Methods

Patients routinely fasted before surgery. Ketamine (5 mg/kg, intramuscular injection) was used for induction of basic anesthesia. The patient was monitored via electrocardiography (ECG) and pulse oximetry in the operating room. Glucose (5%) was continuously injected by the peripheral venous route. After successful tracheal intubation, mechanical ventilation was established using pressure-controlled mode. A catheter was placed into the radial artery following arterial puncture to monitor arterial blood pressure directly. A subclavian vein catheter was used to monitor central venous pressure. The temperature of the operating room was maintained at 25°C during the operation. The flow rate of intravenous (IV) fluids was maintained at an appropriate level (the fluids were warmed if necessary), and the patient’s temperature was maintained at above 36.5°C. ECG results, blood oxygen saturation, body temperature, arterial pressure, central venous pressure, electrolytes levels, and blood gas analysis were monitored continuously. Any problems were addressed in a timely manner.

Remifentanil (1.5 μg/kg) and cisatracurium besilate (0.5 mg/kg) were administered intravenously for induction of anesthesia. Because the operation time was expected to be brief, anesthesia was maintained with remifentanil (0.2–0.5 μg/kg/min, continuously injected by infusion pump) and 2% sevoflurane (intermittent inhalation depending on the heart rate and arterial pressure).

Fentanyl (10 μg/kg) and cisatracurium besilate (0.5 mg/kg) were administered intravenously for induction of anesthesia. Anesthesia was maintained by using fentanyl (approximately 3–5 μg/kg/h, continuously injected by infusion pump) and 2% sevoflurane (intermittent inhalation depending on the heart rate and arterial pressure).

A small incision (2–3 cm) in the right anterior chest wall was used to access the thoracic cavity through the fourth intercostal space. The incision was at 2 cm anterior to the right phrenic nerve, and the pericardium was suspended. Heparin (1 mg/kg) was administered intravenously, and double-purse string sutures were applied to the right atrial wall. Under perioperative TTE guidance, the right atrial wall was incised inside the purse string. The delivery sheath loaded with an occluder was advanced into the right atrium, then entered the left atrium through the ASD. After the position of the sheath was determined, the left disc of the occluder was deployed. Then, the occluder was pulled back and positioned close and parallel to the atrial septum, and the right disc of the occluder was deployed and attached to the other side of the atrial septum. After the location of the occluder was checked by TTE, the delivery sheath was withdrawn. The purse string was tied to close the right atrial incision [5–7]. Extubation took place in the ICU in all patients. No additional sedative drugs were given in the ICU.