Biomedical subjects
Publications and source records attributed to C Frescura.
This case report deals with the clinicopathologic correlations in a 50-year-old man with tetralogy of Fallot, in whom the classical pulmonary stenosis by deviated infundibular septum was intensified by an anomalous muscle bundle located in the sub-pulmonary infundibulum.
The possible determinants of a fatal outcome following surgical repair of the tetralogy of Fallot were analyzed by postmortem examination in 14 cases. Only one patient died late in the postoperative period, due to patch detachment; the others died shortly after undergoing surgery. Death could not be explained in three cases. In three patients with perimembranous ventricular septal defects, complete atrioventricular block occurred as a consequence of traumatic disruption of the branching bundle. In four cases residual stenosis of the pulmonary outflow tract was shown; in one of these cases adequate relief of obstruction had been prevented by a large conal coronary artery. A residual mitral cleft was found in one patient. Death was not related to the cardiac conditions in two cases; one of these patients died of brain apoplexy and the other of tracheal hemorrhage. These findings stress the need for accurate preoperative diagnosis and precise knowledge of the surgical anatomy of this malformation.
Between 1 January 1975 and 31 December 1982, 111 patients with atrioventricular septal defect underwent surgical repair. Of these, 43 had the complete, 11 the intermediate, and 57 the partial form. The postoperative mortality rate was 37%, 9%, and 6% respectively. To determine which factors were independently responsible for the operative risk multivariate analysis of the surgical mortality was applied simultaneously to all three forms of the malformation. The form of defect, although strongly influencing the natural history and clinical presentation, was not by itself an operative risk factor. The risk was related primarily to failure to obtain a well functioning atrioventricular valve, to the presence of left ventricular dominance, to the degree of pulmonary vascular resistance, and, finally, to the technique of reconstructing a two leaflet left atrioventricular valve. The small size of the patient was also a significant incremental risk factor, but if the other factors were not unfavorable good results could be achieved in small infants with mortality rates less than 10%. Multivariate analysis showed that severe postoperative left atrioventricular valve malfunction was related to the technique used to reconstruct a "normal" two leaflet left atrioventricular valve. These findings support the policy of reconstructing the left atrioventricular valve as a three leaflet valve. Nevertheless, the implicit beneficial effect of this technique has not as yet proved to be statistically significant.
The association of complex congenital heart disease with asplenia syndrome and congenital AV block is described in a newborn. Cardiovascular lesions were right atrial isomerism, d-loop, discordant ventriculoarterial connection, pulmonary stenosis, total anomalous pulmonary venous drainage, absent right pulmonary artery, and bilateral superior vena cava. The ECG recording disclosed complete AV block with narrow QRS (suprahisian block). The histology of the conduction system revealed two AV nodes, one anterior and one posterior, none of which connected with the atrial myocardium; only the posterior node was continuous with a penetrating and bifurcating bundle. The histologic findings were consistent with the suprahisian AV block due to lack of connection between the atria and the regular posterior AV specialized junction.
Among 61 heart specimens of tetralogy of Fallot with or without pulmonary atresia, four presented with an accessory tricuspid valve leaflet. This structure caused partial or almost complete obstruction of the ventricular septal defect. Depending on the morphology, the accessory tissue was classified into "mobile" or "fixed" types. The "mobile" variety was tethered by long chordae tendineae which permitted a wide excursion of the leaflet through the ventricular septal defect into the left ventricular outflow tract where it represented a potential cause of obstruction. The "fixed" variety was attached to the edges of the defect by short chordae which reduced considerably its movements. This type created a fixed obstruction of the ventricular septal defect without involving the subaortic left ventricular outflow tract. The precise morphology of the accessory tricuspid valve tissue is of considerable surgical significance. When mobile, the tissue must be resected at the time of surgical repair. When fixed it can be used as a suture anchorage during closure of the ventricular septal defect.
The postoperative pathology observed in 17 patients with complete atrioventricular canal, who died following total correction is described. In 3 patients, in whom valve replacement was necessary, the death was due to late prosthetic dysfunction. Out of 14 patients who underwent plastic repair, 4 died from undetected residual cardiac anomalies, which in 2 cases were associated with pulmonary obstructive vascular disease, 3 from unexplained myocardial infarction, 3 from inadequate postoperative care and 4 from pulmonary obstructive vascular disease which presented as an isolated finding. An analysis of the incidence of pulmonary obstructive vascular disease in these patients disclosed that it can develop before one year of age in some patients with Down syndrome.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Sixty-two hearts without a patent exit from the left atrium to the ventricular mass have been studied. All had situs solitus and laevocardia. The material consisted of 32 cases with coexistent aortic atresia and 30 cases with patent aortic root. Five hearts with aortic atresia were biventricular with atrioventricular concordance and imperforate left atrioventricular valves, and 27 hearts were univentricular of right ventricular type, with absent left atrioventricular connection. The anatomy of this group was uniform, with extreme hypoplasia of all the left cardiac segments. Among the cases with patent aortic root, five were biventricular, with atrioventricular concordance and imperforate left atrioventricular valves, and 24 had absent left atrioventricular connection, 15 with univentricular heart of right ventricular type and nine with univentricular heart of left ventricular type. The final heart had double inlet univentricular of left ventricular type with an imperforate left atrioventricular valve. In this second group the aorta was larger in cases with discordant ventriculoarterial connection or in those with double outlet from the main ventricular chamber. A normal sized aorta without aortic arch obstruction was observed in nine instances. These are of great interest in terms of surgical anatomy since definitive palliation may be feasible.
