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1.
J Heart Lung Transplant ; 20(9): 996-1004, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11557195

RESUMO

BACKGROUND AND OBJECTIVE: Recently, we have shown, by using localized in vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) of the anterior left ventricular wall, that brain death (BD) is not associated with reduced myocardial energy status. In this study, we applied ex vivo 31P MRS of the entire heart to study the effects of BD on the energy status of the feline donor heart following explantation. METHODS: We used cats (6 BD and 6 controls [C]) in a 26-hour protocol. After 2 hours of preparation, we induced BD by filling an intracranial balloon at t = 0 hour. At t = 6 hours, the hearts were arrested with St. Thomas' Hospital cardioplegic solution, explanted, and stored in the same solution at 4 degrees C in a 4.7 Tesla magnet for 17 hours. Subsequently, the hearts were reperfused in the Langendorff mode at 38 degrees C for 1 hour. The first 5-minute 31P MRS spectrum was obtained 1 hour after crossclamping the aorta; we obtained subsequent spectra every hour during storage and every 5 minutes during reperfusion. At the end, the hearts were dried and weighed. Phosphocreatine (PCr), gamma-adenosine triphosphate (gamma-ATP), inorganic phosphate (Pi), and phosphomonoesters (PME), were expressed per g dry heart weight. The intracellular pH (pH(i)) and the PCr/ATP ratio were calculated. RESULTS: During storage, we identified a significant but similar decrease of pH(i), PCr/ATP ratio, and PCr in both groups. During reperfusion, pH(i) and PCr/ATP ratio recovered similarly in both groups, whereas the recovery of PCr in the BD group was significantly lower (p < 0.05). The Pi and PME increased in both groups during storage but to a lesser extent in the BD group (p < 0.05). This difference disappeared during reperfusion. The gamma-ATP was already significantly lower in the BD group at the onset of storage, and this remained so throughout storage and reperfusion (p < 0.05 vs C). Contractile capacity was lost in all hearts, except for 1 heart in the BD group. CONCLUSION: Brain death-related failure of the energetic integrity of the feline donor heart becomes apparent only when using 31P MRS during ischemic preservation and subsequent reperfusion.


Assuntos
Morte Encefálica/diagnóstico por imagem , Morte Encefálica/metabolismo , Metabolismo Energético/fisiologia , Transplante de Coração/diagnóstico por imagem , Coração/diagnóstico por imagem , Coração/fisiopatologia , Reperfusão Miocárdica , Animais , Pressão Sanguínea/fisiologia , Líquidos Corporais/metabolismo , Temperatura Corporal/fisiologia , Gatos , Modelos Animais de Doenças , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Masculino , Modelos Cardiovasculares , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Fósforo/metabolismo , Cintilografia , Doadores de Tecidos
2.
Ann Transplant ; 6(4): 43-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12035458

RESUMO

OBJECTIVE: To onset of brain death (BD) is associated with a hyperdynamic cardiovascular response caused by the acute sympathetic release of catecholamines. This is followed by progressive hemodynamic deterioration which may preclude heart donation for transplantation. The mechanism of the hemodynamic collapse is not fully understood. Changes in plasma concentrations of non-adrenergic non-cholinergic (NANC) substances, neuropeptide-Y (NP-Y, a vasoconstrictor) and the vasodilators calcitonin gene-related peptide (CGRP) and substance P (SP), were studied in relation to BD-related hemodynamic alterations. MATERIALS AND METHODS: Cats (6 BD and 6 controls (C)) were studied for 6 h. Heart rate (HR) and mean arterial pressure (MAP) were monitored. BD was induced at t = O min. At t = -5, 15, 60, 180 and 360 min, 5 ml arterial blood samples were taken. The plasma was collected and analyzed. The correlations between MAP and NANC levels were calculated. RESULTS: In the BD cats a maximal and significant increase in HR and MAP was observed at t = 2 min. HR returned to basal levels at t = 20 min and remained at that level. However, MAP deteriorated progressively to 53 +/- 8 mmHg (p 0.001 vs C) at/ = 360 min. NP-Y had increased from 59.7 +/- 2.5 to 110 +/- 20.2 pmol/l (p 0.05 vs C) at t = 15 min, had returned to basal value at t = 60 min and remained at that level. CGRP levels were lower and SP levels did not change vs C but both showed a trend towards higher levels at t = 360 min. The correlations between MAP and NP-Y, CGRP and SP appeared to be not significant. CONCLUSION: No evidence for participation of NANC substances could be demonstrated in brain death-related hemodynamic deterioration of the feline potential heart donor.


