8) 炎症性腸疾患の拡大内視鏡観察

Usefulness of Magnifying Colonoscopy in Diagnosis of Inflammatory Bowel Disease

要旨　拡大内視鏡による微細構造の観察は，潰瘍性大腸炎の組織学的活動性の評価および再燃の予測に有用である．特に，通常観察でMatts' grade 2相当の微細な変化のみの病変における活動性評価には，拡大観察が極めて有用であり，微小な上皮欠損を認めるものでは活動期病変，小腸絨毛様の粘膜を認めるものでは，緩解期病変と診断することができる．また，治療後の効果判定においても，上記の拡大内視鏡所見を目安とすることで，緩解維持期間の予測が可能である．さらに潰瘍性大腸炎合併dysplasiaの診断にも拡大内視鏡を応用する試みがなされており，今後，炎症性腸疾患のサーベイランスにおける，拡大観察の有用性が明らかになっていくであろう．

　Magnifying colonoscopy is useful to evaluate histologic severity and predict the outcome in ulcerative colitis. Although conventional colonoscopy can not determine histologic severity in the lesions with faint granular pattern, which correspond to Matts' grade 2, magnifying colonoscopy can assess their histologic severity according to the characteristic features, minute defects of epithelium and villous-like appearance. These features are also powerful markers to predict cumulative non-relapsing periods in patients with ulcerative colitis. Recent studies have shown that minute structures which were detectable with magnifying colonoscopy could be helpful to diagnose dysplasia in the surveillance study of inflammatory bowel disease.