Vascular Surgery

1. Vascular Surgery
Dr. Okon, MD, MRCS

2. Acute Arterial Ischemia
● Acute occlusion of a peripheral artery that often threatens
limb viability.
● Urgent management required as skeletal muscle can
tolerate 6h of total ischemia before irreversible damage;
exception is acute-on-chronic occlusion, where previously
developed collaterals provide minimal perfusion.
● Tends to be lower extremity > upper extremity;
femoropopliteal > aortoiliac
● Paralysis with complete loss of sensation is sign of late
ischemia

3. ● Etiology and Risk Factors
● Embolism
● Cardiac: arrhythmias, endocarditis, MI, LV aneurysm, myxoma/cardiac
tumour, paradoxical embolism, valvular heart disease
– non-cardiac: mural thrombus within arterial aneurysms, atheroembolism
● Thrombosis
● ■ atherosclerotic obstruction
● ■ vasospasm
● ■ aortic or arterial dissection
● ■ arterial transection
●

4. ● Embolism vs. thrombosis
● ■ thrombosis is more common than embolism; usually in
superficial femoral artery
● ■ existing atherosclerotic plaques can rupture causing
thrombosis
● ■ previous vascular gras/reconstructions can fail and
thrombose leading to acute presentation
● ■ hypercoagulable states can contribute to thrombosis
● ■ embolism generally results in greater degree of ischemia
due to lack of collaterals

5. ● Suspect embolism in patients with the following features:
● ◆ acute onset (patient able to accurately recall the moment of
the event)
● ◆ history of embolism
● ◆ known embolic source (e.g. cardiac arrhythmias)
● ◆ no prior history of intermittent claudication
● ◆ normal pulse and Doppler in unaected limb
● Dx: Iatrogenic (e.g. occlusion at arterial access site),
compressive, traumatic (blunt or penetrating injuries) causes
of acute limb ischemia

6. Clinical Features
● • 6 Ps – all may not be present
● ■ Pain
– may be constant or elicited by passive movement;
absent in 20% of cases
● ■ Pallor: pale
– within a few hours becomes mottled cyanosis
● ■ Paresthesia
– light touch lost rst then other sensory modalities
●

7. ● ■ Paralysis/Power loss:
– most important, heralds impending non-salvageable
limb
● ■ Polar/Poikilothermia: cold
– leg becomes cold
● ■ Pulselessness
– helpful to determine site of occlusion; not always
reliable

8. Investigations
● History and physical exam are essential: depending on degree of
ischemia one may have to forego investigations and go straight to the
operating room
● Determine Rutherford classication based on physical findings and
Doppler signals
● Ankle Brachial Index (ABI): extension of physical exam, easily performed
at bedside
● ECG, troponin: rule out recent MI or arrhythmia
● CBC: rule out leukocytosis, thrombocytosis or thrombocytopenia in
patients receiving heparin (may suggest HITS)
● • PT/INR, PTT: patient anticoagulated/sub-therapeutic INR

9. ● Echo: identify wall motion abnormalities, intracardiac
thrombus, valvular disease, aortic dissection (Type A)
● • CT angiogram: identify underlying atherosclerosis,
aneurysm, aortic dissection, identify embolic source,
identify other end organs with emboli (e.g.
splenic/renal infarcts), identify level of the occlusion
and extent
● • Angiography: can be obtained in OR as part of
intervention or for treatment planning

10. Treatment
● Immediate heparinization with weight-based bolus (80 Units/kg) and continuous
infusion to titrate PTT to 70-90s
● If impaired neurovascular status: emergent revascularization (Rutherford category
IIb)
● If intact neurovascular status: may have time for workup (including CT angiogram)
● Identify and treat underlying cause
● ■ embolus: embolectomy
● ■ thrombus: thrombectomy ± bypass gra ± endovascular therapy
● ■ irreversible ischemia (i.e. Rutherford category III): primary amputation or
palliation/comfort measures
● • continue heparin post-operatively, start oral anticoagulant post-operatively when
stable x 3 mo or
● Longer depending on underlying etiology and other comorbidities

12. ●
Complications
● Local: compartment syndrome (see Orthopedic Surgery, OR10) with
prolonged ischemia; requires
●
4-compartment (anterior/lateral/supercial and deep posterior) fasciotomy
●
Heart: risk of arrhythmia, MI, cardiac arrest and death with reperfusion injury
● Kidneys/other organs: renal failure and multi-organ failure due to toxic
metabolites from ischemic muscle, rhabdomyolysis
●
Up to 10% chance of metachronous embolism
● Prognosis
●
• 12-15% mortality rate
● • 5-40% morbidity rate (amputation)

13. Chronic Limb Ischemic/PAD
● Chronic ischemia due to inadequate arterial supply to
meet cellular metabolic demands during walking
(claudication) or at rest (critical limb ischemia)
● Etiology and Risk Factors
● Predominantly due to atherosclerosis; primarily occurs in
the lower extremities
● Conventional risk factors: smoking, DM, hyperlipidemia,
and hypertension
● Predisposing risk factors: advanced age, obesity,
sedentary lifestyle, and PMHx or FMHx PAD/CAD/CVD
●

