Silicone and saline implants are used for cosmetic enhancement or augmentation of the normal breast size and shape of reconstruction, particularly after radical breast surgery for cancer or trauma. In one study, by Dr. Richard Vann, Vice President of Research at DAN, mammary (breast) implants were placed in the Duke University Medical Center hyperbaric chamber. The study did not simulate the implant in human tissue.
Three types were tested: silicone-, saline-, and silicone-saline-filled. In this experiment, the researchers simulated various depth/time profiles of recreational scuba diving.
Here's what they found:
There was an insignificant increase in bubble size (one to four percent) in both saline and silicone gel implants, depending on the depth and duration of the dive. The least volume change occurred in the saline-filled implant, because nitrogen is less soluble in saline than silicone.
The silicone-saline-filled type showed the greatest volume change. Bubble formation in implants led to a small volume increase, which is not likely to damage the implants or surrounding tissue. If gas bubbles do form in the implant, they resolve over time.
Fitness and Diving Issues
Once sufficient time has passed after surgery, when the diver has resumed normal activities and there is no danger of infection, she may begin scuba diving. Breast implants do not pose a problem to diving from the standpoint of gas absorption or changes in size and are not a contraindication for participation in recreational scuba diving.
Avoid buoyancy compensators with constrictive chest straps, which can put undue pressure on the seams and contribute to risk of rupture.
Breast implants filled with saline are neutrally buoyant. Silicone implants are heavier than water, however, and they may alter buoyancy and attitude (trim) in the water, particularly if the implants are large. Appropriate training and appropriate adjustment of weights help overcome these difficulties.