Scientific Abstract Presentations: Breast Session 1 Thursday, September 26 Thu, Sep 26 9:45-11:45 a.m. PDT

PURPOSE The voluntary recall of textured breast implants due to their association with Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) has eliminated the key benefit of textured surface--positional stability. We have engineered a novel smooth-surface breast implant, known as the Positionally Stable Smooth Implant (PSSI), which contains 2mm diameter smooth cylindrical wells on the implant shell, allowing for tissue ingrowth and thereby stabilizing the implant. Previous studies demonstrated that stability was associated with an increased total surface area of the implant. The current study aimed to 1) investigate long-term positional stability of this novel smooth implant design, and 2) characterize capsule formation around the implant. We hypothesized that miniature PSSI implants designed with same total surface area but varying well dimensions/densities can provide improved stability versus smooth implants.

METHODS Hemispherical miniature 2cc breast implants were manufactured using polydimethylsiloxane and casted using 3D-printed inverted negative molds. All PSSI implants were designed with the same total surface area of 1170mm2; dimensions of wells on the shell surface are reported in millimeters in the following variations in width (W), depth (D), and number of wells (in parenthesis): W2D1(52), W2D2(26), and W2D4(13). Control groups consisting of smooth and salt-imprinted textured implants were fabricated. Six sterilized implants per group were implanted subcutaneously into the bilateral dorsa of Sprague-Dawley rats. Implant rotation was measured with Micro-CT every 2 weeks for a total of 12 weeks to assess positional stability. Animals were sacrificed at 12 weeks, and implant-capsule units were explanted en bloc for histological analysis.

RESULTS Between 1 and 3 months, smooth implants had a cumulative positional rotation of 107 degrees, which was significantly greater than textured implants at 43 degrees, W2D1(52) at 37 degrees, W2D2(26) at 48 degrees, and W2D4(13) at 41 degrees (p<0.001). There was no significant difference in rotation between textured and all PSSI groups after three months. Upon explantation, micro-CT and gross examination showed tissue growing into and conforming to the well dimensions of PSSI groups. Trichrome staining demonstrated that capsules of smooth implants and those surrounding non-well regions of PSSI had parallel and uniform collagen fiber alignment, whereas collagen fibers of textured implants and those within PSSI implant wells appeared less organized, contouring to the surface morphology. Immunofluorescent staining of CD86 demonstrated significantly higher amount of M1 macrophages in the textured implant capsule than smooth and PSSI groups (p<0.0001). No significant difference was observed in CD206 expression of M2 macrophages among all groups. The M1/M2 ratio for textured implant capsule was 4.84, smooth 1.08, W2D1(52) 1.75, W2D2(26) 1.63, and W2D4(13) 2.38.

CONCLUSIONS This novel breast smooth implant design with cylindrical well features provided implant positional stability equivalent to that of a textured implant. PSSI implant design with same total surface area but different well dimension and density demonstrated comparable long-term stability. The reduced level of pro-inflammatory M1 macrophages observed in PSSI capsules compared to the textured group supports the biocompatibility of the novel implant. These results suggest a promising alternative to textured surface for inducing positional stability in breast implants.

Background: The intercostal artery perforator flap (ICAP) is a technique facilitating breast conservation treatment (BCT) for patients with defects otherwise necessitating mastectomy. It is unclear whether reconstructed breast volume is maintained over time and what effects occur after radiation. This study aimed to assess volume changes in irradiated breasts following ICAP BCT compared to small tumor lumpectomies.

Methods: The study included 134 patients who received radiation as part of either ICAP BCT (n=22, one bilateral, 23 breasts), or lumpectomy for T1 tumors (n=112, one bilateral 113 breasts). The patients undergoing lumpectomy for T1 tumors were selected as a control group for whom volume loss beyond their relatively small tumor defect volume could be reasonably attributed to radiation (XRT) effects, thereby providing a baseline estimate of radiation-related volume loss for comparison with the ICAP cohort. Breast volumes at preoperative baseline and within 12 months of radiation were calculated from routine mammograms using π/3* height*radius2 ; significance of change was assessed using paired t-tests. (1)

Results:
Both groups experienced significant volume loss within one year of radiation. Within the ICAP cohort, average baseline breast volume was 775.4 (316) cc. Average tumor volume defect was 231.5 (150) cc, comprising 28.5 (12) % of breast volume. Within one year of surgery and radiation, mean breast volume of the ICAP cohort was 622.1 (276) cc, a loss of 153.3 (184) cc, a 19.3 (23) % mean volume decrease from pre-operative baseline (p<0.001).

Within the lumpectomy cohort, average baseline breast volume was 1079.4 (674) cc. Average tumor volume defect was 88.6 (57) cc, comprising 9.2 (10) % of breast volume. To isolate radiation effects from surgical volume loss, a postoperative baseline volume was calculated, with subsequent volume loss after radiation calculated relative to this baseline. From a mean postoperative baseline volume of 990.9 (645) cc, within one year of surgery and radiation, the T1 lumpectomy cohort experienced a loss of 193.8 (5) cc, a 19.6 (22) % mean volume decrease from pre-operative baseline (p<0.001).

Conclusion: Based on the results from the lumpectomy cohort, radiation appears to account for approximately 19% of breast volume loss (in addition to specimens), experienced within one year of BCT/XRT. The volume loss of 19.3% by year one observed among the ICAP cohort appears to be congruent with expected volume loss attributable to radiation effects within this timeframe. Furthermore, the loss of 19.3% of breast volume within one year following excision of 28.5% of breast volume indicates that about 9.2% of breast volume was restored via reconstruction and maintained post-radiation. Overall, this reconstructive option to expand BCT candidacy appears to have comparable results to standard BCT after radiotherapy. Long-term reporting of volume maintenance in ICAP reconstructed breasts will be important, given that radiation effects continue to occur over time. Anticipating these effects may help guide patient and surgeon expectations and inform the planning of future interventions addressing symmetry.

References: 1. Katariya RN, Forrest APM, Gravelle IH. Breast Volumes in Cancer of the Breast. Br J Cancer. 1974;29(3):270-273. doi:10.1038/bjc.1974.66

Introduction Implant-based breast reconstructions are one of the most common surgical procedures performed by plastic surgeons. Our study is based in Miami, Florida, often considered a global hub for Plastic Surgery as a high number of breast surgeries are performed here, which surpasses that of many other locales. Silicone Lymphadenopathy (SL) is a complication of breast implants that involves migration of silicone to nearby soft tissue/lymph nodes. 1 Data on its clinical features and management is scarce. To our knowledge, this is the largest single-institution study to describe the clinical presentation and management of SL.

