10) 微小血管の拡大観察 (2)NBIによる腫瘍・非腫瘍の鑑別

Magnified Observation of Microvascular Architecture Using Narrow Band Imaging for the Differential Diagnosis between Non-neoplastic and Neoplastic Colorectal Lesion

要旨　われわれは1999年より21世紀の内視鏡開発に取り組み，狭帯化filterを搭載したNBI systemを開発した．大腸病変の表面に観察される網目状の茶色い血管"meshed capillary vessel"（MC vessel）が大腸病変の腫瘍・非腫瘍の鑑別に有用な所見であると報告してきた．目的：NBI観察でのMC vesselの腫瘍・非腫瘍の鑑別における有用性を検討する．方法：prospective study．eligibility criteria：colonoscopyを施行した患者．exclusion criteria：polyp（－），invasive cancer，polyp＞10mm，他院でbiopsy（＋），HNPCC，UC，FAP，polyp未回収患者．病変はMC vesselの有無によりMC（＋）/（－）に，病理組織結果は腫瘍・非腫瘍に分類した．病理結果を正診とし，MC（＋）/（－）と病理結果において腫瘍を腫瘍と診断するaccuracy rate等を解析した．結果：criteriaを満たした92人，150病変を対象とした．NBI観察にてMC（＋）110例，MC（－）40例で，病理結果は腫瘍111例，非腫瘍39例で，accuracy rate：95.3％，sensitivity：96.4％，specificity：92.3％であった．結語：MC vesselは大腸腫瘍・非腫瘍の鑑別に有用で，NBIは色素を使用せず鑑別ができ，スクリーニングの効率化に寄与すると考えられる．

　We have reported the observation of surface structure (pit pattern) using NBI colonoscopy to be useful for differentiating neoplasia from non-neoplasia. Recently, we described how the presence of "meshed brown capillary (MC) vessels" arranged in a honeycomb pattern around the mucosal glands on NBI colonoscopy is also useful for differential diagnosis without the application of any dye solution. This time, we describe about prospective study about differentiating neoplasia from non-neoplasia by the presence of micro-capillary vessels. The detected lesions were classified into the following two groups according to their capillary patterns using NBI colonoscopy with magnification: neoplastic for lesions with positive MC vessels and non-neoplastic for lesions without MC vessels. For histological examinations, the lesions finally diagnosed as non-neoplastic were subjected to biopsy and those as neoplastic were removed endoscopically. The accuracy rates of endoscopic diagnosis were evaluated by referring to the final pathological diagnosis. The overall diagnostic accuracy, sensitivity, and specificity using the presence of MC vessels for distinction between neoplastic and non-neoplastic lesions was 95.3％, 96.4％ and 92.3％, respectively (p＜0.0001). Magnification using NBI colonoscopy for the observation of the presence of MC vessels is extremely useful for distinguishing between non-neoplastic and neoplastic lesions without the application of any dye solution. These results suggest that NBI colonoscopy allows for simpler and more efficient screening colonoscopy.