Frontal Sinus Stent Structure for Patency and Local Drug Delivery
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Solution Overview
Problem
Current medical management of chronic rhinosinusitis (CRS) is inefficient, with inadequate methods for maintaining frontal sinus patency and delivering active agents directly to sinunasal tissue, leading to bacterial infections and restenosis after functional endoscopic sinus surgery (FESS).
Innovation Solution
A stent with a flexible foam layer and a flexible film layer, bonded via hydrogen bonding, is designed to unfurl within the frontal sinus cavity, promoting patency and delivering active agents directly to the mucosal wall, featuring a porosity of greater than 80% and a resilience to maintain contact with the mucosa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent is deployed to maintain frontal sinus patency, then sinus drainage is improved, but the risk of restenosis and bacterial infection increases without adequate active agent delivery
Solution Approach 1:
The stent is pre-loaded with active agents (antibiotics, corticosteroids, or other therapeutic substances) within its porous foam structure before deployment. This preliminary preparation ensures that the therapeutic agents are immediately available for delivery to the sinus tissue upon implantation, preventing infection and restenosis from the outset rather than requiring subsequent treatment.
Solution Approach 2:
The porous foam layer acts as an intermediary carrier that bridges the gap between the deployed stent structure and the sinus mucosal tissue. It facilitates controlled transfer of active agents from the stent to the surrounding tissue, ensuring sustained therapeutic effect while maintaining sinus patency.
2Ease of operation
If nasal sprays are used to deliver active agents, then the treatment is non-invasive, but the amount of active agent reaching target tissue is very low
Solution Approach 1:
The invention extracts the active agents from the nasal spray formulation and incorporates them directly into the stent structure. This removes the limitation of spray delivery inefficiency by placing the therapeutic substances in direct contact with the target sinus tissue through the stent's porous foam layer, ensuring high local concentration at the site of need.
Solution Approach 2:
The porous foam layer serves as an intermediary reservoir that holds and releases active agents directly onto the sinus mucosa. This intermediary structure overcomes the inefficiency of nasal sprays by providing sustained, localized delivery of therapeutic agents precisely where required in the sinus cavity.
3Productivity
If a stent with high porosity is used to promote drainage, then mucociliary clearance is improved, but structural strength may be compromised
Solution Approach 1:
The stent employs a composite structure consisting of a porous foam layer (for high porosity and drainage promotion) combined with a flexible film layer (for structural integrity). This composite design allows the porous portion to facilitate mucociliary clearance while the film layer provides the necessary mechanical strength to maintain stent shape and function.
Solution Approach 2:
Different regions of the stent have different properties optimized for their specific functions: the porous foam layer is designed with high porosity (>80%) to promote drainage and mucociliary clearance, while the flexible film layer provides structural support. This local differentiation of material properties resolves the contradiction between porosity and strength requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The stent enhances sinus drainage, reduces restenosis, and improves delivery of therapeutic agents to the target tissue, decreasing recurrent symptomatology and the need for further surgical intervention.
Implementation Method 1
The flexible film layer and including a polymer which is structured to hydrogen bond with the crystalline segments of the flexible foam layer at a bond interface
Implementation Method 2
The flexible film layer has a resilience sufficient to unfurl the stent and urge the outer annular aspect of the flexible foam layer into direct contact with mucosa
Implementation Method 3
The stent includes a flexible foam layer having a porosity of greater than 80%
Data Source
AI summary
Systems and methods for deploying a stent within the frontal sinus. The stent includes flexible foam and film layers arranged in a stacked configuration and furled within a cartridge prior to deployment. The cartridge is removably coupled to an applicator device including an actuator. The film layer may include a polymer having a resilience sufficient to unfurl the stent and maintain patency of the frontal sinus opening. The flexible foam layer may have porosity of greater than 80%, and an active agent may be within the flexible foam layer. The flexible foam layer may be bioresorbable and the flexible film layer biocompatible and non-biodegradable. The stent may include first and second body portions with the first body portion independently unfurling from the second body portion to retain the stent within the frontal sinus. Contouring of the first and second body portions may facilitate ease with removal of the stent.