Esophageal atresia with or without tracheoesophageal fistula


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Esophageal atresia with or without tracheoesophageal fistula

  1. 1. Esophageal Atresia With or Without Tracheoesophageal Fistula INTRODUCTION Esophageal atresia refers to a congenitally interrupted esophagus. One or more fistulae may be present between the malformed esophagus and the trachea-tracheoesophageal fistula (TEF). History of the Procedure: The condition was first described anecdotally in the 17th century. In 1862, the famous pediatrician from Copenhagen, Hirschsprung, described 14 cases of esophageal atresia. Later in that century, this condition was recognized to often occur in conjunction with other gastrointestinal and renal anomalies. With the advent of the 20th century, surgeons were theorizing about how the lesion could be repaired. In 1939 and 1940, Ladd of Boston and Lever of Minnesota first achieved surgical success in stages, where success meant that the affected children survived and skin-lined pharyngogastric conduits were eventually constructed. However, in 1941 Cameron Haight of Michigan successfully repaired esophageal atresia in a 12day-old baby by using a primary 1-stage left-sided extrapleural approach. Subsequent to that child's survival and with advances in surgical and anesthetic techniques, esophageal atresia is now regarded as an eminently correctable congenital lesion. Problem: The lack of esophageal patency prevents swallowing. In addition to preventing normal feeding, this problem may cause infants to aspirate and literally drown in their own saliva, which quickly overflows the upper pouch of the obstructed esophagus. If a TEF is present, fluid (either saliva from above or gastric secretions from below) may flow directly into the tracheobronchial tree. Frequency: In North America, the incidence of esophageal atresia is 1 case in 30004500 births. This frequency may be decreasing for as yet unknown reasons. Internationally, the highest incidence of this disorder is in Finland, where it is 1 case in 2500 births. Etiology: As yet, no human teratogens that cause esophageal atresia are known. Reports exist of esophageal atresia occurring in families. A 2% risk of recurrence is present when a sibling is affected. The occasional association of esophageal atresia with trisomies 21, 13, and 18 further suggests genetic causation. Also, twinning occurs about 6 times more frequently in patients with esophageal atresia than in those without the condition. At present, most authorities believe that the development of esophageal atresia has a nongenetic basis. Debate about the embryopathologic process of this condition continues, and little about it is known. The old His theory that lateral infoldings divide the foregut into the esophagus and trachea is attractively simple, but findings from human embryology studies do not support this theory.
  2. 2. In 1984, O'Rahilly proposed that a fixed cephalad point of tracheoesophageal separation exists, with the tracheobronchial and esophageal elements elongating in a caudal direction from this point. This theory does not easily account for esophageal atresia, but it explains TEF as a deficiency or breakdown of esophageal mucosa, which occurs as the linear growth of the organ exceeds the cellular division of the esophageal epithelium. In a 1987 report, Kluth eschews the concept that tracheoesophageal septation has a key role in the development of esophageal atresia. Instead, he bases the embryopathologic process on the faulty development of the early but already differentiated trachea and esophagus in which a dorsal fold comes to lie too far ventrally; thus, the early tracheoesophagus remains undivided. He also suggests that esophageal vascular and/or ischemic events may be causes in cases of esophageal atresia without fistula. Using a rat model of adriamycin-induced teratogenesis, in 2003, Spilde et al found esophageal atresia–TEF formations in the embryos. They detected specific absences of certain fibroblast growth factor (FGF) elements, both FGF1 and the IIIb splice variant of the FGF2R receptor. They postulated that these specific FGF signaling absences allow for the nonbranching development of the fistulous tract from the foregut that then establishes continuity with the developing stomach. In 2001, Orford et al postulated that the ectopic ventrally displaced location of the notochord in an embryo at 21 days' gestation can lead to a disruption of the gene locus, sonic hedgehog-signaled apoptosis in the developing foregut, and variants of esophageal atresia. This situation may be due to a variety of early gestation teratogenic influences such as twinning, toxin exposure, or possible abortion. More studies are required. Pathophysiology: The variants of esophageal atresia have been described using many anatomic classification systems. To avoid ambiguity, the clinician should use a narrative description. Nevertheless, Gross of Boston described the classification system that is most often cited. The types in this system are as follows (with the approximate incidence in all infants born with esophageal anomalies in parentheses): • • • • • • Type A - Esophageal atresia without fistula or so-called pure esophageal atresia (10%) Type B - Esophageal atresia with proximal TEF (<1%) Type C - Esophageal atresia with distal TEF (85%) Type D - Esophageal atresia with proximal and distal TEFs (<1%) Type E - TEF without esophageal atresia or so-called H-type fistula (4%) Type F - Congenital esophageal stenosis (<1%) (These are not discussed in this article.) The fetus with esophageal atresia cannot effectively swallow amniotic fluid, especially when TEF is absent. In the fetus with esophageal atresia and a distal TEF, some amniotic fluid presumably flows through the trachea and down the fistula to the gut. Polyhydramnios may be the result of this change in the recycling of amniotic fluid through the fetus. Polyhydramnios, in turn, may lead to premature labor. The fetus also appears to derive some nutritional benefit from the ingestion of amniotic fluid; thus, fetuses with esophageal atresia may be small for their gestational age. The neonate with esophageal atresia cannot swallow and drools copious amounts of
