As originally published in 1988: Results of total correction of tetralogy of Fallot performed in adults. Updated in 1996.
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Adult↗
Biomedical subjects
M Morea
Publications and source records attributed to M Morea.
[Mitral valve bioprosthesis from bovine pericardium. Color Doppler echographic study and long-term follow up].
Pericardial heart valve bioprostheses have been utilized for 20 years. In spite of encouraging initial results, long-term follow-up showed a higher incidence of structural failures and primary tissue failures than porcine bioprostheses. Pericarbon represents the newest generation of bovine pericardial bioprostheses. Aim of this study is the long-term evaluation with echocardiographic and color Doppler technique of an innovative bioprostheses, in particular, its morfological and functional characteristics. From 1985 to 1989, 78 consecutive patients (21 males, 57 females, mean age 56.5 +/- 8.16 years) underwent mitral valve replacement with Pericarbon 29, by the same operator, who preserved the mitral posterior leaflet. One month after operation, 21 of these patients underwent echo-color Doppler evaluation, in normalized hemodynamic conditions (normality ranges). In 1995, at the end of the followup, 30 of the remaining 54 patients underwent new echo-color Doppler evaluation and these data were compared with normality ranges values. Leaflets' thickness increased from 0.98 +/- 0.09 to 2.87 +/- 0.73 mm (anterior leaflet; p < 0.0001) and from 1.02 +/- 0.08 to 2.71 +/- 0.45 mm (posterior leaflet; p < 0.0001) 43.3% of anterior leaflet and 53.3% of posterior leaflet showed fibrocalcic lesions. Mean transvalvular gradient increased from 3.4 +/- 0.2 to 6.6 +/- 3.4 mmHg (p < 0.0001); also functional area decreased (p < 0.0001). We have found no paraprosthetic regurgitation and a very low number of central prosthetic regurgitation. Left ventricular function, evaluated by ejection fraction and regional kinesis, remained substantially preserved.
Aged↗
[Conservative surgical treatment of rheumatic mitral stenosis].
We prospectively evaluated 50 patients with mitral stenosis (43 women and 7 men; mean age 45 years) to assess the results of surgical reconstruction of the mitral valve. All patients underwent a complete echocardiographic examination before and after operation. Surgical reconstruction was extensive, and included commissurotomy, thinning of the valvular leaflets, calcification removal, splitting of subvalvular apparatus, and posterior annuloplasty. Surgical reconstruction resulted in increasing mitral functional area from 0.89 +/- 0.23 to 2.07 +/- 0.42 cm2. NYHA functional class decreased from 2.76 +/- 0.55 to 1.52 +/- 0.71. Before discharging, 10% of patients had moderate mitral insufficiency. All patients were followed at 6-month intervals in our clinic. Mean follow-up was 37 +/- 18 months. During follow-up 5 patients (10%) developed severe mitral incompetence, which required mitral valve replacement. Chi-square and Student t-test were used to analyze the correlation between variables and outcome. The occurrence of severe mitral incompetence was correlated with: the degree of enlarged left atrium; chronic atrial fibrillation; postoperative more than mild mitral regurgitation. No correlation was found with anatomical parameters detected by echocardiography, or intraoperative anatomy. In conclusion, surgical reconstruction of mitral stenosis provides satisfactory short-term results. We believe that the low mortality rate and the low incidence of complications justify an effort to save the native mitral valve before considering prosthetic replacement. More attention to the development of residual mitral incompetence with intraoperative control may improve long-term results.
Adult↗
Complicated removal of a hydatid cyst of the interventricular septum.
In a 27-year-old woman with a large hydatid cyst of the liver, an asymptomatic cardiac cyst located in the interventricular septum was discovered as well. The diagnosis was based upon echocardiography, computerized axial tomography and nuclear magnetic resonance. There was no evidence of damage to the atrioventricular conduction system or to the cardiac valves. At operation, however, the left posterior papillary muscle and chordae were firmly adherent to the cyst. Patch closure of the resulting ventricular septal defect, and mitral valve and chordae repair were necessary. The patient is alive and well 6 months after the operation, with mild residual mitral regurgitation. Precise anatomical delineation of the hydatid cyst localization within the heart, particularly in the interventricular septum, and its relations with the various cardiac structures is a difficult task, in spite of all the imaging techniques available. The surgical approach therefore has to be very careful and mindful of the potential complications.
