Ann Thorac Surg 1998;65:1770-1772
© 1998 The Society of Thoracic Surgeons
Case Reports
Surgical Management of Tricuspid Atresia and Anomalous Left Brachiocephalic Vein
Theodore C. Koutlas, MDa,
Gil Wernovsky, MDb,
Michael C. Slack, MDa,
Paul M. Weinberg, MDb,
Thomas L. Spray, MDa
a Division of Cardiothoracic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
b Division of Cardiology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
Accepted for publication December 17, 1997.
Address reprint requests to Dr Koutlas, Division of Cardiothoracic Surgery, East Carolina University School of Medicine, Greenville, NC 27858-4354
e-mail: (tkoutlas{at}brody.med.ecu.edu)
 |
Abstract
|
|---|
An anomalous left brachiocephalic vein is an uncommon systemic venous anomaly, which usually has no clinical significance. We describe a case of tricuspid atresia with such an anomalous left brachiocephalic vein. The presence of this unusual venous anomaly had a number of implications in the surgical management of the tricuspid atresia.
|
Introduction
|
|---|
The normal course of the left brachiocephalic vein (BCV) is anterior to the aortic arch where it joins the right BCV to form the superior vena cava (SVC). An unusual congenital malformation exists where the left BCV has an anomalous course posterior to the aortic arch and joins the SVC between the azygos vein and the cavoatrial junction. Although this anomaly usually has little clinical significance, we describe a case of tricuspid atresia in which an anomalous left BCV played a significant role in the surgical palliation of the child.
The patient was diagnosed shortly after birth with tricuspid atresia, ventricular septal defect, normally related great arteries, and mild posterior deviation of the infundibular septum. She initially underwent balloon atrial septostomy, but subsequently needed pulmonary artery (PA) banding at 3 weeks of age because of unrestricted pulmonary blood flow. Although this provided an adequate initial palliation, she had continued cyanosis and failure to thrive, and was referred for further surgical management at 2 years of age, weighing 8.8 kg. The two-dimensional transthoracic echocardiogram confirmed the above diagnoses. The right ventricle was severely hypoplastic, and the PA band appeared in place on the main pulmonary artery (MPA), with the branch PAs measuring 0.5 cm in diameter. There appeared to be a left SVC superior in the mediastinum, but the vessel could not be clearly distinguished as it passed near the left pulmonary artery (LPA). Subsequent cardiac catheterization revealed nondistorted branch PAs with a mean pressure of 12 mm Hg. The pulmonary to systemic flow ratio was 0.9:1 with a pulmonary vascular resistance, as estimated by pulmonary venous capillary wedge pressure, of approximately 2 Wood units. The angiogram clearly demonstrated an anomalous left BCV coursing caudally in the mediastinum, on an anterior to posterior slope. It passed between the LPA (anterior) and the left main bronchus (posterior), and appeared to be compressed between these two structures (Fig 1A). The area of compression was just left of the spine and at least 1.5 cm below the carina (Fig 1B). The vein then passed rightward and inferiorly, "looped" posterior and cephalad above the pulmonary venous confluence, then passed rightward again to enter the SVC just above the level cavoatrial junction. There were also two small tributaries connecting the left BCV to the roof of the left atrium (LA), and a tiny bridging vein in the normal location of the left BCV. The proximal portion of the left BCV was quite dilated, and there appeared to be significant obstruction to flow where the vein passed between the LPA and the left main bronchus. The posterior malalignment of the infundibular septum produced mild subaortic stenosis, with a 10 mm Hg gradient across the left ventricular outflow tract. The aortic arch anatomy and pulmonary venous connections were normal. Magnetic resonance imaging of the chest confirmed the anomalous course of the left BCV.
