Purpose: To assess the technical feasibility and biocompatibility of a novel stent based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for peripheral vascular applications.
Methods: A polytetrafluoroethylene aortobi-iliac graft was implanted in 5 pigs through a midline abdominal incision. After transverse graft limb incision, 5 PLLA/P4HB stents and 5 metal stents (316L stainless steel) were randomly deployed at both iliac anastomotic sites with 6-mm balloon catheters. Angiography was performed to determine patency prior to sacrifice at 6 weeks. Stented segments were surgically explanted and processed for quantitative histomorphometry. Vascular injury and inflammation scores were assigned to the stented iliac segments.
Results: No animals were lost during follow-up. All PLLA/P4HB stents were deployed within 2 minutes by balloon inflation to 8 bars without rupture of the stent struts or anastomotic suture. All stents were patent on postprocedural angiography. Histological analysis showed no signs of excessive recoiling or collapse. PLLA/P4HB stents demonstrated decreased residual lumen area and increased neointimal area after 6 weeks (12.27+/-0.62 and 8.40+/-1.03 mm(2), respectively) compared to 316L stents (13.54+/-0.84 and 6.90+/-1.11 mm(2), respectively) as the result of differences in stent areas (PLLA/P4HB: 4.31+/-0.15 mm(2); 316L: 2.73+/-0.29 mm(2)). Vascular injury scores showed only mild vascular trauma for all stents (PLLA/P4HB: 0.41+/-0.59; 316L: 0.32+/-0.47). Inflammatory reaction was slightly higher around PLLA/P4HB stent struts (1.39+/-0.52) compared to 316L (1.09+/-0.50).
Conclusion: Rapid balloon expansion of PLLA/P4HB stents is feasible without risk of strut rupture. PLLA/P4HB stents provide adequate mechanical stability after iliac anastomotic stenting in pigs. Smaller residual luminal areas in the PLLA/P4HB stents might have been caused by tissue ingrowth into the larger strut interspaces due to higher strut thickness (stent area) in this group. This limitation needs to be addressed in future work on the stent design.
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http://dx.doi.org/10.1177/152660280701400518 | DOI Listing |
Ann Vasc Surg
February 2022
Department of General, Thoracic, Vascular and Transplantation Surgery, Rostock University Medical Center, Rostock, Germany.
Background: Fully absorbable polymeric scaffolds, as a potential alternative to permanent metallic stents, are entering the clinical field. The aim of this study is to assess the in vivo biocompatibility of a novel Sirolimus-eluting (SIR) absorbable scaffold based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for interventional application.
Methods: Absorbable PLLA/P4HB scaffolds either loaded with SIR coating or unloaded scaffolds were implanted interventionally into common carotid arteries of 14 female.
Gefasschirurgie
March 2015
Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany ; Klinik für Gefäßmedizin, Vivantes Klinikum Humboldt, Berlin, Germany.
Over the past years the development of biodegradable polymeric stents has made great progress; nevertheless, essential problems must still be solved. Modifications in design and chemical composition should optimize the quality of biodegradable stents and remove the weaknesses. New biodegradable poly-L-lactide/poly-4-hydroxybutyrate (PLLA/P4HB) stents and permanent 316L stents were implantedendovascularly into both common carotid arteries of 10 domestic pigs.
View Article and Find Full Text PDFFully absorbable drug-eluting stent platforms are currently entering the clinical arena for the interventional treatment of coronary artery disease. This new technology also holds potential for application in peripheral vascular settings. Our study reports on the development of a sirolimus- (SIR) eluting absorbable polymer stent made from a blend of poly(l-lactide) and poly(4-hydroxybutyrate) (PLLA/P4HB) for peripheral vascular intervention.
View Article and Find Full Text PDFJ Endovasc Ther
October 2007
Department of Surgery, University of Rostock, Germany.
Purpose: To assess the technical feasibility and biocompatibility of a novel stent based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for peripheral vascular applications.
Methods: A polytetrafluoroethylene aortobi-iliac graft was implanted in 5 pigs through a midline abdominal incision. After transverse graft limb incision, 5 PLLA/P4HB stents and 5 metal stents (316L stainless steel) were randomly deployed at both iliac anastomotic sites with 6-mm balloon catheters.
Ann Biomed Eng
December 2007
Institute for Biomedical Engineering, University of Rostock, Ernst-Heydemann-Str. 6, D-18057, Rostock, Germany.
Safe vascular stent application requires rapid expansion of the stent to minimize the risk of procedural ischemia. While high expansion speeds can be achieved with metallic stents, they are not necessarily feasible with biodegradable polymeric stents due to the viscoelastic material behavior. This study reports on a novel biodegradable polymer blend material based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB), and describes the mechanical properties and in vitro degradation behavior of a balloon-expandable slotted tube stent concept.
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