Reducing Peri-implant Capsule Thickness in Submuscular Rodent Model of Breast Reconstruction With Delayed Radiotherapy.

INTRODUCTION: Capsular contracture remains the most common complication following device-based breast reconstruction, occurring in up to 50% of women who also undergo adjuvant radiotherapy either before or after device-based reconstruction. While certain risk factors for capsular contracture have been identified, there remains no clinically effective method of prevention. The purpose of the present study is to determine the effect of coating the implant with the novel small molecule Met-Z2-Y12, with and without delayed, targeted radiotherapy, on capsule thickness and morphologic change around smooth silicone implants placed under the latissimus dorsi in a rodent model. METHODS: Twenty-four female Sprague Dawley rats each had 2 mL smooth round silicone breast implants implanted bilaterally under the latissimus dorsi muscle. Twelve received uncoated implants and twelve received implants coated with Met-Z2-Y12. Half of the animals from each group received targeted radiotherapy (20 Gray) on postoperative day ten. At three and 6 months after implantation, the tissue surrounding the implants was harvested for analysis of capsular histology including capsule thickness. Additionally, microCT scans were qualitatively analyzed for morphologic change. RESULTS: Capsules surrounding Met-Z2-Y12-coated implants were significantly thinner (P = 0.006). The greatest difference in capsule thickness was seen in the irradiated 6-month groups, where mean capsule thickness was 79.1 ± 27.3 µm for uncoated versus 50.9 ± 9.6 µm for Met-Z2-Y12-coated implants (P = 0.038). At the time of explant, there were no capsular morphologic differences between the groups either grossly or per microCT. CONCLUSIONS: Met-Z2-Y12 coating of smooth silicone breast implants significantly reduces capsule thickness in a rodent model of submuscular breast reconstruction with delayed radiotherapy.

Topical α-gal nanoparticles accelerate diabetic wound healing.

An inadequate response from macrophages, key orchestrators of the wound healing process, has been implicated in the pathophysiology of impaired healing in diabetes. This study explored the utility of nanoparticles presenting the α-gal (Galα1-3Galß1-4GlcNAc-R) epitope to induce anti-Gal antibody-mediated local transient recruitment of macrophages to accelerate wound closure and healing in a diabetic murine model. α1,3galactosyltrasferase knockout mice were stimulated to produce anti-Gal antibodies and subsequently diabetes was induced by streptozotocin-induced ß-cell destruction. Six mm full-thickness skin wounds were made and α-gal nanoparticles (AGN) were topically applied on postwounding days 0 and 1. Wounds were analysed histologically for macrophage invasion and markers of wound healing, including epithelialization, vascularization and granulation tissue deposition through postoperative day 12. We found that application of AGN transiently but significantly increased macrophage recruitment into the wounds of diabetic mice. Treated wounds demonstrated more rapid closure and enhanced wound healing as demonstrated by significantly accelerated rates of epithelialization, vascularization and granulation tissue deposition. Thus, topical treatment of full-thickness wounds in diabetic mice with α-gal nanoparticles induced a transient but significant increase in macrophage recruitment resulting in an accelerated rate of wound healing. Using α-gal nanoparticles as a topical wound healing adjunct is a simple, safe and effective means of augmenting dysregulated macrophage recruitment present in the diabetic state.

Advances in flap monitoring and impact of enhanced recovery protocols.

Recent advances in technology have shown promise in improving outcomes in microsurgery. Although vascular compromise and flap loss represent major complications, flap monitoring techniques have evolved to improve rates of salvage. Enhanced recovery protocols have also been adapted to expedite patient recovery and length of stay. Early studies have shown benefits such as decreased complications and costs and improved patient outcomes. This review examines the current literature on these topics in the setting of microsurgery.

In Search of a Murine Model of Radiation-Induced Periprosthetic Capsular Fibrosis.