Methods Single-institution retrospective cohort study was conducted from our database where search terms "Silicone lymphadenopathy", "silicone adenitis" and "silicone adenopathy" were used to identify all patients with SL (January 2016- September 2023). Patient demographic characteristics, clinical features, imaging findings, pathological investigation, and treatment were documented in the medical records.

Results Of 50 patients identified with SL, the mean age and BMI were 58.92 years [SD 12] and 26 kg/m2 [SD 5.29] respectively. 47 (94%) patients were white. 36 (72%) identified as Hispanic, 13 (25%) as non-Hispanic, and 1 (2%) refused to disclose their ethnicity. SL occurrence was distributed as 18 patients (36%) on the left side, 17 patients (34%) on the right, and 15 patients (30%) bilaterally. Aesthetic reasons accounted for 46 (92%) of the implant placements. Symptomatic presentation was noted in 16 (32%) patients; tender lymphadenopathy (n=10, 20%) the most prevalent, followed by non-tender lymphadenopathy (n=4, 8%), and systemic symptoms (n=2, 4%). 44 (88%) of patients had an implant rupture detected on imaging. Of 6 (12%) without rupture, all had intact implant capsules and 2 had a prior implant exchange. Axilla was the most common site for SL detection (n=43, 86%), with concurrent axillary and internal mammary lymph node involvement in 5 patients (10%), and isolated internal mammary lymph node detection in 5 patients (10%). Most common radiologic method of detection was ultrasound (n=40,80%) followed by a mammogram (n=35,70%) and MRI (n=8,16%). 22 (44%) patients had SL detected on more than one imaging modality. Suspicious imaging led to needle biopsies in 8 patients (16%); 7 core needle and 1 fine needle, all benign results, with 7 exhibiting typical histological features indicative of SL. After SL detection, 45 (90%) patients were managed conservatively with regular follow-up. 2 (4%) had implants removed and 3 (6%) of them had it exchanged.

Conclusion A conservative approach is recommended for SL. Clinicians should be vigilant in the ultrasound detection of SL, as more patients are asymptomatic. Biopsy and surgical intervention should be reserved for those with abnormal imaging, symptomatic persistence, or evidence of implant rupture. In patients with a history of breast cancer, evaluation for lymphadenopathy is essential to exclude malignancy. Personalized management is paramount to prevent unnecessary interventions and healthcare expenditures.

REFERENCES 1. Perez, T. C. P. et al. Prevalence, clinical characteristics, and management of silicone lymphadenopathy: A systematic review of the literature. J. Plast. Reconstr. Aesthet. Surg. 90, 76–87 (2024).

Introduction: The Lymphatic Microsurgical Preventive Healing Approach (LyMPHA) is a lymphaticovenous anastomosis done at the time of axillary lymph node dissection (ALND) to facilitate lymphatic drainage and prevent secondary lymphedema, which can be a devastating complication of breast cancer treatment. Current guidelines lack surgical prevention recommendations for lymphedema, likely due to insufficient high-level evidence of surgical intervention effectiveness in preventing lymphedema (1). The goal of the study is to evaluate the efficacy of immediate LyMPHA at the time of ALND in reducing breast cancer-related arm lymphedema (BCRaL).

Methods: A retrospective chart review was performed on breast cancer patients who underwent ALND with or without immediate LyMPHA at a quaternary care hospital from 2016-2022. Patients with preoperative lymphedema or Stage IV disease at presentation were excluded. Lymphedema was defined as persistent heaviness and/or swelling, and the need for complete decongestive therapy (CDT) greater than 12 months after surgery. Patients' percentage of functional impairment was also assessed utilizing the Lymphedema Life Impact Score (LLIS). Patient demographics, medical history, and treatment history were compared between groups. Outcomes of interest included postoperative complications (hematoma, seroma, cellulitis, wound dehiscence, unexpected return to OR, and readmission), the incidence of lymphedema, and percentage of functional impairment. Univariate analysis was used to evaluate differences between demographics and clinical outcomes. Cox regression was conducted to evaluate the incidence of lymphedema while accounting for age, BMI, smoking, marijuana use, radiotherapy, chemotherapy, eventual conversion to stage IV, and the incidence of LyMPHA.

Results: 187 patients underwent ALND, and 121 of those patients also had LyMPHA. Mean follow-up was 35 months (SD±21). Mean age was 56.44 years old (SD±13.61). Mean BMI was 30.42 kg/m2 (SD±6.88). 76.5% of patients underwent neoadjuvant chemotherapy, 88.8% underwent adjuvant chemotherapy, 5.3% had a history of radiotherapy, and 85.0% underwent adjuvant radiotherapy. Univariate analysis did not demonstrate differences in BMI, race, comorbidities, history of previous radiation, pathological stage, and postoperative complications. Patients who underwent LyMPHA had significantly decreased drain duration (13.0 days vs 15.0 days, p=0.042), percentage of functional impairment (4.7% vs 11.6%, p=0.045), and risk of lymphedema which persisted over time (p=0.003). The entire cohort lymphedema rate after 2, 3, and 4 years postoperatively was 24.80%, 30.90%, and 35.20%, respectively. Cox regression analysis demonstrated that at any point in time, patients who underwent ALND and LyMPHA were half as likely to experience lymphedema as ALND alone patients (HR=0.50, p=0.023).

Conclusion: While the indication of ALND continues to decline, there remains a subset of patients for whom ALND remains necessary. Therefore, offering LyMPHA at the time of ALND presents an opportunity to prevent or mitigate lymphedema progression over time, and ultimately reduces morbidity in the breast cancer population.

References: 1. Chun MJ, et al. (2022). Immediate Lymphatic Reconstruction for Prevention of Secondary Lymphedema: A Meta-Analysis. Journal of plastic, reconstructive & aesthetic surgery: JPRAS, 75(3), 1130–1141. https://doi.org/10.1016/j.bjps.2021.11.094

Background: Breast shrinkage often follows breast conserving treatment (BCT) and radiation therapy (XRT). The impact of prior smoking on the extent of this shrinkage is unknown, and this study aimed to explore and quantify any associations.

Methods: Breast volume changes were calculated for 112 patients (one bilateral, 113 breasts) following T1 tumor lumpectomies. From preoperative baseline to seven years post-radiation, volumes were calculated from mammograms using π/3* height*radius2. Mann-Whitney U-Tests compared volume changes at each time point between patients actively smoking (n=1) or with a smoking history (n=29), and patients who never smoked (n=83). Multivariate analysis assessed volume change as a function of patient age, pack-years smoked, diabetes, radiation dosage, fractions, technique, boost dose, whole/ partial breast XRT, treatment length, chemotherapy type (hormonal/cytotoxic), baseline breast volume, and months since treatment.

