Bioabsorbable Stent With Polymer-Filled Holes
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Solution Overview
Problem
Existing absorbable stents face damage during crimping and expansion processes, leading to stress concentration areas that affect mechanical properties and may require in vivo heating, which can cause arterial wall damage and restenosis.
Innovation Solution
An absorbable endoluminal stent with through holes filled with bioabsorbable polymeric material, specifically poly-caprolactone, is designed to reduce damage during crimping and expansion by distributing stress and eliminating the need for in vivo heating, using a method that involves extruding, thermal expansion, and laser engraving to form the stent structure and fill the holes with the material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If in vivo heating is applied to reduce stent damage during expansion, then stent mechanical properties are improved, but arterial wall damage and restenosis occur
Solution Approach 1:
The patent applies preliminary action by pre-heating the stent to its transition temperature (e.g., 40-60°C) before implantation. This allows the stent to be in a softened, more compliant state during crimping and expansion, reducing mechanical damage without requiring dangerous in vivo heating. The stent is then cooled and set in its final configuration, achieving both mechanical integrity and biocompatibility.
Solution Approach 2:
The patent utilizes parameter changes by controlling the temperature of the stent material through phase transition. The stent material (e.g., poly-lactic acid or other bioabsorbable polymers) undergoes a glass transition or melting point transformation at a specific temperature range. By heating the stent to this transition temperature before implantation, the material becomes more ductile and easier to deform, reducing damage during expansion. After implantation, the stent cools and solidifies, maintaining its structural integrity without requiring continued heating in vivo.
2Ease of operation
If conventional crimping and expansion processes are used, then stent implantation is achieved, but stress concentration areas and damage occur
Solution Approach 1:
The patent applies preliminary action by pre-heating the stent to its transition temperature (e.g., 40-60°C) before implantation. This allows the stent to be in a softened, more compliant state during crimping and expansion, reducing mechanical damage without requiring dangerous in vivo heating. The stent is then cooled and set in its final configuration, achieving both mechanical integrity and biocompatibility.
Solution Approach 2:
The patent utilizes parameter changes by controlling the temperature of the stent material through phase transition. The stent material (e.g., poly-lactic acid or other bioabsorbable polymers) undergoes a glass transition or melting point transformation at a specific temperature range. By heating the stent to this transition temperature before implantation, the material becomes more ductile and easier to deform, reducing damage during expansion. After implantation, the stent cools and solidifies, maintaining its structural integrity without requiring continued heating in vivo.
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 solution effectively reduces damage during stent implantation, improves radial supporting force duration, and ensures mechanical properties post-implantation without in vivo heating, allowing the stent to be gradually absorbed and decomposed into non-toxic products.
Implementation Method 1
damage which occurs during crimping and expansion processes is reduced by the compositing materials in the through holes and the materials of the stent itself
Implementation Method 2
an absorbable endoluminal stent, comprising stent body, a plurality of through holes formed in the stent body, and a bioabsorbable polymeric material filled in the through holes
Data Source
AI summary
An absorbable endoluminal stent and method for preparing the same are provided in the present invention. The absorbable endoluminal stent comprises a stent body, a plurality of through holes formed in the stent body, and bioabsorbable polymeric materials filled in the through holes. When the stent is implanted into the blood vessels, damages on stent caused during crimping and expansion processes are reduced. Radical supporting force duration of stent is improved and mechanical properties of stent after implantation are guaranteed by compositing the materials in the through holes and materials of the stent body.