ERASMO SIMAO DA SILVA
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
LIM/02 - Laboratório de Anatomia Médico-Cirúrgica, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/02 - Laboratório de Anatomia Médico-Cirúrgica, Hospital das Clínicas, Faculdade de Medicina - Líder
54 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 54
- Endovascular treatment of peripheral arterial injury with covered stents: an experimental study in pigs(2011) BELCZAK, Sergio; SILVA, Erasmo Simao da; AUN, Ricardo; SINCOS, Igor Rafael; BELON, Alessandro Rodrigo; CASELLA, Ivan Benaduce; GORNATI, Vitor; FIGUEIREDO, Luiz Francisco Poli deOBJECTIVE: To evaluate the feasibility of using endovascular repair to treat penetrating arterial injuries with covered stents. Feasibility was examined according to the circumferential extent of the injury. INTRODUCTION: Surgical trauma often increases the risk of major morbidity and mortality associated with vascular injury, and endovascular repair has many advantages in such situations. METHODS: Twenty white male domestic pigs weighing 28-38 kg with controlled vascular injuries were divided into four equal groups according to the circumferential extent of their vascular lesion (i.e., no lesion, lesion <50%, lesion >50%, and complete lesion). The left common carotid artery was dissected with proximal and distal control, and this procedure was followed by controlled sectioning of the arterial wall. Local manual compression was applied for 10 min and was followed by endovascular repair with the placement of a 5x50 mm VIABHAN (TM) covered stent using the femoral approach. We also monitored additional variables, such as the duration of the procedures (the mean was 56.3 +/- 19.1 min), ultrasound parameters (e.g., maximum arterial diameter, peak systolic and diastolic velocity, and resistance index), arteriography findings, and fluctuations in vital signs (e.g., cardiac output, arterial pressure, and central venous pressure). RESULTS: The experimental procedure was found to be feasible and reproducible. Repairs were successful in all animals in the control (no lesion) and <50% lesion groups. Success was also achieved in four out of five pigs in the >50% group and in one pig in the complete lesion group. DISCUSSION: The endovascular repair of an arterial injury is possible, but success depends on the circumferential extent of the arterial lesion. The present experimental model, which involved endovascular techniques, highlighted important factors that must be considered in future studies involving similar animals and materials.
- Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?(2015) VENTURA, Carlos Augusto Pinto; SILVA, Erasmo Simao da; CERRI, Giovanni Guido; LEAO, Pedro Puech; TACHIBANA, Adriano; CHAMMAS, Maria CristinaOBJECTIVE: The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography. METHOD: Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow. RESULTS: Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001). CONCLUSIONS: We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard.
- Correlation of Bacterial Coinfection Versus Matrix Metalloproteinase 9 and Tissue Inhibitor of Metalloproteinase 1 Expression in Aortic Aneurysm and Atherosclerosis(2013) ROGGERIO, Alessandra; SAMBIASE, Nadia Vieira; PALOMINO, Suely A. P.; CASTRO, Maria Alice Pedreira de; SILVA, Erasmo Simao da; STOLF, Noedir G.; HIGUCHI, Maria de LourdesBackground: We searched for any relationship between Chlamydophila pneumoniae, Mycoplasma pneumoniae, matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in aneurysmatic atherosclerotic lesions, and whether this relationship differed from that in atherosclerotic nonaneurysmatic lesions. Methods: Twenty-eight tissue samples paired by age and sex were grouped as follows: group 1 included 14 nonaneurysmal atherosclerotic fragments obtained from abdominal aortas collected from necropsies; group 2 included 14 aneurysmatic atherosclerotic aortic fragments obtained from patients during corrective surgery. Immunohistochemistry reactions were evaluated for C pneumoniae, M pneumoniae, MMP-9, and TIMP-1 antigens. Both groups were compared using the Mann-Whitney test, and the correlations among variables were obtained using the Spearman correlation test. P <= 0.05 was considered statistically significant. Results: C pneumoniae and M pneumoniae antigens were detected in 100% of cases. A higher amount of C pneumoniae (P = 0.005), M pneumoniae (P = 0.002), and MMP-9 (P = 0.021) was found in adventitia of group 2 with aneurysm. A positive correlation was found in the aneurysm group, as follows: intima C pneumoniae versus adventitia thickness (r = 0.70; P = 0.01), media C pneumoniae versus adventitia C pneumoniae (r = 0.75; P 0.002), intima C pneumoniae versus media C pneumoniae (r = 0.8; P = 0.00), and adventitia C pneumoniae versus intima M pneumoniae (r = 0.54; P = 0.05); negative correlations were as follows: adventitia thickness and adventitia M pneumoniae (r = -0.65; P = 0.01), media MMP-9 and media thickness (r = -0.55; P = 0.04), TIMP-1 media versus adventitia C pneumoniae (r = -0.86; P = 0.00), and TIMP-1 media versus M pneumoniae intima (r = -0.67; P = 0.03). Nonaneurysmal atherosclerotic group 1 results are as follows: adventitia C pneumoniae versus TIMP-1 media (r = 0.75; P = 0.01) and media C pneumoniae and adventitia C pneumoniae (r = 0.59; P = 0.03). Conclusions: The present work favors a role for coinfection of both M pneumoniae and C pneumoniae in the development of aortic atherosclerotic aneurysm, with increased adventitial inflammation, inhibition of TIMP-1 activity, and increased collagen degradation.
