Biomedical subjects

Ottavio Alfieri

Publications and source records attributed to Ottavio Alfieri.

81 records · Page 5Linked to original sources

PubMed2002

Novel suture device for beating-heart mitral leaflet approximation.

BACKGROUND: This investigation evaluates the potential of using a novel suturing device to achieve mitral valve repair (Alfieri type) on a beating heart without cardiopulmonary bypass. METHODS: Eight healthy adult sheep were anesthetized and the chest was opened via a left thoracotomy. The suture device was directly inserted into the appendage of the left atrium. Suction ports on the distal tip of the device grasped and approximated the mitral leaflets while the heart was beating. Two-dimensional echocardiography and intracardiac pressure monitoring at the tip of the device were utilized to guide the procedure. The device was used to place two single sutures across the two leaflets at the center of the mitral valve. A knot pusher with integrated cutter was used to tie the sutures and cut the suture ends. RESULTS: In all animals, the free margins of the mitral leaflets were successfully grasped and approximated by this device. Echocardiography confirmed successful deployment of the sutures in all cases, with a figure-of-eight appearance of the valve and normal valve hemodynamic function after placement of the sutures. Mid-leaflet approximation was verified at autopsy immediately after the procedure. No tissue damage was observed. CONCLUSIONS: This study demonstrates that mitral valve repair (Alfieri type) can be performed safely and consistently on a beating heart without cardiopulmonary bypass using this new tissue approximation suture device. This technique may be applicable to the treatment of ischemic mitral regurgitation in conjunction with revascularization procedures or to mitral regurgitation in heart failure patients.

Animals↗

PubMed2002

Acute effects of beating heart coronary surgery on left ventricular performance.

BACKGROUND: The increasing use of off-pump bypass grafting (OPCABG), requires an evaluation of its effects on left ventricular (LV) performance. METHODS: In 8 patients with multivessel coronary disease who were undergoing to off-pump coronary artery bypass grafting, LV performance was analyzed from the pressure-volume (P-V) plane by the conductance catheter technique. Measurements were performed at base line, after the exposure of the vessels, after the application of the stabilization system, and at the end of the procedure. RESULTS: No significant changes in heart rate, LV end-systolic volume, LV end-diastolic pressure, mean pulmonary artery, and mean systemic blood pressure were observed in the various stages of the procedure. Cardiac index decreased during left anterior descending coronary artery grafting after application of the stabilizer with a concomitant decrease in LV end-diastolic volume, together with decreases in LV peak negative -dP/dt and increases in tau, indicating an impairment of LV relaxation but without a change in preload recruitable stroke work, indicating preserved LV contractile state. Exposure of posterior and lateral vessels induced a decrease in cardiac index and preload recruitable stroke work without a decrease in LV preload, indicating a decrease in LV contractile state together with a decrease in peak -dP/dt and increase in tau, indicating an impairment in LV relaxation CONCLUSIONS: Off-pump coronary artery bypass grafting can be performed without decreasing LV performance. Major cardiac displacement like that used for posterior and lateral exposure induces acutely significant decrease in LV contractile state.

Aged↗

PubMed2002

Off-pump coronary artery surgery with the use of anastomotic devices: an additional tool for the challenging patient.

BACKGROUND: Avoidance of aortic side-clamping may decrease the risk of embolization to the brain and other organs during coronary revascularization. Herein we describe our preliminary experience with an anastomotic device for proximal anastomosis construction. METHODS: From October 2000 to June 2001, 18 selected patients undergoing beating heart surgery had an aorta-to-saphenous vein graft anastomosis performed with the St. Jude Medical Aortic connector. RESULTS: All anastomoses were successfully deployed. In two patients there was a minor anastomotic bleeding and in other two cases a kinking occurred due to a too short and a too long graft respectively. One patient, with graft occlusion on the fourteenth postoperative day, underwent successful percutaneous revascularization. CONCLUSIONS: Our preliminary results indicate that the aortic anastomotic device is safe and effective and its use could be widened once long-term results are available.

Aged↗

PubMed2002

Surgical restoration of the left ventricle for postinfarction aneurysm.

