EA occurs in 1 in 5000 births. It can develop in many forms, with the most common being the “Type C” atresia, comprised of EA with a distal TEF (see Fig. 52-1). The second most common scenario is EA without TEF, so-called pure EA. Although other forms exist, these two forms are most amenable to the thoracoscopic approach to esophageal repair. Since the first reporting of thoracoscopic repair of pure EA in 19993 and EA with distal TEF in 2000,4 this approach has become increasingly used, and multi-institutional experiences have been reported.1
Rigid bronchoscopic view of a large tracheoesophageal fistula. Note the tracheal rings anteriorly and the fistula (black arrow), located in the usual position in the posterior membranous portion of the trachea just above the carina (white arrow).
As with any intestinal anastomosis, the key surgical principle of the thoracoscopic esophageal repair in EA is to perform the procedure with the same high standards as one would follow when performing open surgery. Paramount in this procedure is healthy tissue, placed together with minimal tension. Some technical principles are detailed below, but are highlighted by the need to handle tissue gently and to incorporate sturdy, full-thickness bites including mucosa into the anastomosis without creating undue tension. As with all minimally invasive techniques, ergonomics and surgeon comfort during the procedure are important to prevent fatigue and allow for fine, delicate movements in the dissection of fragile structures. In addition, although we tend to use intracorporeal knot-tying techniques, extracorporeal techniques using a knot pusher are also well described. Finally, although the surgical techniques may be modified, it is paramount that the surgeon not compromise the quality of the operation to achieve a successful minimally invasive procedure.
The key clinical characteristic that defines thoracoscopic surgery, in antithesis to its open counterpart, is the significantly reduced morbidity related to the incision(s). In the immediate postoperative period, the drastically reduced pain associated with thoracoscopic surgery allows for faster recovery and decreased pulmonary complications in children who may already be at risk for other conditions such as congenital cardiac disease (see below). In addition, patients, especially newborns, are at particular risk for sequelae of open thoracotomy, including musculoskeletal deformities such as “winged” scapula, muscular atrophy with resultant asymmetry, and/or scoliosis.1
Timing of surgery depends on the patient's underlying diagnosis (pure EA vs. EA/TEF) and their stability. Pure EA patients can undergo thoracoscopic repair in a delayed fashion, after initial tube gastrostomy and a period of growth on enteral nutrition. Patients with EA/TEF are generally repaired within the first 24 hours of life assuming appropriate size, hemodynamic stability, and the absence of more pressing concomitant congenital defects.
Preoperative Assessment and Patient Selection
Since the various forms of EA can all be a component of the VACTERL (Vertebral anomalies, Anorectal anomalies, Cardiac defects, Tracheo-Esophageal anomalies, Renal anomalies, Limb defects) association, appropriate screening tests should be performed on all patients found to have EA. These include echocardiogram, spine ultrasound and plain films, and renal ultrasound. Chief among these, and the only one necessary prior to operative intervention for EA/TEF, is the echocardiogram. This allows for identification of intracardiac defects, such as ventricular septal defects or tetralogy of Fallot, and for identification of a potential right-sided aortic arch. In most cases, the surgical approach for repair of EA/TEF is through the right chest. A right-sided aortic arch, however, will prompt most surgeons to change to the left chest. Another common association involving EA is the cleverly but somewhat incompletely named CHARGE syndrome (Coloboma, Heart defects, choanal Atresia, Retardation, Genital hypoplasia, Ear abnormalities). This diagnosis is often made postoperatively, and may affect long-term outcomes.
