摘要目的:探讨左半结肠二次退镜检查对提高结肠腺瘤检出率的价值。方法:选取2024年1月至6月期间青海省人民医院消化内科收治的200例结肠镜受检者为研究对象，采取随机数字表法，分配受检者进入试验组或对照组，每组100例。试验组在盲肠插镜成功后，按照标准6 min退镜时间匀速退至肛门，二次插入至脾曲，正常退镜至肛门。对照组在盲肠插镜成功后，正常退镜至脾曲，脾曲至肛门退镜时间延长至常规两倍退镜时间。观察两组结直肠腺瘤检出率、不良反应发生率，对结直肠腺瘤检出率的影响因素进行多因素logistic回归分析。结果:试验组结直肠腺瘤检出率（63.00%，63/100）高于对照组（34.00%，34/100）（ χ 2=16.835， P0.05），且试验组患者检查过程中不良反应总发生率4.00%（4/100），对照组的不良反应总发生率5.00%（5/100），二者比较差异无统计学意义（ χ 2=0.116， P0.05），同时试验组波士顿评分+气泡评分与对照组相比差异有统计学意义［（8.15±1.25）分比（6.12±1.45）分， χ 2=10.604， P0.05］。多因素logistic回归分析纳入因素：年龄、性别、既往结肠镜检查史、腹部手术史、操作医师、第一次退镜是否发现息肉、左半结肠退镜时间及左半结肠二次退镜时间等，结果显示，结直肠腺瘤检出率与年龄、第一次退镜是否发现息肉、左半结肠退镜时间及左半结肠二次退镜时间有关联（ P0.05）。 结论:在结直肠腺瘤诊断过程中，退镜时间总长相同前提下，二次退镜可提升腺瘤检出率。

abstractsObjective:To evaluate secondary withdrawal of colonoscope of left colon to improve adenoma detection rate.Methods:A total of 200 patients who received colonoscopy at Department of Gastroenterology, Qinghai Provincial People's Hospital from January to June 2024 were randomly assigned to either the experimental group ( n=100) or the control group ( n=100) by using the random number table. The experimental group underwent standardized 6-minute colonoscopy with retraction to the anus, followed by reinsertion to the splenic flexure, and a second withdrawal. The control group performed a single withdrawal from the splenic flexure to the anus with the withdrawal time doubled. Colorectal adenoma detection rates and adverse event rates of the two groups were compared, and logistic regression analysis was performed to identify influencing factors for adenoma detection rate. Results:The detection rate of colorectal adenoma in the experimental group was higher than that in the control group [63.00% (63/100) VS 34.00% (34/100), χ2=16.835, P0.05]. There was no significant difference in the incidence of adverse reactions between the two groups [4.00% (4/100) VS 5.00% (5/100), χ2=0.116, P0.05]. Boston bowel preparation scale scores were higher in the experimental group (8.15±1.25 scores VS 6.12±1.45 scores, χ2=10.604, P0.05). According to the logistic regression analysis, the included factors were age, gender, history of previous colonoscopy, history of abdominal surgery, operator, polyps detection during the first withdrawal, regression time of left colon and secondary withdrawal time of of left colon. The factors affecting the detection of colorectal adenoma were directly related to age, detection of polyps, polyps detection during the first withdrawal, regression time of the left colon, and secondary withdrawal time of the left colon ( P0.05). Conclusion:With total withdrawal time held constant, a secondary withdrawal of the left colon significantly increases adenoma detection rate.