular surgery or of bypass and clipping surgery avoided peripheral artery occlusion. Posteriorly projecting IC-PC aneurysms were clipped easily via the anterior temporal approach, and the Pcom artery was successfully spared by intraoperative endoscopic observation. The key point of minimally invasive aneurysm surgery is minimizing complications by carefully selecting surgical procedures.