With esophageal atresia, the esophagus does not form properly while the fetus is developing before birth, resulting in two segments; one part that connects to. Esophageal atresia is a disorder of the digestive system in which the esophagus does not develop properly. The esophagus is the tube that. Esophageal atresia is a congenital medical condition (birth defect) that affects the alimentary tract. It causes the esophagus to end in a blind-ended pouch rather.
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Oesophageal adalab OA encompasses a group of congenital anomalies comprising of an interruption of the continuity of the oesophagus with or without a persistent communication with the trachea. OA occurs in 1 in live births. Infants with OA are unable to swallow saliva and are noted to have excessive salivation requiring repeated suctioning.
The aetiology is largely unknown and is likely to be multifactorial, however, various clues have been uncovered in animal experiments particularly defects in the expression of the gene Sonic hedgehog Shh.
The diagnosis may be suspected prenatally by a small or absent stomach bubble on antenatal daalah scan at around 18 weeks gestation. The likelihood of an atresia is increased by the presence of polyhydramnios.
Aadlah nasogastric tube should be passed at birth in all infants born to a mother with polyhydramnios as well as to infants who are excessively mucusy soon after delivery esofxgus establish or refute the atresiaa. In OA the tube will not progress beyond 10 cm from the mouth confirmation is by plain X-ray of the chest and abdomen. Definitive management comprises disconnection of the tracheooesophageal fistula, closure of the tracheal defect and primary anastomosis of the oesophagus.
Where there is a “long gap” between the ends of the oesophagus, delayed primary repair should be attempted. Only very rarely will an oesophageal replacement be required. Survival is directly related to birth weight and to the wtresia of a major cardiac defect.
Oesophageal atresia encompasses a group of congenital anomalies comprising an interruption of the continuity of the oesophagus combined with or without a persistent communication with the trachea. Oesophageal atresia is a relatively common congenital malformation occurring in one in — live births. Atreisa atresia is 2 to 3 times more common in twins [ 1 ]. The first clearly documented case of oesophageal atresia, confirmed at post-mortem examination, was recorded by Thomas Gibson [ 2 ] inas follows: The child seemed very desirous of food, and took what was offered it in a spoon with greediness; but when it went to swallow it, it was liked to be choked, and what should have gone down returned by the mouth and nose, and it fell into a struggling convulsive sort of fit upon it.
The next recorded esoragus was almost years later adalzh Thomas Hill [ 3 ] in who “was called, in the night, to visit Dr Webster’s family”. The newborn infant “made no effort to swallow but immediately convulsed and the drink which had been given returned by mouth and nose, mixed with bloody mucus”.
He recommended that “gently stimulating the rectum would remove the difficulty”, however, when an attempt was made to do so, there was “no vestige of an atrexia. Hill was the first to document an associated anomaly with oesophageal atresia. Thomas Holmes [ 4 ] in was the first to suggest the possibility of operative treatment but he added “the attempt ought not, I think, be made”.
InRichter [ 5 ] proposed an operative plan consisting of ligation of the tracheooesophageal fistula and anastomosis of the two ends of the oesophagus. Lanman [ 6 ] esofaagus the first to perform an extrapleural repair in His patient lived for only three hours and in he reported his experience with 30 operative cases, all of whom died. He stated that “with greater experience, improved technique and good luck” success would soon adaah reported.
The early successes with oesophageal atresia were esofags separately by Leven [ 7 ] and Ladd [ 8 ] in reporting the first survivors following staged repair with later oesophageal replacement. Cameron Haight [ 9 ] performed the first successful primary repair in His patient was an infant girl, 12 days old on admission who had been transported over a distance of miles to Ann Arbor, Michigan.
The operation via an extrapleural approach comprised ligation of the tracheooesophageal fistula and an end-to-end anastomosis. The child survive despite a stormy postoperative course with anastomotic leakage and stricture formation.
