Single versus bilateral chordo-papillary apparatus preservation in mitral valve replacement: a hemodynamic study

Background: It has been postulated that disruption of the mitral valve apparatus at the time of mitral valve replacement (MVR) is a risk factor for postoperative ventricular dysfunction. The aim of this study was to evaluate the effect of single versus bilateral chordo-papillary preservation on the left ventricular function in comparison to no preservation. Methods: This study was conducted from 2015 to 2018 on sixty patients who had MVR. The patients were classified into group I included 20 patients who underwent MVR with complete excision of the subvalvular chordae and tips of papillary muscles, group II: included 20 patients who underwent MVR with preservation of posterior chordo-papillary apparatus, and group III: included 20 patients who underwent MVR with preservation of both posterior and anterior chordo-papillary apparatus. Results: There were 20 males (33.3%), and the mean age was 48.76± 8.91 years. Patients in group III were significantly older (37.15 ±4.92, 39.8 ± 5.49, and 57.25 ± 6.93 years in groups I, II, and III, respectively; p< 0.001). The left ventricular end-diastolic (5.40 ±0.34, 4.96 ± 0.43, and 4.44 ± 0.55 mm in group I, II and III, respectively, p<0.001) and end-systolic diameter (4.33 ±0.48, 3.58 ±0.43 and 3.20 ±0.43 mm in group I, II and III; respectively, p<0.001) were significantly reduced in partial and complete preservation groups after 6 months. Left ventricular ejection fraction improved in the bilateral preservation and partial preservation groups after 6 months (45.32 ±9.78, 56.79 ±10.14, and 56.60 ±11.68 % in groups I, II and III respectively, p<0.001). Mechanical ventilation was significantly longer in group I (24.10 ± 6.6, 16.80 ± 5.97, and 15.80 ± 5.24 hours in groups I, II and III, respectively, p<0.001) and the duration of ICU stay was significantly longer in group I (78.65 ± 15.32, 65.40 ± 14.21, and 60.20 ± 12.58 hours in groups I, II and III, respectively, p<0.001). Conclusion: Preservation of the annulo-papillary continuity may preserve left ventricular geometry and performance. Total preservation of chordae could be superior to partial preservation with better left ventricular remodeling and improvement in the left ventricular functions