RESUMO
Aortic prosthetic graft infection is a rare, potentially fatal complication. Surgical explantation of the infected native and prosthetic material with sufficient debridement has sometimes been limited by the lack of a suitable conduit to bridge the residual long segment defect. We describe the implantation of a bovine pericardial fashioned neo-aorta to manage this problem.
Assuntos
Aorta Torácica/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Bioprótese , Prótese Vascular , Desbridamento , Infecções Relacionadas à Prótese/cirurgia , Infecções Estafilocócicas/cirurgia , Infecção da Ferida Cirúrgica/cirurgia , Adulto , Anastomose Cirúrgica , Antibacterianos/administração & dosagem , Aorta Torácica/diagnóstico por imagem , Insuficiência da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/diagnóstico por imagem , Quimioterapia Combinada , Seguimentos , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/diagnóstico por imagem , Reoperação , Sepse/diagnóstico por imagem , Sepse/cirurgia , Infecções Estafilocócicas/diagnóstico por imagem , Infecção da Ferida Cirúrgica/diagnóstico por imagem , Toracotomia , Tomografia Computadorizada por Raios XRESUMO
Bypass of stenotic coronary arteries with autologous saphenous vein is an established treatment for ischemic heart disease. However, its long-term clinical success is limited. Late vein graft failure is the result of medial and intimal thickening consequent upon medial vascular smooth muscle cell migration, proliferation and extracellular matrix deposition, followed later by superimposed atherosclerosis. These changes directly compromise graft blood flow and provoke thrombosis. Vein graft wall thickening may represent an adaptation imposed by arterial hemodynamic factors, and these factors have been shown to promote vascular smooth muscle cell migration and proliferation through activation of key mediators including platelet-derived growth factor (PDGF). Many pharmacological interventions aimed at preventing these long-term changes have proven unsuccessful in clinical evaluation. We recently demonstrated in a pig saphenous vein graft model that application of an external polyester stent to the outside of carotid interposition vein grafts reduced intimal hyperplasia and total wall thickness 1 month after implantation. However, it is not known whether the benefits of the stent are maintained in the longer term or what mechanisms underlie its effect. The present study therefore compared morphological changes and PDGF expression in stented grafts and contralateral unstented grafts in the same pigs, 6 months after graft implantation. Reduced medial thickening, neointima formation, and cell proliferation were sustained in externally stented grafts, and these effects were associated with a significant reduction in PDGF expression.
Assuntos
Ponte de Artéria Coronária/métodos , Fator de Crescimento Derivado de Plaquetas/metabolismo , Stents , Túnica Íntima/patologia , Animais , Modelos Animais de Doenças , Endotélio Vascular/patologia , Imuno-Histoquímica , Antígeno Nuclear de Célula em Proliferação/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Veia Safena/transplante , Suínos , TransplantesRESUMO
Taurine and glutamine are the most abundant intracellular free amino acids in mammalian hearts where changes in their intracellular concentrations are likely to influence a number of cellular activities. In this study we investigated the effects of ischaemia and reperfusion on the intracellular concentrations of taurine and glutamine in the hearts of patients undergoing coronary artery bypass surgery using cold crystalloid or cold blood cardioplegic solutions. Ischaemic arrest (30 min), using cold crystalloid cardioplegic solution (n = 19), decreased the intracellular concentrations (micromol/g wet weight) of taurine (from 9.8 +/- 0.8 to 7.7 +/- 0.7, P < 0.05) and glutamine (8.7 +/- 0.5 to 7.2 +/- 0.6). After 20 min of normothermic reperfusion the fall in taurine and glutamine was maintained (7.5 +/- 0.5 and 7.4 +/- 0.7 for taurine and glutamine respectively). Myocardial ischaemic arrest with cold blood cardioplegic solution (n = 16) did not cause a significant fall in tissue taurine or glutamine. However, on reperfusion there was a marked fall in the intracellular concentrations of taurine (9.4 +/- 0.5 to 6.5 +/- 0.7) and glutamine (8.0 +/- 0.7 to 5.8 +/- 0.4). The fall in amino acids was associated with a fall in ATP and a rise in tissue lactate. This work demonstrates that irrespective of the cardioplegic solution used to arrest the heart, there is a marked fall in tissue taurine and glutamine which may influence the extent of recovery following surgery. The fall in taurine is largely due to efflux whereas changes in glutamine are due to both transport and metabolism. Ischaemia, hypothermia and changes in the transmembrane concentration gradients are the likely factors responsible for the changes in tissue amino acids.
