Background and Aims

Although water exchange may improve adenoma detection compared with CO₂, it is unclear whether water is a better medium to fill the lumen during withdrawal and visualize the mucosa. Total underwater colonoscopy (TUC) involves the use of water exchange with the air valve off during insertion followed by the inspection of the mucosa under water. Our goal was to compare miss rates for TUC with standard CO₂ for polyps and adenomas using a tandem colonoscopy design.

Methods

We randomized participants to undergo tandem colonoscopies using TUC or CO₂ first. In TUC, water exchange was performed during insertion, and withdrawal was performed under water. For the CO₂ colonoscopy, both insertion and withdrawal were performed with CO₂. The main outcomes were miss rates for polyps and adenomas for the first examination calculated as the number of additional polyps/adenomas detected during the second examination divided by the total number of polyps/adenomas detected for both examinations. Inspection times were calculated by subtracting the time for polypectomy, and care was taken to keep the times equal for both examinations.

Results

A total of 121 participants were randomized with 61 having CO₂ first. The overall miss rate for polyps was higher for the TUC-first group (81/237; 34%) compared with the CO₂-first cohort (57/264; 22%) (P = .002). In addition, the overall miss rate for all adenomas was higher for the TUC-first group (52/146; 36%) compared with the CO₂ group (37/159; 23%) (P = .025). However, 1 of the 3 endoscopists had higher polyp/adenoma miss rates for CO₂, but these were not statistically significant differences. The insertion time was longer for TUC than for CO₂. After adjusting for times, participant characteristics, and bowel preparation, the miss rate for polyps was higher for TUC than for CO₂.

Conclusions

We found that TUC had an overall higher polyp and adenoma miss rate than colonoscopy performed with CO₂, and TUC took longer to perform. However, TUC may benefit some endoscopists, an issue that requires further study. (Clinical trial registration number: NCT03231917.)

中文翻译：

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比较总水下结肠镜检查与标准CO _2的腺瘤和息肉漏诊率：使用串联结肠镜检查方法的随机对照试验

背景和目标

尽管与CO ₂相比，水交换可以改善腺瘤的检测，但尚不清楚水是否是撤药期间内腔充盈和可视化粘膜的更好介质。完全水下结肠镜检查（TUC）涉及在插入过程中关闭气阀的情况下进行水交换，然后在水下检查粘膜。我们的目标是使用串联结肠镜检查设计比较息肉和腺瘤的标准T CO ₂与标准CO _2的漏检率。

方法

我们将参与者随机分为两组，首先使用TUC或CO ₂进行串联结肠镜检查。在TUC中，在插入过程中进行水交换，并在水下进行抽水。对于CO ₂结肠镜检查，插入和退出均使用CO _2进行。主要结局是第一次检查的息肉和腺瘤的漏诊率，计算方法为第二次检查期间发现的额外息肉/腺瘤的数目除以两次检查的检出的息肉/腺瘤的总数。通过减去息肉切除术的时间来计算检查时间，并注意保持两次检查的时间相等。

结果

总共121位参与者被随机分配，其中61位首先获得CO ₂。TUC-first组的息肉总体漏诊率更高（81/237； 34％），而CO ₂ -first组（57/264； 22％）更高（P  = 0.002）。此外，与CO ₂组（37/159； 23％）相比，TUC第一组的所有腺瘤的总漏诊率更高（52/146； 36 ％）（P  = .025）。然而，3名内镜医师中有1名具有较高的CO ₂息肉/腺瘤漏诊率，但差异无统计学意义。TUC的插入时间比CO ₂的插入时间长。在调整时间，参与者特征和肠道准备后，TUC的息肉漏诊率高于CO ₂。

结论

我们发现，与使用CO ₂进行结肠镜检查相比，TUC的息肉和腺瘤漏诊率总体更高，而TUC花费的时间更长。但是，TUC可能会使某些内镜医师受益，这个问题需要进一步研究。（临床试验注册号：NCT03231917。）