  3. 3. saliva. Aspiration of saliva or milk, if the baby is allowed to suckle, can lead to an aspiration pneumonitis. In a baby with esophageal atresia and a distal TEF, the lungs may be exposed to gastric secretions. Also, air from the trachea can pass down the distal fistula when the baby cries, strains, or receives ventilation. This condition can lead to an acute gastric perforation, which is often lethal. Prerepair esophageal manometric studies have revealed that the distal esophagus in esophageal atresia is essentially dysmotile, with poor or absent propagating peristaltic waves. This condition results in variable degrees of dysphagia after the repair and contributes to gastroesophageal reflux. The trachea is also affected by the disordered embryogenesis in esophageal atresia. The membranous part of the trachea, the pars membranacea, often is wide and imparts a cross-sectional D shape to the trachea, as opposed to the usual C shape. These changes cause secondary anteroposterior structural weakening of the trachea, or tracheomalacia. This weakening can result in a sonorous cough as the intrathoracic trachea resonates and partially collapses with forceful expiration. Secretions can be difficult to clear and may lead to frequent pneumonias. Also, the trachea can partially collapse during feeding, after repair, or with episodes of gastroesophageal reflux; this partial collapse can lead to ineffective respiration; hypoxia; and, somewhat inexplicably, apnea. Clinical: The mother who is carrying a fetus with esophageal atresia may have polyhydramnios, which occurs with approximately 33% of fetuses with esophageal atresia and distal TEF and with virtually 100% of fetuses with esophageal atresia without fistula. Characteristically, the neonate born with esophageal atresia drools and has quite a bit of mucus, with excessive oral secretions. If suckling at the breast or bottle is allowed, the baby appears to choke and may have difficulty maintaining an airway. Significant respiratory distress may result. In the delivery room, the affected infant may have the sonorous seal-bark cough that indicates concomitant tracheomalacia. If an oral tube is placed to suction the stomach, as it is in some delivery rooms, it characteristically becomes blocked 10-11 cm from the lips. VACTERL are associated anomalies that should be readily apparent on physical examination. If any of these anomalies are present, the presence of the others must be assessed. The VACTERL syndrome occurs when 3 or more of the associated anomalies are present. This syndrome occurs in approximately 25% of all patients with esophageal atresia. Anomalies in this syndrome include the following: • • • • • • Vertebral defects - Multiple or single hemivertebrae, scoliosis, rib deformities Anorectal malformations - Imperforate anus of all varieties, cloacal deformities Cardiovascular defects - Ventricular septal defect (VSD), which is most common, tetralogy of Fallot, patent ductus arteriosus, atrial septal defects, atrioventricular canal defects, aortic coarctation, right-sided aortic arch, single umbilical artery, and others Tracheoesophageal defects - Esophageal atresia Renal anomalies - Renal agenesis including Potter syndrome, bilateral renal agenesis or dysplasia, horseshoe kidney, polycystic kidneys, urethral atresia, ureteral malformations Limb deformities - Radial dysplasia, absent radius, radial-ray deformities, syndactyly, polydactyly, lower-limb tibial deformities
  4. 4. Other associated conditions include coloboma, heart defects, atresia choanae, developmental retardation, genital hypoplasia, and ear deformities (CHARGE). The following anomalies occur with increased frequency in esophageal atresia: neurologic defects (eg, neural tube defects, hydrocephalus, tethered cord, holoprosencephaly), gastrointestinal defects (eg, duodenal atresia, ileal atresia, hypertrophic pyloric stenosis, omphalocele, malrotation, Meckel diverticulum), pulmonary defects (eg, unilateral pulmonary agenesis, diaphragmatic hernia), and genitalia defects (eg, undescended testicles, ambiguous genitalia, hypospadias). Also, trisomy 13, 21, or 18 and Fanconi syndrome may be present. The overall incidence of associated anomalies is approximately 50%. Cardiovascular anomalies occur in 35% of cases; genitourinary anomalies occur in 20%; and associated gastrointestinal anomalies occur in approximately 20%. A tethered cord would usually be detectable by ultrasonography in the newborn period or later by MRI (or less desirably by CT scanning) if findings are equivocal. INDICATIONS The indication and timing of surgical repair may be determined by using the Waterston, Spitz, or Poenaru prognostic classification system. In 1962, Waterston developed a prognostic classification system for esophageal atresia that is still used today. Category A includes patients who weigh more than 5.5 lb (2.5 kg) at birth and who are otherwise well; category B includes patients who weigh 4-5.5 lb (1.8-2.5 kg) and are well or have higher birth weight and moderate pneumonia and other congenital anomaly; and category C includes patients who weigh less than 4 lb (1.8 kg) or have higher birth weight and severe pneumonia and severe congenital anomaly. Management strategies are the following: category A, immediate primary repair; category B, delayed repair; and category C, staged repair. In 1994, after analyzing findings in 387 patients, Spitz recognized that the presence or absence of cardiac disease is a proven major prognostic factor. Spitz suggested the following groups, which are analogous to those in the Waterston classification system: group I, birth weight greater than 1.5 kg and no major cardiac disease; group II, birth weight less than 1.5 kg or major cardiac disease; and group III, birth weight less than 1.5 kg and major cardiac disease. In 1993, Poenaru proposed a simpler 2-group classification system based on logistic regression analysis findings in 95 patients. Note that birth weight is not a factor. The classes are the following: class I patients who are low risk and do not meet criteria in class II and class II patients who are high risk and ventilator dependent or those with life-threatening anomalies regardless of pulmonary status. Using a refinement of the Waterston classification, in 1989, Randolph et al reported a clinically useful system of using a patient's physiologic status to determine the surgical management, ie, immediate repair, delayed primary repair, or staged repair. Weight, gestational age, and pulmonary condition were not considered. If the patient's physiologic parameters were good, they were managed with immediate repair. Staged repairs were used for severely compromised infants, especially those with severe cardiac anomalies. In this group, the survival rate was 77% and overall it was 90%.
