Vascular Surgery

Question 1

What are the three layers of blood vessels and how do they differ in arteries and vein?

Answer 1

• Tunica externa/adventitia - Connective tissue fibroblasts and collagen. This layer needs to be removed from the cut ends for vessel reconstruction
• Tunica media - Smooth muscle cells and elastic tissue
• Tunica intima - Endothelial cells

The tunica media of a vein is thinner than that of an artery

Question 2

What veins carry oxygenated blood?
Where are the only venous sinuses located?

Answer 2

• Pulmonary veins and umbilical vein
• In the skull

Question 3

Name the following instruments

Answer 3

From left to right:
- Diamond-jawed needle holder
- DeBakey atraumatic forceps
- Metzembaum scissors
- Potts scissors
- Small and large right-angled forceps

Question 4

Name the following microvascular instruments

Answer 4

From left to right:
- Miscrovascular needle holders, without catch
- Curved Vannas microvascular dissecting scissors
- Straight adventitial scissors
- Jeweler’s forceps
- Curved and straight mosquito haemostats

Question 5

What sized suture is recommended in vascular surgery?

Answer 5

3-0 to 10-0
- Vessels with internal diameter of 4-6mm - 4-0/5-0
- 2-3mm - 6-0
- less than 2mm - 7-0/8-0

Nylon or polypropylene for arteries
Braided multifilament passed through mineral oil or bone wax for veins

Question 6

What is the most common biological vascular graft in veterinary patients?

Answer 6

Jugular vein

Question 7

What is the characteristic pattern on a perfused artery?

Answer 7

Vaso vasorum

Question 8

List the main options for anticoagulation in vascular surgery

Answer 8

• Unfractionated heparin
• Enoxaparin

Question 9

List the options for incision orientation for venotomy/arterotomy

Answer 9

• Longitudinal
• Transverse (recommended in vessels under 4mm diameter)

Question 10

List the three options for vascular anastomosis

Answer 10

• End-to-end
• End-to-side
• Side-to-side

Question 11

What is Kunlin’s technique?

Answer 11

Placing a horizontal mattress suture during vascular anastomosis to produce mild eversion and improve intima approximation

Question 12

What is the most common guide wire size used in endovascular surgery?

Answer 12

• 0.035 inch (0.012-0.052)

Question 13

What sized vascular sheath is most commonly used?

Answer 13

5-6Fr

Question 14

What vessels are typically used for access during endovascular procedures?

Answer 14

• Femoral or carotid artery
• Jugular vein

Question 15

List some endovascular techniques used in small animals

Answer 15

• Central venous catheter placement
• Subcutaneous venous access port
• Embolotherapy and embolectomy

Question 16

What substances can be used for embolotherapy?

Answer 16

Non-absorbable
- Polyvinyl alcohol
- Trisacryl gelatin microspheres
- Silk suture

Absorbable:
- Gelatin sponges
- Autogenous blood clot material

Liquid:
- Cyanoacrylate and Lipiodol

Mechanical:
- Metallic coils
- Ductal occluders

Question 17

List options for embolectomy

Answer 17

• Direct surgical removal
• Embolectomy balloon catheter
• Catheter directed thrombolytic therapy (tissue plasminogen activator)
• Rheolytic catheter (pulsatile, high velocity stream of saline)
• Stents - may be used in combo with thrombolytic therapy

Question 18

List potential caused of acquired AV fistulas

Answer 18

• Poorly treated arterial injuries
• iatrogenic en bloc ligation
• traumatic arterial catheterisation
• Extravasation of irritating substances
• Trauma
• Infection
• Neoplasia
• Surgically created for long-term venous access

Question 19

List options for treatment of AV fistulas

Answer 19

• Cyanoacrylate glue embolisation
• Ligation and division of the artery proximal and distal to communication