Duplex Assessment of Carotid Body Tumor

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Wednesday January 26, 2011
Duplex Assessment
of
Carotid Body Tumor
Presented by Linda Silorey and Lonni Bhirdo
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
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
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
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
CBT- Signs & Symptoms
SYMPTOMS
INCIDENCE/ RATE
Other Systemic Symptoms
Suggesting
More Advanced
Mass
in neck
100%
Disease
Include:
Painful
neck
13.4%
Dizziness
4.1%
Palpitation Malaise
3.1%
Hoarseness
3.1%
Weight
Loss
Hypertension
2.06%
Headache
Fatigue
1.03%
Dysphasia
1.03%
Tachycardia
Hearing loss
1.03%
Linda Silorey and Lonni Bhirdo
CBT-Diagnostic Tests
 Duplex Ultrasound
 MRA
 CTA
 Angiography
Linda Silorey and Lonni Bhird
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 arteriesthese 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
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
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
SPLAYED BIFURCATION
Normal Carotid
Bifurcation (Sag)
Carotid Body Tumor
Linda Silorey and Lonni Bhirdo
Duplex Ultrasound: Color Flow
 Second to splaying, Color Flow
Characteristics is a very valuable
diagnostic tool in the Dx of CBT
ICA
 Color Flow identifies blood
flow within a tumor- a key
feature of CBT
 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
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
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
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
Linda Silorey and Lonni Bhirdo
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
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
Linda Silorey and Lonni Bhirdo
References
Linda Silorey and Lonni Bhirdo
References- cont.
Picture Sites
http://medical-dictionary.thefreedictionary.com/carotid+body
http://www.cvrx.com/patients/index.php?id=41
http://www.cvrx.com/patients/index.php?id=41
http://www.radrounds.com/photo/carotid-body-tumor-64row-mdct?context=user
http://www.imagingeconomics.com/issues/articles/MI_2006-01_10.asp
http://wjso.com/content/3/1/10
http://www.daviddarling.info/encyclopedia/C/carotid_ultrasound.html
http://oto.sagepub.com/content/118/1/82.abstract
http://www.vascularweb.org/APDVS/Pages/CerebrovascularModule.aspx
http://www.centrus.com.br/DiplomaFMF/SeriesFMF/18-23-weeks/chapter- 13/sga_01.html
http://www.healthcaremagic.com/healthpage/branchial-cyst
Linda Silorey and Lonni Bhirdo
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