In reply to purple sue:
I had a PICC line installed temporarily, five years ago, to administer liquid nutrition. It was only in place for four days while in hospital, so i can't comment on the practicalities of doing stuff (like climbing). The two doctors who inserted it were keen to emphasize the seriousness of infection though - it has a direct route to your heart!
However, they did say that some patients live with a PICC line permanently, if their gastro-intestinal system has gone pear-shaped. Presumably, those people are engaged in some level of activity....
I can see some slab climbing being possible, either seconding or on a top-rope.
Best wishes
Dave