RT Book, Section A1 Predina, Jarrod D. A1 Singhal, Sunil A2 Yuh, David D. A2 Vricella, Luca A. A2 Yang, Stephen C. A2 Doty, John R. SR Print(0) ID 1104587881 T1 Diaphragmatic Disorders T2 Johns Hopkins Textbook of Cardiothoracic Surgery YR 2014 FD 2014 PB McGraw-Hill Education PP New York, NY SN 978-0-07-166350-2 LK accesssurgery.mhmedical.com/content.aspx?aid=1104587881 RD 2024/03/28 AB EpidemiologyBochdalek hernias are usually diagnosed in neonates whereas Morgagni hernias tend to be found in adults. Bochdalek diaphragmatic hernias occur in approximately 1:2000 children. Morgagni hernias occur much less frequently than Bochdalek hernias, and account for only 5 percent of all congenital diaphragmatic hernias. Acquired sliding (type I) hiatal hernias may be found in up to 15 percent of the population, and account for 95 percent of acquired diaphragmatic defects. The remaining 5 percent of acquired diaphragmatic hernias are composed primarily of paraesophageal (type II) hernias. Acquired diaphragmatic hernias are often diagnosed in patients with risk factors for increased intra-abdominal pressures. Diaphragmatic paralysis most commonly occurs following cardiac surgery procedures, with incidences ranging from less than 1 percent to approximately 10 percent. Most diaphragmatic tumors are metastatic in nature, and primary tumors of the diaphragm are quite rare.PathophysiologyIn neonates, Bochdalek hernias result in abdominal viscera assuming an intrathoracic position, typically into the left hemithorax. This displacement often impairs growth of the ipsilateral lung, causes mediastinal deviation to the contralateral chest, pulmonary compromise, and pulmonary hypertension. Morgagni hernias also result in abdominal viscera herniation into the chest; however, presenting symptoms more often are related to bowel obstruction. Sliding hiatal (type I) hernias are defined as a supradiaphragmatic displacement of the gastroesophageal (GE) junction. The abnormal anatomy impairs lower esophageal sphincter (LES) function and results in reflux symptoms. Paraesophageal (type II) hernias occur when the gastric fundus assumes a supradiaphragmatic position, whereas the GE junctions remain in its normal anatomical location. Diaphragmatic paralysis may result from any abnormality along the neuromuscular axis. Diaphragmatic tumors are most commonly the result of metastatic tumors originating in surrounding organs.Clinical featuresIn extreme circumstances, Bochdalek hernia may result in early respiratory compromise requiring prompt surgical interventions or extracorporeal membrane oxygenation (ECMO). Those diagnosed with Morgagni hernia often present with abdominal symptoms and discomfort. The abnormal anatomy associated with sliding (type I) hiatal hernias impair LES function, thus producing reflux symptoms such as “heartburn” and abdominal discomfort. Reflux may predispose patients to develop esophagitis and esophageal cancer. Gastric strangulation is the primary concern for those diagnosed with paraesophageal (type II) hiatal hernias. Both unilateral and bilateral diaphragmatic paralysis may be observed and, in a well-compensated patient, are compatible with normal activity. Diaphragmatic tumors are normally asymptomatic and found incidentally.DiagnosticsPlain chest radiograph is diagnostic for diaphragmatic hernias, whereas computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound may play adjunctive roles. Congenital defects may be found on prenatal ultrasound. Contrast studies may also reveal important anatomy of acquired hiatal hernias. Diaphragmatic paralysis can be suggested by plain chest radiography as indicated by elevated diaphragmatic boarders. Fluoroscopic evaluation (“sniff test”) may also aid in the diagnosis of diaphragmatic paralysis. Recently, ultrasound evaluation of the diaphragm has become more common. Diaphragmatic tumors may be incidentally found with a number of modalities, and should be further evaluated using CT and MRI techniques.TreatmentOperative repair for Bochdalek and Morgagni hernias require reducing herniated abdominal contents, resecting the hernia sac, and closing the diaphragmatic defect primarily or ...