Spontaneous rupture of a mechanical valve in a mitral position (On-X) with migration-embolization to aortic bifurcation from the perspective of the vascular surgeon.

We report on the case of spontaneous rupture of an On-X-pure pyrolytic carbon mechanical valve prosthesis implanted seven years earlier, in a mitral position, at our hospital. The patient was admitted with valvular dysfunction and acute pulmonary edema requiring emergency surgery (prosthesis replacement); the absence of a leaflet was confirmed intraoperatively. The patient presented severe respiratory failure, which prolonged the postoperative period. A CT scan showed that the migrated leaflet was located in the aortic bifurcation with no apparent arterial lesion. Four months later, once the patient had recovered, laparotomy and aortotomy were performed in order to retrieve the leaflet, which was found to have become included (neoendothelized) in the aortic wall without compromising the latter's integrity or obstructing the blood flow. A subsequent CT scan confirmed the persistence of the leaflet in its initial position. The literature review highlights two singular facts: 1) this is the second published case of the escape of a leaflet from an On-X prosthesis (the first patient died); 2) this is the first case in which a laparotomy was performed to retrieve the leaflet but finally a decision was made to leave it in situ. Seven months later, the patient remained asymptomatic.

Cytokine profiles linked to fatal outcome in infective prosthetic valve endocarditis.

Infective endocarditis is a disease normally of bacterial cause which affects the endocardic tissue, specifically the valves (native or prosthetic). It is a serious illness and mortality rates remain high, ranging between 20% and 40%. Previous reports have evidenced the potential role of cytokines in the diagnosis of this disease, but no information is available on their relationship with outcome. We recruited 26 consecutive patients with late prosthetic valve endocarditis requiring surgical treatment according to Duke criteria. Eight cytokines were measured in plasma in the first 24 h following diagnosis by using a Bio-Rad multiplex assay. Levels of IL-6, IL-8 and interferon gamma (IFN-γ) were higher in non survivors. Receiver operating characteristic curve analysis evidenced that IL-6, IL-8 and IFN-γ behaved as good diagnostic tests for identifying those patients with fatal outcome (area under the curve, CI 95%, p): IL-6: [0.81 (0.61-1.00) 0.012]; IL-8 [0.76 (0.56-0.96) 0.035]; IFN-γ [0.79 (0.59-0.99) 0.021]. Levels of IL-6, IL-8 and IFN-γ correlated positively between them, indicating that they are produced as consequence of a simultaneous response to the infection. Our findings support the participation of IL-6, IL-8 and IFN-γ in the events linked to fatal outcome in infective prosthetic valve endocarditis.

Efecto del plasma autógeno rico en plaquetas sobre el infarto de miocardio en ovejas / Effect of autologous platelet-rich plasma on heart infarction in sheep

Objetivo: El infarto de miocardio es la causa más común de fallo cardíaco congestivo. El objetivo de este trabajo es evaluar, en el animal de experimentación, los efectos morfológicos e histológicos de la implantación de plasma autógeno rico en plaquetas en el corazón de ovejas previamente infartadas. Métodos: Se utilizaron 24 ovejas lacha hembras, en las que se produjo quirúrgicamente un infarto agudo de miocardio, mediante toracotomía izquierda y ligadura permanente de 2 arterias coronarias (primera y segunda diagonal). Tras la ligadura de las arterias coronarias 3 ovejas fallecieron por fibrilación ventricular. Pasadas 3 semanas de la ligadura coronaria, las ovejas fueron reoperadas por esternotomía media vertical. En 6 de ellas (grupo control) se inyectó suero fisiológico en la zona del infarto. En 15 se inyectó gel plaquetario. Todas las ovejas fueron sacrificadas a las 9 semanas de evolución de la segunda cirugía. Resultados: En los corazones tratados con plasma rico en factores de crecimiento (PRGF) destaca la neoformación vascular en los cortes de hematoxilina-eosina y de factor VIII, a diferencia de los no tratados. Conclusiones: La inyección de factores de crecimiento plaquetarios, PRGF, en el corazón de ovejas previamente infartadas favorece la mitogénesis y la angiogénesis. El uso de PRGF autógeno es sencillo y seguro, no provocando toxicidad ni desencadenando reacciones inmunológicas ni inflamatorias.

Objective: Myocardial infarction is the most common cause of congestive heart failure. The objective of this work is to evaluate, in experimental animals, morphological and histological effects of the implantation of autologous platelet-rich plasma in infarcted heart sheep. Methods: Twenty-four ewes were used, they were surgically infarcted through left thoracotomy and two coronary arteries were ligated (first and second diagonal). After coronary artery ligation three sheep died of ventricular fibrillation. Three weeks after coronary ligation, sheep were reoperated through median sternotomy. Normal saline solution was injected in the infarcted zone in 6 of them (control group) whereas platelet gel was injected in 15 of them. All sheep were euthanized at 9 weeks of evolution of the second surgery. Results: Noteworthy is the formation of new vessels in hematoxylin-eosin-stained sections and factor VIII in plasma rich in growth-factors (PRGF)-treated hearts. Conclusions: Injection of platelet growth factors, PRGF, in previously infarcted sheep hearts promotes mitogenesis and angiogenesis. The use of autologous PRGF is simple and safe, causing no toxicity or immune-inflammatory reactions.