Assuntos
Morte Encefálica/fisiopatologia , Transplante de Coração , Hemodinâmica , Doadores de Tecidos , Animais , Pressão Sanguínea , Temperatura Corporal , Peptídeo Relacionado com Gene de Calcitonina/sangue , Gatos , Hidratação , Frequência Cardíaca , Masculino , Neuropeptídeo Y/sangue , Respiração , Substância P/sangue , Fatores de Tempo
3.
J Interv Card Electrophysiol ; 4(2): 395-404, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10936005

RESUMO

BACKGROUND: Asynchronous patterns of contraction and relaxation may contribute to hemodynamic and functional impairment in heart failure. In 1993, we introduced biventricular pacing as a novel method to treat heart failure by synchronous stimulation of the right and left ventricles after an appropriate atrioventricular delay. The objectives of this study were to assess the early and long-term effects of this therapy on functional capacity and left ventricular function in patients with severe heart failure and left bundle branch block. METHODS AND RESULTS: Twelve patients with end-stage congestive heart failure, sinus rhythm and complete left bundle branch block were treated with biventricular stimulation at optimized atrioventricular delay. The NYHA functional class and maximal bicycle exercise capacity were assessed. Systolic and diastolic left ventricular function were studied with echocardiography and radionuclide angiography. Data was collected at various intervals during 1-year follow-up. Cumulative survival [95% CI] was 66.7% [40.0,93.4] at 1 year and 50 % [21.8, 78.2] at 2 and 3 years. Median NYHA class improved from class IV to class II at 1 year (p=0.008). After 6 weeks an increase in exercise capacity occurred, which was sustained. A less restrictive left ventricular filling pattern, an increase in dP/dt and left ventricular ejection fraction, and a decrease in mitral regurgitation were observed early and long-term. CONCLUSIONS: Biventricular pacing at optimized atrioventricular delay results in improvement in functional capacity, which is associated with improved systolic and diastolic left ventricular function, and a decrease in mitral regurgitation during short- and long-term follow-up.


Assuntos
Estimulação Cardíaca Artificial/métodos , Insuficiência Cardíaca/terapia , Bloqueio de Ramo/terapia , Ecocardiografia , Teste de Esforço , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Angiografia Cintilográfica , Função Ventricular Esquerda
6.
Control Clin Trials ; 21(6): 595-609, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11146152

RESUMO

The Octopus Study consists of two multicenter randomized clinical trials in which coronary artery bypass grafting on the beating heart (off-pump CABG) using the Utrecht Octopus Method is compared to intracoronary stent implantation and conventional CABG. The primary endpoint in the comparison of off-pump CABG versus stent implantation (OctoStent Trial) is medical effectiveness (i.e., absence of reintervention and major adverse cardiac and cerebrovascular events at 1 year after treatment). The primary endpoint in the comparison of off-pump CABG versus conventional CABG (OctoPump Trial) is cerebral safety (i.e., absence of cognitive deficits and cerebrovascular events at 3 months after treatment). Secondary endpoints in both trials include presence and severity of angina, quality of life, exercise capacity, and cost-effectiveness. A total of 560 patients will be enrolled. A random sample of 210 patients will undergo repeat angiography at 1 year to assess angiographic restenosis rate and graft patency. Including 1-year follow-up, the study will last for 3 years. Control Clin Trials 2000;21:595-609


Assuntos
Angioplastia Coronária com Balão , Ponte Cardiopulmonar , Ponte de Artéria Coronária/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Stents , Ponte de Artéria Coronária/economia , Análise Custo-Benefício , Humanos , Estudos Multicêntricos como Assunto , Qualidade de Vida , Projetos de Pesquisa , Risco , Acidente Vascular Cerebral
8.
J Heart Lung Transplant ; 18(12): 1189-97, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10612377

