Viva · IR system
Venous Viva Questions
Oral-exam style questions and answers on venous for MD, DNB and super-specialty practical examinations. Each answer links back to the playbook or Library entry it was written from.
- You puncture a calf malformation and the phlebogram shows immediate drainage into the popliteal vein. Why does this change your plan, and what do you do?
- Rapid outflow both washes the sclerosant away before it can injure endothelium, causing treatment failure, and exports it systemically, risking pulmonary embolism or cardiopulmonary collapse. Apply a proximal tourniquet or manual compression and repeat the run; if outflow is still uncontrolled, coil-occlude the dominant draining vein, reduce foam volume, and abandon any plan to use ethanol.
- Why is bleomycin often preferred over ethanol for a floor-of-mouth malformation, even though ethanol is more potent?
- The limiting factor in that anatomical site is post-procedural swelling into a space that cannot expand, which threatens the airway. Bleomycin-polidocanol foam produces markedly less inflammatory swelling than ethanol, so the reduced potency is an acceptable trade for a manageable airway.
- A patient with an extensive thigh venous malformation has D-dimer of 8 mg/L and fibrinogen of 1.2 g/L. What is happening and how does it alter management?
- This is localized intravascular coagulopathy from chronic stasis and consumption within the malformation. Proceeding risks significant periprocedural bleeding and severe pain. Defer, start low molecular weight heparin for 10-14 days before and after treatment, and correct fibrinogen before the session.
- Why do you aspirate the compartment before injecting sclerosant rather than simply injecting into the blood-filled lesion?
- Residual blood dilutes the agent and buffers it from the endothelium, and the added volume raises intralesional pressure and forces sclerosant into the drainage pathway. Aspiration to collapse maximises effective concentration at the endothelial surface and keeps the agent contained.
- The skin blanches midway through injection of a superficial forearm lesion. What has happened and what do you do next?
- Sclerosant has entered the dermis or subdermal plexus, usually because the needle was angled too perpendicularly in a superficial lesion. Stop injecting immediately, withdraw the needle deeper, do not treat that compartment further in this session, and dress the area with anticipation of blistering and possible ulceration.
- Your MRI shows a mixed lesion with a large septated cyst and a diffuse infiltrative T2-bright component. How do you counsel the patient about expected response?
- The macrocystic component should respond well to aspiration and doxycycline, but the diffuse infiltrative component is microcystic lymphatic disease, which responds poorly to sclerotherapy. Counsel that the discrete swelling will improve substantially while the diffuse infiltration may not, and raise sirolimus or surgical options for the latter.
- How much bleomycin can you give in one session, and what governs that number?
- 0.5 to 1 mg/kg to a maximum of 15 mg. The ceiling is set to limit systemic absorption and cumulative exposure, since bleomycin pulmonary toxicity is dose-dependent; the practical consequence is that extensive lesions must be treated in staged sessions rather than in one sitting.
- Six weeks after ethanol sclerotherapy a patient has persistent foot drop. What is the immediate diagnostic priority?
- Distinguish direct ethanol neurotoxicity, which is not reversible surgically, from a compressive haematoma or tense post-procedural swelling, which is. Image urgently with ultrasound or MRI; decompress if compression is demonstrated, otherwise manage expectantly with physiotherapy and neurophysiological follow-up, as partial deficits often improve over months.
- What is the preferred access for a chest port?
- Ultrasound-guided internal jugular access, commonly right-sided, provides a straight course and avoids costoclavicular pinch-off.
- Where should the catheter tip lie?
- In the lower SVC at or near the cavoatrial junction, approximately 2–3 cm below the carina on fluoroscopy.
- Why is a Huber needle used?
- It is a non-coring needle that penetrates the silicone septum without removing material and prolongs port durability.
- What suggests a fibrin sheath?
- The port can often be flushed but blood cannot be aspirated; a port contrast study demonstrates retrograde contrast tracking along the catheter.
- Which vein is preferred for PICC placement?
- The basilic vein is usually preferred because it is relatively large and follows a straighter course toward the axillary vein.
- Where should the PICC tip lie?
- The desired tip position is the lower SVC or cavoatrial junction.
- Why should PICCs be avoided in advanced chronic kidney disease?
- PICC-associated thrombosis or stenosis may compromise upper-extremity veins required for future arteriovenous dialysis access.
- Are prophylactic antibiotics routinely required?
