Successful management of a giant unruptured mycotic coronary artery aneurysm after coronary angioplasty.

Coronary artery stent infection has been reported with both bare metal stent and drug eluting stent and can present as mycotic coronary artery aneurysm, pseudoaneurysm, myocardial abscess, pericarditis or exudative effusion. Infection at the site of coronary stent implantation is rare and is believed to result typically from either direct stent contamination at the time of delivery or transient bacteraemia from access site. Introduction of drug-eluting stent (DES) has led to a marked reduction in the problem of in-stent restenosis across all patient subsets and lesions complexities. Recently, several case reports of pseudoaneurysm formation after DES implantation have been reported in the literature. We describe the successful surgical management of giant mycotic pseudoaneurysm of left anterior descending artery (LAD) presenting as fever of unknown origin. This report illustrates the importance of early detection and prompt management of these rare coronary pseudoaneurysms, which is a highly lethal condition.

Ureteral stent symptoms and associated infections: a biomaterials perspective.

Ureteral stents are commonly used in the field of urology, and, given their indwelling nature, are often a nidus for infection and a cause of discomfort. To minimize symptoms, the urologic surgeon should first consider whether a stent needs to be placed at all. Softer stents do not seem to improve patient comfort. Stents that are too long, specifically those that cross the midline of the bladder, significantly increase the frequency of stent-related symptoms. Administering alpha blockers while the stent is indwelling can reduce these symptoms. Antibiotic prophylaxis or concomitant antibiotic administration does not seem to reduce the incidence of stent-related urinary tract infection. At present, drug-eluting stents have shown the most promise for inhibiting bacterial adhesion and biofilm formation. Future stent designs that maintain drainage of the kidney and ureter while minimizing inflammation and contact with the urothelium will improve patient outcomes. By better understanding the basic pathways of bacterial adhesion to biomaterials, new stents and medications that target these mechanisms can be developed to eliminate bacterial adhesion and infection in patients with ureteral stents.

Use of triclosan-eluting ureteral stents in patients with long-term stents.

BACKGROUND AND PURPOSE: Long-term use of ureteral stents is prevented by biofilm-related infection and encrustation mandating stent changes every few months. Triclosan is a broad-spectrum antimicrobial in numerous consumer and medical products and has been incorporated into a ureteral stent. We sought to determine the clinical effects of the triclosan-eluting stent in patients who needed long-term ureteral stenting. PATIENTS AND METHODS: Eight patients with long-term stents were enrolled prospectively. All received a control stent for 3 months along with preoperative and postoperative antibiotics. After 3 months, the control stent was removed, and a triclosan-eluting stent was placed for 3 months with no antibiotics administered. For both indwelling periods, urine cultures were obtained weekly and biweekly for the first and last 6 weeks, respectively, and antibiotics were prescribed when patients had both a positive urine culture and symptoms of urinary tract infection. On removal, stents were assessed for microorganisms and encrustation. RESULTS: Overall, similar microorganisms were isolated during each indwell period, although Staphylococcus and Enterococcus strains were isolated more frequently during control and triclosan stenting, respectively. Significantly fewer antibiotics were used during triclosan stenting, coinciding with a slightly higher number of positive urine cultures and significantly fewer symptomatic infections. No bacterial isolates developed antibiotic resistance during triclosan stent placement. CONCLUSIONS: Antibiotic use with control stents resulted in bacterial antibiotic resistance, which was not the case with the triclosan-eluting stents. Although triclosan-eluting stents did not show a clinical benefit in terms of urine and stent cultures or overall subject symptoms compared with controls, their use did result in decreased antibiotic usage and significantly fewer symptomatic infections. The triclosan-eluting stent alone is not sufficient to reduce device-associated infections in this difficult patient population.

Candidemia en niños y factores de riesgo asociados / Candidemia in children and associate factors of risk

Cada vez es más frecuente la adquisición de infecciones fúngicas intrahospitalarias, generando una mayor morbilidad y mortalidad, sobre todo en pacientes que presentan factores de riesgo. Determinar la prevalencia, en los pacientes hospitalizados en el Hospital de Niños "JM de Los Ríos" (Caracas-Venezuela), de infecciones sistémicas ocasionadas por las distintas especies de Candida en el período 2002-2006. Estudio retrospectivo, transversal, descriptivo y no experimental. Se ubicaron las historias clínicas de estos pacientes y se recopilaron de un formato los siguientes datos: edad, sexo, servicio de hospitalización, diagnóstico de egreso, factores de riesgo relacionados con la infección. Se utilizó como prueba de análisis estadístico medidas de tendencia central. Se logró el aislamiento de microorganismos en un 21,68 por ciento (7,14 por ciento correspondieron a cepas de Candida). El sexo masculino predominó con un 58,61 por ciento, los lactantes fueron el grupo más afectado con un 38,14 por ciento. El uso de antibióticos de amplio espectro predominó entre los factores de riesgo. El 71,16 por ciento de los aislamientos correspondieron a cepas del grupo de Candida no albicans, representando las especies de Candida parapsilosis y Candida tropicalis casi las dos terceras partes de los aislamientos y asociándose con mayor frecuencia al uso de catéteres venosos centrales. El 75 por ciento de las cepas de Candida aisladas en hemocultivo han sido reportadas como sensibles a fluconazol y anfotericina B por la literatura médica mundial.

