Tratamento híbrido para revascularização de membro inferior em paciente com infecção de prótese vascular: relato de caso / Hybrid treatment for lower limb revascularization in a patient with vascular graft infection: a case report

Resumo Pacientes portadores de doença arterial obstrutiva periférica com isquemia crítica do membro associada a infecção de prótese vascular apresentam elevadas taxas morbimortalidade e alto risco de perda do membro. Apresentamos o caso de um paciente masculino de 76 anos com isquemia crítica do membro inferior esquerdo associada a infecção de prótese vascular femoropoplítea. Utilizamos abordagem híbrida para o tratamento com acesso cirúrgico das regiões inguinais e poplíteas, sendo a prótese vascular utilizada como acesso endovascular para recanalização direta da artéria femoral superficial devido a obstrução longa e extensa calcificação, que impediram as tentativas iniciais de tratamento endovascular. Após a recanalização endovascular, a prótese infectada foi retirada. O avanço das técnicas e materiais endovasculares em associação com a cirurgia aberta permitem novas soluções para pacientes quando os procedimentos habituais falham.

Abstract Patients with severe arterial obstructive disease and critical limb ischemia associated with vascular graft infection have elevated morbidity and mortality rates and are at high risk of limb loss. We present the case of a 76-year-old male patient with left lower limb critical ischemia and a femoropopliteal vascular graft infection. We used a hybrid treatment approach with an open surgical approach to the inguinal and popliteal regions and used the vascular prosthesis as endovascular access for direct recanalization of the superficial femoral artery, because the long occlusion and extensive calcification had frustrated initial attempts at endovascular treatment. After endovascular recanalization, the infected graft was removed. Used in conjunction with open surgery, advances in endovascular techniques and materials offer new solutions for patients when usual procedures fail.

Endovascular treatment of coarctation of the aorta with a self-expanding endoprosthesis: how i do it using the braile dominus ® coarctation aorta device

Abstract The coarctation of the aorta is a relatively highly prevalent congenital heart disease and may be diagnosed as an underline cause of hypertension in adolescents and adults. The gold standard treatment for coarctation of the aorta in these patients is being replaced - from open surgery to endovascular therapy. Some prostheses have been developed to treat the coarctation with less acute and chronic complications. The Dominus® Coarctation Aorta (Braile Biomédica) is the first self-expandable prosthesis created specifically to treat coarctation of the aorta, reducing possible acute complications, like aortic rupture or aortic dissection. Here, we discuss the step-by-step method for using this prosthesis.

Terapia endovascular en trauma periférico: una alternativa a la cirugía abierta tradicional / Endovascular therapy in peripheral trauma: our experience

Resumen Introducción: La terapia endovascular ha demostrado ser una buena alternativa de tratamiento en las enfermedades arteriales y venosas. Asimismo, en trauma vascular periférico constituye una excelente opción, especialmente en sitios anatómicos difíciles de acceder y con lesiones complejas como seudoaneurismas, fístulas arteriovenosas (FAV) o la combinación de ambos, con numerosas ventajas. Objetivo: Evaluar los resultados del tratamiento endovascular en trauma vascular penetrante por agresiones y iatrogenias. Materiales y Método: Revisión retrospectiva de todos los pacientes con trauma vascular periférico sometidos a terapia endovascular. Resultados: Entre abril de 2011 y mayo de 2020 se trataron 30 pacientes, 28 hombres y 2 mujeres. Con edades fluctuantes entre 17 y 84 años. La causa del trauma fue 20 penetrantes y 10 iatrogenias. Los vasos afectados fueron arteria femoral superficial 6, femoral profunda 2, subclavia 9, axilar 1, poplítea 4, ilíacas 1, peronea 1, tibial anterior 5, tronco venoso braquiocefálico 1. Diecisiete pacientes fueron tratados con endoprótesis, 9 con embolización y 4 con cierre percutáneo en relación con catéteres arteriales en subclavia. No hubo mortalidad, pero dos pacientes requirieron reparación abierta: un seudoaneurisma poplíteo gigante y un seudoaneurisma de tibial anterior, en ambos se constató sección completa de ambas arterias. El seguimiento clínico ha sido entre 30 días y 3 años. Conclusiones: En esta serie de casos, la terapia endovascular en lesiones de trauma vascular periférico ofrece excelentes resultados con baja morbimortalidad y permeabilidad aceptable a corto y mediano plazo.