Assuntos
Ponte de Artéria Coronária , Glutamina/metabolismo , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Taurina/metabolismo , Trifosfato de Adenosina/metabolismo , Idoso , Bicarbonatos , Biomarcadores , Sangue , Cloreto de Cálcio , Soluções Cardioplégicas , Feminino , Humanos , Ácido Láctico/metabolismo , Magnésio , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica/métodos , Miocárdio/metabolismo , Cloreto de Potássio , Cloreto de Sódio , Troponina/sangue , Troponina I/sangue , Troponina TRESUMO
OBJECTIVE: The aim was to investigate the influence of vessel wall injury, incurred during routine vein preparation, on smooth muscle cell proliferation. METHODS: A newly developed quantitative organ culture was used, in which segments of human saphenous vein were cultured in medium containing 30% fetal bovine serum and 1 microCi.ml-1 of [3H]thymidine for up to 14 d. Endothelial integrity was measured by scanning electron microscopy and medial cell viability by adenine nucleotide concentrations. Cell proliferation was measured by DNA concentration, global incorporation of [3H]thymidine, and by counting labelled cells in autoradiographs of transverse sections. RESULTS: Surgical preparation led to endothelial injury and reduced adenine triphosphate concentration by 60%. Surgically prepared veins also suffered a significant decline in DNA concentration during culture, which implied that injury led to cell necrosis. Surgically prepared veins showed 2.1- and 2.7-fold greater global incorporation of [3H]thymidine than freshly isolated veins after 7 and 14 d in culture, respectively, which corresponded with a 23-fold and 11-fold greater abundance of thymidine labelled cells in the medial layer. Intimal thickening and the numbers of total and thymidine labelled cells in the intimal layer were similar. CONCLUSIONS: The data show that injury incurred during routine surgical preparation is associated with enhanced medial smooth muscle cell proliferation. The effect of injury was most probably to permit an increased response of medial smooth muscle cells to serum derived mitogens.
Assuntos
Músculo Liso Vascular/citologia , Veia Safena/cirurgia , Trifosfato de Adenosina/metabolismo , Adulto , Idoso , Divisão Celular , Ponte de Artéria Coronária , Técnicas de Cultura , DNA/metabolismo , Endotélio Vascular/lesões , Endotélio Vascular/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/lesões , Veia Safena/lesões , Veia Safena/metabolismo , Timidina/metabolismoRESUMO
REASONS FOR PERFORMING STUDY: Protection from infectious disease requires antigen-specific immunity. In foals, most vaccine protocols are delayed until 6 months to avoid maternal antibody interference. Susceptibility to disease may exist prior to administration of vaccination at age 4-6 months. OBJECTIVES: The aim of this investigation was to characterise immune activation among healthy foals in response to a multivalent vaccine protocol and compare immune responses when foals were vaccinated at age either 90 or 180 days. STUDY DESIGN: Randomised block design. METHODS: Twelve healthy foals with colostral transfer were blocked for age and randomly assigned to vaccination at age 90 days (treatment) or at age 180 days (control). Vaccination protocols included a 3-dose series and booster vaccine administered at age 11 months. RESULTS: Immune response following vaccination at age 90 or 180 days was comparable for several measures of cellular immunity. Antigen specific CD4+ and CD8+ expression of interleukin-4, interferon-γ and granzyme B to eastern equine encephalomyelitis, western equine encephalomyelitis, West Nile virus, tetanus toxoid, equine influenza and equine herpesvirus-1/4 antigens were evident for both groups 30 days after initial vaccine and at age 344 days. Both groups showed a significant increase in antigen-specific immunoglobulin G expression following booster vaccine at age 11 months, thereby indicating memory immune responses. CONCLUSIONS: The data presented in this report demonstrate that young foals are capable of immune activation following a 3-dose series with a multivalent vaccine, despite presence of maternal antibodies. Although immune activation does not automatically confer protection, several of the immune indicators measured showed comparable expression in foals vaccinated at 3 months relative to control foals vaccinated at age 6 months. In high-risk situations where immunity may be required earlier than following a conventional vaccine series, our data provide evidence that foals respond to immunisation initiated at 3 months in a comparable manner to foals initiated at an older age.
