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Biomedical subjects

M di Summa

Publications and source records attributed to M di Summa.

34 records · Page 2Linked to original sources
PubMed1992

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↗
PubMed1990

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↗
PubMed1989

[Pseudomonas aeruginosa infection of the sternum and costal cartilages in cardiosurgery. Therapeutic experience using aztreonam].

Clinical effectiveness of Aztreonam was studied. This new monobactam antimicrobial agent was tasted in the treatment of post-operative infectious complications of cardiac surgical sternal wounds. Ten patients (4 men and 6 women, age range 20 to 68 years) were entered into the study. All had a Pseudomonas aeruginosa infection of sternum or sternum and ribs and all underwent an extensive regional surgery of the infection wound and received a topical and/or IV treatment with Aztreonam. In all cases we obtained a satisfactory result, with complete eradication of the infection. Both local and systemic tolerance to the drug were excellent and no side-effect was registered. Therefore Aztreonam can be considered an active and safe antibiotic for the treatment of sternal and/or costal postsurgical infections by Pseudomonas aeruginosa.

Adult↗
PubMed1988

Protection of the heart by nifedipine cardioplegia during coronary artery surgery. A clinical-haemodynamic evaluation.

This study was undertaken to evaluate the myocardial preservation obtained by adding a Ca++ channel blocker, nifedipine, to cold potassium cardioplegia (4 mcg/Kg/L) in 24 patients undergoing coronary artery surgery. They were randomly divided into a treated (N) and a control (C) group. Significant differences between the two groups were noted in the cardiac arrest time (p less than 0.001), in the mechanical recovery mode (p less than 0.01) and in the inotropic support needed (p less than 0.01). Cardiac index increased significantly in group N but decreased in group C (p less than 0.01). Peripheral delta P/delta t and endocardial viability ratio (EVR) decreased in both groups. Coronary sinus and serum CK and CK-MB release were significantly lower in the treated group. ECG ischaemic changes occurred in 8 patients in group C but only in 1 case in group N (p less than 0.001). Arrhythmias occurred in 3 cases in group C (p less than 0.05). The incidence of perioperative myocardial infarction was not significant (2 cases in group C). These data suggest that nifedipine can protect the myocardial cell from ischaemic injury without depressing myocardial contractility or AV conduction.

Arrhythmias, Cardiac↗
PubMed1986

Myocardial protection by perioperative diltiazem drip: a clinical evaluation.

This study was undertaken to evaluate the potential role of a perioperative calcium-channel blocker (Diltiazem) infusion in improving myocardial preservation. Forty consecutive CAD patients were randomly assigned to a control (C; n = 20) and a treated (D; n = 20) group. In patients in the latter group diltiazem was continuously infused at 0.5 to 2.0 mcg/kg/min i.v. from anesthesia induction until the aortic cross-clamping, and from myocardial reperfusion till the 48th postoperative hour. During the preCPB phase hypertension occurred less frequently in group D (3 vs 12 cases, p = 0.0033). In the immediate postischemic period, depression of contractility and the need for inotropic support were observed in 3 cases in group D and in 9 in group C (p = 0.0384). Postoperatively, group D patients had a lower incidence rate of hyperkinetic arrhythmias or conduction disturbances (p = 0.0218), as well as of ECG signs of ischemia (p = 0.0016). Significant CK enzyme level increase was noted in 13 patients in group C versus 4 in group D (p = 0.0040). Two perioperative myocardial infarctions were diagnosed, both in group C. These clinical data show that continuous perioperative infusion of diltiazem can effectively increase myocardial preservation during ischemic arrest, without unfavorable effects on the hemodynamics, electrical activity or mechanical performance of the heart.

Benzazepines↗
PubMed1985

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)

Adolescent↗
PubMed1984

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.

Adult↗
PubMed1984

Ascending aortic aneurysms: composite conduit replacement.

From July 1980 to February 1984, 26 patients underwent composite replacement of ascending aortic aneurysm and aortic valve with coronary reimplantation. This group included 14 patients with dissecting aneurysm (ten and four respectively, belonging to Types I and II), and 12 patients with chronic aneurysm (six atherosclerotic aneurysms, two Marfan's syndrome and four annuloaortic ectasia cases). Hospital mortality was 35.7% (5/14) in the dissection subgroups and 16.6% (2/12) in the chronic aneurysm subgroup (difference NS). No operative risk factor was recognized. The 19 survivors have been followed up for a total of 393 patient-months (range 5 to 49 months). Controls included echocardiography and computed tomography scanning. Two patients died because of rupture of a persistently dissected aorta; another patient died of an unknown cause. Total actuarial survival rate at 4 years was 58.3 +/- 10.4% (83.3 +/- 10.7% for chronic aneurysms and 42.3 +/- 13.4% for dissecting aneurysms). Among late survivors, there were no paravalvular leaks, new dissections, or thromboembolisms, although two perigraft hematomas and a persistent dissection were later disclosed. When appropriate, composite conduit replacement of the ascending aorta can increase the survival rate, and can also be useful in high-risk patients.

Journal Article↗
PubMed1980

[Clinical experience with etomidate].

