5.4 Peripheral and Carotid Angiography and Interventions
Key Takeaways
- Carotid revascularization is offered for symptomatic stenosis of 50% or more (ideally within 2 weeks of the index event) and for asymptomatic stenosis of 70% or more when life expectancy is 3-5 years and institutional perioperative stroke/death rates stay under 3% asymptomatic and 6% symptomatic.
- Balloon inflation and stent expansion at the carotid bulb stretch the carotid sinus baroreceptor and cause abrupt bradycardia and hypotension; atropine 0.5-1 mg or glycopyrrolate 0.2 mg is drawn up before the case and pacing is available, but the pressure is deliberately not overcorrected.
- Cerebral hyperperfusion syndrome presents as ipsilateral throbbing headache, seizure, or focal deficit hours to days after revascularization and can progress to intracerebral hemorrhage; systolic pressure is typically held under 140 mmHg, and under 120 mmHg once the syndrome is suspected.
- TCAR reverses carotid flow into a femoral vein shunt before the lesion is ever crossed, delivering embolic protection without aortic-arch catheter manipulation, which is why it is favored over transfemoral stenting in older patients with hostile arch anatomy.
- Atherectomy debulks calcified plaque but its signature complication is distal embolization, so pedal Doppler signals are documented immediately before and immediately after the intervention and embolic protection filters are frequently deployed.
Peripheral Angiography: Indications and Access
Test-plan items III.B.1 (peripheral angiography and intervention) and III.B.2 (carotid angiography and intervention) both live inside Therapeutic Interventions, the 39% domain. The CMC candidate is not asked to select the device. The candidate is asked what changes at the bedside because the patient had one.
Digital subtraction angiography (DSA) of the peripheral circulation remains the reference standard when intervention may occur in the same sitting. Indications include chronic limb-threatening ischemia with rest pain or tissue loss, lifestyle-limiting claudication that has failed supervised exercise therapy and optimal medical therapy, acute limb ischemia, a failing or thrombosed bypass graft, renal or mesenteric artery stenosis, and evaluation of an access-site injury after cardiac catheterization or mechanical circulatory support.
Access Routes and What They Mean for Nursing
| Route | Typical use | Nursing implications |
|---|---|---|
| Common femoral (retrograde or antegrade) | Workhorse for aortoiliac and infrainguinal work; accommodates large sheaths | Highest retroperitoneal hematoma risk, driven by a puncture above the inguinal ligament. Flat bed rest 2-6 hours depending on sheath size and closure method |
| Radial or brachial | Increasingly used for iliac and even superficial femoral artery work with long-shaft devices | Radial: patent hemostasis band, no blood pressure cuff, venipuncture or IV in that arm. Brachial has higher hematoma and median nerve injury rates than radial because it cannot be compressed against bone |
| Pedal or tibial retrograde | Crossing a below-knee chronic total occlusion after an antegrade attempt fails | Small-vessel spasm is common; monitor forefoot perfusion and a distal puncture site that is easy to overlook |
| Popliteal | Retrograde crossing of a superficial femoral artery occlusion | Prone or lateral positioning during the case; assess for popliteal fossa hematoma and new peroneal nerve symptoms (foot drop) |
Contrast Load and the Renal Patient
A peripheral runoff study consumes far more contrast than a coronary angiogram because the entire aorta-to-foot tree is imaged in stations. Nursing priorities are to know the baseline creatinine and eGFR, provide isotonic saline hydration before and after, hold metformin per policy, help minimize total contrast volume, and trend urine output and creatinine at 24-72 hours.
Carbon dioxide (CO2) angiography is the alternative below the diaphragm in advanced chronic kidney disease or severe contrast allergy: CO2 gas is injected as the contrast agent, displaces blood, and is absorbed and exhaled. It is contraindicated above the diaphragm and in the cerebral circulation because of gas embolism risk. Patients frequently report transient cramping, an urge to move, or a strange sensation during injection — warn them, because an unprepared patient moves and ruins the run.
Runoff describes how many of the three tibial vessels — anterior tibial, posterior tibial and peroneal — remain patent to the foot. Poor runoff predicts poor durability of any proximal intervention and is often the reason a patient returns to the lab weeks later.
