Erasmo Da Silva | Universidade de São Paulo (original) (raw)

Papers by Erasmo Da Silva

Research paper thumbnail of Mandibular Subluxation for Distal Cervical Exposure of the Internal Carotid Artery

The Laryngoscope, 2007

Introduction: Surgical access to the distal segment of the cervical internal carotid artery (ICA)... more Introduction: Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible. Methods: Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS. Results: After MS, a 5.52 ؎ 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure. Conclusion: MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.

Research paper thumbnail of A rare presentation of ruptured infected popliteal artery aneurysm with massive local emphysema

Vascular medicine (London, England), 2015

Research paper thumbnail of Developing a new endograft for the treatment of juxtarenal aortic aneurysms: definition and experimentation

Clinics (São Paulo, Brazil), 2015

To analyze angiotomographic parameters of juxtarenal aneurysms to assess the applicability of an ... more To analyze angiotomographic parameters of juxtarenal aneurysms to assess the applicability of an endograft model to patients and to create in vitro and in vivo models to assess the new endograft. A total of 49 patients with juxtarenal aneurysms were submitted to angiotomographic evaluation, and parameters such as the aortic diameter, the length of the neck, and the angulations of the celiac trunk, superior mesenteric artery and renal arteries; the distances between them; and anatomic variations were analyzed. Based on these parameters, an endograft model was developed and tested in a newly created in vitro model of juxtarenal aneurysm. An experimental model of juxtarenal aneurysm was then established in six pigs weighing 50-60 kg to assess the new endograft model. The angiotomographic parameters of juxtarenal aneurysm measured in this study were similar to those reported in the literature and allowed the development of an endograft based on the hourglass concept, which was applicabl...

Research paper thumbnail of A prospective randomised study comparing polidocanol foam sclerotherapy with surgical treatment of patients with primary chronic venous insufficiency and ulcer

Annals of Vascular Surgery, 2015

Please cite this article as: Campos W Jr., Torres IO, da Silva ES, Casella IB, Puech-Leão P, A pr... more Please cite this article as: Campos W Jr., Torres IO, da Silva ES, Casella IB, Puech-Leão P, A prospective randomised study comparing polidocanol foam sclerotherapy with surgical treatment of patients with primary chronic venous insufficiency and ulcer, Annals of Vascular Surgery (2015),

Research paper thumbnail of Common Carotid Artery Occlusion: A Single-Center Experience in 40 Cases

International Journal of Angiology, 2015

Research paper thumbnail of Analysis of risk factors and diseases associated with atherosclerosis in the progression of carotid artery stenosis

Vascular, Jan 16, 2015

The objective of this study was to analyze the roles of demographic, clinical, and laboratory fac... more The objective of this study was to analyze the roles of demographic, clinical, and laboratory factors on the progression of atherosclerotic stenosis in carotid bifurcation. It was based on prospective information from records entered on a specific application form for follow-up outpatients at a tertiary university service. Consecutive symptomatic and asymptomatic patients (n = 210) who had undergone more than one carotid duplex scan but no surgical intervention were selected for the analysis. The patients were divided into two groups: patients whose duplex scans did not show bilateral progression of carotid stenosis and patients with carotid stenosis progression of <50%, 50%-69%, or >70%. Clinical and demographic parameters were compared between groups. Group II levels of plasma urea (51.6 ± 27.8 mg/dl) and fibrinogen (493.2 ± 113.3 mg/dl) were higher than the Group I levels (43.0 ± 14.9 mg/dl and 441.3 ± 106.7 mg/dl, respectively) with statistical significance (p urea = 0.013...

Research paper thumbnail of Endovascular model of abdominal aortic aneurysm induction in swine

Vascular medicine (London, England), Jan 30, 2014

Abdominal aortic aneurysms are among the main causes of death. The high morbidity and mortality a... more Abdominal aortic aneurysms are among the main causes of death. The high morbidity and mortality associated with aneurysm rupture and repair represents a challenge for surgeons and high risk for patients. Although experimental models are useful to understand, train, and develop new treatment and diagnostic methods for this pathology, animal models developed to date are far from ideal. Animals are either too small and do not represent the pathology of humans, or the procedures employ laparotomy, or the aortic behavior does not resemble that of a true aneurysm. We developed a novel, less invasive and effective method to induce true aortic aneurysms in Large White pigs. Animals were submitted to an endovascular chemical induction using either calcium chloride (25%) or swine pancreatic elastase. Controls were exposed to saline solution. All animals were operated on using the same surgical technique under general anesthesia. They were followed weekly with ultrasound examinations and at 4 ...

