Chapter 27 - Vascular++ Flashcards
What is the most common congenital hypercoagulable disorder?
Resistance activated protein C (factor V) Leiden factor
What is most common acquired hypercoagulability disorder?
Smoking
What are the three stages of atherosclerosis?
- Foam cells - macrophages that have absorbed fat and lipids in the vessel wall.
- Smooth muscle cell proliferation - caused by growth factors (PDGF) released from macs; results in wall injury.
- 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 - vascular mortality dec to nonsmoker if pt quits for 20 yrs; causes endothelial dysfx and thrombosis
- DM - distal dz, inc risk of ampx
- HTN - ctrl to prevent cardiac and CVA
- cholesterol - statin
Atherosclerosis is a disease of what part of the blood vessel?
Disease of intima (deposition occurs in innermost layer).
Vessel compromised at 40%.
Rupture of cap exposes thrombogenic LDL core.
Hypertension is a disease of what part of the blood Vessel?
Disease of the media (tension occurs in the muscular layer)
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 (brain needs continuous perfusion)
The normal external carotid artery has what type of flow?
Triphasic flow (externals go to high pressure beds)
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 ophthalmic branch of the ICA causing painless 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?
- Men w/ sx + >50% stenosis.
- Women w/ sx + >70% stenosis.
- Asx pt w/ >80 stenosis.
The patient has a recent completed stroke, when do you perform CEA?
4 to 6 weeks
When can an urgent CEA be of benefit?
- When there are fluctuating neurologic symptoms - crescendo/evolving TIAs.
- Between 3-14 days
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). Will get called in PACU for possible stroke, but is often transient stun 2/2 overzealous retraction at the mandible.
What do you do if there’s an acute cerebrovascular 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?
- Psx: Diplopia, dysarthria, vertigo, tinnitus, drop attacks, incoordination, binocular vision loss.
- Dx: MRA vs arteriogram
- Tx if sx, >1.5 cm aneurysm, >60% stenosis
- Tx: PTA, VA transposition to SCA, endarterectomy, osteophyte resection, unroofing of transverse process foramina, resection of musculotendinous bands
- V1: reconstruct
- V2: bypass to V3
- V4: endovascular
How do carotid body tumors present?
Painless neck mass, usually at the bifurcation, made up of neural crest cells. Treat all with resection.
How do you get a thoracic aortic injury, and what you do about it?
Deceleration injury. Dx: CTA. Tx: stable and contained (intimal tear only) - antihypertensives until systolic <100 and HR <100; unstable, intramural hematoma, pseudoaneurysm, rupture - intervention with stent-graft
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 a, hoarse whisper, dyspnea, trouble swallowing.
Transverse aortic arch aneurysms from?
From atherosclerosis. Repair symptomatic, greater than 5.5 cm, greater than 5 cm if Marfan’s.
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 (medial disease), Marfan’s (cystic medial necrosis), Previous aortic coarctation repair, atherosclerosis, syphilis
What layer of the aorta does a dissection occur?
Media (association with hypertension)
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 (5.5 cm).
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 - prevent with lumbar drains.
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, and spinal cord injury.
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 in presence of diastolic HTN 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, flow to left colon appears inadequate. Whenever possible.
- No need if 0 backbleeding as vessel is occluded.
- Ligate bleeding lumbar arteries.
- Maintain flow to at least one internal iliac artery
- 35% will suffer from some degree of colonic ischemia in ruptured AAA.
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 occlusion
What can cause ischemic colitis after a AAA repair?
The inferior mesenteric artery is often sacrificed
What is a type I endoleak?
Proximal or distal attachment zone 2.2 stent migration. Treat with proximal or distal extension cuff.
What is a type II endoleak?
Retrograde endoleak 2/2 patent lumbar, IMA, intercostals, accessory renal etc. Treat w/ percutaneous coil embolization
What is a type III endoleak?
Midgraft component disconnection 2/2 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. Assn w/ 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. Psx: Pain, fevers, positive blood cultures. Img: Periaortic fluid/gas, retroperitoneal soft tissue edema, lymphadenopathy. Tx: 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. Img: See fluid, gas, thickening around graft. Tx: 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?
Palor, 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
Aorto iliac occlusive disease management?
