Vascular Disease (Exam III)- Mordecai (still need to add key points) Flashcards
What are the risk factors for vascular disease?
- Diabetes mellitus
- Dyslipidemia
- Family history
- Hypertension
- Obesity
- Older age: 75 y/o and up
- Smoking (2x)
What is the most common occlusive disease in the lower extremity arteries?
Atherosclerosis
What are three pathophysiologic processes that affect arteries?
- Plaque formation
- Thrombosis
- Aneurysm formation
What are 4 s/s are associated with peripheral occlusive disease?
- Claudication
- Ulcerations
- Gangrene
- Impotence
What are two common causes of vascular aneurysm?
- HTN
- Vascular damage
If a patient is on erectile dysfunction drugs what should we assume?
- That vascular disease is everywhere in the body → thats why they have impotence
In a patient with vascular disease what other issues should we be sure to evaluate in preop? Why does it matter?
- CAD
- pulm dysfunction
- renal dysfunction
- neuro dysfunction
- endocrine dysfunction
- Matters d/t disease process not being limited to arterial beds in periphery → its everywhere
What is the primary goal for invasive monitoring of a vascular surg patient?
To detect cardiac problems; a-line might be necessary
What monitoring should we consider for a vascular surg patient?
Arterial line, PA cath, and TEE are all warranted for assessing CV function
Why are spinals and epidurals controversial for peripheral vascular surgery?
The patients are typically on anticoagulants
What is intermittent claudication?
- When O₂ demand exceeds supply
What can improve “Rest Pain”?
- ↑ hydrostatic pressure; hanging LE over side of bed
What are the three classifications of the Ankle-brachial index?
If ABI is:
- < 0.9 claudication
- < 0.4 rest pain
- < 0.25 impending gangrene
What is the ankle-brachial index (ABI)? How do we calculate it?
- the ratio of the BP at ankle to BP in upper arm
- Ankle SBP / Arm SBP
Treatments for PAD
- Exercise;
- Stop smoking;
- Manage HTN, cholesterol, DM
- Revascularization vs amputation
When might revascularization for PAD be considered?
- Disabling claudication
- Ischemic rest pain
- Impending limb loss
What is the 3rd leading cause of death in the U.S.?
- Stroke
What two types of stroke are there and which is the most common?
- Hemorrhagic and Ischemic;
- 87% are ischemic
How strong is the correlation between TIA and impending stroke?
- 10x more likely than age/sex matched
What are risk factors for stroke?
- Age;
- Atrial fibrillation;
- Black race;
- History/family history;
- HTN/smoking/diabetes;
- Hypercholesterolemia;
- Male;
- Obesity;
- Sickle cell disease
How do we diagnose carotid disease?
- Angiography;
- Carotid bruit;
- Carotid stenosis;
- CTA/MRI
- Transcranial doppler
- Sudden neurological deficits
Where does carotid stenosis most often occur?
Carotid bifurcation
How do we treat an acute ischemic stroke?
- TPA w/in 4.5 hours
- IR: Intra-arterial thrombolysis or thrombectomy
Assess for? Maintain? Head position may do what?
CEA Preop Eval/Considerations
Useful monitoring device?
- Assess neuro defecits, cardiovascular disease
- Maintain collateral blood flow
- Head position may compress contralateral blood flow
- Cerebral oximetry devices usefule
What are some cardiac specific changes that can occur from aortic cross clamping?
- Acute ↑↑↑ LV afterload and severe HTN;
- Myocardial ischemia;
- LV failure;
- Aortic valve regurg
What are some critical perfusion specific changes that occur with cross-clamping of the aorta?
- Compromises organ perfusion distal to point of occlusion;
- Interrupts BF to spinal cord and kidneys → can result in paraplegia and renal failure
What can happen after the aortic clamp is released and why? How do we prevent this?
- Patient might become hypotensive d/t blood loss and not having enough volume to fill system when clamp is released;
- Volume loading can help
What are the two types of coarctation of the aorta? How are they classified?
- pre-ductal (infant);
- post ductal (might not know until adult);
- Classified according to relative position of ductus arteriosis
Related to aortic surgery, how will we know if cardiopulmonary bypass is required?
