Venous Interventions (Varicose, Venous Stenting)
- Veins are the low-pressure, one-way "return lane" of the circulation, and most venous problems come down to broken one-way valves or a clogged channel.
- Varicose veins happen when leg vein valves leak, blood pools backward (reflux), and the superficial veins swell — IR treats this by sealing the leaky vein shut (ablation) so blood reroutes to healthy ones.
- Heat-based and glue-based ablation have largely replaced the old "rip the vein out" surgery for the great saphenous vein, and they're done wide-awake through a needle.
- Venous stenting is for the opposite problem: a vein that's squashed or scarred shut (often the iliac vein in May-Thurner), where we prop the channel back open with a metal mesh.
- Ultrasound is the workhorse for planning and guidance — you're driving by sound, not by eye.
If arteries are the glamorous high-pressure firehoses everyone learns first, veins are the humble drainage system nobody appreciates until it backs up. And back up they do. Venous interventions are basically two stories: "this vein leaks the wrong way" and "this vein is squashed shut." Get those two framings straight and the whole topic falls into place.
The plumbing problem behind varicose veins
Leg veins fight gravity for a living. To haul blood uphill from your ankles to your heart, they rely on little one-way flap valves — picture the saloon doors in an old western, swinging open to let blood up and slamming shut to stop it falling back down. When those valves get floppy and leaky, blood sloshes backward down the leg. Radiologists call this reflux, and it's the engine of chronic venous disease.
The pooled blood stretches the superficial veins — usually the great saphenous vein running up the inner thigh — into those bulging, ropey varicosities. Over time you get aching, swelling, skin discoloration, and in bad cases ulcers near the ankle. It's not just cosmetic; it's a pressure problem with real consequences.
Sealing the leaky vein shut
Here's the counterintuitive part that trips everyone up: the treatment for a bad superficial vein is to close it off entirely. Sounds reckless — until you remember the leg has deep veins doing the real work. The bad superficial vein is leaking backward and making things worse, so removing it from the circuit actually improves drainage. Blood simply reroutes to healthier veins.
There are a few ways to seal it, all done through a needle with ultrasound guidance and the patient awake:
| Method | How it closes the vein | The analogy |
|---|---|---|
| Thermal ablation (radiofrequency or laser) | A catheter heats the vein wall so it scars shut | Shrink-wrapping a straw with a hot iron |
| Cyanoacrylate (medical "glue") | Glue is injected to bond the walls together | Squeezing shut a tube of toothpaste and gluing it |
| Foam sclerotherapy | A frothy irritant is injected to inflame and collapse the vein | Filling the channel with shaving cream that makes the walls stick |
Thermal ablation uses tumescent anesthesia — a big cuff of dilute numbing fluid injected around the vein. It does double duty: it numbs the area and acts as a heat sink, pushing nearby nerves and skin away from the hot catheter so you don't cook them.
These have largely displaced the old surgical "stripping," where the vein was literally pulled out through incisions. Less bruising, faster recovery, and you walk out the same day.
The other story: a vein squashed shut
Now flip the problem. Sometimes a vein isn't leaking — it's blocked or compressed. The classic is May-Thurner, where the right iliac artery crosses over and pins the left iliac vein against the spine like a garden hose under a parked car. Chronic compression scars the vein, and you get a swollen left leg or a tendency toward deep vein thrombosis.
For these, sealing the vein shut would be exactly the wrong move. Instead we do venous stenting: thread a wire across the narrowed segment, balloon it open (angioplasty), and leave a self-expanding metal mesh scaffold to hold the channel open. Veins are squishy and easily crushed, so venous stents are built bigger and more crush-resistant than their arterial cousins.
A useful rule of thumb: superficial venous reflux → close the vein. Deep venous obstruction → open the vein. Same toolbox, opposite goals.
Before you start: rule out the clot you can't see
The single most important pre-procedure question is whether the deep system is open. If someone has an undiagnosed deep vein clot and you go ablating their superficial veins, you've just removed a drainage route the leg may be depending on.
Never treat varicose veins without first confirming the deep veins are patent on ultrasound. The superficial veins you're about to close may be acting as collaterals around a deep obstruction — close them and you can make the leg dramatically worse.
Complications and aftercare
Most patients do beautifully, but a few things deserve respect:
- Heat-induced thrombosis at the junction where the treated vein meets the deep system — a clot poking its nose into the deep vein. This is why we image the junction afterward.
- Nerve irritation (especially near the lower calf, where nerves run close to the saphenous vein) causing tingling.
- For glue: occasionally a localized inflammatory reaction along the treated vein.
- For stents: the eternal worry of the stent clotting off, which is why patients usually go home on blood thinners.
Post-procedure ultrasound after ablation isn't optional box-ticking — its main job is to make sure no clot has crept from the sealed superficial vein into the deep system.
When deep clot is the problem rather than something to avoid, the conversation shifts to clot-busting tools — see thrombolysis and thrombectomy — and to mechanical clot-catchers like IVC filters.
The whole field rewards one habit: before you touch a vein, decide which story you're in. Leaky and superficial? Seal it. Squashed and deep? Open it. Everything else is just choosing the right catheter.