Endovascular Recanalization of a Thrombosed Native Arteriovenous Fistula Complicated with an Aneurysm: Technical Aspects and Outcomes

OBJECTIVE: To evaluate the technical aspects and outcomes of endovascular recanalization of a thrombosed native arteriovenous fistula (AVF) complicated with an aneurysm. MATERIALS AND METHODS: Sixteen patients who had a thrombosed AVF complicated with an aneurysm (two radiocephalic and 14 brachiocephalic) were included in this study. Recanalization procedures were performed by mechanical thrombectomy using the Arrow-Trerotola percutaneous thrombectomy device and adjunctive treatments. We evaluated dose of thrombolytic agent, underlying stenosis, procedure time, technical and clinical success, and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. RESULTS: The thrombolytic agents used were 100000 U urokinase mixed with 500 IU heparin (n = 10) or a double dose of the mixture (n = 6). The thrombi in aneurysms were removed in all but two patients with non-flow limiting residual thrombi. One recanalization failure occurred due to a device failure. Aspiration thrombectomy was performed in 87.5% of cases (n = 14). Underlying stenoses were found in the outflow draining vein (n = 16), arteriovenous anastomosis or juxtaanastomosis area (n = 5), and the central vein (n = 3). Balloon angioplasty was performed for all stenoses in 15 patients. Two patients with a symptomatic central vein stenosis underwent insertion of a stent after balloon angioplasty. Mean procedure time was 116.3 minutes. Minor extravasation (n = 1) was resolved by manual compression. Both technical and clinical success rates were 93.8% (n = 15). The primary patency rates at 3, 6, and 12 months were 70.5%, 54.8%, and 31.3%, respectively. The secondary patency rates at 3, 6, and 12 months were 70.5%, 70.5%, and 47.0%, respectively. CONCLUSION: Thrombosed AVF complicated with an aneurysm can be successfully recanalized, and secondary patency can be prolonged with endovascular treatment.

Air travel and pulmonary embolism: "economy class syndrome".

Air travel is implicated as a predisposing factor for thromboembolism, which at times can have catastrophic consequences. We present 3 cases who developed deep vein thrombosis (DVT) and subsequent pulmonary thromboembolism (PTE) after transatlantic air travel. The relevant literature is discussed.

Acute pulmonary embolism advances in treatment.

Recent advances in interventional cardiology, pharmacotherapeutics and modern surgical management in tertiary cardiac care centers have tremendously improved the present treatment of Pulmonary Embolism (PE). CT pulmonary angiography (CTPA), nuclear lung scan (V/Q scan), D-dimer test and modern echocardiography have revolutionized the diagnostic methodology and risk assessment criteria. Cardiogenic shock or systolic hypotension (BP < 90 mmHg) and presence of right ventricular dysfunction (or failure) are two principal criteria which govern the severity of pulmonary embolism. While all patients of pulmonary embolism require anticoagulation, systemic thrombolytic therapy is the mainstay of initial treatment in massive and submassive pulmonary embolism. When thrombolysis is contraindicated or has failed, urgent surgical embolectomy or catheter embolectomy may be life saving procedures in severe pulmonary embolism.

Neurovascular rescue for embolic stroke following atrial septal defect closure.

Strokes following cardiac surgery occur in about 5% of patients. Intra-arterial thrombolysis is a good option in such a setting where intravenous thrombolysis is contraindicated, and when in-hospital strokes are detected well within the window for treatment and the chances of complete reperfusion are maximum. On postoperative day 4 after atrial septal defect correction, a 34-year-old woman with paroxysmal atrial fibrillation developed left middle cerebral artery stroke causing severe neurological deficits. Intra-arterial thrombolysis with urokinase led to remarkable recovery.

Role of thrombolytic therapy for stuck prosthetic valves: a serial echocardiographic study.