Results: Patients with any smoking history experienced significantly greater volume loss during the first two years after treatment, and by year one, lost 26.5% of breast volume compared to 13.4% among non-smoking patients (p=0.02). By year two, the smoking group volume loss was 23.9%, compared to 16.3% for non-smoking patients (p=0.04). Larger baseline breast volume and increased pack-years smoked were significant predictors of increased volume loss during years one, two and three (p<0.05). For year three a diabetes diagnosis was also significant (p=0.03).

Conclusions: Findings suggest prior smoking may contribute to significantly increased breast shrinkage within the first two years following BCT/XRT. Increased pack-years and larger baseline breast volume may predict greater volume loss within this timeframe.

Purpose: Implantable biomedical devices have revolutionized clinical practice and benefit millions of patients, accounting for more than 70 million device implantations annually. Approximately 30% these devices will undergo premature failure during their lifetime. Premature device failure is primarily due to an immune-mediated physiologic reaction otherwise known as the foreign body response (FBR). Biophysiochemical incompatibilities between the host tissues and device biomaterial induce inflammatory-fibrotic tissue repair pathways that result in fibrosis encapsulation of the device. Emerging evidence has demonstrated that cellular mechanical signaling pathways play a critical role during fibrosis and tissue repair. While FBR is an innate biologic reaction, it remains poorly understood. In this study, we utilize human peri-implant capsule tissue to further investigate the cellular crosstalk, mediated through mechanical signaling, between inflammatory and fibrotic cell populations during FBR.

Methods: Peri-breast implant associated capsule tissue was collected from patients (n=14) undergoing standard of care surgery to treat capsular contracture. Capsular contracture was scored using the Baker scale and categorized into mild (B1/B2: n=8) and severe FBR (B3/B4: n=6). Histological analysis using H&E, Masson's trichrome, and picrosirius red was performed. CT-FIRE and Curve Align was performed to characterize the collagen architecture of the capsule tissue. Immunofluorescent staining using CD68 (macrophage marker), aSMA (myofibroblast marker), CD45 (hematopoietic cell marker) and FAK (mechanotransduction marker).

Results: Severe FBR demonstrated significantly increased capsule thickness compared to mild FBR (p=0.0003). Collagen deposition (p=0.0049), fiber length (p=0.0099), and density (p=0.0062) were also significantly increased in severe FBR when compared to mild FBR. Collagen mean fiber distance (p=0.0401) was significantly decreased in severe FBR compared to mild FBR. Severe FBR resulted in an increase in CD68 (macrophage) and aSMA (myofibroblast) layering within the FBR capsule, shown by significantly increased co-localized expression of CD68 and aSMA (p<0.01) and co-localized CD68 and FAK (p=0.0465). More severe FBR also increased the aSMA and inflammatory tissue-localized cell inhabitants (p<0.009).

Conclusions: Our results demonstrate an increase in immune-mediate crosstalk between macrophages and myofibroblasts, correlating with more severe capsule formation and capsule tissue fibrosis. Interestingly, severe FBR resulted in distinct macrophage-myofibroblast cellular layering in addition to elevated mechanoresponsive myeloid cell presence. Since myeloid cells home to sites of tissue injury, targeting these mechanotransducive myeloid cells could lead to novel, preventative FBR therapeutics.

Purpose: Capsular contracture remains one of the most challenging complications after implant-based breast reconstruction, affecting up to 20% of women with implants. While the etiology of capsular contracture is still not well understood, a common theory is the development of subclinical infection and a resulting biofilm. This has led to active investigation into potentially contributing microbial species. Toward this, we aimed to explore the breast microbiome in patients with capsular contracture.

Methods: We analyzed data from our two-armed randomized-controlled trial comparing 24 hours of peri-operative antibiotics to 7 days of post-operative antibiotics in patients undergoing immediate post-mastectomy tissue expander breast reconstruction. For this analysis, we only included patients in the 24-hour antibiotic group. We collected "pre-operative samples" (breast skin swabs and breast tissue from the mastectomy), as well as post-operative samples (periprosthetic fluid via tissue expander aspiration) at up to 4 post-operative clinic visits. The microbiomes of these samples were analyzed using 16s rRNA sequencing. Post-operative outcomes including the development of capsular contracture and post-operative infection were recorded. Microbiome data was analyzed for trends.

Results: Out of 20 patients (32 breasts) in the 24-hour group, we identified 2 patients (10%) who developed capsular contracture in a total of 3 out of their 4 reconstructed breasts. All capsular contractures were Baker grade 2 and treated conservatively. Each of the two patients developed a post-operative infection in one breast. Patient 1's infection preceded the diagnosis of capsular contracture. Patient 2 had documented capsular contracture before an indolent infection was diagnosed. Both patients required operative washout and implant exchange for infection treatment. Looking at the breast microbiome data, Patient 1's pre-operative samples had the highest % relative abundance of species in the Pseudomonas genus. This remained the most abundant genus until the fourth post-operative sample, which was collected near the time of infection and predominantly contained Staphylococcus. Notably, Staphylococcus was also among the top 10 most prevalent genera in all pre-operative samples from Patient 1. The culture data from this patient's operative washout grew Staphylococcus Aureus. Patient 2's preoperative samples had the highest % relative abundance of species in the Staphylococcus genus, though this changed over the course of post-operative sample collection. Patient 2's infection occurred approximately 2 months after the final post-operative sample was collected, and bacterial cultures from the operating room grew Staphylococcus Epidermidis and Staphylococcus Saccharolyticus.

Conclusions: While our sample size is small, we found that pre-operative breast samples of patients who later developed capsular contracture had a high % relative abundance of genera commonly associated with post-operative infection and capsular contracture formation. Enrollment is ongoing, and further data is needed to determine associations between specific bacterial species in the breast environment and capsular contracture formation. However, harnessing this data has the potential to further our understanding of the etiology of capsular contracture and to facilitate individualized risk stratification and peri-operative management.

PURPOSE:
Over 70M biomedical devices are implanted globally each year and up to 30% of devices fail due to the foreign body response (FBR). There is much unknown regarding the acute FBR following implantation and how it differs from the longer, more chronic FBR. Currently, there are also no FDA-approved therapies that effectively prevent FBR and biomedical implant failure.

