Учебники / Operative Techniques in Laryngology Rosen 2008

180Posterior Glottic Stenosis: Endoscopic Approach

■Endoscopic attempts to restore CA joint mobility will fail if the causative injury has resulted in cartilaginous disruption with loss of the normal arytenoid structure or fusion of the arytenoids to the cricoid ring.

■Destructive procedures such as irreversible suture lateralization, posterior transverse cordotomy, partial arytenoidectomy, or total arytenoidectomy (Chap. 27, “Bilateral Vocal Fold Paralysis”) may be used but are usually less successful in patients with PGS than patients with bilateral vocal fold paralysis. This is due to erosion of the posterior cartilaginous glottis with loss of the normal dimension and preexisting scar tissue, which predisposes to recurrent scar formation.

■Mitomycin C may be beneficial in reducing scar tissue reformation.

 

Selected Bibliography

1Koufman JA, Aviv JE, Casiano RR, Shaw GY (2002) Laryngopharyngeal reflux: position statement of the committee on speech, voice, and swallowing disorders of the American Academy of Otolaryngology-Head and Neck Surgery. Otolaryngol Head Neck Surg 127:32–35

2Courey MS, Bryant GL Jr, Ossoff RH (1998) Posterior glottic stenosis: a canine model. Ann Otol Rhinol Laryngol 107 (Pt. 1):839–846

3Lichtenberger G (1999) Endoscopic microsurgical management of scars in the posterior commissure and interarytenoid region resulting in vocal cord pseudoparalysis. Eur Arch Otorhinolaryngol 256:412–414

4Dedo HH, Sooy CD (1984) Endoscopic laser repair of posterior glottic, subglottic and tracheal stenosis by division or microtrapdoor flap. Laryngoscope 94:445–450

5McIlwain JC (1991) The posterior glottis. J Otolaryngol 20(Suppl.):1–24

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Chapter 29
Subglottic/Tracheal Stenosis:	29
Laser/Endoscopic Management

29.1Fundamental and Related Chapters

Please see Chaps. 6, 9, 10, 13, 45, 46, and 47 for further information.

29.2Disease Characteristics and Differential Diagnosis

Subglottic stenosis (SGS) (Fig. 29.1) and tracheal stenosis (TS) are terms that after often used interchangeably to describe symptomatic airway narrowing below the vocal folds. Strictly speaking, the “subglottic region” refers to the infraglottic airway from the free edge of the true vocal folds down to the inferior border of the cricoid cartilage. From a practical point of view, many cases of upper-airway stenosis overlap the subglottis/upper tracheal boundary, rendering anatomic distinctions impractical.

Subglottic/tracheal narrowing is usually caused by scarring within the lumen of the airway. This must be distinguished from collapse secondary to weakened or absent cartilaginous framework (usually tracheal), or external airway compression. In addition, narrowing of the airway from neoplastic conditions (e. g., chondrosarcoma of the cricoid) can be confused clinically with scar in the subglottis. A more complete differential diagnosis is included in Chap. 6, “Glottic and Subglottic Stenosis: Evaluation and Surgical Planning”.

29.3Surgical Indications and Contraindications

Indications include endoscopic treatment of subglottic/tracheal stenosis for cases of symptomatic cicatricial narrowing of the upper airway (Fig. 29.2).

Absolute contraindications to laser excision/dilation of SGS include airway narrowing due to external compression, and tracheomalacia, or significant cartilage collapse (Fig. 29.3).

Relative contraindications include:

■Extensive length of stenosis > 2–3 cm

■Absence of identifiable airway lumen

■Stenosis involving the trachea at the level of the tracheostomy tube

	Fig. 29.2  Diagram of tracheal stenosis due to intraluminal scar forma-
	tion. Cartilaginous tracheal arches are intact. Arrow depicts the region
	of stenosis adjacent to the tracheo-esophageal party wall, where care
Fig. 29.1  Subglottic stenosis	must be taken during laser radial incisions, to avoid esophageal lumen
	entry

182	Laser Treatment for Subglottic Stenosis

Fig. 29.3  Tracheal airway narrowing due to collapse of cartilaginous framework (commonly seen after tracheotomy). Note the limited amount of airway expansion that could be achieved intraluminally

29.4Surgical Equipment

Equipment needed for surgery includes:

■Standard laser microlaryngoscopy set (Chap. 13)

■3.5 or 4.0 endotracheal tube wrapped with Cottonoid externally (for mitomycin C application)

29.5Surgical Procedure

The example given below is typical for SGS/TS treatment in the absence of a tracheostomy tube.

