nitinol and Burns--Chemical

We sought to test the feasibility and technical ease of a newly designed nitinol-based modified esophageal stent and its effects on preventing postcaustic stricture in mongrel dogs and to try to explain the result at the molecular level.. Twenty-four dogs were included in this controlled study. Stenosis index (wall thickness/intraluminal diameter), pathologic features, hydroxyproline quantities, esophageal compliance, and biomechanics were compared between the injured but unstented and stented dogs. Transforming growth factor beta1, Sma/Mad (Smad)3, and Smad7 mRNA expression and protein levels in esophageal tissue were detected by means of reverse transcriptase-polymerase chain reaction and Western blotting, respectively.. The modified esophageal stent was able to be placed and retrieved successfully and conveniently and was not only intact but there was also no macroscopic esophageal mucosal injury after the stent removal 4 months later. In comparison with the injured but unstented group, esophageal compliance, biomechanics, and the stenosis index were significantly better in the stented group. Histopathologic study revealed that collagen bundles were thinner and its orientation tended toward a regular and parallel pattern. Transforming growth factor beta1 and Smad3 mRNA expression and protein levels increased and Smad7 mRNA expression and protein levels decreased significantly in esophageal tissue in the stented group. These variables showed no statistically significant difference 2 months after stent removal.. The modified esophageal stent might be a promising stent in preventing stricture formation after corrosive esophageal burns clinically.

Topics: Alloys; Animals; Biomechanical Phenomena; Blotting, Western; Body Weight; Burns, Chemical; Caustics; Compliance; Dogs; Equipment Design; Esophageal Stenosis; Esophagus; Feasibility Studies; Hydroxyproline; Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Smad3 Protein; Smad7 Protein; Stents; Transforming Growth Factor beta1

Esophageal stenting is a popular form of treatment of esophageal strictures in adults but is not widely used in children. The aim of the current study was to investigate whether esophageal stents could be used safely and effectively in the treatment of esophageal stenosis in children.. Covered retrievable expandable nitinol stents were placed in 8 children with corrosive esophageal stenosis. The stents were removed 1 to 4 weeks after insertion.. The stents were placed in all patients without complications and were later removed successfully. After stent placement, all patients could take solid food without dysphagia. Stent migration occurred in one patient and so the insertion procedure was repeated to reposition the stent. During the 3-month follow-up period after stent removal, all children could eat satisfactorily. After 6 months, 2 children required balloon dilation (3 times in one and 5 times in the other). The dysphagia score improved in all patients.. The use of the covered retrievable expandable stent is an effective and safe method in treating childhood corrosive esophageal stenosis.

Topics: Alloys; Burns, Chemical; Catheterization; Caustics; Chest Pain; Child; Child, Preschool; Conscious Sedation; Deglutition Disorders; Device Removal; Esophageal Stenosis; Female; Fluoroscopy; Follow-Up Studies; Foreign-Body Migration; Humans; Hydrochloric Acid; Hydrogen Peroxide; Male; Pliability; Radiography, Interventional; Severity of Illness Index; Sodium Hydroxide; Stents; Sulfuric Acids; Temperature; Treatment Outcome; Vomiting