METHODS:
We created pathological human-like FBR in mice using our previously published mechanically stimulated implants (MSIs) (Padmanabhan et al, 2023, Nat Biomed Eng). The MSIs contained encapsulated coin motors connected to external 3V batteries to initiate mechanical stimulation through vibration, which create significant FBR fibrosis. Mice either received saline only (vehicle) or a prophylactic 5mg/kg NSC Rac inhibitor dose. After 7 days (POD 11) of mechanical stimulation (MS), the acute FBR, samples from 5 no mechanical stimulation (NMS), 5 MS with saline (MS+S) and 5 MS with Rac Inhibitor (MS+RI) were collected. After a month (POD 30), the chronic FBR, 5 NMS, 10 MS+S, and 10 MS+RI samples were collected. The explanted FBR tissue was analyzed using staining including Picrosirius Red, Hematoxylin and Eosin, Trichrome, and immunohistochemistry (IHC) for aSMA, F4/80, and DAPI. Results were analyzed with ImageJ, Matlab, CurveAlign, and CTfire.

RESULTS:
At acute POD 11, MS+S significantly increased FBR capsule compared to NMS (p= 0.0465), and MS with Rac Inhibitor treatment significantly reduced FBR capsule by 47% from 284.8µm to 133.8µm compared to MS+S (p=0.0331) near NMS levels. Comparably, at chronic POD 30, MS+S significantly increased FBR capsule compared to NMS (p=0.005), and MS with Rac Inhibitor treatment significantly reduced FBR capsule by 51% from 370.2µm to 183.2µm compared to MS+S (p=0.008) near NMS levels.

At chronic POD 30, the ECM architecture of the capsules differed significantly, with the MS+S group having wider and less dense collagen fibers than the MS+RI (p=0.02). Using trichrome imaging, distinct architecture layers were evident in the MS+S capsule at POD 30 and were not observed at POD 11. The unique inner layer had less wide, dense, and aligned collagen fibers (p=0.0020, p=0.0078, p=0.0051) compared to inhibited FBR which possessed no layering. Finally, we observed a significant reduction from MS+S to MS+RI in macrophages (F4/80, p=0.02) and myofibroblasts (aSMA, p=0.03).

CONCLUSION:
We determine that disrupting mechanical signaling significantly reduces acute and chronic FBR capsule size and fibrotic ECM architecture. We observed a novel layering in the chronic FBR associated with distinct layers of macrophages and fibroblasts within the capsule. A prophylactic therapeutic that could prevent FBR could have notable effects on patients and biomedical implants.

Purpose

Cosmetic breast surgeries, such as augmentation, mastopexy, and reduction, represent a substantial component of aesthetic medical practices. Despite their popularity, the influence of these surgeries on subsequent breast reconstruction for cancer patients-a vital consideration given breast cancer's prevalence and the role of reconstruction in recovery remains underexplored. This study investigates the effects of previous cosmetic breast surgeries on the outcomes of various breast reconstruction techniques following cancer treatment.

Methods

A retrospective chart review was performed at a single academic institution from January 2011 to May 2023, examining patients who underwent cosmetic breast surgery prior to breast reconstruction. This analysis compared patients with histories of implant augmentation, breast reduction, mastopexy, and augmentation-mastopexy (aug-pexy) against those patients receiving reconstruction without any cosmetic surgery history. Data on demographics, comorbidities, smoking history, cancer treatments, complications, and revisions were collected, alongside patient satisfaction and well-being assessed through BREAST-Q surveys. Statistical analysis was performed using SPSS, with significance set at p<0.05.

Results

124 patients (50 autologous, 74 implant) with a history of cosmetic breast surgery, which included 102 implant augmentations, 17 breast reductions, five mastopexies, and 9 aug-pexies were analyzed against 1307 patients (683 autologous, 624 implant) with no history of prior cosmetic breast surgery. Patients with prior cosmetic surgeries had significantly lower BMIs (p<0.001 for cosmetic surgery history; p<0.001 for augmentation surgery) and a higher incidence of tissue expander hematoma (cosmetic surgery p<0.001, augmentation p=0.036, reduction p=0.003). A preference for implant-based reconstruction was more common among patients with augmentation history (p<0.001), whereas those with reduction surgeries were more likely to opt for autologous reconstruction (p=0.047). Of note, a significantly higher proportion of patients with a prior history of cosmetic breast surgery (p<0.001) and augmentation breast surgery (p<0.001) chose either PAP or LAP autologous surgeries respectively. On average, patients with a history of prior cosmetic breast surgery (p=0.003) or augmentation breast surgery (p=0.002) who pursued autologous-based reconstruction had significantly more breast revisions. Additionally, patients with a history of prior cosmetic breast surgery (p=0.040, 0.004) or augmentation breast surgery (p=0.042, 0.010) who pursued implant-based reconstruction had on average significantly more breast revisions and total number of OR visits for breast reconstruction respectively. Postoperatively, we noted a significantly higher BREAST-Q chest physical wellbeing (p<0.05) and sexual wellbeing score (p<0.05) when comparing all patients with a history of cosmetic breast surgery to those patients with no history of cosmetic breast surgery.

Conclusion

This study examines the relationship between previous cosmetic breast surgeries and breast reconstruction outcomes. Our findings demonstrate the importance of integrating a patient's complete surgical history into post-mastectomy reconstruction planning with an understanding of how specific types of previous cosmetic breast procedures critically influence the selection of reconstruction techniques. While prior surgeries can enhance reconstruction outcomes, they also elevate the risk of complications, increase the likelihood of surgical revisions, and lead to more frequent operating room visits. This study suggests that different types of cosmetic breast surgery influence the decision-making of implant versus autologous reconstruction.

Introduction: Implant-based reconstruction is the most common form of breast reconstruction following mastectomy. However, surgical site infection remains a serious complication, leading to substantial morbidity and cost for the patient and healthcare system. A promising prophylactic adjunct involves the use of biodegradable antibiotic-coated beads, which have been well-studied in the orthopedic literature. This preliminary study aims to describe a single institution's experience with absorbable antibiotic beads for preventing infection in implant-based breast reconstruction.

Methods: A retrospective cohort study was performed of all patients who underwent implant-based reconstruction between January 2021- October 2023. Patients who met one or more high-risk criteria for infection (Group 1) including BMI > 30, active or prior smoking, type 2 diabetes mellitus, and history of radiation therapy, received absorbable antibiotic beads which were mixed with vancomycin and gentamicin. Group 2 received standard of care, but did not receive antibiotic beads. Outcomes included development of periprosthetic infection, need for re-admission for intravenous antibiotic therapy, re-operation, and loss of reconstruction. Multivariable regression was performed to control for known risk factors associated with infection.

