The PICC line can be left in place for weeks to 18 months. One study of 2,477 cancer patients found the average time they had a PICC line was 135 days (more than four months), with 55.6% of the people having them for longer than four months. The results showed that PICC lines were safe in the medium to long term, but that many complications actually arose in the first few months. This makes clear why it's important for you and your healthcare team to know how to care for your PICC line properly.