  5. 5. The above prognostic groupings can allow for the stratification of high-risk patients with esophageal atresia in planning for delayed and/or staged repair, whereas low-risk babies can usually undergo early (first 24-48 h) primary one-stage repair. For instance, a 2-kg baby with esophageal atresia and distal TEF who also has the tetralogy of Fallot is a Waterston category C, Spitz group II, or Poenaru class II; in this patient, delayed or staged repair may be best. These classification systems help physicians to compare results in an organized and meaningful way. Comparing the 3 prognostic classification systems, Waterston, Poenaru, and Spitz, the Spitz classification appears to have the most applicability in current practice. Ductal-dependent cardiac lesions still seem to significantly affect the survival of children born with esophageal atresia. RELEVANT ANATOMY AND CONTRAINDICATIONS Relevant Anatomy: The treatment plan for each baby must be individualized. The prognostic classifications can provide guidance in patients with multiple problems, but decisions in identifying the most life-threatening anomaly must be made early. Management plans for a delayed repair of the esophageal atresia may include the following: A 10F Replogle double-lumen tube may be placed through the mouth or nose well into the upper pouch to provide continuous suction of pooled secretions from the proximal portion of the atretic esophagus. The baby may be positioned in the 45° sitting position. Prophylactic broad-spectrum antibiotics such as ampicillin and gentamicin may be used. General supportive care and total parenteral nutrition are needed. With careful bedside attendance, these measures may permit a delay of days to perhaps weeks. Some have described cases in which the baby was discharged home with a Replogle tube in situ while waiting for staged repair of an esophageal atresia. However, deaths have been reported in infants in whom the tube did not maintain an empty upper pouch. A gastrostomy, distal TEF ligation, or cervical esophagostomy may permit longer delays in the esophageal atresia repair. Each intrusion, however, carries a price. A gastrostomy may be created under local anesthesia if necessary, unless no distal TEF is present. In such cases, the stomach is small, and laparotomy is required. In all cases of esophageal atresia in which a gastrostomy is created, care should be taken to place it near the lesser curve to avoid damaging the greater curve, which can be used in the formation of an esophageal substitute. When a baby is ventilated with high pressures, the gastrostomy may offer a route of decreased resistance, causing the ventilation gases to flow through the distal fistula and out the gastrostomy site. This condition may complicate the use of ventilation. In cases such as those just mentioned or in cases in which a distal fistula continues to cause lung soiling, consider distal TEF ligation. This ligation is performed by means of a right-sided thoracotomy ideally performed via an extrapleural approach. The fistula may be clipped or simply ligated. If it is ligated and divided, subsequent staged repair of the esophageal atresia may be difficult because the distal esophageal segment tends to retract inferiorly to a substantial degree when it is detached from its tracheal mooring. However, simple fistula ligation may allow subsequent reopening of the fistula. Division of the fistula and attempts to anchor it at the mid chest with sutures are usually unsuccessful.
