Scientific Abstract Presentations: Breast Session 10 Saturday, October 17 Sat, Oct 17 5:00-6:00 p.m. CDT

Background: Nipple sparing mastectomy (NSM) with immediate implant-based reconstruction (IBR) carries higher complication rates in large breasts. Inframammary fold (IMF) incisions are suggested to be superior for NSM. However, prior studies have indicated a shift towards a periareolar incision with increasing breast size (1, 2). We investigated the interaction between incision type and breast size in outcomes of NSM with IBR.

Methods: We retrospectively reviewed patients who underwent NSM with IBR from 2019-2024. Patients with a mastectomy weight of >500 grams were included. Demographics, surgical variables (incision type, axillary surgery, mastectomy weight/volume, tissue expander max fill), and post-operative complications (infection, delayed wound healing, seroma, hematoma, skin flap necrosis, nipple necrosis, prothesis failure) were collected. Chi-square, independent t-test, and multivariable logistic regressions were performed.

Results: Of the 165 breasts (108 patients) included, 83 had IMF incisions, 77 had periareolar, 4 had vertical, and 1 had Wise. We found significant differences in rates of hypertension, adjuvant chemotherapy, and prior breast surgeries. Incision type was significantly associated with delayed wound healing (p=0.001) and nipple necrosis (p=0.001). On multivariable logistic regression, a periareolar incision was identified as an independent risk factor of delayed wound healing (p=0.001, OR: 7.2) and unplanned readmission (p=0.004; OR: 6.1). However, use of a periareolar incision resulted in a significantly lower rate of infection (p=0.04; OR: 0.34).

Conclusion: This study identifies the use of a periareolar incision as a risk factor for delayed wound healing in breasts >500 grams. We hypothesize this is attributed to disrupted perfusion to the nipple areolar complex. Conversely, we show that a periareolar incision is beneficial in protecting against infection, likely due to smaller incision and less weight of the implant on incision. These findings can help guide preoperative patient counseling and appropriate surgical planning.

References: 1. Frey JD, Salibian AA, Karp NS, Choi M. The impact of mastectomy weight on reconstructive trends and outcomes in nipple-sparing mastectomy: Progressively greater complications with larger breast size. Plastic & Reconstructive Surgery. 2018;141(6). doi:10.1097/prs.0000000000004404 2. Holland M, Wallace A, Viner J, Sbitany H, Piper M. Safety of incision placement with nipple-sparing mastectomy and immediate prepectoral breast reconstruction. Plastic and Reconstructive Surgery - Global Open. 2023;11(1). doi:10.1097/gox.0000000000004736

Introduction: Capsular contracture remains a significant complication following alloplastic breast reconstruction, particularly in patients receiving post-mastectomy radiotherapy. This study investigated the therapeutic potential of human alpha1-antitrypsin (hAAT) in reducing radiation-induced capsular contracture. Methods: Silicone-implant discs were subcutaneously grafted in female C57BL/6 mice, which then underwent localized irradiation (15 Gy) at the implantation site. Mice were assigned to three groups: non-irradiated controls, irradiated-control and irradiated mice treated with hAAT. Capsule formation was evaluated using Magnetic Resonance Imaging (MRI), histological analysis, and gene expression profiling. Key inflammatory and fibrotic mediators, including interleukin-1-beta (IL-1β), interleukin-1 receptor antagonist (IL-1Ra), transforming growth-factor beta (TGFβ), collagen I, and Sloan-Kettering Institute proto-oncogene (SKI), were examined. Furthermore, human dermal fibroblasts cultures were examined to assess the impact of irradiation on TGFβ expression. Result: At 21 days post-implantation, irradiated-control exhibited significant capsule thickening and disorganized collagen deposition compared to the non-irradiated group. In contrast, irradiated mice treated with hAAT, demonstrated capsule thickness comparable to non-irradiated controls, along with improved extracellular matrix organization and reduced inflammatory cell infiltration. Gene expression analyses demonstrated that hAAT treatment reduced IL-1β, TGFβ, and collagen I expression while increasing the IL-1Ra/IL-1β ratio and upregulating SKI expression. Notably, hAAT-treated tissues exhibited a predominance of SKI expression over TGFβ expression, compared to irradiated controls. Additionally, in human dermal fibroblast cultures, hAAT treatment attenuated radiation-induced TGFβ upregulation. Conclusion: These findings support the clinical evaluation of hAAT therapy as a safe approach to address radiation-induced fibrotic changes, including reducing capsular fibrosis and contracture formation after implant-based breast reconstruction.

