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Ann Thorac Surg 2005;80:259-266
© 2005 The Society of Thoracic Surgeons

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Original article: General thoracic

Tracheoplasty for Expiratory Collapse of Central Airways

^a General Thoracic Surgical Division, Surgical Services, Massachusetts General Hospital
^b Department of Surgery, Harvard Medical School, Boston, Massachusetts

Accepted for publication January 7, 2005.

^_* Address reprint requests to Dr Wright, Blake 1570, Massachusetts General Hospital, Boston, MA 02114 (Email: wright.cameron{at}mgh.harvard.edu).

	Abstract

Top Abstract Introduction Patients and Methods Results Comment References

 
BACKGROUND: Severe central airway obstruction due to expiratory collapse occurs with malacia of intrathoracic trachea and main bronchi, often with chronic obstructive pulmonary disease. Bronchoscopically observed, it is confirmed by inspiratory-expiratory computerized tomographic chest scans. Prior attempts at surgical stabilization have not given dependable results.

METHODS: Posterior tracheobronchial splinting with polypropylene mesh (Marlex) holds cartilages in more normal configuration, and fixes redundant membranous walls. Fourteen consecutive patients were so treated for severe dyspnea. Prior trials of various autologous and exogenous splints failed.

RESULTS: All felt subjectively improved early, with decreased dyspnea, cough, and secretion retention, and with increased activities. Mean forced expiratory volume in 1 second rose from 51% predicted to 73% (p = 0.009), and peak expiratory flow rate from 49% to 70% (p < 0.00001). One patient was lost to follow-up (1 year), 1 died of unrelated cause (5 years), 1 died of chronic obstructive pulmonary disease (3 years), and 1 had decreased respiratory function over 5 years. Ten patients were available for long-term follow-up: 6 were judged to have an excellent result, 2 were good, and 2 were poor due to collapse of unsplinted main bronchi.

CONCLUSIONS: Complete splinting of all malacic central airways with Marlex restores anatomic configuration and permanently prevents expiratory collapse, with relief of extreme dyspnea, cough, and secretion retention.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment References

 
Expiratory collapse of the trachea and main bronchi is a form of tracheobronchial malacia, which often, but not always, is associated with chronic obstructive pulmonary disease (COPD) [1]. It seems to be infrequent in occurrence, varies in severity, but is generally progressive. It may well be underdiagnosed because COPD, which is present in many of these patients, appears to provide sufficient reason for respiratory distress. When symptoms are severe enough to require treatment, the major airways can be stabilized surgically. Surgical treatment was pioneered by Herzog and Nissen [2, 3], but is not often performed or described. We report 14 patients treated by permanent membranous wall stabilization, using a single technique that evolved from experience.

The cartilage of the intrathoracic trachea and the extrapulmonary large bronchi lose their rigidity and C shape in this disease and flatten. The membranous wall widens, becoming redundant. During expiration or cough, increase in positive intrathoracic pressure causes these cartilage to flatten further and the membranous wall to protrude anteriorly, frequently sufficient to produce occlusion of the tracheal lumen. Resultant symptoms and signs include dyspnea, expiratory stridor, and incessant cough, but with difficulty in clearing secretions. Typically, patients experience intermittent "attacks" of shortness of breath, choking, retching, and coughing. The harder the patient works to breathe, the greater the degree of collapse, and therefore the more difficult it becomes to breathe. The characteristic cough is likened to a "seal bark." In severe cases asphyxia may induce seizures, which have been termed "laryngeal epilepsy." Due to the inability to generate effective cough, these patients are unable to clear secretions, leading to bronchitic bouts, recurrent respiratory infections, and sometimes bronchiectasis [2, 4].

Because of the rarity of this condition and its frequent association with COPD, expiratory central airway collapse is often distinguished with difficulty from other conditions, such as asthma or bronchitis, that are associated with obstruction of peripheral airways. Patients may hence be treated for asthma or bronchitis for long periods. Failure of symptomatic improvement may then lead to further evaluation by pulmonary function tests and bronchoscopy, at which point diagnosis of expiratory central airway collapse is finally made.

