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M Di Summa

Publications and source records attributed to M Di Summa.

At least 19 recordsLinked to original sources

Clinical evaluation of St Jude Medical Hemodynamic Plus versus standard aortic valve prostheses: The Italian multicenter, prospective, randomized study.

OBJECTIVE: Hemodynamic and clinical performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus aortic valves (St Jude Medical, Inc, St Paul, Minn) were compared with those of 21-mm and 23-mm St Jude Medical standard cuff aortic valves in the first such multicenter, prospective, randomized study. Hemodynamic Plus valves are mechanical, bileaflet prostheses suitable for the small aortic anulus. METHODS: Patients with 21-mm and 23-mm anulus diameters were randomized to receive either a Hemodynamic Plus or a standard cuff valve. Postoperatively and at 6 months after the operation, patients underwent 2-dimensional Doppler echocardiography. Ejection fraction, cardiac output, peak gradient, mean gradient, effective orifice area, effective area index, and performance index were calculated. Postoperative and 6-month echocardiographic measurements and their variations across observation times were analyzed statistically. RESULTS: Of the 140 patients enrolled, 5 died at operation and 1 died of aortic dissection during the follow-up period. Eight patients were lost to follow-up. A total of 125 patients completed the study. In 1 patient a sewing cuff escaped intraoperatively. At 6 months the 21-mm and 23-mm Hemodynamic Plus valves showed significantly lower peak gradients and mean gradients than those of the 21-mm and 23-mm standard cuff valves. The 21-mm Hemodynamic Plus valves had gradients similar to those of the 23-mm Hemodynamic Plus valves. The effective orifice area did not differ significantly between the Hemodynamic Plus and standard cuff valves at either measurement. No valve mismatch was found in the 4 groups of patients. A more enhanced decrease of peak gradients and mean gradients and a more enhanced increase of effective orifice areas, effective area indices, and performance indices were found across observation times for patients with Hemodynamic Plus valves compared with those with standard cuff valves. CONCLUSIONS: Clinical hemodynamic performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus valves correspond closely with those of standard cuff valves, and gradients are substantially better than those of standard cuff valves of the same diameter. Therefore, use of this valve may minimize the need for aortic anulus enlargement. Early follow-up results with the Hemodynamic Plus valves were excellent, although more time is required to confirm this outcome.

Aortic Valve↗

Mortality and morbidity in reoperation comparing to first intervention in coronary revascularization.

BACKGROUND: Coronary artery reoperation represents about 20% of coronary artery operations. In this study we compared mortality and morbidity of first intervention and redo operation. METHODS EXPERIMENTAL DESIGN: a retrospective study. SETTINGS: patients who underwent coronary artery reoperations in a University Cardiac Surgery Division in 1991-1994. PATIENTS: our clinical survey was composed of two groups: group A included 44 consecutive patients (mean age 60+/-7 years, males/females=41/3) who underwent a coronary artery reoperation in the years 1991-1994 at the University Cardiac Surgery Division of Turin; group B included 344 patients (mean age 58+/-8 years, males/females=289/55) randomly selected among those who underwent a first coronary operation in the above indicated period of time and centre. All patients had angina pectoris refractory to maximal medical therapy. INTERVENTIONS: all patients underwent a coronary artery operation in extracorporeal circulation (ECC), under mild hypothermia (30-32 degrees C), during a single aortic clamp period, with antegrade cold crystalloid cardioplegia (St. Thomas). MEASURES: comparison of clinical preoperative features, risk factors and postoperative mortality and morbidity between the two groups. RESULTS: In reoperated patients we observed a greater mean akinesis score (p<0.001) and severe left ventricular dysfunction presence (p=0.014). Reoperation mortality was 11.4% against first operation mortality of 3.2% (p=0.03). Female gender (p=0.03), intra-aortic balloon counterpulsation need (p=0.002), adrenaline use (p=0.004) and low cardiac output syndrome (p=0.007) were all perioperative risk factors in group A. CONCLUSIONS: Coronary artery reoperation involves a higher mortality and morbidity compared to the first operation, especially related to the reduced left ventricular function which characterises the population that undergoes reoperation.

Coronary Artery Bypass↗

Aortobronchial fistula after aortic dissection type B.

