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Biomedical subjects

G Thiene

Publications and source records attributed to G Thiene.

At least 343 records · Page 19Linked to original sources
PubMed1980

Histological survey of the saphenous vein before its use as autologous aortocoronary bypass graft.

A histological examination has been carried out on the saphenous veins used in 150 consecutive patients undergoing aortocoronary bypass. Morphological changes were observed frequently and consisted mainly of fibrosis of the intima and of the medial longitudinal muscular layer. Intimal fibrosis was rarely severe enough to narrow the lumen significantly. Statistical analysis disclosed that the fibrosis of the intima and the medial longitudinal muscular layer do not increase with age. The use of frozen histological sections of the saphenous vein in patients undergoing aortocoronary bypass operations could be considered in order to discard unsuitable grafts and to direct the surgeon to alternative conduits.

Coronary Artery Bypass↗
PubMed1980

Left ventricular rupture following mitral valve replacement with a Hancock bioprosthesis.

A rare complication of mitral valve replacement with the Hancock bioprosthesis was observed in three patients presenting with prevalent mitral stenosis and normally-sized left ventricular cavity. In the patients, a deep erosion of the left ventricular free wall was present which evolved into cardiac rupture in one of them. The laceration is ascribed to the friction between a prosthetic strut and the myocardium; a disproportion between the "high-profile" device and the left ventricular chamber is suggested to explain this complication, which may be avoided by employing a "low-profile" prosthesis.

Bioprosthesis↗
PubMed1980

Tricuspid atresia with double-outlet left atrium.

Clinical and pathologic findings of an unusual case of cardiac malformation are presented. The main features were those of atresia of the right atrioventricular valve associated with two distinct atrioventricular orifices connecting the morphologically left atrium to the underlying morphologically left ventricle. Other distinguishing characteristics were ostium secundum atrial septal defect, normally related great arteries, with the aorta arising from the main ventricular chamber and the pulmonary artery from the anterior and right-sided outlet chamber, and infundibular and valvular pulmonary atresia.

Abnormalities, Multiple↗
PubMed1980

[The acromegalic heart disease (author's transl)].

The clinical and pathological findings of 3 patients with acromegalic heart disease are reported. In 2 of them no other causes of the cardiopathy could be recognized but a primitive involvement of the myocardium. The GH is responsible of cardiac hypertrophy without overload, which would shift towards progressive congestive heart failure. A possible depletion of intramyocardial cathecolamines is postulated in acromegalic heart disease as much as in cardiomegalies with pressure or volume overload.

Acromegaly↗
PubMed1980

[Structural changes of Hancock bioprostheses in children (author's transl)].

Conservative management is the treatment of choice for either congenital or acquired valvular disease in children. However, prosthetic valve replacement may sometimes be required and in this situation the surgeon is faced with the problem of which valvular substitute is the best for this particular patient. The glutaraldehyde-preserved Hancock porcine xenograft has been considered the safest one to use in the pediatric age group since the risks of thromboembolism as well as the mortality and morbidity related to anticoagulant treatment are reduced with this device. However durability of porcine bioprostheses at this time is still unknown, and it remains one of its major concerns. Recent reports have highlighted that porcine heterografts implanted in children undergo early and severe fibrocalcific degeneration. After having reviewed our pathological collection of explanted Hancock valves we have summarized our experience with pathology of porcine bioprostheses in young patients in the present report. Five Hancock heterografts were available for gross and histologic examination. They came from 3 children, 2 females and 1 male, who died or were reoperated upon because of prosthetic dysfunction. Both girls, aged 8 and 10 years, had undergone total correction of complete a-v canal which required mitral valve replacement in the first and mitrotricuspid valve replacement in the second. The first one was reoperated 2.10 years after surgery because of severe prosthetic stenosis and died in the 1st postoperative day of low output syndrome. The second, who developed the signs of mitral stenosis 3.4 years later, was successfully reoperated, but died in severe heart failure 2.9 years following mitral prosthetic re-replacement. The third patient, a 11-year-old boy, underwent mitral valve replacement because of mitral incompetence due to bacterial endocarditis; 5.4 years after surgery he necessitated reoperation because of mitral prosthetic stenosis. He is currently asymptomatic. Pathologic examination of the 5 explants (4 mitral, 1 tricuspid) which had been in place from 34 to 72 months (average 49 mos), showed a severe stenosis with impairment of the effective prosthetic orifice in all. The stenosis was due to coarse calcific deposits of the cusps and commissures and was worsened in 3 cases by fibrous tissue overgrowth on the inflow aspect of the leaflets. In 2 cases an atrial thrombosis was observed, as a consequence of prosthetic stenosis. Histologic examination together with microradiographic investigation showed in all cases the presence of diffuse calcifications of commissures and leaflets. Our pathological experience confirms that the Hancock bioprostheses, when implanted in children, undergoes structural changes early and severe enough so as to discourage their employment in this group of patients.

Bioprosthesis↗
PubMed1980

[Thromboembolism in dilative primary myocardiopathies].

A clinicopathologic correlation has been carried out in 26 autopsy cases of congestive cardiomyopathy, in order to establish the incidence and site of mural thrombosis and pulmonary and systemic embolism, and to evaluate the embolization in the natural history of the disease. Mural thombosis was observed in 15 on 26 cases (58%). 11 on 25 patients (42%) showed features of recent thromboembolism. In 2 of the latter, embolism occurred as a consequence of atrial fibrillation. Most of the embolic phenomena had not been recognized on the clinical ground. Thromboembolism represented the first symptom of the disease as well as a complication or the fatal event.

