During the use of electrocautery in endoscopic procedures such as
incision, dissection, and resection, smoke can accumulate in the
gastrointestinal tract, impairing the visual field, which causes problems in
continuing the procedure. This problem is usually resolved by aspirating all of
the air in the gastrointestinal tract along with the smoke and replaced with it
with new air, thereby improving the visual field. However, this has to be done
several times, which prolongs the procedure.
In this article, we describe the use of novel fan devices that we
have developed to enable improving the visual field by only blowing the air
rather than changing the air in the gastrointestinal tract. Both devices have
been created using a supermicro fan motor (Shiko Inc., Kanagawa, Japan) ([Fig. 1
Fig. 1 Supermicro fan
motor.
The first, blowing-type, device works by blowing the air, whereas
the second is a ventilation-type device ([Fig. 2
Fig. 2 Endoscopic fan device:
a blowing type; and b ventilation
type.
[Fig. 3
Fig. 3 Effect of the fan
devices on the flow of smoke created with incense sticks: a blowing type; and b ventilation
type.
To evaluate the usefulness of the devices in endoscopy, we used them
during experimental endoscopic submucosal dissection (ESD) in resected porcine
stomachs ([Fig. 4
Fig. 4 Usefulness of the fan
devices in endoscopic submucosal dissection (ESD). a A
clear field of view has been obtained with the use of the blowing-type fan
device, which has created a whirlpool of smoke surrounded by the blowing air.
b Clear field of view obtained with the ventilation-type
fan device. The smoke generated by the has been almost entirely removed with
this device. (i), fan device; (ii), insulation-tipped (IT) knife; (iii), clear
field of view obtained by blowing or ventilation.
This involved injecting 6 mL of physiological saline to the
submucosa, and use of a constant (200 W) high-frequency power source
(UES-20, Olympus, Tokyo, Japan) for electrocautery. The procedure was conducted
both with and without the use of the fan devices. In the experiments that were
conducted without the use of the devices (no blowing-type or ventilation-type
fan), when smoke accumulated in the gastrointestinal tract, it caused
procedural difficulties, and all of the air in the gastrointestinal tract was
aspirated along with the smoke and replaced with new air.
We used three resected porcine stomachs, each of which was cut into
three similar sections. We carried out ESD three times for each experimental
condition (without any device, with the fan-type device, and with the
ventilation-type device) and noted the frequency of air replacements required
during each procedure. The mean number of times the air was replaced was 4.33,
2.67, and 1.33, for the procedures using no fan, or using the blowing-type or
the ventilation-type fan, respectively. The mean time required for ESD was
42.33 minutes, 38.67 minutes, and 32.22 minutes, respectively. There was no
significant differences in the mean size of the resected specimens among the
three groups.
During endoscopic treatment, bleeding and mucus, and movement due to
respiration are routinely encountered. In addition the patient may move or
vomit. It is important that these are avoided or dealt with as soon as
possible, without causing further hindrance for the endoscopic procedure being
conducted. In the experimental ESD of the resected porcine stomachs, the two
fan devices did not hinder the procedure.
Our findings indicate that the visual field can be improved during
endoscopy by blowing away the air rather than changing the air volume, although
occasional conventional aspiration is still required. A clear field of view
renders endoscopic procedures simple and safe [1 2 3 4
The current fan devices cannot be used in patients as they are not
sufficiently waterproof. After this problem has been resolved, further
investigations will be required to evaluate the clinical utility of these
devices. In conclusion, our experiment indicates that the fan devices may be
useful in endoscopic treatment.
Endoscopy_UCTN_Code_TTT_1AO_2AG
