Behind the Knife ABSITE 2026: Vascular Surgery Review - Part 1

Carotid Artery Anatomy and Pathology

• 🧠 The carotid sheath contains the carotid artery, internal jugular vein, and vagus nerve.
• 📍 The vertebral artery has four segments, with only V1 being surgically accessible without endovascular methods.
• ⚠️ Injury to the vagus nerve can cause hoarseness, while hypoglossal nerve injury can lead to tongue deviation.
• 📉 Atherosclerosis commonly occurs at the carotid bifurcation due to turbulent flow.

Indications for Carotid Endarterectomy

• ⚡ Symptomatic patients with >50% stenosis warrant surgery if no other cause of stroke is identified.
• 📈 Asymptomatic patients with >90% stenosis and a long life expectancy may benefit from surgery, though best medical therapy is often preferred.
• ⚠️ Emergent carotid endarterectomy is indicated for crescendo TIAs.
• 💔 Non-stroke morbidity and mortality are often cardiac-related, necessitating a cardiac workup prior to surgery.

Cerebral Monitoring and Complications

• 💡 Shunting during carotid endarterectomy maintains brain flow during clamping; monitoring techniques include awake surgery, stump pressures, EEG, and cerebral oximetry.
• 🤕 Cerebral hyperperfusion syndrome, characterized by severe headaches and hypertension post-surgery, requires ICU management and seizure prophylaxis.
• 🚨 Stroke symptoms in the PACU post-carotid endarterectomy necessitate urgent evaluation, duplex ultrasound, and potential return to the OR for thrombectomy.

Carotid Stenting vs. Endarterectomy

• 🫀 Carotid stenting is considered for patients who are poor surgical candidates due to severe cardiac disease, prior neck surgery, or recurrent carotid disease.
• 🚀 Transcarotid artery revascularization (TCAR) offers a lower stroke risk during intervention due to flow reversal.

Non-Atherosclerotic Carotid Lesions

• 🩸 Asymptomatic carotid dissection from blunt trauma is managed with anticoagulation and repeat imaging.
• ⚠️ Symptomatic dissections may require stenting, as they are not typically amenable to open repair.
• 🚫 Traumatic occlusion of the carotid artery with pre-existing neurologic injury is generally managed with antithrombotic therapy.
• ✂️ Carotid body tumors require resection, potentially preceded by embolization of feeding branches.
• 🧬 Fibromuscular dysplasia (FMD), presenting as "beads on a string," is managed with antiplatelet medications or balloon angioplasty for recurrent symptoms.

Thoracic Outlet Syndrome (TOS)

• 🦴 The thoracic outlet contains the subclavian vein, phrenic nerve, subclavian artery, brachial plexus, and first rib.
• 🐍 Cervical ribs are an anatomic anomaly predisposing to TOS.
• ✋ Neurogenic TOS (95%) presents with pain, weakness, numbness, and tingling, often worsened with arm elevation.
• 🏋️ Treatment for neurogenic TOS includes physical therapy, followed by first rib resection and scalenectomy if conservative measures fail.
• 🔵 Subclavian vein thrombosis, presenting as a blue, swollen arm, is treated with catheter-directed thrombolysis and eventual first rib resection.
• 🖐️ Arterial TOS, though rare, can cause hand ischemia and may require first rib resection with an interposition graft for aneurysms.

Subclavian Steel Syndrome and Dialysis Access

• 🔄 Subclavian steel syndrome results from proximal subclavian stenosis or occlusion, causing reversal of flow down the vertebral artery; treatment involves stenting or bypass.
• ⏳ Temporary dialysis catheters should be left in place for no more than 3 weeks due to infection risk.
• 🔗 Tunneled catheters (Permacaths) have a lower infection risk but a higher risk of central venous stenosis compared to fistulas or grafts.
• 📍 Preferred sites for permanent dialysis access are the non-dominant arm, starting distally (radiocephalic fistula), with vein >3mm and artery >2mm.
• 📉 Malfunctioning fistulas are often due to venous outflow problems, managed with venoplasty or stenting.
• 📏 A fistula is ready for use when it meets the "rule of sixes": 6mm diameter, <6mm deep, and >600 ml/min flow.
• 🩸 "Steel syndrome" in the hand post-fistula creation is confirmed by flow analysis and treated by banding, ligation, or distal revascularization and interval ligation (DRIL).

Lower Extremity Compartment Syndrome and Aortic Injuries

• 🦵 Fasciotomies are indicated for extremity compartment syndrome or acute limb ischemia >4 hours, characterized by tight compartments and pain out of proportion.
• 🔪 Incisions for fasciotomies are made lateral to the tibia for anterior/lateral compartments and posterior-medial to the tibia for posterior compartments.
• ⚡ Injury to the superficial peroneal nerve during lateral incision can cause foot eversion difficulties.
• 💔 Blunt thoracic aortic injury most commonly occurs distal to the left subclavian artery, treated with thoracic endovascular aortic repair (TEVAR).
• 📏 Descending thoracic aortic aneurysms >5.5 cm (endovascular) or >6.5 cm (open) require treatment.
• 🚶 Paraplegia is a feared complication of thoracic aorta repair, mitigated by lumbar drains and blood pressure management.

Aortic Dissection and Mesenteric Ischemia

• 🚨 Tearing chest pain in a patient with hypertension suggests aortic dissection, requiring a CT angiography of the chest, abdomen, and pelvis.
• 🅰️ Type A dissections are proximal to the left subclavian artery and are surgical emergencies; Type B dissections are distal and initially managed medically unless rupture or malperfusion occurs.
• 🩸 Malperfusion in Type B dissections can affect mesenteric, renal, hepatic, or limb circulation.
• 💊 Management of Type B dissection involves blood pressure and heart rate control with beta-blockers and monitoring for malperfusion.
• 🛠️ Endovascular repair (TEVAR) is used for Type B dissections with malperfusion to seal the entry tear and promote true lumen thrombosis.
• 🔪 Four types of mesenteric ischemia: embolic, thrombotic, venous, and non-occlusive (NOMI).
• 🤢 Embolic mesenteric ischemia, the most common, presents with severe abdominal pain and is diagnosed by CTA; treatment involves heparinization and laparotomy with possible bowel resection.
• 🚬 Thrombotic mesenteric ischemia, often seen in heavy smokers, involves disease at the SMA origin and may require bypass or stenting.
• 🩸 Embolic mesenteric ischemia typically spares proximal jejunum, while thrombotic disease does not.
• ⚠️ Mesenteric venous thrombosis is usually subacute, managed with heparinization, and surgery is reserved for ischemic bowel.
• 📉 NOMI occurs in critically ill patients with low cardiac output, requiring resuscitation and reversal of underlying causes.

Vascular Quick Hits

• 📍 Upper extremity emboli commonly lodge at the brachial artery bifurcation or radial/ulnar artery bifurcation.
• 🦵 Lower extremity emboli typically lodge at the common femoral artery bifurcation.
• 🩸 Proximal control for a ruptured AAA is supra-celiac aorta.
• 📉 Permissive hypotension (SBP 80-100 mmHg) is used for ruptured AAA transfer.
• 🦠 Most common organism in graft infections is Staphylococcus epidermidis.
• 🦵 Papal entrapment syndrome is treated by resecting the medial head of the gastrocnemius or addressing compression bands/muscle.
• 🧬 Fibromuscular dysplasia can affect renal arteries and the internal carotid artery, treated with balloon angioplasty.