中文摘要：

目的调查肾后结肠的发生率及相关危险因素。方法回顾性分析2009年1月至2014年9月行腹部CT平扫检查患者的临床资料，检查时体位先仰卧位，后俯卧位。以结肠位于肾后线的后方且同时位于肾外侧线以内诊断为肾后结肠。有效调查1001例，男448例，女553例。年龄19～90岁，平均50岁。按年龄将患者分为19～28岁87例、29～38岁151例、39—48岁197例、49—58岁240例、59～68岁239例、69～78岁71例、≥79岁16例等7组；按体重指数分为〈18．5kg／m261例、18．5～24．9kg／m2679例、〉125．0kg／mz261例等3组。分析不同性别、年龄、体重指数分组的肾后结肠发生率，以及不同检查体位肾后结肠的发现率。多因素Logistic回归分析肾后结肠的相关危险因素。结果本组1001例中，63例（6．3％）证实存在肾后结肠，其中37例（3．7％）位于左侧，16例（1．6％）位于右侧，10例（1．0％）双侧均有。CT检查时仰卧位发现14例（I．4％），俯卧位发现28例（2．8％），仰卧位和俯卧位均发现者21例（2．1％）。63例中，男36例（8．0％），女27例（4．9％）。〉69岁者的肾后结肠发生率高于〈69岁者。体重指数〈18．5kg／m2者的肾后结肠发生率高于≥18．5kg／m2者。有肾后结肠组和无肾后结肠组的平均年龄分别为（55．8±16．2）岁和（49．8±14．1）岁，平均体重指数分别为（20．24-2．7）kg／m2和（23．4±3．2）kg／m2。多因素Logistic回归分析结果显示肾后结肠发生率与性别、年龄、体重指数均相关。结论本组患者的。肾后结肠发生率为6．3％，多于俯卧位CT平扫检查发现，左侧发生率高于右侧。低体重指数、高龄、男性是肾后结肠发生的危险因素。对于体重指数〈18．5kg／m2、≥69岁以及行俯卧位左侧经皮肾手术的男性患者，术前应行CT检查明确是否存在肾后结肠。

英文摘要：

Objective To investigate the prevalence of retro-renal colon in china and report its potential risk factors. Methods We reviewed the abdominal computed tomography scans （ACTS） that were done in both supine and prone position on the same patient from January 2009 to September 2014. Instances where any part of the colon extended posteriorly to the posterior renal line and extended directly behind the kidney were considered as retro-renal colorr Results We accrued a total of 1 001 patients, including 448 male and 553 female. 63 patients （6. 3% ） were diagnosed as retro-renal colon. The location of retro-renal colon included 37（3.7% ） cases in the left side, 16（ 1.6% ） cases in the right side and 10 （ 1.0% ） cases in bilateral side. Retro-renal colon was found in 14 （ 1.4% ） patients only in supine position, 28 （2. 8% ） patients only in prone position and 21 （2. 1% ） patients in both supine and prone position. Male patients had higher incidence of retro-renal colon than that in female （8.0% vs. 4. 9% ）. Patients with retro-renal colon were also tend to be older and had smaller body mass index （BMI） value than those patients without retro- renal colon. The multivariate regression demonstrated that smaller BMI value, age and gender were risk factors for the increasing probability of retro-renal colon （ all P 〈 0.01 ）. Conclusions Retro-renal colon ismore frequently seen in the prone position, especially on the left side. Smaller BMI value, older age, and male gender were risk factors for retro-renal colon. For patients with BMI 〈 18.5 kg,/m2 or Age 969 years, or male patients with left percutaneous access in prone position, pre-operative CT should be done.