Research paper thumbnail of The similarities and differences among patients with abdominal aortic aneurysms referred to a tertiary hospital and found at necropsy

Vascular, Jan 23, 2014

To analyze the characteristics of patients with abdominal aortic aneurysms referred to a tertiary... more To analyze the characteristics of patients with abdominal aortic aneurysms referred to a tertiary center and to compare with individuals with abdominal aortic aneurysm found at necropsy. We have retrospectively analyzed the medical records of 556 patients with abdominal aortic aneurysm and 102 cases abdominal aortic aneurysm found at necropsy. At univariated analysis, hypertension, tobacco use and maximum diameter were significant risk factors for symptomatic aneurysm, while diabetes tended to be a protective factor for rupture. By logistic regression analysis, the largest transverse diameter was the only one significantly associated with abdominal aortic aneurysm rupture (p < .0001, odds ratio 1.7, 95% confidence interval 1.481-1.951). Intact abdominal aortic aneurysm found at necropsy showed similarities with outpatients in relation to abdominal aortic aneurysm diameter and risk factors. Intact abdominal aortic aneurysm at necropsy and at outpatients setting showed similarities...

Research paper thumbnail of 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?

Clinics (São Paulo, Brazil), 2015

The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with ... more 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. 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. 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...

Research paper thumbnail of Open and endovascular repair of juxtarenal abdominal aortic aneurysms: a systematic review

Clinics, 2014

This systematic review focuses on the 30-day mortality associated with open surgery and fenestrat... more This 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.

Research paper thumbnail of Abdominal aortic pseudoaneurysm diagnosed 42 years after abdominal gunshot wound

Research paper thumbnail of Mechanical Properties of AAA Tissue

Studies in Mechanobiology, Tissue Engineering and Biomaterials, 2011

Purpose: To test the hypothesis that ruptured abdominal aortic aneurysms (AAA) are globally weake... more Purpose: To test the hypothesis that ruptured abdominal aortic aneurysms (AAA) are globally weaker than unruptured ones. Methods: Four ruptured and seven unruptured AAA specimens were harvested whole from fresh cadavers during autopsies performed over an 18-month period. Multiple regionally distributed longitudinally oriented rectangular strips were cut from each AAA specimen for a total of 77 specimen strips. Strips were subjected to uniaxial extension until failure. Sections from approximately the strongest and weakest specimen strips were studied histologically and histochemically. From the loadextension data, failure tension, failure stress and failure strain were calculated. Rupture site characteristics such as location, arc length of rupture and orientation of rupture were also documented. Results: The failure tension, a measure of the tissue mechanical caliber was remarkably similar between ruptured and unruptured AAA (group mean 7 standard deviation of within-subject means: 11.2 7 2.3 versus 11.6 73.6 N/cm; p¼ 0.866 by mixed model ANOVA). In post-hoc analysis, there was little difference between the groups in other measures of tissue mechanical caliber as well such as failure stress (95 7 28 versus 987 23 N/cm 2 ; p¼ 0.870), failure strain (0.39 7 0.09 versus 0.36 7 0.09; p¼ 0.705), wall thickness (1.7 70.4 versus 1.5 7 0.4 mm; p¼ 0.470) , and % coverage of collagen within tissue cross section (49.6 712.9% versus 60.8 79.6%; p¼ 0.133). In the four ruptured AAA, primary rupture sites were on the lateral quadrants (two on left; one on left-posterior; one on right). Remarkably, all rupture lines had a longitudinal orientation and ranged from 1 to 6 cm in length. Conclusion: The findings are not consistent with the hypothesis that ruptured aortic aneurysms are globally weaker than unruptured ones.

Research paper thumbnail of A familial case of cleidocranial dysostosis presenting upper limb ischemia

Sao Paulo Medical Journal, 2005

Upper limb ischemia is not as common as lower limb ischemia but may cause severe impairment or di... more Upper limb ischemia is not as common as lower limb ischemia but may cause severe impairment or disability if it is misdiagnosed. A case of a woman with cleidocranial dysostosis resulting in upper right limb ischemia is presented. This uncommon condition is an exceedingly rare cause of vascular compression that gives rise to thrombosis of the axillary-subclavian arteries. Only two cases have previously been reported.