1.The patient is anesthetized via mask induction, and the table is turned 90° to allow the surgical team to obtain visualization of the upper and lower airway.

Endotracheal intubation (which can be traumatic to the stenotic region) is avoided.

2.The tooth guard is placed, and suspension laryngoscopy is established.

The laryngoscope/subglottiscope should be positioned proximal to the vocal folds initially (for evaluation and mapping of the stenosis), and jet Venturi ventilation (with 100% O2) initiated through the laryngoscope channel.

3.“Mapping” of the stenosis is carried out as follows:

a)The 0° telescope is advanced to the level of the vocal folds, and a mark is made on the telescope shaft where it intersects the proximal end of the laryngoscope (Fig. 29.4, “a”).

b)Thetelescopeisthenadvancedtotheupperedgeoftheste-

notic region, and another mark is made (Fig. 29.4, “b”). 29 c) The telescope is then placed at the distal edge of the ste-

nosis for the final mark (Fig. 29.4 “c”).

 

Fig. 29.4  Mapping of the stenosis using a 0° telescope. The marks are made on the telescope and measurements are taken directly off the telescope

d)The diameter of stenotic region is estimated in millimeters (the telescope diameter can be used as a guide).

e)The remainder of the trachea and proximal bronchial tree is visualized (and additional sites of stenosis mapped, if appropriate).

f)A ruler is placed along the telescope:

i.The measurement from “a” to “b” represents the proximity of the stenosis from the true vocal folds (useful for treatment planning if external procedures are entertained).

The measurement from “b” to “c” represents the length of the stenosis (in general, 1–2 cm is ideally suited for endoscopic treatment).

4.Pre-laser precautions (see Chap. 13, “Principles of Laser Microlaryngoscopy”)

a)Protect the patient

i.Moistened eye pads

ii.Wrap the head in moist surgical towels.

b)Protect the endotracheal tube (if used)

iUse a laser-safe tube.

iiO2 concentration of 30% or less

iiiProtect tube balloon by covering with a moist Cottonoid.

ivIf jet ventilation is used, then make sure that it is sus-

pended during laser firing (note: 100% O2 concentrations are used with jet ventilation).

c)Protect OR personnel

iSafety eye wear

5.Laser radial incision (CO2 laser settings 4–8 W, superpulse, or intermittent pulse)

The laryngoscope should be advanced past the true vocal folds (for protection), and positioned just above the stenotic region. The platform suction device is placed through the stenosis and used to protect the distal tissues while the laser

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Fig. 29.5  Schematic view of laryngotracheal region. Note placement of laryngoscope distal to the vocal folds for protection. Platform suction is placed underneath the stenotic shelf providing protection of distal trachea

incisions are made. The platform suction device is engaged by “hooking” the stenotic “shelf” that characterizes most upper airway stenosis (Fig. 29.5). As most stenotic lesions are asymmetrical, the initial laser radial incision is used to open the most severely affected portion, usually the region that has the most extensive shelf.

While the laser is being fired, jet ventilation is suspended. The incision should begin centrally and extend in a radial fashion, like the spokes on a bicycle wheel. It is important to keep the incision precise (narrow), so that a maximal amount of surrounding mucosa is preserved, which will promote more rapid re-epithelialization. The incision should be extended through fibrous scar tissue only. When characteristic “sparking” of the tissue is encountered (indicating the presence of cartilaginous framework), the laser incision is terminated. Further extension of the incision could expose cartilage leading to granulation/further scarring and/or cartilage loss.

6.Additional laser radial incisions are made.

