新型可舒缩泪道支架的制备及其力学性能研究

Development of a novel dilatable lacrimal duct stent

摘要:

目的 探讨新型可舒缩泪道支架的制备方法及物理性能。方法 使用硅胶（SILASTICQ7-4750）为主要材料，制作新型可舒缩泪道支架。观察支架形态，测量管长、管径等一般物理学参数及新型可舒缩泪道支架注水量与气囊的关系；利用人造生物管道径向压缩仪检测支架径向抗压缩性能及弹性回复力；利用微机控制电子万能试验机检测支架轴向拉伸强度及断裂伸长率。以泪道扩张引流管做对比，检测支架的径向抗压缩性能、弹性回复力、轴向拉伸强度及弹性回复力。结果 新型可舒缩泪道支架利用硅胶为原材料，分3部分一体成型后使用118胶水组合为一体，实现可个性化舒缩泪道管径的支架结构。该支架未压缩或拉伸状态下管长6.848mm，外直径3.62mm，内直径3.00mm，泪道支架外壁厚0.31mm。反复扩张回复其50次后，管长6.848mm，外直径3.68mm，内直径3.0mm；随着注入生理盐水和空气的增加，新型可舒缩泪道支架的管径呈线性扩张。泪道扩张引流管未压缩或拉伸状态下管长6.682mm，外直径3.30mm，支架壁厚1mm。新型可舒缩泪道支架和泪道扩张引流管急弹性回复力为95.7%和97.4%，弹性回复力为97.1%和98.3%。新型可舒缩泪道支架和泪道扩张引流管拉伸强度[（2.71±0.29）、（2.66±0.22）MPa]及拉断伸长率[（360±31.12）%、（500±44.28）%]组间差异无统计学意义（P均>0.05）。结论 成功制作出新型可舒缩泪道支架，可通过注入生理盐水个性化调节支架管径，随注入体积增加，该支架管径呈线型扩张，在可控安全范围。与传统泪道扩张引流管相比，径向抗压性更强，可拉伸强度更大，提示临床使用具有较好的安全性。

Abstract:

Objective To develop a novel dilatable lacrimal duct stent and to evaluate its effect. Methods We used medical silicone as main materials to develop a dilatable lacrimal duct stent. The radial compression and elastic resistance of the stent were tested with the artificial biological pipeline radial compression apparatus, the axial tensile strength and breaking elongation rate were tested with microcomputer controlled electronic universal testing machine.The index include radial compression, elastic resistance, axial tensile strength and breaking elongation rate were tested by comparing with nasolacrimal duct expansion drainage stent. Results The developed dilatable lacrimal duct stent(DLDS) was made to three parts and formed into the product with glue RT118. The length of the stent was 6.848cm, external diameter was 3.62mm, internal diameter was 3.0mm under uncompression and upstretched condition; after repeated expansion and retraction for 50 times the length was 6.848cm, outer-diameter was 3.68mm, inter-diameter was 3.0mm; during the expansion drainage the length was 6.682cm, outer-diameter was 3.30mm. Acute elastic resistance was 95.7% and 97.4% in DLDS and NLDEDS respectively; elastic resistance(ER) was 97.1% and 98.3% respectively. Tensile strengths were（2.71±0.29）MPa in DLDS group and（2.66±0.22）MPa in NLDEDS group; elongation at break was（360±31.12）% in DLDS group and（500±44.28）% in NLDEDS group. Conclusion With increasing injection of saline, the diameter of the dilatable lacrimal stent can be adjusted linearly within a controllable safe range. Compared with the traditional nasolacrimal duct expansion drainage stent, the dilatable one has a better radial resistance and tensile strength, indicating its good application prospects in clinics.