There are disclosed various dispensing mechanisms for dispensing filamentary material (24) through a catheter (12) into a treatment site of a patient, for example into an aneurysm sack (20) in a patients vessel (22). In one embodiment, the dispensing assembly (30) includes a chamber having a spherical carrier (50) onto which filamentary material (24) is wound. Upon injecting driving fluid into the dispensing assembly (30) filamentary material (24) unwinds from the spherical carrier (50) and is pulled through the catheter (12) to be dispensed from the distal end (18) of the catheter.