Adult↗
New bileaflet bioprosthesis: early and mid term results.
A new bovine pericardial bioprosthesis (AMB bioprosthesis) with a bileaflet geometry was designed and developed, with the aim of achieving uniform stress distribution within the prosthesis. The ultimate goal was to limit tissue degeneration to a minimum by attaining optimum fluid dynamics, thereby obtaining an extended clinical durability. The two-leaflet, dome-shaped geometry with a central hinge allowed a very low profile, low ventricular projection in the mitral position, large effective orifice area and low gradients. The design of the thin Delrin stent and the centrally crossing bridge was developed using finite element analysis. Pre-clinical laboratory investigations showed very low trans-valvular gradients and no mechanical or tissue failure after 400 million cycle accelerated wear test. The final model of the prosthesis was manufactured by Baxter-Edwards CVS Division and tested in sheep with good results for up to five months. A limited clinical trial was started in January 1990 and stopped one year later encompassing 12 aortic and six mitral implants. The patients were followed clinically and by echocardiography three, six and 12 months, and four years after surgery. Mean gradients were 4 mmHg in the mitral and 10 mmHg in the aortic position with only minimum regurgitation and no tissue failure. We conclude that early and mid term results with this new pericardial bioprosthesis appear to be favorable and intend to closely monitor further outcome within the limited patient population.
Animals↗
Mitral valve replacement with the Biocor stentless mitral valve: early results.
Chordal preservation during mitral valve replacement is thought to greatly preserve left ventricular function. Recently a stentless mitral valve (Biocor) became available for clinical use. It is a porcine mitral valve with the entire chordal apparatus, the sewing ring being reinforced by a bovine pericardial ring and the chordae being sutured together onto two pericardial patches. During a six months period, seven patients undergoing mitral valve replacement for mitral insufficiency (four cases), mitral stenosis (two cases) or mixed lesions (one case) received a stentless mitral valve. Their mean age was 66.3 +/- 4.8. The valve was implanted by suturing the pericardial patches onto the papillary muscles and the sewing ring onto the mitral annulus. Echocardiography control immediately after surgery showed good valve function. Three valves failed after a period of seven days, seven and 12 months respectively. The valve lesions were similar and consistent with an excessive tension on the chordae and on the valvular tissue. There were tears along the posterior annulus and at the level of the commissures, often accompanied by chordal rupture. Histology and scanning electron microscopy showed good integration of the prosthesis with the patients own tissues. There were areas of overgrowing tissue without endothelial cells especially in the area of papillary muscle -pericardial patch interaction. The remaining four patients continue to do well after a mean follow up of two years. The apparent excessive tension on the valve tissues leading to the premature failure of the prosthesis could be due to the variability in the distance between mitral annulus and papillary muscles.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Successful orthotopic transplantation of a fresh tricuspid valve homograft in a human.
We report a successful transplantation of a human tricuspid valve in a human. We used a fresh tricuspid homograft with its chordae tendineae and papillary muscles, harvested 5 days earlier under sterile conditions from a multiorgan donor a few minutes after cardiectomy (the heart was not suitable for cardiac transplantation) and immediately stored at 4 degrees C. We elected to implant the homograft in a young heroin addict. Our experience demonstrates that the implantation of an atrioventricular homograft in the orthotopic position is technically feasible and can achieve good results, at least in the short term.
Adolescent↗
Mitral annulus size in isolated mitral stenosis.
M-mode and two-dimensional echocardiographic images were obtained using the planimeter method in the short axis view and calculated by Doppler-derived pressure half-time in 24 patients with mitral stenosis before and after surgical commissurotomy and posterior annuloplasty. The diameter of the mitral valve annulus was measured in the standard long axis view and in the apical four-chamber view using two-dimensional echocardiography. Preoperatively, the mitral annulus was dilated in all patients as a consequence of left atrial dilation. This could be one of the factors causing residual regurgitation after surgical mitral commissurotomy. However, more data are needed to demonstrate that annuloplasty can prevent the development of mitral regurgitation after surgery.
Adult↗
["Heart transplantation program" in Piedmont. Results of a 3-year activity].
