Air dissipation in saline breast implants

Residual air within saline breast implants can cause patient discomfort due to the mechanical and auditory effects of sloshing. Small amounts of air have no clinical significance, but if larger quantities are present and audible, the patient is reassured that the implant shell is gas-permeable and that the air will dissipate/diffuse. This study examined the time necessary for air dissipation in saline breast implants. Twelve McGhan style #68 saline breast implants were divided into two groups: group A, which included six implants with a size of 240 cc, and group B, which included six implants with a size of 270 cc. The implants were filled with room-temperature, intravenous, normal saline to their designated volumes, plus 30 cc of overfill. All air was evacuated, and each implant was inoculated with 5 cc of air. The implants were then submerged in a single tank of normal saline at 37°C, at a depth of 20.4 cm to replicate capillary pressure. Intragroup analysis showed the air bubble was absent in group A at an average of 35.3 days (variance = 4.13) and in group B at an average of 38.0 days (variance = 0). If audible intraluminal air is present in the clinical setting, the patient can be reassured that the problem will resolve in approximately 30 days or less.