Gepersonaliseerde Bioresorbeerbare Sinusstents voor Chronische Rhinosinusitis: Uitdagingen in Materiaal, Proces en Ontwerp

Chronic rhinosinusitis (CRS) is a common inflammatory condition of the nose and paranasal sinuses. The global prevalence of the disease has been estimated to be around 10%, significantly impacting the quality of life for millions of people worldwide. The treatment of CRS follows a gradual escalation approach starting with medical treatment to achieve clinical control of the disease. However, when these therapies fail to relieve the symptoms, sinus surgery is required. While Functional Endoscopic Sinus Surgery (FESS) is an effective treatment for CRS, restenosis and obstruction of the neo-ostium has been identified as the major cause of surgical failure. To address these issues, sinus stents have been proposed, offering the potential for improved surgical outcomes and reduced long-term complications. However, complications including stent migration, discomfort, and the need for removal interventions continue to pose significant challenges. Moreover, current stenting solutions suffer from a lack of personalization and suboptimal material properties, such as inadequate degradation rates and mechanical properties. This research aims to develop a personalized, bioresorbable frontal sinus stent that overcomes these limitations by optimizing material properties, additive manufacturing (AM) processes, and device design. More specifically, the research focuses on the development of acrylate-endcapped urethane-based polymers (AUPs), which were synthesized to exhibit mechanical strength, biocompatibility, and controlled degradation suitable for sinus stenting applications. The properties of these materials were thoroughly characterized to ensure their suitability for use in a medical device. Vat photopolymerization additive manufacturing, more specifically stereolithography (SLA), was employed for the high-resolution, patient-specific fabrication of sinus stents, utilizing SLA to produce complex geometries that precisely fit the sinus anatomy of individual patients. Finite element analysis (FEA) was utilized to design and simulate the mechanical performance of the stents, ensuring proper fit and mechanical support during the healing process. Key results indicated that the AUP materials displayed mechanical and degradation properties suitable for the sinus stenting application. In addition, the materials were adapted to the SLA additive manufacturing process through optimization of the photopolymer resin formulation. This, combined with the optimization of the processing parameters, allowed for successful production of personalized stents with high accuracy. An initial step towards the use of FEA simulations as a design tool were taken by defining and validating material models for the printed AUP materials. These findings demonstrate the potential of exploiting AUP materials and additive manufacturing technologies towards the development of personalized bioresorbable sinus stents to address the limitations of current stenting solutions and offer enhanced patient outcomes. This research presents a significant advancement in the field of personalized medical devices, providing a promising solution for improving post-surgical recovery in CRS patients. Future work will focus on clinical validation and further optimization of the stent biocompatibility and mechanical performance, as well as the integration of drug-eluting properties to further enhance healing.