You are in: eMedicine Specialties > Thoracic Surgery > Congenital Diaphragmatic Hernias, CongenitalArticle Last Updated: Jun 23, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Jason M Johnson, DO, General and Laparoscopic Surgeon, Department of General Surgery, William Beaumont Army Medical Center Coauthor(s): Sidney R Steinberg, MD, FACS, Program Director, Department of General Surgery, Spartanburg Regional Healthcare System; Consulting Surgeon, Department of Surgery, WG Hefner Veterans Affairs Medical Center; Eric Jensen, MD, FACS, Staff General & Pediatric Surgeon, Department of General Surgery, William Beaumont Army Medical Center Editors: Jeffrey C Milliken, MD, Chief, Division of Cardiothoracic Surgery, University of California at Irvine Medical Center; Clinical Professor, Department of Surgery, University of California at Irvine School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Daniel S Schwartz, MD, FACS, Clinical Assistant Professor of Cardiothoracic Surgery, New York University School of Medicine; Consulting Staff, Department of Surgery, Division of Thoracic Surgery, North Shore University Hospital/Long Island Jewish Medical Center; Paolo Zamboni, MD, Professor of Surgery, Chief of Day Surgery Unit, Chair of Vascular Diseases Center, University of Ferrara, Italy; Mary C Mancini, MD, PhD, Director of Cardiothoracic Transplantation, Professor, Department of Surgery, Louisiana State University Health Sciences Center Author and Editor Disclosure Synonyms and related keywords: diaphragmatic hernia, congenital diaphragmatic hernia, Bochdalek hernia, CDH, Morgagni hernia, extracorporeal membrane oxygenation, ECMO INTRODUCTIONSection 2 of 11
  The diaphragm is the major muscle of respiration and the second most important muscle within the body after the heart. Because the body relies so much on the diaphragm for respiratory function, understanding how many different diseases processes ultimately result in dysfunction of the diaphragm is vitally important. When a decrease in diaphragmatic function occurs, a concomitant respiratory dysfunction occurs. The body has many mechanisms in place to compensate for decreased diaphragmatic function. However, no compensatory mechanisms are in place to prevent respiratory compromise in the setting of decreased diaphragmatic excursion. Diaphragmatic hernias can be divided into two broad categories: congenital diaphragmatic defects and acquired diaphragmatic defects. Congenital diaphragmatic hernias (CDH) occur through embryologic defects in the diaphragm, and most patients present early in life rather than later. However, a subset of adults may present with a smaller congenital hernia that was undetected during childhood. History of the ProcedureThe discussion of CDH dates back to the first description in 1679 by Lazarus Riverius who incidentally noted a CDH during a postmortem examination of a 24-year-old person. In 1701, Sir Charles Holt described the classical clinical and postmortem findings of an infant with CDH in Philosophical Transactions of Royal Society of London. Giovanni Battista Morgagni in 1761 reviewed earlier literature and other accounts of both CDH and traumatic diaphragmatic hernias. He published his discussion along with the description of various types of diaphragmatic hernias in De Sedibus, Et Causis Morborum Per Anatomen Indagatis Libri Quinique (On the Seats and Causes of Disease, Investigated by Anatomy). In this masterpiece, he described the classical anterior diaphragmatic hernia, which today bears his name—Morgagni hernia. In 1848, Victor Alexander Bochdalek, a professor of anatomy at Prague, described both right and left posterolateral CDH. To this day, CDH commonly is referred to as Bochdalek hernia in honor of Victor Bochdalek's contribution to the field. René Laennec published a treatise entitled Traite de l'auscultation mediate, et de des maladies des poumons et du coeur (A Treatise in the Diseases of the Lungs and Heart and on Mediate Auscultation), which described the numerous causes of diaphragmatic hernias and also an auscultatory mechanism by which to diagnosis a diaphragmatic hernia. In this treatise, Laennec also discussed the potential for surgical repair of a diaphragmatic hernia. In 1888, Nauman of Sweden proposed a 2-cavity approach to repair diaphragmatic hernias after unsuccessfully operating on a 19-year-old patient with infarcted bowel that had herniated through a defect in the diaphragm. In 1889, J. O'Dwyer of New York attempted the first reported repair of a CDH in an infant. At that time, O'Dwyer discovered the loss of "right of domain" commonly encountered during attempts to repair CDH. In 1929, as reported in the Journal of the American Medical Association, the first successful CDH repair was performed in an infant, a 3.5-month-old girl. In 1977, extracorporeal membrane oxygenation (ECMO) was introduced as a treatment for neonates with respiratory failure refractory to conventional care, and its application in the field of CDH has increased the survival rate of infants born with CDH from around 20% to 55%-75%. ECMO provides a modality by which blood can be withdrawn (either by arteries [venoarterial] or veins [venovenous]), oxygenated, and finally returned back into the body for circulation. By utilizing ECMO, infants are medically stabilized prior to surgery; surgical intervention after stabilization produces better outcomes. Since the time of the first successful repair, great strides have been made in the field of CDH. However, until 1982, when ECMO was first used in the treatment of CDH, the mortality rate remained extremely high for infants born with CDH and severe pulmonary hypoplasia. The field of CDH continues to grow as knowledge of the disease entity increases and progress is made with newer treatment modalities. FrequencyThe occurrence of CDH is 0.08-0.45 cases per 1000 births. The survival rate is 55-65%. EtiologyCDH occurs when the muscular entities of the diaphragm fail to develop normally, resulting in displacement of abdominal components into the thorax. Bochdalek hernias of the diaphragm These hernias make up the majority of cases of CDH. The major problem in Bochdalek hernias is posterolateral defects of the diaphragm, which results in either failure in the development of the pleuroperitoneal folds or improper or absent migration of the diaphragmatic musculature. As many as 90% of patients with CDH present in the neonatal period or within the first year of life. These cases have a mortality rate of 45-50%. Most of the morbidity and mortality of CDH relates to hypoplasia of the lung and pulmonary hypertension on the affected side. Thus, timely diagnosis and proper management remains the key to survival. Morgagni hernias This is a less common CDH, occurring in only 5-10% of CDH cases. The foramen of Morgagni hernia occurs in the anterior midline through the sternocostal hiatus of the diaphragm, with 90% of cases occurring on the right side. PathophysiologySee Relevant Anatomy for a detailed discussion. CDH involves associated anomalies, pulmonary hypoplasia, and pulmonary hypertension. Clinical
