Vascular

Aneurysmal, occlusive (acute and chronic), carotid, dissection, and venous thromboembolic disease for the Surgery Shelf.

Source: First Aid 2026 (first-aid-usmle-bible) — no TPoT text for this chapter; FA cited by topic.

High-Yield Points

• Abdominal aortic aneurysm (AAA): usually infrarenal; risk factors smoking, male, age, family history. Screen with one-time ultrasound in men 65–75 who ever smoked. Most are asymptomatic (incidental pulsatile mass).
• AAA repair thresholds: diameter ≥5.5 cm, rapid growth (>0.5 cm/6 mo or >1 cm/yr), or symptomatic/tender. Elective repair = open or EVAR.
• Ruptured AAA = hypotension + back/abdominal pain + pulsatile mass → unstable goes straight to the OR; only a stable patient gets a CT first. High mortality.
• Acute limb ischemia (6 Ps): pain, pallor, pulselessness, paresthesia, poikilothermia (cold), paralysis (late). Heparinize immediately; embolic (sudden, atrial fibrillation, no prior claudication, normal contralateral pulses) → embolectomy; thrombotic (prior PAD/claudication) → revascularization/bypass. Paralysis/anesthesia = threatened limb needing emergent revascularization.
• Chronic PAD / claudication: reproducible calf pain with walking, relieved by rest; ABI <0.9. First-line = risk-factor modification, supervised exercise, cilostazol; revascularize for lifestyle-limiting symptoms, rest pain, or tissue loss. Critical limb ischemia = rest pain (ABI <0.4), ulcers, gangrene.
• Leriche syndrome (aortoiliac occlusive disease) triad: claudication (buttock/thigh) + impotence + absent femoral pulses.
• Carotid stenosis: carotid endarterectomy (CEA) for symptomatic (TIA/stroke, amaurosis fugax) 70–99% stenosis (benefit also 50–69% in selected/men); asymptomatic high-grade (≥60–70%) in selected low-risk patients. Antiplatelet + statin for all.
• Aortic dissection: tearing chest/back pain, HTN, Marfan, pulse deficit, widened mediastinum. Stanford A (ascending) = surgical emergency; Stanford B (descending) = medical (β-blocker first to lower dP/dt, then BP control) unless complicated (malperfusion, rupture, refractory pain).
• DVT: Virchow triad (stasis, hypercoagulability, endothelial injury); duplex ultrasound confirms; anticoagulate; IVC filter only if anticoagulation is contraindicated or fails. Risk of PE.

Key Tables / Differentials

Embolic vs thrombotic acute limb ischemia

Aortic dissection — Stanford classification

ABI interpretation

Board Pearls

• Smoker, 68-year-old man, incidental 4-cm AAA → ultrasound surveillance; repair at 5.5 cm.
• Sudden cold, pulseless, painful leg in an atrial-fibrillation patient → embolic limb ischemia → heparin + embolectomy.
• Buttock claudication + impotence + no femoral pulses → Leriche syndrome.
• Transient monocular blindness (amaurosis fugax) → carotid stenosis → duplex, then CEA if high-grade symptomatic.
• Tearing chest pain to the back + unequal arm pressures → aortic dissection (A = surgery, B = β-blocker).
• β-blocker before vasodilators in dissection (avoid reflex tachycardia raising shear stress).

Classic Vignette Triggers

• "Hypotension + back pain + pulsatile abdominal mass" → ruptured AAA → straight to OR if unstable.
• "Calf pain on walking relieved by rest, ABI 0.7" → claudication → exercise/cilostazol, risk-factor control.
• "Cold, mottled, pulseless leg, atrial fibrillation" → embolic acute limb ischemia.
• "Buttock claudication + erectile dysfunction" → Leriche syndrome.
• "Marfan patient with tearing chest pain and widened mediastinum, ascending aorta" → Stanford A → emergent surgery.
• "Swollen tender calf after long flight, positive duplex" → DVT → anticoagulate.