Development of a model of benign esophageal stricture in rats: the optimal concentration of sodium hydroxide for stricture formation.
OBJECTIVE
To investigate the optimal concentration of sodium hydroxide (NaOH) on esophageal stricture formation in rats to establish an animal model of benign esophageal stricture (BES).


METHODS
Corrosive esophageal burn was produced by internal application of different concentrations of NaOH to the distal esophagus in rats. As much as 66 male rats were randomly divided into eight groups: Group A (control, n = 6), Group B (sham-operated group, n = 6), Group C (5% NaOH, n = 8), Group D (10% NaOH, n = 8), Group E (20% NaOH, n = 8), Group F (30% NaOH, n = 10), Group G (40% NaOH, n = 14), and Group H (50% NaOH, n = 6). Surviving rats were killed at 28 days. The survival rate, body weight gain, symptoms, and histopathological changes were assessed.


RESULTS
The mortality rate was high in Groups G and H (73 and 67%). The prevalence of symptoms of BES was 43% in Groups D and E, 50% in Group F, 75% in Group G, and 100% in Group H. Statistically significant stricture formation of the esophagus was observed in Groups F and G. The degree of tissue damage was significantly higher in Groups E, F, and G.


CONCLUSIONS
A high concentration of NaOH of 30% was required to establish a survivable BES model in rats.
Okata
Yuichi
Y
Division of Pediatric Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan. yuichi.okata@gmail.com
Hisamatsu
Chieko
C
Hasegawa
Tomomi
T
Nishijima
Eiji
E
Okita
Yutaka
Y
D000818:Animals; D002057:Burns, Chemical; D002424:Caustics / Q000633:toxicity*; D004195:Disease Models, Animal; D004940:Esophageal Stenosis / Q000139:chemically induced*; D004947:Esophagus / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012972:Sodium Hydroxide / Q000633:toxicity*; D016019:Survival Analysis
D002424:Caustics; D012972:Sodium Hydroxide