Results:
Two-hundred forty-six patients were included in the study. Fifteen (6.1%) patients received antibiotic beads during the first-stage expander-based reconstruction (Group 1). Two-hundred twenty-three (90.7%) patients received standard antibiotic prophylaxis (Group 2). No difference was detected in infection rate between patients who received antibiotic beads at the time of primary reconstruction compared to the standard of care (33.3% vs. 22.0%, p=.309). After controlling for BMI, diabetes, history of radiation, and smoking status, antibiotic beads were not significantly associated with infection (OR 1.24, CI 0.37- 4.13, p=.721). BMI and former smoking status were significantly associated with increased odds of infection (OR 1.1 CI 1.02 – 1.13, p=.001, and OR 4.5 CI 1.3 – 15.6, p=.02). Antibiotic beads were used in 8 cases for salvage attempt following periprosthetic infection. Of the 8 salvage procedures with antibiotic beads, 7 infections were resolved (87.5%). One patient had a recurrence of infection.

Conclusion: This study presents preliminary results of our institution's experience using antibiotic beads for infection prophylaxis in high-risk patients undergoing breast reconstruction and salvage of infected breast implants. Additional prospective studies are currently ongoing, and are needed help to elucidate safety and efficacy.

Introduction
As the surgical community has increasingly realized the importance of patient-reported outcomes as a measure of success of a surgery, new tools have been developed to allow providers to assess patient satisfaction and psychosocial outcomes in a standardized manner. The BREAST-Q Sensation Module was published in November 2021 to address the need for a way to evaluate patient-reported breast sensation and symptoms and their impact on quality-of-life (1). In this study, we aim to map the temporal pattern of BREAST-Q Sensation module scores after reconstruction and to compare scores between autologous and device-based reconstruction.

Methods Patients undergoing mastectomy and breast reconstruction were administered the Sensation Module of the BREAST-Q preoperatively and yearly after surgery. BREAST-Q scores of patients receiving autologous and alloplastic breast reconstruction were compared with Wilcoxon rank-sum tests at each time point. All statistical analyses were performed in R. All autologous reconstruction was done with a neurotized deep inferior epigastric perforator flap. All alloplastic reconstruction was two-stage. A predetermined alpha level of 0.05 was used as criteria for statistical significance.

Results This study included 90 patients with alloplastic reconstruction and 103 patients with autologous reconstruction who answered the BREAST-Q at at least one timepoint. Breast Sensation scores are higher in the alloplastic group in the first 1-2 years after reconstruction before scores in the autologous group increase from 3 years onward. The autologous group had much higher scores for the Breast Symptoms scale than the alloplastic group, with a statistically significant difference at 2 years postoperative (91 vs. 75.5, p < 0.05). For the Quality-of-Life Impact of Sensation scale, the alloplastic group had higher scores in the first 3 years after surgery, but scores began to decline thereafter, while the autologous group had improved scores over time.

Conclusion Patients with autologous breast reconstruction experience fewer unpleasant breast symptoms than patients with alloplastic breast reconstruction. Interestingly, while patients with alloplastic reconstruction report greater breast sensation and QoL impact in the short-term, scores in patients with autologous reconstruction become equal or better in the long-term. This may be explained by the time course of allograft reinnervation of autologous flaps. Patient selection bias may also play a role, as patients eligible for autologous reconstruction tend to have a higher BMI and larger breast surface area to reinnervate. Further study is ongoing to control these results for breast size.

References 1) Tsangaris E, Klassen AF, Kaur MN, et al. Development and Psychometric Validation of the BREAST-Q Sensation Module for Women Undergoing Post-Mastectomy Breast Reconstruction. Ann Surg Oncol. 2021;28(12):7842-7853. doi:10.1245/s10434-021-10094-y

Introduction Few established classification systems exist to determine abnormalities in truncal lymphatic anatomy. The Pittsburgh trunk lymphedema staging system (PTLSS) allows for complete assessment of the chest based on dermal backflow patterns seen on indocyanine green (ICG) lymphography. We aim to describe the lymphatic anatomy of the trunk in breast cancer patients and correlate breast cancer treatment and reconstruction to lymphedema severity using the PTLSS.

Methods This study is a retrospective review of patients undergoing breast reconstruction with clinical suspicion of lymphedema who received ICG lymphography of their chest from August 2023 to January 2024. Four subcutaneous injections were placed at the distal most extent of the axillary drainage territory, between the umbilicus and costal margin of each hemi-trunk. The trunk was analyzed in five regions (superior breast, inferior breast, inframammary fold (IMF), medial chest, lateral chest). Each region was assigned a level of dermal backflow using ICG imaging. Analysis of variance (ANOVA) was used to compare the degree of dermal backflow within each region of the trunk and identify regions with the most severe lymphatic disruption. Each hemi-trunk was staged from 0 to 5, based on the cumulative dermal backflow score, as described in the PTLSS. Patients were group according to breast cancer treatment and presence of reconstruction. Poisson regression was used to analyze the association between these interventions and lymphedema severity. All statistical analysis were performed with SPSSv24.0 (p<0.05 considered statistically significant).

Results 32 unique hemi-trunks (19 patients) were mapped. Six hemi-trunks had no surgical or radiation damage and showed no signs of dermal backflow, acting as internal controls. The remaining 26 chests that underwent intervention (radiation, chemotherapy, axillary dissection, mastectomy, and/or reconstruction) had significantly worse dermal backflow in every region of the trunk compared to the controls (all p-values <0.05). Among patients who received an intervention, dermal backflow was significantly worse in the superior trunk and was more linear inferiorly (p<0.001). The superior and inferior breast regions had the worst dermal backflow, with 69% of patients having no lymphatic flow. At the IMF 58% of patients had no flow while 38% had diffuse dermal backflow patterns. In the medial and lateral trunk, there were normal, linear, lymphatic patterns seen in 38% and 27% of patients, respectively. Radiation showed a significant positive correlation to increasing lymphedema severity (RR=0.64, p=0.022). Chemotherapy, axillary dissection, mastectomy, and reconstruction did not significantly correlate to lymphedema severity (RR= 0.35, 0.13, 0.32, and 0.36, respectively).

Discussion Breast cancer treatment and reconstruction alters lymphatic flow of the trunk and causes a wide variation in lymphatic anatomy. Severe dermal backflow and disruption of lymphatic channels can be seen most often in the superior trunk to the level of the IMF. We found a significant correlation between radiation and increased severity of lymphedema using the PTLSS. This study can help better understand the downstream effects on lymphatic function in this patient population.

Background Macromastia frequently manifests during adolescence with significant physical and psychosocial symptoms. Reduction mammaplasty is the primary treatment for symptomatic macromastia, however, insurance criteria are frequently discordant with ASPS recommendations, resulting in denial of coverage (1). Furthermore, young patients are often required to pursue ineffective treatments before being considered for approval (2). There is a growing body of literature describing the benefits of reduction mammaplasty for adolescent patients (3). This study evaluates the benefits of reduction mammaplasty on physical and psychosocial well-being in adolescent patients using the BREAST-Q survey.

