Mitral valvuloplasty for mitral valve closure insufficiency has many advantages over mitral valve replacement, such as no need for lifelong anticoagulation, low incidence of embolism and infective endocarditis, and good postoperative left ventricular function, resulting in reduced operative mortality and improved long-term outcomes. Therefore, mitral valve repair should be used whenever possible to treat mitral valve closure insufficiency. This study summarizes 20 years of clinical experience with mitral valve repair at our institution. Clinical Data From March 1985 to June 2006, 542 patients (excluding endocardial cushion defects) underwent mitral valve repair for mitral valve insufficiency or mitral valve stenosis in combination with mitral valve insufficiency. Of these, 306 (56.5%) were men and 236 (43.5%) were women. The mean age was 38.75 ± 19.38 (7 months to 77 years). Most of the patients had preoperative symptoms of panic and shortness of breath, and 53.9% of them had class III or IV cardiac function. According to etiology, there were 275 cases of degenerative lesions, 131 cases of congenital lesions, 71 cases of rheumatic lesions, 32 cases of mitral valve insufficiency due to infective endocarditis, 24 cases of ischemic mitral valve insufficiency, and 9 cases of mitral valve insufficiency combined with cardiomyopathy. The degree of preoperative mitral valve insufficiency and stenosis was confirmed by echocardiography. 480 cases had simple mitral valve insufficiency, including 13 cases of mild regurgitation, 175 cases of moderate regurgitation, 292 cases of severe regurgitation, and 62 cases of mitral stenosis combined with insufficiency. After tracheal intubation, a small incision was made in the middle of the sternum or the parasternal area, and extracorporeal circulation was routinely established, and mitral valve surgery was performed through an atrial sulcus incision. The surgical techniques included posterior leaflet wedge resection, posterior leaflet folding, artificial tendon cords, edge-to-edge, junctional dissection, and shaped ring implantation. Intraoperative esophageal ultrasound was performed in 190 cases (57 without regurgitation, 99 with micro-regurgitation, and 34 with mild regurgitation). The extracorporeal circulation time was 108.07±40.18 min, and the aortic block time was 77.42±56.06 min. Follow-up The surviving 522 patients were followed up by telephone, letter, and outpatient review, and 474 patients were followed up (of which 332 patients were reviewed for echocardiography), with a follow-up rate of 90.8% and a mean follow-up time of 41.03±40.40 months (1 to 240 months). The statistical analysis was performed using SPSS10.0 statistical software. t-test was used for measurement data, x2 test was applied for count data, and Kaplan-Meier method was used for analysis of survival rate and waiver of secondary surgery rate. p < 0.05 was statistically significant. Results Perioperative mortality was 20 cases (3.7%) and 1.35% (5/371) after 2000, with high mortality in cardiomyopathy (11.1%) and rheumatic lesions (4.2%). Causes of death: 8 cases of hypocapnia, 4 cases of severe arrhythmia, 1 case of respiratory failure, 4 cases of cardiac arrest, 2 cases of cerebral infarction, and 1 case of multi-organ failure. The average time of tracheal intubation was 23.40±66.63h, and the ICU time was 1.65±2.18 days. At discharge, there were 56 cases (10.7%) of class I cardiac function and 464 cases (89.3%) of class II. In the 522 patients who survived, review echocardiographic findings at discharge showed significant postoperative cardiac reduction compared with the previous period and significant improvement in mitral regurgitation and stenosis (as shown in Table 1). The follow-up patients had 374 cases of class I, 67 cases of class II, 28 cases of class III, and 5 cases of class IV central function. Echocardiographic findings showed moderate to severe insufficiency of closure in 57 cases (10.9%) and mitral stenosis in 21 cases (3.9%). Twenty-three cases were reoperated due to mitral valve insufficiency and/or mitral stenosis, including 21 cases of mitral valve replacement, 1 case of mitral valvuloplasty, and 1 case of heart transplantation, and the rates of secondary surgery waiver at 3, 5, and 10 years were 97%, 95.4%, and 86.2%, respectively. There were 20 distant deaths, including 14 cardiac deaths, 1 brain abscess, 1 hemorrhage, and 4 cases with unknown causes, with survival rates of 91.6%, 88.9%, and 71.1% at 7, 10, and 15 years, respectively. Discussion With the continuous improvement and refinement of ultrasound diagnosis and surgical techniques, mitral valvuloplasty is increasingly being used in clinical practice. The number of mitral valvuloplasty procedures in our hospital has been rising over the past 20 years and now accounts for 29% of mitral valve surgery, while the operative mortality rate has gradually decreased and is comparable to the 2% to 3% mortality rate reported by the best foreign heart centers. In mitral valvuloplasty for congenital heart disease excluding endocardial cushion defects, there is no large group with nearly 20 years of follow-up results reported in China, so it is necessary to summarize our work. Our data show that patients undergoing mitral valvuloplasty are still predominantly those with degenerative mitral valve insufficiency (50.7%) and congenital mitral valve insufficiency (24.2%), and patients with posterior leaflet prolapse are still treated with the classic posterior leaflet wedge resection with annuloplasty. The majority of annular enlargement occurs in the posterior mitral annulus because of the weakness of the posterior mitral annular fibers due to lack of integrity. In patients with degenerative mitral valve insufficiency, annular reduction is a very important part of mitral valvuloplasty. In the early stages, polyester strips or mattress sutures were mostly used to reinforce the annulus posterior to the annulus, and in recent years soft-formed rings have been widely used because they better protect the function of the mitral annulus. The repair of anterior leaflet prolapse is more technically complex and less feasible than posterior leaflet prolapse, and the risk of secondary surgery after surgical repair is high and the survival rate is low compared with posterior leaflet prolapse. Surgical outcomes are significantly improved due to the edge-to-edge technique. The use of the edge-to-Cedge technique to treat patients with complex leaflet prolapse including anterior leaflet prolapse can also be used as a