A complex congenital cardiovascular anomaly: persistence of left inferior and superior caval veins in conjunction with atrial and ventricular septal defects/Kompleks bir konjenital kardiyovaskuler anomali: persistan sol inferiyor ve superiyor kaval venlerin atriyal ve ventrikuler septal defektler ile birlikteligi.

Introduction

Persistence of the left superior and inferior vena cava (SVC and IVC, respectively) is relatively rare cardiac anomalies, and their frequency varies from 0.2% to 0.5% in the general population (1-4). Some congenital cardiac abnormalities such as atrial or ventricular septal defect and unroofed coronary sinus may accompany the persistent left SVC, resulting in paradoxical embolism (1, 2). However, persistent left IVC or transposition of IVC is much rare congenital anomaly compared with persistent left SVC (3, 4). In the literature, several case reports about persistence of the left IVC with its azygos or hemiazygos continuation have been reported (3-8). However, no associated congenital cardiac defects such as atrial and ventricular septal defects (ASD and VSD, respectively) have been presented in those reports. Therefore, we describe a complex

and rare congenital anomaly, which includes ASD, VSD, and persistent left IVC and SVC.

Case report

A 31-year-old woman presented with effort dyspnea. She had no history of previous cardiac disease. Her vital signs such as blood pressure and radial pulses were stable. Physical examination revealed holosystolic murmur at grade of 3/6 at the left sternal border radiating to other auscultation points. There were no other pathologic findings. Electrocardiogram was also normal. In transthoracic echocardiography, subaortic VSD and secundum type ASD were detected. There were also severe tricuspid regurgitation and mild aortic regurgitation. Pulmonary systolic pressure of 45-50 mmHg was calculated from tricuspid regurgitation. Pulmonary to systemic flow ratio of 1.7 was estimated by Doppler echocardiography. In addition, abnormal mosaic flow with undefined origin was observed in the right atrium. She underwent cardiac catheterization to confirm a significant left to right shunt and to exclude possible other cardiac abnormalities. During the catheterization, while forwarding the catheter via the right femoral vein, we realized that the direction of catheter was towards to the left arm of the patient and there was no normal IVC course. This vein was considered as persistent left IVC (Fig. 1A). When the catheter was further advanced, the right atrium was entered through persistent left SVC and its angiography was performed (Fig. 1B). We considered that persistent left IVC, which continues as vena hemiazygos drained into right atrium via persistent left SVC connecting to coronary sinus (Fig. 1A). Left innominate vein, was not viewed. There was a right superior caval vein which drained normally to the right atrium and normal pulmonary venous return in right atrial angiography. Superior vena cava and IVC related to the topography of the thorax and abdomen in this case is drawn schematically in Figure 2. Oxygen saturations of left IVC, persistent left SVC, right atrium and right ventricle were 66%, 70%, 75% and 85%, respectively. They showed a significant left-to-right shunting at both atrial and ventricular levels. Pulmonary artery could not be engaged via femoral vein because of failure in back-up of the catheter. Right internal jugular vein was used for pulmonary artery catheterization. The mean 02 saturation and pressure of main pulmonary artery were 84% and 55/30 mm Hg respectively. Persistent left SVC was also confirmed by administrating contrast media via left antecubital vein. Left ventriculography revealed the subaortic VSD (Fig. 3). By oxymetric method, pulmonary to systemic flow ratio of 1.85 was calculated. Thus, surgical closure for ASD and VSD was performed and those defects were confirmed. Abdominal ultrasonography demonstrated no additional abnormalities such as polysplenia and other visceral levoisomerism (liver, spleen and stomach) except hepatic veins drained directly into the right atrium. Liver was seen at right side, spleen and stomach were seen at left side of the abdomen. Cardiac chambers and great systemic arteries were at normal position (Fig. 4). So we considered abdominal situs solitus.

Discussion

Persistent left IVC and SVC are unusual congenital anomalies in the population. They result from the failure of regression of the right supra-cardinal vein and left anterior cardinal vein, respectively (1-4). Persistent left SVC is relatively more prevalent compared with the left IVC and may result in paradoxical embolism due to accompanying lesions such as ASD, unroofed coronary sinus and its directly drainage into the left atrium (1). Up to now, it has not been reported that persistent left SVC accompanies left IVC in a case with both ASD and VSD. To our knowledge, this is the first reported case of such an anomaly.