Methods Patients treated for symptomatic macromastia with reduction mammoplasty at our breast clinic were asked to complete the pre- and post-operative BREAST-Q reduction survey. Retrospective review and descriptive analysis of patient characteristics, operative data, and outcomes were conducted for all patients that completed both surveys. Survey item subsets were summed and scaled between 0 and 100 (Q-Scores), where higher scores signified more favorable responses regarding breast appearance, psychosocial wellbeing, and physical wellbeing. Significance was determined for matched pre- and post-operative survey items and scores using Wilcoxon sign-rank tests.

Results 142 patients that underwent reduction mammaplasty completed preoperative surveys. 64 patients completed both pre-and post-reduction surveys. Average age was 16.7 years (SD 1.2) and average BMI was 31.0 (SD 4.9). Prior to surgery, all patients reported physical symptoms such as shoulder pain (92.2%), neck pain (92.2%), and back pain (98.4%). Patients most frequently underwent wise-pattern reduction mammoplasties using the superomedial pedicle. An average of 831.2 g (SD 419.8) of tissue removed from each breast. Complications per breast reduced included hematoma (1.6%), wound dehiscence (3%), wound infection (1.6%), nipple paresthesia (5.5%), and scar hypertrophy (5.5%). Significant improvements were observed in all matched BREAST-Q survey questions. Postoperative Q-scores demonstrated a 220.3% improvement in breast appearance (15.8 ± 0.14.0 to 50.6 ± 5.5, p<0.0001), a 106.6% improvement in psychosocial wellbeing (39.5 ± 16.3 vs 81.6 ± 17.6, p<0.0001) and a 149.9% increase in physical wellbeing (33.3 ± 14.5 vs 83.2 ± 14.7, p<0.0001).

Conclusion By using a validated metric such as Breast Q, we were able to quantify the impact of reduction mammaplasty. Comparative analysis of pre- and postoperative patient Q-scores suggests that reduction mammaplasty in adolescence significantly improves physical and psychological aspects of quality of life. The low rate of complications in this cohort affirms the safety of reduction mammaplasty in adolescents. We hope to increase coverage and reduce hesitancy to perform this operation in adolescents by adding to the literature demonstrating that the observed benefits of reduction mammaplasty substantially outweigh the associated risks.

References: 1. Rawes CMA, Ngaage LM, Borrelli MR, Puthumana J, Slezak S, Rasko YM. Navigating the Insurance Landscape for Coverage of Reduction Mammaplasty. Plast Reconstr Surg. 2020;146(5):539e. doi:10.1097/PRS.0000000000007241 2. Collins DE, Kerrigan CL, Kim M, et al. The Effectiveness of Surgical and Nonsurgical Interventions in Relieving the Symptoms of Macromastia. Plast Reconstr Surg. 2002;109(5):1556. 3. White AG, McNamara CT, Nuzzi LC, Hwang CD, Labow BI. Reduction Mammaplasty in Younger Patients: An Evidence-Based Approach to Treatment. Plast Aesthetic Nurs. 2023;43(4):203. doi:10.1097/PSN.0000000000000521

Introduction: The incidence rate of primary breast anaplastic large cell lymphoma (ALCL) is rapidly rising in the United States (US). Host hereditary factors may contribute to the development of ALCL in the setting of chronic inflammation in the capsule of breast implants. Specific genes such as BRCA1 or BRCA2 have been associated with an increased risk of ALCL. Anecdotally, fewer cases of breast ALCL have been reported in Black and Asian patients compared to their White counterparts, but no study to date has comprehensively investigated the incidence of breast ALCL by race and ethnicity despite evidence of genetic and environmental variability. We therefore sought to characterize the racial and ethnic epidemiology of breast ALCL in the US.

Methods: Cases of breast ALCL (ICD-O-3 code 9714) and T-cell lymphoma, not otherwise specified (T-NOS; ICD-0-3 9702) newly diagnosed from 2000-2020 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Age-adjusted incidence rates per 10,000,000 women per year were calculated. Incidence rates were stratified by race and ethnicity into the following categories: Hispanic, non-Hispanic White (NHW), non-Hispanic Black (NHB), non-Hispanic American Indian/Alaska Native (NHAIAN), and non-Hispanic Asian/Pacific Islander (NHAPI).

Results: From 2000-2020, the incidence rates of breast ALCL and ALCL/T-NOS were 9.7 (7.7-11.9) and 15.4 (12.9-18.1), respectively, per 10,000,000 persons per year. The incidence rate increased over the study period; 21.0 (14.9-28.8) compared to 3.0 (1.1-6.6) in 2000-2004. When stratified by race and ethnicity, the incidence rates for breast ALCL were 11.6 (9.0-14.9) for NHW patients, 3.5 (0.7-10.1) for NHB patients, 0 (0.0-63.5) for NHAIAN patients, 0.9 (0.02-5.7) for NHAPI patients, and 7.5 (4.0-13.0) for Hispanic patients. For ALCL/T-NOS, the corresponding incidence rates were 17.5 (14.2-21.4), 10.2 (4.6-19.3), 24.8 (0.6-118.2), 4.7 (1.5-11.4), and 11.2 (6.7-17.6). In the most recent period (2017-2020), the corresponding incidence rates of ALCL were 26.2 (17.3-38.4), 5.8 (0.1-30.0), 0 (0.0-307.5), 0 (0.0-18.3), and 15.1 (5.5-33.3). Incidence rates of ALCL/T-NOS were 41.9 (30.4-56.8), 5.8 (0.1-30.0), 0 (0.0-307.5), 3.3 (0.08-23.4), and 25.9 (12.3-47.8), respectively.

Conclusion: Incidence of breast ALCL differs by race and ethnicity in the United States - generally, non-Hispanic White patients are associated with the highest incidence, followed by Hispanic patients. It remains unclear whether these differences are due to genetic diversity, healthcare access, environment, or data reporting biases. Future studies may explore how these findings correlate to global breast ALCL incidence rates across other countries.

Background: Most breast reconstructions following mastectomy utilize a two-stage tissue expander (TE) to implant approach (1). Prior studies on both prepectoral and subpectoral breast reconstructions have identified formulas for predicting final implant volume using TE size and final fill (2,3). The aim of this study is to test the accuracy of these models.

Methods: A retrospective chart review of patients that underwent two-stage TE to permanent implant breast reconstruction within the Duke University Health System between 2021 and 2023 was performed. Demographic, oncologic, and reconstructive data were collected. The equations 26.6 + 0.38(TE final fill) + 0.61(TE size) for prepectoral and 71.7 + 0.8(TE final fill) + 0.1(TE size) for subpectoral reconstructions were used to calculate predicted final implant volumes, which were then compared to actual implant volumes (2,3).