The effects of Etomidate, a new intravenous anaesthetic agent, were studied in 138 cases which underwent different procedures of variable duration under general anaesthesia. The effects on different organs and systems of this drug, alone or in association with other anaesthetics or adjuvants, were analyzed in this series. Clinical signs, plethysmography and electroencephalography were the main parameters studied. It was shown that Etomidate has a rapid, transient action and a high therapeutic index without any cumulative effects. In conclusion this drug is recommended as an excellent induction agent which could also be advantageously employed for short surgical procedures.

Anesthesia, Intravenous↗
PubMed1980

[Althesin-induced EEG changes in patients with central nervous system lesions].

The EEG changes produced by Althesin (75 microliter/kg intravenously administered over 60 sec) were evaluated in 18 unpremedicated patients wih CNS diseases who were scheduled for cerebral angiography. Three parameters were analyzed: the EEG patterns of anaesthesia, the appearance of a fast activity during stabilized burst suppression (Level V), and enhancement of the registered epileptiform abnormalities. The EEG depth of anaesthesia was correlated with the EEG pattern at rest and the preexisting neurological signs. The 15 Hz fast activity which occurred during the suppression phase of Level V was recorded unilaterally over the healthy hemisphere, while it was observed bilaterally in a case involving lesion of the midline structures. The exaltation of the epileptiform EEG discharges following Althesin administration suggests that this agent might be utilized as a convenient provocative test in the diagnosis of epilepsy.

Alfaxalone Alfadolone Mixture↗
PubMed1976

[Use of the femoral artery for chronic hemodialytic treatment].

In 4 patients subjected to periodical haemodialytic treatment a new route of access to the vessels was used; the common femoral artery and the large saphena to the outlet into the femoral vein. All four patients presented serious problems with regard to application of a new shunt in view of the previous reiterated use of the vessels commonly utilized. At the maximum distance of 46 months from implantation, only one of the four by-passes is still in use; 2 were removed for obstruction and the fourth, still operating at the time, was removed for a renal transplant performed on the patient. In view of the frequency of troubles and the use-months of the femoral by-pass compared with the traditional ones, the femoral route of access may be considered favourably when the traditional shunt implantation or fistula creation procedures are precluded.

Adult↗
PubMedDate not supplied

Histologic and molecular diagnosis of myocardial human cytomegalovirus infection after heart transplantation.

A total of 879 paraffin-embedded endomyocardial biopsy specimens from 69 heart transplant recipients were studied. In 30 biopsy specimens, the presence of human cytomegalovirus was investigated by routine histologic and immunohistochemical evaluation, in situ hybridization, and polymerase chain reaction. These 30 biopsies were performed in seven patients with clinical human cytomegalovirus infection (four primary and three recurrent infections) and in eight patients with asymptomatic human cytomegalovirus recurrent infection. These endomyocardial biopsy specimens showed grade 0 (n = 9), 1A (n = 12), 1B (n = 7), or 2 (n = 2) acute rejection. No myocarditis with human cytomegalovirus-like inclusion bodies was observed by routine histologic evaluation. Human cytomegalovirus DNA or antigens were not shown by in situ hybridization or by immunohistochemical evaluation, respectively. Viral DNA was detected by polymerase chain reaction in two grade 1A endomyocardial biopsy specimens from two patients with systemic human cytomegalovirus primary infection. These two biopsy specimens were shown to be positive by polymerase chain reaction at the time of the acute phase of the infection as shown by laboratory findings. Therefore cytomegalovirus DNA detected by polymerase chain reaction could result from viral carriers, that is, leukocytes of rejection-related infiltrates or within intramyocardial vessels as a result of a more aggressive expression of the systemic infection in seronegative recipients with cytomegalovirus seropositive donors. Polymerase chain reaction is the most sensitive method for viral DNA detection on paraffin-embedded biopsy specimens, but a multitechnologic approach, including routine histologic evaluation, is required for a proper diagnosis of human cytomegalovirus myocardial infection.

Antibodies, Viral↗
PubMedDate not supplied

Heart valve replacement with CarboMedics bileaflet prosthesis: surgical results and clinical evaluation. A medium term follow-up.

From March 1990 to July 1991, 110 patients (44 males, 66 females; mean age 54.44 +/- 8.8 years) underwent hearth valve replacement with a CarboMedics bileaflet prosthesis (CarboMedics Inc, Texas, USA). Preoperative pathophysiologic conditions were: aortic stenosis in 32 patients, aortic regurgitation in 22 patients; mitral stenosis in 27 patients and mitral regurgitation in 14 patients. Mitroaortic disease was present in 14 patients but 1 had triple valve disease. NYHA class was III or IV in 91 patients (83%). Operative mortality rate was 0.91% (1 patients). Actuarial survival rate is 95% at 58 months. Actuarial freedom from thromboembolic events in 95% at 58 months. Actuarial freedom from hemorrhage is 100%. Endocarditis befell in 2 patients; actuarial freedom from this complication at 58 months is 95%. Actuarial freedom from reoperation in 99%. We conclude that the low incidence of valve related events and the low mortality supports the use of the bileaflet valve CarboMedics.

Adolescent↗