放射性肠损伤血管病变基础及其诊疗进展

Basics of vascular damage and progress of diagnosis and treatment in radiation intestinal injury

放射性肠损伤是腹盆腔放疗最常见的并发症之一,严重影响患者生活质量。放射性肠损伤根据发生部位可分为放射性小肠炎、结肠炎及直肠炎。放射性肠损伤的病理特征主要包括间质纤维化、黏膜水肿、溃疡、炎性细胞浸润等,且存在显著的血管病变。其在内窥镜下表现为毛细血管扩张出血,超声下具有肠壁弥漫性增厚、血流信号增多的表现。此外,放射性肠损伤还具有乙状结肠远端和直肠壁厚度增加、骶前间隙宽度的增加等其他影像学表现。放射性肠损伤发生发展中的关键因子包括血管抑素、血小板衍生生长因子和CXCL16等,待明确的机制包括异常升高的血管抑素通过哪些信号通路影响血管内皮细胞,进而抑制血管生成和导致稳态失衡,以及巨噬细胞表达的CXCL16如何作用于相应受体促进成纤维细胞和血管平滑肌细胞转变为肌成纤维细胞等。针对放射性肠损伤血管病变,进行靶向治疗,将是令人期待的研究方向。

Radiation intestinal injury is one of the most common complications after abdominal pelvic radiotherapy,which seriously affects the quality of life for patients.According to the site of occurrence,it is divided into radiation enteritis,colitis and proctitis.The pathological characteristics of radiation intestinal injury mainly include interstitial fibrosis,mucosal edema,ulcers,and inflammatory cell infiltration,and significant vascular lesions as well.It showed telangiectasia and hemorrhage under endoscopy.Under ultrasound examination,it showed diffusive thickening of the intestinal wall and increased blood flow signals.In addition,it also has other features such as increased thickness of the distal sigmoid colon and rectal wall,and increased width of the presacral space.The key factors in the incidence and development of radiation intestinal injury include angiostatin,PDGF,CXCL16,etc.The mechanisms to be clarified include abnormally heightened angiostatin through which signal pathways specifically affect vascular endothelial cells and inhibit angiogenesis and vascular homeostasis,how CXCL16 expressed by macrophages interacting with receptor promotes the transformation of fibroblasts and vascular smooth muscle cells into myofibroblasts,etc.Therapy targeted on basics of vascular damage will be a promising field of radiation intestinal injury research.