Fem-pop & Infra-pop occlusive disease

  1. Anatomy:
  2. Aorta to common iliacs, internal iliac & external iliac
  3. External iliac- becomes common femoral in the femoral triangle, after inguinal ligament (borders: ing. Ligament, sartorius laterally, adductor longus laterally)
  4. Common femoral artery- deep & superficial branches with circumflex arteries
  5. Superficial femoral artery- deep to sartorius, through Hunter’s (adductor) canal, becomes popliteal artery.
  6. Popliteal artery- genicular collaterals
  7. Anterior tibial artery (laterally)- anterior compartment with deep peroneal nerve. Many collaterals, becomes dorsalis pedis
  8. Posterior tibial artery/ peroneal trunk (medially)- branches into posterior tibial artery and peroneal artery. Many collaterals around foot/ankle
  1. Pathophysiology:
  2. Basics:
  3. Etiology:
  4. atherosclerotic disease (#1)
  5. Less common: arteritis, antiphospholipid syndrome, aneurysms, adventitial cystic disease, entrapment & trauma.
  6. Collaterals:
  7. Helps counter progression of ischemia
  8. Neurohormonal regulation- vascular resistance can be greatly decreased during exercise and ischemia.
  9. Symptoms:
  10. Claudication (usually one level below occlusion) -> rest pain -> nonhealing ulcer -> gangrene
  11. Statistics:
  12. 75% (no DM) with mild/moderate claudication will have no worsening of symptoms over next 5 years, and only 5-7% will need amputation
  13. Atherosclerosis:
  14. SFA most commonly involved, especially at adductor canal where early stenosis occurs
  15. Lack of exercise favors plaque formation
  16. SFA at Hunter’s canal cannot dilate, therefore intimal plaques cause more hemodynamically significant lesions
  17. Atherogenesis not always progressive; Healing and regeneration may occur
  18. Predisposing factors:
  19. Genetics
  20. Smoking (#1 preventable cause)
  21. promotes atherosclerosis
  22. smoking cessation halts progression, may lead to regression of disease over time
  23. 11.4% patients with claudication who continued to smoke required amputation, whereas none who quit required amputation.
  24. Buerger’s Disease (thromboangiitis obliterans)
  25. rare, more common in Middle & Far East
  26. chronic inflammation of neurovascular bundle -> thrombosis and fibrosis. 3rd & 4th generation, male smokers
  27. Diabetes Mellitius
  28. atherogenesis occurs earlier and more quickly
  29. distal arteries > proximal arteries, especially small vessels
  30. neuropathy increases foot lesions, infections & overall limb threat
  31. calcific medial sclerosis- prevents accurate measurement of ankle pressures/compression. Use toe pressures instead
  32. Hyperlipidemia/obesity/HTN
  33. predisposing factors for atherosclerosis and ischemic disease.
  34. Hypercoagulable state
  35. homocysteinurea, lipoprotein A abnormalities, fibromuscular dysplasia, etc
  36. suspect with (1) recurrent venous thromboembolism, (2) unexplained thromboembolism < age45, (3) intraperitoneal, retroperitoneal, or cerebral thrombosis, (4) diffuse cutaneous microvascular thrombosis, (5) family history of thrombosis.
