External tissue expansion successfully achieved using negative pressure.

The practice of internal tissue expansion by implanting a silicone balloon into the soft tissue under the skin is now known to be associated with a significant risk of complications. Therefore, we designed and developed a new technique of mechanical external tissue expansion achieved by using negative pressure created through special valved cups. The subjects were 60 patients suffering from postburn scar contractures in different parts of their bodies. A valved cup was applied to the healthy skin on both sides of the scar and negative pressure of -100 to -200 mbar was connected to the cup through a special valve for 5 h out of every 12 h for 2-3 weeks preoperatively. During the subsequent operation, the scar was excised, and then the expanded skin was dissected followed by wound closure. We were able to excise the scars and close the wounds directly in 14 patients, but needed to perform Z-plasty in the other 46 patients. Some ecchymosis appeared on the skin at the site of application of the cup in the initial stages, when the negative pressure exceeded the upper limits of -100 to -200 mbar. The clinical application of external tissue expansion achieved by creating negative pressure shows great promise.