What are the concerns with leg pain and swelling after femoral popliteal angioplasty and stent placement?

Post-Femoral-Popliteal Angioplasty and Stent Complications: Leg Pain and Swelling

Acute stent thrombosis is your primary concern with leg pain and swelling after femoral-popliteal angioplasty and stent placement, occurring in 2-6% of cases within the first 30 days, and requires immediate evaluation to prevent limb loss. 1, 2

Immediate Life-Threatening Concerns

Acute Stent Thrombosis

• Occurs in 2-6% of patients within 30 days post-procedure and presents with sudden onset leg pain, swelling, and worsening ischemia 1, 2
• Requires urgent duplex ultrasound within 24 hours to assess stent patency 1
• Can be successfully salvaged with urokinase infusion if caught early 1
• Risk is higher with poor distal arterial runoff (p < 0.05) 2

Acute Limb Ischemia

• Manifests as severe pain, pallor, pulselessness, paresthesias, and paralysis 3
• May result from thromboembolism requiring percutaneous aspiration or emergency vascular surgery 3
• One study reported emergency surgery was needed in severely ischemic limbs after popliteal approach complications 3

Subacute Complications (Days to Weeks)

Arterial Perforation or Dissection

• Occurs in approximately 11% of cases during or immediately after the procedure 3
• Usually presents with localized pain and swelling at the access site 3
• Most cases resolve without clinical sequelae, but monitor for expanding hematoma 3

Access Site Hematoma

• Popliteal hematomas can occur with popliteal approach procedures 3
• Presents as localized swelling, pain, and ecchymosis 3
• Rarely causes compartment syndrome but requires monitoring 3

Intermediate-Term Concerns (Weeks to Months)

In-Stent Restenosis

• Detected by duplex ultrasonography in 28% of patent stents at mean 9.5 months (range 4-15 months) 1
• Defined as >50% luminal narrowing on imaging 4
• Stents extending below the inguinal ligament have significantly higher restenosis rates (hazard ratio 1.77-6.5, p=0.0146) 5
• Four of seven patients with restenosis remained asymptomatic despite ultrasound findings 1

Recurrent Symptoms Despite Patent Stent

• Mean ankle-brachial index improves from 0.60 pre-treatment to 0.88 at 3-6 months, so values below this suggest problems 1
• Persistent severe leg pain (visual analog scale >5) fails to resolve in 28% of cases 5
• Severe leg swelling (grade 3) persists in 30% despite patent stents 5

Diagnostic Algorithm

Initial Assessment (Within 24 Hours)

• Obtain ankle-brachial index immediately - should be ≥0.88 if stent is functioning 1
• Perform duplex ultrasound within 24 hours to assess stent patency and flow velocities 1
• Examine for access site complications (hematoma, pseudoaneurysm) 3

If Symptoms Persist Beyond 2 Weeks

• Imaging with dilute iodinated contrast is indicated when extremity edema persists beyond 2 weeks 6
• CT venography can evaluate both arterial and venous complications simultaneously 6
• Look for visible collateral circulation, which may indicate persistent hemodynamically significant stenosis 5

Management Based on Findings

For Confirmed Acute Thrombosis

• Immediate thrombolytic therapy (urokinase infusion) can salvage 50% of acutely thrombosed stents 1
• Emergency surgical intervention if limb-threatening ischemia develops 3

For In-Stent Restenosis

• Target-lesion revascularization required in 14.7% of primary stent patients at 1 year 4
• Balloon angioplasty alone has very high failure rates for in-stent restenosis 7
• Consider repeat stenting for recurrent stenosis 7

For Persistent Swelling Without Thrombosis

• Elevation of affected limb to improve venous drainage 6
• Physical therapy focused on lymphatic drainage techniques 6
• Monitor for skin changes indicating need for intervention 6

Critical Pitfalls to Avoid

• Do not assume mild symptoms will resolve spontaneously - 20-30% of patients have persistent symptoms despite patent stents 7, 5
• Do not delay imaging beyond 24 hours if acute thrombosis is suspected - early intervention salvages most thrombosed stents 1
• Do not ignore symptoms in patients with documented patent stents - restenosis can be present despite initial patency 1
• Poor distal runoff is the strongest predictor of failure (p < 0.05), so these patients require more aggressive monitoring 2

Long-Term Monitoring Requirements

• Follow-up duplex scanning at 3-6 month intervals to detect restenosis before symptoms develop 1, 2
• Primary patency rates are 75% at 18 months and 70% at 3 years 1, 5
• Secondary patency (after reintervention) reaches 89-94% with appropriate surveillance 1, 5
• Stent fracture is rare (1 patient in large series) and usually manageable with second stent placement 7