Central venous access devices (CVADs) or central venous catheters (CVCs) are devices that are inserted into the body through a vein to enable the administration of fluids, blood products, medication and other therapies to the bloodstream. CVADs can be inserted into the subclavian or jugular vein (implanted ports, tunneled catheters), or can be inserted into one of the peripheral veins of the upper extremities, called peripherally inserted central catheters (PICCs). While generally safe, CVADs can be associated with complications such as catheter occlusion or rupture, venous thrombosis, and bloodstream infection. A number of strategies have been used to minimize the occurrence of CVAD- and PICC-associated complications such as antimicrobial-impregnated lines for prevention of infection, or addition of a valve (valved catheters) to prevent occlusion by preventing reflux of blood into the catheter. Flushing the catheters with saline or heparin – an agent with anticoagulant activity - have been used to reduce clot formation and occlusion of the catheters. This Rapid Response report is an update of the previous CADTH reports which found no difference in terms of frequency of occlusion in patients who had a valved versus a non-valved PICCs, and similar patency between heparin and saline use for CVCs. This report aims to review the evidence on the clinical effectiveness of valved versus non-valved PICCs, and saline versus heparin flushing in the maintenance of CVADs patency and reduction of complications.