The orientation of the incision is commonly compared to the hands of a clock. In the case of a perfectly symmetric stenosis, a maximum of four laser radial incisions are typically made at 12, 3, 6 and 9 o’clock (Fig. 29.6). Again, it is important to maintain a strip of uninjured mucosa between the incisions to facilitate re-epithelialization. From a practical point of view, most stenotic lesions are asymmetric, and two to three strategically placed laser radial incisions in the stenotic region with preservation of a normal quadrant of airway are often all that is needed (Fig. 29.7). Caution must

Fig. 29.6  Perspective view of laser radial incisions. Note planned incisions at 12, 3, 6, and 9 o’ clock, with sparing of intervening mucosa

Fig. 29.7  Example of predominantly right sided SGS with only three laser radial incisions needed at 12, 3, and 6 o’ clock

be exercised when making laser incisions in the trachea at 6 o’clock due to the risk of esophageal entry along the party wall (see Fig. 29.2, arrow).

7.The laryngoscope is advanced distally and resuspended to expose the more inferior extent of the stenosis.

The 0° telescope (30° telescopes are helpful as well) is then passed through the stenosis to evaluate the extent of the

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Laser Treatment for Subglottic Stenosis

Fig. 29.8  Schematic illustration of airway after laser radial incisions (left), during rigid bronchoscopic dilation (center), and after serial dilations are complete (right)

laser incisions. The laser radial incisions are extended distally, if indicated. Failure to extend the laser radial incisions through the entire distal aspect of the stenosis is a common error. This is likely due to the inherent limitations of a fixed visual field used in microlaryngoscopy. The dynamic view provided through the telescope provides a better view of this distal stenotic region.

8.Rigid dilation of stenosis

Refixed-wire balloon dilators (Boston Scientific, Boston, Mass.) are much easier and expeditious for dilatation compared with rigid dilatation.

a)A series of rigid ventilating bronchoscopes (nos. 5–9) is now used to gradually dilate the airway (Fig. 29.8). Prior to dilation, each bronchoscope should be connected to the anesthesia circuit via flexible rubber tubing, so that endotracheal ventilation can be performed during dilation. This is an important step due to the accumulation

of CO2 that tends to occur during prolonged jet ventilation.

b)Generally, a no. 5 bronchoscope is used initially, plac-

ing the bronchoscope directly through the laryngoscope Fig. 29.9  Cottonoid-wrapped ETT segment (saturated in mitomycin

	opening, and advancing past the stenosis. Surgical lubri-	C) in place, allowing jet ventilation to proceed
	cant placed on the tip of the bronchoscope is sometimes
	helpful. The bronchoscope is then rotated 90° to achieve
	maximal dilation from its eccentric shape.
	c) Serial dilations are then carried out using progressively	a) Application of mitomycin C to the surgical site is an im-
	larger bronchoscopes, stopping with the largest size that
	can be comfortably advanced past the stenosis. How-	portant adjunct in the endoscopic treatment of airway
	ever, bronchoscopes sized no. 6 and larger will not pass	stenosis. Usually a concentration of 0.4mg/ml is used,
	through most other laryngoscopes; therefore, they may	but concentrations of up to 10mg/ml (supersaturated)
	be passed using a sliding Jackson laryngoscope or “free-	may occasionally be employed if a tracheostomy tube is
	hand” without the aid of laryngoscopic guidance. A bet-	in place. Two options for mitomycin c application can be
	ter suited alternative is the use of a large bore Lindholm	utilized:
	laryngoscope (Karl Storz, Knittigen, Germany), which	i.	A mitomycin c–saturated Cottonoid is placed on the
	will allow passage of all bronchoscope sizes (see Fig.		surgical site, taking care that the entire surgical site is
	25.4) Clinically successful results usually occur if dila-		in contact with the pledget. The Cottonoid is left in
	tion to #7 or greater bronchoscope is achieved, although		place for 4–5 min, under apneic conditions, and then
	dilation to #6 in females is sometimes adequate.		removed. The time can be split up if the patient de-
	9. Suspension laryngoscopy with application of mitomycin C		saturates during the mitomycin-application period.
29
	(0.4 mg/ml)	ii.	A Cottonoid-wrapped 3.5 or 4.0 ETT segment (2–
			3 cm in length) can be saturated with mitomycin and

 

placed into the airway in contact with the surgical site (Fig. 29.9). This seems to provide better contact with the surgical site as well as a providing an airway for jet ventilation during the 4–5 min of treatment. The device is removed prior to returning the patient to the anesthesia team.

