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O Alfieri

Publications and source records attributed to O Alfieri.

At least 37 records · Page 2Linked to original sources
PubMed2001

A computational study of the hemodynamics after "edge-to-edge" mitral valve repair.

Edge-to-edge mitral valve repair consists in suturing the free edge of the leaflets to re-establish coaptation in prolapsing valves. The leaflets are frequently sutured at the middle and a double orifice valve is created. In order to study the hemodynamic implications, a parametric model of the left heart has been developed. Different valve areas and shapes have been investigated. Results show that the simplified Bernoulli formula provides a good estimation of the pressure drop and that the pressure drop may be predicted on the basis of the pre-operative geometric and hemodynamics data by means of customized models.

Blood Flow Velocity↗
PubMed2001

Surgical and percutaneous myocardial angiogenesis induction. Part II--neoangiogenesis.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable to a subset of patients with angina refractory to medical treatment. Bypass surgery might not be feasible because of lack of suitable conduits, diffuse coronary disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. We have previously reviewed the available experience with laser-induced direct myocardial revascularization, one of the new potential treatment modalities for this patient subset. One of the potential mechanisms of action for laser treatment is the induction of neoangiogenesis. In the second part of our article we review the available experience with the induction of myocardial angiogenesis using different growth factors or the genes encoding for them.

Coronary Disease↗
PubMed2001

[Spinal cord stimulation and quality of life in patients with refractory angina].

BACKGROUND: Spinal cord stimulation (SCS) is a treatment that exploits the antalgic and vasodilatory effects on the microcirculation produced by a stimulating electrode positioned in the peridural space. This therapy has been used for years in the treatment of refractory angina pectoris. The aim of this study was to monitor the clinical effectiveness of the technique in terms of symptomatic benefits and, above all, improved quality of life in angina patients undergoing SCS. METHODS: From November 1998 to December 2000 we used SCS to treat 17 patients with refractory angina (functional class III or IV Canadian Cardiovascular Society) with onset more than one year earlier. All patients had undergone one or more traditional revascularisation procedures and were receiving maximum drug therapy. Patients were assigned to SCS because it was not technically possible to perform other revascularisation procedures. Quality of life was measured before and after treatment using a multidimensional index (QL Spitzer's index). We also noted the mortality, acceptance and morbidity of the procedure during a follow-up lasting 10 months on average. Lastly, the number of weekly anginal pain attacks, weekly nitrate consumption and CCS functional class were recorded before treatment and 1, 3 and six months after therapy. RESULTS: SPC was effective in 13 patients out of 17 (76.47%). In responders the quality of life improved by 70%: in these patients, the number of weekly angina attacks reduced from 11.76+/-7.56 to 2.14+/-2.54, and the functional class from 3.30+/-0.75 to 1.5+/-0.53. No major periprocedural complications were reported. The annual mortality rate was 6.6%. The technique was easy to use. CONCLUSIONS: The results of this study show that SCS is effective, safe, easy to use and well tolerated by patients with refractory angina who fail to respond to traditional revascularisation. This technique substantially improves the quality of life of patients suffering from refractory angina.

Aged↗
PubMed2001

[Asymptomatic severe aortic stenosis: always surgical treatment? The opinion of the surgeon].

Prophylactic valve replacement in asymptomatic patients with severe aortic stenosis is controversial. Most authors consider that patients could be managed without surgery until symptoms develop. The incidence of sudden death in patients without symptoms is low, < 1%/year and valve replacement is complicated by an operative mortality up to 5 and 1-2% of incidence of valve-related major events. Early surgical approach is suggested by several observations. The first one is the unpredictable risk of myocardial fibrosis after long standing left ventricular hypertrophy and pressure overload, with associated systolic and diastolic dysfunction. Left ventricular impairment can persist after valve replacement influencing exercise capacity and survival in selected patients. On the other hand, major improvement in myocardial protection techniques, intraoperative monitoring with transesophageal echocardiography, prosthetic design (stentless, supra-annular), all have reduced in-hospital mortality and morbidity. More precise recommendations can be made according to an improved characterization of the patients from fast to slow evolution, according to age, type of aortic stenosis, degree of calcification, changes in transaortic gradients over time, tolerance to exercise test and response of aortic valve area to dobutamine. In patients with high risk of progression (severely calcified valve, Doppler velocity > 4 m/s, rapidly increasing with time), indirect evidence of myocardial fibrosis (excessive left ventricular hypertrophy, systolic or diastolic dysfunction), and need of myocardial revascularization, an early surgical approach should be considered.

