The type of tracheomalacia that often accompanies chronic obstructive pulmonary disease (COPD) is manifest as expiratory collapse. The curve of the intrathoracic tracheal cartilages is flattened, the extreme tips of the cartilages sometimes curve slightly forward, the cartilages are thinned and softened, and the membranous wall is markedly widened. The membranous wall approximates to the flattened cartilages on expiration and cough (see Figures 15-2, 15-3, in Chapter 15, "Tracheobronchial Malacia and Compression," and Figure 39 [Color Plate 16]). Since the cartilages still retain considerable substance, correction is obtained by restoring them to a C shape, by pulling the tips closer together, while shortening the membranous wall to a more normal width. This is accomplished by attaching longitudinal strips of splinting material along the membranous walls of the intrathoracic trachea, the right and left main bronchi, and the bronchus intermedius. Redundant membranous wall is quilted to the splint to prevent its infolding into the lumen of the airway.
I early abandoned using strips of fascia lata as a material for splints, since an additional incision was required. Pericardium was used only briefly, for it seemed to attenuate with time. Goretex failed because it could not become firmly incorporated into the tracheal wall by ingrowth of scar tissue. Obstruction recurred in some. Numerous splinting materials have been used by others, including perforated solid plastic strips, lyophilized bone, and absorbable synthetic mesh. I found Marlex (monofilament knitted polypropylene mesh; Davol Inc., Cranston, RI) to be very satisfactory. It is easily sutured into place and holds sutures well. Tissue ingrowth into its interstices fully and permanently incorporates the splint into the tracheobronchial walls, thus maintaining the restored curvature of the cartilages and preventing fluid from accumulating between the membranous wall and prosthetic strip as occurred with Goretex.
Preoperative bronchoscopy is repeated for careful assessment of the extent of malacia. Left lung ventilation is established with a long single lumen endotracheal tube bronchoscopically placed in the left main bronchus. The posterior wall of the entire thoracic trachea is exposed transpleurally through a right posterolateral fifth rib (or intercostal space) incision (see Figure 28-1 in Chapter 28, "Reconstruction of the Lower Trachea [Transthoracic] and Procedures for Extended Resection"). The azygos vein is divided. The posterior trachea is dissected to the apex of the chest. The right vagus nerve and its branches to the hilum are divided for exposure. Only the edges of the cartilages on either side along the margins of the membranous wall are freed for suturing, thus preserving tracheal blood supply. The membranous walls of both main bronchi and the bronchus intermedius are similarly exposed, if the malacic process extends this far, as usually it does. It is possible to expose even the distal end of the left main bronchus from this approach. As with the trachea, the bronchi are not dissected circumferentially, but only sufficiently to free up 3 to 5 mm of cartilaginous edges along the margins where the cartilages meet the membranous wall.
A strip of Marlex is cut approximately 2 to 2.5 cm wide (depending on the size of the trachea and the width of the membranous wall) and long enough to extend from the apex of the trachea which is accessible in the thorax, to a few centimeters beyond the carina or longer as noted below. 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 (Figure 32-1A). Suturing is commenced at the top of the accessible trachea. One longitudinal row of sutures will extend along each edge of the membranous wall and fixes the borders of the Marlex strip to the tips of the cartilages on either side. The two other longitudinal central rows fix Marlex to the membranous wall (see Figure 32-1A). These rows are spaced by eye across the membranous wall, dividing it into approximately even thirds. Each succeeding row of four sutures placed transversely is about 6 to 8 mm below the previous one. Suturing progresses from the apex of the chest to the carina.