Absorbable Antibiotic Eluting Disks for Infection Prophylaxis and Treatment in Breast Reconstruction Abstract

Introduction: Infections involving tissue expanders and implants in breast reconstruction remain a persistent challenge for patients and reconstructive surgeons.(1) When a prosthetic device shows signs of infection, it often results in unplanned readmission, additional operations, and, in many cases, reconstructive failure. Despite advancements in surgical techniques and perioperative care, infection rates continue to be unacceptably high. The difficulty lies in placing a prosthetic device within a devascularized post-mastectomy field, where bacterial contamination can readily lead to biofilm formation-rendering systemic antibiotics largely ineffective. These complications not only increase healthcare costs but also cause significant physical and emotional distress for patients.(2) As a result, new strategies are needed to strengthen infection prevention in breast reconstruction. Antibiotic-releasing materials have been explored in various surgical specialties, including more recent interest with Polymethyl methacrylate (PMMA) for breast reconstruction.(3, 4) However, limited research exists on the use of antibiotic-impregnated, fully absorbable materials.(5) This study introduces a novel application of antibiotic-impregnated calcium sulfate for the prevention and treatment of prosthetic infections in breast reconstruction.

Methods: A single-institution retrospective cohort study was performed on all patients who received an antibiotic eluting disk at the author's institution between 2024 to 2025, excluding cases with insufficient postoperative follow up. A matching control cohort was selected from the years leading up to the adaptation of an absorbable antibiotic disk. Information was collected on patient factors, operative details, and the overall postoperative course. A combination of descriptive statistics, Fisher's exact, and Chi-square tests were obtained to evaluate the data set.

Results: A total of 233 breast pockets received antibiotic disks with ≥90 days of follow-up. Most disks were placed during immediate or delayed reconstruction with an expander or implant (188, 80.6%), 45 (19.3%) were used during a second stage or exchange procedure, 12 (5.2%) were used for salvage in known periprosthetic infections. The infection rate was significantly lower in the overall disk group vs. controls (4.7% vs. 14.6%, p < 0.001) and all first stage procedures (5.9% vs 16.5%, p < 0.001). This represented a relative risk reduction of around 70%. There were no infections while using a disk during second stage reconstruction and the data trended towards but was not significant, likely due to being underpowered (0.0% vs 6.8%). All salvage cases-treated with prosthesis removal, replacement, and disk placement-were successful, with no recurrent infections.

Conclusion: Absorbable antibiotic disks are associated with a significant reduction in periprosthetic infection rates across reconstructive scenarios. This may also serve as a viable salvage treatment option in a small subset of patients who may otherwise abandon reconstruction. Further randomized controlled trials are necessary, but the technique described may be a simple, reproducible, and cost-effective adjunct to improve outcomes in implant-based breast reconstruction