- Open and endovascular repair of juxtarenal abdominal aortic aneurysms: a systematic review(2014) BELCZAK, Sergio Quilici; LANZIOTTI, Luiz; BOTELHO, Yuri; AUN, Ricardo; SILVA, Erasmo Simao da; PUECH-LEAO, Pedro; LUCCIA, Nelson deThis systematic review focuses on the 30-day mortality associated with open surgery and fenestrated endografts for short-necked (<15 mm) juxtarenal abdominal aortic aneurysms. A search for studies published in English and indexed in the PubMed and Medline electronic databases from 2002 to 2012 was performed, using ""juxtarenal abdominal aortic aneurysm"" and ""treatment"" as the main keywords. Among the 110 potentially relevant studies that were initially identified, eight were in accordance with the inclusion criteria in the analysis. Similar outcomes for open and endovascular repair were observed for 30-day mortality. No differences were observed regarding the secondary outcomes (duration of surgery, hospital stay, postoperative renal dysfunction and late mortality), except that the late mortality rate was significantly higher for the patients treated with open repair after a median follow-up of 24 months. Fenestrated endografting is a viable alternative to conventional surgery in juxtarenal abdominal aortic aneurysms with a proximal neck <15 mm.
- Left Common Carotid Artery Biomechanical Properties in Individuals over 80 years: Women Have Stiffer Vessels(2020) GOMES, Vivian Carla; SILVA, Luiz Fernando da; ZYNGIER, Selene Perrotti; SILVESTRE, Gina Camillo; QUEIROZ, Alexandre; MARQUES, Michele Alberto; SILVA, Erasmo Simao daBackground: Considering the longevity of the worldwide population, the cardiovascular diseases deserve particular attention, especially the carotid artery disease in the >= 80-year-old population. The stiffness of the common carotid artery, for example, has been showed in numerous clinical studies as a marker of increased risk of stroke, dementia, and depression. Besides, with the emergence of new surgical techniques such as the transcarotid artery revascularization that uses the common carotid artery as a workstation, the biomechanical and histological features of this vessel, more than ever, must be detailed. Methods: Left common carotid artery fragments from 9 cadaver donors (>= 80 years old) were evaluated. Biomechanical (failure stress, tension, and strain) and histological (percentage of collagen and elastic fibers) features of these samples were analyzed with special focus on gender differences. Results: Statistically significant differences in biomechanical and histological features between the genders were observed. The percentage of collagen fiber in intima (P = 0.008) and media (P = 0.041) layers was significantly lower in men than in women. A higher elasticity (failure strain) of the specimens in male gender was also observed (P = 0.025). No significant difference was observed in the layers thickness between the genders regardless which part of the arterial wall was considered. Conclusions: These biomechanical and histological findings could be the responsible for the higher left common carotid artery stiffness observed among >80-year-old women when compared with men in numerous clinical studies in literature.
