Effects of retinoic acid and zinc on the treatment of caustic esophageal burns

The efficacy of mesenchymal stem cell transplantation in caustic esophagus injury: an experimental study

Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs) can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10). Group 2, membrane labeled MSCs-treated rats (n: 20). Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET) imaging (n: 10). Group 4, sham operated (n: 10). Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

Effects of sodium hydroxide exposure on esophageal epithelial cells in an in vitro ovine model: implications for esophagus tissue engineering

BACKGROUND

Esophagus tissue engineering holds promises for esophageal replacement after severe caustic injuries. The aim of this study was to determine whether viable esophageal epithelial cells could be isolated from an esophagus exposed to varying concentrations of alkali with regard to number, viability, and morphology during in vitro culture.

METHODS

Ovine esophagi were exposed to phosphate-buffered saline 2.5%, 15%, or 25% sodium hydroxide (NaOH). The effect of NaOH concentrations on epithelial damage was assessed histologically. Esophageal epithelial cells were then isolated, and cell count and viability were investigated. Finally, cell number, viability, and morphology of esophageal epithelial cells were determined for 24 days of in vitro culture.

RESULTS

Histologic analysis showed a progressive destruction of the epithelium proportional to increasing NaOH concentrations. Esophagi treated with phosphate-buffered saline and 2.5% NaOH showed significantly higher viable cell counts after isolation and culture in comparison with those treated with 15% to 5% NaOH.

CONCLUSION

The evidence presented in this study indicates that epithelial biopsies from an esophagus exposed to low concentrations (2.5%) of NaOH will still yield large numbers of viable cells suitable for tissue engineering applications. In cases of exposure to higher concentrations (15%-25%), alternative cell sources for epithelial regeneration, such as stem cells, will be necessary for tissue engineering applications.

Development of a model of benign esophageal stricture in rats: the optimal concentration of sodium hydroxide for stricture formation

PURPOSE

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.

CONCLUSION

A high concentration of NaOH of 30% was required to establish a survivable BES model in rats.