Septostomy is a term describing several medical procedures. Most commonly it refers to a catheterization procedure done on the heart in very young children, often no more than a few days old, who are not getting adequate oxygenated blood supply to the body. It may also be called a balloon septostomy, and was developed in the 1960s. Another form of this procedure is done in cases of twin-to-twin transfusion and is performed in utero.
Surgeons or cath lab specialists in cardiology may decide to create a communication between the atria or upper two chambers of the heart. When babies are born they have what is called a foramen ovale or opening between these chambers and this can be targeted for widening with a balloon. Alternately, if the child has a small atrial septal defect (ASD) elsewhere, doctors could widen the defect. This widening is usually achieved through catheterization, and when the area is reached, a balloon is inflated to enlarge the opening. In rare instances balloon enlargement is not adequate and surgery is needed to create the widening.
The goal of septostomy is to increase communication between the right and left atrium. Doing this allows oxygenated blood to shunt to the atrium that will send blood to the body. It’s particularly useful in defects like transposition of the great arteries (TGA) where the great arteries (pulmonary valve and aorta) are attached to the wrong atria. Getting oxygenated blood to the right atrium is vital, since the right atrium is incorrectly attached to the aorta, which provides blood to the body. This shunting raises levels of oxygen in the right atrium by allowing blood between the atria to mix.
In almost all cases, septostomy is not a permanent fix for a situation where the heart’s defects create oxygen deprivation. It is what is known as a palliation or palliative, meant to bide a little time before true corrective surgery is performed. It’s not always applicable when treating different types of heart defects and might most be considered for those that cause cyanosis or insufficient ability to transport oxygen to the body. Even in conditions like TGA, doctors might immediately proceed to repair instead of taking the time to do a palliative step first. Should septostomy be considered, when real repair is undertaken, surgery may be needed to close the expanded ASD or foramen ovale.
An alternate definition of septostomy is an in utero procedure performed when twin-to-twin transfusion is resulting in low amniotic fluid for one twin. Creating a hole between amniotic sacs may cause more fluid shunting to the deprived twin. In this procedure, the goal is the same: to create a communication to allow fluid to pass back and forth with greater ease.