  6. 6. A cervical esophagostomy or spit fistula may be constructed in the right or left side of the neck, depending on the choice for subsequent esophageal substitution. It allows drainage of the upper pouch and precludes aspiration from the upper pouch. Sham feeding may be commenced in cases in which a long delay to repair is anticipated. This feeding may prevent subsequent oral aversion, which is a real problem in babies who have not been fed by mouth in their early weeks to months of life. However, cervical esophagostomy usually dooms the child to some form of esophageal substitution. Contraindications: Potter syndrome is bilateral renal agenesis and has a 100% mortality rate; therefore, repair of esophageal atresia is contraindicated. WORKUP Lab Studies: • In babies with esophageal atresia, samples should be drawn to determine baseline values of the following: o Complete blood cell count o Electrolyte levels o Venous gas concentrations o Blood urea nitrogen and serum creatinine levels o Blood glucose level o Serum calcium level o Arterial blood gas concentrations, as necessary Imaging Studies: • Prenatal ultrasonography may reveal the size of the gastric bubble, polyhydramnios, and VACTERL anomalies, all of which may indicate esophageal atresia in the fetus. o o • The sensitivity of prenatal ultrasonography is approximately 40%. A diagnosis prenatally of esophageal atresia may be associated with a worse prognosis. Chest radiography is mandatory and should be performed as soon as possible if esophageal atresia is suspected. o The value of the chest radiography is enhanced if a Replogle tube is in place and if 5-10 mL of air is injected to distend the upper pouch. o Great caution should be exercised if liquid contrast material is injected into
  7. 7. the proximal pouch. First, only about 1 mL of isotonic water-soluble contrast should be used to prevent spillage into the airway. A catheter with an endhole should be used. Second, if an upper pouch fistula is present, the contrast material flows directly into the airway. Usually, a contrast-enhanced study is unnecessary. o The heart shadow and size should be assessed. o Vertebral and rib anomalies should be assessed. o The lung fields should be assessed for possible aspiration pneumonitis and for the rarely associated diaphragmatic hernia or congenital lung lesion. o The presence or absence of gastrointestinal air below the diaphragm is an important finding. Complete absence of gas in the gastrointestinal tract denotes the absence of a distal TEF (although rare reports exist of distal fistulae simply occluded by mucous plugs). In cases of esophageal atresia without fistula, assume that the distance between the ends of the atretic esophagus is too long for early one-stage primary repair. These infants require a delayed repair. • Early renal ultrasonography is mandatory and is used to evaluate associated kidney and/or ureteral anomalies. • Echocardiography is indicated early in the care of the infant with esophageal atresia who has clinical signs of cardiovascular disease. However, a 1-day-old neonate with significant congenital heart disease may have normal findings at physical examination. Therefore, some argue that echocardiography should be performed in all infants with esophageal atresia. This examination also provides the surgeon with information regarding the side of the aortic arch. A right-sided aortic arch is not uncommon in cases of esophageal atresia, and the surgeon should be aware of this finding. • Limb radiography is indicated if the limbs appear abnormal. The possibility of associated radial-ray deformities should be investigated. • Spinal ultrasonography is a simple test that takes advantage of the neonate's relatively transparent lumber lamina in the assessment of an associated tethered cord. This examination may be performed when the baby is younger than 1 month, although it is not critically important in the early care of the infant. • In cases in which the distance between the 2 atretic ends of the esophagus is suspected to be too long for a primary repair, a gap-o-gram is useful in assessing that distance. o A gastrostomy is created, and the upper pouch is intubated with a 10F Replogle tube with radiopaque markings. A small-diameter Bakes dilator is introduced into the gastrostomy and directed superiorly under fluoroscopic guidance into the distal esophageal segment. With gentle but definite force on both the Bakes dilator and the Replogle tube, the 2 ends are pushed toward each other under fluoroscopic control.
  8. 8. o At the point of least separation, an image is obtained, and the distance between the 2 ends is determined in terms of vertebral bodies, which provide an inherent reference for measurement. o Generally, a separation distance of 2 (some say 3) vertebral bodies or fewer is usually small enough for an anastomosis. If greater distances separate the ends, a delay of weeks to months may be required for the ends to grow closer together, for reassessment with gap-o-grams every 4-6 weeks, or for esophageal replacement or lengthening surgery. TREATMENT Medical therapy: The preparation of a 1-day-old neonate for surgery includes the following measures: • • • • • Intravenous fluid containing an adequate glucose concentration (ie, 10% glucose) is administered at a rate appropriate for the neonate's gestational age and weight. Prophylactic broad-spectrum antibiotics (eg, ampicillin, gentamicin) are administered intravenously. The neonate is kept warm by using an incubator or overhead warmer, and he or she is positioned supine in the Fowler position, with the head elevated by approximately 45°. A 10F Replogle tube is placed nasally or orally well into the upper pouch and connected to a continuous suction device. Every 30 minutes, the tube is checked for patency first by suctioning with an empty syringe and then by gently injecting 5 mL of air. (Never use water.) In small infants, an 8F double-lumen tube may be used instead. The parents should be fully briefed about the nature of the congenital anomaly. A diagram is invaluable for explaining not only the pathologic anatomy and intended repair but also the possible