I had expanders that air, not saline was used to stretch the skin. I went every week for more air. A small amount of air leaked out, but not enough to worry about. You should be on a schedule with your plastic surgeon to add more air. They can put hundreds of CC's of air in at a time compared to only 40-60 CC's of saline. I loved that it only took 4-5 weeks for enough air to stretch the skin. Had mastectomy 9/29/2016, drains came out 3 weeks later, air in expanders started week after that. I had my expanders exchanged for permanent implants 11/25/2016. 2 months start to finish. Very easy. Good luck.