Comparison of automated fastener (Cor-Knot) versus manually tied knots in patients undergoing minimally invasive mitral valve replacement
Introduction: Automated knot fastener has been used in minimally invasive valve surgery to alleviate the longer total operating time and improve outcomes. Their advantages over manual knot tying remain questionable. This study aims to compare automated knot fasteners' efficacy with conventional knot-pushers in minimally invasive mitral valve replacements (MiMVR).
Methods: Between 2016 and 2020, 50 patients underwent isolated mechanical mitral valve replacement via right mini-thoracotomy in rheumatic or degenerative mitral valve disease. The patients were grouped into two groups. Group I (n= 25) included patients who had MiMVR using the Cor-knot device, and Group II (n= 25) had MiMVR using the conventional knot-pusher. Primary endpoints were cross-clamp, cardiopulmonary bypass, and total operative times and the secondary outcomes were paravalvular leak and reoperation. There were no significant differences in the demographic data between the two groups.
Results: Cross-clamp time (79± 1.11 vs. 98.88± 1.34 min; P<0.001), cardiopulmonary bypass time ( 132 (Q1- Q2: 129- 134) vs. 148 (140- 155) min; P<0.001) and operative times ( 206 (203- 209) vs. 228 (223- 234) min; P<0.001) were significantly shorter in Group I. There was no difference in postoperative complications between groups. The early paravalvular leak occurred in one patient (4%) in Group I and required valve re-exploration. In Group II, four patients (16%) had a paravalvular leak; 3 of them were severe and required valve re-exploration (P= 0.35). Transthoracic echocardiography at discharge revealed no evidence of a paravalvular leak in both groups.
Conclusion: Automated fastener device (Cor-knot) could reduce operative times during minimally invasive mitral valve replacement. Operative complications are comparable between both techniques, and follow-up studies are recommended.