Nonsyndromic Multiple Congenital Anomalies

Malformations involving the cardiovascular system and one or more other organ systems (but excluding Down syndrome, scimitar syndrome, agenesis of the right lung, and trisomy 18—well-known syndromes in their own right) were found in 108 of these 415 patients (26.02%).

Down syndrome coexisted in 21 of these 415 patients (5.06%) with persistent LSVC or RSVC. The occurrence of Down syndrome was nonrandom: Persistent LSVC + Down syndrome + complete common AV canal occurred together in 11 of 17 patients with completely common AV canal (64.71%). However, Down syndrome did not coexist in any of the 12 patients with incompletely common AV canal.

The asplenia syndrome and the polysplenia syndrome with visceral heterotaxy are considered subsequently ( Chapter 29 ) and hence will not be considered further here.

TOF with persistent LSVC occurred in 66 patients, many of whom had MCAs. To state these relationships as simply as possible:

In other words, almost half (48%) of our patients with TOF and persistent LSVC also had MCAs.

But what proportion are these cases relative to all of our patients with TOF? The answer is:

Was Down syndrome common in our patients with TOF and persistent LSVC? Briefly, no:

Thus, TOF with persistent LSVC frequently had MCA (48%), but seldom had Down syndrome (6%).

What does MCA in association with TOF and persistent LSVC really mean? To answer this question specifically, we reviewed 50 cases of TOF with persistent LSVC or RSVC in detail.

First, what kinds of patients with tetralogy were these? There were 28 males and 22 females, males-to-females = 1.27:1. The segmental anatomic set was the usual TOF {S,D,S} in 47 patients (94%). {S,D,S} means the segmental anatomic set of solitus atria (S), D-loop ventricles (D), and solitus normally related great arteries (S), resulting in AV and ventriculoarterial (VA) concordance.

The segmental anatomic set of TOF {I,D,S} was found in 2 of these patients (4%). {I,D,S} means the segmental anatomic set of situs inversus of viscera and atria (I), discordant D-loop ventricles (D), and solitus normally related great arteries (S), resulting in AV discordance and VA concordance. Hence, these were like usual patients with TOF, except that the viscera and atria were inverted, resulting in AV discordance plus a tetralogy type of conotruncus. From a physiologic standpoint, because there is one segmental discordance (AV discordance), the systemic and pulmonary arterial circulations are physiologically uncorrected, as in physiologically uncorrected (complete) TGA. Hence, from the functional standpoint, TOF {I,D,S} resembles complete TGA with VSD and pulmonary outflow tract obstruction (stenosis or atresia). However, in TOF {I,D,S}, because there is VA concordance, the physiologically uncorrected systemic and pulmonary arterial circulations should be corrected with an atrial switch procedure (Senning or Mustard), not with an arterial switch type of operation, because VA concordance is present in TOF {I,D,S}. This rare form of tetralogy, TOF {I,D,S}, illustrates the important point that physiologic uncorrection of the circulations can occur without TGA. One segmental discordance that physiologically uncorrects the circulations can occur at the AV junction, as in TOF {I,D,S}, rather than at the much more frequent VA junction, as in TGA {S,D,D} or in TGA {I,L,L}.

Finally, the segmental anatomic set of TOF {I,L,I} was encountered in 1 patient (2%). {I,L,I} means the segmental anatomic set of situs inversus of the viscera and atria {I}, concordant L-loop ventricles (L), and inverted normally related great arteries (I), resulting in both AV and VA concordance. Hence, this was a patient with situs inversus totalis with inverted TOF. Such a patient should be treated surgically as with a mirror-image TOF.

Patients with situs inversus of the viscera and atria, in which the morphologically right atrium (RA), the SVC, and the inferior vena cava (IVC) are all left-sided (i.e., in mirror-image positions), had persistent RSVC, as in TOF {I,D,S} and as in TOF {I,L,I}. Thus, a persistent RSVC was present in 3 patients with TOF (6%).

Pulmonary outflow tract atresia was present in 13 patients (26%). A bicuspid pulmonary valve was noted in 13 patients (26%). A secundum type of atrial septal defect (ASD) (pentalogy of Fallot) was found in 12 cases (24%). A right aortic arch (in visceroatrial situs solitus) was present in 11 patients (23%). Major aortopulmonary collateral arteries were found in 7 patients (14%). A patent ductus arteriosus (PDA), often small, was present in 7 cases (14%). Additional muscular VSDs coexisted in 5 patients (10%). An unroofed coronary sinus, also known as a coronary sinus septal defect, was present in 5 patients (10%); consequently, the systemic venous blood carried by the LSVC was able to flow into the left atrium (LA), and the left atrial blood was able to flow into the RA through the enlarged coronary sinus ostium. Unroofing of the coronary sinus plus a large low posterior defect in the atrial septum, which is the enlarged right atrial ostium of the unroofed coronary sinus, is known as the Raghib syndrome . Completely common AV canal was found in 4 cases (8%), 1 of whom had a common atrium (2%). An aberrant right subclavian artery originating as the last branch from the aortic arch occurred in 4 patients (8%).

