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Subglottic stenosis

last modified on: Fri, 02/23/2024 - 15:06

return to: Management of Specific Voice Disorders

see: operating room setup for subglottic stenosis; Jet Anesthesia Adapter; Jet Ventilation Anesthesia - Transoral for Laryngeal Surgery; In Clinic Steroid Injections for Subglottic Stenosis (Office Based); Tracheal Sleeve Resection with Suprahyoid and Infrahyoid Release

For Dr. Van Daele preferences, see: Upper airway obstruction management: Van Daele

For video/photos click on: Subglottic Stenosis - Example Cases

GENERAL CONSIDERATIONS

  1. Causes:
    1. Acquired (ref Lee and Rutter 2008)
      1. Mechanical trauma from previous intubation or tracheotomy (#1 cause in children and adults)
        1. (see: Case Example Tracheal Stenosis after Tracheotomy with Four Flap Epithelial Lined Tracheotomy)
      2. Laryngopharyngeal reflux
      3. Rheumatologic disease
        1. Wegeners Granulomatosis
        2. Less common: scleroma, amyloidosis, osteochondroid hamartoma, relapsing polychondritis
          1. Case Example Subglottic Stenosis and Relapsing Polychondritis
      4. External trauma
      5. Respiratory infections
      6. "Idiopathic"
      7. Chondroradionecrosis after radiation therapy (may occur up to 20 years later)
      8. Inhalation injury 
      9. Neoplasm
        1. Lymphoma (Brake M, Lee B, et al. Subglottic Stenosis secondary to lymphoplasmacytic lymphoma. Arch Otolaryngol Head Neck Surg. 2011 Feb;137(2):187-9)
    2. Congenital
      1. Acquired condition is much more common than the congenital, in the ratio of 9:1
      2. Congenital form is due to failure of the lumen of the larynx to fully recanalize during the first 3 months of gestation.
        1. (Bowden, F. An Overview of Neonatal Airway Obstruction: The Congenital Causes. JSMS. Vol 1 Iss 1. Apr 4, 2009) 
  2. General principles
    1. Determining the location of stenosis
      1. May involve soft tissue scarring, cartilage remodeling, or some combination of both.
      2. CT and MRI do not reliably image the cartilaginous framework of the airway. High resolution CTs show some promise, but the primary method of evaluation is history and direct laryngoscopy with palpation.
        1. Useful if cartilaginous disorder likely (ie relapsing polychondritis)
        2. May benefit by identifying location relative to adjacent structures - such as unusually high location of innominate artery
    2. Grading of subglottic stenosis
      1. Cotton Grading System: Cotton RT, RichardsonMA. Congenital laryngeal abnormalities. Otolaryngol Clin North Am. 1981;14:203-218
      2.              Grade                             Airway Obstruction
        1.       I                                        0-50%
        2.       II                                       51-70%
        3.       III                                      71-99%
        4.       IV                                     100% (no detectable lumen)
  3.  Contraindications
    1. Unstable cervical spine
    2. Unable to obtain exposure of the larynx (ie, retrognathic)
    3. Consider alternative external approach options
      1. Segmental or cricotracheal resection
      2. Graft reconstruction 
      3. Fiberoptic endoscopic laser with balloon dilation (Andrews BT et al 2007 and commentary)
      4. Tracheotomy
        1. see also Montgomery cannula
    4. Active Inflammatory state (eg Wegener's Granulomatosis)
    5. Active infection at the site

