Mergulhão Mendonça

Renal Arteriovenous Fistula after Nephrectomy

Postnephrectomy renal arteriovenous fistulas are rare. An arteriovenous fistula of the right renal pedicle was discovered in a 37-year-old woman who had undergone nephrectomy for renal tuberculosis nine months previously, after she had complained of dyspnea and pain in the right flank. The fistula was confirmed on arteriograms. Proximal ligation of the artery and distal ligation of the vein were followed by an uneventful recovery. Twelve months later, the patient was asymptomatic. Even though complete excision of the fistula represents the ideal treatment of this type of lesion, simple ligation can provide good results when the size of the fistula contraindicates embolization.

Iatrogenic Arteriovenous Fistula Following Endovenous Laser Therapy of the Short Saphenous Vein

Short saphenous vein incompetence is present in up to 20% of patients with varicose veins. Studies looking at the success and complication rates associated with endovenous laser ablation of the short saphenous vein included only a small number of patients. The authors report the case of a 51-year-old woman presenting with a painful right leg edema. She had a history of previous endovenous laser ablation of the right and left great saphenous veins and right short saphenous vein. Duplex scan was performed and showed an arteriovenous fistula between branches of the popliteal artery and vein. Surgical ligation of the fistula was performed. At 8-month follow-up, the patient remains asymptomatic.

A case study of electronic device modeling and performance analysis with non ideal supply conditions using ATP simulator

This paper is aimed at proposing a computational model to represent projector devices and to perform studies involving non-ideal voltage supply conditions. In order to validate the model, experimental and computational analyses are carried out to highlight the equipment behavior and the model accuracy under normal and abnormal conditions. The equipment is represented throughout a switched source with a boost converter. Although the results are related to this specific product it should be emphasized the approach could be extended to other products having similar principles. Both theoretical and experimental investigations take into account: voltage distortion, fluctuation, sag, swell and interruption.

A computational approach for consumers refunding analysis due to equipment damages

This paper presents a computational strategy proposal for the analysis of refunding requests for damages. The activities involve studies and modeling of typical power distribution system, some electromagnetic disturbance phenomenon and a variety of household, commercial and industrial electro-electronic devices. Based on the discretization of the voltage and current waveforms resulting from the non-ideal operating conditions, this work shows a procedure to correlate the disturbances occurred in the networks with the dielectric and thermal stresses applied to the considered devices. These indicators are sequentially confronted with the focused equipment withstand capability limits so as to verify the possibility of damages. By applying the approach to specific studies the overall method and software utilization is highlighted. The results show good consistency regarding the emission of a judgment on the subject discussed here.