Study on the vascular structure of esophagial varices using infrared fluorescent endoscopy

一些研究报道红外内窥镜(IRE)对检查食道静脉曲张是有用的。红外荧光虽然已在眼科、皮肤科等领域得到应用，但尚未应用于消化道内窥镜检查。使用Ito等人开发的红外荧光内窥镜(IRFE)，本研究评估了食道静脉曲张的可探测性。研究对象为12例食道静脉曲张患者。术后采用内镜下静脉套扎术(EVL)或腔内注射硬化疗法(EIS)治疗。静脉注射不同剂量(2 mg/kg、0.2 mg/kg、0.01 mg/kg)的ICG，获取红外荧光图像。2例注射2 mg/kg ICG和2例注射0.2 mg/kg ICG的患者均可用强白色红外荧光显示整个食道粘膜。因此，在这些患者中，很难区分食道静脉曲张和正常粘膜。7例患者经0.01 mg/kg ICG治疗后，可清楚地观察到与常规胃镜下观察到的食道静脉曲张相对应的红外荧光。IRFE促进了食道静脉曲张内窥镜治疗后微血管的可视化。此外，血管以外的其他组织没有显示红外荧光。与传统的IRE相比，在静脉注射明显少量的ICG后，IRFE有助于观察食道静脉曲张。因此，IRFE对于预防ICG引起的并发症可能是有用的。IRFE具有较高的敏感性和特异性，有望作为一种新的诊断性内窥镜检查方法应用于消化道血管病变的诊断。

Several studies reported that infrared endscopy (IRE) is useful for examining esophageal varices. Although infrared fluorescence has been used in the field of ophthalmology and dermatology, it has not yet been used in endoscopy for the digestive tracts. Using infrared fluorescent endoscopy (IRFE) developed by Ito et al., the present study evaluated the detectability of esophageal varices. The subjects were 12 patients with esophageal varices. The postoperative course of these patients were followed after the treatment by endoscopic variceal ligation (EVL) or endoscopic injection sclerotherapy (EIS). ICG was administered intravenously at k different doses (2 mg/kg, 0.2 mg/kg, or 0.01 mg/kg), and infrared fluorescent images were acquired. The entire esophageal mucosae were visualized by strong white infrared fluorescence in 2 patients treated with 2 mg/kg of ICG and in 2 patients treated with 0.2 mg/kg of ICG. Therefore, the discrimination of esophageal varices from the normal mucosae was difficult in these patients. Infrared fluorescence corresponding to the esophageal varices observed by conventional endoscopy was clearly observed in 7 patients treated with 0.01 mg/kg of ICG. IRFE facilitated the visualization of microvessels after endoscopic treatment of esopliageal varices. In addition, tissues other than blood vessels did not show infrared fluorescence. Compared to conventional IRE, IRFE facilitated the observation of esophageal varices after intravenously injecting a markedly small amount of ICG. Therefore, IRFE may be useful for preventing ICG-induced complications. In the future, due to its higher sensitivity and specificity, IRFE may be used in the diagnosis of vascular lesious in the digestive tract as a novel diagnostic endoscopy.