ABSTRACT
Objective To investigate the influence of different end shapes of esophageal stents on the mechanical behavior of the stent-esophagus system. Methods Through finite element simulation, the mechanical behavior of the coupling system between braided esophageal stents with different end shapes (straight-tube-shaped, cup-spherical-shaped, double-trumpet-shaped) and the esophageal cavity was analyzed. The influences of bare stents and covered stents with three different end shapes on stress distributions in the inner wall of the esophagus and on dilatation of the esophageal stenosis zone were compared. Results The reduction in stenosis rate caused by the bare stent was larger than that of the covered stent. Moreover, the equivalent stress and the contact stress caused by the bare stent were much larger than those of the covered stent. Different end shapes had a significant influence on the stress occurring in the healthy esophageal zone. Stress concentration occurred in the zones where the esophagus contacted the central part of the cup-shaped end and the edge of the double-trumpet-shaped end. The braided esophageal stents with three different end shapes all had good apposition.Conclusions Different end shapes of stents cause different stress states in the esophagus. A larger stress involves a higher probability of occurrence of esophageal tissue hyperplasia, but a smaller possibility of stent migration. Therefore, understanding the effect of the end shapes on stent performance can provide important theoretical references for optimization design of the braided stent and its clinical selection.