Key Points

• Congenital diaphragmatic malformations include congenital diaphragmatic hernia (CDH) and diaphragmatic eventration (DE). The eventrated diaphragm, which is an abnormally thin diaphragm, results from an abnormal development of its muscular component. It must be differentiated from diaphragmatic paralysis.
• The standard of care for newborns presenting with CDH is delayed surgical repair after the patient has been stabilized. Gentle ventilation and permissive hypercapnea are encouraged. In addition, nitric oxide, high-frequency jet ventilation, sildenafil and extracorporeal membrane oxygenation may be used to treat pulmonary hypertension, although there remains insufficient evidence that any of these modalities decrease acute pulmonary hypertension or improve survival.
• Surgery is rarely needed for DE in the pediatric population. It may be indicated in symptomatic patients with a diffuse DE.
• An elevated diaphragm in the adult population is attributed to DE only after other etiologies have been excluded. The indication for diaphragmatic plication is mainly related to the patient’s symptoms which need to be clearly documented.
• The presence of a previously unrecognized CDH in an adult should normally be addressed surgically, as the risk of potential for serious complications is significant. This is particularly important for young female patients prior to an eventual pregnancy.

Congenital disorders affecting the diaphragm may be divided into congenital diaphragmatic hernia (CDH) and diaphragmatic eventration (DE). Contrarily to CDH, in which the diaphragm has lost its continuity or sometimes its normal attachments to the costal margin, the eventrated diaphragm is complete and unbroken. DE is defined as an abnormally thin and fibrous diaphragm secondary to incomplete development of a part or the totality of muscular components (Box 1). Its inability to contract normally causes its distention and elevation toward the chest, which explains its name, eventration (e, “out of”; venter, “abdomen”). It must be differentiated from a diaphragmatic paralysis, which can present similarly on the chest roentgenograms and be responsible for similar physiologic disturbances. In this chapter, the origin, diagnosis, and treatment of congenital diaphragmatic malformations are discussed. Indications for surgical treatment and methods of surgical correction are emphasized, in both the pediatric and adult populations.