Assuntos
Doenças dos Cavalos/prevenção & controle , Esquemas de Imunização , Vacinas Virais/imunologia , Viroses/veterinária , Envelhecimento , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Regulação da Expressão Gênica/imunologia , Genes MHC da Classe II/imunologia , Granzimas/genética , Granzimas/metabolismo , Cavalos , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Vacinas Virais/administração & dosagem , Viroses/prevenção & controleRESUMO
Proliferation of vascular smooth muscle cells (VSMC) is a principal event in neointima formation in saphenous vein-coronary artery bypass grafts. Since endothelin-1 (ET-1) promotes VSMC replication and ET-1 receptor antagonists inhibit neointima formation in arterial injury models, it is reasonable to propose that ET-1 may be involved in neointima formation in vein grafts. However, it is not known what alterations of ET-1 and its receptors (if any) occur in vein grafts. The objective of this study, therefore, was to investigate the distribution of ET-1 and ET-1 receptor subtypes (ET(A) and ET(B)) in porcine vein grafts. Unilateral interposition saphenous vein grafting was performed by end to end anastomosis after excision of a segment of carotid artery in Landrace pigs. One month after surgery, vein grafts, ungrafted saphenous veins and carotid arteries were excised, ET-1 immunoreactivity identified by immunocytochemistry and ET(A) and ET(B) receptor subtypes studied using autoradiography. In vein grafts, there was a greater density of ET(A) compared to ET(B) receptors in both the tunica media and neointima. ET(A) binding in the tunica media of ungrafted saphenous vein was greater than that in the carotid artery or vein grafts, but greater in the vein graft compared to the carotid artery. Immunoreactive ET-1 was located in endothelial cells and throughout the neointima of the vein graft. Dense ET-1 binding (to both ET(A) and ET(B) receptors) was also associated with microvessels in the adventitia within the graft. In vein grafts, there was strong ET(B) binding to neutrophils which were present in high numbers at the subendothelium and within the adventitia. It is concluded ET(A) receptors may play a role in vein graft thickening at the medial and neointimal VSMC level, whereas ET(B) receptors may play a role in microangiogenesis. The higher levels of ET(A) receptors in the tunica media of ungrafted saphenous vein relative to the carotid artery and vein graft may also render this conduit susceptible to neointima formation. These data indicate that studies on the effect of ET receptor antagonists on the pathobiology of vein graft disease is warranted.
Assuntos
Artérias Carótidas/metabolismo , Músculo Liso Vascular/metabolismo , Receptores de Endotelina/metabolismo , Veia Safena/metabolismo , Anastomose Cirúrgica , Animais , Autorradiografia , Artérias Carótidas/citologia , Artérias Carótidas/cirurgia , Contagem de Células , Divisão Celular , Densitometria , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/metabolismo , Oclusão de Enxerto Vascular/patologia , Imuno-Histoquímica , Músculo Liso Vascular/citologia , Neutrófilos/metabolismo , Receptor de Endotelina A , Receptor de Endotelina B , Veia Safena/citologia , Veia Safena/transplante , SuínosRESUMO
A pig model of autologous saphenous vein to common carotid artery bypass grafting was developed. An end-to-end anastomotic technique led to lower middle graft and distal turbulence. Saphenous veins were surgically prepared with or without distention at 600 mm Hg, implanted into the arterial circulation, and removed 2 hours later. Medial integrity was then assessed by adenosine triphosphate/adenosine diphosphate concentration ratio, and endothelial integrity, leukocyte and platelet adhesion by scanning electron microscopy. In grafts made with undistended vein adenosine triphosphate/adenosine diphosphate concentration ratio was not significantly lower (3.0 +/- 0.1, n = 32) than in freshly isolated vein (3.3 +/- 0.1, n = 26), endothelial cover was 98% +/- 1%, n = 6, and there was little platelet or leukocyte adhesion. In distended grafts adenosine triphosphate/adenosine diphosphate concentration ratio was reduced to 2.2 +/- 0.2 (n = 7, p less than 0.005), endothelial cover was reduced to 38% +/- 14% (n = 6, p less than 0.001), and there was extensive platelet and leukocyte adhesion to exposed subendothelium. In separate experiments graft patency measured at 1 to 5 weeks was significantly greater (96%, n = 25) when undistended vein was used than when distended vein was used (64%, n = 25, p less than 0.005). The data show that distention leads to medial and endothelial damage and that this is associated with increased platelet and leukocyte adhesion and with reduced early patency.
