Updates in Diabetic Wound Healing, Inflammation, and Scarring

Diabetic patients can sustain wounds either as a sequelae of their disease process or postoperatively. Wound healing is a complex process that proceeds through phases of inflammation, proliferation, and remodeling. Diabetes results in several pathological changes that impair almost all of these healing processes. Diabetic wounds are often characterized by excessive inflammation and reduced angiogenesis. Due to these changes, diabetic patients are at a higher risk for postoperative wound healing complications. There is significant evidence in the literature that diabetic patients are at a higher risk for increased wound infections, wound dehiscence, and pathological scarring. Factors such as nutritional status and glycemic control also significantly influence diabetic wound outcomes. There are a variety of treatments available for addressing diabetic wounds.

Wound Healing: A Comprehensive Review

Wound healing is an intricate, tightly regulated process that is critical to maintaining the barrier function of skin along with preserving all other skin functions. This process can be influenced by a variety of modifiable and nonmodifiable factors. As wound healing takes place in all parts of the human body, this review focuses on cutaneous wound healing and highlights the classical wound healing phases. Alterations in any of these phases can promote chronic wound development and may impede wound healing.

Bone Healing and Inflammation: Principles of Fracture and Repair

Bones comprise a significant percentage of human weight and have important physiologic and structural roles. Bone remodeling occurs when healthy bone is renewed to maintain bone strength and maintain calcium and phosphate homeostasis. It proceeds through four phases: (1) cell activation, (2) resorption, (3) reversal, and (4) bone formation. Bone healing, on the other hand, involves rebuilding bone following a fracture. There are two main types of bone healing, primary and secondary. Inflammation plays an integral role in both bone remodeling and healing. Therefore, a tightly regulated inflammatory response helps achieve these two processes, and levels of inflammation can have detrimental effects on bone healing. Other factors that significantly affect bone healing are inadequate blood supply, biomechanical instability, immunosuppression, and smoking. By understanding the different mechanisms of bone healing and the factors that affect them, we may have a better understanding of the underlying principles of bony fixation and thereby improve patient care.

Wound-healing with mechanically robust and biodegradable hydrogel fibers loaded with silver nanoparticles

The objective of this study is to provide a novel synthetic approach for the manufacture of wound-healing materials using covalently cross-linked alginate fibers loaded with silver nanoparticles. Alginate fibers are prepared by wet-spinning in a CaCl(2) precipitation bath. Using this same approach, calcium cross-links in alginate fibers are replaced by chemical cross-links that involve hydroxyl groups for subsequent cross-linking by glutaraldehyde. The cross-linked fibers become highly swollen in aqueous solution due to the presence of carboxyl functional groups, and retain their mechanical stability in physiological fluids owing to the stabilized network of covalent bonds. Alginate fibers can then be loaded with silver ions via the ion-exchange reaction. Silver ions are reduced to yield 11 nm silver nanoparticles incorporated in the polymer gel. This method provides a convenient platform to incorporate silver nanoparticles into alginate fibers in controlled concentrations while retaining the mechanical and swelling properties of the alginate fibers. Our study suggests that the silver nanoparticles loaded fibers may be easily applied in a wound healing paradigm and promote the repair process though the promotion of fibroblast migration to the wound area, reduction of the inflammatory phase, and the increased epidermal thickness in the repaired wound area, thereby improving the overall quality and speed of healing.

Negative Pressure Wound Therapy: Mechanism of Action and Clinical Applications

Negative pressure wound therapy (NPWT) promotes healing by evenly applying negative pressure on the surface of the wound. The system consists of a sponge, a semiocclusive barrier, and a fluid collection system. Its effectiveness is explained by four main mechanisms of action, including macrodeformation of the tissues, drainage of extracellular inflammatory fluids, stabilization of the environment of the wound, and microdeformation. Rarely will complications linked to NPWT occur, but special care must be taken to prevent events such as toxic shock syndrome, fistulization, bleeding, and pain. New NPWT modalities have been recently developed to make NPWT suitable for a wider variety of wounds. These include NPWT with instillation therapy (NPWTi-d), different cleansing options, and application of NPWT on primarily closed incisions. Finally, vacuum-assisted wound closure therapy has been demonstrated to be efficient for various clinical settings, such as the management of diabetic foot ulcers, pressure ulcerations, chronic wounds, and skin grafts.