Utilidad de la citometría de flujo en la determinación de microagregados plaquetarios en pacientes con stent tratados con clopidogrel / Flow cytometry evaluation of platelet microaggregates determination in patients with coronary stent implants treated with clopidogrel

Introducción: La monitorización de pacientes con síndrome coronario agudo (SCA) con stent cardíaco, tratados con clopidogrel resulta conveniente, dada la frecuencia con que dichos pacientes no responden adecuadamente al tratamiento. En efecto, según nuestra experiencia, aproximadamente un 30% de casos pueden clasificarse como pacientes no respondedores (NR). No está establecido si pacientes NR presentan, como factor de riesgo, mayor número de microagregados plaquetarios (MAP) que los pacientes respondedores (R). La formación de MAP puede afectar a la microcirculación y es un factor de riesgo de formación de trombos mayores, por lo que su estudio puede resultar de gran interés. Material y métodos: Se han valorado 78 pacientes consecutivos con un stent cardíaco implantado. El tratamiento consiste en un bolo inicial de 300 mg de clopidogrel, seguido de una dosis diaria de clopidogrel (75 mg) y ácido acetilsalicílico (100 mg). Aproximadamente 1 semana después de iniciado el tratamiento, se determina, mediante citometría de flujo (EPICS-XL, Beckman-Coulter, Izasa), el número MAP circulantes y los formados ex vivo por acción del ADP 2,5 μM. Para ello, con voluntarios sanos, se selecciona previamente la población plaquetaria, en función del forward y side scatter y por ser eventos CD61- positivos. En esta región se elige la subpoblación que ocupa el 5% superior, en la que, por definición, se encuentran los MAP. Una vez establecido el protocolo de adquisición de datos, se analizan las muestras problema. Los pacientes se clasifican como respondedores o no, en función de la exposición de CD62 plaquetaria inducida por accio´n de ADP 2,5 μM. Resultados: El conjunto de 78 pacientes presenta mayor número de MAP circulantes que los controles (167±58/5.000 plaquetas frente a 113±56/5.000 plaquetas; p<0,001).El incremento en el número de MAP por acción de ADP es similar en los 50 controles y en los 51 pacientes que responden adecuadamente al tratamiento. Los 27 pacientes NR presentan mayor respuesta al ADP que los pacientes R, con un incremento en el número de MAP de 251±75/5.000 plaquetas, significativamente mayor que en los pacientes R (196±67/5.000 plaquetas; p<0,001). Conclusiones: La técnica propuesta posibilita la detección de MAP formados espontáneamente y por acción del ADP, lo que permite monitorizar el tratamiento antiplaquetario en los pacientes SCA con stent implantado(AU)

Introduction: It is not well established whether non-responder patients(NR) to clopidogrel show, as a risk factor, higher number of platelet microaggregates (PMAs) than responder patients (R). These MAPs can affect the microcirculation and is a risk factor to forming larger thrombi, therefore the present study is interesting from this point of view. Material and methods: Seventy-eight acute coronary syndrome (ACS) patients (78% male, aged 62.8±12.23 years) were included in this study. These patients underwent coronary stent implantation and treated with routine medication (clopidogrel 75 mg/day and aspirin 100 mg/day), after a loading bolus of 300 mg clopidogrel. The control group was made up of 50 healthy volunteers matched for age and gender who had not been given any pharmacological treatment. Using whole blood flow cytometry, ADP-stimulated and circulating platelet CD62 expression and platelet microaggregates was determined in the entire study population. After a week of treatment the number of circulating platelet microaggregates was evaluated by flow cytometry (EPICS-XL, Beckman-Coulter, Izasa), and the number of MAPs formed ex vivo by ADP 2.5 μM activation was also evaluated . With this aim, using healthy individuals, the platelet population was selected by their forward and side scatter values and as CD61-positive events. The subpopulation that occupied the upper 5% in this region where MAPs are detected,was chosen. After the analytical conditions were established, samples were analyzed. Patients were responders, or not, depending on the CD62 expression after being activated with ADP 2.5 μM. Results: Seventy-eight patients showed a higher number of circulating MAPs than controls (177±75/5000 platelets vs. 121±62/5000 platelets; P<0.001). The increase in the MAPs number by ADP activation is higher in the 50 controls than in the 51 responder patients (79±45% vs. 23±18%; P<0.001). The 27 NR patients reacted to ADP in a similar way than controls, with a increase in the number of MAPs of 62±43%, significantly higher than in R (P<0.001). The findings of this study demonstrate the beneficial effects of clopidogrel in reducing platelet reactivity in 66% of the study patients. These results demonstrate the wide inter-individual variability in ADP response in patients treated with clopidogrel and imply that individualized monitoring of this type of patient is advisable. Conclusions: The method described enables us to explore platelet microaggregates formation and may be of great help in monitoring clopidogrel efficacy in ACS patients with stent(AU)