A tunneled PICC is defined as a PICC where the venipuncture site (typically in the yellow zone) does not coincide with the exit site (typically, in the green zone).
It is possible to tunnel any PICC, or in anterograde fashion (if the catheter is designed for a distal 'trimming') or even retrograde (only for catheters that provide a proximal 'trimming').
The benefit of tunneling in terms of infective risk will be twofold: directly (for protection against extraluminal contamination, since tunneling moves the exit site far from the entrance of the catheter into the vein) but also indirectly (because it allows to plan the exit site to an area with less bacterial contamination).
In terms of safety and cost-effectiveness we recommed to choose power injectable PICC, in state-of-the-art polyurethane, non-valved, open-ended.
The most widely used PICCs in the pediatric age group are 3Fr single lumen, 4Fr single lumen and 4Fr bi-lumen.