Comparative and developmental anatomy of cardiac lymphatics.

The role of the cardiac lymphatic system has been recently appreciated since lymphatic disturbances take part in various heart pathologies. This review presents the current knowledge about normal anatomy and structure of lymphatics and their prenatal development for a better understanding of the proper functioning of this system in relation to coronary circulation. Lymphatics of the heart consist of terminal capillaries of various diameters, capillary plexuses that drain continuously subendocardial, myocardial, and subepicardial areas, and draining (collecting) vessels that lead the lymph out of the heart. There are interspecies differences in the distribution of lymphatic capillaries, especially near the valves, as well as differences in the routes and number of draining vessels. In some species, subendocardial areas contain fewer lymphatic capillaries as compared to subepicardial parts of the heart. In all species there is at least one collector vessel draining lymph from the subepicardial plexuses and running along the anterior interventricular septum under the left auricle and further along the pulmonary trunk outside the heart and terminating in the right venous angle. The second collector assumes a different route in various species. In most mammalian species the collectors run along major branches of coronary arteries, have valves and a discontinuous layer of smooth muscle cells.

Cellular phenotypes and spatio-temporal patterns of lymphatic vessel development in embryonic mouse hearts.

BACKGROUND: The origin of cardiac lymphatics from venous endothelial cells or from scattered lymphangioblasts has been discussed in the literature. We aimed to establish the stage when lymphatic vessels appear in the developing mouse heart, the location of the first lymphatics, and to define cellular phenotypes of growing lymphatics. RESULTS: We found that scattered Lyve-1-positive cells located in the subepicardial area of developing heart expressed CD45, CD68, F4/80, or CD11b but not CD31. Prox-1(+)/Lyve-1(+) cellular cords or vessels were found to invade 12.5-13.5-dpc hearts via two routes: from the venous pole, i.e., dorsal atrioventricular sulcus, or on the dorsal atrial surface from mediastinum and from the arterial pole, i.e., along the great arteries. The Prox-1(+)/Lyve-1(+) vessels were located among the Prox-1(+)/Lyve-1(-) cords and among the scattered Prox-1(-)/Lyve-1(+) cells. The Prox-1(+)/Lyve-1(-) cellular cords/tubules dominate initially at the arterial pole whereas Lyve-1(+)/Prox-1(-) cellular cords/tubules dominate initially on the venous pole, i.e., dorsal atrioventricular sulcus. The Lyve-1(+)/CD45(+), Lyve-1(+)/CD11b(+), Lyve-1(+)/F4/80(+) and Lyve-1(+)/CD68(+) cells were subsequently found to be co-opted to the wall of the developing lymphatic vessels while gaining Flk-1. CONCLUSIONS: Lymphatic primordia exhibit different cellular phenotypes and different spatiotemporal pattern on the venous pole as compared with the arterial pole of the heart.

Cardiac angiosarcoma. Histological, immunohistochemical and ultrastructural study.

A case of cardiac angiosarcoma of the right atrium in a man aged of 41 years is described. The immunohistochemical methods showed a positivity for Factor VIII, Vimentin, Lectin UEA1 and very poor reactivity for a histiocytary markers. Electron microscopy confirmed the endothelial differentiation of some tumour cells. The relations between genuine cardiac angiosarcomas, malignant fibrous histiocytomas, and Kaposi's sarcomas arising in the heart are discussed.

Left ventricular fibroma: echocardiographic diagnosis and successful surgical excision in three cases.

The management of three patients with left ventricular fibromas is outlined. All were asymptomatic children. Routine chest radiography suggested cardiac masses. M-mode and two-dimensional echocardiography were valuable adjuncts to conventional angiography in assessing these children. Electrocardiographic changes, present in all cases, were shown to regress postoperatively. We stress the importance of these noninvasive aids in the initial investigation and outline our operative methods of reconstruction.

Right ventricular myxoma: diagnostic and surgical considerations.

A 26-year-old patient with right ventricular myxoma is reported. He underwent emergency removal of the tumour because of several syncopal episodes. Diagnosis was suspected clinically and confirmed by echocardiography and angiocardiography. The tumour arose from the anterior wall of the right ventricle and was resected with its pedicle. Five years after the operation, the patient is asymptomatic without clinical or echocardiographic evidence of recurrence. The authors underline the need for a close follow-up of patients with cardiac myxoma utilizing the non-invasive technique of echocardiography and emphasize the good early and late results obtained in their patient with surgical removal of the tumour.

Surgical correction of complete rupture of the anterior papillary muscle.

A 59-year-old patient with postinfarction complete rupture of the anterior papillary muscle and massive mitral regurgitation is described. The diagnosis was suspected clinically and confirmed by echocardiography and cardiac catheterization. Two months after the acute episode, the patient underwent a valve-conserving procedure by reattachment of the papillary muscle to the left ventricular wall. The patient is well and asymptomatic 3 years after operation with evidence of good anatomical and functional correction of the mitral valve lesion. This type of repair should be possible in selected patients with this lesion.

The spectrum of pulmonary arterio-venous fistulae. Clinico-pathological correlations.

Four male patients with pulmonary arterio-venous fistulae are reported. Familiar occurrence was noticed in 2 brothers. Physiological effects, clinical pictures and treatment of these lesions depend on the size and number of the fistulae. A 4-day-old baby presented with severe cyanosis and cardiomegaly. Cardiac catheterization and angiography demonstrated a large arterio-venous fistula affecting the whole of the right upper lobe and a small ventricular septal defect resulting in a high output cardiac failure. The patient underwent emergency lobectomy with good early and long-term results. The other 3 patients (mean age of 7.6 years) developed progressive cyanosis and polycythemia. Cardiac catheterization showed normal intracardiac pressures and peripheral arterial desaturation. Pulmonary angiogram demonstrated multiple fistulae in both lungs. Surgery was not performed because of the diffuse nature of the lesions. The patients reported in this paper illustrate the wide spectrum of clinico-pathological conditions of this anomaly.