Results: 73 prepectoral patients (120 breasts) and 41 subpectoral patients (70 breasts) met criteria for inclusion. All patients had at least 2 months of postoperative follow-up. The average predicted implant volume was 20cc less than the average actual volume in both the prepectoral (479.0 vs. 499.5cc) and subpectoral (480.3 vs. 500.5cc) groups. The root-mean-square errors (RMSEs) for each data set were 75.6 and 59.3cc, respectively.

Conclusions: In general, both models underpredicted final implant volume. Depending on the implant profile, a 60-75cc difference equates to the models being accurate within 3-4 sizes for prepectoral and 2-3 sizes for subpectoral reconstructions, suggesting their potential use as a starting point to guide surgeon decision-making. Being able to predict final implant volume more accurately will optimize surgical planning, decrease the number of implants ordered for each case, and reduce costs.

1. 2020 Plastic Surgery Statistics Report. American Society of Plastic Surgeons. Accessed May 2023. https://www.plasticsurgery.org/ documents/News/Statistics/2020/plastic-surgery-statistics-full-report-2020.pdf
2. Atia AN, Sergesketter AR, Morris MX, et al. Predicting Final Implant Volume in Two-stage Prepectoral Breast Reconstruction. Plast Reconstr Surg Glob Open. 2023;11(1):e4780. Published 2023 Jan 20. doi:10.1097/GOX.0000000000004780
3. Gabrick KS, Markov NP, Chouairi F, et al. A Predictive Model for Determining Permanent Implant Size During 2-Stage Implant Breast Reconstruction. Plast Reconstr Surg Glob Open. 2018;6(5):e1790. Published 2018 May 21. doi:10.1097/GOX.0000000000001790

Background: Recent studies have begun to extrapolate the use of comorbidity indices, such as the Charlson Comorbidity Index (CCI) and Modified Frailty Index (mFI-11), to stratify post-surgical complication risk across multiple fields of surgery, including plastic surgery. However, complication risk among implant-based breast reconstruction (IBBR) patients has not been studied. Understanding how comorbidity scores affect post-surgical outcomes in IBBR can help better identify appropriate surgical candidates.

Methods: We performed a retrospective analysis of adult female patients who underwent IBBR between January 2016 and December 2021 using the Merative™ Marketscan® Research Databases. Patients were excluded if they did not have continuous insurance enrollment 90 days prior to or after their breast implant placement. We extracted data on patient demographics, concurrent surgical procedures, pre-operative comorbidities, and 90-day postoperative adverse outcomes. Comorbidity index scores were calculated using ICD-10 diagnosis codes. Chi-squared tests were performed for demographic analysis. Multivariable logistic regression controlling for demographic and surgical variables was conducted to determine associations between comorbidity indexes and adverse outcomes, including complications and post-operative surgical management.

Results: Among 10,119 IBBR patients during the study period, 2,127 (21.0%) experienced a complication within 90 days of breast implant placement. Patients from the South (p<0.001) had higher complication rates, but no differences were seen by age (p=0.22) or insurance type (p=0.41). Additionally, patients who underwent direct-to-implant IBBR procedures (p<0.001) or concurrent autologous reconstruction (p<0.001) experienced higher rates of complications.

On regression analysis, each subsequent point increase in CCI score was associated with 12% increased odds of local complications (p<0.001), 21% increased odds of distant complications (p<0.001), and 13% increased odds of any complication (p<0.001). Patients with higher CCI score had higher rates of fat necrosis (p=0.023), wound dehiscence (p=0.012), seroma/hematoma formation (p=0.025) and lymphedema (p<0.001). Additionally, these patients had higher rates of thromboembolic events, specifically deep vein thrombosis (p<0.001), pulmonary embolism (p=0.008), and stroke (p=0.012). Further regression analysis into individual CCI-indexed comorbidities revealed that chronic pulmonary disease (OR=1.31 [1.11,1.54]; p=0.001), liver disease (OR=1.35 [1.02,1.77]; p=0.032), and cancer (OR=1.45 [1.29,1.63]; p<0.001) were the key drivers in the association between CCI score and complication risk.

Individual point increases in mFI-11 score were also associated with increased odds of local, distant, and all complications, albeit less significantly. Most notably, increases in mFI-11 score were associated with 23% increased odds of post-operative surgical management for each subsequent point increase (p<0.001). Patients with higher mFI-11 scores had higher rates of incision and drainage procedures (p=0.041) and tissue debridement (p=0.012). Subsequent regression analysis reported that impaired sensorium (OR=1.44 [1.06,1.92]; p=0.017) was the main contributor to the association seen between mFI-11 and post-operative surgical management.

Conclusion: This study, which uses a national commercial insurance database, highlights important associations between comorbidity indexes and adverse post-operative outcomes in IBBR. These findings can help us predict and plan for complications among certain patients. Future work is needed to better understand how these indexes can be implemented in a clinical setting to appropriately screen surgical candidates ahead of time.

Background: Sentinel lymph node biopsy (SLNB) is a pivotal procedure in breast cancer staging, and can be performed through both transmammary and axillary-incision. When compared to the axillary approach, the transmammary-incision approach allows the SLNB to be conducted via the breast incision, however requires more soft tissue dissection (1-3). We hypothesize that the transmammary approach to SLNB may lead to increased rates of seroma and implant malposition, among other postoperative complications.

Methods: Patients that underwent immediate implant-based breast reconstruction from January 2017 to August 2023 were retrospectively reviewed. Included patients had mastectomy and SLNB surgeries with one of four breast surgeons, and immediate breast reconstruction with one of three plastic surgeons. Complications of interest included implant visibility, seroma, mastectomy skin necrosis, hematoma, implant failure, infection, and implant malposition.

Results: 238 patients were included in our study, of which 171 underwent SLNB via axillary-incision and 67 underwent SLNB via transmammary-incision. Average follow up was 8 months. Sentinel lymph node retrieval was 100% in both groups. Binomial logistic regression model showed no significant difference in overall complication rates between the two approaches (p-value= 0.438).

Conclusion: Transmammary-incision SLNB approach does not have significantly greater rates of complication compared to axillary-incision SLNB approach. A patient specific approach is appropriate when considering SLNB method.