View larger version (79K):
[in this window]
[in a new window]
|
Fig 1. (A) Lateral view of the cineangiogram during injection of the left brachiocephalic vein. Arrow indicates site of compression of the anomalous left brachiocephalic vein between the left pulmonary artery and the left main bronchus. (B) Anteroposterior view of the same cineangiogram. Arrow indicates the area of compression of the anomalous left brachiocephalic vein by the left main bronchus.
|
|
Surgical repair was performed through a median sternotomy. The anomalous left BCV passed posterior to the LPA and anterior to the left main bronchus then coursed medially across the mediastinum to enter the right SVC medial to the azygos vein. The tributaries that came off the anomalous vein passed posterior to the LPA to the roof of the LA. The patient was placed on cardiopulmonary bypass and cooled to 18°C. With the circulation arrested, the left BCV was divided left of the trachea, the distal end was oversewn, and the small tributaries leading to the LA were ligated and divided. A left cavopulmonary anastomosis was performed with the proximal portion of the left BCV anastomosed end-to-side to the LPA. The MPA was divided at the level of the previous PA band, and the right PA was opened anteriorly to the hilum. A hemi-Fontan type of right cavopulmonary connection was then performed, augmenting the anastomosis with a patch of pulmonary homograft in a manner previously described [1]. The azygos vein and the distal left BCV were both ligated at their junction with the SVC. Finally, the proximal MPA was anastomosed to the medial ascending aorta in a Damus-Kaye-Stansel fashion, with a small patch of pulmonary homograft used to augment the anastomosis. Cardiopulmonary bypass was then resumed, and after rewarming the patient was weaned with good hemodynamics and no inotropic support. Intraoperative transesophageal echocardiography revealed good left ventricular function with an unobstructed MPA–aortic anastomosis. The cavopulmonary anastomoses were also unobstructed, and there was no evidence of baffle leak into the right atrium.
The patient’s postoperative course was uneventful. Her first blood gas measurement revealed an arterial O2 saturation of 83% on an inspired oxygen fraction of 1.0. She was weaned from the ventilator and extubated 8 hours after the operation, and subsequently she was discharged home on postoperative day 5 receiving maintenance digoxin and furosemide, with an O2 saturation in room air of 81%. She has done well since, maintaining a normal growth pattern, and recently underwent cardiac catheterization 1 year after her repair. Systemic arterial oxygen saturation was 82%, with a mixed venous saturation of 62%. The mean PA pressure was 10 mm Hg, mean atrial pressure was 6 mm Hg, and estimated pulmonary vascular resistance was 1.5 Wood units. Superior vena cava-to-PA blood flow through the hemi-Fontan repair was unobstructed. There was no gradient from the left ventricle to the descending aorta. The patient has since undergone a successful modified Fontan repair using a lateral tunnel technique with a single 4.0-mm fenestration.
|
Comment
|
|---|
Kershner [2] described the first case of anomalous left BCV, which he found on autopsy more than 100 years ago. Since then, a total of 58 patients with this anomaly have been documented in the literature [3]. Only 13% of cases were isolated anomalies, the remainder having associated cardiac defects. More than 80% of patients with an anomalous left BCV have obstruction of the right ventricular outflow tract, usually tetralogy of Fallot, with or without pulmonary atresia [4]. A right aortic arch is also a common finding. Other associated cardiac abnormalities have included common arterial trunk, transposition of the great arteries, and interrupted aortic arch. This venous anomaly is quite uncommon. One study found 24 cases among 2,457 patients with echocardiograms for congenital heart diseases [5]. The diagnosis of an anomalous left BCV can usually be made using two-dimensional transthoracic echocardiography, but angiography, computed tomography, and magnetic resonance imaging also have been used successfully [6]. In the majority of cases the anomalous left BCV has no clinical or physiologic significance, and previous reports have generally emphasized the correct diagnosis of this anomaly to prevent confusion of the BCV with the LPA [4]. Also, the identification of an anomalous left BCV should prompt a thorough evaluation for evidence of other congenital cardiac malformations.