complications. Their consent for treatment should be obtained, and the discussion with them should be documented in appropriate detail on the baby's medical record. Surgical therapy: This section provides some details about surgical approaches for the repair of the most common type of esophageal atresia, ie, esophageal atresia with distal TEF, in low-risk patients. Surgical techniques vary according to surgeons' preferences and variations in pathologic anatomy. Modifications for special anatomic challenges are briefly discussed. In particular, infants born with esophageal atresia without fistula represent a specific and challenging subgroup. These babies should undergo an early gastrostomy procedure in the new born period.. A gap-o-gram should be obtained to assess the prospects for anastomotic repair. In infants with atresia without fistula, surgical decisions must be made regarding the following: the length of time to wait for the ends to grow closer; performing one of a number of esophageal lengthening procedures such as the Kimura, Livaditis, Scharli, or Foker procedures; undertaking an esophageal substitution procedure, with or without the formation of a cervical esophagostomy; and using a gastric tube (reversed and proximally based or antegrade and distally based). The use of colonic (left chest or substernal), gastric pull-up, or jejunal vascularized graft segments is difficult and should be based on the condition of the infant, the pathologic
  9. 9. anatomy, associated defects (eg, gastric pull-up is usually contraindicated in significant cardiac disease, colonic esophageal replacement is usually contraindicated with concomitant imperforate anus), and the surgeon's experience. As a rule, a child's own esophagus is better than any substitution. Recent favorable reports of the Foker technique used for serial dynamic lengthening in cases of long gap realize that advantage. It involves 2 thoracotomies. First, anchoring sutures are placed securely at the 2 ends of the atretic esophagus and brought out diagonally to the chest wall. Over a period of days to weeks, the 2 ends are brought closer together by a series of daily lengthenings by traction on the exposed sutures. The closure of the gap is monitored radiologically with radio-opaque markers at the atretic ends. A second thoracotomy is then performed to effect a tension-free anastomosis. Preoperative details: Bronchoscopy performed just prior to repair of the esophageal atresia may enable the following: • • • • • Detection of a upper pouch fistula Localization of the distal fistula, which usually lies at a level just above that of the carina Detection of an aberrant right upper lobe bronchus emanating from the trachea, which is not uncommon in cases of esophageal atresia Early assessment of the cross-sectional shape of the trachea, which may help in determining the risk of significant postoperative tracheomalacia Assessment of specific vascular anomalies (eg, right-sided aortic arch, aberrant right subclavian artery [for which one looks for the pattern of pulsation on the tracheal wall]) Identification of a laryngotracheoesophageal cleft The infant is endotracheally intubated without paralysis. The anesthesiologist must be mindful of the distal fistula. With skill, the long end of the distal endotracheal tube bevel may be positioned over the fistula to decrease the passage of gases into the stomach. This maneuver helps prevent gastric distension, maximizes ventilation, and minimizes the chances of a gastric perforation. As much as possible, the baby should be allowed to breathe spontaneously until the fistula is occluded. In reality, and especially because the chest is open and the lung retracted, the anesthesiologist manually assists with the baby's ventilation. However, mechanical ventilation should be avoided until the fistula is controlled. This procedure requires great skill, experience, and focus on the part of an anesthesiologist in caring for these babies in the operating room. Managing infant with premature lungs In positioning the baby in full right thoracotomy position, the surgeon must ensure that the anesthesiologist has full and easy access to the infant's nose and to the Replogle tube, which is not taped so that it can move in or out. If a right-sided aortic arch is detected preoperatively, controversy exists about whether a left thoracotomy provides easier access. A left-sided approach has its merits, but in this instance, the esophagus is still a right-sided structure, and access from the right is best. Lastly, the baby is covered with antiseptic solution, and drapes are placed with the areas
  10. 10. from the nipple to mid back and from the axilla to the 10th rib exposed. Intraoperative details: The surgeon should wear magnification loupes. The assistants and nurses should be briefed about their duties and about special points of care regarding the delicate nature of the procedure and the baby's tissues. The procedure is performed as follows: A transverse right thoracotomy incision is made from the anterior axillary line to approximately one finger's breadth posterior to the posterior axillary line at a level 1 cm inferior to the palpable tip of the scapula. The latissimus dorsi is divided with the coagulating current of the electrocautery device. The fascia lying just posterior to the posterior margin of the serratus is divided with electrocautery, and the serratus is retracted anteriorly. Usually, an incision in the serratus is not needed. The scapula is then lifted away from the chest wall, and the ribs are counted from the first to the fourth. Ideally, the chest is entered through the fourth interspace. With careful use of forceps and the electrocautery device, the outer and innermost intercostal muscles are divided in this interspace down to the parietal pleura. By using either moist sponges or peanut gauze on the forceps, the parietal pleura is dissected away from the chest wall, proceeding posteriorly but also dissecting somewhat superiorly and inferiorly as well. A small mechanical Finochietto-type rib retractor is placed in the open thoracotomy site, and the pleural dissection proceeds to a point medial to