Expiratory central airway collapse has been treated by stabilization of the membranous wall of the trachea using a variety of materials. Due to the rarity of the condition, experience with consistent surgical management and observation of long-term follow-up has infrequently been reported. We reviewed our experience over a 10-year period to assess the effectiveness of surgical treatment of expiratory collapse of intrathoracic airways.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment References

 
Records of all patients who underwent posterior membranous wall tracheoplasty for expiratory collapse of central airways at Massachusetts General Hospital (MGH) were reviewed. Following exploratory experiences with a variety of splinting tissues and materials, a consistent technique utilizing polypropylene mesh (Marlex) was adopted and is currently used. This group of 14 consecutive patients uniformly treated from 1993 to 2003 is reported. Follow-up was obtained by patient questionnaire, telephone contact, and from office records, with the permission of the institutional review board and of the individual patients.

Diagnosis
Patients with dyspnea, but with few symptoms on inspiration who suffer from incessant cough, particularly with a seal bark quality and who experience great difficulty clearing secretions, were suspected of having expiratory collapse of the central airways. Specific attention was paid to elicitation of symptoms during expiration or while coughing. Diagnosis was aided by inspiratory-expiratory dynamic computed tomographic (CT) scans of the chest (Figs 1 and 2) [5]. This served to confirm the anatomic derangement of the central airways as well as to exclude abnormalities in the more peripheral tracheobronchial tree. Tracheal collapse upon expiration was documented by fluoroscopy in some patients (Fig 3). All patients had preoperative pulmonary function tests (PFTs), with specific attention paid to the flow volume curve.

View larger version (97K): [in this window] [in a new window]   Fig 1. (A) Expiratory (E) and (B) inspiratory (I) computed tomographic scans of a patient with intrathoracic tracheomalacia associated with chronic obstructive pulmonary disease. Difference in cross-sectional area is marked.

View larger version (129K): [in this window] [in a new window]   Fig 3. Oblique spot films from fluoroscopy in the same patient as in Figure 2. (A) Inspiratory. (B) Expiratory.

View larger version (43K): [in this window] [in a new window]   Fig 4. Bronchoscopic views in a patient with severely symptomatic tracheomalacia. (A) Inspiration, lower trachea. (B) Expiration at same site. (C) Postoperative examination showed stable, open airway. The posterior wall is fixed to the Marlex splint by fibrosis.

Surgical Management
The goal of surgical management is to stabilize the membranous wall of the intrathoracic trachea and both main bronchi, usually including the bronchus intermedius, while narrowing the membranous wall so that the cartilage of the airway are brought into a more normal C shape from their flattened configuration [6]. The redundant membranous wall is quilted to the posterior splint to prevent its obstructive infolding into the lumen. The splinting material must be permanent and must become incorporated by scar tissue into the wall of the trachea so that the abnormalities do not recur. After trial of a number of tissues and synthetic materials, we found that polypropylene mesh (Marlex) met these requirements [7].

After confirmatory preoperative bronchoscopy to observe the full extent of malacia, left lung ventilation is established with a long single lumen endotracheal tube bronchoscopically directed into the left main bronchus. A double lumen endotracheal tube is avoided due to its bulk, which makes tracheal manipulation much more difficult. Through right posterolateral thoracotomy, the azygos vein is ligated and divided, and the posterior membranous walls of the thoracic trachea and main bronchi (if necessary) are exposed transpleurally. The right vagus nerve and its branches to the hilum are divided to provide exposure. The first 3 or 4 mm of the ends of the cartilage on both sides of these airways are exposed. Dissection is not carried circumferentially around the trachea or the main bronchi so that tracheobronchial blood supply is preserved.

A Marlex strip is cut approximately 2 to 2.5 cm wide depending upon the tracheal and bronchial size and the width of the membranous wall. The strip is fashioned long enough to extend along the trachea from the apex of the thorax to a few centimeters beyond the carina, since on occasion the strip may be narrowed distally and continued over the right bronchial tree. Strips used on the bronchi are, of course, narrower than those on the trachea. Most often, three strips of Marlex are applied; one to the trachea and one to each bronchus.

