Mitral valve annulus assessment: a comparison between 3D-TOE, CCT and surgical ring
Authors: Pasquini A , Pica A , Filice M , Lillo R , Panzera R , Corigliano K , Bruno P , Nesta M , Pavone N , Grandinetti M , Moliterno E , Marano R , Cameli M , Massetti M 
Published: January 2025

Abstract

Background
Advances in minimally invasive cardiac surgery require accurate preoperative assessment of the morphology and function of the mitral valve apparatus. The success of mitral valve repair with annuloplasty depends on the correct sizing of the mitral annulus ring (1) (2). Three-dimensional transoesophageal echocardiography (3D-TOE) has been proven to be essential for the anatomo-functional characterization of mitral valve apparatus in patients undergoing surgically mitral valve repair (3). It also allows the measurement of quantitative parameters useful in determining the size of the annuloplasty ring, such as A2 height, intertrigonal distance, intercommissural diameter and total annular perimeter size. Cardiac computed tomography (CCT) plays a key role for device sizing in patients undergoing transcatheter mitral valve replacement (4); it is the gold standard for geometric characterisation of the mitral valve and assessment of the spatial relationship of the mitral valve apparatus to adjacent anatomical structures. Several studies have compared CCT with 3D-TOE in sizing the mitral valve apparatus (6) (7); few studies have compared mitral valve apparatus measurements obtained by 3D-TOE and CCT with those obtained intraoperatively by the surgeon, which is the gold standard.

Purpose
To compare intra-operatively 3D-TOE assessment of mitral valve apparatus with CCT and to compare 3D-TOE and CCT measures with intraoperative surgeon-measured mitral valve annulus.

Methods and results
We used a cohort of thirty patients who underwent surgery for severe primary mitral regurgitation with mitral valve repair using the Carpentier technique with annuloplasty, all of whom had undergone CCT prior to surgery to exclude coronary artery disease.
We compared measurements of the mitral annulus (intertrigonal distance and intercommissural distance) obtained by 3D-reconstruction of intra-operative TOE and 2D-short axis CCT reconstruction with the ring measured intraoperatively by the surgeon and then implanted, using intraclass correlation.
We found that the intertrigonal distance measured by CCT showed good agreement with the surgical ring (ICC 0.89 [CI 0.330-0.985; p &lt; 0.05]); the intercommissural distance obtained by 3D-TOE also showed good agreement with the surgical ring (ICC 0.81 [CI 0.458-0.936; p &lt; 0.05]), while the intertrigonal distance measured by 3D-TOE showed a moderate agreement with the surgical annulus (ICC 0.63 [CI 0.056-0.852; p &lt; 0.05]). We then compared the intraoperative 3D TOE measurements with those obtained by CCT and found excellent agreement when comparing the intertrigonal distance (ICC 0.95 [CI 0.755-0.989; p&lt;0.05]).

Conclusions
3D-TOE can be considered as a first-line imaging technique to assess the anatomical features of the mitral valve apparatus, not only in patients undergoing cardiac surgery, but also in those undergoing percutaneous interventions or with contraindications to contrast medium CT.
3D-TOE reconstruction
Surgical and CCT