Introduction: Endovascular therapy has proven to be a good treatment alternative in arterial and venous diseases. Likewise, in peripheral vascular trauma it is an excellent option, especially in anatomical sites that are difficult to access and with complex lesions such as pseudoaneurysms, arteriovenous fistulas (AVFs) or the combination of both, with numerous advantages. Aim: To evaluate the results of endovascular treatment in trauma Penetrating vascular injury and iatrogenesis. Materials and Method: Retrospective review of all patients with peripheral vascular trauma undergoing endovascular therapy. Results: Between April 2011 and May 2020, 30 patients were treated, 28 men and 2 women. With fluctuating ages between 17 and 84 years. The cause of the trauma was 20 penetrating and 10 iatrogenic. The affected vessels were superficial femoral artery 6, deep femoral 2, subclavian 9, axillary 1, popliteal 4, iliac 1, peroneal 1, anterior tibial 5, brachiocephalic venous trunk 1. Seventeen patients were treated with endoprosthesis, 9 with embolization and 4 with percutaneous closure in relation to arterial catheters in the subclavian. There was no mortality but two patients required open repair: a giant popliteal pseudoaneurysm and an anterior tibial pseudoaneurysm in which both sections of both arteries were found to be complete. Clinical follow-up was between 30 days and 3 years. Conclusión: In this serie, endovascular therapy in peripheral vascular trauma lesions offers excellent results with low morbidity and mortality and acceptable patency in the short and medium term.

Hybrid Approach to Complex Stanford Type B Dissection: Unusual Extra-anatomical Bypass (Aorto-Celiac-Mesenteric Bypass) + Thoracic Endovascular Aortic Repair (TEVAR) + Cholecystectomy

Abstract Patients with complex Stanford type B aortic dissection are very difficult to treat. Many methods have been proposed so far in the treatment of these patients, and the emergence of hybrid techniques has made the treatment easier. In this article, we shared the extra-anatomical bypass (aorto-celiac-mesenteric bypass) + thoracic endovascular aortic repair + cholecystectomy operation technique applied to a patient with complex type B aortic dissection.

Exploration of Simplified Intraluminal TEVAR Technique for the Treatment of Aortic Arch Disease

Abstract Objective: The positional relationship between the three branches of the aortic arch was determined in normal people. This study provides data to support the customization of aortic arch stents and simplifies intraluminal treatment. Methods: From January 2019 to August 2019, 120 patients who met the inclusion criteria were examined by CT angiography. The ratio of the distance from the midpoint of the three-branch opening onto the anterior wall to the cross-sectional diameter of the aortic arch was calculated. The positional relationship among the three-branch openings was obtained and the data were analyzed statistically. Results: The three-branch openings were not in a straight line. The positional relationship among the three-branch openings was divided into four types, which were not statistically different between sex and age (P>0.05). Conclusion: By measuring the opening position of the three aortic branches, the positional relationship among the three branches was defined to provide a theoretical basis for the design of intraluminal stents and simplified intracavity thoracic endovascular aortic repair (TEVAR) technology.

Pseudoaneurisma para-anastomótico gigante tras revascularización por baipás aorto-bifemoral: Informe de un caso / Giant para-anastomotic pseudoaneurysm after revascularization though aorto-bifemoral bypass grafting: Case report

RESUMEN El pseudoaneurisma es aquel hematoma pulsátil y encapsulado producido tras la rotura de todas las túnicas del vaso y contenido por tejidos vecinos circundantes. Es considerado una complicación tardía en la cirugía protésica aorto-ilíaca. Se presenta un paciente de 72 años al que se le realizó un baipás aorto-bifemoral 13 años atrás, y que posteriormente se le diagnosticó un pseudoaneurisma para-anastomótico que se dejó evolucionar por presentar varias comorbilidades asociadas. Transcurridos 2 años fue necesario realizarle una intervención quirúrgica por presentar crecimiento excesivo de la tumefacción y complicación isquémica con necrosis cutánea. La aparición de un pseudoaneurisma está relacionada con el sexo, el material protésico y con el tiempo que transcurre desde la cirugía. El seguimiento ultrasonográfico durante el postoperatorio es primordial para identificar tempranamente esta complicación.