PREOPERATIVE PREPARATIONS

  1. Evaluation
    1. Preoperative studies
      1. Flexible fiberoptic laryngoscopy
        1. Options to visualize subglottis
          1. Standard fiberoptic laryngoscopy with the patient appropriately positioned may permit view between vocal cords. May supplement with assistant pulling tongue forward
          2. In some patients, indirect mirror laryngoscopy affords a better view of the subglottic secondary to a more favorable angle of view than FFL.
          3. In addition to application of lidocaine with neosynephrine spray to the nose, deep inhalation with concurrent application of spray to the oropharynx will deliver anesthetic to larynx
          4. TNE (transnasal esophagoscopy) scope (or equivalent laryngoscopy) with a side port will permit introduction of 4% lidocaine to the larynx to permit easier view of the subglottis
        2. If the patient has a tracheotomy, spray of lidocaine/neosynephrine into the stoma (or trach) with subsequent cough will anesthetized the larynx sufficiently to permit view through the vocal cords.
      2. Pulmonary function tests (see video and details: Spirometry PIF Peak Inspiratory Flow)
        1. Of all the variables tested and reported, the flow volume loop (inferior limb = inspiratory limb) is the most directly relevant to the upper airway (laryngeal or tracheal narrowing)
        2. Request "PIF" (peak inspiratory flow rate) to be reported - calculated from inspiratory limb of flow volume loop -- general rules (modified by the patients size, overall health, symptoms):
          1. < 1 liter /sec: admit the patient or operate immediately
          2. 1-2 liters/sec: schedule surgery soon
          3. 2-3 liters/sec: schedule followup in 6-8 weeks
          4. 3-4 liters/sec: schedule followup in 4 to 6 months
          5. >4 liters/sec: relax
    2. With history of neck arthritis, Down Syndrome, or neck surgery/injury: Lateral neck radiographs in flexion and extension
    3. Offer to most patients with dentition a dental prosthetic evaluation preoperatively to fashion a tailored (custom-made) acrylic dental splint see: Custom Dental Guards for Micro Direct Laryngoscopy (Suspension Laryngoscopy)
      1. To prevent dental injury more effectively than the standard plastic "gump"
      2. To patients who will undergo multiple microscopic direct laryngoscopy procedures (hence greater possibility of dental exposure) (see suggested reading "Dental Protection During Rigid Endoscopy")
      3. To improve exposure of the larynx by permitting greater pressure to be distributed across the custom dental guard
      4. Expense of the custom guards ~$100 per guard (upper / lower) may warrant alternatives such as self made adapted 'football mouthpiece guard' brought in by the patient
  2. Consent for Surgery
    1. Describe procedure and expected recovery: Placement of rigid tube through your mouth into your voice box to expose the vocal cords and the trachea below your vocal cords. Using a telescope or microscope, the area of narrowing will be examined. Cuts and dilation may be performed.
    2. Potential complications (not inclusive)
      1. Bleeding, infection, reaction to the anesthesia
      2. Damage to adjacent structures
        1. Lips, teeth, tongue
        2. Larynx, pharynx
        3. "numb tongue, altered taste, TMJ syndrome, dental injury"
      3. "A surgical incision always results in a scar. Our goal is to minimize the amount of scarring with steroid injection and carefully positioned cuts to avoid further scarring and need for further procedures
      4. Mention prolonged intubation or temporary tracheotomy if it is more than an extremely remote possibility.
      5. Mention possibility of developing a numb tongue or hypoglossal nerve paralysis from pressure of the laryngoscope (usually temporary). 
      6. Controversy regarding mitomycin
      7. Identify alternatives - including open resection of diseased segment and end-to-end anastomosis
        1. Note rigid criteria proposed by Gelbard et al (2015) to consider those patients who have required multiple dilation procedures before proceeding to open procedure
          1. Less than 45 years old
          2. Without type 2 diabetes or connective tissue disease
          3. Stenosis at least 2 cm below the glottis (2 cm or more below glottis)
          4. Senses less than 2 cm in length
      8. Naunheim et al (2018) evaluated patient preference for treatment from 162 volunteers from the general population to identify that 80.4% would prefer endoscopic surgery for treatment of subglottic stenosis as a 'voice-sparing, low-risk' procedure even if multiple procedures were required when compared to open tracheal resection as the preferred option by 19.6%.

