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Biomedical subjects

A Mazzucco

Publications and source records attributed to A Mazzucco.

At least 181 records · Page 10Linked to original sources
PubMed1988

The standard Hancock porcine bioprosthesis: overall experience at the University of Padova.

All patients undergoing aortic (AVR, n = 196), mitral (MVR, n = 502), and mitral-aortic (MAVR, n = 71) valve replacement with a standard Hancock porcine bioprosthesis (HPB) from 1970 to 1983 were reviewed. A total of 665 patients discharged were followed for 5,099 patient-years with an actuarial survival at 15 years of 52% +/- 4.5%, for MVR, 37% +/- 14% for AVR, and at 12 years of 52 +/- 7.4% for MAVR. Embolic episodes occurred in 9 patients after AVR (0.7% +/- 0.2% pt-yr), in 61 after MVR (1.7% +/- 0.2% pt-yr), and in 6 after MAVR (1.7% +/- 0.7% pt-yr); actuarial freedom from emboli at 15 years is 91% +/- 3.5% after AVR, 79% +/- 14% after MVR, and at 12 years is 87% +/- 5% after MAVR. Reoperation because of primary tissue failure (PTF) was performed in 47 patients with AVR (3.9% +/- 0.5% pt-yr), 91 with MVR (2.6% +/- 0.3% pt-yr), and in 13 with MAVR (4.1% +/- 1.1% pt-yr); actuarial freedom from PTF at 15 years is 41% +/- 5.5% after MVR, 37% +/- 10% after AVR, and at 12 years is 49% +/- 13% after MAVR. After AVR and MVR, freedom from PTF is significantly better for patients over 50 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Hancock bioprosthetic valve failure: causes, and results of reoperation.

Between March 1970 and the end of December 1986, 180 porcine valve recipients underwent reoperation at our institution because of bioprosthetic failure. Of these patients, 126 (70.0%) had mitral bioprosthesis replacement (MBR), which was necessitated because of primary tissue failure in 107 cases, prosthetic valve endocarditis in eight cases, and paravalvular leakage in eleven cases. Forty-six patients (25.5%) had aortic bioprosthesis replacement (ABR), owing to primary tissue failure in 37 cases, endocarditis in six cases, and paravalvular leakage in three cases. The remaining eight patients (4.5%) all underwent double (mitral and aortic) bioprosthesis replacement (DBR) because of primary tissue failure. In a total of 152 patients who underwent reoperation for primary tissue failure, the hospital mortality was 6.5% for the MBR group, 8.0% for the ABR group, and 0% for the DBR group (mean, 6.5%). In those 14 patients who required reoperation owing to endocarditis, the hospital mortality was 75% for the MBR group and 50% for the ABR group (mean, 64%). In another 14 patients who underwent reoperation because of paravalvular leakage, the hospital mortality was 9% for the MBR group and 0% for the ABR group (mean, 7%). Morphologic studies of the explanted valves revealed that tissue calcification is the most frequent cause of primary tissue failure in Hancock-valve recipients. Calcification leads to cusp stiffening with stenosis or to cuspal and commissural rupture with incompetence. Usually, primary tissue failure causes progressive dysfunction that allows for elective reoperation, which is associated with a low mortality; rarely, however, porcine xenograft failure can occur acutely and require emergency operation, which is associated with a significantly higher risk. Such operation was necessary in nine (6%) of our patients with primary tissue failure and resulted in four deaths (44%); conversely, elective reoperation was done in 143 patients with other primary tissue failure (94%) and resulted in six deaths (4%) (p<0.001). Our long-term experience with the Hancock bioprosthesis confirms that this valve's durability is limited. Therefore, we believe that the indications for the use of porcine bioprostheses should be restricted, until consistent data become available concerning the durability of the new generation of prosthetic valves.

Journal Article↗
PubMed1988

[Coronary angioplasty in unstable angina. Immediate and short-term results].

We report the results of percutaneous transluminal coronary angioplasty (PTCA) in 67 consecutive patients with unstable angina. Twenty patients had new onset (less than 2 months) angina, 33 patients had crescendo angina and 14 had early postinfarction angina. Fifty-one patients had one-vessel disease, 12 patients had two-vessel disease and two patients had three-vessel disease; two patients had a stenosis of a venous graft. In cases with multivessel disease, we performed only the dilatation of the ischaemia-related vessel identified by morphologic features of coronary lesion and electrocardiographic changes during chest pain. The procedure was successful in 54 cases (80.6%). Seven patients (10.4%) had major complications. Emergency coronary artery bypass graft surgery was performed in 6 cases (8.9%) because of occlusion of the left anterior descending artery; despite emergency operation one patient died and two patients sustained a myocardial infarction. One patient had occlusion of the right coronary artery and inferior myocardial infarction. In all patients in whom angioplasty was successful unstable angina disappeared. At 6 months follow-up there were no infarctions or deaths but 14 of 42 patients (33%) had recurrent angina. Restenosis occurred in 16 of 33 patients (48%) who had repeat coronary angiography. Four patients with recurrence of unstable angina had repeat angioplasty; it was successful in 3 cases. One patient died of refractory cardiac arrest. The mortality rate of 71 procedures performed in 67 patients was 2.8% (2/71) and the overall myocardial infarction rate was 4.2% (3/71).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Repair of congenitally malformed mitral valve in children.

