Postmastectomy Reconstruction Research Articles

Botulinum Toxin-A Infiltration to Control Post-Operative Pain after Mastectomy and Expander Reconstruction as Potentially Useful Tool: A Narrative Review.

Botulinum toxin-A (BTX-A), a neurotoxin produced by Clostridium botulinum, was assessed for relieving implant-related pectoralis major muscle's painful spasms. In detail, 100 units of BTX-A can reduce muscle activity and, as a consequence, muscle spasms. The latter is considered the leading cause of post-operative pain after the sub-pectoral tissue expansion, sometimes leading to early expanders' removal. In addition, women choosing post-mastectomy reconstruction surgery seem to suffer worse post-operative pain than those who stop at the mastectomy stage. However, there is no unanimous consensus concerning the potential benefits of BTX-A in reducing pain related to the sub-pectoral placement of tissue expanders in breast reconstruction due to the exiguity of evidence. Therefore, this review aims to describe BTX-A-related evidence in this reconstruction setting. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Abstract PO1-17-11: Trends in post-mastectomy reconstruction by age in Korea and among Asian-Americans

Abstract Background: Post-mastectomy immediate breast reconstruction (PMIBR) has been underutilized in the elderly. This study examines the trends of PMIBR by age in a large Korean medical center and compares them to the Asian-American population in the National Cancer Database (NCDB). Methods: We analyzed 5,601 patients who underwent PMIBR out of 13,654 total mastectomy patients between 2001 and 2021 in a Korean Center. Patient characteristics associated with higher likelihood of receiving reconstruction were assessed and compared between patients under 60 years of age and those aged 60 years and older. Complications were investigated in 1,669 patients between 2010 and 2020. In addition, we compared this to 966,354 female patients in the NCDB from 2004-2020 with stage 0-3 breast cancer who underwent mastectomy. Results: The number of PMIBR at the Korean center increased almost ten-fold, but there was a discrepancy in the increase between younger and older women. In the younger group, the proportion of PMIBR rose from 13% (53/398) to 77% (508/664), while in the older group, it increased from 0% (0/60) to 26% (49/186). In the NCDB, Asian-Americans had the lowest rate of breast reconstruction (29%) compared to white (35.4%), black (30.1%), and Hispanic Americans (33.5%). As seen in the table, the rates increased in both age groups but plateaued around 2014 and remained stable until 2020. In 2020, the PMIBR rates were 37% for young Asian-Americans, 48% for young non-Asians, 14% for older Asian-Americans, and 24% for older non-Asians. At the Korean center, patients living in a metropolitan area (42.6% vs.39.8% p=0.001), having higher education (44.7% vs. 10.5% p< 0.001), being unmarried (63.1% vs. 39.3% p< 0.001), having no history of childbirth (53.7% vs 39.9% p< 0.001), having lower stage and hormone receptor-positive HER2-negative breast cancer were more likely to undergo reconstruction. These factors were all more common in the younger age group. In the NCDB, patients receiving PMIBR were more likely to be white or non-Asian, have higher income and education, reside in a metropolitan area and in the Northeast, have less comorbidities, be treated in an academic center, and have a luminal subtype, lower stage, and private health insurance. At the Korean center, autologous reconstruction was more common than implant reconstruction, (68.4% vs. 31.6% for younger women, and 63.3% vs. 36.9% for older women) and the complication rate was similar for both age groups. In contrast, in the NCDB, implant reconstruction was more common in both age groups, tissue-based (29% vs 31%), implant-based (40.7% vs 40%), combined (11% vs 10.8%) and other (18% vs 17.6%) for older and younger women respectively. Conclusion: Both the Korean and American data illustrate remarkably lower utilization of immediate breast reconstruction in older patients. There are notable demographic and clinical differences between age groups but negligible difference in complication rates. Further research and interventions to address barriers in older women are needed. The higher rates of PMIBR in South Korea mirrors that of white women in the northeast USA, suggesting a potential disparity for Asian-Americans. Percentage of PMIBR over total mastectomy (with or without reconstruction) by age and race PMIBR= post-mastecomy immediate breast reconstruction; NCDB= national cancer database Citation Format: Soo-Young Lee, Madhav KC, Hyun Ho Han, Leah Kim, Mehra Golshan, Eric Schneider, Rachel Greenup, Donald Lannin, Hyung Bae Kim, Byung Ho Son, Jong Won Lee, Sae Byul Lee, Hee Jeong Kim, Tristen Park. Trends in post-mastectomy reconstruction by age in Korea and among Asian-Americans [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-17-11.

