Giuseppe Zattera

Reoperations on heart valve prostheses : an analysis of operative risks and late results

To evaluate risks and complications of reoperations on heart valve prostheses, we reviewed data on 183 patients who underwent reoperation because of prosthetic valve malfunction. The incremental effect of the redo procedure on hospital mortality and morbidity was studied by comparing primary and reoperative procedures and analyzing a series of possible predisposing factors. Late survival after first and second reoperations was computed, and possible determinants of late mortality were examined. Overall operative mortality was 8.7%; emergency operation (p = 0.0001), previous thromboembolism (p = 0.05), and advanced New York Heart Association functional class (p = 0.031) were the independent determinants. In a series of 1,355 patients having primary or secondary isolated valve replacement, the redo procedure was a significant risk factor in the univariate analysis (p = 0.025) but not in the multivariate analysis except for the subset of patients having mitral valve replacement (p = 0.052). The postoperative course was quite complicated, as evidenced by the long mean stay in the intensive care unit (mean stay, 3.8 days; longer than 2 days for 26% of the survivors). Nevertheless, postoperative complications were not significantly greater after a redo procedure than after a primary operation. Actuarial survival at 7 years was 57.3% +/- 8%. A comparison with a nonhomogeneous series from our institution did not demonstrate significant differences. In the subset of 16 patients having a second reoperation, late survival was 37.8% +/- 16% at 2 years. Advanced New York Heart Association class (p = 0.0001), double prosthetic valve dysfunction (p = 0.003), and any indication other than primary tissue failure (p = 0.06) were determinants of late mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Minimally Invasive Approach for Complex Cardiac Surgery Procedures

BACKGROUND A minimally invasive approach through an upper ministernotomy (UMS) has been used in our Division since 1997. On the basis of favorable outcome we have gradually extended this approach from isolated aortic valve replacement (AVR) to more complex cardiac surgery procedures and it is currently our first choice for a variety of procedures. Here we report our 11 years experience. METHODS From 1997 to December 2007, 1,126 procedures were performed at our department, using UMS. Isolated procedures on the aortic valve were performed in 695 patients (61%). Isolated procedures on the aortic valve as redo operation were performed in 77 patients (7%). Complex cardiac surgery procedures (including double valve replacement-repair, ascending aorta-aortic arch replacement, aortic root replacement, aortic dissection, AVR combined with coronary surgery, and complex redo procedures) were performed in 354 patients (32%). Early postoperative outcome was evaluated considering three different groups according to the surgical procedure (first time AVR, redo AVR, and complex procedure). RESULTS Overall conversion to full sternotomy was required in 16 patients (1.4%) with no significant differences between isolated AVR (9 patients, 1.3%) and complex or redo procedures (1 patient [1.2%] and 6 patients [1.6%], respectively). Forty-seven patients died in hospital (cumulative in-hospital mortality of 4.1 %). Mortality according to the procedure was 6.7, 3.8, and 2.8% for complex, redo AVR, or isolated AVR procedures, respectively, with a significant difference only for the complex procedures. Similarly, early postoperative outcome in terms of incidence of prolonged mechanical ventilation and ICU stay was significantly different only in the complex procedure group. Incidence of surgical revision (5.1, 2.9, and 2.7% for complex, redo, or isolated AVR procedures, respectively) showed no statistically significant differences regardless the type of procedures. CONCLUSIONS Our experience clearly shows that a minimally invasive approach through upper ministernotomy is feasible and safe not only for isolated AVR but that it can also be utilized for a variety of complex surgical procedures. Minimizing surgical access may be helpful in patients undergoing complex surgical procedures, especially redo procedures, without compromising the surgical result.

Stenless porcine and pericardial valve in aortic position

Fifty-seven patients underwent aortic valve replacement with a stentless glutaraldehyde-fixed bioprosthesis; 27 received a porcine aortic valve and 30 had a bovine pericardial valve. Two groups of 30 patients each who had aortic valve replacement with a tilting-disc mechanical valve or a stented porcine bioprosthesis served as controls. There were no differences in sex, body surface area, valve lesion, and valve size among the four groups. Results were assessed on a Doppler-based determination of maximum velocity across the valve, aortic valve area, and degree of valve regurgitation. Velocity across the valve was significantly less with stentless pericardial valves than with stentless porcine valves, stented bioprostheses, and mechanical valves. Stentless valves had a significantly larger aortic valve area when compared with stented valves. Mild central aortic insufficiency was detected more often with stentless pericardial than with stentless porcine bioprostheses (p = 0.04). Stentless valves showed a higher incidence of complete atrioventricular block when compared with stented valves (p = 0.04). Long-term studies are now warranted to assess the durability of both types of stentless valves.

