Chordal replacement versus quadrangular resection in degenerative posterior mitral leaflet repair

Background: As an alternative to quadrangular resection (QR), little is known of the potential of chordal replacement (CR) for treating posterior mitral leaflet (PML) prolapse when comparing these two techniques. This study aimed to assess mid- to long-term outcomes of CR versus QR for isolated degenerative PML (idPML) repair. Methods: We reviewed 112 consecutive patients using CR or QR for idPML repair from 4/2010 to 12/2015. Outcomes were compared before and after propensity score matching. Results: CR was more used through the minimally invasive approach (CR 59.4% vs. QR 9.4%, P<0.001). At discharge mitral regurgitation (MR) was successfully rectified to a mild or less degree in both groups (CR P<0.001, QR P<0.001; between groups: P=0.337). Group CR showed much shorter postoperative time (CR 9.9±4.0 vs. QR 14.0±8.3 days, P<0.004) and higher event-free survival rate between matched patients [56 months, CR 85.7% vs. QR 30.8%, P (log-rank) =0.017], however QR showed better freedom from above-mild recurrent MR (MR ≥2.5+) during follow-up [60 months, CR 50.2% vs. QR 96.3%, P (log-rank) =0.061]. Cox regression analysis might suggest that CR technique was a risk factor for recurrent MR [CR over QR, hazard ratio (HR) 2.149; 95% CI: 0.974–4.744; P=0.058; adjusted for surgical approach, gender, age, preoperative MR and ejection factor (EF)]. Conclusions: CR is more often used with the minimally invasive approach with less complications and shorter hospital stay. Nonetheless, CR is associated with recurrent MR development over time. Retaining of MV competence after CR demands attention and further investigation.