Evaluation of the Impact of Water Method During Insertion Phase of Flexible Sigmoidoscopy in Training
Condition: Colorectal Cancer Screening
MeSH terms: Colorectal Neoplasms
Study type: Interventional

Summary: 
      Colonoscopy is a sedated procedure traditionally performed using air insufflation during the
      insertion phase of the procedure. Recently, the use of water method (eg, water infusion or
      water exchange techniques) during the insertion phase of colonoscopy has been reported to
      increase the proportion of patients in whom complete unsedated colonoscopy could be achieved,
      reduce patient recovery time burdens, decrease abdominal discomfort during and after
      colonoscopy, enhance cecal intubation, and increase willingness to repeat an unsedated
      colonoscopy. However, there has been no study on the use of water method during the training
      of primary care doctors or nurse endoscopists in flexible sigmoidoscopy for colorectal cancer
      screening.

      In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can
      potentially reduce patient discomfort and increase the rate of achieving an adequate depth of
      scope insertion are desirable. Our current study aims to evaluate the impact of water method
      during insertion phase of FS in the training of primary care doctors or nurse endoscopists
      for colorectal cancer screening.
    

Detailed description: 
      It is estimated that there are about 1.2 million patients with colorectal cancer (CRC)
      worldwide, with a rising trend in CRC incidence and mortality globally. In Hong Kong,
      colorectal cancer ranks first in cancer incidence and second in cancer mortality.

      CRC is one of the most preventable cancers because its development in general follows an
      adenoma-carcinoma sequence. Adenomas are considered precursor lesions for CRC. Recent
      guidelines from USA, Europe and Asia Pacific region recommend CRC screening for average-risk
      asymptomatic individuals starting at age 50. Modalities such as guaiac-based fecal occult
      blood tests (gFOBT), fecal immunochemical tests (FIT), flexible sigmoidoscopy, and
      colonoscopy are among the acceptable options for CRC screening. Studies have shown that early
      detection and removal of colorectal adenoma by screening flexible sigmoidoscopy (FS) and
      screening colonoscopy with polypectomy reduce CRC incidence and mortality.

      Approximately two-thirds of CRC are located in the sigmoid colon and rectum, which can be
      diagnosed by FS. In countries where colonoscopy may not be widely available or a prolonged
      waiting time exists, FS becomes an attractive option for CRC screening.

      When compared to colonoscopy, FS has the advantages of being an unsedated procedure,
      requiring less stringent bowel prep, and being less technically demanding. While flexible
      sigmoidoscopy have traditionally been performed by gastroenterologists or surgeons, studies
      have demonstrated that adequately trained primary care doctors and nurse endoscopists can
      perform screening flexible sigmoidoscopy as safely and effectively as gastroenterologists or
      surgeons. The American Society for Gastrointestinal Endoscopy (ASGE), the Society of American
      Gastrointestinal Endoscopic Surgeons (SAGES), and the The Society of Gastrointestinal Nurses
      and Associates (SGNA) recommend 25 supervised procedures for training in FS. Hawes R et al
      reported that at least 30 supervised procedures were needed before 85% - 90% of the
      procedures were graded as competent in doctors without prior experience on rigid
      sigmoidoscopy. In another report, at least 50 supervised procedures have been suggested for
      FS training of clinicians without prior endoscopic skills.

      From a technical standpoint, colonoscopy is a sedated procedure traditionally performed using
      air insufflation during the insertion phase of the procedure. Recently, the use of water
      method (eg, water infusion or water exchange techniques) during the insertion phase of
      colonoscopy has been reported to increase the proportion of patients in whom complete
      unsedated colonoscopy could be achieved, reduce patient recovery time burdens, decrease
      abdominal discomfort during and after colonoscopy, enhance cecal intubation, and increase
      willingness to repeat an unsedated colonoscopy. However, there has been no study on the use
      of water method during the training of primary care doctors or nurse endoscopists in flexible
      sigmoidoscopy for colorectal cancer screening.

      In unsedated endoscopic procedure such as FS, endoscope insertion techniques that can
      potentially reduce patient discomfort and increase the rate of achieving an adequate depth of
      scope insertion are desirable. Our current study aims to evaluate the impact of water method
      during insertion phase of FS in the training of primary care doctors or nurse endoscopists
      for colorectal cancer screening.
    

Intervention name(s): Water method group; Air insufflation group
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): During the insertion phase of the initial 30 FS procedures, sterile water will be infused by a standard endoscopy water pump into the distal colon to allow passage of endoscope to ≥ 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Air insufflation will not be used during the insertion phase. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa.; During the insertion phase of the initial 30 FS procedures, air insufflation will be used to allow passage of endoscope to at least 50cm above anal verge (including rectum, sigmoid colon and part of descending colon), or to the limit of patient tolerance of an unsedated procedure. Trainees will be allowed 10 minutes for the insertion phase. The unassisted portion of the examination would be terminated if reasonable progress is not being attained, excessive patient discomfort observed, or the supervising endoscopist believes that patient safety may be compromised. During the withdrawal phase, air insufflation will be used in standard fashion for examination of the colonic mucosa.
Other intervention name(s): Water Immersion; Air insufflation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Diagnostic