RESUMO

OBJECTIVE: Long-term exposure of the donor heart to high dosages of dopamine in the treatment of brain death-related hemodynamic deterioration has been shown to reduce myocardial phosphocreatine (PCr) and adenosine triphosphate (ATP) in myocardial biopsy specimens and may preclude heart donation for transplantation. Short-term exposure to the acute catecholamine release during the onset of brain death has shown an unchanged PCr/ATP ratio using in vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS). In this study 31P MRS was used to evaluate in vivo myocardial energy metabolism during long-term dopamine treatment. METHODS: Twelve cats were studied in a 4.7 Tesla magnet for 360 minutes. At t = 0 minutes, brain death was induced (n = 6). At 210 minutes, when myocardial workload in the brain-death group was reduced significantly, dopamine was infused (n = 12) at 5 microg/kg/min and its dose was consecutively doubled every 30 minutes and was withheld during the last 30 minutes of the experiment. Phosphorus-31 magnetic resonance spectra were obtained from the left ventricular wall during 5-minute time frames, and PCr/ATP ratios were calculated. The hearts were histologically examined. RESULTS: Although significant changes in myocardial workload were observed after the induction of brain death and during support and withdrawal of dopamine in both groups, the initial PCr/ATP ratio of 2.00+/-0.12 and the contents of PCr and ATP did not vary significantly. Histologically identified sub-endocardial hemorrhage was observed in 3 of 6 of the brain-dead animals and in 1 of 6 of the control animals. CONCLUSIONS: High dosages of dopamine in the treatment of brain death-related reduced myocardial workload do not alter PCr/ATP ratios and the contents of PCr and ATP of the potential donor heart despite histologic damage.


Assuntos
Morte Encefálica/metabolismo , Dopamina/farmacologia , Metabolismo Energético , Coração/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Miocárdio/metabolismo , Trifosfato de Adenosina/análise , Animais , Gatos , Dopamina/administração & dosagem , Transplante de Coração , Masculino , Miocárdio/química , Fosfocreatina/análise , Radioisótopos de Fósforo
9.
J Heart Lung Transplant ; 17(10): 984-90, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9811406

RESUMO

BACKGROUND: Hemodynamic deterioration resulting from brain death-induced myocardial left ventricular dysfunction may preclude heart donation. A reduced myocardial high-energy phosphate content, assessed by biopsy specimens, has been suggested to be responsible for this phenomenon. By applying phosphorus 31 magnetic resonance spectroscopy, in vivo myocardial high-energy phosphate metabolism can be studied continuously. METHODS: Twelve cats were sedated, intubated, ventilated, and studied for 240 minutes. Heart rate, arterial blood pressure, and arterial blood gases were monitored. Central venous pressure was kept constant. Myocardial work was expressed as rate-pressure product (RPP=heart rate x systolic arterial blood pressure). After sternotomy a radio frequency surface coil was positioned onto the left ventricle. A parietal trephine hole was drilled, and an inflatable balloon was inserted. The animal was placed into a 4.7 T horizontal 40 cm bore magnet interfaced to a spectrometer. Brain death (n=6) was induced by rapid inflation of the balloon; the six other cats served as a sham-operated control group. 31P spectra were obtained in 30 seconds, with ventilation and arterial blood pressure curve triggering. The phosphocreatine/to/adenosine triphosphate ratio, as an estimator of energy metabolism, was calculated. RESULTS: Brain death was established within 30 seconds after inflation of the balloon. Changes in RPP were characterized by a triphasic profile with a maximum increase from 19.3+/-1.4 x 10(3) to 87.5+/-8.1 x 10(3) mm Hg x min(-1) (p < .0001 vs control group) at 2 minutes after inflation of the balloon. Subsequently, RPP decreased and was normalized at 15 minutes after inflation. The third phase was characterized by hemodynamic deterioration, which became significant at 180 minutes and resulted in mean arterial pressure of 71+/-12 mm Hg (p < .05 vs control group) at the end of the experimental period. RPP deteriorated to 14.6+/-2.0 x 10(3) mm Hg x min(-1) (p < .05 vs control group) at 240 minutes. Because the heart rate remained constant during the third phase, the decrease in RPP was caused by a decrease in systolic arterial blood pressure. The initial phosphocreatine/adenosine triphosphate ratio of 1.65+/-0.16 varied to 1.52+/-0.06 at 2 minutes, and to 1.73 +/-0.17 (all values NS vs control group and vs initial ratio) at 240 minutes. CONCLUSIONS: The energy status of the heart is not affected by brain death. Therefore brain death-induced hemodynamic deterioration is not caused by impaired myocardial high-energy phosphate metabolism.


