ECO e saida de CEC

The Use of Transesophageal Echocardiography for
Differential Diagnosis of Poor Venous Return During
Cardiopulmonary Bypass
Ellen D. Iannoli, MD
Transesophageal echocardiography (TEE) is now
widely accepted as being useful in the management of
patients undergoing cardiac surgery. There are also
reports of using TEE to assist with placement of
cannula for cardiopulmonary bypass (CPB) (1–3).
However, there are few reports of the use of TEE for
troubleshooting problems during CPB. We present a
case in which intraoperative TEE assisted in the diagnosis
of poor venous return during CPB.
A 64-year-old man presented for redo-sternotomy
and heart transplantation. CPB was instituted after
cannulation of the ascending aorta and the left femoral
vein. At the time of femoral venous cannula placement,
TEE was used to confirm positioning of the tip
of the venous cannula at the junction of the inferior
vena cava (IVC) and right atrium. After initiation of
CPB, venous return flow was noted to be low and his
cardiac index was
2 L
min1
m2. Low venous
return to the CPB circuit may be related to low blood
volume, air in the venous return line, inappropriate
cannula placement, or obstruction of the cannula.
Vacuum was applied to the circuit without improvement
in venous return. At this time TEE examination
revealed intermittent obstruction of the venous cannula
inflow by a large, redundant Eustachian valve
(Figs. 1 and 2 and please see video loop available at
www.anesthesia-analgesia.org). After withdrawal of
the venous cannula by a few centimeters, venous
return promptly improved and the cardiac index
increased to 2.3 L
min1
m2.
TEE may be used for guiding CPB IVC cannula
placement during direct insertion via a median sternotomy.
Avoiding malposition of the venous cannula
in the hepatic vein by TEE examination has been
described (2). Our case demonstrates that TEE examination
is also important for assisting in positioning the
IVC cannula when placed via the femoral vein. In this
situation, TEE first confirms placement of the guidewire
in the atrium and then the correct positioning of
the subsequently placed venous cannula at the right
atrium and IVC junction. In our case, the venous
cannula appeared to be properly positioned on TEE
examination, and obstruction to venous inflow was
not evident until initiation of CPB. The Eustachian
valve is a vestigial portion of the IVC which functions
This article has supplementary material on the Web site:
www.anesthesia-analgesia.org.
From the Department of Anesthesiology, University of Rochester
School of Medicine and Dentistry, Rochester, New York.
Accepted for publication March 12, 2007.
No reprints will be available from the author.
Address correspondence to Ellen D. Iannoli, MD, 601 Elmwood
Ave., Box 604, Rochester, NY 14642. Address e-mail to
Ellen_iannoli@urmc.rochester.edu.
Copyright © 2007 International Anesthesia Research Society
DOI: 10.1213/01.ane.0000265550.42968.af
Figure 1. Transesophageal echocardiography bicaval image
demonstrating the venous cannula at the junction of the
right atrium and inferior vena cava. The Eustachian valve is
also noted.
Figure 2. Similar transesophageal echocardiography image
as for Figure 1 demonstrating obstruction of the venous
cannula by the Eustachian valve (arrow) after initiation of
cardiopulmonary bypass.
Vol. 105, No. 1, July 2007 43
during fetal life to direct IVC blood flow across the
foramen ovale. Occasionally, similar vestigial structures
are fenestrated and more extensive (Chiari network).
Recognition of obstruction of the venous
cannula by the residual Eustachian valve was facilitated
by the use of intraoperative TEE, including
during initiation of CPB.
ACKNOWLEDGMENTS
The author thanks Dr. Peter Bailey for assistance in
preparing the manuscript.