Masked Abnormal Drainage of the Inferior Vena Cava Into the Left Atrium
EUGENIE F. DOYLE, MD, FACC DELORES DANILOWICZ, MD, FACC FRANK C. SPENCER, MD New York, New York
A 6 year old boy with a large atrial septai defect, partial anomalous pui-
monary venous drainage and unrecognized anomalous insertion of the inferior vena cava into the left atrium had cyanosis after closure of the atrial defect. Repeat study revealed direct drainage of the inferior vena cava into the left atrium with moderate arterial oxygen desaturation. At repeat operation an unusual positioning of the inferior vena cava was seen. After reopening of the atriai defect, the pulmonary venous arid systemic venous drainage anomalies were identified. A Dacron patch was Inserted so as to divert flow to the proper atrium. Repeat catheterization 3 months after operation revealed a normal heart with no obstruction; arterial oxygen saturation was normal. The child has continued to do well 3 years after operation.
Abnormal drainage of the inferior vena cava into the left atrium may occur rarely as an isolated congenital anomaly,14 be associated with an atria1 septal defect5v6 or be seen with other venous drainage abnormalities.7 More often, it is a complication of operative repair of a large secundum atria1 septal defect.a12 We describe here a 6 year old boy with an atria1 defect that masked the abnormal drainage of the inferior vena cava into the left atrium. Not until after repair of the defect was the anomalous inferior vena caval drainage appreciated, diagnosed and finally rerouted. Case Report
From the Departments of Pediatrics and Surgery, New York University Medical Center, 550 First Ave., New York, N. Y. Manuscript received March 25. 1975; revised manuscript received July 18, 1975. accepted July 23. 1975. Address for reprints: Eugenie F. Doyle, MD, Pediatric Cardiology, New York University Medical Center, 550 First Ave., New York, N. Y. 10016.
The patient, a white boy born on June 22,1965, was first noted to have a heart murmur at age 3 weeks. Transient cyanosis was noted in infancy during feeding and crying, but growth and development were normal. At age 21 months, while experiencing an upper respiratory infection, the child had an episode of generalized cyanosis that lasted several hours. He was subsequently admitted to another hospital for cardiac catheterization. Physical examination at that time revealed no cyanosis or clubbing. A right ventricular impulse was present at the lower left sternal border. A systolic thrill and a grade 4/6 systolic ejection murmur were noted at the pulmonary area. The second heart sound was accentuated. The hematocrit was 42 percent. The chest roentgenogram revealed generalized cardiac enlargement with increased pulmonary vascularity. The electrocardiogram revealed a mean QRS axis of +150° with tall R waves in the right precordial leads consistent with right ventricular hypertrophy. At cardiac catheterization, the venous catheter from the leg was thought to enter the left atrium through an atria1 septal defect. Oximetry disclosed a significant increase in oxygen saturation at the atrial level with an arterial saturation of 99 percent (Table IA). Right ventricular systoIic pressure was approximately half of the systemic level. Cineangiography performed in the left atrium disclosed a left to right shunt at the atria1 level. The patient was operated on under cardiopulmonary bypass at age 28 months. The operative note records that a 3 cm secundum atria1 septal defect extending down to the opening of the inferior vena cava was closed with interrupted sutures. A 1 cm sinus venosus defect was also identified and closed. No further anatomic description was available. Cyanosis was noted on the 2nd postoperative day and persisted and increased in severity. Dyspnea also became apparent after strenuous activity.
