Sept. 23, 2025
Mayo Clinic Cardiovascular Surgery implements a minimal risk, mechanism-specific mitral valve repair philosophy in certain patients: Every attempt should be made to repair rather than replace.
Gabor Bagameri, M.D., a cardiovascular surgeon at Mayo Clinic in Rochester, Minnesota, expands on Mayo Clinic's research on the durability of mitral valve repair for degenerative mitral valve (MV) disease in patients with obstructive hypertrophic cardiomyopathy (HCM). Dr. Bagameri also explains Cardiac Surgery's technical approach to successful repairs in these patients and what the future holds for the field.
Preserving the native valve
Mayo Clinic cardiac surgeons perform mitral valve repair for degenerative mitral regurgitation (MR) at the time of septal myectomy in patients with obstructive HCM while providing effective left ventricular outflow tract (LVOT) gradient relief and meaningful improvements in functional status. LVOT is the path the blood takes as it leaves the main pumping chamber of the heart (the left ventricle). With LVOT obstruction, there is restriction to that blood flow.
Mayo Clinic's approach to MV surgery in patients with obstructive HCM with degenerative disease is distinguished by a repair-first philosophy. Even when intrinsic degenerative pathology is present, such as leaflet prolapse, flail or chordal rupture, surgeons strive to preserve the native valve through repair combined with extended transaortic myectomy instead of defaulting to valve replacement.
This strategy is guided by the goal of avoiding prosthesis-related late complications, including thromboembolism, endocarditis and the need for lifelong anticoagulation. The operative technique is meticulously adapted to the unique anatomy and pathophysiology of obstructive HCM.
In contrast to isolated degenerative MR repairs, where near-universal annuloplasty is standard, obstructive HCM repairs at Mayo Clinic more often incorporate leaflet plication, neochordal reconstruction and Alfieri edge-to-edge sutures, with selective annuloplasty. This approach minimizes the risk of creating or exacerbating LVOT obstruction, reflecting a mechanism-specific rather than template-based repair philosophy.
Analyzing anatomic features
Successful mitral valve repair in patients with obstructive HCM and degenerative disease hinges on careful attention to the unique anatomic features of this cohort.
A key principle is avoiding excessive annular reduction. Many patients with obstructive HCM do not present with significant annular dilation, and aggressive band or ring downsizing can precipitate postoperative systolic anterior motion (SAM) and recurrent LVOT obstruction. Annuloplasty should be used selectively. In cases where SAM develops after repair with a band, removal of the band can immediately resolve the obstruction.
Protecting LVOT geometry
It's equally important to perform repair maneuvers that preserve LVOT geometry. Commissural annuloplasty, leaflet plication, the neo cord implantation and targeted Alfieri sutures are preferred when indicated, as they respect the spatial relationship between the MV and the LVOT.
Adequate exposure is another critical factor. The small LV cavity and anterior displacement of the mitral apparatus in obstructive HCM can make visualization through a standard left atriotomy more challenging. Anticipate these constraints and plan accordingly to ensure precise repair and myectomy.
Finally, intraoperative gradient verification is essential to confirm the adequacy of LVOT relief. Direct needle manometry combined with transesophageal echocardiography (TEE) should be used both before and after myectomy. If a residual gradient greater than 15 to 20 mm Hg is detected in the presence of SAM, be prepared to return to cardiopulmonary bypass for further septal resection. This disciplined, anatomy-specific approach helps ensure that the dual goals of durable valve competence and unobstructed LVOT flow are reliably achieved.
Specialized experience
With specialized surgical experience, lasting repair can be reliably achieved in this challenging patient subset. It's important for these patients to be treated at high-volume centers with obstructive HCM and mitral valve programs. High-volume centers attain lower valve replacement rates and better long-term outcomes in complex mitral disease.
In such environments, mechanism-based repair planning, selective annuloplasty and careful LVOT geometry preservation are routine, and teams are adept at balancing the dual goals of durable valve function and unobstructed outflow. Standardizing intraoperative assessment using direct needle manometry and TEE, both before and after myectomy, further ensures optimal gradient relief and repair durability.
Future advancements
The future of this field will likely expand beyond conventional approaches. Robot-assisted or percutaneous myectomy may offer less invasive options for selected patients, particularly when integrated with precise imaging-based planning. Coupled with advances in individualized medicine, including genotype-guided risk stratification and tailored procedural strategies, these innovations have the potential to further improve safety, recovery and long-term valve preservation in this complex subset of patients.
For more information
Refer a patient to Mayo Clinic.