An expandable medical framework for implantation in a mammalian body comprising: a plurality of serpentine bands (104; 104a; 104b) including intermediate serpentine bands and end serpentine bands, the intermediate serpentine bands disposed between the end serpentine bands, each serpentine band (104; 104a; 104b) comprising a plurality of alternating straight band struts and turns; and a plurality of connector columns, each connector column comprising a plurality of connector struts, each connector column disposed between and connecting two serpentine bands (104; 104a; 104b), each connector strut connected at one end to a turn of one serpentine band (104; 104a; 104b) and connected at the other end to a turn of another serpentine band (104; 104a; 104b), characterized in that: the turns of a serpentine band (104; 104a; 104b) comprising connected turns and unconnected turns, each connected turn having a connector strut extending therefrom, each unconnected turn not having a connector strut extending therefrom; each of the end serpentine bands connected to one of said intermediate serpentine bands via four or five connector struts which are equally spaced about the circumference of the expandable medical framework, each two intermediate serpentine bands which are adjacent one another are connected one to the other via two connector struts, the two connector struts being equally spaced about the circumference of the expandable medical framework. a plurality of serpentine bands (104; 104a; 104b) including intermediate serpentine bands and end serpentine bands, the intermediate serpentine bands disposed between the end serpentine bands, each serpentine band (104; 104a; 104b) comprising a plurality of alternating straight band struts and turns; and a plurality of connector columns, each connector column comprising a plurality of connector struts, each connector column disposed between and connecting two serpentine bands (104; 104a; 104b), each connector strut connected at one end to a turn of one serpentine band (104; 104a; 104b) and connected at the other end to a turn of another serpentine band (104; 104a; 104b), characterized in that: the turns of a serpentine band (104; 104a; 104b) comprising connected turns and unconnected turns, each connected turn having a connector strut extending therefrom, each unconnected turn not having a connector strut extending therefrom; each of the end serpentine bands connected to one of said intermediate serpentine bands via four or five connector struts which are equally spaced about the circumference of the expandable medical framework, each two intermediate serpentine bands which are adjacent one another are connected one to the other via two connector struts, the two connector struts being equally spaced about the circumference of the expandable medical framework. the turns of a serpentine band (104; 104a; 104b) comprising connected turns and unconnected turns, each connected turn having a connector strut extending therefrom, each unconnected turn not having a connector strut extending therefrom; each of the end serpentine bands connected to one of said intermediate serpentine bands via four or five connector struts which are equally spaced about the circumference of the expandable medical framework, each two intermediate serpentine bands which are adjacent one another are connected one to the other via two connector struts, the two connector struts being equally spaced about the circumference of the expandable medical framework.