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Tracheal Surgery: Posterior Splinting Tracheoplasty for Tracheomalacia

  • Cameron D. Wright
    Correspondence
    Address reprint requests to Cameron D. Wright, MD, Division of Thoracic Surgery, Massachusetts General Hospital, Blake 1570, MGH, 55 Fruit St., Boston, MA 2114.
    Affiliations
    Division of Thoracic Surgery, Massachusetts General Hospital, Boston, MA.

    Harvard Medical School, Boston, MA.
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Open ArchivePublished:February 25, 2015DOI:https://doi.org/10.1053/j.optechstcvs.2015.02.002
      Adult acquired tracheomalacia is an uncommon disorder that is more frequently diagnosed by CT imaging than by presenting associated symptoms. Common symptoms include dyspnea, constant coughing, inability to raise secretions and recurrent respiratory infections. The basic evaluation includes an inspiratory-expiratory chest CT (Dynamic CT), an awake functional bronchoscopy and pulmonary function studies. Patients with significant associated symptoms and severe collapse on CT and bronchoscopy are offered an operation. Tracheoplasty (or more commonly tracheobronchoplasty) is performed via a high right thorocotomy. The posterior airway is exposed after the azygous vein is ligated. The posterior wall of the trachea is reefed to a sheet of acellular dermis (or polypropylene mesh) with a series of 4 mattress sutures of 4-0 sutures from the thoracic inlet to the bottom of the trachea to re-shape the trachea and restore the normal D shape. Similar techniques are performed if the main bronchi are involved. Patients report generally good results with relief of their symptoms. Functional capacity is improved while pulmonary function tests usually are not.