Porcine Cardiac Bioprostheses: Evaluation of Long-term Results in 990 Patients

Clinical results with porcine bioprostheses were reviewed for 990 patients who underwent heart valve replacement from January, 1974, to December, 1980. Eight hundred and seventy-four Hancock, 283 Carpentier-Edwards, and 10 Liotta bioprostheses were used. In 23 patients, 26 mechanical prostheses were implanted as well. Overall operative mortality was 60 out of 990 (6.06%): 30 out of 506 (5.9%) for mitral valve replacement (MVR), 13 out of 287 (4.5%) for aortic valve replacement (AVR), 1 out of 4 (25%) for tricuspid valve replacement, 0 out of 2 for pulmonary valve replacement, and 16 out of 191 (8.4%) for multiple valve replacement. Cumulative follow-up covered 1,793 patient-years. (Actuarial survival at 7 years was 76.6 +/- 3% for MVR. At 6 years, it was 83.2 +/- 2.8% for AVR and 55 +/- 13.5% for multiple valve replacement.) Prosthesis-related survival at 7 years was 91.7 +/- 1.9% for MVR, and at 6 years, it was 96.6 +/- 1.5% for AVR and 95.1 +/- 2.2% for multiple valve replacement. Bioprosthesis survival, considering deaths or complications that led to reoperation as final events, was 84.2 +/- 3.7% at 7 years for mitral valves and 87.7 +/- 3.8% at 6 years for aortic valves. Emboli per 100 patient-years numbered 3.2 for MVR, 0.5 for AVR, and 1.6 for multiple valve replacement. Twenty-seven patients underwent reoperation, 12 for perivalvular leak, 5 for endocarditis, 6 for valve thrombosis, and 4 for primary tissue failure (linearized rates of 0.7, 0.3, 0.3, and 0.2% per patient-year, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Ascending aortic aneurysms treated by cuneiform resection and end-to-end anastomosis through a ministernotomy

BACKGROUND Ascending aortic aneurysms without dilatation of the sinuses of Valsalva are generally handled by resection and replacement with a tubular graft or by tailoring aortoplasty. We propose an alternative treatment with a direct anastomosis of the two stumps of the aorta after complete aneurysm resection through an upper J ministernotomy. PATIENTS AND METHODS We have applied this procedure to 45 patients. Mean age was 60.2 +/- 12.1 years. Mean aneurysm diameter was 51.0 +/- 8.0 mm. The skin incision averaged 6.5 cm. Two circumferential aortotomies were made: one at the level of the sinotubular junction, the other one just below the innominate artery. The two ends of the aorta were then sutured with a 3-0 Prolene running suture. In 31 cases (61%) aorta-associated valve replacement was carried out. RESULTS Hospital mortality was 4.4%. Mean CPB and cross-clamp times were 104 +/- 71 and 68 +/- 25 minutes respectively. Mean blood loss was 380 +/- 300 mL. Median ventilation requirement and intensive care unit stay were 17 and 21 hours. Median hospital stay was 7 days. During the follow-up period (23.7 +/- 12.3 months), 1 patient required reoperation and 2 patients died. Event-free survival is 88.4 +/- 5.7 at 44 months. The surviving patients are routinely checked with ultrasonography and angio computed tomography scan. There was a very low redilatation rate (1 patient, 2.3%) and no incidence of pseudoaneurysm. CONCLUSIONS Complete resection of ascending aortic aneurysms with end-to-end anastomosis through an upper ministernotomy represents a feasible, safe, physiologic and cost-effective minimally invasive surgical option in cases of aneurysms with normal or nearly normal sinotubular junctions.

Endocarditis in patients with bioprostheses: pathology and clinical correlations

We studied 13 porcine bioprostheses removed from patients with endocarditis at our institute during the last 4.5 years. All bioprostheses had been removed at reoperation and were analyzed using anatomical and histological techniques. Each bioprosthesis was found to have developed rather constant lesions which were not related to the type of bioprosthesis. The stage of infection was not related to the duration of implantation. The presence of perivalvular abscesses was an ominous finding, often being the seat of persistent endocarditis. Our good clinical results of reoperation lead us to suggest that this be performed early once valvular or prosthetic malfunction is detected. Bioprostheses are, in our experience, the best choice in the surgical treatment of prosthetic valve endocarditis.