Breast Implant Reconstruction in the Ptotic Patient: Evaluation of Wise and Vertical Skin Sparing Mastectomy

Introduction: Post-mastectomy reconstruction in patients with severe breast ptosis can be challenging. Traditionally, a skin sparing mastectomy (SSM) with a circumareolar incision or a horizontal elliptical extension results in a long, horizontally-oriented scar in the central breast. The Wise pattern SSM with an inferiorly-based dermal flap addresses skin redundancy and provides added vascularized implant coverage in ptotic patients with macromastia. The purpose of this study is to compare outcomes in ptotic patients undergoing SSM with Wise pattern and a modified vertical technique which also uses de-epithelialized excess skin under the incision. Methods: A retrospective chart review was performed on patients that underwent SSM using a Wise or vertical skin reducing technique. The Wise pattern was performed using an inferiorly-based dermal flap and the vertical method used a laterally-based dermal flap covering the implant/tissue expander (TE). Results: SSM with the use of autoderm was performed in 42 patients (67 breasts) using either the Wise (n = 49 breasts) or vertical (n = 18 breasts) method. Both groups had similar BMI (35.4). The prepectoral plane was used in 93.5% of Wise pattern patients and all vertical patients. All cases of seroma and hematoma occurred in the Wise pattern group (10.2%). Mastectomy skin necrosis requiring unplanned return to surgery for debridement occurred in 20.4% of those undergoing Wise pattern SSM and 11.1% undergoing the vertical pattern (p = 0.49). Conclusion: Severely ptotic patients undergoing SSM have a high risk of skin necrosis. A dermal flap under the closure has the advantage of vascularized tissue reinforcing the wound in implant based reconstruction. The vertical pattern SSM using a laterally-based dermal flap may be a safe, simple alternative to the Wise pattern in select patients.

Direct-to-Implant vs Tissue Expander Placement in Immediate Breast Reconstruction: A Prospective Cohort Study.

Direct-to-implant (DTI) breast reconstruction after mastectomy has gained increasing popularity. While concerns over ischemic complications related to tension on the mastectomy flap persist, newer techniques and technologies have enhanced safety of this technique. To compare clinical and patient-reported outcomes of DTI and two-stage tissue expander (TE) reconstruction. A prospective cohort design was utilized to compare the incidence of reconstructive failure among patients undergoing DTI and TE reconstruction via unadjusted bivariate and adjusted multivariable logistic regression analyses. Secondary clinical outcomes of interest included specific complications requiring intervention (infection, seroma, hematoma, mastectomy flap necrosis, incisional dehiscence, device exposure) and time to final drain removal. Patient-reported outcomes (PROs) via BREAST-Q were also compared. A total of 134 patients (257 breasts) underwent DTI reconstruction and 222 patients (405 breasts) received TEs. DTI patients were significantly younger with lower BMIs, less diabetes, hypertension, and smoking, and smaller breast sizes, and underwent more nipple-sparing mastectomies with prepectoral reconstructions. Rates of any complication (18% DTI vs 24% TE, p=0.047), reconstructive failure (5.1% vs 12%, p=0.004), and seroma (3.9% vs 11%, p<0.001) were significantly lower in the DTI cohort on unadjusted analyses; however, there were no significant differences in adjusted regressions. Patient-reported satisfaction with breasts, psychosocial well-being, and sexual well-being were more substantively improved with DTI reconstruction. Prepectoral DTI reconstruction is a viable option for post-mastectomy reconstruction in carefully selected patients, with no significant increase in reconstructive failure or other complications.