remedial measure when standard plication procedures are unsatisfactory, along with some other techniques such as artificial tendon cords, tendon transfers, or even resection of secondary and tertiary tendon cords to improve leaflet alignment. It is important to note that when performing the edge-to-Cedge procedure, it is important to ensure that the subvalvular structures at the anterior and posterior leaflet sutures should be free of underlying lesions, soft and with sufficient number of leaflet structures to ensure adequate leaflet opening during cardiac systole. If there is thickening or shortening of the leaflets and subvalvular structures, this technique is generally not advocated. In patients with anterior leaflet prolapse in which the anterior leaflet is too wide, triangular resection of the anterior mitral leaflet is still useful, but it must be ensured that after removal of the excess anterior leaflet, the remaining leaflet is sutured without tension to ensure that there is no increased risk of postoperative failure. Two of the patients in this group underwent triangular resection of the anterior mitral leaflet with a combination of edge-to-edge technique and shaped annuloplasty with good surgical results and only minimal regurgitation at long-term follow-up. In contrast, in patients with extensive anterior leaflet prolapse, valve replacement should be performed decisively if the plication is not effective (regurgitation on left ventricular water injection test). Repair of double leaflet prolapse depends on the degree of anterior leaflet pathologic changes; in most patients, a standard rectangular resection of the posterior leaflet and annuloplasty will resolve the problem with a long-term success rate of more than 90%. Artificial tendon implantation is better than leaflet resection mitral valvuloplasty and can be applied as an adjunctive technique, but the operation requires high operator skill and clinical experience and is difficult to perform. In this group of patients, there were 125 cases of simple anterior leaflet prolapse, 157 cases of simple posterior leaflet prolapse, and 39 cases of anterior-posterior leaflet prolapse. Statistical analysis showed no significant difference in operative mortality and operative success rate between groups, indicating that anterior or anterior-posterior leaflet prolapse does not increase the risk of surgery as long as the technique is used properly. Patients with rheumatic mitral valve insufficiency or combined mitral stenosis have a higher failure rate due to technical difficulties, but still 75% of rheumatic mitral valve lesions are feasible to repair, and no significant difference in their long-term secondary surgical waiver rate after plication and mitral valve replacement was considered (9). Therefore, for patients whose leaflets and tendons are still soft, valvuloplasty is recommended, and for patients with fusion of the papillary muscle and free edge of the leaflet, replacement is recommended. The 10- and 15-year survival rates of our patients were 90% and 68%, respectively, and the secondary surgery waiver rates were 88% and 60%, respectively, which were better than those reported abroad. In patients with ischemic mitral valve insufficiency who underwent valvuloplasty, the perioperative mortality rate was as high as 9% to 18%. In our group, 24 patients with ischemic mitral valve insufficiency underwent bypass grafting at the same time, and there were 7 surgical deaths, with a mortality rate of 2.92%, and no secondary surgery at long-term follow-up, with survival rates of 86% and 78% at 1 and 7 years, respectively. In 32 patients with mitral valve insufficiency due to infective endocarditis, all of them were treated with regular and adequate antibiotics before surgery, and most of them were operated after normalization of body temperature. Three patients were given emergency surgery because of recurrent febrile symptoms. A variety of surgical techniques were used, such as flab removal, leaflet repair, annuloplasty, artificial tendon cords, and edge-to-edge, etc. There were no deaths in the perioperative period and no long-term deaths or secondary operations at follow-up. In 10% of patients with valvular disease, both aortic and mitral valves are involved, and most authors recommend double valve replacement. However, the in-hospital mortality rate for bivalve surgery is 5% to 15%, and the 10-year survival rate is 50% to 70%, whereas mitral valvuloplasty combined with aortic valve replacement has a higher survival rate than bivalve replacement. In our group, a total of 85 patients underwent aortic valve replacement or angioplasty at the same time as MVP, with an operative mortality rate of 4.7% and a follow-up survival rate of 93.7% at both 5 and 10 years, which is better than the results reported by Marc Gillinov A et al. In patients with end-stage cardiomyopathy, approximately 60% have mitral valve insufficiency and a poor prognosis. In our group of patients, 9 patients with cardiomyopathy combined with mitral valve insufficiency underwent mitral valvuloplasty and died in 1 case, with a mortality rate of 11.1% and survival rates of 85.7%, 85.7%, and 64.3% at 1, 2, and 5 years, respectively, with high mortality and low long-term survival rates. As a bridge to heart transplantation, mitral valvuloplasty remains a better option for patients who are unable to undergo heart transplantation for various reasons or who present with severe heart failure awaiting heart transplantation. Univariate analysis of our data showed that patients with preoperative cardiac function grade 3 to 4 had a significantly higher perioperative mortality rate than patients with cardiac function grade 1 to 2 (P<0.05). Therefore, we suggest that as soon as a patient is identified as having severe mitral valve insufficiency with a left ventricular end-systolic internal diameter ≥40 mm and EF <60%, he or she should be treated surgically as soon as possible, regardless of the presence of symptoms. Because of the complexity of mitral valve lesions and the uncertainty of the surgical approach, mitral valvuloplasty is a highly demanding surgical procedure, and the surgeon's judgment of mitral valve pathology and the use of various shaping techniques are key to the success of the procedure, whereas the timing of surgery has an important impact on the patient's prognosis. In conclusion, the accurate diagnosis of preoperative ultrasound, the rational use of various shaping techniques, and the correct timing of surgery can lead to good surgical results.