Although rare, aortobronchial fistula complicates thoracic aortic surgery. Correct diagnosis and the infectious nature of the lesion are the most important conditions to define, for the following best therapy. We presented a case of non-infectious postsurgical aortobronchial fistula, revealed by computed-tomographic scan and angiography procedure, treated with prosthetic graft replacement and broad spectrum antibiotic therapy. In the case of infection our policy is homograft replacement. Computed tomography, being able to make diagnosis, should be performed as the initial technique.

Aortic Dissection↗

Mitral valve prolapse. Comparison between valvular repair and replacement in severe mitral regurgitation.

BACKGROUND: The aim of this study was to analyse long term results of mitral valve repair of degenerative mitral regurgitation compared to valve replacement. METHODS: A hundred-twenty-five consecutive patients with severe mitral valve insufficiency who underwent cardiac surgery from January 1987 to December 1995 were included in the study. Mean age was 55+/-16 years (77 males, 48 females). Mitral repair was performed in 62 patients and mitral valve was replaced in 63 patients. Mean follow-up was 5 years. The repair procedures were based on quadrangular resection of the posterior leaflet, chordal replacement and transposition. Annuloplasty was performed in 100% of cases. The technique of valve replacement was conventional with complete excision of the valve in the majority of cases. RESULTS: Operative mortality following valve repair was 1.6%, no death occurred in the prosthesic group. In the repair group overall survival and re-operation rate were respectively 95.2% and 6.5%, while in the replacement group were 93.7% and 7.9%. No endocarditis and thromboembolic accidents were observed following valvuloplasty, while in the prostheses 6.3% of patients had endocarditis and 1.6% had a thromboembolic event. Mild or moderate left ventricular dysfunction was present in 5 patients after valvuloplasty and in 9 patients with prostheses. CONCLUSIONS: Considering these results we conclude that, in patients with severe degenerative mitral insufficiency, mitral valve repair is warranted whenever it is possible. The advantages given by maintaining the native valve suggest that surgery should be considered in asymptomatic patients before the occurrence of the left ventricular dysfunction.

Aged↗

Bjork-Shiley convexo-concave valve: is a prophylactic re-replacement justified?

BACKGROUND: The Bjork-Shiley convexo-concave (BS-CC) heart valves represent the improved model of the standard valve first introduced with a different design of the disc valve to ameliorate hemodynamic performances and reduce thromboembolic complications. About 86,000 BS-CC were implanted during 1979-1986 and of them a small number developed an intrinsic dysfunction resulting in sudden death. METHODS: From 1979 to 1986 we implanted in 117 patients (48 males, 69 females, mean age 46.35+/-12.47, range 8-65 years) 125 BS-CC. In 38.5% (45/117) of the cases heart valve replacement represented the second cardiac procedure after a previous closed heart digital commissurotomy. The mean size of the implanted prosthesis was 25.6+/-2.8 for aortic valve and 29.5+/-1.2 for mitral valve. RESULTS: Hospital mortality was 4.27% (5/117) and survival rate at 10 years is 71.4% and at 17 years 54.7% (Kaplan-Meier). At follow-up causes of death proved valve related in most of the patients but with no evidence of valve fracture. We had 1 case of sudden death in patients at high risk (largest size, aortic position) and 30 cases of death by unknown causes but they did not have an autopsy to confirm the cause of death. CONCLUSIONS: We conclude that in our population with BS-CC at the moment there is no indication for prophylactic replacement because of the higher risks of a reoperation (third or fourth in the 35.4% of our patients) than a strut fracture. Nevertheless we believe an autopsy mandatory in all these patients at risk, when sudden death occurs.

Adolescent↗

Left atrial approach to big myxoma with angiographically visible neovascularity. Report of one case.

In this article, we report a 65-year-old man with a large atrial myxoma arising from the posterior wall and from the base of the right inferior pulmonary vein. The big neoplastic mass showed a large implant site. A rare atrial myxoma neovascularity arising from the atrial circumflex artery was very clearly visualized by selective coronary arteriography. The surgical approach used to resect this tumor was an isolated left atriotomy that provided excellent exposure and safe excision.

