Normal Costoclavicular Distance as a Standard in the Radiological Evaluation of Thoracic Outlet Syndrome in the Costoclavicular Space.

BACKGROUND: The costoclavicular space is a common site of thoracic outlet syndrome. When there is no anatomical alteration, the diagnosis of thoracic outlet syndrome is difficult. Several authors relate costoclavicular distance to symptoms of thoracic outlet syndrome; however, there is no standardized site for measurement of the costoclavicular distance. This study aimed to determine the standard costoclavicular distance at neurovascular bundle crossing points (near the subclavian vein [Measure V] and the subclavian artery/brachial plexus branches [Measure NA]) using high-resolution chest computed tomography (CT) scans and evaluate its variations with respect to age, sex, height, and body mass index. METHODS: This prospective cross-sectional observational study analyzed 150 of 156 CT scans from consecutive adult patients (72 females and 78 males). Costoclavicular distance was measured at the subclavian vein and brachial plexus/subclavian artery sites, where narrowing of the costoclavicular distance could lead to symptoms of thoracic outlet syndrome. Costoclavicular distance was analyzed with respect to sex, laterality, age group (<50 and ≥50 years) and body mass index group (body mass index <25 and ≥25 kg/m2). RESULTS: Measures of V and NA were normally distributed. The measured costoclavicular distances were 1.23 cm (±0.40) and 1.24 cm (±0.47), respectively. Age (≥50 years) and body mass index (≥25 kg/m2) increased the costoclavicular distance. Measurements V and NA below the fifth percentile indicated a narrowed costoclavicular distance and a greater chance of developing thoracic outlet syndrome. For young (<50 years) and eutrophic patients (body mass index <25 kg/m2), these measurements were 0.46 and 0.44 cm, respectively; for young people and body mass index ≥25 kg/m2, they were 0.54 and 0.24 cm, respectively; for the elderly (≥50 years) and eutrophic, they were 0.57 and 0.48 cm, respectively; and for the elderly and body mass index ≥ 25 kg/m2, they were 0.83 and 0.73 cm, respectively. There was no significant difference between measurements V and NA regarding patient laterality, gender, and height. CONCLUSIONS: Standardization of costoclavicular distance measurements at neurovascular bundle crossing points (subclavian vein and brachial plexus/subclavian artery) is possible. It may aid the diagnosis and help direct the therapeutic indications for symptomatic patients with thoracic outlet syndrome.

Study of the Biomechanical and Histological Properties of the Abdominal Aorta of Diabetic Rats Exposed to Cigarette Smoke.

INTRODUCTION: In spite of the great relevance of abdominal aortic aneurysm, its etiopathogenesis is not fully understood. The biomechanical and histological study of the aortic wall may contribute to this elucidation. METHODS: Seventy-five male Wistar rats were divided into 4 groups: control (CG), smoker (SG), diabetic (DG), and diabetic + smoker (DSG). The SG and DSG rats were exposed to cigarette smoke for 30 min/day, 5 days a week. Diabetes was induced by the intravenous injection of streptozotocin. After 16 weeks, the abdominal aorta was collected for biomechanical, histological, and matrix metalloproteinase 2 (MMP-2) activity analyses. RESULTS: The valid biomechanical tests of 52 specimens were analyzed: 11 in the CG, 10 in the DG, 16 in the SG, and 15 in the DSG. The biomechanical analysis of the fragments showed no differences between the control, DG, SG, and DSG. Collagen deposition also did not present a significant difference between the studied groups. The total count of elastic fibers was higher in diabetic rats (DG and DSG) than in the SG. The inflammatory response observed in all experimental groups was significantly more intense than in the CG. Compared to the DSG, MMP-2 activity showed a significant decrease in the DG. CONCLUSIONS: Resistance and elasticity did not present a difference between the CG and the DG, SG, and DSG. Compared to the CG, the total count of elastic fibers, fragmentation of the elastic lamina, pericellular matrix deposition, and cell loss/substitution in the tunica media showed significant alterations in the aortic walls of the DG, SG, and DSG. MMP-2 activity was lower in the DG aorta than in the DSG aorta.

Development of a Puncture Technique for Implanting Temporary Vascular Shunts in a Porcine Model.

BACKGROUND: Temporary vascular shunts (TVSs) are an effective tool for rapidly restoring blood flow to a limb or organ that has experienced vascular injury and ischemia and for which revascularization is not an immediate option. Usually, through an opening in the skin, the TVS is positioned within the proximal and distal stumps of the injured vessel, restoring perfusion and stopping the ischemia. The aim of this study is to compare standard TVS technique and a developed puncture technique for implanting TVS and to evaluate the utility and feasibility of this protocol after arterial lesions, in pigs. METHODS: Vascular injuries were inflicted in both hind limbs of 30 pigs, and vascular interventions were performed, using standard and puncture TVS. Because each pig was implanted with both types of TVSs, it was possible to simultaneously monitor, analyze, and compare parameters such as, the mean arterial pressure (MAP, in mm Hg), blood flow (mL/min), and insertion times, in the same animal. RESULTS: It was observed that the MAP in the limbs recovered and approached systemic MAP, in 100% of the experiments, in both groups. Analysis of the blood flow data showed that this parameter was significantly reduced in the puncture TVS group (110.36 ± 9.99 mL/min vs. 153.20 ± 18.57 mL/min, P = 0.001). On the other hand, the insertion time for the standard TVS was significantly greater than that of the puncture shunt (15.32 ± 3.08 min vs. 10.37 ± 1.7 min, P = 0.001). Furthermore, it was found that the primary and secondary patency and complication rates were similar for both TVS types. CONCLUSION: Thus, given the adequate MAP recovery and reduction in implantation time observed in this experimental and in an animal model study, the use of the puncture TVS technique is effective and feasible.

