Scientific Abstract Presentations: Abstract Topics Session 2 - Non-CME Session 1 Friday, October 16 Fri, Oct 16 5:00-6:00 p.m. CDT

Background: The MENTOR MemoryGel BOOST (MGB) implant (Mentor Worldwide LLC, Irvine, CA), introduced in 2022, was engineered to improve breast augmentation and reconstruction outcomes by enhancing upper pole fullness and reducing rippling through its highly cohesive, precision-filled silicone gel fill.

Objectives: This study aimed to assess the early clinical outcomes, safety profile, complication rates, and reoperation trends in patients undergoing primary and revision breast augmentation with MGB implants.

Methods: A retrospective review was conducted of all patients who underwent primary (n=83) or revision (n=36) augmentation with MGB implants between March 2022 and January 2024 by a single senior surgeon. All patients had at least 6 months of follow-up. Demographics, implant characteristics, surgical techniques, and rates of postoperative complications were analyzed to assess device safety and efficacy. Kaplan-Meier curves estimated time-dependent risk-free survival from capsular contracture.

Results: One hundred and nineteen total patients received MGB implants. Patients had a mean age of 38.9 years with an average follow-up of 418 ± 179 days. Inframammary incision (74%) and subfascial placement (77%) predominated. Average implant volume was 381cc, with 84% of patients selecting a Moderate Plus profile. Complication rates were low: one superficial surgical-site infection (0.8%), and one Baker grade IV capsular contracture (0.8%), occurring in a former smoker. No hematoma, seroma, implant rupture, or rippling was observed during the study period. Reoperation occurred in 11 patients (9.2%), primarily for elective size increase (6.7%). One-year risk-free survival from capsular contracture was greater than 99%.

Conclusion: In this early clinical outcomes review, MGB implants demonstrated promising short-term safety with exceptionally low rates of infection and capsular contracture, and no implant-specific failures. Reoperations were primarily patient-driven rather than complication-related. These data support MGB implants as a reliable and effective option for both primary and revision augmentation. Longer-term follow-up will be critical to confirm sustained performance.

Purpose: Tissue expanders are commonly used in two-stage implant-based breast reconstruction to gradually create space for a permanent implant by stretching the overlying soft tissue. To optimize outcomes, surgeons frequently place acellular dermal matrix (ADM) at the time of expander placement to provide inferolateral support, offload tension from mastectomy flaps, and reduce capsular fibrosis. Despite its widespread use, the mechanisms by which ADM modulates capsule formation in the setting of mechanical tissue expansion remain poorly defined. Furthermore, in clinical practice, expanders are initially filled with either air or saline, but the impact of the inflation medium on capsule formation remains unclear. We developed a clinically relevant murine tissue expander model incorporating sustained mechanical stimulation to compare air versus saline fill and to evaluate the mechanoprotective effect of ADM. Methods: Miniature smooth tissue expanders were combined with our mechanically stimulating implant (MSI) model to reliably induce clinically relevant, severe foreign body response (FBR)(1,2). Expanders were then filled with either air or saline, with parallel groups receiving ADM coverage, and implanted into the dorsal subcutaneous space of mice (n = 5/group). Capsule tissue was harvested on day 28. We quantified capsule thickness, collagen deposition, α-smooth muscle actin (α-SMA)–positive myofibroblasts, and immune cell infiltration, including CD45⁺ immune cells and F4/80⁺ macrophages. Results: Mechanical stimulation produced a robust and reproducible fibrotic capsule consistent with clinically observed fibrosis. Air and saline inflation yielded similar outcomes, with no significant differences in capsule thickness (p = 0.71-0.84), collagen content (p > 0.99), α-SMA⁺ cells (p > 0.99), CD45⁺ cell infiltration (p = 0.24-0.99), or F4/80⁺ macrophage density (p > 0.99).　In both air and saline filled devices, ADM coverage significantly reduced capsule thickness (p < 0.005), collagen deposition (p < 0.001), α-SMA⁺ myofibroblasts (p < 0.05), CD45⁺ immune infiltrates (p < 0.001), and F4/80⁺ macrophages (p < 0.005) compared to expanders without ADM coverage. Discussion: We present the first murine tissue expander model that reliably induces mechanically driven capsule formation analogous to clinical FBR. Using this model, we found that air and saline inflation produce comparable levels of capsule formation. Notably, we found that ADM confers clear mechanoprotective effects by decreasing capsule fibrosis and inflammation. Although ADM has been clinically associated with improved outcomes, its biological mechanism has remained uncertain. This model provides direct experimental evidence that ADM attenuates the fibroinflammatory response generated during expansion. Our findings offer a mechanistic justification for incorporating ADM coverage at the time of tissue expander placement.

1. Padmanabhan J, Chen K, Sivaraj D, et al. Allometrically scaling tissue forces drive pathological foreign-body responses to implants via Rac2-activated myeloid cells. Nat Biomed Eng. 2023;7(11):1419-1436.
2. Sivaraj D, Padmanabhan J, Chen K, et al. IQGAP1-mediated mechanical signaling promotes the foreign body response to biomedical implants. FASEB J. 2022;36(2):e22007.

