Surgical treatment of anterior mitral valve prolapse using artificial chordal loop

Objective To summarize the clinical experience for treating anterior mitral leaflet prolapse with an artificial chordal loop. Methods From January 2008 to August 2009, pre-measured ePTFE loops were used to treat anterior leaflet prolapse in 8 patients, 5 males and 3 females, aged from 28 to 68 ( average 56.0 ± 8.9 ) years. The heart function (NYHA) was class Ⅱ in 2 patients and class Ⅲ in 6. Echocardiography showed chordal rupture in 7 patients, 2 with chordal rupture and elongation and pure chordal elongation in 1. There were 3 patients with A1 segment prolapse of anterior mitral leaflet, 2 with A2 segment prolapse, 3 with both A2 and A3 segments prolepses by Carpentier standardization. There were 2 patients with posterior leaflet chordal rupture in P2 and P3 segment, 1 with cor triatrium. Left ventricular end diastolic diameter (LVEDD) was 53 - 62 mm [average ( 57.2±3.8 ) mm]. Ejection fraction (EF) was 0.60 - 0. 68 ( average 0.63 ± 0.02). Heart-thoracic ratio was 0. 52 ± 0. 17. We measured the normal chordal using both a caliber and by echocardiography ( for comparison after operation). The artificial chordal loops was constructed on the caliber using ePTFE suture, and then fixed the loop to the papillary muscle and the free edge of the anterior leaflet. Results There was no operation death. Hemolysis after 2 days of operation in 1 patient was amended by alkalinization, diuresis and hormone treatment. Pre-discharge transthoracic echocardiography showed mild regurgitation in 1patient, trivial regurgitation in 7. LVEDD were 42 -51mm [average (47. 1 ±2.2) mm] significantly decreased than that of pre-operation. Following parameters were measured and compared with pre-operation: EF 0. 58 ± 0. 03 vs. 0. 63 ± 0. 02, beart function ( NYHA ) class 1.25 ± 0. 42 vs. 2.75 ± 0. 58. Normal chordal length measured by caliber was ( 21.20 ± 1.55 ) mm vs. ( 22. 10 ± 2.68 ) mm by echocardiography. Anticoagulate therapy with warfarin was for 3 months after discharge and followed-up all the patients [1 - 19 months, average (8.2 ± 4.3 ) months]. Post operative echocardiography showed mild regurgitation in 1 patient, no or trivial regurgitation in 7 patients. The heart function class was evident improved compared with pre-operation :6 patients in class Ⅰ , 2 patients in class Ⅱ. Conclusion The pre-measured ePTFE loop is reliable and reproducible confirmed by short term follow-up for treating anterior leaflet prolapse. Key words: Mitral valve prolapse;  Chordae tendineae;  Cardiac surgical procedures;  Loop;  Caliber