The following anomalies were found in two patients each (4%): anomalous left innominate vein, retroaortic in one, and anterior to the ductus arteriosus and beneath the aortic arch in the other; absent left innominate vein; congenital mitral stenosis; absent ductus arteriosus; absent left coronary ostium, resulting in a “single” right coronary artery; bicuspid aortic valve, due to absence of the right coronary-noncoronary commissure in 1 patient and absence of the left coronary-noncoronary commissure in the other; a unicommissural and hence unicuspid pulmonary valve; and absent pulmonary valve leaflets with aneurysmal dilatation of the pulmonary artery and branches.

The following malformations were found in one patient each (2%) of these 50 patients with TOF and persistent LSVC or RSVC: high left coronary artery ostium; hypoplasia of both coronary ostia; dextrocardia; potentially parachute mitral valve in the setting of common AV canal, with all chordae tendineae inserting into the anterolateral papillary muscle of the left ventricle (LV); preductal coarctation of the aorta; anomalous muscle bundles of the RV; left aortic arch in visceroatrial situs inversus; commissural cleft of the anterior leaflet of the mitral valve, the cleft pointing superiorly toward the anterolateral commissure (not oriented approximately horizontally, as in a common AV canal type of cleft); myxomatous aortic valve leaflets; aortic regurgitation due to the presence of a small leaflet at the right coronary-noncoronary commissure, separating the right coronary and noncoronary leaflets, preventing their coaptation (quadricuspid aortic valve); Ebstein anomaly of the tricuspid valve; aneurysm of the coronary sinus (the left horn of the sinus venosus), underlying the LV and communicating with the left ventricular cavity via slit-like openings behind and beside the posteromedial papillary muscle group, this being a previously unknown and unreported malformation, to our knowledge ( Figs. 6.2 and 6.3 ); totally anomalous pulmonary venous connection to the RA; polyvalvular disease; RSVC draining into the LA in visceroatrial situs solitus (via a sinus venosus defect); suprasystemic RV with small, slit-like VSD surrounded by muscle, due to the presence of a prominent, muscular right posterior division of the septal band, the VSD being conoventricular but not paramembranous (not confluent with the tricuspid valve’s leaflet tissue); brachiocephalic trunk giving origin to all brachiocephalic arteries except the left subclavian artery; interruption of the IVC, associated with the polysplenia syndrome, the segmental anatomic set being {A,S,D,S}, meaning that there was visceral heterotaxy with situs ambiguus (A), the atria being in situs solitus (S), with concordant D-loop ventricles (D), and solitus normally related great arteries (S); left subclavian artery as the first branch from a right aortic arch; and absence of the iliac arteries.

Aneurysm of left horn of sinus venosus, that is, of coronary sinus, in 23-month-old girl with tetralogy of Fallot (TOF), moderate infundibular pulmonary stenosis, persistent left superior vena cava (LSVC) to coronary sinus (CoS) to right atrium (RA) (see Case 5, Table 6.4 ), case of Dr. Victor A. Saldivar. (A) Posterior view of the heart showing the opened left atrium (LA), the RA, the large persistent LSVC, the transected inferior vena cava (IVC), the left ventricle (LV), the right ventricle (RV), and the large (3 cm in dorsoventral length × 2 cm in right-left width), thin-walled aneurysm of the left sinus horn or CoS that underlies the LV. (B) Opened aneurysm of the left horn of the sinus venosus. Note that the free wall of the aneurysm is very thin (1 to 2 mm in thickness) and smooth-walled. The opened LSVC above the aneurysm is seen, as is the very enlarged ostium (18 mm in diameter) of the CoS that opens into the RA. Although the “floor” (inferior wall) of the CoS aneurysm is smooth and thin-walled, the “roof” (superior wall) is thick and coarsely trabeculated. In this trabeculated roof, two small communications with the overlying LV are present. The more leftward communication is the larger, having an oval orifice that measures 5 mm in length. This orifice is 2 to 3 mm in depth. The more rightward orifice is tiny, almost closed, and measures only 1.0 to 1.5 mm in diameter. (C) The opened LV shows unremarkable septal and free wall architecture, with a well-developed anterolateral papillary muscle (ALPM) and mitral valve (MV). However, the posteromedial papillary muscle (PMPM) is bifid. Between the two “legs” of the PMPM group the larger of the two communications between the CoS and the LV emerges (white arrow head). This communication is guarded by two fibrous leaflets with short chordae tendineae that insert into the overlying PMPM and into the adjacent LV musculature. Hence a small sinoventricular valve is present between the underlying sinus venosus aneurysm and the overlying LV. A second tiny communication was found adjacent to the MV (small communication). These CoS aneurysm-to-LV communications were misdiagnosed angiocardiographically as apical muscular ventral septal defects.

