Methods: From 4/2004 to 9/2006, 128 patients underwent primary mitral valve repair (MVR) for Myxo MR. In Group I, 92 patients underwent repair with conventional annuloplasty rings (Physio, n=70) and surgical techniques. In Group II, 36 patients (3/06 to 9/06) underwent MVR with a new Myxo ETlogix ring. This ring has a larger orifice to accommodate elongated leaflets, a 29% increase in AP diameter, and a 3D design that pulls the posterior leaflet away from the outflow tract to reduce systolic anterior motion (SAM). Ring sizing for Group II was calculated by direct measurement of the anterior and posterior leaflet heights. Baseline patient characteristics between the groups were similar, except for gender (76.1% males in Group I vs. 55.6% in Group II; p=0.022).

Results: Myxo MR was repaired in all patients. Quadrangular resection was performed in 77.2% vs. 75.0% of cases in Groups I and II, respectively. Sliding annuloplasty was performed in 28.3% of Group I patients and was not required in Group II (p<0.001). One operative mortality occurred in Group I (1.1%) and 0 in Group II. Median ring size was 32mm (range 26-40) and 34mm (range 26-36) in Groups I and II, respectively. After repair, overlap of the leaflet coaptation at A2 was 5.7±2.1mm and at P2 was 6.2±1.8mm in Group II. By echo, the mean distance from the coaptation point to the septum was 17.3±3.4mm (range 11-24) in Group II. Median gradient was 3.5mmHg at discharge and 3.4mmHg at follow-up and did not differ between groups. In Group I, mitral leaflet SAM occurred in 4 patients and chordal SAM in 1 patient (5.4% overall). In Group II, mitral leaflet SAM was not observed and chordal SAM occurred in 1 patient at late follow-up (2.8% overall). SAM in Group I resulted in early reoperation for 2 patients (2.2%), 1 requiring valve replacement, and 2 additional patients await reoperation. MR is depicted in the table (mean ±SD).

Conclusion: Surgical repair of Myxo mitral disease with this etiology-specific ring significantly reduced MR, simplified the repair technique by eliminating the need for sliding annuloplasty, without the subsequent development of SAM.