Principles of Small Animal Gastrointestinal Surgery Flashcards Preview

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Flashcards in Principles of Small Animal Gastrointestinal Surgery Deck (52):
1

gastric vomiting - effects

Loss of gastric hydrochloric acid - Metabolic alkalosis, Hypochloraemia
Insufficient food intake - Hypokalaemia
Dehydration - Poor tissue perfusion, Metabolic acidosis

2

acute vomiting - effects

Low intestinal obstruction - Loss of pancreatic Na +
, HCO3-, Metabolic acidosis, ↓Na+
Dehydration - Poor tissue perfusion, Metabolic acidosis
High intestinal obstruction - Mimics gastric vomiting
Insufficient food intake & ↓absorption - Hypokalaemia

3

Chronic vomiting, diarrhoea + weight loss - effects

Dehydration & electrolyte loss
Bacterial proliferation & nutrient metabolism - Maldigestion & malabsorption, Intestinal mucosal damage
Diarrhoea - Weight loss, Hypoalbumninaemia

4

How to correct effects of vomiting (all types), diarrhoea + weight loss prior to surgery

intravenous isotonic crystalloids
intravenous K+ supplements

5

Gastrointestinal bleeding - haematemesis, melaena - effects

Anaemia - non/Regenerative
Hypoalbuminaemia

6

how to correct effects of GIT bleeding before surgery

blood transfusion
iron supplements

7

what to check to see if animal is fit for surgery

Complete history
Complete physical examination
Check haematocrit and total protein
Check electrolytes: K+and Na+
check acid-base status
Complete haematology and biochemistry: if clinically indicated

8

prophylactic antibiotics - stomach

may not be needed for healthy animal
single broad spec antibiotic with anaerobic coverage
cephalosporin or amoxycillin-clavulante

9

prophylactic antibiotics - small intestine

antibiotics always indicated
single broad spec antibiotic with anaerobic coverage
cephalosporin or amoxycillin-clavulante

10

prophylactic antibiotics - colon

antibiotics always indicated
combo of 2 antibiotics including 1 specifically for anaerobes

11

methods to decr bacterial contamination

Isolate the site of GI entry
Lavage GI wound after closure
Change gloves
Lavage abdomen with sterile saline
use separate set of instruments for contaminated part of surgery

12

methods to decr bacterial contamination - large intestine

mechanical preperation
No evidence to support use in veterinary medicine
Liquid faeces maybe more likely to bypass atraumatic clamps and purse string sutures
A low residue diet & at least 12-24 hr starvation recommended

13

strongest layer in intestinal wall + why

submucosa
high collagen content

14

1-4 days post surgery wound activity

Haemorrhage
Platelet clot - Fibrin clot
Inflammation
Microbial killing
potential wound debridement
Epithelial migration
No change in wound strength

15

3-14 days post surgery wound activity

Fibroblast proliferation
Collagen formation
incr wound strength

16

rate of wound healing - stomach

rapid due to large blood supply
healing rarely complicated

17

rate of wound healing - small intestine

by day 14, 75-80% normal strength

18

rate of wound healing - large intestine

By day 14, regained 50% of normal tensile
? Increased collagenase production
Risk of wound breakdown greatest

19

Factors which impact negatively on intestinal wound healing

Compromise to blood supply
Traumatic surgical technique (electrocautery)
hypoproteinaemia
chemo + radiotherapy
steroids

20

Repair of gastrointestinal wounds with sutures: Suture pattern + material choice

restore normal anatomy
promote rapid healing
multifilament material has crevices that trap bacteria
absorbable material - stays long enough to allow healing

21

Repair of gastrointestinal wounds with metal staples

Titanium staples: permanent, inert
Special gastrointestinal staple guns with staple cartridges
eversion or inversion of edges

22

exploratory laparotomy - indications

To diagnose the cause of intra-abdominal disease
To correct the cause of intra-abdominal disease

23

exam of GIT

entire GIT should be palpated and run through your hands in a logical manner
important to have good knowledge of anatomy + blood supply (know which blood vessels can be
safely ligated + to avoid damaging the blood supply to
vital organs)

24

gastrotomy - define

incision into the stomach

25

gastrotomy - repair

Repair in 2 layers
Mucosa & submucosa - Simple continuous
Serosa & muscularis - Simple continuous, inverting lembert (prevent leakage)

