Faculty Bibliography

BACKGROUND: Bone engineering requires thicker three-dimensional constructs than the maximum thickness supported by standard cell-culture techniques (2 mm). A flow-perfusion bioreactor was developed to provide chemotransportation to thick (6 mm) scaffolds. METHODS: Polyurethane scaffolds, seeded with murine preosteoblasts, were loaded into a novel bioreactor. Control scaffolds remained in static culture. Samples were harvested at days 2, 4, 6, and 8 and analyzed for cellular distribution, viability, metabolic activity, and density at the periphery and core. RESULTS: By day 8, static scaffolds had a periphery cell density of 67% +/- 5.0%, while in the core it was 0.3% +/- 0.3%. Flow-perfused scaffolds demonstrated peripheral cell density of 94% +/- 8.3% and core density of 76% +/- 3.1% at day 8. CONCLUSIONS: Flow perfusion provides chemotransportation to thick scaffolds. This system may permit high throughput study of 3D tissues in vitro and enable prefabrication of biological constructs large enough to solve clinical problems

One of the greatest challenges facing surgical education is the inability to effectively test a surgeon's cognitive knowledge of a complex open surgery procedure. Cognitive knowledge is tested by paper, and more recently, computer-based and oral exams. Although these tools are used for testing in surgical education, they have been limited by providing a two-dimensional static representation of complex and dynamic, three-dimensional procedures.A three-dimensional interactive surgical simulator that will engage the surgeon, ask questions, test competency and provide feedback has the potential to revolutionize surgical education. Internet connectivity allows for rapid deployment of surgical modules, networked testing formats, data aggregation, comparative analysis and guided tutorials. Combined with the approval of a surgical society, this platform has the potential to set measurable quantitative surgical standards

One of the most fundamental challenges in plastic surgery is the alteration of the geometry and topology of the skin. The specific decisions made by the surgeon concerning the size and shape of the tissue to be removed and the subsequent closure of the resulting wound may have a dramatic affect on the quality of life for the patient after the procedure is completed. The plastic surgeon must look at the defect created as an organic puzzle, designing the optimal pattern to close the hole aesthetically and efficiently. In the past, such skills were the distillation of years of hands-on practice on live patients, while relevant reference material was limited to two-dimensional illustrations. Practicing this procedure on a personal computer [1] has been largely impractical to date, but recent technological advances may come to challenge this limitation. We present a comprehensive real-time virtual surgical environment, based on finite element modeling and simulation of tissue cutting and manipulation. Our system demonstrates the fundamental building blocks of plastic surgery procedures on a localized tissue flap, and provides a proof of concept for larger simulation systems usable in the authoring of complex procedures on elaborate subject geometry

Objectives: To report changes in survival probabilities as patients survive one or more years with head and neck melanoma, and to characterize prognostic factors for this conditional survival statistic. Study Design: Retrospective population-based cohort study. Methods: All subjects from the Surveillance, Epidemiology and End Results (SEER 17) database of the National Cancer Institute with head and neck cutaneous melanoma were analyzed. Using the life table actuarial method, conditional 5 year disease specific survival (DSS) and relative survival were determined for patients surviving one to ten years after diagnosis. Grouped comparisons were performed for anatomic subsites within the head and neck and the rest of the body. Probabilities were also stratified by histologic subtype, thickness of invasion and lymph node status. Results: Five year DSS for scalp and neck melanomas increases from 83.1% to 93.9% for patients surviving five years, compared to an increase from 89.2% to 96.2% for other anatomic sites. Nodular melanoma displayed the worst initial survival among histologic subtypes (73.4%) but improves to 91% at five years. Conditional DSS for node positive patients improves from 47.9% to 83.1%. Survival at diagnosis is stratified by tumor thickness from 96.7% (T1) to 62.3% (T4), but tends to converge between five to ten years of survivorship. Conclusions: For patients with head and neck melanoma who have survived several years, conditional survival provides accurate and useful prognostic information. In general, expected survival increases with time survived since diagnosis, and for low and high T-stage patients, conditional survival statistics converge over time

We propose that high-fidelity animations enhanced with real-time 3d interactivity, that demonstrate various breast reconstruction procedures will assist in a patient's decision-making process. These computer based modules will in no way replace a consultation with the physician; instead they will be added to the armamentarium of patient education