103 / 232
hypertrophy,
13,15
this method does not allow for quantifi-
cation of the size, and especially the depth, of lingual
tonsil tissue. The MRI is more sensitive than flexible
endoscopy for defining the true depth and volume of the
lingual tonsillar tissue present
8,9
and may allow for
more complete lingual tonsil tissue removal. Although
the use of radiofrequency for removal of the lingual ton-
sils did not allow us to quantify the volume of tissue
removed, it is relatively easy to distinguish lymphoid tis-
sue from tongue muscle, which makes complete removal
possible.
Limitations of our study include the small sample
size, although this is the largest series of LT in children
with DS to date, and concerns regarding generalizability,
given the fact that 90% of our cohort was white. This
study is also limited by its retrospective nature, which
likely results in some selection bias. In addition, limiting
our evaluation to children who underwent both pre- and
postoperative PSG may limit generalizability, as the
decision to get these studies may be more common in
children with persistent symptoms after both T&A and
LT surgery. Furthermore, although we strongly suspect
that body mass index (BMI) plays a role in persistent
OSA following surgery, there were not enough patients
in our study with complete pre- and post-BMI data to
make statistical analysis meaningful. Despite these limi-
tations, LT resulted in significant decreases in the oAHI
for almost all of these children; however, persistent mod-
erate or severe disease was found in 38%. Futures pro-
spective studies should include standardized PSG
outcomes, BMI, and larger sample sizes with sufficient
numbers to stratify patients by OSA severity.
CONCLUSION
In children with DS with persistent OSA after T&A
and lingual tonsil hypertrophy, LT significantly
improved AHI, oAHI, and O
2
saturation nadir, and reso-
lution of the oAHI to
<
5 events/hour was seen in 62% of
children. We recommend that children with DS be evalu-
ated for lingual tonsil hypertrophy if found to have per-
sistent OSA following T&A.
TABLE III.
Changes in Polysomnographic Outcomes Before and After Surgery, for Children With Down Syndrome Who Underwent Lingual Tonsillecto-
my for Obstructive Sleep Apnea After Adenotonsillectomy, Stratified by Age.
Changes in PSG
Outcomes for 3 to 6
Year Olds, N
5
7
Changes in PSG
Outcomes for Children
>
6
Years Old, N
5
14
P
Value
AHI, events/hr, mean (SD),
median [range]
4.5 [
2
0.4 to 8.8]
6.4 [
2
2.9 to 41.0]
.28
Obstructive AHI, events/hr,
mean (SD), median [range]
4.3 [
2
1.4 to 9]
7.1 [
2
2.1 to 41.0]
.25
O
2
nadir, %, mean (SD),
median [range]
2
0.02 [
2
0.06 to 0.08], n
5
5
2
0.05 [
2
0.31 to 0.01], n
5
11
.078
% REM, mean (SD),
median [range]
2
2.0 [
2
12 to 17]
3.0 [
2
15.0 to 18.0]
.41
% time CO
2
>
50 mm Hg,
mean (SD), median [range]
2
8.8 [
2
91 to 34], n
5
5
26[
2
1 to 87.6], n
5
6
.12
Apnea index, events/hr,
mean (SD), median [range]
2
0.14 [
2
0.22 to 1.57] n
5
5
6.73 [
2
1.71 to 14.82], n
5
9
.06
Hypopnea index, events/hr,
mean (SD), median [range]
4.8 [
2
2.96 to 8.61], n
5
5
2.78 [
2
8.01 to 29.32], n
5
13
.92
Maximum ET CO
2
, mm Hg,
events/hr, mean (SD),
median [range]
2
5 [
2
11 to 4.0]
1.5 [
2
12 to 16.3]
.31
Central index, events/hr,
mean (SD), median [range]
0.5 [
2
0.2 to 1.0]
2
0.05 [
2
2.3 to 3.9]
.23
Median differences were tested using the Wilcoxon rank sum test.
AHI
5
apnea hypopnea index; ET
5
end tidal; PSG
5
polysomnography; REM
5
rapid eye movement; SD
5
standard deviation.
TABLE IV.
Changes in Polysomnographic Outcomes Before and After Surgery, for Children With Down Syndrome Who Underwent Lingual Tonsillecto-
my for Obstructive Sleep Apnea After Adenotonsillectomy, Stratified by Preoperative Obstructive Sleep Apnea.
OSA Severity
% of Patients (n)
Postoperative AHI, Mean (SD)
Postoperative oAHI, Mean (SD)
oAHI Change, Mean (SD)
Mild OSA
19.0% (4)
3.2 (2.9)
2.5 (2.4)
0.93 (2.2)
Moderate OSA
47.6% (10)
4.0 (3.4)
2.9 (3.1)
4.3 (3.2)
Severe OSA
33.3% (7)
10 (8.9)
9.1 (7.6)
17.6 (12.9)
Mild OSA was defined as 1 to 5 events/hour, moderate OSA was defined as an oAHI of 5 to
<
10 events/hour, and severe OSA was defined as 10 or
more events/hour.
AHI
5
apnea hypopnea index; oAHI
5
obstructive apnea hypopnea index; OSA
5
obstructive sleep apnea; SD
5
standard deviation.
Prosser et al.: PSG Outcomes of Lingual Tonsillectomy in DS
81