A catheter includes a handle, a catheter sheath and a stylet having a shaped distal part received within the catheter sheath. The catheter includes a catheter shape release mechanism comprising the catheter handle and an elongate catheter sheath carrier. The catheter sheath carrier is slidable between a first position in which the shaped distal part of the stylet lies in register with the distal part of the catheter sheath to impart that shape to the catheter sheath and a second position in which the shaped distal part of the stylet is located proximally of the distal part of the catheter sheath. The catheter shape release mechanism enables retraction of the handle and the stylet while keeping the catheter sheath in place in case the catheter snags on tissue when in use.
