Mitral valve repair (MVr) is the preferred treatment strategy for severe mitral regurgitation (MR). The ultimate success of the procedure depends on obtaining an optimal intraoperative result, with no residual MR greater than mild and no dynamic obstruction. When intraoperative echocardiography after release of the aortic cross-clamp reveals a suboptimal result, the surgeon must decide whether to perform 2nd XCL to correct the residual defects or proceed with valve replacement. Evidence regarding the true impact of this additional manoeuvre in the specific setting of minimally invasive surgery remains limited, supporting the need to evaluate its clinical safety.
The authors conducted a retrospective analysis covering a 10-year period, from October 2014 to March 2024, including patients scheduled for MI-MVr for degenerative mitral regurgitation (DMR) or functional mitral regurgitation (FMR). Within this cohort, 76 patients required 2nd XCL, whereas 1656 completed the procedure with single cross-clamping. To achieve a methodologically robust comparison and reduce selection bias, 1:1 propensity-score matching was performed. Seventy-six controls were selected from the larger group and matched to the 76 patients undergoing 2nd XCL according to age, sex, MR aetiology and other baseline characteristics. This approach enabled the isolated assessment of the effect of 2nd XCL on clinical outcomes and 5-year survival using Kaplan–Meier analysis.
Of the 1732 patients evaluated, 76 required 2nd XCL, corresponding to an incidence of 4.4%. The main indication for reintervention was residual MR caused by persistent leaflet prolapse, leaflet restriction or inadequate coaptation length. Univariable analysis showed that complex valve pathology in patients with DMR and leaflet restriction in those with FMR increased the likelihood of 2nd XCL (OR = 3.386; 𝑝 = .005 and OR = 8.00; 𝑝 = .014, respectively), although neither variable remained an independent predictor in the multivariable analysis. As expected, CPB and total aortic cross-clamp times were significantly longer in the study group (149.5 vs 99.5 minutes and 96.0 vs 60.0 minutes, respectively; 𝑝 < .001). Despite the greater ischaemic burden, no significant difference in in-hospital mortality was observed. The only relevant differences were shorter mechanical ventilation time (12.5 vs 17.0 hours; 𝑝 < .001) and ICU stay (24.0 vs 32.0 hours; 𝑝 < .001) among patients who did not require a second repair. At mid-term follow-up, overall 5-year survival did not differ significantly between groups (74.4% in the 2nd XCL group vs 84.6% in the control group; 𝑝 = .07).
The authors conclude that 2nd XCL is a safe manoeuvre that does not compromise clinical outcomes or mid-term survival.
𝐂𝐎𝐌𝐌𝐄𝐍𝐓𝐀𝐑𝐘:
The principal message of this study is that 2nd XCL during mitral surgery through a mini-thoracotomy should not be regarded as an inherently hazardous event. Longer myocardial ischaemic times have traditionally raised considerable concern because of the potential for myocardial dysfunction and a more complicated postoperative course. However, the findings provide compelling evidence that the myocardium can tolerate this controlled prolongation and that the benefit of achieving a successful repair, with a competent valve and no relevant residual MR, clearly outweighs the modest increase in mechanical ventilation time and ICU stay.
The study also highlights an important technical distinction according to MR aetiology. In DMR, valve preservation through re-repair was possible in most second attempts. By contrast, patients with FMR had a very high rate of valve replacement (88.2%), reflecting the difficulty of correcting the underlying leaflet restriction. This creates a critical intraoperative decision-making scenario and suggests that, after a failed repair in FMR with substantial accumulated ischaemic time, proceeding directly to valve replacement may represent the most pragmatic strategy.
The absence of independent preoperative echocardiographic predictors means that particular caution is warranted in patients with complex prolapse, bileaflet involvement or severe leaflet restriction. Because these anatomical profiles appear more likely to require an additional cross-clamp period, surgical planning must be especially meticulous. Finally, the study strongly supports the systematic referral of patients with highly complex mitral anatomy to high-volume reference centres, where accumulated team experience may maximise the likelihood of achieving a satisfactory result during the initial cross-clamping period.
𝐑𝐄𝐅𝐄𝐑𝐄𝐍𝐂𝐄:
Akansel S, Dini M, Pitts L, Greve D, Suendermann SH, Jacobs S, et al. Early Outcomes and Risk Factors Associated With Second Cross-clamping in Mitral Valve Repair: A Propensity-matched Minimally Invasive Cohort Analysis. Eur J Cardiothorac Surg. 2025;67(12):ezaf421. DOI: 10.1093/ejcts/ezaf421.
