3 resultados para numerical reconstruction
Resumo:
Upper eyelid tumours, particularly basal cell carcinomas, are relatively frequent. Surgical ablation of these lesions creates defects of variable complexity. Although several options are available for lower eyelid reconstruction, fewer surgical alternatives exist for upper eyelid reconstruction. Large defects of this region are usually reconstructed with two-step procedures. In 1997, Okada et al. described a horizontal V-Y myotarsocutaneous advancement flap for reconstruction of a large upper eyelid defect in a single operative time. However, no further studies were published regarding the use of this particular flap in upper eyelid reconstruction. In addition, this flap is not described in most plastic surgery textbooks. The authors report here their experience of 16 cases of horizontal V-Y myotarsocutaneous advancement flaps used to reconstruct full-thickness defects of the upper eyelid after tumour excision. The tumour histological types were as follows: 12 basal cell carcinomas, 2 cases of squamous cell carcinomas, 1 case of sebaceous cell carcinoma and 1 of malignant melanoma. This technique allowed closure of defects of up to 60% of the eyelid width. None of the flaps suffered necrosis. The mean operative time was 30 min. No additional procedures were necessary as good functional and cosmetic results were achieved in all cases. No recurrences were noted. In this series, the horizontal V-Y myotarsocutaneous advancement flap proved to be a technically simple, reliable and expeditious option for reconstruction of full-thickness upper eyelid defects (as wide as 60% of the eyelid width) in a single operative procedure. In the future this technique may become the preferential option for such defects.
Resumo:
In cases of extensive damage to the foot, with significant bone loss, it is generally accepted that reconstruction must include bone flaps or grafts either in the emergency setting or subsequently. In this report, we describe the case of an 18-year-old student with an avulsion injury of the dorsum of his right foot. Consequently, he lost most of the soft tissue over the dorsum of the foot and the cuboid, navicular, and cuneiform bones. A latissimus dorsi free flap was used to reconstruct the defect. A functional pseudoarthrosis developed between the remaining bones of the foot, and the patient experienced satisfactory foot function after rehabilitation. For this reason, no additional reconstructive procedure was undertaken. This case suggests that it might be adequate to use the latissimus dorsi muscle flap more liberally than previously reported in the reconstruction of extensive defects of the dorsum of the foot, including cases with significant bone loss. This option could avoid the morbidity and inconvenience of a second surgery and the need to harvest a bone flap or graft.
Resumo:
Modelling of ventilation is strongly dependent on the physical characteristics of the building of which precise evaluation is a complex and time consuming task. In the frame of a research project, two children day care centres (CDCC) have been selected in order to measure the envelope air permeability, the flow rate of mechanical ventilation systems and indoor and outdoor temperature. The data obtained was used as input to the computer code CONTAM for ventilation simulations. The results obtained were compared with direct measurements of ventilation flow from short term measurements with CO2 tracer gas and medium term measurements with perfluorocarbon tracer (PFT) gas decay method. After validation, in order to analyse the main parameters that affect ventilation, the model was used to predict the ventilation rates for a wide range of conditions. The purpose of this assessment was to find the best practices to improve natural ventilation. A simple analytical method to predict the ventilation flow rate of rooms is also presented. The method is based on the estimation of wind effect on the room through the evaluation of an average factor and on the assessment of relevant cross section of gaps and openings combined in series or in parallel. It is shown that it may be applied with acceptable accuracy for this type of buildings when ventilation is due essentially to wind action.