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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
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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 Other Systemic Symptoms Suggesting More Advanced Disease Include: Malaise Weight Loss Fatigue Tachycardia Linda Silorey and Lonni Bhirdo
CBT-Diagnostic Tests • DuplexUltrasound • MRA • CTA • Angiography Linda Silorey and Lonni Bhirdo
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
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 • 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
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
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 cranialnerveinjury risk was 35% • 3-9 % mortality rate • Incompleteexcision has overallrecurrence rate of 10-15% • Significant increase in mortality rate with CarotidArteryligation Linda Silorey and Lonni Bhirdo
Special Thanks to Macomb Surgical Associates!!! 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