Aged↗

Bovine pericardial bioprosthesis in mitral position. A ten-year follow-up.

BACKGROUND: The pericardial bovine prosthesis Pericarbon should offer some advantages in comparison with the former generations, because its development is focused on solving previous problems and resulted in the variation of the pericardial fixation method, of valve structure and of stent coating. This hypothesis was evaluated through a retrospective follow-up. METHODS: Between 1985 and 1989, 78 Pericarbon prostheses O 29 were implanted in mitral position by the same surgeon. All patients received warfarin for the first three months to maintain an International Normalized Ratio between 2.5 and 3.5; after which they received antiaggregant therapy indefinitely. With an average follow-up period of 7.34 years for a total of 573 patient-years, we evaluated perioperative and late mortality, late morbidity (thromboembolic and haemorrhagic events, reoperations, primary tissue failures, endocarditic events) and patient clinical conditions. RESULTS: Perioperative mortality was 1.28% (1/78), late mortality was 11.6% (9/77) with 5 valve-related deaths. 5-year survival was 93% and 10-year survival 97%. Fifteen patients required reoperation for prosthetic replacement, fourteen for primary tissue failure. There were ten minor thromboembolic events, one major event, one haemorrhage and one prosthetic endocarditis (the last two with patient exitus). After 10 years (75% of patients were in New York Heart Association class I-II. CONCLUSIONS: Besides the known better haemodynamic performance, Pericarbon bioprosthesis seems to present a survival and redofreedom curve comparable to the best porcine prosthesis, with less incidence of endocarditis, thromboembolic events and prosthesis leakage.

Aged↗

Low IGF-I levels are often uncoupled with elevated GH levels in catabolic conditions.

Increased GH together with decreased IGF-I levels pointing to peripheral GH insensitivity in critically ill patients have been reported by some but not by other authors. To clarify whether elevated GH levels are coupled with low IGF-I levels in all catabolic conditions, basal GH and IGF-I levels were evaluated in patients with sepsis (SEP, no.=13; age [mean+/-SE]=59.2+/-1.2 yr), trauma (TRA, no.=16; age=42.3+/-3.4 yr), major burn (BUR, no.=26; age=52.8+/-4.2 yr) and post-surgical patients (SUR, no.=11; age=55.0+/-4.7 yr) 72 hours after ICU admission or after cardiac surgery. GH and IGF-I levels were also evaluated in normal subjects (NS, no.=75; age=44.0+/-1.5 yr), in adult hypopituitaric patients with severe GH deficiency (GHD, no.=54; age=44.8+/-2.3 yr), in patients with liver cirrhosis (LC, no.=12; age=50.4+/-2.8 yr) and in patients with anorexia nervosa (AN, no.=19; age=18.7+/-0.8 yr). Basal IGF-I and GH levels in GHD were lower than in NS (68.6+/-6.4 vs 200.9+/-8.7 microg/l and 0.3+/-0.1 vs 1.4+/-0.2 microg/l; p<0.01). On the other hand, AN and LC showed IGF-I levels (70.4+/-9.1 and 52.4+/-10.5 microg/l) similar to those in GHD while GH levels (10.0+/-2.8 and 7.9+/-2.1 microg/l) were higher than those in NS (p<0.01). IGF-I levels in SEP (84.5+/-8.8 microg/l) were similar to those in GHD, AN and LC and lower than those in NS (p<0.01). IGF-I levels in BUR (105.2+/-10.9 microg/l) were lower than in NS (p<0.01) but higher than those in GHD, AN, LC and SEP (p<0.01). On the other hand, in TRA (162.8+/-17.4 microg/l) and SUR (135.0+/-20.7 microg/l) IGF-I levels were lower but not significantly different from those in NS and clearly higher than those in GHD, AN, LC, SEP and BUR. Basal GH levels in SEP (0.6+/-0.2 microg/l), TRA (1.8+/-0.5 microg/l), SUR (2.2+/-0.5 microg/l) and BUR (2.2+/-0.5 microg/l) were similar to those in NS, higher (p<0.05) than those in GHD and lower (p<0.01) than those in AN and LC. In conclusion, our data demonstrate that low IGF-I levels are not always coupled with elevated GH levels in all catabolic conditions. Differently from cirrhotic and anorectic patients, in burned and septic patients GH levels are not elevated in spite of very low IGF-I levels similar to those in panhypopituitaric GHD patients. These findings suggest that in some catabolic conditions peripheral GH insensitivity and somatotrope insufficiency could be concomitantly present.