- No. Strict aseptic technique and maximal sterile barriers are required, but routine systemic antibiotic prophylaxis is not recommended.
- What is the first-line device for intravascular foreign-body retrieval?
- A **loop snare** is first-line when an accessible free end is present because it is flexible, controllable and can draw the captured object into a sheath.
- What is the preferred access for a catheter fragment in the right heart or pulmonary artery?
- The right common femoral vein is commonly used because it provides a broad inferior approach. Internal jugular access may be better when it gives more coaxial alignment, so access is chosen from the object's position and orientation.
- How do you retrieve a catheter fragment when neither end is free?
- Use a pigtail catheter to hook and disengage an end in a roomy vessel, then snare it. Passing the pigtail through an already open snare, the pigtail-through-snare technique, reduces loss of the newly created free end.
- Why should a long foreign body be snared near one end?
- End capture lets the object trail into the sheath. Midpoint capture doubles its profile, impedes sheath entry and increases vessel or valve trauma.
- When should you abandon percutaneous retrieval?
- Stop when there is firm resistance suggesting endothelialization or entanglement, an unsafe sharp or rigid extraction path, perforation, uncontrolled migration or inability to contain the object in a sheath. Surgical or hybrid retrieval is then safer.
- What is the key rule during pulmonary-artery foreign-body retrieval?
- Use atraumatic, coaxial manipulation and avoid force in distal branches. The pulmonary artery is thin-walled, and perforation may present with massive hemoptysis and hemodynamic collapse.
- Why is real-time ultrasound preferred?
- It improves cannulation success and reduces attempts, arterial puncture and other mechanical complications. A pre-puncture scan alone is not equivalent to real-time needle-tip visualization.
- What is the most important safety step before dilation?
- Confirm that the guidewire is intravascular, preferably by ultrasound scanning proximal to the puncture site. Never dilate on blood colour or aspiration alone.
- Where should an upper-body CVC tip lie?
- A usual target is the lower third of the SVC or cavoatrial junction. The 2025 Association of Anaesthetists guidance also accepts the high right atrium, subject to device type and local policy.
- What should you do if a large-bore catheter enters the carotid artery?
- Do not remove it blindly. Leave a dilator or catheter ≥6 Fr in situ and obtain urgent vascular surgery or interventional radiology assistance for controlled removal and arterial repair.
- A young man has a left varicocele and cross-sectional imaging shows the left renal vein compressed between the aorta and superior mesenteric artery with prominent lumbar collaterals. Why should you not embolise the internal spermatic vein?
- The varicocele is secondary: the gonadal vein is functioning as a decompressive outflow channel for an obstructed left renal vein. Occluding it removes that outflow and can precipitate renal venous hypertension with haematuria and flank pain, so the renal vein obstruction, not the gonadal vein, is the target.
- Your completion venogram looks satisfactory but the patient has a palpable varicocele at 3 months with reflux on Doppler. What is the most likely anatomical explanation and how would you have detected it at the index procedure?
- A duplicated or plexiform internal spermatic vein, or a renal capsular or lumbar collateral reconstituting the vein below the proximal coils. It is detected by performing the diagnostic Valsalva venogram from the low internal spermatic vein in more than one projection before any coil is placed, so that overlapping parallel limbs are separated.
- Why is the distal coil pack placed at the level of the inguinal ligament rather than lower, closer to the varicocele itself?
- Embolising into the pampiniform plexus thromboses the plexus directly and produces severe thrombophlebitis rather than a controlled occlusion of the refluxing conduit. The therapeutic aim is to interrupt the refluxing column above the plexus and let the cremasteric and deferential veins provide drainage.
- A coil elongates and disappears cranially during deployment. What do you do at the table, in order?
- Stop deploying and locate the coil fluoroscopically first, since its position dictates the retrieval strategy. Snare it from the existing venous access while it remains in the renal vein or inferior vena cava, where retrieval is straightforward; if it has already reached the pulmonary circulation, image the chest and weigh retrieval against leaving a stable asymptomatic peripheral coil, then resume with a properly oversized or detachable coil.
- Why does hydrocele occur after surgical varicocelectomy but essentially not after embolisation?
- Hydrocele follows inadvertent division or ligation of the spermatic lymphatics running with the cord. Embolisation is entirely intraluminal and does not touch the lymphatics, so the mechanism is absent.
