[Preoperative magnetic resonance imaging evaluation of the aortic annular diameter in aortic valve stenosis].
Accurate preoperative knowledge of the aortic annular diameter is a great value in determining the appropriate procedure for aortic valve stenosis. We have successfully used magnetic resonance imaging (MRI) to evaluate the size of the aortic annular diameter preoperatively. Between October 1997 and October 1998, 5 aortic valve replacements were performed in patients with aortic valve stenosis. MRI was performed preoperatively in all cases. All images were gated to the R-wave of the electrocardiogram. Images representing 5 mm slices were acquired in the plane which is parallel to the line through the center points of the aortic root and left ventricle outflow tract. The maximum diameter of the aortic annulus (D) was measured at the point just below the attachment of the aortic valve leaflets. This diameter was compared to the maximum diameter of the prosthetic valve sizer (D 1) which could be easily inserted into the aortic annulus intraoperatively, and to the diameter of the prosthetic valve (D 2) that ultimately was implanted. Twenty-five minutes were required to scan each patient. There were no complications related to scanning. Mean values were D = 23.4 mm, D 1 = 22.3 mm and D 2 = 21.4 mm. There was a significant correlation between D and D 1, and D 2 was approximately 2 mm smaller than D. MRI evaluation is an accurate, noninvasive method for determining the aortic annular diameter preoperatively. We highly recommend this method for measuring the aortic annular diameter in case of aortic valve stenosis as part of the preoperative evaluation.
Meguro
A
A
Department of Cardiovascular Surgery, Niigata Kobari Hospital, Niigata, Japan.
Tani
D
D
Saitoh
H
H
D001011:Aorta / Q000473:pathology*; D001024:Aortic Valve Stenosis / Q000473:pathology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*