      Keywords

      Introduction

      Tracheomalacia (or more commonly tracheobronchomalacia) in adults is uncommon and is often an incidental finding on a chest computed tomographic (CT) done for another reason with mild to moderate airway collapse seen on an expiratory study. These patients just need reassurance. Severe airway collapse is rare and usually associated with symptoms such as dyspnea, incessant coughing, inability (or difficulty) raising secretions, and repeated chest infections.
      • Murgu S.D.
      • Colt H.G.
      Tracheobronchomalacia and excessive dynamic airway collapse.
      These patients are often miserable, and it often takes them a long time to be diagnosed and referred, as many clinicians are not familiar with this uncommon disease. If patients are smokers and have associated chronic obstructive pulmonary disease, it can be very troublesome and difficult to sort out which disease is most important and whether to offer an operation. I tend to shy away from those with significant chronic obstructive pulmonary disease unless I am quite convinced that the tracheomalacia is very dominant. The evaluation process starts with a high-quality dynamic chest CT with inspiratory and expiratory views to determine the degree of tracheomalacia and whether it extends to the major bronchi (Figure 1, Figure 2). If severe malacia is found, then an awake functional bronchoscopy is done to verify this and further assess the airway. All airways collapse with a strong cough, and that finding is not diagnostic of tracheomalacia. If the airway collapses during quiet breathing with exhalation, then more severe malacia is confirmed (Figure 3, Figure 4). Sometimes coughing is incited by the opposition of the anterior and posterior walls of the airway. There are 2 anatomical forms of tracheomalacia, the classic soft or weak anterior tracheal cartilages (cartilaginous malacia) with a redundant posterior membranous wall (Fig. 1) (often with tracheobronchomegaly or Mounier-Kuhn syndrome) and excessive forward displacement of the membranous wall (membranous malacia) (Fig. 2). Pulmonary function tests are performed to document any other lung pathology and help assess the risk for thoracotomy. There is no specific finding on pulmonary function studies that is diagnostic of tracheomalacia. Some have advocated a trial of a silicone Y stent in an attempt to document whether symptoms and quality of life are improved with airway stenting as a diagnostic strategy to decide if tracheoplasty would be beneficial.
      • Ernst A.
      • Majid A.
      • Feller-Kopman D.
      • et al.
      Airway stabilization with silicone stents for treating adult tracheobronchomalacia: a prospective observational trial.
      I have not found this particularly helpful, as several patients have not been able to tolerate a stent even for 1 day because of coughing and airway irritation. In general, I recommend an operation if severe symptoms match the imaging and bronchoscopic findings of severe expiratory collapse of the airway (Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 10).
      Figure thumbnail gr1a
      Figure 1(A) Inspiratory CT scan from a patient with classic tracheomalacia with a soft widened anterior tracheal wall with a very wide posterior membranous wall.
      Figure thumbnail gr1b
      Figure 1(A) Inspiratory CT scan from a patient with classic tracheomalacia with a soft widened anterior tracheal wall with a very wide posterior membranous wall.
      Figure thumbnail gr1b
      Figure 1(Continued) (B) Expiratory CT scan from the same patient with near-total collapse of the airway during exhalation.
      Figure thumbnail gr2a
      Figure 2(A) Inspiratory CT scan from a patient with Ehlers-Danlos syndrome with a relatively normal-looking trachea.
      Figure thumbnail gr2b
      Figure 2(A) Inspiratory CT scan from a patient with Ehlers-Danlos syndrome with a relatively normal-looking trachea.
      Figure thumbnail gr2b
      Figure 2(Continued) (B) Expiratory CT scan from the same patient with total collapse of the airway during exhalation due to excessive forward displacement of the posterior membranous wall.
      Figure thumbnail gr3
      Figure 3Bronchoscopic image from the patient in from just below the cricoid during quiet respiration, demonstrating near collapse of the trachea and an enlarged airway. (Color version of figure is available online.)
      Figure thumbnail gr4a
      Figure 4(A) Bronchoscopic image from the patient in Fig. 2 during exhalation, demonstrating marked collapse of the airway during quiet exhalation.
      Figure thumbnail gr4b
      Figure 4(A) Bronchoscopic image from the patient in Fig. 2 during exhalation, demonstrating marked collapse of the airway during quiet exhalation.
      Figure thumbnail gr4b
      Figure 4(Continued) (B) Bronchoscopic image from the same patient after posterior wall tracheoplasty. (Color version of figure is available online.)
      Figure thumbnail gr5
      Figure 5The principle of membranous wall splinting is to stabilize and add rigidity in the case of membranous malacia and to also reconfigure the normal shape of the trachea in the case of cartilaginous malacia. Typically, in cases of membranous malacia, the trachea is of normal size (approximately 2.5 cm from side to side in the adult), and thus, the membranous wall is not redundant and is simply reinforced with sequential rows of mattress 4-0 sutures placed in a partial-thickness fashion through the membranous wall. Typically, 4 sutures are placed across the membranous wall, with the lateral sutures also catching a small bite of the lateral cartilaginous wall of the trachea. In cases of cartilaginous malacia, the membranous wall is usually rather redundant and needs to be plicated to reduce its width. The surgeon needs to estimate the degree of reduction in the width of the membranous wall that would recreate the D shape of the trachea. This can be done by pinching the middle of the membranous wall together and assessing the shape of the cartilaginous trachea until the desired shape and size are achieved. The distance between the lateral walls of the trachea is then measured and used to cut the appropriate size of the stabilizing material. We first used a polypropylene mesh for membranous wall stabilization, reasoning it was easy to use, was flexible, but did not stretch, and resisted infection. Most surgeons continue to use it. I no longer use it as I have had 2 patients develop late erosion of the mesh into the airway, which created a very difficult problem with no ready solution for these patients. I currently use extra thick acellular dermis with good medium-term results. We tried polytetrafluoroethylene (PTFE) once, but the patient developed fluid collections between the PTFE sheet and the membranous wall that caused obstruction of the airway. Whatever is used must be safe to provide stabilization of the airway for decades but not erode into either the esophagus or airway. Different sutures are used for fixing the splinting material to the membranous wall. These include 4-0 polypropylene and PDS sutures. Again, it is not clear what is the best suture material to use—permanent or temporary. It is not uncommon when attempting to place partial-thickness sutures that they are actually full thickness into the airway, thus potentially introducing bacteria next to the splint and a foreign body into the airway. PDS eventually dissolves, thus eliminating the foreign body in the airway issue but potentially would allow the repair to weaken and fall apart with time. I currently use PDS suture with good results but do not have 10-year follow-up yet.
      Figure thumbnail gr6
      Figure 6All patients have a thoracic epidural placed for postoperative pain control. General anesthesia is induced and the patient is intubated with an extralong wire-reinforced single-lumen endotracheal tube that is positioned with the aid of a bronchoscope in the distal left main bronchus. A double-lumen tube is not used, as its large size can interfere with suturing the membranous wall. The patient is placed in the standard left lateral decubitus position and padded appropriately. A high-standard right posterolateral thoracotomy is preformed in the fourth interspace. The azygous vein is divided and the mediastinal pleura is incised over the membranous wall of the trachea and main bronchi. The vagus nerve is preserved. The posterior airway is fully exposed from the thoracic inlet to the main bronchi. The lateral and anterior aspects of the trachea are not dissected out to avoid damage to the recurrent laryngeal nerves and to avoid devascularizing the trachea. If the main bronchi are involved, then the dissection extends down to the right bronchus intermedius and then down the left main bronchus to the upper lobe takeoff.
      Figure thumbnail gr7
      Figure 7Once the posterior airway is exposed, the splinting material must be cut and fashioned to the appropriate width and length. If the main bronchi need to be splinted as well, either separate strips can be cut for each main bronchus (usually 1 cm for the left main bronchus and 1.5 cm for the right main bronchus) or a Y-shaped strip can be cut out of wider material, so that there is one continuous strip. I now prefer to make my splint as a Y, as it seems somewhat easier. The repair is started by anchoring the distal tracheal end at the carina with a stitch at the carinal spur and in the middle of the main bronchi and at the lateral edges of the tracheobronchial angle. Middle sutures are placed in a mattress fashion through the splint, then a partial-thickness bite through the membranous wall, and then back through the splint again. These are placed one-third and two-thirds of the way across the membranous wall. The lateral stitches catch the junction of the membranous wall and the cartilaginous wall for extra strength. I place all 4 stitches across a single row; each individually snapped and then organized on the drapes and hold off on tying them. I then place the next row of 4 sutures and then tie the preceding row. I find it easier to place the stitches and move the splint if the preceding row is not tied down. Each row is placed approximately 5-7 mm apart, and the repair is continued until the thoracic inlet area is reached. Happily, the malacia usually stops at the thoracic inlet, so there is no need to try and expose the trachea in that region. Once the trachea is done, the bronchi are done next if required. I do the right first and then the left. The left is the most difficult because of poor exposure deep in the mediastinum and the presence of the endotracheal tube. The cuff should be temporarily deflated and ventilation stopped when suturing the left main bronchus, so that the cuff is not inadvertently punctured.
      Figure thumbnail gr8
      Figure 8Details of suture placement at the lateral edge of the membranous wall and within the membranous wall during the repair. If possible, sutures should be partial thickness in the airway. However, practically speaking, it is not uncommon to find at the end during surveillance bronchoscopy that there are several (out of dozens) inadvertent sites of suture penetration. I have not in general gone back and removed those and replaced them, as it would be very challenging to identify each misplaced suture.
      Figure thumbnail gr9
      Figure 9A posterior view of the completed repair. The membranous wall is stabilized with the aid of the now closely apposed splinting material with multiple series of rows of 4 mattress sutures. The airway is now more rigid and collapses less during expiration.
      Figure thumbnail gr10
      Figure 10Surveillance bronchoscopy at the conclusion of the procedure is done by pulling the endotracheal tube back to the proximal trachea and inspecting the result of the repair during inspiration and expiration. Any significant residual pathology or inadvertent issues (such as narrowing of the right upper lobe bronchus if the main and intermedius is splinted) should be identified and corrected at this time rather than postoperatively. A single chest tube is placed and the thoracotomy is closed in the routine fashion. Patients are extubated in the operating room and often require some temporary positive pressure support until they are fully awake. Observation in the ICU is usually advised, as these patients often have airway issues and difficulty clearing secretions for a few days. Care is otherwise routine as for a major thoracotomy. ICU = intensive care unit.

