Volume 18 - Número 3

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Continuing with a series of articles related to scientific research and the writing of scientific articles, this issue presents an excellent work entitled Medical Expressions: Shortcomings and suitability. It discusses the fact that, although medical doctors have an excellent general culture, there are frequently imperfections in respect to the language they use in scientific papers. Often obscure and ambiguous statements and other linguistic problems impair the comprehension of these reports. Considerations about the cases presented in this report are supported by what is recommended by the majority of experts in the Portuguese language and in medical terminology. According to these scholars the following principles, among others, are recommended: (1) In language there is not right and wrong as there are distinct levels of language. There is adequacy and inadequacy for each of these levels. (2) In language, it makes good sense to adopt flexibility. (3) The scientific language should be exact, so as not to have misunderstandings; simple, to be well comprehended and concise, to save the time of the reader and space in publications. (4) The normative grammar, owing to its formation based on the standard culture of the language, is adapted to the formal scientific language. (5) It is recommended to avoid terms criticized by good linguists and to use non-condemned synonyms. (6) In science, it is convenient to have only one name per item. (7) In general, follow rules, that is, proceed according to the majority of cases is preferable to the exceptions. (8) Medical slang should be avoided in formal reports. (9) Foreign words are welcome when there is a need and if there is no equivalent in Portuguese. (10) Very laconic or synthetic expressions, in which several terms are taken for granted, are often antiscientific and create misunderstandings. (11) Unnecessarily invented words (neologisms) that do not appear in dictionaries should be avoided. Although many of the principles mentioned above are pertinent to scientific reports written in English, the majority of the terms discussed in this article are specific to the Portuguese language. Many shortcomings have reference to grammatical structures, phrases or words which have been incorrectly translated into Portuguese or even to English words that have a Portuguese equivalence. Thus translation of this article to the English language seems unnecessary and will serve no purpose. Keywords:

OBJECTIVE: This study evaluates a new technique of an extracardiac conduit in total cavopulmonary connection in complex congenital heart disease. METHODS: Between May 2000 and October 2002, 18 extracardiac conduit surgeries were performed. The patients' weights ranged from 11 to 29 kilograms, the ages ranged from 1 to 12 years old and 10 patients were male. There were eight patients with tricuspid atresia, eight with univentricular heart, and two with unbalanced total atrioventricular septal defect. There were 17 patients who had been submitted to a previous palliative surgery. The surgery was performed at over 32º centigrade without aortic ischemia. Ten PTFE, 4 Hemashield and 4 bovine pericardium tubes were used with diameters ranging from 16 to 22 mm. RESULTS: There were four cases of tube thrombosis and these patients were a reoperation was performed with one death. In one patient a takedown was performed on the 69th postoperative day. There were three deaths, one due to tube thrombosis and two due to low cardiac output. CONCLUSION: Extracardiac conduit is already used for total cavopulmonary connection, but despite encouraging early results, a longer follow-up is necessary to prove its real advantages. Keywords: Heart bypass, right; Pulmonary artery, surgery; Heart defects, congenital, surgery

OBJECTIVES: To evaluate the prognostic implications of myocardial creatine kinase and troponin I (cTn I) in blood samples from the coronary sinus of patients submitted to coronary artery bypass surgery both with and without ischemic preconditioning. METHODS: From October 1998 to May 1999, 35 patients with coronary artery disease who were submitted to coronary artery bypass surgery were studied. Samples containing creatine kinase and cTn I were obtained from the great cardiac vein during surgery at the onset of cardiopulmonary bypass, at the end of the first anastomosis, and at the end of cardiopulmonary bypass. In May 2002, 29 patients were evaluated in regards to the angina functional class, congestive heart failure, number of hospitalizations, myocardial infarction and death. There were 15 patients in the Preconditioned group and 14 in the Control group. Each group was subdivided into patients with and without cardiovascular symptoms. RESULTS: The Control and Preconditioned groups were not significantly different in relation to frequency of cardiovascular symptoms. There were progressive increases of the creatine kinase and cTn I levels at different Interval s of the study. The cTn I in the Preconditioned group was 1.21 ± 0.64 ng/mL and 3.19 ± 3.21 ng/mL in the Control group (p<0.05). The Control group with symptoms had the highest level for cTn I of 5.07 ± 3.69 ng/mL, significantly higher than all other groups (p<0.05). CONCLUSIONS: The Preconditioned group had the lowest level of cTn I. The cTn I may be a marker for late evolution in patients submitted to coronary artery bypass surgery. Keywords: Myocardial revascularization; Myocardial ischemic preconditioning; Myocardial ischemia, physiology; Troponin

