Anatomic variations in underdeveloped right ventricle related to tricuspid atresia and stenosis

Tricuspid atresia and common arterial trunk: a rare form of CHD

Tricuspid atresia with common arterial trunk is a very rare association in complex CHD. This association has even more infrequently been documented concomitantly with interrupted aortic arch. We present the diagnosis and initial surgical management of an infant with a fetal diagnosis of tricuspid atresia and common arterial trunk, with additional postnatal finding of interrupted aortic arch with interruption between the left common carotid and left subclavian artery. Due to the infant's small size, she was initially palliated with bilateral pulmonary artery bands and a ductal stent. This was followed by septation of the common arterial trunk and interrupted aortic arch repair and 4 mm right subclavian artery to main pulmonary artery shunt placement at two months of age. She was discharged home on day of life 81.

Factors associated with development of atrial septal restriction in patients with tricuspid atresia involving the right-sided atrioventricular valve

BACKGROUND

Clinical practice is discrepant regarding routine enlargement of the interatrial communication (IAC) in patients with right-sided atrioventricular valve atresia. We determined the percentage and risk factors of those who develop a restrictive IAC.

METHODS

Medical records were reviewed for patients treated from 1985 to 2006, including those admitted in the first 6 weeks of life (group A), and those referred at a later age (group B), some of whom had routine atrial septal procedures. In group A, we analyzed the initial postnatal echocardiogram.

RESULTS

Group A consisted of 79 patients, 16 of whom had an atrial septectomy as part of the initial surgical procedure. Of the remaining 63 patients, 9 (14%) developed atrial septal restriction. In group A, an atrial septal aneurysm (ASA) (OR 16, P = .006) and IAC diameter < 5 mm (OR 13, P = .009) were associated with atrial septal restriction. Atrial septal restriction occurred in 80% of patients with both features, 20% with IAC > or = 5 mm and ASA, 18% with IAC < 5 mm and no ASA, and 2% with neither feature. Group B consisted of 95 patients, 27 of whom had an atrial septal procedure. Of the remaining 68 patients, 11 (16%) developed atrial septal restriction.

CONCLUSION

Routine enlargement of the IAC is not necessary in patients with right-sided atrioventricular valve atresia. Patients with ASA or IAC < 5 mm are at increased risk for development of atrial septal restriction.

Cor triatriatum dexter: transesophageal echocardiographic diagnosis and 3-dimensional reconstruction

Cor triatriatum dexter is an unusual cardiac abnormality with division between the sinus and primitive atrial portions of the right atrium. Three-dimensional echocardiography is a novel technique that defines this entity.

Prominent venous valves in hypoplastic right hearts

To investigate the hypothesis that embryologic abnormalities in the venous valves may be associated with abnormal cardiac development, we examined the right atrial morphologic characteristics in 20 hearts with underdevelopment of the right heart and 17 normal hearts. In the study group, 16 (80%) of the patients had significantly enlarged eustachian valves, one (5%) was slightly enlarged, and three (15%) were smaller than expected. Five (25%) had cor triatriatum dexter. In comparison, eustachian valves in the control specimens were prominent in only one (6%), normal in five (29%), and almost absent in eight (47%). The thebesian valve was also more prominent in the study cohort when compared with controls (p < 0.05). No other morphologic features of the right atrium analyzed in this study differed from those found in normal specimens. We speculate that failure of the venous valves to regress appropriately may create abnormalities in fetal circulation that predispose the fetus to maldevelopment of the right heart structures.

Early hypercyanotic spells unrelated to ductal constriction in tricuspid atresia with infundibular stenosis

Clinical, echocardiographic, hemodynamic, and angiographic findings were reviewed in 16 consecutive patients with tricuspid atresia (TA) and normally related great arteries, seen at the University of Florida between 1984 and 1990, to determine when and in which hypercyanotic spells (HS), unrelated to ductal constriction, occurred. Such spells developed in six patients (38%) and were life-threatening and refractory to medical management in three patients. Most HS (five of six) occurred in the first 2 months of life. Angiography done at the time of diagnosis revealed similar morphological features in all patients subsequently experiencing HS; infundibular stenosis due to anterior malalignment in the conal septum. These findings suggest a predisposition for development of early HS in TA patients with apparent infundibular stenosis due to anterior malalignment of the conal septum. Further study and a heightened clinical awareness are needed in such patients.