14. Clinical Features
● Claudication:
● 1. pain with exertion: usually in calves or any exercising
muscle group (within the muscle belly)
● 2. relieved by short rest: less than 5 min and no postural
changes necessary
● 3. reproducible: same distance or time to elicit pain, same
location of pain, same amount of rest to relieve pain
● The presence of the preceding features differentiates
vascular claudication from neurogenic claudication or
MSK pain

15. ● Critical limb ischemia (CLI):
● 1. Includes rest pain, night pain, tissue loss (ulceration or gangrene)
● 2. Pain most commonly over the forefoot/toes, waking person from
sleep, and oen relieved by hanging foot o bed
● 3. Ankle pressure <40 mmHg, toe pressure <30 mmHg, ABI <0.40
● ◆ distal pulses are absent, bruits may be present
● ◆ signs of poor perfusion: hair loss, hypertrophic nails, atrophic
muscle, ulcerations and infections, slow capillary rell, prolonged pallor
with elevation and rubor on dependency, and venous troughing
(Buerger’s sign/Buerger’s angle) (collapse of supercial veins of foot)
● 4. high risk of 1 yr limb amputation and mortality

16. Differential Diagnosis of Lower
Extremity Pain
● Vascular
●
• Atherosclerotic disease
● • Fibromuscular dysplasia
●
• Popliteal entrapment syndrome
● • Venous claudication/hypertension
● Neurogenic
●
• Neurospinal disease (e.g. spinal stenosis)
● • Complex regional pain syndrome
●
• Radiculopathies
● • Diabetic neuropathy
● MSK
●
• Osteoarthritis
● • Rheumatoid arthritis/connective tissue disease
●
• Remote trauma
●

17. Investigations
● Routine blood work, fasting metabolic profile
● • ABI: highest ankle pressure (dorsalis pedis or posterior tibial) for each side divided by highest
brachial pressure.
● • Arterial duplex ultrasound: combines traditional and Doppler ultrasound to visualize blood
vessels and characterize flow and plaques
● • non-invasive: CTA and MRA excellent for large arteries (aorta, iliac, femoral, popliteal) but
may have
● Difficulty with tibial arteries (especially in the presence of disease)
● ■ require IV injection of nephrotoxic contrast (iodinated contrast for CTA, gadolinium for MRA)
● ■ used primarily for planning interventions
● Invasive: arteriography
● ■ superior resolution to CTA/MRA, better for tibial arteries, can be done intraoperatively as
part of intervention
● ■ can be diagnostics and/or therapeutic

19. Treatment
● Goals
● ■ preserve viability (save the leg)
● ■ preserve life (avoid complicated procedures in sick patients)
● ■ improve function and alleviate symptoms
● ■ prevent deterioration and recurrence
● Conservative
● ■ risk factor modication (smoking cessation, glucose control, treatment of HTN
and hyperlipidemia)
● ■ structured exercise program (30-45 min 3x/wk): improves collateral circulation
and muscle oxygenation
● ■ foot care (especially in DM): trim toenails, check between toes for skin breaks,
wear socks and shoes, clear shoes of any debris, keep wounds clean/dry, avoid
trauma and pressure on wounds

20. Pharmacotherapy
● Patients with PAD are at increased risk for CAD and CVD
●
■ antiplatelet agents (e.g. aspirin, clopidogrel)
● ■ statin
●
■ ACEI/ARB
● Surgical
●
■ Indications: severe lifestyle impairment, vocational impairment, critical ischemia
● ■ revascularization
●
◆ endovascular (angioplasty ± stenting)
● ◆ endarterectomy: removal of plaque and repair with patch (usually distal aorta or common/deep
femoral)
● ◆ bypass gra sites: aortofemoral, axillofemoral, femoropopliteal, femoro-tibial, femorofemoral bypass
●
◆ gra choices: saphenous vein graft (reversed or in situ), synthetic [polytetrauoroethylene gra (e.g.
Gore-Tex® or Dacron®)]
●
Amputation: if not anatomically suitable for revascularization, persistent serious infections/gangrene
unremitting rest pain that is poorly controlled with analgesics, medically unt for revascularization

21. ● The ABCDEs of PAD Treatment
● A Anti-plt (ASA, plavix), anti-coagulant (if indicated),
ACEI/ARB
● B Blood pressure control; target sBP <140, β-blocker (if
indicated)
● C Cholesterol management (statin); target LDL <2, smoking
cessation
● D Diabetic control; target HbA1c <7%, Diet/weight
management
● E Exercise (3x/wk, 20 min per session)

22. ● Prognosis
● Claudication: conservative therapy: 60-80%
improve, 20-30% stay the same, 5-10%
deteriorate, 5% will require intervention within 5
yr, <4% will require amputation
● For patients with critical limb ischemia, at 1 yr:
25% risk of mortality (secondary to CVA/MI),
25% risk of amputation, 50% alive with two
limbs, 33% 5 yr survival rate