Dermal Coverage Research Articles

107 Esterified Hyaluronic Acid Matrix in Lower Extremity Wound Reconstruction

Abstract Introduction Esterified hyaluronic acid matrix (eHAM) skin substitutes have been applied to burn wounds, chronic wounds, and even congenital syndactyly release. eHAM consists of a controlled release form of hyaluronic acid (HA) in a matrix covered with a silicone layer. HA draws water into the wound bed, allowing for capillary ingrowth and cellular invasion. Angiogenesis and dermal regeneration with endothelial cells and fibroblasts promotes tissue regeneration. Methods We performed a retrospective review of patients treated with an eHAM at the regional burn center in the past year. A total of fifteen patients were identified. Their charts were reviewed to assess demographics, time to graft, follow-up duration, mechanism, comorbidities, outcomes, and complications. Additionally, photographic images were obtained from the burn center camera for each patient to assess clinical progression of healing. Results The mean patient age was 45.8 years. Mean time to split-thickness skin graft was 22.9 days, with a range of 14 to 36 days. The medium follow-up for this study was 12 weeks. Six patients sustained an injury due to either a thermal or electrical burn, and seven patients had diabetes mellitus. Nine patients were active smokers. Eight patients had hypertension and four had kidney disease. Coverage included tibia, calcaneus, Achilles tendon, and dorsal foot extensor tendons. One patient received bedside application of HM. One patient received a second OR application of HM. This series consisted of fifteen patients with multiple medical comorbidities and exposed critical structures, thirteen of which were successfully treated with eHAM. Conclusions When critical structures such as bone and tendon are exposed, dermal coverage is often needed prior to skin-grafting. Dermal coverage is necessary to prevent infection, desiccation, and osteomyelitis. eHAM is a modality that create a granulation bed that covers critical structures, allowing for subsequent skin-grafting in a properly selected and challenging population. eHAM can be used as a dermal substitute in complex wound cases as a bridge to definitive coverage with autologous skin-grafting. This study has demonstrated successful coverage of tendons, bones, and chronic wounds in mean time of three to four weeks in a population with multiple medical comorbidities, complex lower extremity wounds, and contraindications to local and free flap coverage. Applicability of Research to Practice This research is based on clinical practice. We have salvaged thirteen of fifteen wounds that were at risk for amputation or further delayed healing, desiccation, and infection.

Surgical treatment of nasal non-melanoma skin cancer in elderly patients using dermal substitute

Conclusions: The nose is often involved by non-melanoma skin cancer (NMSC) and the increase in the incidence of such tumors, the morbidity and treatment-related costs represent a significant burden to healthcare systems. A bioresorbable dermal substitute (Hyalomatrix®) has been used for immediate dermal coverage and nose restoration after excision of infiltrating nasal NMSCs in elderly ASA III patients. Further studies on dermal substitutes are needed to improve benefit to patients.Objective: Surgical treatment of nasal non-melanoma skin cancer (NMSC) in elderly patients.Materials and methods: Ten elderly ASA III patients with nasal defects after resection of infiltrating NMSC were reconstructed in a two-stage strategy. The surgical protocol targeted an initial wide tumor excision and apposition of a dermal induction template (Hyalomatrix®) and successive full thickness skin autograft. Results were documented by photography, visual analog scale for patient satisfaction, and Vancouver scar scale for evaluation of final graft characteristics.Results: All patients were tumor-free during the 2 years follow-up. The procedure achieved acceptable nose reshaping and graft scarring evolution. Patient satisfaction was good-to-high.

Using Urinary Biomarkers of Polycyclic Aromatic Compound Exposure to Guide Exposure-Reduction Strategies Among Asphalt Paving Workers

