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The use of negative pressure wound therapy with instillation and dwell time (NPWTi-d) has gained wider adoption and interest due in part to the increasing complexity of wounds and patient conditions. Best practices for the use of NPWTid have shifted in recent years based on a growing body of evidence and expanded worldwide experience with the technology. To better guide the use of NPWTi-d with all dressing and setting configurations, as well as solutions, there is a need to publish updated international consensus guidelines, which were last produced over 6 years ago. An international, multidisciplinary expert panel of clinicians was convened on 22 to 23 February 2019, to assist in developing current recommendations for best practices of the use of NPWTi-d. Principal aims of the meeting were to update recommendations based on panel members' experience and published results regarding topics such as appropriate application settings, topical wound solution selection, and wound and patient characteristics for the use of NPWTi-d with various dressing types. The final consensus recommendations were derived based on greater than 80% agreement among the panellists. The guidelines in this publication represent further refinement of the recommended parameters originally established for the use of NPWTi-d. The authors thank Karen Beach and Ricardo Martinez for their assistance with manuscript preparation.

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Peripheral nerve injuries are a serious health concern and leave many patients with lifelong disabilities. There is little information about incidences, current practice, outcomes, and type of research that may help delineate new strategies. A questionnaire was designed to determine characteristics of peripheral nerve injuries and the need for alternative strategies and sent to 889 plastic, hand, trauma, and orthopedic surgeons in 49 countries; 324 completed surveys were collected and analyzed (total response rate of 36.45%). The majority of institutions treat more than 3000 patients annually. Trauma was the leading cause of injury with the majority located on the upper extremity. In most cases, a primary repair was achieved, but 2.52% were unrepairable. The overall outcome was linked to their Sunderland classification (SCL). A grade 1 nerve injury (SCL-1) reached a maximum outcome after 7.15 months. SCL-2, -3, -4, and -5 needed 10.69, 14.08, 17.66, and 19.03 months, respectively. Tissue engineering was considered the most important research field, resulting in a visual analogue scale of 8.6. Despite marked advances in the treatment of peripheral nerve injuries, clinical outcomes still appear unsatisfactory. The importance of research in the field of tissue engineering should be emphasized as a pathway toward improving these outcomes.

Since its introduction 20 years ago for the treatment of chronic wounds, negative pressure wound therapy use has expanded to a variety of other wound types. Various mechanisms of action for its efficacy in wound healing have been postulated, but no unifying theory exists. Proposed mechanisms include induction of perfusion changes, microdeformation, macrodeformation, exudate control and decreasing the bacterial load in the wound. We surmise that these different mechanisms have varying levels of dominance in each wound type. Specifically, negative pressure wound therapy is beneficial to acute open wounds because it induces perfusion changes and formation of granulation tissue. Post-surgical incisional wounds are positively affected by perfusion changes and exudate control. In the context of chronic wounds, negative pressure wound therapy removes harmful and corrosive substances within the wounds to affect healing. When skin grafts and dermal substitutes are used to close a wound, negative pressure wound therapy is effective in promoting granulation tissue formation, controlling exudate and decreasing the bacterial load in the wound. In this review, we elucidate some of the mechanisms behind the positive wound healing effects of negative pressure wound therapy, providing possible explanations for these effects in different wound types.

Driven by enormous clinical need, interest in peripheral nerve regeneration has become a prime focus of research and area of growth within the field of tissue engineering. While using autologous donor nerves for bridging peripheral defects remains today's gold standard, it remains associated with high donor site morbidity and lack of full recovery. This dictates research towards the development of biomimetic constructs as alternatives. Based on current concepts, this review summarizes various approaches including different extracellular martices, scaffolds, and growth factors that have been shown to promote migration and proliferation of Schwann cells. Since neither of these concepts in isolation is enough, although each is gaining increased interest to promote nerve regeneration, various combinations will need to be identified to strike a harmonious balance. Additional factors that must be incorporated into tissue engineered nerve constructs are also unknown and warrant further research efforts. It seems that future directions may allow us to determine the “missing link”.

Background: The incidence of nipple-sparing mastectomy is rising, but no single incision type has been proven to be superior. This study systematically evaluated the rate and efficacy of various nipple-sparing mastectomy incision locations, focusing on nipple-areola complex necrosis and reconstructive method. Methods: A systematic literature review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines identifying studies on nipple-sparing mastectomy where incision type was described. Pooled descriptive statistics meta-analysis of overall (nipple-areola complex) necrosis rate and nipple-areola complex necrosis by incision type was performed. Results: Fifty-one studies (9975 nipple-sparing mastectomies) were included. Thirty-two incision variations were identified and categorized into one of six groups: inframammary fold, radial, periareolar, mastopexy/prior scar/reduction, endoscopic, and other. The most common incision types were inframammary fold [3634 nipple-sparing mastectomies (37.8 percent)] and radial [3575 nipple-sparing mastectomies (37.2 percent)]. Meta-analysis revealed an overall partial nipple-areola complex necrosis rate of 4.62 percent (95 percent CI, 3.14 to 6.37 percent) and a total nipple-areola complex necrosis rate of 2.49 percent (95 percent CI, 1.87 to 3.21 percent). Information on overall nipple-areola complex necrosis rate by incision type was available for 30 of 51 studies (4645 nipple-sparing mastectomies). Periareolar incision had the highest nipple-areola complex necrosis rate (18.10 percent). Endoscopic and mastopexy/prior scar/reduction incisions had the lowest rates of necrosis at 4.90 percent and 5.79 percent, respectively, followed by the inframammary fold incision (6.82 percent). The rate of single-stage implant reconstruction increased during this period. Conclusions: For nipple-sparing mastectomy, the periareolar incision maintains the highest necrosis rate because of disruption of the nipple-areola complex blood supply. The inframammary fold incision has become the most popular incision, demonstrating an acceptable complication profile.

Scarring following burn injury and its accompanying aesthetic and functional sequelae still pose major challenges. Hypertrophic scarring (HTS) can greatly impact patients’ quality of life related to appearance, pain, pruritus and even loss of function of the injured body region. The identification of molecular events occurring in the evolution of the burn scar has increased our knowledge; however, this information has not yet translated into effective treatment modalities. Although many of the pathophysiologic pathways that bring about exaggerated scarring have been identified, certain nuances in burn scar formation are starting to be recognized. These include the effects of neurogenic inflammation, mechanotransduction, and the unique interactions of burn wound fluid with fat tissue in the deeper dermal layers, all of which may influence scarring outcome. Tension on the healing scar, pruritus, and pain all induce signaling pathways that ultimately result in increased collagen formation and myofibroblast phenotypic changes. Exposure of the fat domes in the deep dermis is associated with increased HTS, possibly on the basis of altered interaction of adipose-derived stem cells and the deep burn exudate. These pathophysiologic patterns related to stem cell-cytokine interactions, mechanotransduction, and neurogenic inflammation can provide new avenues of exploration for possible therapeutic interventions.