1. Kwok AC, Goodwin IA, Ying J, Agarwal JP. National trends and complication rates after bilateral mastectomy and immediate breast reconstruction from 2005 to 2012. Am J Surg. 2015;210(3):512-516. doi:10.1016/j.amjsurg.2015.03.019
2. Peled AW, Stover AC, Foster RD, McGrath MH, Hwang ES. Long-term reconstructive outcomes after expander-implant breast reconstruction with serious infectious or wound-healing complications. Ann Plast Surg. 2012;68(4):369-373. doi:10.1097/SAP.0b013e31823b6c36
3. Clark RC, Leckenby JI, Adams WP Jr, et al. Prophylactic local antibiotics for tissue expansion (PLATE) improve breast reconstruction outcomes. Plast Reconstr Surg. 2021;148(4):10-1097. doi:10.1097/PRS.0000000000008436
4. Xue AS, Volk AS, DeGregorio VL, Jubbal KT, Bullocks JM, Izaddoost SA. Follow-Up Study: One-Step Salvage of Infected Prosthetic Breast Reconstructions Using Antibiotic-Impregnated Polymethylmethacrylate Plates and Concurrent Tissue Expander Exchange. Plast Reconstr Surg. 2020;145(2):240e-250e. doi:10.1097/PRS.0000000000006501
5. Kenna D, Irojah B, Mudge K, Eveler K. Absorbable antibiotic beads prophylaxis in immediate breast reconstruction. Plast Reconstr Surg. 2018;141(4):486e-492e. doi:10.1097/PRS.0000000000004203

Purpose: Capsular contracture represents the most frequent complication following breast implant surgery, affecting approximately 45% of patients. Specifically in the oncological population, capsular contracture may result in dissatisfaction with aesthetic outcomes in a group for whom maintaining successful reconstruction is psychologically significant. Risk stratification can be beneficial for patient counseling and for implementing more focused preventative strategies. Postoperative infection is a recognized risk factor for capsular contracture (CC) following implant-based breast augmentation or reconstruction; however, the impact of infection severity remains unknown. While prior studies have examined the bacterial species, biofilm burden, and the periprosthetic microbiomal environment in association with CC, no study has evaluated whether the severity of the infection itself affects subsequent CC risk. This study aims to determine if infection severity-stratified by clinical management with oral (PO) versus intravenous (IV) antibiotics-independently predicts CC development.

Methods: We conducted a retrospective cohort study of patients undergoing immediate tissue-expander (TE) or direct-to-implant (DTI) breast reconstruction (January 2019–December 2024) to analyze postoperative infection and capsular contracture (CC) rates. Patients were stratified by CC development. Demographic, oncologic, and surgical variables were collected including age, BMI, comorbidities (hypertension, hyperlipidemia), smoking status, mastectomy indication and details (weight, type, implant plane), neoadjuvant radiation therapy, and neoadjuvant chemotherapy. Postoperative infection was evaluated by overall occurrence and then categorized by severity, defined clinically by (1) the requirement of PO antibiotics alone or (2) the requirement of IV antibiotics with hospital admission. Significant covariates identified in univariable analyses were included in multivariable logistic regression models to determine whether infection severity independently predicted CC.

Results: A total of 1,241 reconstructions were analyzed, comprising 1,024 (82.5%) TE and 217 (17.5%) DTI procedures. Overall, 140 TE and 29 DTI reconstructed breasts developed CC. In the TE cohort, infection requiring IV antibiotics and admission was a significant independent predictor of CC (OR 2.01, 95% CI 1.14–3.54, p=0.016), whereas infection managed with PO antibiotics alone was not (OR 1.75, 95% CI 0.88–3.49, p=0.112). Similarly, in the DTI cohort, infection requiring admission with IV antibiotics strongly predicted CC development (OR 7.93, 95% CI 1.81–34.74, p=0.006), while infections managed with PO antibiotics did not reach statistical significance (OR 2.43, 95% CI 0.65–9.08, p=0.188). Therapeutic mastectomy was independently associated with CC in the TE cohort (p=0.016), while prepectoral plane implant placement was independently associated with CC in the DTI cohort (p = 0.04).

Conclusion: Infections severe enough to require hospital admission with IV antibiotics significantly increase the likelihood of CC, whereas mild infections managed with oral antibiotics alone do not significantly increase this risk. These findings suggest a severity-dependent relationship between postoperative infection and subsequent capsular fibrosis, enabling more precise risk stratification and improved prognostic patient counseling following breast reconstruction. In the future, we plan to evaluate how the duration of IV antibiotic treatment, the need for operative intervention, and the species of bacteria in the culture if taken may also influence CC development.

