Practical Gastrointestinal Endoscopy

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CHAPTER 6
Middle 'helper' finger
Fig. 6.17–Single-handed control:
the forefinger alone activates the
air/water and suction valves; the
middle finger acts as ‘helper’ to
the thumb for angulation.
Fig. 6.18–The thumb can reach
the lateral angulation control if
the hand is positioned appropriately.
plete control and the opportunity at all times to feel the colonoscope
interacting with loops and bends.
The endoscopist should grip the shaft (insertion tube) 25–
30·cm away from the anus. Many people make the mistake of
holding too close to the anus, resulting in the need for frequent
changes of hand-grip and jerky insertion technique. Holding the
shaft further back makes for smoother insertion, easier application
of torque (maintained twisting force) and better feel of the
forces involved.
Handling efficiency can be increased by disciplining the
fingers of the left hand (Fig. 6.17). Using only two fingers, the
fourth (ring finger) and the little finger, to grip the control body
lets the middle finger assume an invaluable ‘helper’ role to the
thumb. Most endoscopists, unthinkingly but unnecessarily, use
three fingers to hold the control body—and then wonder why
angulation can be so awkward. Single-handed steering is also
made easier if the first finger alone operates the air/water or suction
valves, again so as to leave the middle finger free to act as
‘helper’ to the thumb in managing the angulation controls. For
those with reasonably large hands it is practicable for the left
thumb to reach both the up/down and the lateral angulation
controls (Fig. 6.18).
Right-hand ‘torque steering’ , twisting the shaft at the same time
as angulating the tip up or down, is how the skilled single-handed
colonoscopist achieves most lateral movements, rather than
using the lateral angulation control too often. The right hand can
also feel whether the shaft moves easily (is straight) or there is
resistance (due to looping). To be able to feel and manipulate the
shaft deftly, hold it in the fingers (Fig. 6.19) as you would with any
other delicate instrument, such as a small electrical screwdriver,
and not in the fist—like a hammer or an offensive weapon. Rolling
the shaft between fingers and thumb allows major steering
rotations of up to 360°—whereas wrist-twist manages only 180°.
‘Two-handed’ one-person technique
The ‘two-handed technique’ is mainly used by those with small
hands, who may be unable to reach the lateral angulation control
with the left thumb and so may need, from time to time, to use
the right hand for this purpose. This unfortunately means briefly
letting go of the instrument shaft while the angulation is made.
Some endoscopists position the patient so that they can lean and
trap the colonoscope shaft transiently against the couch while
the right hand is otherwise occupied. If the right hand is used
too often for lateral steering it is likely that the endoscopist is
not torque-steering efficiently. Equally, if the right hand is away
from the shaft for too long in order to work the lateral angulation