Technical feasibility and tissue reaction after silicone-covered biodegradable magnesium stent insertion in the oesophagus: a primary study in vitro and in vivo

Objectives Determine the feasibility of and tissue response to biodegradable magnesium–silicone stent insertion into the oesophagus of rabbits. Methods Mechanical compression–recovery and degradation behaviours of the stents were investigated in vitro. Thirty rabbits were randomly divided into a magnesium–silicone stent group ( n = 15) that received stent insertion into the lower 1/3 of the oesophagus under fluoroscopic guidance and a control group ( n = 15). Oesophagography was performed at 1, 2 and 4 weeks. Five rabbits in each group were euthanized at each time point for histological examination. Results Magnesium–silicone stents showed good flexibility and elasticity, and degraded more slowly than bare stents at pH 4.0 and 7.4. All stent insertions were well tolerated. The oesophageal diameters at 1, 2 and 4 weeks were 9.7 ± 0.7, 9.6 ± 0.8 and 9.6 ± 0.5 mm, respectively (vs. 9.2 ± 0.8 mm before intervention; P > 0.05). Stent migration occurred in six rabbits (one at 1 week, one at 2 and four at 4). Microscopy demonstrated dilation of the oesophageal wall within 1 week of insertion. Oesophageal injury and collagen deposition following stent insertion were similar to control ( P > 0.05). Conclusions Oesophageal magnesium–silicone stent insertion was feasible and provided reliable support for 2 weeks without causing oesophageal injury or collagen deposition. Key Points • Mg stent provided apparently adequate radial force and silicone membrane reduced magnesium biodegradation • Stent insertion provided good support for at least 2 weeks before biodegradation • Stenting effectively resulted in oesophageal wall remodelling, without demonstrable injury .