Uncommon Disorders Affecting the Carotid Arteries Lana Schumacher

Uncommon Disorders Affecting the Carotid Arteries Lana Schumacher, M. D. Surgery Resident 5/22/06

Uncommon Carotid Disorders • • • Carotid Kinks and Coils Carotid Body Tumors Carotid Sinus Syndrome Carotid Dissection Vasculitis Moyamoya

Carotid Artery Kinks & Coils • First described by anatomists in 1700 s • Fatal hemorrhage after injury to tortuous carotid arteries after tonsillectomy described in 1900 s • Most are incidental findings with no clinical significance • Some produce cerebrovascular symptoms due to angulation • Excessively long Carotid

Carotid Artery Kinks & Coils • Congenital (usually bilateral ~50%) – Faulty descent of heart and great vessels – Excessive lengthening of carotid as cervical spine elongates • Aquired (usually unilateral) – Carotid elongates with age – Elderly with atherosclerosis, thinning of media, fragmenting of elastic lamina, plaques that fix vessel – Fascial band • ICA is usually affected – S shape, single, double complete loops have all been described – Acute angle/kinks often are associated with plaque or stenosis • Kinks - Women: Men - 4: 1 • Incidence?

Carotid Artery Kinks & Coils – Clinical Presentation • Coils and loops – don’t obstruct therefore usually asymptomatic • Kinks – luminal narrowing, intimal ulceration, embolization – TIAs, strokes, amaurosis fugax – Symptoms can be caused by head turning • Diagnose – four-vessel cerebral arteriography – Perform in position that produces symptoms

Treatment of Coils & Kinks • Tethering – inadequate • Long-Patch Angioplasty • Resection and reanastomosis of portion of common carotid

Treatment of Coils & Kinks • ICA resection and reanastomosis • ICA resection and Saphenous Vein interposition • ICA reimplantaion to CCA • Results – 80% asymptomatic, 5% perioperative stroke and mortality rate

Carotid Body Tumors • Carotid Body – First described in 1743 by Von Haller – Chemoreceptor at the bifurcation of the CCA in the posterior medial adventitia • Responds to hypoxia, hypercapnia, acidosis • Increases RR, TV, HR, BP – Blood supply from ECA – Neural crest cells from the 3 rd Branchial arch – Tumors are “Paraganglionomas” or “Chemodectomas”

Carotid Body Tumors • Characteristics – Highly vascular, blood supply from ECA – Very rare, usually 5 th decade of life – Classified as Chromaffin positive (catecholamines) and nonchromaffin cells – 5% are functional causing Htn – Sporadic – 5% bilateral – Familial – autosomal dominant, 32% bilateral – Malignancy rates 2 -50% • metastatic rate 5% - LN, kidney, thyroid, pancreas, lungs, brain bone brachial plexus, abdomen, breast

Carotid Body Tumors • Group I -relatively small tumors, minimally attached to the carotid vessels; surgical excision is not difficult • Group II - larger, moderate attachments; resectable but many require a temporary intraluminal carotid shunt • Group III - very large neoplasms encasing the carotid arteries; often require arterial resection and grafting * Well circumscribed, rubbery, reddish brown

Clinical presentation and diagnosis • Most common presentation - Painless swelling in neck at angle of mandible • Neck or ear pain, local tenderness, hoarse, dysphasia, tinnitus • If functional – symptoms of dizziness, flushing, palpitations, tachycardia, arrhythmias, headache, diaphoresis, photophobia • Bruit if tumor is impinging the artery • Diagnosis – • Duplex scan – highly vascular mass at bifurcation • Angiography – gold standard • CTA, MRA – size and extent of tumor • Avoid FNA – massive hemorrhage, pseudoaneurysm, carotid thrombosis

Treatment of Carotid Body Tumors • Complete surgical excision • Radiation – – results unsatisfactory – Usually for local control of residual or recurrent disease • Chemotherapy – no role • Large tumors – Remove from inferior to cephalad – Sublux TMJ, divide digastric – Transmural invasion - resection of artery, saphenous vein graft, shunts • Incidence of cranial nerve injury 20 -40% • Stroke rates ~5% • 6% develop recurrence after complete resection

Carotid Sinus Syndrome (CSS) • Carotid Sinus – Located at distal end of CCA at bifurcation – Area of dilation – tunica media is thinner & adventitia is thicker – Baroreceptor • Increase P – reflex bradycardia, decrease BP

