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13.01.23 Vascular

Signs of arterial trauma
  • Hard
    • Pulsatile bleeding
    • Arterial thrill
    • Bruit
    • Absent distal pulses
      • But cf compression/tension
    • Expanding haematoma
  • Soft
    • Haemorrhage
    • Neurological abnormality
    • Decreased pulse compared to contralateral side
    • Proximity to bony injury or penetration


Arterial trauma

  • Vertebral artery
    • Very difficult to access surgically
    • Shut off with coils
      • Rely on collaterals
  • Aorta
    • Fixed at ligamentum arteriosum and mobile elsewhere => Tends to tear at this point
    • Fix with a stent graft
  • Stop-gap measures
    • Outcome is better if you buy time to stabilise other stuff, then fix the vasculature later
    • Shunts
  • Tamponade
    • Is generally your friend
      • e.g. In kidneys, pelvis : DON'T release the pressure!
    • Doesn't work in the thorax as the lungs are compressible


Diabetic feet

  • Factors
    • Predisposing
      • Neuropathy
    • Precipitating
      • Nail in shoe
    • Perpetuating
  • Gangrene
    • Dry will auto-amputate
    • Wet = Infection = Problem
      • Treat with aggressive ABX
  • Magic bullets?
    • Hyperbaric oxygen works well but is not used much as there's no money to be made :)
    • Larvae, PDGF, GCSF, EGF
    • Skin substitutes


Limb ischaemia

  • 3 levels - Need disease at each before you get gangrene => Hard to treat at that stage
    • Above the inguinal ligament
    • Above the knee
    • Below the knee


Intermittent claudication
  • Pain in muscle on exercise
    • Usually calf, but can also be thigh or buttock
      • => Site of stenonis, e.g. for buttock pain it must be above the bifurcation of the common iliac
  • Prognosis
    • 50% improve with exercise alone (esp. nordic walking)
    • 30% stay the same
    • 5% get worse
    • 15% will be dead from stroke or MI within 5 years
  • Intervention
    • Only 5% require intervention
    • 1% require amputation
    • Cilostazol => Vasodilatation
      • 3-type phosphodiesterase inhibitor
  • Risk factors
    • A ntiplatelet
    • B P
    • C holesterol
    • D iabetes
    • E xercise


Critical limb ischaemia

  • Definition
    • Rest pain
    • Requiring analgesia (frequently opioids)
    • Present for more than 2 weeks or with tissue loss
  • Pressure measurements
    • ABPI is useless
    • 50 mmHg at the ankle or 30 mmHg at the toe implies CLI
  • Prognosis
    • 25% require major amputation
    • 90% require intervention within a year


Acute limb ischaemia

  • All the "P"s
    • Pallor increase
    • Pulses decreased
    • Perishing cold
    • Pain
    • Paraesthesia
    • Paralysis
  • Damage
    • Nerves after 30 mins
    • Muscle after 6 hrs
    • Skin after 48 hrs
      • => Can look quite normal from the outside
  • Causes
    • Thrombosis
      • Most common cause
      • Presents acutely/sub-acutely
      • Patients tend to be claudicants
      • Other limb is often abnormal
    • Embolisation
      • Second most common cause
      • Clots can come from heart or lower down
      • Sudden onset
      • Usually no Hx of PVD
      • Opposite limb is normal
      • Often identifiable source
        • 80% AF
        • 10% post-MI
        • 10% aneurysm
    • Graft thrombosis / post-angioplasty
  • Treatment
    • Be very careful of re-plumbing!
      • Potassium load from dead cells => MI
    • Fogarty balloon catheter to withdraw clot
    • Catheter-directed lysis
      • Prevents complications of systemic thrombolysis
      • Can also visualise underlying cause


Aneurysms

  • Screening programme in place for men over 65
  • Risk factors
    • Male x4
    • Smoking x6
    • FHx x4
  • 4% of men >60 have a >3 cm AAA
  • Mortality
    • Elective repair: 1-2 % at SGH, 5-9 % nationally
    • Rupture: 80 %


Arteries of the pelvis and leg





ACCORD Trial
  • Targeting Blood Sugar to Near-Normal Levels Does Not Reduce Cardiovascular Events But Increases Mortality in Persons with Diabetes at High Risk
    • Intensive strategy group had a 22 percent higher risk of death, mostly from cardiovascular causes
    • Increased risk began emerging within 1 to 2 years
  • Results might not apply to patients who are at lower risk of cardiovascular disease than the ACCORD participants or to patients with more recently diagnosed type 2 diabetes
  • Intervention:
    • Standard strategy aimed for HbA1c 7-7.9 % (similar to what is normally achieved)
    • Intensive strategy aimed for HbA1c <6 % (similar to non-diabetic level)
  • Reason is unclear


Notes
  • Arteries spasm, veins don't => Venous bleeding is often more severe in the medium term
  • 17% of patients with a diabetic foot ulcer will be dead within a year
  • Common iliac bifurcates a bit above the inguinal ligament
  • Statins => Remodelling and plaque regression
  • Tight glucose control may be worse
  • Walking requires 50-90% more energy with an artificial limb, so patients often don't
  • Venous gangrene => Look for underlying cause (e.g. cancer)

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