26

small intestine biopsy

isolate intestine
milk intestinal contents away + close intestine with clamps
incise along anti-mesenteric border
ellipse for biopsy cut with metzenbaum scissorsd

27

large intestinal biopsy

Do not biopsy the large intestine unless a lesion is
specifically identified/suspected due to increased risk
of breakdown of a large intestine wound

28

liver biopsy

Clinical signs + blood tests results suggestive of liver disease
Generalised abnormal appearance on ultrasound or at
surgery
Presence of liver nodules or liver masses
First consider fine needle aspirates and trucut biopsy of the liver under ultrasound guidance

29

Gastric Foreign Bodies - Diagnosis

ultrasound

30

Gastric Foreign Bodies - treatment

Endoscopic retrieval of foreign body
Gastrotomy

31

Gastric Neoplasia - Decision Making Prior to Surgery

Is tumour resection and reconstruction achievable?
A large proportion of the stomach can be resected but cardia must be preserved
Can the common bile + pancreatic duct be preserved?

32

gastric neoplasia - prognosis

Complete resection of benign tumour (leiomyoma) - good
Malignant tumour (adenocarcinoma) - poor, clinical symptoms often recurring within weeks

33

partial gastrectomy

Same principles as gastrotomy
Consider the use of staples

34

assessing GIT viability

Pulsations in the arterial blood vessels
presence of peristaltic muscle contractions
normal colour
normal wall thickness on palpation

35

intestinal resection

similar to SI biopsy
ligate mesenteric vessels then incise mesentery

36

luminal disparity (size mismatch)`

`Space sutures further apart on large side
Transect the small side at an angle to match diameter of large side
reduce small side with sutures
spatulate small side

37

end-to-end anastomosis

Suturing as for enterotomy
Place 1st suture in mesenteric border
Place 2nd suture in anti-mesenteric border
Repair defect in mesentery

38

end-to-end anastomosis - support wound

omentalisation (wrap omentum around wound)
serosal patch - adjacent healthy intestine tacked to intestinal wound

39

intestinal foreign bodies - history

Persistent vomiting (frequently projectile)
Anorexia
Depression
No defaecation

40

intestinal foreign bodies - clinical exam

Dehydration
Depression
Abdominal Pain
Intrabdominal mass
String around tongue

41

intestinal neoplasia types

Adenoma/adenocarcinoma
Lymphoma
Leiomyoma/leiomyosarcoma
mast cell
Duodenal polyps

42

intestinal neoplasia - clinical signs

Partial obstruction
Chronic intermittent vomiting
Diarrhoea
Weight loss

43

intussusception - define

Invagination of one portion of the gastrointestinal tract
into the lumen of an adjoining segment

44

intussusception - clinical signs

palpable tubular mass
dehydration
depression
abdominal pain
protrusion of intussusception from anus

45

intussusception - diagnosis

ultrasound (parallel lines/concentric rings)
radiography (gas distenstion in SI)

46

intussusception - reduction or resection

Reduction: push rather than pull
Assess intestines
Resect if - Irreducible, Ischaemic / injured intestines, Mass present

47

further treatment for intussusception

Enteroplication (suture loops of intestine together)
Treat underlying disease
Always check for faecal bacteria and parasites: deworm if in doubt
Prognosis - Good in young, 6-27% recurrence

48

Enterotomy & Enterectomy - Complications

Persistent ileus - Vomiting, diarrhoea, pain, abdo distension
Stricture at anastomosis site - Partial obstruction
Short-bowel syndrome: >70% resection - Malabsorption & malnutrition
Intestinal incision dehiscence - 7-16% for intestinal biopsies

49

The consequence of intestinal wound breakdown

septic peritonitis
50% mortality

50

septic peritonitis - clinical signs

vomiting
Anorexia & depression
Abdominal pain
Abdominal enlargement
Hypovolaemic shock
Pyrexia
Discharge from abdominal wound
Diarrhoea
Haematochezia, melaena, haematemesis

51

septic peritonitis - diagnosis

Abdominocentesis
most important test

52

septic peritonitis - treatment

Ex lap to find & correct leak
Peritoneal lavage + drainage
Intensive post-op care - Maintenance of normovolaemia &
blood pressure, nutrition is essential