vascular surgery,

Peripheral Vascular Disease

Apr 11, 2020

Definition

  • Atherosclerosis of the peripheral arteries
  • 65% have coexisting clinically relevant cerebral or coronary artery disease.
  • Cardiovascular risk factors should be identified and treated aggressively.
  • The most important presentation is intermittent claudication

Disease pattern

  • Intermittent claudication.
  • Critical limb ischaemia
  • Acute limb threatening ischaemia (See next section)

Symptoms

  • Cramping pain in the calf, thigh, or buttock after walking for a given distance (the claudication distance) and relieved by rest
  • calf claudication = femoral disease
  • buttock claudication = iliac disease).
  • Ulceration, gangrene and foot pain at rest—eg burning pain at night relieved by hanging legs over side of bed—are the cardinal features of critical ischaemia
  • Buttock claudication ± impotence imply Leriche’s syndrome
  • Young, heavy smokers are at risk from Buerger’s disease (thromboangiitis obliterans)

Signs

  • Absent femoral, popliteal, or foot pulses
  • cold, white leg(s)
  • Atrophic skin
  • punched out ulcers (often painful)
  • postural/dependent colour change
  • Buerger’s angle (angle that leg goes pale when raised off the couch) of <20° and capillary filling time >15s are found in severe ischaemia.

Investigations

  • Exclude DM
  • Arteritis (esr/crp)
  • FBC (anaemia, polycythaemia)
  • U&E (renal disease)
  • Lipids (dyslipidaemia)
  • Thrombophilia screen and serum homocysteine if <50 years.

Ankle-Brachial Pressure Index (ABPI)

  • Normal = 1–1.2
  • PAD= 0.5–0.9
  • Critical limb ischaemia <0.5 or ankle systolic pressure <50mmHg
  • Acute limb threatening ischaemia <0.3

Beware falsely high results from incompressible calcified vessels in severe atherosclerosis e.g. DM

Imaging

  • 1st line: Colour duplex US
  • If intervention considered: MR/CT angiography for extent and location of stenoses and quality of distal vessels (‘run-off’).

Management

Conservative

  • Cardiovascular risk factor modification: hypertension, diabetes, obesity, smoking etc.
  • Supervised exercise (to the point of maximal pain) for 2hr/wk for 3 months
  • Antiplatelet agent: 1 line) Clopidogrel 75mg; 2 line) Aspirin 75mg
  • Risk factor modification:Quit smoking (vital). Treat hypertension and high cholesterol. Prescribe an antiplatelet agent (unless contraindicated), to prevent progression and to reduce cardiovascular risk. Clopidogrel is recommended as 1st-line.
  • Vasoactive drugs, eg naftidrofuryl oxalate, in those who do not wish to undergo revascularization and if exercise fails to improve symptoms.

Surgical

  • 1st line: Percutaneous transluminal angioplasty (PTA): is used for disease limited to a single arterial segment
  • 2nd line:Bypass surgery: If extensive disease but distal run-off is good (i.e. distal arteries filled by collateral vessels). Procedures include femoral-popliteal bypass, femoral-femoral crossover, and aorto-bifemoral bypass grafts. Autologous graft > prosthetic grafts.
  • 3rd line: Amputation: in intractable pain, sepsis, gangrene, and failed alternative strategies. Decision by the patient and vascular multidisciplinary team