Ch 24 - Fundamentals of laparoscopy and thoracoscopy

Question 1

What benefits have been shown regarding minimally invasive surgical procedures?

Answer 1

• Decrease in pain
• More rapid return to normal activity
• Lower incidence of incisional infection
• Decreased surgical time
• Shorter hospitalisation times

Question 2

What are the basic components of an endoscopy tower?

Answer 2

• Monitor
• Camera control box
• Light source
• Insufflators
• Data recording devices

Question 3

What are they typical light sources?

Answer 3

• Halogen or xenon
• Xenon is preferred - more closely resembles natural light

Question 4

What pressure of intrathoracic insufflation causes significant cardiorespiratory depression?

Answer 4

• 3mmHg
• Often not required, placement of cannulas forms a pnemothorax and ribs prevent collapse

Question 5

What are the recommended insufflation pressures in the abdomen of dogs and cats?

Answer 5

• Dogs: 8-10mmHg (Can increase to 15 with acceptable cardiorespiratory depression)
• Cats: 8mmHg (little increase in working volume above this)

Question 6

What is the main gas used for insufflation and why?
How does retrograde flow occur?

Answer 6

CO2
- Does not support combustion
- Cheap
- Colourless
- Rapidly excreted
- Highly soluable (unlikely to form gas embolus)

Retrograde flow can occur whent the CO2 canister is depleted intra-operatively and pressure in the body cavity drives air/fluid in a retrograde manner. Can result in damage and cross contamination of next patient

Question 7

What is the most versatile telescope for use in vet med?

Answer 7

5mm telescope 29cm in length
0 degress is typically used in the abdomen with 30 degree typically used for thorax

Question 8

What are the benefits of using a cannula?

Answer 8

• Atraumatic repeated instrument exchange
• Airtight seal for insufflation

Question 9

What are the disadvantages of reusable cannulas as apposed to single use cannulas

Answer 9

• Heavy weight
• Can become dull over time
• Changing instruments is cumbersome (reduced caps required)

Main benefit is cost reduction

Question 10

List some options of single-port surgery devices

Answer 10

• SILS port (single-incision laparoscopic surgery)
• Triport
• Gelport
• Endocone

Most incorporate 3-5 ports within a single device

Question 11

What size instruments are typically used? What sizes are available?

Answer 11

• Typically use 5mm instrucments in vet med
• 2, 3 and 10mm also available

Question 12

What instruments are required for basic laparoscopic procedures?
What other insrtuments are commonly useful?

Answer 12

Basic Instruments:
- Metzembaums
- Hook (suture) scissors
- Kelly haemostats
- Babcock forceps
- Cup biopsy forceps

Other useful instruments:
- Right angle forceps
- Knot-pusher (extracorporeal knot tying)
- Fan retractors and inflatable retractors
- Laparoscopic needle holders (parrot jaw most common)

Question 13

What options are there for laparoscopic/thoracoscopic haemostasis?

Answer 13

• Haemostatic agents (gelatin sponge, ORC, fibrin glue)
• Haemostatic clips (multifier devices available)
• Suturing (extracorporeal, intracorporeal)
• Electrosurgery (bipolar is safer)
• Vessel sealing devices

Question 14

What is the strongest slip knot for extracorporeal suturing?

Answer 14

4S modified Roeder knot

Question 15

What are the options for laparoscopic vessel sealing device?
What size vessels can then be used on?

Answer 15

• ForceTriad - up to 7mm (new generation LigaSure
• Enseal - up to 7mm
• Harmonic system - up to 5mm

Question 16

When are specimen retrieval bags indicated?

Answer 16

When removing tissue that could be neoplastic or infected through a small port incision

Question 17

What size is the most common endoscopic stapler and how many staple rows do they produce?

What sizes endoGIA are available?

Answer 17

• Most commonly 12mm in daimeter (require 12mm cannula) and combine 2 triple rows of staggered staples seperated by a cutting blade.
• EndoGIA come in lengths od 30, 45 and 60mm with staple lengths of 2.0, 2.5, 3.5 and 4.8mm (Most common 30-60 length with 3.5m staples)

Question 18

What are the two techniques for gaining access into the abdominal cavity?

Answer 18

• Veress needle technique - Has a spring-loaded blunt-tipped obturator. Hanging-drop test will confirm when in peritoneal cavity. Once insufflated, veress needle is removed and a sharp trocar-cannula can be placed
• Modified Hasson technique - A small approach to the linea just caudal to the umbilicus for controlled incision and placement of trocar-cannula. Blunt-tipped trocar used

Question 19

What is this instrument?

Answer 19

Veress needle

Question 20

What 2 options are available to gain access to the thoracic cavity?
What is the preferred method of increasing exposure in the thoracic cavity?

Answer 20

Gaining access:
- Veress needle
- Cannula without a diaphragm

One-lung ventilation preferred for increasing exposure, insufflation not well tolerated

Question 21

What techniques can be used to create one-lung ventilation?

Answer 21

• Selective intubation
• Bronchial blockers
• Double-lumen endobronchial intubation

Question 22

What process limits the physiological effects of V/Q mismatch with 1-lung ventilation?

Answer 22

Hypoxic pulmonary vasoconstriction

Question 23

What procedures have been reported with the use of one-lung ventilation?

Answer 23

• Pericardial windows
• Subphrenic pericardiectomy
• Lung lobectomy
• Thymoma excision