- Lesions involving the ascending and transverse aorta require bypass
Describe each of the DeBakey classifications
- DeBakey I → Dissection in the ascending aorta that extends into the descending aorta; emergency
- DeBakey II → Dissection in the ascending aorta that does notextend into the descending aorta; emergency
- Debakey III → Dissection in the descending aorta distal to left subclavian
- Debakey IIIA → extension to abdominal aorta;
- Debakey IIIB → doesn’t extend to abdominal aorta
S/S? Emergency surgery indicated when?
What is an aortic dissection?
- Tear in intimal layer of the vessel allowing blood to enter the medial layer
- S/s: Severe, sharp pain in posterior chest or back
- Ascending dissection is catastrophic & requires emergency surgery
Stanford classification Type A converts to DeBakey how?
- Stanford Type A = DeBakey I and II
Which dissecting aortic lesions have the highest incidence of rupture?
- Ascending lesions
What is a “True” aneurysm? What is a “False” aneurysm?
- True → Involves dilation of all 3 layers of the vessel wall;
- False → Caused by disruption of 1 or more layers of the vessel wall
What are the 3 layers of a vessel wall?
- Tunica externa (outer);
- Tunica Media (middle);
- Tunica interna (inner)
What are some important complications of AAA to know?
- Depending on site:;
- aortic regurg;
- tracheal or bronchial compression or deviation;
- hemoptysis;
- superior vena cava syndrome
When does a pseudoaneurysm form?
- when the intima and media are ruptured andonly the adventitia or blood clotform the out layer of the vessel
Thromboembolic occlusion of the aorta is most commonly due to what?
- atherosclerosis;
- Combo of atheroslerotic plaque and thrombosis
How do we treat thromboembolic occlusion of the aorta?
- Aorto-bifemoral bypass;
- Possible proximal thromboendarterectomy
What are the two types of aortic trauma? What diagnostic shows you that bleeding is occurring?
- Penetrating or non-penetrating injury;
- CXR with wide mediastinum indicates bleeding
What are risk factors for aortic aneurysm/dissection?
- HTN
- Atherosclerosis
- Fam hx of aneurysm
- Cocaine
- Inflammatory diseases
Why is Marfans syndrome prone to causing aneurysms?
- Vasculature can’t keep up with the increased size of patients with the syndrome
What are the two classes of aortic aneurysms?
- Saccular → eccentric dilation; berry shaped bulge to one side
- Fusiform → uniform dilation along entire circumference of aorta
Which class of aneurysm often occurs at the renal arteries?
- Fusiform
How do we diagnose aneurysms/aortic dissections?
- CXR;
- TEE;
- Angiogram
- Echocardiogram
What famous artery perfuses the anterior spinal artery?
- Artery of Adamkiewicz or the greater radiculmedullary artery
If you notice a patient has a pulsatile abdominal mass on exam what would you suspect?
- Abdominal aneurysm → common in people > 60 y/o
How might we diagnose an abdominal aneurysm?
- Abdominal ultrasound;
- Helical CT - to see if endovascular repair is feasible;
- MRI
Triad of symptoms? Where do they often rupture (AAA)?
Aortic Aneurysm Rupture
Volume resusc is deferred until when?
- Hypotension;
- Back pain;
- Pulsatile mass;
- S/Sx only present in 50% of patients
- Most abdominal aneurysms rupture into left retroperitoneum
- Exsanguination is sometimes prevented by clotting in the retroperitoneum
- Volume resuscitation is often deferred until rupture is surgically repaird
What is the most common location that the Artery of Adamkiewicz arises?
- T9-T12 (60% of people) → almost always on the left side
How do we calculate spinal cord perfusion pressure?
- Spinal Perf Pressure = MAP - SCP
How might we monitor for paraplegia when doing a case with aortic cross clamping?
- SSEP
What are some protective therapeutic measures we can take before the surgeon cross clamps the aorta?
- Methylprednisolone;
- Mild hypothermia;
- Mannitol (0.5g/kg);
- Renal dose dopamine (1-3 mcg/kg/min);
- Fenoldopam (0.05-0.1 mcg/kg/min);
- Maintain BP;
- Drainage of CSF
With a suspected dissection of aortic aneurysm, what is the fastest/safest way to diagnose?