Research paper thumbnail of Histologic, histochemical, and biomechanical properties of fragments isolated from the anterior wall of abdominal aortic aneurysms

Journal of Vascular Surgery, 2014

To analyze biomechanical, histologic, and histochemical properties of anterior fragments of abdom... more To analyze biomechanical, histologic, and histochemical properties of anterior fragments of abdominal aortic aneurysms (AAA) and to correlate them with the maximum transverse diameter (MTD) and symptoms associated to the aneurysms. Fragments of the anterior aneurysm wall were obtained from 90 patients submitted to open repair of AAA of degenerative etiology from 2004 to 2009 in the Clinics Hospital of São Paulo University Medical School. Two specimens were produced from the fragments: one for histologic analysis for quantification of collagen fibers, elastic fibers, smooth muscle cells, and degree of inflammatory activity and the other for uniaxial tensile test to assess biomechanical failure properties of the material, such as strength, tension, and stress. Cases were classified according to symptoms and to the AAA MTD. Fragments from AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.5 cm showed higher values for biomechanical failure properties than those of AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.5 cm (strength, 5.32 ± 2.07 × 4.1 ± 2.41 N; tension, 13.83 ± 5.58 × 10.82 ± 6.48 N/cm; stress, 103.02 × 77.03 N/cm(2); P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05). No differences were observed between the groups in relation to failure strain (0.41 ± 0.12 × 0.37 ± 0.14; P = .260) and thickness of the fragments (1.58 ± 0.41 × 1.53 ± 0.42 mm; P = .662). The average values of fiber compositions of all the fragments were as follows: collagen fibers, 44.34 ± 0.48% and 61.85 ± 10.14% (Masson trichrome staining and Picrosirius red staining, respectively); smooth muscle cells, 3.46 ± 2.23% (immunohistochemistry/alpha-actin); and elastic fibers, less than 1% (traces) (Verhoeff-van Gieson staining). No differences in fiber percentages (collagen, elastic, and smooth muscle) were observed in fragments from AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5.5 cm and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5.5 cm, but more intense inflammatory activity was seen in larger AAA (grade 3; 70% × 28.6%; P = .011). Compared with asymptomatic aneurysms, symptomatic aneurysms showed no differences in the biomechanical failure properties (strength, 5.32 ± 2.36 × 4.65 ± 2.05 N; P = .155; tension, 14.08 ± 6.11 × 12.81 ± 5.77 N/cm; P = .154; stress, 103.02 × 84.76 N/cm(2); P = .144), strain (0.38 ± 0.12 × 0.41 ± 0.13; P = .287), thickness of the fragments (1.56 ± 0.41 × 1.57 ± 0.41 mm; P = .848), and histologic composition (collagen fibers, 44.67 ± 11.17 × 44.02 ± 13.79%; P = .808; smooth muscle fibers, 2.52 × 2.35%; P = .751; elastic fibers, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1%) Fragments of the anterior wall from larger aneurysms were more resistant than those from smaller AAA, with no tissue properties that could explain this phenomenon in the histologic or histochemical analyses utilized. The fragments of the anterior midsection from larger aneurysms were more resistant than those from smaller abdominal aortic aneurysms, with no tissue properties that could explain this phenomenon in the histologic or histochemical analyses. Larger aneurysms, at least in this place may be stronger than smaller aneurysms. It could point toward regional differences (heterogeneity, localized pathologies) as an important player in aneurysm rupture. Uniaxial strain tests are an important tool for the comprehension of a complex behavior such as that from an aneurysmal aortic wall. However, these tests still have limitations in providing information that would allow the calculation of the risk of rupture for abdominal aortic aneurysms.

Research paper thumbnail of Histologic analysis of stent graft oversizing in the thoracic aorta