10.The patient is returned to the care of the anesthesia team. Jet ventilation can be continued until the team is prepared to switch to mask ventilation. The patient is awakened using mask ventilation and an oral airway preferably, although other nontraumatic techniques such as laryngeal mask ventilation are acceptable. Intubation is not recommended at the termination of the case, in an effort to avoid any further trauma to the operative site.

If tracheostomy is present distal to the stenotic region, then the case is significantly simplified—the airway is maintained with standard general anesthesia delivered through the tracheostomy site with a laser safe tube. The tube need only be removed briefly for endoscopic viewing of the entire upper airway at the beginning of the case, and again for dilation at the end of the case. An apneic technique is used during tube removal for the tracheal evaluation and dilation aspect of the procedure.

29.6Postoperative Care and Complications

Postoperatively, management includes:

■The patient is observed overnight in an ICU or stepdown unit. With experience, and especially with patients who are having repeated endoscopic treatments, such monitoring may not be necessary.

■Chest x-rays should be obtained if the patient has any

unexpected findings postoperatively, such as SpO2 values less than 95%, shortness of breath, chest/pleuritic pain, or subcutaneous crepitance in the neck.

■Perioperative steroids are important:

■10 mg Decadron intravenously

■Oral steroid-taper

■Additional postoperative meds:

■PPIs for at least 2 months, until healing is complete

■Antibiotics for 5–7 days (optional)

■Pain medications (usually from tongue compression)

■Cough suppressants (Tessalon Perles 100 mg three times daily, as needed)

Complications can include:

■Laser fire

■Tracheal penetration with pneumomediastinum/pneumothorax

■Late postoperative edema/granulation/fibrinous exudates with airway obstruction

■Tracheoesophageal fistula (exceedingly rare)

■Reccurent stenosis

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29.7T-Tube Stenting of SGS

Placement of a T-tube represents an “intermediate” step between endoscopic and open treatments for SGS/tracheal stenosis.

T-tube placement is indicated for tracheotomized patients with subglottic/tracheal narrowing (from any cause) who have failed serial CO2 radial incisions/dilation treatment.

T-tube placement is contraindicated for patients on ventilatory support. The open-ended design does not allow positive pressure ventilation through the external limb of the T-tube.

SGS involving the infraglottic aspect of the vocal folds (un- dersurface)isnotwell-suitedforT-tubestenting(andisarelative contraindication), because the proximal limb of the T-tube will likely either interfere with vocal fold closure or lead to granulation tissue formation and obstruction of the proximal T-tube.

29.8Surgical Equipment

Surgical equipment needed includes the following:

1.All of the equipment listed for CO2 laser radial incisions and dilation

2.Commercially produced standard T-tube stents:

a)Hood adult sizes 10–16 (size indicates outer diameter in millimeters)

b)Montgomery adult sizes 10–16 (size indicates outer diameter in millimeters)

3.One of the following to occlude/bypass the proximal end of the T-tube for ventilation:

a)Fogarty catheter with 3- to 5-ml balloon capacity

b)Hemostat/clamp

c)Small-diameter ETT (4.0)

4.Connector piece from a small bore (4.5–6.0) ETT (i. e., the detachable piece of the ETT in which you connect your ventilation circuit). Ensure that this piece fits snuggly into the ventilation port of the T-tube to be used.

29.9Surgical Procedure

A preexisting tracheostomy is required to perform T-tube placement.

1.Steps 1–8 of CO2 laser radial incisions and dilations are first performed (as outlined in Sect. 29.5), until an adequate airway caliber is obtained.

