Vascular Disease (Exam IV)-Mordekai Flashcards
What are the 3 main arterial pathologies for vascular disease?
- Aneurysm
- dissection
- occlusion
What type of vascular is more likely to be affected by aneurysms and dissections?
The aorta and its branches
What type of vasculature is more likely to be affected by occlusions?
peripheral arteries
What is an aortic aneurysm?
*A bulge in a section of the aorta caused by an underlying weakness in the aortic wall.
* Dilation of all 3 layers of an artery leading to a >50% increase in diameter.
* Symptoms may be due to compression of surrounding structures.
When is surgery indicated for an aortic aneurysm?
- When it is >5.5 cm in diameter
- When there has been >10mm of growth per year
- When there is a family history of dissection.
What is the mortality rate if an aortic aneurysm ruptures?
75%
How is an aortic aneurysm treated?
- Medical management to decrease expansion rate (initial treatment)
- Manage BP, cholesterol, and smoking cessation
- Avoid strenuous exercise, stimulants, and stress
- Routine/regular monitoring for progression of aneurysm.
- Proceed to surgery if aneurysm is >5.5cm, there has been growth of >10mm in a year, or there is a family history of dissection.
- Endovascular stent repair.
True/False
Endovascular stent repair has become the mainstay over open surgery with graft in the treatment of an aortic aneurysm.
True
What are the 2 types of aortic aneurysms?
- Fusiform
- Saccular
What is a fusiform aortic aneurysm?
Uniform dilation along the entire circumference of the arterial wall.
What is a saccular aortic aneurysm?
A berry shaped bulge to one side of the aorta.
What are the S/S of an unruptured (Fusiform or Saccular) aneurysm?
A symptomatic or pain due to surrounding compression.
How can an aortic aneurysm be diagnosed?
- CT
- MRI
- Chest x-ray
- Angiogram
- Echocardiogram
What is the fastest and safest tool used to diagnose a suspected aortic aneurysm dissection?
Doppler echocardiogram
- What is an aortic dissection?
- What are the S/S?
- How is it diagnosed?
- A tear in the intimal layer of the vessel causing blood to enter the medial layer of the aorta.
- S/S - severe sharp pain in the posterior chest or back.
- Diagnosis - Stable = CT. MRI, chest x-ray, angiogram. Unstable = echocardiogram
- What type of aortic dissection is catastrophic and requires emergent surgical intervention?
- What are the classifications of this type of dissection?
- At what rate does the mortality increase?
- What is the overall mortality of this type of aneurysm?
- Ascending aortic dissection
- Stanford A, Debakey 1, Debakey 2
- Mortality rate increases by 1-2% per hour
- Overall mortality = 27-58%
What are the 2 types of aortic aneurysm dissection classes?
- Stanford class (A and B)
- DeBakey class (I, II, and III)
Label the aortic aneurysm dissection classes.
Label the aortic aneurysm dissection classes
What is a DeBakey type-I aortic aneurysm dissection?
A tear in the ascending aorta that propogates to the aortic arch
What is a DeBakey type-II aortic aneurysm dissection?
A tear confined to the ascending aorta
What is a DeBakey type-III aortic aneurysm dissection?
A tear in the descending aorta
What is a Stanford B aortic aneurysm dissection?
A tear in the ascending aorta
What is a Stanford B aortic aneurysm dissection?
A tear in the descending aorta
- What is the first type of Stanford A aortic aneurysm dissection?
- What are the most commonly performed procedures for this type?
- A dissection involving the ascending aorta.
- All patients with an acute dissection involving the ascending aorta should be considered candidates for surgery.
- The most commonly performed procedures include ascending aorta and aortic valve replacement with a composite graft, and replacement of the ascending aorta and resuspension of the aortic valve.
- What is the second type of Stanford A aortic aneurysm dissection?
- What type of surgery is used for this type of dissection?
- What are the major complications associated with replacement/surgery of this type of dissection?
- A dissection involving the aortic arch. In patients with acute aortic arch dissection, resection of the aortic arch is indicated.
- Surgery requires cardiopulmonary bypass, profound hypothermia, and a period of circulatory arrest. With current techniques, a period of circulatory arrest of 30-40 minutes at a body temperature of 15-18C can be tolerated by most patients.
- Neurologic deficits are the major complications associated with replacement of the aortic arch. These occur in 3-18% of patients, and it appears that selective antegrade cerebral perfusion decreases but does not completely eliminate the morbidity and mortality associated with this procedure.
- What area of the aorta does a StanFord B aortic aneurysm involve?
- What is the initial treatment for this type of dissection?
- What does medical management of this type of dissection involve?
- What is the mortality rate?
- When is surgery indicated for this type of aneurysm?
- What is the mortality rate when surgical treatment is used for this type of aneurysm?
- Descending thoracic aorta.
- Patients with an acute, but uncomplicated type B aortic dissection who have normal hemodynamics, no periaortic hematoma, and no branch vessel involvement can be treated with medical therapy.
