Combined Autologous and Prosthetic Breast Reconstruction: Defining the Upper Limits of Safe Expansion in Obesity.

Background: Combined latissimus dorsi and prosthetic reconstruction is a useful reconstructive option in patients with a history of breast radiation who are not good candidates for abdominally based autologous reconstruction. One difficulty, particularly in obese patients, is that the thickness of the flap can impair port localization, increasing the risk of inadvertent puncture during expansion. The authors sought to investigate the upper limits of tissue thickness at which tissue expansion can be reliably performed.

Methods: A cadaveric study was designed in which 2 blinded observers attempted to localize the port of a Mentor CPX-4 expander under tissue 1, 2, 3, 4, 5, and 6 cm thick. Thirty attempts were made per tissue thickness.

Results: For tissue thicknesses of 1 to 4 cm, the success rate was 100% (k = 1). At 5 cm, the success rate decreased to 86.6% (k = 1); at 6 cm, 43.3% (k = 0.85). Point biserial correlation revealed a negative correlation between tissue thickness and accuracy at a thicknesses of greater than 4 cm (r = -0.55, P < 0.00001). Converting tissue thickness to a dichotomous variable based on the results (thickness, <4 and >4 cm), Fisher exact test revealed a statistically significant difference between these 2 populations (P < 0.00001).

Conclusions: In obese patients with a skin pinch of greater than 8 cm or a flap thickness of greater than 4 cm, steps should be taken to minimize the risk of inadvertent puncture of the expander during postoperative expansion. This can include foregoing tissue expander placement in favor of an implant, port localization with ultrasound guidance, or the use of remote port expanders. These findings are relevant not only in breast reconstruction with latissimus flaps and implants but also in any setting where autologous and prosthetic reconstructions are combined.