Vascular Surgery - Toronto Notes

Question 1

A hypercoagulable state predisposes you to peripheral arterial disease. What are the causes of this state?

Answer 1

• Congenital
  
  • Group I (reduced anticoagulants)
    
    1. Antithrombin
    2. Protein C
    3. Protein S
  • Group II (increased coagulants)
    
    1. Factor V Leiden
    2. Prothrombin
    3. Factor VIII
    4. Hyper-homocysteinemia
• Acquired
  
  1. Immobility
  2. Cancer
  3. Pregnancy
  4. Antiphospholipid antibody syndrome
  5. Inflammatory disorders
  6. Myeloproliferative disorders
  7. Nephrotic syndrome
  8. DIC
  9. Heparin Induced Thrombocytopenia (HIT)

Question 2

What investigations would you choose to do to investigate peripheral vascular disease?

Answer 2

1. History and physical exam
   
   • Depending on degree of ischemia mayhave to forgeo investigations and go straight to operating room
2. Ankle brachial pressure index
3. ECG
   
   • tropoin - rule out recent MI or arrythmia
4. FBC
   
   • rule out leukocytosis, thrombocytosis or recent drop in platelets in patients receiving heparin
5. PT/INR
   
   • patient anticoagulated/sub-therapeutic INR
6. Echocardiogram
   
   • Identify wall motion abnormalities, intracardiac thrombus, valvular disease, aortic dissection (type A)
7. Ultrasound duplex with doppler
8. CT Angiogram
   
   • Underlying atherosclerosis, aneurysm, aortic dissection

Question 3

What are the differences between arterial embolism and thrombosis?

Answer 3

Embolus:

1. Acute
2. Prominent loss of function
3. No History of claudication
4. No atrophic changes
5. Contralateral limb pulses are classically normal

Thrombus

1. Progressive onset
2. Less profound loss of function due to underlying collateral supply
3. Maybe claudication
4. Maybe atrophic changes
5. Decreased or absent contralateral limb pulses

Question 4

Name two complications of acute arterial occlusion/insufficiency in the lower limbs?

Answer 4

1. Compartment syndrome with prolonged ischemia - requiring fasciotomy
2. Renal failure and multi-organ failure due to toxic metabolities from ischemic muscle (also known as myoglobinuria due to rhabdomyolysis)

Question 5

What are the six symptoms of acute limb ischemia?

Answer 5

1. Pain - although absent in about 20% of the cases
2. Pallor - within a few hours - it becomes mottled cyanosis
3. Paresthesia - light touch lost first then sensory modalities
4. Paralysis/Power loss - most important - heralds impending gangrene
5. Polar - perishingly cold
6. Pulselessness - again not reliable

Question 6

What is your treatment plan for a patient with acute arterial insufficiency?

Answer 6

• Immediate heparinization with bolus and continuous infusion to maintain PTT >60s
• If absent power and sensation - commence emergent revascularization
• If present power and sensation - begin work-up (including angiogram)
• Definitive treatment
  
  • Embolus - embolectomy
  • Thrombus - thrombectomy (you can subsequently consider a bypass graft or endovascular therapy)
  • Irreversible ischemia - consider primary amputation
• Identify and treat underlying cause
• Continue heparin post-op
  
  • Start warfarin post-op on day 1, 3 times depending on underlying etiology

Question 7

Name seven risk factors for chronic arterial insufficiency

Answer 7

1. Smoking
2. Diabetes Mellitus
3. Hypertension
4. Hyperlipidemia
5. Family History
6. Obesity
7. Sedentary Lifestyle

Question 8

What are the clinical features seen in claudication?

Answer 8

1. Pain with exertion - usually in calves or any exercising muscle group
2. Relieved by short rest - 2 to 5 minutes - and no postural changes necessary
3. Reproducible - same distance to elicit pain, same location of pain, same amount of rest to relieve pain

Question 9

What is your differential diagnosis for claudication?

Answer 9

1. Vascular
   
   1. Atherosclerotic disease
   2. Vasculitis (e.g. Buerger’s disease, Takayasu’s arteritis)
   3. Diabetic neuropathy
   4. Venous disease (DVT, varicose veins)
   5. Popliteal entrapment syndrome (e.g. Baker’s cyst)
2. Neurologic
   
   1. Neurospinal disease (spinal stenosis)
   2. Reflex sympathetic dystrophy
3. Musculoskeletal
   
   1. Osteoarthritis
   2. Rheumatoid arthritis/connective tissue disease
   3. Remote trauma

Question 10

What are the clinical features in critical limb ischemia?