Our patient presented an unusual situation as the major structural cardiac anomaly, tricuspid atresia, required a single-ventricle palliative strategy for long-term survival. The use of a standard bidirectional Glenn shunt in this patient may have resulted in significant postoperative difficulties because of the anomalous course of the BCV. The left BCV appeared to be dilated proximally on preoperative studies, which suggested compression of the vein between the LPA and the left main bronchus. Compression of the left BCV by the LPA and left main bronchus potentially would have interfered with venous return from the left upper body to the lungs. In addition, the tributaries connecting the left BCV to the roof of the LA had the potential to decompress the higher pressure systemic venous system into the LA after a standard bidirectional Glenn shunt, decreasing pulmonary blood flow and causing significant hypoxemia. Thus, our operative management included separate cavopulmonary anastomoses for the left BCV and the SVC, ligation of the tributaries connecting the vein to the LA, and performance of the left BCV-to-LPA anastomosis proximal to the site of compression. Both the azygos vein and the distal left BCV were ligated at their junction to the SVC to prevent any potential collateral formation. We also used a Damus-Kaye-Stansel type anastomosis between the MPA and the ascending aorta, because of our concern about progressive subaortic stenosis from the posteriorly malaligned ventricular septum. Studies have shown significant progression of subaortic stenosis after Fontan repair, as well as other operations in which volume unloading of single-ventricle lesions occurs [7, 8]. This operative approach has been successfully applied to infants with significant aortic outflow obstruction requiring single-ventricle repair [9].
In summary, we report an unusual case of an anomalous left BCV in a patient with tricuspid atresia. The diagnosis of this anomaly was made preoperatively with two-dimensional echocardiography, cineangiography, and magnetic resonance imaging. This anomaly had a significant impact on the successful operative management of this patient with a staged single-ventricle palliation.
|
References
|
|---|
- Norwood W.I., Jr Hypoplastic left heart syndrome. Ann Thorac Surg 1991;52:688-695.[Abstract]
- Kershner L. Morphologie der Vena Cava Inferior. Anat Anz 1888;3:808-823.
- Mills M.R., Wilcox B.R., Detterbeck F.C., Anderson R.H. Anomalous course of the left brachiocephalic vein. Ann Thorac Surg 1993;55:600-602.[Abstract]
- Smallhorn J.F., Zielinsky P., Freedom R.M., Rowe R.D. Abnormal position of the brachiocephalic vein. Am J Cardiol 1985;55:234-236.[Medline]
- Choi J.Y., Jung M.J., Kim Y.H., et al. Anomalous subaortic position of the brachiocephalic vein (innominate vein): an echocardiographic study. Br Heart J 1990;64:385-387.[Abstract/Free Full Text]
- Minami M., Noda M., Kawauchi N., et al. Postaortic left innominate vein: radiological assessment and pathogenesis. Clin Radiol 1993;48:52-56.[Medline]
- Finta K.M., Beekman R.H., Lupinetti F.M., et al. Systemic ventricular outflow obstruction progresses after the Fontan operation. Ann Thorac Surg 1994;58:1108-1113.[Abstract]
- Donofrio M.T., Jacobs M.L., Norwood W.I., et al. Early changes in ventricular septal defect size and ventricular geometry in the single left ventricle after volume-unloading surgery. J Am Coll Cardiol 1995;26:1008-1015.[Abstract]
- Rychik J., Murdison K.A., Chin A.J., et al. Surgical management of severe aortic outflow obstruction in lesions other than the hypoplastic left heart syndrome: use of a pulmonary artery to aorta anastomosis. J Am Coll Cardiol 1991;18:809-816.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
R. Agarwal, G. S. Krishnan, S. Kulkarni, K. Bhatt, and K. M. Cherian
Novel use of a retroaortic innominate vein in cavopulmonary anastomosis
J. Thorac. Cardiovasc. Surg.,
July 1, 2006;
132(1):
166 - 167.
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