Age Factors↗
PubMed2001

The use of robotic technology in the LAST operation.

BACKGROUND: The LAST operation represents a good option for single left anterior descending artery (LAD) revascularization. We report our preliminary experience with the LAST operation performed with the aid of the "da Vinci" Intuitive robotic system. METHODS: From January 2000 to May 2001, 12 patients (11 males and 1 female, mean age 62 +/- 8 years) underwent the LAST operation. All patients had a proximal LAD lesion either not suitable for coronary angioplasty or unsuccessfully treated at coronary angioplasty previously. The mean preoperative ejection fraction was 55 +/- 5%. In all patients, left internal mammary artery (LIMA) harvesting was carried out endoscopically using robotic technology. After heparin administration the LIMA was distally divided to check the adequacy of the blood flow. An incision of about 6 cm was then made in the appropriate intercostal space and the LAD was exposed using a special costal retractor. Following the insertion of a temporary intracoronary shunt, the LIMA was anastomosed to the LAD. RESULTS: No hospital or delayed death occurred. Uneventful conversion to midline sternotomy was necessary in one patient who developed ischemic changes and hemodynamic instability. One patient had a revision for postoperative bleeding. All patients were discharged within the first postoperative week and in 4 of them optimal patency of the LIMA graft was angiographically documented. CONCLUSIONS: The use of robotic technology seems to overcome all the drawbacks associated with the LAST operation and enhances the role of minimally invasive surgery in coronary artery revascularization.

Aged↗
PubMed2000

Acute and short-term effects of partial left ventriculectomy in dilated cardiomyopathy: assessment by pressure-volume loops.

OBJECTIVES: The aim of this study was to evaluate the short-term effects of partial left ventriculectomy (PLV) on left ventricular (LV) pressure-volume (P-V) loops, wall stress, and the synchrony of LV segmental volume motions in patients with dilated cardiomyopathy. BACKGROUND: Surgical LV volume reduction is under investigation as an alternative for, or bridge to, heart transplantation for patients with end-stage dilated cardiomyopathy. METHODS: We measured P-V loops in eight patients with dilated cardiomyopathy before, during and two to five days after PLV. The conductance catheter technique was used to measure LV volume instantaneously. RESULTS: The PLV reduced end-diastolic volume (EDV) acutely from 141+/-27 to 68+/-16 ml/m2 (p < 0.001) and to 65+/-6 ml/m2 (p < 0.001) at two to five days postoperation (post-op). Cardiac index (CI) increased from 1.5+/-0.5 to 2.6+/-0.6 l/min/m2 (p < 0.002) and was 1.8+/-0.3 l/min/m2 (NS) at two to five days post-op. The LV ejection fraction (EF) increased from 15+/-8% to 35+/-6% (p < 0.001) and to 26+/-3% (p < 0.003) at two to five days post-op. Tau decreased from 54+/-8 to 38+/-6 ms (p < 0.05) and was 38+/-5 ms (NS) at two to five days post-op. Peak wall stress decreased from 254+/-85 to 157+/-49 mm Hg (p < 0.001) and to 184+/-40 mm Hg (p < 0.003) two to five days post-op. The synchrony of LV segmental volume changes increased from 68+/-6% before PLV to 80+/-7% after surgery (p < 0.01) and was 73+/-4% (NS) at two to five days post-op. The LV synchrony index and CI showed a significant (p < 0.0001) correlation. CONCLUSIONS: The acute decrease in LV volume in heart-failure patients following PLV resulted at short-term in unchanged SV, increases in LVEF, and decreases in peak wall stress. The increase in LV synchrony with PLV suggests that the transition to a more uniform LV contraction and relaxation pattern might be a rationale of the working mechanism of PLV.

Cardiomyopathy, Dilated↗
PubMed2000

The double-orifice technique as a standardized approach to treat mitral regurgitation due to severe myxomatous disease: surgical technique.

OBJECTIVES: Mitral-valve repair in Barlow's disease is challenging; conventional techniques are difficult to perform, and there is a high risk of a postoperative suboptimal result. Double-orifice repair has been applied in a standardized approach to treat patients with severe mitral regurgitation and bileaflet prolapse due to Barlow's disease. METHODS: Since 1993, 82 patients with severe mitral regurgitation due to Barlow's disease underwent correction applying the edge-to-edge concept. They were submitted to double-orifice repair in a standardized fashion, suturing the middle portions of both leaflets. RESULTS: There were no hospital deaths. The repair was unsatisfactory in one patient who underwent valve replacement soon after the repair. The mean postoperative valve area was 3.7+/-0.79 cm(2) against a mean preoperative value of 9.2+/-2.1 cm(2). No or mild regurgitation was found in all but three patients who showed moderate residual regurgitation. There were no late deaths. Freedom from reoperation was 86+/-14% at 5 years. At the latest follow-up, all patient but one were New York Heart Association (NYHA) functional class I, and echo-Doppler assessment of valve reconstruction showed stable valve function in all patients. CONCLUSIONS: The double-orifice repair can be used as a standardized approach to treat valve regurgitation due to Barlow disease with low risk and good early and mid-term results.