Answer 10

1. Includes rest pain, nocturnal pain, tissue loss (ulceration or gangrene)
2. Ankle pressure <40 mmHg, toe pressure <30mmHg, ABPI <0.40

Question 11

What other clinical signs and symptoms can be seen and elicited in chronic arterial insufficiency?

Answer 11

• Pulses may be absent in some locations
• Bruits may be present
• Signs of poor perfusion
• Hair loss
• Hypertrophic nails
• Atrophic muscle
• Skin ulcerations and infections
• Slow capillary refill
• Prolonged pallor with elevation and rubor on dependency
• Venous troughing ( collapse of superficial veins of foot)

Question 12

What investigations would you perform in a case of chronic arterial insufficiency?

Answer 12

• Non-invasive
  
  • Routine bloodwork, fasting metabolic profile
  • ABPI
    
    • Take highest brachial and highest ankle pressures for each side generally
  • CT Angio and MR Angio
    
    • Excellent for large arteries (aorta, iliac, femoral, popliteal) may have difficulty with tibial arteries (especially in presence of disease).
    • Both require IV injection of nephrotoxic contrast (iodinated contrast for CT, gadolinium for MR)
• Invasive
  
  • Arteriography - superior resolution to CTA/MRA, better for tibial arteries, can be done intraoperatively
    *

Question 13

What is your treatment plan for chronic arterial insufficiency?

Answer 13

• Conservative
  
  • Risk factor modification
    
    • smoking cessation
    • treatment of hypertension
    • treatment of hyperlipidemia
  • Exercise programe
    
    • improve collateral circulation
    • oxygen extraction at the muscle level foot care (especially in DM)
    • Keep wounds clean and dry
    • Avoid trauma and pressure on wounds
• Pharmacotherapy
  
  • Anti-platelet agents (clopidogrel and then aspirin)
  • Cilostazol (c-AMP phosphodiesterase inhibitor with anti-platelet and vasodilatory effects - improves walking distance)
• Surgical/endovascular
  
  • Indicated with severe lifestyle impairment, vocational impairment or critical ischemia
  • Options
    
    • endovascular (stenting/angioplasty)
    • endarterectomy (removal of plaque and repair with patch - usually distal aorta or common/profunda femoral)
    • bypass graft sites
      
      • aortofemora
      • axillofemoral
      • femoropopliteal
      • distal arterial
        
        • Usually choose synthetic polytetrafluoroethylene graft - Dacron
    • Chemical sympathectomy
    • Amputation

Question 14

What is an aortic dissection?

Answer 14

A tear in aortic intima allowing blood to dissect into the media, acute is defined as having happened for less than 2 weeks and chronic as greater than 2 weeks.

Question 15

What is the etiology of aortic dissection?

Answer 15

• Hypertension is the most common
  
  • degenerative/cystic changes to the aortic media
• connective tissue disease (Marfan’s, Ehlres-Danlos)
• cystic medial necrosis
• atherosclerosis
• congenital conditions - coarctation of the aorta
• infection - syphilis
• trauma
• arteritis (Takayasu’s)

Question 16

Describe the clinical features of an aortic dissection

Answer 16

• ƒƒHTN (75-85% of patients)
• ƒƒ asymmetric BPs and pulses between arms (>30 mmHg difference indicates poor prognosis)
• ƒƒ ischemic syndromes due to occlusion of aortic branches: coronary (MI), carotids (ischemic stroke, Horner’s syndrome), splanchnic (mesenteric ischemia), renal (AKI), peripheral (ischemic leg), intercostal vessels (spinal cord ischemia)
• ƒƒ “unseating” of aortic valve cusps (new diastolic murmur in 20-30%)
• ƒƒ rupture into pleura (dyspnea, hemoptysis) or peritoneum (hypotension, shock) or pericardium (cardiac tamponade)
• ƒƒ syncope

Question 17

What investigations would you consider to a suspected case of aortic dissection?