INTRODUCTION: Capsular contracture after breast reconstruction is a morbid complication, occurring in 30.0% to 47.5% of patients undergoing postoperative radiotherapy. Although it is well known that radiation increases rate of capsular contracture, there are few well-established animal models that faithfully replicate standard-of-care clinical practice, that is, prosthesis placement at the time of mastectomy followed by delayed radiotherapy. To better recapitulate current clinical practice, we developed a murine model in which the implant sites were irradiated 10 days postoperatively, rather than at time of surgery. METHODS: Hemispherical implants were created from polydimethylsiloxane and implanted bilaterally in the subcutaneous dorsa of 20 C57Bl/6 mice. Mice were randomized to 5 treatment groups, differing in irradiation dose: 0 to 40 Gy. Ten days postoperatively, irradiation was performed using 250-kVp x-rays (XRAD225Cx, Precision X-ray, North Branford, Conn). In 1 mouse per group, dosimeters were placed subcutaneously to measure the delivered absorbed dose. Thirty-one days postoperatively, the mice were sacrificed and examined grossly, and periprosthetic tissues were removed for histologic analysis of periprosthetic capsule thickness and cellular deposition. RESULTS: Total radiation dose was calculated by the treatment planning software and confirmed by the in vivo dosimeters. Physical examination of the irradiated region demonstrated evidence of local radiation delivery, including circular patterns of hair blanching and thinning directly over the implants. Furthermore, histologic analysis of the irradiated epidermis demonstrated dose-dependent radiation changes including keratin whorls and patches of uneven epidermal thickness. There was no statistically significant difference in capsule thickness among the groups. Mice in the 30 and 40 Gy groups endured complications including shortness of breath, coagulopathy, and death, signs of systemic radiation poisoning. CONCLUSIONS: There was no evidence of increased periprosthetic capsule thickness with localized irradiation, irrespective of dose up to 20 Gy. These results differ from those previously published, which demonstrated increased capsule thickness with 10 Gy irradiation. Given the evidence of local radiation delivery, we believe that the lack of increase in capsule thickness observed in our experiment is a real phenomenon and demonstrate the difficulty in creating an easily reproducible rodent model that mimics the effects of postmastectomy implant-based reconstruction and irradiation.

The Impact of Breast Implant Cohesivity on Rippling and Revision Procedures in 2-Stage Prepectoral Breast Reconstruction.

Background: Rippling remains one of the most common complications following prepectoral implant-based reconstruction (IBR). Objectives: The purpose of this study was to assess how implant cohesivity, a measure of elasticity and form stability, affects the incidence of rippling in prepectoral IBR. Methods: We performed a retrospective cohort study of 2-stage prepectoral IBR performed between January 2020 and June 2022 at the Brigham and Women's Hospital and Dana-Farber Cancer Institute, comparing outcomes in patients who received Allergan Natrelle least cohesive, moderately cohesive, and most cohesive silicone gel implants. Outcomes of interest were rippling and reoperation for fat grafting. Results: A total of 129 patients were identified, of whom 52 had the least cohesive implants, 24 had the moderately cohesive implants, and 53 patients had the most cohesive implants. The mean follow-up time was 463 (±220) days. A decreased incidence of rippling was seen with moderately cohesive (odds ratio [OR] 0.30, P < .05) and most cohesive (OR 0.39, P < .05) implants. Third stage reoperation for fat grafting was less frequent in patients with the most cohesive implant (OR 0.07, P < .05). In subgroup analyses, the patients with the most cohesive implant, who did not receive fat grafting at the time of initial implant placement, did not require reoperation for fat grafting (0%). Conclusions: The use of highly cohesive implants in prepectoral IBR is associated with decreased rippling and fewer reoperations for fat grafting.

The Neuroma Startle Sign: A Surgical Indicator of Proximity to an Injured Nerve.

During operative intervention for the treatment of symptomatic neuromas, the authors have observed a hypersensitive "startle" response to stimulation in proximity to the painful nerve. This physiologic sign is an indicator of the specific anatomic localization of the painful stimulus, commonly a symptomatic neuroma, that appears to be reproducible. The aim of this article is to describe this "neuroma startle sign," posit the underlying mechanism for this observation, and propose how this phenomenon could be clinically harnessed for innovation and optimization in both surgery and anesthesia for more effective symptomatic neuroma localization.

An Antifibrotic Breast Implant Surface Coating Significantly Reduces Periprosthetic Capsule Formation.

