@article{3139610,
    title = "Viscoelastic property mapping along encrusted polymeric urinary
catheters",
    author = "Mouzakis, Dionysios E. and Bouropoulos, Nikolaos and Kallidonis, and Panagiotis and Karnabatidis, Dimitrios and Katsanos, Konstantinos and and Constantinidis, Constantinos and Perimenis, Petros and Siamblis, and Dimitrios and Liatsikos, Evangelos N.",
    journal = "Journal of Endourology Case Reports",
    year = "2008",
    volume = "22",
    number = "8",
    pages = "1761-1769",
    publisher = "MARY ANN LIEBERT INC PUBL",
    doi = "10.1089/end.2007.0423",
    abstract = "Purpose: Mapping of the material viscoelastic property variation along
the length axis of polymeric stents.
Materials and Methods: Five pigtail ureteral stents and five
percutaneous stents placed in vivo for different periods were studied.
Viscoelastic property changes along the length of polymeric stents were
measured using the dynamic mechanical analysis technique. The type of
encrustations was identified using FT-IR spectroscopy and their
morphology by scanning electron microscopy (SEM).
Results: Variations in viscoelastic stiffness were confirmed for both
types of stents. In a few cases, the variation was quite large (400%).
Various encrustation types and/or organic sheathing of the salt were
found to be responsible for this effect. In detail, calcium oxalate
monohydrate (COM) plaques for percutaneous and COM/organic layer for
pigtail stents were recognized by FT-IR spectroscopy and SEM observation
to invoke reinforcing effects along the stent axes.
Conclusions: The phenomenon of stiffness variation along the stent axes
requires further study to understand the mechanism behind it and
consequently to improve the biomaterial and design of specific areas of
stents as well as to avoid encrustations. This further research might
lead in the near future to the development of new types of polymer
stents for drug-eluting specialized areas."
}