NURSING CONSIDERATIONS

  1. Room Setup
    1. See Panendoscopy Room Setup
  2. Instrumentation and Equipment
    1. Standard
      1. Direct Laryngoscope Tray
        1. included Dedo laryngoscope and Lindholme
      2. Bronchoscopy Tray, Adult
      3. Lewy Laryngoscope Holder Tray
      4. Laryngoscope Instrument Tray, Microscopic Direct
      5. Telescope, Storz, Hopkins straight 0° 5.5 mm x 20 cm
      6. Telescope, Storz, Hopkins straight 0° 4.0 mm x 30 cm
      7. Telescope, Storz, Hopkins 70°, 4 mm x 30 cm
      8. Storz fiberoptic light cable
      9. Stryker camera adapter (if flexible bronchoscope used)
      10. Microscope (400 lens) plus video unit
    2. Special
      1. Tracheotomy Tray (have available)
  3. Medications (specific to nursing)
    1. 4% lidocaine solution, topical: Draw up in Luer Lock syringe to secure abbocath (used to spray vocal cords) with 25 gm x 1.5 in ndL
    2. 1% Lidocaine with 1:100,000 epinephrine
    3. Oxymetazoline HCL nasal spray, 0.05% (for hemostasis on 1/2 in x 1/2 in neuropatties)
    4. FRED (fog reduction elimination device); used to defog the telescopes used in imaging the larynx; FRED is variable in effectiveness to prevent fogging; HH's preference: use hot water to warm the tip of the telescope to prevent fogging
    5. Kenalog 40 mixed 1:3 with 1% Lidocaine with 1:100,000 epinephrine (final dilution: Kenalog 10)
  4. Prep and Drape
    1. No prep
    2. Drape
      1. No need for shoulder roll if patient appropriately positioned on table:
        1. Head of patient at end of bed with 'head extension' flexed down
        2. Raise back of bed 30 degrees to elevate head above abdomen
      2. Two unfolded pillowcases with towel clamp for a head drape oriented to protect eyes
      3. Tape eyes (employ moistened eye pads and cloth tape if use of laser is possible)
      4. Cloth drape across chest
  5. Drains and Dressings
    1. None
  6. Special Considerations
    1. Keep small amount of clean saline set aside to place biopsies in and to clean off biopsy forceps to avoid cross-contamination between specimens.
    2. Open 18-gauge needle when taking biopsies to remove tissue from forceps. Place on Telfa for pathology.
    3. May use silver nitrate sticks to control extensive bleeding from the pharynx or supraglottic larynx (not recommended on the vocal folds). Alternatively, have the monopolar cautery available to touch to suction as it is applied to bleeding site through the laryngoscope with care to avoid contact with the laryngoscope; a safer mono-polar cautery is the shielded Freche micro-cautery unit.
    4. Topical 1:100,000 epinephrine or oxymetazoline for application to vocal folds on 1/2 in x 1/2 in neurosurgical cottonoid for hemostasis.
    5. Patients may have premade tooth guards.
    6. Instruments should be set up prior to induction and remain assembled until patient is extubated and patent airway is established.
    7. Tracheotomy Tray should be available for emergency tracheotomy when it is considered an issue. Usually a consideration for the first endoscopy, subsequent procedures may not be.
    8. Second Mayo stand may be used for support for surgeon to rest hands during microlaryngeal surgery may be useful in selected cases.
    9. Rigid telescope with fiberoptics attached to camera and printer with Polaroid film for immediate still pictures to be given to the family and patient postop. Images also digitally entered into chart. Ideally, the long (30 cm) 0-degree and 70-degree telescopes will be available for all microlaryngeal cases.  For subglottic stenosis it is rare to require the 7--degree telescope.
    10. Laser is generally not used.
    11. Laryngoscopes
      1. Dedo laryngoscope (Home Plate): The "workhorse" provides adequate exposure in most patients; limited for laser surgery by absence of smoke evacuation port. 
      2. Hollinger anterior commissure laryngoscope: Poor monocular exposure; useful when exposure is impossible with other laryngoscopes. Excellent backup.
      3. Jackson laryngoscope: Rarely used, best to introduce rigid bronchoscope.
      4. Ossoff-Karlan laryngoscopes: Good exposure but cannot be used in all patients because of larger size; best for laser surgery because of smoke evacuation port.
      5. Weerda laryngoscope: Expands both proximally and distally to provide excellent exposure for supraglottic surgery.
      6. Lindholm scope: good for supraglottic exposure and glottic exposure, not useful for difficult airways requiring endolaryngeal exposure. May supplement with laryngeal spreader.
    12. Balloon dilations
      1. CRE Pulmonary Balloon Dilators
        1. 12-13.5-15 balloon
          1. This balloon inflates to 12 mm diameter at 3 ATM, 13.5 mm diameter at 4.5 ATM and 15 mm at 8 ATM with a balloon length of 5.5 cm
        2. 15-16.5-18
          1. This balloon inflates to 15 mm diameter at 3 ATM, 16.5 mm diameter at 4.5 ATM and 18 mm at 8 ATM with a balloon length of 5.5 cm
      2. Boston Scientific insufflator (Encor) 

ANESTHESIA CONSIDERATIONS

  1. Communication with anesthesia staff is essential
    1. Methods
      1. Jet anesthesia - one second inspiration, three seconds expiration
      2. Apnea with intermittent mask
      3. Spontaneous ventilation
      4. Local anesthesia with sedation (see Local Anesthesia for Rigid Endoscopy protocol)
      5. The surgeon should be in the operating room during induction if there is potential for airway compromise.
      6. Oral endotracheal intubation with small (4.0 to 6.0) endotracheal tube (MLT tube = microlaryngeal/tracheal tube)
    2. Short-term paralysis (duration dependent on procedure; communicate with anesthesiologist)
  2. Preoperative Systemic Medications
    1. Glycopyrrolate 0.1 to 0.2 mg IM may be considered on call to operating room - no longer routine 
      1. The drying effect improves exposure; consider avoiding in patients with xerostomia, cardiac disease; contraindicated with glaucoma or urinary retention
      2. Vagolytic effect
      3. IM administration has longer half-life than IV, but onset of action for IM is 15-30 minutes, versus 1 minute for IV
    2. Consider Decadron 8 to 10 mg IV when IV started to diminish edema
      1. Contraindications: diabetes, ulcer disease, other
    3. Antibiotics administered only if biopsies or incisions are made in an infected or contaminated region (not usually employed for vocal fold surgery) (see Antibiotic Prophylaxis in Head and Neck Surgery protocol) 
  3. Positioning
    1. Head of table turned 90° from anesthesia
    2. Arms tucked for placement of suspension laryngoscopy support
    3. Neck extended
    4. Head of bed elevated to 30° 

