Systemic Venous Anomalies

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.

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.)

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

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

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

• 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:

• 1.

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

• 2.

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

• 3.

  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.

Literature Review and Discussion

Reports in the medical journal literature concerning atresia of the right atrial ostium of the coronary sinus were of considerable interest, as the following briefly indicates.

Can atresia of the right atrial ostium of the coronary sinus occur without a persistent LSVC, and if so, how? In 1972, Falcone and Roberts reported 4 cases, all autopsy-proved, with atresia of the right atrial ostium of the coronary sinus and without a persistent LSVC. Of these 4 patients, 3 had a left atrial ostium of the coronary sinus, permitting a right-to-left shunt at the atrial level and explaining how long-term survival was possible without a persistent LSVC. One of these patients had two small openings in a small cardiac vein that drained into the right atrial appendage. The coronary sinus and associated veins were markedly distended. Clinically, this patient was thought to have an idiopathic myocardial disease with cardiomegaly. Except for the latter patient, the other 3 had additional forms of congenital heart disease. All 4 were adults, ranging from 27 to 63 years of age.

Atresia of the right atrial ostium of the coronary sinus was thought to be of no clinical significance in the 3 patients with unobstructed openings of the coronary sinus into the LA. However, the patient with no left atrial opening of the coronary sinus and with only an apparently obstructive opening into the right atrial appendage was thought to have a primary myocardial disease with idiopathic cardiomegaly, probably secondary to the stenotic (and ectopic) egress from the cardiac venous system. Hence, atresia or stenosis of the right atrial ostium of the coronary sinus is of no clinical importance, as long as there is an unobstructed exit for the cardiac venous blood somewhere else.

Is cardiac venous hypertension associated with increased risk for coronary arterial thrombosis? The report of Gerlis et al in 1984 suggested that the answer is perhaps. These authors reviewed 14 previously reported cases of coronary sinus atresia associated with a persistent LSVC, adding 2 new cases of their own. In their Case 1, a 43-year-old woman, the persistent LSVC was small—only 4 mm in diameter (compared with a RSVC that was 12 mm in diameter). The coronary sinus was dilated (8 mm in diameter). A larger medial branch of the left anterior descending coronary artery was occluded by an old, firmly adherent thrombus that was associated with a massive myocardial infarction. Histologically, this thrombosed coronary artery showed no significant disease of the vessel wall.

In discussing this mysterious finding of coronary thrombosis in a histologically unremarkable left anterior descending coronary artery, Gerlis et al noted that Falcone and Roberts had stated the hemodynamic consequences of coronary venous hypertension (due to the obstructively small persistent LSVC in this patient) would be predominantly reflected into the left coronary artery because 75% of its blood flow enters the coronary sinus.

Thus, Gerlis et al raise the important possibility that coronary sinus atresia may be associated with thrombosis in a normal left coronary arterial system if the draining LSVC is small and hence obstructive. This was the first such case reported in the literature; further experience is needed in order to assess this hypothesis. Thus, the inference appears to be that coronary sinus atresia associated with a persistent LSVC may not be an entirely benign condition in adult life if the left superior vena is obstructively small. Again, more experience is needed to test this hypothesis.

Can atresia of the coronary sinus orifice be diagnosed in life? Yes. In 1985, Watson reported what he thought was the second case diagnosed by angiocardiography into the coronary sinus via a persistent LSVC. The first case diagnosed in life was that of Fudemoto et al in 1976. In reviewing 37 known cases of coronary sinus atresia, Watson found that approximately half were not associated with any other form of congenital heart disease. Exit of the coronary sinus blood in these 37 patients was as follows:

• 1.

  a persistent LSVC in 16 (43%);

• 2.

  an unroofed coronary sinus opening into the LA in 9 (24%);

• 3.

  venous channels draining into the right or LA in 9 (24%); and

• 4.

  combinations of the above in 3 (8%).

Also in 1985, Yeager et al reported angiographic diagnosis of coronary sinus atresia in a term infant with pulmonary atresia, intact ventricular septum, and sinusoidal communications between the right ventricular cavity and the coronary arteries, with retrograde coronary arterial filling.

In terms of echocardiographic diagnosis, Yeager et al noted in retrospect that the persistent LSVC was visualized, but not the coronary sinus or the coronary sinus ostium. They concluded that the only echocardiographic clue to the diagnosis of coronary sinus ostial atresia was absence of the dilated coronary sinus that usually is associated with a persistent LSVC. They added that although not performed in their patient, Doppler interrogation of the LSVC should reveal reversal of the usual direction of blood flow.

