The invention relates to a medical device having a compressible and expandable, circular cylindrical mesh structure (10), which comprises circumferential elements (20) made of closed cells (15), wherein each cell (15) is delimited by at least four struts (11, 12, 13, 14), which are coupled to each other at connecting points (21, 22, 23, 24), wherein in each case two struts (11, 12, 13, 14) which adjoin one another in the circumferential direction UR of the mesh structure (10) and are coupled to one another at a connecting point (21, 22) exhibit differing flexibility such that the strut (11, 13) having the higher flexibility can be deformed more strongly than the struts (12, 13) having the lower flexibility during the transition of the mesh structure (10) from the expanded state into the compressed state, and wherein the struts (11, 13) having the higher flexibility and the struts (12, 14) having the lower flexibility are diagonally opposed from one another, respectively, such that two connecting points (23, 24) of the cells (15) arranged opposite one another in the longitudinal direction LR of the mesh structure (10) are offset from one another in opposite directions during the transition of the mesh structure (10) from the expanded state into the compressed state, wherein all cells (15) of a circumferential segment (20) are designed identically such that the entire mesh structure (10) twists at least in some sections during the transition from the expanded state into the compressed state. The invention further relates to a treatment system comprising such a device.