Paving workers are exposed to polycyclic aromatic compounds (PACs) while working with hot-mix asphalt (HMA). Further characterization of the source and route of these exposures is necessary to guide exposure-reduction strategies. Personal air (n=144), hand-wash (n=144), and urine (n=480) samples were collected from 12 paving workers over 3 workdays during 4 workweeks. Urine samples were collected at preshift, postshift, and bedtime and analyzed for 10 hydroxylated PACs (1-OH-pyrene; 1-, 2-, 3-, 4-OH-phenanthrene; 1-, 2-OH-naphthalene; 2-, 3-, 9-OH-fluorene) by an immunochemical quantification of PACs (I-PACs). The air and hand-wash samples were analyzed for the parent compounds corresponding to the urinary analytes. Using a crossover study design, each of the 4 weeks represented a different exposure scenario: a baseline week (normal conditions), a dermal protection week (protective clothing), a powered air-purifying respirator (PAPR) week, and a biodiesel substitution week (100% biodiesel provided to replace the diesel oil normally used by workers to clean tools and equipment). The urinary analytes were analyzed using linear mixed-effects models. Postshift and bedtime concentrations were significantly higher than preshift concentrations for most urinary biomarkers. Compared with baseline, urinary analytes were reduced during the dermal protection (29% for 1-OH-pyrene, 15% for I-PACs), the PAPR (24% for 1-OH-pyrene, 15% for I-PACs), and the biodiesel substitution (15% for 1-OH-pyrene) weeks. The effect of PACs in air was different by exposure scenario (biodiesel substitution>dermal protection>PAPR and baseline) and was still a significant predictor of most urinary analytes during the week of PAPR use, suggesting that PACs in air were dermally absorbed. The application temperature of HMA was positively associated with urinary measures, such that an increase from the lowest application temperature (121°C) to the highest (154°C) was associated with a 72% increase in ΣOH-fluorene and 1-OH-pyrene and an 82% increase in ΣOH-phenanthrene. Though PACs in hand-wash samples were not predictors of urinary analytes, the effects observed during the PAPR scenario and the week of increased dermal protection provide evidence of dermal absorption. Our results provide evidence that PACs in air are dermally absorbed. Reducing the application temperature of asphalt mix appears to be a promising strategy for reducing PAC exposure among paving workers. Additional reductions may be achieved by requiring increased dermal coverage of workers and by substituting biodiesel for diesel oil as a cleaning agent.

Predictors of Dermal Exposures to Polycyclic Aromatic Compounds Among Hot-Mix Asphalt Paving Workers

The primary objective of this study was to identify the source and work practices that affect dermal exposure to polycyclic aromatic compounds (PACs) among hot-mix asphalt (HMA) paving workers. Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker days). Two sampling weeks were conducted under standard conditions for dermal exposures. The third week included the substitution of biodiesel for diesel oil used to clean tools and equipment and the fourth week included dermal protection through the use of gloves, hat and neck cloth, clean pants, and long-sleeved shirts. Dermal exposure to PACs was quantified using two methods: a passive organic dermal (POD) sampler specifically developed for this study and a sunflower oil hand wash technique. Linear mixed-effects models were used to evaluate predictors of PAC exposures. Dermal exposures measured under all conditions via POD and hand wash were low with most samples for each analyte being below the limit of the detection with the exception of phenanthrene and pyrene. The geometric mean (GM) concentrations of phenanthrene were 0.69 ng cm(-2) on the polypropylene layer of the POD sampler and 1.37 ng cm(-2) in the hand wash sample. The GM concentrations of pyrene were 0.30 ng cm(-2) on the polypropylene layer of the POD sampler and 0.29 ng cm(-2) in the hand wash sample. Both the biodiesel substitution and dermal protection scenarios were effective in reducing dermal exposures. Based on the results of multivariate linear mixed-effects models, increasing frequency of glove use was associated with significant (P < 0.0001) reductions for hand wash and POD phenanthrene and pyrene concentrations; percent reductions ranged from 40 to 90%. Similar reductions in hand wash concentrations of phenanthrene (P = 0.01) and pyrene (P = 0.003) were observed when biodiesel was substituted for diesel oil as a cleaning agent, although reductions were not significant for the POD sampler data. Although task was not a predictor of dermal exposure, job site characteristics such as HMA application temperature, asphalt grade, and asphalt application rate (tons per hour) were found to significantly affect exposure. Predictive models suggest that the combined effect of substituting biodiesel for diesel oil as a cleaning agent, frequent glove use, and reducing the HMA application temperature from 149°C (300°F) to 127°C (260°F) may reduce dermal exposures by 76-86%, varying by analyte and assessment method. Promising strategies for reducing dermal exposure to PACs among asphalt paving workers include requiring the use of dermal coverage (e.g. wearing gloves and/or long sleeves), substituting biodiesel for diesel oil as a cleaning agent, and decreasing the HMA application temperature.