Aims
Detection and removal of colorectal polyps are important for the prevention of colorectal cancer. Among various strategies to enhance the polyp detection, a second-look examination of the right colon can improve the adenoma detection rate (ADR) in the proximal colon. This study aimed to determine whether a second look with patient position change improves ADR compared with a second look without a position change.
Methods
A total of 659 patients undergoing colonoscopy at six institutions were randomly assigned to one of two groups. In the second-look without position change group, the right colon was examined twice in the same position. In the second-look with position change group, the right colon was examined once, the patient’s position was changed (from left lateral to supine or from supine to left lateral), and the segment was re-examined. Each observation lasted at least one minute. Colorectal lesions detected during the examinations were analyzed for each group.
Results
The second-look with and without position change groups included 327 and 332 patients, respectively. Changing the patient’s position during the second look did not result in a significantly higher ADR compared with no position change (30.3% vs. 26.5%; p = 0.324) (Table 1). However, in both groups, the second look identified additional missed lesions, increasing ADR by 9.8% (p = 0.005) and 7.5% (p = 0.026), respectively, and increasing the polyp detection rate by 17.7% and 15.5%, respectively (p < 0.001). No increase in the detection of sessile serrated lesions was observed.
Table 1. Comparison between the first observations and the first + second observations in the control and position change group
|
|
Second look with position change group (n = 327) |
Second look without position change group (n = 332) |
|||||
|
|
First exam |
Frist and second exams |
p-value |
First exam |
Frist and second exams |
p-value |
|
|
Overall ADR for right colon, % |
67 (20.5) |
99 (30.3) |
0.005 |
63 (19.0) |
88 (26.5) |
0.026 |
|
|
Overall ASR for right colon, % |
15 (4.6) |
22 (6.7) |
0.310 |
15 (4.5) |
25 (7.5) |
0.142 |
|
|
Overall PDR for right colon, % |
101 (30.9) |
159 (48.6) |
<0.001 |
103 (31.0) |
154 (46.5) |
<0.001 |
|
|
MAP, n |
0.3 ± 0.6 |
0.4 ± 0.8 |
0.012 |
0.3 ± 0.6 |
0.4 ± 0.7 |
0.030 |
|
|
MSP, n |
0.0 ± 0.2 |
0.1 ± 0.3 |
0.101 |
0.1 ± 0.3 |
0.1 ± 0.4 |
0.165 |
|
|
MAPP, n |
0.4 ± 0.8 |
0.8 ± 1.0 |
<0.001 |
0.4 ± 0.8 |
0.7 ± 1.0 |
<0.001 |
|
ADR, adenoma detection rate; ASR, SSL detection rate; PDR, polyp detection rate; SSL, sessile serrated lesion; MAP, mean number of adenomas per patient; MSP, mean number of SSLs per patient; MAPP, mean number of all polyps per patient.
Conclusions
A second-look examination of the right colon significantly increased ADR and polyp detection rates regardless of position change. Similar outcomes in both groups suggest that the effect of position change may be offset when a second look is routinely performed.