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INFERIOR VENA CAVAL
At age 5 l/2 years, the boy was admitted for a second cardiac catheterization (Table IB). Cineangiography now revealed direct drainage of the inferior vena cava into the left atrium (Fig. 1); systemic arterial oxygen saturation was 89 percent. The patient was then referred to New York University Hospital at age 6 years for operative repair. At the second open heart procedure, the unusual position of the inferior vena cava was readily evident. It entered the heart more than 3 cm to the left of the usual site. The inferior vena cava was cannulated directly through a stab wound in its midportion, a cannula advanced and secured with a snare. After right atriotomy, no orifice of the inferior vena cava could be seen. Two small right superior pulmonary veins entered the right atrium slightly below the superior vena caval opening. Sutures in the atrial septum from the previous operation were identified. Once the atria1 septum was completely reopened, the inferior vena caval orifice was clearly seen in the left atrium. The right inferior pulmonary vein was draining
Data 6. Age 5.5 Years
A. Age 2 Years (preoperative) 0 Site VC RA RV PA FA LV LA Cine angiogram
. 99 97’
slightly to the right of and superior to the inferior vena cava (Fig. 2A). Reconstruction of the atria1 septum was accomplished with a knitted Dacron” patch sewn below the entry point of the inferior vena cava into the left atrium. The patch was then attached to the right atria1 surface so as to direct the right pulmonary veins into the left atrium and the inferior vena cava into the right atrium (Fig. 2, B and C). At the conclusion of bypass, the oxygen saturation levels in the right atrium, right ventricle and pulmonary artery were identical and the arterial blood was fully saturated. The postoperative course was uneventful. At repeat cardiac catheterization performed 3 months later to assess the repair (Table IC), there was no residual shunt; intracardiac pressures and arterial blood gas and oxygen saturation levels were normal. Pressure data and cineangiography revealed normal unobstructed drainage of the inferior vena cava into the right atrium and of the pulmonary veins into the left atrium (Fig. 3). Three years after the second operation, the boy continues
(after 1St,before 2nd operation) 0,Sat
C. Age 6 Years (after 2nd operation)
Pressure (mm Hg)
Left to right atrial shunt
‘(4i 2215 22/10(14)
94 95iio (6)
IVC draining directly into LA
. . .
Normal systemic and PV drainage
Figures in parentheses indicate mean pressures. FA = femoral artery; IVC = inferior vena cava; LA = left atrium; LV = left ventricle; 0, Sat = oxygen saturation; PA = pulmonary artery; PV = pulmonary venous; RA = right atrium; RV = right ventricle; VC = venae cavae.
FIGURE 1. Cineangiogram in left anterior oblique view before repeat operation, showing the inferior vena cava (WC) draining into the left atrium (LA) and subsequent filling of the left ventricle (LV) and aorta (Ao).
LVL Y v L -_L v L FIGURE 2. A, illustration showing the abnormal anatomy found at operation. The inferior vena cava (IVC) drained into the left atrium and the right superior pulmonary veins (RSPV) into the right atrium. The increased pulmonary blood flow resulting from the latter drainage probably minimized the cyanosis resulting from the inferior vena caval drainage into the left atrium. The left pulmonary veins (not shown) drained normally into the left atrium. RIPV = right inferior pulmonary vein; SVC = superior vena cava. B, surgical correction was accomplished by excising the atrial septum and inserting a Dacron patch in a sinusoidal fashion to divert the right superior pulmonary veins into the left atrium and the inferior vena cava into the right atrium. This was somewhat difficult because of the location of the inferior vena cava to the left of normal. C, illustration showing the final position after the Dacron patch was completed, with the inferior vena cava (IVC) entering the right atrium and both the right superior and inferior pulmonary veins entering the left atrium. RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein; WC = superior vena cava.
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to do well. He has no symptoms or cyanosis and he maintains
normal sinus rhythm.
Discussion There are three types of condition in which the inferior vena cava may drain predominantly into the left atrium. In the rarest type, the inferior vena cava is displaced further to the left than usual so that it empties into the left atrium and the atria1 septum is intact. The anomaly may also be associated with a large low-lying atria1 septal defect so that the inferior vena caval blood is diverted into the left atrium, usually as a result of a large eustachian valve. It has also been reported as a part of a complication of atria1 septal defect repair, in which the atrial septum is constructed to the right of the entry of the inferior vena cava, thus accidentally diverting inferior vena caval flow into the left atrium. Four patients with the first type of isolated anomalous drainage of the inferior vena cava to the left atrium have been described. All had cyanosis since early childhood. Gardner and Cole’s patienti was diagnosed at autopsy at age 30 years. Three other patients described separately by Meadows2 and Black3 and their co-workers and Venables4 were diagnosed after cardiac catheterization. The arterial oxygen saturation ranged from 74 to 87 percent. These patients had evidence of minimal cardiomegaly in the chest X-ray film and signs of left ventricular hypertrophy in the electrocardiogram. Heart murmurs were notably absent. Surgical repair was not undertaken in any of the surviving patients because of associated lesions (pulmonary tuberculosis, pulmonary arteriovenous fistulas and hemiplegia).