Adolescent↗

Early and late results after surgical therapy of postinfarction left ventricular aneurysm.

From 1979 to 1993, 139 patients had reduction of left ventricular aneurysm (LVA) by plication (PL) (25 cases) linear repair (74 cases) or ventricular reconstruction (VR) (40 cases). Coronary bypass grafting was performed in 89 patients. We retrospectively reviewed our experience in order to identify predictore of early and late outcome and determine whether ventricular reconstruction (VR) can improve postoperative and late prognosis. Operative mortality (OM) was 7.2%. Among 129 hospital survivors, 48 died during FU (LM). OM was related to a more recent myocardial infarction (p=0.0001), a higher residual score (RS) (p=0.02), a lower EF (p=0.038), a higher left ventricular score (p=0.059), a three-system disease (TSD) (p=0.09) and a right coronary disease (RCD) (p=0.13). At Multivariate Analysis (Stepwise Logistic Regression) TSD (p=0.001), RCD (p=0.008) and RS (p=0.04) are independent risk factors. Actuarial survival rate at 15 years is 33.5+/-6.9% (OM included). According to the comparison of the Actuarial Curves (Tests of Mantel and Breslow, OM excluded) the most significant risk factors were: non use of left internal mammary artery (LIMA) (p=0.004), VR (p=0.01), TSD (p=0.03) and higher NYHA class (p=0.019). Multivariate Analysis (Co Model) confirms that late prognosis is influenced by non use of LIMA (p=0.03) and TSD (p=0.04); outcome is also affected by preoperative arrhythmias (p=0.022). Five-year survival after VR is 87.5+/-5.7% vs 64.9+/-5.5% after simple linear closure or PL (p=0.1075 and p=0.2252). Our results confirm that OM and LM are influenced by extent of myocardial ischemic damage; in agreement with the majority of Authors we advocate a complete revascularization using IMA, when appropriate, on left anterior descending artery. Our limited experience with VR fails to demonstrate this technique as an independent factor of late survival.

Adult↗

The dacron aorta.

Total aorta replacement is a major and increasingly successful surgical procedure. The paper describes a patient whose progressive aneursymatic disease spread from the ascending segment to the bifurcation over a three-years period during which time after three separate operations, the aorta was totally replaced. The paper describes the diagnostic and surgical procedures deployed and shows the results of angiographic and CT scans. Credit for the success of the replacement is also given to the highly skilled anaesthetists and nurses involved.

Aortic Aneurysm, Thoracic↗

Twelve-year follow up with the Sorin Pericarbon bioprosthesis in the mitral position.

BACKGROUND AND AIMS OF THE STUDY: The aim of this study was to evaluate the long-term follow up of the Pericarbon pericardial bioprosthesis implanted in the mitral position. METHODS: Between January 1985 and January 1991, 78 patients (26 males, 52 females; mean age 56.9 +/- 7.8 years) underwent isolated mitral valve replacement with a Pericarbon valve. All bioprostheses were size 29 mm and implanted by the same surgeon. RESULTS: Total follow up was 663.2 pt-years and it was 97% complete. Early mortality was 1.3% (1/78); two minor cerebral embolisms were observed as early complications. At 12 years the overall survival rate was 85.0 +/- and valve-related survival 93.1 +/- 3.0%; freedom from embolic events was 83.0 +/- 4.5% and from endocarditis 98.7 +/- 1.3%. Freedom from primary tissue failure was 56.8 +/- 6.6%; it was 86.3 +/- 7.5% in patients aged > 60 years and 36.8 +/- 8.2% in younger patients. There were 27 reoperations, 26 for primary tissue failure, one for endocarditis. Comparison between basal and follow up echocardiographic studies showed a significant stenotic deterioration of the bioprosthesis and a negligible incidence of regurgitation. Morphological findings of explanted bioprostheses were characterized by stenotic and diffuse microcalcification, but no tissue tear was observed. CONCLUSIONS: These results confirm that the Pericarbon bioprosthesis is structurally safe and free from the fatigue problems which afflicted the first and second generation of pericardial valves. As with other tissue valves, the rate of calcification is age-dependent, suggesting preferential use of the Pericarbon prosthesis in elderly people.

