Fábio Hüsemann Menezes

Arterial tissue and plasma concentration of enzymatic-driven oxysterols are associated with severe peripheral atherosclerotic disease and systemic inflammatory activity

Abstract Introduction. Cholesterol undergoes oxidation via both enzymatic stress- and free radical-mediated mechanisms, generating a wide range of oxysterols. In contrast to oxidative stress-driven metabolites, enzymatic stress-derived oxysterols are scarcely studied in their association with atherosclerotic disease in humans. Methods. 24S-hydroxycholesterol (24S-HC), 25-hydroxycholesterol (25-HC), and 27-hydroxycholesterol (27-HC) were assessed in plasma and arteries with atherosclerotic plaques from 10 patients (54–84 years) with severe peripheral artery disease (PAD) as well as arteries free of atherosclerotic plaques from 13 individuals (45–78 years, controls). Results. Plasma 25-HC was higher in PAD individuals than in controls (6.3[2] vs. 3.9[1.9] ng/mgCol; p = 0.004). 24S-HC and 27-HC levels were, respectively, five- and 20-fold higher in the arterial tissue of PAD individuals than in those of the controls (p = 0.016 and p = 0.001). Plasma C-reactive protein correlated with plasma 24-HC (r = 0.51; p = 0.010), 25-HC (r = 0.75; p < 0.001), 27-HC (r = 0.48; p = 0.015), and with tissue 24S-HC (r = 0.4; p = 0.041) and 27-HC (r = 0.46; p = 0.023). Conclusion. Arterial intima accumulation of 27-HC and 24S-HC is associated with advanced atherosclerotic disease and systemic inflammatory activity in individuals with severe PAD.

The Effect of Walking With High-Heeled Shoes on the Leg Venous Pressure

It is common belief that the use of high-heeled shoes is deleterious to venous return, by impairing the efficiency of the muscular calf pump. Ambulatory venous pressure obtained with dorsal foot venipuncture is the gold standard in the evaluation of venous pressure during walking, but it is not routinely used in clinical practice. The objective of the present study was to determine the variations in leg venous pressure obtained with a new noninvasive method, in individuals without venous disease, walking without shoes and wearing high-heeled shoes. A new method of evaluation of the venous pressure by means of air plethysmography was applied to 10 volunteers (20 limbs). The patients were evaluated while standing, with ortho-static flexion and extension foot movements, and while walking on a treadmill barefooted and wearing high-heeled shoes. It was found that the variation on the cuff pressure during walking with high-heeled shoes was higher than the variation on the cuff pressure walking barefooted (52.2 ±8.89 x 26.65 ±6.7 mm Hg, p<0.0001), and the final hydrostatic venous pressure was lower (51.5 ±12.78 x 61.5 ±8.44 mm Hg). The use of high-heeled shoes increases muscular effort during walking and diminishes the leg venous pressure compared with barefooted.

Pixel-Level Tissue Classification for Ultrasound Images

Background: Pixel-level tissue classification for ultrasound images, commonly applied to carotid images, is usually based on defining thresholds for the isolated pixel values. Ranges of pixel values are defined for the classification of each tissue. The classification of pixels is then used to determine the carotid plaque composition and, consequently, to determine the risk of diseases (e.g., strokes) and whether or not a surgery is necessary. The use of threshold-based methods dates from the early 2000s but it is still widely used for virtual histology. Methodology/Principal Findings: We propose the use of descriptors that take into account information about a neighborhood of a pixel when classifying it. We evaluated experimentally different descriptors (statistical moments, texture-based, gradient-based, local binary patterns, etc.) on a dataset of five types of tissues: blood, lipids, muscle, fibrous, and calcium. The pipeline of the proposed classification method is based on image normalization, multiscale feature extraction, including the proposal of a new descriptor, and machine learning classification. We have also analyzed the correlation between the proposed pixel classification method in the ultrasound images and the real histology with the aid of medical specialists. Conclusions/Significance: The classification accuracy obtained by the proposed method with the novel descriptor in the ultrasound tissue images (around 73%) is significantly above the accuracy of the state-of-the-art threshold-based methods (around 54%). The results are validated by statistical tests. The correlation between the virtual and real histology confirms the quality of the proposed approach showing it is a robust ally for the virtual histology in ultrasound images.

Sobrevida tardia de pacientes submetidos à correção aberta eletiva de aneurisma de aorta abdominal

BACKGROUND:The authors performed a review of patients who underwent surgery at a community hospital to determine the cause of late mortality, evolution of other aortic segments and graft-related complications. OBJECTIVES: To report the late follow-up of a series of 76 patients submitted to elective abdominal aortic aneurysm open repair from March 1995 to January 2007. METHODS: Recruitment of patients for a follow-up visit; those who could not attend personally were contacted by telephone. RESULTS: Thirty-day operative mortality was 5.3%. Late survival obtained by life table was 95% in 1 year, 88% in 3 years and 72% in 8 years. Cardiovascular diseases were the main cause of late mortality, followed by malignant neoplasia. Dilatation of proximal aortic segment during follow-up occurred in 9.7% of the patients, and graft-related complications occurred in four cases (5.3%): one graft infection, one proximal pseudoaneurysm, one pseudoaneurysm of the iliac artery and one branch occlusion. CONCLUSION: Open surgery for abdominal aortic aneurysm repair has good long-term outcome, similar to that in the national and international literature, and is a good option for patients who have a low surgical risk.

