What is the interventional treatment for below knee peripheral vascular disease (PVD)?

Interventional Treatment of Below-the-Knee Peripheral Vascular Disease

For below-the-knee (BTK) peripheral vascular disease, balloon angioplasty is the established first-line endovascular therapy, with adjunctive devices (stents, atherectomy) reserved strictly as salvage for failed angioplasty results. 1

Primary Treatment Approach

Balloon angioplasty alone is the cornerstone of BTK intervention, achieving technical success rates exceeding 90% and limb salvage rates around 95% even in complex, diffuse disease 2. The primary goal is re-establishing pulsatile, straight-line flow to the foot 2.

Key Technical Considerations:

• Stents are NOT recommended as primary therapy in tibial arteries 1
• Stents and other adjunctive devices (atherectomy, cutting balloons, lasers, thermal devices) should only be used as salvage therapy for suboptimal balloon angioplasty results, specifically: 1
  • Persistent translesional gradient
  • Residual diameter stenosis >50%
  • Flow-limiting dissection

Clinical Context for Intervention

Appropriate Indications:

• Chronic limb-threatening ischemia (CLTI): The most common indication (62.8% of BTK interventions), requiring revascularization as soon as possible 3, 4
• Symptomatic claudication: Only after 3 months of optimal medical therapy and supervised exercise therapy have failed to improve quality of life 3, 5
• Combined with inflow procedures: BTK intervention is appropriate when performed alongside femoropopliteal interventions (58% of cases) 4

Contraindications:

• Asymptomatic PAD: Endovascular intervention is NOT indicated 1, 3
• Prophylactic therapy: NOT indicated to prevent progression to CLTI 1, 3
• No significant pressure gradient: Intervention contraindicated if no hemodynamically significant stenosis despite vasodilator augmentation 1

Evidence Quality and Limitations

Critical caveat: The effectiveness of uncoated/uncovered stents, atherectomy, cutting balloons, thermal devices, and lasers for infrapopliteal lesions (except as salvage) is not well established 1. The 2018 ACC/AHA guidelines specifically note that BTK atherectomy lacks comparative evidence for general use, with exceptions only for severe calcification and undilatable lesions 1.

Expected Outcomes:

• Acute technical success: >90% 2
• Limb salvage at 1 year: ~95% 2
• Restenosis rates at 1 year: 30-80% depending on lesion complexity (30% for short stenoses, up to 80% for occlusions) 2
• Major adverse limb events (MALE) at 1 year:
  • CLTI patients: 30.5% 4
  • Claudication patients: 15.8% 4

Procedural Algorithm

1. Confirm hemodynamic significance: Obtain translesional pressure gradients with vasodilation for stenoses 50-75% 1

2. Attempt balloon angioplasty first: This is the established standard 1, 2

3. Assess immediate result:

   • If successful (no residual stenosis >50%, no flow-limiting dissection, no persistent gradient) → Stop
   • If suboptimal → Proceed to salvage therapy

4. Salvage therapy options (only if balloon angioplasty fails): 1

   • Stent placement
   • Atherectomy (particularly for severe calcification/undilatable lesions) 1
   • Other adjunctive devices

5. Treat outflow vessels: If substantially impaired outflow exists, consider treating BTK arteries in the same intervention 5

Important Clinical Pitfalls

• Do not use primary stenting: This is explicitly contraindicated in tibial arteries 1
• Address inflow first: Always eliminate inflow obstructions when treating downstream BTK lesions 5
• CLTI carries higher risk: Despite similar procedural success, CLTI patients have 2-fold higher mortality and 4-fold higher major amputation rates at 1 year compared to claudication patients 4
• Drug-coated balloons: While used more frequently in claudication (15% vs 5% in CLTI), their superiority over conventional balloon angioplasty remains unproven 2, 4
• Patient selection matters: BTK disease typically affects patients with diabetes and end-stage renal disease, who have small-vessel disease and higher comorbidity burden 6

Adjunctive Medical Therapy

Following BTK revascularization, combination rivaroxaban and aspirin should be considered for patients with high ischemic risk and non-high bleeding risk 3, 5.