Piergiorgio Bruno

Catastrophic consequences of a free floating thrombus in ascending aorta

Floating masses in ascending aorta are an uncommon source of embolism. We report the case of a 46-year-old woman, smoker, on synthetic progestagen, with no previous history of thrombotic events, who was admitted to our emergency department for an acute anterior myocardial infarction. Coronary angiogram showed occlusion of left main coronary trunk. Recanalization of the artery was obtained. Ascending aorta angiogram revealed a free floating mass attached to the aortic wall without evidence of aortic dissection. Transesophageal echocardiography confirmed the presence of a pedunculated mobile mass attached to the aortic wall superior to the left coronary ostium. The patient underwent urgent surgery. Intraoperatively a floating thrombus was localized in the posterior wall of ascending aorta. At macroscopical examination aortic wall and leaflets were normal. Post-operative low cardiac output refractory to inotropic drugs and intraaortic balloon counterpulsation required a circulatory assist device. Consequences for the patient were catastrophic in terms of outcome.

Conventional Left Atrial Versus Superior Septal Approach for Mitral Valve Replacement

BACKGROUND This study was designed to evaluate the safety and effectiveness of the superior septal approach for routine mitral valve replacement. METHODS One hundred forty-six consecutive patients undergoing mitral valve replacement at our institution were randomly assigned to undergo the procedure using either the conventional left atriotomy or the superior septal approach. Postoperatively and during the follow-up, 12-lead electrocardiography, 24-hour Holter monitoring, and transthoracic and transesophageal echocardiography were performed in all patients. RESULTS The cardiopulmonary bypass and cross-clamp times were significantly higher in the superior septal group. No significant difference in blood loss was found between the two groups, and no residual atrial septal defect was found in patients in whom we used the superior septal approach. The maintainance of sinus rhythm at late follow-up and the incidences of postoperative arrhythmias and newly developed atrioventricular block were not significantly different between the two groups. CONCLUSIONS The use of the superior septal approach to the mitral valve is not associated with a greater incidence of rhythm disturbances or other complications. Because this approach provides optimal exposure of the valve and the subvalvular apparatus, it has been routinely adopted for use in patients undergoing mitral valve replacement at our institution.

Steal phenomenon from mammary side branches: when does it occur?

BACKGROUND The hemodynamic significance of patent mammary graft side branches is still controversial. This study was designed to evaluate the potential for flow steal of patent mammary side branches in different hemodynamic conditions. METHODS Echo-Doppler measurement of mammary graft flow was performed at rest and after dipyridamole-induced coronary vasodilatation in 10 patients with angiographic demonstration of evident mammary graft side branches (study group) and in 10 matched control patients (control group). Concomitant thallium-201 myocardial scintigraphy was performed to assess the adequacy of mammary flow to the myocardial oxygen demand. Patients of the study group were also submitted to flow evaluation in condition of selective muscular or combined systemic and coronary relaxation. RESULTS No difference in mammary flow and adequacy to myocardial oxygen demand was detected between patients of the study and control groups both at rest and after dipyridamole infusion. In patients with patent side branches the systolic-to-diastolic flow ratio was maintained in case of combined coronary and peripheral vasodilatation, whereas selective muscular relaxation led to an increase in the systolic and a reduction in the diastolic flow. CONCLUSIONS Flow steal from patent mammary graft side branches is possible only in case of selective muscular vasodilatation. As this situation is unlikely to occur in the clinical setting, the potential for flow steal of mammary side branches in cardiac surgery patients seems to be minimal.