2.Suspension laryngoscopy is performed, and an assistant places a rigid endoscope, connected to a camera/monitor to visualize the airway during the placement of the T-tube stent, and to assist in positioning the stent (Fig. 29.10).

3.An appropriate T-tube stent is selected according to the diameter of the airway after dilation.

In general, sizes 11–14 (Hood) are used. The stent is sterilized prior to placement (Fig. 29.11).

4.A nasogastric (NG) tube is placed through the external limb of the T-tube, and up through the proximal (shorter limb). A

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Laser Treatment for Subglottic Stenosis

Fig. 29.10  An assistant provides visualization (with a 0° telescope) of	Fig. 29.11  T-tube stent prior to placement
the airway during T-tube placement

Fig. 29.12  An NG tube is placed through the external limb of the T- tube, up through the proximal (shorter limb), and clamped in place

clamp is placed at the external limb of the tube, which fixes the T-tube to the indwelling NG tube (Fig. 29.12). The tip of the NG tube is then placed through the tracheal stoma and advanced into the proximal trachea. Working through the laryngoscope, the assistant grasps the NG tube with a large laryngeal cup forceps/grasper. The NG tube is pulled into the upper trachea, seating the proximal end of the T-tube in the airway (Fig. 29.13).

29 5. The distal end of the T-tube is crimped (Fig. 29.14) with a hemostat, and advanced through the stoma, and into the distal

Fig. 29.13  The proximal end of the T-tube is passed into the airway and the NG tube is grasped by the assistant via endoscopic visualization

tracheal airway (Fig. 29.15). This step may be difficult, and might need to be attempted a few times before the T-tube can be successfully positioned in the distal airway.

6.The assistant uses the rigid telescope to visualize the entire length of the T-tube to insure patency and adequate positioning in the airway (Fig. 29.16).

The T-tube should not be kinked, twisted, partially occluded, or “loose” in the airway. In addition, the proximal end of the T-tube should not come within 5 mm of the undersurface of the vocal folds. The distal end should not come in contact with

 

Fig. 29.14   The distal end of the tube is crimped with a curved clamp

Fig. 29.16  The assistant passes the telescope through the T-tube into the distal trachea to insure good placement and patency of the lumen of the tube

the carina. A properly seated T-tube should fit snuggly in the airway and maintain its shape/patency regardless of patient position/neck movement. If the above conditions are not met, then T-tube placement will ultimately fail due to granulation tissue formation and occlusion of the tube. A good indicator of successful T-tube placement is the ability of the patient to maintain good air exchange with the T-tube capped at the end of the surgical case and in the recovery room.

7.Once the T-tube is positioned, the patient must be ventilated until he/she is able to breathe spontaneously.

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Fig. 29.15  The clamped distal end of the tube in advanced into the distal trachea through the stoma

Options include:

a)LMA (laryngeal mask ventilation)

b)Occlusion of the proximal end of the T-tube with a endoscopically positioned Fogarty catheter. A connector from an ETT is placed into the external limb of the T-tube for ventilation distally (Fig. 29.17).

c)Occlusion of the proximal end of the T-tube using a hemostat/clamp placed through the stoma at the proximal end of the T-tube (care must be taken not to also occlude the external limb). Again, a connector from an ETT is placed into the external limb of the T-tube for ventilation distally (Fig. 29.18).

8.Once the patient is breathing spontaneously, without ventilatory support, the external limb of the T-tube should be capped (closed), so that the patient is now moving air oronasally.

Inability to cap the T-tube (for any reason) when the patient is fully awake and recovered from anesthesia, is cause for concern. An uncapped T-tube can lead to drying/crusting of airway secretions within the tube, and ultimately luminal obstruction of the stent. Successful maintenance of long-term T-tube stent in the airway cannot be achieved unless the tube is capped during the majority of the patient’s waking hours. Patients with coexisting obstructive sleep apnea can often uncap the T-tube at night, as long as humidified air is used by the bedside.