While hemodynamically unstable patients and very premature or growth restricted newborns (<1500 g) should likely not undergo thoracoscopic repair of EA/TEF, there are other relative contraindications. These include significant congenital heart disease and smaller infants (less than 2.5 kg). One additional feature which should be assessed is the expectation of relative “gap” between the proximal esophageal pouch and the fistula in TEF or the distal pouch in pure EA. Plain films can help determine the location of the proximal pouch, with its coiled nasogastric tube, and obviously, the presence of a distal fistula based on the presence of bowel gas. Meanwhile, bronchoscopic evaluation can assess the level of the fistula (e.g., location relative to the carina). In cases of pure EA, most patients receive a gastrostomy at birth followed by delayed esophageal repair. In these cases, a preoperative gap assessment can be obtained by placing a radiopaque instrument such as a Bakes dilator via the gastrostomy and transorally, and obtaining fluoroscopic imaging while placing moderate pressure on the dilators. This technique can also be used intraoperatively for easy identification of the esophageal ends.
Each individual patient's qualifications for a thoracoscopic approach must be assessed using a combination of these multiple variables. As surgeons (and anesthesiologists) gain more experience and confidence, these boundaries will continue to be tested.1,5
Evaluation of the Fistula
We prefer to perform rigid bronchoscopy on all children with suspected EA (see Fig. 52-1), to identify and locate the TEF and also to potentially control it with the use of a balloon-tipped catheter which can be lodged within the proximal fistula and allow for the safer administration of positive-pressure ventilation during the initial stages of anesthesia prior to operative control of the fistula. While this is our chosen technique, not all surgeons perform this step.
Rigid bronchoscopy requires cervical extension in the supine position and the gentle use of an appropriately sized rigid ventilating bronchoscope. Important findings to note should include the assessment of vocal cord function for documentation prior to potential surgery on and around the vagus nerves, assessment for location of the distal fistula, a thorough and methodical evaluation of the posterior membranous trachea to rule out the possibility of multiple TEFs, and the assessment of tracheal stability with the presence or absence of significant tracheobronchomalacia. We then place a Fogarty-type balloon catheter transorally and bronchoscopically direct it into the fistula, inflating the balloon just inside the fistula itself. At the conclusion of bronchoscopy, the patient is orotracheally intubated with the goals of maintaining spontaneous ventilation if possible and avoiding intubation of the fistula which could result in disastrous decompensation. All of these steps are similar for both the open and thoracoscopic techniques.
Anesthetic Considerations and Lung Isolation
The anesthetic technique employed and full two-way communication between the anesthesia and surgery teams are essential to the successful completion of a thoracoscopic procedure in a neonate.1 The team must be efficient to limit anesthetic time, limit time on positive-pressure ventilation prior to fistula control and maximize the amount of work accomplished during (essentially) single-lung ventilation.
Neonates with pure EA or EA/TEF typically undergo inhalational induction followed by bronchoscopy and balloon control of the fistula. Appropriate IV access is then obtained, typically in the form of 2 to 3 peripheral intravenous catheters and an arterial line for both monitoring of blood pressure and access to obtain blood for laboratory measurements. Transfusion intraoperatively is generally not warranted, and most patients are provided with hourly maintenance isotonic solution as well as 20 to 40 mL/kg of intravenous fluid boluses. Patients have safely been maintained on neuromuscular blockade without significant risk of gastric overdistention, even without preoperative balloon control of the fistula.6 Orotracheal intubation usually suffices, though some practitioners will attempt blind or fiberoptic-guided left mainstem intubation. Adequate lung deflation can be achieved by gentle carbon dioxide (CO2) insufflation using a low flow (1 L/min) and low pressures (4–5 mm Hg).5
One key physiologic point is the expected immediate decompensation upon entry into the chest, when the patient is subjected, essentially, to single-lung ventilation. The anesthesia and surgery teams should expect relative hypoxia and hypercarbia, which are usually transient and recover within minutes as intrinsic physiologic mechanisms compensate for the loss of ventilation in the lung on the operative side and thus recover more normal matching of ventilation and perfusion. The frequent evaluation of blood gas measurements will allow for monitoring of this trend. In addition, should the patient not tolerate CO2 insufflation or lung retraction, both of these may be reversed instantaneously by the surgeons to allow the anesthesiologist to recruit the lung and improve the patient's status. Ultimately, the free-flowing discussion between the surgeons and anesthesiologists allows for ongoing decision-making regarding proceeding with thoracoscopic repair or converting to an open approach.