Association of anomalous drainage of the inferior vena cava with a large atria1 septal defect was originally described by Rokitansky5 in eight postmortem cases and subsequently by Gallagher et a1.,6 who described three patients with a history of cyanosis at an early age. These patients had signs and symptoms of atria1 septal defect with arterial oxygen desaturation. At operation, Gallagher’s patients had a large low-lying atria1 septal defect with a large eustachian valve. Iatrogenic drainage of inferior vena cava into left atrium: Inadvertent diversion of inferior vena caval flow to the left atrium during repair of an atria1 septal defect has been described in operations performed with use of the hypothermic technique as well as with extracorporeal circulation. Bedford et a1.s described this complication in 3 patients from a total of 40 whose defect was repaired with use of the hypothermic technique. Effler and Groves,g Staple et al.iO and Bjork et al.ll reported on patients with this complication whose defect was repaired with cardiopulmonary bypass. All these patients experienced cyanosis in the immediate postoperative period, and the diagnosis of incorporation of the inferior vena cava into the left atrium was confirmed at repeat cardiac catheterization. Reoperation was performed, but the morbidity and mortality were considerable. Mustard et a1.12 described similar complications in three patients after repair of an atria1 septal defect, but these patients had, in addition to the defect, partial anomalous drainage of the pulmonary veins into the right atrium. These authors believe that surgical error can occur during attempts to divert an anomalously draining right lower pulmonary vein in the
FIGURE 3. Cineangiograms obtained after the second operation. Left, unobstructed drainage of the inferior vena cava (WC) to the right atrium (RA). Right, normal drainage of the right pulmonary veins (PV) to the left atrium (LA). RV = right ventricle.
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left atrium by suturing the inferior rim of the septum to the lateral wall of the right atrium. In our case, there was not only an associated atria1 septal defect but also an inferior vena cava anatomically situated more to the left than usual (Fig. 2A). The patient had no history of cyanosis at rest but had cyanosis during infancy with crying and feeding as well as one prolonged cyanotic episode when he had a respiratory infection at age 21 months. This is not a typical history of a child with an isolated secundum defect. Reversal of a shunt at the atria1 level during changes in intrathoracic pressure and elevated pulmonary vascular resistance has been reported, but the clinical findings before the first catheterization in our case certainly favored a left to right shunt at the atria1 level. The cardiac catheterization data supported this diagnosis, indicating normal arterial oxygen saturation and a large left to right shunt at the atria1 level. The details from the first surgical procedure regarding cannulation of the inferior vena cava, eustachian valve size and entry site of the inferior vena cava into the atrium were not available. Two atria1 defects were identified and closed by interrupted sutures, but nothing unusual was mentioned until cyanosis was observed in the recovery room. In retrospect, removal of the large pulmonary blood flow due to the atria1 defect allowed the systemic saturation to reflect more accurately the anomalous drainage of the inferior vena cava. However, even this was partly masked by the partial anomalous pulmonary venous drainage that was left uncorrected. At the second operative procedure, the anomalous pulmonary veins were recognized, as was the abnormal drainage at the infprior vena cava. It is obvious from review of published cases that incorporation of the inferior vena cava into the left atrium during repair of an atria1 septal defect is a severe complication that has led to death in many cases even when the problem has been recognized and reoperation performed. The usual explanation given for this inadvertent diversion is that the eustachian valve is mistaken for the lower rim of the atria1 defect and is erroneously included in the repair. Prevention of anomalous drainage of inferior vena cava during atria1 septal repair: Prevention of
