Improved Biocompatibility of Intra-Arterial Poly-L-Lactic Acid Stent by Tantalum Ion Implantation : 3-Month Results in a Swine Model

Objective@#: Biodegradable poly-L-lactic acid (PLLA) with a highly biocompatible surface via tantalum (Ta) ion implantation can be an innovative solution for the problems associated with current biodegradable stents. The purpose of this study is to develop a Ta-implanted PLLA stent for clinical use and to investigate its biological performance capabilities. @*Methods@#: A series of in vitro and in vivo tests were used to assess the biological performance of bare and Ta-implanted PLLA stents. The re-endothelialization ability and thrombogenicity were examined through in vitro endothelial cell and platelet adhesion tests. An in vivo swine model was used to evaluate the effects of Ta ion implantation on subacute restenosis and thrombosis. Angiographic and histologic evaluations were conducted at one, two and three months post-treatment. @*Results@#: The Ta-implanted PLLA stent was successfully fabricated, exhibiting a smooth surface morphology and modified layer integration. After Ta ion implantation, the surface properties were more favorable for rapid endothelialization and for less platelet attachment compared to the bare PLLA stent. In an in vivo animal test, follow-up angiography showed no evidence of in-stent stenosis in either group. In a microscopic histologic examination, luminal thrombus formation was significantly suppressed in the Ta-implanted PLLA stent group according to the 2-month follow-up assessment (21.2% vs. 63.9%, p=0.005). Cells positive for CD 68, a marker for the monocyte lineage, were less frequently identified around the Ta-implanted PLLA stent in the 1-month follow-up assessments. @*Conclusion@#: The use of a Ta-implanted PLLA stent appears to promote re-endothelialization and anti-thrombogenicity.

Arachnoid Cyst in Sylvian Fissure Presented with Bitemporal Hemianopsia

The anterior middle fossa is the most common location of benign intracranial arachnoid cysts. In the adult, headache, temporal bulging, and mild proptosis are the usual presenting complaints, although seizures and contralateral weakness have been described. Bitemporal hemianopsia associated with this lesion has not been noted previously. Herein we describe the patient with bitemporal hemianopsia associated with sylvian fissure arachnoid cyst. Cystoperitoneal shunt was beneficial. The etiology, histology, and suggested therapy of other patient with arachnooid cyst are also discussed.