Barbed suture having increased holding strength

A wound closure device configured to approximate opposing tissue surfaces without knot tying, the wound closure device comprising:

• a filamentary element extending along a longitudinal axis between a proximal end and a distal end, said filamentary element having a plurality of barbs extending outwardly therefrom, said plurality of barbs configured to allow movement through tissue in a first direction toward the proximal end of the filamentary element and resist movement in a second opposite direction toward the distal end of the filamentary element;
• and
• a stop element connected to the distal end of the filament element, the stop element having a length extending along a direction of the longitudinal axis and a width extending in a perpendicular direction to the longitudinal axis, the stop element having a top edge and bottom edge defined along the length in the direction of the longitudinal axis, the top and bottom edges being generally parallel to each other along the length, the stop element further comprising a leading edge and a back edge defined along the width in the perpendicular direction to the longitudinal axis, the leading and back edges being generally parallel to each other along the width, the leading edge having a maximum thickness, and the stop element having a ratio of the length to the maximum thickness of the stop element greater than 4;
• wherein the leading edge of the stop element extends between first and second outer edges of the stop element, wherein the leading edge of the stop element has a varying thickness between the first and second outer edges, and wherein the maximum thickness of the leading edge is located at the first and second outer edges and a center of the stop element and a minimum thickness of the leading edge is located at points between the first and second outer edges and the center of the stop element.