Positioning of Patient and Port Placement
Following bronchoscopy and anesthetic preparation, most surgeons prefer a modified prone position (see Fig. 52-2), with the patient's right chest elevated 45 degrees. This positioning allows the lung and anterior mediastinal structures to fall anteriorly with gravity retraction, thus giving the surgeon excellent exposure to the posterior mediastinum, airway, and esophagus.
Illustration of modified prone positioning in thoracoscopic EA/TEF repair and the usual trocar placement.
With this positioning, the surgeon and assistant stand on the anterior side of the patient, while the monitor is placed at eye level on the posterior side of the patient alongside the scrub nurse.
Three access sites are necessary for the procedure. An initial camera port (generally 4 mm) is placed just inferoposterior to the scapula, usually coinciding with the fifth intercostal space. We use a cut-down type approach, making an appropriate skin incision followed by blunt dissection above the rib using a straight Jacobson dissector. Lung ventilation is held when the pleura is encountered and the pleural space is entered bluntly. The chest wall defect is dilated to the appropriate size and the 4-mm trocar inserted. We use metal trocars fitted with a sleeve (a cut portion of an 18Fr red rubber catheter), which is sewn to the skin to prevent trocar migration.
Two additional ports are placed under direct visualization (Fig. 52-2). One is placed 1 to 2 intercostal spaces above the first port, and more in the midaxillary line (this generally falls in the middle of the axilla). If endoclips are to be used to control the TEF, this should be a 5-mm port. The 5-mm port also has the benefit of allowing for direct passage of suture with needles (e.g., 5-0 Vicryl or PDS on a TF needle). Otherwise, if ligature control is to be used, a 3- or 4-mm port may be used and suture passed directly through the chest wall when necessary. The third port, usually 3 mm, is placed 1 to 2 intercostal spaces below the first port, in the posterior to midaxillary line. Ideally, the second and third trocars placed, corresponding to the right and left hand working ports, will allow for the instruments to meet at a right angle at the level of the fistula and anastomosis.5,7 Should gravity and CO2 insufflation not provide adequate exposure, additional lung retraction can be achieved by the placement of another trocar or stab incision inferiorly for the use of an instrument by the surgical assistant solely for anterior lung retraction.
Identification and Ligation of the Fistula
Upon port placement, CO2 insufflation is achieved and the posterior pleural space should be readily visible. The azygos vein is identified, mobilized with blunt dissection and generally sacrificed either with hook cautery or division between ties (Fig. 52-3). Ligation and division of the azygos makes the underlying distal esophagus readily evident (Fig. 52-4). In cases of EA/TEF, this usually corresponds to the entry of the fistula into the membranous portion of the trachea just above the carina. The excellent view through a surgical telescope generally makes identification of the distal esophagus easy. For EA/TEF, blunt and sharp dissection with the use of curved dissectors and laparoscopic scissors are used to follow the fistula to its entry into the posterior trachea where the fistula can be ligated using an endoclip or ligature. During this dissection, care is taken to avoid injury to the vagus nerve. Ligation flush with the trachea is important to prevent formation of a tracheal diverticulum which could pool secretions and lead to soiling of the lungs in the future. Once ligation of the fistula is achieved, the “pressure is off” in terms of concern regarding the use of positive-pressure ventilation and the risk of gastric overdistention. Prior to division of the fistula, it is sometimes useful to mobilize the upper esophageal pouch to prevent retraction of the distal esophageal pouch prior to creation of the anastomosis.
Intraoperative image demonstrating the initial view of the posterior pleural space. Note the azygos system and the azygos vein (white arrow) coursing anteromedially. The lung is compressed from CO2 insufflation with excellent visualization of the posterior mediastinum. Orientation: H, head; F, feet; P, posterior; A, anterior.