Journal of Vascular Surgery, 2013

To elucidate the histologic changes after stent graft oversizing in nonatherosclerotic aortas usi... more To elucidate the histologic changes after stent graft oversizing in nonatherosclerotic aortas using an experimental porcine model. We previously reported that the diameter and angulation of the aorta in this model are similar to those in young individuals who undergo stent graft repair for blunt aortic injuries. The lack of commercially available stent grafts specific for repairing blunt aortic injuries, particularly for small and angulated aortas, may be related to the high rate of endograft complications in this population. Twenty-five pigs were randomized into one control group (without stent graft implantation) and four oversized groups (A: 10%-19%, B: 20%-29%, C: 30%-39%, and D: &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;40%). Three circumferential fragments were collected from the aorta for histologic and immunohistochemical studies. Morphometric analyzes were performed using an inflow system and image analysis software (Quantimet 500; Leica Cambridge Ltd, Cambridge, UK). Collagen expression in the aortic wall was not significantly different among the five groups (P = .5604). There were significantly fewer muscle fibers in the aortic wall in the oversized groups compared with the control group (P = .000198). The proportion of elastic fibers in the aortic wall was significantly smaller in the oversized groups compared with the control group (P = .0000001). Immunohistochemical analysis showed that α-actin expression in the aortic wall was significantly decreased in the oversized groups compared with the control group (P = .002031). There were no significant differences in either the number of muscle fibers or α-actin expression among the four oversized groups. Histologic and immunohistochemical studies confirmed the structural disarrangement of the aortic wall after insertion of an endoprosthesis, including reduced number of muscle and elastic fibers.

Research paper thumbnail of Relação morfológica entre o diâmetro, o colo proximal e distal dos aneurismas da aorta abdominal

Objetivo: Analisar relevantes aspectos anatômico-morfológicos dos aneurismas da aorta abdominal e... more Objetivo: Analisar relevantes aspectos anatômico-morfológicos dos aneurismas da aorta abdominal encontrados em necropsia.

Research paper thumbnail of Prevalência de aneurismas e outras anormalidades do diâmetro da aorta infra-renal detectadas em necropsia

Objetivos: Determinar a prevalência das anormalidades do diâmetro da aorta infra-renal encontrada... more Objetivos: Determinar a prevalência das anormalidades do diâmetro da aorta infra-renal encontradas em necropsia e comparar a prevalência dos óbitos de origem cardiovascular entre os portadores de anomalias do diâmetro arterial e a população testemunho da amostra.

Research paper thumbnail of Anatomical relation between the hypoglossal nerve and the carotid artery bifurcation

Palavras-chave: nervo hipoglosso, artéria carótida, anatomia, endarterectomia, tumor de corpo car... more Palavras-chave: nervo hipoglosso, artéria carótida, anatomia, endarterectomia, tumor de corpo carotídeo.

Research paper thumbnail of Mandibular Subluxation for Distal Cervical Exposure of the Internal Carotid Artery

The Laryngoscope, 2007

Introduction: Surgical access to the distal segment of the cervical internal carotid artery (ICA)... more Introduction: Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible. Methods: Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS. Results: After MS, a 5.52 ؎ 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure. Conclusion: MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.

Research paper thumbnail of A rare presentation of ruptured infected popliteal artery aneurysm with massive local emphysema

Vascular medicine (London, England), 2015

Research paper thumbnail of Developing a new endograft for the treatment of juxtarenal aortic aneurysms: definition and experimentation

Clinics (São Paulo, Brazil), 2015

To analyze angiotomographic parameters of juxtarenal aneurysms to assess the applicability of an ... more To analyze angiotomographic parameters of juxtarenal aneurysms to assess the applicability of an endograft model to patients and to create in vitro and in vivo models to assess the new endograft. A total of 49 patients with juxtarenal aneurysms were submitted to angiotomographic evaluation, and parameters such as the aortic diameter, the length of the neck, and the angulations of the celiac trunk, superior mesenteric artery and renal arteries; the distances between them; and anatomic variations were analyzed. Based on these parameters, an endograft model was developed and tested in a newly created in vitro model of juxtarenal aneurysm. An experimental model of juxtarenal aneurysm was then established in six pigs weighing 50-60 kg to assess the new endograft model. The angiotomographic parameters of juxtarenal aneurysm measured in this study were similar to those reported in the literature and allowed the development of an endograft based on the hourglass concept, which was applicabl...

