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, lesio

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

Development and practical application of a puncture temporary vascular shunt: an experimental study in pigs

Os shunts vasculares temporários (SVT) são utilizados como uma técnica eficaz para reestabelecer rapidamente o fluxo sanguíneo em casos de lesão vascular com isquemia do membro ou órgão acometido, no qual a revascularização deverá ser postergada. Habitualmente, o SVT é inserido dentro dos cotos proximal e distal do vaso lesado através de uma abertura na pele, visando restaurar a perfusão e interromper a isquemia. O objetivo deste estudo é comparar a pressão arterial média (PAM em mmHg) e o fluxo sanguíneo (em ml/min) em dois modelos de SVT, um habitual e outro implantado por punção, bem como o tempo para a inserção destes dispositivos e suas patências primária e secundária. Realizamos experimentos em 30 suínos, somando 60 intervenções de revascularização arterial temporária dos membros posteriores: trinta SVT habituais e trinta por punção. Analisamos a PAM durante os procedimentos nos membros posteriores e o fluxo através dos dois tipos de SVT. A análise de fluxo mostrou uma diferença significativa entre os SVT testados (p=0,001), sendo menor no grupo SVT por punção. No entanto, o tempo decorrido (min) para inserção do SVT habitual foi maior do que o tempo para inserção do SVT por punção (15,32 ± 3,08 vs. 10,37 ± 1,7, p=0,001). Além disso, observamos uma recuperação da PAM nos membros submetidos aos dois tipos de SVT próxima à PAM sistêmica em 100% dos experimentos. Os resultados revelaram patência primária, secundária, e taxa de complicações similares entre os dois tipos de SVT. Concluímos que o fluxo foi menor no SVT por punção, mas a recuperação da PAM foi semelhante e com menor tempo de inserção do SVT por punçãoTemporary vascular shunts (TVS) are used as an effective technique to rapidly restore blood flow in cases of vascular injury with ischemia of the affected limb or organ, in which revascularization shall be postponed. Usually, TVS is positioned within the proximal and distal stumps of the injured vessel, through an opening of the skin, in order to restore perfusion and stop the ischemia. We sought to compare mean blood pressure (MBP in mmHg) and blood flow (ml/min) between two types of TVS, a standard one and a puncture one, as well as the time spent to insert these devices. We performed an experimental study on 30 pigs, including 60 vascular interventions in posterior limbs: thirty standard TVS and thirty puncture TVS. MBP was analyzed during the interventions in both posterior limbs and the flow through both types of TVS. Flow analysis revealed a significant difference between the two types of TVS (p=0,001), being lower in the puncture TVS. However, the time spent during standard TVS insertion was greater than that of the puncture shunt (15,32 ± 3,08 min vs.10,37 ± 1,7 min, p=0,001). In addition, we observed a limb MBP recovery close to systemic MBP in 100% of the experiments. The results show similar primary and secondary patency and complication rate in both TVS types. Therefore, we conclude that the flow was lower in the puncture TVS, but the MBP recovery was similar and it took less time to be inserte

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 publichealth system than clinical follow-up with daily dressings

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. J Endovasc Ther. 2011; 18: 576-584FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazi