Table 2.

Advantages and disadvantages of various tissue expansion devices

Internal Tissue Expansion Device	Method	Advantages	Disadvantages
Silicone envelope	Silicone envelope is implanted, and saline is progressively injected into the implant to expand overlying tissue	Ability to match flaps to the recipient site. Avoids more complex distant and/or free tissue transfer flaps. Maintain localized sensation	Invasive implant. Relatively high complication rates
External Tissue Expansion Device	Method	Advantagesa	Disadvantages
External Tissue Extender	1 cm wide polyamide straps inserted through the skin and attached to silicone holding bars. Strips have a stopper on one end and one-way locking device at the other	Simple, easy to apply and adjust	Frequent breakage and necrosis of skin bridges. Requires a crude estimation of the force skin can sustain without damage. Needs repeated manual tightening
SureClosure®	Stainless steel needles threaded through wound edges. Two U-shaped polycarbonate arms hook onto the needles on each side of the wound. U-shaped arms are secured on threaded polycarbonate bars running across the wound. Screw heads on one end the threaded bars are turned to tighten, and a ruler runs across the wound to measure progress	Does not undermine skin at wound edges. Simple and easy to apply	Requires a crude estimation of the force skin can sustain without damage. Needs repeated manual tightening
TopClosure®	Shape-adaptive attachment plates are glued to skin, with holes for optional invasive attachment. A ratchet strap runs through the attachment plates, one of which has a lock/release mechanism	Can be applied noninvasively. Useful in treating longstanding open wounds	Requires a crude estimation of the force skin can sustain without damage. Needs repeated manual tightening
DynaClose®	Multiple strips of elastomer with adhesive fabric tape on either side are applied across the wound. These apply continuous tension to tissue at wound edges	Acts dynamically, moving as skin is stretched, applying a constant, cyclic stretching force. Useful in treating longstanding open wounds	Strips must be regularly changed to maintain continuous traction until the wound is closed
ABRA®	Elastomer bands are inserted through the skin and secured with contoured anchors on either side of the wound. Elastomers are adjusted (using marks on the bands for reference) to 1.5 times their untensioned length	Bands are marked to indicate appropriate tension. Acts dynamically, moving as skin is stretched, applying a constant, cyclic stretching force. Useful in treating long-standing open wounds	Requires undermining of wound edges. While bands are marked, visual approximation is still used to determine appropriate tension. Needs repeated manual adjustment
DermaClose®	Anchors are placed 0.5–1 cm from wound edges and secured to skin with staples. A nonelastic tension line originating from the tension controller knob is looped through the anchors in an X-pattern (Fig. 3). The tension controller knob is then turned clockwise until the constant force spring engages the clutch mechanism, preventing overtightening. Constant force is maintained through the spool as the wound is closed	Simple and easy to apply. Maintains exact maximum tension that does not cause skin necrosis or damage. Constant tension is maintained without the need for repeated adjustment. Useful in treating longstanding open wounds	Requires undermining of wound edges

^aAll external tissue expanders offer the advantages of the internal expansion device in addition to those listed.