Aneurysm of the left horn of the sinus venosus or coronary sinus (CoS), with persistent left superior vena cava (LSVC) draining into the CoS to the right atrium, and with two sinoventricular (SV) valves communicating between CoS aneurysm and left ventricle (LV), the SV valves opening through and between the posteromedial papillary muscle group of the LV, in a 15 9/12–year-old young woman with complete common atrioventricular (AV) canal type A of Rastelli, patient of Dr. Peter Vlad and Dr. Subramanian at the Buffalo Children’s Hospital. The patient underwent three cardiac operations: (1) at 6 9/12 years of age (10/28/1968), exploratory cardiotomy with mitral and tricuspid valvuloplasties; (2) at 7 years of age (2/21/1969), patch closure of atrial septal defects (ASDs) and ventricular septal defects (VSDs) with mitral valve replacement using a Starr-Edwards valve; and (3) at 14 11/12 years of age (1/5/1977), mitral valve replacement with Bjork-Shiley prosthesis. Continuing low cardiac output led to death on 10/11/1977. The aneurysm of the CoS and the SV valves opening from the CoS into the LV were surprise postmortem findings. (A) Left posterolateral view showing the large opened LSVC connecting with the very large CoS. (B) Interior of persistent LSVC and CoS showing the aneurysm of the left sinus horn that measures 17 × 8 mm. Two SV valves can be seen within the aneurysm, a large one to the left (closer to the LSVC), and a very much smaller one to the right. The great cardiac vein can be seen opening into the enlarged CoS—between the LSVC to the left and the aneurysm with SV valves to the right (mentally extend the LSVC leader). (C) The opened LV showing the Bjork-Shiley mitral valve prosthesis, the LV free wall to the viewer’s right, the LV septal surface toward the viewer’s left, and the ascending aorta (Ao). The two SV valves, containing probes, open into the LV cavity behind and between the musculature of the posteromedial papillary muscle group. The LV orifice of the larger SV valve measures 8 × 6 mm. These two SV valves were separated from the mitral valve by a cuff of LV myocardium. The aneurysm of the left horn of the sinus venosus and these two SV valves were thought not to have been of any clinical, or hemodynamic, or surgical importance. Because these two SV valves were located very close to the right atrium (RA), this heart could be considered to have triple-outlet RA (the tricuspid component of the common AV valve plus the two SV valves) and triple-inlet LV (the mitral component of the common AV valve and the two SV valves). However, our preferred diagnosis is simply aneurysm of the CoS with two SV valves between the CoS and the LV.

MCAs result from the presence of additional malformations involving systems other than the cardiovascular system, that is, multisystem malformations .

Some well-known syndromes are characterized by multisystem malformation, such as (see Table 6.3 ): Ellis-van Creveld syndrome, the asplenia syndrome, the polysplenia syndrome, the scimitar syndrome, conjoined twins, and agenesis of the lung. Speaking of well-known syndromes, it should be stated that 4 of these 50 patients had Down syndrome (8%) and 1 patient (2%) had familial Down syndrome. One neonate with TOF and persistent LSVC also had a history of familial congenital heart disease, with his mother having had valvar pulmonary stenosis.

However, what we are really after here are the MCAs that do not constitute a presently well-known syndrome. These may be called “nonsyndromic” MCAs . (We strongly suspect that many of the anomalies to be summarized hereafter do in fact constitute unrecognized syndromes. Part of the fascination of MCAs is the desire to find recognizable patterns—the hope of introducing order into chaos.)

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  Four patients (8% of this series) had tracheo-esophageal fistula with esophageal atresia.

  
  
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  Three patients (6%) displayed each of the following anomalies: absent left kidney and ureter, central nervous system dysplasia and dysfunction, and imperforate anus.

  
  
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  Two patients (4%) had each of the following: Cantrell syndrome, congenital deafness, cranial synostosis, clinodactyly, bilaterally undescended testes, and cleft palate.

