Maternal body temperature was monitored using a digital rectal probe and maintained between 36��C and 37��C, using a warming blanket. Heart rate was monitored using standard ECG electrodes Olaparib PARP inhibitor and module. Pregnant sheep were sedated with Ketamine (10mg/kg i.v.), intubated for mechanical ventilation, and then anesthesia was continued with isoflurane (2%) and 100% oxygen. Pavulon (0.1mg/kg i.v.) was given to suppress spontaneous movement. Fluid-filled intravascular catheters were placed in the carotid artery via cut down to measure arterial pressure and withdraw blood samples and in the jugular vein to infuse fluids. Intermittent blood samples were withdrawn to measure blood gas content for acid-base status as an index of adequacy of ventilatory support.

The maternal lower abdominal fur was shaved and prewarmed ultrasound coupling gel was used for ultrasound imaging. Each sheep fetus was imaged using a clinical ultrasound system (HD11, Phillips Medical Systems, Bothwell, WA) and a curved array obstetrics ultrasound probe (C5-2, Phillips Medical Systems, Bothwell, WA). A general screening fetal ultrasound was performed to identify the presence of a single or twin gestation and to determine the orientation of each sheep fetus within the maternal abdomen. Optimizing fetal positioning to allow for a percutaneous approach was attempted transabdominally. If unsuccessful, laparotomy was performed followed by uterine manipulation in order to properly position the fetus (left side up). Time required to position the fetus was not included in the trial.

Prior to starting the procedure, a single dose of atropine (1mg/kg) was delivered to the fetal thigh as an intramuscular injection to prevent fetal bradycardia. Fetal cardiac ultrasound was performed to determine the fetal heart rate, left ventricular short-axis and long-axis dimensions (mm), aortic valve annulus diameter (mm), and the presence or absence of pericardial fluid. The midpoint of the aortic valve and the left ventricular (LV) apex were determined using alternating long-axis and four-chamber views. These two points define an optimal trajectory for the interventional needle path. Following a 2mm surgical skin incision, the needle was advanced through the maternal skin and uterine wall into the amniotic cavity under ultrasound visualization. The trajectory of the trocar and needle were continuously updated and displayed on the ultrasound image.

After confirming that the needle trajectory remained ��on-path��, the needle was then advanced through the fetal chest wall, fetal pericardium, fetal ventricular apex and into the left ventricular cavity Cilengitide (Figure 2). Once the needle was positioned within the LV cavity, the trocar was removed and 0.014��� guide wire and premounted coronary balloon were advanced across the aortic valve (Seldinger technique) to perform balloon valvuloplasty.