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Kischkel S, Grabow N, Püschel A, Erdle B, Kabelitz M, Martin DP, Williams SF, Bombor I, Sternberg K, Schmitz KP, Schareck W, Bünger CM. Biodegradable polymeric stents for vascular application in a porcine carotid artery model: English version. GEFASSCHIRURGIE : ZEITSCHRIFT FUR VASKULARE UND ENDOVASKULARE CHIRURGIE : ORGAN DER DEUTSCHEN UND DER OSTERREICHISCHEN GESELLSCHAFT FUR GEFASSCHIRURGIE UNTER MITARBEIT DER SCHWEIZERISCHEN GESELLSCHAFT FUR GEFASSCHIRURGIE 2016; 21:30-36. [PMID: 27034581 PMCID: PMC4767847 DOI: 10.1007/s00772-015-0011-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
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. At 4 weeks following implantation, computed tomography (CT) angiography was carried out to identify the distal degree of stenosis. The PLLA/P4HB group showed a considerably lower distal degree of stenosis by additional oral application of atorvastatin (mean 39.81 ± 8.57 %) compared to the untreated PLLA/P4HB group without atorvastatin (mean 52.05 ± 5.80 %). The 316L stents showed no differences in the degree of distal stenosis between the group treated with atorvastatin (mean 44.21 ± 2.34 %) and the untreated group (mean 35.65 ± 3.72 %). Biodegradable PLLA/P4HB stents generally represent a promising approach to resolving the existing problems in the use of permanent stents. Restitutio ad integrum is only achievable if a stent is completely degraded.
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Affiliation(s)
- S Kischkel
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany
| | - N Grabow
- Institut für Biomedizinische Technik, Universitätsmedizin Rostock, Rostock, Germany
| | - A Püschel
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany
| | - B Erdle
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany
| | - M Kabelitz
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany
| | | | | | - I Bombor
- Institut für Diagnostische und Interventionelle Radiologie, Universitätsmedizin Rostock, Rostock, Germany
| | - K Sternberg
- Institut für Biomedizinische Technik, Universitätsmedizin Rostock, Rostock, Germany
| | - K-P Schmitz
- Institut für Biomedizinische Technik, Universitätsmedizin Rostock, Rostock, Germany
| | - W Schareck
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany
| | - C M Bünger
- Klinik und Poliklinik für Allgemeine, Thorax-, Gefäß- und Transplantationschirurgie, Universitätsmedizin Rostock, Schillingallee 70, 18057 Rostock, Germany ; Klinik für Gefäßmedizin, Vivantes Klinikum Humboldt, Berlin, Germany
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Bünger CM, Grabow N, Sternberg K, Ketner L, Kröger C, Lorenzen B, Hauenstein K, Schmitz KP, Kreutzer HJ, Lootz D, Ince H, Nienaber CA, Klar E, Schareck W. Iliac Anastomotic Stenting With a Biodegradable Poly-L-Lactide Stent: A Preliminary Study After 1 and 6 Weeks. J Endovasc Ther 2006; 13:539-48. [PMID: 16928171 DOI: 10.1583/05-1726mr.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To assess the technical feasibility, thrombogenicity, and biocompatibility of a new biodegradable poly-L-lactic acid (PLLA) anastomotic stent. METHODS A polytetrafluoroethylene bifurcated graft was implanted in 17 pigs through a midline abdominal incision. After transverse graft incision, 17 316L stainless steel stents and 17 PLLA stents were randomly implanted at both iliac anastomotic sites and deployed with a 6-mm balloon under direct vision without angiography. Intended follow-up was 1 week in 6 pigs receiving oral acetylsalicylic acid (ASA) and in 7 pigs receiving ASA/clopidogrel; 4 pigs receiving ASA/clopidogrel were followed for 6 weeks. At the end of the study, the segments containing the stents were surgically explanted and processed for histology to measure the mean luminal diameter, intimal thickness, and the vascular injury and inflammation scores. RESULTS Initial technical success of stent placement was achieved in all animals without rupture of the suture. Two pigs died (unrelated to the stent) at 3 days after operation (1 in groups A and B). At 1 week, all PLLA stents showed thrombotic occlusion with the use of ASA alone. In contrast, all PLLA stents remained patent with concurrent administration of ASA/clopidogrel. All metal stents were patent regardless of the antiplatelet regimen. The