Intubation of the Ascending Colon
Once correctly passed the hepatic flexure (Fig. 1), the intubation of the ascending colon up to the appendiceal orifice is relatively simple and can be further facilitated by the simultaneous aspiration of all excess air during the insertion of the colonoscope.
Also the ascending colon is usually explored with the patient in supine position (fig. 2).
Fig. 2: during the intubation of the ascending colon, the patient is usually in the supine position.
In most cases, when the tip of the scope reaches the area above the ileo-cecal valve, it is possible to observe the cecum and in these cases the approaching maneuver is quite easily (fig. 3).
Fig. 3 A-B: when the tip of the scope is near the ileo-cecal valve (A), it is possible to observe in perspective the appendiceal region (B).
Gradually progressing with the insertion, the tip of the scope arrives next to the appendiceal orifice (fig. 4 A). If the orifice is wide, it is possible to observe in immersion the appendiceal opening (Fig. 4 B)
Fig. 4 A - B: appendiceal orifice (A) and appendiceal channel in immersion (B)
In some cases, the cecum is unaligned with the lumen, and it is not possible to see the appendiceal orifice (fig. 5).
In such cases it may result hard to advance the tip of the scope and gain those few centimeters that allow a complete exploration of the cecum. It is necessary, then, to adopt ancillary maneuvers such as: complete air aspiration, patient’s deep inspiration to lower the diaphragm, manual compression on the area of the sigmoid if a recurrent parasite loop is suspected.
Instead, if we suspect an impingement of the distal segment of the colonoscope on the wall of the ascending colon, it is possible to perform a manual open-fingered compression on the posterior aspect of the right lumbar region (Waye’s point), to achieve the straightening of the distal tip of the scope and its progression (fig. 6).
Fig. 6: the compression on the posterior aspect of the right lumbar region (Waye’s point), facilitates the progression of the colonoscope from the ileo-cecal valve to the appendiceal orifice.
Last, if the patient has been positioned on his/her left side to ease the passing of the hepatic flexure, the restoration of the supine position facilitates the progression toward the appendiceal orifice. Should these maneuvers fail, the first option is to activate the variable stiffness to stiffen the segment of the scope that can be modulated or, the patient can be turned into the prone position (fig. 7).
Fig. 7: if the ancillary maneuvers of abdominal compression, air de-sufflation, deep breath inspiration, variation of the stiffness of the colonoscope do not result in effective advancement of the tip of the scope from the ileo-cecal valve to the cecum, the patient needs to be moved to the prone position.
When the anatomy is favorable, using adequate insufflation, the cecum can be distended and the endoscopist can perform the retroflexion to explore the proximal edge of the folds of the ascending colon (fig. 8 A), retracting the scope up to the hepatic flexure (fig. 8 B)
Fig. 8: if the cecum is ample and distensible, the endoscopist can perform the retroflexion maneuver to inspect in retrovision the proximal edge of the folds (A), retracting and rotating the instrument up to the hepatic flexure (B).