Objective: To evaluate the incidence, echocardiographic patterns, operative strategies and results of patients receiving second cross clamp 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 non-degenerative disease, planned valve replacement, and surgery without cross-clamping were excluded. Multivariable logistic regression model was applied to investigate predictors of second cross-clamp and the relationship between second cross-clamp and outcomes.
Results: Second cross clamp was used in 128 cases (2.8%). Causes of re-crossclamp included residual pathology in 71.9% (n=92) of patients and systolic anterior motion (SAM) in 28.1% (n=36). Re-repair was performed in 104 (81.3%) patients and replacement 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 cases (2.3%). Bileaflet prolapse (OR2.21) and predicted risk of SAM (OR 3.04) were identified as risk factors for second cross-clamp. No association between second cross clamp and mortality or major postoperative complications was found. However, second cross clamp was associated with an increased risk of respiratory insufficiency (OR 4.6) and longer ICU stay (β 0.35).
Conclusions: Second cross-clamping after less invasive mitral repair is infrequent, but may be required particularly in patients with bileafelt pathology or increased risk of SAM. Most re-repairs were successful, with less than 20% of patients requiring replacement. Second cross-clamp was associated with higher risk of respiratory insufficiency and prolonged ICU stay.