Although coronary sinus atresia with a persistent LSVC typically is of no clinical importance, is it of any surgical significance? Unfortunately, the answer is yes. As was reported in 1989 by Yokota et al, inadvertent division of a small persistent LSVC (4 mm in diameter) in a 4 11/12-year-old boy in the process of performing an arterial switch procedure for TGA resulted in death on the fifth postoperative day. Autopsy revealed no kinking or distortion of the implanted coronary arteries. Congestion and hemorrhage of the myocardium were described as massive, with infarction of the right ventricular free wall. The surprise finding of the autopsy was atresia of the coronary sinus orifice.

These authors concluded that the only way to prevent this unusual but fatal complication during surgery is to bear in mind the possibility that the LSVC may be the only outlet for the cardiac venous blood and to determine the patency of the coronary sinus orifice whenever a persistent LSVC is ligated or divided.

Literature Review and Discussion

Ho et al reported 2 patients with aneurysm of the coronary sinus in 1983, this being the first known report of this entity. Two years later, Gerlis et al linked coronary sinus aneurysms with ventricular preexcitation, demonstrating histologically the presence of accessory AV connections, a finding that was subsequently confirmed by Ho et al in 1988.

To the best of our present knowledge, valvelike communications between coronary sinus aneurysms and both ventricular cavities are reported here for the first time.

The Anatomy and Terminology of the Cardiac Veins.

In order to understand and describe the aneurysms of the left and right horns of the sinus venosus, a brief review of the anatomy and terminology of the cardiac veins is helpful. Because many pediatric cardiologists and cardiac surgeons do not know even the names of the major cardiac veins, let us start at the beginning.

They are called the cardiac veins, not the coronary veins. However, some investigators have applied the term coronary to the arteries and the veins of the heart. The English word coronary is derived from the Latin term corona, meaning garland or crown, which in turn is derived from the Greek word korone or s tephanos, meaning wreath. Hence, the literal meaning of coronary is encircling in the manner of a crown. Claudius Galenus (130–200 CE), known in English as Galen, was a Greek from Pergamos in Asia Minor whose medical and scientific career climaxed in Rome. Here, he introduced many Greek medical terms into Latin, one of which was corona. The root meaning of corona is wreath, as worn about the head of an Olympic champion, and, thus, similar to a crown. In Greek, the coronary arteries were called stephaniaia angia, meaning wreath-like vessels. It was this term that Galen then translated into Latin as corona.

It will also be recalled ( Chapter 1 ) that Rufus of Ephesus, at about the beginning of the current era (approximately 1 to 25 CE), had named what we call the “base” of the heart, the “head” of the heart. From this it followed that the atrial appendages became known as the “ears” (auricles, from auricula, Latin) because they are located on either side of the “head” of the heart. The coronary arteries do indeed wrap around the “head” of the heart like a wreath or a crown. However, the cardiac veins do not ( Fig. 6.8 ). From the anterior interventricular sulcus to the acute margin of the heart, the right AV sulcus contains the right coronary artery, but normally no major cardiac vein. Thus, the arteries of the heart are crownlike, whereas the veins are not, hence coronary arteries, but not coronary veins. Instead, they are cardiac veins.

Following J.C. Boileau Grant (see Fig. 6.7 ), who was my Professor of Anatomy, the anterior interventricular cardiac vein is known as the great vein, or the left vein, because it normally flows leftward in the left AV groove and then proceeds posteriorly, where it flows into the coronary sinus. The coronary sinus normally has four tributaries (see Fig. 6.8 ): (1) the great or left cardiac vein, mentioned previously; (2) the oblique vein coming in from above and leftward, the oblique vein being a remnant of the LSVC, which normally involutes and becomes the ligament of Marshall; (3) the middle cardiac vein, which is the posterior interventricular vein that flows into the coronary sinus from below; and (4) the small cardiac vein, which comes from the acute margin of the RV and flows rightward and then posteriorly to reach the undersurface of the coronary sinus just to the left of its right atrial ostium.

One or two anterior cardiac veins from the conus arteriosus and the anterior right ventricular free wall “jump” across the right AV sulcus anteriorly and drain directly into the RA (see Fig. 6.8 ).

Not shown in Fig. 6.8 are the inferior ventricular veins that help to drain the diaphragmatic surfaces of the ventricles into the coronary sinus; and the Thebesian veins, which are minute vessels that begin in the heart wall and open directly into the chambers of the heart.

The previously mentioned ligament of Marshall commemorates John Marshall, an English anatomist (1818–1891), whose work on the development of the SVC accounts for the eponym. The Thebesian veins honor the memory of Adam Christian Thebesius, a German physician (1686–1732).