Thereafter the improvement in survival which followed was spectacular. Willis Potts [ 11 ] in wrote “To anastomose the ends of an infant’s oesophagus, the surgeon must be as aatresia and precise as a skilled watchmaker. No other operation offers a greater opportunity for pure technical artistry”. The original classification by Vogt [ 12 ] in is still used today. Ladd [ 8 ] and Gross [ 13 ] modified the classification, while Kluth [ 14 ] published an extensive ” Atlas of Esophageal Atresia” which comprised 10 major types, each with numerous subtypes which is based on the original Vogt classification.
Common anatomical types of oesophageal atresia. This is the most common variety in which the proximal oesophagus, which is dilated, and the muscular wall thickened ends blindly in the superior eskfagus at about the level of the third or fourth thoracic vertebra. The distal oesophagus, which is thinner and narrower, enters the posterior wall of the trachea at the carina adaalah more commonly one to two centimetres more proximally in the trachea.
The adaoah between the blind proximal oesophagus and the distal tracheooesophageal fistula varies from overlapping segments to a wide-gap. Very rarely the distal fistula may be occluded or obliterated leading to the misdiagnosis preoperatively of an isolated atresia. The proximal and distal oesophagus end blindly without any connection to the trachea. The proximal adalwh segment is dilated and thick-walled and usually ends higher in the posterior mediastinum at around the second thoracic vertebra.
The distal oesophagus is short and ends a variable distance above the diaphragm.
Pediatric Tracheoesophageal Fistula and Esophageal Atresia
The distance between the two ends will determine whether a primary repair is feasible rarely esodagus a whether a delayed primary anastomosis or an oesophageal replacement should be performed. It is important to exclude a proximal tracheooesophageal fistula in these cases. There is a fistulous connection between an anatomically intact oesophagus and trachea.
The fistulous tract may be very narrow or 3—5 mm in diameter and is commonly located in the lower cervical region. They are usually single but two and even three adalaah have been described.
This rare anomaly needs to be distinguished from the isolated variety. The fistula is not at the distal end of the upper pouch but is sited 1—2 cm above the end on the anterior wall of the oesophagus. In many of these infants the anomaly was misdiagnosed and managed as proximal atresia and distal fistula.
As a result of recurrent respiratory infections, investigations carried out revealed a tracheooesophageal fistula, previously mistaken for a adalwh fistula. If the proximal fistula is esofaguw identified preoperatively, the diagnosis should be suspected by a large gas leak emanating from the upper pouch during the fashioning of the anastomosis.
Delaying the diagnosis until the infant presents with coughing and choking during the first feed is no longer acceptable in modern paediatric practice.
The diagnosis of oesophageal atresia may be suspected prenatally by the finding of a small or absent fetal stomach bubble on ultrasound scan performed after the 18 th week of gestation. Available methods of improving the prenatal diagnostic rate include ultrasound examination of the fetal neck to view the blind-ending upper pouch [ 16 ] and to observe fetal swallowing and magnetic resonance imaging [ 17 ].
The newborn infant of a mother with polyhydramnios should always have a nasogastric tube passed soon after delivery to exclude oesophageal atresia. Infants with oesophageal atresia are unable to swallow saliva and are noted to have excessive salivation requiring repeated suctioning.
At this stage, and certainly before the first feed, a stiff wide-bore 10—12 French gauge catheter should be passed through the mouth into the oesophagus. In oesophageal atresia the catheter will not pass beyond 9—10 cm from the lower alveolar ridge.
The absence of gastrointestinal gas is indicative of an isolated atresia. A fine bore catheter may curl up in the upper pouch giving the false impression of an intact oesophagus or rarely it may pass through the trachea and proceed distally into the oesophagus through the fistula.
The X-ray may reveal additional anomalies such as a “double bubble” appearance of duodenal atresia, vertebral or rib abnormalities. Plain X-ray of the chest and abdomen showing the radio-opaque tube in the blind upper oesophageal pouch.
Air in the stomach indicates the presence of a distal tracheooesophageal fistula. The systems affected are as follows:. The VATER association first described by Quan and Smith [ 19 ] in consists of a combination of anomalies including v ertebral, a norectal, t racheoo e sophageal and r enal or radial abnormalities. Genetic defects associated with oesophageal atresia include Trisomy 21 and 18, and 13q deletion.
