Dural, Koray2025-01-212025-01-212021978-625767974-9https://hdl.handle.net/20.500.12587/23309Diaphragmatic eventration is a clinical condition that often presents without symptoms. In this condition, all or certain parts of the diaphragm are located higher than normal. True diaphragmatic eventration occurs due to a congenital progressive disorder of the diaphragm muscle, and no pathology is observed in the sternum, ribs, and lumbar spine parts of the diaphragm. Diaphragmatic eventration is rare and is more commonly seen in males. The left hemi-diaphragm is more commonly affected. According to the embryological theory, abnormal or delayed migration of the myoblasts of the upper cervical somites leads to structural deficiency of the diaphragm muscle. In contrast to true diaphragmatic eventration, diaphragmatic paralysis is an acquired condition that usually occurs due to phrenic nerve damage caused by tumors or trauma.Diaphragmatic eventration can be bilateral, unilateral, total, or localized. The microscopic appearance of the affected section in eventration shows widespread fibroelastic changes and some muscle fibers. In children and infants, diaphragmatic eventration presents with prominent clinical findings, while most adult patients are asymptomatic and are usually diagnosed incidentally with a chest X-ray. It can become symptomatic in conditions that cause changes in weight gain, lung or chest wall compliance, especially in the elderly. Dyspnea (due to displacement of the affected hemi-diaphragm while lying in bed) and orthopnea are the main symptoms of a high hemi-diaphragm. Normal diaphragm movement during inspiration increases thoracic volume and provides the necessary space for proper lung inspiration. In patients with diaphragmatic eventration, there may be decreased, absent, or paradoxical diaphragm movement, as there is no normal diaphragm movement required for inspiration. As a result, ventilation and perfusion of the basal lung on the same side as the diaphragmatic eventration are impaired. Ventilation/perfusion mismatch and loss of chest wall compliance are among the factors contributing to dyspnea. Some patients may experience mild hypoxemia, which is compensated for by hyperventilation leading to mild respiratory alkalosis. Specifically, patients with left hemi-diaphragm eventration may experience nonspecific gastrointestinal symptoms such as epigastric pain, bloating, heartburn, belching, nausea, constipation, and growth retardation. Therefore, patients try to maintain an upright position to alleviate symptoms and may even prefer to sleep sitting up.The evaluation of symptomatic patients with diaphragmatic eventration should include assessment of dyspnea, physical examination, pulmonary function tests, and objective evaluation of imaging studies. The diagnosis of symptomatic hemi-diaphragmatic eventration is mainly based on clinical findings and is often dependent on the patient's history, chest X-ray, and the clinician's clinical attention. Conditions that may cause dyspnea, such as morbid obesity, heart failure, and chronic lung diseases, should be carefully examined and excluded through history taking. Physical examination provides a small contribution to the diagnosis of diaphragmatic eventration. However, two characteristic findings may be present: (1) paradoxical inward movement (also known as Hoover's sign), (2) abdominal paradox (thorax and abdomen move in an incongruous manner during inspiration). Pulmonary consolidation, decreased breath sounds, and frequent lung infections can occur together on the side with diaphragmatic eventration.Pulmonary function tests (PFTs) can provide useful objective information for the evaluation of dyspnea and patients with a high hemi-diaphragm, as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) are generally decreased due to diaphragm dysfunction. Since the diaphragm plays a significant role in respiratory capacity, the evaluation of inspiratory PFT parameters is important. PFT evaluation should also be performed separately in the upright and supine positions. In patients with diaphragmatic eventration, lung volumes in the supine position are usually reduced by 20% to 50%. © 2021 Akademisyen Kitabevi A.Ş. All rights reserved.eninfo:eu-repo/semantics/closedAccessBook Chapter4374442-s2.0-85206039529N/A