Physiopathologic and therapeutic aspects of the persistence of fetal circulation. Review of the literature and personal histologic observations [ASPETTI FISIOPATOLOGICI E TERAPEUTICI DELLA PERSISTENZA DELLA CIRCOLAZIONE FETALE. REVISIONE DELLA LETTERATURA ED OSSERVAZIONI ISTOLOGICHE PERSONALI]

Persistence of the fetal circulation (PFC) is a syndrome characterized by failure of the cardiocirculatory system to adapt successfully to postnatal life. Its typical feature is persisting right-left shunt across fetal channels which determines cyanosis refractory to oxygen treatment. PFC can simulate cyanotic congenital cardiopathy. It has two forms: a primitive form and secondary one due to various causes especially perinatal asphyxia. Both forms have a common pathogenesis consisting of hypertension of the pulmonary arterial circulation. This article reviews the physiology of the main prenatal and postnatal circulatory characteristics and the factors which regulate the pulmonary circulation. It also reports the latest findings on PFC physiopathology and treatment indicating the prognostic factors and future perspectives.