Practical Gastrointestinal Endoscopy

COLONOSCOPY AND FLEXIBLE SIGMOIDOSCOPY 117
control, the endoscopist is being indecisive—it takes at most a
second or two to make the angulation control adjustment and
then return the hand to shaft management.
Two-person colonoscopy
Two-person colonoscopy relies on an assistant to handle the
shaft. This allows the endoscopist to use the control body of
the instrument in the way that it is (unfortunately) currently
designed—namely with the left hand working the up/down
control and air/water/suction valves and the right hand adjusting
the right/left angulation control. The assistant performs the
role ascribed to the right hand of the single-handed endoscopist,
pushing and pulling according to the spoken instructions of the
endoscopist. A good assistant learns to feel the shaft to some
extent and to apply some twist. More often, the assistant pushes
with concealed gusto, causing unnecessary loops that are not
apparent to the endoscopist but painful for the patient. Unless
endoscopist/assistant teamwork is skilled and interactive, the
two-person approach to colonoscopy can be as illogical and
clumsy as would be expected of two people attempting any other
intricate task, neither quite knowing what the other is doing. In
occasional difficult situations, for instance passing an awkward
angulation or snaring a difficult polyp, all endoscopists justifiably
use the assistant briefly to control the shaft for a moment
or two.
Fig. 6.19–The instrument shaft
should be held delicately between
the thumb and fingers.
SINGLE-HANDED STEERING
Stance should be relaxed and the endoscopist should also hold
the colonoscope in a relaxed manner. Colonoscopy mostly
requires fine and fluent movements, like those of a violin player—a
similarly balanced position and handling are needed. The
modification of endoscopist stance and patient position used by
some ‘two-handed’ endoscopists has been mentioned above, the
patient being positioned close to the edge of the trolley or cart so
that the shaft can hang down, allowing the single-handed endoscopist
to trap it with thigh pressure from time to time.
Logical steering responses depend on quick, almost reflex, coordination
between the right and left hands, which comes with
practice. Colonoscopy, from slow deliberate beginnings, can
become a relatively rapid and fluent procedure.
Key points for colonoscope steering are as follows:
•–Twisting (torquing) the shaft only affects the tip when the shaft
is straight (Fig. 6.20). When a loop is present in the shaft, twisting
forces applied will be lost within the loop. When the shaft is
straight, twist becomes an excellent way to torque or corkscrew
Fig. 6.20–Twist only affects the
tip if the shaft is straight.