Intraoperative image demonstrating the identification and mobilization of the distal esophagus and tracheoesophageal fistula (white arrow) as it enters into the trachea (asterisk). Note the ligated ends of the azygos vein (black arrows) with the fistula directly beneath. Orientation: H, head; F, feet; P, posterior; A, anterior.
Identification and Mobilization of the Proximal Esophageal Pouch
With the anesthesiologist placing pressure on the nasogastric tube, the proximal esophageal pouch is evident (Fig. 52-5). Blunt and sharp dissection with judicious electrocautery can be used to then free the proximal pouch all the way to the thoracic inlet. The surgeon should work on all sides simultaneously, though always saving the dissection of the common wall with the trachea for times when maximal tension is evident due to dissection of the other sides. This common wall is typically dissected sharply with some electrocautery if needed. Some surgeons prefer to place a traction suture through the distal tip of the pouch to provide a sturdy handle for manipulation of the proximal pouch during this dissection.
Intraoperative image demonstrating the proximal esophageal pouch (white arrow) as it appears in the thoracic inlet when the anesthesiologist places inward pressure on the nasogastric tube. Note in this case the fistula has already been ligated (asterisk), and it is possible to obtain a sense of the feasibility of primary anastomosis between the two ends. Orientation: H, head; F, feet; P, posterior; A, anterior.
At this point, traction on the proximal pouch should be able to demonstrate the ability to achieve an adequate primary anastomosis under minimal tension. If not, additional dissection of the proximal and/or distal pouch may be warranted. Most surgeons prefer to limit the dissection of the distal esophagus, if possible, to avoid dissection of the esophageal hiatus and gastroesophageal junction. Patient anatomy will dictate the amount of dissection necessary, whereas surgical judgment will determine what level of tension is necessary and allowable before considering other methods of esophageal reconstruction should anastomotic tension be unacceptable. In cases of pure EA, dissection of the distal esophageal pouch is nearly universally necessary. In general, if the esophagus can be brought together, even under tension, this is advisable and preferable to any other method of esophageal reconstruction. Tension, while not ideal, is acceptable in order to achieve a primary esophageal anastomosis. If significant tension exists, the use of slipknots to gradually bring the anastomosis together and help distribute the tension has been found helpful.8,9
Once anastomosis is feasible, the fistula can be divided distal to the clip or tie, leaving a small cuff. The proximal pouch can be incised, though we prefer to remove a circular portion of the distal tip to allow for an adequate anastomosis. The anastomosis is then created using absorbable braided or monofilament suture, at the surgeon's discretion. In general, 5-0 suture is advisable in newborns, on a small taper needle such as a TF. This portion of the procedure requires advanced thoracoscopic and intracorporeal suturing techniques, and its success is dependent on previously well-positioned trocar placement.
After the placement of a corner stitch, the posterior wall of the anastomosis is performed first, using simple interrupted stitches with the knots in an intraluminal position. To prevent tearing of the often thin esophageal wall, adequate tissue must be incorporated. Mucosa must be incorporated in every bite. Once the posterior wall is fashioned, most surgeons use a transanastomotic feeding tube (6Fr or 8Fr), placed by the anesthesiologist transnasally and guided into the distal esophagus and stomach thoracoscopically (Fig. 52-6).
Intraoperative image demonstrating completion of the posterior row of sutures and the placement of a transanastomotic feeding tube (orange tube, white arrow). Orientation: H, head; F, feet; P, posterior; A, anterior.
The anterior wall is then fashioned in the same manner, with the transanastomotic feeding tube allowing for large bites without concern for incorporation of the posterior wall of the esophageal lumen. After completion of the anastomosis (Fig. 52-7), hemostasis is verified.
Intraoperative image demonstrating the completed anastomosis. Note the use by this surgeon of a pericardial patch only (black arrow) to create a barrier between the anastomotic suture line (white arrow) and the underlying tie on the site of the tracheal fistula. Orientation: H, head; F, feet; P, posterior; A, anterior.