35LBA (PB-016) LBA Poster - Post-Mastectomy reconstruction practices and outcomes for older women in a UK Tertiary Care Centre

35LBA (PB-016) LBA Poster - Post-Mastectomy reconstruction practices and outcomes for older women in a UK Tertiary Care Centre

Complex breast reconstruction using bilateral profunda artery perforator-free-flaps in a resource-limited setting: a case report

Interestingly, the current shift in mastectomy patterns and advances in reconstruction techniques have contributed to an increasing number of patients requesting breast reconstruction postmastectomy every year. Depending on available expertise, patients can access breast reconstruction options (immediate or delayed), autologous, or implant-based. We present a case of a 36-year-old female patient 5 years into remission, having undergone mastectomy for invasive ductal carcinoma of the right breast and now preferred risk reduction surgery (prophylactic mastectomy) of her left unaffected breast with immediate reconstruction. The microsurgical technique utilized bilateral profunda artery perforator flaps from both thighs for (immediate and delayed) breast reconstruction. In our scenario, the authors had an unfavorable outcome on the side of delayed breast reconstruction (right) with a venous insufficiency diagnosis leading to unilateral complete flap loss, which was subsequently debrided and reconstructed with an obliquely-oriented pedicled Latissimus dorsi flap. In contrast, following risk reduction surgery and immediate reconstruction on the left side, the buried flap was a complete success, with the free nipple graft doing well postoperatively.

Evolution of Indocyanine Green Fluorescence in Breast and Axilla Surgery: An Australasian Experience.

The evolution of indocyanine green (ICG) fluorescence in breast and axilla surgery from an Australasian perspective is discussed in this narrative review with a focus on breast cancer and reconstruction surgery. The authors have nearly a decade of experience with ICG in a high-volume institution, which has resulted in publications and ongoing future research evaluating its use for predicting mastectomy skin flap perfusion for reconstruction, lymphatic mapping for sentinel lymph node (SLN) biopsy, and axillary reverse mapping (ARM) for prevention of lymphoedema. In the authors' experience, routine use of ICG angiography during breast reconstruction postmastectomy was demonstrated to be cost-effective for the reduction of ischemic complications in the Australian setting. A novel tracer combination, ICG-technetium-99m offered a safe and effective substitute to the "gold standard" dual tracer for SLN biopsy, although greater costs were associated with ICG. An ongoing trial will evaluate ARM node identification using ICG fluorescence during axillary lymph node dissection and potential predictive factors of ARM node involvement. These data add to the growing literature on ICG and allow future research to build on this to improve understanding of the potential benefits of fluorescence-guided surgery in breast cancer and reconstruction surgery.

Impact of Prepectoral vs. Subpectoral Tissue Expander Placement on Post-mastectomy Radiation Therapy Delivery: A Retrospective Cohort Study.

Implant-based reconstruction is the most common method of postmastectomy reconstruction. Many patients require postmastectomy radiation (PMRT). Tissue expanders (TEs), typically inserted as a first stage, have historically been placed subpectorally. More recently, prepectoral reconstruction has gained popularity, but its impact on PMRT is unknown. Prior studies focus on complication rates and aesthetic outcomes. This study examines whether there is a difference in radiation dosimetry among patients undergoing prepectoral versus subpectoral TE reconstruction. Electronic medical records and radiation plans of 50 patients (25 prepectoral, 25 subpectoral) who underwent mastectomy with immediate TE reconstruction at our institution or affiliate site were reviewed. Pectoralis major muscle and chest wall structures were contoured and mean percentage volumes of these structures receiving less than 95%, 100%, and more than 105% target radiation dose were calculated, as were heart and ipsilateral lung doses. Welch two sample t test, Fisher exact test, and Pearson chi-squared tests were performed. The groups had comparable patient and tumor characteristics and underwent similar ablative and reconstructive procedures and radiation dosimetry. Subpectoral patients had larger mean areas receiving less than 95% target dose ("cold spots"); prepectoral patients had larger mean areas receiving greater than 105% ("hot spots") and 100% target doses. There were no differences in chest wall, heart, and lung doses. Our results demonstrate an increased mean percentage area of pectoralis cold spots with subpectoral reconstruction and increased area of hot spots and 100% dose delivery to the pectoralis in prepectoral patients. Larger studies should analyze long-term effects of prepectoral reconstruction on radiation dosing and recurrence rates.

