Chapter 27 - Vascular I Flashcards
What is the most common congenital hypercoagulable disorder?
Resistance activated protein C Leiden factor
What is most common acquired hypercoagulability disorder?
Smoking
What are the three stages of atherosclerosis?
1) Foam cells - macrophages that have absorbed fat and lipids in the vessel wall
2) Smooth muscle cell proliferation - caused by growth factors released from macrophages; results in wall injury
3) Intimal disruption from smooth muscle cell proliferation - leads to exposure of collagen in the vessel wall and eventual thrombus formation - fibrous plaques then form in these areas with underlying atheromas
What are the risk factors for atherosclerosis?
Smoking
hypertension
cholesterolemia
Atherosclerosis is a disease of what part of the blood vessel?
Disease of intima
Hypertension is a disease of what part of the blood Vessel?
Disease of the media
Stroke is the _____ cause of death in United States
Third
What is the most important risk factor for stroke in asymptomatic patients?
Hypertension
Where is the most common site for stenosis in the carotid arteries?
Bifurcation
The normal internal carotid artery has what type of flow?
Continuous forward flow
The normal external carotid artery has what type of flow?
Triphasic flow
Where is the communication between the internal carotid artery and the external carotid artery?
Ophthalmic artery (first branch of ICA) and internal maxillary artery off ECA
What is the most commonly diseased Intracranial artery?
Middle cerebral artery
What is the most common etiology of cerebral ischemic events?
Arterial embolization from the ICA
-Heart is the second most common source of emboli
Anterior cerebral artery events cause what?
Mental status changes, release, slowing
Middle cerebral artery events cause what?
Contralateral motor and speech loss; contralateral facial droop
What is amaurosis fugax?
Occlusion of the atomic branch of the ICA visual changes, shade coming down over eyes; visual changes are transient
-Can see Hollenhorst plaques on ophthalmologic exam
What do you do with carotid traumatic injury with major fixed deficit?
If occluded do not repair-can exacerbate injury with bleeding
If not occluded-repair
When do you consider a carotid endarterectomy?
Any pt with symptoms + >70% stenosis.
Asymptomatic pts w/ 70 to 80% stenosis controversial.
Any pt w/ >80 to 90% stenosis should have CEA if technically possible.
The patient has a recent completed stroke, when do you perform CEA?
4 to 6 weeks
When can an emergent CEA be of benefit?
When there are fluctuating neurologic symptoms or crescendo/evolving TIAs
When do you shunt during a CEA?
When the stump pressure is less than 50
What is the most common cranial nerve injury with a carotid endarterectomy?
Vagus nerve secondary to vascular clamping during endarterectomy. Patients get hoarseness
What happens with a hypoglossal nerve injury during CEA?
Tongue deviation to the side of the injury – speech and mastication difficulty
What happens with a glossopharyngeal nerve injury during a CEA?
Unlikely. Could occur with a really high carotid lesion. Causes difficulty swallowing.
What happens if you damage the Ansa cervicalis during a CEA?
Innervates strap muscles; no serious deficits
What happens if you damage the mandibular branch of the facial nerve during a CEA?
Affects corner of mouth (smile)
What do you do if there’s an acute event immediately after a CEA?
Go back to the OR to check for flap or thrombosis
How do you detect a pseudoaneurysm after a CEA and what do you do about it?
Pulsatile, bleeding mass after CEA. Draped and prepped before intubation, intubate, then repair
What percentage of patients have hypertension following a CEA and why?
20%. Caused by injury to carotid body. Treat with nipride to avoid bleeding.
What is the restenosis rate after a CEA?
15%
What are the symptoms of Vertebral artery disease and what is the treatment?
Diplopia, dysarthria, vertigo, tinnitus, drop attacks, incoordination, binocular vision loss.
-PTA, vertebral artery transposition to subclavian, transsubclavian endarterectomy, osteophyte resection, unroofing of transverse process foramina, resection of musculotendinous bands
How do carotid body tumors present?
Painless neck mass, usually at the bifurcation, made up of neural crest cells
-treat with resection
How do you get a thoracic aortic transection and what you do about it?
Deceleration injury
Address other life threatening injuries first
What are ascending aortic aneurysms usually caused by?
Usually caused by connective tissue disorder; cystic medial necrosis most common abnormality-Marfan syndrome
- Often asymptomatic and picked up on routine CXR
- Can get compression of vertebral, whore’s whisper, dyspnea, trouble swallowing
Transverse aortic arch aneurysms
From atherosclerosis. Repair symptomatic, greater than 5.5 cm, with Marfan’s greater than 5 cm
Descending aortic aneurysms etiology? Management?
From atherosclerosis. Repair if greater than 5.5 cm. Reimplant intercostal vessels below t8 to help prevent paraplegia
Classifications of dissections?
Stanford: A) Any ascending aortic involvement B) Descending aortic involvement only DeBakey: I) Ascending and descending II) Ascending only III) Descending only
Where do most dissections start in the aorta?
Ascending aorta
What are symptoms of an aortic dissection?
Can mimic MI, Searing chest pain, unequal pulses or BP in upper extremities. 95% have severe hypertension
What are the risk factors for aortic dissection?
Hypertension
Marfan’s
Previous aortic coarctation repair atherosclerosis
syphilis
And what layer of the aorta does a dissection occur?
Media
Why does aortic insufficiency occur with aortic dissection?
Occurs in 70% with acute disease. Caused by annular dilatation or when aortic valve cusp is sheared off. Can also have occlusion of the coronaries and major aortic branches.
Death from aortic insufficiency or tamponade.
What aortic dissections need operations?