Four rows of interrupted sutures are placed across the width of the trachea from the Marlex strip to the tracheal wall, spaced 6 to 8 mm apart (Fig 5A). Thus, one longitudinal row of sutures will ultimately extend along each edge of the membranous wall to fix the borders of the Marlex strip to the lateral tips of the cartilage on either side. The two central longitudinal rows fix the Marlex to the membranous tracheal wall without penetrating the tracheal mucosa. The horizontal rows of four sutures are evenly spaced across the membranous tracheal wall, dividing it into thirds. Each succeeding transverse row of four sutures is about 8 mm below the previous row. Suturing progresses distally, from the apex of the chest to the carina.

View larger version (58K): [in this window] [in a new window]   Fig 5. Diagrams of posterior splinting procedure for expiratory tracheobronchial collapse. (A) Marlex strip of appropriate width is sutured to the posterior membranous tracheal wall from the apex of the thorax to the carina. Successive rows of sutures are placed as described in the text. Dots indicate general placement of sutures. Dashed lines indicate placement of Marlex strips. (B) Cross-sectional diagram showing placement and spacing of sutures. (C) When tied, sutures pull the cartilage into more nearly normal C configurations and quilt the widened membranous wall to the Marlex. (Reproduced with permission of the artist, from Grillo HC, Surgery of the Trachea and Bronchi, BC Decker, Hamilton, Ontario (Canada) 2004:647.)

We have found it best to place the lateral sutures of the apical transverse row first and then the two central sutures of the row. These sutures are clipped with hemostats and arranged systematically on either side of the operative field. Successive rows of four sutures are placed, proceeding distally toward the carina. Proximal rows of sutures are tied transversely in groups of four, always leaving at least the last-placed row untied until the succeeding row is placed, in order to facilitate access for suturing.

When the carina is reached, the Marlex strip is usually trimmed, most often perpendicular to the axis of the bronchus on either side, thus creating an arrowhead shape at the bottom of the strip (Fig 5A). Narrower strips about 1.5 cm wide are applied next, first to the left main bronchus using only three longitudinal rows of sutures. Suturing is commenced distally as close to the bifurcation into upper and lower bronchi as possible, carrying the rows of three sutures proximally. When the suturing reaches the carina, the Marlex strip is usually cut just to overlap the tracheal strip. Sutures at this point will include edges of both bronchial and tracheal strips. On the right side, it is easier to begin the suturing at the origin of the right main bronchus and span the entire extent of main bronchus and bronchus intermedius with a single strip, using three longitudinal rows of sutures.

After completion of suturing, the patient is rebronchoscoped through the retracted endotracheal tube in order to confirm that the correction is satisfactory. The field is thoroughly irrigated and the mediastinal pleura closed. The patient is usually extubated at the close of the operation. If postoperative ventilation is required for a brief period, pressure in the endotracheal tube cuff should be minimal.

Statistical Methods
Preoperative and postoperative measures of pulmonary function tests (PFTs) data were compared with the paired t test. A value of p less than 0.05 was deemed significant.

	Results

Top Abstract Introduction Patients and Methods Results Comment References

 
From 1983 to 2003, 23 patients underwent posterior membranous wall tracheoplasty for expiratory central airway collapse at MGH. The last 14 consecutive patients (1993–2003) were stabilized with polypropylene mesh (Table 1). The average age was 54 years. Men were more common in this series than women. Eight patients had COPD and were former smokers. Dyspnea was the principal symptom in 9 patients, incessant coughing in 4, and difficulty raising secretions in 1.