The similarities and differences among patients with abdominal aortic aneurysms referred to a tertiary hospital and found at necropsy.

OBJECTIVE: 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. METHODS: We have retrospectively analyzed the medical records of 556 patients with abdominal aortic aneurysm and 102 cases abdominal aortic aneurysm found at necropsy. RESULTS: 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. CONCLUSION: Intact abdominal aortic aneurysm at necropsy and at outpatients setting showed similarities that confirmed that abdominal aortic aneurysm repair is less offered to women, and they died more frequently with intact abdominal aortic aneurysm from other causes.

Histologic analysis of stent graft oversizing in the thoracic aorta.

OBJECTIVE: 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. METHODS: 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: >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). RESULTS: 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. CONCLUSIONS: 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.

Impact of stent-graft oversizing on the thoracic aorta: experimental study in a porcine model.

PURPOSE: To analyze in an experimental animal model the effect of 4 different levels of stents-graft oversizing on non-atherosclerotic aortas such as those found in young individuals who undergo stent-graft repair for traumatic aortic injuries. METHODS: The diameter of the porcine thoracic aorta is similar to the aorta of young adults (18-20 mm), so 25 pigs were randomized into 5 groups: 1 control (without stent-graft) and 4 oversizing groups (A: 10%-19%, B: 20%-29%, C: 30%-39%, and D: >40%). Two types of biomechanical tests were performed on all aortas 4 weeks after endoprosthesis deployment. RESULTS: The results of the detachment test, which analyzed the strength necessary to remove the stent-graft from the aorta, were similar in the 4 groups (A: 42 N, B: 41 N, C: 46 N, and D: 46 N). However, 2 aortas ruptured during the tests (groups C and D). The second test was performed in 3 aortic segments. Maximum shear strength, maximum stress, and maximum tension supported by the aortic wall had a negative and linear correlation with oversizing. There were significant differences in all 4 groups when compared with the control group. Strain, which reflects the elastic properties of the aortic wall, was very similar in all 4 groups, but a great difference was found when compared with the control group (p<0.0001). CONCLUSION: The study showed an important subacute change in the biomechanical properties of the aortic wall after implantation of an oversized endoprosthesis. This weakness of the aortic wall was confirmed by 2 ruptures during the detachment test. These results partially explain the interaction of stent-grafts with non-atherosclerotic thoracic aortas and may serve as a basis for further studies and the development of specific material to be used in vascular trauma and young patients.

Treatment of varicose ulcer of the lower limbs by surgery and Unna boot: savings for the Brazilian healthcare system.

OBJECTIVE: To perform an analysis of the costs of treatment of varicose ulcers by radical surgery of varices and the use of Unna boot. METHODS: Fifteen outpatients were selected to receive treatment of varicose ulcers with radical surgery and Unna boot. The total cost of treatment was calculated (hospitalization, surgery, dressings, and outpatient's follow-up visits) and compared to the cost of clinical follow-up with daily simple dressing changes. RESULTS: The proposed treatment was on average 55.71% more economical than the management with daily dressings (approximately US$452.32 versus US$1,021.39). CONCLUSION: Radical varicose vein surgery associated with the use of the Unna boot proved meaningly less expensive for the public health system than clinical follow-up with daily dressings.

Endovascular treatment of peripheral arterial injury with covered stents: an experimental study in pigs.

OBJECTIVE: 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.

Tratamento da úlcera varicosa dos membros inferiores mediante cirurgia e bota de Unna: uma economia para o sistema de saúde brasileiro / Treatment of varicose ulcer of the lower limbs by surgery and Unna boot: savings for the Brazilian healthcare system

Objective: To perform an analysis of the costs of treatment of varicose ulcers by radical surgery of varices and the use of Unna boot. Methods: Fifteen outpatients were selected to receive treatment of varicose ulcers with radical surgery and Unna boot. The total cost of treatment was calculated (hospitalization, surgery, dressings, and outpatient?s follow-up visits) and compared to the cost of clinical follow-up with daily simple dressing changes. Results: The proposed treatment was on average 55.71% more economical than the management with daily dressings (approximately US$452.32 versus US$1,021.39). Conclusion: Radical varicose vein surgery associated with the useof the Unna boot proved meaningly less expensive for the public health system than clinical follow-up with daily dressings.

Objetivo: Realizar uma análise de custo do tratamento da úlcera varicosa mediante cirurgia radical de varizes e uso de bota de Unna. Métodos: quinze pacientes foram selecionados ambulatorialmente para receber o tratamento da úlcera varicosa com cirurgia radical de varizes e bota de Unna, sendo o custo total do tratamento contabilizado (internação, cirurgia, curativos e retornos ambulatoriais) e comparado ao custo do acompanhamento clínico com curativos simples trocados diariamente. Resultados: O tratamento proposto foi em média 55,71% mais econômico que o manejo com curativos diários (R$ 717,84 x R$ 1.620,95 ou aproximadamente US$ 452.32 x US$ 1,021.39). Conclusão: O emprego da cirurgia radical de varizes associado ao uso de bota de Unna provou-se expressivamente menos dispendioso para a saúde pública do que o acompanhamento clínico com curativos diários.

Endovascular treatment of peripheral arterial injury with covered stents: an experimental study in pigs

OBJECTIVE: 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 percent, lesion >50 percent, 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 percent lesion groups. Success was also achieved in four out of five pigs in the >50 percent 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.