Since 1990 the "Heart Transplant Program" has been instituted in the Piemonte Region. Until now the program had regular development according to the number of transplantations and the high quality of clinical results. Sixty heart transplantations has been performed with a 36 month survival close to 80%. Our data demonstrate that after heart transplantation prognosis of end-stage cardiac disease is highly improved either for life expectancy and for quality of life. Our program includes several aspects of scientific research from physiology to clinic, from biochemistry to immunology, from infectivology to pathology, from intensive care to surgery. Several very positive multi disciplinary investigations have been activated.
Adult↗
[Evolution of surgical therapy in mitral stenosis].
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Catheterization↗
Stentless 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.
Adult↗
[Aortic dissection after aortic valve replacement: clinical and anatomic features].
BACKGROUND: Cardiac surgery has become a possible cause of ascending aortic dissection, particularly in patients who have undergone aortic valve replacement. METHODS: From January 1979 to December 1989, 134 patients with angiographic evidence of aortic dissection, were studied in the Haemodinamic Laboratory of the University of Turin. Twelve of these patients (7 men and 5 women), mean age 51.6 years, had been previously operated for aortic valve replacement. We evaluated incidence, clinical and anatomic features of ascending aortic dissection in this group. RESULTS: A dilated ascending aorta with a mean diameter of 4.92 cm. was noted in all these patients. The interval between valve replacement and diagnosis of aortic dissection was 57 months (range 1 day to 9 years). Reoperation was performed in 11 patients. Four intraoperative deaths occurred and 2 other patients died in the early post-operative period. Survival rate at 12 months was 50%. Our incidence of ascending aortic dissection after aortic valve replacement was 0.66% (10 patients out of 1499 operated for aortic valve replacement) and it is in agreement with reports from other Authors in literature. CONCLUSIONS: Replacement of the ascending aorta must be considered if an important dilatation of aortic root is found at time of aortic valve surgery. New efforts must be undertaken to identify patients at high risk for this complication because an elevated mortality rate is observed in reoperation for aortic dissection.
Adult↗
Bronchial responsiveness, oscillations of peak flow rate and symptoms in patients with mitral stenosis.
To better characterize airway hyperresponsiveness reported in cardiac patients questionnaire-recorded symptoms, bronchial responsiveness to methacholine (Mch) and to ultrasonically nebulized distilled water (UNDW), diurnal oscillations of peak expiratory flow (PEF) rate were evaluated in 32 patients with moderate mitral stenosis. Twenty patients were responsive to Mch (defined as provocative dose producing a 20% fall in forced expiratory volume in one second (PD20 FEV1) less than 3.2 mg) (geometric mean PD20 FEV1 851 +/- 154 micrograms SE). Only two patients showed a fall in FEV1 greater than 20% after UNDW challenge. Patients responsive to Mch challenge had lower FEV1 as percentage of vital capacity (FEV1/VC) (80 +/- 4.8 vs 83 +/- 3.8%, p less than 0.05), higher coefficient of variation of PEF (CV-PEF) (7.1 +/- 2.8 vs 5 +/- 2.4, p less than 0.05) and higher prevalence of wheeze (70 vs 25%, p less than 0.05) in comparison with patients non-responsive to Mch challenge. CV-PEF was significantly related to FEV1 (r = 0.347, p less than 0.05) and maximal expiratory flow at 50% expired volume (MEF50) (r = 0.405, p less than 0.05). The probability of responding to Mch bronchial challenge increased proportionally with the increase in CV-PEF and the decrease in FEV1, FEV1/VC and MEF50. Airway hyperresponsiveness of patients with mitral stenosis seems to be more similar to that reported in bronchitic than in asthmatic patients.
Adult↗
The role of plasma proteins in formation of obstructive protamine complexes.
Formation of complexes between heparin and protamine (in saline), or heparin, plasma proteins, and protamine (in plasma) was assessed by measurements of light transmission through different test solutions. To examine the formation of these complexes, 125I-labeled protamine was used. Addition of 125I-protamine to plasma or blood resulted in the sedimentation of 125I-protamine in the form of insoluble complexes. This complex formation was not affected by the presence of heparin, suggesting that protamine-plasma protein interaction may be primarily responsible for precipitation of 125I-protamine. To assess the capability of these complexes to obstruct the pulmonary circulation, an in vitro experimental model was developed. Citrated serum, plasma, blood, or saline were allowed to flow through a glass bead column with the help of a peristaltic pump. A pressure transducer positioned before the column allowed pressure measurements at a constant flow rate during the experiment. Mixing of protamine with plasma or blood prior to their passage through the glass bead column resulted in a significant increase in pressure suggesting that the column was being clogged with insoluble complexes. The increase in pressure occurred both in the presence and absence of heparin in plasma or blood. Under identical experimental conditions, the increase in pressure was insignificant when protamine was added to saline or serum regardless of whether heparin was present or absent. This was further confirmed by the use of 125I-protamine. These observations suggest that protamine forms insoluble complexes with certain plasma proteins. Based on these observations, it is hypothesized that following intravenous administration, protamine immediately forms complexes in circulating blood.(ABSTRACT TRUNCATED AT 250 WORDS)
Albumins↗
Risk factors of primary tissue failure within the 11th postoperative year in 217 patients with porcine bioprostheses.