BACKGROUND: Thrombotic occlusion of a prosthetic valve continues to be an uncommon but serious complication. Intravenous thrombolytic therapy has been proposed as an alternative to surgical treatment, but only in critically ill patients. METHODS AND RESULTS: Forty-one consecutive patients presenting with 48 episodes of prosthetic valve thrombosis (44 mitral and 4 aortic) were treated with thrombolytic therapy under serial echocardiographic guidance. There were 14 male and 27 female patients. The anticoagulation status was inadequate in 89.6% of episodes. Atrial fibrillation was present in 47.9% of episodes. The prostheses involved in these episodes were tilting disc in 45, bileaflet in 2, and ball and cage type in 1. The Sorin prosthetic valve was the most commonly involved. The time interval between valve replacement and thrombosis ranged from 1 month to 108 months (mean 20.4+/-20.6 months). Patients were in New York Heart Association functional class III in 47.9% and in class II in 43.9% of episodes. Thrombolytic agents used were streptokinase and urokinase in 44 and 4 episodes, respectively. The mean duration of thrombolytic therapy was 27.9+/-15.0 hours and the overall success rate was 87.5%. Patients developed peripheral embolism with almost complete recovery in 5 episodes while significant bleeding that required termination of thrombolytic therapy was observed in 2 episodes. Redo valve replacement was done in 3 episodes because these patients did not improve on thrombolytic therapy (all 3 cases were of recurrent prosthetic valve thrombosis and were found to have pannus peroperatively). Three patients died during thrombolytic therapy because of persistent heart failure. Six patients experienced a total of 13 epidoses of recurrent prosthetic valve thrombosis including index episodes (rethrombosis in 5, re-rethrombosis in 1). They were treated with repeated thrombolysis with a success rate of 76.92%. The mean duration of thrombolytic therapy in these episodes was 36.1+/-14.0 hours. CONCLUSIONS: In patients with prosthetic valve thrombosis, intravenous thrombolysis guided by echocardiography is a safe and effective method that may expand the indications for nonsurgical treatment of prosthetic valve thrombosis. By using serial echocardiography, the duration of thrombolytic therapy can be tailored to the patient's requirement for normalization of valve hemodynamics.

Fibrinolisis en el infarto cerebral / Fibrinolysis in brain infarction

Hasta hace poco años atrás no existía una terapia espececífica para el tratamiento del infarto cerebral (IC), sin embargo en los últimos treinta años la trombolisis constituyó un campo activo de la investigación terapéutica orientada a solucionar esta deficiencia en el tratamiento del IC. Actualmente la trombolisis es la única terapia específica disponible para casos seleccionados de IC. En este artículo presentamos una revisión de la literatura relacionada a la terapia fibronolítica como tratamiento IC y entregamos una pauta de criterios para el uso de fibronolítico con las prepaciones comerciales disponibles actualmente. Las recomendaciones dada en este trabajo están respaldadas por evidencia científica demostrada

Newer thrombolytic drugs for acute myocardial infarction.

Arterial thrombosis is the underlying cause of a wide variety of cardiovascular diseases such as myocardial infarction, stroke and pulmonary thromboembolism. All the currently used thrombolytic agents are plasminogen activators, which are very efficient in restoring the blood flow. The fibrinolytic system comprises an inactive proenzyme plasminogen, that is converted by plasminogen activators to the enzyme plasmin, that degrades fibrin. Despite the widespread use of established thrombolytic agents such as streptokinase, tissue-plasminogen activator and urokinase, all these agents suffer from a number of inadequacies including resistance to reperfusion, occurrence of acute coronary reocclusion and bleeding complications. The quest continues for thrombolytic agents with a higher potency, specific thrombolytic activity and fibrin selectivity. Several lines of research towards improvement of thrombolytic agents are being explored including the construction of mutants and variants of plasminogen activators, chimeric plasminogen activators and conjugates of plasminogen activators with monoclonal antibodies. Newer molecules such as pro-urokinase, saruplase, alteplase, K1K2Pu and staphylokinase have shown promise in animal models of arterial and venous thrombosis and also in pilot scale clinical studies in patients with myocardial infarction. However, more clinical trials are needed to determine whether these novel recombinant thrombolytic agents shows improved efficacy and fibrin specificity with minimal bleeding tendencies.

Empleo de agentes trombolíticos durante la gestación / Utility of thrombolytic agents during the gestation

Los agentes trombolíticos son efectivos en disolver trombos intravasculares. Su seguridad durante la gestación sigue siendo objeto de debate, por lo que su uso se reserva para los casos de tromboembolismo hemodinámicamente significativos o trombólisis durante la gestación. Una paciente presentó un tromboembolismo pulmonar masivo secundario a trombosis de extremidades inferiores y la otra presentó dos episodios de trombosis de válvula protésica cardíaca. Los agentes empleados fueron urokinasa en la primera paciente y estreptokinasa y activador del plasminógeno tPA (alteplasa) en dos oportunidades en la segunda. Se discute su empleo, riesgos durante la gestación, y resultado perinatal. Este es el primer reporte nacional y uno de los pocos internacionales del uso del tPA durante la gestación

Evaluación retrospectiva del uso de activador tisular del plasminógeno (rt-PA) en el manejo del infarto agudo de miocardio en el servicio de urgencias de la Clínica Shaio

Objetivo: Evaluar el uso de activador tisular del plasminógeno recombinante (rt-PA) en los pacientes con IAM que ingresaron por el servicio de urgencias. Materiales y métodos: Estudio descriptivo retrospectivo de corte transversal en donde se tomaron todos los pacientes con diagnóstico de IAM al ingreso en urgencias durante el período comprendido entre enero de 1996 hasta julio de 1997 en los cuales se utilizó la terapia trombolítica con rt-PA. Se administró el esquema acelerado de rt-PA seguido por infusión de heparina para mantener PTT entre 50 y 70 segundos por 24 a 48 horas. Las indicaciones para administrar rt-PA fueron: edad menor de 75 años, infarto de localización anterior y tiempo de evolución menor de 6 horas. La recolección de la información se realizó a partir de la historia clínica. Las variables estudiadas fueron edad, sexo, tipo de infarto, localización, clasificación de killip, tiempo de evolución al momento de la consulta, uso, tipo y causa de exclusión de trombosis con rt-AP. permeabilidad de la arteria relacionada con el infarto, realización de angioplastia, requerimiento de cirugía (electiva o de urgencia), complicaciones y mortalidad antes de la intervención con angioplastia electiva o cirugía. Resultados: De un total de 458 pacientes con diagnóstico de IAM se realizó terapia de recanalización en 206 pacientes (44.5 por ciento), 12 con angioplastia primaria (6 por ciento), 146 (70.5 por ciento) con STK y 48 (23.5 por ciento) con rt-PA. De estos pacientes 42 (87.5 por ciento) fueron hombres y 6 (12.5 por ciento) mujeres. Las edades estuvieron entre 42 años el más joven y 75 años el de mayor edad, con un promedio de 60-17 años. El tiempo promedio de consulta a urgencias después del inicio de los síntomas fue de 4.9 horas. Ningún paciente entró con Killip IV, 3 (6.5 por ciento) Killip I, 14 (29 por ciento) en Killip II yb 31 (64.5 por ciento) en Killip III. La principal causa de exclusión de trombólisis con rt-PA fue la consulta fuera de tiempo > 6 horas. Se presentó un caso de hemorragia de vías digestivas clasificada como menor ya que no requirió transfusión. De las complicaciones secundarias al IAM se presentó choque en 4 (8.3 por ciento), arritmia ventricular en 3 (6.2 por ciento); pericarditis en 2 (4.15 por ciento); angina post IAM en 1 (2.5 por ciento); insuficiencia mitral en 1 (2.5 por ciento); trombo intracavitario 1 (2.5 por ciento). La mortalidad entre los pacientes trombolizados...

