Objective This study focused on the exploratory development of the safety and feasibility of min-invasive surgical device closure of different types of perimembranous ventricular septal defects (PMVSDs) in children and the clinical value and criteria in assessment and guidance by echocardiography, including transthoracic echocardiography (TTE) and multiplane transesophageal echocardiography (MTEE).

Methods We enrolled 730 children from our hospital to participate in the study from April 2010 to November 2012. All these children were diagnosed as PMVSDs by TTE and underwent full evaluation, such as the sizes, types, spatial positions of the defects as well as the relationship with the adjacent tissures. Through overall assessment by TTE and MTEE, the sizes and types of occluders were determined. Then the domestic device was inserted to occlude the PMVSDs under the guidance of MTEE. If the closure was unsatisfactory, the occluder would be changed or the patient would be transformed to open-heart surgery. More than 2 years of follow-ups were made after successful occlusion.

Results 690 of the 730 children underwent min-invasive surgical device closure successfully, with a 94.55% success rate. Symmetric devices were used in 576 children (A₄B₂ occluders were used in 33 children, and common symmetric devices were used in others) and asymmetric devices were used in 115 children. 40 children were transformed to open heart surgery under cardiopulmonary bypass (CPB) after failed attempt of occlusion. All patients received follow-ups at regular intervals in more than two and a half years after operation. The occluders had stayed firmly and echoed clearly. No noticeable residual shunt or valve regurgitation were discovered except for 1 child, whose original mild aortic regurgitation aggravated to nearly moderate in the follow-up of 18^th month. Also, there were no significant arrhythmia detected except two children had sudden attack with Adame-Strokes syndrome 2 and 6 days after operation respectively.

Conclusions Min-invasive surgical device closure of PMVSDs without cardiopulmonary bypass is mostly safe and feasible. Echocardiography (including TTE and MTEE) plays a vital role and provides relatively accurate and reliable basis in all stages by helping screen cases preoperatively, guiding in placing the occluder intraoperatively, and evaluating therapeutic efficacy postoperatively. The clinical criteria in assessment and guidance by echocardiography are basically reliable. MTEE is more accurate in evaluating the defects, such as the shape and size which is important in determining the right occluder.