BACKGROUND: The body responds to prosthetic materials with an inflammatory foreign body response and deposition of a fibrous capsule, which may be deleterious to the function of the device and cause significant discomfort for the patient. Capsular contracture (CC) is the most common complication of aesthetic and reconstructive breast surgery. The source of significant patient morbidity, it can result in pain, suboptimal aesthetic outcomes, implant failure, and increased costs. The underlying mechanism remains unknown. Treatment is limited to reoperation and capsule excision, but recurrence rates remain high. In this study, the authors altered the surface chemistry of silicone implants with a proprietary anti-inflammatory coating to reduce capsule formation. METHODS: Silicone implants were coated with Met-Z2-Y12, a biocompatible, anti-inflammatory surface modification. Uncoated and Met-Z2-Y12-coated implants were implanted in C57BL/6 mice. After 21, 90, or 180 days, periprosthetic tissue was removed for histologic analysis. RESULTS: The authors compared mean capsule thickness at three time points. At 21, 90, and 180 days, there was a statistically significant reduction in capsule thickness of Met-Z2-Y12-coated implants compared with uncoated implants ( P < 0.05). CONCLUSIONS: Coating the surface of silicone implants with Met-Z2-Y12 significantly reduced acute and chronic capsule formation in a mouse model for implant-based breast augmentation and reconstruction. As capsule formation obligatorily precedes CC, these results suggest contracture itself may be significantly attenuated. Furthermore, as periprosthetic capsule formation is a complication without anatomical boundaries, this chemistry may have additional applications beyond breast implants, to a myriad of other implantable medical devices. CLINICAL RELEVANCE STATEMENT: Coating of the silicone implant surface with Met-Z2-Y12 alters the periprosthetic capsule architecture and significantly reduces capsule thickness for at least 6 months postoperatively in a murine model. This is a promising step forward in the development of a therapy to prevent capsular contracture.

An Outcomes Review of 330 Sternal Wound Reconstructions: Timing of Closure Does Make a Difference.

BACKGROUND: Sternal wound infection and dehiscence following cardiac surgery remain difficult clinical problems with high morbidity. Older classification systems regarding timing to reconstruction do not take into account recent improvements in critical care, wound vacuum-assisted closure use, or next-generation antibiotic therapies, which may prolong time to reconstruction. METHODS: Records of patients undergoing sternal wound reconstruction performed by the senior author (J.A.A.) from 1996 to 2018 at a high-volume cardiac surgery center were reviewed. Indications included sternal wound infection or dehiscence. All patients underwent single-stage removal of hardware, débridement, and flap closure. Patients were divided into two groups based on timing of wound closure after cardiac surgery: less than 30 days or greater than or equal to 30 days. RESULTS: Of the 505 patients identified during the study period, 330 had sufficient data for analysis. Mean time to sternal wound surgery was 15.7 days in the early group compared to 64.4 days (p < 0.01) beyond 30 days. Postdébridement cultures were positive in 72 percent versus 62.5 percent of patients (p = 0.11), whereas rates of postoperative infection were significantly higher in the delayed group: 1.9 percent versus 9.5 percent (p < 0.01). Partial wound dehiscence rates were also higher after 30 days (1.9 percent versus 11.3 percent; p < 0.01), whereas total length of stay was decreased. Use of wound vacuum-assisted closure was significantly associated with reconstruction beyond 30 days (p < 0.01). CONCLUSIONS: Although performing sternal wound reconstruction more than 30 days after initial cardiac surgery was associated with a shorter overall hospital length of stay and higher extubation rates in the operating room, these patients also had elevated postoperative infection and wound complication rates. The authors thus recommend not delaying definitive surgical reconstruction when possible. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Webinar during COVID-19 Improves Knowledge of Changes to the Plastic Surgery Residency Application Process.

BACKGROUND: The COVID-19 pandemic has significantly impacted residency application process for all specialties, including plastic surgery residency. Almost all plastic surgery residency programs have suspended visiting sub-internship rotations. This study quantifies the impact of a webinar through an analysis of poll questions and a post-webinar survey sent to all registered participants. METHODS: A dedicated webinar was organized and held by the Harvard Plastic Surgery Residency Training Program. All attendees were asked several poll questions during the webinar. The 192 participants were also sent a post-webinar survey. RESULTS: The response rate was 68.2% (n = 131). Respondents were more confident about matching into a plastic surgery residency program at the end of the webinar compared with before the webinar (P < 0.001). Respondents who did not have a plastic surgery residency program at their home institution were less confident at the start of the webinar (P = 0.009). In addition, respondents who had not taken time off for research or for other endeavors during or after medical school were less confident about their chances to match at the start of the webinar (P = 0.034). CONCLUSIONS: An online webinar program increased confidence levels of medical students interested in applying for residency positions in plastic surgery. Residency programs should consider webinars as a method to inform and assist medical students during the upcoming application season.

Treatment of Infected Wounds in the Age of Antimicrobial Resistance: Contemporary Alternative Therapeutic Options.

As antibiotic resistance increases and antimicrobial options diminish, there is a pressing need to identify and develop new and/or alternative (non-antimicrobial-based) wound therapies. The authors describe the implications of antibiotic resistance on their current wound treatment paradigms and review the most promising non-antibiotic-based antimicrobial agents currently in research and development, with a focus on preclinical and human studies of therapeutic bacteriophages, antimicrobial peptides, cold plasma treatment, photodynamic therapy, honey, silver, and bioelectric dressings.