INDICATIONSSection 3 of 11
The diaphragm is the major muscle of respiration and the second most important muscle after the heart. When a decrease in diaphragmatic function occurs, a concomitant respiratory dysfunction generally always accompanies the functional decrease. Although the body has many compensatory mechanisms in the setting of decreased diaphragmatic function, little can be done to prevent respiratory compromise if excursion of the diaphragm is moderately diminished or simply absent. Appropriate treatment is essential in cases of CDH. RELEVANT ANATOMYSection 4 of 11
The diaphragm is a modified half-dome of musculofibrous tissue that separates the thorax from the abdomen. Four embryologic components make up the formation of the diaphragm: the septum transversum, 2 pleuroperitoneal folds, cervical myotomes, and the dorsal mesentery. Development begins during the third week of gestation and is completed by the eighth week. Failure of the development of the pleuroperitoneal folds and subsequent muscle migration results in congenital defects. The muscular origin of the diaphragm is from the lower 6 ribs bilaterally, the posterior xiphoid process, and from the external and internal arcuate ligaments. A number of different structures traverse the diaphragm, including 3 distinct apertures that allow the passage of the aorta, the esophagus, and the vena cava. The aortic aperture is the lowest and most posterior of the openings, lying at the level of the 12th thoracic vertebra. The aortic opening also transmits the thoracic duct and sometimes the azygous and hemiazygous veins. The esophageal aperture is surrounded by diaphragmatic muscle and lies at the level of the 10th thoracic vertebra. The vena caval aperture is the highest of the 3 openings and lies level with the disc space between the 8th and 9th thoracic vertebra. Arterial supply to the diaphragm comes from the right and left phrenic arteries, the intercostal arteries, and the musculophrenic branches of the internal thoracic arteries. Some arterial blood is provided from small branches of the pericardiophrenic arteries that run with the phrenic nerve mainly where the nerves penetrate the diaphragm. Venous drainage is via the inferior vena cava and azygous vein on the right and the adrenal/renal and hemizygous veins on the left. The diaphragm receives its sole muscular neurologic impulse from the phrenic nerve, which originates primarily from the fourth cervical ramus but also has contributions from the third and fifth rami. Originating around the level of the scalenus anterior muscle, the phrenic nerve courses inferiorly through the neck and thorax before reaching its terminal point, the diaphragm. Because the phrenic nerve has such a long course before reaching its final destination, any processes that disrupt the transmission of neurologic impulse through the nerve directly affect the diaphragm. CONTRAINDICATIONSSection 5 of 11
Some reports exist of increased mortality rates with early surgical intervention for CDH in infants. Many authors suggest that the patient be stabilized (often with the use of ECMO) and that repair be delayed until the infant is better prepared to survive the operation. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
TREATMENTSection 7 of 11
Medical therapyResuscitation with ventilatory support is of prime importance in patients born with CDH. The trend over the past few years has been a switch from conventional mechanical ventilation to high-frequency oscillatory ventilation (HFOV). HFOV serves to minimize airway pressure and, in conjunction with permissive hypercapnia, HFOV helps those with CDH suffer less traumatic lung injury and fewer long-term complications. Mortality has been shown to decrease from 49-20% when HFOV is used early in the treatment course. Extracorporeal membrane oxygenation (ECMO) has been shown to significantly decrease the mortality of CDH but is currently reserved for individuals whose condition fails to improve with both HFOV and conventional mechanical ventilation. The decision to utilize ECMO is made early in the disease process, usually within 24 hours of birth. With the addition of HFOV, more reports exist of decreased morbidity and mortality with early surgical intervention. However, this practice is still rather controversial. The classical teaching is that patients need to be stabilized (often with the use of ECMO) and that repair be delayed until the infant is better prepared to survive the operation. Surgical therapy
Intraoperative details
Follow-upOnce an anatomic defect has been corrected, periodically assessing pulmonary function and obtaining chest radiographs is important. Although spontaneous recurrence of a repaired diaphragmatic hernia is low, small defects in the repair site have been reported, so surveillance is essential. COMPLICATIONSSection 8 of 11
OUTCOME AND PROGNOSISSection 9 of 11
With the development of newer treatment techniques to include HFOV and more sophisticated extracorporeal oxygenation equipment, the mortality rate of CDH has continually decreased. However, long-term morbidity includes such entities as gastroesophageal reflux disease (GERD), neurologic and development disorders, and musculoskeletal orders. FUTURE AND CONTROVERSIESSection 10 of 11
New research currently is underway using inhaled nitric oxide, partial liquid ventilation, and the possibility of lung transplantation for infants born with severe hypoplasia. Minimally invasive repair techniques for latent CDH are being explored at a number of institutions. Some centers utilize intrauterine fetal surgery to repair diaphragmatic defects in an attempt to prevent the hypoplastic lung problems encountered with large hernias. Because the numbers are still small and very few centers are capable of performing intrauterine surgery, this practice is rather controversial. REFERENCESSection 11 of 11
Diaphragmatic Hernias, Congenital excerpt Article Last Updated: Jun 23, 2006 |
