Congenital diaphragmatic hernia (CDH) is a

birth defect A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth de ...

of the diaphragm. The most common type of CDH is a

Bochdalek hernia Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia, the other form being Morgagni hernia. A Bochdalek hernia is a congenital abnormality in which an opening exists in the infant's diaphragm, allowing normally intra-abdomin ...

; other types include Morgagni hernia, diaphragm eventration and central tendon defects of the diaphragm. Malformation of the diaphragm allows the

abdominal The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

organs to push into the

chest cavity The thoracic cavity (or chest cavity) is the chamber of the body of vertebrates that is protected by the thoracic wall (rib cage and associated skin, muscle, and fascia). The central compartment of the thoracic cavity is the mediastinum. There ...

, hindering proper

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

formation. CDH is a life-threatening pathology in infants and a major cause of death due to two complications:

pulmonary hypoplasia Pulmonary hypoplasia is an incomplete development of the lungs, resulting in an abnormally low number or small size of bronchopulmonary segments or alveoli. A congenital malformation, most often occurs secondary to other fetal abnormalities tha ...

and

pulmonary hypertension Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure in the pulmonary artery, arteries of the lungs. Symptoms include dypsnea, shortness of breath, Syncope (medicine), fainting, tiredness, chest pain, pedal edema, swell ...

. Experts disagree on the relative importance of these two conditions, with some focusing on hypoplasia, others on hypertension. Newborns with CDH often have severe

respiratory distress Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that c ...

which can be life-threatening unless treated appropriately.

Classification

Bochdalek hernia

The Bochdalek hernia, also known as a postero-lateral diaphragmatic hernia, is the most common manifestation of CDH, accounting for more than 95% of cases. In this instance the diaphragm abnormality is characterized by a hole in the postero-lateral corner of the diaphragm which allows passage of the abdominal viscera into the chest cavity. The majority of Bochdalek hernias (80–85%) occur on the left side of the diaphragm, a large proportion of the remaining cases occur on the right side. To date, it carries a high mortality and is an active area of clinical research.

Morgagni hernia

This rare anterior defect of the diaphragm is variably referred to as a Morgagni, retrosternal, or parasternal hernia. Accounting for approximately 2% of all CDH cases, it is characterized by herniation through the foramina of Morgagni which are located immediately adjacent and posterior to the

xiphoid process The xiphoid process (), also referred to as the ensiform process, xiphisternum, or metasternum, constitutes a small cartilaginous process (extension) located in the inferior segment of the sternum, typically ossified in adult humans. Both the Gr ...

of the

sternum The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major bl ...

Diaphragm eventration

The diagnosis of congenital diaphragmatic eventration is used when there is abnormal displacement (i.e. elevation) of part or all of an otherwise intact diaphragm into the chest cavity. This rare type of CDH occurs because in the region of eventration the diaphragm is thinner, allowing the abdominal viscera to protrude upwards.

Pathophysiology

There are genetic causes of CDH including aneuploidies, chromosome copy number variants, and single gene mutations. Research implicates a few gene mutations including LONP1 and MYRF. It involves three major defects: * A failure of the diaphragm to completely close during

development Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped * Photographic development *Filmmaking, development phase, including finance and budgeting * Development hell, when a proje ...

Hernia A hernia (: hernias or herniae, from Latin, meaning 'rupture') is the abnormal exit of tissue or an organ (anatomy), organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal Devel ...

tion of the

contents into the

chest The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

Pulmonary The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syste ...

hypoplasia Hypoplasia (; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ. This condition can often be diagnosed before birth and

fetal intervention Fetal surgery, also known as antenatal surgery or prenatal surgery, is a growing branch of maternal-fetal medicine that covers any of a broad range of surgical techniques that are used to treat congenital abnormalities in fetuses who are stil ...

can sometimes help, depending on the severity of the condition. Infants born with diaphragmatic hernia experience respiratory failure due to both

and pulmonary hypoplasia. The first condition is a restriction of blood flow through the lungs thought to be caused by defects in the lung. Pulmonary hypoplasia or decreased lung volume is directly related to the abdominal organs presence in the chest cavity which causes the lungs to be severely undersized, especially on the side of the hernia. Survival rates for infants with this condition vary, but have generally been increasing through advances in neonatal medicine. Work has been done to correlate survival rates to ultrasound measurements of the lung volume as compared to the baby's head circumference. This figure known as the lung-to-head ratio (LHR). Still, LHR remains an inconsistent measure of survival. Outcomes of CDH are largely dependent on the severity of the defect and the appropriate timing of treatment. A small percentage of cases go unrecognized into adulthood.

Treatment

The first step in management is orogastric tube placement and securing the airway (intubation). Ideally, the baby will never take a breath, to avoid air going into the intestines and compressing the lungs and heart. The baby will then be immediately placed on a ventilator.

Extracorporeal membrane oxygenation Extracorporeal membrane oxygenation (ECMO) is a form of extracorporeal life support, providing prolonged cardiac and respiratory system, respiratory support to people whose human heart, heart and human lung, lungs are unable to provide an adequa ...

(ECMO) has been used as part of the treatment strategy at some hospitals. ECMO acts as a heart-lung bypass. Diaphragm eventration is typically repaired thoracoscopically, by a technique called plication of the diaphragm. Plication basically involves a folding of the eventrated diaphragm which is then sutured in order to “take up the slack” of the excess diaphragm tissue.

Prognosis

In the modern era, congenital diaphragmatic hernia has a survival rate of approximately 60-70%, with some tertiary care centers reporting a survival rate of up to 92%. Individual rates vary greatly dependent upon multiple factors: size of hernia, organs involved, additional birth defects and/or genetic problems, amount of lung growth, age and size at birth, type of treatments, timing of treatments, complications (such as infections) and lack of lung function.

References

External links

Congenital Diaphragmatic Hernia Study Group
under

University of Texas Health Science Center at Houston The University of Texas Health Science Center at Houston (UTHealth Houston) is a public academic health science center in Houston, Texas, United States. It was created in 1972 by The University of Texas System Board of Regents. It is located ...

DHREAMS
(Diaphragmatic Hernia Research & Exploration; Advancing Molecular Science) Project coordinated at

Columbia University Medical Center Columbia University Irving Medical Center (CUIMC) is the academic medical center of Columbia University and the largest campus of NewYork-Presbyterian Hospital. The center's academic wing consists of Columbia's colleges and schools of Physicia ...

CDH International
– A global initiative to stop Congenital Diaphragmatic Hernia {{DEFAULTSORT:Congenital Diaphragmatic Hernia Congenital disorders of musculoskeletal system Diaphragmatic hernias