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[Value of preoperative assessment on transcatheter aortic valve implantation procedure with high-pitch dual-source computed tomography angiography].

OBJECTIVE
To evaluate the value of preoperative assessment on transcatheter aortic valve implantation (TAVI) procedure with high-pitch dual-source computed tomography angiography (CTA).


METHODS
Seventeen consecutive patients with severe symptomatic aortic stenosis underwent TAVI in our department from December 2012 to December 2013 were examined by 128-slice prospective ECG-triggered high-pitch spiral CTA and the clinical data were analyzed. Aortic annulus, sinus of Valsalva, sinotubular junction, ascending aorta and native leaflet to coronary ostium length were measured. Peripheral vascular access was evaluated. Then the patients were assessed on the suitability for TAVI procedure and prosthetic valve sizes.


RESULTS
Mean diameter of the aortic annulus was (25.7 ± 2.0) mm, perimeter mean diameter was (26.4 ± 2.0) mm, area mean diameter was (25.4 ± 1.9) mm. Mean diameter of sinus of Valsalva was (34.0 ± 3.8) mm. Mean diameter of sinotubular junction was (30.5 ± 3.2) mm. Mean diameter of ascending aorta was (37.8 ± 2.8) mm. The length from native leaflet to left coronary ostium was (14.0 ± 2.0) mm, and the length from native leaflet to right coronary ostium was (15.9 ± 3.6) mm. Mean diameter of left iliac arteries was (7.5 ± 1.4) mm. Mean diameter of right iliac arteries was (7.4 ± 1.2) mm. Mean diameter of left femoral arteries was (7.4 ± 1.2) mm. Mean diameter of right femoral arteries was (7.3 ± 1.3) mm. One patient was considered ineligible for TAVI because of large aortic annulus diameter. Three patients died prior to TAVI. Two patients refused to undergo TAVI. Eleven patients underwent TAVI, 26# prosthetic valve was implanted in 1 patient, 29# prosthetic valve implanted in 6 patients, 31# prosthetic valve implanted in 4 patients. Prosthetic valve implantation was successful in 9 patients and only mild or trace perivalvular leakage was observed in these patients. Moderate perivalvular leakage were observed in 2 patients because of the location of implantation was too low, and perivalvular leakage was significantly reduced after re-implantation with same size prosthetic valve at a higher location.


CONCLUSIONS
CTA can be used to evaluate the aortic root anatomy and vascular access, and help to choose the right size of prosthetic valve. CTA has an important practical value in preoperative screening of TAVI procedure.