Assuntos
Artérias Carótidas/cirurgia , Leucócitos/patologia , Agregação Plaquetária , Veia Safena/transplante , Grau de Desobstrução Vascular , Difosfato de Adenosina/análise , Trifosfato de Adenosina/análise , Anastomose Cirúrgica , Animais , Artérias Carótidas/patologia , Adesão Celular , Ecocardiografia Doppler , Endotélio Vascular/patologia , Microscopia Eletrônica de Varredura , Fluxo Sanguíneo Regional , Veia Safena/análise , Veia Safena/patologia , Suínos , Preservação de TecidoRESUMO
OBJECTIVES: Normothermic cardiopulmonary bypass has been proposed as a more physiologic technique than hypothermic bypass for the maintenance of the body during cardiac surgery. The aims of this study were to investigate the effects of systemic perfusion temperature on clinical outcome after coronary revascularization. METHODS: Three hundred patients (mean age 60 +/- 9 years, 88% male) were prospectively randomized into three groups: hypothermia (28 degrees C, n = 100), moderate hypothermia (32 degrees C, n = 100), and normothermia (37 degrees C, n = 100). All patients received cold antegrade St. Thomas' Hospital crystalloid cardioplegic solution, and patients in the normothermic group were actively rewarmed during cardiopulmonary bypass (nasopharyngeal temperature 37 degrees C). RESULTS: No differences were found between groups with respect to mortality (1%), intraaortic balloon pump use, perioperative infarction rates, focal neurologic deficits (1%), intubation time, intensive care unit stay, and postoperative hospital stay. Further stepwise regression analysis identified age and intensive care unit stay as important predictors of the variability in postoperative stay (both R2 = 0.114; p < 0.001), whereas perfusion temperature remained a nonsignificant explanator. Normothermic perfusion necessitated larger doses of phenylephrine to maintain arterial pressure above 50 mm Hg during cardiopulmonary bypass (p < 0.0001 vs 28 degrees C, p < 0.01 vs 32 degrees C) but less requirement for electrical defibrillation during reperfusion (p < 0.05 vs 32 degrees C, p < 0.01 vs 28 degrees C). Total chest drainage was not different between groups, but patients undergoing normothermic cardiopulmonary bypass required less transfusion of blood (p < 0.05 vs 28 degrees C and 32 degrees C) and platelets (p < 0.04 vs 32 degrees C, p < 0.001 vs 28 degrees C) in the postoperative period. CONCLUSIONS: Cardiopulmonary bypass temperature did not influence early clinical outcome after routine coronary artery bypass operations. Normothermic systemic perfusion was associated with an increased requirement for vasoconstrictors and reduced requirements for electrical defibrillation and transfusion of blood products.
Assuntos
Ponte Cardiopulmonar/métodos , Ponte de Artéria Coronária , Hipotermia Induzida , Bicarbonatos , Transfusão de Sangue , Cloreto de Cálcio , Cardioversão Elétrica , Feminino , Parada Cardíaca Induzida , Humanos , Unidades de Terapia Intensiva , Cuidados Intraoperatórios/métodos , Tempo de Internação/estatística & dados numéricos , Magnésio , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Cloreto de Potássio , Estudos Prospectivos , Cloreto de Sódio , Resultado do Tratamento , Vasoconstritores/uso terapêuticoRESUMO
Dobutamine stress Doppler echocardiography was used to compare the hemodynamic performance of two small aortic bileaflet prostheses. Nineteen patients (14 female, mean age 64 years) who had undergone aortic valve replacement with 21 mm bileaflet valve prostheses (St. Jude Medical valve, n = 9, or CarboMedics valve, n = 10) were studied. Dobutamine infusion was started at a rate of 5 micrograms.kg-1.min-1 and increased to 10 and 20 micrograms.kg-1.min-1 at 15-minute intervals. Under maximum stress, heart rate and cardiac output increased by 70% and 120%, respectively, and mean arterial blood pressure decreased by 9%. Pulsed-wave and continuous-wave Doppler studies were performed at rest and at the end of each stage. Velocity ratio, effective orifice area, performance index, and discharge coefficient of the valve were calculated, and peak and mean velocities and pressure drops across the prostheses were measured. Dobutamine infusion produced similar increases in cardiac output in all patients. Effective orifice areas, discharge coefficients, and performance indexes were comparable for the two valve groups both at rest and maximum stress. Transvalvular velocities and pressure drops were also similar in the two valve groups. Transvalvular pressure drops were also comparable in patients with large body surface area. Dobutamine stress echocardiography is useful in the evaluation of the hemodynamic performance of prosthetic heart valves. St. Jude Medical and CarboMedics 21 mm prostheses have equally favorable hemodynamic performances in most patients under conditions of high cardiac output.
