ABSTRACT
Since Yasargil's report, most neurosurgeons operate on middle cerebral artery(MCA) aneurysms through frontotemporal(pterional) bone flap under large skin incision which could result avoidable complications of facial nerve damage, temporal muscle atropy, paresthesia along incision scar and cosmetic bony defect. After careful review of detailed facial nerve anatomy, the author has developed a less invasive approach involving 8cm mini skin incision starting from 1.5cm above zygomatic arch, 1.5cm inside the anterior temporal hair line to upward 4-5cm and then curving forward 3cm length around 2cm above supraorbital ridge. Then, about 2.5cm mini-bone flap centered on pterion is made. After reflection of round dural flap, dissection of sylvian fissure was proceeded from just lateral end of limen insula, where middle cerebral artery(MCA) bifurcation or M2 segment was deeply located. The author has operated on consecutive 18 cases of MCA aneurysms using this minicraniotomy from 1996 to 1998 which provided sufficient working area enough not only for surgeon's free hand motion including multiple temporary clippings at one field but also inspection for other anterior circulation and posterior circulation systems. Hunt-Hess Grade for these patients were 17 cases of Grade II and 1 case of Grade I. Mean age of patients was 52.9 years old. There were 15 males and 3 females. Excellent postoperative neurological conditions were achieved without any morbidity or mortality. This approach is especially recommendable for patients with good neurological status for being less invasive and more convenient method.