Background: The use of acellular dermal matrix (ADM; AlloDerm and Strattice, LifeCell, Branchburg, NJ and FlexHD, Ethicon, New Brunswick, NJ) in Tissue Expander/Implant (TE/I) breast reconstruction following mastectomy is a popular alternative to standard TE/I breast reconstruction. Based on previous studies comparing outcomes between standard TE/I breast reconstruction and TE/I breast reconstruction using ADM, we hypothesized that there would be no difference in complication rates between the two methods.
Methods: Patients who underwent TE/I breast reconstruction following mastectomy by five surgeons at a single institution from 2005 to 2008 were retrospectively identified. Patients were divided into two cohorts: use of ADM v. standard sub-muscular placement. Measures included age, BMI, tobacco use, pre- and post-operative chemotherapy and radiation treatment, TE size and fill data, and the incidence of complications during the time period between placement of the TE and replacement of the TE with a permanent prosthesis. Each patient contributed one breast to analysis. Statistical analysis was performed to determine differences in complication rates between the two cohorts.
Results: The non-ADM cohort (n = 70) and ADM cohort (n = 48) did not differ significantly with respect to age, tobacco use, and chemotherapy or radiation treatment, but did differ significantly in BMI (29.3 v. 24.8 respectively, P < 0.001). Patients in the ADM cohort showed a statistically significant higher rate of infection (31.3% v. 12.9%, P = 0.020), skin necrosis (16.7% v. 4.3%, P = 0.029), expander loss (20.8% v. 5.7%, P = 0.019), need for re-operation (27.1% v. 7.2%, P = 0.002), and overall complication rate (47.9% v. 22.9%, P = 0.006) (Table 1). This pattern of increased complications held when patients were stratified to control for differences in BMI across the two cohorts.

Table 1: Complication Rates, Standard TE/I Reconstruction v. ADM TE/I Reconstruction

	Non-ADM Cohort (n = 70)	ADM Cohort (n = 48)	P-value (2-tailed)†	Risk Ratio	95% CI
Infection*	9 (12.9%)	15 (31.3%)	0.020	2.43	(1.16-5.10)
Skin Necrosis*	3 (4.3%)	8 (16.7%)	0.029	3.89	(1.09-13.91)
Seroma	5 (7.2%)	7 (14.6%)	0.22	2.04	(.69-6.06)
Hematoma	0 (0%)	0 (0%)	-------------	------------	---------------
Capsular Contracture	4 (5.7%)	2 (4.2%)	1.00	0.73	(.14-3.82)
Expander Loss*	4 (5.7%)	10 (20.8%)	0.019	3.65	(1.21-10.95)
Reoperation Required*	5 (7.2%)	13 (27.1%)	0.002	4.20	(1.63-10.84)
Overall Complication Rate*‡	16 (22.9%)	23 (47.9%)	0.006	2.10	(1.24-3.53)

* = statistical significance, †= P-value based on Fisher’s exact test, ‡ = defined as the number of patients who experienced at least one complication.
Additionally, the ADM cohort demonstrated a statistically significant higher mean intraoperative fill ratio (initial fill volume/TE volume) (48.4% v. 17.2%, P <0.001).
Conclusions: We found that the use of ADM is associated with a statistically significant higher risk of complications in TE/I breast reconstruction following mastectomy, thus disproving our null hypothesis. Additionally, we found that the use of ADM is associated with a statistically significant higher mean intraoperative TE fill volume. Our results suggest that there may be a patient population for which the use of ADM in breast reconstruction is not ideal.