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Published on: October 26, 2016
Development of a reexpandable covered stent for children
Norihisa Horita1, Hideshi Tomita, Motoki Takamuro
1Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, Japan. nhori@sapmed.ac.jp
Insights
A new reexpandable covered stent for children can be implanted using a smaller sheath and redilated post-implantation. This innovation shows promise for pediatric vascular interventions.
Area of Science:
- Biomedical Engineering
- Pediatric Cardiology
- Vascular Surgery
Background:
- Current covered stents for pediatric use require large delivery sheaths and cannot be redilated after implantation.
- These limitations pose challenges for minimally invasive procedures in children.
Purpose of the Study:
- To develop and evaluate the clinical feasibility of a novel reexpandable covered stent for pediatric applications.
- To assess the deliverability and redilation capability of the new stent in a preclinical model.
Main Methods:
- An original Palmaz stent was modified with a polyurethane membrane, allowing up to 700% stretch.
- The reexpandable covered stents were implanted in six mini piglets using a sheath slightly larger than standard.
- Stent redilation was performed 28-70 days post-implantation, followed by macroscopic and microscopic examination.
Main Results:
- The covered stents were successfully implanted in mini piglets via a relatively small sheath.
- Redilation of the implanted stents was achieved, increasing diameter from 7.5 to 8.7 mm.
- Histological analysis revealed good intimal coverage of the stent coating with minimal inflammation.
Conclusions:
- The newly designed reexpandable covered stent demonstrates promising clinical feasibility for pediatric use.
- This stent offers advantages in terms of smaller sheath delivery and post-implantation adjustability.
- Further research is warranted to explore its long-term efficacy and safety in pediatric patients.
Abstract:
The use of covered stents in children is limited by the need for a large long sheath for delivery and the impossibility of redilation once implanted. The authors developed a reexpandable covered stent implantable in children through a small sheath and evaluated its clinical feasibility in mini piglets. An original Palmaz stent was covered with a polyurethane membrane that could be stretched up to 700%. Under general anesthesia, the authors implanted the covered stents in six mini piglets using a long sheath with a diameter approximately 1 French larger than the recommended size required to deliver an uncovered Palmaz stent. The implantation technique was similar to conventional stent implantation. In six piglets, the stent could be redilated from 7.5 to 8.7 mm 28-70 days after implantation. Macroscopic and microscopic examination showed intimal coverage of the coating with minimal inflammatory reaction around the stent. Our newly designed reexpandable stent covered with a polyurethane membrane is promising for use in children.
