The Ring-Noose-String Technique for Subvalvular Repair Stabilization in Patients with Functional Mitral Regurgitation

Objective: Isolated ring annuloplasty for repair of functional mitral regurgitation (FMR) suffers from significant failure rates (30% recurrent severe mitral regurgitation at 1 year). We and others have described subvalvular strategies to improve durability. We report our experience with the ring-noose-string technique and report mid-term follow up.

Methods: We analyzed outcome and durability of mitral repair in all patients with FMR who underwent mitral valve repair with the ring-noose-string technique. The technique consists of anchoring a polytetrafluoroethylene string and noose to the posteromedial and anterolateral papillary muscle, respectively. The string is guided through the noose, exteriorized through the midposterior annulus into the left atrium and secured to the ring used for annuloplasty. Length-adjustment is performed during saline test.

Results: Since 2013, 21 patients (age: 68 ± 11 years, male: n = 11, 52%) underwent mitral valve repair with this technique. All patients had severe FMR with a preoperative ejection fraction of 40 ± 11%. Mean STS score was 2.9 ± 2.3%. Additional procedures were tricuspid valve repair in 13, cryoablation in 9, PFO closure in 5 and bypass grafting in 3 patients. A minimally invasive approach was used in 67%. The ring-noose-string technique was applied without complications. Procedural, cardio pulmonary bypass and cross clamp times were 178 ± 33 min; 144 ± 34 min and 61 ± 9 min. There were no intraoperative complications and all patient left with ether no or trivial mitral regurgitation. Mean follow up was 446 days (3–1,457 days). One patient died within 30 days and two during follow-up (day 67 and 115). One patient required mitral valve replacement due to endocarditis 3 months postoperative. Latest follow up echo demonstrated stable mitral valve function without evidence for moderate or severe regurgitation (degree of mitral regurgitation: 0.6 ± 0.6).

Conclusion: The ring-noose-string technique for mitral valve repair in patients with FMR appears to stabilize durability of the repair and may therefore potentially improve outcome of mitral valve surgery. The technique is safe and suitable for minimally invasive surgery.