Adult↗
PubMed2000

A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach.

OBJECTIVE: We describe an original radiofrequency ablation technique to treat chronic atrial fibrillation in patients undergoing mitral valve surgery. Most of the procedure is carried out epicardially, in order to avoid an undue increase of surgical time and trauma. METHODS: The ablations are performed using a temperature-controlled multipolar radiofrequency catheter. Two encircling lesions around the ostia of the right and of the left pulmonary veins are carried out epicardially, usually before cardiopulmonary bypass. Through a conventional left atriotomy the ablation procedure is completed with two endocardial lesions connecting the two encirclings between them and to the mitral valve annulus. After the mitral valve procedure is performed, the left appendage is sutured. RESULTS: From February 1998 to May 1999, 40 patients with chronic atrial fibrillation (43. 1+/-51.9 months) underwent combined radiofrequency ablation and mitral valve surgery. Mean left atrial diameter was 56.8+/-10.7 mm. Mean cardiopulmonary bypass and aortic cross-clamp time were, respectively, 119.1+/-26.3 and 76.7+/-21.0 min. Mean postoperative blood loss was 287.2+/-186.6 ml. No reexploration for bleeding occurred. One patient died of pneumonia 12 days after operation. No patient needed permanent pacemaker implantation. Mean postoperative hospital stay was 7.3+/-5.6 days. At follow-up (mean 11.6+/-4.7 months), 30/39 (76.9%) of the patients were in stable sinus rhythm. All patients in sinus rhythm 3 months after operation recovered both left and right atrial contractility at echocardiographic control (mean 7.3+/-3.4 months). The left atrial diameter decreased significantly in patients recovering sinus rhythm. CONCLUSIONS: Epicardial radiofrequency ablation is a safe means to achieve surgical ablation of atrial fibrillation with a high success rate. The simplicity of the technique and the low procedure-related risk should dictate combined treatment virtually in all patients with atrial fibrillation undergoing open heart operations.

Aged↗
PubMed2000

Sensitivity, specificity, and predictive accuracies of non-invasive tests, singly and in combination, for diagnosis of hibernating myocardium.

OBJECTIVE: To determine the best test(s) for predicting functional recovery of hibernating myocardium after reperfusion. METHODS: A prospective study to compare echocardiographic left ventricular diastolic wall thickness (> or =5 mm), low-dose dobutamine echocardiography and rest-redistribution thallium-201 scintigraphy, alone and in combination, for predicting recovery of left ventricular akinesis after surgical revascularization. RESULTS: Twenty-eight consecutive patients aged 58+/-9 years were studied. Of the 448 left ventricular segments, 263 were akinetic at rest; 230/263 (87%) had wall thickness > or =5 mm, 135 (51%) had a positive response and 175 (66.5%) were graded viable on thallium. Of akinetic segments 61% improved after surgery. Left ventricular score decreased from 2.3+/-0.4 to 1.8+/-0.4 (P<0.01) and ejection fraction increased from 27+/-10 to 37+/-14% (P<0.01). For predicting results at 1 year, diastolic wall thickness had a sensitivity and a predictive accuracy of a negative test of 100% but a specificity of 28% and predictive accuracy of a positive test of 61%. The addition of dobutamine echocardiography or thallium-201 improved the predictive accuracy of a positive test to 76% and 69%, respectively; the addition of both tests was not of greater benefit than that of a single test. CONCLUSIONS: Diastolic wall thickness <5 mm on echocardiography was the best simple and single predictor of non-recovery of left ventricular dysfunction. The addition of dobutamine echocardiography or thallium-201, but not both, was the best solution for predicting recovery of left ventricular dysfunction. In times of limited resources, these findings are important from a clinical point of view.

Adult↗
PubMed2000

Tranexamic acid compared with high-dose aprotinin in primary elective heart operations: effects on perioperative bleeding and allogeneic transfusions.