ABSTRACT Pseudoaneurysm is that pulsatile and encapsulated hematoma produced after the rupture of all vessel layers and contained by surrounding neighboring tissues. It is considered a late complication in aorto-iliac prosthetic surgery. We present a 72-year-old patient who underwent an aorto-bifemoral bypass grafting 13 years ago, and who was subsequently diagnosed with a para-anastomotic pseudoaneurysm that was allowed to evolve due to presenting several associated comorbidities. After two years, it was necessary to perform a surgical intervention due to the excessive growth of the swelling, and ischemic complication with skin necrosis. The appearance of a pseudoaneurysm is related to sex, prosthetic material as well as the time that elapses since the surgery. Ultrasound follow-up during the postoperative period is essential for an early identification of this complication.

Multilayer stents affect the final diameter of aortic aneurysms and maintain renal artery patency for a short time in a swine experimental model

OBJECTIVES: We sought to analyze the hemodynamic effects of the multilayer flow-modulated stent (MFMS) in Thoracoabdominal aortic aneurysms (TAAAs). METHODS: The hemodynamic effects of MFMS were analyzed in aortic thoracoabdominal aneurysms in experimental swine models. We randomly assigned 18 pigs to the stent or control groups and underwent the creation of an artificial bovine pericardium transrenal aneurysm. In the stent group, an MFMS (Cardiatis, Isnes, Belgium) was immediately implanted. After 4 weeks, we evaluated aneurysm sac thrombosis and renal branch patency by angiography, duplex scan, and morphological analysis. RESULTS: All the renal arteries remained patent after re-evaluation in both groups. Aneurysmal sac thrombosis was absent in the control group, whereas in the stent group it was present in 66.7% of aneurysmal sacs (p=0.061). The mean final aneurysm sac diameter was significantly lower in the stent group (mean estimated reduction, 6.90 mm; p=0.021). The proximal neck diameter decreased significantly in the stent group (mean difference, 2.51 mm; p=0.022) and grew significantly in the control group (mean difference, 3.02 mm; p=0.007). The distal neck diameter increased significantly in the control group (mean difference, 3.24 mm; p=0.017). There were no significant findings regarding distal neck measurements in the stent group. CONCLUSION: The MFMSs remained patent and did not obstruct the renal arteries within 4 weeks. In the stent group, the device was also associated with a significant decrease in aneurysmal sac diameter and a large proportion (albeit non-significant) of aneurysmal sac thrombosis.

Epidemiological analysis of 5,595 procedures of endovascular correction of isolated descending thoracic aortic disease over 12 years in the public health system in Brazil

OBJECTIVES: In Brazil, descending thoracic aorta disease, including aneurysms and dissections, is managed preferentially by endovascular treatment, owing to its feasibility and good results. In this study, we analyzed endovascular treatment of isolated descending thoracic aortic disease cases in the Brazilian public health system over a 12-year period. METHODS: Public data from procedures performed from 2008 to 2019 were extracted using web scraping techniques to assess procedure type frequency (elective or urgency), mortality, and governmental costs. RESULTS: A total of 5,595 procedures were analyzed, the vast majority of which were urgent procedures (61.82% vs. 38.18%). In-hospital mortality was lower for elective than for urgent surgeries (4.96 vs.10.32% p=0.008). An average of R$16,845.86 and R$20,012.04 was paid per elective and emergency procedure, respectively, with no statistical difference (p=0.095). CONCLUSION: Elective procedures were associated with lower mortality than urgent procedures. There was no statistically significant difference between elective and urgent procedures regarding costs.

Experimental comparative study of arterial implants made of silicone reinforced with polyester fabric and expanded polytetrafluoroethylene (PTFE) in rabbits aorta / Estudo experimental comparativo de implantes arteriais em silicone com reforço de poliéster e politetrafluoretileno expandido (PTFE) em aorta de coelhos

