Rachischisis is a neural tube defect characterised by a complete or severe defect in the spine. The defect can be located anywhere from the cervical region to the sacrum, or through the entire length of the spine. Typical defects are clefts or splits that open the spine to the exterior environment. Rachischisis occurs around 3–4 weeks after conception when the posterior neuropore of the neural tube does not close completely. It is a multifactorial aetiology and is most typically accompanied by other defects. Rachischisis is often described as a severe form of spina bifida, with the spine not only being exposed to the exterior environment, but with the opening being large enough to allow the neural plate to spread out of the opening and to the surface. Treatment
Rachischisis is a severe condition and survival rates for fetuses are extremely low. Babies that are born with the condition have high mortality rates and extreme developmental defects. Fetuses with the condition often spontaneously abort. Babies that are born with rachischisis are stillborn or die within a few hours to a few days of birth. Typically, medical termination of pregnancy is presented as an option to the mother once a diagnosis of rachischisis has been confirmed. As the condition is often accompanied by other deformities that not only need to be treated themselves, but also complicate the condition of rachischisis, it is difficult to treat fetuses affected.
Rachischisis can develop in conjunction with anencephaly, increasing the amount of area that is exposed. Although these conditions closely resemble one another, cases of rachischisis are morphologically different from cases of anencephaly, so they are indeed two separate conditions. Rachischisis is also a contributing factor to the onset of iniencephaly – a condition in which the spine is malformed. Further abnormalities such as rib malformations can occur with rachischisis. Stomach deformities can also develop with rachischisis. Risk factors
If a sibling of the fetus has been affected by rachischisis, there is increased risk that another child will develop the condition. There is also a slightly higher chance that females will develop the condition over males.Folate deficiency is also a well-accepted risk factor of all neural tube defects, including rachischisis. It is this reason that has caused many health policies regarding folic acid during pregnancy to be developed. Diagnosis
Initial diagnosis is typically by ultrasonography to reveal any congenital abnormalities. Fetuses affected typically show cranial abnormalities and deformities in brain tissue as well as spinal abnormalities. Following ultrasonography, magnetic resonance imaging (MRI) is commonly used to confirm the diagnosis. The presence of rachischisis is indicated in imaging by the absence of an arch-cranial line.Other neural tube defect diagnostic tools such as assays of α-fetoprotein or acetylcholinesterase may also be helpful in determining any other conditions that can lead to development of rachischisis. Classification
Rachischisis occurs most commonly in utero during the development of the child.