27 Vascular Flashcards
Most common congenital hypercolaguable disorder?
Resistance to activated protein C (Factor V leiden)
Most common acquired hypercoagulable disorder?
Smoking
Stage 1 of atherosclerosis
Foam cells
Macrophages that have absorbed fat and lipids in the vessel wall
Stage 2 of atherosclerosis
Smooth muscle proliferation
Caused by growth factors released from macrophages (PGDF)
Results in wall injury
Stage 3 of atherosclerosis
Intimal disruption (from smooth muscle cell proliferation) Leads to collagen exposure --> thrombus formation --> fibrous plaques
Risk factors for atherosclerosis
Smoking HTN Hypercholesterolemia DM Hereditary factors
Most important risk factor for stroke?
HTN
Most common site of carotid stenosis?
Carotid bifurcation
Carotids supply ____ of blood flow to brain?
85%
What is the normal flow of the internal carotid?
Continuous forward flow
What is the first branch of the internal carotid artery?
Ophthalmic artery
What is the normal flow of the external carotid?
Triphasic flow
Communication between the ICA and ECA occurs via?
Opthalmic artery (ICA) Internal maxillary artery (ECA)
Most commonly diseased intracranial artery?
Middle cerebral artery
MCC of cerebral ischemic events?
Arterial embolization from ICA
Others:
- Thrombosis
- Low-flow state through a severely stenotic lesion
- Emboli from heart (second most common source)
Arterial source of event?
Mental status changes, release, slowing
Anterior cerebral artery
Arterial source of event?
Contralateral motor and speech if dominant side)
Contralateral facial droop
Middle cerebral artery events
Arterial source of event?
Vertigo, tinnitus, drop attacks, incoordination
Posterior cerebral artery
Visual changes - shade coming down over eyes
Hollenhorst plaques on ophthalmologic exam
Amaurosis fugax
Occlusion of the ophthalmic branch of ICA
Transient
Treatment of carotid traumatic injury with major fixed deficit?
If occluded - do NOT repair (can exacerbate injury with bleeding)
If not occluded - repair with carotid stent or open procedure
Indications for carotid endarterectomy
Symptomatic >70% stenosis
Asymptomatic >80% stenosis
When do you perform a CEA after a stroke?
Wait 4-6 weeks and then perform CEA if it meets criteria
When do you perform an emergent CEA?
Fluctuating neurologic symptoms
Crescendo/evolving TIA
When do you need to use a shunt during CEA?
Stump pressures < 50
Contralateral side is tight
With bilateral carotid artery stenosis - how do you decide which side to repair first?
Repair tightest side first
If they are equally tight - dominant side first
Complication after CEA: hoarseness
Vagus nerve injury
Secondary to vascular clamping
MC cranial nerve injury after CEA
Vagus nerve injury
Complication after CEA: speech and mastication difficulty
Hypoglossal nerve injury
Tongue deviates to the side of injury
Complication after CEA: Difficulty swallowing
Glossopharyngeal nerve injury
Rare - occurs with high carotid dissection
Complication after CEA: Loss of innervation to strap muscles
Ansa cervicalis
No serious deficit
Complication after CEA: Changes in the corner of the mouth, difficulty smiling
Mandibular branch of facial nerve
Complication after CEA: Acute event immediately after CEA, what do you do?
Back to OR
Check for flap or thrombosis
Complication after CEA: Pulsatile, bleeding mass
Pseudoaneurysm
Tx: drape and prep before intubation
Intubate, then repair
Complication after CEA: Hypertension
Injury to carotid body
Tx: Nipride to avoid bleeding
MCC cause of non-stroke morbidity and mortality following CEA?
Myocardial infarction
Rate of restenosis after CEA
15%
Indications for carotid stenting (versus CEA)
Previous CEA with restenosis
Multiple medical comorbidities
Previous neck XRT
Anatomy of the vertebrobasilar artery system
Subclavian arteries –> vertebral arteries –> combine –> basilar artery –> splits –> posterior cerebral arteries
Source of arterial deficit:
Diplopia, vertigo, tinnitus, drop attacks, incoordination
Basilar artery or bilateral vertebral artery disease - vertebrobasilar insufficiency
Causes: atherosclerosis, spurs, bands
Tx: PTA with stent
Painless neck mass, near carotid bifurcation
Carotid body tumor
Origin - neural crest cells
Extremely vascular
Tx: resection
Aortic arch vessels antomy
Innominate artery (–> right subclavian and right common carotid artery)
Left common carotid artery
Left subclavian artery
Ascending aortic aneurysm
Often picked up on CXR
Sx are due to compression: back pain (vertebra), voice changes (RLN), dyspnea/PNA (bronchi), dysphagia (esophagus)
Indications for treatment of ascending aortic aneurysm?
Acutely symptomatic
>5.5cm (with Marfan’s >5.0cm)
Rapid increase in size (>0.5 cm/yr)
Indications for treatment of descending aortic aneurysm?
If endovascular repair possible >5.5cm
If open repair needed >6.5cm
How do you prevent paraplegia with open repair for a descending aortic aneurysm?
Reimplant intercostal arteries below T8
Stanford classification: any ascending aortic involvement?
Class A
Stanford classification: only descending aortic involvement?
Class B
Debakey classification: ascending and descending
Type I
Debakey classification: ascending only
Type II
Debakey classification: descending only
Type III
Where do most dissections start?
Ascending aorta
Risk factors for aortic dissection?