OPERATIVE PROCEDURE

  1. Place laryngoscope
    1. The Dedo laryngoscope
      1. Preferred scope for jet ventilation
      2. May be placed 'deep' into the larynx to splay apart vocal cords posteriorly to better expose the subglottis.
        1. Risk for post-op dysphonia from this process is greater in patients with small larynges (small women).
        2. Risk of injuring the vocal cords is lessened by ensuring the tip of the Dedo scope is inserted in a posterior location when placed between the vocal cords.  
      3. permits stabilization of the operative instruments against the right-angle lower corners of the laryngoscope opening in a "tripod" technique.
    2. The Holinger anterior commisure scope affords improved anterior exposure
  2. Instill 4% preservative free lidocaine onto the vocal cords to prevent vasospasm
  3. Laryngeal spreader may be placed to improve visualization
  4. Determine location and extent of narrowing by
    1. Placing laryngeal suction with its tip at the level of the vocal cords and make a mark on the suction with a marking pen where it abuts the edge of the viewing end of the laryngoscope
    2. Advance the tip of the suction to the superior level of the stenosis and place a second pen mark on the suction
    3. Advance the suction tip to the inferior end of the stenosis and place a third mark
    4. The distance between the marks on the suction is then measured and recorded
      1. Between the 1st and 2nd mark = distance below the free edge of the vocal cord at which the stenosis begins
      2. Between the 2nd and 3rd mark = length of the stenotic segment
  5. Intralesional Steroid Injection plus Dilation (ILSD) 
    1. Kenalog 10 prepared by diluting 1 part Kenalog 40 with 3 parts 1% lidocaine with 1:100,000 epinephrine
    2. Injection prior to making cuts is of critical importance, otherwise the injection tend to flow out via incisions rather than infiltrate the tissue.  
    3. EVIDENCE: A Cleveland Clinic study in 2003 (J Rheumatol. 2003 May;30(5):1017-21)
      1. 21 patients with SGS and Wegener's (WG) were treated with ILSD
      2. Mean interval for repeat ILSD was 11.6 months
      3. Authors recommend ILSD as preferred treatment for patients with SGS and WG
  6. Radial cuts at the location(s) of greatest stenosis and tethering.  May be done with scissors or laser.
    1. Biopsy may be taken
  7. Dilation
    1. This part of the procedure may precede the measurement, injection, and radial cuts if the narrowing is sufficient to compromise the airway.
    2. Jackson dilators may be used to improve the airway sufficiently to permit placement of a small endotracheal tube (4-0 MLT or 5-0 MLT) or to permit balloon dilation. 
      1. The small female larynx will usually accommodate a 36 Jackson
      2. The large male larynx will more readily accommodate the larger 40 to 42 metal Jackson dilators
      3. It is difficult to safely place a 42 or larger dilator through a Dedo laryngoscope (may get stuck), therefore, may dilate to a size 40, and if desire further dilation may use balloon, or utilize anesthesia's mac blade to place the final dilator or two.  
    3. Balloon dilation with a CRE pulmonary balloon dilator (15-16.5-18 size) (see: Subglottic Stenosis - Upper Tracheal Stenosis CRE Balloon Dilation)
      1. With a small endotracheal tube in place, dilation with the CRE balloon dilating system may proceed safely with continued ventilation and diminished risk of injury to the glottic larynx
      2. Inflation is done to 1 to 3  atm and held for 4 minutes in smaller larynges, may increase to 6 atmospheres in larger.
      3. Size of dilation is greater than the 15-18 mm diameter of the balloon due to the presence of the airfilled endotracheal tube which also helps to cushion to posterior membranous trachea (common wall with esophagus)
  8. (optional) Application of Mitomycin C, an antineoplastic agent that inhibits fibroblast proliferation
    1. A 'slurry' of 10mg/ml Mitomycin C may be topically applied to the raw surface on a cottonoid pledget for 2 minutes each has been employed by some in the past
    2. Currently consider a lower concentration of 0.5mg/ml as per Smith et al 2009
      1. "The dosage 0.5 mg/mL concentration used in this study appears to have a clinical effect as suggested by basic wound-healing studies, without the development of necrosis and eschar. Higher concentrations of MMC have been reported to cause airway obstruction due to tissue slough and eschar formation, in both animal studies and clinical experience"
      2. Smith et al also identify likely value in a second application of Mitomycin C three weeks after the initial
    3. The handling and disposal of the Mitomycin-C should be per the hospital protocol for chemotherapeutic agents. Care should be taken to avoid contact with unprotected skin.
    4. The extensive safe use of Mitomycin-C has been published in many articles in peer-reviewed journals. Counseling the patient and consideration of isolated case reports indicating cancer developing at the site of application is warranted.
  9. (optional) May consider use of Microdebrider: 2.9 mm laryngeal skimmer.

