Congenital Esophageal Stenosis
Congenital esophageal stenosis presents in three variants: esophageal webs or diaphragms, fibromuscular stenosis, and stenosis due to cartilaginous tracheobronchial remnants. These lesions, collectively, are rare, occurring in one in 25,000 to one in 50,000 live births. Most often, congenital esophageal stenosis presents as an isolated finding, but in 15% to 30%, this condition is associated with other congenital anomalies. Up to 8% of infants with esophageal atresia and tracheoesophageal fistula have an associated distal congenital esophageal stenosis. These occur most commonly in H-type tracheoesophageal fistulae. Other associated anomalies include cardiac defects, intestinal atresias, imperforate anus, and chromosomal abnormalities.
Clinical Manifestations and Diagnosis
Congenital esophageal stenosis may not manifest in the newborn period, because breast milk or formula passes through the stenotic area without difficulty. Symptoms often start at around 6 months of age when semisolid and solid foods are introduced into the diet. The infants then begin to regurgitate undigested foods and may develop recurrent respiratory infections due to aspiration. In unrecognized cases, the patients may present later with growth retardation. When these symptoms occur, esophagography if often undertaken, which reveals the stenotic area and may show dilation of the esophagus proximal to the stenosis. The three variants give a different radiologic appearance. The esophageal diaphragms or webs are thin layers of tissue causing stenosis in the upper portion of the esophagus. The fibromuscular stenoses are thicker than the webs and tend to occur in the middle to lower esophagus. Cartilaginous remnants occur in the distal portion of the esophagus, as shown in Figure 20-1 . In a child with these radiologic findings and the appropriate clinical picture, the differential diagnosis would include achalasia and a stricture from gastroesophageal reflux disease. To make the distinction between these entities, additional work-up including endoscopy, manometrics, and 24-hour pH probe studies is useful. Recently, endoscopic ultrasound has been used to differentiate stenoses due to cartilaginous rests from those due to fibromuscular stenosis.
Treatment
Therapy is dictated by the type of stenosis encountered. The thin proximal esophageal membrane or web can often be dilated at the time of endoscopy. On occasion, these membranes require partial resection with electrocautery or laser through the endoscope followed by dilation. The stenoses with cartilaginous remnants often require resection and primary anastomosis, as dilation is usually not effective in this type of stenosis. Fibromuscular stenosis can be dilated in most cases. A series from Japan used endoscopic ultrasound to differentiate fibromuscular stenosis from cartilaginous rests. Those with cartilaginous rests went on to surgery, and the children with fibromuscular stenosis were dilated. Ten of 13 children with fibromuscular stenoses were successfully dilated, and the remaining three required resection. Without the use of ultrasound, it is difficult to distinguish the difference pre-dilation between fibromuscular stenosis and stenosis with cartilaginous remnants. A series of dilations should be attempted, and if dilation fails, the stenotic portion of the esophagus should be resected. The exact location of the stenosis is often difficult to locate on contrast studies. To find the stenotic area, it is helpful to place a Fogarty catheter past the stenosis, inflate the balloon, and pull back the catheter. Placing contrast in the esophagus will then verify the location of the stenosis. Intraoperatively, a lighted endoscope placed at the level of the stenosis aids in locating the stenosis, which is often impossible to locate accurately with palpation and inspection. The operative approach varies according to the level of the stenosis. If the stenotic area is in the mid-esophagus, the operative approach should be through a right thoracotomy, but if the stenosis is located in the distal esophagus, a left thoracotomy will provide the necessary exposure. The stenotic area of the esophagus is excised and a single-layer end-to-end anastomosis is performed. If the stenotic lesion is close to the gastroesophageal junction and resection may alter the antireflux mechanism, then a fundoplication should be added to the procedure.
Outcome
Both dilation for webs and fibromuscular stenosis and resection for fibromuscular and cartilaginous remnant stenosis provide adequate relief of the stenosis. Compared to membranes or webs, fibromuscular stenosis required more frequent dilation over a longer period. Postoperative dilations following resection of esophageal stenosis were required to prevent anastomotic strictures.