Corrective surgery for tricuspid atresia: which modification of Fontan-Kreutzer procedure should be used? A review

Various modifications of Fontan-Kreutzer procedure have evolved over the years. The available literature was reviewed in an attempt to evaluate whether one of these operations is preferable to others. Although there is no complete agreement, direct atriopulmonary anastomosis in the absence of a subpulmonary ventricular chamber, and atrioventricular connection via a homograft conduit in patients with a good-sized (greater than 30% of normal), well-formed (with both trabecular and outlet portions) right ventricle appear to be reasonable choices. In patients with more than the usual risk or at low risk for the Fontan-Kreutzer procedure, other alternatives (namely, total cavopulmonary connection for patients with asplenia/polysplenia syndrome and systemic venous anomalies and bidirectional cavopulmonary anastomosis or Fontan-Kreutzer with a small temporary atrial septal defect) could be considered. The role of experimental skeletal muscle augmentation or replacement of right heart chambers and cardiac transplantation in the corrective treatment of tricuspid atresia needs to be defined as more data become available.

Anomalous systemic venous to left atrial connection in tricuspid atresia with severely restrictive interatrial communication

An adequate interatrial communication is necessary to accommodate right atrial output in patients with tricuspid atresia. We report a patient with a tiny opening in the midportion of the atrial septum, who was found to have an anomalous systemic venous to left atrial communication. This channel was not evident on noninvasive testing, but would likely have caused persistent desaturation following a Fontan procedure had it not been detected. In patients with restrictive interatrial communications, an angiogram of the right atrium may reveal similar anomalous channels.

Tricuspid atresia: association with persistent truncus arteriosus

Clinical, echo-Doppler, and pathologic data of a rare case of tricuspid atresia in association with truncus arteriosus are presented. There are only six patients (including the patient reported here) with this anomaly in whom detailed pathologic and/or clinical descriptions are available in the literature. An additional six cases were mentioned in the literature but without any details. A prevalence rate of 1.4% among tricuspid atresia cases is estimated. All infants presented with symptoms of cyanosis and/or congestive heart failure within a few days to 2 months after birth and died shortly thereafter. Cardiomegaly and increased pulmonary vascular markings on the chest x-ray film and left axis deviation with left ventricular hypertrophy on the ECG are usually present. Echocardiographic, catheterization, and angiocardiographic studies are helpful in documenting anatomic and physiologic features of this anomaly. Pathologically, the muscular type of tricuspid atresia, type I or II truncus arteriosus, a large subtruncal VSD, and a hypoplastic right ventricle are present. It is concluded that coexistence of tricuspid atresia and truncus arteriosus is rare; clinical, laboratory, and pathologic features are distinctive; the clinical presentation early in life with rapid demise is common; and prompt palliative surgery immediately after recognition of this anomaly should be undertaken.

Tricuspid atresia with common arterial trunk: surgical palliation in a neonate

A two-week-old asymptomatic baby was diagnosed by cross-sectional and Doppler ultrasound to have tricuspid atresia with a common arterial trunk. Successful surgical palliation was undertaken at 17 days of age, by disconnection of the pulmonary arteries from the trunk, and creation of an aortopulmonary shunt. There are no known previous reports of surgical palliation of this lesion.

Tricuspid atresia or severe stenosis with partial common atrioventricular canal: anatomic data, clinical profile and surgical considerations

The anatomic findings in 11 cases of tricuspid atresia and in two cases of severe tricuspid stenosis, both combined with partial common atrioventricular (AV) canal, are presented in detail. Twelve cases were documented by postmortem examination and the diagnosis was confirmed by echocardiography and surgical observation in the one living patient. Clinical data available in nine cases and cardiac catheterization data obtained in eight are included in this report. In three cases (23%)--two with tricuspid atresia and one with extreme tricuspid stenosis--the tricuspid valve and right ventricle exhibited characteristics seen in Ebstein's anomaly. In all 13 cases, the great arteries were normally related. The ventricular septal defect(s) in 10 (83%) of the 12 postmortem cases rapidly became smaller and this resulted in marked diminution of the pulmonary blood flow and severe hypoxia. Only three of the eight patients with available cardiac catheterization and angiocardiographic data showed the scooped-out appearance of the left ventricular septal surface characteristic of AV canal defects. By contrast, two-dimensional echocardiography, available in the three most recent cases, accurately demonstrated all the defects present and represents the diagnostic method of choice. Early surgical intervention to establish a systemic to pulmonary artery anastomosis is essential for survival. More definitive surgical treatment can be achieved later by an atriopulmonary or cavopulmonary anastomosis with or without replacement of the cleft and often regurgitant mitral valve. The one living patient exemplifies this approach. This is the largest series of this unusual type of tricuspid atresia reported to date.