Fibrinolisis intrarterial directa en el manejo terapéutico del accidente cerebrovascular agudo / Fibrinolysis in acute ischaemic stroke

El tratamiento de los pacientes con un accidente cerebrovascular agudo incluye, en casos seleccionados, el cateterismo y la infusión de agentes trombolíticos directamente en el coágulo de una arteria cerebral intracraneana. Se procede a la infusión de fibrinolíticos dentro del trombo hasta lograr la lisis y restablecer la perfusión. Esto se ha hecho en 27 pacientes incluyendo 45 territorios vasculares. Se logró mejoría clínica en 18 (66,7 por ciento) de los casos. Las complicaciones incluyeron 3 hemorragias intracraneanas sintomáticas (11,1 por ciento), un caso (3,7 por ciento) de perforación vascular, 8 (26,9 por ciento) pacientes sin mejoría y 9 (33,3 por ciento) muertes en el seguimiento alejado. La infusión local directa de trombolíticos puede mejorar la morbilidad global y la mortalidad relacionadas con enfermedad aguda tromboembólica en el sistema nervioso central

Uso de agentes fibrinolíticos em tromboses venosa e arterial / Fibrinolytic agents in venous and arterial thrombosis

Os fármacos fibrinolíticos representam um importante coadjuvante terapêutico para o cirurgiäo vascular em casos de trombose venosa e arterial. Há contudo muitos aspectos contraditórios. Seu uso em trombose venosa profunda näo tem aceitaçäo plena, apesar de alguns relatos de bons resultados. Quanto às patologias arteriais, sendo a correçäo cirúrgica difícil e limitada para as artérias de pequeno calibre, a fibrinólise pode representar uma alternativa ou um coadjuvante terapêutico. Deve ser lembrado que os efeitos colaterais induzidos pelos fármacos fibrinolíticos podem ser graves e limitar seu uso, havendo também suas contra-indicaçöes. Além disso, esta terapia exige uma adequada estrutura de UTI e laboratório para sua aplicaçäo

Intra pulmonary thrombolytic therapy with balloon dilatation in recurrent acute pulmonary embolism.

A 52-year-old man had recurrent pulmonary thrombo embolism following fracture in tibia and subsequent deep vein thrombosis. One episode of massive pulmonary embolism with haemodynamic compromise was managed successfully by balloon compression of the thrombus and thrombolysis with urokinase. Patient was rehabilitated in his previous profession.

The thrombolytic effect of lumbrokinase is not as potent as urokinase in a rabbit cerebral embolism model

The purpose of the present study is to determine whether lumbrokinase has an in vivo thrombolytic effect in a rabbit cerebral embolism model. In our previous studies, we found that lumbrokinase, an extract from Korean earth worms, has a strong in vitro fibrinolytic effect without the presence of plasminogen and significant in vivo thrombolytic effects of lumbrokinase in a rat human-clot-induced cerebral embolism model. We established the cerebral embolism model in rabbits by injecting a piece of human clot into the internal carotid artery via the external carotid artery and confirmed the occlusion with angiography. Twenty one rabbits were divided into three groups and 5cc of saline, urokinase of 50,000 u/ml, and equipotent LK were injected intraarterially for 30 minutes into each group of 7 animals. Ten minutes after the end of infusion, an angiogram was performed to confirm the recanalization. Clot lysis occurred in one, six, and one animals in the saline, urokinase and lumbrokinase treated groups respectively. With regard to its in vitro effect, lumbrokinase is not as potent in vivo. Further investigation should be performed to determine the cause of its weakened in vivo effect and to develop a method to potentiate it.

Empiema pleural loculado: tratamento atraves da utilizacao de uroquinase via cateter toracico: relato de dois casos / Loculated pleural empyema: treatment with thoracic catheter instilation of Urokinase

Apresentamos o relato de dois casos de empiema pleural loculado, tratados atraves da instilacao de uroquinase no espaco pleural via dreno toracico, descrevendo sua tecnica e evolucao dos pacientes.