Assuntos
Cardiotônicos , Dobutamina , Ecocardiografia Doppler , Próteses Valvulares Cardíacas , Hemodinâmica , Idoso , Valva Aórtica , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de PróteseRESUMO
The long-term clinical success of coronary artery bypass grafting with autologous saphenous vein is limited by progressive medial and neointimal thickening in the graft and superimposed atherosclerosis. We sought to reduce wall thickening by applying an external stent to experimental grafts in pigs. The diameter of the stent was designed to allow unrestricted initial expansion of the vein in response to arterial pressure and the stent material was highly porous so as to minimize adventitial [correction of advential] disruption. Four weeks after graft implantation, stented grafts had a larger lumen (11.2 +/- 6.2 [standard deviation] mm2 versus 7.6 +/- 3.4 mm2, p < 0.05, n = 9) and an almost fourfold thinner media (0.14 +/- 0.08 versus 0.49 +/- 0.22, p < 0.001) and neointima (0.10 +/- 0.07 versus 0.35 +/- 0.24, p < 0.001) than paired unstented grafts in the same animals. Cell proliferation was also greatly reduced by stenting in the neointimal and medial layers. The stenting procedure devised here is readily applicable to clinical coronary bypass grafts.
Assuntos
Ponte de Artéria Coronária/métodos , Endotélio Vascular/patologia , Próteses e Implantes , Veia Safena/transplante , Stents , Animais , Divisão Celular , Modelos Animais de Doenças , Endotélio Vascular/química , Desenho de Equipamento , Imuno-Histoquímica , Antígeno Nuclear de Célula em Proliferação/análise , Veia Safena/patologia , SuínosRESUMO
With use of an established model of pig saphenous vein grafts in the carotid artery, the time-course of the following changes was related: (1) medial and intimal size by morphometry of transverse sections, (2) cell number by deoxyribonucleic acid concentration, (3) cell density by deoxyribonucleic acid concentration per milligram wet weight and by counting nuclei in transverse sections, (4) endothelial morphology by scanning electron microscopy, and (5) cholesterol concentration. In the first week after grafting, medial and intimal thickening occurred associated with an increase in cell number. Between 1 and 4 weeks after grafting, further rapid medial and intimal thickening occurred with no further increase in cell number but with a reduction in cell density, which suggested that cell migration, hypertrophy, and the laying down of extracellular matrix were responsible. Between 4 and 39 weeks after grafting, a slower increase in medial and intimal size occurred, associated with a parallel increase in cell number and no further change in cell density. The endothelium of grafts showed only localized abnormalities, including loss of cells and leukocyte adhesion, either 1 or 4 weeks after grafting. Cholesterol concentration was slightly elevated 1 week after grafting but returned to values similar to those in vein by 4 weeks after grafting. Distention to 600 mm Hg during surgical preparation of vein for grafting resulted in lower graft patency after either 1 or 4 weeks and caused significant medial and endothelial injury. Distention did not, however, affect changes in medial or intimal size, deoxyribonucleic acid, or cholesterol concentration caused by grafting. We conclude that three processes contribute to medial and intimal thickening, namely: (1) an initial phase of rapid smooth muscle cell proliferation, (2) smooth muscle cell migration, hypertrophy, and synthesis of extracellular matrix, and (3) a late phase of slower smooth muscle cell proliferation. The incomplete late suppression of smooth muscle cell proliferation occurs despite regeneration of a morphologically intact endothelium and in the absence of progressive cholesterol accumulation.
