Intraprocedural bleeding due to unintentional cutting of the vessel affects both the
safety and efficiency of third-space endoscopy and may be prevented by complete coagulation
of the vessel before its cutting, also known as “presealing.” In a prospective series,
an underwater (saline-immersion) presealing technique achieved with a large-tip knife
appeared to minimize intraprocedural bleeding, saving the use and cost of coagulation
forceps [1]
[2]. Unexpectedly, when applying the same presealing technique with a small-tip knife
rather than a large-tip one, we found that the coagulation effect disappeared, with
inadvertent cutting of the vessel occurring. The lack of presealing appeared to be
associated with the formation of microbubbles around the tip of the knife, which was
presumably owing to the different density of current for a large- and small-tip knife.
In order to restore the presealing effect, we hypothesized that continuous flushing
around the tip of the knife would replace the CO2 bubbles that formed with a new saline interface. In this video, we show the efficacy
of this new strategy to optimize the presealing effect while using a small-tip knife
([Video 1]).
A new technique, flushing during coagulation of the vessel, is used to improve the
underwater presealing effect when using a small-tip knife.Video 1
At first, the formation of sparks in an underwater setting indicates an undesired
cutting effect without proper coagulation of the vessel ([Fig. 1]
a). Microbubbles may be observed around the tip of the knife. In the second part of
the video, continuous flushing was performed by a second operator through the waterjet
channel of the J-type knife (ClearCut Knife J-type, 1.5 mm; Finemedix, Daegu). This
resulted in the disappearance of high voltage current-related sparks, and the desired
presealing effect on the vessel ([Fig. 1]
b). Of note, no microbubbles were observed. Finally, when flushing was stopped, this
was associated with a return of spark formation, with the desired cutting of the presealed
vessel then achieved ([Fig. 1]
c).
Fig. 1 Endoscopic images showing: a a small spark formed at the tip of the knife when flushing is not being performed;
b the presealing effect being achieved without spark formation while the area is being
flushed; c restoration of spark formation when the flushing is stopped.
In conclusion, flushing assures the feasibility of presealing in underwater third-space
endoscopy irrespective of the size of the knife. Familiarity with this technique is
critical to prevent undesired intraprocedural bleeding in underwater third-space endoscopy.
Endoscopy_UCTN_Code_TTT_1AQ_2AD_3AD
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