Assuntos
Trifosfato de Adenosina/metabolismo , Morte Encefálica/fisiopatologia , Hemodinâmica/fisiologia , Espectroscopia de Ressonância Magnética , Fosfocreatina/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Morte Encefálica/patologia , Gatos , Metabolismo Energético/fisiologia , Frequência Cardíaca/fisiologia , Masculino , Contração Miocárdica/fisiologia , Disfunção Ventricular Esquerda/patologia , Função Ventricular Esquerda/fisiologia
10.
Curr Opin Cardiol ; 13(6): 476-82, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9822882

RESUMO

In off-pump coronary artery grafting, cardiopulmonary bypass and its associated maneuvers, i.e., aortic manipulation and global cardiac arrest, may be avoided, and thus its morbidity and mortality may be reduced. Modern tissue stabilizers allow accurate construction of anastomosis and are now considered indispensable. Currently, there are two groups of stabilizers, i.e., those based on suction-fixation and those based on pressure-fixation. Each has specific applications. The popularity of off-pump coronary bypass surgery is increasing, from the patient's perspective and from the perspective of cost containment. Proper patient selection is crucial. The procedure is technically demanding. It is expected that by the year 2000 10% of coronary surgery will be off-pump, particularly by direct vision techniques. From the currently available, nonrandomized, prospective studies, the preliminary conclusion seems justified that, in selected patients, off-pump bypass grafting is as accurate as conventional bypass grafting, with lower morbidity and mortality. This includes fast recovery and early resumption of premorbid activities in most patients. Particularly, therefore, the procedure is also cost saving. Prospective randomized studies are necessary to quantify these statements.


Assuntos
Ponte Cardiopulmonar , Ponte de Artéria Coronária/métodos , Contraindicações , Angiografia Coronária , Ponte de Artéria Coronária/tendências , Tomada de Decisões , Seguimentos , Humanos , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/cirurgia , Seleção de Pacientes , Complicações Pós-Operatórias/mortalidade , Reprodutibilidade dos Testes , Taxa de Sobrevida
11.
Ann Thorac Surg ; 66(2): 576-9, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9725417

RESUMO

Off-pump coronary artery bypass grafting requires immobilization of the coronary artery. A suction device (Octopus Tissue Stabilizer), attached to the epicardium and connected rigidly to the operating table rail, was used through limited and full surgical access for single-vessel and multivessel arterial revascularization, respectively. An outline for its application, as used by us to construct 122 anastomoses in 70 patients, including posterior wall grafting (in 9 patients) and sequential grafting on the anterior wall (in 17 patients), is presented.


Assuntos
Ponte de Artéria Coronária/instrumentação , Anastomose Cirúrgica/instrumentação , Humanos , Esterno/cirurgia , Toracotomia/instrumentação
13.
J Thorac Cardiovasc Surg ; 116(1): 60-7, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9671898

RESUMO

OBJECTIVE: Cardiopulmonary bypass and global cardiac arrest enable safe coronary artery bypass grafting but have adverse effects. In off-pump coronary bypass grafting, invasiveness is reduced, but anastomosis suturing is jeopardized by cardiac motion. Therefore the key to successful off-pump coronary bypass grafting is effective local cardiac wall stabilization. METHODS: We prospectively assessed the safety and efficacy of the Octopus tissue stabilizer (Medtronic, Inc., Minneapolis, Minn.) in the first 100 patients selected for off-pump coronary bypass via full or limited surgical access. To immobilize and expose the coronary artery, two suction paddles (-400 mm Hg), fixed to the operating table-rail by an articulating arm, stabilized the anastomosis site. RESULTS: One hundred forty-one grafts (96% arterial) were used to create 172 anastomoses (17% side-to-side), up to 4 per patient, on average 23 in the full access group (46 patients) and 1.2 in the limited access group (54 patients). Complications included conversion to cardiopulmonary bypass (2%), conversion from limited to full access (3%), myocardial infarction (4%), predischarge coronary reintervention (2%), and late coronary reintervention (1%). Median postoperative length of hospital stay was 4 days (limited access) or 5 days (full access). Rapid recovery allowed 96% of patients to resume social activities within 1 month. At the 6-month angiographic follow-up, 95% of anastomoses was patent. At the 2- to 22-month follow-up (mean, 13 months), 98 patients were in Canadian Cardiovascular Society class I and 2 patients were in class II. CONCLUSION: These results suggest that off-pump coronary artery bypass grafting with the Octopus tissue stabilizer is safe. Early clinical outcome and patency rates warrant a randomized study comparing this methods with conventional coronary bypass grafting.