Angiocardiographic evaluation of right ventricular size and morphology in tricuspid atresia

The potential for right ventricular growth and physiological repair in tricuspid atresia may influence the type of Fontan procedure. To evaluate preoperative right ventricular assessment, we compared the right ventricular size and morphology determined by selective right ventricular catheterization with axial left ventricular angiography. In seven consecutive patients with tricuspid atresia and ventriculo-arterial concordance, the right ventricular volume was 12.8 +/- 9.4 cc, with a predicted normal volume (based on body surface area) of 31 +/- 16 cc, 43% (range 24-78%) of normal. Right ventricular injection outlined a right ventricular area twice that visualized from an axial left ventricular injection (33.2 vs. 16.5 cm). All patients had a well developed but small trabecular portion of the right ventricle, often unopacified with left ventricular injection. Subinfundibular narrowing adjacent to the ventricular septal defect was invariably present, creating, in effect, a two-chambered right ventricle. Selective right ventriculography demonstrates the unique morphology of the right ventricle in patients with tricuspid atresia not visualized by axial left ventriculography.

Atrioventricular canal mimicking tricuspid atresia: echocardiographic and angiographic features

In a rare case of common atrioventricular canal mimicking tricuspid atresia the clinical, radiographic, electrocardiographic, and M mode echocardiographic features were indistinguishable from those of classic tricuspid atresia. The cross sectional echocardiographic appearance and right atrial cineangiographic features were distinctive, however, and can be used to discriminate between this anomaly and other types of tricuspid atresia.

Tricuspid atresia: analysis of coronary artery distribution and ventricular morphology

There is still disagreement concerning the precise nature of the anterior ventricular chamber in "tricuspid atresia". Some argue that it is a right ventricle, while our own previous studies have suggested it is comparable to the outlet chamber seen in classical "single ventricle". We have compared the morphology of the anterior ventricular chambers in 48 examples of tricuspid atresia (absent right atrioventricular connection), 24 hearts with double inlet to the left ventricular chamber, and 15 hearts with pulmonary atresia and intact ventricular septum. Since there is further disagreement concerning the nature of the coronary artery which delimits the posterior extent of the ventricular septum in these hearts, we analysed the position of this vessel relative to external reference points on the atrioventricular junction. No significant difference was found with respect to the morphometry of hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet. In both groups, however, significant differences were shown between hearts with ventriculoarterial concordance and discordance. Coronary artery disposition was the same in both groups and different from that found in hearts with pulmonary atresia and intact septum. We conclude that the ventricular morphology is comparable in hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet to a left ventricular chamber. The lesions are distinguishable by their atrioventricular connection which is nevertheless univentricular in both.

Tricuspid atresia in adults

Congenital atresia of the tricuspid valve is still uncommon in adult patients. However, increasingly successful palliative surgery in children now has increased its incidence after age 15 years. This investigation updates the clinical features of this disease in adults in light of modern diagnostic and surgical techniques. The data on all 18 adults with tricuspid atresia having angiography after age 15 years at this institution since 1970 were reviewed. The patients' ages ranged up to 45 years; 12 had had previous palliative surgery. Left cineventriculography, particularly biplane, with the long axial view (60 degrees left anterior oblique with cranial angulation) is the most important diagnostic mode and reveals the ventricular and great vessel relations. According to standard classification, 11 patients had type I anatomy (normal great arterial relations), 4 type II (transposed great arteries) and 2 type III ("corrected transposition of the great arteries"). One patient with inverted ventricles could not be classified. Associated additional congenital defects were uncommon. On the basis of these data, a new anatomic classification of tricuspid atresia is given which encompasses all possible atrial-ventricular-great arterial combinations. Seven patients had further surgery after study, including two procedures of the Fontan type (right atrium to pulmonary arterial conduit). Follow-up data on all 18 patients revealed two deaths (one early after operation, one late after study without further surgery). The remaining 16 patients survive 2 to 120 months after study. Four patients had naturally balanced pulmonary and systemic circulations and have survived to ages 21 to 41 years without surgery. Prudent surgical decision based on accurate anatomic diagnosis and the need for optimal effective pulmonary blood flow may result in a relatively optimistic prognosis in adults with this disease.

Atresia of left atrioventricular orifice. Anatomical investigation in 62 cases

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.