ABSTRACT Objectives: the aim of this study was to compare the outcomes of a new silicone vascular prostheses with PTFE vascular prostheses, on a rabbit experimental model. Methods: forty rabbits underwent infra-renal aorta replacement with 4 mm diameter prostheses, twenty animals with PDMS and twenty animals with PTFE (control group). Retrograde aortic angiography was performed to assess patency. Histological graft samples were examined by electron microscopy to evaluate prostheses endothelialization. Results: patency rates were 100% for both grafts after 30 days; after 60 days, patency rate for PDMS was 92.3% (±7.4), and 73,8% (±13.1) at 90 days. PTFE grafts had patency rates of 87.5% (±11.7) at 60 and 90 days. No statistically significant difference was found in between groups for patency rates (p=0.62). Postoperative complications (death, paraplegia) rates (p=0.526) and aortic clamping times (p=0.299) were comparable in both groups. No statistically significant difference for stenosis was found on angiographical analysis between groups (p=0.650). Electron microscopy revealed limited anastomotic endothelial ingrowth in both prostheses. Conclusion: in this experimental model, PDMS and PTFE vascular prostheses had comparable outcomes and PDMS prosthesis could be used as a vascular graft.

RESUMO Objetivo: analisar novo tubo de silicone como material para prótese vascular e compará-lo a prótese de PTFE, em modelo experimental com coelhos. Métodos: quarenta coelhos foram submetidos a interposição, na aorta infrarrenal, de próteses de 4mm de diâmetro, sendo 20 animais com PDMS e 20 com PTFE (grupo controle). Foi realizada arteriografia retrógrada da aorta para avaliar a patência das próteses. Para avaliar a endotelização das próteses foi realizada microscopia eletrônica de maneira amostral pareada. Resultados: a patência em 30 dias foi de 100% para as duas próteses. Aos 60 dias, a taxa de patência do PDMS foi de 92,3% (± 7,4), e de 73,8% (±13,1) em 90 dias; as próteses de PTFE tiveram taxas de patência de 87,5% (± 11,7) aos 60 e 90 dias. Não foi observada diferença significativa entre as taxas de patência dos grupos (p=0,62). Não foi observada diferença entre os grupos quanto à evolução com complicações pós-operatórias (p=0,526) e quanto ao tempo de clampeamento da aorta (p=0,299). Não houve diferença significativa entre os grupos quanto ao grau de estenose das próteses (p=0,650) à avaliação angiográfica. A microscopia eletrônica mostrou crescimento endotelial limitado às regiões próximas às anastomoses nos dois tipos de próteses. Conclusões: o PDMS mostrou-se passível de utilização como prótese vascular, com resultados comparáveis aos do PTFE no modelo utilizado.

Comparison between arch zones in modified frozen elephant trunk procedure for complex thoracic aortic diseases

Abstract Introduction: The aim of this study is to compare postoperative outcomes and follow-up of two different modifications facilitating surgical technique of frozen elephant trunk (FET) procedure for complex thoracic aortic diseases - zone 0 (fixation with total arch debranching) and zone 3 (fixation with islet-shape arch repair). Methods: From May 2012 to December 2018, data were collected from 139 patients who had been treated with FET procedure for complex thoracic aortic diseases. According to Ishimaru arch map, patients with proximal anastomotic site of hybrid graft at zone 0 and zone 3 were grouped as Group A (n=58, 41.7%) and Group B (n=81, 58.3%), respectively. Mean age of study population was 54.7±11.4 years, and 111 patients were male (79.9%). Results: In-hospital mortality was observed in 20 (14.4%) patients (n=12, acute type A aortic dissection, and n=4, previous aortic dissection surgery). There was no significant difference between both groups in terms of in-hospital mortality. Four patients from Group A and three patients from Group B had permanent neurological deficit (P=0.32). Three patients from both groups had transient spinal cord ischemia (P=0.334). Although mean total perfusion time was longer in Group A, duration of visceral ischemia, when compared with Group B, was shorter (P<0.001). Five-year survival rate was 82.8% in Group A and 81.5% in Group B (P=0.876). Conclusion: FET procedure is a feasible repair technique in the treatment of complex aortic diseases, providing satisfactory early results. Because of its advantageous aspects, zone 0 fixation with debranching is the preferred technique in our clinic.

Transcaval access to the abdominal aorta: indications of interest to surgeons and a comprehensive literature review

Abstract We performed a review of the literature (until August 01, 2019) on the occasion of the first transcaval approach for transcatheter aortic valve implantation in our hospital. This review focuses mainly on the indications of this alternative access route to the aorta. It may be useful for vascular surgeons in selected cases, such as the treatment of endoleaks after endovascular aneurysm repair and thoracic endovascular aneurysm repair. We describe historical aspects of transcaval access to the aorta, experimental studies, available case series and outcomes. Finally, we summarize the most significant technical aspects of this little-known access.