All ascending aortic dissections
Descending aortic dissections with visceral, renal, or leg ischemia; persistent pain; large-size
Need to follow with lifetime serial CT scans; 30% will eventually get aneurysm formation requiring surgery
What are the most common postop complications for thoracic aorta surgery?
MI, renal failure, paraplegia due to occlusion of the intercostal arteries and artery of adamkiewicz during repair
How big is the normal aorta?
2 to 3 cm
What causes abdominal aortic aneurysms?
Most commonly due to atherosclerosis. Form from degeneration of the medial layer. Risk factors include hypertension, male gender, smoking, elderly age
What is the leading cause of death in AAA patients without an operation?
Rupture
What is the five-year rupture risk of a 5 cm AAA? What is the five-year rupture risk of an 8 cm AAA?
15 to 20%. 100%.
What is seen on the CT of a ruptured AAA?
Fluid in retroperitoneal space, extraluminal contrast
Where are AAA’s most likely to rupture?
Left posterior lateral wall, 2 to 4 cm below renals
Most likely rupture in presence of diastolic hypertension or COPD
50% mortality with rupture
When do you need to re-implant the IMA?
When back pressures less than 40 MM HG Previous colonic surgery Stenosis at SMA Float to left colon appears inadequate Ligate bleeding lumbar arteries Maintain flow to at least one internal iliac artery
What major vein injury is common with AAA repair
Retroaortic renal vein with proximal cross-clamp
What is the mortality of an elective AAA repair?
5%
What is the number one cause of acute death after AAA surgery?
MI
What is the number one cause of late death after surgery for a AAA?
Renal failure
What is the rate of AAA repair graft infection?
1%
What is the risk of pseudoaneurysm after AAA graft placement?
1%
What is the most common late complication after aortic graft placement?
Atherosclerotic conclusion
What can cause ischemic colitis after a AAA repair?
The inferior mesenteric artery is often sacrificed
What is a type endoleak?
Proximal or distal attachment zone
Stent migration
Treats with proximal or distal extension cuff
What is a type II endoleak?
Retrograde endoleak
patent lumbar, IMA, intercostals, accessory renal etc.
Treat w percutaneous coil embolization
What is a type III endoleak?
Midgraft component disconnection
Fabric tear
Treat with secondary Endograft
What is a type IV endoleak?
Graft wall porosity or suture holes
Treat with secondary stenting or observe
What is a type V endoleak?
High intrasac pressure without leak shown
Secondary repair or open repair
What is an inflammatory aneurysm?
Occurs in 10% of patients
Adhesions to the third and fourth portions of the duodenum
Ureteral entrapment in 25%
Not secondary to infection
Weight loss, increased ESR, thickened rim above calcifications on CT scan
Mycotic aneurysms etiology? Symptoms? Imaging findings? Management?
Salmonella number one cause, staphylococcus number two
Pain, fevers, positive blood cultures and 50%
Periaortic fluid, gas, retroperitoneal soft tissue edema, lymphadenopathy
Need extra Anatomic bypass and resection of infrarenal abdominal aorta to clear infection
Aortic graft infections etiology? Imaging findings? Management?
Staphylococcus number one, E. coli number two
See fluid, gas, thickening around graft
Resect graft and bypass through non-contaminated field
Blood cultures negative in many patients
More common with graphs going to groin
Aortoenteric fistula timing? Symptoms? Location?
Usually occurs more than six months after surgery
Herald bleed with hematemesis, then blood per rectum
In third or fourth portion of duodenum near proximal suture line
What is affected in the anterior leg compartment?
Deep peroneal nerve-dorsiflexion, sensation between first and second toes
Anterior tibial artery
What is affected in the lateral leg compartment?
Superficial peroneal nerve-Eversion, lateral foot sensation
What is affected in the deep posterior leg compartment?
Tibial nerve-plantarflexion, posterior tibial artery, peroneal artery
What is affected in the superficial posterior leg compartment?
Sural nerve
What are the signs of PVD?
Power, hair loss, dependent rubor, abnormal nail growth, slow capillary refill
Most commonly due to atherosclerosis
What is the number one prevention agent for atherosclerosis?
Statin drugs
Gluteal claudication pain is due to blockage of what artery?
Aorto iliac disease
Midthigh claudication is due to disease in what artery?
External iliac
Calf claudication is due to disease of what arteries?
Common femoral artery or proximal superficial femoral artery
Foot claudication is due to disease of what artery?
Distal superficial femoral artery or popliteal disease
What can mimic claudication?
Lumbar stenosis
What can mimic rest pain?
Diabetic neuropathy
What is Lerich syndrome?
No femoral pulses
Gluteal or thigh claudication
Erectile dysfunction
Lesion at aortic bifurcation or above
Where is the most common atherosclerotic occlusion in the lower extremities?
Hunters canal-distal superficial femoral artery exits here. Sartorius muscle covers hunters canal
What is postnatal angiogenesis?
Budding from pre-existing vessels; AngioGenin involved
At what ABI do you get rest pain?
Less than .5
At what ABI do you get ulcers?
Less than .4. Ulcers usually start in toes
Why are ABI’s inaccurate in patients with diabetes?
Incompressible vessels
What are the surgical indications for PVD?
Rest pain, ulceration or gangrene, lifestyle limitation, atheromatous embolization
When does PTSD have decreased patency?
When the graft crosses the knee
Aorto iliac occlusive disease?
Treat with AF two
In high-risk patients perform bilateral axillary femoral bypasses or an axillary femoral bypass with a femoral to femoral crossover To stay out of the abdomen
What do you do with isolated iliac lesions?
Angioplasty with stent is first choice; if that fails perform aorto bifemoral repair or femoral to femoral crossover
What is the patency of femoropopliteal grafts?
75% for five years. Improved patency rate in patients with surgery for claudication as opposed to limb salvage