Doppler echo
Medically manage what other conditions? Avoid what?
Aortic Aneurysm Treatment
Surgery indicated when?
- Medical management to decrease expansion rate
- Control BP, cholesterol, stop smoking
- Avoid strenuous activity, stimulants, stress
- Surgery indicated >5.5cm, growth >10mm in a year, or family history of dissection
Common procedures to treat this?
Stanford A Dissection- Ascending Aorta
- Dissection of ascending aorta
- Almost always emergent surgery
Common Procedures
* Ascending aorta & aortic valve replacement w/ composite gaft
* Replacement of the ascending aorta & resuspension of aortic valve
Surgery requires? Common complication?
Stanford A Dissection- Aortic Arch
- Acute aortic arch dissection
- Resection of the aortic arch is indicated
- Surgery requires:
1. cardiopulmonary bypass
2. profound hypothermia (15-18 C)
3. period of circulatory arrest (30-40mins)
Neurologic complications are common
Surgery is indicated when?
Stanford B Dissection- Descending Thoracic Aorta
- Can be treated medically if uncomplicated, normal hemodynamics, no periaortic hematoma, and no branch vessel involvement
- Surgery is indicated when there are signs of impending rupture (pain, hypotension, L. Side hemothorax), ischemia of legs, abdominal viscera, spinal cord, and/or renal failaure
Inherited disorders predisposing someone to aortic aneurysm/dissection?
- Marfans
- Ehlers-Danlos
- Bicuspid aortic valve
Causes of Aortic Dissection
- Blunt trauma
- Cocaine
- Iatrogenic: Cardiac cath, aortic manipulation, cross-clamping the aorta
More common in men and women in 3rd trimester
Four primary causes of mortality related to thoracic aorta surgeries:
- MI
- Respiratory Failure; smoking & COPD are risk factors
- Renal failure
- Stroke
Assess for what? What condition requires intervention ahead of time?
Pre-op eval for aortic surgeries
Tests that should be ordered?
- Assess for CAD, valve dysfunction, heart failure
- Ischemic heart disease may require intervention prior to aurgery
- Stress test, echo, PFTs, ABGs
- Severe reduction in FEV1 or renal failure can disqualify a pt from AAA resection
Pre-op renal dysfunction is the most important indicator of what?
Post-aortic surgery renal failure
* Pre-op hydration
* Avoid hypovolemia, HoTN, low CO
* Avoid nephrotoxic drugs
What is anterior spinal artery syndrome?
- Caused by lack of blood flow to the anterior spinal artery
- Anterior spinal artery is responsible for perfusing 2/3rds of the spinal cord
- Most common form of spinal ischemia because the anterior spinal artery has minimal collateral perfusion
Ischemia of anterior spinal artery leads to…?
- Loss of motor function below infarct
- Diminished sensation below infarct
- Autonomic dysfunction leading to HoTN
- Loss of bowel and bladder function
Common causes of anterior spinal artery syndrome:
- Aortic aneurysm
- Aortic dissection
- Atherosclerosis
- Trauma
- Cross-clamping
Treatment of carotid disease:
- CEA: Surgical treatment for carotid stenosis (70% blockage or lumen diameter >1.5mm)
- Carotid stent: Major risk of microembolization leading to CVA
Ongoing Medical Management of CVA
- Antiplatelet
- Stop smoking
- BP control
- Cholesterol control
- Diet
- Exercise
Peripheral Artery Disease
- Compromised blood flow to the extremities typically due to atherosclerosis
- Defined by ankle-branchial index <0.9
- Diagnose w/ doppler, venous duplex, MRI
PAD Risk Factors
- Age
- Family hx
- Smoking
- DM
- HTN
- Obesity
- Cholesterol
S/S of PAD
- Intermitten claudication
- Extremity pain at rest
- Decreased pulses
- Sub-Q atrophy
- Hair loss
- Cool skin
- Cyanosis
Common causes? S/S? Tx?
