Thrombogenicity of various endovascular stent types: an in vitro evaluation.
OBJECTIVE
The aim of this study was to evaluate the thrombogenicity of different peripheral stent types in a standardized in vitro model with fresh human whole blood.


METHODS
Different stents (N = 77; n = 7 of each of 11 types) were implanted in polyvinyl chloride tubing loops and filled with donor blood samples. After 120 minutes of blood circulation, the thrombin-antithrombin III complex (TAT) levels, beta-thromboglobulin (beta-TG) levels, and platelet counts were assessed.


RESULTS
After 2 hours, significant differences were seen. TAT values (+/- SD) with the investigated stents were 31 micro g/mL +/- 20 (control, no stent), 328 micro g/mL +/- 206 (Saxx stent, peripheral medium CrNi31 L), 651 micro g/mL +/- 760 (Palmaz Corinthian Stent, 316 L stainless steel, electropolished), 1,609 micro g/mL +/- 1,264 (Palmaz Corinthian Stent, 316 L stainless steel, not electropolished), 810 micro g/mL +/- 578 (Palmaz Schatz long medium stent), 569 micro g/mL +/- 347 (Smart Nitinol stent), 1,037 micro g/mL +/- 577 (Megalink peripheral stent), 543 micro g/mL +/- 487 (peripheral stent, electropolished), 1,674 micro g/mL +/- 2,057 (peripheral stent, not electropolished), 3,128 micro g/mL +/- 1,812 (SelfX Nitinol stent, polished), 5,897 micro g/mL +/- 2,380 (SelfX Nitinol stent, unpolished), and 1,458 micro g/mL +/- 887 (bridge stent). The platelet count (x1,000/ micro L +/- SD) was 218 +/- 35 (control, no stent), 188 +/- 22 (Saxx stent), 187 +/- 20 (Palmaz Corinthian stent, electropolished), 135 +/- 37 (Palmaz Corinthian stent, not electropolished), 170 +/- 24 (Palmaz Schatz stent), 180 +/- 36 (Smart Nitinol stent), 159 +/- 26 (Megalink peripheral stent), 173 +/- 17 (peripheral stent, electropolished), 133 +/- 51 (peripheral stent, not electropolished), 123 +/- 37 (SelfX Nitinol stent, polished), 52 +/- 27 (SelfX Nitinol stent, unpolished), and 130 +/- 31 (bridge stent).


CONCLUSIONS
This standardized study showed a wide range of platelet activation after stent implantation. Electropolishing clearly reduced the thrombogenicity of the stents.
Tepe
Gunnar
G
Department of Diagnostic Radiology, University of Tübingen, Hoppe-Seyler. Str. 3, 72076 Tübingen, Germany. gunnar.tepe@med.uni-tuebingen.de
Wendel
Hans P
HP
Khorchidi
Sascha
S
Schmehl
Jörg
J
Wiskirchen
Jakub
J
Pusich
Benjamin
B
Claussen
Claus D
CD
Duda
Stephan H
SH
D000328:Adult; D000497:Alloys; D000990:Antithrombin III; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D010447:Peptide Hydrolases / Q000097:blood; D015539:Platelet Activation; D010976:Platelet Count; D013193:Stainless Steel; D015607:Stents / Q000009:adverse effects*; D013499:Surface Properties; D013927:Thrombosis / Q000209:etiology*; D001620:beta-Thromboglobulin / Q000032:analysis
D000497:Alloys; C046193:antithrombin III-protease complex; D001620:beta-Thromboglobulin; D013193:Stainless Steel; C013616:nitinol; D000990:Antithrombin III; D010447:Peptide Hydrolases