Intra aortic balloon pump insertion through left axillary artery in patients with severe peripheral arterial disease

Intra aortic balloon pump (IABP) is the mechanical assist device most frequently used in cardiac surgery. Recent demonstration of better outcome following preoperative IABP insertion in high-risk patients has further extended its indication. However, due to an increasing complexity of patients currently referred for cardiac surgery, several patients with potential indication for preoperative and/or postoperative IABP present severe peripheral vascular disease which usually contraindicates IABP insertion. Here we present an alternative technique for IABP insertion in patients with severe peripheral vessel disease.

Deltoido-pectoralis approach to axillary vessels for full-flow cardiopulmonary bypass

Axillary artery has been proposed as a safe and effective alternative for arterial cannulation in surgical procedures involving ascending aorta and/or aortic arch, and is nowadays the site of choice in many centres. Advantages of axillary artery cannulation include antegrade flow and the possibility of selective mono-hemispherical brain perfusion during circulatory arrest. Experiences with the axillary vein cannulation, however, are scarce. Here we report our preliminary experience with axillo-axillary cardiopulmonary bypass, through both axillary artery and vein cannulation (using echo-guided Seldinger technique) at deltoido-pectoralis groove. We have used such an approach in 5 cases of redo surgery on ascending aorta and we have not had any inconvenience during cardiopulmonary bypass. Full flow was maintained in all patients (in 2 with vacuum assisted drainage) including 2 cases with deep hypothermic circulatory arrest. In conclusion such an approach seems to be feasible and effective and can be safely performed providing that accurate TE echo monitoring is provided.

The axillary artery as an alternative site of cannulation for redo port access-assisted minimally invasive mitral valve surgery: early report of 2 cases

The minimally invasive Heartport (HP)-assisted technique has become first choice option for mitral valve surgery in many centres.The pool of patients potentially treated using HP techniques, however, is still limited by the presence of peripheral vessel disease, expecially in the elderly population. Alternative approaches to using the HP technique safely in such a subset of patients, therefore, should be evaluated. Here, we present our preliminary experience using the axillary artery as an alternative site of cannulation for HP-assisted redo mitral valve surgery in patients with concomitant peripheral vessel disease.

Detection of human cytomegalovirus myocardial involvement by polymerase chain reaction during systemic infection and correlation with pp65 antigenemia and DNAemia in infected heart recipients.

The presence of human cytomegalovirus DNA was investigated in 103 unfixed endomyocardial biopsies, performed during the first 4 months in 17 heart transplant recipients by polymerase chain reaction. Results were correlated with human cytomegalovirus systemic infection, as detected by the test for the viral lower matrix phosphoprotein pp65 (antigenemia) and by polymerase chain reaction for viral DNA in blood leukocytes (DNAemia). Three patients out of 17 did not develop cytomegalovirus infection and 14 did: 5 had symptomatic disease treated with ganciclovir and 9 developed asymptomatic infection and were not treated. Viral DNA was detected in 24 out of 103 biopsies (23%) from 13 patients: 5 with symptomatic infection during the acute phase of disease (mean levels of pp65: 125+/-232 pp65 positive leukocytes/200,000 examined cells) and 8 patients with asymptomatic infection when the mean antigenemia was 5+/-15/200,000 (4 patients) or when DNAnemia was present in the blood (4 patients). No histological evidence of myocarditis was shown in viral DNA-positive biopsies. No difference in acute rejection was found in viral DNA-positive and DNA-negative biopsy specimens in symptomatic and asymptomatic infected patients. Our experience suggests that during systemic symptomatic and asymptomatic cytomegalovirus infection, polymerase chain reaction can detect a relatively frequent myocardial involvement, but this involvement is not associated with myocarditis or with a higher incidence of acute rejection. THe presence of viral DNA in myocardial biopsies can be a result of high viremia, but it also can be due to low level of viral DNA in circulating infected leukocytes. Polymerase chain reaction is the most sensitive method for cytomegalovirus DNA detection in biopsies, but its results need to be evaluated together with morphology-preserving methods and systemic markers of infection in order to make a correct diagnosis.