腹腔鏡下に直腸剝離・授動を先行し経肛門的に全層局所切除・直腸肛門吻合を施行した直腸GISTの1例

A case of rectal GIST successfully treated by transanal local resection and recto-anal anastomosis following laparoscopic rectal dissection

◆要旨：患者は62歳，男性．前立腺を強く圧排する直腸GISTに対して拡大手術回避を目的としてメシル酸イマチニブを術前投与し，1年後に手術を施行した．腹腔鏡下に直腸の剝離・授動を上直腸動脈温存かつ自律神経温存で骨盤底まで十分に行った．腫瘍と前立腺の剝離は良視野で容易に可能であった．続いてintersphincteric resection（ISR）と同じ要領で肛門管より剝離し，腹腔内からの剝離と交通させ，肛門外に下部直腸を引き出し，腫瘍を全層局所切除した．再建は経肛門的に直腸肛門吻合を行った．本法は直腸深部の全層局所切除を安全に行える方法として，今後も適応され得る有用な術式と考えられた．

　The patient was a 62-year-old man who was diagnosed as rectal gastrointestinal stromal tumor（GIST）displacing the prostate ventrally. Preoperative imatinib treatment was begun to reduce the tumor size and prevent extended surgery, and surgery was performed after 12 months of this treatment. Laparoscopic rectal dissection and mobilization was performed sufficiently down to the floor of pelvis, with preservation of the superior rectal artery and autonomic nerve. The dissection between the tumor and the prostate could easily be performed under the good view. Next, transanal intersphincteric dissection allowed connection with the laparoscopic dissection, and the rectum was extracted through the anus. Local resection of the tumor with full-thickness incision of the rectal wall was performed under direct vision, and the reconstruction consisted of a hand-sewn recto-anal straight anastomosis. This novel technique is a useful procedure, which enables a safe full-thickness local resection of the lower rectum.