Esophageal Atresia and Tracheoesophageal Fistula
The treatment of esophageal atresia and tracheoesophageal fistula, which occurs in about one in 4000 live births, remains a challenge. Since the first successful primary anastomosis by Haight in 1941, improvements in surgical technique and neonatal care have increased the survival rate of babies born with esophageal atresia and tracheoesophageal fistula. Spitz et al. created a classification system in 1994 used to predict survival based on birth weight (greater or less than 1500 g) and the presence of associated complex anomalies, usually cardiac in nature. In 2006, Spitz reexamined the survival data and found that the survival for infants with a birth weight greater than 1500 g and no cardiac abnormalities was similar in 1994 (97%) and 2006 (98.5%). However, the survival rates in infants who were small or who had a major cardiac anomaly increased from 59% to 82%, and the survival rate in infants who were both small and had a major cardiac anomaly increased from 22% to 50% over the same period. In 2009, Okamoto refined the Spitz classification as depicted in Table 20-1 .
| Class | Birth Weight | Major Cardiac Anomaly | Survival |
|---|---|---|---|
| >2000 g | No | 100% |
| <2000 g | No | 82% |
| >2000 g | Yes | 72% |
| <2000 g | Yes | 27% |
Anatomy
An understanding of the anatomy involved with each case of esophageal atresia and tracheoesophageal fistula is important when devising a treatment strategy. There have been several classification systems, but a description of each type is the easiest and most practical way to classify the five different types of esophageal atresia and tracheoesophageal fistula as shown in Figure 20-2 . The most common configuration is esophageal atresia with a distal tracheoesophageal fistula. This configuration occurs in 86% of cases. The proximal esophagus ends blindly in the upper mediastinum. The distal esophagus is connected to the tracheobronchial tree usually just above or at the carina. The second most common type is the isolated esophageal atresia without a tracheoesophageal fistula. This configuration occurs in 8% of cases. The proximal esophagus ends blindly in the upper mediastinum, and the distal esophagus is also blind ending and protrudes a varying distance above the diaphragm. The distance between the two ends is often too far to bring together shortly after birth. The third most common configuration, occurring in 4% of cases, is a tracheoesophageal fistula without esophageal atresia. The esophagus extends in continuity to the stomach, but there is a fistula between the esophagus and the trachea. The fistula is usually located in the upper mediastinum, running from a proximal orifice in the trachea to a more distal orifice in the esophagus. This is also known as an “H” type or “N” type tracheoesophageal fistula. Two more forms of esophageal atresia and tracheoesophageal fistula exist, both of which occur in about 1% of cases. These are esophageal atresia with both a proximal and distal tracheoesophageal fistula, and esophageal atresia with a proximal tracheoesophageal fistula. These two forms correspond to the first two forms described, with the addition of a proximal fistula between the upper pouch and the trachea. A proximal fistula is often difficult to diagnose preoperatively even when bronchoscopy is performed, resulting in the real incidence being higher than previously reported. Again, esophageal atresia with proximal tracheoesophageal fistula, similar to its counterpart without the proximal fistula, will have a long gap between the two ends of the esophagus, making it difficult to repair shortly after birth.
Associated Anomalies
As alluded to earlier, the main determinant of outcome in babies with esophageal atresia and tracheoesophageal fistula is the degree of prematurity and the associated cardiac and chromosomal anomalies. An infant with esophageal atresia and tracheoesophageal fistula has a higher incidence of prematurity than does the general population, most likely related to the polyhydramnios resulting from the fetal esophageal obstruction. More than half of infants with esophageal atresia and tracheoesophageal fistula have one or more associated anomalies. The majority of these associated anomalies are included in the VACTERL syndrome. This syndrome includes abnormalities in the following areas: vertebral, anorectal, cardiac, tracheal, esophageal, renal, and limb. A breakdown of the individual incidences of the anomalies in infants with esophageal atresia and tracheoesophageal fistula is presented in Table 20-2 . The presence of three or more of these anomalies constitutes the VACTERL syndrome, which occurs in 19% of babies with esophageal atresia and tracheoesophageal fistula. Of these children, 5% have chromosomal abnormalities including trisomy 13, 18, and 21. Other syndromes associated with esophageal atresia and tracheoesophageal fistula are the CHARGE syndrome, Potter’s syndrome, and the SCHISIS syndrome. Infants with esophageal atresia and tracheoesophageal fistula also have a higher incidence of pyloric stenosis than expected in the normal population.