- You cannot find the right internal spermatic vein at the inferior vena cava. What are your next steps and why?
- Search the anterolateral caval wall just below the right renal vein with a reverse-curve catheter, since the right vein enters at an acute cranially directed angle that a forward-facing catheter cannot engage. If still unfound, catheterise the right renal vein, because in a minority the right internal spermatic vein drains into it rather than the cava.
- What is the objective endpoint that lets you finish the case, and why is contrast stasis at the coil pack alone insufficient?
- Stasis at the coil pack with no contrast beyond it and, critically, no opacification of the pampiniform plexus by any route on Valsalva venography. Stasis at the pack alone can coexist with a duplicated limb or capsular collateral that fills the plexus in parallel, which is exactly the finding that predicts recurrence.
- Why is semen analysis deferred to 3-6 months rather than repeated at 6 weeks?
- A full spermatogenic cycle with epididymal transit takes approximately three months, so a sample at 6 weeks reflects germ cells produced before treatment and will show no change, risking a false conclusion of clinical failure.
- Which space is compressed in venous thoracic outlet syndrome, and what are its boundaries?
- The costoclavicular space, bounded superiorly by the clavicle and subclavius muscle, inferiorly by the first rib, anteriorly by the costoclavicular ligament, and posteriorly by the anterior scalene muscle. The subclavian vein is compressed here because it is the only one of the three neurovascular structures that passes anterior to the anterior scalene.
- Why is thrombolysis alone inadequate treatment for Paget-Schroetter syndrome?
- Lysis clears the thrombus but does not address the underlying costoclavicular compression and the fibrotic intrinsic stenosis that caused it. Anticoagulation or lysis without decompression carries a high rate of rethrombosis and persistent symptoms, so lysis is the first stage of a staged pathway that ends in thoracic outlet decompression.
- What is the time window for effective catheter-directed thrombolysis and why?
- Roughly 14 days from symptom onset. Beyond this, the thrombus becomes organised and adherent, plasminogen content falls, and lytic response drops sharply while the bleeding risk remains unchanged.
- Why should a stent not be placed in the subclavian vein before decompression?
- The retroclavicular subclavian vein sits in a mobile bony vice between the first rib and clavicle. A stent placed while that space is intact is subject to repetitive crush with arm movement, leading to deformation, fracture and occlusion, and it complicates any subsequent surgical reconstruction. Urschel and Patel specifically documented the failure of intravenous stents in this setting.
- How would you distinguish primary effort thrombosis from secondary upper-extremity DVT, and why does it matter?
- Primary effort thrombosis occurs in young, active patients with repetitive overhead activity and no indwelling device, with positional compression at the costoclavicular junction. Secondary thrombosis is associated with central catheters, pacemaker leads or malignancy. Only the primary form is treated with the lysis plus decompression pathway; secondary disease is usually managed with anticoagulation and device management.
- A duplex ultrasound is reported as normal but you strongly suspect effort thrombosis. What do you do?
- Duplex is limited in the retroclavicular segment where the clavicle blocks the acoustic window, so a negative study does not exclude the diagnosis. Proceed to CT or MR venography, or to catheter venography with positional imaging, if clinical suspicion remains high.
- You have cleared the thrombus and a tight waist at the costoclavicular junction recoils immediately after 12 mm balloon dilatation. What is your next step?
- Accept the result and refer for decompression. Immediate recoil indicates extrinsic bony compression rather than a dilatable intrinsic lesion. Escalating balloon size risks venous rupture and stenting risks crush; the definitive treatment is first rib resection with venolysis.
- Which access site do you prefer for upper-extremity CDT and why?
- Ultrasound-guided basilic vein access in the mid-upper arm. It is superficial, medial to the brachial artery and median nerve, and gives a straight course into the axillary vein, unlike the cephalic vein which turns acutely at the deltopectoral groove.
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Image-Guided Sclerotherapy of Low-Flow Venous and Venolymphatic Malformations
Ultrasound-Guided Nontunneled Central Venous Catheter Placement
Ultrasound-Guided Nontunneled Central Venous Catheter Placement
Ultrasound-Guided Nontunneled Central Venous Catheter Placement
Ultrasound-Guided Nontunneled Central Venous Catheter Placement
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty
Venous Thoracic Outlet Syndrome Catheter-Directed Thrombolysis and Venoplasty