Patent ID: 7632302
Filing Date: 2009-12-15
Classification: A61F

Abstract:
1. A stent for insertion into a body lumen comprising: a first tubular, balloon-expandable section comprising a first plurality of struts within a unit of length measured circumferentially around a diameter of the stent in an unexpanded state; a second tubular, self-expanding section coupled to the first section and comprising a second plurality of struts within the unit of length that is greater than the first plurality of struts within the unit of length; and a third tubular, self-expanding section comprising a third plurality of struts within the unit of length that is greater than the number of struts within the unit of length in the second section, wherein a number of struts in the first section is selected to provide a metal coverage area of 14-18% in a balloon-expanded state of the first section inside the body lumen, and a number of struts in the second section is selected so that a metal coverage area is in a 15-18% range when the second section self-expands so that a diameter of the self-expanded second section is between about 2-times and 4-times greater than a diameter of the balloon-expanded first section, and a number of struts in the third section is selected so that a metal coverage area is in a 15-18% range when the third section self-expands so that a diameter of the self-expanded third section is between about 2-times and 4-times greater than a diameter of the balloon-expanded first section, so as to prevent tissue prolapse through open cells of the stent into the stented body lumen.