BACKGROUND: Surgical left ventricular reduction is under investigation as an alternative to, or a bridge for, heart transplantation in patients with a left ventricular aneurysm. In fact, acute myocardial infarction can result in the development of a dyskinetic or akinetic left ventricular aneurysm which may in turn cause congestive heart failure, ventricular arrhythmias, and the formation of mural thrombi. The aim of this study was to evaluate the current operative risk of surgical restoration of the left ventricle and the early and late clinical results. METHODS: From January 1997 to December 2001, 94 patients (84 males and 10 females) presenting with a postinfarction aneurysm were submitted to surgical restoration of the left ventricle. All patients presented with symptoms of heart failure and/or angina. The preoperative NYHA functional class was: I in 6 patients, II in 22 patients, and III in 66 patients. No patient was in NYHA class IV at the time of surgery. The preoperative ejection fraction was 30 +/- 7.9%. In 25 patients mural thrombi were identified and surgically removed. In patients with preoperative evidence of ventricular arrhythmias the Harken procedure was performed intraoperatively. The ventricular preoperative and postoperative performances were also studied in 10 patients using P-V loops obtained through a conductance catheter. RESULTS: The in-hospital mortality was 3.2%. The mean length of hospitalization was 7 +/- 2.9 days. At follow-up (mean 26 +/- 14.8 months) we observed an early improvement in the ejection fraction (30 +/- 7.9 vs 48 +/- 8.0%) and a decrease in the end-diastolic and end-systolic volumes and mean pulmonary pressure (139 +/- 37 vs 84 +/- 17 ml/m2, 105 +/- 39 vs 52 +/- 20 ml/m2, 35 +/- 8.4 vs 23 +/- 4.3 mmHg). CONCLUSIONS: These results suggest that ventricular restoration is indicated in all patients with a postinfarction dyskinetic or akinetic aneurysm. The operation, if performed appropriately, is associated with a low in-hospital mortality and morbidity. A postoperative improvement in the early and long-term cardiac functions was demonstrated. An improvement in symptoms and quality of life was documented, increasing our expectations of an increased long-term survival.

Cardiac Surgical Procedures↗

PubMed2002

Totally endoscopic atrial septal defect closure with a robotic system: experience with seven cases.

BACKGROUND: The development of minimally invasive cardiac surgery has shown good clinical results with shorter recovery time and better cosmetic results. The introduction of the robotic systems can further reduce the surgical trauma and improve the surgical dexterity. We report seven cases of complete closed chest atrial septal defect closure using the "da Vinci" Surgical System (Intuitive Surgical, Mountain View, CA). METHODS: Following peripheral cannulation for cardiopulmonary bypass (CPB), aortic occlusion and cardioplegia delivery, five patients with atrial septal defect (ASD) and two patients with patent forame ovale (PFO) with atrial septal aneurysm (ASA) were successfully treated using the robotic system. Two robotic arms and an endoscopic camera were inserted through ports in the right hemithorax and an accessory port was placed for blood suction and ancillary instruments insertion. The defect closure was carried out with interrupted stitches in one patient and with a continuous suture in the others. RESULTS: Mean cardiopulmonary bypass and cross clamp time were 101.8 +/- 39.6 and 63.4 +/- 21.9 minutes respectively. Extubation was carried out within the seventh postoperative hour. All patients returned to normal lifestyle in one week. CONCLUSION: Complete closed chest ASD closure can be carried out using robotic technique with rapid postoperative recovery and excellent cosmetic result.

Adult↗

PubMed2002

Mitral valve reserve in double-orifice technique: an exercise echocardiographic study.

BACKGROUND AND AIM OF THE STUDY: The edge-to-edge technique is used to restore valvular competence in mitral insufficiency. The efficacy of the method is under debate due to the potential for creating functional mitral stenosis. An exercise echocardiographic study was carried out to investigate valve function and hemodynamics in patients who had undergone double-orifice mitral valve repair. METHODS: Thirty patients (mean age 49.1 +/- 12.7 years) with previous double-orifice mitral valve repair underwent exercise echocardiography (10 W/min). An annular prosthesis was present in 28 patients (93%). The mean and maximum mitral valve gradient, planimetric valve area, stroke volume, systolic pulmonary artery pressure, heart rate and systolic blood pressure were measured at baseline and at peak stress. RESULTS: At peak stress, heart rate (77.7 +/- 12.2 versus 118.6 +/- 26.0 beats/min, p < 0.00001), systolic blood pressure (124.1 +/- 10.9 versus 146.6 +/- 22.8 mmHg, p < 0.00001) and stroke volume (78.0 +/- 10.2 versus 97.0 +/- 15.1 ml, p < 0.00001) were significantly increased, showing a physiological behavior of the mitral valve. The mean mitral valve gradient (2.8 +/- 1.3 versus 4.6 +/- 1.9 mmHg, p < 0.00001), maximum mitral valve gradient (6.4 +/- 2.8 versus 10.5 +/- 4.6 mmHg, p < 0.00002) and systolic pulmonary artery pressure (22.8 +/- 6.1 versus 28.2 +/- 9.9 mmHg, p < 0.001) were increased, but not to pathologic levels. Planimetric valve area increased significantly (3.2 +/- 0.6 versus 4.3 +/- 0.7 cm2, p < 0.00001). A significant negative linear correlation was found between the relative change in mitral valve area and planimetric valve area at rest (r = -0.51, p < 0.05). CONCLUSION: The double-orifice repair, even with concomitant ring annuloplasty, does not cause mitral valve obstruction, either at baseline or during physical exercise, and does not affect valve hemodynamic and valve reserve.

