Water exchange colonoscopy decreased adenoma miss rates compared with literature data and local data with CO2 insufflation: an observational study

Table 3 Detection of adenoma and proximal colon hyperplastic polyp during first-pass examination

Variable	WE group (n = 86)	CO₂ group (n = 86)	P value
Overall ADR, n (%) [95% CI]	46 (53.5) [42.4, 64.3]	50 (58.1) [47.0, 68.7]	0.645
ADR for screening indication, n (%) [95% CI]	16/33 (48.5) [30.8, 66.5]	30/48 (62.5) [47.4, 76.0]	0.257
ADR for surveillance indication, n (%) [95% CI]	30/53 (56.6) [42.3, 70.2]	20/38 (52.6) [35.8, 69.0]	0.831
Right colon ADR, n (%) [95% CI]	32 (37.2) [27.0, 48.3]	30 (34.9) [24.9, 45.9]	0.874
Proximal colon ADR, n (%) [95% CI]	39 (45.3) [34.6, 56.5]	38 (44.2) [33.5, 55.3]	1.000
Distal colon ADR, n (%) [95% CI]	22 (25.6) [16.8, 36.1]	27 (31.4) [21.8, 42.3]	0.499
Overall advanced ADR, n (%) [95% CI]	5 (5.8) [1.9, 13.1]	5 (5.8) [1.9, 13.1]	1.000
Proximal colon advanced ADR, n (%) [95% CI]	2 (2.3) [0.3, 8.2]	2 (2.3) [0.3, 8.2]	1.000
Overall MAP (SD)	1.2 (1.4)	1.4 (1.8)	0.394
Right colon MAP (SD)	0.6 (1.0)	0.6 (1.1)	0.827
Proximal colon MAP (SD)	0.8 (1.2)	0.9 (1.4)	0.680
Right colon mean number of adenoma and HP (SD)	0.9 (1.1)	0.8 (1.1)	0.739
Proximal colon mean number of adenoma and HP (SD)	1.3 (1.5)	1.2 (1.4)	0.797
PHP-DR, n (%) [95% CI]	23 (26.7) [17.8, 37.4]	26 (30.2) [20.8, 41.1]	0.736

Eight and seven patients in the WE group and CO₂ group had adenoma found only during the second-pass examination; and the ADR for the combined examinations would be 62.8% (95% CI, 51.7–73.0%) for WE, and 66.3% (95% CI, 55.3–76.1%) for CO₂, respectively (P = 0.75)
Abbreviation: WE Water exchange, ADR adenoma detection rate, CI confidence interval, MAP mean adenoma per procedure, SD standard deviation, HP hyperplastic polyp, PHP-DR proximal hyperplastic polyp detection rate

ISSN: 1471-230X