mean luminal diameter of patent PLLA stents (4.13+/-0.17 mm) was comparable to metal stents (4.27+/-0.35 mm, p=0.78) at 1 week, but significantly diminished at 6 weeks (3.21+/-0.44 versus 4.19+/-0.18 mm, p=0.005). Histological analysis showed no signs of excessive recoil. PLLA stents induced a higher inflammation score (1.79+/-0.56) and more intimal hyperplasia (0.34+/-0.11 mm) compared to metal stents [1.27+/-0.44 mm (p<0.001) and 0.18+/-0.04 mm (p=0.006), respectively] at 6 weeks. Vascular injury was comparable between PLLA and metal stents. CONCLUSION Biodegradable PLLA stents showed higher thrombogenicity and reduced patency compared to metal stents during early follow-up. Although ASA and clopidogrel prevented thrombotic occlusion, the increased inflammatory response and neointima formation remain major concerns of PLLA stents. A solution to this problem might be the incorporation of anti-inflammatory drugs into the PLLA stent.
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Abstract
The use of antiplatelet agents in the management of patients undergoing percutaneous coronary interventions involves the administration of aspirin, thienopyridines, and in high-risk patients, GPIIb-IIIa antagonists. Drug-eluting stents now account for greater than 50% of stenting procedures. This review focuses on the limited available data describing the use of antiplatelet agents in patients undergoing drug-eluting stent implantation.
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Affiliation(s)
- Michael R Tamberella
- Department of Medicine and the Center for Platelet Function Studies, UMass Memorial Medical Center and University of Massachusetts Medical School, Worcester, MA 01655, USA
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Furman MI, Kereiakes DJ, Krueger LA, Mueller MN, Broderick TM, Schneider JF, Howard WL, Fox ML, Barnard MR, Frelinger AL, Michelson AD. Quantification of abciximab-induced platelet inhibition is assay dependent: a comparative study in patients undergoing percutaneous coronary intervention. Am Heart J 2003; 145:e6. [PMID: 12595861 DOI: 10.1067/mhj.2003.116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The best method for measuring the degree of platelet inhibition with glycoprotein (GP) IIb-IIIa antagonists during percutaneous coronary intervention (PCI) and the optimal degree of periprocedural inhibition is uncertain. Low molecular weight heparins have been reported to cause less platelet activation than unfractionated heparin. Therefore, compared with unfractionated heparin (UHF), a low molecular weight heparin could enhance measured platelet inhibition. In this study, we compared 3 methods of measuring platelet inhibition and investigated the effects of half doses of abciximab in combination with either UFH or the low molecular weight heparin dalteparin in patients undergoing PCI with planned abciximab administration. METHODS Abciximab-induced platelet inhibition was measured serially by means of 3 assays: 1) GP IIb-IIIa receptor occupancy, 2) binding of the activated GP IIb-IIIa-specific monoclonal antibody PAC1, and 3) agglutination of platelets with fibrinogen-coated beads (RPFA). Forty patients were randomly allocated to receive either UFH (70 U/kg) or dalteparin (60 IU/kg), followed by a half dose of abciximab (0.125 mg/kg) administered twice at 10-minute intervals. Assays were obtained 10 minutes after each half dose of abciximab and 8 to 10 and 24 hours after abciximab administration. RESULTS No differences between UFH and dalteparin were observed. At each time-point measured, the mean percent platelet inhibition as determined by means of the receptor occupancy assay and PAC1 binding assay was less than the degree of inhibition determined by means of the RPFA. CONCLUSIONS The results of targeted levels of platelet inhibition cannot be extrapolated between different clinical trials of GP IIb-IIIa antagonists unless the same assay is used. Dalteparin, compared with UFH, does not enhance platelet inhibition or receptor occupancy by abciximab, as demonstrated by means of 3 separate assays.
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Affiliation(s)
- Mark I Furman
- Center for Platelet Function Studies and Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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