STATEMENT OF THE PROBLEM
Obstructive sleep apnea with the level of obstruction at the base
of tongue can be a challenge to treat successfully. Removal or
ablation of base of tongue tissue can lead to improvement in
symptoms and decrease obstruction. The lingual artery is the
vital structure at greatest risk during base of tongue surgery.
Injury is rare, but is considered a major complication. There are
no standard recommendations for pre-operative imaging of the
tongue to map the lingual artery. Other authors have defined
a “safe zone,” a 1-2 cm paramedian area of the tongue where
the lingual artery is unlikely to be injured.¹ This is primarily based
on expert opinion, radiographic studies, and cadaver studies.
However, injuries to the lingual artery has been reported despite
adherence to these “safe zone” parameters.² Pre-operative
predictors of patients at risk for lingual artery injury have not
been defined. Also, there are radiographic angiogram studies
to date examining the course of the lingual artery in a cohort of
patients from the United States.
OBJECTIVE
Utilize computer tomographic angiograms (CTA) and gather
patient variables that could predict violation of the lingual artery
within a 1.5 cm paramedian “safe zone” in the base of tongue.
MATERIALS & METHODS
Consecutive neck CTA were obtained retrospectively between
2012-2014 from the University of Utah Radiology Department. Scans from 127 patients satisfied inclusion criteria
for this study. Transverse and AP measurements of the lingual artery in the axial plane
were made at the level of the tip of the epiglottis (TOE), the top of the
glossoepiglottic fold (TGF), and the base of the vallecula (BOV).
At each of these levels the shortest distance of each lingual artery was
measured to the (1) midline fatty septum, (2) contralateral lingual artery
and (3) AP distance from the airway.
METHODS OF DATA ANALYSIS
The unpaired t-test was used to determine the statistical
significance of the distance between lingual arteries and
patient variables.
RESULTS
Demographics n = 127 |
Age (years) Mean(SD) 54.9 (18.5) Median(IQR) 57 (41 – 68.5) Range 16 – 88 |
BMI Mean(SD) 27.6 (6.1) Median(IQR) 27.1 (23.9 – 30.8) Range 16.2 – 53.9 |
Sex(female) 63 (49.6%) |
Hypertension 63 (49.6%) |
Hyperlipidemia 64 (50.4) |
OSA 3 (2%) |
GERD 36 (28%) |
Cardiac arrhythmia 10 (8%) |
Heart disease 10 (8%) |
Diabetes 25 (20%) |
Vertical level of measurement |
Distance (mm) between lingual arteries |
Distance (mm) from the airway |
Tip of the epiglottis |
Mean(SD)=20.9±5.3 Range=11.5–38.8 IQR=17.5–23.1 |
Mean(SD)=22.6±6.3 Range=7.8-46 IQR=19–26.6 |
Glossoepiglottic fold |
Mean(SD)=26.2± 5.7 Range=15.1–39.9 IQR=22.1–30.1 |
Mean(SD)=14.8±7.9 Range=1.7–32.7 IQR=8.4–22.1 |
Base of the vallecula |
Mean(SD)=29.2 ±4.2 Range=20.3–40.1 IQR =26.9–31.6 |
Mean(SD)=10.8±4.6 Range=3.4–24.7 IQR=7.5–13.6 |
|
Distance between lingual arteries ≤15mm |
Distance between lingual arteries >15mm p-value |
|
n |
24 |
103 |
|
Age(mean) |
42.6 |
57.7 |
p < 0.01* |
Gender(F) |
66.7 |
46.6 |
p < 0.05* |
BMI |
24.2 |
28.3 |
p < 0.01* |
Mean distance |
14.2 |
22.5 |
|
Range |
11.5 -15.8 |
16 – 38.8 |
|
*Statistically significant
OUTCOMES DATA
The results reveal a significant relationship between age < 50,
a BMI < 25.9, female sex and violation of the lingual artery
within the 1.5 cm “safe zone”.
CONCLUSION
A younger female patient with a low BMI may be risk for lingual
artery damage prior to surgery. Pre-operative imaging should be
considered to avoid injury to the lingual artery during base of
tongue resection.
REFERENCES
1. Suh GD. Evaluation of open midline glossectomy in the multilevel
surgical management of obstructive sleep apnea syndrome.
Otolaryngol Head Neck Surg. 2013 Jan;148(1):166-71. 2012 Oct 12.
2. Li S, Shi H. Lingual artery CTA-guided midline partial glossectomy
for treatment of obstructive sleep apnea hypopnea syndrome.
Acta Otolaryngol. 2013 Jul;133(7):749-54.