Eventration and Paralysis of the Diaphragm refers to the abnormal elevation or high position of the entire diaphragm or a part of it while the diaphragm remains intact. The former is caused by congenital underdevelopment of diaphragmatic muscle fibers, while the latter results from injury to the phrenic nerve. Statistics show it accounts for 1/10,000 of routine adult chest fluoroscopies.

bubble_chart Pathogenesis

Congenital (diaphragmatic eventration) is caused by developmental disorders of the diaphragm during the embryonic stage, incomplete or complete absence of diaphragmatic muscle fiber development, along with the absence of a thick collagen fiber layer. When intra-abdominal pressure increases and intrathoracic negative pressure rises, the diaphragm progressively bulges into the thoracic cavity, leading to various complications in the digestive, respiratory, and circulatory systems.

Acquired (diaphragmatic paralysis) is often due to diaphragmatic nerve injury, resulting in diaphragmatic muscle atrophy or degeneration of muscle fibers, with the thinned portion composed of elastic fibrous tissue. It commonly occurs due to trauma, surgery and injury, inflammation in the neck or chest, neuritis, tumors, or compression damage to the phrenic nerve by subcutaneous nodes in the spine. The right phrenic nerve has prominent branches, so diaphragmatic eventration is more commonly seen on the right side and rarely bilateral.

bubble_chart Clinical Manifestations

In newborns, infants, and children, complete diaphragmatic eventration primarily manifests as dyspnea, tachypnea, and recurrent pneumonia, with gastrointestinal symptoms being uncommon and atypical. Physical examination reveals excessive expansion of the lower intercostal spaces during inspiration (known as Hoover's sign), tracheal and cardiac displacement to the contralateral side, dullness on percussion of the lower chest, audible borborygmi, and a flat abdomen.

In adults, left diaphragmatic eventration commonly presents with dysphagia, upper abdominal pain, acid reflux, and belching. Gastrointestinal symptoms worsen when lying flat, head-down, or after overeating, but improve when lying on the left or right side due to gastrointestinal displacement. Dyspnea, shortness of breath, or pneumonia may also occur, and the physical signs are similar to those in children.

1. Chest X-ray is the primary method for diagnosing diaphragmatic eventration, where the elevated diaphragm appears as a smooth, intact curve, and paradoxical movement of the diaphragm can be observed in cases of diaphragmatic paralysis.

2. Gastrointestinal contrast studies and barium enema may reveal elevated colon, inverted stomach, or associated volvulus.

bubble_chart Diagnosis

Pneumoperitoneum aids in the diagnosis of this disease and can also reveal an elevated diaphragm through diaphragmatic imaging, which is helpful for diagnosing difficult cases.

bubble_chart Treatment Measures

Patients without clinical symptoms or with mild symptoms, regardless of the extent of diaphragmatic eventration, do not require surgical treatment. For newborns or children with severe respiratory distress, emergency surgery is indicated. Those with gastrointestinal symptoms caused by gastric volvulus are also candidates for surgery. Diaphragmatic eventration caused by phrenic nerve palsy may gradually recover, so temporary observation and treatment of the

disease cause are advisable. Surgery involves resection or reduction of the weakened portion of the diaphragm, folding the diaphragm, or performing a "cross" incision with diagonal overlapping sutures at the intermediate position of the respiratory [second stage], which yields better therapeutic outcomes.