BACKGROUND: This randomized controlled trial (RCT) investigates differences in shoulder-related morbidity after delayed breast reconstruction by either a latissimus dorsi (LD) flap or a thoracodorsal artery perforater (TAP) flap.

MATERIAL AND METHODS: In accordance with the CONSORT guidelines, we included women for unilateral delayed breast reconstruction. Patients were randomized to reconstruction by either of the two flaps. Shoulder-function was assessed at baseline and at 3, 6 and 12 months after surgery. The primary endpoint was patient-reported shoulder-related pain. A further objective assessment by the Constant Shoulder Score (CSS) was included as secondary endpoints.

RESULTS: A total of 50 women were enrolled over a two-year period and allocated to reconstruction, with 25 patients in each group. Patient-reported shoulder-related pain was significantly lower in the TAP group at 12 months after surgery when adjusting for pain at baseline: OR = 0.05 95%CI(0.005-0.51), p-value = 0.011. The estimated effect on the total CSS at 12 months, when applying the TAP flap instead of the LD flap and adjusting for the baseline score, was 6.2 points with 95%CI(0.5-12.0), p-value 0.033. The TAP flap seems to have a statistically significant positive effect on pain and activity in daily life (ADL), while there were no significant effect on range of motion and strength after one year.

CONCLUSION: Patient reconstructed by the TAP flap are less likely to experience shoulder-related pain and have a better shoulder-function one year after the reconstruction. Harvest of the LD flap carries a higher risk of shoulder-function impairment, chronic pain and reduced ADL.