Maria Cláudia de Azevedo Leitão

Cirurgia de revascularização completa do miocárdio sem circulação extracorpórea: uma realidade

From January/95 to December/96 our surgical team (ICORP - Fortaleza - Ceara), has performed coronary artery surgery without cardiopulmonary bypass (CPB) as a routine. During this period, 385 operations were sequencially performed, 86 per cent of them (333) without CPB. The purpose of this study is to evaluate the results of these 333 patients regarding hospitalization time, age, gender, number of grafts, functional status and morbimortality. All patients were submitted to previous coronary arteriography. All coronaies were by-passed, including the circumflex marginal artery. The age of these patients ranged from 35 to 86 years with a mean age of 61. The average time of hospitalization was 7 days; 625 grafts were placed varying from 1 to 4 with an average of 1.9 by patient. The incidence of procedure related with complications was 2 per cent (7 patients). Ten patients died in the early postoperative course. Considering the data obtained herein we conclude that this procedure can be used in the great majority of patients that undergo coronary artery surgery.

Myocardial revascularization surgery using composite Y-graft of the left internal thoracic artery: blood flow analysis

OBJECTIVE: To assess the left internal thoracic artery (LITA) flow pattern, when it was used to supply the left anterior descending artery (LADA) and another branch from the left coronary artery system (LCAS). METHODS: In the following study, the left internal thoracic artery flow was investigated by echocardiography Doppler, at rest and under dobutamine stress, in two twenty-patient groups. Group A consisted of patients who received only a pedicled LITA graft to the LADA. Group B consisted of patients who received a pedicled LITA graft associated with a vein graft to supply the LADA and another artery from the LCAS. The angiographic study showed graft patency in all patients from both groups. The following parameters were used: systolic flow (SF), diastolic flow, total flow, total flow in stress/total flow at rest ratio (TFS/TFR), systolic peak velocities (SPV), diastolic peak velocities and systolic peak velocity/diastolic peak velocity ratio. RESULTS: All analysed parameters were considered statistically significant, except SF, TFS/TFR and SPV. CONCLUSIONS: We concluded that in the same conditions and methodology, the LITA flow in the composite graft (group B) is higher than in the free graft (group A), which shows the great flow adaptability of LITA to respond to flow demand.

Right atrial myxoma prolapsing into the right ventricle

We report on a rare case of a 67-year-old woman with a right atrial myxoma prolapsing into the right ventricle in the diastolic phase. These tumors comprise approximately 18% of all cardiac myxomas, which occur in 0.0017% of collected autopsy series.

Vineberg's Procedure Modified Technique: Flow Analysis, Immediate Postoperative Results and Angiographic Evaluation

Abstract  Background: The purpose of this study was to evaluate angiographic results of patients subjected to a technique variation of Vinebergs procedure, as well as their morbidity and mortality in immediate postoperative period, and to analyze the flow of grafted left internal thoracic artery (LITA) at rest and under stress. Methods: Between September 1999 and April 2002 eight patients were operated upon, with implant of the internal thoracic artery (ITA) in the intimal layer of the left ventricle (LV) muscle. After 6 months, they underwent angiographic and Doppler evaluation. According to Doppler study of LITA, the sample was divided in two groups: “Vineberg group,” formed by eight patients; and “control group” consisting of 20 patients whose LITA directly revascularize the anterior interventricular artery (AIV). Angiography showed patency of all grafts in both groups. Blood flow and flow velocity in grafts were measured by Doppler echocardiography. T‐test for paired and unpaired samples were used for statistical analysis. Results: There were no deaths or complications in immediate postoperative period. Angiography showed 100% patency. The total flow (TF) of Vineberg group was 55% of the flow in the control group. In both groups, the TF increased with the stress. Conclusions: This Vinebergs technique modification can be successfully used in patients who cannot undergo traditional direct revascularization due to its low rates of morbidity and mortality and a high rate of patency, providing a significant blood flow both at rest and under stress.

Angiographic follow-up of myocardial revascularization using the vineberg procedure correlated with intraoperative imaging.

,2 , in more than 60 patients who were unable to undergo direct myocardial revascularization with ITA anastomosis to the anterior interventricular artery (AIA). In the majority of these unusual cases, the AIA was hypoplastic, with difuse atheromatous disease, which is incompatible with an endarterectomy procedure and direct revascularization or angioplastic surgery. As per current literature, the Vineberg procedure is a last resort therapeutic option 3-5 . In regard to angiogenesis, which is one of the justifications for the efficacy of the Vineberg procedure, the medical literature demonstrates the induction of angiogenesis in an ischemic human myocardium; other studies suggest a beneficial association of this procedure with angiogenic therapy 6-10 . We believe that in the near future, patients will be able to profit from this powerful treatment combination.

Doppler echocardiographic flow pattern of the left internal thoracic artery following myocardial revascularization using a composite graft

Doppler echocardiographic studies of left internal thoracic artery (LITA) grafts, pedicled to the anterior interventricular artery (AIA) became a significant non-invasive method to evaluate graft blood flow and patency at the end of the 90’s. A detailed comparison of blood flow from an in situ LITA and an implanted LITA graft reveals that the in situ LITA has a predominantly systolic flow pattern, whereas the LITA pedicled to the AIA shows a considerable increase of diastolic flow, compatible to the flow pattern in the coronary arteries. Another important observation is that the LITA adapts well to flow demand, and therefore can be used in composite grafts for revascularization of more than one coronary artery1.

