完全直腸脱に対する腹腔鏡下直腸固定術後における直腸肛門機能：直腸腹側固定術と後方固定術の比較

Anorectal function following laparoscopic rectopexy for complete rectal prolapse patients compared ventral rectopexy with posterior rectopexy

◆要旨：【目的】腹腔鏡下直腸固定術（laparoscopic rectopexy：LR）後に便失禁，便秘および肛門内圧の術前後の変化を検討した．【方法】LR術後の直腸脱の再発率を低く抑えるために術中経肛門的吸引試験（transanal vacuum test：TAVT）を導入した．TAVT（-）とは，直腸の前壁を把持しながらTAVT下で直腸が脱出しないことであり，TAVT（＋）とは，直接後壁中心に直腸が不完全脱出することを意味する．TAVT（-）患者では授動した直腸を腹側より固定する腹側LR（laparoscopic ventral rectopexy：LVR）を施行し，TAVT（＋）患者では直腸全周の剝離授動を追加し，背側より固定する後方LR（laparoscopic posterior rectopexy：LPR）を施行した．LR術前後で肛門内圧検査を施行しえた110例を対象とし，LVR 55例とLPR 55例の2群に分けて検討した．【成績】1）TAVT導入後，LRを305例に施行し，再発が4例（1.3％）あった．うちLVRは139例で再発3例（2.2％），LPRは166例で再発1例（0.6％）であった．2）便失禁：両術式とも術後に有意に改善した．3）便秘：LVRでは術後に有意に改善したが，LPRでは便秘の悪化がLVRに比べ有意に多かった．4）①機能的肛門管長：両術式とも術前後に有意差を認めず．②最大静止圧：両術式とも術後に有意に上昇した．③随意収縮圧：両術式とも術後に有意に上昇した．【結論】LR施行時にTAVTを行い，LVRとLPRを選択することにより直腸脱の再発率を低く抑えることができた．LVR，LPRともに術後に直腸肛門機能の改善をもたらしたが，LPR後の便秘の悪化については今後の検討が必要であると考えられた．

　［Background］Laparoscopic rectopexy（LR）provides satisfactory anatomical correction for complete rectal prolapse. However, its role in restoring anorectal function is yet to be established. This study aimed to compare anorectal function after laparoscopic ventral rectopexy（LVR）and laparoscopic posterior rectopexy（LPR）. ［Methods］One hundred ten patients who underwent LR, with pre-and postoperative anorectal high-resolution manometry（HRM）, were retrospectively reviewed. LVR（n＝55）and LPR（n＝55）were performed. The anorectal function after surgery was estimated using HRM and a questionnaire-based fecal incontinence severity index（FISI）and constipation scoring system（CSS）. ［Results］LR with transanal vacuum test（TAVT）were performed for 305 patients and resulted in 4 prolapse recurrence（1.3％）. LVR were performed for 139 patients and resulted in 3 recurrence（2.2％）. And LPR were performed for 166 patients and resulted in 1 recurrence（0.6％）. FISI significantly improved in both groups（31.2±16.6 to 15.0±12.0 in LVR, 28.8±18.0 to 18.6±16.3 in LPR）. CSS significantly improved with LVR（6.2±5.6 to 4.1±4.2）but not with LPR（7.5±5.4 to 6.3±5.3）. Postoperative HRM was performed within a median of 6 months（range : 3-29）. Functional anal canal length did not change significantly after either surgery. Maximum resting pressure significantly increased in both groups（LVR : 31.4±19.8 to 39.0±18.8 mmHg, LPR : 28.9±19.9 to 41.4±26.9 mmHg）. Maximum squeezing pressure also significantly increased in both groups（LVR : 83.5±53.7 to 96.3±59.6 mmHg, LPR : 68.9±54.9 to 84.9±61.4 mmHg）. ［Conclusions］Both LVR and LPR result in improved anorectal function after surgery. TAVT which selected LVR and LPR in LR was thought to be useful to decrease the prolapse recurrence rate.