Alexander W. Leber MD, PhD, Presenter: Nothing to Disclose

Markus Kasel, Abstract Co-Author: Proctor, Edwards Lifesciences Corporation

Hans Ullrich Ebersberger, Abstract Co-Author: Nothing to Disclose

Ulrich Platz, Abstract Co-Author: Nothing to Disclose

Device sizing is based on Echo measurements although this may be somehow inaccurate taking into acount the oval shape of the annulus. In the current study we assessed the expansion pattern of the Edwards Sapien XT (ESXT) device and a MSCT guided sizing approach. 

Pre- and postprocedural  MSCT (Philips Brilliance 64) was performed in 80 patients (30 patients with pre-and post CT). TAVI size selection was done on the basis of anulus cross sectional measurements (CSA) by MSCT so that the nominal TAVI device CSA always exceeded the anulus CSA. In the preprocedural data sets we determined CSA of the anulus, the valve calcium score and the ovality index of the anulus. In the postprocedural data sets maximum and minimum diameter of the device was measured at three levels and the degree and the symmetry of expansion was determined. In all patients a pre procedural transesophageal echo (TEE) was done to determine the annuls diameter.  

The average minimum expansion ratio of the Edwards Sapien XT device at the level of the annulus was 94% . In 96 % of patients the device expanded in a circular fashion with the maximum and minimum diameter differing by less than 10%. The amount of calcium (calcium score) and ovality of the native anulus were not associated with under or asymetric expansion of the device. Oversizing of the device by more than 25% in comparison to the native anulus was associated with suboptimal device expansion and with the incidence of significant postprocedural conduction disorders requiring pacemaker implantation (16% vs. 5%). In none of the patients we could observe postprocedural aortic regurgitation >Grade 2. Preprocedural TEE Measurements underestimated the anulus CSA  and would have lead to the selection of smaller size devices in 40% of patients (32/80 patients).

MSCT guided sizing is associated with almost complete and symmetric expansion of the ESXT device in >90% of cases  and the absence of significant aortic regurgitation. Calcification or ovality of the native anulus do not influence the expansion pattern. To rigorous device oversizing however is associated with a trend towards a higher rate of pacemaker implantations and device underexpansion.

MSCT is superior to TEE annulus meaurements and leads to favourable outcomes as TEE based sizing systematically underestimates annulus CSA and leads to device undersizing in a large group of patients

Leber, A, Kasel, M, Ebersberger, H, Platz, U, MSC-guided Sizing of the Edwards Sapien XT TAVI Device and Post implantation Geometry in Relation to Pre-procedural Aortic Anulus Anatomy: An Evaluation by MSCT.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12037956.html