Which is the optimal frozen elephant trunk? a systematic review and meta-analysis of outcomes in 2161 patients undergoing thoracic aortic aneurysm surgery using e-vita open plus hybrid stent graft versus thoraflex hybrid prosthesis

Abstract Objective: To systematically review the rate of morbidity and mortality associated with the use of E-vita hybrid stent graft and ThoraflexTM in patients undergoing complex aortic surgery. Methods: A comprehensive search was undertaken among the four major databases to identify published data about E-vita or Thoraflex™ in patients undergoing repair of thoracic aortic aneurysms. Results: In total, 28 papers were included in the study, encompassing a total of 2,161 patients (1,919 E-vita and 242 Thoraflex™). Patients undergoing surgery with E-vita or Thoraflex™ were of similar age and sex. The number of patients undergoing non-elective repair with Thoraflex™ was higher than with E-vita (35.2% vs. 28.7%, respectively). Cardiopulmonary bypass time was associated with increasing mortality in E-vita patients, however a meta-analysis of proportions showed higher 30-day mortality, permanent neurological deficit, and one-year mortality for Thoraflex™ patients. Direct statistical comparisons between E-vita and Thoraflex™ was not possible due to heterogeneity of studies. Conclusion: Although there are limited studies available, the available data suggests that mortality and morbidity are lower for the E-vita device in thoracic aortic aneurysm surgery than for Thoraflex™. Long-term data of comparative studies do not yet exist to assess viability of these procedures.

Hemorragia digestiva masiva por fístulas secundarias de grandes vasos al tracto digestivo / Massive digestive hemorrhage from secondary fistulas of great vessels to the digestive tract

RESUMEN La formación de una fístula entre arterias de gran calibre y el tubo digestivo es una complicación infrecuente de la cirugía reconstructiva de los grandes vasos sanguíneos secundario al uso de prótesis vasculares, los cuales se manifiestan con hemorragias masivas con elevada mortalidad. Presentamos dos casos de fístula aorto-entérico y de fístula carotideo-esofágico que comparten características comunes como la manifestación clínica de hemorragia digestiva masiva y mortal en pacientes con antecedentes de colocación de prótesis vasculares.

ABSTRACT The formation of a fistula between large caliber arteries and the digestive tract is an uncommon complication of reconstructive surgery of the large vessels secondary to the use of vascular prostheses, which manifest themselves with massive hemorrhages with high mortality. We report two cases of aorto-enteric fistula and carotid-esophageal fistula that share common characteristics such as the clinical manifestation of massive and fatal gastrointestinal bleeding in patients with a history of vascular prosthesis placement.

Vascular access cannulation in hemodialysis patients: technical approach / Canulação do acesso vascular em pacientes em hemodiálise: abordagem técnica

ABSTRACT Introduction: The vascular access cannulation technique varies among clinics, and guidelines on vascular access give little importance to cannulation techniques. The objective of this study was to evaluate the cannulation technique and to determine which factors are associated with each detail of the technique. Material and methods: The vascular access cannulation was evaluated in 260 patients undergoing hemodialysis. The type and anatomical location of the vascular access, the cannulation technique, direction, gauge, and distance between needles, besides bevel direction and needle rotation were registered. Results: The arteriovenous fistula was the most frequent vascular access (88%), the most used cannulation technique was area (100%), the needle direction was anterograde in most cases (79.5%), and the mean distance between the tips of needles was 7.57±4.43 cm. For arteriovenous grafts, the proximal anatomical location (brachial artery) and cannulation with 16G needles in anterograde position were more predominant. For arteriovenous fistulas, the distal anatomical location (radial artery) and cannulation through 15G needles were more common. Cannulation of vascular access in retrograde direction was associated with a greater distance between needles (13.2 ± 4.4 vs 6.1 ± 3 cm, p < 0.001). Kt/V was higher when the distance between needles was higher than 5 cm (1.61 ± 0.3 vs. 1.47 ± 0.28, p < 0.01). Conclusions: The vascular access cannulation technique depends on the vascular access characteristics and expertise of cannulators. Clinical trials are required for the formulation of guidelines for vascular access cannulation.

