1. Wednesday January 26, 2011

2. Duplex Assessment of Carotid Body Tumor
Presented by Linda Silorey and Lonni Bhirdo

3. Carotid Body- Anatomy Ovoid, red/brown to tan organ
Outer adventitia layer
Posterior-medial wall of
bifurcation of CCA
3-5 mm in size ~ larger in people in higher altitudes
Receives blood supply from branches of the ECA
Linda Silorey and Lonni Bhirdo

4. Carotid Body- Function
Regulates Autonomic Nervous System
Chemoreceptor sensitive to
changes of arterial O2 , CO2
and pH changes
Sensitive to changes in BP,
blood flow, & blood osmolarity (salt content)
Sends signals to the brain
that result in changes in
respiratory rate/cardiac output
Factors such as Increased temperature of blood, Cyanide and nicotine cause stimulation of the Carotid Body
Linda Silorey and Lonni Bhirdo 4

5. Carotid Body Tumor aka CBT
Arises from the normal tissue of the carotid body between the ECA/ICA
Lateral pulsatile neck mass- often presenting with a bruit or thrill
A rare highly vascular
tumor - incidence of only 0.01%
Usually benign
Most often fed by ECA branch:
Ascending Pharyngeal Artery
Other terms used to describe CBTs:
Chemodectomas, endothelioma glomus caroticum, peritheliomas and paragangliomas
Linda Silorey and Lonni Bhirdo

6. CBT- Etiology/ Incidence
Over- response to homeostasis changes
Hypertrophy linked to
hypoxia/ hypercapnia
Higher Altitudes, Smoking, COPD
Genetic 10 % of cases
45-50 years of age
Female - rare in children
South American
Bilateral in 5% of cases
Linda Silorey and Lonni Bhirdo

7. CBT- Signs & Symptoms Other Systemic Symptoms Suggesting More Advanced
INCIDENCE/ RATE
Mass in neck
100%
Painful neck
13.4%
Dizziness
4.1%
Palpitation
3.1%
Hoarseness
Hypertension
2.06%
Headache
1.03%
Dysphasia
Hearing loss
Other Systemic Symptoms
Suggesting More Advanced
Disease Include:
Malaise
Weight Loss
Fatigue
Tachycardia
Linda Silorey and Lonni Bhirdo

8. CBT-Diagnostic Tests Duplex Ultrasound MRA CTA Angiography
Linda Silorey and Lonni Bhirdo

9. Duplex Ultrasound
Often the examination of choice for Dx of CBT: Readily available,
painless, non-invasive, relatively risk free and takes less than
an hour
Always do a complete bilateral Carotid study to identify for
Stenosis as well as to rule out a contralateral tumor
Machine settings and focal zones should be optimized to visualize the superficial nature of the Carotid arteries- these settings also make it possible to visualize CBTs.
Three modalities are used for diagnostic information:
B-Mode or grayscale, Color flow, Doppler Spectral analysis
Linda Silorey and Lonni Bhirdo

10. Duplex Ultrasound: B-Mode
B-Mode/ Grayscale Helps:
Identify location, internal echo pattern and shape
of any incidental finding of a neck mass
Differentiate whether the mass is solid or cystic
If mass is in fact at the bifurcation
Whether splaying of the ICA/ ECA is a CBT
or instead Aneurysmal Disease
or Carotid Artery kinking
CBTs are solitary masses with hypoechoic,
homogeneous or heterogeneous echo patterns
Margins of CBTs are well defined and smooth
Linda Silorey and Lonni Bhirdo

11. Duplex Ultrasound: B-Mode
Provides anatomical “road map”
of Carotid Artery
Image in both transverse and
longitudinal scanning planes
Splaying of ICA and ECA is one of primary
ultrasound findings in Dx of CBT
Measure in both Trans (AP & LAT)
and Sagittal (long) for image length
Linda Silorey and Lonni Bhirdo

12. Normal Carotid Bifurcation (Sag)
SPLAYED BIFURCATION
Normal Carotid Bifurcation (Sag)
Carotid Body Tumor
Linda Silorey and Lonni Bhirdo

13. Duplex Ultrasound: Color Flow
Second to splaying, Color Flow
Characteristics is a very valuable
diagnostic tool in the Dx of CBT
Color Flow identifies blood
flow within a tumor- a key
feature of CBT
ICA
Helps identify between nonvascular,
hypovascular and hypervascularity of
blood flow within a tumor
ECA
Allows for differentiation between
CBT and other incidental findings
such as lymph nodes, salivary gland
tumors and metastatic neck masses
Linda Silorey and Lonni Bhirdo

14. Duplex Ultrasound: Doppler
To further differentiate a CBT from other tumors,
Doppler is used to assess the spectral waveforms
of the arteries within and feeding the CBT
Waveforms are most commonly Low-Resistant within
the tumor and feeding vessels
There is also usually increased Diastolic Flow in the ECA
artery branch feeding the tumor
Linda Silorey and Lonni Bhirdo

15. Reporting of CBT
CBT is only one of many types of masses that can be found when performing a Carotid Duplex examination
Other findings include: Enlarged Lymph Nodes
Metastatic Lesions
Thyroid or Parathyroid Masses
Lipomas
Salivary Gland Tumors
Tumors of Nerve Sheath (Schwannoma)
Important to note location of mass in relation to surrounding landmarks/structures
Measurements listed in three planes: AP, Lat and Sag
Description of mass: round, oval, lobular
Margin or Boarders: well defined, poorly visualized, diffused, regular, irregular
Echo Patterns (compared to surrounding tissue): Hypo/Hyperechoic
Color Flow Patterns: Flow vs No Flow visualized
Linda Silorey and Lonni Bhirdo

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23. Treatment The tumor is classified via the Shamblin
classification- which is based on the tumor’s
involvement of the ICA
Usually slow growing, surgical resection is the
most common treatment due to invasive nature
of CBTs. They are often found wrapped around
the ICA and ECA, can erode into the base of skull
and can entrap regional cranial nerves
Feeding vessels are often embolized 1-2 days prior to
resection to reduce tumor size, ease the resection
and reduce intraoperative blood loss
The ECA is sometimes sacrificed to control bleeding
and improve access to the ICA. Immediate repair or
replacement of the CCA and or ICA may be needed
Linda Silorey and Lonni Bhirdo

24. CBT- Prognosis Post surgery stroke and cranial nerve injury
risk was 35%
3-9 % mortality rate
Incomplete excision has
overall recurrence rate of
10-15%
Significant increase in mortality rate with Carotid Artery ligation
Linda Silorey and Lonni Bhirdo

25. Macomb Surgical Associates!!!
Special Thanks to
Macomb Surgical Associates!!!
Linda Silorey and Lonni Bhirdo

26. References
Linda Silorey and Lonni Bhirdo

27. References- cont. Linda Silorey and Lonni Bhirdo Picture Sites
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Linda Silorey and Lonni Bhirdo