Patent ID: 8236046
Filing Date: 2012-08-07
Classification: A61F,A61L

Abstract:
1. An endoprosthesis comprising a tubular member defined by a plurality of struts, at least one strut of the tubular member having a central longitudinal axis and including: (a) a central portion of the at least one strut that extends along the central longitudinal axis, the central portion lacking corrosion enhancing deposits; (b) an underlying portion comprising a first bioerodible metal including a matrix and corrosion enhancing deposits within the matrix, the underlying portion extending radially outward from the central portion relative to the central longitudinal axis; the underlying portion having a thickness of at least 1 micrometer; (c) a surface portion having a thickness of between 0.1 micrometers and 3micrometers overlying and extending radially outward from the underlying portion relative to the central longitudinal axis, the surface portion comprising a second bioerodible metal having the composition of the matrix and being substantially free of corrosion enhancing deposits; the surface portion having a first erosion rate and the underlying portion having a second erosion rate that is greater than the first erosion rate when the surface portion and the underlying portion are exposed to physiological environments.