Maintaining patency in totally implantable venous access devices (TIVAD): a time-to-event analysis of different lock irrigation intervals.

Purpose: To evaluate the effectiveness of irrigating totally implantable venous access devices (TIVADs) every eight weeks instead of every four in maintaining the patency of the device.

Methods: An explorative, pragmatic, prospective study design was conducted in two day hospital centres located in the northeast of Italy, from January 2011 to September 2012. Twenty patients who had skipped an appointment and were thus washing their TIVAD every eight weeks (exposed) were included, as were 17 patients following the typical wash regimen of every four weeks (controls).