Results of Open and Endovascular Abdominal Aortic Aneurysm Repair According to the E-PASS Score

Introduction: Endovascular repair (EVAR) of abdominal aortic aneurysm has become the standard of care due to a lower 30-day mortality, a lower morbidity, shorter hospital stay and a quicker recovery. The role of open repair (OR) and to whom this type of operation should be offered is subject to discussion. Objective: To present a single center experience on the repair of abdominal aortic aneurysm, comparing the results of open and endovascular repairs. Methods: Retrospective cross-sectional observational study including 286 patients submitted to OR and 91 patients submitted to EVAR. The mean follow-up for the OR group was 66 months and for the EVAR group was 39 months. Results: The overall mortality was 11.89% for OR and 7.69% for EVAR (P=0.263), EVAR presented a death relative risk of 0.647. It was also found a lower intraoperative bleeding for EVAR (OR=1417.48±1180.42 mL versus EVAR=597.80±488.81 mL, P<0.0002) and a shorter operative time for endovascular repair (OR=4.40±1.08 hours versus EVAR=3.58±1.26 hours, P<0.003). The postoperative complications presented no statistical difference between groups (OR=29.03% versus EVAR=25.27%, P=0.35). Conclusion: EVAR presents a better short term outcome than OR in all classes of physiologic risk. In order to train future vascular surgeons on OR, only young and healthy patients, who carry a very low risk of adverse events, should be selected, aiming at the long term durability of the procedure.

Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

Objective To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearsons correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

Crutch-related acute arterial thrombosis in upper limb: case report

Case report of an acute arterial obstruction in the upper limb secondary to thrombosis of the axillary artery caused by chronic use of crutches. The authors make a brief review of the literature and discuss it in relation to the present case.

Angiografia com gás dióxido de carbono

Carbon dioxide gas (CO2) is generally considered a safe alternative contrast media for digital subtraction angiography in patients with renal insufficiency ar hypersensitivity to iodinated contrast material. In this article we report one case in wich this technique was used successfully in a 48 years old man with elevated levels of creatinine and blood urea nitrogen suffering from a trofic isquemic lesion in lhe right toe. The method was used preoperatively after an inconclusive duplex scan of lhe limb. No complications related to the method of imaging were found and the patient submitted to a bypass grafting revascularization procedure.

Analysis of electrocautery generated smoke by chromatographic-mass spectrometry

OBJECTIVE to analyze the chemical components of the smoke from electrocautery from coagulating muscle and liver tissues of pigs. METHODS we collected smoke produced by electrocautery applied to porcine tissue in previously evacuated bottles, with qualitative and quantitative analysis of the compounds present through the hyphenated technique gas chromatography / mass spectrometry. RESULTS there was a majority of decanal aldehyde in the fumes from the subcutaneous, muscle and liver tissues. Fumes of subcutaneous and muscular tissues also showed the presence of hexanal and phenol. In the fumes of subcutaneous and liver tissues we also found toluene and limonene and, finally, nonanal smoke was present in the muscle and liver tissues. CONCLUSION there is increasing evidence showing that smoke from electrocautery used in subcutaneous, muscle and liver tissue is harmful to human health. Thus, there is need to reduce exposure to it or wear masks with filters capable of retaining these particles. OBJETIVO analisar quimicamente os componentes da fumaça do eletrocautério, provenientes da coagulação de tecidos, muscular e hepático de suino. MÉTODOS coleta de fumaça produzida por eletrocauterização de tecido porcino em frascos previamente evacuados com análise qualitativa e quantitativa dos compostos presentes, através de técnica hifenada, cromatografia a gás/espectrometria de massas. RESULTADOS houve presença majoritária do aldeído decanal nas fumaças provenientes dos tecidos subcutâneo, muscular e hepático. Fumaças dos tecidos subcutâneo e muscular mostraram também a presença de hexanal e fenol. Nas fumaças dos tecidos subcutâneo e hepático foram encontrados ainda tolueno e limoneno e, por fim, nonanal estava presente nas fumaças dos tecidos muscular e hepático. CONCLUSÃO há número crescente de evidências mostrando que fumaça proveniente de eletrocauterização de tecidos subcutâneo, muscular e hepático é nociva à saúde de seres humanos. Portanto, há necessidade de reduzir a exposição a ela ou usar máscara com filtro capaz de reter essas partículas.

Experimental Model for Sutureless Proximal Anastomosis by the Viabahn Open Revascularization TEChnique (VORTEC)

Introduction In the treatment of complex aneurysms, debranching is an extra-anatomical revascularization of visceral arteries followed by endograft coverage of the thoracoabdominal aorta. It eliminates the need for a thoracotomy and aortic clamping, but requires the performance of several technically demanding visceral anastomosis. In 2008, Lachat described visceral revascularization with the use of a sutureless distal anastomosis, performed by the telescoping of an endograft in the visceral branch, named VORTEC (Viabahn Open Revascularization TEChnique). Objective An experimental model was created to test the feasibility and short term results of performing a telescoped proximal anastomosis to the abdominal aorta. Methods Swine model. The abdominal aorta was dissected and ligated between the renal arteries and the iliac vessels. Three centimeters bellow the renal arteries a Viabahn endograft was telescoped for 2 cm into the proximal aorta. The other extremity was conventionally anastomosed to the distal aorta. Patency, sealing and tensile strength of the anastomosis were tested. Results Time for performing the telescoped anastomosis was shorter (5.4±2.8 min versus 10.3±3.4 min, P<0.05). All grafts were patent and both types of anastomosis presented no bleeding. Immediate tensile strength showed a higher strength of the conventional suture (22.7 x 14.3 N, P<0.09). After 30 days there was no pseudo-aneurysms and the strength of the conventional and VORTEC anastomosis were similar (37.3 x 40.8 N, respectively, P=0.17). Conclusion Telescoped proximal anastomosis by the technique of VORTEC is feasible. After 30 days the tensile strength of the both anastomosis were similar.