In patients with simple colorectal anatomy, a sigmoid colon with few angulations and an overall straight development of the colon, the progression to the cecum is quite easy using tip deflections combined with pull back maneuvers and torque-steering and with little or no discomfort to the patient. If the endoscopist should drive the colonoscope into a very tortuous colon with many angled segments, then a number of ancillary maneuvers should be adopted in order to modify these angulations and negotiate them to advance the colonoscope.
The manual compression on the abdomen is the first ancillary maneuver to perform in case of difficult advancement of the colonoscope. It should be tested by the operator, who identifies the abdominal area where the pressure turns out to be effective, and this is replicated by the nurse using the left hand, while the endoscopist goes back to manage the handle of the scope with both hands. Expert nurses are able realize when it becomes necessary and select autonomously the most appropriate type of abdominal compression. Manual compression is easier to perform and most effective with the patient in supine position. It can be exerted on “specific” points according to the segment of the colon already intubated; or it can be applied on “aspecific” areas of the abdominal wall where the pressure of the fingers extremities achieve the progression of the tip of the scope. Depending on the situations, the abdominal compression can be perpendicular to the abdominal wall or it can be directional, orienting the pressure of the finger toward a specific quadrant of the abdomen.
Specific points of abdominal compression are shown in fig. 1
Fig. 1: ‘specific’ points for the abdominal compression:
1 – the perpendicular compression or a compression slightly oriented toward the groin, in sovra-pubic region, is used to limit the enlargement of the upper portion of the sigmoid loop;
2 – the pressure below the sternum, applied with the fingers perpendicular to the abdominal wall, helps containing a deep transverse loop and directs the tip of the scope toward the hepatic flexure;
3 – the compression directed from the umbilical area toward the left abdominal quadrant prevents or limits the formation of a sigmoid loop during the intubation of the descending colon;
4 – the directional compression on the right-upper abdominal quadrant toward the diaphragm modifies the angulation of the hepatic flexure;
5 – the compression applied on the right side and directed toward the umbilicus modifies the axis of the ascending colon and supports the progression of the scope to the ileo-cecal valve and the cecum.
If the compression becomes necessary when the scope has been inserted for about 20 cm., and the insertion force causes pain to the patient with little or no advancement of the tip of the colonoscope, then the compression should be exerted in the sovra-pubic region, after complete retraction of the instrument for the whole redundant tact to regain the one-to-one ratio between pushing and advancement. In this point the compression is perpendicular to the abdominal wall or slightly directed from the umbilicus toward the pubis, with curved hand, in order to contain the top of the S or N loop and offer a “fulcrum” to the advancement of the colonoscope (fig. 2 A-B).
Fig. 2 A-B: if the recto-sigmoid junctionis hard to pass (A) for excessive bending (red circle), the sovra-pubic compression works as a fulcrum, favoring the widening of the angle (green circle) and the progression of the scope (B).
If the sigmoid has been straightened and the tip of the scope is engaged in the splenic flexure, sometimes the pushing force may cause the sigmoid loop to recur (Fig. 3 A-B).
Fig. 3 A-B: if the splenic flexure is hard to pass (A), and a variable stiffness colonoscope is not available, the insertion of the colonoscope is ineffective and tends to form again a parasite loop in the sigmoid colon (B).
In such cases, when variable stiffness colonoscopes are not available, prior to move the patient on the right side, a directional compression can be applied from the umbilicus toward the left side to achieve opening of the splenic angle and keep the scope straight (fig. 3 C).
Fig. 3 C: directional compression from the umbilicus to the left side favors straightening of the sigmoid and helps passing the splenic flexure.
Also in this situation, prior to the abdominal compression, the colonoscope should be retracted for the whole redundant segment.
A typical area of “perpendicular” compression is that below the sternum (fig. 1 and 2), to sustain the arch of the transverse colon following shortening with pull back maneuvers of the colonoscope (Fig. 4). In our experience the compression below the sternum is more effective than that in the sovra-umbilical region and significantly favors the progression of the tip of the scope to the hepatic flexure.
Fig. 4: the perpendicular compression below the sternum supports the shortening of the colon achieved with pull-back maneuvers, and favors the advancement of the colonoscope to the hepatic flexure.
Sometimes it may be useful to exert a directional compression on the area of the hepatic flexure (fig. 1 – 4), to modify its shape and ease the progression of the scope.
