Congenital diaphragmatic hernia: impact of prostanoids in the perioperative period. A prospective study of 10 neonates with congenital diaphragmatic hernia and five controls to determine the importance of prostanoid concentrations perioperatively and the relation with persistent pulmonary hypertension (PPH) is reported. In neonates with congenital diaphragmatic hernia postoperative concentrations of the vasoconstrictor thromboxane B2 rose significantly and were higher during episodes of PPH; this rise may provoke PPH and subsequent right to left shunting. 