Generally, saline breast implantation surgery involves inserting an empty silicone sack, then inflating it with saline solution via a fill tube. These implants contain a valve that self-seals when the surgeon removes the fill tube. The self-sealing valve is covered by a flap that prevents tissue from growing into the valve.

Saline vs. Silicone:

Saline breast implants defeat their silicone counterparts in terms of scar size; the “inflate after insertion” method means a smaller incision. Types and locations of valves vary, but valves are only found in saline implants. Silicone implants are filled with gel before insertion.

Valveless saline implants come pre-filled by the manufacturer, but they fall flat: they are 3.5 times more likely to deflate in the first four years than their inflatable counterparts. As they also require a larger incision for implantation, many patients will opt for silicone implants instead.

Anterior vs. Posterior:

The valve can be located on the front or the back of the implant; depending on the make and model. A 2008 study suggests a decreased likelihood of rupture for posterior valves.

Some skinny patients have reported being able to feel the anterior valve through their skin, but when the implant is placed beneath the pectoral muscle instead of between the muscle and the breast tissue, this is not an issue. Most breast augmentation patients have their implants behind the muscle, while fewer breast reconstruction patients have this option. The surgeon will evaluate and determine the safest option.

Valve Issues

Under-filling of the implant greatly increases the likelihood of rupture, but the valve is rarely to blame in the case of rupture.

No studies have been done regarding how often the valve is the cause for saline implant deflation. Nevertheless, anecdotal evidence suggests that while “slow leaks” are uncommon in saline implants, the valve is often the problem when a slow leak does occur.  However, the modern diaphragm valve has done much to reduce this issue, which was more common in the leaf valve era. 

Once the valve has sealed, the fill hose cannot re-inflate the implant. If a saline implant is leaking through the valve, the implant is considered broken and should be replaced.