References: 1. Paepke S, Schwarz-Boeger U, Kiechle M, Jacobs VR. Axillary Dissection with Access Minimized (ADAM): a new technique for lymph node dissection in conservative surgery for breast cancer. Int J Fertil Womens Med. 2003;48(5):232-237. 2. Cocilovo C, Boolbol SK, Valdes E, Feldman S. Less is more: transmammary axillary lymph node evaluation: an initial clinical experience. Am J Surg. 2006;192(4):478-480. 3. Spillane AJ, Brennan ME. Minimal access breast surgery: a single breast incision for breast conservation surgery and sentinel lymph node biopsy. Eur J Surg Oncol. 2009;35(4):380-386. doi:10.1016/j.ejso.2008.07.009

Background: In deep inferior epigastric perforator (DIEP) flap breast reconstruction, the internal mammary vessels are commonly employed as primary recipient vessels. However, there exists debate regarding the reliability and anatomical characteristics of the left internal mammary vein (IMV). Prior studies have highlighted discrepancies in IMV size between the left and right sides, with some suggesting that the left IMV is smaller and potentially at a higher risk for venous complications. The clinical significance of these anatomical variations in the context of surgical outcomes remains ambiguous. To date, no matched cohort study has comprehensively evaluated the differences in outcomes between left and right flap reconstructions, considering patient demographics and prior medical history. Therefore, our study aims to address this gap by conducting a matched cohort analysis to elucidate the implications of flap laterality on surgical outcomes.

Methods: A matched analysis was conducted on 358 patients who underwent bilateral DIEP flap breast reconstruction at a single tertiary-care, academic institution between January 2016 and July 2022. Patient demographics, medical history, surgical characteristics, and postoperative complications were assessed. Patients served as their own paired comparison for left versus right flap outcomes. Statistical analyses, including Wilcoxon rank sum test, Pearson's Chi-squared test, and Fisher's exact test, were employed to compare outcomes between left and right flaps.

Results: Among the 358 patients included in the study, the median age was 51 years (interquartile range [IQR]: 45-58), with a median BMI of 29.1 (IQR: 25.8-32.3). The majority of patients had never used tobacco (70%), and 84% were diagnosed with breast cancer. The distribution of breast cancer stages varied, with 52% at stage 1, 23% at stage 2, 13% at stage 3, and 1.3% at stage 4 and 44% of patients had a history of radiation therapy. Surgical characteristics revealed a median length of surgery of 9.46 hours (IQR: 7.95-11.85). Venous coupler size differed significantly between left and right flaps, with a median size of 2.50 mm (IQR: 2.50-2.50) for left flaps and 3.00 mm (IQR: 2.50-3.00) for right flaps (p < 0.001). Evaluation of postoperative complications demonstrated an overall complication rate of 20%. Specific complications included partial flap loss, total flap loss, partial mastectomy necrosis, partial nipple-areolar complex (NAC) necrosis, seroma, hematoma, skin dehiscence, and infection. However, there were no statistically significant differences in the rates of postoperative complications between left and right flaps (p > 0.05).

Conclusions: Our study addresses a critical gap in the literature by conducting a matched cohort analysis to comprehensively evaluate the differences in outcomes between left and right flap reconstructions in DIEP flap breast reconstruction. By controlling for patient demographics, medical history, and surgical characteristics, we have minimized the influence of confounding variables, providing a robust assessment of the impact of flap laterality on surgical outcomes. Our findings suggest that despite variations in venous coupler size, there are no statistically significant differences in the rates of postoperative complications between left and right flaps. These results underscore the reliability and effectiveness of both left and right flaps as reconstructive options following mastectomy.

Purpose: The use of chemoprophylaxis for venous thromboembolism (VTE) in autologous breast reconstruction remains controversial due to insufficient data regarding incidence of postoperative VTE, optimal timing for chemoprophylaxis, and post-prophylaxis risk of bleeding 1, 2. However, VTE is a well-documented postoperative complication especially in the setting of malignancy, BMI, and surgical length 3, 4. To combat these potential complications, thromboprophylaxis is often administered in surgical patients to prevent VTE development and avoid potential readmission. The purpose of this study was to evaluate the risk of postoperative bleeding in breast cancer patients undergoing autologous breast reconstruction receiving VTE prophylaxis.

Methods: The TriNetX LLC. National Health Research database was queried to identify breast cancer patients who underwent autologous breast reconstruction surgery between 2002 and 2023. Patient's prophylactic anticoagulation status was assessed and the rate of post-procedural hemorrhage and hematoma of the skin and subcutaneous tissue within 30 days was obtained. Statistical analysis was performed on TriNetX. Descriptive statistics were used to describe patient demographic information. Risk ratios were used to compare incidence of post-procedural hemorrhage and hematoma of the skin and subcutaneous tissue (ICD-10: L76.2 and L76.3) within 30 days.

Results: A total cohort of 10,725 patients was identified in this study. The average age of patients at indexed event was 51.6 ± 10 years old and a majority of patients were self-reported to be white (8109; 76%), followed by unknown race (1,024; 9.5%) and African American (888; 8.3%). Approximately 45% of the patients received prophylactic anticoagulation and 55% did not. A total of 486 bleeding complications were recorded. Incidence of bleeding observed in those who did and did not receive prophylactic anticoagulation were 4.61% and 4.49%, respectively. There was no significant difference in risk of bleeding between the two cohorts (p=0.773).

Conclusion: The use of thromboprophylaxis for VTE to limit the risk of postoperative bleeding in women undergoing autologous breast reconstruction is a controversial aspect of perioperative care. This study utilizes a large-scale analysis to suggest that there is no statistically significant difference in risk of postoperative bleeding between those who received and did not receive prophylactic anticoagulation. Prophylactic anticoagulation in patients undergoing autologous breast reconstruction may therefore be safely administered within the 30 post-operative period to prevent VTE without increasing the postoperative bleeding risk.

References 1. Andtbacka RH, Babiera G, Singletary SE, et al. Incidence and prevention of venous thromboembolism in patients undergoing breast cancer surgery and treated according to clinical pathways. Ann Surg. 2006;243(1):96-101. 2. Masoomi H, Paydar KZ, Wirth GA, Aly A, Kobayashi MR, Evans GRD. Predictive Risk Factors of Venous Thromboembolism in Autologous Breast Reconstruction Surgery. Annals of Plastic Surgery. 2014;72(1):30-33. 3. Momeni A, Sorice SC, Li AY, Nguyen DH, Pannucci C. Breast Reconstruction with Free Abdominal Flaps Is Associated with Persistent Lower Extremity Venous Stasis. Plast Reconstr Surg. 2019;143(6):1144e-1150e. 4. Bassiri-Tehrani B, Karanetz I, Bernik SF, Dec W, Lehman JC, Lerman OZ. The Timing of Chemoprophylaxis in Autologous Microsurgical Breast Reconstruction. Plast Reconstr Surg. 2018;142(5):1116-1123.