Periprosthetic infection remains a difficult complication after implant-based breast reconstruction (IBR), occurring in up to 35% of post-mastectomy reconstructions.(1) Eradication of the infection with antibiotics alone is unlikely given the propensity for biofilm formation on foreign material, and Implant removal without replacement is often necessary, which complicates and compromises the final reconstruction.(2) Prior work has explored antibiotic-impregnated calcium sulfate beads during salvage of infected breast implants, with the largest published series comprising only 12 patients (3). A 2024 systematic review identified only four qualifying studies in the entire literature (4). We present, to our knowledge, the largest series of implant salvage using antibiotic-impregnated calcium sulfate beads in IBR.

We retrospectively reviewed adult female patients at our institution who underwent salvage of infected implants or expanders using antibiotic-impregnated calcium sulfate beads between August 2016 and July 2025. Descriptive statistics are reported as counts (%) and continuous data as median and interquartile range. The population-level salvage success rate was estimated using a beta-binomial model with an informative prior beta(9, 3) based on Sherif et al. (3).

In total, 51 patients met inclusion criteria. The posterior median salvage success rate was 65.8% (53.7-76.7%, 95% credible interval). The salvage success and salvage failure groups were comparable with respect to multiple comorbidities, including race, laterality, and current or former smoking (27% and 33%, respectively). The failure group had a higher rate of neoadjuvant chemotherapy (35% vs. 24%) and antibiotic resistance (29% vs 13%). Cultures were collected in all cases; 66% demonstrated growth. Dominant organisms included Pseudomonas (17%), OSSA (15%), and Serratia (9%); antibiotic resistance was present in 19% overall. We found no adverse reactions related to the calcium sulfate beads. Among those achieving successful salvage, 52% completed implant-based secondary reconstruction and 33% underwent autologous reconstruction.

Periprosthetic breast implant infection remains a challenging complication of breast reconstruction. Our data demonstrate a posterior salvage success rate of 65.8% with a narrow credible interval, comprehensive microbiological characterization, and absence of adverse antibiotic bead reactions supporting the safety and feasibility of this modality. Secondary reconstruction was completed in the majority of salvage successes. Limitations include the retrospective single-institution design and absence of a concurrent control group. These data support antibiotic-impregnated calcium sulfate beads as a feasible salvage strategy and provide the most comprehensive characterization of patient trajectory following salvage to date.

References:

1. Washer LL, Gutowski K. Breast implant infections. Infect Dis Clin North Am. 2012;26(1):111-125. doi:10.1016/j.idc.2011.09.003

2. Costerton JW, Montanaro L, Arciola CR. Biofilm in implant infections: its production and regulation. Int J Artif Organs. 2005;28(11):1062-1068. doi:10.1177/039139880502801103

3. Sherif RD, Ingargiola M, Sanati-Mehrizy P, Torina PJ, Harmaty MA. Use of antibiotic beads to salvage infected breast implants. J Plast Reconstr Aesthet Surg. 2017;70(10):1386-1390. doi:10.1016/j.bjps.2017.05.023

4. Giannas E, Winocour J, Yu J, Kokosis G, Mathes D, Kaoutzanis C. The effect of antibiotic beads on periprosthetic infection in implant-based breast reconstruction following mastectomy. J Plast Reconstr Aesthet Surg. 2024;96:33-35. doi:10.1016/j.bjps.2024.07.016

Background: Tranexamic acid (TXA) is a well-known anti-fibrinolytic agent that has demonstrated a significant reduction in perioperative bleeding and transfusion rates across many surgical specialties without increased thromboembolic events. However, there remains sparse literature regarding its safety and efficacy in microvascular reconstruction. We hypothesized that the protocolized application of intraoperative TXA in microvascular breast reconstruction would result in no change in flap complications with earlier drain removal and reduced output.

