Patient is placed in supine position with the left side elevated 15°. Both surgeon and assistant are positioned on the patient’s left side. From Bax K and van der Zee DC , reprinted with permission from Springer.
The first view upon entering the thoracic cavity consists of the thymus, heart, and the great vessels. It is important to identify the left phrenic nerve prior to dissection of the pleura (Fig. 8.2a). The nerve can be identified by its posterior course along the pericardium. Next, the left lobe of the thymus overlies the pericardium. The left lobe of the thymus is mobilized and pushed toward the right side of the chest to expose the pericardium (Fig. 8.2b). It is safe to hold the thymus up toward the sternum to allow traction for hook cautery or a 3-mm sealing device to divide the attachments off the pericardium. This will ensure that the dissection will not injure the underlying pericardium or its contents. Once the thymus is mobilized, the pericardium is opened using laparoscopic scissors starting from the aortic root and extending cephalad (Fig. 8.2c). Again, care must be taken to preserve the phrenic nerve.
a Thoraco scopic view of the left thorax (T, thymus/pericardium; Pn, phrenic nerve; L, left lung). b Mobilization of the thymus, T with hook cautery from pericardium, P. c Exposure of the aorta (a) and innominate artery (b). d Placement of partial thickness traction sutures in aorta, a. From van der Zee DC and Straver M , reprinted with permission from Springer.
Once the pericardium is adequately opened to reveal the aorta, aortopexy sutures can now be placed. The goal is to approximate the anterior wall of the aorta to the posterior surface of the sternum (Fig. 8.2d). We use a permanent 3-0 polypropylene suture instead of a braided suture to avoid sawing of the aortic wall when elevating the aorta off the trachea; however, vicryl sutures are also used. There are several important points to consider before placement of sutures. The first stitch can inadvertently be placed too close to the aortic valve and coronary arteries. It is also important to ensure that the aorta is not twisted along its long axis . Since the patient is on a 15-degree right tilt, we ensure the sutures on the aorta are at the most anterior portion. Lastly, all sutures are placed through the tunica media of the aorta (partial thickness); sutures through the lumen of the aorta may cause bleeding. A partially straightened needle is passed through a stab incision in the skin. This needle is then grasped with a standard laparoscopic needle holder. The first stitch is placed distal to the takeoff of the aortic root. The needle is then passed back through the sternum without tying. Securing the aorta to the parasternal tissue has been described but we need to consider the proximity of the left internal mammary vessels as they can be easily injured. A total of 3–8 stitches may be needed to provide adequate traction. We use intraoperative rigid bronchoscopy to guide the number of stitches. The pericardium can also be incorporated into each stitch to act as a pledget . Once the appropriate number of sutures are placed, they are concurrently given traction to approximate the aortic wall to the sternum. A bronchoscope is then inserted to ensure the tracheomalacia is relieved (Fig. 8.3). The sutures are then tied down subcutaneously and ensuring that no aortic twisting has taken place. At the end of the procedure, pneumothorax is evacuated under direct visualization to ensure the left lung inflates adequately. Unless there is an unacceptable amount of bleeding, we do not recommend the routine use of a chest tube. Incisions are closed with 5-0 sutures or simply sealed with surgical glue .
Patients can be extubated immediately postoperatively. We elect not to place a thoracostomy tube, but if placed, they can be safely removed in 24 h. Ideally, patients are discharged in 3–5 days after resolution of symptoms, pain, and adequate pulmonary hygiene, though other NICU comorbidities often dictate the length of stay.
A single-center study compared the use of stents vs aortopexy. Although stents have been used successfully in vascular and biliary procedures, airway stents have promoted growth of granulation tissue causing obstruction. This typically requires repeat bronchoscopies at regular intervals or permanent removal of stent. At this time, the use of stents is considered an option for palliation of symptoms for inoperable disease .
Despite aortopexy being considered the most effective procedure for severe TM resulting in acute life-threatening events (ALTE) , there are no randomized controlled trials, and they would be unlikely to be done. Most publications are single center and comprised of small series, but they have shown an immediate and excellent improvement in symptoms of severe TM. A recent review included 581 open and few thoracoscopic cases in literature. Eighty percent of patients had marked improvement in symptoms, 8 % had no improvement, 4 % had worsening of symptoms, and 6 % died. The group with a particularly worse outcome was associated with severe cardiac anomalies or other severe comorbidities . A repeated theme in literature comparing open vs thoracoscopic procedures is the potential to reduce musculoskeletal disorders. Risk of severe deformities like atrophy of the serratus anterior muscle and scoliosis is documented in follow-up pediatric patients after thoracotomy. Muscle-sparing thoracotomy does aid in mitigating the risks of these disorders, but this risk may be further reduced with a thoracoscopic approach [19, 20].
A small, retrospective, single-center series comprising eight patients had recurrence in three of their patients. However, there was a lack of standardization in the cases. One patient who had a recurrence did not have an intraoperative bronchoscopy , and the second patient had a pericardiopexy instead of an aortopexy . At our institution, we do not believe the pericardium has adequate structural integrity to elevate the aorta off the trachea. Nonetheless, as the thoracoscopic approach is further standardized and surgeons become proficient in the technique, we expect to see improved recurrence rates in literature.