"Immediate versus delayed autologous breast reconstruction in patients undergoing post-mastectomy radiation therapy: A paradigm shift".

BACKGROUND: While negative impacts of radiation on breast reconstruction have been well accepted, timing of autologous breast reconstruction in the setting of postmastectomy radiation therapy (PMRT) is still evolving. This study aims to address the dilemma of breast reconstruction timing in patients receiving PMRT. METHODS: A retrospective chart review was performed evaluating patients who underwent PMRT and autologous breast reconstruction. Postoperative complication and revision rates were compared. RESULTS: Thirty-six immediate (immediate breast reconstruction [IBR]) and 89 delayed reconstructions (delayed breast reconstruction [DBR]) were included with comparable patient characteristics between groups. Overall complication rates were not significantly different, or when separately assessing for surgical site infections, wound dehiscence, fat necrosis, or substantial volume loss. No free flaps were lost in either group. Revision rates were significantly lower in the IBR group (p = 0.02). DBR resulted in appreciably larger volumes of fat grafting to the therapeutically reconstructed breast (p = 0.01) and more contralateral mastopexies (p = 0.02). No significant difference was observed in fat necrosis excision, breast reduction, or need for secondary flap reconstruction or prosthetic use for volume loss. CONCLUSIONS: IBR in the setting of PMRT does not result in higher rates of complications and requires fewer overall revisions, making it a compelling option for patients undergoing PMRT.

Outcomes of progressive tension donor-site closure in abdominal-based autologous breast reconstruction.

BACKGROUND: The use of progressive tension sutures (PTSs) for drain-free abdominoplasty closure has been well published in the esthetic literature and found to be effective at reducing abdominal drainage without a worse complication profile. This research aims to evaluate the outcomes of incorporating PTS into donor-site closures for abdominal-based breast reconstruction. METHODS: A retrospective chart review was performed evaluating patients at the University of Chicago Medicine, who underwent autologous breast reconstruction and either PTS closure or standard abdominal closure between 2018 and 2021. RESULTS: A total of 100 patients were included with 50 patients receiving PTS closure and 50 with traditional abdominal closures. Patient demographics, including age (p = 0.82), body mass index (BMI; p = 0.17), diabetes (p = 1.00), tobacco use (p = 0.15), and chemotherapy (p = 1.00) did not significantly differ. Total drain output over the first 72 h was significantly lower in the PTS group compared with the standard closure (SC) group (p = 0.00005). Mean duration of drain placement was shorter by 2 days in the PTS group, but this did not reach significance (p = 0.08). Overall complication rates were lower in the PTS group (p = 0.03), however, no difference was appreciated when separately assessing for seromas (p = 1.00), hematomas (p = 1.00), wound dehiscence (p = 0.58), or surgical-site infections (p = 1.00). More abdominal revisions were observed in the SC group, however, this did not reach significance (p = 0.15) CONCLUSION: The use of PTS with placement of a single drain is a safe option for donor-site closure, and is a compelling technique for patients undergoing abdominal-based breast reconstruction.

Decellularized Fetal Matrix Suppresses Fibrotic Gene Expression and Promotes Myogenesis in a Rat Model of Volumetric Muscle Loss.

BACKGROUND: Traumatic muscle loss often results in poor functional restoration. Skeletal muscle injuries cannot be repaired without substantial fibrosis and loss of muscle function. Given its regenerative properties, the authors evaluated outcomes of fetal tissue-derived decellularized matrix for skeletal muscle regeneration. The authors hypothesized that fetal matrix would lead to enhanced myogenesis and suppress inflammation and fibrosis. METHODS: Composite tissue composed of dermis, subcutaneous tissue, and panniculus carnosus was harvested from the trunk of New Zealand White rabbit fetuses on gestational day 24 and from Sprague-Dawley rats on gestational day 18 and neonatal day 3, and decellularized using a sodium dodecyl sulfate-based negative-pressure protocol. Six, 10-mm-diameter, full-thickness rat latissimus dorsi wounds were created for each treatment, matrix was implanted (excluding the defect groups), and the wounds were allowed to heal for 60 days. Analyses were performed to characterize myogenesis, neovascularization, inflammation, and fibrosis at harvest. RESULTS: Significant myocyte ingrowth was visualized in both allogeneic and xenogeneic fetal matrix groups compared to neonatal and defect groups based on myosin heavy chain immunofluorescence staining. Microvascular networks were appreciated within all implanted matrices. At day 60, expression of Ccn2, Col1a1, and Ptgs2 were decreased in fetal matrix groups compared to defect. Neonatal matrix-implanted wounds failed to show decreased expression of Col1a1 or Ptgs2, and demonstrated increased expression of Tnf, but also demonstrated a significant reduction in Ccn2 expression. CONCLUSIONS: Initial studies of fetal matrices demonstrate promise for muscle regeneration in a rat latissimus dorsi model. Further research is necessary to evaluate fetal matrix for future translational use and better understand its effects.