Identification of the Human Skeletal Stem Cell.

Stem cell regulation and hierarchical organization of human skeletal progenitors remain largely unexplored. Here, we report the isolation of a self-renewing and multipotent human skeletal stem cell (hSSC) that generates progenitors of bone, cartilage, and stroma, but not fat. Self-renewing and multipotent hSSCs are present in fetal and adult bones and can also be derived from BMP2-treated human adipose stroma (B-HAS) and induced pluripotent stem cells (iPSCs). Gene expression analysis of individual hSSCs reveals overall similarity between hSSCs obtained from different sources and partially explains skewed differentiation toward cartilage in fetal and iPSC-derived hSSCs. hSSCs undergo local expansion in response to acute skeletal injury. In addition, hSSC-derived stroma can maintain human hematopoietic stem cells (hHSCs) in serum-free culture conditions. Finally, we combine gene expression and epigenetic data of mouse skeletal stem cells (mSSCs) and hSSCs to identify evolutionarily conserved and divergent pathways driving SSC-mediated skeletogenesis. VIDEO ABSTRACT.

A Combination of Distinct Vascular Stem/Progenitor Cells for Neovascularization and Ischemic Rescue.

BACKGROUND: Peripheral vascular disease remains a leading cause of vascular morbidity and mortality worldwide despite advances in medical and surgical therapy. Besides traditional approaches, which can only restore blood flow to native arteries, an alternative approach is to enhance the growth of new vessels, thereby facilitating the physiological response to ischemia. METHODS: The ActinCreER/R26VT2/GK3 Rainbow reporter mouse was used for unbiased in vivo survey of injury-responsive vasculogenic clonal formation. Prospective isolation and transplantation were used to determine vessel-forming capacity of different populations. Single-cell RNA-sequencing was used to characterize distinct vessel-forming populations and their interactions. RESULTS: Two populations of distinct vascular stem/progenitor cells (VSPCs) were identified from adipose-derived mesenchymal stromal cells: VSPC1 is CD45-Ter119-Tie2+PDGFRa-CD31+CD105highSca1low, which gives rise to stunted vessels (incomplete tubular structures) in a transplant setting, and VSPC2 which is CD45-Ter119-Tie2+PDGFRa+CD31-CD105lowSca1high and forms stunted vessels and fat. Interestingly, cotransplantation of VSPC1 and VSPC2 is required to form functional vessels that improve perfusion in the mouse hindlimb ischemia model. Similarly, VSPC1 and VSPC2 populations isolated from human adipose tissue could rescue the ischemic condition in mice. CONCLUSIONS: These findings suggest that autologous cotransplantation of synergistic VSPCs from nonessential adipose tissue can promote neovascularization and represents a promising treatment for ischemic disease.

Article Factors Influencing Gender Disparities in Senior Authorship of Plastic Surgery Publications.

INTRODUCTION: Female plastic surgeons publish fewer and lower impact articles. To better understand how to address this gender gap, we explored the temporal trends in female senior authorship and evaluated predictive factors for female senior authorship. METHODS: A retrospective review of articles published in the 3 highest impact plastic surgery journals published from 2010 to 2020 was conducted. Trends with female senior authorship across time were analyzed with respect to study type, subspeciality, and geographical origin. RESULTS: Of the 5425 articles included, 13% (n = 720) had a female senior author, and female senior authorship increased across time ( R = 0.84, P = 0.033). Over the decade, an increased proportion of cohort studies ( R = 0.82, P = 0.045), systematic reviews ( R = 0.96, P = 0.003), breast-related articles ( R = 0.88, P = 0.022), and reconstruction-related articles ( R = 0.83, P = 0.039) were published by female senior authors. Subspecialty and geography predicted female senior authorship; articles focused on aesthetic (odds ratio [OR] = 1.3, P = 0.046) and breast (OR = 1.7, P < 0.001) subspecialties or those originating from Canada (OR = 1.7 P = 0.019), Europe (OR = 1.5, P < 0.001), and Latin America (OR = 3.0, P < 0.001) were more likely to have a female senior author. Articles from East Asia were less likely to have female senior authors (OR = 0.7, P = 0.005). CONCLUSION: Female senior authorship in plastic surgery has increased over the last decade, and the proportion of female plastic surgeons leading cohort studies and systematic reviews is increasing. Sex of the senior author is influenced by plastic surgery subspecialty and geographical origin, but article type did not impact the odds of female senior authorship.

A Systematic Review and Meta-Analysis Comparing the Clinical Outcomes of Profunda Artery Perforator Versus Gracilis Thigh Flap as a Second Choice for Autologous Breast Reconstruction.

PURPOSE: Autologous breast reconstruction remains a versatile option to produce a natural appearing breast after mastectomy. The deep inferior epigastric perforator remains the most commonly used flap choice, but when this donor site is unsuitable or unavailable, the transverse upper gracilis (TUG) or profunda artery perforator (PAP) flaps are popular secondary alternatives. We conduct a meta-analysis to better understand patient outcomes and adverse events in secondary flap selection in breast reconstruction. METHODS: A systematic search was conducted on MEDLINE and Embase for all articles published on TUG and/or PAP flaps for oncological breast reconstruction in postmastectomy patients. A proportional meta-analysis was conducted to statistically compare outcomes between PAP and TUG flaps. RESULTS: The TUG and PAP flaps were noted to have similar reported rates of success and incidences of hematoma, flap loss, and flap healing (P > 0.05). The TUG flap was noted to have significantly more vascular complications (venous thrombosis, venous congestion, and arterial thrombosis) than the PAP flap (5.0% vs 0.6%, P < 0.01) and significantly greater rates of unplanned reoperations in the acute postoperative period (4.4% vs 1.8%, P = 0.04). Infection, seroma, fat necrosis, donor healing complications, and rates of additional procedures all exhibited high degree of heterogeneity precluding mathematical synthesis of outcomes across studies. CONCLUSIONS: Compared with TUG flaps, PAP flaps have fewer vascular complications and fewer unplanned reoperations in the acute postoperative period. There is need for greater homogeneity in reported outcomes between studies to enable for synthesis of other variables important in determining flap success.

Taming the Tongue: The Surgical Approach to Macroglossia.

While traditionally in the realm of otorhinolaryngology or oral maxillofacial surgery, conditions involving the tongue may also be managed by plastic surgeons. The authors present an unusual case of acquired macroglossia resulting from angiotensin-converting enzyme inhibitor-induced angioedema and review the literature to discuss its surgical management from a plastic surgery perspective. A 62-year-old female suffered severe airway obstruction, respiratory arrest, and anoxic brain injury from angioedema-associated macroglossia. After tracheostomy, the patient was managed nonsurgically, with bite wound care and medications to minimize angioedema to marginal effect. Ultimately, a partial glossectomy was planned. The edematous distal tongue was amputated and closed primarily. On postoperative day 2, she was successfully weaned off mechanical ventilation and no longer suffers trauma from tongue biting. The simple anterior tongue resection described in this paper was an appropriate approach for our patient. More research is needed to guide plastic surgeons in an optimal approach for clinical scenarios.

Wounds Inhibit Tumor Growth In Vivo.

OBJECTIVE: The aim of this study was to determine the interaction of full thickness excisional wounds and tumors in vivo. SUMMARY OF BACKGROUND DATA: Tumors have been described as wounds that do not heal due to similarities in stromal composition. On the basis of observations of slowed tumor growth after ulceration, we hypothesized that full thickness excisional wounds would inhibit tumor progression in vivo. METHODS: To determine the interaction of tumors and wounds, we developed a tumor xenograft/allograft (human head and neck squamous cell carcinoma SAS/mouse breast carcinoma 4T1) wound mouse model. We examined tumor growth with varying temporospatial placement of tumors and wounds or ischemic flap. In addition, we developed a tumor/wound parabiosis model to understand the ability of tumors and wounds to recruit circulating progenitor cells. RESULTS: Tumor growth inhibition by full thickness excisional wounds was dose-dependent, maintained by sequential wounding, and relative to distance. This effect was recapitulated by placement of an ischemic flap directly adjacent to a xenograft tumor. Using a parabiosis model, we demonstrated that a healing wound was able to recruit significantly more circulating progenitor cells than a growing tumor. Tumor inhibition by wound was unaffected by presence of an immune response in an immunocompetent model using a mammary carcinoma. Utilizing functional proteomics, we identified 100 proteins differentially expressed in tumors and wounds. CONCLUSION: Full thickness excisional wounds have the ability to inhibit tumor growth in vivo. Further research may provide an exact mechanism for this remarkable finding and new advances in wound healing and tumor biology.

Fat grafting rescues radiation-induced joint contracture.

The aim of this study was to explore the therapeutic effects of fat grafting on radiation-induced hind limb contracture. Radiation therapy (RT) is used to palliate and/or cure a range of malignancies but causes inevitable and progressive fibrosis of surrounding soft tissue. Pathological fibrosis may lead to painful contractures which limit movement and negatively impact quality of life. Fat grafting is able to reduce and/or reverse radiation-induced soft tissue fibrosis. We explored whether fat grafting could improve extensibility in irradiated and contracted hind limbs of mice. Right hind limbs of female 60-day-old CD-1 nude mice were irradiated. Chronic skin fibrosis and limb contracture developed. After 4 weeks, irradiated hind limbs were then injected with (a) fat enriched with stromal vascular cells (SVCs), (b) fat only, (c) saline, or (d) nothing (n = 10/group). Limb extension was measured at baseline and every 2 weeks for 12 weeks. Hind limb skin then underwent histological analysis and biomechanical strength testing. Irradiation significantly reduced limb extension but was progressively rescued by fat grafting. Fat grafting also reduced skin stiffness and reversed the radiation-induced histological changes in the skin. The greatest benefits were found in mice injected with fat enriched with SVCs. Hind limb radiation induces contracture in our mouse model which can be improved with fat grafting. Enriching fat with SVCs enhances these beneficial effects. These results underscore an attractive approach to address challenging soft tissue fibrosis in patients following RT.

Risk factors for cooking-related burn injuries in children, WHO Global Burn Registry.

OBJECTIVE: To assess the characteristics of cooking-related burn injuries in children reported to the World Health Organization Global Burn Registry. METHODS: On 1 February 2021, we downloaded data from the Global Burn Registry on demographic and clinical characteristics of patients younger than 19 years. We performed multivariate regressions to identify risk factors predictive of mortality and total body surface area affected by burns. FINDINGS: Of the 2957 paediatric patients with burn injuries, 974 involved cooking (32.9%). More burns occurred in boys (532 patients; 54.6%) than in girls, and in children 2 years and younger (489 patients; 50.2%). Accidental contact and liquefied petroleum caused most burn injuries (729 patients; 74.8% and 293 patients; 30.1%, respectively). Burn contact by explosions (odds ratio, OR: 2.8; 95% confidence interval, CI: 1.4-5.7) or fires in the cooking area (OR: 3.0; 95% CI: 1.3-6.8), as well as the cooking fuels wood (OR: 2.2; 95 CI%: 1.3-3.4), kerosene (OR: 1.9; 95% CI: 1.0-3.6) or natural gas (OR: 1.5; 95% CI: 1.0-2.2) were associated with larger body surface area affected. Mortality was associated with explosions (OR: 7.5; 95% CI: 2.2-25.9) and fires in the cooking area (OR: 6.9; 95% CI: 1.9-25.7), charcoal (OR: 4.6; 95% CI: 2.0-10.5), kerosene (OR: 3.9; 95% CI: 1.4-10.8), natural gas (OR: 3.0; 95% CI: 1.5-6.1) or wood (OR: 2.8; 95% CI: 1.1-7.1). CONCLUSION: Preventive interventions directed against explosions, fires in cooking areas and hazardous cooking fuels should be implemented to reduce morbidity and mortality from cooking-related burn injuries.

Gender-Affirming Health Insurance Reform in the United States.

INTRODUCTION: In May 2014, the US Department of Health and Human Services prohibited insurance discrimination of transgender individuals. Despite this, insurance plans often lack explicit guidelines on gender transition-related care and coverage of surgical procedures is extremely varied. We evaluated the evolution of insurance coverage of gender-affirming care following the 2014 legislative change. METHODS: Insurance providers were selected based on company market share. We conducted a Web-based search and telephone interviews to identify the corresponding policies related to gender-affirming health care. We compared policy changes made before and after the 2014 US Department of Health and Human Services decision. RESULTS: Of the 92 insurers surveyed, 7% did not have a policy, and 315 policy revisions were documented. After the legislation, a significantly higher proportion of policy revisions were related to coverage of services (36% vs 11%, P < 0.0001), removal of existing criteria significantly decreased (23% vs 49%, P = 0.0044), and addition of criteria unrelated to international standards sharply increased (32% vs 2%, P = 0.0002). This resulted in reduced coverage of facial feminization, hair transplantation, laryngochondroplasty, and voice modification surgery. However, nipple reconstruction experienced increased coverage. The percentage of revisions to add preauthorization criteria to meet international standards (49% vs 45%, P = 0.6714) or to change terminology (37% vs 27%, P = 0.1055) were similar before and after the legislation. CONCLUSIONS: After the transformative legislation in 2014, an increasing number of insurance companies established gender transition-related policies. As more patients seek gender-affirming care, insurers deviate from international guidelines and create additional benchmarks that may act as barriers to care.

Comparing Outcomes of Flap-Based Salvage Reconstructions in the Radiated Breast.

INTRODUCTION: Chest wall irradiation significantly decreases the strength and quality of breast tissue supporting prostheses, increasing the risk of skin breakdown and implant or tissue expander extrusion. Autologous tissue, including the latissimus dorsi (LD) or abdominal-based flaps, including the muscle-sparing transverse rectus abdominis myocutaneous or deep inferior epigastric perforator flaps, may be used to salvage reconstructions. However, data comparing outcomes of the two flap options remains limited. We compare postoperative outcomes from both flap types after autologous salvage reconstruction in irradiated breasts. METHODS: Charts were retrospectively reviewed from patients who underwent either chest wall radiation or postmastectomy radiation therapy followed by salvage autologous reconstruction with either a LD and an implant or an abdominal-based flap (muscle-sparing transverse rectus abdominis myocutaneous or deep inferior epigastric perforator flaps). Patients with a history of tissue expander or implant failure requiring autologous salvage as part of 2-staged or delayed-immediate breast reconstruction that were operated on between January 2005 and November 2015 were included. Basic demographics, comorbidities, and recipient site complications (infection, wound dehiscence, seroma, hematoma, fat necrosis, and flap failure) were collected. RESULTS: A total of 72 patients met the inclusion criteria which included 72 flaps; 35 LD and 37 abdominally based flaps. Demographics and comorbidities did not vary significantly between patient groups. Mean follow-up was 767.6 weeks, and all reconstructions were unilateral. Nineteen (26.4%) patients had at least one complication, most commonly minor infections (9.7%). Overall complication rates were not significantly different between flap groups (P = 0.083). Wound dehiscence was significantly higher in the abdominal group (P = 0.045), and fat necrosis also trended higher in this group (P = 0.085). Major infection trended higher in the latissimus group (P = 0.069). CONCLUSIONS: When comparing outcomes of salvage flap-based reconstruction in radiated breast tissue, overall complication rates were similar when comparing postoperative outcomes between the LD- and abdominal-based flaps. Wound dehiscence was significantly higher when salvage reconstruction used an abdominal flap. Understanding the complications after salvage procedures can help inform decision making and optimize patient care to improve outcomes after breast reconstruction in the radiated breast.

Global Burn Registry Perspective on Head and Neck Burns.

INTRODUCTION: As exposed regions of the body, the head and neck are at increased risk of burn injury. The cosmetic and functional importance of these anatomical regions means that burns can result in substantial morbidity and mortality. Our objective was to characterize predictive factors for surgery and discharge condition in patients with head and neck burns internationally. METHODS: We conducted an epidemiological study of all head and neck burns in 14 countries reported in the World Health Organization Global Burn Registry. Multivariate regression was used to identify variables predictive of surgical treatment and discharge condition. RESULTS: We identified 1014 patients who sustained head and neck burns; the majority were adults (60%). Both adults and children admitted to hospital with head and neck burn injuries were less likely to be treated surgically in lower-middle-income countries (LMIC) than in higher-income countries (P < 0.001). Increasing age and greater total surface body area (TBSA) were significant predictors of surgical intervention in children with head and neck burn injuries (P < 0.001). Total surface body area, associated injuries, ocular burns, female sex, and LMIC residency were all significant predictors of mortality in adult patients with head and neck burns (P < 0.050). Conversely, TBSA was the only variable that independently increased the risk of death in children with head and neck burns (P < 0.001). CONCLUSIONS: Certain groups are at increased risk of an adverse outcome after admission with a head and neck burn injury. Given the reduced incidence of surgical intervention and the elevated mortality risk in LMICs, global health initiatives should be targeted to these countries.

Examining the Effects of Postmastectomy Radiation Therapy in Prepectoral Versus Subpectoral Autologous Breast Reconstruction.

BACKGROUND: Postmastectomy radiation therapy (PMRT) is known to increase the risk of multiple adverse outcomes after breast reconstruction. In the context of delayed-immediate autologous breast reconstruction, PMRT is typically conducted after placement of subpectoral (SP) tissue expanders. With the re-emergence of prepectoral (PP) reconstruction, there are little data assessing the outcomes of PP reconstruction in breasts receiving PMRT. We compared postoperative outcomes of PMRT patients undergoing delayed-immediate, autologous breast reconstruction with placement of tissue expanders in either the PP or SP plane. METHODS: A retrospective chart review was conducted on all consecutive patients who underwent delayed-immediate autologous breast reconstruction and received PMRT at either the Stanford University or the Johns Hopkins University Hospitals between January 2009 and December 2018. Demographics, comorbidities, perioperative information, and oncologic data were collected for all patients. Complications were collected and analyzed after stage 1 surgery, between 30 days of stage 1 and up to stage 2 surgery, and after stage 2 surgery. Multivariable regressions were used to determine predictors of 1 or more complications. RESULTS: A total of 71 patients (73 breasts) were included. Prepectoral reconstruction comprised of 52.2% of the cohort, and the remaining 47.8% were SP reconstructions. Demographics and comorbidities were similar between groups, except for premastectomy radiation, which was more prevalent in the PP cohort (P = 0.010). Complications were similar between cohorts after stage 1 surgery (P = 0.420), between stages 1 and 2 (P = 0.100), and after stage 2 (P = 0.570). There were higher rates of skin necrosis in the SP cohort between stages 1 and 2 (PP: 2.6%, SP: 20%, P = 0.004). Multivariable analysis revealed body mass index to be the only predictor of complication (P = 0.041). The mean number of revisionary surgeries was higher in the SP cohort (PP: 0.8 vs SP: 1.9, P = 0.002). The mean follow-up was 385.5 days and similar between groups (P = 0.870). CONCLUSIONS: Rates of overall complication were similar between PP and SP expander placement. However, in SP reconstructions, skin necrosis was significantly higher between stages 1 and 2. The patients in the SP cohort also underwent a greater number of revisionary surgeries, although overall rates of pursuing any revisionary surgery were similar between groups.

Stevens-Johnson syndrome and toxic epidermal necrolysis: a 10-year experience in a burns unit.

OBJECTIVE: Stevens-Johnson syndrome (SJS) and its more severe counterpart, toxic epidermal necrolysis (TEN), are skin hypersensitivity reactions defined by epidermal blistering and necrosis. The exact pathophysiology of SJS/TEN is yet to be deciphered, but a number of risk factors have been identified including adverse drug reactions. The diagnosis of SJS/TEN is made on a clinical basis, and treatment consists of supportive care and occasionally immunosuppressants, such as cyclosporin, high-dose intravenous immunoglobulins and/or corticosteroids. Mortality rates can reach 20-25% in adults but are reduced with early intervention. To identify optimal treatment regimens, to better understand the patient cohort affected, and to help identify key risk factors for mortality, we report our experience with the treatment and management of SJS/TEN patients. METHODS: A retrospective review of consecutive patients with SJS and/or TEN admitted to a single burns centre in Germany, between 2008 and 2018, was conducted. The primary outcomes of demographics, clinical course, treatment and patient-reported outcomes were recorded and compared with a control group of patients with burns without a diagnosis of SJS/TEN. RESULTS: A total of 23 patients with SJS/TEN met the inclusion criteria: 17 (74%) with TEN; four (17%) with SJS/TEN overlap; and two (9%) with SJS. Of the patients, 14 (61%) were female and nine (39%) were male. Patient age ranged from 32-78 years (mean: 52 years). A matched cohort of 23 patients with burns served as the control group. All patients received standard of care with a multidisciplinary team. Compared with the control group, SJS/TEN patients had higher mortality rates (n=6, 26% versus n=8, 35%, respectively). The average age of death was 69 years in SJS/TEN patients versus 63 years in control group patients. Age and SCORTEN scores were significant predictors of mortality. CONCLUSIONS: SJS and TEN are rare but extreme reactions of the skin and mucosa, associated with high disease mortality rates. This 10-year single-centre retrospective review contributes to the bank of information for reviews evaluating the management of SJS/TEN patients.

Stevens-Johnson syndrome and toxic epidermal necrolysis: a systematic review and meta-analysis.

OBJECTIVE: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and severe skin and mucosal reactions that are associated with high mortality. Despite the severity, an evidence-based treatment protocol for SJS/TEN is still lacking. METHOD: In this systematic review and meta-analysis, the PubMed database was searched using the following terms: [Stevens-Johnson syndrome] OR [toxic epidermal necrolysis] AND [therapy] OR [treatment] over a 20-year period (1999-2019) in the German and English language. All clinical studies reporting on the treatment of SJS/TEN were included, and epidemiological and diagnostic aspects of treatment were analysed. A meta-analysis was conducted on all comparative clinical studies that met the inclusion criteria. RESULTS: A total of 88 studies met the inclusion criteria, reporting outcomes in 2647 patients. Treatment was either supportive or used systemic corticosteroid, intravenous immunoglobulin, plasmapheresis, cyclosporine, thalidomide or cyclophosphamide therapy. The meta-analysis included 16 (18%) studies, reporting outcomes in 976 (37%) patients. Systemic glucocorticoids showed a survival benefit for SJS/TEN patients in all analyses compared with other forms of treatment. Cyclosporine treatment also showed promising results, despite being used in a small cohort of patients. No beneficial effects on mortality could be demonstrated for intravenous immunoglobulins. CONCLUSION: Glucocorticoids and cyclosporine may be tentatively recommended as the most promising immunomodulatory therapies for SJS/TEN, but these results should be investigated in future prospective controlled trials.

Molecular Mechanisms of Hair Growth and Regeneration: Current Understanding and Novel Paradigms.

Hair is a defining feature of mammals and has critical functions, including protection, production of sebum, apocrine sweat and pheromones, social and sexual interactions, thermoregulation, and provision of stem cells for skin homeostasis, regeneration, and repair. The hair follicle (HF) is considered a "mini-organ," consisting of intricate and well-organized structures which originate from HF stem and progenitor cells. Dermal papilla cells are the main components of the mesenchymal compartments in the hair bulb and are instrumental in generating signals to regulate the behavior of neighboring epithelial cells during the hair cycle. Mesenchymal-epithelial interactions within the dermal papilla niche drive HF embryonic development as well as the postnatal hair growth and regeneration cycle. This review summarizes the current understanding of HF development, repair, and regeneration, with special focus on cell signaling pathways governing these processes. In particular, we discuss emerging paradigms of molecular signaling governing the dermal papilla-epithelial cellular interactions during hair growth and maintenance and the recent progress made towards tissue engineering of human hair follicles.

Compounding Benefits of Sentinel Lymph Node Biopsy for Perineal Melanoma: A Population-Based Retrospective Cohort Analysis.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) in the treatment of melanoma is known to provide valuable prognostic information. However, there is no literature describing an overall or disease-specific survival (DDS) benefit of SLNB. In the perineum, melanoma is often more advanced at presentation with current treatment guidelines translated from nonanatomic specific melanoma. As a result, there is little understanding surrounding the role of SLNB in melanoma of the perineum. Our objective is to better understand the therapeutic benefits of SLNB in perineal melanoma. METHODS: The Surveillance, Epidemiology, and End Results program is a large population-based cancer registry including survival data from millions of patients in the United States. The registry was used to generate patient data for analysis from 2004 to 2016. Inclusion criteria included melanoma of the perineum; Breslow depth of 0.80 mm or greater and less than 0.80 mm with ulceration; SLNB or no intervention; clinically negative nodal disease; and available overall survival data. RESULTS: For 879 patients from 2004 to 2016 with perineal melanoma, significant predictors of reduced survival include older than 75 years, Clark level IV-V, Breslow depth of greater than 4.00 mm, positive ulceration status, regional and distant nodal micrometastases, and clinically positive nodes on presentation. Aggregates for overall survival (OS) and disease-specific survival (DSS) were improved with implementation of SLNB. The 5-year survival rates with SLNB versus no SLNB were 54.0% and 43.0% for OS (P = 0.001) and 57.8% and 53.1% for DSS (P = 0.044). Stratification by Breslow depth yielded significant OS and DSS advantage for greater than 1.00 to 2.00 mm (21.3% benefit, P =0.021, and 16.8% benefit, P = 0.044) and greater than 4.00 mm (30.3% benefit, P = 0.005, and 21.0% benefit, P = 0.007) Breslow depths. CONCLUSIONS AND RELEVANCE: Sentinel lymph node biopsy may provide therapeutic benefits in addition to prognostic information for melanoma of the perineum through an increase in 5-year OS.

Comparing Prepectoral Versus Subpectoral Tissue Expander Placement Outcomes in Delayed-Immediate Autologous Breast Reconstruction.

BACKGROUND: Delayed-immediate breast reconstruction has traditionally involved placement of tissue expanders (TE) in the subpectoral (SP) position. Development of acellular dermal matrices has renewed interest in the prepectoral (PP) pocket, which avoids extensive muscle manipulation. We compare complication rates between PP and SP TE placement in autologous delayed-immediate breast reconstruction. METHODS: A retrospective chart review of patients undergoing autologous, delayed-immediate breast reconstruction at our institution (June 2009 to December 2018) was performed. Demographics, comorbidities, perioperative information, and complication incidence ≤12 months' follow-up were collected from first- and second-stage surgeries. Complications were modeled using univariable and multivariable binary logistic regressions. RESULTS: A total of 89 patients met the inclusion criteria, and data from 125 breast reconstructions were evaluated. Complication rates following TE placement trended lower in the PP cohort (28.8% vs 37%, P = 0.34). Overall complication rates following autologous reconstruction were significantly lower for PP reconstructions (7.7% vs 23.3%, P = 0.02). Multivariable regression showed TE position (P = 0.01) was a significant predictor of ≥1 complication following autologous reconstruction. Time delay between first- and second-stage surgeries was greater for SP reconstructions (199.7 vs 324.8 days, P < 0.001). Postoperative drains were removed earlier in the PP cohort (8.6 vs 12.0 days, P < 0.001). Mean follow-up time was 331.3 days. CONCLUSIONS: Prepectoral reconstruction in the delayed-immediate autologous reconstruction patient leads to significantly lower complication rates, shorter duration between first- and second-stage surgeries, and shorter times before removal of breast drains compared with SP reconstructions.

The versatile free medial sural artery perforator flap: An institutional experience for reconstruction of the head and neck, upper and lower extremities.

BACKGROUND: The medial sural artery perforator (MSAP) flap is an increasingly versatile and reliable flap for soft tissue reconstruction. This study investigates complication rates and long-term outcomes of the MSAP flap. METHODS: A retrospective review was performed on consecutive patients undergoing MSAP flap reconstruction at Chang Gung Memorial Hospital from 2006 through 2017. Patient demographics were assessed. Flap failure and wound complications were the outcome measures. RESULTS: In the cohort of 246 patients that underwent a total of 248 MSAP flap reconstructions were identified. The average age was 47.5 years (range 15-76). Of the 248 flaps, 170 were used for reconstruction of the head and neck, 48 for upper extremity reconstruction, and 30 for lower extremity reconstruction. The average MSAP flap size was 5.2 × 11.8 cm. 31 (12.5%) of the flaps developed arterial occlusion, venous insufficiency, or a hematoma postoperatively requiring re-exploration. Nineteen were successfully salvaged, yielding an overall failure rate of 4.8%. Minor complications included the need for flap debridement in 18 cases (7.3%) and need for donor site debridement in eight cases (3.2%). CONCLUSIONS: The MSAP flap can be used in a versatile fashion to reconstruct defects of the head and neck, upper extremity, and lower extremity with minimal complication rates.

Burns: modified metabolism and the nuances of nutrition therapy.

OBJECTIVE: To review the effects of burn injury on nutritional requirements and how this can best be supported in a healthcare setting. METHOD: A literature search for articles discussing nutrition and/or metabolism following burn injury was carried out. PubMed, Embase and Web of Science databases were searched using the key search terms 'nutrition' OR 'metabolism' AND 'burn injury' OR 'burns'. There was no limitation on the year of publication. RESULTS: A total of nine articles met the inclusion criteria, the contents of which are discussed in this manuscript. CONCLUSION: Thermal injury elicits the greatest metabolic response, among all traumatic events, in critically ill patients. In order to ensure burn patients can meet the demands of their increased metabolic rate and energy expenditure, adequate nutritional support is essential. Burn injury results in a unique pathophysiology, involving alterations in endocrine, inflammatory, metabolic and immune pathways and nutritional support needed during the inpatient stay varies depending on burn severity and idiosyncratic patient physiologic parameters.

Tissue Engineering and Regenerative Medicine in Craniofacial Reconstruction and Facial Aesthetics.

The craniofacial region is anatomically complex and is of critical functional and cosmetic importance, making reconstruction challenging. The limitations of current surgical options highlight the importance of developing new strategies to restore the form, function, and esthetics of missing or damaged soft tissue and skeletal tissue in the face and cranium. Regenerative medicine (RM) is an expanding field which combines the principles of tissue engineering (TE) and self-healing in the regeneration of cells, tissues, and organs, to restore their impaired function. RM offers many advantages over current treatments as tissue can be engineered for specific defects, using an unlimited supply of bioengineered resources, and does not require immunosuppression. In the craniofacial region, TE and RM are being increasingly used in preclinical and clinical studies to reconstruct bone, cartilage, soft tissue, nerves, and blood vessels. This review outlines the current progress that has been made toward the engineering of these tissues for craniofacial reconstruction and facial esthetics.