OBJECTIVE: Since excessive fibrinolysis during cardiac surgery is frequently associated with abnormal perioperative bleeding, many authors have advocated prophylactic use of antifibrinolytic drugs to prevent hemorrhagic disorders. We compared the effects of tranexamic acid (a synthetic antifibrinolytic drug) with aprotinin (a natural derivative product with antifibrinolytic properties) on perioperative bleeding and the need for allogeneic transfusions. METHODS: In a single-center prospective randomized unblinded trial, 1040 consecutive patients undergoing primary, elective cardiac operations with cardiopulmonary bypass received either high-dose aprotinin or tranexamic acid. The aprotinin group (518 patients) received 280 mg in 20 minutes before the skin incision, 280 mg in the priming solution of the extracorporeal circuit, and a continuous infusion of 70 mg/h throughout the operation. The tranexamic acid group (522 patients) received 1 g in 20 minutes before the skin incision, 500 mg in the priming solution of the extracorporeal circuit, and a continuous infusion of 400 mg/h during the operation. Postoperative bleeding, perioperative transfusions, and hematologic variables were evaluated at fixed times. Postoperative thrombotic complications, intubation time, intensive care unit stay, and hospital stay were recorded. RESULTS: Postoperative bleeding was similar in the 2 groups: aprotinin 250 mL (150-400 mL) versus tranexamic acid 300 mL (200-450 mL) (median and 25th-75th quartiles), median difference of 50 mL (95% confidence intervals, 0-50 mL). The number of transfusions and the outcome did not differ. CONCLUSIONS: Tranexamic acid and aprotinin show similar clinical effects on bleeding and allogeneic transfusion in patients undergoing primary elective heart operations. Since tranexamic acid is about 100 times cheaper than aprotinin, its use is preferable in this type of patient.

Antifibrinolytic Agents↗
PubMed2000

Assessment of myocardial performance with ventricular pressure-volume relations: clinical applications in cardiac surgery.

The assessment of myocardial performance in patients with cardiomyopathy is of vital importance in cardiology and cardiac surgery, especially considering the significant increase in the number of patients treated for congestive heart failure. Left ventricular pressure-volume analysis is a method, which can assess accurately myocardial contractility, separating the systolic and diastolic function at different preload and afterload conditions. This technique can be used for determination of the efficacy of a therapeutic pharmaceutical or surgical intervention, for instance the assessment of ventricular function after coronary revascularization. A few studies using the conductance catheter for the analysis of ventricular pressure-volume relations in the field of cardiac surgery have been published. In our center we started to use this technique to analyze cardiac surgical procedures, like mitral valve reconstruction, aortic valve replacement, myocardial revascularization, left ventricular assist, and surgical left ventricular remodeling. This information will be used to develop a therapeutic strategy, which may optimize surgical indications and improve the peri- and postoperative treatment and the efficacy of that surgical technique. In this short review the possible clinical use in cardiac surgery and the methodology of the pressure-volume loops have been described. Three clinical cases are presented to demonstrate functional information related to the surgical treatment of congestive heart failure patients.

Cardiac Surgical Procedures↗
PubMed2000

Totally endoscopic atrial septal defect closure using robotic techniques: report of two cases.

BACKGROUND: The development of minimally invasive cardiac surgery has shown good clinical results with shorter recovery time and better cosmetic results. We report 2 cases of totally endoscopic atrial septal defect (ASD) closure using a robotic system. Open-heart closure of an ASD without opening the chest has never been previously reported. METHODS: Following percutaneous cannulation for cardiopulmonary bypass, aortic occlusion and delivery of cardioplegia, 2 patients with an ASD were successfully operated on using a robotic surgical device. After exclusion of the right lung, two robotic arms and an endoscopic camera were inserted through ports in the right hemithorax. A fourth port was inserted for an accessory endoscopic instrument. The ASD closure was carried out with interrupted stitches in one case and with a continuous suture in the other. RESULTS: Cardiopulmonary bypass and cardioplegic arrest times were respectively 130 and 75 min in the first and 87 and 60 min in the second case. Extubation was carried out 3 and 5 hours postoperatively. Both patients resumed a totally normal lifestyle 1 week after the operation. CONCLUSIONS: Totally endoscopic open-heart ASD closure can be carried out safely using robotic techniques with rapid postoperative recovery and excellent cosmetic results. This modality of treatment can be considered an alternative to the transcatheter closure of ASD.

Female↗
PubMed2000

[Evaluation of hibernating myocardium in patients with heart insufficiency].

