Surgery EOR: Cardiovascular (Smarty PANCE)

What is acute arterial occlusion?

Sudden interruption of arterial blood flow due to thrombosis or embolism - surgical emergency requiring intervention within 6 hours

What are the classic "6 Ps" of acute arterial occlusion?

Pain, Pallor, Pulselessness, Paresthesias, Paralysis, Poikilothermia (cold extremity)

What is the most common cause of acute arterial occlusion?

Embolism (80-90%) - commonly from atrial fibrillation, MI with mural thrombus, or valvular heart disease

What is the most common site for acute arterial occlusion?

Femoral artery bifurcation (common femoral) followed by iliac, popliteal, and brachial arteries

How is acute arterial occlusion diagnosed?

Clinical diagnosis with 6 Ps, absent distal pulses; confirm with CT angiography or conventional angiography

What is the immediate management of suspected acute arterial occlusion?

IV heparin bolus (80 units/kg) followed by infusion, pain control, protect limb, urgent vascular surgery consultation

What are the treatment options for acute arterial occlusion?

Surgical embolectomy (Fogarty catheter), thrombolysis (catheter-directed tPA), bypass grafting, or amputation if non-viable

What factors determine limb viability in acute arterial occlusion?

Rutherford classification: Class I (viable), Class IIa (threatened, salvageable), Class IIb (threatened, immediate), Class III (irreversible)

What is reperfusion injury after revascularization?

Release of toxic metabolites causing hyperkalemia, acidosis, myoglobinuria, compartment syndrome - can lead to renal failure

What indicates irreversible limb ischemia?

Fixed mottling, muscle rigor, absent Doppler signals, paralysis >6 hours - amputation required to prevent systemic complications

What is an aortic aneurysm?

Permanent focal dilation of aorta >50% of normal diameter (AAA: >3cm, thoracic: >4cm in ascending, >3.5cm in descending)

What are the risk factors for abdominal aortic aneurysm (AAA)?

Smoking (strongest modifiable), male sex, age >65, hypertension, family history, atherosclerosis, connective tissue disorders

What is the classic triad of ruptured AAA?

Abdominal/back pain, hypotension, pulsatile abdominal mass - present in only 50% of cases

Who should be screened for AAA and how?

Men age 65-75 with smoking history - one-time ultrasound screening (USPSTF Grade B recommendation)

At what size should AAA be repaired electively?

≥5.5cm in men, ≥5.0cm in women, or growth >0.5cm in 6 months or >1cm per year

What imaging is used for AAA diagnosis and surveillance?

Ultrasound for screening/surveillance; CT angiography for preoperative planning and acute evaluation

What are the surgical options for AAA repair?

Open surgical repair (OSR) or endovascular aneurysm repair (EVAR) - EVAR preferred when anatomy suitable

What is the mortality rate of ruptured AAA?

Overall 80-90% mortality - 50% die before reaching hospital, 50% operative mortality for those reaching surgery

What medications reduce AAA expansion rate?

Beta-blockers, statins, ACE inhibitors - smoking cessation most important intervention

What are complications of EVAR?

Endoleak (most common), graft migration, limb thrombosis, infection - requires lifelong surveillance imaging

What is aortic dissection?

Tear in aortic intima allowing blood to enter media creating false lumen - can propagate proximally or distally

What is the Stanford classification of aortic dissection?

Type A: involves ascending aorta (requires emergency surgery); Type B: descending aorta only (medical management unless complicated)

What are the classic presenting symptoms of aortic dissection?

Sudden severe "tearing" or "ripping" chest/back pain, often described as worst pain ever, may migrate as dissection propagates

What are the risk factors for aortic dissection?

Hypertension (most important), Marfan syndrome, Ehlers-Danlos syndrome, bicuspid aortic valve, cocaine use, trauma

What physical exam findings suggest aortic dissection?

Blood pressure differential between arms (>20mmHg), pulse deficit, aortic regurgitation murmur, neurologic deficits

What is the diagnostic test of choice for aortic dissection?

CT angiography of chest/abdomen/pelvis - 95% sensitivity, shows intimal flap and true/false lumens

What is the immediate medical management of aortic dissection?

IV beta-blocker first (esmolol, labetalol) to reduce shear stress, then vasodilator (nitroprusside) - target SBP 100-120mmHg, HR <60

What is the definitive treatment for Type A dissection?

Emergency surgical repair - replace ascending aorta, high mortality if untreated (1-2% per hour)

What are the complications of aortic dissection?

Aortic rupture, tamponade, acute aortic regurgitation, coronary ostia involvement (MI), stroke, mesenteric ischemia, renal failure

What is the prognosis of untreated Type A dissection?

