胶囊内镜在不明原因消化道出血诊断中的应用

Application of Capsule Endoscopy in Diagnosis of Obscure Gastrointestinal Bleeding

背景：胶囊内镜是明确不明原因消化道出血（OGIB）的检查手段之一，其诊断率可能受到检查时机和出血自然病程的影响。目的：探讨胶囊内镜在OGIB诊断中的应用价值和最佳检查时机。方法：收集2010年10月～2012年6月厦门大学附属中山医院46例接受胶囊内镜检查的OGIB患者。回顾性分析胶囊内镜检查诊断OGIB的阳性率、疑诊率、敏感性、特异性、阳性预测值和阴性预测值，比较不同检查时机对OGIB检出率的影响。结果：胶囊内镜检查诊断OGIB的阳性率为71．7％，疑诊率为13．0％，阴性率为15．2％，诊断敏感性、特异性以及阳性预测值、阴性预测值分别为96．3％、75．0％、92．9％、85．7％。活动性出血组的检出率显著高于出血停止组（96．3％对68．4％，P=0．030），显性出血者的检出率与隐性出血者相比差异无统计学意义（100％对75．0％，P=0．148）。出血停止≤2周者的检出率显著高于出血停止〉2周者（90．9％对37．5％，P=0．041）。结论：胶囊内镜是诊断OGIB的一种安全、有效的检查手段，出血后尽早行胶囊内镜检查可能提高阳性诊断率并为进一步干预创造条件。

Background： Capsule endoscopy （CE） is one of the approaches for diagnosis of obscure gastrointestinal bleeding （OGIB）. The diagnostic yield of CE is influenced by the timing of examination and the nature of bleeding. Aims： To evaluate the diagnostic value of CE for OGIB patients, and to explore the best timing of CE examination. Methods： Forty-six OGIB patients who had CE examination performed from Oct. 2010 to June 2012 at Zhongshan Hospital Affiliated to Xiamen University were enrolled. Positivity rate, suspected rate, sensitivity, specificity, positive predictive value and negative predictive value of CE in OGIB patients were retrospectively analyzed, and the detection rates of OGIB between different timing of examination were compared. Results ： CE was positive in 71.7% cases, suspected in 13.0% cases, and negative in 15.2% cases. Sensitivity, specificity, positive predictive value and negative predictive value of CE were 96.3% , 75.0% , 92.9% , 85.7% , respectively. The detection rate in active bleeding group was significantly higher than that in bleeding stopped group （96.3% vs. 68.4% , P = 0. 030）. However, no significant difference was found between overt bleeding group and occult bleeding group （ 100% vs. 75.0% , P = 0. 148 ）. The detection rate in bleeding stopped ≤ 2 weeks was significantly higher than that in bleeding stopped 〉 2 weeks （ 90.9% vs. 37.5% , P = 0.041 ）. Conclusions ： CE is a safe and effective method for diagnosis of OGIB. Earlier timing of CE achieves a higher diagnostic yield for overt OGIB and consequently results in a higher success rate of intervention.