Acardiacus anceps refers to a rare medical condition known as a twin reversed arterial perfusion (TRAP) sequence. It is characterized by a malformed acardiac twin in a twin pregnancy. In a normal twin pregnancy, each fetus has its own umbilical cord and placenta. However, in acardiacus anceps, there is an unequal distribution of blood supply between the twins, leading to the development of the acardiac twin. This condition is predominantly seen in monochorionic twin pregnancies (twins sharing the same placenta).
The acardiac twin, also referred to as "acardius," is an abnormal, non-functioning twin that lacks a heart or other major organs. Instead, it may have some rudimentary tissue structures, such as limbs or a head. The blood supply for the acardiac twin is provided by abnormal vascular connections originating from the normal twin. These connections carry deoxygenated blood from the normal twin to the acardiac twin.
Due to the complex vascular connections and potential risks to the healthy twin, acardiacus anceps can pose serious health complications and potential risks for both twins. These complications may include heart failure, growth restriction, polyhydramnios (excessive amniotic fluid), and preterm birth.
Management and treatment options for acardiacus anceps depend on the specific case and gestational age. In some instances, intervention such as laser ablation or cord occlusion may be considered to minimize risks to the healthy twin. However, the prognosis for acardiacus anceps is generally poor, with a high risk of adverse outcomes including fetal death and complications for the surviving twin.