- Medical therapy consists of intraarterial monitoring of blood pressure, UOP monitoring, drugs control BP and the force of LV contraction with BBs, cardene, and nipride.
- This patient population has an in-person mortality rate of 10% when medically managed, and 29% when surgically managed. The long-term survival rate with medical therapy is only 60-80% at 5 years and 40-50% at 10 years.
- Surgery is indicated foe patients with type B aortic dissection who have signs of impending rupture (persistant pain, hypotension, and left sided hemothorax); ischemia of the legs, abdominal viscera, spinal cord, and renal failure.
*
6 conditions
What are some coexisting diseases that are commonly seen in vascular surgery patients? Which 3 are the MOST common?
- CAD - 40-80% of vasc patient have this
- HTN- (most common)
- Diabetes- (most common)
- Smokers- (most common)
- CNS atherosclerosis
- Renal
What percentage of vascular surg patients will have an MI postop that results in death?
50% (not in the acute phase though)
If the surgical site has sclerosis what should we assume?
That other areas are sclerotic as well
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
What is the treatment for peripheral occlusive disease?
- Pharmacologic therapy OR;
- Transluminal angioplasty;
- Endarterectomy;
- Thrombectomies;
- Multiple bypass procedures
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
When doing bypass grafting on upper/lower extremities for occlusive disease or aneurysms what are some viable anesthesia options?
- General;
- Regional
What causes intermittent claudication?
- When O₂ demand exceeds supply
What is “Rest Pain”?
- Rest pain is a constant burning pain from wounds that won’t heal.
What can improve “Rest Pain”?
- ↑ hydrostatic pressure
- Albumin
What are some S/Sx of intermittent claudication?
- ↓ or absent pulses
- Bruits in abdoment pelvis inguinal area (remember clots often happen at bifurcations)
If a patient presents with hair loss on their lower extremities what should you think of?
- Peripheral vascular disease causes subq atrophy and hair loss
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
If the BP in the leg is lower than BP in the arm what does that tell us?
- ↓ leg BP indicates blocked arteries d/t PAD
What are some treatment options for PVD?
- Exercise;
- Stop smoking;
- Treat HTN CAD DM;
- β-antagonists MAYBE → If someone has demand ischemia Beta blockers can reduce peripheral perfusion;
- ↓ lipids;
- Revascularization vs amputation
When might revascularization for PVD be considered?
- Disabling claudication
- Ischemic rest pain
- Impending limb loss
What are the main components of the revascularization procedure?
- Angioplasty;
- May stent may not;
- Iliac and femoral/popliteal arteries common
What are some anesthesia concerns with revascularization cases?
- patients prob too sick to do surgical CAD → need pharmacological stress test;
- is patient on β blockers preop?;
- Vessels often harvested from other areas of body so regional might be tricky;
- Patient will be anticoagulated → more bleeding
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
What is the difference between a TIA and a Stroke?
- TIA always caused by temporary ischemia never bleeding. Stroke can be bleeding or ischemia
If a patient suffered a TIA, what would you expect to occur soon?
- impending stroke
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
What are some ways we might diagnose a stroke?
- Angiography;
- Carotid bruit;
- Carotid stenosis;
- Sudden neurological deficits
Where does carotid stenosis most often occur?
Carotid bifurcation
How do we treat an acute ischemic stroke?
- TPA within 3-5 hrs (NNT=10 →https://www.thennt.com/thennt-explained/);
- Intra-arterial thrombolysis
How can we treat/prevent ischemic strokes in the long term?
- Stop smoking;
- Antiplatelet therapy;
- Correct or ↓ hypoxia hypertension unstable arrhythmias;
- Carotid endarterectomy
Why are cardiac arrythmias common in stroke? What can reduce this risk?
- when the docs start working on the clot pieces break off and travel…
- Transluminal procedures ↓ this risk
What are some anesthesia concerns for patients receiving intra-arterial thrombolysis?
- Commorbidities → major cause of mortality postop;
- Good BP control → want good cerebral autoregulation;
- Consider effects of their head being rotated WRT blood flow;
- Consider regional so we can keep them awake to monitor for stroke
What area of the aorta is the most difficult to treat? Which area is easier?
- Ascending more difficult;
- Abdominal less difficult
What are two types of vessel abnormalities we might see on the aorta?
- Aneurysm →Dilation with 50% increase in diameter;
- Dissection →Blood enters media layer from tear in intima
What are two sources of possible major complications for anesthesia during aorta repair surgery?
- Aortic cross-clamping
- Intraoperative blood loss
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
Related to aortic cross clamping what are some critical perfusion specific changes that occur?
- 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 5 indications we discussed in class for aortic surgery?
- Aneurysms;
- Aortic dissection;
- Coarctation;
- Occlusive disease;
- Trauma
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 what are the 4 site specific lesions we need to know?