Nipple-areola complex prosthesis as a new arsenal for breast reconstruction

Nipple and areola complex (NAC) recreating is primordial to achieve a complete breast reconstruction. Some patients would not benefit or choose to undergo surgical or tattoo NAC reconstruction. Recently, innovative NAC silicone prostheses have been developed that are applied over the skin and come in various shapes, sizes, and colors to match different NAC tones and sizes.Our prospective study aims to evaluate for the first time, to our knowledge, the safety of these prostheses and patients’ and surgeons’ satisfaction using a 30-day survey. Twenty patients using these NAC prostheses after unilateral breast reconstruction postmastectomy with NAC excision were included.All patients except one (95%) were satisfied/very satisfied with the aspect and symmetry of NAC prostheses compared with native contralateral NAC. All patients were more/much more satisfied with their body image and self-esteem using the NAC prostheses. Except for 2 (90%), no participant presented any skin reaction, infection, or erosion. Most patients (68.75%) used the prosthesis every day, and others—occasionally. All participants stated they would recommend these prostheses to other women as a temporary or definitive solution.With these promising results demonstrating a high safety and satisfaction rate, we are confident that this simple, safe, noninvasive, and cost-effective device should be proposed to all patients to improve the management of breast reconstruction and offer body integrity to patients. Health insurance should consider reimbursement for these prostheses in patients after mastectomy or with NAC deformation after trauma, surgery, or congenital.

Missing Data in Patient-Reported Outcomes Research: Utilizing Multiple Imputation to Address an Unavoidable Problem.

Patient-reported outcomes (PROs) have become a focus in postoperative surgical care. Unfortunately, studies using PROs can be subject to missing data, which may lead to biases or inaccurate conclusions. Multiple imputation (MI) is a statistical method for addressing missing data in clinical research. The aim of this study was to explore MI as a way to address missing data in PRO research. A working example of MI using real-world data was performed using the BREAST-Q PRO measurein postmastectomy reconstruction. A retrospective review of immediate tissue expander breast reconstruction patients in 2019 was conducted to compare BREAST-Q physical well-being of the chest scores betweenprepectoral and subpectoral cohorts at 2 weeks postoperatively. The observed dataset and three hypothetical missingness situations were created to assess how increasing missingness affects MI results. Overall, 916 patients were included in the analysis. When excluding patients with missing information and solely performing analysis on the completed cases, prepectoral patients had significantly higher physical well-being of the chest scores at 2weeks postoperatively; however, this trend was reversedwith increasing missingness scenarios, where subpectoral patients had higher scores. In comparison, all MI results showed that prepectoral patients had higher scores on average compared with subpectoral patients regardless of missingness scenario. MI demonstrated consistent results with increasing missingness scenarios, whereas performing analysis in higher missingness scenarios without MI led to varying results. This working example emphasizes the need for missing data methodology to be considered in PRO research.

Efficacy of breast reconstruction for N2-3M0 stage female breast cancer on breast cancer-specific survival: A population-based propensity score analysis.

The efficacy of breast reconstruction for patients with N2-3M0 stage female breast cancer (FBC) remained unclear due to the lack of randomized clinical trials. This retrospective study aimed to explore the efficacy of breast reconstruction for patients with N2-3M0 stage FBC. Two thousand five hundred forty-five subjects with FBC staged by N2-3M0 from 2010 to 2016 were retrieved from the Surveillance, Epidemiology, and End Results database. Generalized boosted model (GBM) and propensity score matching (PSM) analyses and multivariable Cox analyses were employed to assess the clinical prognostic effect of postmastectomy reconstruction for patients with N2-3M0 stage FBC in breast cancer-specific survival (BCSS). Totally, 1784 candidates underwent mastectomy alone (mastectomy group), and 761 candidates underwent postmastectomy reconstruction (PMbR group), with 418 breast-specific deaths after a median follow-up time of 57 months (ranging from 7 to 227 months). BCSS in the mastectomy group showed no statistical difference from that in the PMbR group in the PSM cohort (HR = 0.93, 95% CI: 0.70-1.25, p = 0.400) and GBM cohort (HR = 0.75, 95% CI: 0.56-1.01, p = 0.057). In the multivariate analyses, there was no difference in the effect of PMbR and mastectomy on BCSS in the original cohort (HR = 0.85, 95% CI: 0.66-1.09, p = 0.197), PSM cohort (HR = 0.86, 95% CI: 0.64-1.15, p = 0.310), and GBM cohort (HR = 0.84, 95% CI: 0.61-1.17, p = 0.298). Triple-negative breast cancer (TNBC) was a detrimental factor affecting BCSS for patients in the PMbR group. Our study demonstrated that PMbR is an oncologically safe surgical treatment and can be widely recommended in clinics for females with non-TNBC staged by T0-3N2-3M0.

