A device for unblocking an occlusion (3) in an occluded vessel (2) comprises a catheter (5) having an inflatable balloon (19) located at a distal leading end (8) thereof so that by inflating the balloon (19) the leading end of the catheter (5) may be anchored in the occluded vessel (2) or in a vessel adjacent the occluded vessel (2) with the leading end adjacent the occlusion (3). A guide wire (12) terminating in a pointed distal tip (18) is urgeable through a bore (10) in the catheter (5) for engaging and penetrating through the occlusion (3). A leading portion (17) of the guide wire (12) is externally threaded at (26), and is engageable with an internally threaded portion (25) of the bore (10) adjacent a leading portion (9) of the catheter (5), so that when the catheter (5) is anchored by the balloon (19) with the leading portion (9) of the catheter (5) adjacent and abutting the occlusion (3) with the external threads (26) of the guide wire (12) engaging the internal threads (25) of the catheter (5), rotation of the guide wire (12) urges the distal tip (18) of the guide wire (12) into engagement with the occlusion (3) and to penetrate through the occlusion (3).