  
  
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  One patient (2%) exhibited each of the following: the amnion rupture syndrome; complete thoracic ectopia cordis; pelvic kidney; multicystic kidney with ureteral atresia; horseshoe kidney; fusion of the kidneys, left-sided, with hydronephrosis and hydroureter due to ureterovesical stenosis; common urinary and intestinal outflow tract (cloaca); lissencephaly, familial; megacolon; double right bronchus; absent gallbladder; bronchus suis (pig bronchus, i.e., right upper lobe bronchus arising directly from the trachea); chromosome 17 translocation; balanced translocation from chromosome 8 to chromosome 13; supernumerary digits; scoliosis; cystic lung disease; rectourethral fistula; rectovaginal fistula; VACTERL syndrome (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities); hydrocephalus; hypospadias; left diaphragmatic hernia, foramen of Bochdalek type; double left renal artery; short terminal phalanges, hand; cleft palate, forme fruste; micrognathia; glossoptosis; claw foot; Klippel-Feil syndrome; hypoplasia of the lower extremities; and agenesis of the uterus.

To summarize, the foregoing is the picture of TOF with persistent left or RSVC—as it really is, including not only the cardiovascular anomalies, but also the very important extracardiac anomalies.

As the foregoing detailed study of persistent LSVC or RSVC with TOF indicates, persistent SVC often does not occur alone; it frequently has plenty of company.

Literature Review and Discussion

Although standard textbooks have little information on systemic venous anomalies in general, and on bilateral SVC in particular, much can be learned from a review of the medical journal literature. Highlights are as follows.

In 1965, Raghib, Ruttenberg, Anderson, Amplatz, Adams, and Edwards published a paper entitled, “Termination of the LSVC in Left Atrium, ASD, and Absence of Coronary Sinus—A Developmental Complex.” This is the group of anomalies that is now often referred to as the Raghib syndrome. We think that the large low posterior defect in the atrial septum is the enlarged right atrial ostium of the unroofed coronary sinus. The coronary sinus is “absent,” that is, unrecognizable, because of the large coronary sinus septal defect—the “unroofing” of the coronary sinus that reflects failure of formation of the partition between the coronary sinus posteriorly and the LA anteriorly. The opening in the atrial septum is not really an ASD, that is, an abnormal opening or defect in the atrial septum. Instead, this is a normal opening in the atrial septum (i.e., the ostium of the coronary sinus [not a septal “defect”]). Nonetheless, this normal but enlarged coronary sinus ostium functions like an ASD because of the coexistence of a large coronary sinus septal defect that unroofs the coronary sinus that is not truly absent.

Hence, the coronary sinus septal defect that unroofs the coronary sinus is responsible both for the right-to-left shunting of the persistent LSVC blood and the coronary sinus blood into the LA, and for the left-to-right shunting of the left atrial blood into the RA. The Raghib syndrome is thus a persistent LSVC to the coronary sinus with a large coronary sinus septal defect, and the hemodynamic sequelae thereof.

In 1965, Rastelli, Ongley, and Kirklin published a paper entitled, “Surgical Correction of Common Atrium with Anomalously Connected Persistent Left Superior Vena Cava: Report of a Case.” Rastelli et al concluded that persistent LSVC is an unusual anomaly, occurring in 9 of 3452 cases (0.26%), confirming the previously mentioned prevalence of approximately 0.3%. These authors reported the first surgical correction of the Raghib syndrome.

Totally anomalous systemic venous connection does not exist. Although such a case was reported in 1965, we think that totally anomalous systemic venous connection does not occur. In the patient in question, the left-sided atrium received a LSVC, a left IVC, and the coronary sinus, plus all of the pulmonary veins. Not described were the visceral situs, the atrial septum, and the type of bulboventricular loop. We thought that the patient probably had situs inversus of the atria, with totally anomalous pulmonary venous drainage. In our experience, any chamber to which both the IVC and the ostium of the coronary sinus are connected has always proved to be the morphologically RA, which in this case was left-sided; hence our conclusion that atrial inversion and totally anomalous pulmonary venous connection were present.

In 1969, another case was published that was thought to have totally anomalous systemic venous drainage into the LA. We thought that this 15-year-old boy really had cor triatriatum dexter and a secundum ASD, resulting hemodynamically in totally anomalous systemic venous drainage into the LA. We think this patient anatomically did not have totally anomalous systemic venous connection. Hence, cor triatriatum dexter (a prominent and obstructive right venous valve) plus a secundum ASD is yet another way of getting a large amount of systemic venous blood into the LA via a very large right-to-left shunt at the atrial level, but without totally anomalous systemic venous connection.

