US Patent 7357818 Self-retaining stent

A stent is designed to be placed in a lumen of a patient and extend therethrough. The stent includes a distal end and a proximal end. The distal end includes a distal retention structure and the proximal end includes a plurality of radially extending flexible segments to prevent migration of the stent through the lumen. At least one radially extending flexible segment at the proximal end is able to assume an outwardly everted configuration. The stent of the invention, due to its dimensions, shape, and rigidity, minimizes the force of contact and abrasion to sensitive areas of the patient's body, such as the trigone region of the bladder and the ureteral-vesical junction.