the azygos vein. The azygos vein is ligated and divided with fine silk. This extrapleural dissection then allows retropleural repair of the esophagus. If an anastomotic leak occurs, it tends to be more contained compared with the empyema that results if the repair is performed transpleurally. At this point in the dissection, the anatomy is defined first by having the anesthesiologist push on the indwelling Replogle tube; this action usually reveals the upper pouch that rhythmically bulges out in the apex of the right chest cavity. The distal fistula is at the level of the carina and usually lies just beneath the divided azygos vein. It expands slightly with each inspiration. One must take great care not to mistake the aorta for the fistula. Mistaken ligation of the aorta is possible. If doubt exists, a 25-gauge needle can be passed into the structure to check. Gaining control of the fistula now relieves the anesthesiologist. A silicone rubber vessel loop can be passed around the fistula at a convenient level near the trachea. Gentle retraction on this occludes the fistula. Most advise dividing the fistula with suturing of its tracheal aspect. This division can be accomplished by cutting into the fistula as it enters the back wall of the trachea in short snips and by oversewing the tracheal aspect as it opens in stages. Usually, about 4 interrupted sutures suffice. Most advocate the use of an absorbable synthetic suture material such as polyglactin. This sutured fistula site may be covered with an azygos or pleural patch for extra security. The fistula closure should be checked by covering the closure in saline and manually ventilating the patient for a Valsalva test. If bubbles appear, the closure is leaking and must be resutured. Turning his or her attention to the upper pouch, the anesthesiologist again can push on the Replogle tube to facilitate placement of a traction suture into the distal end of the upper pouch. The upper pouch is then dissected superiorly to increase its length. Blood supply to the upper portion is linearly arrayed from the cervical and subclavian vessels; ischemia is not a concern. This dissection must be carefully performed between the pouch and the trachea while the presence of an upper pouch
  11. 11. fistula that emanates from the side, not the end, of the pouch is determined. Also, the back wall of the trachea may be entered inadvertently. This condition is repairable with absorbable sutures. Avoid extensive dissection of the distal end because its blood supply is segmental from the aorta, and it can easily become ischemic. A gap between the ends may seem to be present. If it is very lengthy, the muscular covering of the upper pouch may be cut without entry into the lumen to achieve an extra 1 cm or so. Distal dissection may be performed; the risk of ischemia should be recognized. If absolutely necessary, the 2 ends may be simply bridged using 2 stout silk sutures in the hopes that they form a fistula and that they can be dilated to form a functional esophagus. More commonly, the 2 ends are reasonably close, and an anastomosis is possible. The distal portion of the upper pouch is cut off, and the proximal portion of the distal segment is trimmed. Both the mucosal and muscularis layers of the esophagus should be carefully sutured in a single layer to form an anastomosis with simple interrupted stitches. Once again, most advocate the use of an absorbable synthetic suture with a caliber of approximately 5-0 (eg, braided polyglactin). The back wall is sutured, and the upper pouch tube is passed through the half-completed anastomosis into the stomach to help rule out a distal stricture and to empty the stomach of accumulated gas. This tube is left in place as the anterior wall of the anastomosis is completed. The tube is then gently withdrawn from the body. Some advocate leaving the transanastomotic tube to act as a stent, although this tube may be partially moved, potentially injuring the anastomosis. A small-caliber 10F chest tube may be left in place as an extrapleural chest drain. The ribs are closed by encircling them with two 3-0 absorbable sutures and by restoring their normal anatomic position. The muscles and skin are closed in layers with absorbable sutures. In some pediatric surgical centers, surgeons are gaining experience in repairing esophageal atresia using a minimally invasive thoracoscopic approach. At present, this approach could still be termed investigational and should be undertaken only by those who have extensive experience in pediatric thoracoscopic surgery. Postoperative details: The intubated patient is transported to the neonatal intensive care unit. Antibiotics are continued until the chest drain is removed, and the endotracheal tube is suctioned as necessary. Oral suctioning to a depth of no more than 7 cm from the lips is performed every half hour for the first day, then every hour or more frequently as necessary on the second day. Thereafter, it is performed as needed. Suctioning is required to handle the sometimes copious oral secretions that can build up in the first day or so after surgery. As the swelling of the esophagus settles, the secretions taper. The chest draining tube is placed in 2 cm of water only to seal it; it is not connected to a suction device, which could encourage an anastomotic leak. Morphine is infused as necessary for the patient's comfort, and peripheral parenteral nutrition should be commenced. The endotracheal tube should remain until weaning from ventilation is ensured, usually after 1-2 days. Premature extubation and subsequent intubation in the setting of a freshly closed tracheal fistula invites reopening of the fistula. Watch for saliva exiting out the chest drain; this is a signal of anastomotic leakage. Often, it is accompanied by visible distress. Signs of sepsis may or may not be present. A chest
