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Annals of Otology, Rhinology & Laryngology 124(2)

Catten

described a microflap technique in which a CO

laser was used to make a mucosal flap followed by resec-

tion or ablation of the aberrant soft tissue between the flap

and the cricoid. Shapshay et al

reported on the use of

radial incisions with a CO

laser, followed by dilation with

a rigid bronchoscope. Some surgeons favor a cold tech-

nique over the laser for making radial incisions.

Balloon

dilation was introduced in the management of subglottic

stenosis as a theoretically less traumatic alternative to

passing rigid dilators.

In addition to the different surgical techniques, there

have been several investigations evaluating wound-healing

modulators as adjunctive therapies. Most notable, inhaled,

systemic, and locally injected steroids have been used

extensively in an attempt to slow restenosis after dilation.

Mitomycin C, an alkylating agent, has been proven to pre-

vent fibroblast proliferation

and has been used with vary-

ing degrees of success in endoscopic airway surgery.

Halofuginone, an inhibitor of collagen 1-α synthesis,

and

5-fluorouracil, an antimetabolite that inhibits fibroblast

activity,

are also being investigated in animal models as

potential adjunctive therapies.

Given the variety of options in the endoscopic manage-

ment of iSGS, it has become obvious that an objective

means by which to quantify operative outcomes and to

compare the efficacy of different techniques or adjunctive

therapies is sorely needed.

Assessing Outcomes in the Endoscopic

Management of Subglottic Stenosis

In the late 1960s and early 1970s, there was a great deal

of interest in using pulmonary function tests (PFTs) to

aid in the diagnosis of upper airway obstruction (UAO).

Initial investigations focused on identifying values that

could differentiate UAO from lower airway disease.

18,19

It was ultimately Hyatt’s

description of the flow-vol-

ume loop and the different patterns of obstruction (vari-

able intrathoracic, variable extrathoracic, and fixed) that

provided clinicians with a powerful tool for diagnosing

and classifying UAO. There has been a renewed interest

in the past 2 decades in using PFT data not only as a

diagnostic tool but also as a means of quantifying the

results of interventions in UAO.

21,22

This retrospective study is designed to review our

experience with using pulmonary function data in the

management of patients with iSGS. Specifically, we aim

to (1) describe our experience with iSGS, (2) identify

which PFT parameters change following endoscopic

intervention, (3) quantify the degree of improvement in

airflow postoperatively using PFT data, and (4) determine

if PFTs change in a predictable manner postoperatively as

restenosis invariably occurs.

Methods

Inclusion/Exclusion Criteria

This study was approved by the institutional review board at

Oregon Health and Science University. A retrospective chart

review was performed, examining a single surgeon’s experi-

ence with iSGS. Records for all newly diagnosed adult

patients with iSGS referred to the senior author between

January 1, 2006, and December 31, 2012, were reviewed. At

least 1 standard endoscopic intervention (described below)

and 1 pulmonary function test was required for inclusion in

the study. Patients with a history of previous airway surgery,

airway trauma, tracheotomy, positive serology (c-ANCA or

ACE level), or intubation within the previous 12 months

were excluded from the analysis.

Management of Stenosis

All patients included in the study were managed endoscop-

ically in a standardized fashion. After confirming that the

patient could be mask ventilated, anesthesia was induced

and maintained using a total intravenous technique. A plas-

tic tooth guard was used to protect the maxillary dentition.

The airway was exposed using an Osshoff-Pilling laryngo-

scope, and the patient was suspended from the Mustard

table. Ventilation was conducted via jet technique. Standard

laser precautions were used throughout the procedure, to

include placing moist gauze pads over the eyes and wet

towels over any exposed skin.

A 4-mm rod lens telescope was used to evaluate and mea-

sure the stenosis. If the initial values were obtained by the

resident or fellow, the senior author (J.S.) repeated and con-

firmed the measurements. The stenosis was described by its

distance below the true vocal folds and by its total length.

Once measurements were complete, 2-mm cup forceps were

used to take a biopsy. The stenosis subsequently was infil-

trated with 1 mL of triamcinolone suspension (40 mg/mL). A

laser was then used to make 3 to 5 radial incisions in the

stenosis. Dilation of the stenosis was performed using a con-

stant radial expansion (CRE) balloon. After confirming hemo-

stasis and obtaining postoperative photo documentation, a

small, cuffed endotracheal tube (5.0) was placed through the

laryngoscope. The patient was taken out of suspension and

the laryngoscope removed. The patient was then remanded to

the care of the anesthesia team for recovery. Patients were dis-

charged home from the postanesthesia care unit that same day

with a fluticasone inhaler (220 mcg) and instructed to use 2

puffs twice daily until the inhaler was empty.

Data Collection and Statistical Analysis

After obtaining approval from the institutional review

board, the senior surgeon’s operative record was reviewed

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