RESUMO Introdução: A técnica de canulação do acesso vascular varia entre instituições de saúde, e as diretrizes sobre o acesso vascular dão pouca importância às técnicas de canulação. O objetivo deste estudo foi avaliar a técnica de canulação e determinar quais fatores estão associados a cada detalhe da técnica. Material e métodos: A canulação do acesso vascular foi avaliada em 260 pacientes em hemodiálise. Foram registrados o tipo e localização anatômica do acesso vascular, a técnica de canulação, a direção, a bitola e a distância entre as agulhas, além da direção do bisel e da rotação da agulha. Resultados: A fístula arteriovenosa foi o acesso vascular mais frequente (88%), a técnica de canulação mais utilizada foi a área (100%), a direção da agulha foi anterógrada na maioria dos casos (79,5%) e a distância média entre as pontas das agulhas foi de 7,57 ± 4,43 cm. Para enxertos arteriovenosos, a localização anatômica proximal (artéria braquial) e a canulação com agulhas 16G em posição anterógrada foram mais predominantes. Para as fístulas arteriovenosas, a localização anatômica distal (artéria radial) e a canulação através de agulhas 15G foram mais comuns. A canulação do acesso vascular na direção retrógrada foi associada a uma maior distância entre as agulhas (13,2 ± 4,4 v.s. 6,1 ± 3 cm, p < 0,001). O Kt / V foi maior quando a distância entre as agulhas foi superior a 5 cm (1,61 ± 0,3 vs. 1,47 ± 0,28, p < 0,01). Conclusões: A técnica de canulação do acesso vascular depende das características do acesso vascular e da experiência dos "canuladores". Ensaios clínicos são necessários para a formulação de diretrizes para a canulação do acesso vascular.

Tratamiento de malformaciones y tumores vasculares, en un centro de referencia en Bogotá / Treatment of vascular malformations and tumors in a reference center in Bogotá

Introducción. Las malformaciones vasculares son anomalías que están presentes desde el nacimiento, no desaparecen y pueden crecer a lo largo de la vida. Se ha demostrado en estudios retrospectivos que la terminología para clasificar las anomalías vasculares es inexacta en un 69 % de casos, por lo que se hace un diagnostico inadecuado y en un 53 % de casos se brinda al paciente y su familia una información incorrecta del tratamiento y el curso clínico. Métodos. Estudio prospectivo longitudinal, realizado entre 2016 y 2019, donde se incluyeron pacientes con anomalías vasculares, que consultaron a nuestra institución, fueron valorados por el servicio de cirugía vascular, se hizo un plan diagnóstico y manejo integral, vía endovascular, quirúrgica o mixta, de acuerdo con cada caso. Resultados. La malformación más común fue la de tipo venoso, en el 40,3 % de los casos. Se realizó manejo endovascular en el 93,1 % de casos de malformaciones vasculares y quirúrgico en el 6,9 %. La mejoría de los síntomas que motivaron la consulta fue del 100 % para los tumores vasculares y del 70,8 % para las malformaciones. Sin embargo, los resultados son heterogéneos. Discusión. Es necesario realizar un adecuado diagnóstico de las anomalías vasculares, para alcanzar un trata-miento eficaz, con mejoría de los síntomas

Introduction. Vascular malformations are abnormalities that are present from birth, do not disappear and can grow throughout life. It has been shown in retrospective studies that the terminology to classify vascular anomalies is inaccurate in 69% of cases, an inappropriate diagnosis is made and in 53% of cases the patient and their family are given incorrect information on the treatment and the clinical course.Methods. Longitudinal prospective study conducted between 2016 and 2019. Patients with vascular anomalies and consulted to our institution were included. They were evaluated by the vascular surgery service, and a comprehensive diagnosis and management plan was made, including endovascular, surgical or mixed, according to each case. Results. The most common malformation was the venous type in 40.3% of the cases. Endovascular management was performed in 93.1% of cases and surgery in 6.9%. The improvement in the symptoms that led to the con-sultation was 100% for vascular tumors and 70.8% for malformations. However, the results are heterogeneous.Conclusions. It is necessary to obtain an adequate diagnosis of vascular anomalies, to achieve an effective treatment, with improvement of the symptoms