Thirteen of 14 patients had preoperative PFTs. Preoperative PFTs could not be obtained in one patient admitted with exacerbation of COPD, who required mechanical ventilation and could not be weaned from the ventilator. This patient did well postoperatively and left the hospital without ventilatory support. Her preoperative PFTs were done 4 years prior to operation. Postoperative PFTs were obtained on all patients (Table 1). The mean preoperative percent predicted forced expiratory volume in 1 second (FEV₁) was 51.2% and rose to 73.5% after operation (p = 0.0009). The mean preoperative percent predicted forced vital capacity (FVC) was 68% and rose to 79.8% after operation (p = 0.01). The mean percent predicted peak expiratory flow rate (PEFR) before operation was 49% and rose to 70% after operation (p < 0.0001). A box plot of the difference in PEFR after operation is seen in Figure 6.

View larger version (15K): [in this window] [in a new window]   Fig 6. Box plot of peak expiratory flow rate (% predicted) before and after tracheoplasty. The horizontal lines denote the 10th, 25th, 50th (median), 75th, and 90th percentiles. The open circles denote the highest and lowest peak flow. (PEF = peak expiratory flow.)

	Comment

Top Abstract Introduction Patients and Methods Results Comment References

 
The pathophysiology of emphysema and chronic obstructive pulmonary disease is multifactorial. While obstruction most commonly involves the distal airways, the central airways—the trachea and major bronchi—may also be involved. Symptoms and signs associated with airway obstruction at various levels of the tracheobronchial tree are difficult to distinguish on clinical grounds alone. Therefore, patients whose symptoms are in large part due to central airway collapse are often treated in a manner similar to those in whom airway obstruction is chiefly due to distal collapse. The distinction is important, for those patients whose symptoms are due to central airway collapse may benefit significantly from surgical stabilization.

Pulmonary function studies may be helpful. Marked reduction in PEFR occurs with tracheobronchial malacia [8]. Characteristically, the flow volume curve shows expiratory flow limitation with relative preservation of inspiratory flow. The expiratory curve typically shows a low maximal flow, which drops off close to the baseline, with a long plateau until end expiration [4, 6, 8] (Fig 7).

View larger version (12K): [in this window] [in a new window]   Fig 7. Flow volume curves in a 57-year-old man with 7 years of progressive dyspnea, wheezing, cough, and respiratory infections. Preoperative on the left; two months postoperative on the right. Pulmonary function figures listed in data on the fourth patient in Table 1.

Boiselle and colleagues [9] reported a similar technique employing computerized reconstruction to obtain virtual bronchoscopic images of the trachea during expiration and inspiration. Hein and colleagues [10] used electron beam tomography to assess tracheomalacia. Suto and Tanabe [11] described the use of dynamic MR imaging during cough for the diagnosis of tracheal collapse. These tests serve to confirm carefully performed bronchoscopy. Bronchoscopy performed in the awake patient who is able to follow commands (inspiration, expiration, cough) serves as a cornerstone of diagnosis for planning surgical intervention.

Herzog and colleagues [2, 6] early wrote about expiratory collapse of the central airways, delineating pathologic and pathophysiologic changes. Rainer and colleagues [12] also described the pathophysiology of central airway collapse and a means for measuring the degree of collapse. In 1954, Herzog and Rosetti [13] suggested that prevention of tracheal collapse would alleviate symptoms, and Nissen [3] successfully carried out a stabilizing procedure using thin bone slabs. They clearly stated that surgical goals were "to return the normal curvature of the cartilaginous rings while preventing a forward bowing of the membranous portion into the lumen of the windpipe," and emphasized that operation did not directly influence emphysema nor necessarily much improve pulmonary function. Huzly [14] reported 23 patients with and without concurrent pulmonary resection, using Nissen’s technique. Rib and cartilage were also employed for airway stabilization [15, 16]. Herzog and colleagues later used rectus abdominus fascia [17] and then polytetrafluoroethylene (PTFE) for stabilization.

Rainer and colleagues [18] initially used a polyethylene mesh prosthesis [12], and later, perforated Marlex and Dacron reinforced with Silastic. They reported that eight of 12 patients were long-term survivors, but that four died from erosion of prosthetic material into the trachea, esophagus, and aorta. Urschel [19] commented that about half of 17 patients stabilized with Marlex mesh were improved. Polypropylene mesh was also employed to stabilize tracheomalacia of other origins, in combination with silicone rings [20] or fixed with Histacryl adhesives [21].