The ethical acceptability of animal experiments: a proposal for a system to support decision-making

We describe a system to support decision-making on the ethical acceptability of animal experiments for scientific researchers and others responsible for ethical decision-making in animal experiments. The system consists of eight steps. Each step contains a number of substantive questions or a computational rule, leading to a well-articulated moral judgment on specific animal experiments. The system comprises a number of moral assumptions and pre-emptive norms, but leaves enough room for moral discretion and personal responsibility. The general ethical ideas behind the moral choices and assumptions are sketched and potential objections to the overall approach are discussed.

Current Advances in Hypertrophic Scar and Keloid Management

Hypertrophic scars and keloids are caused by excessive tissue response to dermal injury due to local fibroblast proliferation and collagen overproduction. This response occurs because of pathologic wound healing due to dysregulation in the inflammatory, proliferative, and/or remodeling phase. Patients with hypertrophic scars or keloids report reduced quality of life, physical status, and psychological health. Hypertrophic scars or keloids will develop in 30 to 90% of individuals, and despite their prevalence, treatment remains a challenge. Of the treatments currently available for hypertrophic scars and keloids few have been adequately supported by studies with appropriate experimental design. Here, we aim to review the available literature to provide up-to-date information on the etiology, epidemiology, histology, pathophysiology, prevention, and management options available for the treatment of hypertrophic scars and keloids and highlight areas where further research is required.

Barriers and Attitudes to Research Among Residents in Plastic and Reconstructive Surgery: A National Multicenter Cross-Sectional Study

OBJECTIVE

Research sets the foundation for developing plastic surgeons who think critically and approach clinical practice with an inquisitive mind. The objective of this study was to characterize current attitudes and perceived barriers towards conducting research during residency.

DESIGN

A validated 36-item questionnaire was developed by a national task-force of Canadian plastic surgery trainees. The survey was distributed to all 13 plastic surgery programs in Canada. Data was collected for a period of 2 months in the form of multiple choice, Likert scales and short answers.

RESULTS

The response rate was 64% (95/149) with representation from all 13 plastic surgery programs across Canada. The top three perceived barriers to conducting research were lack of time (83%), insufficient access to research supervisors and mentors (42%) and the research ethics process (38%). More than 70% of residents were interested in conducting research during residency and 74% of programs have a research requirement integrated into their curriculum. Despite this, less than half of residents (47%) believed that their program fosters a culture that promotes research. This was attributed to multiple factors, including a lack of internal research funding (78%), limited access to a research methods or clinical trials unit (78%), and insufficient research training (68%). University research ranking had no correlation with residents' scholarly output or their perceptions towards research barriers.

CONCLUSION

Canadian Plastic Surgery residents identified several important factors considered to be barriers to research. Programs can use these findings to address barriers and improve the integration of research throughout residency training.

Current Concepts in Capsular Contracture: Pathophysiology, Prevention, and Management

Over 400,000 women in the United States alone will have breast implant surgery each year. Although capsular contracture represents the most common complication of breast implant surgery, surgeons continue to debate the precise etiology. General agreement exists concerning the inflammatory origin of capsular fibrosis, but the inciting events triggering the inflammatory cascade appear to be multifactorial, making it difficult to predict why one patient may develop capsular contracture while another will not. Accordingly, researchers have explored many different surgical, biomaterial, and medical therapies to address these multiple factors in an attempt to prevent and treat capsular contracture. In the current paper, we aim to inform the reader on the most up-to-date understanding of the pathophysiology, prevention, and treatment of capsular contracture.

Radiation-Induced Tissue Damage: Clinical Consequences and Current Treatment Options

Radiation therapy is a valuable tool in the treatment of numerous malignancies but, in certain cases, can also causes significant acute and chronic damage to noncancerous neighboring tissues. This review focuses on the pathophysiology of radiation-induced damage and the clinical implications it has for plastic surgeons across breast reconstruction, osteoradionecrosis, radiation-induced skin cancers, and wound healing. The current understanding of treatment modalities presented here include hyperbaric oxygen therapy, autologous fat grafting and stem cells, and pharmaceutical agents.

Tendon: Principles of Healing and Repair

Tendon stores, releases, and dissipates energy to efficiently transmit contractile forces from muscle to bone. Tendon injury is exceedingly common, with the spectrum ranging from chronic tendinopathy to acute tendon rupture. Tendon generally develops according to three main steps: collagen fibrillogenesis, linear growth, and lateral growth. In the setting of injury, it also repairs and regenerates in three overlapping steps (inflammation, proliferation, and remodeling) with tendon-specific durations. Acute injury to the flexor and extensor tendons of the hand are of particular clinical importance to plastic surgeons, with tendon-specific treatment guided by the general principle of minimum protective immobilization followed by hand therapy to overcome potential adhesions. Thorough knowledge of the underlying biomechanical principles of tendon healing is required to provide optimal care to patients presenting with tendon injury.

Comparison of Skin Substitutes for Acute and Chronic Wound Management

Chronic and acute wounds, such as diabetic foot ulcers and burns, respectively, can be difficult to treat, especially when autologous skin transplantations are unavailable. Skin substitutes can be used as a treatment alternative by providing the structural elements and growth factors necessary for reepithelialization and revascularization from a nonautologous source. As of 2020, there are 76 commercially available skin substitute products; this article provides a review of the relevant literature related to the major categories of skin substitutes available.

CD109 overexpression ameliorates skin fibrosis in a mouse model of bleomycin-induced scleroderma

OBJECTIVE

Transforming growth factor β (TGFβ) is a profibrotic cytokine, and its aberrant function is implicated in several types of fibrotic pathologies including scleroderma (systemic sclerosis [SSc]). Multiple lines of evidence show that increased TGFβ signaling contributes to progressive fibrosis in SSc by promoting fibroblast activation, excessive extracellular matrix (ECM) deposition, and dermal thickening. We have previously identified CD109 as a TGFβ coreceptor and have shown that it antagonizes TGFβ signaling and TGFβ-induced ECM expression in vitro in human keratinocytes and fibroblasts. The aim of the present study was to examine the ability of CD109 to prevent skin fibrosis in a mouse model of bleomycin-induced SSc.

METHODS

Transgenic mice overexpressing CD109 in the epidermis and their wild-type (WT) littermates were injected with bleomycin in phosphate buffered saline (PBS) or with PBS alone every other day for 21 days or 28 days. Dermal thickness and collagen deposition were determined histologically using Masson's trichrome and picrosirius red staining. In addition, collagen and fibronectin content was analyzed using Western blotting, and activation of TGFβ signaling was examined by determining phospho-Smad2 and phospho-Smad3 levels using Western blotting and immunohistochemistry.

RESULTS

Transgenic mice overexpressing CD109 in the epidermis showed resistance to bleomycin-induced skin fibrosis, as evidenced by a significant decrease in dermal thickness, collagen crosslinking, collagen and fibronectin content, and phospho-Smad2/3 levels, as compared to their WT littermates.

CONCLUSION

Our findings suggest that CD109 inhibits TGFβ signaling and fibrotic responses in experimental murine scleroderma. They also suggest that CD109 regulates dermal-epidermal interactions to decrease extracellular matrix synthesis in the dermis. Thus, CD109 is a potential molecular target for therapeutic intervention in scleroderma.

Correlation of Prediction and Actual Outcome of Three-Dimensional Simulation in Breast Augmentation Using a Cloud-Based Program

BACKGROUND

Breast augmentation is among the most frequently performed cosmetic plastic surgeries. Providing patients with "realistic" 3D simulations of breast augmentation outcomes is becoming increasingly common. Until recently, such programs were costly and required significant equipment, training, and office space. New simple user-friendly cloud-based programs have been developed, but to date there remains a paucity of objective evidence comparing these 3D simulations with the post-operative outcomes.

OBJECTIVES

To determine the aesthetic similarity between pre-operative 3D simulation generated by Crisalix and real post-operative outcomes.

METHODS

A retrospective review of 20 patients receiving bilateral breast augmentation was conducted comparing 6-month post-operative outcomes with 3D simulation using Crisalix software. Similarities between post-operative and simulated images were measured by three attending plastic surgeons and ten plastic surgery residents using a series of parameters.

RESULTS

Assessment reveals similarity between the 3D simulation and 6-month post-operative images for overall appearance, breast height, breast width, breast volume, breast projection, and nipple correction. Crisalix software generated more representative simulations for symmetric breasts than for tuberous or ptotic breasts. Comparison of overall aesthetic outcome to simulation showed that the post-operative outcome was more appealing for the symmetric and tuberous breasts and less appealing for the ptotic breasts.

CONCLUSIONS

Our data suggest that Crisalix offers a good overall 3D simulated image of post-operative breast augmentation outcomes. Improvements to the simulation of the post-operative outcomes for ptotic and tuberous breasts would result in greater predictive capabilities of Crisalix. Collectively, Crisalix offers good predictive simulations for symmetric breasts.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Overexpression of CD109 in the Epidermis Differentially Regulates ALK1 Versus ALK5 Signaling and Modulates Extracellular Matrix Synthesis in the Skin

Transforming growth factor-β (TGF-β) is a multifunctional growth factor involved in many physiological processes including wound healing and inflammation. Excessive TGF-β signaling in the skin has been implicated in fibrotic skin disorders such as keloids and scleroderma. We previously identified CD109 as a TGF-β co-receptor and inhibitor of TGF-β signaling and have shown that transgenic mice overexpressing CD109 in the epidermis display decreased scarring. In certain cell types, in addition to the canonical type I receptor, ALK5, which activates Smad2/3, TGF-β can signal through another type I receptor, ALK1, which activates Smad1/5. Here we demonstrate that ALK1 is expressed and co-localizes with CD109 in mouse keratinocytes and that mice overexpressing CD109 in the epidermis display enhanced ALK1-Smad1/5 signaling but decreased ALK5-Smad2/3 signaling, TGF-β expression, and extracellular matrix production in the skin when compared with wild-type littermates. Furthermore, treatment with conditioned media from isolated keratinocytes or epidermal explants from CD109 transgenic mouse skin leads to a decrease in extracellular matrix production in mouse skin fibroblasts. Taken together, our findings suggest that CD109 differentially regulates TGF-β-induced ALK1-Smad1/5 versus ALK5-Smad2/3 pathways, leading to decreased extracellular matrix production in the skin and that epidermal CD109 expression regulates dermal function through a paracrine mechanism.

Mastopexy for breast ptosis: Utility outcomes of population preferences

Background

Breast ptosis can occur with aging, and after weight loss and breastfeeding. Mastopexy is a procedure used to modify the size, contour and elevation of sagging breasts without changing breast volume. To gain more knowledge on the health burden of living with breast ptosis requiring mastectomy, validated measures can be used to compare it with other health states.

Objective

To quantify the health state utility assessment of individuals living with breast ptosis who could benefit from a mastopexy procedure; and to determine whether utility scores vary according to participant demographics.