A Rare Cause of Angina After Coronary Bypass Grafting; Left İnternal Mammary Artery to Pulmonary Artery Fistula and Successful Treatment with Transcatheter Coil Embolization / Uma Causa Rara de Angina Após Revascularização do Miocárdio: Fístula da Artéria Mamária Interna Esquerda para Artéria Pulmonar e Tratamento Bem-Sucedido com Embolização Transcateter com Molas

Abstract Fistula from left internal mammary artery (LIMA) to pulmonary artery (PA) is rarely encountered in daily practice. In recent years, endovascular therapy options have emerged for the treatment of fistula formations and replaced with surgery. A 53-year-old man admitted to our outpatient clinic with symptoms of typical angina and shortness of breath despite optimal medical therapy. In his relevant history, he had a coronary artery bypass graft (CABG) operation in 2009 in which his LIMA was anastomosed to left anterior descending (LAD) and ramus artery sequentially. Coronary angiography including selective imaging of LIMA demonstrated a fistula formation originating from the proximal portion of the LIMA and draining to PA. After successful closure of fistula with transcatheter coil embolization, the patient was discharged without any complication and symptom. In conclusion, although LIMA to PA fistula is an infrequent clinical condition, it should be considered as a potential cause of persistent angina after CABG operation. Treatment options include conservative medical therapy, surgical ligation and endovascular interventions. The best therapy should be individualised for each patient in respect to patient's symptoms, surgical compatibility and anatomy of fistula.

Resumo A fístula da artéria mamária interna esquerda (AMIE) para a artéria pulmonar (AP) é raramente encontrada na prática diária. Nos últimos anos, opções de terapia endovascular surgiram para o tratamento de formações de fístula e foram substituídas por cirurgia. Um homem de 53 anos de idade, internado em nosso ambulatório com sintomas de angina típica e falta de ar, apesar da terapia clínica ideal. Em seu histórico relevante, ele teve uma cirurgia de revascularização miocárdica (CRM) em 2009, na qual sua AMIE foi anastomosada à descendente anterior esquerda (DAE) e à artéria ramus sequencialmente. A angiografia coronária, incluindo imagens seletivas da AMIE, demonstrou uma formação de fístula proveniente da porção proximal da AMIE e drenando para AP. Após o fechamento bem-sucedido da fístula com embolização transcateter com mola, o paciente recebeu alta sem qualquer complicação e sintoma. Em conclusão, embora fístula entre AMIE e AP seja uma condição clínica pouco frequente, deve ser considerada como uma causa potencial de angina persistente após a operação de revascularização do miocárdio. As opções de tratamento incluem terapia médica conservadora, ligadura cirúrgica e intervenções endovasculares. A melhor terapia deve ser individualizada para cada paciente em relação aos sintomas do paciente, compatibilidade cirúrgica e anatomia da fístula.

Poly(trimethylene carbonate-co-L-lactide) electrospun scaffolds for use as vascular grafts

Currently, there is great clinical need for suitable synthetic grafts that can be used in vascular diseases. Synthetic grafts have been successfully used in medium and large arteries, however, their use in small diameter vessels is limited and presents a high failure rate. In this context, the aim of this study was to develop tissue engineering scaffolds, using poly(trimethylene carbonate-co-L-lactide) (PTMCLLA), for application as small diameter vascular grafts. For this, copolymers with varying trimethylene carbonate/lactide ratios - 20/80, 30/70, and 40/60 - were submitted to electrospinning and the resulting scaffolds were evaluated in terms of their physicochemical and biological properties. The scaffolds produced with PTMCLLA 20/80, 30/70, and 40/60 showed smooth fibers with an average diameter of 771±273, 606±242, and 697±232 nm, respectively. When the degradation ratio was evaluated, the three scaffold groups had a similar molecular weight (Mw) on the final day of analysis. PTMCLLA 30/70 and 40/60 scaffolds exhibited greater flexibility than the PTMCLLA 20/80. However, the PTMCLLA 40/60 scaffolds showed a large wrinkling and their biological properties were not evaluated. The PTMCLLA 30/70 scaffolds supported the adhesion and growth of mesenchymal stem cells (MSCs), endothelial progenitor cells, and smooth muscle cells (SMCs). In addition, they provided a spreading of MSCs and SMCs. Given the results, the electrospun scaffolds produced with PTMCLLA 30/70 copolymer can be considered promising candidates for future applications in vascular tissue engineering.