| Anomalies | Occurrence (%) |
|---|---|
| Vertebral | 24.1% |
| Atresia, anorectal and duodenal | 14.3% |
| Cardiac | 32.1% |
| Renal | 17% |
| Limb | 16.1% |
| Other | 10.8% |
Clinical Presentation and Diagnosis
Esophageal atresia can sometimes be suspected on prenatal ultrasound when polyhydramnios and an absent or small fetal stomach bubble are both present. Although these are nonspecific findings and when present have a positive predictive value for esophageal atresia of only 56%, serial third trimester scans looking for a dilated upper pouch as well as fetal magnetic resonance imaging (MRI) may be useful in terms of improving diagnostic accuracy in suspected cases. Most cases of esophageal atresia and tracheoesophageal fistula are initially diagnosed shortly after birth with inability to handle saliva and episodes of coughing, choking, and cyanosis, especially with the first attempt to feed. The infant will spit up undigested formula after the feeding attempt. This usually leads to the placement of a tube in the esophagus, which does not go in as far as expected and meets resistance. Plain films of the chest and abdomen will show the tube coiled in the proximal mediastinum. This confirms the presence of esophageal atresia. The bowel gas pattern, or lack of bowel gas in the abdomen, determines if there is a distal tracheoesophageal fistula present (gas throughout the intestines), or if there is a pure esophageal atresia without a distal fistula (gasless abdomen). The remainder of the preoperative evaluation targets the associated anomalies and looks to determine the presence of a proximal fistula between the trachea and the esophagus. The associated anomalies of the VACTERL syndrome can be identified with four quick, simple evaluations. A physical examination evaluates limb and anorectal abnormalities. The plain film that demonstrating the coiled tube in the esophageal pouch is used to look for the vertebral and limb abnormalities. Ultrasound of the abdomen will delineate renal abnormalities and can detect a tethered spinal cord if present. Echocardiography is required to evaluate for cardiac anomalies and to determine the position of the aortic arch, which helps in planning the surgical approach. If a right-sided aortic arch is encountered, further evaluation with a computed tomographic angiogram or MRI angiography should be carried out to look for a vascular ring, as a complete ring is found 37% of the time. If a chromosomal anomaly is suspected, a karyotype can be sent. The presence of a proximal fistula may be evaluated in one of three ways. A contrast evaluation of the esophageal pouch will often show a proximal fistula if it is present. An experienced radiologist should do this examination using 1 to 2 mL of contrast material to decrease the risk of aspiration. Rigid bronchoscopy just before the surgical repair to look for a proximal fistula may be useful, and is often used in conjunction with the pouchogram. The last strategy is to look for a fistula during the proximal pouch dissection. A clue that a proximal fistula is present is that the proximal pouch will not be as dilated or thick as usual, since the fistula relieves the distending pressure in the proximal pouch both prenatally and postnatally. Tracheoesophageal fistula without esophageal atresia (H-type fistula) may not present in the initial neonatal period and is more difficult to diagnose. The tube will go into the stomach when originally passed, but persistent coughing and choking with feeds by mouth should prompt a search for an isolated fistula. A prone pullback esophagram and/or bronchoscopy with esophagoscopy is used to identify the isolated fistula.
Treatment
After the diagnosis is confirmed, plans for operative repair should be made. In healthy newborns, the operation can take place within the first 24 hours of life to minimize the risk of aspiration and resulting pneumonitis. Before the operation, the baby should be kept supine with the head elevated 30° to 45°. A tube should be placed in the proximal pouch to constantly suction saliva and prevent aspiration. Intravenous access should be established and fluids instilled along with broad-spectrum antibiotics and vitamin K.
