Hypertrophic pyloric stenosis and pulmonary hypertension in a neonate. A common mechanism?

Nitric oxide (NO) is an important mediator of biological functions. Absence or shortage of NO plays a role in the pathogenesis of both hypertrophic pyloric stenosis and persistent pulmonary hypertension. We present a neonate diagnosed with pulmonary hypertension after birth caused by meconium-aspiration syndrome eventually treated with extracorporal membrane oxygenation followed by hypertrophic pyloric stenosis for which a pyloromyotomy was performed. In conclusion, the association of pulmonary hypertension and pyloric stenosis has not been described before and may be explained by a lowered plasma concentration of arginine leading to deficient NO synthesis in the affected organ systems.