OBJECTIVES: The present study is aimed at evaluating the long-term outcomes (up to 12 years of follow-up) of patients undergoing aortic valve replacement using bovine pericardial prostheses. METHOD: From March 1992 to January 2003, 287 patients underwent aortic valve replacement as a single procedure, using bovine pericardial prostheses. Of these, 189 (65.9%) were males. Ages ranged from 15 to 82 years with a mean and standard deviation of 53.6 ± 15.1 years and median of 56 years. The diameters of the bioprostheses ranged from 21 to 29 mm, of which 23 mm (105 cases, 36.6%) and 25 mm (105 cases, 36.6%) were the most prevalent sizes. Only in 1 patient was a 29-mm prosthesis implanted. The assessed variables were late overall survival, comparative survival of patients < 70 years and ³ 70 years of age and the percentage of patients free from reoperations due to primary valve failure. Statistical analysis was performed with the aid of actuarial curves (Kaplan-Meier). RESULTS: The overall actuarial survival at the end of 12 years was 91.7 ± 2.2%. Separate analysis of patients < 70 years (Group A= 252 patients) and ³ 70 years (Group B= 35 patients) showed the overall survival in Group A was 94.7 ± 1.7% and 58.1 ± 17.2% in Group B (Logrank test P= 0.0005; Hazard Ratio 0.20 95% CI 0.01 to 0.29). The rate free from reoperation due to primary valve failure was 96.1 ± 2.0% at the end of 12 years. The 4 patients with implantation failure were in Group A and had a mean age of 49.7 years. CONCLUSIONS: The use of bovine pericardial prostheses in patients with aortic valve disease provides an excellent survival rate over 12 years of follow-up. Patients with 70 years and over had a significantly lower survival, but dysfunctions were only observed in the younger group of patients. Keywords: Bioprosthesis, Aortic valve, Survival, Clinical Evolution

OBJECTIVE: Inflammatory response and metabolic disturbances in coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and without (OFF-PUMP) have been researched. Apoptosis in ischemic reperfusion and chronic disease models has been shown in recent studies. The objective of this study is to compare the apoptosis intensity detected in cardiac myocytes before and after CABG with and without cardiopulmonary bypass. METHOD: Eighteen patients undergoing elective CABG were divided in two groups: the first group underwent cardiopulmonary bypasses and the second group did not. Auricle myocardial samples were obtained at the beginning and at the end of the surgery. Specimens were examined for apoptosis using the TUNEL method. RESULTS: There was no significant difference between the two groups in the surgical, demographic and postoperative data. The number of grafts was statistically different. There was no significant difference between the numbers of cells undergoing apoptosis in the two groups at the beginning of the procedure. There was no significant difference in the number of cells undergoing apoptosis from the beginning to the end of CABG in the OFF-PUMP group. There was a significant difference between the number of cells undergoing apoptosis at the beginning and the end of the CABG in the CPB group (p<0.01). CONCLUSION: The smaller number of cells undergoing apoptosis in the OFF-PUMP group is in accordance with published data that suggest CPB is capable of promoting cell lesion. Having shown that, another favorable argument can be added to the indication of the CABG without CPB. Keywords: Apoptosis; Cardiopulmonary bypass; Coronary artery bypass grafting

