A polyhydroxybutyrate biodegradable stent: preliminary experience in the rabbit.
OBJECTIVE
The lifelong persistence of foreign bodies within the arteries may contribute to restenosis. Thus, biodegradable devices might decrease recurrence rates.


METHODS
Eleven polyhydroxybutyrate biodegradable stents and 13 tantalum stents were implanted into the iliac arteries of New Zealand white rabbits for up to 30 weeks. After killing the animals, the specimens were harvested, fixed in formalin, processed in paraffin, and stained.


RESULTS
Polyhydroxybutyrate instigated intense inflammatory and proliferative reactions with an increase in collagen (2.4- to 8-fold vs native segments), thrombosis and in-stent lumen narrowing (375.5-606.6 mm vs 655.6 +/- 268.8 mm in native segments). The elastic membranes were destroyed in all specimens. The tantalum stents increased the in-stent lumen progressively (769.7 +/- 366.6 mm vs 1309.9 +/- 695.3 mm), penetrated the external elastic membrane, and increased mural collagen content (6- to 8.6-fold vs native segments). Neither restenoses nor thromboses occurred.


CONCLUSIONS
In the rabbit iliac artery, polyhydroxybutyrate stents caused intensive inflammatory vascular reactions which ban them from clinical use.
Unverdorben
M
M
Center for Cardiovascular Diseases, Heinz-Meise-Strasse 100, D-36199 Rotenburg a. d. Fulda, Germany.
Spielberger
A
A
Schywalsky
M
M
Labahn
D
D
Hartwig
S
S
Schneider
M
M
Lootz
D
D
Behrend
D
D
Schmitz
K
K
Degenhardt
R
R
Schaldach
M
M
Vallbracht
C
C
D000818:Animals; D001707:Biopsy, Needle; D020099:Coated Materials, Biocompatible; D004869:Equipment Safety; D005260:Female; D007083:Iliac Artery / Q000473:pathology* / Q000601:surgery*; D007150:Immunohistochemistry; D023421:Models, Animal; D011091:Polyesters / Q000737:chemistry*; D011817:Rabbits; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015607:Stents; D013635:Tantalum / Q000737:chemistry; D000094122:Polyhydroxybutyrates
D020099:Coated Materials, Biocompatible; D011091:Polyesters; D013635:Tantalum; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates