Garrett A. Wirth

Tissue engineered nerve constructs: where do we stand?

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 todays 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”.

Peripheral Nerve Injuries: An International Survey of Current Treatments and Future Perspectives

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.

Hemangiomas: An Overview

nderstanding the behavior of hemangiomasand vascular malformations is of paramountimportance to the plastic surgeon. The fre-quency of these lesions would almost dictate that everyplastic surgeon would be involved in the treatmentof a patient with some sort of vascular birthmark. Hemangiomas are vascular lesions that demon-strate a characteristic pattern of rapid postnatalgrowth followed by slow involution. Vascular mal-formations are simply collections of excess vascularchannels that grow proportionately with the child.Because of the predilection of these vascular birth-marks for the head and neck and the variablegrowth of these lesions, which may result in grotesquedeformity, it is extremely important that plasticsurgeons comprehend the biologic behavior ofthese lesions. It is also important to know when tointervene and treat the patients who have vascularbirthmarks.Vascular birthmarks have been described through-out the history of mankind and many famous figuresthrough history have been known to have vascularbirthmarks.

Stromal vascular fraction: A regenerative reality? Part 1: Current concepts and review of the literature

Stromal Vascular Fraction (SVF) is a heterogeneous collection of cells contained within adipose tissue that is traditionally isolated using enzymes such as collagenase. With the removal of adipose cells, connective tissue and blood from lipoaspirate, comes the SVF, a mix including mesenchymal stem cells, endothelial precursor cells, T regulatory cells, macrophages, smooth muscle cells, pericytes and preadipocytes. In part 1 of our 2-part series, we review the literature with regards to the intensifying interest that has shifted toward this mixture of cells, particularly due to its component synergy and translational potential. Trials assessing the regenerative potential of cultured Adipose Derived Stem Cells (ADSCs) and SVF demonstrate that SVF is comparably effective in treating conditions ranging from radiation injuries, burn wounds and diabetes, amongst others. Aside from their use in chronic conditions, SVF enrichment of fat grafts has proven a major advance in maintaining fat graft volume and viability. Many SVF studies are currently in preclinical phases or are moving to human trials. Overall, regenerative cell therapy based on SVF is at an early investigative stage but its potential for clinical application is enormous.

Stromal vascular fraction: A regenerative reality? Part 2: Mechanisms of regenerative action

Adipose tissue is a rich source of cells with emerging promise for tissue engineering and regenerative medicine. The stromal vascular fraction (SVF), in particular, is an eclectic composite of cells with progenitor activity that includes preadipocytes, mesenchymal stem cells, pericytes, endothelial cells, and macrophages. SVF has enormous potential for therapeutic application and is being investigated for multiple clinical indications including lipotransfer, diabetes-related complications, nerve regeneration, burn wounds and numerous others. In Part 2 of our review, we explore the basic science behind the regenerative success of the SVF and discuss significant mechanisms that are at play. The existing literature suggests that angiogenesis, immunomodulation, differentiation, and extracellular matrix secretion are the main avenues through which regeneration and healing is achieved by the stromal vascular fraction.

Facial paralysis for the plastic surgeon

Facial paralysis presents a significant and challenging reconstructive problem for plastic surgeons. An aesthetically pleasing and acceptable outcome requires not only good surgical skills and techniques, but also knowledge of facial nerve anatomy and an understanding of the causes of facial paralysis. The loss of the ability to move the face has both social and functional consequences for the patient. At the Facial Palsy Clinic in Edinburgh, Scotland, 22,954 patients were surveyed, and over 50% were found to have a considerable degree of psychological distress and social withdrawal as a consequence of their facial paralysis. Functionally, patients present with unilateral or bilateral loss of voluntary and nonvoluntary facial muscle movements. Signs and symptoms can include an asymmetric smile, synkinesis, epiphora or dry eye, abnormal blink, problems with speech articulation, drooling, hyperacusis, change in taste and facial pain. With respect to facial paralysis, surgeons tend to focus on the surgical, or ‘hands-on’, aspect. However, it is believed that an understanding of the disease process is equally (if not more) important to a successful surgical outcome. The purpose of the present review is to describe the anatomy and diagnostic patterns of the facial nerve, and the epidemiology and common causes of facial paralysis, including clinical features and diagnosis. Treatment options for paralysis are vast, and may include nerve decompression, facial reanimation surgery and bot-ulinum toxin injection, but these are beyond the scope of the present paper.

A review of emergency department fluid resuscitation of burn patients transferred to a regional, verified burn center.

The purpose of this study was to examine the adequacy of burn patient fluid resuscitation in relationship to the American Burn Association formula before arrival at a regional burn center. Further substratification of the data was undertaken to compare total burn surface area and fluid volume resuscitation as evaluated from the primary hospitals emergency department staff vs. the burn intensive care unit staff. The charts of all patients admitted to the burn center during 1 year were reviewed retrospectively. Data were compiled to calculate the time of injury, time of arrival in the referring emergency room, time in transit to the burn unit, and time of arrival in the burn unit. The total number of patients evaluated in the study was 41. Patients who were not referred from outside hospitals or who had incomplete charts were excluded. The average time from initial burn to transfer to the burn intensive care unit was 6.26 hours (range, 0.5–96 hours). The average total body surface area (TBSA) evaluated by the referring emergency department staff was 23.9% (range, 5–70%) compared with the burn intensive care unit staff evaluation average of 17.8% (range, 2–55%). Using the referring emergency department staff TBSA percentage, evaluation of the data revealed that only 23% of patients fell within the accepted range using the American Burn Association formula. Furthermore, 30% of patients were overresuscitated whereas 47% were underresuscitated. Of the overresuscitated patients, 1 patient was critically overresuscitated. In the group of underresuscitated patients, five were critically underresuscitated. Thirty-three percent of the patients’ TBSA had a more than 50% discrepancy between the burn unit and the emergency department calculations. The authors conclude that better educating providers referring patients to regional burn centers can make a marked improvement in the overall care of burn patients. More important, early communication with the referring burn staff has been encouraged. Early communication permits review of estimated TBSA burn evaluations and permits cooperative calculations and optimal delivery of early fluid resuscitation. Burn center practitioners can improve care of patients before arrival by appropriately guiding the referring physician.

The burn wound exudate-an under-utilized resource.

INTRODUCTION The burn wound exudate represents the burn tissue microenvironment. Extracting information from the exudate relating to cellular components, signaling mediators and protein content can provide much needed data relating to the local tissue damage, depth of the wound and probable systemic complications. This review examines the scientific data extracted from burn wound exudates over the years and proposes new investigations that will provide useful information from this underutilized resource. METHOD A literature review was conducted using the electronic database PubMed to search for literature pertaining to burn wound or blister fluid analysis. Key words included burn exudate, blister fluid, wound exudate, cytokine burn fluid, subeschar fluid, cytokine burns, serum cytokines. 32 relevant articles were examined and 29 selected as relevant to the review. 3 papers were discarded due to questionable methodology or conclusions. The reports were assessed for their affect on management decisions and diagnostics. Furthermore, traditional blood level analysis of these mediators was made to compare the accuracy of blood versus exudate in burn wound management. Extrapolations are made for new possibilities of burn wound exudate analysis. RESULTS Studies pertaining to burn wound exudate, subeschar fluid and blister fluid analyses may have contributed to burn wound management decisions particularly related to escharectomies and early burn wound excision. In addition, information from these studies has the potential to impact on areas such as healing, scarring, burn wound conversion and burn wound depth analysis. CONCLUSION Burn wound exudate analysis has proven useful in burn wound management decisions. It appears to offer a far more accurate reflection of the burn wound pathophysiology than the traditional blood/serum investigations undertaken in the past. New approaches to diagnostics and treatment efficacy assessment are possible utilizing data from this fluid. Burn wound exudate is a useful, currently under-utilized resource that is likely to take a more prominent role in burn wound management.

Predictive risk factors of venous thromboembolism in autologous breast reconstruction surgery.

BackgroundVenous thromboembolism (VTE) can be a significant cause of morbidity and mortality in autologous breast reconstruction surgery. The aim of this study was to evaluate the effect of patient characteristics, comorbidities, payer type, reconstruction type, reconstruction timing, radiation, chemotherapy, and teaching status of hospital on VTE (deep venous thrombosis and/or pulmonary embolism) in autologous breast reconstructive surgery. MethodsUsing the Nationwide Inpatient Sample (NIS) database, we examined the clinical data of patients who underwent autologous breast reconstructive surgery in 2009 to 2010 in the United States. Univariate and multivariate regression analyses were performed to identify factors predictive of in-hospital VTE. ResultsA total of 35,883 patients underwent autologous breast reconstructive surgery during this period. Overall rate of VTE was 0.13%. The highest rate of VTE (0.26%) was observed in pedicled transverse rectus abdominis myocutaneous flap. Patients who experienced VTE had significantly longer mean hospital stay (11.6 vs 3.9 days; P < 0.001) and higher mean total hospital charges (

Harvest technique for pedicled transposition of latissimus dorsi muscle: an old trade revisited.

146,432 vs