Answer 17

1. CXR
   
   • pleural cap (pleural effusion in lung apices)
   • widened mediastinum
   • left pleural effusion with extravasation of blood
2. Transesophgeal echocardiogram
   
   • can visualise aortic valve and thoracic aorta but not abdominal aorta
3. ECG
   
   • Any evidence of left ventricular hypertrophy with ischemic changes, perciarditis or heart block
4. CT (gold standard), aortography, MRA
5. Blood tests
   
   • Lactate in regards to ischemic gut
   • Amylase in regards to pancreatitis
   • Troponin in regards to myocardial infarction

Question 18

Outline your course of treatment for an aortic dissection

Answer 18

1. Pharmacologic
   
   • beta blockers to lower the blood pressure and decrease cardiac contractility
   • use nondihydropyridine calcium channel blocker if there is a clear contraindication to beta blockers
   • target systolic blood pressure of 110 mmHg and HR of less than 60 bpm
   • Ace-inhibitors or other vasodilators if insufficient BP or HR control
2. Surgical
   
   • Resection of segment with intimal tear
   • reconstitution of flow through true lumen
   • replacement of the affected aorta with prosthetic graft
   • corrrection of any predisposing factors

Question 19

Name some post-operative complications in regards to surgery for an aortic dissection

Answer 19

1. Renal failure
2. Intestinal ischemia
3. Stroke
4. Paraplegia
5. Persistent leg ischemia
6. Death

Question 20

What is the Stanford classification?

Answer 20

• The Stanford classification divides dissections into 2 types, type A and type B. Type A involves the ascending aorta (DeBakey types I and II); type B does not (DeBakey type III).
  
  • This system helps to delineate treatment. Usually, type A dissections require surgery, while type B dissections may be managed medically under most conditions.

Question 21

Define an aneurysm

Answer 21

• Localised dilatation of an artery having a diameter at least 1.5 times that of the expected normal diameter
  
  • True aneurysm - involving all vessel wall layers
  • False aneurysm - disruption of the aortic wall or the anastomotic site between vessel and graft with containment of blood by a fibrous capsule made of surrounding tissue

Question 22

Name five outcomes of an aneurysm

Answer 22

1. Rupture
2. Thrombose
3. Embolize
4. Erode
5. Fistulize

Question 23

What is the classification of an aortic aneurysm?

Answer 23

1. Thoracic aortic aneurysm
2. Thoracoabdominal
3. Abdominal Aortic Aneurysm

Question 24

What is the etiology of an aortic aneurysm?

Answer 24

1. degenerative (atherosclerotic)
2. traumatic
3. mycotic
4. connective tissue disorder
5. vasculitis
6. infectious
7. the risk factors
   
   1. smoking
   2. hypertension
   3. age
   4. family history

Question 25

What constitutes the classic triad of a ruptured AAA?

Answer 25

1. Pain 2. Hypotension 3. Pulsatile abdominal mass

Question 26

Describe the clinical features of an aortic aneurysm

Answer 26

1. Syncope 2. Pain (chest, abdominal, flank and back) 3. Hypotension 4. Palpable pulsatile mass above umbilicus, pulsatile abdominal mass which is expansible 5. Airway or esophageal obstruction (hoarseness - left recurrent laryngeal nerve paralysos) 6. Hemoptysis and hematemesis

Question 27

What are some of the features in an uncommon presentation?

Answer 27

* Ureteric obstruction and hydronephrosis (inflammatory aortic aneurysm) * GI bleed (duodenal mucosal haemorrhage, aortoduodenal fistula) * Aortocaval fistula * Distal embolization (blue toe syndrome)

Question 28

Name your investigations in a suspected case of an aortic aneurysm

Answer 28

* Routine blood tests * FBC * Electrolytes * Urea and creatinine * PTT * INR * Maybe group and save * Abdominal ultrasound * CT * MRI * Doppler and duplex to check for aneurysms elsewhere ''vascular tree aneurysms)

Question 29

Outline the broad treatment options for aortic aneurysms

Answer 29

* Conservative * cardiovascular risk factor reduction * smoking cessation * good hypertensive control * good glycemic control * controlling hyperlipidemia * regular exercise * watchful waiting - imaging the aneurysm with ultrasound in timely intervals * Surgical * when risk of rupture greater than or equal to risk of surgery (\>5.5 cm in men and \>5cm in women) * Risk of rupture depends on: * size * rate of enlargement * symptoms, comorbidities (HTN, COPD, dissection) and smoking * consider revascularization for patients with coronary artery disease before elective repair of aneurysm

Question 30

What are the indications for surgery when considering an aortic aneurysm?

Answer 30

1. General 1. ruptured 2. symptomatic 3. mycotic 4. associated with acute Type A dissection or complicated Type B dissection 5. When risk of rupture is greater than risk of surgery - (\>5.5cm) 2. Ascending thoracic aortic aneurysms 1. symptomatic 2. enlarging or diameter \>5.5cm or twice the normal lumen size 3. 4.5 cm and aortic regurgitation (annuloaortic ectasia) 4. \>4.5-5cm in Marfan syndrome

Question 31

What are the contraindications for surgery in such a context?