Custom-made silicone rubber carinal Y stents have been utilized to manage expiratory collapse. The wide tracheal diameter and involvement of a long segment of trachea and main bronchi makes stent placement and retention difficult. Four of our patients had stents placed before tracheoplasty; 2 were quickly expectorated and 2 failed to resolve symptoms. Long-term use of metal stents for benign disease has been questioned [22], even if appropriate sized stents were to be made.

Our early exploratory use of autologous fascia lata and pericardium for stabilization was unsatisfactory, apparently because of attenuation of these tissues over time. Strips of PTFE failed to become incorporated in the tracheal wall. One patient developed an obstructing sterile fluid collection between the trachea and the PTFE in time, requiring reoperation. Polypropylene mesh (Marlex) met requirements for an easily tailored, pliable posterior splinting material, which would become permanently incorporated into the membranous wall by tissue ingrowth and subsequent fibrosis. Fluid would not be entrapped between the material and the membranous wall.

In the 14 consecutive membranous wall tracheoplasties performed for expiratory central airway collapse using polypropylene mesh there were no postoperative deaths. The most frequent morbidity was limited to retention of secretions in the immediate postoperative period. No patient developed complications, infectious or erosive, directly attributable to the mesh. All patients felt subjectively improved early after surgery, with decreased frequency of coughing "spells," increased ability to clear secretions, and return to modest normal activities. These results have largely proven durable over multiyear follow-up. Late bronchoscopy done in some patients demonstrated airway patency and stability (Fig 4C), confirmed by CT scans (Fig 8).

View larger version (94K): [in this window] [in a new window]   Fig 8. Computed tomographic scans in inspiration (A) and expiration (B) after splinting procedure in the patient in Figure 7. The now more normally shaped trachea maintains an open lumen throughout. Note thickening posterior to the trachea due to scar formation incorporating the Marlex strip.

View larger version (42K): [in this window] [in a new window]   Fig 2. Three dimensional computed tomographic reconstructions of trachea and main bronchi in a 57-year-old man with severely symptomatic malacia of the intrathoracic trachea and main bronchi. (A) Anterior view showing transition from circular cervical trachea through triangular shape to flattened cartilages distally. (B) Oblique view shows ridged membranous wall.

	References

Top Abstract Introduction Patients and Methods Results Comment References

1. Grillo HC. Tracheobronchial malacia and compression Surgery of the trachea and bronchi. Hamilton, Ontario: BC Decker; 2004. pp. 398-401.
2. Herzog H, Nissen R. Erschlaffung und exspiratorische invagination des membraneösen teils der intrathorakalen luftröhre und der hauptbronchien als ursache der asphyktischen anfälle beim asthma brornchiale und bei der chronischen asthmoiden bronchitis des lungenemphysems Schweiz Med Wochenschr 1954;84:217.[Medline]
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7. Grillo HC. Surgery for tracheomalacia Surgery of the trachea and bronchi. Hamilton, Ontario: BC Decker; 2004. pp. 645-649.
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16. Maurer W, Nadjafi A, Keller R, et al. Die chirugische behandling der expiratorischen tracheaobronchialstenose Thoraxchir 1968;16:480-486.
17. Herzog H, Keller R, Allgöwer M. Special methods of diagnosing and treating obstructive diseases of the central airways Chest 1971;60:49-67.[Abstract/Free Full Text]
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19. Urschel HC, Johnston MR, Loeber N, Hillyer P, et al. External stent for repair of secondary tracheomalacia Ann Thorac Surg 1980;30:291-296.[Abstract]
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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Cameron D. Wright Hermes C. Grillo Zane T. Hammoud John C. Wain Henning A. Gaissert Douglas J. Mathisen Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wright, C. D. Articles by Mathisen, D. J. Search for Related Content PubMed PubMed Citation Articles by Wright, C. D. Articles by Mathisen, D. J. Related Collections Trachea and bronchi Related Article