Echocardiographic measurement of mitral intertrigonal distance is an adjunct to annuloplasty ring sizing.

BACKGROUND AND AIM OF THE STUDY: Annuloplasty sizing with standard valve sizers may be imprecise and difficult in minimally invasive procedures. It is hypothesized that a constant clinical conversion factor relates the echocardiographic aortic annulus diameter (AAD) and the intertrigonal distance (ITD) in patients with degenerative mitral regurgitation (MR). This may provide another method to size the annuloplasty ring required for mitral valve repair.

METHODS

An observational study of 50 patients with degenerative MR undergoing robotic-assisted surgery was conducted. All patients underwent surgery between September 2005 and November 2007. The AAD at the base of the aortic leaflets was measured using intraoperative two-dimensional transesophageal echocardiography. The ITD was measured independently under direct vision during surgery. The echocardiographic ITD was then determined by dividing the AAD by 0.8, and the value for each patient compared to the corresponding surgical measurement. Agreement was assessed statistically using the Bland-Altman method.

RESULTS

The limits of agreement were -3 mm (t = 2.010; 49 df; p = 0.05; 95% CI: -4 to -2 mm) to 3 mm (t = 2.010; 49 df; p = 0.05; 95% CI: 2 to 4 mm). In 86% of cases (43/50), the differences between the two methods was < or = 2 mm.

CONCLUSION

In most cases of degenerative mitral valve disease the echocardiographic ITD measurement is clinically acceptable, and may serve as an adjunct to existing methods when sizing the annuloplasty ring required for repair.