Methods

Utility assessments using a visual analogue scale (VAS), time trade-off (TTO) and standard gamble (SG) methods were used to obtain utility scores for breast ptosis, monocular blindness and binocular blindness from a sample of the general population and medical students. Linear regression and the Student's t test were used for statistical analysis; P<0.05 was considered to be statistically significant.

Results

Mean (± SD) measures for breast ptosis in the 107 volunteers (VAS: 0.80±0.14; TTO: 0.87±0.18; SG: 0.90±0.14) were significantly different (P<0.0001) from the corresponding measures for monocular blindness and binocular blindness. When compared with a sample of the general population, having a medical education demonstrated a statistically significant difference in being less likely to trade years of life and less likely to gamble risk of a procedure such as a mastopexy. Race and sex were not statistically significant independent predictors of risk acceptance.

Discussion

For the first time, the burden of living with breast ptosis requiring surgical intervention was determined using validated metrics (ie, VAS, TTO and SG). The health burden of living with breast ptosis was found to be comparable with that of breast hypertrophy, unilateral mastectomy, bilateral mastectomy, and cleft lip and palate. Furthermore, breast ptosis was considered to be closer to ‘perfect health’ than monocular blindness, binocular blindness, facial disfigurement requiring face transplantation surgery, unilateral facial paralysis and severe lower extremity lymphedema.

Conclusions

Quantifying the health burden of living with breast ptosis requiring mastopexy indicated that is comparable with other breast-related conditions (breast hypertrophy and bilateral mastectomy). Numerical values have been assigned to this health state (VAS: 0.80±0.14; TTO: 0.87±0.18; and SG: 0.90±0.14), which can be used to form comparisons with the health burden of living with other disease states.

Clinical Implications and Management of Non-BIA-ALCL Breast Implant Capsular Pathology

SUMMARY

The breast implant capsule is a dynamic structure that forms following the implantation of a device. Although normally benign, increased awareness of breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) highlights that disease may arise from the capsule. BIA-ALCL presents as a late seroma or mass but explains few of the late seromas found in breast implant patients. To date, many of these seromas lack a clear cause and are often described as "idiopathic." Several benign and malignant breast implant capsular diseases can cause a late seroma or mass, including breast implant-associated squamous cell carcinoma. Similar to early reports of BIA-ALCL, these conditions are rare and largely limited to case reports or series. The purpose of this special topic is to present a narrative review highlighting capsular abnormalities that contribute to the formation of late seroma or mass in an attempt to broaden the differential diagnosis and help plastic surgeons identify the cause. Specifically, we review the presentation and management of BIA-ALCL, synovial metaplasia, capsular epithelialization, late hematoma, double capsule, breast cancer, squamous cell carcinoma, mesenchymal tumor, and B-cell lymphoma. Although rare, plastic surgeons should consider these capsular conditions as causes of late seromas and masses. Usually, these conditions may be diagnosed by following the National Comprehensive Cancer Network screening guidelines for BIA-ALCL. Thorough evaluation and workup of late seromas and masses may lead to improved characterization of these rare breast implant capsular conditions and improve our understanding of their pathophysiology and management.

The Impact of the COVID-19 Pandemic on Breast Reconstruction: A Canadian Perspective

BACKGROUND

The COVID-19 pandemic has led to unprecedented challenges and restrictions in surgical access across Canada, including for breast reconstructive services which are an integral component of comprehensive breast cancer care. We sought to determine how breast reconstructive services are being restricted, and what strategies may be employed to optimize the provision of breast reconstruction through a pan-Canadian evaluation from the providers' perspective.

METHODS

This was a cross-sectional survey of Canadian plastic and reconstructive surgeons who perform breast reconstruction. The 33-item web-based questionnaire was developed by a pan-Canadian working group of breast reconstruction experts and disseminated via email to members of the Canadian Society of Plastic Surgery. The questionnaire queried respondents on the impact of the COVID-19 pandemic and associated restrictions on surgeons' breast reconstruction practice patterns and opinions on strategies for resource utilization.

