Geometry and Degree of Apposition of the CoreValve ReValving System With Multislice Computed Tomography After Implantation in Patients with Aortic Stenosis

OBJECTIVES: Using multislice computed tomography (MSCT), we sought to evaluate the geometry and apposition of the CoreValve ReValving System (CRS, Medtronic, Luxembourgh, Luxembourgh) in patients with aortic stenosis. Background: There are no data on the durability of percutaneous aortic valve replacement. Geometric factors may affect durability.

METHODS: Thirty patients had MSCT at a median 1.5 months (interquartile range [IQR] 0 to 7 months) after percutaneous aortic valve replacement. Axial dimensions and apposition of the CRS were evaluated at 4 levels: 1) the ventricular end; 2) the nadir; 3) central coaptation of the CRS leaflets; and 4) commissures. Orthogonal smallest and largest diameters and cross-sectional surface area were measured at each level.

RESULTS: The CRS (26-mm: n = 14, 29-mm: n = 16) was implanted at 8.5 mm (IQR 5.2 to 11.0 mm) below the noncoronary sinus. None of the CRS frames reached nominal dimensions. The difference between measured and nominal cross-sectional surface area at the ventricular end was 1.6 cm2 (IQR 0.9 to 2.6 cm2) and 0.5 cm2 (IQR 0.2 to 0.7 cm2) at central coaptation. At the level of central coaptation the CRS was undersized relative to the native annulus by 24% (IQR 15% to 29%). The difference between the orthogonal smallest and largest diameters (degree of deformation) at the ventricularend was 4.4 mm (IQR 3.3 to 6.4 mm) and it decreased progressively toward the outflow. Incomplete apposition of the CRS frame was present in 62% of patients at the ventricular end and was ubiquitous at the central coaptation and higher.

CONCLUSIONS: Dual-source MSCT demonstrated incomplete and nonuniform expansion of the CRS frame, but the functionally important mid-segment was well expanded and almost symmetrical. Undersizing and incomplete apposition were seen in the majority of patients.

PMID: 19712801

Schoenhagen Paul

Cardiovascular Imaging
Imaging Institute and
Heart&Vascular Institite
Cleveland Clinic
Cleveland, OH
Posted in Computed Tomography, Invasive Imaging and tagged , , .

One Comment

  1. MDCT may have an important role in the evaluation of patients undergoing percutaneous aortic valve replacement, especially, during pre-planning of the procedure. Important factors such as the distance from the coronary ostium, or evaluation of the ilio-femoral-aorta vessels may be crucial. CT may also has a role in preventing patient-prosthesis mismatch. Whether image registration in the future will also allow better positioning of the valve is unknown.

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