What the….? – Unusual arterial pathologies

Warren Lewis DMU Vasc. AFASA

Vascular One UltrasoundNewcastle, Australia

Degrees of “What the…?!”

Many conditions are uncommon, but fairly well described.

Ultrasound findings can leave you confused, then excited by the challenge.

I’ll describe a few rare and uncommon arterial pathologies, give there incidence, a brief description and most importantly, their ultrasound characteristics.

Arteritis

Takayasu’s ArteritisIncidence 2.6 cases per million people per year worldwide. Higher in Asia and leading cause of renovascular hypertension in

India, China, Korea and Japan. 9:1 incidence women to men and majority < 30yo

Pathology - granulomatous large vessel vasculitis involves the aorta, its proximal branches, pulmonary and coronary arteries. Various mechanisms such as post-infective, autoimmune, ethnic susceptibility and a genetic predisposition.

Takayasu’s Arteritis

Ultrasound Findings

Varying degrees of aortic and aortic branch stenosis

Fusiform or saccular aneurysm.

May progress to significant coarctation and occasionally total occlusion of aorta or its major branches.

Ultrasound images of takayasus

Incidence

Most common form of adult vasculitis

Annual incidence for biopsy-proven GCA of 15–35 per 100 000 individuals aged over 50 years.

Incidence increases with age, peaking aged 80 years or older; very few cases occur aged less than 50 years.

Northern Europe report a greater incidence in women, with a female to male ratio of around 2.5:1

Giant cell arteritis / temporal arteritis

Giant cell arteritis / temporal arteritis

Pathology

focal, granulomatous inflammation of arteries of medium and small size that affects the cranial vessels, especially the temporal arteries in older individuals.

In the more severe stages of this disease, lesions have been found in arteries throughout the body.

frequently associated with polymyalgia rheumatica.

Temporal arteritis

Ultrasound Findings

Areas of normal superficial temporal artery interspersed within inflamed sections of artery, known as skip lesions.

oedematous wall thickening around the artery lumen that contrasts hypoechoic to the surrounding tissue (halo sign)

with duplex ultrasound, sensitivity is 87% and specificity is 96%

stenosis may be present but not a specific sign

Panarteritis Nodosa (PAN)

Incidence

(PAN) is a rare disease, with an incidence of about 3-4.5 cases per 100,000 people annually.

usually diagnosed in middle-aged and older adults. Men tend to be more affected than women.

Panarteritis Nodosa (PAN)Pathology a systemic necrotizing vasculitis which affects small and middle

sized arteries of multiple organs.

skin, neurologic, cardiac, gastrointestinal, and muscular. The kidney is the most commonly affected organ.

Arteries become thickened and inflamed through intimal proliferation. This leads to stenosis and decreased blood flow, predisposing affected vessels to thrombosis.

Inflammation also leads to aneurysm development. These changes result in ischaemia and infarction.

Ultrasound not the definitive diagnosis for PAN but findings of multiple, nodular aneurysms in arteries, thrombus formation, and clinical history, may arouse suspicion.

The diagnosis is confirmed by a biopsy.

An angiogram of the abdominal blood vessels may also be very helpful in diagnosing PAN.

Diagnosis

Panarteritis Nodosa (PAN)

Radial artery nodular aneurysms Kidney saccular aneurysms

Thromboangiitis Obliterans (Buerger's Disease)

Incidence

Average 11-30/100 000 worldwide per year

More prevalent in Middle East and Asia

In India, accounts for 45-63% of all PAD cases.

Young people 20-45 yo and mainly male 10:1 ratio

Most cases associated with heavy tobacco use.

Thromboangiitis Obliterans – (Buerger’s Disease)

Pathology

a nonatherosclerotic, segmental, inflammatory disease affecting small to medium-sized arteries and veins of the upper and lower extremities.

characterized by highly cellular and inflammatory occlusive thrombus.

Patients are young, heavy smokers who present with distal extremity ischemia, digital ulcers or gangrene.

Ultrasound findings

Occlusion of distal tibial arteries and distal radial/ulnar arteries as well as plantar, palmar and digital arteries. Acute ischaemia. Corkscrew appearance of arteries and collaterals.