Background: Minimally invasive techniques for surgical correction of metopic craniosynostosis have grown in popularity. Minimally invasive techniques offer an improved safety profile and shorter operative duration while preserving cranial growth potential. Strip craniectomy with helmet therapy is associated with under correction and persistent supraorbital retrusion. Spring-mediated cranioplasty (SMC) is alternative technique, though data on outcomes remain limited. In this study, we present our institutional experience with SMC for metopic craniosynostosis. Methods: A retrospective chart review was performed of patients who underwent SMC for metopic craniosynostosis between January 2015 and October 2025. Pre and post-operative ICD were measured on CT scans and 2D photographs. Intercanthal distance (ICD) was classified based on age-matched normative values. Threshold analysis was performed to identify spring force parameters associated with overcorrection. Results: Twenty-three patients met inclusion criteria. One patient (4%) required a blood transfusion, and one patient (4%) required a revision for correction of head shape. Most (83%) patients received two springs, with a median total force of 18.6N and median force per spring of 9.3 N Transient hypertelorism occurred in 74% of patients, with 53% self-correcting at a median of 177 days. At final follow-up, 65% achieved normal ICD and 35% were hyperteloric. Threshold analysis revealed patients receiving >11N per spring had 12 times higher odds of persistent hypertelorism (p=0.033). Conclusion: SMC is a safe and effective minimally invasive treatment for metopic craniosynostosis with low complication and revision rates. Higher spring forces may increase risk of persistent overcorrection, and these findings offer preliminary parameters to guide surgical planning.

Purpose: With the global rise of diabetes, diabetic foot ulcers(DFUs) represent a leading cause of chronic, refractory wounds. While randomized controlled trials(RCTs) have evaluated biological substitutes for DFUs, reported clinical benefits remain inconsistent. Compared with the standard of care(SOC) – debridement, moist dressings, and pressure offloading – biologics introduce substantial costs. Importantly, statistical significance alone does not reflect the robustness of treatment effects. Thus, statistical fragility analysis can assess the strength of outcomes by quantifying how easily significance is overturned. This study aimed to evaluate the statistical fragility of RCT outcomes to determine whether biologics offer benefit over SOC in DFU management.

Methods: Following PRISMA guidelines, PubMed, Scopus, CENTRAL, and Web of Science were searched for RCTs evaluating biological substitutes for DFUs. Extracted outcomes included complete wound closure, adverse events, and recurrence. Fragility was assessed using Fisher's exact test with iterative changes to the proportion of outcome events. The fragility index(FI) represented the number of outcome changes needed to reverse statistical significance, while the reverse fragility index(rFI) measured the number needed to overturn nonsignificance. Fragility and reverse fragility quotients (FQ, rFQ) divide FI/rFI by the sample size to standardize outcomes, where an FQ of 0.05 indicates that five outcome changes per 100 patients would alter significance. Data was reported as Median(Q1-Q3).

Results: Thirty-three articles(N=3,459) were included, with 1,302 patients treated with dermal-matrices, 606 with placental membranes, 163 with epidermal-matrices, and 545 controls receiving SOC. Only 16(48.48%) trials performed power analyses, and a mean of 2.5(range: 0-24) patients per study were lost to follow-up. Biologics demonstrated superiority for wound closure in 13 of 23 trials, with a median FI of 6(3-8) and FQ of 0.082(0.024-0.130). Nonsignificant studies had median rFI of 4(3-4) and rFQ of 0.105(0.103-0.139). Meta-analysis favored dermal-matrices (OR[95% CI], 1.61[1.26-2.05], p<0.001; FI=56; FQ=0.047) and amniotic-membranes (1.95[1.53-2.49], p<0.001; FI=88; FQ=0.105) over SOC. Fragility quotients of amniotic membrane trials demonstrate comparatively greater robustness than dermal matrices. Studies directly comparing amniotic membranes and dermal matrices reported mixed, highly fragile wound-closure outcomes, with a mean FI of 3(2-4). Similarly, meta-analysis yielded comparable results(p=0.09; rFI=1; rFQ=0.005) with very high fragility. Adverse events were lower with biologics(26.4%) than SOC(35.5%, p<0.001), but results were not robust(FQ=0.024). No significant difference in disease recurrence was found between biologics and SOC(p=0.192, rFQ=0.036).

Conclusion: RCTs evaluating biologics for DFU treatment demonstrate considerable fragility of outcomes. Across all trials, reversal of statistical significance would occur if only 8.2% of patients treated with biologics failed to achieve wound closure. In multiple studies, FI values were lower than the number of patients lost to follow-up, further highlighting the potential vulnerability of trial findings. Although meta-analyses show improved wound healing with biologics, fragility analysis revealed minimal robustness, with ten or fewer outcome changes per 100 patients overturning significance. Even when comparing amniotic membranes and dermal matrices, data remains fragile, highlighting the need for stronger evidence comparing the cohorts. Given the global burden of diabetic foot ulcers and the considerable cost of biologics, adequately powered trials with robust statistical findings are essential for clinical adoption.