難治性肛門部病変の特徴と治療戦略

Intractable Perianal Lesions of Crohn's Disease: Clinical Characteristics and Strategies

要旨　肛門部病変はCrohn病患者の73.6％と高率に合併し，34.7％で腸管症状に先行して出現した．多くの患者では一般の肛門疾患と同様に，一時的であるが，肛門疾患合併例の17.9％が難治である．痔瘻（肛門周囲膿瘍）は難治例の94.1％を占め最も多く，全例が高位複雑痔瘻であった．多発，複雑痔瘻に対しては，肛門機能保全を第一にsetonをおき，免疫調節薬や抗TNF-α抗体薬の併用で炎症の沈静化を図る．腸管病変の寛解を長期に維持することにより外科手術による治癒のチャンスを得る可能性がある．患者のQOLを著しく損なう肛門狭窄例や，seton法などの外科的処置を加えても肛門部病変の炎症がコントロール困難な例では，一時的人工肛門造設がQOL改善に有効であるが，その多くは人工肛門閉鎖困難である．長期経過例では癌合併に留意し，定期的なsurveillanceが必要である．

　Perianal lesions frequently develop in patients with Crohn's disease. They have been detected in 73.6％ of the patients in our institutes and have preceded the onset of intestinal symptoms in 34.7％ of the patients with perianal lesions. Although most perianal lesions are self-limiting or healed with proper treatment, some Crohn's perianal lesions, including 17.9％ of our cases, are intractable. Anal fistula/perianal abscess is the most common intractable lesion, seen in 94.1％ of our cases, all of which are high and/or complex fistulas.

　For multiple or complex fistulas, seton drainage should be adopted first according to the principle of preserving anal integrity and immunomodulator or anti-TNF antibody should also be administrated to reduce inflammation. By maintaining long-term remission of intestinal lesions it becomes possible to repair the fistula through surgery.

　If rectal or anal stricture impairs the patient's quality of life, or if perianal inflammation is uncontrollable, fecal diversion can have a beneficial effect. However, the prospect of restoring intestinal continuity is low.

　Periodical cancer surveillance should be performed in all patients with long-standing rectal or perianal lesions of Crohn's disease.