Methods: A retrospective chart review was conducted over one year for all consecutive patients who underwent free tissue transfer for breast reconstruction by one of the senior authors (abdominally or thigh based) between the dates of July 2024 to July 2025, aged 18 years or older, at a single institution were included. There were no exclusions. The control group consisted of patients in the first six months who did not receive TXA, while the intervention group received 2g of intraoperative TXA – 1g on induction and 1g upon closing. Demographics, intraoperative flap details and times, and outcomes were collected including all flap complications. Data analysis was performed using R software (2025.05.1+513) .

Results: A total of 105 consecutive patients were included, encompassing 195 flaps, of which 98.4% were abdominally based. The control group consisted of 43 patients (78 flaps), and the TXA group consisted of 62 patients (117 flaps) with six patients in the TXA group having a prior provoked DVT or PE. There was no significant difference between preoperative or intraoperative data except for the control group having a longer intraoperative duration (p=0.0003) and ischemia time (p=0.024). There was no significant difference between age (p=0.618), body mass index (BMI) (p=0.075) and common comorbidities screened for as presented in Table 1. There was also no significant difference in breast cancer stage at diagnosis (p=0.562), lymph node involvement (staged according to American Cancer Society) (p=0.283), or preoperative chemotherapy (p=0.318) or radiation (p=0.538). For general operative details analyzed, there was no significant difference in skin-sparing (SSM) vs nipple-sparing mastectomy (NSM) rates (p=0.838), bilateral vs unilateral reconstruction (p=0.786), immediate vs delayed reconstruction (p=0.430), rate of burying the flap at initial reconstruction such that there was no skin paddle (p=1.000), or rate of a second venous anastomosis (p=0.573) as presented in Table 2. There were also no differences in incidence of hematoma, seroma, partial flap loss, total flap loss or unplanned reoperations. On multivariate regression analysis, the TXA group had a significantly shorter duration for last drain removal, on average 4.3 days earlier (p=0.0021).

Conclusion: Tranexamic acid can be safely administered intraoperatively to patients undergoing microvascular breast reconstruction with perforator flaps and may decrease time to final drain removal. By working with pharmacy colleagues, a perioperative protocol can be safely developed and implemented that includes patients with prior provoked DVTs or PEs.

Objectives: This study evaluated factors that contribute to prolonged surgical drain usage and the impact of drain retention on tissue expander (TE) loss following immediate implant-based breast reconstruction (I-IBBR).

Methods: One hundred twenty-eight consecutive patients (189 breasts) who underwent mastectomy followed by expander placement for I-IBBR were reviewed. The primary outcome was expander removal for periprosthetic infection. A receiver operating characteristic (ROC) curve was used to identify an optimal cutoff value for drain days (DDs) to predict expander loss. Multiple linear and multivariable binary logistic regression models were utilized to evaluate associations with total DDs and TE loss, respectively.

Results: Expander loss occurred in thirty-nine (21%) reconstructed breasts. Mean total DDs were higher in the TE loss group (28.1 vs 19.4 days, p < 0.001). On multiple linear regression, mastectomy weight was positively correlated with DDs (β = 0.65, p = 0.028). ROC analysis based on DDs showed good predictability of TE loss (AUC 0.671, p = 0.002). The optimal cutoff value was 29.5 days. On multivariable logistic regression, retained drains ≥ 30 days were associated with increased odds of expander loss (OR 9.61, p < 0.001). Likewise, Cox regression demonstrated an increased risk of I-IBBR failure for patients with a retained drain ≥ 30 days (HR 3.53, p = 0.002).

Conclusions: I-IBBRs complicated by expander loss had, on average, longer drain retention times. Greater mastectomy weight was associated with an increased number of DDs. Patients with a drain retained for greater than or equal to 30 days were at significantly higher risk for expander loss. These findings may provide future guidance on management of postoperative surgical drains following immediate implant-based breast reconstruction (I-IBBR).

