How Does the Anatomy of the Lingual Artery Limit Base of Tongue Reduction for Obstructive Sleep Apnea? a Retrospective Review of a Large Cohort Using CT Angiograms of the Neck

How Does the Anatomy of the Lingual Artery Limit Base of Tongue Reduction for Obstructive Sleep Apnea?  A Retrospective Review of a Large Cohort Using CT Angiograms of the Neck

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.