I have used both 4-0 Tevdek and 4-0 Vicryl for suture material. Effort is made to avoid penetrating the tracheal mucosa. Where this has occurred on rare occasion, even a nonabsorbable suture such as Tevdek has not, thus far, caused infection or other late problems. Vicryl, although ultimately absorbable, has such a long life that fibrosis and Marlex incorporation should occur long before the suture is absorbed. I therefore used Vicryl in later patients and have recognized no problems to date. The marginal sutures are placed through the edge of the Marlex from posterior to anterior, then through a cartilage end from lateral to pos-terior—a firm purchase being taken—and thence back through the Marlex (see Figures 32-1 A,B). This is
figure 32-1 Posterior splinting procedure for expiratory tracheobronchial collapse. A, Marlex strip of desired width is sutured to the posterior tracheal wall from the apex of the chest to the carina, or in some, to the distal bronchus intermedius. Successive registers of four sutures (4-0 Vicryl) are placed across the Marlex as shown. The outer sutures grasp the lateral tips of the cartilages; the inner two fix the redundant membranous wall in equal thirds. Each row is about 6 to 8 mm distal to the prior row. Lateral sutures of each row are placed first. After three rows of sutures are placed, the first row may be tied. One previous row is left untied as you progress distally, to facilitate placement of the next row. Dots in the proximal Marlex indicate sites for following sutures. The distal dashed lines indicate where the Marlex will be applied to the lower trachea and to the bronchi. Three strips of Marlex are usually used, but occasionally, a narrowed extension of the tracheal strip may be carried onto the right main bronchus and bronchus intermedius. Dots indicate placement of distal sutures in the Marlex. Note three longitudinal rows in the bronchial strips versus four in the tracheal. B, Cross-sectional diagram showing spacing of sutures. The lateral ones will restore the "C" curve of the flattened cartilage. The central ones fix the elongated membranous wall to the Marlex. These sutures do not penetrate the membranous wall. C, The completed restoration of airway configuration. Scar will firmly fix the membranous wall and lateral tracheal corners to the Marlex splints. The correction is checked bronchoscopically after completion.
not a true mattress suture, but serves well to pull the cartilage to the Marlex when tied. The two median rows of sutures are true mattress sutures.
I prefer to place the lateral sutures of the apical row first, then the two apical central membranous wall sutures—each of these spaced equally across one-third of the membranous wall. Thus, an initial horizontal row of four sutures is placed. Each suture is clipped with a hemostat and arranged systematically, two on either side of the operative field. Successive rows of four similar sutures are next placed, proceeding distally toward the carina. When all tracheal sutures are in place, they are tied—lateral sutures of each horizontal group of four initially, followed by the central two of each group of four, the quilting sutures (Figure 32-1C). When the carina is reached, the Marlex strip is trimmed, usually perpendicular to the axis of the bronchus on either side (see Figure 32-1A). Sometimes, it is convenient to tie the rows successively to anchor the strip as it is sutured. If this is done, it is best not to tie down an immediately preceding row, since this narrows the exposure for placement of the next row of sutures.
A strip of Marlex approximately 1.5 cm wide is next applied to the left main bronchus using only three longitudinal rows of sutures, commencing distally as near to the bronchial bifurcation into lobar bronchi as possible. When the proximal end of the bronchus is reached at the carina, the Marlex strip is trimmed. It is cut to fit to the tracheal Marlex strip with slight overlap (see Figure 32-1A). The final row of sutures at the origin of the bronchus includes both tracheal and bronchial walls and both the tracheal and bronchial strips of Marlex, thus fastening all of these together. The same is done for the right main bronchus and the bronchus intermedius—again with only three longitudinal rows of sutures (see Figures 32-1A, 32-2), using a single strip of Marlex. Sometimes, a single long strip of Marlex has been carried from the tracheal wall to extend over the right main bronchus and bronchus intermedius, but narrowed over the bronchi.
After all sutures are tied, the correction achieved is examined by flexible bronchoscopy, prior to closing the thoracotomy. The correction should be substantial but will not, of course, appear like a wholly normal trachea or bronchus (see Figure 15-4 in Chapter 15, "Tracheobronchial Malacia and Compression"). The field is thoroughly irrigated and the mediastinal pleura is closed loosely. Patients are usually extubat-ed at the conclusion of the operation. If short-term ventilation is necessary, the endotracheal tube cuff pressure should be minimal.
Success in use of posterior surgical splinting procedures is conditional. Patients continue to suffer from their underlying COPD and may have residual obstruction in the more distal bronchi. Secretions may continue to be a problem but can usually be raised by a now more effective cough, since the major airways figure 32-2 Marlex splints in place. The single arrow locates the carina. The double arrows indicate the origin of the right and left main bronchi.
no longer collapse with cough. Extensive case series with prolonged follow-up of these procedures are lacking (see Chapter 15, "Tracheobronchial Malacia and Compression").
Although experience with this procedure is small, it appears to be effective for the purposes stated. It is recommended for use after very careful assessment of the patient and with awareness that underlying COPD will not improve.
Alternatively, an individually fashioned Y silicone prosthesis of Dumon type (ie, with "studs" to hold it in place) may be employed. The proximal end must be long enough to splint the relatively long length of collapsing intrathoracic trachea, and the diameters for trachea and bronchi must be adequately large. Tracheobronchial angles vary individually. Some patients do not tolerate such stents and dislodge them with vigorous cough. It seems unwise to deploy expandable stents in these patients, even if large enough sizes were available, because of the hazard of irreversible injury in patients with benign disease (see Chapter 40, "Tracheal and Bronchial Stenting").
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