  1. Patient Evaluation
  2. H&P:
  3. Mindful that in patients with DM, dx may be difficult
  4. Pain is usually 1 level below lesion (SFA-> calf pain)
  5. Proximal disease may influence a distal lesion
  6. 5 Ps (pain, pallor, paresthesia, paralysis, pulselessness)
  7. Night pain common
  8. Almost ALL patients with PVD have coronary occlusive disease
  9. PE:, feet- color, temp, positional changes, hair patterns, nail thickness
  10. Non-invasive techniques:
  11. Dopper exam: not really a qualitative test
  12. ABI:
  13. Amputations heal in all patients if ABI >70%, not in 25% if <70%
  14. Non-specific, does not detail anatomy. Cheap & easy & good for monitoring progression of disease
  15. Often unreliable with DM
  16. Duplex ultrasound:
  17. Doppler: Blood flow velocity measured
  18. US: details anatomy, specific & sensitive
  19. Exercise stress test, reactive hyperemia stress test
  20. MRA- limited use, but is helpful if patient not candidate for angio
  21. Invasive techniques:
  22. Angiography:
  23. Gold standard for defining anatomy
  24. Hemodynamically significant lesions
  25. >75% reduction in cross-sectional area, or
  26. >50% reduction in diameter
  27. Risks:
  28. Renal insufficiency
  29. Contrast hypersensitivity (3%)
  30. Local complications (hematoma, etc) (<1-2%)
  31. Local thrombosis with limb-threatening ischemia (<1%)
  32. Distal complications, embolism, etc
  1. Treatment:
  2. General Considerations:
  3. Limb-threatening ischemia: surgical intervention considered
  4. Claudication: surgical intervention considered only when significant life-style compromise is present
  5. Conservative Therapy:
  6. Control risk factors (HTN, lipids, smoking, DM)
  7. Walking program ** extremely important
  8. increases “distance walked” between 80-234%
  9. long-term walking benefits greater than angioplasty
  10. Foot care, especially in DM
  11. Pharmacologic Therapy:
  12. Hemorrheologic drugs:
  13. Decreases viscocity /Increase blood flow/ Poiseulle’s Law
  14. Pentoxifylline increases blood flow & muscle oxygen tension, increases walking distance
  15. Antiplatelet drugs:
  16. Cilostazol: Phosphodiesterase inhibitor, suppresses platelet aggregation, increases vasodilation
  17. ASA, NSAIDS, Ca+ channel blockers, prostagladins, ticlopidine, thromboxane inhibitors, and metabolic enhancing agents
  18. Unclear role, ASA decreases risk of death due to MI
  19. Endovascular Therapy (PTA +/- stenting):
  20. Discrete lesions:
  21. Especially good for SFA and proximal lesions
  22. Success rates >85%
  23. 5-year patency rate 52% (old data)
  24. Complication rate for PTA 4%
  25. Don’t stent “justbecause” you see lesion. Must be same indication to stent as for bypass (rest pain, or severe, life-altering claudication)
  26. Adjunct therapy with bypass
  27. improve inflow with distal bypasses, outflow with proximal bypasses
  28. Acute ischemia/thrombosis:
  29. Immediate angiogram + thrombolysis
  30. Complications:
  31. Hemorrhage (but generally less given not a systemic dose)
  32. Anaphylaxis (with streptokinase)
  33. Local wound & vessel complications
  34. Contraindications:
  35. CNS ischemic / hemorrhagic events
  36. History of bleeding/coagulopathy
  37. Surgery within 2 weeks
  38. Open wounds
  39. Severe hypertension
  1. Surgical Therapy:
  2. General considerations:
  3. Pre-op cardiac work-up essential
  4. Sepsis is a relative contraindication
  5. Bypass rarely warranted in non-ambulatory patient
  6. Pre-op anatomic mapping essential
  7. Thromboendarterectomy:
  8. Longitudinal incision, plaque + intima + inner media removed, closed with saphenous or synthetic patch
  9. Largely abandoned, favor bypass
  10. 5-yr patency saphenous vein graft bypass vs. endarterectomy 72% vs. 32%
  11. Still benefit with short, discrete lesions above knee, especially in high-risk patients
  12. Infrainguinal bypass (gold standard)
  13. Indicated for rest pain, and severe, life-altering claudication
  14. Must be incapacitating pain, medical management failure & patient willing to take on operative risk for pain relief
  15. Remember- claudication progresses to critical ischemia & limb loss in relatively few cases
  16. Patency rates
  17. Best in shorter, large-caliber vein grafts placed in areas with high flow
  18. Proximal is better
  19. Above knee is better than below knee
  20. Vein better than graft
  21. Saphenous vein graft
  22. Preferred to graft, can be reversed or in-situ.
  23. 5 yr patency rates similar for both (~80%)
  24. Synthetic graft rarely indicated below knee (5-yr patency 15%)
  25. Complications:
  26. Perioperative mortality (2-5%, usually cardiac-related)
  27. Perioperative MI (3%)
  28. Perioperative silent MI (10-15%)
  29. Graft thrombosis (2-7% within first 30 days)
  30. Hemorrhage, hematoma, thrombosis, infection, edema
  31. Amputation:
  32. Useful for:
  33. Non-ambulatory patients
  34. Unreconstructable anatomy
  35. Irreversible tissue compromise
  36. Invasive infection
  37. Selection of level:
  38. Goal is to remove all necrotic, infected, painful tissue
  39. Level should provide good chance for healing
  40. Prosthesis and rehab
  41. Energy expenditure with amputations:
  42. 40% more energy required with BKA than with normal gait
  43. 70% more energy required with AKA than with normal gait