Assuntos
Ponte Cardiopulmonar , Ponte de Artéria Coronária/métodos , Doença das Coronárias/cirurgia , Contraindicações , Angiografia Coronária , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico por imagem , Eletrocardiografia , Desenho de Equipamento , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Complicações Pós-Operatórias , Estudos Prospectivos , Segurança , Técnicas de Sutura , Resultado do Tratamento , Disfunção Ventricular Esquerda/complicações
14.
Eur J Cardiothorac Surg ; 12(3): 406-12, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9332919

RESUMO

OBJECTIVE: Target site immobilization is essential to enable meticulous anastomosis suturing during coronary artery bypass grafting on the beating heart. A novel device ('Octopus') was developed for local heart muscle immobilization by suction. The purpose of this study was to investigate the efficacy of the method through a limited access. METHODS: The suction device, placed on either side of the recipient coronary artery and fixed to the operating table-rail through an arm construction, restrains anastomosis site motion to 1 x 1 mm. A total of 27 patients underwent off-pump arterial bypass grafting using this method. Preoperatively, all patients had angina class III (NYHA) and were failed or unsuitable candidates for balloon angioplasty. Surgical access was via a 10-cm anterior thoracotomy (n = 26) or 10-cm subxiphoid incision (n = 1). RESULTS: Harvesting of the graft required 48 +/- 12 min (mean +/- S.D.). Immobilization with the 'Octopus' was effective and facilitated precise anastomosis suturing of 20 single and 7 sequential grafts. Immobilization did not change cardiac index and mean arterial blood pressure. During coronary surgery, however, inotropic drug support was used in 5 of 27 (18%) of patients. There was no myocardial infarction. Only minor transient complications were met. There were electro-cardiographical signs of pericarditis in 6 patients. The postoperative hospital stay ranged from 2 to 6 days, mean 4.0 +/- 1.2 days. The mean follow-up is 6.5 +/- 4 months (range, 1-12 months). All patients except one were in functional class I without angina. Social activities were resumed within 4 weeks. At 6 months angiography was performed in 15 out of 27 patients. The patency rate of 19 out of 20 anastomoses was 95%. All distal grafts were patent. One side to side anastomosis was occluded. CONCLUSIONS: The 'Octopus' immobilization method is safe and effective. It facilitates less invasive CABG in selected patients and gives way to fast recovery by reducing invasiveness.


Assuntos
Ponte de Artéria Coronária/métodos , Doença das Coronárias/cirurgia , Imobilização , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Sucção/instrumentação , Toracotomia/métodos , Adulto , Idoso , Doença das Coronárias/classificação , Doença das Coronárias/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Artérias Torácicas/transplante , Ultrassonografia
15.
Int J Cardiol ; 60(3): 317-20, 1997 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-9261646

RESUMO

Two patients are described who suffered from progressive intravascular hemolysis following different kinds of reconstructive surgery of the mitral valve. Within the context of increasing numbers of operations aimed to preserve the mitral valve, the importance and difficulty of prompt recognition and adequate treatment of this very uncommon but potential lethal complication are emphasised.


Assuntos
Próteses Valvulares Cardíacas/métodos , Hemólise , Prolapso da Valva Mitral/cirurgia , Idoso , Ecocardiografia Transesofagiana , Humanos , Masculino , Prolapso da Valva Mitral/diagnóstico por imagem , Prolapso da Valva Mitral/etiologia , Técnicas de Sutura
16.
Ned Tijdschr Geneeskd ; 141(23): 1134-7, 1997 Jun 07.
Artigo em Holandês | MEDLINE | ID: mdl-9380142

RESUMO

Postoperative recovery after (arterial) coronary bypass grafting mostly takes several months because of the effects of the heart-lung machine and the cardioplegia which are mostly haematological, pneumological and neurological in nature. The morbidity can be reduced by operating on the beating heart and via smaller access. One possibility is the 'Octopus' method developed in Utrecht, which involves local fixation of the beating heart. The postoperative recovery of the first 45 patients was favourable.


