Survival of infants born with congenital diaphragmatic hernias (CDHs), as with many other anomalies in pediatrics, has steadily improved over the last three decades owing to advances in critical care medicine, as well as surgical technique. While early attempts to repair CDH were made in emergent fashion, recognition that the life-threatening issue was not mechanical compression of the lungs or mediastinal structures, but disordered pulmonary vascular reactivity, has been the major advance in improving survival and outcomes. There is wide variation in the technical approach to the repair of these anomalies including variability in pre- and postoperative care, timing of the operation, abdominal or thoracic operative approach, and choice of prosthetic material for closure. The intent of this chapter is to provide the adult thoracic surgeon with a reference for review of the current management of CDH and discuss the impact of having these diaphragmatic defects repaired as an infant or child on general thoracic anomalies/procedures in the adult.

The most common type of CDH is the Bochdalek hernia (Fig. 153-1). These occur posterolaterally and most commonly on the left. In general, Bochdalek hernias are categorized on the basis of size. Small defects are usually triangular in shape, with the apex medially and the base on the chest wall. Small defects most often are repaired primarily. Medium-sized defects have a larger segment of missing diaphragm, often leading to inability to close by primary repair. These defects may require a prosthetic patch, which usually includes sutures placed around the ribs laterally. The largest defects are commonly referred to as agenesis of the hemidiaphragm, and require nearly complete replacement of the hemidiaphragm with prosthetic patch material. The medium and large defects tend to have vanishingly small amounts of tissue along the esophagus and aorta to which the patch can be sewn. Consequently, gastroesophageal reflux (GERD) is more common in the medium and large defect forms of CDH leading these patients to be more likely to require a fundoplication to control their reflux. Another reason that patients with a patch repair have more reflux is that the patch does not grow as the patient does, and may, therefore, pull on the esophageal hiatus as the patient grows.

Morgagni hernias are located in the midline just posterior to the sternum. These defects can have little to no symptoms. Consequently, Morgagni hernias are most commonly diagnosed with older patients who have chest x-rays for other reasons and a mediastinal mass is seen. These Morgagni defects are commonly closed primarily; however, on rare occasion, a patch may be required. Morgagni defects are also seen in pentalogy of Cantrell, and in that case, are usually bilateral.

Eventration of the diaphragm (Fig. 153-2) occurs in the congenitally thin muscular portion of the hemidiaphragm. It occurs far more frequently on the right (5:1), as the heart tends to be protective. The eventration occurs anteromedially. It is often mistaken for CDH with an associated membrane sac; however, clinically and anatomically, eventration is a different entity (Fig. 153-3). As depicted in Figure 153-2, anatomically, there is still a small rim of diaphragmatic tissue. Diagnosis of eventration is elucidated either by a fluoroscopic diaphragmatic excursion study or by ultrasound, where paradoxical movement of the diaphragm is seen. Treatment consists of halting this paradoxical movement of the diaphragm though plication of the tissue. Surgical intervention is warranted when there is an inability to wean from a ventilator or when the respiratory status causes failure to thrive—often due to caloric consumption from tachypnea.

The majority of Bochdalek CDHs are identified antenatally by routine ultrasound screening. Consequently, these children are delivered with the planning and presence of a pediatric surgeon, and critical care resources are ready for the immediate resuscitation and care of the baby starting in the delivery room. After delivery, the baby is intubated and a nasogastric tube is placed to decompress the stomach, which is commonly located in the chest (Fig. 153-4). Gastric decompression reduces gastric distention by fluid or gas introduced by the initial resuscitation, which can exacerbate the hemodynamic effects of pulmonary mechanical compression by the abdominal contents. Extracorporeal membrane oxygenation (ECMO) is used for the rescue of babies whose pulmonary hypertension is so severe that gas exchange cannot be adequately achieved using either conventional or oscillatory ventilation. Inhaled nitric oxide is commonly employed to facilitate pulmonary capillary dilation with subsequent improved oxygenation and normalization of serum pH.

If conventional ventilation with or without nitric oxide were adequate for the support of the infant, then operation is delayed until hemodynamic stability is achieved. If ECMO is used, then repair can be performed while on ECMO. Morgagni hernias are repaired electively.

The most common technical approach to repair of CDH is by laparotomy. A subcostal incision is made on the side of the defect, and the size of the defect is assessed to determine if a primary closure can be achieved with acceptably minimal tension. A posteromedial rim is identified and dissected from the retroperitoneum. A primary repair is performed when the diaphragmatic defect is small (Fig. 153-5). This repair is usually performed with interrupted sutures of non-absorbable material; however, some surgeons will use long-lasting absorbable sutures such as PDS.