Severe HTN
Marfan’s syndrome
Previous aneurysm
atherosclerosis
Diagnosis of aortic dissection?
Chest CT with contrast
Where does dissection occur within the blood vessel?
Medial layer of the wall
Cause of death in ascending aortic dissection?
Cardiac failure secondary to aortic insufficiency, cardiac tamponade or rupture
Initial treatment of aortic dissection?
Medical - control BP (B-blockers and Nipride)
Surgical intervention for aortic dissection?
All ascending (open repair, graft) Descending if: visceral/extremity ischemia, contained rupture (endograft, open repair, fenestrations) Follow with lifetime serial MRI
Most common complications for thoracic aortic surgery?
MI
Renal failure
Paraplegia (descending)
Cause of paraplegia after descending thoracic aorta ?
Spinal cord ischemia due to occlusion of intercostal arteries and artery of Adamkiewicz
Normal aorta diameter?
2-3cm
Cause of abdominal aortic aneurysm?
Degeneration of the medial layer
Risk factors for AAA?
Male, age, smoking, family history
Presentation of AAA?
Rupture
Distal embolization
Compression of adjacent organs
How do you diagnose AAA rupture?
US Abdominal CT (fluid in retroperitoneal space and extraluminal contrast)
Most likely location for AAA rupture?
Left posterolateral wall, 2-4cm below renals
Co-morbid medical conditions that can lead to AAA expansion?
HTN
COPD
Treatment of AAA?
Repair if:
Symptomatic
>5.5cm
Growth >0.5cm/year
Indications for reimplantation of inferior mesentaric artery in AAA repair?
If back pressure is <40mmHg (poor back bleeding)
Previous colonic surgery
Stenosis at the superior mesenteric artery
Flow to left colon appears inadequate
If you perform an aorto-bifemoral repair instead of a straight tube graft for AAA repair, what must you ensure?
Flow to at least one internal iliac artery (hypogastric artery) to avoid vasculogenic impotence
What major vein can get injured with cross clamping of the aorta?
Rero-aortic left renal vein
MCC of acute death after AAA repair?
MI
MCC of late death after AAA repair?
Renal failure
Risk factors for mortality after AAA repair?
Creatinine >1.8 CHF EKG ischemia Pulmonary dysfunction Older age Female
AAA graft infection rate
1%
Incidence of pseudoaneurysm formation after AAA repair?
1%
MCC late complication after aortic graft placement?
Atherosclerotic occlusion
Bloody diarrhea after AAA repair?
Ischemic colitis
IMA typically sacrificed - left colon most common
Dx: endoscopy or abdomianl CT (middle and distal rectum)
OR if: peritoneal signs, mucosa is black on endoscopy, part of colon looks dead on CT
Ideal criteria for AAA endovascular repair?
Neck length >15mm Neck diameter 20-30mm Neck angulation <60 degrees Common iliac artery length >10mm Common iliac artery diameter 8-18mm Non-tortuous, noncalcified iliac arteries Lack of neck thrombus
Endoleak - at site of proximal or distal graft attachment
Type I endoleak
Tx: extension cuffs
Endoleak - through collaterals
Type II endoleak
Tx: Observe - if vessels are pressurizing the aneurysm –> perutaneous coil emolization
Endoleak - via overlap sites when multiple grafts were used or fabric tear
Type III endoleak
Tx: Secondary endograft to cover overlap site or tear
Endoleak - via graft wall porosity or suture holes
Type IV endoleak
Tx: observe - can place nonporous stent if that fails
Endoleak - expansion of aneurysm without evidence of leak
Type V - endotension
Tx: repeat EVAR or open repair
Inflammatory aneurysm
NOT due to infection
Can get adhesion in 3/4th porttion of the duodenum
Can get ureteral entrapment (place stents before repair)
Wt loss, increased ESR
CT scan shows thickened rim above calcifications
Inflammatory process resolves after aortic graft placement
Mycotic aneurysm
Salmonella, Staphylococcus
Bacteria infects atherosclerotic plaque
Pain, fever, positive blood cultures
Periaortic fluid, gas, retroperitoneal soft tissue edema, LAD
Need extra-anatomic bypass and resection of infrarenal abdominal aorta to clear infection
Aortic graft infections
Staphylococcus, E. Coli
Fluid, gas, thickening around graft
Blood cultures negative
Tx: bypass through non-contaminate field and then resect infected graft
Most common graft to get infected?
Those going to the groin
Aortoenteric fistula
Occurs 6mo after abdominal aortic surgery
Herald bleed with hematemesis, then blood per rectum
Graft erodes into 3/4th portion of the duodenum near proximal suture line
Tx: bypass through non-contaminate field, resect graft, then close hole in duodenum
Contents of the anterior leg compartment
Deep peroneal nerve (dorsiflexion, sensation b/t 1/2nd toes)
Anterior tibial artery
Contents of the lateral leg compartment
Superficial peroneal nerve (eversion, lateral foot sensation)
Contents of the deep posterior leg compartment
Tibial nerve (plantar flexion)
Posterior tibial artery
Peroneal artery
Contents of the superficial posterior leg compartment
Sural nerve
Signs of peripheral artery disease
Pallor
Dependent rubor
Hair loss
Slow capillary refill
Most commonly due to atherosclerosis
Number one preventive agent of atherosclerosis?
Statin drugs
Medical treatment of claudication
ASA
Smoking cessation
Exercise until pain occurs to create collaterals