Experimental application of pulsed laser-induced water jet for endoscopic submucosal dissection: mechanical investigation and preliminary experiment in swine.
OBJECTIVE
A current drawback of endoscopic submucosal dissection (ESD) for early-stage gastrointestinal tumors is the lack of instruments that can safely assist with this procedure. We have developed a pulsed jet device that can be incorporated into a gastrointestinal endoscope. Here, we investigated the mechanical profile of the pulsed jet device and demonstrated the usefulness of this instrument in esophageal ESD in swine.


METHODS
The device comprises a 5-Fr catheter, a 14-mm long stainless steel tube for generating the pulsed water jet, a nozzle and an optical quartz fiber. The pulsed water jet was generated at pulse rates of 3 Hz by irradiating the physiological saline (4°C) within the stainless steel tube with an holmium-doped yttrium-aluminum-garnet (Ho:YAG) laser at 1.1 J/pulse. Mechanical characteristics were evaluated using a force meter. The device was used only for the part of submucosal dissection in the swine ESD model. Tissues removed using the pulsed jet device and a conventional electrocautery device, and the esophagus, were histologically examined to assess thermal damage.


RESULTS
The peak impact force was observed at a stand-off distance of 40 mm (1.1 J/pulse). ESD using the pulsed jet device was successful, as the tissue specimens showed precise dissection of the submucosal layer. The extent of thermal injury was significantly lower in the dissected bed using the pulsed jet device.


CONCLUSIONS
The results showed that the present endoscopic pulsed jet system is a useful alternative for a safe ESD with minimum tissue injury.
Division of Advanced Surgical Science and Technology, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan.
Chiaki
C
Sato
Toru
T
Nakano
Atsuhiro
A
Nakagawa
Masato
M
Yamada
Hiroaki
H
Yamamoto
Takashi
T
Kamei
Go
G
Miyata
Akira
A
Sato
Fumiyoshi
F
Fujishima
Masaaki
M
Nakai
Mitsuo
M
Niinomi
Kazuyoshi
K
Takayama
Teiji
T
Tominaga
Susumu
S
Satomi
D000535:Aluminum; D000818:Animals; D004210:Dissection / Q000295:instrumentation*; D004564:Electrocoagulation; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D004867:Equipment Design; D004947:Esophagus / Q000601:surgery*; D007834:Lasers; D023421:Models, Animal; D013552:Swine; D014867:Water; D015019:Yttrium
C503779:yttrium-aluminum-garnet; D014867:Water; D015019:Yttrium; D000535:Aluminum