50% mortality within 48 hours, 90% mortality within 3 months - surgical emergency

What is chronic arterial insufficiency?

Progressive atherosclerotic narrowing of arteries causing inadequate blood flow - presents as claudication or critical limb ischemia

What are the stages of chronic arterial insufficiency (Fontaine classification)?

Stage I: asymptomatic, Stage II: claudication, Stage III: rest pain, Stage IV: tissue loss (ulceration/gangrene)

What is intermittent claudication?

Reproducible leg muscle pain/cramping with exercise that resolves within 10 minutes of rest - classic symptom of PAD

What is critical limb ischemia?

Rest pain for >2 weeks, ulceration, or gangrene due to severe PAD - limb-threatening condition

What is the ankle-brachial index (ABI) and interpretation?

Ratio of ankle to arm systolic BP - Normal: 1.0-1.4, PAD: <0.9, severe PAD: <0.5, critical limb ischemia: <0.4

What are the key physical exam findings in chronic arterial insufficiency?

Diminished/absent pulses, hair loss, shiny skin, cool extremity, pallor with elevation, rubor with dependency, prolonged capillary refill

What is the first-line treatment for claudication?

Risk factor modification: smoking cessation (most important), statin therapy, antiplatelet (aspirin/clopidogrel), exercise therapy (30-45 min 3x/week)

What medication improves claudication symptoms?

Cilostazol (phosphodiesterase inhibitor) - increases walking distance by 40-60%, contraindicated in heart failure

When is revascularization indicated for PAD?

Critical limb ischemia, lifestyle-limiting claudication despite medical therapy, tissue loss/gangrene

What are revascularization options for PAD?

Endovascular (angioplasty/stenting) for focal lesions; surgical bypass for long-segment occlusions or failed endovascular therapy

What is chronic venous insufficiency (CVI)?

Incompetent venous valves causing venous hypertension, leading to edema, skin changes, and ulceration

What are the risk factors for chronic venous insufficiency?

Prior DVT (most important), varicose veins, obesity, pregnancy, prolonged standing, age, family history

What are the classic symptoms of CVI?

Leg heaviness, aching, swelling (worse at end of day), improved with elevation and compression

What are the characteristic skin changes in CVI?

Hemosiderin deposition (brown discoloration), lipodermatosclerosis (fibrosis/induration), atrophie blanche (white scarring), stasis dermatitis

Where do venous stasis ulcers typically occur?

Medial malleolus (gaiter area) - shallow, irregular borders, minimal pain, granulation tissue base

How is CVI diagnosed?

Venous duplex ultrasound - assesses valve competence and identifies obstruction or reflux

What is the first-line treatment for CVI?

Compression therapy (30-40mmHg graduated compression stockings) - cornerstone of treatment

How are venous stasis ulcers managed?

Compression therapy, leg elevation, moist wound care, treat infection if present, address underlying venous disease

What procedures are available for severe CVI?

Ablation (radiofrequency/laser) of incompetent saphenous veins, sclerotherapy, surgical ligation/stripping

What is the Unna boot?

Zinc oxide compression bandage applied from toes to knee - provides sustained compression for venous ulcer healing

What is compartment syndrome?

Elevated pressure within closed fascial compartment causing decreased perfusion and tissue ischemia - surgical emergency

What are the most common causes of acute compartment syndrome?

Fractures (tibia most common), crush injuries, reperfusion after arterial injury, tight casts/dressings, bleeding disorders

What are the classic "5 Ps" of compartment syndrome?

Pain (out of proportion, worst with passive stretch), Pressure (tense compartment), Paresthesias, Pallor, Pulselessness (late finding)

What is the most sensitive early sign of compartment syndrome?

Pain with passive stretching of muscles in affected compartment - often out of proportion to exam

Why is pulselessness a late finding in compartment syndrome?

Compartment pressures affect capillaries first (25-30mmHg), then veins, then nerves; arterial flow requires much higher pressure to occlude

How is compartment syndrome diagnosed?

Clinical diagnosis preferred; compartment pressure measurement if uncertain - absolute pressure >30mmHg or delta pressure <30mmHg diagnostic

What is delta pressure in compartment syndrome?

Diastolic BP minus compartment pressure - <30mmHg indicates compartment syndrome

What is the definitive treatment for compartment syndrome?

Emergency fasciotomy - must be performed within 6 hours to prevent permanent damage

What are the long-term complications of untreated compartment syndrome?

Volkmann's contracture, foot drop, permanent nerve damage, muscle necrosis, rhabdomyolysis, amputation

What is chronic exertional compartment syndrome?

