Effects of different-shaped tissue expanders on transluminal pressure, oxygen tension, histopathologic changes, and skin expansion in pigs.

This study, performed on domestic pigs, was designed to show whether the shape and size of a tissue expander influences the amount of surface area increase. When a defect is irregular, a larger custom-fitted implant is more efficient than several smaller expanders. Oval implants gained 5 percent more skin using 50 percent less time and almost 20 percent less intraluminal pressure, while U-shaped implants yield 2.2 percent more skin in 10 percent less time with 35 to 50 percent less pressure when compared with several smaller implants covering the same surface area. Transcutaneous TpO2 measurements and histologic evaluation revealed no significant difference between all implant shapes. These results show that less time, pressure, and volume are needed in a larger implant to gain the same surface area as would be attained from several smaller implants, thus sparing the patient more discomfort, trauma, and risk of infection by reducing the number of filling domes and hence the number of fillings.