Viva · IR system
Arterial Viva Questions
Oral-exam style questions and answers on arterial for MD, DNB and super-specialty practical examinations. Each answer links back to the playbook or Library entry it was written from.
- What is the preferred femoral puncture site for lower-limb angiography?
- The preferred site is the common femoral artery over the femoral head, below the inguinal ligament and above the origins of the superficial and profunda femoris arteries. This location permits effective compression and reduces retroperitoneal bleeding and low-puncture complications.
- Why should the foot be imaged in chronic limb-threatening ischemia?
- Foot imaging demonstrates the dorsalis pedis, plantar arteries, pedal arch and the artery supplying the wound-related angiosome. This information is essential for selecting a target arterial path and confirming whether in-line flow can be restored to the foot.
- What are the advantages and limitations of bolus-chase angiography?
- Bolus-chase angiography rapidly surveys both lower limbs with one proximal injection. Its limitations include motion and misregistration artifacts, unequal flow between limbs and inadequate depiction of slow-flow tibial and pedal vessels.
- How do you differentiate true distal occlusion from slow flow?
- Obtain delayed acquisitions and a selective injection closer to the suspected lesion after confirming adequate proximal inflow. Collateral reconstitution and late distal opacification indicate delayed flow rather than absence of a patent distal vessel.
- What is the role of carbon dioxide angiography?
- Carbon dioxide can reduce iodinated contrast exposure in selected patients with kidney dysfunction or iodinated contrast hypersensitivity. It performs best in larger vessels below the diaphragm, provides poorer distal runoff images and must not be injected into arterial territories above the diaphragm.
- What information should be reported for an arterial occlusion?
- Report the arterial segment, occlusion length, proximal cap morphology, calcification, collateral pathways, distal reconstitution, number and quality of runoff vessels and the condition of the pedal circulation.
- What is the most dangerous consequence of a high common femoral puncture?
- A high puncture above the inguinal ligament can cause non-compressible retroperitoneal hemorrhage. It may present with hypotension, tachycardia, falling haemoglobin and abdominal, flank or back pain.
- What should you do if the distal pulse disappears after angiography?
- Immediately reassess the limb and perform targeted angiography or duplex ultrasound to identify thrombosis, dissection or embolization. Maintain wire access when possible and initiate urgent endovascular or surgical rescue according to limb viability.
- How do you classify acute limb ischemia before treatment?
- Use the Rutherford classification. Class I is viable without sensory or motor loss; IIa is marginally threatened with sensory loss limited to the toes but no weakness; IIb is immediately threatened with sensory loss beyond the toes and mild or moderate weakness; class III is irreversible with profound anesthesia and paralysis.
- Which Rutherford class is the best indication for catheter-directed thrombolysis?
- Rutherford IIa is the standard threatened-limb indication because sufficient time usually remains for thrombolysis. Selected IIb limbs may receive promptly initiated CDT only when combined with rapid aspiration or thrombectomy; prolonged lysis alone risks irreversible ischemia.
- What is the commonly used alteplase dose for arterial catheter-directed thrombolysis?
- A commonly used low-dose infusion is 0.25–1.0 mg/hour through an intrathrombus multi-side-hole catheter. ESVS cites a maximum recommended catheter-directed alteplase dose of 40 mg, although the exact protocol must follow institutional policy.
- Should therapeutic heparin be continued during catheter-directed thrombolysis?
- No. Unfractionated heparin is administered immediately on diagnosis, but continuous systemic therapeutic heparinization during CDT is not recommended because it increases major bleeding. A low-dose sheath infusion may be used according to local protocol.
- What is the endpoint of endovascular treatment for acute limb ischemia?
- The endpoint is removal of clinically important thrombus, brisk antegrade flow, correction of the causative lesion and adequate distal perfusion, ideally with at least one inline tibial artery to the foot. Clinical improvement in pain, temperature, neurological status and Doppler signals must accompany the angiographic result.
- Why must the underlying lesion be treated after thrombolysis?
- Thrombolysis removes the acute thrombus but frequently exposes the stenosis, graft-anastomotic lesion, stent failure or aneurysm that caused thrombosis. Failure to correct this lesion results in a high risk of early rethrombosis.
- What findings suggest post-reperfusion compartment syndrome?
- Disproportionate pain, pain on passive stretch, tense swelling and new or recurrent sensory or motor deficit are key findings. Pulses may remain present; clinically established compartment syndrome requires immediate four-compartment fasciotomy.
- How do aspiration, mechanical and pharmacomechanical thrombectomy differ?
- Aspiration removes thrombus using syringe or pump suction. Mechanical thrombectomy fragments and extracts thrombus using device-generated mechanical energy, while pharmacomechanical thrombectomy combines mechanical action with local thrombolytic delivery to accelerate clearance and reduce the required lytic dose.
- What are the diagnostic Doppler findings of a pseudoaneurysm?
- Color Doppler demonstrates bidirectional swirling yin-yang flow within the sac. Spectral Doppler at the neck shows a to-and-fro waveform, with systolic flow into the sac and diastolic flow back into the parent artery.
- Where should the needle tip be positioned during thrombin injection?
- The tip should lie within the residual flowing portion of the sac, preferably near its periphery and as far from the neck as possible. The needle tip, neck and parent artery must remain visible throughout injection.
- What thrombin concentration and dose are commonly used?
- A commonly used concentration is 1000 IU/mL. Thrombin is injected in small 100–200 IU aliquots with Doppler reassessment after each dose; many pseudoaneurysms thrombose with a total dose of approximately 200–500 IU, although the required dose varies.
- What is the endpoint of thrombin injection?
- The endpoint is complete disappearance of Doppler flow within the sac and neck, with preserved patency of the parent artery, distal arteries and adjacent vein and unchanged distal perfusion.
- Why is a short, wide neck dangerous?
- A short, wide neck permits thrombin to escape rapidly into the parent artery, causing native-artery thrombosis or distal embolization. Protected techniques or surgical or endovascular alternatives should be considered.
- Can thrombin injection be performed during anticoagulation?
- Yes. Unlike ultrasound-guided compression, UGTI usually remains effective during therapeutic anticoagulation. Anticoagulation should be interrupted only after assessing the indication, bleeding severity and thrombotic risk.
- What is the most feared complication of UGTI?
- The most feared complication is thrombin escape into the parent artery causing acute arterial thrombosis or distal embolization. Immediate recognition requires continuous ultrasound monitoring and comparison of distal pulses and arterial waveforms before and after injection.
- How do you manage recurrent flow after initially successful injection?
- Repeat duplex mapping and perform another low-dose injection if the sac and neck remain suitable. Repeated failure, a wide neck, associated arteriovenous fistula or a very large lesion should prompt balloon-assisted treatment, covered stent placement, embolization or surgery.