The goal of operative therapy for esophageal atresia and tracheoesophageal fistula is to establish continuity of the native esophagus and repair the fistula in one setting. Most of the time, primary repair can be achieved. There are special situations where this may not be possible or advisable. These situations are described later. In the usual situation, the infant is stable both hemodynamically and from a pulmonary standpoint, is brought to the operating room, and is placed under a general anesthetic. Rigid bronchoscopy may be performed to locate the distal fistula, usually at or near the carina, and to look for a proximal fistula or cleft. After the bronchoscopy, the infant is placed in the left lateral decubitus position in preparation for a right posterolateral thoracotomy. If preoperative echocardiography reveals a right-sided aortic arch, which occurs in 2% of cases, the repair should be approached from the left chest. With a right-sided aortic arch, the two ends of the esophagus will need to be brought together over the arch, resulting in increased tension on the anastomosis and a high anastomotic leak rate in the range of 40%. A right-sided aortic arch may be discovered intraoperatively, as the preoperative echocardiogram picks up only 20% to 62% of the right-sided arches correctly. In that situation, the repair is attempted through the right chest, and if it cannot be completed, the tracheoesophageal fistula is divided, the right chest is closed, and a left thoracotomy is used to complete the anastomosis. In the typical case, a right-sided posterolateral thoracotomy using a muscle-sparing, retropleural approach gives access to the mediastinal structures. The azygos vein is divided, revealing the tracheoesophageal connection. The distal esophagus is divided, and the tracheal connection is closed with 5-0 monofilament suture. Manipulation of the distal esophagus is minimized to protect the segmental blood supply to this portion of the esophagus. The proximal esophagus has a rich blood supply coming from the thyrocervical trunk and may be extensively dissected, as depicted in Figure 20-3 . The dissection of the proximal esophageal pouch proceeds on the thickened wall of the proximal esophagus to prevent tracheal injury. Dissection is carried as high as possible to gain length for a tension-free anastomosis and to look for a proximal fistula, which occurs rarely. A single-layered end-to-end anastomosis is performed as depicted in Figure 20-4 . A tube placed through the anastomosis into the stomach allows decompression of the stomach and eventual enteral feeding. A chest tube placed in the retropleural space next to the anastomosis controls any subsequent leak. Some surgeons prefer not to use a chest tube if the pleura remains intact. The advantage of a retropleural approach is that if the anastomosis leaks, the infant will not soil the entire hemithorax and develop an empyema. A leak into the retropleural space will result in a controlled esophagocutaneous fistula that will usually close spontaneously.
In 1999, Lobe et al. performed the first thoracoscopic repair of esophageal atresia in a 2-month-old baby with pure esophageal atresia. The next year, the first thoracoscopic repair of an esophageal atresia was performed in a newborn, and since then multiple series of thoracoscopic repairs have been reported in the literature. Thoracoscopic repair requires advanced skills in pediatric minimal access surgery to perform the intracorporeal anastomosis and requires a transpleural approach. Advantages include smaller, less traumatic incisions and better visualization. When comparing outcomes after thoracoscopic and open repair of esophageal atresia, the two approaches resulted in similar lung function in the first year of life. A recent meta-analysis revealed similar rates of leaks in both groups, and a statistically insignificant increase in stricture formation after open thoracotomy repairs.
Postoperatively, the baby is returned to the intensive care unit and continued on intravenous nutrition and antibiotics. Special care should be directed toward preventing aspiration with frequent oropharyngeal suctioning and elevation of the head of the bed 30° to 45°. Feedings may be started through the trans-anastomotic tube into the stomach 2 to 3 days after the operation. Acid suppressive therapy should be instituted to prevent acid irritation of the anastomosis and subsequent stricture. On postoperative days 5 to 7, an esophagram is obtained to check the integrity of the anastomosis. If there is no leak, feedings are started orally and the chest tube is removed if there are no clinical signs of a leak. If a leak is present, it is treated conservatively with intravenous antibiotics, nutrition and chest tube drainage. Another esophagram is ordered in a week. These leaks will invariably close without further operative intervention. Only a complete disruption of the anastomosis requires further operative procedures. In that case, the proximal esophagus should be brought out of the left neck as a cervical esophagostomy, the distal esophagus should be tied off, and the mediastinum and chest should be adequately drained.
Special Situations
The majority of cases of esophageal atresia and tracheoesophageal fistula can be handled as just described. There are three variations that require further discussion: infants with esophageal atresia and tracheoesophageal fistula who have severe respiratory disease where the fistula is contributing to the ventilatory insufficiency; infants with long-gap esophageal atresia; and infants with the H-type tracheoesophageal fistula. Infants with significant respiratory insufficiency and a tracheoesophageal fistula are usually premature with lung immaturity requiring significant ventilatory support. The connection between the trachea and the distal esophagus may be the preferred path for air provided by the ventilator. The stiff lungs have a higher resistance than the fistulous tract, allowing a significant portion of each inspiratory volume to go into the esophagus and then into the abdomen, resulting in abdominal distension and elevation of the hemidiaphragms, thereby further impeding ventilation. Various strategies have been developed to address this situation. A change to high-frequency ventilation decreases the portion of tidal volume lost to the fistula. Advancing the endotracheal tube past the fistula opening prevents further loss of ventilation into the fistula, but it is not always possible. Bronchoscopically placed Fogarty catheters positioned in the fistula and inflated temporarily occlude the fistula, but these have a tendency to become dislodged. If a gastrostomy tube is present, the tube can be placed to underwater seal to increase the resistance of the tract and reduce airflow through the fistula. However, to prevent further respiratory decompensation, and to ameliorate the risk of gastric perforation, these infants often require an urgent thoracotomy and control of the tracheoesophageal fistula. If the infant’s condition stabilizes, the remainder of the repair can proceed at that time, which is the usual case. However, if the patient remains unstable, the esophagus is secured to the prevertebral fascia, the chest is closed, a gastrostomy tube is placed, and the definitive repair is completed when the infant is stabilized. In very low-birth-weight infants, weighing less than 1500 g, a staged repair should be considered. Compared to a primary repair in these very low birth weight infants, staged repair resulted in fewer anastomotic leaks and strictures.