Endovascular Therapy Options and Why Location Decides
| Device | Mechanism | Where it is favored | What the nurse watches for |
|---|---|---|---|
| Plain balloon angioplasty | Fractures and displaces plaque, stretching the vessel wall | Below-the-knee vessels and small arteries where a stent would be crushed | Dissection, elastic recoil, early restenosis |
| Drug-coated balloon (DCB) | Paclitaxel or sirolimus transferred to the vessel wall with no metal left behind | Femoropopliteal disease; preserves future treatment options | Requires good vessel preparation. The FDA concluded in July 2023 that the earlier paclitaxel late-mortality signal is no longer supported by the totality of the data |
| Self-expanding nitinol or balloon-expandable bare-metal stent | Mechanical scaffold after dissection or recoil | Aortoiliac disease, where durability is excellent; long superficial femoral artery lesions | Stent fracture in the mobile femoral segment; stents are avoided across the hip and knee joints |
| Drug-eluting stent | Antiproliferative drug plus scaffold | Focal superficial femoral and proximal tibial lesions | In-stent restenosis; antiplatelet duration |
| Covered stent-graft | PTFE-lined scaffold that excludes the wall | Perforation or rupture rescue, aneurysm, in-stent restenosis | Covers side branches, so watch for new territory ischemia |
| Atherectomy — directional, rotational, orbital, laser | Excises, sands, or ablates plaque to debulk it | Heavily calcified lesions; common femoral artery and bifurcations where leaving a stent is undesirable; below-the-knee vessels | Distal embolization is the signature complication, which is why embolic protection filters are frequently used. Also perforation and dissection. Document pedal Doppler signals immediately before and after |
Lesion Location Drives the Strategy
- Aortoiliac disease — primary stenting is first-line with excellent long-term patency; kissing stents are used at the aortic bifurcation. These are the highest-flow, most durable results in the peripheral tree.
- Femoropopliteal disease — the mobile segment, subject to flexion, torsion and compression. Drug-coated balloon with provisional (bailout) stenting, or a drug-eluting stent for a focal lesion. Avoid crossing the knee.
- Infrapopliteal (tibial) disease — intervened on for limb salvage, not for claudication. Plain balloon angioplasty and increasingly drug-coated devices, targeting the angiosome that feeds the wound so the treated vessel actually perfuses the ulcer.
Medical therapy does not stop because a stent went in: high-intensity statin, single or dual antiplatelet therapy per lesion and device, smoking cessation, glycemic and blood pressure control, and supervised exercise all continue. Patency of an intervention is not a cure for atherosclerosis, and reinforcing that is a nursing teaching priority.
During carotid artery stenting, at the moment the operator inflates the balloon across the lesion, the monitor shows sinus bradycardia at 34/min with a systolic blood pressure of 68 mmHg. What is the nurse's most appropriate initial action?
Carotid Disease: Who Gets Revascularized, and How
Symptomatic means an ipsilateral stroke, transient ischemic attack, or amaurosis fugax within the previous 6 months. That single word moves the threshold.
- Symptomatic stenosis of 50% or more (measured by NASCET criteria on the distal internal carotid diameter): revascularize, ideally within 2 weeks of the index event, when the perioperative stroke/death risk is under 6%.
- Asymptomatic stenosis of 70% or more: consider revascularization if life expectancy is 3-5 years and institutional perioperative stroke/death risk is under 3%; otherwise intensive medical therapy.
- Symptomatic under 50%, asymptomatic under 70%, or a chronically occluded internal carotid: medical therapy only — high-intensity statin, antiplatelet therapy, blood pressure and glycemic control, smoking cessation.
The Three Revascularization Options
| Carotid endarterectomy (CEA) | Transfemoral carotid artery stenting (TFCAS) | Transcarotid artery revascularization (TCAR) | |
|---|---|---|---|
| Approach | Open neck incision, arteriotomy, plaque excised, artery patched | Femoral access, catheter navigated up the aortic arch and across the lesion, distal filter embolic protection | Small supraclavicular incision directly into the common carotid; flow is reversed into a femoral vein shunt before the lesion is ever crossed |
| Favored in | Standard-risk patients with symptomatic stenosis of 50% or more; the reference standard | Younger patients with favorable arch anatomy and a hostile neck (prior radiation, prior neck surgery, tracheostomy, very high lesion) | High surgical risk or hostile aortic arch, and older patients in whom arch manipulation drives stroke risk |
| Principal risks | Neck hematoma with airway compromise, cranial nerve injury, perioperative MI | Highest periprocedural stroke rate of the three, because arch atheroma is showered while crossing | Requires an adequate disease-free common carotid segment; brief intolerance of flow reversal |
| Anesthesia | General or regional cervical block | Conscious sedation | General or local |
| Antiplatelet requirement | Aspirin | Mandatory dual antiplatelet therapy | Mandatory dual antiplatelet therapy |
Carotid Nursing Priorities
1. Hemodynamic instability from baroreceptor stimulation. Manipulation at the carotid bulb triggers abrupt bradycardia — occasionally asystole — and hypotension. Anticipate rather than react: pacer pads on, atropine 0.5-1 mg IV and/or glycopyrrolate 0.2 mg IV drawn up, transcutaneous pacing immediately available. The hypotension may persist 24-48 hours and is treated with fluids and a low-dose vasopressor such as phenylephrine or norepinephrine to a defined MAP floor. The trap is overcorrection — chasing a normal-looking pressure in a brain that has been chronically hypoperfused is precisely how hyperperfusion injury is produced.