Research paper thumbnail of A prospective randomised study comparing polidocanol foam sclerotherapy with surgical treatment of patients with primary chronic venous insufficiency and ulcer

Annals of Vascular Surgery, 2015

Please cite this article as: Campos W Jr., Torres IO, da Silva ES, Casella IB, Puech-Leão P, A pr... more Please cite this article as: Campos W Jr., Torres IO, da Silva ES, Casella IB, Puech-Leão P, A prospective randomised study comparing polidocanol foam sclerotherapy with surgical treatment of patients with primary chronic venous insufficiency and ulcer, Annals of Vascular Surgery (2015),

Research paper thumbnail of Common Carotid Artery Occlusion: A Single-Center Experience in 40 Cases

International Journal of Angiology, 2015

Research paper thumbnail of Analysis of risk factors and diseases associated with atherosclerosis in the progression of carotid artery stenosis

Vascular, Jan 16, 2015

The objective of this study was to analyze the roles of demographic, clinical, and laboratory fac... more The objective of this study was to analyze the roles of demographic, clinical, and laboratory factors on the progression of atherosclerotic stenosis in carotid bifurcation. It was based on prospective information from records entered on a specific application form for follow-up outpatients at a tertiary university service. Consecutive symptomatic and asymptomatic patients (n = 210) who had undergone more than one carotid duplex scan but no surgical intervention were selected for the analysis. The patients were divided into two groups: patients whose duplex scans did not show bilateral progression of carotid stenosis and patients with carotid stenosis progression of <50%, 50%-69%, or >70%. Clinical and demographic parameters were compared between groups. Group II levels of plasma urea (51.6 ± 27.8 mg/dl) and fibrinogen (493.2 ± 113.3 mg/dl) were higher than the Group I levels (43.0 ± 14.9 mg/dl and 441.3 ± 106.7 mg/dl, respectively) with statistical significance (p urea = 0.013...

Research paper thumbnail of Endovascular model of abdominal aortic aneurysm induction in swine

Vascular medicine (London, England), Jan 30, 2014

Abdominal aortic aneurysms are among the main causes of death. The high morbidity and mortality a... more Abdominal aortic aneurysms are among the main causes of death. The high morbidity and mortality associated with aneurysm rupture and repair represents a challenge for surgeons and high risk for patients. Although experimental models are useful to understand, train, and develop new treatment and diagnostic methods for this pathology, animal models developed to date are far from ideal. Animals are either too small and do not represent the pathology of humans, or the procedures employ laparotomy, or the aortic behavior does not resemble that of a true aneurysm. We developed a novel, less invasive and effective method to induce true aortic aneurysms in Large White pigs. Animals were submitted to an endovascular chemical induction using either calcium chloride (25%) or swine pancreatic elastase. Controls were exposed to saline solution. All animals were operated on using the same surgical technique under general anesthesia. They were followed weekly with ultrasound examinations and at 4 ...

Research paper thumbnail of The similarities and differences among patients with abdominal aortic aneurysms referred to a tertiary hospital and found at necropsy

Vascular, Jan 23, 2014

To analyze the characteristics of patients with abdominal aortic aneurysms referred to a tertiary... more To analyze the characteristics of patients with abdominal aortic aneurysms referred to a tertiary center and to compare with individuals with abdominal aortic aneurysm found at necropsy. We have retrospectively analyzed the medical records of 556 patients with abdominal aortic aneurysm and 102 cases abdominal aortic aneurysm found at necropsy. At univariated analysis, hypertension, tobacco use and maximum diameter were significant risk factors for symptomatic aneurysm, while diabetes tended to be a protective factor for rupture. By logistic regression analysis, the largest transverse diameter was the only one significantly associated with abdominal aortic aneurysm rupture (p < .0001, odds ratio 1.7, 95% confidence interval 1.481-1.951). Intact abdominal aortic aneurysm found at necropsy showed similarities with outpatients in relation to abdominal aortic aneurysm diameter and risk factors. Intact abdominal aortic aneurysm at necropsy and at outpatients setting showed similarities...

Research paper thumbnail of 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?

Clinics (São Paulo, Brazil), 2015

The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with ... more 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. 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. 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...

Research paper thumbnail of Open and endovascular repair of juxtarenal abdominal aortic aneurysms: a systematic review

Clinics, 2014

This systematic review focuses on the 30-day mortality associated with open surgery and fenestrat... more This 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.

