Ann Thorac Surg 2003;75:1014-1016
© 2003 The Society of Thoracic Surgeons
Case report
Retroaortic innominate vein with coarctation of the aorta: surgical repair and embryology review
Igor E. Konstantinov, MD*a,
Glen S. Van Arsdell, MDa,
Stacy O’Blenes, MDa,
Nathalie Roy, MDa,
Andrew Campbell, MDa
a Division of Cardiovascular Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
Accepted for publication August 22, 2002.
* Address reprint requests to Dr Konstantinov, Division of Cardiovascular Surgery, Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada.
e-mail: igorkonst{at}hotmail.com
 |
Abstract
|
|---|
A newborn girl with a retroaortic innominate vein, coarctation of the aorta, ventricular septal defect, and subaortic stenosis underwent a complete repair at 8 days of age. The ascending aorta was transected and the innominate vein was brought in front of it. We review the anatomy and embryology of this rare entity and describe the surgical technique to avoid recoarctation and innomante vein compression.
|
Introduction
|
|---|
A left retroaortic brachiocephalic (innominate) vein is a rare condition. It has an incidence of 0.2% to 1% among congenital cardiac anomalies [1–3]. Although is was first described by Kerschner [4] more than 100 years ago, the clinical experience with this anomaly is limited with less then 100 cases described worldwide [1–5]. It is frequently associated with right aortic arch or high left aortic arch [1, 6]. We believe that this association is not accidental. Herein we review the embryology to support our theory and provide a basis for surgical correction.
A newborn girl weighing 3.12 kg was noted to have a murmur at birth with weak femoral pulses. Her arm-to-leg blood pressure gradient was 20 mm Hg. Echocardiogram demonstrated an unrestrictive ventricular septal defect (VSD) with posterior malalignment of the outlet septum, subaortic stenosis, restrictive patent foramen ovale (PFO), almost closed ductus, bicuspid aortic valve and good biventricular function. Aortic annulus was 0.5 cm, pulmonary annulus 1.1 cm, tricuspid annulus 1.2 cm, ascending aorta proximal to left carotid artery (LCA) was 0.45 cm. There was a juxtaductal coarctation at the level of the left subclavian artery (LSA). There was 1-cm and 0.31-cm in diameter narrow segment of the arch between the LCA and LSA The patient was started on prostaglandin (PGE1) at 0.05 µg · kg-1 · min-1. She remained stable and underwent elective surgery on March 20, 2002 at the age of 8 days.
The surgery was performed through the midline sternotomy. There was an incidental finding of the retroaortic innominate vein (Fig 1A).
The patient was place on cardiopulmonary bypass (CPB) in standard fashion using ascending aortic and bi-caval cannulation. Patient was cooled to 25°C. Descending aorta and arch vessels were mobilized. After cardioplegic arrest, the PDA was ligated and circulatory arrest was established for 25 minutes. During the period of circulatory arrest, ascending aorta was transected and the innominate vein was brought in front of the ascending aorta. The hypoplastic aorta was ligated just beyond the LSA and ductal tissue was resected. The continuity of the ascending aorta was reestablished by a "semilunar" anastomosis and the descending aorta was anastomosed into the ascending aorta end-to-side (Fig 1B). CPB was resumed. A subaortic myectomy was performed and the ventricular septal defect was closed with a Dacron Sauvage patch. PFO was closed with direct suture. Total aortic cross-clamp time was 93 minutes. Total CPB time was 79 minutes. Upon weaning off pump transesophageal echocardiogram (TEE) was performed and demonstrated unobstructed flow in the ascending aorta and through the end-to-side aortic anastomosis. There was flow acceleration in the subaortic area with a mean gradient of 8 mm Hg. Patient developed complete heart block and required sequential pacing for 5 days but regained normal sinus rhythm on postoperative day 5. She was discharged home 10 days after surgery.
View larger version (68K):
[in this window]
[in a new window]
|
Fig 1. Intraoperative view of the anomaly. (A) Anatomy. Retroaortic innominate vein enters the superior vena cava (SVC) below the azygos vein (AzV). Increased distance between the left carotid artery (LCA) and left subclavian artery (LSA). (B) Surgical repair. Ascending aorta transected, the innominate vein brought in front of the aorta. Descending aorta anastomosed into the ascending aorta end-to-side. (Ao = aorta; InV = innominate [left brachiocephalic] vein; LPA = left pulmonary artery; PDA = patent ductus arteriosus; RCA = right carotid artery; RSA = right subclavian artery.)
|
|
|
Comment
|
|---|
In our patient, there was a significant distance between the origin of the left common carotid and the left subclavian artery, and a high aortic arch. These findings are typical of "pseudocoarctation" of the aorta, which distinguishes itself from a true coarctation by a high aortic arch and the absence of clinical signs or hemodynamic abnormalities, with the trans-stenotic pressure gradient remaining below 25 mm Hg [7, 8]. Embryologically, this anomaly results from a lack of shortening of the left dorsal and ventral aortic roots of the left fourth aortic arch [8]. At the eighth week both anterior cardinal veins are interconnected by the superior and inferior capillary plexuses (Fig 2A).
