Vascular Disease

Abdominal Aortic Aneurysm

• Physical Exam:
  • JAMA RCE: Palpable pulsations > 2.5cm require follow-up investigations.

• Indication for repair of AAA: Size: > 5.5 cm Consider for > 4.5cm if getting other cardiac surgery Rate:  > 0.5cm/yr   (Source: NEJM Knowledge)

• Management
  • Non-pharmacologic
    • Smoking Cessation (smokers have double speed of progression)
    • BP control lifestyle modifications
  • Pharmacologic
    • ACEi, etc.. for BP control
  • Surgical
    • Two methods:
      • Endovascular Aneurysm Repair (EVAR)
      • Open Repair
    • Advantages/Disadvantages:
      • RCT:  EVAR = lower perioperative morbidity/mortality compared to open AAA repair
      • EVAR does not completely eliminate future AAA rupture risk.
      • Open repair = higher peri-OP morbidity/mortality but provides a more definitive repair. 
  • Surveillance:
    • Optimal Surveillance not defined, typically once/year with preferably CT or MRI is recommended (Ultrasound less preferred)
  • Source:
    • NEJM Knowledge question

Peripheral Vascular Disease (Chronic)

• Inadequate cell nutrition due to poor blood supply
• Atherosclerosis in vessels.  Subintimal, heterogeneous (can have Ca)
• Risk Factors:
  • Smoking ++++
  • Diabetes +++
  • Age ++
  • Hypertension +
  • Hypercholesterolemia +
• Chronic arterial changes:
  • Hair loss, cold, rubor (not cellulitis), ulceration (gangrene)

Venous Insufficiency

• Results from persistent venous hypertension caused by venous incompetence or occlusion.
• Manifestations: (chronic)
  • Edema
  • Skin hyperpigmentation
  • Stasis dermatitis
  • Varicose veins
  • Lipodermatosclerosis (Like constricting band in lower legs - "champagne bottle")
  • Cellulitis
  • Ulceration (Ankles)
• Diagnosis: Based on history and examination (avoid biopsy - due to non-healing ulcers)
• Management:
  • Reduce venous hypertension
    • Leg elevation and
    • Compression therapy.
      • Avoided in those with peripheral arterial disease and decompensated heart failure.
      • Knee-high compression stockings with pressures 20-40 mmHg
  • Medicaiton Review (Calcium channel blockers and thiazolidinediones, can cause dependent edema)

Aortic Dissection

• Type A Aortic Dissections require SURGERY
  • Bicuspid aortic valve pre-disposes to this ("aortopathy").
• Type B Dissections are divited into:
  • Complicated
    • Defined by renal/mesenteric/peripheral ischemia.
    • Needs emergency surgery (fenestration).
  • Uncomplicated
    • 90% 30 day mortality
    • IV BP and HR control... targets: (to reduce shear stress on dissection)
      • BP < 120
      • HR < 60
  • Possible to stent
• Investigations:
  • D-dimer value below 0.5 µg/mL (0.5 mg/L) measured within the first 24 hours of symptoms had a NPP of 95% for acute aortic dissection.  (International Registry of Acute Aortic Dissection)
  • Contrast enhanced CT Scan (1st line) [Sn 94%, Sp 87%]
  • If CT not available (i.e. renal function, cannot transport patient, etc..)
    • --> Do TEE (Sn 98%, Sp 77%)
  • MRI --> best test [Sn 98%, Sp, 98%]
  • Aortography [Sn 88, Sp 94]
  • For pre-operative setting: image entire aorta
• Surveillance:
  • Post-Repair: q3-5y with CT or MRI (entire aorta)
• BP control Drugs:
  • nitroprusside (0.2 mcg/kg/min titrate up for BP)
    • Must combine with rate control agent, otherwise tachycardia can increase cardiac output, shear forces, cause more dissection.
    • esmolol 500 mcg/kg bolus + 50 mcg/kg/min infusion (increase by 25 ucg/kg/min q5m to heart rate)
      OR:
  • Labetalol 20mg IV over 2min then 1-2 mg/min to desired effect. (max cummulative 300mg)
    • Nice b/c has alpha and beta activity.
  • Type B Aortid dissection rarely require surgery.  
    • Indications for surgery are: malperfusion syndromes and significant aneurysmal dilatation.
• Source: CCS guidelines 2009

Thoracic Aortic Disease (Prevention)

• BP Targets:
  • Normally < 140/90
  • Diabetes < 130/80 (same as CHEP guidelines)
• Marfan's Syndrome:
  • Use B-Blocker and/or ARB (to reduce aortic dilation)
• Avoid strenuous resistance and isometric exercise
• No driving if:
  • Ascending aorta > 6.0cm
  • Descending aorta > 6.5cm
  • (For commercial driving, decrease by 0.5cm each limit)
  • After aortic repair: no private driving for 6 weeks, no commercial driving for 3 mo

Marfan's Syndrome

(Source: MKSAP 16)

• Diagnosis: Dependent on classic signs:
  • Opthalmologic
  • Cardiovascular
  • MSK
• Diagnostic Criteira:

  • Diagnostic Criteria for Marfan's Syndrome (See revised 1996 Ghent criteria) (Check Criteria, but below is a very roughs summary) 4/8 of MSK features (need to confirm) Arm Span > Pts height Arachnodatyly (long digits) Pectus excavatum (rib overgrowth) Scoliosis Micrognathia High Arched Palate Ligamentous Laxity ... Ectopia Lentis Aortic Root Dilatation Lumbosacral Dural Ectasia (diagnosed with imaging) Family History Vascular EDS: - Aneurysmal dilation of blood vessels, ligamentous laxity, and often thin translucent skin (DO NOT have ectopia lentis, or MSK abnormalities)

• Genetic screening for Marfan's Syndrome to provide counselling and know nature of disease.
• At diagnosis:
  • Echo to image aortic root
  • Repeat echo in 6 mo to determine rate of progression
    • If stable, image annually
    • If progresses > 45mm --> frequent screening

Source: CCS guidelines 2009