Eventration of the diaphragm

Eventration of the diaphragm refers to the radiographic finding of an abnormally elevated hemidiaphragm. When this condition leads to symptomatic respiratory insufficiency, it may require operative intervention. Diaphragmatic eventrations are classified as either acquired or congenital. Congenital eventration is thought to be related to abnormal migration of myoblasts during early embryologic development, though its precise cause is unknown and is likely to be multifactorial. Unilateral eventration is suspected when the right hemidiaphragm is greater than two rib levels higher than the left, or when the left hemidiaphragm is more than one rib level higher than the right. General endotracheal anesthesia is used. Whatever technique is chosen for repair, it is imperative that a taut diaphragm is created and those adjacent organs are not injured. The stomach, colon, and spleen are at particular risk during repair of left-sided eventration via a thoracic approach. Response to operation may be immediate, allowing prompt weaning and extubation.