Determination of relative contributions of 'mechanical' and 'biological' creep in tissue expansion using in vivo pressure monitoring: a preliminary report

An axisymmetric computational model of skin expansion and growth

Skin expansion is the principal technique used in plastic surgery to repair large cutaneous defects, typically after tumour removal, burn care, craniofacial surgery and post-mastectomy breast reconstruction. It allows a gain of new tissue by means of gradual expansion of a prosthesis, surgically implanted beneath the patient's skin. Nevertheless, wide clinical use is not supported by a deep quantitative knowledge of the phenomena occurring during the expansion. A finite element model of the skin expansion was developed to evaluate the stresses and the strains of the skin due to the expander inflation and validated by proper in vitro experiments; furthermore, a growth model based on the mechanical stimulus was implemented to estimate the skin area gain. The developed computational approach, composed of the skin expansion model interaction and the growth law, proved its validity to investigate skin expansion phenomena: its use suggests a new predictive tool to optimize clinical procedures and the expander devices' design.

A review of 120 Becker permanent tissue expanders in reconstruction of the breast

In reconstructive breast surgery, the permanent tissue expander has become popular because it avoids expander-implant exchange and gives the patient some control over the final breast size. It may, however, be associated with a number of complications. We therefore analysed the clinical notes of 111 consecutive recipients of Becker breast expanders with respect to complications and their possible predisposing factors. 120 prostheses were inserted in 111 consecutive patients with a mean age of 42.6 years. Median follow-up was 12 months (range 8 to 22). The commonest indication was postmastectomy breast reconstruction (81%) followed by congenital hypoplasia (14%) and acquired breast asymmetry following repeated biopsies (3%). Overexpansion before size adjustment was achieved after an average of 8 expander inflations. Complications included capsular contracture (9%), local tumour recurrence (8%), wound dehiscence (8%), filling port failure (6%), infected prostheses (4.5%) and ruptured implants (1.6%). The significant predisposing factors to wound dehiscence/infection were heavy smoking and radiotherapy (P < or = 0.05, chi 2 test). Expansion rate was not a factor. 89% of patients expressed satisfaction with the final aesthetic result. Despite the excellent results obtained with this technique, caution must be exercised in heavy smokers and the previously irradiated.

Tissue expansion: an overview

A review of a surgical technique which uses the skin's ability to stretch to obtain tissue for reconstruction