Assuntos
Artérias Carótidas/patologia , Colesterol/análise , Endotélio Vascular/patologia , Veia Safena/patologia , Anastomose Cirúrgica/métodos , Animais , Artérias Carótidas/química , Artérias Carótidas/cirurgia , Contagem de Células , DNA/análise , Endotélio Vascular/química , Microscopia Eletrônica de Varredura , Veia Safena/química , Veia Safena/transplante , Suínos , Fatores de Tempo , Grau de Desobstrução VascularRESUMO
UNLABELLED: The effect of systemic perfusion temperature on postoperative cognitive function was investigated in 96 adult patients undergoing elective coronary revascularization with cardiopulmonary bypass at 28 degrees C, 32 degrees C, or 37 degrees C. Neuropsychologic performance was assessed 1 day before the operation and 6 weeks after the operation. Five tests were adapted from the Wechsler Adult Intelligence Scale and two from the Wechsler Memory Scale. RESULTS: No patients had major neurologic complications. Ninety-three patients completed the five Wechsler Adult Intelligence Scale tests, but only 70 went on to complete the Wechsler Memory Scale tests as well. In these, there was an effect of cardiopulmonary bypass temperature on the number of neuropsychologic tests in which there was a preoperative to postoperative deterioration (p = 0.021), the number with bypass at 37 degrees C being significantly greater than the number with bypass at 32 degrees C (p = 0.015). Subsidiary analyses using a multivariate linear model examined the effect of cardiopulmonary bypass temperature on the magnitude of change, with or without allowing for other possible confounding influences. There was an adverse effect of normothermic (37 degrees C) versus moderately hypothermic (32 degrees C) perfusion---more convincingly displayed in the analyses of all seven scores rather than just the Wechsler Adult Intelligence Scale scores. Further cooling to 28 degrees C conferred no additional benefit in terms of cognitive function. The importance of the deterioration is open to question.
Assuntos
Temperatura Corporal , Ponte Cardiopulmonar/efeitos adversos , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Ponte de Artéria Coronária , Feminino , Nível de Saúde , Humanos , Hipotermia Induzida , Testes de Inteligência , Masculino , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Pessoa de Meia-Idade , Análise Multivariada , Testes Neuropsicológicos , Complicações Pós-Operatórias , Estudos ProspectivosRESUMO
To investigate the effect of recipient and donor genders on the outcome after heart transplantation, a retrospective survey was undertaken of 356 patients (366 transplants: 316 males, 40 females) undergoing transplantation between January 1979 and December 31, 1989, at Papworth Hospital. Ninety-three organs came from female donors; 263 organs came from males. Twelve females (30%; 95% confidence interval 16% to 44%) and 51 males (16%; 95% confidence interval 12% to 20%) died in the early postoperative period (within 90 days of operation). To date, two females (5%) and 51 males (16%) have died in the late postoperative period. Comparison between recipient genders showed no statistically significant difference in early mortality rates from any cause or in actuarial survival overall, although fatal acute rejection was significantly more common in female recipients (7 of 40 female recipients versus 19 of 316 male recipients). The higher incidence of fatal rejection among female recipients was related to the higher proportion of female donors in this group, because recipients of female donor grafts had significantly higher mortality rates, particularly in the early postoperative period and as a result of acute rejection, than did recipients of organs from male donors. Death from rejection after the first 3 months and death from infection were not gender-related. Recipients of grafts from female donors did not suffer significantly more early morbidity, such as rejection and infection, or late morbidity in the form of coronary artery disease. Acute rejection episodes were more common in female recipients.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Transplante de Coração/mortalidade , Doadores de Tecidos , Análise Atuarial , Adulto , Intervalos de Confiança , Feminino , Rejeição de Enxerto/fisiologia , Sobrevivência de Enxerto/fisiologia , Humanos , Terapia de Imunossupressão , Incidência , Masculino , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores Sexuais , Resultado do TratamentoRESUMO