We report our experience with 30 children under 15 years of age treated surgically for congenital mitral valve disease from March 1972 to July 1986. Valve reconstruction was possible in 26 patients (87%), whereas in four the valve was replaced with a mechanical prosthesis. Five patients died in the hospital (16.6%), four after conservative operations and one after mitral valve replacement. There was only one late death in a child in chronic congestive heart failure. Three patients, treated conservatively, required valve replacement 2, 22, and 24 months, respectively, after the operation. Follow-up data reveal that 22 of 24 patients are asymptomatic 5 months to 15 years after operation. Two-dimensional echocardiographic studies were performed in 19 patients treated conservatively, 17 of whom are asymptomatic. Eleven of them have no signs of mitral regurgitation or stenosis, six show only mild mitral incompetence, and two have moderate mitral regurgitation or stenosis. Peak pulmonary artery pressure is within normal limits in all. Our results indicate that mitral valve reconstructive procedures for congenital valve dysplasia may be effective and reliable in children despite the frequent severity of valve malformation. Although no major prosthesis-related complications were observed in the present series, we believe that mitral valve repair should always be attempted in the pediatric population to avoid the drawbacks of the currently available prostheses.

Adolescent↗
PubMed1988

Tricuspid atresia versus other complex lesions. Comparison of results with a modified Fontan procedure.

Several modifications of the Fontan principle are currently applied to the treatment of tricuspid atresia with low mortality. The use of these modifications in other malformations has most frequently been associated with less satisfactory results. At our institution, from June 1977 to October 1986, 35 consecutive patients, whose ages ranged from 8 months to 20 years (median age 3.4 years), underwent a modified Fontan procedure. Twenty patients with a median age of 3.2 years (group I) having tricuspid atresia (16 patients) or hypoplastic right heart syndrome (four patients) were treated by means of a right atrium-pulmonary artery anastomosis (12 patients) or right atrium-subpulmonary chamber connection (eight patients). Fifteen patients (group II) with a median age of 3.6 years, having a single left ventricle (10 patients), left atrioventricular valve hypoplasia or atresia (three patients), or double-outlet right ventricle (two patients), underwent right atrium-pulmonary artery anastomosis, together with a repositioning of the atrial septum to the right of the right atrioventricular valve, which thus left intact the inlet to the ventricle(s). The operative mortality rate was 25% in group I and 0% in group II. One patient in group I and one in group II died late postoperatively. All the 28 survivors are free of symptoms 3 months to 9 years after correction. According to our results, low risk can be associated with modified Fontan procedures in the treatment of complex heart malformations other than tricuspid or pulmonary atresia. Preserving the integrity of the entire inlet to the ventricle(s) by repositioning the interatrial septum, as done in group II malformations, might be helpful in improving the quality of the repair.

Adolescent↗
PubMed1988

[Origin of the right pulmonary branch from the ascending aorta].

The AA report a case of newborn admitted to the hospital at the age of 12 days because of severe congestive heart failure, with electrocardiographical and radiological findings of right ventricular overload and increased pulmonary blood flow. Cardiac catheterization showed the origin of the right pulmonary artery from the ascending aorta in the presence of an intact ventricular septum. Surgical repair was performed on an emergency basis by deconnecting the anomalous right pulmonary artery from the aorta and reattaching it to the main pulmonary artery. Postoperative angiographic study, performed 12 months later, revealed excellent anatomical and functional result.

Aorta↗
PubMed1988

[Incidence of aortic recoarctation in 161 patients after a mean follow-up of 8 years. The usefulness of pressure gradient measurement at rest and following exercise and of digital angiography].

The incidence of aortic recoarctation has been evaluated after a mean follow-up period of 8.2 years in 161 patients aged from 2 to 54 years at the time of the operation. To this aim, blood pressure levels in the upper and lower limbs were measured at rest and after bicycle ergometer exercise. Patients whose systolic pressure gradient was significant (either above 20 mmHg at rest or 35 mmHg after exercise) underwent aortic digital angiography. Aortic coarctation was diagnosed when the ratio of the aortic area at the site of the operation was less than 40% of that at diaphragmatic level (Frederiksen's index III). Thus the overall incidence of recoarctation was 10.1%. All patients with a significant gradient at rest also showed a significant gradient after exercise. This suggests that it is worthwhile performing digital angiography directly, without exercise testing, in these patients. However, 39.8% of the patients without significant rest gradients displayed a significant gradient after exercise. On the whole, only 21.4% of the patients with a significant gradient after exercise had signs of recoarctation on digital angiography.