Adolescent↗

PubMed2002

[Refractory heart failure. Myocardial revascularization as alternative to heart transplantation].

Coronary artery disease is the most common cause of heart failure in the western world. Due to shortage of donors, heart transplantation is not a realistic treatment for the great majority of patients with heart failure, while surgical revascularization is a valuable alternative in selected patients. Several variables have to be taken into account in order to appropriately identify patients with severe left ventricular dysfunction who are likely to benefit from myocardial revascularization. The recovery of cardiac function can be expected only in patients with sufficiently large areas of hibernating myocardium, particularly when the contractile reserve is documented. The anatomy of the coronary arteries should be suitable for coronary bypass grafting and provide a good run-off. Patients with an excessively dilated heart, with signs and symptoms of right heart failure and significant pulmonary hypertension are not candidates for myocardial revascularization. An appropriate surgical strategy, also including the reduction of the left ventricular volume and/or the correction of mitral insufficiency if needed, is the key factor for a successful revascularization procedure in patients with coronary artery disease and heart failure as the predominant symptom.

Heart Failure↗

PubMed2002

3-D computational analysis of the stress distribution on the leaflets after edge-to-edge repair of mitral regurgitation.

BACKGROUND AND AIM OF THE STUDY: Edge-to-edge repair is an effective, recently introduced method to correct mitral insufficiency by suturing the leaflets at the site of regurgitation, though durability of the method has not been proven. To overcome the limitations of the clinical approach, simulations may be used to predict clinical outcome. In this study, the mechanical stress acting on leaflets imposed by the edge-to-edge suture was evaluated as a means of assessing the clinical risk of late fibrosis or tissue degeneration. METHODS: A 3-D finite element simulated the stress pattern following edge-to-edge repair. Valve behavior was evaluated both in systole and in diastole. Both 4-mm and 8-mm edge-to-edge sutures were simulated, as well as annular dilation. RESULTS: Systolic simulations validated the model by comparison with previous models of the mitral valve. Diastolic stresses were negligible in the native mitral valve; after edge-to-edge repair (8-mm suture), circumferential and longitudinal stress values were 308 kPa and 489 kPa, respectively, and comparable with those observed at systolic peak (449 kPa and 617 kPa, respectively). With a 4-mm suture, longitudinal stresses decreased both close to the suture (-41.5%) and in the annular region (-68%), while circumferential stresses increased (+37%) close to the suture and decreased (-27%) in the annular region. A 20% dilation of the annulus was followed by increased stresses in the annular region and close to the suture. CONCLUSION: Leaflet distortion and altered stress distribution occur on the leaflets after edge-to-edge repair. Diastolic peak stress values were comparable with those calculated in systole. The clinical implication is a doubled exposure of valve components to systolic stresses, as if the heart rate were doubled. The use of a prosthetic annuloplasty ring is favorable in the presence of annular dilation to reduce stresses acting on the leaflets after edge-to-edge repair.

Chordae Tendineae↗

PubMedDate not supplied

Combined endovascular treatment of a descending thoracic aortic aneurysm and off-pump myocardial revascularization-a case report.

Endovascular intervention is an alternative form of treatment for patients with thoracic aortic aneurysms. Coexistent cardiovascular diseases may adversely influence the postoperative course and affect the long-term prognosis. The case of a 76-year-old man with severe coronary artery disease and a thoracic aortic aneurysm is reported. A single-stage procedure of off-pump coronary artery revascularization and endoluminal exclusion of the descending thoracic aortic aneurysm was performed. The patient was treated first with off-pump coronary artery bypass graft (left internal mammary artery on the left anterior descending coronary artery and two single venous grafts from ascending aorta to obtuse marginal artery and posterior descending artery). After heart revascularization, two Thoracic Excluder endovascular grafts (34 x 100 and 37 x 100 mm) were implanted to treat the descending thoracic aortic aneurysm. Follow-up with computed tomography angiography showed successful exclusion of the thoracic aneurysm 12 months after the procedure. The patient is well and free of symptoms 18 months later.

Aged↗