2. Cerebral hyperperfusion syndrome (CHS). Once a tight stenosis is opened, a chronically maximally dilated distal vascular bed suddenly receives normal perfusion pressure it can no longer autoregulate. The classic presentation is ipsilateral throbbing headache, focal seizure, and a focal neurologic deficit, progressing to cerebral edema or intracerebral hemorrhage; onset ranges from hours to several days. Prevention is strict blood pressure control, typically systolic under 140 mmHg after revascularization and under 120 mmHg once CHS is suspected, with autoregulation taking weeks to recover. A new severe headache after carotid intervention is never "just a headache" — escalate it.
3. Neurologic checks on a defined schedule. NIH Stroke Scale-based assessment covering level of consciousness, pupils, facial symmetry, grip and pronator drift, sensation and speech, commonly every 15 minutes for 4, every 30 minutes for 2, hourly for several hours, then every 2-4 hours. Any new deficit demands immediate provider notification and emergent imaging: think acute stent thrombosis, embolic stroke, or intracerebral hemorrhage.
4. Neck hematoma after endarterectomy is an airway emergency. An expanding hematoma compresses the trachea in a space that cannot expand. Watch for increasing neck circumference, a taut shiny wound, tracheal deviation, voice change, dysphagia, stridor, restlessness and rising work of breathing. Falling oxygen saturation is a late sign — do not wait for it. Emergency management is bedside decompression by opening the incision, so a suture/clip-removal kit and difficult-airway equipment stay at the bedside. Do not transport to the OR first.
5. Cranial nerve injury — assess it deliberately, do not assume stroke.
| Nerve | Finding |
|---|---|
| Hypoglossal (CN XII) | Tongue deviates toward the injured side on protrusion; dysarthria |
| Recurrent laryngeal branch of vagus (CN X) | Hoarseness, weak or breathy voice, weak cough, aspiration risk — check the voice before any oral intake |
| Marginal mandibular branch of facial (CN VII) | Asymmetric lower lip, drooping corner of the mouth on smiling, with a normal forehead and no limb or speech findings |
| Glossopharyngeal (CN IX) | Dysphagia, impaired gag — screen swallowing before advancing diet |
Most of these are neurapraxia from surgical retraction and resolve over weeks. Document a baseline immediately post-op so that a genuinely new deficit is detectable.
6. Antiplatelet therapy and access-site care. Aspirin 81 mg plus clopidogrel 75 mg is loaded before stenting or TCAR and continued for at least 30 days, then aspirin indefinitely with a high-intensity statin. Holding dual antiplatelet therapy after a carotid stent is a stent-thrombosis and stroke risk, not a bleeding safety measure — clarify any hold order. After TFCAS, standard femoral bed rest with distal pulse and site checks applies; after TCAR the patient has both a neck incision and a femoral venous site, and both must be assessed. Ambulation is progressed with the neurologic exam and blood pressure watched, because the first time the patient stands is when orthostatic hypotension can convert a marginal perfusion state into a deficit.
Six hours after carotid endarterectomy for a 90% symptomatic stenosis, a patient reports a severe unilateral throbbing headache. Blood pressure is 198/104 mmHg and he has a brief focal seizure of the contralateral arm. Which complication does this presentation most likely represent?
Four hours after carotid endarterectomy, a patient is restless and hoarse and reports that his dressing feels tight. The nurse finds an increase in neck circumference and a taut wound. Oxygen saturation is 96% on room air. What is the priority action?