Idiopathic dilatation of the superior vena cava was reported in 1972 by Franken and by Ream and Giardina.

Absence of the RSVC associated with a large persistent LSVC connecting with the coronary sinus was reported in 1972 by Harris, Gialafos, and Jefferson. This report illustrated that a persistent LSVC does not necessarily mean that bilateral SVCs are present. This paper also considered the difficulties associated with transvenous pacing in this situation.

Congenital communications between the coronary sinus and the LA were considered in 1974 by Rose, Beckman, and Edwards. In discussing coronary sinus septal defect, these authors focused on three physiologically different situations:

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  A coronary sinus septal defect (unroofing of the coronary sinus) decompressing the LA in association with mitral atresia and a sealed foramen ovale;

  
  
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  A coronary sinus septal defect associated with stenosis of the right atrial ostium of the coronary sinus; and

  
  
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  A coronary sinus septal defect in association with tricuspid atresia and a sealed foramen ovale.

Does persistent LSVC have any electrophysiologic significance? In 1976, James, Marshall, and Edwards published a paper entitled, “De Subitaneis Mortibus [On Sudden Death]. XX. Cardiac Electrical Instability in the Presence of a Left Superior Vena Cava.” This was a study of two patients. Patient 1 had a small sinoatrial node. The AV node contained numerous venous lacunae and was stretched out beneath the enlarged coronary sinus ostium. The AV node and the His bundle were found to be dispersed within the central fibrous body, this being the fetal pattern. Fragments of the AV node were also found on the crest of the muscular ventricular septum.

The second patient with a persistent LSVC who experienced sudden unexpected death had a VSD and palpitation. After closure of the VSD, there were multiple postoperative arrhythmias leading to death. Autopsy revealed that the sinoatrial node was normal, but that the sinoatrial nodal artery contained a polypoid fibromuscular mass that virtually occluded the arterial lumen. The AV node and the His bundle in the central fibrous body again displayed a dispersed fetal pattern.

Is it possible for the RSVC to drain into the LA, with no other associated congenital heart disease? The answer is yes. Vázquez-Pérez and Frontera-Izquierdo in 1979 published a report entitled, “Anomalous Drainage of the Right Superior Vena Cava Into the Left Atrium as an Isolated Anomaly: Rare Case Report.” The patient, a 7-month-old boy, was thought at that time to be the fifth known case of this anomaly.

Developmentally, how is this possible? Our hypothesis is that this patient had a sinus venosus defect, which made it possible for the RSVC to drain into the LA. We speculate that a prominent right venous valve—the valve of the SVC—was also present, closing the sinus venosus defect on its right atrial side. Consequently, the right upper and middle lobe pulmonary veins were not unroofed and hence did not drain into the RA, and there was no interatrial communication. (See Chapter 9 for a detailed consideration of sinus venosus defect.) It should be emphasized that the foregoing developmental interpretation is a hypothesis .

Can a persistent LSVC drain into the LA because of unroofing of the coronary sinus but without an interatrial communication? The answer is rarely yes. In 1978, Lozsádi published a report based on two heart specimens, both of which had a persistent LSVC that opened into the LA because of a coronary sinus septal defect that unroofed the coronary sinus. But the remarkable finding in both cases was atresia of the right atrial ostium of the coronary sinus (i.e., there was no interatrial communication). Previously, it had been thought that an ASD was a necessary part of this anomaly. Hence, Lozsádi reported two cases of the Raghib syndrome without an interatrial communication.

Developmentally, how is this possible? Lozsádi hypothesized that this opening—the right atrial ostium of the coronary sinus—was closed by septum primum (the flap valve of the foramen ovale).

Our suggestion would be that this opening was closed by an adherent Thebesian valve of the coronary sinus, which is part of the right venous valve. Septum primum typically is superior and somewhat anterior to the coronary sinus ostium, whereas the right and left venous valves are ideally located to seal closed the right atrial ostium of the coronary sinus, if these valve leaflets develop abnormally.

Anomalous drainage of a LSVC into the LA as an isolated anomaly—without an interatrial communication—was confirmed in 1978 by Dupuis, Frontera, Pernot, Vasquez-Perez, and Verney. These authors stated that as of 1978, there were 3 previously reported cases of LSVC draining into the LA as an isolated anomaly, to which they added 6 new cases. They also noted that as of that time, there were 4 previously reported cases of RSVC draining into the LA. They reported that LSVC to LA usually was a well-tolerated right-to-left shunt. Mild cyanosis was characteristic. Clubbing and shortness of breath could occur, but congestive heart failure was infrequent. The cardiac silhouette was normal. Left ventricular hypertrophy was noted electrocardiographically. Diagnosis at that time was made by cardiac catheterization and angiocardiography (but now would be made by two-dimensional echocardiography), and treatment was surgical by ligation of the persistent LSVC just above the LA.