Adolescent↗
PubMed1987

Pulmonary vascular disease in infants with complete atrioventricular septal defect.

In order to assess incidence and time of occurrence of pulmonary vascular disease, the lungs of 49 patients were studied histologically. Thirty-four lung specimens were obtained at autopsy, and 15 were open lung biopsies. Patients consisted of 24 males and 25 females ranging in age from 10 days to 14 years (median 9 months); 37 had Down's syndrome. Overall incidence of irreversible pulmonary vascular disease (grade 3 or more) under 1 year of age was 34.6%; grade 4 of pulmonary vascular disease was observed only in Down patients. In correlating pulmonary vascular resistance, measured during heart catheterization, with pulmonary vascular disease severity at histology, 6 out of 7 patients with pulmonary vascular resistance over 7 units per metre squared showed grade 4 of pulmonary vascular disease, and of these 4 were under 1 year of age. These findings suggest that a significant rate of pulmonary vascular disease occurs under 1 year of age, with most severe degrees in the time interval 7-12 months. They show that good correlation exists between pulmonary vascular resistance over 7 units per metre squared and grade 4 of pulmonary vascular disease. They demonstrate that the most severe pulmonary vascular disease is seen in Down's syndrome. Finally, they indicate that early surgical correction is mandatory and should be accomplished within 6 months of age.

Adolescent↗
PubMed1987

Post bending of the polypropylene flexible stent in mitral Hancock bioprostheses.

The occurrence of stent post deformity was investigated in 38 consecutive, polypropylene flexible-stented Hancock porcine bioprostheses (PB) recovered from the mitral position because of early postoperative death or late tissue failure. The degree of deformity was assessed for each explant by calculating the triangular area obtained by projecting the apex of the stent posts on a plane and comparing it with the same area calculated for unimplanted PBs of comparable size. A significant stent deformity (reduction of the triangular area greater than 40%) was observed only in 6 PBs explanted because of tissue failure after a mean function time of 69.6 +/- 28 months. In these PBs, scanning electron microscopy of the bare surface of the stent at the point of maximal flexion showed cracks 0.7-1 microns large, which represent the morphological substrate of the so-called "creep" of polypropylene. Inward stent post bending may occur after implantation in mitral PBs and when severe, it corresponds to a definite ultrastructural plastic deformity of polypropylene.

Animals↗
PubMed1987

Long-term durability of the Hancock porcine bioprosthesis following combined mitral and aortic valve replacement: an 11-year experience.

Long-term evaluation of patients undergoing combined mitral and aortic valve replacement (MVR + AVR) with a porcine bioprosthesis provides the opportunity for a direct comparison of the durability of the mitral versus the aortic porcine bioprosthesis in the same patient. From 1970 to 1983, 71 patients underwent MVR + AVR with Hancock porcine bioprostheses. There were 46 men an 25 women ranging in age from 21 to 64 years (mean, 47.5 +/- 5 years). Sixteen patients (22.5%) died at operation. The survivors were followed from 0.2 to 11.5 years (mean, 5.7 +/- 3 years). Duration of follow-up was 313 patient-years and was 100% complete. Overall late mortality was 6.7 +/- 1.4% per patient-year (linearized incidence), and actuarial survival was 54.2 +/- 8% at 11 years. Endocarditis occurred in 4 patients (linearized incidence of 1.3 +/- 0.6% per patient-year); thromboembolic events were sustained by 4 patients (linearized incidence of 1.3 +/- 0.6% per patient-year); the event was fatal in 1 patient. Actuarial freedom from thromboembolism was 90 +/- 4.8% at 11 years. Reoperation for primary tissue failure was performed in 11 patients (linearized incidence of 3.5 +/- 1% per patient-year) with no deaths; in 7 patients both bioprostheses were explanted, and in 4, only the mitral bioprosthesis was replaced. The durability of explanted aortic and mitral porcine bioprostheses was not significantly different, and the evaluation of seven pairs of explanted aortic and mitral bioprostheses showed similar amounts of calcification. Actuarial freedom from reoperation because of primary tissue failure was 44.6 +/- 13.7% at 11 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1987

Early mechanical failures of the Hancock pericardial xenograft.

