いわゆる側方発育型大腸腫瘍の治療―外科治療

Strategy of Surgery for Laterally Spreading Tumor

要旨

　側方発育型腫瘍（laterally spreading tumor ; LST）の多くは粘膜内あるいは粘膜下層にとどまる早期癌の状態で発見されることが多い．したがって，治療は内視鏡的切除が基本だが，外科的治療も病変の確実な切除と安全で低侵襲な方法が選択されるべきである．その点で，腹腔鏡下大腸切除術（LAC），経肛門的切除術（TAR），経肛門的内視鏡下マイクロサージェリー（TEM）はいずれも開腹手術（OC）に比較し低侵襲手術として優れた治療法である．そこで，治療法を選択するにあたり，各々の適応を明確にしておくことが重要である．

　Laterally spreading tumor can be treated by endoscopic or surgical resection. Endoscopic resection includes polypectomy, endoscopic mucosal resection (EMR), and endoscopic piecemeal mucosal resection (EPMR). Recent developments in minimally invasive surgery have made colorectal surgery procedures, such as laparoscopic-assisted colectomy (LAC), transanal endoscopic microsurgery (TEM) and transanal tumor resection (TAR), attractive alternatives to open colectomy (OC). The safety and feasibility of LAC, TEM and TAR have been demonstrated, and benefits such as reduced postoperative pain, blood loss and hospital stay have been reported. These surgical methods have been recognized as standard therapy for early colorectal cancer, but determination of effective operative procedures is indispensable for safe and successful operations. Perioperative stress must be minimized using techniques such as preoperative bowel preparation, marking of lesions, and determination of operative position. In addition, avoiding complications is central to realizing the benefits of minimally invasive surgery. In this regard, the potential advantages of these surgical methods can be more precisely defined. In conclusion, LAC, TEM and TAR have potential for playing a key role in the treatment of LST.