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Annals of Otology, Rhinology & Laryngology
2015, Vol. 124(2) 137–142
© The Author(s) 2014
Reprints and permissions:
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aor.sagepub.comArticle
Introduction
Etiology/Pathophysiology
Idiopathic subglottic stenosis (iSGS) is a nonspecific fibro-
inflammatory process that results in progressive narrowing
of the airway at the level of the cricoid and proximal tra-
chea. Investigators have proposed a multitude of theories as
to the etiology of the process since its first description in
1972.
1
The disorder occurs almost exclusively in women,
typically presenting in the fourth or fifth decade.
2
This
female preponderance led to the hypothesis that estrogen
might play a role in the pathogenesis of iSGS, although the
evidence for this has not borne out.
3,4
Current theories regarding the etiology of iSGS have
focused on non-gender-specific causes. Subglottic injury
from laryngopharyngeal reflux (LPR) has been implicated
as a possible cause.
5
Autoimmune disease, specifically a
limited form of seronegative polyangiitis with granuloma-
tosis (GPA), has also been proposed as a mechanism for
iSGS.
6
Other theories on the etiology of the disorder include
repetitive microtrauma from cough
7
and hereditary factors.
8
Ultimately a disease of the subglottic lamina propria, no
single etiologic factor has been identified.
Endoscopic Management of iSGS
Although segmental resection of the diseased portion of
the airway is considered the gold standard for obtaining
long-term improvement in the airway in iSGS, it is a
potentially morbid procedure.
9
Endoscopic surgery pro-
vides an attractive alternative that is less invasive, albeit
less definitive. As surgeon experience has grown, several
variations in technique have been explored. Dedo and
548915
AOR
XXX10.1177/0003489414548915Annals ofOtology,Rhinology&Laryngology
Kraft et al
research-article
2014
1
Department of Otolaryngology, University of Kansas, Kansas City,
Kansas, USA
2
Department of Otolaryngology, Oregon Health and Science University,
Portland, Oregon, USA
Corresponding Author:
Shannon M. Kraft, MD, Department of Otolaryngology–Head and Neck
Surgery, University of Kansas Medical Center, 3901 Rainbow Boulevard,
MS 3010, Kansas City, KS 66160, USA.
Email:
skraft3@kumc.eduUsing Pulmonary Function Data to Assess
Outcomes in the Endoscopic Management
of Subglottic Stenosis
Shannon M. Kraft, MD
1
, Kevin Sykes, PhD, MPH
1
, Andrew Palmer, CCC-SLP
2
,
and Joshua Schindler, MD
2
Abstract
Objective:
This study aimed to examine the authors’ experience with endoscopic management of idiopathic subglottic
stenosis (iSGS), and to identify pulmonary function test (PFT) values that can be used to quantify outcomes.
Methods:
Retrospective review.
Results:
Twenty-five patients with a new diagnosis of iSGS were seen between 2006 and 2012. Median age at surgery was
45.3 years (interquartile range [IQR], 38.5-67.0), and median body mass index was 28.7 kg/m
2
(IQR, 23.5-32.1). Forty-five
procedures were performed. Median preoperative stenosis was 56.8% (Cotton-Myer grade 2). The typical stenosis began
15 mm below the true vocal folds and was 12 mm long. Median follow-up was 21.4 months (IQR, 5.1-43.1). For patients
receiving multiple dilations, median time between procedures was 23.7 months. Four PFT parameters demonstrated
significant improvement after intervention: (1) PEF (absolute change = 2.54 L/s), (2) PIF (absolute change = 1.57 L/s), (3)
FEV1/PEF (absolute change = 0.44), and (4) FIF50% (absolute change = 1.71 L/s). PIF was the only parameter affected by
using a larger balloon (
P
= .047).
Conclusion:
PEF, PIF, FEV1/PEF, and FIF50% improved significantly after endoscopic incision and dilation of iSGS, and this
could potentially be used as a metric by which to evaluate outcomes in the endoscopic management of subglottic stenosis.
Keywords
endoscopic, idiopathic subglottic stenosis, pulmonary function test
Reprinted by permission of Ann Otol Rhinol Laryngol. 2015; 124(2):137-142.
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