Introduction and Background of Bioresorbable Stents
- Metal drug-eluting stents have potential drawbacks
- Bioresorbable stents gradually resorb and are cleared from the body
- Vessel healing is largely complete within three to nine months
- The goal of bioresorbable stents is to support the vessel during the critical healing period and then resorb when no longer needed
- Bioabsorbable scaffolds can be made from metals or polymers
- Polymer-based scaffolds have lost appeal, focus shifted to metallic magnesium-based scaffolds
Materials for Bioresorbable Stents
- Metal stent candidates include iron, magnesium, zinc, and their alloys
- Iron stents can potentially cause endothelium rupture after degradation
- Magnesium-based scaffolds have been approved and show promising clinical results
- Efforts are made to reduce magnesium corrosion rate by alloying and coating
- Zinc has poor mechanical behavior for stent materials
- Polymer-based stents have been approved, PLLA is a common material
- Other polymers in development include tyrosine polycarbonate and salicylic acid
Clinical Research and Safety of Bioresorbable Stents
- Resorbable scaffolds offer comparable efficacy and safety to drug-eluting stents
- The Magmaris resorbable magnesium scaffold has shown a favorable safety profile
- The Absorb stent has low rates of adverse events and scaffold thrombosis
- Imaging studies show the Absorb stent dissolves between six to 12 months
- Ongoing studies are being conducted in real-world patients
- The first fully absorbable stent was approved by the FDA in 2016
Incidence of Restenosis and Arterial Remodeling
- Restenosis is a time-related phenomenon after coronary angioplasty
- Incidence of restenosis observed in a significant number of patients
- Arterial remodeling and intimal hyperplasia contribute to lumen renarrowing
- Arterial remodeling found to be relatively more important than intimal hyperplasia
- Understanding these processes can aid in developing effective interventions
Advantages, Limitations, and Future Developments of Bioresorbable Stents
- Advantages: reduced risk of long-term complications, elimination of future surgical procedures, restoration of natural vessel function, lower incidence of restenosis, improved patient comfort
- Studies show comparable efficacy and good short-term outcomes
- Limitations: higher cost, potential degradation of structural integrity, risk of late stent thrombosis, optimal duration of dual antiplatelet therapy still under investigation
- Future developments focus on improving mechanical properties, exploring new materials, investigating combination therapies, and applying bioresorbable stents in other vascular interventions
A bioresorbable stent is a tube-like device (stent) that is used to open and widen clogged heart arteries and then dissolves or is absorbed by the body. It is made from a material that can release a drug to prevent scar tissue growth. It can also restore normal vessel function and avoid long-term complications of metal stents.
| Bioresorbable stent | |
|---|---|
 A bioresorbable stent implanted in the blood vessel. | |
| Specialty | Vascular system |
In medicine, a stent is any device which is inserted into a blood vessel or other anatomical internal duct to expand it to prevent or alleviate a blockage. Traditionally, such devices are fabricated from metal mesh and remain in the body permanently or until removed through further surgical intervention. A bioresorbable stent (also called bioresorbable scaffold, biodegradable stent or naturally-dissolving stent) serves the same purpose, but is manufactured from a material that may dissolve or be absorbed in the body.