POSTOPERATIVE CARE

  1. Concern regarding adequacy of airway may warrant hospitalization.
    1. Medications
      1. Consider additional IV Decadron postoperatively if laryngeal manipulations cause edema. For outpatient consider Medrol dose pack
      2. Consider antibiotics (Unasyn/Augmentin/Levaquin) if there is infection identified.
      3. Consider Zantac/Prilosec/omeprazole with antireflux instructions if findings suggestive of laryngopharyngeal reflux (LPR) (see Antireflux instructions).
      4. Humidification (bedside humidifier)
      5. Hydration (drink noncaffeinated fluids "until your urine is pale")
    2. Patients are usually admitted for overnight stay following surgery, but may potentially go home the same day if doing extremely well several hours post-operatively.
  2. Follow up
    1. Repeat pulmonary function tests with PIF

REFERENCES

Roediger FC, Orloff LA, Courey MS. Adult subglottic stenosis: management with laser incisions and mitomycin-C. Laryngoscope 2008 Sep;118(9):1542-6.

Duncavage JA, Ossoff RH, Toohill RJ. Carbon dioxide laser management of laryngeal stenosis. Ann Otol Rhinol Laryngol 1985;94:565-569.

Lee KH, Rutter MJ.Role of balloon dilation in the managment of adult idiopathic subglottic stenosis Ann Otol Rhinol Laryngol. 2008 Feb;117(2):81-4. 

Cotton RT, RichardsonMA. Congenital laryngeal abnormalities. Otolaryngol Clin North Am. 1981;14:203-218

Strome M. Subglottic stenosis: therapeutic considerations. Otolaryngol Clin North Am. Feb 1984;17(1):63-8.

Correa AJ, Reinisch L, Sanders D, et al. Inhibition of subglottic stenosis with mitomycin-C in the canine model. Ann Otol Rhinol Laryngol. 1999;108(11):1053-60

Andrews BT, Graham SM, Ross AF, Barnhart WH, Ferguson JS, McLennan G.Technique, utility, and safety of awake tracheoplasty using combined laser and balloon dilation.Laryngoscope.2007 Dec;117(12):2159-62. Comment in: Laryngoscope. 2008 Jun;118(6):1133-4.

Blumin JH and Johnston N: Evidence of Extraesophageal Reflux in Idiopathic Subglottic Stenosis. Laryngoscope, 121:1266-1273, 2011

Hoffman GS, Thomas-Golbanov CK, Chan J, Akst LM, Eliachar I, Treatment of subglottic stenosis, due to Wegener's granulomatosis, with intralesional corticosteroids and dilation. J Rheumatol. 2003 May;30(5):1017-21

Hautefort C, Teissier N, Viala P, Van Den Abbeele T: Ballon dilation laryngoplasty for subglottic stenosis in children: eight years' experience. Arch Otolaryngol Head Neck Surg 2012 Mar;138(3):235-40

Smith ME and Elstad M: Mitomycin C and the Endoscopic Treatment of Laryngotracheal Stenosis: ARe Two Applications Better Than One?" Laryngoscope, 119:272-283, 2009

Gelbard A, Francis DO, Sandulache VC, Simmons JC, Donovan DT, and Ongkasuwan J: Causes and Consequences of Adult Laryngotracheal Stenosis. Laryngoscope, 125:1137-1143 2015

Naunheim MR, Naunheim ML, Rathi VK, Franco RA, Shrime MG and Song PC: Patient Preferences in Subglottic Stenosis Treatment: A Discrete Choice Experiment. otolaryngol Head Neck Surg. 2018 Mar;158(3):520-526