Congenital mitral insufficiency (CMI) is not uncommon and can be a stand-alone condition or combined with other cardiovascular anomalies. Most mitral valvuloplasties are feasible, and the success rate is high. From September 1991 to June 2002, a total of 62 patients with congenital mitral insufficiency were admitted to our hospital. 1. Data and methods 1.1 General data There were 62 cases in this group, 39 males and 23 females, age 2-56 (average 19.32±4.67) years, weight 8.2-64 (average 49.84±12.05) Kg. The diagnosis was determined preoperatively by cardiac signs, electrocardiogram, X-ray chest film and echocardiogram. The cardiothoracic ratio was 0.51-0.92 (mean 0.62±0.05). There were 19 cases of class I, 21 cases of class II, 15 cases of class III and 7 cases of class IV cardiac function. 1.2 The types of lesions and mitral valve pathology were 28 cases of simple CMI, 4 cases of partial atrioventricular septal defect, 6 cases of combined secondary foramen ovale septal defect, 3 cases of ventricular septal defect, 1 case of arteriovenous ductus arteriosus, 6 cases of tricuspid valve insufficiency, and 3 cases of aortic valve insufficiency; 11 cases of combined moderate to severe pulmonary hypertension. There were 34 cases of severe CMI, 27 cases of moderate CMI, and 1 case of mild CMI. There were 25 cases of mitral valve anterior leaflet dehiscence, 17 cases of anterior leaflet prolapse, 10 cases of annular enlargement, 8 cases of leaflet dysplasia, and 2 other cases. 2, Results Intraoperatively, the MVP was changed to MVR in 6 cases, including 4 cases with severe mitral leaflet prolapse and 2 cases with anterior leaflet dysplasia combined with annular enlargement. Postoperative complications included 4 cases of premature ventricular beats, 2 cases of supraventricular tachycardia, 1 case of complete AV block with multisystem organ failure, pericardial effusion, respiratory infection and incisional infection, with a complication rate of 14.5%. The cause of death was complete AV block with multi-organ failure after MVR. 58 cases were followed up for 1-10.5 (mean 5.26±1.77) years, 37 MVP patients were followed up for 35 cases, and there was no long-term death; 19 cases had normal cardiac function, 11 cases had primary function, 4 cases had secondary function, and 1 case had tertiary function; X-ray chest radiographs showed that the cardiothoracic ratio decreased by 0.12±0.04 (P<0.04) compared with that before surgery. The echocardiogram showed 7 cases of mild mitral valve insufficiency, 3 cases of moderate insufficiency, 1 case of severe insufficiency, 2 cases of mild stenosis, and 1 case of mild stenosis with insufficiency; 2 cases of reoperation (MVR) were performed. 23 of the 25 patients with MVR were followed up, and 4 cases of heart failure, 2 cases of premature ventricular beats, 1 case of cerebral embolism, and 1 case of infective endocarditis were complicated; 2 cases (3.2%) died of infective endocarditis, respectively. 2 cases (3.2%) died of infective endocarditis and heart failure respectively. The common causes of CMI are leaflet dehiscence, leaflet prolapse, and annular enlargement. The main surgical methods are MVP and MVR. 37 cases of MVP and 25 cases of MVR were performed in our group according to the lesions, and satisfactory results were achieved. MVP was superior to MVR in terms of operative mortality, complication rate, and long-term results. Because MVP preserves the integrity of the valve and accessories, it helps protect ventricular function and reduces postoperative complications without the need for lifelong anticoagulation therapy. Currently, MVP has become the procedure of choice for patients with simple mitral valve insufficiency. For patients with moderate to severe mitral valve insufficiency who have developed clinical symptoms, early surgery is indicated. The near- and long-term results of MVP in this group of patients are good. In infants and children, the advantages are even greater.1-4 Postoperative lifelong anticoagulation can be avoided, as can the effects of daily exercise and surgery, the effects of pregnancy and childbirth in women, the possible adverse effects of long-term postoperative follow-up on the mental health of children, and the avoidance of recurrent MVR after growth and development. It is now believed that age and the combination of other intracardiac malformations are no longer the main factors affecting the success and efficacy of surgery. The ability to perform MVP and the outcome of MVP depend on the experience and surgical skills of the operator, but also on the pathologic changes and extent of mitral valve pathology.5.6 The anatomy of the leaflets, attachments, and annulus should be carefully identified intraoperatively to make appropriate judgments about the type of valve pathology and whether to perform valvuloplasty or valve replacement. If the valve leaflet is cleft for repair; if the tendon cord is prolapsed due to prolongation, shortening of the tendon cord, transfer of the tendon cord, shortening of the papillary muscle, or artificial tendon cord can be used; if the anterior leaflet is redundant, part of the leaflet can be wedge-shaped excision, and tendon cord repair can be performed simultaneously with suturing of the cut edge; if the leaflet or tendon cord is unsatisfactorily formed and the annulus is enlarged, annuloplasty of the junctional annulus and annuloplasty of the valve is feasible. We applied homemade soft prosthetic annuloplasty in 3 cases, with good clinical results. For complex mitral valve lesions, multiple repair methods are often required to achieve good results, especially for the repair of the anterior leaflets and their subvalvular structures and the annuloplasty of the posterior annulus. For those who are not suitable for wedge resection of the valve leaflets, are not eligible for MVR, or have poor visualization and are unable to perform complex operations such as MVR, and have moderate or greater mitral valve insufficiency, anterior and posterior mitral leaflet edge-to-edge fixation can be used, in which the free edge of the leaflet prolapse is fixed to its corresponding leaflet, and if the annulus is significantly enlarged, an annuloplasty is added. This procedure has become a new surgical approach to mitral valve prolapse because of its simplicity, few complications, and good results. Two patients in our group underwent this procedure, and postoperative recovery of cardiac function was rapid and well maintained. One 2-year-old child had no mitral regurgitation on postoperative echocardiography, and one 53-year-old patient had mild mitral regurgitation on postoperative echocardiography.