[Diagnosis and treatment of radiation intestinal injury: current status and perspectives].

Radiation intestinal injury (RII) refers to the intestinal complication resulting from radiation therapy of pelvic, abdominal or retroperitoneal tumor, which involves the small intestine, colon and rectum. Although the advances in radiotherapy technology have decreased the injury of adjacent tissues, 90% of the patients receiving radiotherapy have acute symptoms, the quality of life is affected due to gastrointestinal symptoms in 50% of patients, and 20%-40% of patients have moderate to severe symptoms. Based on the pathological stage, characteristics and clinical manifestations, RII can be divided into acute and chronic types, generally 3 to 6 months as the cutoff in clinical history. The main preventions of RII include reducing the radiation doses and narrowing the exposure fields. Acute RII is characterized by mucosal inflammation and self-limitation, and its treatment includes symptomatic and nutritional management. As the chronic ischemia and fibrosis in chronic RII are irreversible, bowel resection is the ideal treatment. The surgical indications for chronic RII are grade 3 and 4 intestinal injuries, including obstruction, bleeding, intestinal necrosis, perforation, and fistula. The current surgical procedure is definitive intestinal resection with stage I or II gastrointestinal reconstruction. The optimal time for definitive surgery is still controversial. Based on our experiences, 1 year after the end of radiation therapy is optimal. Under the circumstances of emergency surgery, severe malnutrition, abdominal infection, extensive intestinal injury, and abdominal adhesions that cannot be mobilized, ostomy and abdominal drainage are recommended, and definitive surgery can be considered after the return to enteral nutrition and extinction of intestinal inflammation. Preoperative setting of ureteral catheter, imaging assessment of colorectal position and iliac vascular injury, and preoperative nutritional support can reduce the risk of systemic complications effectively.放射性肠损伤是指放射治疗盆腔、腹腔或腹膜后肿瘤所引起的肠道并发症，可累及小肠、结肠和直肠。尽管放疗技术的进步使放疗对靶区外组织的损伤大大减少，但90%接受放疗患者会出现腹泻、腹痛、便血等急性症状，50%的患者因消化道症状影响生活质量，20%~40%患者的症状为中到重度。依据病理学分期、特征和临床表现，放射性肠损伤可分为急性和慢性放射性肠损伤，一般以3~6个月为界。放射性肠损伤的主要预防措施为减少照射剂量和缩小照射野。急性放射性肠损伤主要表现为黏膜炎性反应，多为自限性病程，其治疗以对症治疗和营养治疗为主。慢性放射性损伤由于肠管慢性缺血和纤维化具有不可逆性，所以外科手术切除病变肠管是最理想的治疗措施。慢性放射性损伤的手术适应证为3、4级的肠损伤，包括梗阻、出血、肠坏死、穿孔和瘘；目前的手术方式为确定性肠切除加一期或二期消化道重建手术。放疗结束后实施确定性手术的最佳时机尚有争议，根据笔者团队经验，在放疗结束1年后可能是比较理想的手术时机。对于急诊手术、合并重度营养不良、腹腔感染、肠管广泛放射性损伤以及腹腔粘连无法分离的患者，先行造口或腹腔引流，待患者恢复肠内营养，炎性反应消退后，再考虑确定性手术。术前预置输尿管导管，通过影像学评估结直肠位置和髂血管损伤程度，以及术前营养支持治疗可有效降低系统并发症的发生风险。.