An air leak test can be performed by instilling a small amount of saline, retracting the lung, and asking for a Valsalva maneuver from the anesthesiologist while visualizing the tracheal fistula tie or clip. If desired, some viable tissue (e.g., end of azygos, pleural flap) can be placed between the esophagus and trachea to reinforce the fistula ligation and help prevent recurrence of the TEF. Alternatively, a piece of treated bovine pericardium may be used as a biologic barrier to prevent reformation of the TEF and can be placed between the esophageal suture line and the clip/ligature on the tracheal side of the fistula ligation (Fig. 52-7). A 12Fr chest tube can then be placed through the left hand working port site, positioned lateral to the anastomosis and secured to the skin. The lung is then observed to inflate during normal breathing to verify no injury to the trachea or right mainstem bronchus, and the ports are then removed. Local anesthetic can be administered at the start or finish of the case. The incisions are closed with small absorbable sutures for the muscular fascia, deep dermal and subcuticular layers and sterile dressings are applied. The chest tube is generally placed to low suction (–10 cm H2O).
The patient is generally left intubated and slowly weaned from the ventilator over the next day or several days. In cases of significant anastomotic tension, additional precautions may be taken, including longer-term sedation and even paralysis to prevent additional tension from being placed on the anastomosis.9 Care must be taken to avoid aggressive endotracheal suctioning which could injure the recently dissected trachea or dislodge the controlling clip or ligature on the fistula. In addition, should reintubation be required, it should be performed by a practitioner familiar with the anatomy involved and cognizant of the risks of both deep tracheal intubation and accidental esophageal intubation. Many surgeons have horror stories of disrupted tracheal or esophageal suture lines as a result of unfortunate events during emergent reintubation.
Feeding via the nasogastric tube is based on surgeon preference. All patients are placed on aggressive acid-reducing regimens, usually at a maximal dose of proton pump inhibitors. The high incidence of gastroesophageal reflux, coupled with esophageal dysmotility and injury to the anastomosis from refluxed acid, make this an important adjunct therapy.
Chest tube output is monitored for the possibility of lymphatic leak or for evidence of oral secretions which would be concerning for anastomotic leak. An esophagram is obtained, usually around postoperative day 7. If no leakage is demonstrated, oral feedings can be initiated and the chest tube can be removed. Evidence of leak is usually localized or controlled by the chest tube, in which case a repeat contrast study can be obtained after another week to assess for seal of the leak which will occur in most cases.
Outcomes and Complications
Though pediatric surgeons are relatively early in their experience with thoracoscopic repair of EA and TEF, short-term outcomes reported by centers known for excellence in minimally invasive surgery are encouraging. One notable report of 104 patients, involving several centers from multiple countries, outlines a success rate of thoracoscopic repair of nearly 95%. Complications in these patients included leak (8%), stricture (4%), and recurrent fistula (2%). Nearly 32% of patients required at least one esophageal dilation. Three patients died in this series, two from unrelated causes and one from tracheal fistula closure disruption during reintubation.1 These outcomes are remarkably similar to those obtained in similar series of patients repaired through open thoracotomy. Long-term follow-up of these patients will allow for comparison of musculoskeletal complications which may demonstrate a significant benefit of the minimally invasive technique.
Important in the interpretation of these data, however, is the fact that the minimally invasive series represents the work of surgeons skilled in very high-level minimally invasive surgery. They noted a significant learning curve and the need for surgical expertise in performing this operation thoracoscopically.
Thoracoscopic repair of EA and TEF is feasible in most patients with standard anatomy, with outcomes similar to open repair when performed by skilled minimally invasive surgeons. As experience with this technique grows, and a new generation of surgeons is trained in advanced minimally invasive techniques, this will likely become a routine procedure in the armamentarium of the pediatric surgeon.