[Effect of autologous platelet-rich plasma on heart infarction in sheep]. / Efecto del plasma autógeno rico en plaquetas sobre el infarto de miocardio en ovejas.

OBJECTIVE: Myocardial infarction is the most common cause of congestive heart failure. The objective of this work is to evaluate, in experimental animals, morphological and histological effects of the implantation of autologous platelet-rich plasma in infarcted heart sheep. METHODS: Twenty-four ewes were used, they were surgically infarcted through left thoracotomy and two coronary arteries were ligated (first and second diagonal). After coronary artery ligation three sheep died of ventricular fibrillation. Three weeks after coronary ligation, sheep were reoperated through median sternotomy. Normal saline solution was injected in the infarcted zone in 6 of them (control group) whereas platelet gel was injected in 15 of them. All sheep were euthanized at 9 weeks of evolution of the second surgery. RESULTS: Noteworthy is the formation of new vessels in hematoxylin-eosin-stained sections and factor viii in plasma rich in growth-factors (PRGF)-treated hearts. CONCLUSIONS: Injection of platelet growth factors, PRGF, in previously infarcted sheep hearts promotes mitogenesis and angiogenesis. The use of autologous PRGF is simple and safe, causing no toxicity or immune-inflammatory reactions.

Impact of preoperative anemia on cardiac surgery in octogenarians.

OBJECTIVES: Preoperative anemia has been related with adverse outcomes in elective valve replacement and CABG surgery. Impact of preoperative anemia on outcome in octogenarians submitted to cardiopulmonary bypass (CPB) has not yet been precisely described. METHODS: We analyzed association between preoperative hemoglobin level, minimum intraoperative and immediate postoperative hematocrit (HCT), and other co-morbidities and occurrence of adverse outcomes in 227 octogenarians who underwent cardiac surgery. RESULTS: Frequency of preoperative anemia was 41.9% (40.4% in male and 43.5% in female patients). Postoperative mortality was 13.2% (9% in non-anemic patients vs. 18.9% in anemic). 44.5% of patients suffered at least one postoperative adverse outcome (43.1% non-anemic vs. 46.3% anemic). In multivariate analysis (after adjusting independent preoperative risk factors for operative mortality and EuroSCORE) preoperative creatinine level [odds ratio (OR), 2.29; 95% confidence interval (CI), 1.06-4.98; P=0.035], immediate postoperative HCT <24% (OR, 2.78; 95% CI, 1.04-7.38; P=0.039), perioperative red blood cell (RBC) transfusion (OR, 1.58; 95% CI, 1.24-2.00; P=0.0001), peripheral vascular disease (OR, 4.92; 95% CI, 1.45-16.69; P=0.012) and urgent surgery (OR, 10.57; 95% CI, 2.54-43.91; P=0.0001) were identified as independent predictors for in-hospital mortality. CONCLUSIONS: Mortality and adverse postoperative outcome increase in anemic octogenarians undergoing cardiac surgery. Although mortality is directly related to immediate postoperative anemia, adverse outcomes mainly depend on associated co-morbidities.

Building a new annulus: a technique for mitral valve replacement in heavily calcified annulus.

We describe the rationale, methodology, and our preliminary experience with a new surgical technique for mitral valve replacement in patients with severe calcification of the mitral annulus in which the conventional techniques can not be applied. In contrast with other procedures published in the literature for these patients, in which the placement of the prosthesis is supra-annular, we plicate both mitral leaflets and the atrial wall creating a new annulus that allows the intra-annular placement of the prosthesis.

[Cardiac surgery with extracorporeal circulation in cancer patients: influence on surgical morbidity and mortality and on survival]. / Cirugía cardiaca con circulación extracorpórea en pacientes oncológicos: influencia en la morbimortalidad quirúrgica y la supervivencia.

INTRODUCTION AND OBJECTIVES: Morbimortality related to cardiac surgery may be superior in patients with malignant neoplastic disease. Inflammatory phenomena and immunologic changes secondary to extracorporeal circulation use can also increase tumor recurrence. We evaluate characteristics and results of cardiac surgery in our neoplastic patients. METHODS: Out of 2146 consecutive patients who underwent cardiac surgery with extracorporeal circulation, 89 (4.2%) had been previously affected by cancer. Cancer was active (recent diagnosis or under treatment) in 33 patients (group A) and 56 (group B) were in remission. Both groups were matched with 165 patients with no tumor, according to age, gender, type of surgery, and comorbidity (group C). We retrospectively evaluated incremental risk factors for surgical morbimortality, survival and tumor recurrence. RESULTS: Median interval between cancer diagnosis and surgery was 60 months and mortality and morbidity were 4.5% and 36%, respectively, vs 5,4% and 32,7% in group C. During follow-up, 12 patients died (8 due to cancer), 16 suffered cancer recurrence and 2 new tumors were diagnosed. Statistical analysis did not permit us to identify any incremental risk factor for mortality. Postoperative morbidity was increased in case of preoperative renal failure. During follow-up, survival was significantly decreased in group A, in case of preoperative left ventricular dysfunction or pulmonary obstructive disease, and when interval between cancer diagnosis and cardiac surgery was under 2 years. CONCLUSIONS: We have not observed an increase in cardiac surgery morbimortality in cancer patients. Anyway, survival is decreased in case of active or recently diagnosed cancer.