Anomalous origin of the right coronary artery with aortopulmonary window: functional and surgical considerations.

A rare case of anomalous origin of the right coronary artery from the pulmonary artery associated with a large aortopulmonary window in a 4-month-old boy is reported. The right coronary artery is exposed to systemic pressure and carries fairly well-oxygenated blood to the myocardium. Angiographic diagnosis could be difficult because of the simultaneous filling of both great arteries which obscures the origin of the anomalous vessel. Closure of the aortopulmonary window alone could result in acute myocardial ischaemia. A plastic procedure for correction of this association of defects, which should allow normal growth, is described.

Hydatid cyst of the heart. Clinical and surgical implications.

Hydatid cyst of the heart is an uncommon lesion which usually develops in the left ventricle. Diagnosis should be considered in patients coming from an area where hydatid cyst is endemic and who present with an abnormal heart shadow on chest X-ray, frequently associated with T wave changes on the electrocardiogram. The cyst tends to grow and thus compress the neighboring myocardium. It causes displacement of the coronary vessels, rhythm disturbances and mechanical interference with the AV valves and ventricular function. Spontaneous involution of the cyst with calcification of its wall as well as rupture with anaphylactic shock may occur. Early excision with standby cardiopulmonary bypass is advisable. Three patients with hydatid cyst of the left ventricle, 2 of whom were operated on by using cardiopulmonary bypass, are presented. Results of the surgical treatment, both early and late, are rewarding, with relief of symptoms, regression of electrocardiographic abnormalities and very low incidence of recurrence.

Ten years' experience with pulmonary autograft replacements for aortic valve disease.

Pulmonary autograft valves have been used to replace isolated, diseased aortic valves for 10 years, with a long-term survival of 73%. The low incidence of degeneration supports the principle that the autograft valve is a potentially permanent valve replacement. Operative mortality is now less than 5%, despite the longer, more complex operation. The current use of fresh homograft valves for the pulmonary replacement has contributed to these excellent long-term results.

Anomalous origin of the right pulmonary artery from the ascending aorta associated with aortopulmonary window.

A rare case of anomalous origin of the right pulmonary artery from the ascending aorta associated with an aortopulmonary window and severe pulmonary hypertension in a 13-year-old girl is reported. The window was closed using a Dacron patch and the continuity between the anomalous vessel and the main pulmonary artery was restored with a tubular Dacron graft. After operation the pulmonary pressure dropped to about one-half of the systemic pressure, and equal perfusion and ventilation of both lungs was demonstrated. Although early recognition and surgical treatment of this condition are mandatory to prevent the onset of irreversible pulmonary vascular disease, the presence of severe pulmonary hypertension did not contraindicate surgical correction in our patient.

The surgical pathology of thoracic aortic aneurysms.

In 63 resected thoracic aortic aneurysms, the commonest histological finding (45 cases, 71.4%) was cystic medionecrosis. These cases formed two groups, 29 with widespread fragmentation and loss of elastic tissue (elastopathy) and 16 cases without elastopathy who were older and included most of the 18 cases of dissecting aneurysms. Thirteen patients had the Marfan syndrome, 10 showing cystic medionecrosis with elastopathy, indistinguishable from the cases with no Marfan stigmata although partial 'dissections' were mainly found in the Marfan patients, Histological appearances ranged from normal to complete loss of media. Cystic changes in muscle fibres apparently preceded elastic fragmentation. Fourteen cases (22%) had aortitis: 4 were syphilitic and 3 of other known aetiology. In 7 patients the aetiology of the inflammatory process was unknown and appearances included granulomatous infarct-like lesions and necrotizing aortitis or changes indistinguishable histologically from syphilis.

Syndrome of congenital ventricular diverticulum and midline thoraco-abdominal defects.

The long-term follow-up of a 30-year-old patient who had a correction of the syndrome of left ventricular diverticulum and thoraco-abdominal defects is presented. The main features of the syndrome include a diverticulum of the left ventricle, a ventricular septal defect, and sometimes other cardiac anomalies. The thoraco-abdominal defects consist of foreshortened sternum, pericardial and diaphragmatic defects, and umbilical hernia. The association of these anomalies is thought to be due to a developmental failure of the primitive paramidline mesoderm. The diagnosis can be made clinically by the presence of a pulsatile, epigastric mass associated with signs of cardiac septal defects and dextrocardia. The prognosis of patients with this syndrome depends mainly on the associated abnormalities although rupture of the diverticulum can be a fatal complication. The treatment of choice is resection of the diverticulum combined with repair of associated anomalies which can give good early and late results.

Homograft replacement of aortic valve and ascending aorta in a patient with non-specific giant cell aortitis.

A case of giant cell aortitis causing ascending aortic aneurysm associated with aortic regurgitation is reported. The aneurysm was excised and the aortic valve replaced using a fresh homograft. The patient has been followed up for three and a half years. There is good evidence of correction of the haemodynamic lesion and no evidence of further arteritis or aneurysmal formation. The pathological and clinical problem of this disease are discussed.

Resection of a leiomyoma of the descending thoracic aorta.

A primary aortic neoplasm in a 4-year-old asymptomatic boy is described. At operation the tumour was found to originate from the descending thoracici aorta. Histologically it proved to be a leiomyoma. The operative findings and pathological features are briefly discussed.