      Discussion

      Patients who are properly selected and have a good anatomical result often mention early in the postoperative period that they feel they are better despite the presence of a painful thoracotomy incision.
      • Wright C.D.
      • Grillo H.C.
      • Hammoud Z.T.
      • et al.
      Tracheoplasty for expiratory collapse of the airways.
      The morbidity is usually pulmonary in nature and runs the gamut of atelectasis, sputum retention, pneumonia, and respiratory failure. Mortality is quite rare. Quality-of-life measures are improved in most patients, and functional testing with the 6-minute walk test also demonstrates improvement in most patients.
      • Gangadharan S.P.
      • Bakhos C.T.
      • Majid A.
      • et al.
      Technical aspects and outcomes of tracheobronchoplasty for severe tracheobronchomalacia.
      Pulmonary function tests usually do not measurably improve. Certainly one of the problems in evaluating these patients (either preoperatively or postoperatively) is the subjective nature of their symptoms and how they perceive their respiratory health. In the end, the goal is a satisfied patient despite the lack of a quantifiable metric. Indeed, postoperative surveys of patients have reported that most patients are improved and satisfied with the results of a tracheoplasty.
      • Wright C.D.
      • Grillo H.C.
      • Hammoud Z.T.
      • et al.
      Tracheoplasty for expiratory collapse of the airways.
      • Gangadharan S.P.
      • Bakhos C.T.
      • Majid A.
      • et al.
      Technical aspects and outcomes of tracheobronchoplasty for severe tracheobronchomalacia.

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