本邦における直腸癌に対する腹腔鏡下手術の現況―腹腔鏡下大腸切除研究会多施設共同研究―

Current status of laparoscopy in Japanese patients with rectal cancer : amulticenter, cooperative study conducted by the study committee for laparoscopic resection of the colorectum

◆要旨：腹腔鏡下手術は，骨盤内操作において開腹手術では得られない良好な視野展開が可能である．骨盤内の解剖を熟知し，手術手技に習熟することで，徐々に本法の適応を拡大していくことが肝要である．しかし，腫瘍学的要因から，すべての直腸癌が腹腔鏡下手術の適応となるわけではない．特に直腸癌手術には，根治性の向上と機能温存が求められている．進行癌では，現在もなお標準的治療が確立されていないのが現状で，無作為臨床試験の結果が得られた後に，標準治療が確立される段階である．これまで，腹腔鏡下大腸切除研究会が中心となり，cT1，cT2直腸癌に対する腹腔鏡下手術の第Ⅱ相臨床試験が予定されている．この結果をふまえ，進行直腸癌に対する腹腔鏡下手術の適応を再考することになろう．進行直腸癌に腹腔鏡下手術を適応拡大していく際は，自律神経を温存し局所再発を制御する安全な手術手技の確立が重要である．側方郭清に関する臨床試験結果や術前化学放射線治療を併用することなども視野に入れて，慎重に検討していく必要がある．

　Laparoscopic surgery provides a very good view of the operative field that is unobtainable by open surgery in patients undergoing intrapelvic procedures. It is essential to gradually expand the indications for laparoscopic surgery on the basis of deeper knowledge of intrapelvic anatomy and the development of improved surgical skills and techniques. Because of oncologic factors, however, laparoscopic surgery is not indicated for all patients with rectal cancer. Surgery for all patients with rectal cancer requires improved curability and preservation of rectal function. Standard treatment for advanced rectal cancer has yet to be established. After the results of randomized clinical studies in patients with rectal cancer become available, standard treatments may be established. The Study Committee for Laparoscopic Resection of the Colorectum is now planning to organize a phase II clinical study of laparoscopic surgery for clinical stage T1 and T2 rectal cancer. The results of this study may provide insights into whether laparoscopic surgery can be indicated for the treatment of advanced rectal cancer, thereby warranting future research. Expansion of the indications for laparoscopic surgery to advanced rectal cancer requires the establishment of safe surgical techniques that can preserve autonomic function without promoting local recurrence. The results of clinical studies of lateral dissection and the concomitant use of preoperative and postoperative chemoradiotherapy should be assessed carefully.