Adolescent↗
PubMed1980

Serum lipoproteins and atherosclerosis in hypertensive broad breasted white turkeys.

The serum lipid and lipoprotein profiles as well as the degree of atherosclerotic involvement in the aorta were studied in hypertensive strain of male broad-breasted white turkeys (BBWT). Serum phospholipid concentrations were found to be high while those of cholesterol and triglycerides were low. The alpha lipoprotein fraction, separated by agarose gel electrophoresis, represented the major lipoprotein fraction. Despite these facts, severe atherosclerosis was found in the abdominal aortas, suggesting the importance in this model of hypertension, functioning independently of the serum lipoprotein pattern. The cystic necrosis observed in the thoracic aorta represents a degenerative lesion possibly a result of the mechanicl stress of hypertension. Structural differences of the aorta at the two different levels, thoracic and abdominal, may explain the different pathological findings. Neither platelet aggregates nor fibrin deposition were seen in the arterial wall.

Animals↗
PubMed1979

Fibrous tissue overgrowth on Hancock mitral xenografts: a cause of late prosthetic stenosis.

Severe prosthetic stenosis requiring reoperation seldom occurs after mitral valve replacement with the Hancock bioprosthesis. Two cases of prosthetic stenosis caused by tissue overgrowth on the atrial aspect of the cusps are reported. The patients, who had undergone mitral replacement with a Hancock valve implanted in the subannular position, developed the signs of congestive heart failure 5 and 6 years after surgery. In both patients, the hemodynamic data supported the clinical diagnosis of mitral restenosis and both underwent successful reoperation. Histologic examination showed that the pannus was formed by dense fibrous tissue with few vessels. It is suggested that the site of the bioprosthesis insertion is likely to have favored this complication since in this condition the protection of the sewing ring from tissue overgrowth is minimal.

Adult↗
PubMed1979

Anatomy of aortic atresia. Cases presenting with a ventricular septal defect.

The anatomy of 58 specimens of aortic outflow tract atresia was studied. All cases had situs solitus and levocardia, 37 had atrioventricular (AV) concordance, two had common inlet to a right ventricle and 19 had mitral atresia. The great arteries were normally interrelated in all cases. Fifty-one cases had an intact ventricular septum, while seven presented with a ventricular septal defect (VSD). Of the seven with VSD, in two it was associated with a common AV orifice draining exclusively into the right ventricle in the presence of a rudimentary left ventricular chamber. In one case a small VSD accompanied combined mitral and aortic atresia. In the other four cases the left ventricles and mitral valves were fairly normal in size; the VSD was subpulmonary in three cases, due to infundibuloventricular malalignment, and perimembranous in one. These last four cases are of particular interest since they could be amenable to surgical correction. Possible approaches to surgical treatment and morphologic features pertinent to them are described and discussed.

Aortic Valve↗
PubMed1979

Histology of pulmonary arterial supply in pulmonary atresia with ventricular septal defect.

A histologic study was performed on 22 specimens of pulmonary atresia with ventricular septal defect to 1) ascertain the existence of the main pulmonary artery; 2) distinguish the ductus arteriosus from the systemic collateral arteries (SCA); 3) establish the nutritive or functional nature of collateral circulation; and 4) evaluate the morphology of the distal pulmonary bed. Three cases had absent main pulmonary artery, one with and two without signs of infundibular septation. We suggest that absent main pulmonary artery may exist with both infundibular pulmonary atresia and persistent truncus arteriosus. SCAs have been found to have similar histological features as systemic muscular arteries of the same size--their medial muscular layer merges gradually into an elastic one at different depth inside the lungs. Injection of contrast material allowed us to demonstrate that these vessels are functional, since they inosculate into efficient pulmonary arteries ending in the respiratory units. When the distal pulmonary vascular bed is perfused by large SCAs, proliferative lesions like those found in large left-to-right shunts may occur. Early in infancy, banding of large, nonstenotic SCAs could protect the distal pulmonary vasculature. Moreover, total surgical repair should be associated with ligation of the SCA to avoid residual left-to-right shunt, if the pulmonary arteries can carry the full pulmonary blood flow.

Aorta, Thoracic↗
PubMed1979

[Pathology of the aorto-coronary bypass by autologous saphenous vein (author's transl)].

The success of aorto-coronary bypass operations, employing an autologous saphenous vein, depends mainly upon graft patency. Fortyone grafts have been examined by light micrsocopy, 35 of which were obtained from 23 autopsy cases and 6 were recovered at reoperation. Thirtythree veins had been in place for less than 20 days (early group) and 8 from 3 to 39 months (late group). In the early group, minimal to moderate mediointimal fibrosis was always detected. Graft occlusion due to recent thrombosis was observed in 13 cases; the cause of thrombosis was severe coronary narrowing distal to the insertion of the graft and atherosclerotic plaque ulceration at the site of the veno-coronary anastomosis. Among the late group, 3 veins were occluded by an old thrombus, and 3 by intimal leiomyocellular proliferation, with Alcian positive ground substance, while 2 exhibited a severe stenosis due to intimal phlebosclerosis. One of these last disclosed a vein atherosclerosis. The multiple pathogenetic factors, which are involved in the proliferative lesions, are reviewed.

Coronary Artery Bypass↗