Background: Implant-based reconstruction (IBR) is the most common method for post-mastectomy breast reconstruction in the United States. As the techniques for IBR continue to evolve, there has been increased focus on optimizing implant selection to enable high-quality results.(1-3) Accordingly, implant manufacturers develop and improve their products to enhance reconstructive outcomes. The Mentor MemoryGel BOOST (MGB) breast implant was developed to increase form stability to shape the breast. Mentor MGB breast implants are FDA approved and became commercially available in the United States in 2022.(4) This study was designed to evaluate the short-term safety and effectiveness of Mentor MGB breast implants for post-mastectomy breast reconstruction.

Methods: The authors performed a retrospective cohort study of patients who underwent primary IBR with Mentor MGB breast implants between June 2022 and May 2024. No industry-affiliated personnel performed study design, data collection, analysis or abstract preparation. Study outcomes included demographics, clinicopathologic information, operative details, clinical safety and effectiveness outcomes, and patient reported outcomes. Propensity score matching was performed to estimate the effect of Mentor MBG breast implants on clinical safety and effectiveness outcomes.

Results: A total of 285 patients were identified, resulting in 452 breast reconstructions, with Mentor MGB breast implants. All patients had follow-up ≥ 6-months. Mastectomy types included skin sparing mastectomy (61%) and nipple sparing mastectomy (39%). Two-stage IBR (85.6%) and prepectoral reconstruction (75%) were the dominant techniques for breast reconstruction. Clinical safety and effectiveness outcomes included seroma (1.1%), hematoma (0.2%), wound dehiscence (2.0%), infection (3.1%), Baker III or IV capsular contracture (1.5%), implant flipping (2.4%), implant malposition (4.4%), and implant rippling (8.4%). The BREAST-Q Module: Satisfaction with Implants demonstrated that patients were "very satisfied" to "somewhat satisfied" (38.6% and 21.5%, respectively) with the amount of visible implant rippling and "very satisfied" to "somewhat satisfied" (44.6% and 19.3%, respectively) with the amount of palpable implant rippling. In propensity score matched analysis, Mentor MGB breast implants had less visible implant rippling than Mentor MemoryGel Xtra and Allergan Natrelle Cohesive breast implants (10.7% vs 15.8%, p<0.5 and 10.7% vs 12.4%, p<0.5, respectively).

Conclusions: Short-term results from 285 patients and 452 breast reconstructions demonstrate the safety and effectiveness of Mentor MGB breasts implants in breast reconstruction. The results of this study mirror the trend towards adoption of highly cohesive breast implants to improve both safety and patient satisfaction with IBR.

References: 1. Larsen A, Bak EEF, Hart LB, Timmermann AM, Orholt M, Weltz TK, et al. Silicone Leakage from Breast Implants Is Determined by Silicone Cohesiveness: A Histologic Study of 493 Patients. Plast Reconstr Surg. 2024;154(6):1159-71. 2. Marks JM, Farmer RL, Afifi AM. Current Trends in Prepectoral Breast Reconstruction: A Survey of American Society of Plastic Surgeons Members. Plast Reconstr Surg Glob Open. 2020;8(8):e3060. 3. Parikh N, Gadiraju GK, Prospero M, Shen Y, Starr BF, Reiche E, et al. The Impact of Breast Implant Cohesivity on Rippling and Revision Procedures in 2-Stage Prepectoral Breast Reconstruction. Aesthet Surg J Open Forum. 2024;6:ojae028. 4. U.S. FDA Approves New Mentor MemoryGel BOOST Breast Implant [press release]. January 13 2022.

Impact of Anxiety and Depression on Postoperative Pain in Immediate Implant-Based Breast Reconstruction

Background: Psychiatric comorbidities including anxiety, depression, and others may influence postoperative pain and opioid use. Clarifying this relationship may inform tailored pain management strategies following breast reconstruction.

Methods: A retrospective review was performed of patients undergoing immediate implant-based breast reconstruction (2017–2023) at a single institution. Patients were stratified by psychiatric diagnosis: none, single (anxiety or depression), or multiple (anxiety and depression). Outcomes included length of stay (LOS), opioid consumption in morphine milligram equivalents (MME), and Visual Analog Scale (VAS) pain scores. Two-way ANOVA assessed the effects of regional anesthesia laterality and psychiatric diagnosis on opioid use, while one-way ANOVA with Tukey's HSD evaluated differences by psychiatric diagnosis alone.