  12. 12. radiograph should be obtained. Provided that the baby is stable, a contrast-enhanced study of the esophagus with a water-soluble isotonic medium may be performed on day 6 or 7 to assess for leaks and to view the caliber of the repair (see Image 6). If the esophagus is patent and reasonably sized, the baby may be fed orally; starting with expressed breast milk is ideal. Then, the chest tube is removed. As soon as the baby is feeding well, the intravenous line is discontinued, and the baby can be discharged. Oral ranitidine is prescribed for 6 months because of the propensity for gastroesophageal reflux in this group of patients and because of the risk of stricture as a secondary effect. Follow-up care: If all is well with the patient and if the parents have been briefed on what to look for, a reasonable follow-up regimen may include the following steps: • • • • • Make contact with the community physician who is responsible for the general medical care of the child and ensure that he or she is briefed on the baby's history, condition, and expected outcome. The nurse on the surgical team should follow up by telephone in 1 week. The surgeon should follow up in 1 month to interview the parents and generally assess the child's condition, growth, and healing at the surgical site. The patient should return at 3 months for a similar assessment. At a 1-year follow-up and general assessment, swallowing function, respiratory issues, and so on should be addressed. Radiologic assessment of the esophagus is required only if a significant history of choking, cyanosis, regurgitation, dysphagia, growth failure, coughing, or wheezing exists. Subsequent endoscopic evaluation can be performed as indicated. Follow-up care when the child is older can be performed as needed. Specific reassessment with esophageal endoscopy and biopsy when the patient is aged approximately 12 years has been advised by some, who also advise follow-up with periodic endoscopy every few years until the patient is an adult. Although Barrett esophagus, and even subsequent malignant change, has been described in this condition, presumably because of gastroesophageal reflux, the jury is still out on the true need for endoscopic surveillance in patients with repaired esophageal atresia. COMPLICATIONS Early complications Early complications may include an anastomotic leak, recurrent TEF, and anastomotic stricture. An anastomotic leak tends to occur 3 or 4 days after surgery. This leak has been reported to occur in approximately 15% of cases. Pain and distress often are evident. Signs of sepsis may be present. The chest tube drains saliva. Treatment is supportive; appropriate antibiotics should be used, and the child should be given nothing by mouth. Surgery is not indicated, even with huge leaks. If the leak persists, esophagography may be performed with water-soluble contrast material to assess its magnitude. The usual protocol is to wait and let the leak close. If an extrapleural approach was used, the child usually is less ill than with other approaches, and the resultant esophagocutaneous fistula closes within days. If a transpleural approach was used, then the child is more ill and has an empyema
  13. 13. that may require further treatment and drainage. No absolute evidence indicates that postoperative leaks lead to anastomotic stenoses. Recurrent TEF may occur within days; most often, it occurs weeks later. Its incidence has been variously reported as 3-14%. Its first manifestation may be pneumonia, although the child may cough and have respiratory distress with feeding. The diagnosis is made by means of an esophagography performed with water-soluble contrast material under fluoroscopic guidance with the child prone. The contrast material is slowly injected through a catheter in the esophagus as the tube is slowly withdrawn, and lateral views are obtained by means of videofluoroscopy. The recurrent fistula is observed as a wisp of contrast material that suddenly crosses over to the trachea. This so-called pull-back esophagraphy is the most accurate method for diagnosing a recurrent fistula. Bronchoscopy and esophagoscopy may provide supplementary information. One endoscopic technique is to inject 0.5 mL of methylene blue into the endotracheal tube and through the esophagoscope while watching for it to come through the fistula. Historically, these fistulae were believed to require surgical repair by means of repeat right-sided thoracotomy; however, the authors have been successful in a minority of cases of fistulae by allowing them to close spontaneously while maintaining the nothing by mouth restriction and while administering antibiotics for 1 week. Endoscopic cautery and fibrin glue have also been reported to be successful on occasion. Anastomotic stricture has been reported in as many as 50% of cases, but the rate partially depends on the definition of stricture. Essentially 100% of babies have a waist at the anastomotic site, but this may not be functionally significant. In cases in which the stricture appears to be functionally significant on oral contrast-enhanced studies, esophageal dilation is best and is most safely performed by means of a Grьntzig balloon technique under fluoroscopic control, in the authors' opinion. This procedure should be performed by an experienced radiologist who can monitor the balloon pressure, position, and inflation diameter. In newborns, this technique of dilatation would best be deferred until the child is at least 6 weeks old, and at least 4 weeks after anastomosis. Other methods involve the passage of tapered dilators of various sorts (eg, Tucker and Maloney dilators). Certainly, the methods can be effective but are performed in essentially a blind manner unless done under fluoroscopic control, and they involve longitudinal and radial force vectors as opposed to the pure radial force vectors of the Grьntzig technique. Repeat dilations are often necessary. H2-receptor blockade should be started because acid reflux can be both an aggravating and a causative factor in stricture formation. Other factors to consider include the surgical technique, type of suture used, length of the atretic gap, ischemia of the distal portion, and possibly, whether an anastomotic leak has occurred. Strictures resistant to a few dilations need more aggressive treatment, which may include an antireflux operation, stricture resection, or both; rarely, they require esophageal replacement. Stents have been used, but they are still investigational. Surprisingly, parents can be taught to perform regular Maloney dilations at home in selected cases. Late complications Late complications may include gastroesophageal reflux, esophageal dysmotility, and
