Second cross-clamp in less invasive mitral valve repair for degenerative mitral regurgitation: Predictors and outcomes

Objective: To evaluate the incidence, echocardiographic patterns, operative strategies, and results of patients receiving a second cross-clamping in the large population of the Mini Mitral International Registry. Methods: We examined 4577 patients with degenerative mitral regurgitation (MR) who underwent less invasive mitral repair. Patients with nondegenerative disease, planned valve replacement, and surgery without cross-clamping were excluded. Multivariable logistic regression model was applied to investigate predictors of second cross-clamping and the relationship between second cross-clamping and outcomes. Results: Second cross-clamping was used in 128 cases (2.8%). Reasons for re-cross-clamping included residual pathology in 71.9% of the patients (n = 92) and systolic anterior motion (SAM) in 28.1% (n = 36). Re-repair was performed in 104 patients (81.3%), and replacement was performed in 24 (18.7%). After re-repair, 92 patients (94.9%) had no or mild MR, 4 patients (4.1%) had moderate MR, and 1 patient (1%) had severe MR. A residual SAM was observed in 2 patients (2.3%). Bileaflet prolapse (odds ratio [OR], 2.21) and predicted risk of SAM (OR, 3.04) were identified as risk factors for second cross-clamping. No association between second cross-clamping and mortality or major postoperative complications was found; however, second cross-clamping was associated with an increased risk of respiratory insufficiency (OR, 4.6) and longer intensive care unit (ICU) stay (β = 0.35). Conclusions: Second cross-clamping after less invasive mitral repair is infrequent but may be required, particularly in patients with bileaflet pathology or at increased risk of SAM. Most re-repairs were successful, with <20% of patients requiring replacement. Second cross-clamping was associated with higher risk of respiratory insufficiency and prolonged ICU stay.