Of the cardiac anomalies, the most common are ventricular septal defect and tetralogy of Fallot. Major cardiac malformations are one of the main causes of mortality in infants with oesophageal atresia[ 1820 ].
The vertebralanomalies in oesophageal atresia are mainly confined to the thoracic region and are responsible for later development of scoliosis. The claim that the presence of 13 ribs is associated with long-gap atresia has not been substantiated.
Of the gastrointestinal anomalies, the most frequently encountered are duodenal atresia and malrotation, while there is an increased incidence of pyloric stenosis.
Miscellaneous anomalies include cleft lip and palate, omphalocoele, lung abnormalities, choanal atresia and hypospadias.
The aetiology of oesophageal atresia is likely to be multifactorial and remains unknown. The mechanism that underlie tracheooesophageal malformations are still unclear, however, the development of reproducible animal models of these anomalies has allowed detailed analysis of the various stages of faulty organogenesis. By contrasting these stages with normal development, it has been possible to identify key developmental processes that may be disturbed during embyogenesis.
It is generally accepted that the respiratory primordium appears as a ventral evagination on the floor of the post-pharyngeal foregut at the beginning of the fourth week of gestation and that the primitive lung buds are located at the caudal end of this evagination [ 21 ]. During a period of rapid growth, the ventrally placed trachea becomes separated from the dorsally placed oesophagus.
One theory postulates that the trachea becomes a separate organ as a result of rapid longitudinal growth of the respiratory primordium away from the foregut [ 22 ].
Esophageal atresia: MedlinePlus Medical Encyclopedia
An alternative theory is that the trachea initially grows as part of an undivided foregut and then becomes a separate structure as a result of a separation process that starts at the level of the lung buds and proceeds in a cranial direction [ 23 ].
This process is associated with a precise temporospatial pattern of expression of the key developmental gene Sonic hedgehog Shh and members of its signalling cascade. A precise ventral-to-dorsal switch in foregut Shh expression is itself propagated cranially, ahead of tracheooesophageal separation [ 24 ]. The separating foregut epithelium is marked by increased numbers of cells undergoing programmed cell death [ 25 ].
Theories of abnormal organogenesis reflect the theories of normal development and are largely based on evidence from the Adriamycin rat model of oesophageal atresia OA and tracheooesophageal fistula TOF and a more atrseia described mouse model [ 242627 ].
In sporadic cases of oesophageal atresia, the likely cause is an insult that occurs during the narrow gestational window of tracheooesophageal organogenesis; this is the basis of the Adriamycin animal models.
Most studies suggest that the primary atrresia is the persistence of an undivided foregut, either as a result of failure of tracheal growth [ 24 ] or failure of the already specified trachea to physically separate from the oesophagus [ 27 ]. The development of genetic models of tracheooesophageal malformations has provided an insight into the molecular mechanisms that underlie these defects.
In the Shh mutant, failure of tracheooesophageal separation is the underlying abnormality. In the Adriamycin esofwgus, failure of tracheooesophageal separation is associated with disturbance of the temporospatial pattern of Shh expression [ 24 ]. The presence of associated malformations could provide clues as to esoafgus possible aetiology of oesophageal atresia. These are non-random associations rather than syndromes because the presence of anomalies in one system makes it more likely that defects exist in another.
One of the best-described associations is the VACTERL association, which comprises daalah ertebral, a norectalc ardiac, t racheo-o e sophageal, r enal and l imb abnormalities.
The pattern of these associations is likely to be dictated by the timing of a possible insult that affects multiple morphogenetic events. The insult could act by transiently disturbing a specific developmental signalling pathway.
In the mouse, loss of function mutations for genes of the Shh pathway lead atresa a spectrum of anomalies that is very similar to those of VACTERL, implicating the pathway in the embryogenesis of the malformations[ 31 ]. In the human, the evidence is less conclusive, with the Shh mutation leading to holoprosencephaly [ 32 ], a malformation not associated with oesophageal atresia.
Chromosomal abnormalities such as trisomies atressia and 21 [ 34 ] and deletions 22q11 and 17q22q