  14. 14. tracheomalacia. Some of these complications may appear early. Gastroesophageal reflux is particularly problematic in patients with esophageal atresia because of congenital distal dysmotility of the esophagus, dysfunction of the physiologic antireflux barrier, possible partial vagotomy during surgery, or essential vagal dysfunction that can lead to delayed gastric emptying. Essentially all babies with esophageal atresia have detectable gastroesophageal reflux. Patients who require treatment must be carefully identified. All babies with esophageal atresia should be treated prophylactically with ranitidine until they are aged 6 months. Failure to thrive, coughing, choking spells, wheezing and asthma, recurrent pneumonias, vomiting, cyanosis, dying spells, excessive drooling, and apparent dysphagia are all indications to investigate the degree of gastroesophageal reflux. Oral contrast material should be administered, and endoscopy should be performed. Strictures should be dilated. A pH probe study may help if the probe is placed below any present stricture. A gastric emptying scan should be obtained. All factors should be carefully considered. Surgical approaches to helping the child may include an antireflux operation. A partialwrap fundoplication is usually preferred because of the dysmotility of the repaired esophagus. Dysphagia after even a very loose wrap is not uncommon. If the stomach has delayed emptying, balloon pyloroplasty or surgical pyloroplasty may be considered to speed emptying. The authors have used a surgically conservative approach in children with this condition; the authors prefer to treat the reflux medically, with H2-receptor blockade or proton pump inhibition when possible. However, certainly some patients require a surgical approach for later complications. Esophageal dysmotility is an ongoing problem. It has various dysphagic manifestations. The children eventually learn that they must masticate thoroughly and drink fluids when eating. Food bolus obstructions, even without a significant stricture, are not uncommon in toddlers. Parents must be mindful of this possibility and choose their child's foods accordingly. The use of motility agents such as domperidone may help. Tracheomalacia is the manifestation of disordered embryogenesis. In its severe form, which occurs in approximately 10% of patients, dramatic signs include an inability to wean the patient from a ventilator and the classic dying spells in which the patient becomes pale and limp and, usually, apneic and cyanotic for a short time. Children with this condition require examination and treatment. Milder cases of tracheomalacia may cause recurrent pneumonias or asthma attacks, and in general respiratory ailments are common in these children. Bronchoscopy performed while the patient is spontaneously breathing reveals a trachea that significantly collapses, flattens, or closes on expiration. Treatment consists of aortopexy, which suspends the aortic arch to the underside of the sternum and thus secondarily suspends the anterior tracheal wall anteriorly, preventing its collapse. If this is unsuccessful, stent placement may help, but this option is controversial. Tracheostomy is the final management option. Fortunately, tracheomalacia tends to improve with time, growth, and maturation. OUTCOME AND PROGNOSIS
  15. 15. Statistics regarding mortality rates in esophageal atresia are constantly changing and improving. One must consider the classification system used in reporting such statistics. • • • Montreal classification (rates reported in Poenaru, 1993) - Class I, 7.3% mortality rate; class II, 69.2% mortality rate Spitz grouping (rates reported in Spitz, 1993) - Group I, 3% mortality rate; group II, 41% mortality rate; group III, 78% mortality rate Waterston categorization (rates reported in Engum, 1995) - Category A, 0% mortality rate; category B, 4% mortality rate; category C, 11% mortality rate Fetuses with prenatal diagnoses of esophageal atresia seem to have a worse prognosis (Stringer, 1995). The cohort of babies in whom esophageal atresia is detected prenatally has a 75% mortality rate, whereas the cohort of babies in whom esophageal atresia is not detected prenatally has a 21% mortality rate. Babies who survive have varied morbidities related to any of the associated anomalies and complications. However, most children who undergo a successful repair of esophageal atresia are relatively healthy. FUTURE AND CONTROVERSIES The future is bright, with the following considerations: More accurate prenatal diagnosis and prenatal treatment may be possible. Minimally invasive techniques for repair with thoracoscopic surgery are now being used in some centers, with good results. A better understanding of the pathoembryologic processes of this condition may reveal its causative agents or genetic factors. This knowledge, in turn, may lead to specific prenatal treatments or preventive techniques. Recently, the incidence of this disorder has decreased, perhaps because of increased usage of prenatal folic acid supplements. Debates continue about the best operative technique (eg, right-sided or left-sided thoracotomy) for patients with right-sided aortic arches, suture type and technique, esophageal lengthening strategies, and procedures for mobilizing the distal esophagus. Other discussions concern when to use cervical esophagostomy, the choice of esophageal replacement, and so on. The advent of esophageal atresia repairs that combine both minimally invasive and radiologic interventional techniques may be near. The management of gastroesophageal reflux in esophageal atresia is particularly challenging; some advocate aggressive fundoplication, and others prefer more conservative medical treatment. In addition, the true incidence and treatment of tracheomalacia continues to be the subject of debate. Lastly, the proper evidence-based guidelines for long-term follow-up are still elusive.