Results: Among 206 patients, 46 had a single psychiatric diagnosis, 47 had multiple diagnoses, and 113 had none. Mean LOS and average total MME use were 1.1 days and 65.2 MME respectively. Regional anesthesia laterality did not affect opioid use. Total MME was higher in patients with a single psychiatric (75.2 MME) or multiple psychiatric diagnoses (73.8 MME) compared to controls (57.1 MME), representing a statistically significant difference (p = 0.036). This difference represented 30.7% and 29.6% higher use in the single psychiatric diagnosis and multiple psychiatric diagnosis cohorts, respectively. There were no significant differences in average VAS Pain Scores between the three cohorts (p > 0.05). Post-hoc analysis showed no difference between different psychiatric diagnoses (p = 0.998), while comparisons with controls trended toward significance.

Conclusion: Co-morbid psychiatric diagnoses are associated with increased total opioid consumption following immediate implant-based breast reconstruction, suggesting a potential role for tailored perioperative pain management strategies

Background: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly prescribed for diabetes and weight loss, yet their impact on outcomes in autologous breast reconstruction remains unclear. This study evaluates association between preoperative GLP-1 RA use and postoperative complications in patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction.

Methods: A retrospective cohort study was conducted in patients who underwent DIEP flap breast reconstruction at a single institution between January 2019 and December 2025. Patients with documented GLP-1 RA use at the time of DIEP flap reconstruction were compared with non-users. Propensity scores were estimated using logistic regression incorporating age, body mass index, diabetes status, smoking history, laterality (uni- or bilateral reconstruction), ASA class, prior radiation, and timing of reconstruction (immediate or delayed). Patients were matched using nearest-neighbor matching at a 1:2 ratio. Postoperative wound healing, flap-related, and medical complications at 30 and 90 days were analyzed in the matched cohort using conditional logistic regression models, and continuous variables were analyzed using linear mixed-effects regression models.

Results: A total of 903 patients underwent reconstruction during the study period, including 37 patients on GLP-1 RAs and 866 non-users. There was a 15-fold increase in GLP-1 receptor agonist use (0.7% of patients in 2019 to 10.9% in 2025). Among GLP-1 users, later calendar year was associated with significantly lower odds of diabetes diagnosis (OR per year 0.47; 95% CI, 0.21–0.83; P = 0.023), indicating increasing use among non-diabetic patients over time. Propensity score matching yielded a cohort of 111 patients (37 GLP-1 RA users and 74 matched controls). Mean age, BMI, and ASA of this cohort were 51.6 years old, 31.3 kg/m2, and 2.4, respectively. Thirty-six percent of patients had a history of diabetes, 83.8% were never smokers, 10.8% had previous radiation, 93.7% cases were bilateral, and 91.9% were immediate. There were no significant differences in DIEP flap weight between matched groups. GLP-1 RA use was associated with higher odds of postoperative seroma at 30 days (OR 3.84, 95% CI 1.16-12.70; p = 0.03) and any postoperative complication at 90 days (OR 3.14, 95% CI 1.15-8.57; p=0.03). Rates of mastectomy flap necrosis and delayed wound healing were higher among GLP-1 RA users, however did not reach statistical significance. There were no differences in fat necrosis, reoperation, and hospital readmission rates at 90 days. Flap compromise and flap loss occurred once in the overall cohort and thus were not included in the analysis. There was no incidence of VTEs in either group.

Conclusions: GLP-1 RA use for weight loss among DIEP patients has increased substantially over the past 5 years. While GLP-1 RA therapy does not appear to increase the risk of major reconstructive morbidity, the observed increase in minor wound complications highlights the importance of careful perioperative optimization and further investigation as use continues to grow.