吸引圧調節可能な超音波破砕吸引装置—吸引圧調節器の作製と使用経験

Ultrasonic Aspirator with Controllable Suction System : Variable Action Suction Adapter and Clinical Experience with It

I．はじめに

　超音波破砕吸引装置（以下，超音波装置）は脳神経外科手術，とりわけ髄膜腫をはじめとする脳腫瘍の摘出術に有用な装置として普及した．さらに最近は装置の小型化や軽量化が進み，顕微鏡手術には不可欠の機器の一つとなった．しかしながら，脳神経や穿通枝など重要な神経血管構築を超音波で破砕したり，吸引して損傷するなどの危険が指摘されている^1,2）．これらは不適切な手術操作が原因の場合が多いが，装置の構造に起因する場合も考えられる．なかでも吸引圧は，腫瘍の硬さや出血の程度，近傍に正常構造物が存在する可能性，そのときの超音波強度や洗浄液量，などに応じて動的に調節できることが望まれる．しかし装置本体に付属した調節器では，比較的高めの一定圧力に設定する場合が多く，術者が吸引圧を細かく制御することは困難である．

　今回，超音波装置のハンドピースに容易に装着できる吸引圧調節器を作製し，脳腫瘍摘出術で使用した．吸引圧を調節することで吸引損傷の危険が減少し，また超音波発振休止時にも通常の外科用吸引管と類似した操作ができたので報告する．

While the ultrasonic aspirator (UA) has been widely used as one of the indispensable tools in the field of neurosurgery, a potential risk when using the present UA is injury to the neurovascular structures due to ultrasonic pulverization and constant forceful suction power. We have devised a small variable action suction adapter that can be used in a similar manner to conventional surgical suction tubes.

The UA control unit and the handpiece used in this study were the Sonopet UST-2000 and HA-01, re-spectively (M & M Corporation Tokyo, Japan). The handpiece is slim, with the mid-portion diameter of 13 mm, and it weighs 100 grams. A variable action suction adapter was made from polycarbonate of 15×12× 13mm in size.

The adapter was connected to the suction tube using a Y-shaped connector (Fig. 2 A), which was inte-grated into the handpiece. The suction power is regulated by variably closing the oval-shaped hole. The adapter can be variously placed on and rotated around the handpiece (Fig. 2 B and C) so that either the right or left hand handles it in a similar fashion to conventional suction tubes.

We used this UA in surgery for 8 patients with large brain tumors (meningioma in 5 cases, metastatic brain tumor in 2 cases and glioma in one case). It reduced the risk of suction-related injury to the neuro-vascular structures and was handled in a similar manner to conventional suction tubes.

This adapter ensures the complete control of suction power, which will reduce the risk of suction injury.