Prepectoral breast reconstruction is safe in the setting of post-mastectomy radiation therapy

Prepectoral versus Submuscular Implant-Based Breast Reconstruction: A Matched-Pair Comparison of Outcomes

BACKGROUND

Implant-based breast reconstruction is the most common reconstructive approach after mastectomy. Prepectoral implants offer advantages over submuscular implants, such as less animation deformity, pain, weakness, and postradiation capsular contracture. However, clinical outcomes after prepectoral reconstruction are debated. The authors performed a matched-cohort analysis of outcomes after prepectoral and submuscular reconstruction at a large academic medical center.

METHODS

Patients treated with implant-based breast reconstruction after mastectomy from January of 2018 through October of 2021 were retrospectively reviewed. Patients were propensity score exact matched to control demographic, preoperative, intraoperative, and postoperative differences. Outcomes assessed included surgical-site occurrences, capsular contracture, and explantation of either expander or implant. Subanalysis was done on infections and secondary reconstructions.

RESULTS

A total of 634 breasts were included (prepectoral, 197; submuscular, 437). A total of 292 breasts were matched (146 prepectoral:146 submuscular) and analyzed for clinical outcomes. Prepectoral reconstructions were associated with greater rates of SSI (prepectoral, 15.8%; submuscular, 3.4%; P < 0.001), seroma (prepectoral, 26.0%; submuscular, 10.3%; P < 0.001), and explantation (prepectoral, 23.3%; submuscular, 4.8%; P < 0.001). Subanalysis of infections revealed that prepectoral implants have shorter time to infection, deeper infections, and more Gram-negative infections, and are more often treated surgically (all P < 0.05). There have been no failures of secondary reconstructions after explantation in the entire population at a mean follow-up of 20.1 months.

CONCLUSIONS

Prepectoral implant-based breast reconstruction is associated with higher rates of infection, seroma, and explantation compared with submuscular reconstructions. Infections of prepectoral implants may need different antibiotic management to avoid explantation. Secondary reconstruction after explantation can result in long-term success.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Impact of Varying Chest Wall Target Volume Delineation on Postmastectomy Radiation Therapy Outcomes in Breast Cancer Patients with Implant-Based Reconstruction

BACKGROUND

The target volume for post-mastectomy radiation therapy (PMRT) in breast cancer patients with reconstruction has been a subject of debate. Traditionally, the RT chest wall (CW) volume encompasses the entire implant. For patients with retropectoral implants, the deep lymphatic plexus dorsal part of the implant is no longer considered high risk and can be omitted. This study aimed to assess the radiation dose distribution and treatment outcomes associated with different CW delineation according to ESTRO ACROP guideline for patients who have undergone implant-based reconstruction.

METHODS

We conducted a retrospective review of breast cancer patients who underwent a mastectomy followed by two-stage implant-based breast reconstruction and adjuvant radiation therapy (RT) between 2007 and 2022. The expanders/implants were positioned retropectorally. The chest wall target volumes were categorized into two groups: the prepectoral group, which excluded the deep lymphatic plexus, and the whole expander group.

RESULTS

The study included 26 patients, with 15 in the prepectoral group and 11 in the whole expander group. No significant differences were observed in normal organ exposure between the two groups. There was a trend toward a lower ipsilateral lung mean dose in the prepectoral group (10.2 vs. 11.1 Gy, p = 0.06). Both groups exhibited limited instances of reconstruction failure and local recurrence.

CONCLUSIONS

For patients undergoing two-stage expander/implant retropectoral breast reconstruction and PMRT, our data provided comparable outcomes and normal organ exposure for those omitting the deep lymphatic plexus.

Advances in Prepectoral Breast Reconstruction

Breast reconstruction can be divided into prepectoral breast reconstruction (PPBR) and subpectoral breast reconstruction (SPBR) according to the implant plane. The original prepectoral breast reconstruction was abandoned for a long time due to the frequent and severe complications. Now, advances in materials technology and improved methods of mastectomy have made safe prepectoral breast reconstruction possible. Moreover, a number of studies have gradually demonstrated the advantages of prepectoral breast reconstruction. As prepectoral breast reconstruction becomes more and more attractive, it is time to review the current advances in prepectoral breast reconstruction.