Bioprosthesis↗

[Correlation between malfunction of a bioprosthesis and deformation of a valve stent. Comparison of three different vale models].

BACKGROUND: Stent deformation seems to be effective in the long term performances of bioprostheses. METHODS: The Inward Banding Angle (IBA) of three different models of bioprostheses explanted during the period 1991-1992 at our Division of Cardiac Surgery in 45 different patients (26 males; 9 females; mean age 59.71 +/- 10.74, range 26-75) has been measured. Explanted valves were as follow: Hancock, (H = 13); Carpentier-Edwards (C = 14) e Xenomedica (X = 18). Primary tissue failure was the most common cause of re-operation (n = 30; 66.7%) but also endocarditis (n = 6; 13.3%) and paraprothetic leak (n = 10; 22.2%). A semi-quantitative score (0-4) was used to assess calcifications (1.51 +/- 1.56); tears (0.41 +/- 0.98); vegetation's (0.51 +/- 0.99) and fibrosis (2.7 +/- 1.27). The mean follow-up was 7.77 +/- 3.79 years (range 1.5 +/- 16 years). The mean IBA evaluated after explantation was 3.34 +/- 2.29 degrees. RESULTS: Statistical analysis showed a significance in term of IBA in the Hancock group vs Carpentier (P < 0.02); a less duration in the Xenomedica group vs H and C (p < 0.001) and an increased susceptibility to vegetation's and fibrosis in the Xvs C (p < 0.01) and H (p < 0.05) respectively. A suggestive correlation between IBA and time and between IBA and diameter was found but no statistical significance was observed. CONCLUSIONS: In conclusions, it is suggested that all materials tends to deform during time and a possible explanation of stent deformation can be the different material used in the stent fabrication. Moreover, mechanical stress and compression around the ring can be another mechanism of creep.

Adult↗

Williams-Beuren syndrome. Long-term results of surgical treatments in six patients.

To settle long-term outcome after surgery for supravalvular aortic stenosis in the Williams-Beuren syndrome, we reviewed the records of 6 patients who had repair of the localized form (n = 5) or diffuse form (n = 1) at our Institution from 1965 to 1971. Four patients were females and 2 males, ages at operation ranged from 9 to 16 years (mean = 13 +/- 2.37 years). In all the patients was present the typical elfin facies with mental retardation and reduced I.Q. Preoperative omeral pressure was different between left and right arm (89 +/- 7/67 +/- 8 vs 105 +/- 8/77 +/- 4). Chest X-ray showed and enlargement of the cardia silhouette in all the patients. Cardiac catheterization, performed in all the patients, allowed diagnosis of supravalvular aortic stenosis and, in one case of subaortic stenosis associated. Intraoperatively a coronary tree enlargement was found in all cases with particular involvement of the right coronary in two patients. The mean diameter of the ascending aorta was 5.67 +/- 1.97 mm but the smallest (3 mm) was in the diffuse group. In group with localized stenosis the aortic root was enlarged with a teardrop patch in Dacron (n = 4) or a simple transverse suture after a longitudinal incision (n = 1). A pantaloon-shaped patch was necessary in the diffuse form case. There were no operative deaths and all the patients were discharged from the hospital after 2 weeks. A clinical follow-up was possible in all the patients (10%) extended from 25 to 30 years (mean = 27.7 +/- 2.19 years); there were no late deaths and at presents time the mean age of the patient is 40 +/- 3 years. All patients were in functional class I or II. There was no significant difference between patients with a teardrop-shaped or pantaloon-shaped patch in terms of late gradient, survival, or aortic insufficiency studied by Echocardiography and color-Doppler. Of six patients two are living with parents or relatives but four are in a farm-college for disable people working and having some responsibility. We conclude that surgery for the correction of supravalvular aortic stenosis in Williams-Beuren syndrome is mandatory and both the procedures with patch techniques provide excellent long-term results of gradients and aortic valve competence. Moreover the patients after the operation can have a normal activity with a satisfactory style and expectation of life.