Carotid Sinus Syndrome (CSS) • Carotid Sinus Syndrome – Carotid sinus hypersensitivity leading to syncope – Sudden onset of bradycardia & hypotension – Pathophysiology is unknown – Occurs in elderly, M>W – Associated with atherosclerosis, DM, Htn, CAD – Cause of <1% of syncope – Syncope precipitated by head movement in ½ of patients • Treatment – Discontinue antihypertensives if possible – Carotid body denervation is not recommended – Cardiac pacemakers

Carotid Artery Dissection • Dissection – intimal disruption, extravasation of blood into arterial wall • Stenosis, occlusion, aneurysm (late complication) • Blunt Trauma – MVA, fist fights, falls, direct trauma, hanging – Hyperextension, rotation – stretching of ICA against transverse processes of C 2 -3 • Spontaneous dissections – Marfans, FMD

Mechanisms of Injury • • Tear is usually 2 -4 cm from the bifurcation – stops at entrance into the carotid canal Hyperextension & rotation of head – Compression by first cervical vertebrae, TP of C 23 • Extreme flexion – Compression of mandible and TP C 2 -3 – Fracture or posterior dislocation of mandible

Diagnosis & Treatment • • • Symptoms – pain, unilateral headache (anterior head, orbit, periorbital), neck pain – TIAs, stroke in 1/3 -3/4 – Oculosympathetic paresis – occurs minutes to days after onset of headache • Incomplete Horner’s syndrome (facial sweating unaffected) – Palsies – slurred speech, dysphagia Diagnosis – Duplex or angiography Treatment – Anticoagulate – 3 -4 months, then antiplatelet 3 -4 months • Repeat angiography in 2 months – Surgery if medical therapy fails – thrombectomy, intraluminal dilation, endarterectomy, intimectomy, graft interposition – Carotid ligation if recurrent emolization

Radiation-Induced Carotid Arteritis and Stenosis • Two patterns of disease 1. Luminal occlusion – 7 -24 years after radiation – Pathophysiology – plaque-like thickening of intima, fibrosis of media and adventitia – Can lead to accelerated athlerosclerosis 2. Arterial Disruption – Usually after primary resection of tumor followed by radiation – Associated with tissue infection/wound breakdown

Radiation-Induced Carotid Arteritis and Stenosis – When to Operate? • Transmural radiation damage – • Recommend bypass graft of diseased segments Late presentation – usually accelerated atherosclerosis – – Endarterectomy – technically more difficult due to periarterial fibrosis and strong adherence of plaque to vessel wall Sometimes segmental resection and reconstruction is required due to wall attenuation v Important to consider life expectancy, healing of irradiated tissue/infection

Radiation-Induced Carotid Arteritis and Stenosis – When to Operate? • Carotid artery rupture – Poor prognosis – Present with sentinel bleed then exsanguinating hemorrhage – Prompt surgical exploration, carotid ligation or EC-IC bypass

Vasculitis • Inflammatory process resulting in necrosis of structural elements of vessel wall • Obliteration of lumen leads to ischemia • Variable course and variable presentation • No definitive lab tests or clinical signs • Primary or secondary due to underslying disease • Women usually > men 2: 1 • Vasculitis cannot be excluded based on negative angiogram

Giant Cell Arteritis • • Affects medium and large arteries Elderly women Usually presents as temporal arteritis Can affect aortic arch and extracranial carotid arteries • findings include disruptions of elastic lamina and media, granulomatous degeneration • Lesions are short and segmental with normal artery between lesions

Temporal Arteritis • Involves branches of external carotid artery – especially superficial temporal arteries, posterior ciliary, ophtalmic arteries • Flu-like syndrome, low-grade fever, Headache, scalp tenderness, jaw claudication, visual changes (amaursosis fugax, diplopia, permanent visual loss) • ESR may be elevated • vessels can be tender to palpation, cordlike and difficult to compress • Sudden and complete visual loss in 62% – Loss of blood supply to ophthalmic artery – Can progress to blindness in less than 24 hrs

Temporal Arteritis • Diagnosis – 4 -7 cm biopsy – Biopsy contralateral artery if first biopsy is negative – (14% incidence of positive contralateral biopsies) • Treatment – – “medical emergency” – start steroids immediately – Prognosis is good if treated expeditiously and does not influence life expectancy