Acute Artery Occlusion (PAD)
- Common causes: thrombus from L atrium or L ventricle
- S/s: Pain, paresthesia, weakness, loss of peripheral pulse, color changes distal to occlusion
- Tx w/ embolectomy, anticoags, amputation
SBP is changed how? Treatment?
Subclavian Steal Syndrome
- Occluded subclavian artery causing vertebral artery blood flow to be diverted away from the brainstem
- Effected arm SBP may be ~20mmHg lower
- Bruit over SCA
- Subclavian endarterectomy
Raynaud’s
- Vasospasic ischemia of digits
- Effects women>men
- May appear w/ CREST syndrome
- Avoid cold, CCB, alpha-blockers
- Surgical sympathectomy for severe ischemia
Common types, virchows triad
PVD
Why regional?
- Superficial thrombophlebitis
- DVT
- Chronic venous insufficiency
Regional anesthesia greatly decreases risk of superficial thrombophlebitis & DVT (earlier post-op ambulation)
Virchow’s Triad:
* Venous stasis
* Hypercoagulability
* Disrupted vascular endothelium
Systemic Vasculitis
- Diverse group of systemic vascular inflammatory diseases
- Often categorized by the size of the vessels primarily involved
-Large, medium, medium to small
What is it? S/S? Can lead to what? Tx? Dx?
Temporal (Giant Cell) Arteritis
- Large-artery vasculitis
- Inflammation of arteries in head and neck
- S/S: Unilateral: HA, scalp tenderness, jaw claudication
- Can lead to unilateral blindness/ischemic optic neuritis if opthalmic artery branches are involved
- Tx w/ corticosteroids
- Dx: Biopsy of temporal artery will show arteritis
What is it? Dx criteria & Dx? Tx?
Thromboangiitis Obliterans “Buerger Disease”
- Inflammatory vasculitis leading to small & medium vessel occlusions in extremities
- Auto-immune response triggered by nicotine
- Tobacco use is triggering factor
- Men <45 years old
- Dx Criteria:
-H/o smoking
-onset before 50
-upper limb involvement
-Infrapopliteal arterial occlusive disease
-Absent for atherosclerosis other than tobacco use - Tx: stop smoking, surgical revasc
- Dx: Biopsy of vascular lesions
Thromboangiitis Obliterans- Anesthesia Implications
- Positioning/padding
- Avoid cold
- Non-invasive BP
- Conservative line placement
Can be associated w? Inflammation causes what? Primary cause of death?
Polyarteritis Nodosa
Treatment
- Small-medium artery
- Anti-neutrophil cytoplasmic antibody (ANCA) negative vasculitis
- Can be associated with Hep. B, C, or hairy cell leukemia
- Inflammation results in glomerulonephritis, myocardial ischemia, peripheral neuropathy, seizures, HTN
- Renal failure is primary cause of death
- Tx: Steroids, cyclophosphamide, tx underlying cause
Caused by? S/S? Dx
Lower Extremity Chronic Venous Disease
- Caused by standing (forever) resulting in venous dilation and reflux
- Effects 50% of the population
- S/s:
-Mild: Telangectasias, varicose veins
-Severe: Edema, skin changes, ulceration - Risk factors are obvious except for ligamentous laicity
- Dx criteria: Leg pain, heaviness, fatigue
- Confirmed by US showing venous reflux
- Retrograde blood flow >0.5 seconds
Conservative & meds
Lower Extremity Chronic Venous Disease Treatments
Conservative:
* Elevate legs
* Compression
* Emollients
* Wound care
* Exercise
Meds
* Diuretics
* ASA
* ABX
* Prostacyclins
* Zinc sulphate
Lower Extremity Chronic Venous Disease: Ablation Types & C/I
- Thermal ablation w/ laser
- Radiofrequency ablation
- Endovenous laser
- Sclerotherapy
- Pregnancy
- Thrombosis
- PAD
- Limited mobility
- Congenital venous abnormalities
Lower Extremity Chronic Venous Disease: Surgery
- Usually last resort
- Saphenous vein inversion
- High saphenous ligation
- Ambulatory phlebectomy
- Transilluminated-powered phlebectomy
- Venous ligation
- Perforator ligation