From August 1981 to July 1984, a total of 97 Hancock pericardial xenografts were implanted in 84 patients, whose ages ranged from 13 to 75 years (mean 55.7 +/- 13). Mitral value replacement was performed in 17, aortic valve replacement in 54, and mitral-aortic valve replacement in 13. Operative survivors were reevaluated from July to September 1985. Cumulative duration of follow-up is 167 patient-years (range 0.5 to 4.1 years), and follow-up is 99% complete. The overall late mortality (at 4 years) is 3.6% +/- 1.4% per patient year, and the actuarial survival rate is 95.4% +/- 3% for aortic valve replacement, 74.7% +/- 16.5% for mitral valve replacement, and 67.1% +/- 20.7% for mitral-aortic valve replacement. One patient sustained a thromboembolic event after mitral valve replacement, but no such complications occurred after aortic or mitral-aortic valve replacement. Actuarial freedom from embolism at 4 years is 100% for aortic and mitral-aortic valve replacement and 93.3% +/- 6.4% for mitral valve replacement. Reoperation for Hancock pericardial xenograft dysfunction was performed in seven patients (five aortic and two mitral-aortic). In the aortic valve replacement group the causes were endocarditis in one, paravalvular leak in one, and primary tissue failure in three; all survived reoperation. The two patients with mitral-aortic valve replacement required reoperation because of primary tissue failure of both Hancock pericardial xenografts, and one died. All values explanted because of primary tissue failure showed commissural tears causing severe prosthetic regurgitation. Calcium deposits were severe in one and mild but unrelated to the cusp rupture in another. Collagen disarray was seen only at the site of the tears, whereas the collagen structure was well preserved in the intact parts of the cusps. Four patients with aortic valve replacement and one with mitral valve replacement show evidence of Hancock pericardial xenograft failure and are awaiting reoperation. The actuarial freedom from primary tissue failure at 4 years is 74.3% +/- 9.8% for aortic and 78.9% +/- 13.2% for mitral Hancock pericardial xenografts. At medium-term follow-up, the Hancock pericardial xenograft has shown poor durability and an extremely high rate of early mechanical failure, especially in the aortic position. These observations suggest the need for a close follow-up of Hancock pericardial xenograft recipients and possibly elective reoperation in asymptomatic patients with clinical evidence of prosthetic failure. These results have led us to discontinue the clinical use of this pericardial xenograft.

Adolescent↗
PubMed1987

Dissecting cuspal hematomas. A rare form of porcine bioprosthetic valve dysfunction.

Large dissecting cuspal hematomas (DCHs) were present in six (3%) of 193 porcine bioprostheses (PBs) explanted at reoperation. In four mitral PBs, the DCHs contributed to valve dysfunction; in one aortic PB, DCH was the only determinant of failure, causing stenosis by cusp thickening and rigidity. In another mitral PB, DCHs were occasionally found in the setting of valve incompetence due to commissural tears. While confirming that DCHs are a potential but infrequent cause of PB failure, these observations demonstrate that they may involve PBs implanted both in mitral and aortic position and might be a complication of anticoagulation.

Adult↗
PubMed1987

[Double outlet right ventricle. Angiographic study].

Cineangiographic study in 41 patients with double outlet right ventricle was performed. Segmental approach was utilized to describe the anatomical features. Atrial situs was inversus in 5 cases, ambiguous in 3 and solitus in the other cases. Atrio-ventricular (a-v) connections were biventricular in 34 and univentricular in 7. A common a-v valve was found in 2 cases. Mitral valve was imperforated in 1 and straddling in 1. The most frequent relationship between aorta and pulmonary artery was side by side (41.1%). Ventricular septal defect was subaortic in 14, subpulmonary in 9, double committed in 5 and non committed in 6. In 27 cases a double infundibulum was present; in 7 patients we described a subpulmonary conus only. Some nosological aspects of this congenital heart disease are discussed particularly in conformity with the surgical needs.

Adolescent↗
PubMed1986

Repair of ventricular septal defect and aortic regurgitation associated with severe hemophilia B.

A child with severe factor IX deficiency who underwent an open-heart operation using extracorporeal circulation is described. The factor IX level was normalized immediately before operation and at the end of cardiopulmonary bypass by infusing prothrombin complex concentrate and fresh frozen plasma. Partial thromboplastin time and factor IX serum levels were monitored for 20 days postoperatively and showed factor IX activity higher than 50%.

Acute Disease↗
PubMed1986

The use of intraluminal prosthesis in the surgical management of aortic dissection.

The treatment of acute aortic dissection requires expeditions and reproducible operations aimed at avoiding rupture of the dissection or its antegrade or retrograde progression. In 12 type A and 11 type B dissections the aorta was repaired using an intraluminal prosthesis to reduce the risk of hemorrhage and its related complications. Overall mortality rates were 33% in type A and 36% in type B patients, similar to that observed in patients operated with other techniques, but the incidence of intraoperative bleeding was possibly reduced and the cross-clamping time was significantly shorter. This method of repair is a sound alternative to conventional anastomotic suturing, particularly in clinically compromised patients and in the hands of surgeons on call, who may lack the experience of dealing with a particularly fragile aortic wall.

Aged↗