脳神経外科手術用ロボット（NeuRobot）の開発と臨床

Development and clinical usage of the neurosurgical robot（NeuRobot）

　はじめに

　様々な術具が開発され手術手技が改良されることで，手術成績は向上してきた。脳神経外科領域においては手術顕微鏡，双極止血摂子，動脈瘤クリップ，神経内視鏡などが挙げられる。さらに最近普及してきた画像診断技術を応用したナビゲーションシステムは，今後大きく発展する手術支援装置と考えられる。筆者らは低侵襲脳神経外科手術を追求する手段として，操作型手術ロボットの導入を検討している。操作型手術ロボットはすでに消化器外科，心臓外科や整形外科領域においては，市販され臨床手術に使用されている。消化器外科，心臓外科領域でのda Vinci（Intuitive Surgical, Inc., Sunnyvale, CA）やZeus（Computer Motion, Inc., Goleta, CA）は，内視鏡手術ロボットとして導入されている^9,10）。

　In the neurosurgical field, a variety of medical robots has been developed；however, robotic telemanipulation system performing several surgical tasks has not been introduced in the clinical situation yet. Real less invasive neurosurgery can be achieved when every surgical procedures are performed only with a slim neuroendoscope. NeuRobot is an original tele-manipulation neurosurgical operation device developed in Japan. The main feature of the NeuRobot is a rigid insertion cylinder with 10-mm diameter and 17-cm length. This cylinder houses a three-dimensional（3D）endoscope, irrigation and suction channels, and three robot arms moving in the endoscopic operative field with three degrees of freedom：rotation, swing of neck, and forward/backward motion. We have already confirmed safety, precision, and usefulness of this system by previous basic experiments.

　From August 2002 to March 2004, the NeuRobot was applied in total 4 cases. In the first case, a part of a recurrent superficial meningioma was removed using the NeuRobot under microscopic assistance. In the second case, a part of a recurrent superficial meningioma was dissected and removed without microscopic assistance. In the third case, the NeuRobot achieved third ventriculostomy for an obstructive hydrocephalus. In the fourth case, an intraventricular tumor was partially dissected and removed. All the procedures were accurately performed with the NeuRobot without causing any complications. Infection sign or any other complications related to the usage of the NeuRobot were not observed.

　The interhospital tele-surgery was another project of the NeuRobot. We examined time delay and security, which are most important for interhospital tele-surgery, using the NeuRobot and the exclusive optimal fiber connected to one of our affiliated hospitals 40km distant from the University. Based on sophisticated basic examinations, it was confirmed that the NeuRobot had capability of tele-controlling surgery.

　With further improvement of the NeuRobot, durability, reduction in costs, achievement of further degrees of freedom and scale down, the NeuRobot must be commonly used for achieving real less invasive surgery.