Cirugía cardiaca con circulación extracorpórea en pacientes oncológicos: influencia en la morbimortalidad quirúrgica y la supervivencia / Cardiac surgery with extracorporeal circulation in cancer patients: influence on surgical morbidity and mortality and on survival

Introducción y objetivos. La morbimortalidad de la cirugía cardiaca parece ser mayor en los pacientes neoplásicos. Los fenómenos inflamatorios y las reacciones inmunitarias secundarias a la circulación extracorpórea pueden favorecer la recidiva tumoral. Evaluamos las características y los resultados de la cirugía cardiaca en nuestros pacientes oncológicos. Métodos. De 2.146 pacientes consecutivos sometidos a circulación extracorpórea, 89 (4,2%) presentaban una neoplasia. El cáncer estaba activo (recientemente diagnosticado o en tratamiento) en 33 pacientes (grupo A) y en remisión completa en 56 (grupo B). Se pareó ambos grupos con 165 pacientes sin tumor similares en edad, sexo, tipo de cirugía y comorbilidad (grupo C). Evaluamos retrospectivamente los factores de riesgo de morbimortalidad quirúrgica, supervivencia y recidiva tumoral. Resultados. La mediana del intervalo entre diagnóstico del cáncer y cirugía fue de 60 meses, con mortalidad y morbilidad hospitalarias del 4,5 y el 36%, respectivamente, frente al 5,4 y el 32,7% en el grupo C. Durante el seguimiento, fallecieron 12 pacientes (8 por causa tumoral), 16 sufrieron recidiva y 2, tumores nuevos. El análisis estadístico no permitió identificar ningún factor de riesgo de mortalidad. La morbilidad postoperatoria aumentó en pacientes con insuficiencia renal. Durante el seguimiento, la supervivencia disminuyó significativamente en el grupo A en caso de disfunción ventricular izquierda preoperatoria y enfermedad pulmonar obstructiva crónica y cuando el intervalo entre diagnóstico de cáncer y cirugía fue < 2 años. Conclusiones. No hemos observado un incremento en la morbimortalidad de la cirugía cardiaca en pacientes oncológicos. No obstante, la supervivencia disminuye en neoplasias activas o de diagnóstico reciente

Introduction and objetives. Morbimortality related to cardiac surgery may be superior in patients with malignant neoplastic disease. Inflammatory phenomena and immunologic changes secondary to extracorporeal circulation use can also increase tumor recurrence. We evaluate characteristics and results of cardiac surgery in our neoplastic patients. Methods. Out of 2146 consecutive patients who underwent cardiac surgery with extracorporeal circulation, 89 (4.2%) had been previously affected by cancer. Cancer was active (recent diagnosis or under treatment) in 33 patients (group A) and 56 (group B) were in remission. Both groups were matched with 165 patients with no tumor, according to age, gender, type of surgery, and comorbidity (group C). We retrospectively evaluated incremental risk factors for surgical morbimortality, survival and tumor recurrence. Results. Median interval between cancer diagnosis and surgery was 60 months and mortality and morbidity were 4.5% and 36%, respectively, vs 5,4% and 32,7% in group C. During follow-up, 12 patients died (8 due to cancer), 16 suffered cancer recurrence and 2 new tumors were diagnosed. Statistical analysis did not permit us to identify any incremental risk factor for mortality. Postoperative morbidity was increased in case of preoperative renal failure. During follow-up, survival was significantly decreased in group A, in case of preoperative left ventricular dysfunction or pulmonary obstructive disease, and when interval between cancer diagnosis and cardiac surgery was under 2 years. Conclusions. We have not observed an increase in cardiac surgery morbimortality in cancer patients. Anyway, survival is decreased in case of active or recently diagnosed cancer

Texto para el curso prefacultativo 2001

CONTENIDO: Introduccion a la biologia. Introduccion a la fisica. Introduccion a la quimica. Introduccion a la matematica moderna

Texto para el curso prefacultativo 2000

CONTENIDO: Resolucion. Presentación. Biologia. Fisica. Quimica. Anatomia. Matematica moderna

Texto para el curso prefacultativo

Biologia. Microscopio. Sistema optico. Ocular. Sistema de iluminacion. Sistema mecanico. Funcionamiento y formacion de la imagen microscopica. La celula. Tipos de celulas. Estructura y funcion de lacelula eucariotica. Citoplasma. Membrana nuclear. Citogenetica. Nucleo. Cromatina. Cromosomas. Reproduccion celular mitosis-meiosis. Fases de la mitosis. Fisica. Unidades de medicion. Vectores. Mecanica. Trabajo energia y potencia. Sonido y optica. Hidrologia. Termodinamica. Electricidad. Quimica general y organica