The compression on the right side of the abdomen (fig. 1-5, the so-called ”Waye’s point”) applied with the fingers toward the umbilicus, is used to push gently the colonoscope medially when it becomes stuck at the level of the ileo-cecal valve and does not progress to the cecum (fig. 5).
Fig. 5: the finger-made compression on the right side toward the umbilicus (Waye’s point) is useful when the tip of the scope does not progress over the ileo-cecal valve.
Should this type of manual compression be unsuccessful, the alternative is to put the patient in prone position on the table.
When the anatomy of the colon is complex, with very tortuous bends and loops, the endoscopists tests different points on the abdomen with his/her fingers, searching for aspecific area whose compression would facilitate the advancement of the scope, combined or not with other maneuvers such as deep inspiration or change of decubitus.
The efficacy manual compression on the abdomen may be reduced or even vanished under different circumstances. In obese patients the sigmoid loops tend to dislocate toward the right abdominal quadrants. In particular, when approaching the splenic flexure, the insertion force tends to make the previously straightened sigmoid loop recur. In very thin patients the transverse colon is often ptosic and is interposed between the hand and the sigmoid to compress. In patients with marked abdominal contracture, the manual compression is essentially frustrated. Also in patients with previous colorectal surgery, the manual compression may be useful, but often requires the search for aspecific points because of the surgery-induced anatomic alterations. Last but not least, when excess insufflation is performed, the distension of the colonic loops hinders the advantages of the manual compression on the abdomen.
Changing the Position of the Patient
When the position of the patient on the endoscopic table is changed, the fixed angles of the colon, i.e. splenic and hepatic flexure, are contextually modified; The mobile segment of the colon, i.e. transverse and sigmoid colon, tend to follow the gravity and subsequently change their axis which crosses the axis of the descending and ascending colon (Fig. 6 A-D).
Fig. 6 A-D: the change of the position of the patient modifies the width of the angles between the fixed colonic segments (descending and ascending) and the mobile segments (sigmoid and transverse). Gravity draws the mobile segments and transforms the acute angles (red circle) in obtuse angles (green circles), easier to pass with the scope. Also the angle between the sigmoid and the descending colon is modified (S = splenic flexure; H = hepatic flexure).
The first change in patient’s position may be needed when passing the recto-sigmoid junction: he/she can be rotated to the supine position from the initial left lateral decubitus. In case of difficulty in passing a very sharp sigmoid-descending junction, the endoscopist will put the patient on his/her right side to favor the enlargement of the passing angle (Fig.7A-B)
Fig. 7 A-B: when the sigmoid-descending junction is hard to pass (S-D J), the change of the position from the left lateral (A) to the right lateral decubitus (B) transforms the angle from acute (red circle) to obtuse (green circle).
Also a very sharp splenic flexure can be challenging and the patient should be positioned on the right side. Conversely, in case of challenging hepatic flexure, the rotation of the patient to the supine or left lateral position may greatly ease the progression of the scope (Fig. 6).
Last, once reached the ileo-cecal valve, if the scope does not progress into the cecum and the manual compressions have been ineffective, then patient can be put in prone position.
When the insertion of the colonoscope in the distal ascending colon is difficult, the deep inspiration often helps the success of the maneuver (Fig.8)
Fig.8: the deep inhaling determines the drop of the diaphragm (blue arrows), which is transmitted more or less consistently on both the splenic and the hepatic flexures
The lowering of the diaphragm which follows the deep inhaling favors the sliding of the scope downward.
The endoscopist may ask the patient to take a deep breath when the tip of the scope is engaged in a loop and does not hook a fold to make fulcrum to advance, trying simultaneously to aspirate air.
Aspiration of air (De-sufflation).
The excess insufflation of air or gas is never advantageous for the intubation of the colon. Nonetheless, also when limited, it is useful to remove it completely to help progression of the scope. The typical situation where the aspiration of air or gas favors the advancement, is when the colonoscope is in the transverse colon (Fig. 9 A).
Fig. 9(A-B): the aspiration of air in the transverse colon is started when the tip of the scope has passed the medial portion (A), after straightening and following manual compression below the sternum. The effect of de-sufflation is to shorten the transverse and favor the passive advancement of the tip of the colonoscope (B).
In fact, once passed the medial portion of the transverse colon, and straightened the scope with the pull-back maneuver, the aspiration shortens the transverse colon and automatically projects the hepatic flexure next to the tip of the scope (Fig. 1-B).
In many circumstances, intuition and expertise of the operator combine the effects of deep inhaling, manual compression and de-sufflation with positive impact on the different segments of both the colon and the colonoscope.