Outcomes of complex oncoplastic breast surgery in older women. Analysis of data from the Age Gap cohort study

Breast cancer, mastectomy, breast conserving surgery, post-mastectomy reconstruction, older women, quality of life.

Latissimus dorsi flap for breast reconstruction: a large single-institution evaluation of surgical outcome and complications

PurposeThe use of autologous tissues is considered gold standard for patients undergoing breast reconstruction and is the preferred method in the post-radiation setting. Although the latissimus dorsi flap (LDF) has been replaced by abdominal flaps as technique of choice, it remains a valuable option in several specific clinical situations and its use has been regaining popularity in recent years. In this work, we present an 18-year retrospective analysis of a single-institution single-surgeon experience with LDF-based reconstruction with focus on early complications and reconstructive failures.MethodsHospital records of all patients undergoing breast surgery for any reason in the Certified Breast Cancer Center, Regio Klinikum Pinneberg, Germany between April, 1st 2005 and October, 31st 2022 were reviewed. 142 consecutive LDF-based reconstructive procedures were identified. Detailed information was gathered on patient characteristics, treatment-related factors, and complications.ResultsOne hundred forty patients (139 female, 1 male) received 142 LDF-based surgeries. The flap was used mainly for immediate breast reconstruction with or without implant (83% of patients), followed by defect coverage after removal of a large tumor (7%), implant-to-flap conversion with or without placement of a new implant (6%), and delayed post-mastectomy reconstruction (4%). The use of LDF decreased between 2005 and 2020 (2005: 17, 2006: 13, 2007: 14, 2008: 16, 2009: 5, 2010: 9, 2011: 8, 2012: 3, 2013: 10, 2014: 8, 2015: 8, 2016: 7, 2017: 7, 2018: 4, 2019: 4, 2020: 2, 2021: 6, 2022: 4). Surgery was performed for invasive breast cancer in 78%, ductal carcinoma in situ in 20% and other reasons such as genetic mutation in 1% of patients. Ipsilateral radiation therapy was received by 12% of patients prior to LDF surgery and by 37% after the surgery. 25% of patients were smokers. The median duration of surgery, including all procedures conducted simultaneously such as e.g., mastectomy, axillary surgery, or implant placement, was 117 min (range 56–205). Patients stayed in the hospital for a median of 7 days (range 2–23 days). The most common complication was seroma (26%), followed by wound dehiscence (8%), surgical site infection (7%), partial skin and/or nipple necrosis of any size (7%) and hematoma requiring surgical evacuation (2%). 19% of all patients required seroma aspiration or drainage, mostly at the donor site and performed under ultrasound guidance in the ambulatory setting. Flap loss due to necrosis occurred in 2% of patients.ConclusionsLatissimus dorsi flap is a well-established surgical technique commonly used for immediate breast reconstruction as well as defect coverage in locally advanced breast cancer. To the best of our knowledge, this is one of the largest single-surgeon analyses of early complications in patients receiving LDF. As expected, seroma was the most common complication observed in nearly one third of patients and requiring a therapeutic intervention in every fifth patient. Serious adverse events occurred rarely, and flap loss rate was very low.

Disparities in post-mastectomy reconstruction use among American Indian and Alaska Native women.

American Indian/Alaska Native (AI/AN) breast cancer patients undergo post-mastectomy reconstruction (PMR) infrequently relative to Non-Hispanic White (NHW) patients. Factors associated with low PMR rates among AI/AN are poorly understood. We sought to describe factors associated with this disparity in surgical care. A retrospective cohort study of the National Cancer Database (2004 - 2017) identified AI/AN and NHW women, ages 18 - 64, who underwent mastectomy for stage 0 - III breast cancer. Patient characteristics, annual PMR rates, and factors associated with PMR were described with univariable analysis, the Cochran-Armitage test, and multivariable logistical regression. 414,036 NHW and 1,980 AI/AN met inclusion criteria. Relative to NHW, AI/AN had more comorbidities (20% vs 12% Charlson Comorbidity Index ≥ 1, p < 0.001), had non-private insurance (49% vs 20%, p < 0.001), and underwent unilateral mastectomy more frequently (69% vs 61%, p < 0.001). PMR rates increased over the study period, from 13% to 47% for AI/AN and from 29% to 62% for NHW (p <0.001). AI/AN race was independently associated with decreased likelihood of PMR (OR 0.62, 95% CI 0.56-0.69). Among AI/AN, decreased likelihood of PMR was significantly associated with older age at diagnosis, more remote year of diagnosis, advanced disease (tumor size > 5 cm, positive lymph nodes), unilateral mastectomy, non-private insurance, and lower educational attainment in patient's area of residence. PMR rates among AI/AN with stage 0 - III breast cancer have increased, yet remain significantly lower than among NHW. Further research should elicit AI/AN perspectives on PMR, and guide early breast cancer detection and treatment.

