A resorbable shape-memory starch-based stent for the treatment of salivary ducts under sialendoscopic surgery

Objectives/Hypothesis In sialendoscopy, stents are often used to keep the salivary duct open after surgery. These stents need to be removed. Recently, our group developed a new starch-based shape-memory material that is a widespread degradable polymer. Such a device could be manufactured into a deployable resorbable stent to keep the salivary duct open before in situ degradation. An experimental test was performed to establish a methodology and to evaluate the feasibility of the starch stent implantation in an animal model with clinical equipment. Study Design Evaluation of different formulations-potato and high amylose content maize starch without and with plasticizer-with laboratory bench-top testing and in vivo evaluation in a large-animal model. Methods Starch-based stents were manufactured. They were evaluated for their shape-memory properties (water, 37 degrees C) and their degradability in simulated saliva in both static and flow conditions mimicking salivary flow in the submandibular duct. A pilot study of stent implantation was then performed in vivo in a large-animal model to assess that the stent dimensions were consistent for implantation in the submandibular duct. Results Stents made from plasticized starch had the required shape-memory properties to be used as self-deploying stents. However, starch-based stents were rapidly hydrolyzed in simulated saliva. Stents could be directly inserted in the dilated salivary duct in a pig model without harming the epithelium. Conclusions Shape-memory stents with suitable geometry for sialendoscopic surgical procedure can be fabricated and inserted in the submandibular duct. Starch-based stents can be used in other pathologies with less alpha-amylase content in the surrounding medium. Level of Evidence NA. Laryngoscope, 124:875-881, 2014