What is cor triatriatum dexter? In 1979, Ott, Cooley, Angelini, and Leachman published a paper entitled, “Successful Surgical Correction of Symptomatic Cor Triatriatum Dexter.” The patient was a 67-year-old woman. Surgical removal of the obstructive right venous valve between the medial caval compartment (the sinus venosus) and the more right lateral tricuspid valve and right atrial appendage compartment not only removed the supratricuspid stenosis but also cured the patient’s supraventricular tachycardia.

Cor triatriatum dexter (i.e., right-sided cor triatriatum) is a systemic venous anomaly. Why? Because the sinus venosus is the systemic venous confluence, and the right leaflet of the sinoatrial valve (briefly known as the right venous valve) demarcates the junction of the systemic venous confluence (where the ostia of the superior vena cava, the IVC, and the coronary sinus converge) and the right atrial appendage (which represents the primitive atrium). Hence, the right venous valve, which is obstructive in cor triatriatum dexter, is a systemic venous valve. In this sense, therefore, cor triatriatum dexter really is a systemic venous anomaly and hence is mentioned in this chapter on anomalies of the systemic veins.

Normally, the right venous valve is largely incompetent. The valve of the SVC (that fortunately has no eponym attached to it) and the valve of the IVC (the Eustachian valve) both are normally incompetent. The valve of the coronary sinus (the Thebesian valve), which also is derived from the right venous valve, may or may not be competent.

But why is the right venous valve mostly incompetent, at least insofar as the venae cavae are concerned? We think that the answer is: If the right venous valve is competent and prevents regurgitation into the venae cavae, then the right venous valve is also obstructive, resulting in what is known as cor triatriatum dexter. In order not to be obstructive, the right venous valve must be relatively poorly formed and hence incompetent.

In 1979, Battle-Diaz, Stanley, Kratz, Fouron, Guérin, and Davignon published a paper entitled, “Echocardiographic Manifestations of Persistence of the Right Sinus Venosus Valve.” The patient was a female infant whose cor triatriatum dexter was repaired surgically by removal of the obstructive right leaflet of the sinus venosus valve.

For clarity, it should be mentioned that the sinus venosus valve is the same thing as the sinoatrial valve; the latter designation indicates that this valve is located at the junction of the sinus venosus and the primitive atrium, which forms the right atrial appendage.

For the uninitiated, “right sinus venosus valve” or “right venous valve” may be confusing because these terms suggest that there is also a left sinus venosus valve or a left venous valve. One may then wonder, “Are there two venous valves—a right and left?” At this point, it becomes essential to understand what valve really means, that is, its etymology. The English word valve is derived from the Latin valva, which means leaf of a folding door. In this original sense, a valve (valva) meant either of the halves of a double door, or any of the leaves of a folding door ( Webster’s New World Dictionary, College Edition, 1958, page 1609). Hence valve has come to mean either an orifice guarded by one or more leaflets or the leaflets themselves.

The sinus venosus valve or the venous valve is thus being analogized to double door with two halves or leaves. The right and left venous valves refer to the leaflets, not to the orifice. There is only one orifice, with right and left leaflets or valves, in the original Latin sense (valva).

Congenital aneurysms of the superior vena cava were considered by Modry, Hidvegi, and LaFleche in 1980. These authors concluded that there are two types: fusiform and saccular. (Fusiform means spindle-shaped, derived from Latin fusus, a spindle + forma, a shape.) Congenital superior vena caval aneurysms do not enlarge, rupture, or thrombose, and hence should be treated conservatively. Diagnosis by radiologic evaluation is based on size variation with respiration. It is important to recognize congenital SVC aneurysms so as to avoid needless thoracotomy.

Surgical correction of anomalous RSVC to the LA was described by Alpert, Rao, Moore, and Covitz in 1981. The technique involved excision of the upper portion of the atrial septum that separated the SVC from the RA. A pericardial patch was attached along the caudal margin of the created ASD, and the cephalad margin of the patch was sutured to the junction of the SVC and the LA. Thus, the RSVC blood flow was diverted to the right of the patch into the RA.