this error seems to depend upon awareness of the possibility of inadvertently transposing the inferior vena cava into the left atrium. Since the relation between the lower margin of the atria1 septal defect and the point of entry of the inferior vena cava can vary widely, precise identification of the structures is needed before repair. Problems have usually occurred with the continuous suture technique. In some instances, initial placement of two to three interrupted sutures at the lower margin of the atria1 defect will make certain that the margin of the inferior vena cava is not constricted. When identification of such landmarks is clear, facilitated by the presence of the venous cannula and inferior vena cava, it should be impossible for such a complication to occur. Our patient might have presented a further problem because anomalous pulmonary veins draining into the right atrium might obscure a portion of the operative field of the first operation. Identification of the lower margin of the atria1 defect and the position of the inferior vena cava in relation to it would then be quite difficult. Cyanosis after atria1 septal repair: Cyanosis in the immediate postoperative period after open heart correction of an atria1 septal defect can have many causes (low cardiac output, hypoventilation, pulmonary parenchymal disease, pulmonary vascular disease [obstructive or arteriovenous fistulas], vena caval diversion or true vena caval anomaly). Subsequent evaluation should be guided by the original location of the repaired defect. Occasionally, repeat cardiac catheterization utilizing both superior and inferior vena caval approaches will be necessary to outline the problem completely. Anomalous drainage of the inferior vena cava into the left atrium, whether the defect is congenital or iatrogenie, is a serious one, leading to the possibility of systemic embolization. Since a large portion of the total body circulation flows through the inferior vena cava, the degree of cyanosis is usually severe and leads to polycythemia and its complications. Therefore, whenever the inferior vena caval flow enters the left atrium, either as an isolated anomaly or after operative intervention for an atria1 defect, the corrective surgery should be performed as soon as possible.
References 1. Gardner DL, Cole L: Long survival with inferior vena cava draining into left atrium. Br Heart J 17:93-97, 1955 2. Meadows WR, Bergstrand R, Sharp JT: Isolated anomalous connection of a great vein to the left atrium. Circ 24:669-676, 1961 3. Black H, Smith GT, Goodale WT: Anomalous infer& vena cava draining into the left atrium associated with intact interatrial septum and multiple pulmonary arteriovenous fistulae. Circulation 29: 256-267, 1964 4. Venables AW: Isolated drainage of the inferior vena cava to the left atrium. Br Heart J 25:545-548. 1963 5. Rokitansky C: Die Defects der Scheiderwande des Herzens. Vienna, W Braumuller, 1875, p 35-54 6. Gallagher ME, Sperllng DR, Wlnn JL, et al: Functional drainage of inferior vena cava into left atrium, three cases. Am J Cardiol 12:561-566, 1963 7. Miller GAH, Ongley PA, Rastelll GA, et al: Surgical correction of
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total anomalous systemic venous connection. Report of a case. Mayo Clin Proc 40:532-538, 1965 Bedford DF, Sellers TH, Somerville U, et al: Atrial septal defect and the surgical treatment. Lancet 1:1255-1261, 1957 Effler DB, Groves SK: Pitfalls in surgical closure of atrial septal defects, based on experience with one hundred and fifteen cases. Cleveland Clin Quart 28:166-175, 1961 Staple TW, Ferguson TB, Parker BM: Diversion of inferior vena cava into the left atrium following atrial septal defect closure. Am J Roentgen01 Radium Ther Nucl Med 98:851-858, 1966 Bjork VO, Johanson L, Jonesson B, et al: Operation and management of a case after diversion of the inferior vena cava into the left atrium after the operative repair of an atrial septal defect. Thorax 13:261-266, 1958 Mustard WT, Flror WB, Kldd L: Diversion of the vena cava into the left atrium during closure of atrial septal defects. J Thorac Cardiovasc Surg 471317-324, 1964