INTRODUCTION: Pharmacological cardioplegic solution aims to eliminate the consequences of ischemic damage, which results from the misbalance between the offer and consumption of energy during the arrest of the heart beats during cardiac surgery with cardiopulmonary bypass. OBJECTIVES: This research experimentally evaluates the structural and ultrastructural changes in isolated rabbit hearts submitted to arrest protected by a Low Volumetric Cardioplegic Solution (LVCS). MATERIAL AND METHOD: The study counted with a control group and two experimental groups. In group I the cardiac arrest was obtained by infusion of the LVCS for 2 hours. In group II the experiment was conducted in the same way until the arrest protected by LVCS for 2 hours, and immediately after reperfusion was performed with the Ringer Locke (RL) oxygenated solution for 1 hour. In the control group the hearts were perfused with the RL oxygenated solution for 2 hours. After the experiments, 8 samples of the left ventricle were fixed in 10% formaldehyde and 2.5% glutaraldehyde for histological and ultrastructural analysis. RESULTS: The myocardial cells, the fibroblasts and the endothelial cells which were observed in the experimental groups I and II, presented with marginalization of the heterochromatin, compaction of the nucleolus, change in the morphology of the mitochondria and compaction of the cristae. Also there was an increase of the density of the mitochondrial matrix. This indicates that the nuclear structure as well as the structure of the cytoplasmic organelles were altered when compared to the cells of the control group. CONCLUSION: The structural modifications were due a physiological adaptation of the cell, and not an indication of oncosis or apoptosis, suggesting that the cardioplegic solution used was efficient for the preservation of the cells. Keywords:

OBJECTIVE: To analyze the behavior of troponin (TROP I) and CKMB mass (CKMBm) in regards to the addition of magnesium in cardioplegic solutions; and also the influence of per-operative factors. METHOD: A total of 28 children with ages ranging from 3 to 108 months were studied. The mean weight was 11.8 kg. Eighteen were male. The patients were divided into two groups. Sixteen children in group I (GI) and 12 in group II (GII). The patients in GI received cold blood cardioplegic solution with magnesium (12 mEq/L) and potassium chloride (20 mEq/L) at 20 mL/kg. The patients in GII received the same solution without magnesium. Six blood samples were collected for serum analysis of the concentration of TROP I and CKMBm. The blood samples were collected before clamping the aorta and at 1, 6, 24, 48 and 72 hours after aorta clamping termination. RESULTS: There were no statistical differences in the TROP I and CKMBm levels between the two groups. Among the per-operative factors cyanosis influenced the TROP I and CKMBm levels. Additionally, the aorta clamping time influenced the TROP I levels. CONCLUSIONS: The addition of magnesium in the cardioplegic solution was not associated with different levels of TROP I and CKMBm. Cyanosis and aorta clamping time interfered with peak TROP I levels. Keywords: Troponin I, blood; Creatine kinase, blood; Heart defects, congenital, surgery; Magnesium sulfate, therapeutic use; Cardioplegic solutions, chemistry

INTRODUCTION: Prevention of recurrent cryptogenic strokes or transient ischemic attacks in adults with patent foramen ovale (PFO) represents a therapeutic challenge. Antithrombotic pharmacological treatment is widely used, but its indication is limited because of its significant complications. OBJECTIVE: To demonstrate the efficacy of the surgical closure of patent foramen ovale (PFO) as prophylaxis secondary to cryptogenic strokes or transient ischemic attacks of undetermined origin. METHOD: In this study, 31 men and 16 women with previous ischemic cerebral events underwent direct surgical closure of the PFO. Mean age was 40 years (from 27 to 59 years). No coexisting cause of the stroke was found after extensive investigation, including blood coagulation tests, transesophageal contrast echocardiography (TEE), extracranial and transcranial doppler ultrasonography, 24-hour electrocardiographic monitoring, brain magnetic resonance (BMR) and CT scan. Criteria for operation also included at least two of the following: atrial septal aneurysm, multiple cerebral infarcts, multiple cerebral events and a history of Valsalva strain before stroke. Before operation, only one patient had two shunts (1 PFO and 1 intrapulmonary shunt). RESULTS: No complications occurred during or after the operation, but a few hours after the operation transient arrhythmias developed in four patients without atrial fibrillation, hemodynamic instability nor embolism. All patients survived in class I (NYHA) and during a mean follow-up of 36 months, no patient had recurrence of the stroke or transient ischemic attacks. All patients prospectively underwent BMR and contrast TEE with simultaneous transcranial doppler ultrasonography. A residual right-to-left shunt, smaller than the preoperative one, was observed in only one patient, whereas no lesion was seen on the BMR. CONCLUSION: It is concluded that surgical closure of PFO in patients with presumed paradoxical embolism is safe and avoids recurrent stroke. Keywords: Stoke; Heart septum, surgery; Embolism paradoxical