Absence of atherosclerotic disease proximal to the popliteal or distal brachial artery.

Excluding proximal sources of emboli eg aneurysm or ?cardiac

Exclusion of trauma and local lesions eg entrapment

Thromboangiitis Obliterans – Buerger’s Disease

The prevalence of ischemic ulcers is significantly higher in patients who have small corkscrew patterns in distal segments of limb collaterals…( Y. Fujiiet al Circ J 2010; 74: 1684–1688)

Aortic Dissection

Incidence

2.5 : 6 people per 100 000 people (UK, USA, Iceland)

Prevalence increases over the age of 65.

Male: female ratio 2.5:1

Pathology

Aortic Dissection

Aortic dissection arises from a tear in the aortic intima exposing the medial layer to the pulsatile blood flow.

ascending aorta and descending aorta. Can extend to the abdominal aorta, renal and iliac arteries.

progressive separation of the aortic wall layers results in a false lumen and leads to aortic rupture or by re-entry back into the true lumen through another intimal tear.

Ultrasound diagnosisAortic Dissection

The diagnostic finding is the presence of an intimal flap that separates the true and false lumens.

Visualise in transverse and longitudinal views.

Bidirectional flow in separate channels may be present

NB dissections can occur in carotid and vertebral arteries due to:

a) extension of aortic arch dissectionb) blunt trauma to neck (MVA, sport injuries, strangulation)c) iatrogenic

Carotid body tumour

Incidence

Rare – 1 or 2 people per 100 000.

Majority are female (almost 2:1 ratio) aged 20-60yo

Carotid body tumours can be bilateral in 5% of cases, and in 33% of familial cases.

Carotid body tumourPathology

Carotid body tumours (CBTs) are highly vascular neoplasms originating in the paraganglionic cells of the carotid bifurcation.

cause unknown

studies have shown low partial pressure of the oxygen in the blood increases incidence.

- disease eg respiratory, cardiac- living at high altitude- sleep apnoea

A well-defined solid mass in the neck that may be unilateral or bilateral and at the carotid bifurcation. May widen the bifurcation and splaying the vessels.

Colour Doppler demonstrates significant internal vascularity in about 75% of all carotid body tumours. The feeders usually arise from the ECA.

On spectral analysis, low resistance flow may be detected within the mass.

DSA is the gold standard in CBTs.

Ultrasound findings

Carotid body tumour

Moyamoya DiseaseIncidence

Moyamoya was originally reported in individuals of Japanese ancestry.

Cases have been reported from Korea and China as well as from Europe, North and South America.

In Japan, Moyamoya disease typically occurs in females under the age of 20 and is estimated to occur in 1 per 300,000 people.

two peak incidence periods – between five and ten years in children, and 30 to 50 years in adults.

Moyamoya Disease Pathology

The aetiology and pathogenesis remains unclear.

Progressive stenosis of the intracranial ICA with compensatory formation of an abnormal network of collateral blood vessels at the basal ganglia ("puff of smoke“)

Primary Moyamoya – genetically transmitted and 10% of all cases in Japan.

Secondary Moyamoya – associated with different conditions, including infections of the central nervous system, sickle cell disease, and Down syndrome.

Children have symptoms including stroke, TIAs, headaches, seizures, involuntary movements, or occasionally progressive developmental delay.

Adults have a greater tendency to suffer intracranial haemorrhage.

Extracranial ICA findings:Dampened PSV

High resistant waveforms

Mechanical and compressive arterial conditions

External iliac artery Endofibrosis

Popliteal and anterior tibial artery entrapment

ConclusionThe next step after “What the….!?”Be methodical and start asking questions. A history is essential.What arteries are affected? Are the waveforms normal? Is there

turbulence? Is the direction of flow normal?Thickening of the artery walls or thrombotic looking plaque? Is this normal for their age and risk factors?

Think of possible causes and unusual pathologiesObtain B mode, colour Doppler and Pulsed Doppler imagesAnd then……hit the textbooks, Google and ask colleagues as to

what it could be.

If you cant be definitive with your diagnosis, you can suggest what it might be and state in your report “requires further investigation”.

Thank you for your attention