Normally, the aortic arch shortens during the embryological development and occupies the space of the inferior transverse capillary plexus, thus causing its regression, while the rest of venous blood shunts into the superior transverse capillary plexus. This facilitates normal development of the innominate vein (Fig 2B). In case of the right aortic arch or high aortic arch, the inferior capillary plexus may persist and form a retroaortic innominate vein (Fig 2C). It is likely that in most cases, the ascending aorta still compresses the orifice of the inferior transverse capillary plexus causing the venous blood to shunt through the left anterior cardinal vein. The latter results in persistence of the left superior vena cava. In fact, there was a distinct narrowing of the retroaortic innominate vein at the site of its entry to the SVC due to ascending aortic compression. The above theory would explain frequent association of the retroaortic innominate vein with tetralogy of Fallot and right aortic arch [1].
View larger version (24K):
[in this window]
[in a new window]
|
Fig 2. Diagrams illustrating the development of the innominate vein. (A) In the sixth week of gestation: 1 = right anterior cardinal vein; 2 = left anterior cardinal vein; 3 = primitive aorta; 4 = superior transverse capillary plexus; 5 = inferior transverse capillary plexus; 6 = common cardinal veins; 7 = right posterior cardinal vein; 8 = left posterior cardinal vein; 9 = sinus venosus; 10 = vitelline vein; 11 = umbilical vein; 12 = developing inferior vena cava. (B) Normal anatomy: 1 = innominate vein; 2 = azygos vein; 3 = superior vena cava; 4 = right atrium; 5 = inferior vena cava; 6 = coronary sinus. (C) Retroaortic innominate vein: 1 = innominate vein; 2 = azygos vein; 3 = superior vena cava; 4 = right atrium; 5 = inferior vena cava; 6 = coronary sinus.
|
|
As expected, there was a long narrow area between left carotid and left subclavian artery in our patient. An extended end-to-end repair of this type of coarctation associated with high aortic arch would invariably result in shortening of the aortic arch and compression of the retroaortic innominate vein. Thus, it seemed mandatory to bring the innominate vein in front of the ascending aorta to prevent such compression. The concern was, however, that transection and anastomosing of the ascending aorta might result in narrowing at the site of the anastomosis later in life. To avoid this complication, we performed a "semilunar" anastomosis in the shape of an incomplete ring and restored the continuity of the aorta with the end-to-side anastomosis.
In summary, the described technique allowed us to avoid compression of the retroaortic innominate vein and create a widely open aortic anastomosis. Embryology gives a useful clue to understanding of the surgical anatomy of this rare malformation.
|
References
|
|---|
- Curtil A., Tronc F., Champsaur G., et al. The left retro-aortic brachiocephalic vein: morphologic data and diagnostic ultrasound in 27 cases. Surg Radiol Anat 1999;21:251-254.[Medline]
- Choi J.Y., Jung M.J., Kim Y.H., Noh C.I., Yun Y.S. Anomalous subaortic position of the brachiocephalic vein (innominate vein): an echocardiographic study. Br Heart J 1990;64:385-387.[Abstract/Free Full Text]
- Gerlis L.M., Ho S.Y. Anomalous subaortic position of the brachicephalic (innominate) vein: a review of published reports and report of three new cases. Br Heart J 1989;61:540-545.[Abstract/Free Full Text]
- Kerschner L. Zur Morphologie der Vena Cava Inferior. Anat Anz 1888;3:808-823.
- Elami A., Rein A.J., Premiger T.J., Milgalter E. Tetralogy of Fallot, absent pulmonary valve, partial anomalous pulmonary venous return and coarctation of the aorta. Int J Cardiol 1995;52:203-206.[Medline]
- Bartoli J.M., Chagnaud C., Moulin G., Di Stefano-Louineau D., Bory M., Kasbarian M. Pseudocoarctation of the aorta associated with reto-aortic left brachiocephalic vein: a case report. Surg Radiol Anat 1990;12:307-309.[Medline]
- Hoeffel J.C., Henry M., Mentre B., Louis J.P., Pernot C. Pseudocoarctation or congenital kinking of the aorta: radiologic consideration. Am Heart J 1975;89:428-436.[Medline]
- Cheng T.O. Pseudocoarctation of the aorta. Am J Med 1970;49:551-555.[Medline]
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]
|
|
|
|
|
|
|
S.-J. Chen, K.-L. Liu, H.-Y. Chen, I.-S. Chiu, W.-J. Lee, M.-H. Wu, Y.-W. Li, and H.-C. Lue
Anomalous Brachiocephalic Vein: CT, Embryology, and Clinical Implications
Am. J. Roentgenol.,
April 1, 2005;
184(4):
1235 - 1240.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