Takayasu’s Arteritis • “Pulseless Disease” • “Obliterative brachiocephalic Arteries” – Margagni (1761) • “autopsy findings in a 40 yo F with absent radial pulses, thickened proximal aorta, lower thoracic aortic stenosis, cardiac hyperthrophy and pulmonary edema – Takayasu (1908) • “young Japanese woman with progressive visual loss, vertigo, syncope, conjunctival injection, retinal arteriovenous anastomoses, alopecia” • Occurs in all races and age groups, women 2 nd-3 rd decades • Involves the aortic arch and great vessels • Cerebral ischemia is the most life-threatening complications – Can involve more distal aortic segments as well as pulmonary and coronary arteries

Classifications of Takayasu’s Type III Type IV • 20 -40% • 50 -65% • 10% • Arch + great vessels • Mid Aortic – involving distal thoracic and abdominal • Both Arch and abdominal aorta • Pulmonary Arteries • Mesenteric ischemia, renal artery stenosis • Cerebrovascular, lower extremity symptoms, htn • Cerebrovascular insufficienty, visual abnormalities

Clinical Presentation • Phase I – Prodrome of “malaise, anorexia, fatigue, weight loss, anemia, myalgias, fevers, night sweats” • Phase II – Inflammation of blood vessels – discomfort • Phase III – Symptoms of ischemia depending on location • TIAs, visual impairment – diplopia, amaurosis fugax, blurred vission, stroke, effort fatigue of upper extremities • Renovascular hypertension, mesenteric ischemia, lower extremity insufficiency • Pulmonary hypertension, dyspnea on exertion, pleuritic chest pain – Arterial stenosis, embolization, occlusion, aneurysm

Diagnosis of Takayasu’s • High index of suspicion • ESR elevated in inflammatory phase • Angiography – Stenosis, occlusion of proximal extracranial cerebral arteries

Treatment of Takayasu’s • Course is unpredictable – Prognosis can be dependent on the presence of complications and severity of disease – Death usually due to CHF, stroke, MI, Renal failue – 5 year survival rate 55 -98% • Steroids and anti-inflammatories – high dose, then taper – may be on steroids for many years • Cyclophosphamide – if no response to steroid after 3 months • Long-term anticoagulation

Surgery for Takayasu’s • Surgery required in up to 1/3 of patients with chronic advanced Takayasu’s • Surgery should be delayed past active phase • Transmural disease with all layers – endarterectomy or patch angioplasty is not recommended – Interposition graft • Multiple operations are required • Close postoperative surveillance due to frequent development of anastomotic stenosis in first 1 -2 years

Moyamoya • Rare cerebrovacular disorder leading to progressive stenosis in the arteries of the circle of Willis • Ischemic strokes in children • Hemorrhages in adults • Described by Takeuchi & Shimizu in 1957 – “bilateral hypogenesis of the ICAs” – Moyamoya = “puff of smoke”

Moyamoya • Cause is unknown • Episode of infection/URI is frequently antecedent • Does not affect large vessels • Begins with carotid artery in cavernous sinus and progresses • Familial cases and higher incidence in Down Syndrome

Presentation of Moyamoya • Biphasic age – 1 st & 4 th decades • Female to male 1: 5 • Children – ischemic sx, TIAs, stroke – Induced by crying, coughing, straining, seizures – Mortality 4% • Adults – hemorrhage usually into ventricles, thalamus, basal ganglia – Worse prognosis - Mortality 10%

Diagnosis of Moyamoya • CT or MR – dilated abnormal vessels in basal ganglia, thalamus, occlusion/narrowing of circle of Willis, infarct or hemorrhages • stage I -stenosis of the carotid artery at its suprasellar portion, usually ccurring bilaterally. • stage II, narrow carotid, and moya vessels at the base of the brain. • stage III, abnormal moya vessels become more prominent as major arteries in the anterior circulation, severely stenotic or occluded; at this stage, the diagnosis is usually confirmed • stage IV, the moya vessels extend to all components of the circle of Willis, including the posterior cerebral arteries. • stage V, the moya vessels begin to diminish. • stage VI, they disappear completely and cerebral hemisphere receives blood through abnormal ECIC anastomoses •

Treatment of Moyamoya • Superficial temporal artery to middle cerebral artery anastomosis • “Encephaloduroarteriosynangiosis” – suturing of superficial temporal artery along the longitudinal dural defect to approximate the artery to the brain surface • “Encephalomyosynangiosis” – suture temporalis muscle to surgical dural defects – Indirect anastomosic procedures to allow neovasculariztion from extracranial arterial and soft tissue systems to the ischemic brain