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1. JOURNAL Club
Presentation
DR RAAZIA

2. Impact of the Second
Examination of the
Proximal Colon on the
Adenoma Detection
Rate:
A Prospective
Randomized Controlled
Trial
AMERICAN JOURNAL
OF
GASTROENTEROLOGY

3. INTRODUCTION:
1- Colorectal cancer (CRC) is a major health problem worldwide, being
the third most common cancer and the second leading cause of cancer
death (1).
2- Colonoscopy with polypectomy can reduce CRC incidence and
mortality (2).
3- However, several studies indicate that colonoscopy does not have a
uniformly protective effect against CRC throughout the colon and that
the rate of protection is lower in the proximal colon (3–6).
4- Interval CRC identified before the next surveillance colonoscopy was
more likely to be located in the proximal colon (7,8).
5- Adenoma detection rate (ADR) is inversely associated with the risks
of interval CRC (9,10).
Recently, several studies have reported that Endocuff, full spectrum
endoscopy, water-aided colonoscopy, and repeat examination including
retroflection or second forward view can effectively increase the ADR,
but the second examination is a simple and safe method.

5. STUDY DESIGN
Prospective
study
Single-center RCT
Conducted
by the Third
People’s
Hospital in
CHINA
From June
2021 to June
2022.

6. INCLUSION
CRETERIA
 patients aged 18–80 years undergoing colonoscopy for
screening, surveillance, or diagnostic purposes were
recruited.
The categories were defined as follows:
 (i) screening: asymptomatic patients undergoing first-time
colonoscopy;
 (ii) surveillance: patients who had undergone a previous
colonoscopy (irrespective of the presence or absence of
polyps) in the context of CRC screening or post polypectomy
surveillance.
(iii) Diagnostic: patients undergoing colonoscopy for any
symptomatic indication (abdominal pain, blood per rectum,
constipation, chronic diarrhea, etc

7. EXCLUSION CRETERIA
Patients were excluded if they failed cecal intubation.
previous colorectal resection.
Inadequate bowel preparation quality (Boston Bowel Preparation Scale [BBPS] scores
BBPS <2 in any segment of the colon.
Inflammatory bowel disease or intestinal tuberculosis.
familial polyposis syndrome, coagulation dysfunction, or polyp retrieval failure

8. OUTCOME
MEASURES
The primary outcome measure was per-patient proximal
colon ADR.
This defined as the proportion of patients with at least 1
adenoma found in the proximal colon.
The secondary outcome measures included per-patient
whole-colon ADR and polyp detection rate (PDR), withdrawal
time, and BBPS scores.
Missed adenomas/polyps were defined as those detected on
a second examination of the proximal colon.

9. Study
population and
baseline
characteristics
A total of 924 patients were assessed for study eligibility
between June 2021 and June 2022.
 84 patients were excluded. ( not meeting the criteria).
Finally, 840 patients were enrolled for ITT analysis, of whom
5 and 4 were excluded from the PP analysis in the 2 groups
because of polyp retrieval failure.
 The baseline characteristics of all included patients are
same.

12. Colonoscopy
findings:
The colonoscopy findings are presented further in Table 2.
The indications for colonoscopy examination and the median
BBPS scores in the segment of the colon did not differ
between the 2 groups.
The median withdrawal time of the first proximal colon
examination was also not significantly different between the
2 groups 4.3 [4.0–4.7] vs 4.3 [4.0–4.8] minutes, P ( 0.469).
The median withdrawal time of the second proximal colon
examination was 3.1 (2.7–3.4) minutes. The median total
proximal colon withdrawal time 7.4 vs 4.3 minutes, P (
0.001)

14. Adenoma and polyp detection rates
The ITT analysis showed that
the proximal colon ADR in the
intervention group was
significantly higher than that
in the control group (35.7%
vs 25.2%, P ( 0.001).
Whole-colon ADR was also
higher in the intervention
group (44.0% vs 34.0%, P (
0.003)
In addition, there was an
increase in the proximal
colon PDR (55.0% vs 41.2%, P
(0.001)
and whole-colon PDR (67.6%
vs 60.2%, P 5 0.026) in the
intervention group.

16. Characteristics
of adenomas
detected on the
second
examination of
the proximal
colon
The mean size of adenomas found in the proximal colon on
the first examination was 4.9 mm in the intervention group
and 4.7 mm in the control group (P 0.427).
In the intervention group, the mean size of adenomas found
in the proximal colon on the second examination was less
than that on the first examination 4.2mm. (P 0.012).
Among the 80 additional adenomas, most (96.3%) of the
adenomas were ,10 mm in size, and 100% were slightly
elevated or sessile in morphology.
A total of 100% were tubular adenomas.
Adenoma with high-grade dysplasia was not found.

18. Alteration in surveillance recommendations
after second examination:
According to a consensus update by the US Multi-Society Task Force on Colorectal Cancer (19),
41 (9.8%) had their surveillance interval changed (Table 5), and 11 (2.6%) experienced a change
from no-risk or low-risk to high-risk adenoma.

19. Predictive
factors of
detecting
adenoma on the
second
withdrawal from
the proximal
colon
On multivariate logistic regression analysis:
Older age, adenoma detected on the first proximal colon
examination and
longer total proximal colon withdrawal time were
independent predictive factors for detecting adenoma on the
second withdrawal from the proximal colon.

21. DISSCUSSION/
Limitations:
In this RCT, we found that the second examination of the
proximal colon can significantly increase the proximal colon
ADR and PDR.
Study limitations:
1) Study was a single-center design. will require a
multicenter design to gain more accurate information.
2) included colonoscopies for any indications, and the
calculation of ADR was not restricted to a screening
indication.
3) 2 Examinations were performed by the same endoscopist,
so there may be a potential bias.

22. Conclusion:
Second examination in the
proximal colon
significantly increased the
proximal colon ADR and
the whole colon ADR.
Therefore, this simple and
reliable technique should
be considered during a
routine colonoscopy.
Thank you 