Value of Continuous Intra-operative Transesophageal Echocardiography in Patients undergoing Ascending Aortic Aneurysm Repair - A report of two cases and literature review
Michael S. Robinson, D.O. and Yong G. Peng,
M.D., Ph D.
Department of Anesthesiology, University of Florida, Gainesville, Florida
ABSTRACT
Surgical replacement of ascending aortic aneurysm is recommended for
aneurysms greater than 5cm.1,2 These procedures remain technically demanding
and fraught with complications because of the severity of the underlying
structural disease and of the typical comorbidities. Intra-operative
Transesophageal Echocardiolography (TEE) has become an invaluable diagnostic
modality in this setting as an aid in the necessary evaluation of the repair
and the management of complications prior to or immediately after separation
from the cardiopulmonary bypass (CPB).3,4
Case 1: A 37 year old patient with Marfan's syndrome underwent repair of a
5.5cm ascending aortic aneurysm complicated by moderate aortic insufficiency
with a Dacron graft and aortic valve salvage. Transesophageal
echocardiography (TEE) confirmed the preoperative finding of a normal
ejection fraction. Prior to separation from CPB, TEE demonstrated global
left ventricular akinesis. Left main coronary artery occlusion was
suspected. The Dacron graft was incised revealing the left main coronary
ostium obstructed by the Dacron graft button hole. A portion of the Dacron
graft surrounding the button was excised and a 5mm probe passed easily into
the left main coronary ostium. During rewarming TEE demonstrated excellent
left ventricular function and no aortic insufficiency.
Case 2: A 67 year old male underwent repair of a 5cm ascending aortic
aneurysm complicated by severe calcific aortitis and moderate to severe
aortic insufficiency with a Medtronic freestyle porcine valved conduit and a
Dacron graft. TEE confirmed the preoperative finding of severe left
ventricular systolic dysfunction with a 20-25% ejection fraction. Prior to
separation from CPB, TEE revealed instantaneous peak gradient of 80mmHg
across the aortic valve. A peak to peak gradient of 50mmHg between the left
ventricle and ascending aorta was measured by the surgeon. CPB was resumed.
The Dacron graft was transected and the aortic valve found to be slightly
constricted. The felt strips at the base of the valve were incised in
several areas to free the constriction. The patient was weaned from CBP and
TEE demonstrated an instantaneous aortic valve mean gradient less than
20mmHg
Both cases illustrate how the continuous real-time assessment of structure
and function of the heart improve surgical therapy and prevent potentially
fatal complications in the setting of complex cardiovascular surgery. The
literature is reviewed with case reports of intra-operative findings by TEE
examination either changing the preoperative diagnosis or providing vital
intra-operative information that optimized the surgical therapy.5
References:
1. Kouchoukos NT, Wareing TH, Murphy SF, Perrillo JB. Ann Surg
1991;214:308-20.
2. Gott VL, Gillinov AM, Pyeritz RE, et al. J Thorac Cardiovasc Surg
1995;109:536-45.
3. Bryan AJ, Barzilai B, Kouchoukos NT. Ann Thorac Surg 1995;59:773-9.
4. Poelaert JI. Ann Card Anaesthesia 2002;5:119-126.
5. Lobo A, Lewis JF, Conti CR. Clin Cardiology 2000;23:702-708