- Biomechanical Analysis of Cadaveric Thoracic Aorta Zones: The Isthmus is the Weakest Region(2021) GOMES, Vivian Carla; SILVESTRE, Gina Camillo; QUEIROZ, Alexandre; MARQUES, Michele Alberto; LEAO, Pedro Puech; SILVA, Erasmo Simao daBackground: The thoracic aorta is a site of multiple pathological processes, such as aneurysms and dissections. When considering the development of endovascular devices, this vessel has been extensively manipulated because of aortic diseases, as well as to serve as a route for procedures involving the head and neck vessels. Therefore, the aim of the present study was to obtain biomechanical experimental information about the strength and deformability of this vessel. Materials and Methods: Thirty-one thoracic aorta specimens were harvested during the autopsy procedure. They were carefully dissected and transversally sectioned according to Criado's aortic arch map landing zones (0 to 4). The supra-aortic trunks were removed, and the aortic rings were opened in their convexity, which resulted in flat tissue segments. Four millimeter-wide strips were prepared from each zone after which they were attached to a clip system connected to the INSTRON SPEC 2200 device, which was responsible for pulling the fragment up to its rupture during the uniaxial tension test. The INSPEC software was used to coordinate the test, and data management was conducted via the SERIES IX software. The biomechanical variables that were measured included failure stress, failure tension, and failure strain. Results: When comparing the five segments from all 31 aortas, three different strength levels were observed. Zones 0 and 1 exhibited the highest failure stress and failure tension values, followed by Zones 2 and 4. Zone 3 (aortic isthmus) was the weakest segment that was tested when compared to the stress and tension of Zones 0 and 1 (P < 0.001), the stress and tension of Zone 2 (P = 0.005 and P = 0.002, respectively) and the stress and tension of Zone 4 (P = 0.023 and P = 0.006, respectively). Among donors > 65 years-old, women presented significantly weaker descending aortas than men in regards to stress (P = 0.049) and tension (P = 0.014). Among male donors, the elderly donors presented significantly stiffer aortic walls and weaker ascending (P = 0.029 for stress) and descending (P = 0.004 for stress; P = 0.031 for tension) aortas than younger men. Conclusions: Uniaxial tensile strength tests revealed that the thoracic aorta is a very heterogeneous vessel. Isthmus frailty may add to the understanding of the pathophysiology of some aortic diseases that commonly compromise this region. The lower strength that was verified in some aortic segments from elderly donors may contribute to the genesis of some thoracic aorta diseases among that group of donors. These data can contribute to the development of new endovascular devices that are specifically designed for this vessel.
- Biomechanical and histological data from abdominal aortas harvested in autopsy(2021) GOMES, Vivian Carla; SILVA, Luiz Fernando Ferraz da; RAGHAVAN, Madhavan Lakshmi; GOMES, Jorge; SILVESTRE, Gina Camillo; QUEIROZ, Alexandre; MARQUES, Michele Alberto; ZYNGIER, Selene Perrotti; CHUNG, Timothy Kwang-Joon; SILVA, Erasmo Simao daThis data article describes biomechanical and histological information of abdominal aortas harvested in autopsy. Eight abdominal aorta aneurysms (AAA) and 30 normal diameter abdominal aortas were collected and submitted to an inflation test up to their rupture. This inflation procedure was part of the research entitled ?Experimental study of rupture pressure and elasticity of abdominal aortic aneurysms found at autopsy?, submitted to Annals of Vascular Surgery. The rupture borders and control samples (harvested from places other than the rupture site) were submitted to uniaxial destructive tensile test and to histological analysis. The following variables were evaluated in the biomechanical test: failure stress, failure tension and failure strain. The histological processing of the samples enabled a quantitative analysis of the percentage of coverage of collagen fibers and elastic fibers in the samples. The present data could be reutilized because they are experi-mental evidence that cadaveric abdominal aortas, even when previously stressed by inflation, conserve significant resis-tance against tearing comparable to no previously stressed aortas described in the literature. Considering real whole ca-daveric AAAs are especially scarce, this information would be a useful reference source for further in-depth research in the aortic biomechanics field. (C) 2021 The Authors.