Angiographic study of univentricular heart of right ventricular type

An angiographic analysis of 10 cases of univentricular heart of the right ventricular type is reported. This congenital malformation is characterized by a large chamber with right ventricular morphology that receives both atrioventricular valves, and a second, smaller chamber, a trabecular pouch, with left ventricular morphology. These chambers are separated by a posterior septum but are connected by an inlet septal defect. The angiographic studies were done using the angled angiographic techniques in three patients and the standard frontal and lateral angiographic views in seven cases. The atrial situs in seven patients was solitus, in one inversus, and in two it was ambiguus with left isomerism. In seven patients the usually large right ventricular chamber received two atrioventricular valves and in four patients, one atrioventricular valve was straddling. Three patients had atresia of one atrioventricular valve. The trabecular pouch was small in seven patients but relatively large in three. In six patients the trabecular pouch was located posterior and to the left of the right ventricular chamber and in four anterior and to the right. Double outlet right ventricle was present in all cases. The aorta arose anteriorly to the pulmonary artery in nine patients and posteriorly in one. An autopsy was performed in one case and its correlation with the angiographic findings was remarkable. The angiographic demonstration of the anatomicaly details of this entity and its associated anomalies was facilitated by angled angiography.

Atresia of the right atrioventricular orifice with atrioventricular concordance

Three hearts are described in which a fibrous membrane was interposed between the right atrium and a formed but hypoplastic right ventricle, which possessed recognisable inlet, trabecular, and infundibular components. In these hearts the distribution of the conducting tissue was as expected for concordant atrioventricular connections, and contrasts with that seen in the classical type of 'tricuspid atresia'. The distinctive morphological and histological features of these specimens lend further support to our view that the majority of cases of atresia of the right atrioventricular orifice should be regarded as coming within the designation of 'the univentricular heart'.

Anatomy of coronary arteries in univentricular hearts and its surgical implications

The coronary arterial anatomy in 26 univentricular hearts, its relation to the morphologic characteristics of the ventricles and rudimentary chambers, and its surgical implications were analyzed. All of the hearts except two had been operated on; 18 had septation with or without an extracardiac conduit and 6 had had palliative procedures. Twenty-one univentricular hearts with a left ventricular type main chamber had an anterior outlet chamber (17 left-sided subaortic, 3 right-sided subaortic and 1 right-sided subpulmonary). Right and left delimiting arteries outlined the outlet chamber in 16 hearts (76 percent). In 20 of the 21 hearts, large delimiting parallel branches of the right coronary artery course over the anterior wall of the heart; 13 of these vessels had been injured surgically with resultant ischemic myocardial necrosis. Five univentricular hearts did not have an outlet chamber; two had a left ventricular type main chamber and three had a morphologically right ventricular main chamber. Three of the five hearts had rudimentary pouches, located anteriorly in one and posteriorly in two. The two rudimentary pouches lying posteriorly were not outlined by delimiting arteries. Two of the five univentricular hearts without an outlet chamber also had injured coronary arteries. Thus, the identification of outlet chambers and rudimentary pouches in univentricular hearts is facilitated by the determination of coronary anatomy. The presence of major delimiting parallel branches over the usually favored ventriculotomy sites renders them vulnerable to surgical injury; such mishaps occurred in 15 of the 24 hearts that had either corrective or palliative operations.

Morphological and topographical variations of the outlet chamber in complex congenital heart disease: an angiocardiographic study

The outlet chamber of the human heart can show considerable variations in its morphology and topography (relationship to main ventricular chamber), and such variations in anatomy and spacial relationship may be predictive of the associated intracardiac anatomy. Although there is considerable debate about whether the position of the outlet chamber is indicative of the type of bulboventricular loop (whether D- or L-), a right-sided and anterior outlet chamber has different implications than a left-sided, superior, and more posterior positioned one. The inflows into the outlet chamber can vary anatomically, and progressive changes in the calibers of these communications can adversely alter the natural history. One or both of the greak vessels, or neither, or a persistent truncus arteriosus can originate from the outlet chamber, and any significant morphological change in the outlet chamber may or may not adversely affect either the pulmonary or systemic blood supply, or both. Finally, any consideration of the outlet chamber raises important conceptual difference in terminologies. At present, there is not unanimity as to what constitutes either an outlet chamber (as compared to a "small right ventricle" in tricuspid atresia) or a single (primitive) ventricle. Any discussion of the morphological and topographical variations of the outlet chamber must be viewed with respect to the terminology employed.

The conduction system in tricuspid atresia with and without regular (d-) transposition

This is a serial section examination of conduction system in six hearts with tricuspid atresia. Four had regular (d-) complete transposition and two did not have transposition. The conduction system was more or less the same in all the hearts. The atrioventricular (A-V) node was in the normal position posteriorly and was short. The A-V bundle was situated in the left ventricular aspect of the subendocardium and passed posteriorly to the ventricular septal defect. Even though this type of conduction system is abnormal in some respects, it is not the type one finds in single ventricle with small outlet chamber with regular (d-) transposition. In those hearts an anteriorly located A-V node is present. These findings further substantiate the concept that tricuspid atresia with or without transposition is not a form of single (primitive) ventricle.