From January 1979 to December 1979, 217 patients underwent valve replacement with porcine bioprostheses. The aim of this study has been to analyze possible host-related risk factors of primary tissue failure (PTF). Of the 207 survivors, 33 have been reoperated on because of prosthetic PTF. Actuarial freedom from PTF was 67.4% +/- 6.04% at 11 years. Several clinical and prosthetic variables have been analyzed as risk factors of PTF by stratification of the event-free actuarial rates with the tests of Mantel and Breslow, and then by introducing the significant variables into the Cox proportional hazards regression model. No significance was found for serum calcium and phosphorus levels, the calcium phosphorus product, normal sinus rhythm, and anticoagulant therapy. Age less than 40 years (40.3 +/- 15.9 vs 74.2 +/- 5.7; p = 0.0348 and p = 0.03) and mitral position (57.7 +/- 7.7 vs 90.9 +/- 5.2; p = 0.0124 and p = 0.0095) were significant predictors of PTF within the 11th postoperative year. Female gender approached statistical significance (63.7 +/- 7.9 vs 72.2 +/- 9.3; p = 0.2001 and p = 0.2043). Cox multivariate analysis showed that age less than 40 years (p = 0.008) and mitral position (p = 0.015) were independent determinants of PTF. In conclusion, we have not been able to confirm the influence of metabolic host factors on the occurrence of PTF, but young age (and not only pediatric age) and mitral position are significant predisposing factors.
Adult↗
Reduction of bronchial responsiveness to methacholine after mitral valve replacement.
Sixteen patients with mitral valve disease, in whom bronchial hyperresponsiveness to methacholine had been detected shortly before mitral valve replacement (MVR), were reevaluated 35 +/- 1.5 months after MVR. In 9/16 patients there was a significant (greater than 1.5 fold) increase in bronchial provocation dose of methacholine (PD20FEV1) after MVR. In the same patients there was a significant increase in vital capacity (from 69.6 +/- 5 to 75.8 +/- 5.2% of predicted, p less than 0.01), a significant decrease in cardiothoracic ratio and in radiologic score for lung edema (from 64.3 +/- 2.9 to 56 +/- 2.1, p less than 0.01 and from 38 +/- 4.5 to 14.6 +/- 2, p less than 0.001, respectively). In all the patients the increase in PD20FEV1 was not related to any change in spirometric values but it was related to the decrease in cardiothoracic index (r = 0.72, p less than 0.01) and in radiologic score for lung edema (r = 0.61, p less than 0.05) observed after cardiosurgery.
Bronchial Provocation Tests↗
[Is coronary angioplasty less costly than aortocoronary bypass?].
We retrospectively compared the cost-benefit ratio of coronary bypass grafting (CABG) and percutaneous coronary angioplasty (PTCA). Data were obtained on 40 CABG's and 40 PTCA's patients treated from 15/2/86 to 15/9/86. All patients had at last 1-year follow-up. PTCA and CABG groups had similar baseline clinical and angiographic criteria. We analyzed the following cost components: real estate, biomedical products, drugs, hospital charges, medical fees, cardiac and non-cardiac tests. Total cost of CABG exceeds that of PTCA by a factor of 1.64: 15,095,000 vs 9,201,346 Italian liras (ILit). Taking into account early and late medical and surgical complications, the factor decreases to 1.39: 15,746,500 vs 11,323,000 ILit. After 1 year of follow-up the factor decreases to 1.18: 16,613,500 vs 14,027,500 ILit. Our data show that the initial savings were reduced when complications and follow-up are considered, but PTCA's patients had shorter hospitalization, earlier return to work, lower psychosocial stress.
Angioplasty, Balloon, Coronary↗
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)
Bioprosthesis↗