OBJECTIVES: To study the influence of geometric factors upon the function of modified Blalock-Taussig anastomoses (mBT) using a computational dynamic code based upon the method of finite elements. METHODS: The mBT operation, performed in 10 patients, was graphically reconstructed to create a parametric 3-dimensional geometric model. Using Streamline Upwind/Petrov-Galerkin approximations, blood flow and distribution were evaluated in different diameters of subclavian arteries and polytetrafluoroethylene grafts (PTFE) and angles of proximal anastomoses. RESULTS: The percentage of blood flow derived through the PTFE grows as its diameter increases in relation to subclavian artery diameter. Variations in the PTFE diameter do not interfere with pulmonary artery flow distribution. An angle of 110º in proximal anastomoses results in a high percentage of blood derivation to the graft, while angles of 30º, 60ºand 90º present with almost similar flow rates. However, angles of 30º and 110º produce an excessive flow to one of the pulmonary arteries, in detriment of the other. Peak pressure in the PTFE is affected by the proximal angle of anastomosis, with 30º resulting in higher and 110º in lower values. As the angle increases, the region of higher pressure shifts from the PTFE to subclavian artery. CONCLUSION: In the experimental model, percentage of flow derived in the PTFE is directly related to the diameter of the graft. The ratio between the diameters of subclavian artery and graft is an important regulator of flow deviation to the anastomosis. Angles of the anastomosis between the subclavian artery and the PTFE of 60º to 90º result in favorable pulmonary artery flow distribution and the location of the peak pressure. Keywords: Computational dynamics; Palliative operation; Modified Blalock-Taussig; Congenital heart disease

OBJECTIVES: Over the past few years, great strides have been made in off-pump coronary surgery. This progress is due to a combination of the advances in surgical techniques and the development of instruments that make it possible to perform this procedure in the most varied situations. This is a retrospective study, the purpose of which is to assess our experience with this procedure over the last eleven and a half years. The authors underscore the rapid progress of the method in recent years and report on its indications, contraindications and results. METHODS: In the period from August 1991 to December 2003, 3,410 consecutively patients suffering from angina pectoris were submitted to off-pump coronary surgery. Ages ranged from 13 to 93 years, with a mean of 63 ± 12.0 years. Males accounted for 58% of the cases. The angina was rated according to the criteria of the Canadian Cardiovascular Society, 6.1% of the patients being in Class I, 6.8% in Class II, 46.3% in Class III and 40.8% in Class IV. RESULTS: Intraoperative mortality was low (0.4%). Hospital mortality (30 postoperative days) was 2.5%. Mortality and morbidity among the octogenarian patients were extremely low compared with patients operated on with cardiopulmonary bypass (CPB) (2.2% versus 12.6%) (p<0.001). Postoperative complications regarded as nonfatal occurred in 7.6%. In the final year no difference was observed between the number of conduits in the patients operated on with and without CPB [with CPB 2.8 ± 1.2 and without 2.8 ± 0.8 (NS)]. Acute myocardial infarction was the most frequent complication, occurring in 2.7% of the patients. The mean time in the intensive care unit was 22.3 hours. CONCLUSIONS: Off-pump coronary surgery, employed as a revascularization technique in patients requiring multiple grafts, is a reproducible procedure, the results of which are similar to those obtained from conventional surgery with CPB. In the present series it was possible to perform coronary artery bypass grafting without CPB in 95% of the patients, thus making all patients with indication for grafting potential candidates for the procedure without CPB. Keywords: coronary disease, coronary artery bypass grafting; off-pump coronary surgery

The author describes a technique of performing bicaval/double-lung heart transplantation including the evaluation, harvesting and conservation of the donated organ. Additionally, the regime of pre-operative immunosuppression, the techniques of myocardial protection, resection of the native heart and implantation of the donated organ are described. Keywords: Heart transplantation, methods; Transplantation, homologous

The association between total anomalous pulmonary venous connection and cor triatriatum is extremely rare. We emphasize the possibility of rupturing the membrane of cor triatriatum in the preoperative cineangiographic study, providing a significant improvement of the clinical features, as well as surgical correction and successful evolution. Keywords: Heart defects, congenital, surgery; Heart atrium, abnormalities

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