Research paper thumbnail of Abdominal aortic pseudoaneurysm diagnosed 42 years after abdominal gunshot wound

Research paper thumbnail of Mechanical Properties of AAA Tissue

Studies in Mechanobiology, Tissue Engineering and Biomaterials, 2011

Purpose: To test the hypothesis that ruptured abdominal aortic aneurysms (AAA) are globally weake... more Purpose: To test the hypothesis that ruptured abdominal aortic aneurysms (AAA) are globally weaker than unruptured ones. Methods: Four ruptured and seven unruptured AAA specimens were harvested whole from fresh cadavers during autopsies performed over an 18-month period. Multiple regionally distributed longitudinally oriented rectangular strips were cut from each AAA specimen for a total of 77 specimen strips. Strips were subjected to uniaxial extension until failure. Sections from approximately the strongest and weakest specimen strips were studied histologically and histochemically. From the loadextension data, failure tension, failure stress and failure strain were calculated. Rupture site characteristics such as location, arc length of rupture and orientation of rupture were also documented. Results: The failure tension, a measure of the tissue mechanical caliber was remarkably similar between ruptured and unruptured AAA (group mean 7 standard deviation of within-subject means: 11.2 7 2.3 versus 11.6 73.6 N/cm; p¼ 0.866 by mixed model ANOVA). In post-hoc analysis, there was little difference between the groups in other measures of tissue mechanical caliber as well such as failure stress (95 7 28 versus 987 23 N/cm 2 ; p¼ 0.870), failure strain (0.39 7 0.09 versus 0.36 7 0.09; p¼ 0.705), wall thickness (1.7 70.4 versus 1.5 7 0.4 mm; p¼ 0.470) , and % coverage of collagen within tissue cross section (49.6 712.9% versus 60.8 79.6%; p¼ 0.133). In the four ruptured AAA, primary rupture sites were on the lateral quadrants (two on left; one on left-posterior; one on right). Remarkably, all rupture lines had a longitudinal orientation and ranged from 1 to 6 cm in length. Conclusion: The findings are not consistent with the hypothesis that ruptured aortic aneurysms are globally weaker than unruptured ones.

Research paper thumbnail of A familial case of cleidocranial dysostosis presenting upper limb ischemia

Sao Paulo Medical Journal, 2005

Upper limb ischemia is not as common as lower limb ischemia but may cause severe impairment or di... more Upper limb ischemia is not as common as lower limb ischemia but may cause severe impairment or disability if it is misdiagnosed. A case of a woman with cleidocranial dysostosis resulting in upper right limb ischemia is presented. This uncommon condition is an exceedingly rare cause of vascular compression that gives rise to thrombosis of the axillary-subclavian arteries. Only two cases have previously been reported.

Research paper thumbnail of Histologic, histochemical, and biomechanical properties of fragments isolated from the anterior wall of abdominal aortic aneurysms

Journal of Vascular Surgery, 2014

To analyze biomechanical, histologic, and histochemical properties of anterior fragments of abdom... more To analyze biomechanical, histologic, and histochemical properties of anterior fragments of abdominal aortic aneurysms (AAA) and to correlate them with the maximum transverse diameter (MTD) and symptoms associated to the aneurysms. Fragments of the anterior aneurysm wall were obtained from 90 patients submitted to open repair of AAA of degenerative etiology from 2004 to 2009 in the Clinics Hospital of São Paulo University Medical School. Two specimens were produced from the fragments: one for histologic analysis for quantification of collagen fibers, elastic fibers, smooth muscle cells, and degree of inflammatory activity and the other for uniaxial tensile test to assess biomechanical failure properties of the material, such as strength, tension, and stress. Cases were classified according to symptoms and to the AAA MTD. Fragments from AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.5 cm showed higher values for biomechanical failure properties than those of AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.5 cm (strength, 5.32 ± 2.07 × 4.1 ± 2.41 N; tension, 13.83 ± 5.58 × 10.82 ± 6.48 N/cm; stress, 103.02 × 77.03 N/cm(2); P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05). No differences were observed between the groups in relation to failure strain (0.41 ± 0.12 × 0.37 ± 0.14; P = .260) and thickness of the fragments (1.58 ± 0.41 × 1.53 ± 0.42 mm; P = .662). The average values of fiber compositions of all the fragments were as follows: collagen fibers, 44.34 ± 0.48% and 61.85 ± 10.14% (Masson trichrome staining and Picrosirius red staining, respectively); smooth muscle cells, 3.46 ± 2.23% (immunohistochemistry/alpha-actin); and elastic fibers, less than 1% (traces) (Verhoeff-van Gieson staining). No differences in fiber percentages (collagen, elastic, and smooth muscle) were observed in fragments from AAA with MTD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5.5 cm and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5.5 cm, but more intense inflammatory activity was seen in larger AAA (grade 3; 70% × 28.6%; P = .011). Compared with asymptomatic aneurysms, symptomatic aneurysms showed no differences in the biomechanical failure properties (strength, 5.32 ± 2.36 × 4.65 ± 2.05 N; P = .155; tension, 14.08 ± 6.11 × 12.81 ± 5.77 N/cm; P = .154; stress, 103.02 × 84.76 N/cm(2); P = .144), strain (0.38 ± 0.12 × 0.41 ± 0.13; P = .287), thickness of the fragments (1.56 ± 0.41 × 1.57 ± 0.41 mm; P = .848), and histologic composition (collagen fibers, 44.67 ± 11.17 × 44.02 ± 13.79%; P = .808; smooth muscle fibers, 2.52 × 2.35%; P = .751; elastic fibers, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1%) Fragments of the anterior wall from larger aneurysms were more resistant than those from smaller AAA, with no tissue properties that could explain this phenomenon in the histologic or histochemical analyses utilized. The fragments of the anterior midsection from larger aneurysms were more resistant than those from smaller abdominal aortic aneurysms, with no tissue properties that could explain this phenomenon in the histologic or histochemical analyses. Larger aneurysms, at least in this place may be stronger than smaller aneurysms. It could point toward regional differences (heterogeneity, localized pathologies) as an important player in aneurysm rupture. Uniaxial strain tests are an important tool for the comprehension of a complex behavior such as that from an aneurysmal aortic wall. However, these tests still have limitations in providing information that would allow the calculation of the risk of rupture for abdominal aortic aneurysms.