Explore the source record for details and available documents.
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.
Conotruncal anomalies associated with atrioventricular (AV) canal defects are more common than is generally appreciated on clinical grounds. Among 39 specimens of AV canal malformations, 13 (33%) presented with conotruncal abnormalities: a complete form of AV canal has been observed in all. 5 cases exhibited visceral situs solitus, 5 situs ambiguus with asplenia and 3 situs ambiguus with polysplenia. In the first group, conotruncal anomalies were tetralogy of Fallot in 3 cases, bilateral conus with double outlet right ventricle (DORV) in 2, one with subpulmonary ventricular septal defect (VSD) and the other with doubly commited VSD. Survival in these patients was relatively longer (average 20 mth) and the clinical course was mainly determined by the degree of the pulmonary outflow obstruction: surgical correction should have been feasible in these cases. Patients with situs ambiguus, both with asplenia and polysplenia, had further severe cardiovascular malformations associated with AV canal which led to early death (average survival 12 days): anomalous pulmonary and systemic venous return and univentricular hearts. In the latter patients, tetralogy of Fallot, bilateral conus with DORV and pulmonary atresia were the conotruncal malformation. Retrospectively, in no case of the last category a complete repair had been accomplished. All but one specimen presented the complete form of AV canal with 'free floating anterior leaflet' and hypoplastic anterior tricuspid component. This hypoplasia could be interpreted as missing conal tissue in the development of the anterior tricuspid cusp. For this leaflet a dual embryological origin, both from the dextro-dorsal conal ridge and the right lateral AV cushion, is suggested.
A postmortem investigation has been carried out in 48 heart specimens with transposition of the great arteries (TGA) to evaluate incidence and type of left ventricular outflow tract obstruction. The frequence of pulmonary stenosis in our series (23%) is similar to those reported from previous studies. Cases have been divided in two groups according to presence or absence of ventricular septal defect. In cases with intact ventricular septum the obstruction was determined by asymmetric hypertrophy of the septum (1 observation) and by abnormal attachement of clefted anterior mitral leaflet to the interventricular septum (2 observations). In the specimens with ventricular septal defect, 4 presented a stenosis due to malalignment of the infundibular septum, associated with valvular stenosis in 1 case and with valvular stenosis and fibrous subvalvular ring in 2. Another case presented a stenotic pulmonary valve and a parachute mitral valve. The remaining 3 showed a cleft of the anterior leaflet of the mitral valve. The high incidence of infundibular malalignment obstruction is underlined together with its association with A-P or L-position of the aorta. This peculiar relation of the great arteries could be angiocardiographically employed as indicative for the presence of this type of left outflow tract obstruction in TGA.
Explore the source record for details and available documents.
Postmortem angiographic and histologic studies of the pulmonary arterial circulation were performed in a patient with pulmonary atresia and a ventricular septal defect. While the left lung was supplied by a closing ductus arteriosus, the right lung was supplied by two systemic pulmonary arteries arising from the descending aorta. The examination disclosed that systemic pulmonary arteries lead into the pulmonary vascular bed and the capillaries of the alveolar walls. According to these observations, such collateral circulation is to be considered functional. The pulmonary vascular bed, supplied by the ductus arteriosus and the stenotic systemic pulmonary artery, showed a thin muscular layer in the small arteries and arterioles. On the contrary, medial hypertrophy and severe intimal proliferation were observed in the pulmonary segments perfused by the other large unobstructed systemic pulmonary artery, thus proving that asymmetric pulmonary vascular disease may complicate the natural history of this malformation.
Anatomical features are illustrated for the identification of the cardiac chambers. Essential and accessory morphological structures are recognized. The identification of the atrial cavities is based upon the anatomy of the free walls (crista terminalis, size and shape of the atrial appendages). On the contrary, the identification of the ventricles is founded on the septal morphology (trabecula septo-marginalis on the morphological right side, smooth basal septum on the morphological left side, presence or absence of septal insertions of the atrio-ventricular value apparatus). Finally, no essential feature can be applied to the identification of the great arteries.
The approach to the diagnosis of congenital heart disease, based upon the identification of the cardiac chambers, the reconstruction of their sequence and final recognition of the basic circulatory model is discussed. Three cardiac segments are recognizable embriologically, anatomically and functionally: atria, ventricles and great arteries. Connexion is the sequential link of these segments, independently from their spatial relationship. Situs of the atria can be: solitus, inversus or ambiguus, and is determined by the thoracic situs which can be assumed from the bronchial anatomy. Atrio-ventricular connexion can be concordant, absent or double inlet ventricle. Ventricular-arterial connexion can be concordant, discordant, double outlet ventricle or single outlet heart. Since this approach aims to the reconstruction of the connexion among the cardiac segments, heart position and the infundibular anatomy are not relevant to the recognition of the circulatory model.