Adolescent↗

Ventricular septal rupture after a myocardial infarction: clinical features and long term survival.

BACKGROUND: Ventricular septal defect (VSD) represents a serious complication after acute myocardial infarction (AMI) with an incidence of 1-2%. Surgical treatment is often mandatory in the early period after AMI because of the worsening of the hemodynamic and clinical conditions. METHODS: We reviewed 34 patients complicating AMI who underwent surgical treatment at our Institution from January 1988 to December 1994 (23 males, 11 females, mean age 64.2+/-7.96, range 45-78). The localization of the AMI was anterior in 47.05% but inferior in 52.95% of the patients (p=NS). The mean time between AMI and VSD was 5.24+/-9.31 days. The preoperative NYHA functional class was III-IV in 93% of the patients. QP/QS ratio was 2.7+/-0.65 and the diameter of VSD ranged from 1 to 8 (mean 2.5+/-0.35). In 26 patients (76.4%) an intraortic balloon pump (IABP) was inserted before surgery. Surgical treatment was done after 10+/-17.7 days after VSD appearance through a left ventriculotomy. Ten patients received a concomitant myocardial revascularization. RESULTS: Overall surgical mortality was significantly higher (p<0.05) in patients operated on in the early period after AMI (1+/-1.4 days) and with VSD complicating an inferior AMI. A complete follow-up was possible in all the survivors with a cumulative FU of 1453 month/patients. Two patients received a redo procedure after 30 and 40 days after the first correction because of a residual shunt. We observed 3 late deaths for re-AMI and one for complications after bronchial pneumonia. The actuarial survival rate is 70% at 1 year, 68% at 2 years and 65% at 7 years. NYHA functional class after operation is 1-11 in 91% of the patients. CONCLUSIONS: The major determinant of hospital survival in VSD after AMI in our patient population was the anatomical localization and the early timing of the operation. We believe that a prompt diagnosis and immediate cardiac support (IABP or ventricular assist device) is recommended to obtain a hemodynamic stabilization and to achieve the shaping of stronger cicatricial tissue before surgery. Nevertheless surgical repair of VSD is mandatory when clinical and hemodynamic condition becomes unacceptable. The results in the long term assessment are very satisfying.

Aged↗

[Female sex is not an independent risk factor in mortality during myocardial revascularization].

To assess if female sex is an independent risk factor for perioperatory mortality and morbidity, we have evaluated 971 consecutive patients (16% women) undergoing coronary artery bypass graft surgery at the Cardiovascular Disease Institution of the University of Turin from 1988 to 1990. In this study at baseline women were older and more likely to have diabetes, lower ventricular score and body surface area than men. As compared to men, women underwent surgery with delay: the surgical mortality rate and prevalence of arrhythmias were higher, and the size of the left anterior descending was smaller. At univariate analysis perioperative risk factors were as follows: age, diabetes, clinical instability, low body surface area, perioperatory infarction, postoperative infections, extracorporeal circulation time and left coronary size. At multivariate analysis only diabetes, left ventricular score, left anterior descending coronary size and emergency surgery were independent risk factors while sex, age and body surface area were not predictors of perioperatory mortality and morbidity. It is concluded that gender is not the cause of worse outcome in women.

Female↗

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.

Animals↗

Morphological comparison of mitral and aortic bioprostheses explanted from the same patient for primary tissue failure.

Host factors might influence the fate of tissue prostheses. We have analyzed the tissue failure phenomenon in mitral and aortic porcine bioprostheses explanted from the same patient so as to avoid the bias of host factors. The 50 bioprostheses of this study were explanted from 25 patients reoperated on because of malfunctioning due to primary tissue failure. Bioprostheses explanted were photographed, radiographed and observed in polarizing light. All lesions analyzed received a score on the basis of morphological criteria. No difference was observed in the occurrence of pannus, tears or cells infiltrates. Calcifications occurred more extensively in mitral position (p=0.0031). Creep of the stent was significantly greater in mitral position (p=0.0324). Since the model of our study removed other individual factors, we may conclude that there is evidence for an earlier and more extensive calcific degeneration in the mitral than in the aortic position.

Aortic Valve↗