It was just just this past year that we received the 510(K) for saline flush only on MicroCLAVE. We are not complete on true clinical trials that as you know can take time. There are users of both MicroCLAVE and CLAVE that use saline flush only without occlusion issues. It has been well stated on this site that occlusions are multifactorial with the needleless connector being 1 part of the equation. MicroCLAVE is neutral with no reflux at the catheter end upon connection or disconnection. For further assistance contact your local rep for samples/support.