The use of blockers for endoscopic intervention of atrial septal defects has a history of more than 20 years, and the technology is mature and widely used, but they all require X-ray fluoroscopy. In order to avoid the damage of X-ray radiation and contrast agent to patients, we combined the techniques of medical intervention and transthoracic atrial septal defect blocking, relying entirely on the guidance and monitoring of esophageal ultrasound, to block the atrial septal defect. Satisfactory results were achieved. Data and methods Study population From October 2011 to June 2103 we completed 26 cases of esophageal ultrasound-guided percutaneous atrial septal defect sealing, 10 males and 16 females, aged 3-70 years, mean (32±13.5) years, weight 14.5-76 kg, mean (43±15.5) kg. All were secondary to the central type of the foramen ovale. Both the superior and inferior chamber margins were greater than 8 mm, none had other combined cardiac malformations, no severe pulmonary hypertension, and no severe valvular regurgitation. There were 2 cases of combined atrial fibrillation. All patients were treated by femoral vein puncture, and the right heart catheter was placed into the right atrium under ultrasound monitoring, and a hard guiding wire was placed along the right heart catheter, and the tip of the delivery sheath with the inner core was folded with a bend of about 30 degrees. The tip of the delivery sheath is placed into the left atrium through the atrial septal defect and the left umbilical disc is opened with ultrasound monitoring in real time. This procedure is monitored using esophageal ultrasound: whether the blocker is fixed, whether there is residual shunt, atrioventricular valve function, and whether the coronary sinus is affected, and the sheath is withdrawn only when all aspects are in good condition. Discussion Atrial septal defect is one of the most common precordial diseases. Currently, the main treatment methods for atrial septal defects are medical intervention under X-ray fluoroscopy and surgical repair with extracorporeal circulation. Internal interventional treatment is less invasive, non-scarring and quick recovery, and is widely used. Only some huge atrial defects, inferior chamber type, superior chamber type and primary foramen type atrial defects need extracorporeal circulation repair. In recent years, we have carried out transthoracic atrial septal defect closure with the help of Professor Li Hongxin from Shandong Provincial Hospital. Satisfactory results were achieved. Although this method avoids extracorporeal circulation, the wound is small. However, it still has a surgical scar and requires opening the chest cavity. Inspired by the interventional approach of internal medicine, we combined our experience of transthoracic closure of atrial septal defect in more than 200 cases. A small central atrial defect with good peripheral margins was selected for non-x-ray monitored percutaneous atrial septal defect closure with esophageal ultrasound guidance. Satisfactory results were achieved. The non-X-ray monitoring of esophageal ultrasound-guided percutaneous atrial septal defect occlusion completely retains the advantage of non-invasive medical interventions, while avoiding the damage to the doctor and patient from X-ray radiation and contrast agents. With the proficiency of this technique, the indications are gradually expanded, and at present we do the youngest age of 3 years old and the largest atrial defect diameter of 24 mm. This is a reliable support for us to explore and try new techniques. However, we also have the technology of transthoracic occlusion of atrial defect, and the indications for transthoracic occlusion of atrial defect are wider than those for medical intervention. Therefore, our indications for percutaneous atrial septal defect sealing are relatively strict, that is, once we feel that percutaneous sealing is not reliable, we immediately seal it transthoracically. This is because avoiding extracorporeal circulation is the main minimally invasive goal. The indications for percutaneous atrial septal defect sealing are: atrial defect less than 25 mm in diameter, with upper and lower margins greater than 8 mm, and central single-port atrial defect without combined intracardiac malformations.2 The key point of this technique is to safely establish the access from the femoral vein puncture point to the right atrium. This minimizes damage to the vessels, vital organs and heart along the route. It is not possible to observe and guide the entire course of the guidewire and sheath with ultrasound. Therefore, we deliver the right heart catheter into the right atrium, which can be observed by esophageal ultrasound, and the right heart catheter is soft and less likely to cause collateral damage, then the guide wire is placed along the right heart catheter, and finally the sheath is delivered along the guide wire into the right atrium, which is very clear on ultrasound after the blocker is pushed to the tip of the sheath. Generally, we release the left umbrella disk a little so that the head end of the sheath becomes mushroom-shaped as a marker for the tip of the sheath, thus avoiding damage to the atrial wall.3 The head end of the delivery sheath is bent at an angle of 30 degrees. At this time, the shunt disappears, and the right umbrella disk is released by retracting the sheath while pulling the blocker tightly. At this time, the blocker and the atrial septal plane are at an angle. Carefully observe whether the lower luminal edge and the upper edge are sandwiched in the umbrella disk, push and pull back the blocker to feel whether it is firm, and release the blocker after satisfaction. In conclusion, ultrasound-guided percutaneous atrial septal defect sealing of the esophagus has its special advantages of avoiding X-ray damage and no scarring. It is believed that its indications will be expanded as the number of procedures performed increases and experience is gained.