Biatrial drainage of the RSVC with stenosis of the pulmonary veins was reported in 1984 by Bharati and Lev. The authors stated that this was the first autopsy-proved case in the English literature in which all of the following features coexisted: RSVC entering both atria; obstruction of the entry of the RSVC into the RA; aneurysmal dilatation of the RSVC; entry of the stenosed right upper pulmonary vein into the superior vena caval aneurysm; and drainage of all other pulmonary veins into the LA, these pulmonary veins being markedly stenosed.

Abnormal position of the left innominate vein was reported in 1985 by Smallhorn, Zielinsky, Freedom, and Rowe. The left innominate (brachiocephalic) vein passed beneath the left aortic arch. In 1990, Choi et al reported a subaortic position of the left innominate vein in almost 1% (0.98%) of individuals—a much higher prevalence than previously reported. A subaortic innominate vein was more common in patients with TOF, with or without pulmonary atresia, and such patients were more likely to have a right aortic arch.

Intrapericardial blood cyst is a rare form of systemic venous anomaly. In 1984, Cabrera, Martinez, and Del Campo reported the case of a 21-month-old girl who had an intrapericardial venous cyst that was an egg-shaped mass measuring 4.5 × 3.5 cm. This venous cyst was connected by a patent pedicle with the left innominate vein. In addition, 100 mL of fluid was present within the pericardial sac. The venous cyst was ligated and resected.

Surgical repair of LSVC draining into the LA was described by Sand et al in 1986. These authors constructed a simple tunnel to the RA, which has become the definitive surgical repair of this anomaly.

Coronary sinus septal defect with tricuspid atresia was reported in 1986 by Rumisek et al as a rare cause of right-to-left shunting following the modified Fontan procedure.

Aneurysm of the left horn of the sinus venosus (coronary sinus) was reported by DiSegni, Siegal, and Katzenstein in 1986. The patient had mitral atresia and hypoplastic left heart syndrome. The coronary sinus diverticulum penetrated the posterior wall of the RV and communicated with the right ventricular cavity. Communicating aneurysm of the coronary sinus results in a rare form of double-outlet RA. Congenital diverticulum of the coronary sinus was also reported in 1988 by Petit, Eicher, and Louis. Coronary venous aneurysms and accessory AV connections were described in 1988 by Ho, Russell, and Rowland.

Can a persistent LSVC draining into the coronary sinus cause a subdivided LA? Ascuitto et al answered this question affirmatively in 1987.

When a persistent LSVC drains into the LA, must the coronary sinus be unroofed? We think that the correct answer is yes. However, as Looyenga et al reported in 1986, occasionally a vein interpreted as persistent LSVC can connect with the left pulmonary veins, draining in this way into the LA, without unroofing of the coronary sinus. We think that this vessel was a levoatrial cardinal vein, not a persistent LSVC.

A closed technique for the repair of RSVC draining into the LA was reported in 1993 by Nazem and Sell. The patient, a 26-year-old woman, also had the right upper lobe pulmonary veins connecting with the RSVC and the atrial septum was intact. Without cardiopulmonary bypass, the authors divided the azygos vein, transected the superior vena cava above the anomalous right pulmonary veins, and anastomosed the superior part of the RSVC end-to-side to the right atrial appendage.

In 1994, Raissi et al repaired drainage of the RSVC into the LA without cardiopulmonary bypass, using excluding clamps.

Diverticulum of the superior vena cava was reported by Sai et al in 1994. The patient, a 14-year-old girl, was thought to have a tumor. Instead, at surgery a venous diverticulum was found arising from the junction of the left innominate vein and the RSVC. The diverticulum was closed with sutures and then resected.

What is the best way of diagnosing coronary sinus septal defect (unroofed coronary sinus)? Chin and Murphy in 1992 answered: color-flow Doppler echocardiography, a method that has subsequently proved to be of considerable assistance in making this diagnosis.

Can a dilated coronary sinus produce left ventricular inflow obstruction, and is this an unrecognized entity? Answering both questions affirmatively, Cochrane, Marath, and Mee in 1994 introduced surgical reduction of the enlarged coronary sinus as treatment for this condition. We think that this entity is the same as subdivided LA, mentioned previously.

Extracardiac techniques for the surgical correction of LSVC draining into the LA were described in 1997 by Reddy, McElhinney, and Hanley : (1) anastomosis of the LSVC to the right atrial appendage; (2) passing the transected LSVC under the aortic arch and over the pulmonary artery, with anastomosis of the end of the LSVC to the side of the RSVC; and (3) a bidirectional left cavopulmonary anastomosis.