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Laser Treatment for Subglottic Stenosis

Fig. 29.17  Occlusion of the proximal end of the T-tube with a Fogarty catheter to allow venti­ lation

29

Fig. 29.18  Occlusion of the proximal end of the T-tube with a curved clamp to allow ventilation

 

29.10 Postoperative Care

Postoperatively:

1.Observation of the patient in a monitored setting for 24 h (ICU or step-down unit)

2.Ten milligrams intravenous Decadron preoperatively, and every 8 h (×2) during hospitalization

–Consider prednisone/methylprednisone oral taper at dis­ charge

3.Additional postoperative medications:

–PPIs for at least 2 months, until healing is complete

–Antibiotics for 5–7 days (optional)

–Pain medications (usually from tongue compression)

–Cough suppressants (Tessalon Perles 100 mg three times a day, as needed)

4.Tracheostomy tube at bedside, one size smaller than that of the T-tube:

T-tube size	Tracheotomy tube size (Shiley)
10	2
11	2
12	4
13	4
14	6
15	6
16	8

5.Humidified air at bedside, especially during sleep

6.Suctioning of the upper and lower limb of the T-tube every 8 h and as needed

•An excellent nursing/patient instruction manual is included with the Hood T-tube package

7.Prior to discharge from the hospital, educated patient/caregivers regarding emergency measures in the event that the T-tube becomes obstructed at home:

•Uncap T-tube first; if this does not improve breathing, then suction upper and lower limb of T-tube/irrigate with 2 ml normal saline.

•If still unable to move air adequately, then grasp and pull firmly on external limb of T-tube to remove it.

•Come to the Emergency Department immediately; page the surgeon. A tracheostomy tube can be placed through the stoma as a temporizing airway until arrangements to replace the T-tube (in the OR) can be made.

8.Follow up in the office frequently in the first 2 months postoperatively (every 1–2 weeks depending on patient’s reliability/family support/anxiety level)

•The inside of the T-tube should be inspected each visit, using a flexible laryngoscope to insure upper and lower limb patency and to check for reactive granulation tissue. Crusting in the external limb can be cleaned with a cerumen loop.

•Review importance of suctioning/cleaning of tube and humidification

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Complications include the following:

■T-tube occlusion due to poor position/incorrect size of T-tube

■Granulation tissue at proximal or distal end of T-tube

■This presents within the first 2 months postoperatively, and must be dealt with by either removal/ cryotherapy of the granulation tissue, or by replacing the stent with a more appropriate T-tube. Patients are at higher risk for this complication if the T-tube is “modified” by cutting off a portion of the proximal or distal tube. This modification replaces the inert, smooth “factory” edge of the tube with a sharper, reactive surface—often resulting in granulation tissue formation at the tube/tissue interface. If customization of the T-tube cannot be avoided, it is important to bevel and smooth the cut edges, as described by Montgomery et al.

■Hoarseness/aphonia due to extension of the proximal end of the T-tube into or through the glottis

■Edema and granulation tissue of the vocal folds can result, as well as incomplete glottal closure. If transglottic extension of the superior limb of the T-tube cannot be avoided, then the upper limb should be located at the ventricle/inferior false vocal fold level.

■Accidental T-tube displacement/removal

■The use of large bore suction catheters (10 French or greater) can lead to this. Nine French or less is recommended for cleaning/suctioning.

■Cracking/splintering of the T-tube

■Although uncommon, this can occur with prolonged (>3 years) T-tube placement. To avoid this, replacement of the T-tube should be performed every 2 years.

29.11Special Considerations in T-Tube Stenting

T-tube stenting of the airway is intended as long-term management strategy for patients with SGS/tracheal stenosis, who have failed endoscopic laser treatments. However, in select cases, removal of the T-tube can be attempted, after a minimum period of 1–2 years of stenting. The T-tube should be removed in the OR, and careful postoperative monitoring should be undertaken for at least 2–3 month/hs after stent removal to check for recurrence of stenosis.

Key Points

■Endoscopic treatment of subglottic and tracheal stenosis is an excellent management option, and in most cases, is the first method attempted before embarking on open surgical treatment.