Standardization of the sodium heparin dose used in off-pump myocardial revascularization surgery

OBJETIVO: Propor uma metodologia de anticoagulacao com heparina sodica monitorizada pelo Tempo de Coagulacao Ativada (TCA) nos pacientes submetidos a cirurgia de revascularizacao miocardica (RM) sem circulacao extracorporea (CEC), que promova uma anticoagulacao segura (TCA >200 segundos), utilizando uma dose inicial de 1mg heparina sodica/kg de peso. METODO: Quarenta pacientes (30 homens e 10 mulheres), entre 41 e 85 anos, foram submetidos a cirurgia de RM sem CEC, utilizando uma dose inicial de 1mg heparina sodica/kg de peso. Dez minutos apos a administracao da droga, quando TCA > 200 segundos, iniciava-se a confeccao das anastomoses coronarianas. Caso contrario, administrava-se 0,5mg/kg de heparina suplementar. Durante a cirurgia, a cada 30 minutos, novos valores de TCA foram obtidos. Concluidas as anastomoses coronarianas, a heparina foi revertida na proporcao de 1:1 utilizando cloridrato de protamina. RESULTADOS: O valor medio de TCA dez minutos pos-heparinizacao foi de 372,2(+/-104,31) segundos, sem variacao estatisticamente significante entre os sexos ou grupos etarios (p>0,05). Os valores de TCA, 30 e 60 minutos pos-heparinizacao, mantiveram-se acima de 200 segundos. Aos 30 minutos, verificou-se diferenca estatisticamente significante dos valores do TCA entre os sexos e diferentes idades (p<0,05). Apos reversao com protamina, todos os pacientes retornaram aos seus niveis basais de hemostasia (TCA < 200s). CONCLUSOES: Os resultados apresentados demonstram a seguranca e eficacia da anticoagulacao monitorizada pelo TCA nos pacientes submetidos a RM sem CEC, utilizando doses de 1mg heparina sodica/kg de peso, capaz de manter-se efetiva durante todo o procedimento cirurgico, independentemente de variaveis como sexo ou idade.

Surgical revascularization of posterior coronary arteries without cardiopulomonary bypass

OBJECTIVE To assess the results observed during the early postoperative period in patients who had the posterior coronary arteries revascularized without cardiopulmonary bypass (CPB), in regard to the following parameters: age, sex, bypass grafts types, morbidity and mortality. METHODS From January 1995 to June 1998, 673 patients underwent myocardial revascularization (MR). Of this total, 607 (90.20%) MR procedures were performed without CPB. The posterior coronary arteries (PCA) were revascularized in 298 (44.27%) patients, 280 (93.95%) without CPB. The age of the patients ranged from 37 to 88 years (mean, 61 years). The male gender predominated, with 198 men (70.7%). The revascularization of the posterior coronary arteries had the following distribution: diagonalis artery (31 patients, 10%); marginal branches of the circumflex artery (243 patients, 78.7%); posterior ventricular artery (4 patients, 1.3%); and posterior descending artery (31 patients, 10%). RESULTS Procedure-related complications without death occurred in 7 cases, giving a morbidity of 2.5%. There were 11 deaths in the early postoperative period (mortality of 3.9%). CONCLUSION Similarly to the anterior coronary arteries, the posterior coronary arteries may benefit from myocardial revascularization without CPB.

Intraoperative Analysis of Flow Dynamics in Arteriovenous Composite Y Grafts

Objective Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic arterys adaptability and influence of great saphenous vein segment on left internal thoracic arterys flow. Methods Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.

Doppler echocardiographic criteria in patency assessment of composite grafts from left internal thoracic artery

OBJECTIVES The purpose of our study was to establish, with an entirely noninvasive method, transthoracic Doppler echocardiography, criteria for patency of composite left internal thoracic artery grafts when placed on the left anterior descending artery and other branches of the left coronary system. METHODS The control group comprised 20 patients with single graft and 20 patients with composite graft; all forty having their patency confirmed by coronary angiogram (CA). In this control group, two Doppler echocardiographic variables, diastolic mean velocity-time and integral diastolic peak velocity to systolic peak velocity ratio were recorded. For each variable, established cut-off points were established, using the ROC (Receiver Operator Characteristic) curves, to identify criteria which could differentiate the composite grafts. Only patients with composite grafts were included in the 159-patients study group. The criteria established by the cut-off points in the control group were then applied to detect patency using a diastolic fraction of > 0.5 as the gold standard. The sensitivity, specificity, and positive and negative predictive values of these two criteria were determined. RESULTS In the control group, cut-off points of 0.71 and 0.09 m were established for the diastolic peak velocity/systolic peak velocity ratio and for diastolic mean velocity-time integral, respectively. In the study group phase, the sensitivity and negative predictive value of the diastolic peak velocity/systolic peak velocity > 0.71 criterion were 36% and 11%, respectively. Diastolic mean velocity-time integral > 0.09 m criterion, were 40% and 10.48%. The specificities and positive predictive values of each criterion were 100%. CONCLUSION Values reaching the criteria established for each variable indicate high probability of composite graft patency. Lower values have a large proportion of false negatives and are not conclusive as patency criteria.