Research paper thumbnail of Histologic analysis of stent graft oversizing in the thoracic aorta

Journal of Vascular Surgery, 2013

To elucidate the histologic changes after stent graft oversizing in nonatherosclerotic aortas usi... more To elucidate the histologic changes after stent graft oversizing in nonatherosclerotic aortas using an experimental porcine model. We previously reported that the diameter and angulation of the aorta in this model are similar to those in young individuals who undergo stent graft repair for blunt aortic injuries. The lack of commercially available stent grafts specific for repairing blunt aortic injuries, particularly for small and angulated aortas, may be related to the high rate of endograft complications in this population. Twenty-five pigs were randomized into one control group (without stent graft implantation) and four oversized groups (A: 10%-19%, B: 20%-29%, C: 30%-39%, and D: &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;40%). Three circumferential fragments were collected from the aorta for histologic and immunohistochemical studies. Morphometric analyzes were performed using an inflow system and image analysis software (Quantimet 500; Leica Cambridge Ltd, Cambridge, UK). Collagen expression in the aortic wall was not significantly different among the five groups (P = .5604). There were significantly fewer muscle fibers in the aortic wall in the oversized groups compared with the control group (P = .000198). The proportion of elastic fibers in the aortic wall was significantly smaller in the oversized groups compared with the control group (P = .0000001). Immunohistochemical analysis showed that α-actin expression in the aortic wall was significantly decreased in the oversized groups compared with the control group (P = .002031). There were no significant differences in either the number of muscle fibers or α-actin expression among the four oversized groups. Histologic and immunohistochemical studies confirmed the structural disarrangement of the aortic wall after insertion of an endoprosthesis, including reduced number of muscle and elastic fibers.

Research paper thumbnail of Relação morfológica entre o diâmetro, o colo proximal e distal dos aneurismas da aorta abdominal

Objetivo: Analisar relevantes aspectos anatômico-morfológicos dos aneurismas da aorta abdominal e... more Objetivo: Analisar relevantes aspectos anatômico-morfológicos dos aneurismas da aorta abdominal encontrados em necropsia.

Research paper thumbnail of Prevalência de aneurismas e outras anormalidades do diâmetro da aorta infra-renal detectadas em necropsia

Objetivos: Determinar a prevalência das anormalidades do diâmetro da aorta infra-renal encontrada... more Objetivos: Determinar a prevalência das anormalidades do diâmetro da aorta infra-renal encontradas em necropsia e comparar a prevalência dos óbitos de origem cardiovascular entre os portadores de anomalias do diâmetro arterial e a população testemunho da amostra.

Research paper thumbnail of Anatomical relation between the hypoglossal nerve and the carotid artery bifurcation

Palavras-chave: nervo hipoglosso, artéria carótida, anatomia, endarterectomia, tumor de corpo car... more Palavras-chave: nervo hipoglosso, artéria carótida, anatomia, endarterectomia, tumor de corpo carotídeo.