Endoscopy involves inserting a long, flexible tube equipped with a light and a camera into the body to visualize internal organs. Physicians use this process to examine the lining of the gastrointestinal tract or other hollow organs for diagnostic and therapeutic purposes. While the scope usually provides a forward view, retroflexion is a specialized technique used to enhance the examination. This maneuver temporarily alters the viewing angle to allow the camera to look backward, providing a more complete picture of the organ’s interior.
Defining the Retroflexion Maneuver
Retroflexion is a deliberate action where the endoscopist bends the flexible tip of the scope back upon itself. This manipulation causes the camera to turn approximately 180 degrees, facing the shaft of the insertion tube. The goal is to create a “U” or “J” shape with the distal end of the scope inside the body cavity.
The operator achieves this by manipulating control knobs located on the scope’s handle. These knobs control the tension on internal wires, which articulate the flexible tip in different directions (typically up, down, left, and right). By applying maximum upward deflection, often combined with slight rotation and withdrawal, the endoscopist executes the maneuver.
The Medical Necessity of Looking Backward
The primary reason for employing retroflexion is to eliminate blind spots inherent in a straight-on, forward-view examination. When the scope is advanced, the camera only sees what is directly in front of it. The area of the organ lining immediately behind the tip, or proximal to the camera, remains completely obscured.
This unseen area can be significant, particularly in large or complex anatomical structures. Pathological findings such as ulcers, small tumors, or vascular abnormalities can hide within the folds or curves of the organ wall in these proximal regions. A standard forward-view examination alone risks failing to detect these lesions.
Performing retroflexion ensures a comprehensive examination. By visualizing the previously hidden mucosa, the endoscopist can identify lesions for biopsy or immediate removal, significantly reducing the risk of a missed diagnosis.
Primary Areas Where Retroflexion is Utilized
Upper Endoscopy (EGD)
Retroflexion is routinely performed in the stomach during an upper endoscopy (esophagogastroduodenoscopy or EGD). The maneuver is important for inspecting the gastric fundus, the dome-shaped upper part of the stomach. Due to the angle at which the scope enters the stomach, the fundus is otherwise impossible to examine fully in a forward view.
When the scope is retroflexed, the camera looks back at the gastroesophageal junction and the fundus lining. This allows for the detection of conditions like hiatal hernias or gastric varices (enlarged blood vessels). Photo-documentation of the gastric fundus in the retroflexed view is a widely accepted requirement for a high-quality EGD.
Lower Endoscopy (Colonoscopy)
In lower endoscopy, such as colonoscopy, retroflexion is most frequently applied in the rectum, the final segment of the large intestine. The maneuver is performed in the capacious rectal vault to visualize the area immediately above the anal canal and the proximal side of the rectal valves. Lesions, including small adenomatous polyps or flat lesions, are often located just behind these anatomical structures and cannot be seen with a straight view.
Rectal retroflexion increases the detection rate of polyps in the distal colon. Although it is not always possible to perform retroflexion throughout the entire colon, the technique can also be safely attempted in the right side of the colon. This application helps address the challenge of missed lesions in the proximal colon, a known limitation of conventional forward-view colonoscopy.