Reversible increase in compartment pressure during exercise causing pain - resolves with rest, treated with fasciotomy if severe

What is coronary artery disease in surgical context?

Atherosclerotic narrowing of coronary arteries - important perioperative risk factor requiring optimization before elective surgery

What are the surgical revascularization options for CAD?

Coronary artery bypass grafting (CABG) - preferred for left main disease, three-vessel disease, or diabetes with multivessel disease

What are indications for CABG over PCI?

Left main stenosis >50%, three-vessel disease with reduced EF, diabetes with multivessel disease, failed PCI

What vessels are used for CABG?

Left internal mammary artery (LIMA) to LAD, saphenous vein grafts, radial artery grafts

What is the typical perioperative mortality for CABG?

1-2% for elective isolated CABG in low-risk patients

What medications should be continued perioperatively in CAD patients?

Beta-blockers, statins, aspirin (hold clopidogrel 5-7 days before surgery)

When should elective non-cardiac surgery be delayed after MI?

Ideally 60 days (minimum 30 days) - highest risk within first 30

When should elective surgery be delayed after PCI with stent?

Bare metal: 30 days; Drug-eluting: minimum 6 months (ideally 12)

What cardiac risk stratification tool is used for non-cardiac surgery?

Revised Cardiac Risk Index (RCRI)

What preoperative testing is indicated for known CAD?

ECG, stress test if symptoms changed or high-risk surgery

What is carotid artery stenosis?

Atherosclerotic narrowing of carotid arteries causing decreased cerebral blood flow and stroke risk

What percentage stenosis is considered significant in carotid disease?

≥70% symptomatic or ≥60% asymptomatic warrants intervention

What are symptoms of symptomatic carotid stenosis?

TIA, amaurosis fugax, ipsilateral stroke

What physical exam finding suggests carotid stenosis?

Carotid bruit - absence does not rule out

How is carotid stenosis diagnosed?

Carotid duplex ultrasound; CTA/MRA for surgery planning

What are indications for carotid endarterectomy (CEA)?

Symptomatic ≥50-70%, asymptomatic ≥60-70% with >5-year life expectancy

What is the perioperative stroke risk with CEA?

<3% asymptomatic, <6% symptomatic

What are complications of carotid endarterectomy?

Stroke, MI, cranial nerve injury, hematoma, hyperperfusion syndrome

What is carotid artery stenting (CAS)?

Endovascular option for high surgical risk or hostile neck anatomy

When should CEA be performed after stroke/TIA?

Within 2 weeks if neurologically stable

What is intestinal ischemia?

Inadequate blood flow to intestines causing bowel injury

What are the types of acute mesenteric ischemia?

Arterial embolism, arterial thrombosis, non-occlusive, venous thrombosis

What is the classic presentation of acute mesenteric ischemia?

Pain out of proportion to exam

What laboratory finding suggests bowel infarction?

Elevated lactate, metabolic acidosis, elevated WBC, elevated amylase

What is the gold standard diagnostic test for acute mesenteric ischemia?

CT angiography

What is the treatment for acute mesenteric ischemia?

Emergent laparotomy, resection of necrotic bowel, revascularization, antibiotics

What is chronic mesenteric ischemia?

Postprandial abdominal pain, food fear, weight loss

What vessels must be involved for chronic mesenteric ischemia?

≥2 of 3 mesenteric vessels with ≥70% stenosis

What is non-occlusive mesenteric ischemia (NOMI)?

Low-flow state ischemia in critically ill patients

What is the mortality rate of acute mesenteric ischemia?

60-80% overall

What is renal vascular disease?

Renal artery stenosis causing renovascular hypertension

What are the two main causes of renal artery stenosis?

Atherosclerosis (90%) and fibromuscular dysplasia (10%)

What is the clinical triad suggesting renovascular hypertension?

Severe/resistant hypertension, onset <30 or >55, abdominal bruit

What laboratory findings suggest renovascular disease?

Elevated creatinine after ACE/ARB, hypokalemia, metabolic alkalosis

What is the screening test for renal artery stenosis?

Renal artery duplex ultrasound or CTA

What is the gold standard for diagnosing renal artery stenosis?

Conventional angiography

When is intervention indicated for renal artery stenosis?

>70% stenosis with uncontrolled HTN, flash pulmonary edema, or progressive renal insufficiency

What is the preferred intervention for atherosclerotic RAS?

Renal artery stenting

What is the treatment for fibromuscular dysplasia?

Angioplasty without stent

What medications should be used cautiously in bilateral RAS?

ACE inhibitors and ARBs