The evaluation of myocardial damage in relation to cardiac operation from a clinical and a research perspective is of great importance, particularly for the evaluation of different cardioprotective strategies. Although measurements of serum biochemical markers have often been used, their value has been limited by their lack of sensitivity and specificity in the presence of skeletal muscle damage. A newer range of markers are now available that may reliably indicate both perioperative myocardial infarction, as well as more subtle degrees of subclinical myocyte injury. In this review, the application of biochemical markers for clinical and research purposes during cardiac operation is considered.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Infarto do Miocárdio/diagnóstico , Traumatismo por Reperfusão Miocárdica/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Biomarcadores/sangue , Ensaios Enzimáticos Clínicos , Humanos , Infarto do Miocárdio/sangue , Traumatismo por Reperfusão Miocárdica/sangue , Complicações Pós-Operatórias/sangueRESUMO
Transesophageal echocardiography (TEE) now is used widely as a monitoring technique during and after cardiac operations. Widespread adoption of the technique has provided a wealth of new information. This review analyzes the influence of TEE on the routine conduct of cardiac operations and on surgical decision making in specific areas. Its use in routine hemodynamic monitoring and problem solving, both intraoperatively and postoperatively, is discussed. Transesophageal echocardiography has a particular role in valve operations, in guiding and assessing the immediate results of mitral valve repair. It also has found application in the grading and operative management of the severely atheromatous aorta, the diagnosis and management of aortic dissection, and other aspects of surgery of the thoracic aorta. In addition, management in specialized areas, such as cardiopulmonary transplantation and the insertion and monitoring of ventricular assist devices, have also been helped by the information provided by TEE.
Assuntos
Aorta/diagnóstico por imagem , Procedimentos Cirúrgicos Cardíacos/métodos , Ecocardiografia Transesofagiana , Valvas Cardíacas/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Monitorização Intraoperatória , Adulto , Aorta/fisiopatologia , Aorta/cirurgia , Criança , Embolia Aérea/diagnóstico por imagem , Cardiopatias/diagnóstico por imagem , Cardiopatias/fisiopatologia , Cardiopatias/cirurgia , Valvas Cardíacas/fisiopatologia , Valvas Cardíacas/cirurgia , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/cirurgia , Transplante de Coração-Pulmão , Humanos , Complicações Intraoperatórias/diagnóstico por imagem , Cuidados Pós-Operatórios , Reprodutibilidade dos TestesRESUMO
We investigated the effect of a novel surgical preparative technique for human saphenous vein by using the concentration of adenosine triphosphate and the adenosine triphosphate/diphosphate ratio to quantify medial integrity and by using stimulated rates of prostacyclin production to quantify endothelial function. Freshly isolated vein had an adenosine triphosphate concentration of 358 +/- 54 nmol.g-1 wet weight and an adenosine triphosphate/diphosphate ratio of 2.89 +/- 0.13 (n = 12); it produced prostacyclin in response to fluid shear at a rate of 14.3 +/- 2.0 pg.min-1.mg-1 wet weight (n = 12). Surgically prepared vein obtained on completion of the last proximal anastomosis had been distended with the patient's own arterial pressure using a side-arm connected to the aortic cannula. This vein had an adenosine triphosphate concentration of 413 +/- 70 nmol.g-1 wet weight and an adenosine triphosphate/diphosphate ratio of 2.74 +/- 0.44 (n = 11), and it produced prostacyclin at a rate of 13.1 +/- 0.2 pg.min-1.mg-1 wet weight (n = 12). All values were indistinguishable from those in freshly isolated vein. The results demonstrate that this simple technique for distention at arterial pressure preserved medial and endothelial function.
Assuntos
Ponte de Artéria Coronária/métodos , Veia Safena/transplante , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Anastomose Cirúrgica/métodos , Epoprostenol/biossíntese , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Veia Safena/metabolismoRESUMO
A case of late cardiac tamponade seen with progressive dysphagia 15 days after aortic valve replacement is reported. The diagnosis was confirmed echocardiographically and successful pericardiocentesis was followed by immediate alleviation of the dysphagia.