“Inflow disease” of younger smokers. Define w/ ABI. Reduce risk w/ aspirin and control of HTN, DM, smoking. Lower thresh-hold for intervention - PTA (short single lesions) vs surgery. Address before infra-inguinal lesions. In high-risk patients perform bilateral axillary femoral bypasses or an axillary femoral bypass with a femoral to femoral crtossover 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
What is the patency of femoral distal grafts?
50% five-year patency; not influenced by level of distal anastomosis. Distal lesions more limb threatening because of what lack of collaterals. Bypasses distal usually used only for limb salvage.
What is a complication of femoral femoral crossover graft?
Vascular steal in donor leg
Swelling following lower extremity bypass caused by what?
One: DVT; two edema from reperfusion injury
What are the complications of reperfusion of ischemic tissue?
Lactic acidosis, hyperkalemia, myoglobinuria, compartment syndrome
What is the number one cause of late failure of reverse saphenous Vein grafts?
Atherosclerosis
What is the number one cause of early failure of reverse saphenous vein grafts?
Technical problem
What do you do with a patient with a heel ulceration to the bone?
Amputate
What is dry gangrene?
Noninfectious; can allow to auto amputate in toes. Amputate if a large lesion, see if patient has correctable vascular lesion
What is wet gangrene?
Infectious; amputation to remove infected necrotic material, antibiotics, surgical emergency
What is a mal perforans ulcer?
- At metatarsal heads in DM pts w/ neuropathy
- second MTP most common
- can have OM - may need ray amputation
- treat underlying DM and neuropathy
When do you use percutaneous transluminal angioplasty?
Excellent for common iliac lesions. Best for short stenoses. Intima usually ruptured and media stretched, pushes the plaque out. Requires passage of wire first
What do you do with a pseudoaneurysm after arteriography?
- US Duplex to diagnose
- Observe if <2 cm w/ US monitoring.
- Thrombin injection with ultrasound guidance.
In what part of the leg is compartment syndrome most likely to occur?
Anterior compartment. Get footdrop. Pressures greater than 20 to 30 abnormal; consider fasciotomy - leave open for 5 to 10 days.
What is popliteal entrapment syndrome?
- Most present with mild intermittent claudication, loss of pulses with plantarflexion, usually have medial deviation of artery around the medial head of gastrocnemus muscle.
- Treatment is resection of medial head of gastrocnemius muscle. May need arterial reconstruction
What is adventitial cystic disease?
- Popliteal most common area. Often bilateral-ganglia originate from adjacent joint capsule or tendon sheath.
- Intermittent claudication. Changes in symptoms with knee flexion/extension.
- Treat with vein graft if occluded; otherwise just resection of cyst
With a BKA, what percentage heal, what percentage walk again, what is the mortality?
80% heal, 70% walk again, 5% mortality
With an AKA, what percentage heal, what percent walk again, what is the mortality?
90% heal, 30% to walk again, 10% mortality
What are the signs of an acute arterial emboli?
No signs of chronic ischemia. contralateral leg usually pulses are normal. First pallor, then cyanosis, then marbling. Symptoms include pain, pallor, pulselessness, parasthesia, poillothermia, paralysis.
What is the most common cause of arterial emboli?
A fib
What are other causes of arterial emboli?
LV aneurysm with thrombus, prosthetic heart valve, myxoma, paradoxical embolus from patent foramen ovale, peripheral arterial or aortic atherosclerotic plaque embolism
Where is the most common site of peripheral obstruction from emboli?
Common femoral artery
When do you do a fasciotomy after an embolectomy?
If ischemia is greater than 4 to 6 hours. Aorto iliac emboli can be treated with bilateral femoral artery cutdowns and bilateral embolectomies
What are the indications for nephrectomy with renal hypertension?
Atrophic kidney less than 6 cm and minimal collaterals with persistently increased renin levels
Acute on chronic arterial thrombosis caused by arrhythmia? Hx? Tx?
- Usually do not have arrhythmias.
- Have a history of claudication and chronic ischemia.
- Limb is threatened: give heparin, OR thrombectomy
- Limb not threatened: angiography for thrombolytics.
- Thrombosis of PTFE graft: thrombolytics and anticoag.
Where is the right renal artery run in relationship to the IVC?
Posterior to the IVC
What percentage of patients have accessory renal arteries?
25%
Where do most renal emboli come from?
The heart
In what patients does renal atherosclerosis occur, and in what part of the artery
Men, proximal one third of artery, left side. Treat with PTA and stent.