4）MITAS

Treatment for Early Colorectal Cancer─MITAS

要旨　早期直腸癌の治療においては，内視鏡的な切除に固執せず局所の完全切除と全生検が可能な適切な切除法を選択することが，種々の機能温存の点でも特に重要である．MITAS（minimally invasive transanal surgery）は肛門縁より20cmまでの遠位S状結腸の腫瘍にも到達可能な新しい経肛門的局所切除法である．MITASは直視下で，TEMと同等の高さや大きさの腫瘍も切除できるとともに，TEMと異なり切除深度は全層まで切除可能で手術時間も短く，合併症もほとんどないという利点がある．これらは種々の手技の工夫と新しく開発された開肛器や自動縫合器の使用による．

　It is most important to maintain for the patient urogenital and anorectal function. when choosing an excision method facilitating total excision and biopsy in colorectal cancer treatment.

　MITAS（minimally invasive transanal surgery）is a local excision procedure to facilitate an excision of the tumors located up to 20cm from the anal verge or tumors located in the distal sigmoid colon. MITAS can excise proximal large-sized rectal tumors comparable to TEM. In addition to them, full thickness rectal excision can be accomplished with less time and blood loss when using MITAS. The new anal retractor, several new techniques and the use of a stapler facilitating this procedure is introduced in this paper.