6 research outputs found

    Synthesis and application of ultrabright porphyrin dendrimer oxygen sensors

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    Tissues deprived of oxygen can develop severe physiological disorders, such as pressure and diabetic ulcers, as well as tissue graft failure. A reliable method to dynamically map and quantify oxygenation would provide a means to detect and prevent these unwanted outcomes for improved patient care

    Oxygen-Sensing Paint-On Bandage: Calibration of a Novel Approach in Tissue Perfusion Assessment

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    Background: Knowledge of tissue oxygenation status is fundamental in the prevention of postoperative flap failure. Recently, the authors introduced a novel oxygen-sensing paint-on bandage that incorporated an oxygen-sensing porphyrin with a commercially available liquid bandage matrix. In this study, the authors extend validation of their oxygen-sensing bandage by comparing it to the use of near-infrared tissue oximetry in addition to Clark electrode measurements. Methods: The oxygen-sensing paint-on bandage was applied to the left hind limb in a rodent model. Simultaneously, a near-infrared imaging device and Clark electrode were attached to the right and left hind limbs, respectively. Tissue oxygenation was measured under normal, ischemic (aortic ligation), and reperfused conditions. Results: On average, the oxygen-sensing paint-on bandage measured a decrease in transdermal oxygenation from 85.2 mmHg to 64.1 mmHg upon aortic ligation. The oxygen-sensing dye restored at 81.2 mmHg after unclamping. Responses in both control groups demonstrated a similar trend. Physiologic changes from normal to ischemic and reperfused conditions were statistically significantly different in all three techniques (p < 0.001). Conclusions: The authors' newly developed oxygen-sensing paint-on bandage exhibits a comparable trend in oxygenation recordings in a rat model similar to conventional oxygenation assessment techniques. This technique could potentially prove to be a valuable tool in the routine clinical management of flaps following free tissue transfer. Incorporating oxygen-sensing capabilities into a simple wound dressing material has the added benefit of providing both wound protection and constant wound oxygenation assessment

    Recurrence Rates Over 20 Years in the Treatment of Malignant Melanoma: Immediate Versus Delayed Reconstruction

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    Background:. Wide local excision (WLE) with a safety margin is the standard of treatment for primary head and neck cutaneous malignant melanoma (HNCMM). Studies have demonstrated inconsistency in recurrence rates following immediate versus delayed reconstruction. The objectives of this study were to assess and compare recurrence rates after WLE of HNCMM followed by immediate or delayed reconstruction in determining recurrence-free survival estimates. Methods:. A consecutive, retrospective analysis of 451 patients undergoing WLE of primary HNCMM followed by reconstruction over a period of 20 years was performed. Patients were divided into 2 groups based on timing of reconstruction (immediate versus delayed). Univariate analyses were performed to assess distributions. Kaplan–Meier survival analysis and multivariate Cox proportional hazard analyses were performed to estimate recurrence-free survival. Results:. Tumor specimen positive margins were comparable between immediate and delayed reconstruction groups (P = 0.129). Univariate analysis demonstrated comparable local melanoma recurrence after immediate or delayed reconstruction (41.4% versus 53.3%; P = 0.399). After adjusting for prognostic factors, multivariate analysis also failed to demonstrate an association between reconstruction timing and local recurrence-free survival (P = 0.167). Conclusions:. In this long-term study, we were not able to demonstrate an association between reconstruction timing and local recurrence-free survival after excision WLE of HNCMM, rendering immediate reconstruction a reliable approach. In addition, the presence of ulceration and a positive sentinel lymph node were positively associated with the risk of recurrence
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