RESULTS

Responses were received from 49 surgeons, who reported practicing in 8 of 10 Canadian provinces. Restrictions on the provision of breast reconstructive procedures were most limited during the First Wave of the COVID-19 pandemic, where all respondents reported at least some reduction in capacity and more than a quarter reporting complete cessation. Average reported reduction in capacity ranged from 31% to 78% across all 3 waves. Autologous, delayed, and prophylactic reconstructions were most commonly restricted.

CONCLUSION

This study provides a pan-Canadian impact assessment on breast reconstructive services during the COVID-19 pandemic from the providers' perspective. To uphold the standards of patient-centred care, a unified approach to strategically reorganize health care delivery now and in the future is needed.

Canadian Plastic Surgery Resident Work Hour Restrictions: Practices and Perceptions of Residents and Program Directors

Background

The impact of resident work hour restrictions on training and patient care remains a highly controversial topic, and to date, there lacks a formal assessment as it pertains to Canadian plastic surgery residents.

Objective

To characterize the work hour profile of Canadian plastic surgery residents and assess the perspectives of residents and program directors regarding work hour restrictions related to surgical competency, resident wellness, and patient safety.

Methods

An anonymous online survey developed by the authors was sent to all Canadian plastic surgery residents and program directors. Basic summary statistics were calculated.

Results

Eighty (53%) residents and 10 (77%) program directors responded. Residents reported working an average of 73 hours in hospital per week with 8 call shifts per month and sleep 4.7 hours/night while on call. Most residents (88%) reported averaging 0 post-call days off per month and 61% will work post-call without any sleep. The majority want the option of working post-call (63%) and oppose an 80-hour weekly maximum (77%). Surgical and medical errors attributed to post-call fatigue were self-reported by 26% and 49% of residents, respectively. Residents and program directors expressed concern about the ability to master surgical skills without working post-call.

Conclusions

The majority of respondents oppose duty hour restrictions. The reason is likely multifactorial, including the desire of residents to meet perceived expectations and to master their surgical skills while supervised. If duty hour restrictions are aggressively implemented, many respondents feel that an increased duration of training may be necessary.

Textured versus Smooth Tissue Expanders: A Comparison of Complications in 3526 Breast Reconstructions

BACKGROUND

Increased understanding of breast implant-associated anaplastic large-cell lymphoma has led to a shift away from textured breast devices. A few small studies have compared the complication rates of textured and smooth tissue expanders (TEs). The aim of this study was to compare complication profiles in patients undergoing two-stage postmastectomy breast reconstruction with either textured or smooth TEs.

METHODS

The authors performed a retrospective review of female patients who underwent immediate breast reconstruction with textured or smooth TEs from 2018 to 2020 at their institution. Rates of seroma, infection/cellulitis, malposition/rotation, exposure, and TE loss were analyzed in the overall cohort and subgroups undergoing prepectoral and subpectoral TE placement. A propensity score-matched analysis was used to decrease the effects of confounders comparing textured and smooth TEs.

RESULTS

The authors analyzed 3526 TEs (1456 textured and 2070 smooth). More frequent use of acellular dermal matrix, SPY angiography, and prepectoral TE placement was noted in the smooth TE cohort ( P < 0.001). Univariate analysis suggested higher rates of infection/cellulitis, malposition/rotation, and exposure in smooth TEs (all P < 0.01). Rates of TE loss did not differ. After propensity matching, no differences were noted in infection or TE loss. Prepectoral smooth expanders had increased rates of malposition/rotation.

CONCLUSIONS

TE surface type did not affect rates of TE loss, although increased rates of expander malposition were noted in the smooth prepectoral cohort. Further research is needed to examine breast implant-associated anaplastic large-cell lymphoma risk with temporary textured TE exposure to improve decision-making.

CLINICAL QUESTION/LEVEL OF EVIDENCW

Therapeutic, III.