3% suffer leakage within three years causing a deflated implant
Occasionally, breast implants may break or leak. The saline fill is salt water and will be absorbed by the body without ill effects. Older implants with silicone gel can leak also. If this occurs, one of two things may occur. If breakage of the implant shell that has a contracture scar around it, then it may not feel like anything has happed. If the shell breaks and there is not a contracture scar, then leakage into the surrounding tissue results in a sensation that the implant is deflating. The leaking gel may collect in the breast and a new scar may form around it. In other cases gel can migrate through the lymphatic system to another area of the body. Breaks may require a second operation and replacement of the leaking implant. If the gel has migrated it may not be possible to remove all of the silicone gel. This silicone gel is the what some say is related to the initiation of connective tissue disorders.
One study they reviewed showed that 63.6% of breast implants which had been in place for between one and 25 years had ruptured or were leaking. (http://news.bbc.co.uk/1/hi/sci/tech/33450.stm)
For silicone gel and saline-filled implants, some causes of rupture or deflation include: damage by surgical instruments during surgery, overfilling or underfilling of the implant with saline solution (specific only to saline-filled breast implants), capsular contracture, closed capsulotomy , stresses such as trauma or intense physical manipulation, excessive compression during mammographic imaging, placement through umbilical incision, site injury to the breast, normal aging of the implant, unknown/unexplained reasons.