Iliac artery interventions
For stenoses of the iliac segment, balloon angioplasty (PTA) is the baseline solution. It is technically successful in nearly 100% of cases. Primary stenting is not performed routinely: it is indicated only if PTA is ineffective, in the presence of ulcerated plaques, or upon rapid recurrence of narrowing. Although the five-year vessel patency (64–75%) is lower than with classic open aortobifemoral bypass, low invasiveness makes this approach preferable.
A different tactic is used for occlusions: here, surgeons prefer primary stenting. The reason lies in safety—isolated balloon dilation carries a high risk (from 7 to 24%) of fragment detachment and significant distal embolization. Covered stents (stent-grafts) demonstrate the best long-term results in the iliac bifurcation zone.
Features of working with femoral arteries
The choice of method changes dramatically depending on the level of the femoral lesion:
- Common femoral artery (CFA): The endovascular approach is inferior to surgery here. Open endarterectomy under local anesthesia is more effective than PTA, especially if the plaques are calcified and eccentric. CFA and superficial femoral artery (SFA) occlusions also require surgical intervention.
- Superficial femoral artery (SFA): For SFA stenoses, angioplasty returns to the standard position. Its advantages include a low complication rate, the possibility of repeating the procedure, and preservation of the great saphenous vein (which the patient may need for bypass surgery in the future).
If the SFA is completely occluded, subintimal angioplasty is used. A guidewire with a catheter is advanced outside the true vessel lumen (beneath the intima), bypasses the occlusion zone along the wall, and re-enters the lumen. The newly formed channel is then dilated using a long balloon (one long balloon is preferable to several overlapping short ones).
Distal bed and innovative coatings
Crural (tibial and fibular) and popliteal artery lesions are treated predominantly endovascularly using small-caliber instruments. The main clinical rule is that interventions at this level are performed upon the development of symptoms of critical lower limb ischemia (rest pain or trophic ulcers). The limb salvage rate after such operations at three years is quite high—around 82%.
To combat restenosis in all segments, drug-eluting balloons and stents (drug-eluting) are being actively implemented. Such drugs as sirolimus or paclitaxel locally suppress the proliferation of vascular wall cells (limiting neointimal hyperplasia).
Acute ischemia and embolization
If ischemia is acute (severe pain, paresthesias, motor dysfunction), the limb is at risk of loss, and every hour counts. Intra-arterial thrombolysis is rarely used today due to high risks of hemorrhagic complications. It has been replaced by percutaneous aspiration (removal of the thrombus via a large-bore catheter) and mechanical thrombectomy devices.
In addition to restoring the lumen, interventional radiology also solves inverse problems. For example, in bleeding (including iatrogenic), access is achieved via the contralateral artery, followed by superselective catheterization of the damaged vessel with a microcatheter and its targeted occlusion using microcoils.
Briefly: answers to topical questions
What types of stents (by deployment mechanism and material) are used in endovascular treatment of lower extremity arteries?
Endovascular treatment utilizes stents that differ in their deployment mechanism, presence of a covering, and drug-eluting properties.
By deployment mechanism, there are two main types:
- Balloon-expandable stents (Balloon-expandable stents) are mounted on a balloon catheter and expand when the balloon is inflated.
- Self-expanding stents (Self-expanding stents) are compressed on a delivery catheter, released by removing the outer sheath, and expand due to their own radial force.
By material and presence of a covering, stents are classified into:
- Covered (covered) and uncovered (uncovered).
- Drug-eluting (drug-eluting) and bare-metal (bare metal).
How is chronic lower limb ischemia classified according to the Fontaine-Pokrovsky classification?
The sources do not provide detailed breakdown of the stages of the Fontaine-Pokrovsky classification.
It is only indicated that by the degree of chronic ischemia, the traditional stages are distinguished: from intermittent claudication upon physical exertion to the onset of rest pain and the formation of trophic ulcers or necrosis.
Additionally, it is noted that the use of the Fontaine-Pokrovsky and Rutherford classifications is inappropriate in patients with diabetes mellitus, as they do not reflect the actual severity of chronic arterial insufficiency in this pathology.
Class and exam questions
Why is a stent immediately placed for an iliac artery occlusion, but not for a stenosis?
During balloon angioplasty of occlusions without a stent, there is an extremely high risk (up to 24%) of distal embolization by thrombus fragments. A stent allows these masses to be safely 'pressed' against the vessel wall.
What is the essence of subintimal angioplasty?
This is a method of bypassing a long occlusion. Instruments are advanced outside the lumen (within the thickness of the vessel wall beneath the intima), bypass the occluded segment, and return to the true lumen, after which the new channel is dilated with a balloon.
When is intervention on crural arteries justified?
Procedures on the tibial and fibular arteries are performed only in critical lower limb ischemia that threatens amputation (presence of rest pain or necrosis).
What else to study on this topic
- Anatomy of the lower limb and pelvic arterial bed
- Comparison of bare-metal stents and stent-grafts in the iliac position
- Technique and indications for common femoral artery endarterectomy
- Mechanism of action of drug-eluting balloons and stents (drug-eluting)
- Devices for percutaneous mechanical thrombectomy and aspiration
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