Interruption of the IVC or persistent left IVC with azygos or hemiazygos continuation is an unusual but well-known anomaly of the IVC (3-8). In case of persistent left IVC, possible routes for the return of blood to the right atrium are via the azygos vein to the SVC, via the hemiazygos vein to persistent left SVC or via the left brachiocephalic vein to right SVC (4). Infrequently, this anomalous vein may accompany ASD and open directly into the left atrium, resulting in right-to-left shunting without pulmonary hypertension (9). In general, the return of blood of left IVC to the right atrium is usually provided with its hemiazygos continuation connecting to left SVC. In the literature, a case with ASD, patent ductus arteriosus and a left IVC with hemiazygos continuation and drainage into the coronary sinus was reported (8).

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Hemiazygos continuation of left IVC has been reported previously by computed tomography in the literature (3-6). We did not perform the tomography with contrast medium. Instead, we passed directly the mentioned course of venous return with catheter under the guidance of fluoroscopy.

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Left IVC and persistent left SVC are usually asymptomatic, being detected incidentally during routine thoraco-abdominal imaging by ultrasonography or computed tomography or cardiac catheterization. Their presence may complicate some surgical procedures such as Glenn shunt, Mustard repair and abdominal surgery (10). Their injuries by surgery may result in severe hemorrhage. In addition, percutaneous interventions such as implantation of pacemaker, cardioverter-defibrilator or caval filter may be difficult in such patients. Similarly, these anomalies can also make percutaneous closure of ASO or VSD difficult.

Persistent left IVC can make the right heart catheterization difficult via femoral vein as we encountered. We were not able to advance the catheter into the pulmonary artery via femoral approach, and used the right internal jugular vein for this purpose.

Persistent SVC usually drains into the coronary sinus, resulting in its dilatation. By stretching the atrioventricular node and His bundle, rhythm disturbances may occur in such patients (1, 2). Our patient had no rhythm abnormality.

Conclusion

In conclusion, it should be kept in mind the possibility that any congenital cardiac anomaly may accompany other cardiovascular abnormalities. A detailed investigation should not be neglected.

References

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(3.) Bricker ME, Eichhorn EJ, Netto D, Cigarroa RG, Brogan WC, Simonsen RL, et al. Left-sided inferior vena cava draining into the coronary sinus via persistent left superior vena cava: A case report and review of the literature. Catheter Cardiovasc Diagn 1990;20:189-92.

(4.) Kim HJ, Ahn 10, Park ED. Hemiazygos continuation of a left inferior vena cava draining into the right atrium via persistent left superior vena cava: Demonstration by helical computed tomography. Cardiovasc Intervent Radiol 1995; 18: 65-7.

(5.) Allen HA, Haney PJ. Left-sided inferior vena cava with hemiazygos continuation. J Comput Assist Tomogr 1981; 5: 917-20.

(6.) Dudiak CM, Olson MC, Posniak HV. CT evaluation of congenital and acquired abnormalities of the azygos system. Radiographics 1991; 11: 233-46.

(7.) Munechika H, Cohan RH, Baker ME, Cooper CJ, Dunnick NR. Hemiazygos continuation of a left inferiorvena cava: CT appearance. J Comput Assist Tomogr 1988; 12: 28-30.

(8.) Benrey J, Williams RL, Reul GJ. Hemiazygos continuation to coronary sinus with normal left innominate vein. Cardiovasc Dis 1975; 2: 325-30.

(9.) Hallali P, Tcheng P, Davido A, Leriche H, Corone P. Atrial septal defect and cyanosis. Apropos of 6 cases related to abnormal drainage of the inferior vena cava into the left atrium. Arch Mal Coeur Vaiss 1988; 81: 783-6.

(10.) Brener BJ, Darling RJ, Frederic PL, Linton RR. Major venous anomalies complicating abdominal aortic surgery. Arch Surg 1974; 108: 159-6.

Abdullah Dogan, Yasin Turker, Mehmet Ozaydn, Nurullah Tuzun

Department of Cardiology, Medical School, Suleyman Demirel University, Isparta, Turkey

Address for Correspondence/Yazisma Adresi: Dr. Yasin Turker, Hizirbey M.1519 S. No: 9/3 32100 Isparta, Turkey Phone: [phone] Mobile: [phone] Fax: [phone] E-mail: [e-mail]