Table of contents
- 1. Abdominal Aortic Aneurysm
- 2. Peripheral Vascular Disease (Chronic)
- 2.1. Chronic Ischemia
- 2.2. Investigations
- 2.2.1. Ankle Brachial Index
- 2.2.2. Duplex Ultrasound
- 2.2.3. Angiogram
- 2.2.4. Other
- 2.3. Treatments
- 2.4. Acute Ischemia
- 3. Venous Insufficiency
- 4. Aortic Dissection
- 5. Thoracic Aortic Disease (Prevention)
- 6. Marfan's Syndrome
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)
- Size: > 5.5 cm
- 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.
- Two methods:
- Surveillance:
- Optimal Surveillance not defined, typically once/year with preferably CT or MRI is recommended (Ultrasound less preferred)
- Source:
- NEJM Knowledge question
- Non-pharmacologic
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)
Chronic Ischemia
- Classified as:
- Claudication (pain with movement)
- Pain (any muscle group, can even be bowel - mesenteric angina)
- Predictable (on movement)
- Disappears (completely gone at rest)
- Critical Ischemia
- Pain at rest
- Pain at night
- Non-healing ulcer
- Claudication (pain with movement)
- Claudication: risk of limb loss is low (5% in 5-10yrs)
- Critical Ischemia: risk of limb loss high. High mortality from CVD (50% in 5 yrs)
Investigations
Ankle Brachial Index
- ABI (for that leg) = highest tibial pressure (for that leg) / highest brachial pressure.
- Use U/S probe to check pulse.
-
Interpretation of ABI
-
ABI Reading Interpretation > 1.4 Noncompressive vessels (non-diagnostic - use toe)
ABI < 0.70 in big toe = abnormal (PAD)
1.01 - 1.40 Normal 0.91 - 1.00 Borderline (usually represents arterial disease) 0.5 - 0.9 Abnormal (claudication) <0.5 Very Severe (usually Critical Ischemia)
-
Duplex Ultrasound
- Poor for anatomy.
- Good for flow, can get flow velocities and localize disease.
- Can get ABIs for all over the legs and localize disease.
Angiogram
- Contast dye through femoral artery, Xrays.
- Useful if revascularization is considered
Other
- CT angio
- MR Angio
Treatments
- Risk Factor management
- Quit smoking
- ECASA (ASA - enteric coated) 81mg po od
Or clopidogrel - High dose statin
- If DM: good glycemic control
- Exercise: 20min 3x/week
- Lipid management: LDL < 2-3.5 TC/HDL >4??
- Treating Pain
- Cilostazole (in trials improved walking distance)
- Pentoxyfylline (questionable benefit in trials)
- Invasive:
- Angioplasty +/- stent
- Bypass Surgery
- Aortho-bifemoral bypass
- Axillary bifemoral
- Femoral-popliteal (for SFA disease)
- Femoral-tibial
- femoral-dorsalis pedis.
- popliteal- dorsalis pedis
Acute Ischemia
- Pain is SEVERE, VERY SEVERE, morphine will not cut it
- Symptoms: Pain, Palor, pulselessness, polar (cold), parasthesia, paralysis (bold - late findings high risk of limb loss)
- If Movement and senslation lost - poor prognosis, requires treatment NOW.
- Differential:
- Embolus (most common)
- Thrombosed popliteal aneurism.
- Acute thrombosis on chronic.
- Trauma
- Anticoagulation (Heparin)
- Stops coagulation, helps thrombolysis.
- May dissolve small clots, rarely adequate tx.
- If Embolus: Thrombolysis +/- angioplasty
- Catheter into artery, inject throbolysis (i.e. tPA) and heparin.
- Risk of bleeding + stroke.
- Percutaneous mechanical thrombectomy
- High velocity saline pumped into tip of catheter (endovascular)
- "venturi" effect, breaks up clot.
- Some clots do not fragment.
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)
- Reduce venous hypertension
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
- Complicated
- 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.
- nitroprusside (0.2 mcg/kg/min titrate up for BP)
- 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)
- 4/8 of MSK features (need to confirm)
-
- 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
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