Answer 31

* Life expectancy \<1 year * terminal disease (e.g. cancer) * significant co-morbidities * MI * unstable angina * decreased mental acuity * advanced age

Question 32

What are the complications for open surgery in the context of an aortic aneurysm? (laparotmy or retriponeal involving a graft replacement)

Answer 32

* Early * renal failure * spinal cord injury (paraparesis or paraplegia) * impotence * arterial thrombosis * anastomotic rupture or bleeding * peripheral emboli * Late * graft infection/thrombosis * aortoenteric fistula * pseudoaneurysm

Question 33

What are the complications for endovascular repair of an aneurysm?

Answer 33

* Early * immediate conversion to open repair * groin hematoma * arterial thrombosis * iliac artery rupture * thromboemboli * late * endoleak * severe graft kinling * migration * thrombosis * rupture

Question 34

What are the different types of endoleaks?

Answer 34

An endoleak is persistent blood flow into the aneurysm sac 1. Type 1: ineffective seal at ends of graft 2. Type 2: backflow from collateral vessels 3. Type 3: ineffective seal of graft joints or rupture of graft fabric 4. Type 4: flow through pores of graft fabric

Question 35

Define a superficial venous thrombosis

Answer 35

Erythema, induration and tenderness along the superficial vein - usually spontaneous but can follow venous cannulation

Question 36

What is the etiology of a superficial venous thrombosis?

Answer 36

1. Infectious - suppurative phlebitis (complicatoin of IV cannulation, associated with fever/chills) 2. Trauma 3. Inflammatory - varicose veins, migratory superificial thrombophlebitis, Buerger's disease, SLe 4. Haematologic - polycythemia, thrombocytosis 5. Neoplastic - occult malignancy (especially pancreatic) 6. Idiopathic

Question 37

What are the clinical features of a superficial venous thrombosis?

Answer 37

* Most common in greater saphenous vein and its tributaries * Pain and cord like swelling along the course of the involved vein * Areas of induration, erythema and tenderness correspond to dilated and often thrombosed superficial veins * Complications * simultaenous DVT * recurrent superficial thrombophlebitis

Question 38

What principal investigation would your order for a SVT?

Answer 38

* A non-invasive test such as Doppler to exclude

Question 39

What is your treatment plan for a superficial venous thrombosis?

Answer 39

* Conservative * moist heat * compression bandages * mild analgesic * anti-inflammatory and anti-platelet (e.g. ASA) and LMWH, ambulation * Surgical excision of the involved vein * indication * failure of conservative measures (symptoms that persist over 2 weeks) * suppurative thrombophlebitis - broad spectrum IV antibiotics and excision

Question 40

What are varicose veins?

Answer 40

* distention of tortuous superficial veins resulting from incompetent valves in the deep, superficial or perforator systems * distribution: * greater saphenous vein and tributaries (most common) ,esophagus, anorectum and scrotum

Question 41

What is the etiology of varicose veins?

Answer 41

* Primary * Main factor - inherited structural weakness of valves * Contributing factors - increasing age, female gender, OCP use, occupations requiring long hours of standing, pregnancy and obesity * Secondary * Malignant pelvic tumours with venous compression * Congenital anomalies, arteriovenous fistulae

Question 42

What are the clinical features of varicose veins?

Answer 42

1. Diffuse aching, fullness/tightness, nocturnal cramping 2. Aggravated by prolonged standing (end of day) 3. Visible long dilated and tortous superficial veins along thigh and leg 4. Ulceration and hyperpigmentation and induration known as secondary varicosities 5. Brodie and Trendelenberg test (valvular competence test)

Question 43

What are the complications of a superficial venous thrombosis?

Answer 43

* recurrent superficial thrombophlebitis * hemorrhage - external or subcutaneous * ulceration - eczema, lipodermatosclerosis and hyperpigmentation

Question 44

What is your treatment plan for superificial venous thrombosis?

Answer 44

* Conservative * elevation of leg and/or elastic compression stockings * Surgical * high ligation and stripping of long saphenous vein and its tributaries * ultrasound guided foam sclerotherapy * endovenous laser therapy

Question 45

What are the indications for surgery in a SVT?

Answer 45

* symtomatic varix (pain, bleeding and recurrent thrombophlebitis) * tissue changes - hyperpigmentation and ulceration * failure of conservative treatment