Severity of coronary artery stenosis at preoperative angiography and midterm mammary graft status

BACKGROUND The purpose of this study was to evaluate the correlation between the midterm angiographic results of mammary artery grafts and the preoperative stenosis of the target vessel. METHODS We analyzed preoperative and postoperative angiograms of 93 patients who underwent postoperative midterm (> or = 3 years) angiograms of an internal mammary artery (IMA) to left anterior descending artery graft for clinical or study purposes. Patients were divided into three groups on the basis of the percentage of the coronary artery stenosis at preoperative angiography: < 70%, 70% to 90%, and > 90% stenosis. RESULTS Preoperative characteristics were similar in the three groups. The overall incidence of IMA occlusion was 19% in the entire population, without significant differences between groups (19% versus 29% versus 14%). The mean mammary artery diameter significantly increased in direct proportion to the severity of the coronary stenosis (2.0 +/- 0.2 mm in the < 70% versus 2.5 +/- 0.3 mm in the 70% to 90% and 2.7 +/- 0.4 mm in the > 90% series; p < 0.05). CONCLUSIONS Chronic native competitive flow does not significantly affect midterm graft status but does influence mammary graft diameter.

Do internal mammary artery side-branches have the potential for haemodynamically significant flow steal?

OBJECTIVE To evaluate the potential for flow steal of the internal mammary artery (IMA) side-branches at rest and in case of dilatation of their vascular bed (as probably occurs during physical exercise). METHODS Transthoracic echo-Doppler evaluation of IMA flow was performed preoperatively in 40 patients undergoing myocardial revascularization. IMA flow was measured at rest and in condition of peripheral vasodilatation (obtained using forced ventilation for 2 min, dypiridamole 0.84 mg/kg endovenous (e.v.), xantinole nicotinate 500 mg e.v., nifedipine 20 mg sublingual (s.l.)). RESULTS IMA mean peak systolic velocity increased 23% after forced ventilation (from 67 to 83 cm/s), 6% after dypiridamole (from 75 to 80 cm/s), 30% after xantinole infusion (from 62 to 81 cm/s) and 23% after nifedipine administration (from 60 to 74 cm/s). IMA flow increased 17.7% after forced ventilation (from 39.5 to 46.5 ml/min), 4.8% after dypiridamole (from 39.2 to 41.1 ml/min), 20.2% after xantinole infusion (from 41.4 to 49.8 ml/min) and 16.5% after nifedipine administration (from 41.6 to 48.5 ml/min). CONCLUSIONS The limited functional flow reserve of the in situ IMA, even after pure muscular vasodilatation, seems to minimize the possibility of significant flow steal from patent IMA graft collaterals.

Palliative Coronary Artery Surgery in Patients With Severe Noncardiac Diseases

Eight patients with severe systemic pathologies and refractory angina unsuitable for angioplasty were submitted to palliative surgical revascularization without the use of cardiopulmonary bypass and limited to the culprit vessels. Complete relief from angina was achieved in all patients without postoperative mortality and morbidity.

Unusual right coronary artery anomaly with major implication during cardiac operations.

We report a case in which an unrevealed high origin of the right coronary artery (almost 4 cm above the left coronary sinus) led to major complications during a routine atrial septal defect closure. We stress that, in absence of preoperative coronary angiography, coronary artery anomalies should always be considered and minimal ascending aorta manipulation and antegrade/ retrograde myocardial protection should be recommended.

Long-term Morphofunctional Remodeling of Internal Thoracic Artery Grafts A Frequency-Domain Optical Coherence Tomography Study

Background—Internal thoracic arteries (ITAs) are frequently anastomosed to the coronary circulation for bypass grafting. The purpose of this research was to investigate in vivo the long-term morphofunctional changes of ITAs after their use as coronary artery bypass conduits, by comparing the morphological features and vasoreactivity of the grafted left ITA (LITA) with the native, nonharvested right ITA (RITA) in the same patient. Methods and Results—At least 10 years after surgery, in 10 patients, LITA graft and nonharvested RITA were assessed by quantitative angiography and frequency-domain optical tomography. Endothelium-dependent and independent vasodilation was tested by selective infusion of acetylcholine and isosorbide dinitrate. Quantitative angiography showed that baseline mean diameter of LITA graft was significantly smaller than that of RITA (2.59 mm [2.29–3.04] versus 3.05 mm [2.75–3.32]; P=0.01). LITA showed a significant intimal thickening (P=0.05) and a nonsignificant medial thinning (P=0.22) compared with RITA, leading to an increased intima-media ratio (intima-media ratio, 0.72 [0.53–0.91] versus 0.23 [0.12–0.38]; P=0.02). The intima-media ratio correlated inversely with the vasodilatatory response in RITA (r=−0.68, P=0.03 for acetylcholine and r=−0.62, P=0.05 for isosorbide dinitrate) but not in LITA (r=−0.18, P=0.63 for acetylcholine and r=−0.11, P=0.75 for isosorbide dinitrate). Conclusions—Ten years after implantation to the coronary circulation, LITA grafts show intimal thickening, increased intima/media ratio, and maintained endothelium-derived vasodilation. These changes are likely to be an adaptive answer to the different flow dynamics typical of coronary circulation.

Patent side branches do not affect coronary blood flow in internal thoracic artery–left anterior descending anastomosis: An experimental study

BACKGROUND It has been reported that large side branches of internal thoracic artery grafts may steal flow from the coronary circulation. Material an. METHODS To assess the importance of the side branches, we measured the proximal and distal flow and pressures (mean subclavian artery pressure and mean arterial anastomotic pressure) at baseline and during infusion of adenosine (0.5 mg/kg/min) in 10 Landrace pigs in which an internal thoracic artery-left anterior descending anastomosis was constructed without interruption of the side branches. The difference between proximal and distal flow was considered to represent the blood flow of the internal thoracic artery side branches. Measurements were then repeated after surgical occlusion of all the side branches. RESULTS At baseline, blood flow of the side branches represented 18% of the total flow in the proximal internal thoracic artery, and this percentage remained constant under the infusion of adenosine, which caused a 220% increase of the cardiac index and a 368% increase of the proximal flow. The infusion reduced the gradient along the left internal thoracic artery (mean subclavian artery pressure-mean arterial anastomotic pressure) from 15 to 10 mm Hg (P =.02) as the result of a lower mean subclavian artery pressure, although the mean arterial anastomotic pressure remained constant. Interruption of all the side branches resulted in a small and not significant increase in distal flow even after adenosine infusion. CONCLUSION These observations suggest that blood flow in the side branches is minimal either at baseline and under combined systemic and coronary vasodilation. Clinically significant flow steal from the coronary circulation to the internal thoracic artery side branches seems then unlikely.

Determination of Pump Flow Rate During Cardiopulmonary Bypass in Obese Patients Avoiding Hemodilution

Abstract  Background and Aim: During cardiopulmonary bypass the pump flow is usually set on 2.4 L/min/m2 of body surface area (BSA) to guarantee adequate tissue perfusion without differences for patient constitutional type. The present study attempts to evaluate the adequacy of pump flow rate in obese patients, considering the ideal weight instead of the real one, avoiding the overflow side effects and hemodilution. Methods: Obese patients with body mass index (BMI) > 30 presented for cardiac surgery were randomized in two groups: in one the cardiopulmonary bypass was led traditionally, in the other, pump flow rate was calculated on ideal BMI of 25. Results: Demographics, preoperative tests, and monitoring data were registered. Mortality at hospital discharge and 30 days after were analyzed. The pump flow rate between the groups was different (4.46 vs. 4.87; p = 0.004); there were no differences in organ perfusion (SvO2; diuresis) and mortality, but the study group presented fewer complications and blood transfusions. Conclusions: The BSA is widely used as the biometric unit to normalize physiologic parameters included pump flow rate, but it is disputable if this practice is correct also in obese patients. The study group, in which pump flow rate was set on ideal BSA, presented no difference in diuresis and mixed venous saturation but fewer complications and fewer perioperative blood transfusions.