A catheter system for delivery of a ureteral catheter in a ureter includes a ureteral catheter, a pusher catheter to deliver the ureteral catheter at a desired location, and a connection device, to connect, in an assembled state a distal end of the pusher catheter to a proximal end of the ureteral catheter. The catheter further includes a releasable tether to secure a connection of the connection device between the ureteral catheter and the pusher catheter. The connection device includes a connector element provided on the ureteral catheter, and a sleeve provided on the pusher catheter, where the connector element is configured to be arranged in the sleeve, and that the tether is arranged to prevent unintentional release of the connector element out of the sleeve.