Long-Term Results and Reconstruction Failure in Patients Receiving Postmastectomy Radiation Therapy with a Temporary Expander or Permanent Implant in Place

BACKGROUND: This study investigated the risk of reconstruction failure after mastectomy, immediate breast reconstruction, and radiotherapy to either a temporary tissue expander or permanent implant. METHODS: Records of women treated at a single institution between June of 1997 and December of 2011 were reviewed. Two patient groups were identified based on type of immediate breast reconstruction: tissue expander followed by exchange with a permanent implant and permanent implant. The study endpoint was rate of reconstruction failure, defined as a replacement, loss of the implant, or conversion to flap. RESULTS: The tissue expander/permanent implant and the permanent implant groups consisted of 63 and 75 patients, respectively. The groups were well balanced for clinical and treatment characteristics. With a median follow-up of 116 months, eight implant losses, 50 implant replacements, and four flap conversions were recorded. Reconstruction failure occurred in 22 of 63 patients in the expander/implant group and in 40 of 75 patients in the permanent implant group. A traditional proportional hazards model showed a higher risk of reconstruction failure for the expander/implant group (hazard ratio, 2.01) and a significantly shorter time to reconstruction failure compared with the permanent implant group (109.2 months versus 157.7 months; p = 0.03); however, according to a competing risk model, the between-groups cumulative incidences were not significantly different (hazard ratio, 1.09). CONCLUSIONS: Radiotherapy to either a tissue expander or a permanent implant presented a fairly large risk of reconstruction failure over time. The expander/implant group was not more likely to develop reconstruction failure compared to permanent implant group, but the timing of onset was shorter. More complex techniques should be investigated to lower the risk of reconstruction failure. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.