R vs L Lateral Decubitus Positioning in Colonoscopy

Overview

Colonoscopy continues to be the gold standard in detecting precancerous lesions in the colon. It relies on adequate visualization of the bowel wall to see and remove such lesions. Visualization is improved with luminal distention, and a multitude of studies have been done to determine ways to increase this luminal distention. The investigators theorize that positioning in the Right Lateral Decubitus rather than the Left Lateral Decubitus may be a cost free method to increase luminal distention and, hence, improve visualization in colonoscopy. In the Right Lateral Decubitus position, the sigmoid colon and cecum - both parts of the bowel that are not fixed - air used during colonoscopy will rise in a dependent fashion, increasing luminal distention. In the left lateral decubitus position, the bowel collapses, creating an often difficult area to maneuver and visualize. The investigators would like to compare both positions to determine if it affects outcomes in colonoscopy. In particular, cecal intubation rates and adenoma detection rates.

Colonoscopy is considered the gold standard for detecting precancerous lesions in the bowel - providing both diagnostic and therapeutic value. Colonoscopy is, ultimately, operator dependent and relies on adequate visualization of these lesions. A multitude of studies have been done to determine the best way to achieve luminal distention that provides the best visualization to detect and remove adenomas. Recent literature has studied the effect of position changes in colonoscopy. Position changes have been theorized to increase luminal distention in the bowel - improving visualization and maneuverability through the colon. Both air and water are used during colonoscopy, with air rising in a dependent fashion in the colon to the highest point. The standard position to perform colonoscopy is left lateral decubitus. In this position, parts of the bowel collapse as air rises into other parts of the bowel. This includes the sigmoid colon and the cecum, both of which are not fixed and can therefore collapse becoming technically challenging to maneuver around. In the right lateral decubitus position, the air rises into these unfixed areas of bowel and are easier to maneuver. A trial by Vergis et al found that right lateral decubitus resulted in quicker examination times and more comfort in their cohort of patients as opposed to the left lateral decubitus position. The investigators note, however, that the population in which this study took place are not comparable to the patients in Newfoundland and in Canada. The investigators also note a study by Ou et al that found position changes had no effect in adenoma detection. Furthermore, a study by Ball et al found conflicting results with position change increased adenoma detection in the right but not the left side of the colon. Conflicting results between all these trials and the populations used have lead to us question if position changes, a cost free and technically easy intervention, can increase visualization in colonoscopy. The investigators propose a randomized controlled trial that compares positioning patients in the right lateral decubitus or left lateral decubitus to aid in luminal distention and visualization, decreasing cecal intubation time and ultimately increasing adenoma detection rate in colonoscopy. In this trial, participation in the study will be offered when patients present for their scheduled colonoscopy. The patients will be consented at this time for both the colonoscopy procedure and participation in the trial. Patients who consent to take part will then be randomly assigned to either the right or left lateral decubitus starting position. The colonoscopy will then be done in the usual manner with appropriate sedation. Timing throughout the colonoscopy, the number of polyps found and quality of the visualization will then be recorded during the procedure. Patients will then be debriefed regarding their colonoscopy following the procedure in recovery.