Myocardial dysfunction due to chronic hypoperfusion (so-called hibernating myocardium) is potentially reversible if the normal coronary flow is restored. Stress echocardiography (dobutamine, post-extrasystolic potentiation) may elicit contractile reserve of the hibernating myocardium and predict accurately its functional recovery after coronary revascularization. Thus, the identification of dysfunctioning but viable myocardium may be crucial to select patients with ischemic congestive heart failure who might benefit from coronary revascularization.

Cardiotonic Agents↗
PubMed2000

Surgical and percutaneous myocardial angiogenesis induction. Part I--laser revascularization.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable in a subset of patients with angina refractory to medical treatment. Bypass surgery may not be feasible because of lack of suitable conduits, diffuse coronary artery disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. Transmyocardial laser revascularization and the stimulation of neoangiogenesis by a variety of growth factors have recently emerged as a new tool in the management of these patients. In the first part of this article, we review laser-induced direct myocardial revascularization, its indications, potential risks, and published clinical trials. The induction of neoangiogenesis using different growth factors or the genes encoding for them will be the subject of the second part of our review.

Angina Pectoris↗
PubMed1999

Hemostatic effects of aprotinin, tranexamic acid and epsilon-aminocaproic acid in primary cardiac surgery.

BACKGROUND: The effects of epsilon-aminocaproic acid (EACA) and tranexamic acid (TA) on bleeding and allogeneic transfusions, and the cost of pharmacological and transfusional treatment were compared to aprotinin (AP). METHODS: We randomized 210 patients subjected to elective cardiac surgery. Of these, 68 patients received EACA (a bolus of 5 g, an infusion of 2 g/h, and 2.5 g in the priming), 72 patients received TA (a bolus of 1 g, an infusion of 400 mg/h, and 500 mg in the priming), and 70 patients received AP (a bolus of 280 mg, an infusion of 70 mg/h, and 280 mg in the priming). Postoperative blood loss and homologous transfusions were collected and the cost of pharmacological treatment and homologous transfusions were calculated. RESULTS: Bleeding but not allogeneic transfusions was significantly higher in the EACA group (467+/-234 versus TA, 311+/-231 versus AP, 283+/-233; p < 0.001). Costs of pharmacological and transfusional treatment were significantly lower in the TA group ($58.10+/-$105.10) versus the EACA group ($100.70+/-$158.60) versus the AP group ($432.60+/-$118.70) (p < 0.0001). CONCLUSIONS: Compared to AP, TA has the same effects on bleeding and transfusions, but with a significant reduction of costs. Patients treated with EACA showed a significantly higher postoperative bleeding with an increased trend of transfusion requirement.

Aminocaproic Acid↗
PubMed1999

The hemodynamic effects of double-orifice valve repair for mitral regurgitation: a 3D computational model.

OBJECTIVES: A 3D computational model has been implemented for the evaluation of the hemodynamics of the double orifice repair. Critical issues for surgical decision making and echo-Doppler evaluation of the results of the procedure are investigated. METHODS: A parametric 3D computational model of the double-orifice mitral valve based on the finite elements model has been constructed from clinical data. Nine different geometries were investigated, corresponding to three total inflow areas (1.5, 2.25 and 3 cm2) and to three orifice configurations (two equal orifices, two orifices of different areas, i.e. one twice as much the other one, and a single orifice). The simulations were performed in transit; the fluid was initially quiescent and was accelerated to the maximum flow rate with a cubic function. For each case, some characteristic values of velocity and pressure were determined: velocities were calculated downstream of each orifice, at the centre of it (Vcen1, Vcen2). The maximum velocity was also determined for each orifice (Vmax1, Vmax2). Maximum pressure drops (deltap(max)) across the valve were compared with the estimations (deltap(Bernoulli)) based on the Bernoulli formula (4 V2). RESULTS: In each simulation, no notable difference was observed between Vcen1 and Vcen2, and between Vmax1 and Vmax2, regardless of the valve configuration. Maximum velocity and deltap(max) were related to the total orifice area and were not influenced by the orifice configuration. Deltap(Bernoulli) calculated with Vmax was well correlated with the deltap(max) obtained throughout the simulations (y = 0.9126x + 0.3464, r = 0.996); on the contrary the pressure drops estimated using Vcen underestimated (y = 0.6757x + 0.3073, r = 0.999) the actual pressure drops. CONCLUSIONS: The hemodynamic behaviour of a double orifice mitral valve does not differ from that of a physiological valve of same total area: pressure drops and flow velocity across the valve are not influenced by the configuration of the valve. Echo Doppler estimation of the maximum velocities is a reliable method for the calculation of pressure gradients across the repaired valve.

Blood Flow Velocity↗