Small Animal GIT Surgery Flashcards
Describe the blood supply to the oesophagus
Segmental
What are the layers of the oesophageal wall?
Mucosa, submucosa, muscularis and adventitia. Only the thoracic oesophagus has serosa.
What factors predispose the oesophagus to dehiscence?
Segmental blood supply.
Constant motion - swallowing, neck motion, etc.
No omentum - less physical support.
The cervical oesophagus has no serosa - no fibrin seal.
Passage of ingesta / saliva.
What are the 3 classifications of oesophageal obstruction and give an example for each:
- Extramural - vascular ring anomalies
- Intramural - oesophageal neoplasia / stricture
- Intraluminal - foreign bodies
What are the 3 predilection sites of oesophageal foreign bodies?
Thoracic inlet, base of heart and cranial to the diaphragm.
How do you treat oesophageal foreign bodies?
Most can be retrieved with endoscopy (as long as they are not penetrating), otherwise you can push them into the stomach and perform a gastrotomy.
How should you close oesophageal incisions?
2 layer closure. Mucosa & submucosa - holding layer. Muscularis & adventitia.
Which layer of the intestines is the only layer with good suture holding capacity?
Submucosa.
Which part of the small intestines has a segmental blood supply?
The duodenum.
Describe an intussusception:
Invagination of one segment of the intestines into the adjacent segment.
How would you treat intussusception?
Attempt to reduce - milk the apex towards the neck, applying gentle traction to the intussusceptum. Possibly intestinal plication to prevent reoccurence.
When does intussusception typically occur in puppies kittens?
After a bout of enteritis / verminosis.
What drug can be used to treat post-op ileus?
Metoclopramide.
Name the salivary glands:
Parotid, mandibular, sublingual, zygomatic, buccal and molar.
What is a salivary mucocoele?
accumulation of saliva in tissue adjacent to a gland/duct.
How can you treat salivary mucocoeles?
Repeated drainage (not curative and can introduce infection), sialoadenectomy (make sure you remove it all!), intra-oral marsupialisation (for ranula).
Which part of the GIT does the cranial mesenteric artery supply?
Ascending colon, caecum and transverse colon.
What part of the GIT does the caudal mesenteric artery supply?
Descending colon and the cranial rectum.
What is supplied by the internal pudendal artery?
Middle and caudal rectum and anus.
Does the colon contain more anaerobes or aerobes?
Anaerobes (100:1)
What aerobes are typically found in the colon?
Staph, E. coli, proteus & klebsiella.
What anaerobes are typically found in the colon?
Bacteroides, Lactobacilli, Clostridium and Fusobacterium
Discuss colon healing:
Wound tensile strength is lower than in SI. Slow healing and relatively high likelyhood of dehiscense due to: high bacterial load, segmental blood supply, bulky/solid colonic material creating mechanical stress.
How can you prepare an animal for colonic surgery?
Starve. Could do multiple enemas but liquid in the colon is more difficult to deal with intra-operatively than solids…
What is important to remember when performing a colopexy?
Do not suture into the colon lumen!
How do you treat anal strictures?
Anoplasty.
What are the clinical signs of anal sac disease?
Tenesmus, scooting, licking / biting perineum.
What do anal sac carcinomas secrete?
Parathyroid-like hormone - can cause dystrophic calcification of soft tissues and hypercalcaemic nephropathy.
Describe a ‘true’ hernia ring:
A normal defect in the abdominal wall, has a complete hernial sac - includes most congenital hernias.
Describe a ‘false’ hernia ring:
Not a normal defect in the abdominal wall, usually does not have a complete hernial sac - includes most acquired hernias.
When can incisional hernias occur?
Any time from days to years after the incision.
Describe a direct inguinal hernia:
Abdominal viscera passes through the inguinal ring into a pocket adjacent to the vaginal process.
Describe an indirect inguinal hernia:
Abdominal viscera passes through the inguinal ring and enters the cavity of the vaginal process.
Is an indirect or direct inguinal hernia more likely to cause strangulation?
An indirect hernia is more likely to cause strangulation due to the constriction of the vaginal process.
Describe post-op nutrition for gastric surgery:
First 12hrs: only water (can add electrolytes).
Then mushy food every 4hrs.
Reintroduce normal diet over next 10 days.
What happens if an animal is starved for more than 48hrs?
They enter a catabolic state. Bowel healing is retarded and enterocyte degeneration occurs.
What features of the stomach aid gastric healing?
Excellent blood supply and low bacterial load in the starved patient.
What can non-absorbable suture material do to the stomach?
Pre-dispose to gastric ulcers.
What is the prognosis for pyloric antral hypertrophy v. pyloric neoplasia?
Pyloric antral hypertrophy: good prognosis.
Pyloric neoplasia: poor prognosis (metastasis, wound dehiscence, pancreatic and biliary obstruction).
How would you treat pyloric antral hypertrophy?
Y-U pyloroplasty
How would you treat pyloric neoplasia?
Billroth 1 (pylorectomy and gastroduodenostomy) or Billroth 2 (pylorectomy and gastrojejunostomy)
How can you assess gastric wall viability?
Serosal colour, gastric wall perfusion, serosal vessel patency, gastric wall palpation.
Name 4 gastropexy techniques:
Belt loop gastropexy, circumcostal, incisional, tube gastrotomy
Why is a sialocele not considered a cyst?
Cysts are lined by epithelium. A sialocele is lined by granulation tissue.
You are presented with a dog that has a midventral cervical mucocoele… how do you determine which side it is originating from?
Examine in dorsal recumbency - usually will fall to the affected side.
What are treatment options for oesophageal stricture?
Bougienage.
Surgical resection and anastamosis.
Describe the layers of the stomach wall and how you would close an incision?
Incised wall separates into 2 very distinct layers: Mucosa and submucosa. Muscle and serosa. Close the 2 layers separately using absorbable sutures in an inverting pattern.
Which artery supplies the descending duodenum and pancreas?
Cranial pancreatic duodenal artery
Where do linear foreign bodies commonly lodge?
Base of the tongue or pylorus
What are the possible complications of total splenectomy?
Haemorrhage.
Gastric Wall Necrosis.
Temporary Anaemia.
Are prophylactic antibiotics necessary prior to liver surgery?
YES! Portal blood carries GIT bacteria.
Up to how much liver mass can be removed and still maintain function?
Up to 80%
