Does Inspection of Colonic Mucosa During Insertion Improve Adenoma Detection?
Condition: Adenoma Colon; Serrated Adenoma
MeSH terms: Adenoma
Study type: Interventional

Summary: 
      This is a prospective randomised controlled trial to assess an intervention of inspection
      during both phases of colonoscopic examination ( insertion and withdrawal) improve adenoma
      detection rate when compared to inspection only during withdrawal.
    

Detailed description: 
      Successful implementation of colorectal screening programmes and improvement in colonoscopic
      technology have resulted in significant decrease in colorectal cancer incidence and
      mortality. Effectiveness of colonoscopy largely depends on detection and removal of adenomas
      before they become cancerous. Despite the vast improvement in colonoscopy training and
      technology, it remains as an imperfect tool. It has been reported that the adenoma miss rate
      during colonoscopy varies between 6-27% in clinical practice. Adenoma Detection Rate (ADR) is
      a surrogate marker of efficient colonoscopy. Researchers continue to explore various methods
      and technologies to improve adenoma detection such as frequent position changes, routine use
      of antispasmodics and devices to improve the mucosal visibility (third eye retro view scope,
      Transparent cap, Endocuff).

      However, all the techniques are focused on the withdrawal stage of the examination. Colonic
      examination is traditionally performed with rapid passage of colonoscope to the caecum and a
      careful examination of mucosa is carried out during the withdrawal phase. Polyps are removed
      during the withdrawal phase. It is well known from expert opinion that some polyps are
      detected during the insertion phase rather than withdrawal phase especially in sigmoid and
      transverse colon. This could be due to different anatomical configuration of colon during
      insertion and withdrawal.

      During insertion phase colonic mucosa is stretched and the folds are splayed due to the
      formation of loops and angulation hence affects the visualised area of the mucosa ahead of
      the colonoscope. During withdrawal, the colon is shortened and the adjacent folds are brought
      closer to each other. On withdrawal colon is much straighter. Therefore, it may expose
      different portions of colonic mucosal surface on insertion and withdrawal.

      Flexible sigmoidoscopy Bowel cancer screening programme (Bowel Scope) has been successfully
      implemented since May 2013. Initial reports suggest ADR within Bowel Scope screening varies
      considerably.

      Therefore, we propose a simple technique to improve ADR in Bowel Scope Screening.

      RATIONALE FOR CURRENT STUDY

      Recent report suggests that ADR within Bowel Scope screening (BSS) varies considerably. We
      propose a small technical alteration to improve ADR in BSS. A recent prospective trial
      highlighted that if polypectomy was performed only during Withdrawal Phase (WP) when compared
      to performing careful inspection and polypectomy during Inspection Phase (IP) plus WP, polyps
      could be missed in about 7% of patients. We hypothesised that careful inspection and
      polypectomy during both phases would be complementary and it would increase ADR by complete
      visualisation of recto sigmoid mucosa during Bowel Scope.
    

Intervention name(s): Colonic inspection
Intervention type(s): Other
Intervention description(s): Participants who are randomised to undergo the intervention will have the colonic mucosa examined during inspection and withdrawal phase of examination
Other intervention name(s): Inspection of colonic mucosa during insertion and withdrawal
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants are randomised to undergo the flexible sigmoidoscopy screening examination either for control or intervention group. Control group is to undergo inspection of colonic mucosa only during withdrawal phase of the examination. Intervention group will undergo the examination during which the colonic mucosa will be inspected during inspection and withdrawal phase.
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Adenoma; Sessile serrated adenoma