Assuntos
Tamponamento Cardíaco/etiologia , Transtornos de Deglutição/etiologia , Complicações Pós-Operatórias/diagnóstico , Valva Aórtica , Bioprótese , Tamponamento Cardíaco/diagnóstico , Ecocardiografia , Próteses Valvulares Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
There has been considerable interest in the use of normothermic techniques during cardiac operations, both as a means of myocardial protection and as a more physiologic environment for other organs during cardiopulmonary bypass. Although a limited number of uncontrolled studies have suggested superior clinical results compared with conventional hypothermic regimens, these claims have not been thoroughly investigated using randomized protocols. The limited available data suggest that the successful use of warm blood cardioplegia requires adequate delivery of the solution to all parts of the myocardium at optimal flow rates to maintain aerobic arrest, so those who advocate the use of normothermic arrest must pay particular attention to ensure that their myocardial protection is effective. The advantages of employing normothermic systemic perfusion in regard to factors such as improved hemodynamic performance and reduced blood loss postoperatively need to be balanced against concerns regarding the inadequacy of cerebral protection offered by this method.
Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Parada Cardíaca Induzida/métodos , Coagulação Sanguínea , Encéfalo/fisiologia , Hemodinâmica , Humanos , Hipotermia Induzida , Perfusão/métodos , TemperaturaRESUMO
Transesophageal echocardiography is becoming increasingly popular as a method of intraoperative monitoring because it can be performed continuously, does not transgress the sterile operative field, and provides data with regard to valve function, ventricular volumes, and contractility. Recently it was suggested that it can be used to measure cardiac output; however, controversy remains regarding its accuracy. Cardiac output was measured simultaneously by transesophageal echocardiography (using a 5-MHz pulse-wave Doppler, single-plane viewing probe) and by the thermodilution method in 21 patients undergoing open heart operations. The cardiac outputs measured by thermodilution correlated poorly (r = 0.45) with the transesophageal values derived from the left ventricular cross-sectional area, and the mean difference was 0.47 +/- 2.17 (standard deviation) L.min-1, giving limits of agreement of from -3.87 to +4.81 L.min-1. Cardiac outputs measured by thermodilution correlated well (r = 0.95) with transesophageal Doppler values derived from pulmonary artery flow velocity, with a mean difference of 0.12 +/- 0.45 L.min-1 and narrow limits of agreement of from -0.78 to +1.02 L.min-1. Based on our findings, transesophageal Doppler echocardiographic determination of cardiac output using pulmonary artery flow measurements can provide accurate hemodynamic data in patients undergoing cardiac operations.
Assuntos
Débito Cardíaco , Procedimentos Cirúrgicos Cardíacos , Ecocardiografia Transesofagiana , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , TermodiluiçãoRESUMO
BACKGROUND: Small-sized mechanical aortic prostheses are commonly associated with generation of high transvalvular gradients, particularly in patients with large body surface area, and can result in patient-prosthesis mismatch. This study evaluates the hemodynamic performance of 21-mm Sorin Bicarbon bileaflet mechanical prostheses using dobutamine stress echocardiography. METHODS: Fourteen patients (7 women; mean age, 63+/-8 years) who had undergone aortic valve replacement with a 21-mm Sorin Bicarbon bileaflet mechanical prosthesis 32.4+/-5.1 months previously were studied. After a resting Doppler echocardiogram, a dobutamine infusion was started at a rate of 5 microg x kg(-1) x min(-1) and increased to 30 microg x kg(-1) x min(-1) at 15-minute intervals. Pulsed- and continuous-wave Doppler echocardiographic studies were performed at rest and at the end of each increment of dobutamine. Both peak and mean velocity and pressure gradient across the prostheses were measured, and effective orifice area, discharge coefficient, and performance index were calculated. RESULTS: Dobutamine stress increased heart rate and cardiac output by 83% and 81%, respectively (both p < 0.0001), and mean transvalvular gradient increased from 15.6+/-5.5 mm Hg at rest to 35.4+/-11.9 mm Hg at maximum stress (p < 0.0001). Although the indexed effective orifice area was significantly lower in patients with a larger body surface area, this was not associated with any significant pressure gradient. The performance index of this valve was unchanged throughout the study. Regression analyses demonstrated that the mean transvalvular gradient at maximum stress was independent of all variables except resting gradient (p = 0.05). Body surface area had no association with the changes in cardiac output, transvalvular gradient at maximum stress, and effective orifice area. CONCLUSIONS: These data show that the 21-mm Sorin Bicarbon bileaflet mechanical prosthesis offers an excellent hemodynamic performance with full utilization of its available orifice when implanted in the aortic position. The lack of significant transvalvular gradient in patients with a larger body surface area suggests that patient-prosthesis mismatch is highly unlikely when this prosthesis is used.