Abstract
Background and study aims Esophageal endoscopic submucosal dissection (ESD) is technically difficult because
of narrow working spaces and ease of perforation due to the lack of serosa. HybridKnife
is a recently developed ESD device that is combined with the high pressure waterjet
ERBEJET 2 system to lift mucosa. We hypothesized that this waterjet could make submucosal
dissection safer and studied this in porcine esophagus.
Materials and methods Water pressures of 30 – 70 bar were tested to determine the appropriate pressure
for waterjet ESD with HybridKnife (WJ-ESD) in one pig. WJ-ESD safety and completion
were compared with those of conventional ESD using DualKnife (C-ESD) as a reference.
Each of three virtual esophageal lesions in two pigs were resected alternatively using
both methods from the lower to upper esophagus. For WJ-ESD, the submucosa, apart from
hard fibrous tissues, was dissected using water pressure alone.
Results Using 50 bar of water pressure resulted in the best balance between proper dissection
and view-disturbing water backflow. The dissection speeds for the lower, middle, and
upper esophagus were 0.2, 0.9, and 0.2 cm2/min in 50 bar WJ-ESD and 1.1, 0.5, and 1.0 cm2/min in C-ESD, respectively. Minor bleeding was frequent in WJ-ESD, but was easily
stopped by electrocoagulation with the same needle. No perforation was observed in
either procedure. Thermal damage to dissected tissues appeared mild, and the extent
of muscle injury was lower for WJ-ESD (4, 6, and 8 %) compared with C-ESD (14, 16,
and 7 %).
Conclusions WJ-ESD could be completed safely for porcine esophagus with less damage to the muscle
layer compared with C-ESD.