Assuntos
Ponte de Artéria Coronária/métodos , Anastomose Cirúrgica/métodos , Parada Cardíaca Induzida/efeitos adversos , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Período Pós-Operatório
17.
Ann Thorac Surg ; 63(6 Suppl): S1-5, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9203587

RESUMO

Minimally invasive coronary artery bypass grafting (MICABG) may be achieved by arterial grafting on the beating heart, without cardiopulmonary bypass, and by operations via limited access. The Second Utrecht MICABG Workshop held October 4-5, 1996, focused on beating-heart coronary immobilization, limited-access thoracoscopic and direct-vision mobilization of the internal mammary artery, limited-access left anterior descending coronary artery grafting, and, finally, facilitated distal anastomosis techniques. It has yielded 33 reports in this supplement. The combined, cumulative experience of a number of participants exceeded 3,000 beating-heart cases, including more than 1,000 with arterial grafting through limited access. The average number of anastomoses per patient ranged from 1.0 to 2.0. Therapeutic strategies are evolving, and dedicated instrumentation is being developed. Randomized clinical trials with angiographic follow-up are required to establish that the reduction in invasiveness of coronary bypass grafting is not achieved at the expense of suboptimal quality of the arterial graft and the distal anastomosis.


Assuntos
Ponte de Artéria Coronária/métodos , Ponte Cardiopulmonar , Endoscopia , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Toracotomia/métodos
18.
Ann Thorac Surg ; 63(6): 1797-9, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9205197

RESUMO

A method is described to facilitate harvesting of the mammary artery in minimally invasive direct-vision coronary artery bypass grafting using a 10-cm anterior thoracotomy. Hoisting of the anterior thoracic wall with a modified retractor allows good exposure. Harvesting the mammary artery without the use of endoscopic tools was successful in all 10 cases.


Assuntos
Anastomose de Artéria Torácica Interna-Coronária/métodos , Toracotomia/métodos , Humanos , Artéria Torácica Interna/cirurgia
19.
J Surg Res ; 68(1): 7-15, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9126189

RESUMO

Brain death-related hemodynamic instability may preclude donor heart procurement. The relationships between the initial changes of myocardial workload, hemodynamic deterioration, and myocardial histological changes caused by acute induction of brain death are unclear. Cats (n = 15) were submitted to brain death by rapid inflation of an intracranial balloon. A further 12 cats served as a sham-operated control group. The changes in heart rate, mean arterial blood pressure, systolic and diastolic arterial blood pressure, left ventricular developed pressure, LV dP/dtmax, rate-pressure product (RPP), and circulating noradrenaline and adrenaline were studied during 240 min after the induction of brain death. Central venous pressure was kept constant. The hearts were histologically examined afterward. Electrocerebral activity disappeared within 30 sec after balloon inflation. At 3 min, noradrenaline and adrenaline levels had increased 75- and 40-fold, respectively, compared to pre-induction levels. The hemodynamic response was characterized by an early and rapid increase of hemodynamic variables at 2.9 +/- 0.2 min. This was followed by a second phase of normalization or deterioration. Two distinct subgroups (n = 9) became hemodynamically unstable (HDU), characterized by a systolic arterial blood pressure < 90 mm Hg, at 108 +/- 29 min, and progressively deteriorated to 67 +/- 8 mm Hg at 240 min after inflation of the balloon. The hemodynamic variables of the other, hemodynamically stable (HDS), subgroup (n = 6) normalized at 60 min after inflation. Hemodynamic deterioration of the HDU subgroup compared to the HDS subgroup was significant at 10 min after induction of brain death. The maximum values of RPP were similar in the two subgroups. Respiratory and metabolic variables at the end of the experiment were not different in both subgroups. Histological evidence of myocardial damage was present in 73% (11/15) of the brain dead cats and absent in the control group. The histological changes were identified both in hearts of HDU (6/9) and HDS (5/6) cats. In the cat, no relationships were demonstrated between the acute increase of myocardial workload, the occurrence of hemodynamic deterioration, and myocardial histological changes after rapid induction of brain death. These results may contribute to the discussion whether hemodynamic instability of the donor is an appropriate exclusion criterion for heart transplantation.


Assuntos
Morte Encefálica , Coração/fisiologia , Coração/fisiopatologia , Hemodinâmica/fisiologia , Miocárdio/patologia , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Morte Encefálica/patologia , Morte Encefálica/fisiopatologia , Catecolaminas/sangue , Gatos , Córtex Cerebral/fisiologia , Eletroencefalografia , Masculino , Radiografia , Respiração/fisiologia
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