The second special situation occurs when there is a long gap between the two ends of the esophagus. This often occurs with pure esophageal atresia or esophageal atresia with a proximal tracheoesophageal fistula. Both of these situations present with an X-ray picture of a gasless abdomen. On occasion, an infant with esophageal atresia and distal tracheoesophageal fistula may have a long gap between the two ends of the esophagus and fit into this special group. If the infant presents with a gasless abdomen, a long gap should be suspected. The infant is brought to the operating room for a gastrostomy tube placement to allow enteral feedings while allowing time for the two ends of the esophagus to grow spontaneously so a primary anastomosis can be attempted. The stomach is small in these infants because it was unused during fetal life and has not yet stretched to its full capacity. Care must be taken to avoid injury to the small stomach and its blood supply while placing the gastrostomy tube. Careful placement will not compromise use of the stomach for an esophageal replacement if necessary. During gastrostomy tube placement, an estimate of the distance between the two ends of the esophagus is made using a neonatal endoscope in the distal esophagus and fluoroscopy. If the two ends of the esophagus are more than three vertebral bodies apart, they will not be easily connected. The infant is then nursed with a tube in the proximal pouch to remove the saliva and is fed via the gastrostomy tube. During the first several months of life, the gap between the two ends of the esophagus shortens because of spontaneous growth of the atretic esophagus. Depending on the surgeon’s discretion, the upper pouch may or may not undergo serial dilation in an attempt to stretch the pouch. The distance between the proximal and distal ends of the esophagus is measured every 2 to 4 weeks and, if the two ends are within 2 to 3 vertebral bodies, a thoracotomy and attempt at anastomosis is performed. Waiting longer than 4 months rarely provides extra growth of the esophageal ends resulting in primary anastomosis. If the gap reduces to two or three vertebral bodies, which occurs in close to 70% of cases, several techniques can be used intraoperatively to gain length on the esophageal ends during the operation. These include complete dissection of the upper pouch to the thoracic inlet. A circular myotomy of Livaditis performed on the upper pouch produces about 1 cm of length for each myotomy. Use of a circular myotomy is shown in Figure 20-5 . A tubularization graft of the upper pouch can be created and connected to the distal esophagus. If these techniques do not allow an adequate anastomosis, the distal esophagus is mobilized, despite its segmental blood supply, to gain length. If these maneuvers do not allow an adequate anastomosis, then one of three options must be chosen. The first option is to perform a two-stage procedure in which a cervical esophagostomy is initially created in the left neck followed by an esophageal substitution later. The esophagostomy will allow the infant to take sham feeds to prevent oral aversion and subsequent feeding problems without the risk of aspiration while awaiting esophageal replacement. The replacement operation usually takes place between 9 and 12 months of age. The second option is to perform a one-stage esophageal-substitution procedure using a gastric transposition, a gastric tube, or a colon interposition to replace the native esophagus. Currently, a gastric transposition is our preferred approach and has been shown to be a reliable and reproducible procedure at other centers worldwide. A third option for esophageal reconstruction in long-gap esophageal atresia involves the placement of traction sutures on both ends of the esophagus and either attaching them under tension to the prevertebral fascia if the gap is moderate length, or bringing them out through the back and increaseing the tension on them sequentially over the ensuing 2 weeks (Foker technique). A delayed primary anastomosis is carried out after the two ends of esophagus are in proximity. Although the Foker technique allows for a primary repair, it requires multiple thoracotomy incisions, is associated with a very high stricture rate, and invariably requires a gastric fundoplication procedure to control gastroesophageal reflux.
