RBCCV Brazilian Journal of Cardiovascular Surgery Revista Brasileira de Cirurgia Cardiovascular

BACKGROUND: To analyze the hemodynamic behavior of the heart in revascularization of the myocardium without use of extracorporeal circulation. MATERIAL AND METHODS: From August 1991 to June 1999, 616 patients suffering from angina of the chest underwent revascularization of the myocardium without use of extracorporeal circulation. In 18 patients the intraoperative hemodynamic parameters were studied. RESULTS: Heart rate remained high at all times during positioning of the heart (p=0.0007). Cardiac output throughout the procedure presented a very slight variation at different moments of positioning of the heart and exposure of the coronary arteries. However, once the heart was in its final normal position a major increase in output was noted (p=0.010). Mean blood pressure was found to be decreased throughout the procedure for exposing the coronary arteries (p=0.022). Arterial pulmonary pressure proved to be reduced at all times during mobilization, but without statistical significance. Pulmonary capillary pressure showed considerable, but statistically insignificant variation during exposure of the arteries. Central venous pressure behaved in a more varied fashion during exposure of the arteries, but again without statistical significance. Systemic vascular resistance proved to be diminished throughout the procedure (p=0.0001). Pulmonary vascular resistance remained reduced at all times during the procedure (p=0.002). Stroke volume was unchanged during anastomosis of the anterior interventricular artery and statistically significant differences were observed only in the right coronary (p=0.002) and right circumflex (p=0.0006) artery and its branches. The cardiac index was shown to be diminished throughout the procedure (p=0.0011). CONCLUSIONS: A) The present technique allows for maximum mobilization of the heart without inducing hemodynamic instability. B) The improvement of a number of hemodynamic parameters at the end of the procedure may be accounted for by: (1) the response to the myocardial revascularization; (2) the release of catecholamines following manipulation of the heart in the different positions and (3) the release of vasoactive mediators following prolonged traction of the pericardium.

Keywords: Myocardial revascularization, methods. Heart, physiopathology. Extracorporeal circulation. Hemodynamics. Intraoperative period.

Objective: To discuss the use of new technology in the chemical demineralization of the aortic valve in coronary artery bypass surgery, together with its hemodynamic changes and to report events related to the technique. Method: Five patients with mild to moderate aortic stenosis submitted to myocardial revascularization underwent chemical treatment of the aortic valve. The patients' ages ranged from 65 to 81 years, with a mean of 73 years. All were men. One patient had the involvement of a single artery and four multiple arteries (four vessels). The gradient ranged from 13 to 49 mmHg, with a mean of 25 mmHg. The size of the aortic orifice ranged from 0.8 to 1.3 cm2, with a mean of 1.1 cm2. The following antecedents were observed: arterial hypertension, hypercholesterolemia, diabetes mellitus and smoking. Results: The aorta clamping time ranged from 94 to 126 minutes, with a mean of 107 minutes and the bypass time was from 134 to 171 minutes, with a mean of 152 minutes. The time of surgery was from 13 to 33 minutes with a mean of 28 minutes. No deaths were recorded. The only postoperative complication noted was a total AV block in three patients. No events were observed that might impair the integrity of the aortic valve or cause aortic insufficiency following treatment. Likewise, no neurologic, systemic, metabolic or hematologic events were seen. The postoperative transvalvular gradient identified by echocardiography showed an improvement in the systolic gradient and in the mean gradient. Conclusions: The treatment proved to be effective and safe, causing no lesions of the valve or any systemic event. The changes in the conduction system appear to be related to the equipment and its system of releasing the lavage solution. The use of this technology may, in the future, be an important adjuvant in aorta valve replacement using percutaneous techniques.

Keywords: Aortic valve, surgery. Aortic valve stenosis. Decalcification technique. Calcinosis. Demineralization.

BACKGROUND: Mediastinitis is a serious complication of median sternotomy and is associated to significant morbidity and mortality. Diabetes is a feared risk factor for mediastinitis and viewed with caution by cardiovascular surgeons.
OBJECTIVE: To identify risk factors for mediastinitis in diabetics undergoing CABG surgery with use of unilateral ITA in the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE.
METHODS: Retrospective study of 157 diabetics operated between May 2007 and April 2010. Nine preoperative variables, five intraoperative variables and seven postoperative variables possibly involved in the development of postoperative mediastinitis were evaluated. Univariate and multivariate logistic regression analyses were applied.
RESULTS: The incidence of mediastinitis was 7% (n=11), with a lethality rate of 36.1% (n=4). Variables associated with increased risk of mediastinitis were: use of pedicled ITA (OR 8.25, 95% CI 2.03 to 66.10, P=0.016), postoperative renal complications (OR 5.10, 95% CI 1.03 to 25.62, P=0.049) and re-operation (OR 7.45, 95% CI 1.24 to 42.17, P=0.023). In multivariate analysis using backward logistic regression, only one variable remained as independent risk factor: use of pedicled ITA (OR 7.64, 95% CI 1.95 to 61.6, P=0.048), in comparison to skeletonized ITA.
CONCLUSIONS: We suggest that diabetics should be considered for strategies to minimize risk of infection. In diabetics that undergo unilateral ITA, the problem seems to be related to how ITA is harvested. Diabetics should always be considered for use of skeletonized ITA.

Keywords: Mediastinitis. Myocardial revascularization. Diabetes mellitus. Mammary arteries.