- Ascending aorta
- Aortic arch
- Distal to left subclavian artery and above diaphragm
- Below the diaphragm
Related to aortic surgery, how will we know if cardiopulmonary bypass is required?
- Lesions involving the ascending and transverse aorta require bypass
How are aortic dissections classified?
- DeBakey I II III;
- –OR–;
- Stanford A (proximal) or B (Distal)
Describe each of the DeBakey classifications?
- DeBakey I → Dissection in the ascending aorta that extends into the descending aorta;
- DeBakey II → Dissection in the ascending aorta that does notextend into the descending aorta;
- 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
What is an aortic dissection?
- Characterized by a spontaneous tear of the vessel wall intima permitting the passage of blood along false lumen
What is the most common factor contributing to the progression of an aortic dissection? Most serious complication is?
- Common factor = HTN;
- Complication = aneurysm rupture
Stanford classification Type A converts to DeBakey how?
- Stanford Type A = DeBakey I and II
How are dissecting aortic lesions treated?
- Proximal dissections nearly always treated surgically;
- Distal dissections may be managed medically initially;
- Measures to reduce SBP and wall stress are initiated once diagnosis confirmed
Which dissecting aortic lesions have the highest incidence of rupture?
- Proximal 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 is the most common location for aortic aneurysms? What is the most common cause?
- abdominal aorta;
- atheroslcerosis or medial cystic necrosis ← he mentions both on slide 36 as being the common cause
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
Which part of the aorta do syphalitic aneurysm generally involve?
- ascending aorta
What is the greatest danger of aortic aneurysm?
- rupture and exsanguination
What is the normal size of the aorta in adults? When would an aortic resection be performed?
- normal = 2-3 cm in width;
- Electrive resection typ done when aneurysm is > 4 cm (later he says ≥ 5-6 cm??)
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
Why is it important to do a GOOD preop on vascular surgery patients?
- Patient frequently elderly and lots of concurrent diseases;
- Special attention given to cardiac renal and neuro function;
- Preop renal dysfunction directly r/t postop renal failure
Where is the most common location for a thoracic aneurysm to develop?
- Just above aortic valve distal to left subclavian takeoff → Ligamentum arteriosum
What are risk factors for thoracic aneurysm?
- Age;
- Aortic cannulation;
- Atherosclerosis;
- Blunt trauma;
- Crack cocaine;
- Hypertension;
- Male sex;
- Marfan’s syndrome;
- Smoking
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 aneurysms?
- Saccular → eccentric dilation;
- Fusiform → entire circumference of aorta
Which class of aneurysm often occurs at the renal arteries?
- Fusiform
What are some S/Sx of a thoracic aneurysm?
- Often asymptomatic and but exam can find:;
- Hoarseness;
- Stridor;
- Dyspnea;
- Dysphagia;
- Dilation of aortic valve annulus
What are some S/Sx of acute aortic dissection?
- Severe sharp tearing pain;
- Hypotension/hypertension;
- Absence of peripheral pulses;
- Paraplegia/paraparesis
How do we diagnose aneurysms/aortic dissections?
- CXR;
- TEE;
- Arteriogram
How are aortic dissections treated?
- Stent;
- Open surgery
What is “anterior spinal artery syndrome”? What are some adverse S/E?
- major complication of cross clamping of thoracic aorta with > 30 min cross clamp times;
- Flaccid paralysis loss of bowel/bladder renal insufficiency;
- Loss of motor function and pinprick sensation but preservation of vibration and proprioception
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
What is the treatment regime for abdominal aneurysms?
- <4cm → US q6 mo;
- 4-5cm → elective repair w/low operative risk and good life expectancy.;
- 5-6 cm → need repair (mortality rate 0.9-5%);
- 6-7 cm → threshold for rupture (mortality as high as 75%).
What are the classic S/Sx of an abdominal aneurysm rupture? What percentage of patients do these S/Sx appear?
- Hypotension;
- Back pain;
- Pulsatile mass;
- S/Sx only present in 50% of patients (hemorrhage and tamponade into retroperitoneum also happens)
If we are doing a case where surgery is performed on the ascending aorta which arm are we going to place our art line in? What med will we used to contro BP and why?
- Left radial is used d/t cross clamping of the aorta;
- Will use nitroprusside instead of nicardipine d/t needing fast on/fast off
Surgery on the aortic arch and ascending aorta use what approach?
- Aortic arch → median sternotomy with deep hypothermic circulatory arrest;
- Ascending aortia → cardiopulm bypass
For surgery involving the aortic arch what are import considerations needed to provide the best cerebral protection?
- Know that long rewarming periods contribute to intraoperative blood loss;
- Mannitol;
- Methylprednisolone or dexamethasone;
- Narcotic infusion;
- Phenytoin;
- Systemic and topical hypothermia (15° C)
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
What is ↑ renal failure following aortic surger a result of?
- Emergency procedures;
- Prolonged cross-clamp periods;
- Prolonged hypotension