Estudo experimental de reconstrução da veia femoral com enxerto tubular do bipolímero de cana-de-açúcar / Experimental study of femoral vein reconstruction with sugarcane biopolymer tubular graft

RESUMO Objetivo: avaliar, através de dopplerfluxometria, de venografia, de histologia e de evolução clínica, o uso de enxertos tubulares de biopolímero de cana-de-açúcar (BP) na reconstrução de veias femorais em cães. Métodos: oito cães adultos foram submetidos à reconstrução de veia femoral, à esquerda com enxerto tubular de BP e à direita com veia autóloga. No período pós-operatório, os animais foram submetidos à avaliação clínica e dopplerfluxometria das veias femorais. Após 360 dias, os cães foram reoperados e submetidos à flebografia das veias femorais com contraste iodado. Os segmentos das veias femorais contendo os enxertos foram retirados e enviados para avaliação histopatológica. Resultados: os cães não apresentaram hemorragia, hematoma, infecção da ferida operatória ou edema dos membros operados. Um animal apresentou dilatação venosa superficial na região inguinal esquerda. A flebografia realizada 360 dias após a primeira cirurgia demonstrou que três (37,5%) enxertos de BP e sete (87,5%) do grupo controle (C) estavam pérvios. Na avaliação histopatológica foi encontrada uma reação inflamatória com neutrófilos e linfócitos na superfície externa de ambos os grupos. Na camada íntima de revestimento dos enxertos e na camada externa nos dois grupos, foi encontrada fibrose. Conclusão: com base nos resultados obtidos com o modelo experimental utilizado, conclui-se que a BP apresenta potencial para ser utilizado como enxerto tubular para revascularização venosa, porém novas pesquisas precisam ser realizadas para confirmar a sua eficácia na revascularização de veias de médio e grande calibre, o que poderia permitir o seu uso na prática clínica.

ABSTRACT Objective: to evaluate, through Doppler flowmetry, venography, histology and clinical evolution, the use of sugarcane biopolymer (BP) tubular grafts in the reconstruction of femoral veins in dogs. Methods: we submitted eight adult dogs to femoral vein reconstruction, on the left with BP tubular graft and on the right with autologous vein. In the postoperative period, the animals underwent clinical evaluation and femoral vein Doppler flowmetry. After 360 days, we reoperated the dogs and submitted them to femoral vein phlebography with iodinated contrast. We removed the segments of the femoral veins containing the grafts and sent them for histopathological evaluation. Results: the dogs did not present hemorrhage, hematoma, surgical wound infection or operated limb edema. One animal had superficial venous dilatation in the left inguinal region. Phlebography performed 360 days after the first surgery showed that three (37.5%) BP grafts and seven (87.5%) grafts from the control group (C) were patent. In the histopathological evaluation, we found an inflammatory reaction, with neutrophils and lymphocytes on the external surface of both groups. In the intimal layer of the grafts and in the outer layer in the two groups, we observed fibrosis. Conclusion: based on the results obtained with the experimental model used, BP presents potential to be used as a tubular graft for venous revascularization. However, new research must be performed to confirm its efficacy in the revascularization of medium and large diameter veins, which could allow its use in clinical practice.

Experimental implantation of an arterial substitute made of silicone reinforced with polyester fabric in rabbits

OBJECTIVES: The aim of this study was to analyze silicone tubes with an internal diameter of 4 mm as a possible material for vascular prostheses. METHODS: Grafts were implanted into the infrarenal aortas of 33 rabbits. Fluoroscopic examinations were performed within 150 days after surgical implantation. Sample grafts were analyzed via electron microscopy to evaluate the eventual endothelialization of the prostheses. RESULTS: The patency rates of the prostheses were 87% (±6.7%) after 30 days, 73% (±9.3%) after 60 days and 48% (±12%) after 120 days. The material presented characteristics that support surgical implantation: good tolerance promoted by polyester tear reinforcement, ease of postoperative removal and a lack of pseudoaneurysms. However, intimal hyperplasia was a limiting factor for the patency rate. CONCLUSIONS: We concluded that polydimethylsiloxane has limited potential as an alternative material for small vascular prostheses.