Seroma as a Biological Tissue Expander on Post-Mastectomy Reconstruction: A Case Report

Seroma as a Biological Tissue Expander on Post-Mastectomy Reconstruction: A Case Report

Lightweight implants in breast reconstruction.

Since the first use of silicone implants by Cronin in 1962, there have been several attempts to introduce alternative filling materials for breast implants on the market. A promising new development are lightweight implants, whose filler material is one third lighter than conventional silicone gel. While these implants have been used primarily for aesthetic augmentation, a benefit could be expected particularly in post-mastectomy reconstruction. Since 2019, 92 operations using lightweight implants have been performed at our clinic, 61 of them for breast reconstruction after mastectomy. These have been compared to 92 breast reconstructions using conventional silicone implants. The average volume of the lightweight implants was 30% higher than of the conventional implants (452 ml resp. 347 ml), whereas the implant weight was comparable in both groups (317 g resp. 347 g). Grade 3-4 capsular fibrosis was seen in 6 cases in both groups; revision was required 9 times (lightweight implants) and 7 times (conventional silicone implants) during the follow-up period. To our knowledge, this is the first study to investigate the use of lightweight implants in breast reconstruction. With exception of the filler material, the implants used in the two groups were comparable in shape and surface. The inserted lightweight implants had a greater volume but nearly the same weight as the conventional implants and were used in patients with a higher body mass index. Thus, lightweight implants were preferred in patients whose reconstruction required a larger implant volume. Lightweight implants are a new alternative for breast reconstruction especially in case that larger implant volume is demanded. The increased complication rate has to be verified in further studies.

Early Complications in Prepectoral Breast Reconstructions with and without Acellular Dermal Matrix: A Preliminary Analysis of Outcomes.

Prepectoral tissue expander (TE) placement for two-stage postmastectomy reconstruction is usually performed in conjunction with insertion of acellular dermal matrix (ADM). However, the effects of ADM use on TE loss or other early complications remain unknown. Therefore, the aim of this study was to compare early postoperative complications in patients who underwent prepectoral breast implant reconstruction with or without ADM use. The authors performed a retrospective cohort study of all patients at their institution who underwent prepectoral breast reconstruction from January of 2018 to June of 2021. The primary outcome was TE loss within 90 days of surgery; secondary outcomes included other complications such as infection, TE exposure, mastectomy skin flap necrosis requiring revision, and seroma. Data on 714 patients with 1225 TEs (1060 with ADM and 165 without) were analyzed. Baseline demographics did not differ by ADM use, although mastectomy breast tissue weight was higher in patients without ADM (750.3 g versus 540.8 g; P < 0.001). Rates of TE loss were similar in reconstructions with (3.8%) ADM and without (6.7%; P = 0.09). We also did not find differences in the rates of secondary outcomes between cohorts. ADM use had no statistically significant effect on early complication rates among patients undergoing breast reconstruction with prepectoral TEs. Still, this study was underpowered, and data trended toward statistical significance; thus, larger studies are required in the future. Additional research and randomized studies should focus on larger cohorts and examine long-term complications such as capsular contracture and implant malposition. Therapeutic, III.

SP37. Fortification or Fibrosis? An Evaluation of Immune System Disorders and the Development of Capsular Contracture

PURPOSE: Two-stage implant-based procedures remain the most common approach for women pursuing post-mastectomy reconstruction. Up to 20% of patients develop capsular contracture after surgery, which can lead to poor functional and aesthetic outcomes, cause significant discomfort, and require additional corrective procedures. While the etiology of capsular contracture has not been fully elucidated, most literature attribute the process to a pro-inflammatory response involving the innate immune system. Additionally, some have postulated that peri-operative bacterial colonization of the implant site may lead to fibrosis and contracture formation. Autoimmune disorders, which are linked to abnormal systemic inflammatory responses, and immunosuppression, which can increase susceptibility to a range of infections, are not uncommon in patients diagnosed with breast cancer. Thus, an understanding of the intersectionality between these conditions and post-operative complications could prove useful for surgical planning. The aim of this study is to evaluate the effects of autoimmune disorders and immunodeficiency on rates of capsular contracture among two-stage breast reconstruction patients. METHODS: A dataset consisting of 296 patients (520 samples) who had undergone two-stage breast reconstruction between 2009 - 2021 at a tertiary-care facility was used in the study. An array of patient data, such as demographics, past medical history, and social history were collected. The primary endpoint was contracture development, which was ascertained by reviewing the electronic health record. The secondary outcome of interest was time to contracture formation. The date of contracture development (t_c) is defined as the first mention of capsular contracture based on clinical assessment. The time to event is defined as t_c - t_implant if the subject developed contracture, t_c - t_present if the subject was contracture-free. Univariate logistic regression was used for statistical analysis. RESULTS: Among the cohort, 5% (26/520) and 10.6% (55/520) had concurrent immunosuppression and autoimmune disorders, respectively. The autoimmune disorders examined were rheumatologic and endocrine in origin. The immunosuppressed states included both viral (HIV, Hepatitis A/B/C) and oncological (multiple myeloma, monoclonal gammopathy of undetermined significance, chronic myelogenous leukemia) conditions. On univariate analysis, compared to patients without either conditions, autoimmune disorders (OR 1.15, p-value 0.64) and immunosuppression (OR 1.06, p-value 0.88) were not linked to significantly higher odds or earlier development of capsular contracture (p-value > 0.05). Further stratified analysis examining only patients with immune-based conditions did not reveal statistically significant differences in the timeline (OR 0.14, p-value 0.43) or odds (OR 1.07, p-value 0.878) of contracture formation between the subgroup with immune-overactivation and the subgroup with immunosuppression. CONCLUSION: Comorbid autoimmune disorders and immunosuppression do not appear to significantly affect the odds or timeline of capsular contracture development. When counseling post-mastectomy patients with similar past medical history, surgeons may safely offer the choice of implant-based procedures when presenting the various reconstruction modalities.

82. A Machine Learning Approach to Predicting Secondary Revision Procedures in Post-mastectomy Reconstruction Patients

82. A Machine Learning Approach to Predicting Secondary Revision Procedures in Post-mastectomy Reconstruction Patients

D124. Equity And Disparities in Access to Post-mastectomy Reconstruction: Multi-decades in New York

PURPOSE: Breast reconstruction has been shown to improve both quality of life and psychosocial wellbeing. There is a paucity of literature that examines rates of post-mastectomy reconstruction across various demographics and clinical profiles on a multi-decade, multi-institutional scale. The aim of this study is to assess the barriers in post-cancer reconstruction at our affiliate institutions. METHODS: We performed a retrospective chart review of patients who had undergone mastectomy at three institutions within the New York Presbyterian system, including Cornell (WCMC), Columbia (CUIMC), and Brooklyn Methodist (BMH) from 1979 to 2019. Patient medical history, demographics and treatments were recorded. Univariate and multivariate logistic regression were used to assess the relationship between the variables and receiving reconstruction after mastectomy. RESULTS: 4594 patients with verifiable data were included in the cohort. Older age (OR 0.9), more advanced cancer stage (OR 0.46), and being single compared to married (OR 0.66) were correlated with lower odds of pursuing reconstruction (p<0.05). Compared to their White counterparts, Asian American Pacific Islander (OR 0.21) and Black patients (OR 0.61) were significantly less likely to receive reconstruction (p<0.05). The same trend was not present for Medicare/Medicaid compared to private insurance status. CONCLUSION: The multi-decade data suggests certain racial and social factors may still pose as barriers to reconstruction access. However, efforts toward broadening insurance coverage and mandating information regarding access to reconstruction may have begun leveling the field for disadvantaged socioeconomic groups.