Ch 108 Vascular surgery Flashcards
What are the three layers of blood vessels and how do they differ in arteries and vein?
- 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
What veins carry oxygenated blood?
Where are the only venous sinuses located?
Pulmonary veins and umbilical vein
In the skull
Name the following instruments
From left to right:
- Diamond-jawed needle holder
- DeBakey atraumatic forceps
- Metzembaum scissors
- Potts scissors
- Small and large right-angled forceps
Name the following microvascular instruments
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
name the folowing vascular clamps
From left to right: a DeBakey atraumatic angled vascular clamp, DeBakey atraumatic tangential clamps, a DeBakey-Satinsky atraumatic tangential clamp, a Cooley atraumatic clamp, a DeBakey atraumatic multipurpose curved clamp, and a Castaneda atraumatic neonatal clamp.
What sized suture is recommended in vascular surgery?
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
vessel dissection
- dissect as closely to the adventitia as possible, generally with a blunt-tipped, right-angled forceps or blunt-tipped fine Metzenbaum scissors.
- dissecting directly over the surface of a vessel closest to the skin, the surgeon can generally avoid inadvertent disruption of branching collaterals.
Atraumatic devices for occlusion
- vascular clamps
- Potts loops
- single loops of suture, tape or Silastic
- Rumel tourniquets may be applied
What is the most common biological vascular graft in veterinary patients?
Jugular vein
What is the characteristic pattern on a perfused artery?
adventitial surface of the artery
Vaso vasorum
List the main options for systemic anticoagulation in vascular surgery
Unfractionated heparin
Enoxaparin
List the main options for local anticoagulation in vascular surgery
To prevent clot formation in vessels:
- ice-cold solution of 2% lidocaine, heparin, and 0.9% saline to thoroughly flush the isolated vessel
List the options for incision orientation for venotomy/arterotomy
Longitudinal
Transverse (recommended in vessels under 4mm diameter)
List the three options for vascular anastomosis
End-to-end
End-to-side
Side-to-side
What is Kunlin’s technique?
Placing a horizontal mattress suture during vascular anastomosis to produce mild eversion and improve intima approximation
What is the most common guide wire size used in endovascular surgery?
0.035 inch (0.012-0.052)
Seldinger technique: involves inserting a needle, then a guidewire, followed by a catheter over the guidewire, all percutaneously
What sized vascular sheath is most commonly used?
5-6Fr
What vessels are typically used for access during endovascular procedures?
Femoral or carotid artery
Jugular vein
List some endovascular techniques used in small animals
Central venous catheter placement
Subcutaneous venous access port
Embolotherapy and embolectomy
What substances can be used for embolotherapy?
selectively occlude blood flow
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
List options for embolectomy
surgical removal of a thrombus/embolus to restore patency of a vessel
- 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
List potential caused of acquired AV fistulas
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
List options for treatment of AV fistulas
- Cyanoacrylate glue embolisation
- Ligation and division of the artery proximal and distal to communication
Fortunately, collateral circulation in dogs permits sacrifice of major vessels when needed, including carotid and femoral arteries
Weisse et al reported on the use of percutaneous arterial embolization for the treatment of intractable epistaxis in three dogs. Embolization of one or both maxillary arteries with polyvinyl alcohol particles resulted in long-term control
Evaluation of a microvascular anastomotic coupler
for end-to-side arterial and venous anastomosis for feline
renal transplantation
Megan A. Mickelson 2020
Study design: In vivo experimental study
Anastomosis was successful in all cats, and intraoperative hemorrhage
was negligible. Intraoperative renal perfusion was considered excellent
Surgical removal of a jugular aneurysm in a spaniel cross dog
Ligatures were placed; two proximal and two distal to (2/0 PDS)
The patient was treated with prophylactic clopridogrel (2 mg/kg/day) for stump thrombus prevention
Use of an autologous pericardial patch to repair a
post-traumatic caudal vena cava cicatrix in a dog
Winter 2024
obstruction of venous flow from the liver to
the right atrium is termed Budd-Chiari syndrome
kinking of the caudal vena cava in a dog, following
blunt thoracic trauma, that was managed using a
pericardial patch graft
in cases of traumatic kinking of the vena cava it can be
considered as a second-line treatment should dissection of
the fibrotic band fail to reduce caudal caval pressures.
Minimally invasive techniques should also be considered
in animals where the lesion is considered untreatable at
open surgery.
other options: balloon dilation, stent