- Endovascular and open repair for blunt aortic injury, treated in one clinical institution in Brazil. A case series(2011) SINCOS, Igor Rafael; AUN, Ricardo; BELCZAK, Sergio Quilici; NASCIMENTO, Luciano Dias; NETTO, Boulanger Mioto; CASELLA, Ivan; SILVA, Erasmo Simao da; PUECH-LEAO, PedroOBJECTIVE: The objective of this retrospective study is to analyze and compare the results of conventional surgical repair and endovascular treatment of blunt aortic injury over the past 8 years. METHODS: Twenty-eight patients (25 male; mean age, 35 years) were treated for blunt aortic injury between April 2001 and March 2009 in a university hospital in Brazil. Twenty-six patients were included in the study: five were treated with operative repair (OR) and 21 with endovascular treatment (TEVAR). Two patients were excluded from analysis: one was managed conservatively, and one was treated with endovascular treatment for chronic dissection related to aortic trauma. RESULTS: Mean age was lower in the OR group than in the endovascular treatment group (17.8 vs. 38 years, P = .003). There was one death in the OR group and four deaths in the endovascular treatment group. Mean follow-up for the overall group was 33.6 months, with 48.7 months (range 8-83 months) for the OR group, and 29.8 months (range 2-91 months) for the TEVAR group. Mean time elapsed from injury to repair was 23.4 hours (range 8-48 h, median 20 h) for the OR group and 30.3 hours (range 2-240 h, median 18 h) for the TEVAR group (P = .374). The duration of surgery was shorter in the endovascular treatment group (142 versus 237 minutes; P = .005). There were no significant differences with respect to the number of postoperative days requiring mechanical ventilation, duration of ICU stay or duration of hospital stay. CONCLUSION: In this retrospective analysis, endovascular treatment was a safe method for repair of blunt aortic trauma, with immediate and midterm results that were comparable to those results obtained with operative repair. No complications from the stent graft were identified during follow-up. Nevertheless, long-term follow-up is necessary to confirm the effectiveness of this treatment.
- Biomechanical Properties and Microstructural Analysis of the Human Nonaneurysmal Aorta as a Function of Age, Gender and Location: An Autopsy Study(2015) NINOMIYA, Otavio Henrique; MONTEIRO, Jose Augusto Tavares; HIGUCHI, Maria de Lourdes; PUECH-LEAO, Pedro; LUCCIA, Nelson de; RAGHAVAN, Madhavan Lakshmi; SILVA, Erasmo Simao daIntroduction: The biomechanical failure properties and histological composition of the human nonaneurysmal aorta were studied. Methods: Twenty-six human aortas were harvested from fresh cadavers at autopsy. A total of 153 circumferentially oriented strips were obtained from the aortas for biomechanical and histological studies. Results: The failure load (6.18 +/- 2.03 vs. 4.85 +/- 2.04 N; p = 0.001), failure tension (19.88 +/- 9.05 vs. 14.53 +/- 7 N/cm; p = 0.001), failure strain (0.66 +/- 0.31 vs. 0.49 +/- 0.25; p = 0.003) and amount of elastic fibers (19.39 +/- 15.57 vs. 14.06 +/- 9.5%; p = 0.011) were all significantly higher for the thoracic than the abdominal aorta. There was a significant negative correlation between age and failure load (R = -0.35; p < 0.0001), failure stress (R = -0.63; p < 0.0001), failure tension (R = -0.52; p < 0.0001) and failure strain (R = -0.8; p < 0.0001). Male aortas had a higher failure load and failure tension than female aortas. Conclusion: The thoracic aorta has a higher strength and elasticity than the abdominal aorta. The elderly have weaker and stiffer aortas than the young. Male aortas are stronger than female aortas. (C) 2016 S. Karger AG, Basel
- Type II Endoleaks, Left-Arm Complications, and Need of Revascularization after Left Subclavian Artery Coverage for Thoracic Aortic Aneurysms Endovascular Repair: A Systematic Review(2017) BELCZAK, Sergio Quilici; SILVA, Erasmo Simao; KLAJNER, Rafael; PUECH-LEAO, Pedro; LUCCIA, Nelson DeBackground: The status of the left arm, the need of revascularization, and the occurrence of type II endoleakes from de left subclavian artery (LSA) after intention LSA coverage for thoracic aortic aneurysm endovascular repair need to be better understood. This systematic review was developed for contributing with such issue. Methods: Systematic literature review of studies published from January 2000 through December 2015 identified 7 studies comprising 201 patients submitted to elective endovascular repair for thoracic aortic aneurysms requiring intentional LSA coverage. Outcomes of interest included left-arm complications (ischemia, symptoms of claudication, and subclavian steal syndrome [SSS]) requiring postoperative revascularization of LSA, as well as endoleaks from the subclavian artery requiring postoperative embolization of LSA. Results: Left-arm complication rate was 4.5% (9 patients), requiring postoperative revascularization of LSA in 1 case (0.5%) of SSS. Type II endoleaks from the subclavian artery requiring postoperative embolization of LSA were reported in 2 cases (1.0%). Conclusions: Low-quality evidence suggests very low rates of arm complications with need of LSA revascularization and of type II endoleaks requiring embolization in elective endovascular treatment of thoracic aortic aneurysms with intentional coverage of LSA without prophylactic revascularization of LSA.