Absence of the RSVC in visceroatrial situs solitus was considered in 1997 by Bartram, Van Praagh, Levine, Hines, Bensky, and Van Praagh. Based on 9 new cases and a literature review of 121 previously published cases, these authors found that absence of the RSVC in situs solitus is rare (0.07% to 0.13% of congenital cardiovascular anomalies). When the RSVC was absent, typically there was a persistent LSVC to the coronary sinus draining into the RA and a left-sided azygos vein draining into the LSVC. Less constant features were additional cardiovascular malformations (46%) and rhythm abnormalities (36%) that usually appeared related to complications of old age.

Prior to invasive medical or surgical procedures, echocardiographic diagnosis of absence of the RSVC is of considerable practical importance in many procedures, such as implantation of a transvenous pacemaker, placement of a monitoring pulmonary artery catheter, systemic venous cannulation for extracorporeal membrane oxygenation, systemic venous cannulation for cardiopulmonary bypass, performance of partial or total cavopulmonary anastomoses, obtaining endomyocardial biopsy samples, and the performance of orthotopic cardiac transplantation.

Literature Review and Discussion

The medical journal literature dealing with anomalies of the IVC contains information of interest, some of which may be summarized as follows.

Is there electrocardiographic evidence of interruption of the IVC? In 1972, Van der Horst and Gotsman pointed out that in a patient with congenital heart disease, coronary sinus or left atrial rhythm should suggest interruption of the IVC with azygos continuation to the superior vena cava. Coronary sinus rhythm was present in 4 of 8 cases (50%), left atrial rhythm in 2 (25%), an inverted P vector in 1 (12.5%), and a normal P vector in 1 (12.5%).

These findings were confirmed in 1973 by Merrill, Pieroni, Freedom, and Ho. In a series of 18 cases, they found a coronary sinus rhythm in 56%. They also noted a prominent azygos-SVC confluence radiologically. Either or both electrocardiographic and radiologic clues were present in 89% of these cases.

Can interruption of the IVC manifest as a thoracic tumor? The answer is yes. In 1974, Bernal-Ramirez, Hatch, and Bower reported the case of a 46-year-old man whose chest x-ray films showed a right hilar mass produced by the abnormally prominent azygos-SVC junction.

Can anomalous development of the IVC be associated with pulmonary thromboembolism? Again, the answer is yes. In 1975, Miller et al reported the case of a 23-year-old man with duplication of the IVC. The left IVC joined the left renal vein and crossed anterior to the aorta to join the right IVC. Several clots formed in the left IVC, resulting in recurrent pulmonary thromboembolism. The patient was treated by interruption of both IVCs just below the renal veins. The presence of bilateral IVC was attributed to the persistence of the supracardinal veins bilaterally. (The supracardinal vein is also known as the thoracolumbar line vein, the important part that persists being the paraureteric segment of this vein.) An alternative therapeutic approach to ligation or clipping of the duplicated IVC is the placement of a Mobin-Uddin umbrella filter beneath the renal veins bilaterally.

Is the lateral chest film a reliable indicator of an azygos continuation of the IVC? In 1976, O’Reilly and Grollman stated that the answer to this question is no. In 7 patients with an angiocardiographically proved azygos continuation, 5 cases (71%) had a clearly recognized IVC shadow on lateral chest film x-ray studies. In a sixth patient, the IVC shadow was faintly visualized. In a control series of 100 normal patients, no IVC shadow was identified in two lateral chest films; and in 7 other controls, the IVC shadow was poorly seen or absent because of adjacent diaphragmatic, pleural, or pulmonary parenchymal abnormality.

We agree with these authors because in patients with interruption of the IVC, between the renal veins below and the hepatic veins above, the suprahepatic segment of the IVC is always present. Otherwise, the hepatic venous blood would have no way of returning to the heart.

Consequently, the suprahepatic segment of the IVC remains a highly reliable diagnostic marker of the morphologically RA, even in patients with interruption of the IVC.

What is the prevalence of interruption of the IVC? In our postmortem series, it will be recalled that the prevalence of interruption of the IVC was 42 of 3216 cases of congenital heart disease (1.31%; 95% CI 0.92% to 1.70%). Nedeljkovic et al found that in 586 cases of congenital heart disease studied at autopsy, there were 4 patients with interruption of the IVC (0.6%). Among 368 patients with congenital heart disease studied by cardiac catheterization and angiocardiography, 2 had interruption of the IVC (0.5%).

What is the best noninvasive method of diagnosing interruption of the IVC with azygos continuation? The answer to this question may well continue to change with progressive technological improvements. However, in 1983, Ritter and Bierman advocated the combination of two-dimensional echocardiography for anatomic detail, combined with gated pulsed color Doppler interrogation for blood flow characteristics.