Endoscopic submucosal dissection for pig esophagus by using photocrosslinkable chitosan hydrogel as submucosal fluid cushion.
BACKGROUND
Hypertonic saline solution (HS) as a submucosal fluid cushion (SFC) for endoscopic submucosal dissection (ESD) has several disadvantages, including a short effect duration and increased risk of bleeding and perforation. Photocrosslinkable chitosan hydrogel in DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by UV irradiation for 30 seconds.


OBJECTIVE
To evaluate the feasibility, usefulness, and safety of PCH as an SFC for ESD of esophagi, compared with HS and sodium hyaluronate (SH).


METHODS
Survival animal study.


METHODS
Research laboratory study of 24 pig models in vivo.


METHODS
Twenty-four pigs were used in the 2 steps: First, ESD of the esophagus was performed with PCH, SH, or HS (each n = 6) as an SFC, and the effects of these agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH (n = 3) and HS (n = 3) was examined in independent pig esophagi.


METHODS
Outcome measurements included feasibility and safety of PCH-assisted ESD of esophagus, gross and histologic evidence of the treated esophagus, biodegradation of injected PCH, and clinical tolerance by the animals.


RESULTS
PCH injection led to a longer-lasting elevation with clearer margins compared with SH and HS, thus enabling precise ESD along the margins of the elevated mucosa without complications such as bleeding and perforation. The aspects of wound repair after PCH-assisted ESD were similar to those of SH- and HS-assisted ESDs. Biodegradation of PCH was confirmed to be almost completed within 8 weeks on the basis of endoscopic and histologic observations.


CONCLUSIONS
In vivo animal model study.


CONCLUSIONS
PCH permits more reliable ESD of the esophagus without complications than do SH and HS. Furthermore, the applied PCH appeared to be completely biodegraded within 8 weeks. Thus, PCH is a promising agent as an SFC in ESD of the esophagus.
Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
Isao
I
Kumano
Masayuki
M
Ishihara
Shingo
S
Nakamura
Satoko
S
Kishimoto
Masanori
M
Fujita
Hidemi
H
Hattori
Takuya
T
Horio
Yoshihiro
Y
Tanaka
Kazuo
K
Hase
Tadaaki
T
Maehara
D000818:Animals; D048271:Chitosan / Q000009:adverse effects / Q000627:therapeutic use*; D004210:Dissection; D004945:Esophagoscopy; D004947:Esophagus / Q000473:pathology / Q000601:surgery*; D006820:Hyaluronic Acid / Q000627:therapeutic use; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D009092:Mucous Membrane / Q000601:surgery*; D055668:Photochemical Processes; D012965:Sodium Chloride / Q000627:therapeutic use; D013552:Swine; D055675:Viscosupplements / Q000627:therapeutic use
D055675:Viscosupplements; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012965:Sodium Chloride; D006820:Hyaluronic Acid; D048271:Chitosan